src/common/config/session-config.c

   1 /*
   2  * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #include "lttng/tracker.h"
   9 #define _LGPL_SOURCE
  10 #include <assert.h>
  11 #include <ctype.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <inttypes.h>
  16 #include <dirent.h>
  17 #include <unistd.h>
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #include <stdbool.h>
  21
  22 #include <common/defaults.h>
  23 #include <common/error.h>
  24 #include <common/macros.h>
  25 #include <common/utils.h>
  26 #include <common/dynamic-buffer.h>
  27 #include <common/compat/getenv.h>
  28 #include <lttng/lttng-error.h>
  29 #include <libxml/parser.h>
  30 #include <libxml/valid.h>
  31 #include <libxml/xmlschemas.h>
  32 #include <libxml/tree.h>
  33 #include <lttng/lttng.h>
  34 #include <lttng/snapshot.h>
  35 #include <lttng/rotation.h>
  36 #include <lttng/userspace-probe.h>
  37
  38 #include "session-config.h"
  39 #include "config-internal.h"
  40
  41 #define CONFIG_USERSPACE_PROBE_LOOKUP_METHOD_NAME_MAX_LEN 7
  42
  43 struct handler_filter_args {
  44         const char* section;
  45         config_entry_handler_cb handler;
  46         void *user_data;
  47 };
  48
  49 struct session_config_validation_ctx {
  50         xmlSchemaParserCtxtPtr parser_ctx;
  51         xmlSchemaPtr schema;
  52         xmlSchemaValidCtxtPtr schema_validation_ctx;
  53 };
  54
  55 LTTNG_HIDDEN const char * const config_element_all = "all";
  56 const char * const config_str_yes = "yes";
  57 const char * const config_str_true = "true";
  58 const char * const config_str_on = "on";
  59 const char * const config_str_no = "no";
  60 const char * const config_str_false = "false";
  61 const char * const config_str_off = "off";
  62 const char * const config_xml_encoding = "UTF-8";
  63 const size_t config_xml_encoding_bytes_per_char = 2;    /* Size of the encoding's largest character */
  64 const char * const config_xml_indent_string = "\t";
  65 const char * const config_xml_true = "true";
  66 const char * const config_xml_false = "false";
  67
  68 const char * const config_element_channel = "channel";
  69 const char * const config_element_channels = "channels";
  70 const char * const config_element_domain = "domain";
  71 const char * const config_element_domains = "domains";
  72 const char * const config_element_event = "event";
  73 const char * const config_element_events = "events";
  74 const char * const config_element_context = "context";
  75 const char * const config_element_contexts = "contexts";
  76 const char * const config_element_attributes = "attributes";
  77 const char * const config_element_exclusion = "exclusion";
  78 const char * const config_element_exclusions = "exclusions";
  79 const char * const config_element_function_attributes = "function_attributes";
  80 const char * const config_element_probe_attributes = "probe_attributes";
  81 const char * const config_element_symbol_name = "symbol_name";
  82 const char * const config_element_address = "address";
  83 const char * const config_element_offset = "offset";
  84
  85 LTTNG_HIDDEN const char * const config_element_userspace_probe_lookup = "lookup_method";
  86 LTTNG_HIDDEN const char * const config_element_userspace_probe_lookup_function_default = "DEFAULT";
  87 LTTNG_HIDDEN const char * const config_element_userspace_probe_lookup_function_elf = "ELF";
  88 LTTNG_HIDDEN const char * const config_element_userspace_probe_lookup_tracepoint_sdt = "SDT";
  89 LTTNG_HIDDEN const char * const config_element_userspace_probe_location_binary_path = "binary_path";
  90 LTTNG_HIDDEN const char * const config_element_userspace_probe_function_attributes = "userspace_probe_function_attributes";
  91 LTTNG_HIDDEN const char * const config_element_userspace_probe_function_location_function_name = "function_name";
  92 LTTNG_HIDDEN const char * const config_element_userspace_probe_tracepoint_attributes = "userspace_probe_tracepoint_attributes";
  93 LTTNG_HIDDEN const char * const config_element_userspace_probe_tracepoint_location_provider_name = "provider_name";
  94 LTTNG_HIDDEN const char * const config_element_userspace_probe_tracepoint_location_probe_name = "probe_name";
  95
  96 const char * const config_element_name = "name";
  97 const char * const config_element_enabled = "enabled";
  98 const char * const config_element_overwrite_mode = "overwrite_mode";
  99 const char * const config_element_subbuf_size = "subbuffer_size";
 100 const char * const config_element_num_subbuf = "subbuffer_count";
 101 const char * const config_element_switch_timer_interval = "switch_timer_interval";
 102 const char * const config_element_read_timer_interval = "read_timer_interval";
 103 LTTNG_HIDDEN const char * const config_element_monitor_timer_interval = "monitor_timer_interval";
 104 LTTNG_HIDDEN const char * const config_element_blocking_timeout = "blocking_timeout";
 105 const char * const config_element_output = "output";
 106 const char * const config_element_output_type = "output_type";
 107 const char * const config_element_tracefile_size = "tracefile_size";
 108 const char * const config_element_tracefile_count = "tracefile_count";
 109 const char * const config_element_live_timer_interval = "live_timer_interval";
 110 LTTNG_HIDDEN const char * const config_element_discarded_events = "discarded_events";
 111 LTTNG_HIDDEN const char * const config_element_lost_packets = "lost_packets";
 112 const char * const config_element_type = "type";
 113 const char * const config_element_buffer_type = "buffer_type";
 114 const char * const config_element_session = "session";
 115 const char * const config_element_sessions = "sessions";
 116 LTTNG_HIDDEN const char * const config_element_context_perf = "perf";
 117 LTTNG_HIDDEN const char * const config_element_context_app = "app";
 118 LTTNG_HIDDEN const char * const config_element_context_app_provider_name = "provider_name";
 119 LTTNG_HIDDEN const char * const config_element_context_app_ctx_name = "ctx_name";
 120 const char * const config_element_config = "config";
 121 const char * const config_element_started = "started";
 122 const char * const config_element_snapshot_mode = "snapshot_mode";
 123 const char * const config_element_loglevel = "loglevel";
 124 const char * const config_element_loglevel_type = "loglevel_type";
 125 const char * const config_element_filter = "filter";
 126 LTTNG_HIDDEN const char * const config_element_filter_expression = "filter_expression";
 127 const char * const config_element_snapshot_outputs = "snapshot_outputs";
 128 const char * const config_element_consumer_output = "consumer_output";
 129 const char * const config_element_destination = "destination";
 130 const char * const config_element_path = "path";
 131 const char * const config_element_net_output = "net_output";
 132 const char * const config_element_control_uri = "control_uri";
 133 const char * const config_element_data_uri = "data_uri";
 134 const char * const config_element_max_size = "max_size";
 135 const char * const config_element_pid = "pid";
 136 const char * const config_element_pids = "pids";
 137 const char * const config_element_shared_memory_path = "shared_memory_path";
 138
 139 LTTNG_HIDDEN const char * const config_element_process_attr_id = "id";
 140 LTTNG_HIDDEN const char * const config_element_process_attr_tracker_pid = "pid_process_attr_tracker";
 141 LTTNG_HIDDEN const char * const config_element_process_attr_tracker_vpid = "vpid_process_attr_tracker";
 142 LTTNG_HIDDEN const char * const config_element_process_attr_tracker_uid = "uid_process_attr_tracker";
 143 LTTNG_HIDDEN const char * const config_element_process_attr_tracker_vuid = "vuid_process_attr_tracker";
 144 LTTNG_HIDDEN const char * const config_element_process_attr_tracker_gid = "gid_process_attr_tracker";
 145 LTTNG_HIDDEN const char * const config_element_process_attr_tracker_vgid = "vgid_process_attr_tracker";
 146 LTTNG_HIDDEN const char * const config_element_process_attr_trackers = "process_attr_trackers";
 147 LTTNG_HIDDEN const char * const config_element_process_attr_values = "process_attr_values";
 148 LTTNG_HIDDEN const char * const config_element_process_attr_value_type = "process_attr_value_type";
 149 LTTNG_HIDDEN const char * const config_element_process_attr_pid_value = "pid";
 150 LTTNG_HIDDEN const char * const config_element_process_attr_vpid_value = "vpid";
 151 LTTNG_HIDDEN const char * const config_element_process_attr_uid_value = "uid";
 152 LTTNG_HIDDEN const char * const config_element_process_attr_vuid_value = "vuid";
 153 LTTNG_HIDDEN const char * const config_element_process_attr_gid_value = "gid";
 154 LTTNG_HIDDEN const char * const config_element_process_attr_vgid_value = "vgid";
 155 LTTNG_HIDDEN const char * const config_element_process_attr_tracker_type = "process_attr_tracker_type";
 156
 157 /* Used for support of legacy tracker serialization (< 2.12). */
 158 LTTNG_HIDDEN const char * const config_element_trackers_legacy = "trackers";
 159 LTTNG_HIDDEN const char * const config_element_pid_tracker_legacy = "pid_tracker";
 160 LTTNG_HIDDEN const char * const config_element_tracker_targets_legacy = "targets";
 161 LTTNG_HIDDEN const char * const config_element_tracker_pid_target_legacy = "pid_target";
 162 LTTNG_HIDDEN const char * const config_element_tracker_pid_legacy = "pid";
 163
 164 LTTNG_HIDDEN const char * const config_element_rotation_schedules = "rotation_schedules";
 165 LTTNG_HIDDEN const char * const config_element_rotation_schedule_periodic = "periodic";
 166 LTTNG_HIDDEN const char * const config_element_rotation_schedule_periodic_time_us = "time_us";
 167 LTTNG_HIDDEN const char * const config_element_rotation_schedule_size_threshold = "size_threshold";
 168 LTTNG_HIDDEN const char * const config_element_rotation_schedule_size_threshold_bytes = "bytes";
 169
 170 const char * const config_domain_type_kernel = "KERNEL";
 171 const char * const config_domain_type_ust = "UST";
 172 const char * const config_domain_type_jul = "JUL";
 173 const char * const config_domain_type_log4j = "LOG4J";
 174 const char * const config_domain_type_python = "PYTHON";
 175
 176 const char * const config_buffer_type_per_pid = "PER_PID";
 177 const char * const config_buffer_type_per_uid = "PER_UID";
 178 const char * const config_buffer_type_global = "GLOBAL";
 179
 180 const char * const config_overwrite_mode_discard = "DISCARD";
 181 const char * const config_overwrite_mode_overwrite = "OVERWRITE";
 182
 183 const char * const config_output_type_splice = "SPLICE";
 184 const char * const config_output_type_mmap = "MMAP";
 185
 186 const char * const config_loglevel_type_all = "ALL";
 187 const char * const config_loglevel_type_range = "RANGE";
 188 const char * const config_loglevel_type_single = "SINGLE";
 189
 190 const char * const config_event_type_all = "ALL";
 191 const char * const config_event_type_tracepoint = "TRACEPOINT";
 192 const char * const config_event_type_probe = "PROBE";
 193 LTTNG_HIDDEN const char * const config_event_type_userspace_probe = "USERSPACE_PROBE";
 194 const char * const config_event_type_function = "FUNCTION";
 195 const char * const config_event_type_function_entry = "FUNCTION_ENTRY";
 196 const char * const config_event_type_noop = "NOOP";
 197 const char * const config_event_type_syscall = "SYSCALL";
 198 const char * const config_event_type_kprobe = "KPROBE";
 199 const char * const config_event_type_kretprobe = "KRETPROBE";
 200
 201 const char * const config_event_context_pid = "PID";
 202 const char * const config_event_context_procname = "PROCNAME";
 203 const char * const config_event_context_prio = "PRIO";
 204 const char * const config_event_context_nice = "NICE";
 205 const char * const config_event_context_vpid = "VPID";
 206 const char * const config_event_context_tid = "TID";
 207 const char * const config_event_context_vtid = "VTID";
 208 const char * const config_event_context_ppid = "PPID";
 209 const char * const config_event_context_vppid = "VPPID";
 210 const char * const config_event_context_pthread_id = "PTHREAD_ID";
 211 const char * const config_event_context_hostname = "HOSTNAME";
 212 const char * const config_event_context_ip = "IP";
 213 const char * const config_event_context_perf_thread_counter = "PERF_THREAD_COUNTER";
 214 LTTNG_HIDDEN const char * const config_event_context_app = "APP";
 215 LTTNG_HIDDEN const char * const config_event_context_interruptible = "INTERRUPTIBLE";
 216 LTTNG_HIDDEN const char * const config_event_context_preemptible = "PREEMPTIBLE";
 217 LTTNG_HIDDEN const char * const config_event_context_need_reschedule = "NEED_RESCHEDULE";
 218 LTTNG_HIDDEN const char * const config_event_context_migratable = "MIGRATABLE";
 219 LTTNG_HIDDEN const char * const config_event_context_callstack_user= "CALLSTACK_USER";
 220 LTTNG_HIDDEN const char * const config_event_context_callstack_kernel = "CALLSTACK_KERNEL";
 221 LTTNG_HIDDEN const char * const config_event_context_cgroup_ns = "CGROUP_NS";
 222 LTTNG_HIDDEN const char * const config_event_context_ipc_ns = "IPC_NS";
 223 LTTNG_HIDDEN const char * const config_event_context_mnt_ns = "MNT_NS";
 224 LTTNG_HIDDEN const char * const config_event_context_net_ns = "NET_NS";
 225 LTTNG_HIDDEN const char * const config_event_context_pid_ns = "PID_NS";
 226 LTTNG_HIDDEN const char * const config_event_context_user_ns = "USER_NS";
 227 LTTNG_HIDDEN const char * const config_event_context_uts_ns = "UTS_NS";
 228 LTTNG_HIDDEN const char * const config_event_context_uid = "UID";
 229 LTTNG_HIDDEN const char * const config_event_context_euid = "EUID";
 230 LTTNG_HIDDEN const char * const config_event_context_suid = "SUID";
 231 LTTNG_HIDDEN const char * const config_event_context_gid = "GID";
 232 LTTNG_HIDDEN const char * const config_event_context_egid = "EGID";
 233 LTTNG_HIDDEN const char * const config_event_context_sgid = "SGID";
 234 LTTNG_HIDDEN const char * const config_event_context_vuid = "VUID";
 235 LTTNG_HIDDEN const char * const config_event_context_veuid = "VEUID";
 236 LTTNG_HIDDEN const char * const config_event_context_vsuid = "VSUID";
 237 LTTNG_HIDDEN const char * const config_event_context_vgid = "VGID";
 238 LTTNG_HIDDEN const char * const config_event_context_vegid = "VEGID";
 239 LTTNG_HIDDEN const char * const config_event_context_vsgid = "VSGID";
 240
 241 /* Deprecated symbols */
 242 const char * const config_element_perf;
 243
 244 enum process_event_node_phase {
 245         CREATION = 0,
 246         ENABLE = 1,
 247 };
 248
 249 struct consumer_output {
 250         int enabled;
 251         char *path;
 252         char *control_uri;
 253         char *data_uri;
 254 };
 255
 256 static int config_entry_handler_filter(struct handler_filter_args *args,
 257                 const char *section, const char *name, const char *value)
 258 {
 259         int ret = 0;
 260         struct config_entry entry = { section, name, value };
 261
 262         assert(args);
 263
 264         if (!section || !name || !value) {
 265                 ret = -EIO;
 266                 goto end;
 267         }
 268
 269         if (args->section) {
 270                 if (strcmp(args->section, section)) {
 271                         goto end;
 272                 }
 273         }
 274
 275         ret = args->handler(&entry, args->user_data);
 276 end:
 277         return ret;
 278 }
 279
 280 LTTNG_HIDDEN
 281 int config_get_section_entries(const char *override_path, const char *section,
 282                 config_entry_handler_cb handler, void *user_data)
 283 {
 284         int ret = 0;
 285         const char *path;
 286         FILE *config_file = NULL;
 287         struct handler_filter_args filter = { section, handler, user_data };
 288
 289         /* First, try system-wide conf. file. */
 290         path = DEFAULT_DAEMON_SYSTEM_CONFIGPATH;
 291
 292         config_file = fopen(path, "r");
 293         if (config_file) {
 294                 DBG("Loading daemon conf file at %s", path);
 295                 /*
 296                  * Return value is not very important here since error or not, we
 297                  * continue and try the next possible conf. file.
 298                  */
 299                 (void) ini_parse_file(config_file,
 300                                 (ini_entry_handler) config_entry_handler_filter,
 301                                 (void *) &filter);
 302                 fclose(config_file);
 303         }
 304
 305         /* Second is the user local configuration. */
 306         path = utils_get_home_dir();
 307         if (path) {
 308                 char fullpath[PATH_MAX];
 309
 310                 ret = snprintf(fullpath, sizeof(fullpath),
 311                                 DEFAULT_DAEMON_HOME_CONFIGPATH, path);
 312                 if (ret < 0) {
 313                         PERROR("snprintf user conf. path");
 314                         goto error;
 315                 }
 316
 317                 config_file = fopen(fullpath, "r");
 318                 if (config_file) {
 319                         DBG("Loading daemon user conf file at %s", path);
 320                         /*
 321                          * Return value is not very important here since error or not, we
 322                          * continue and try the next possible conf. file.
 323                          */
 324                         (void) ini_parse_file(config_file,
 325                                         (ini_entry_handler) config_entry_handler_filter,
 326                                         (void *) &filter);
 327                         fclose(config_file);
 328                 }
 329         }
 330
 331         /* Final path is the one that the user might have provided. */
 332         if (override_path) {
 333                 config_file = fopen(override_path, "r");
 334                 if (config_file) {
 335                         DBG("Loading daemon command line conf file at %s", override_path);
 336                         (void) ini_parse_file(config_file,
 337                                         (ini_entry_handler) config_entry_handler_filter,
 338                                         (void *) &filter);
 339                         fclose(config_file);
 340                 } else {
 341                         ERR("Failed to open daemon configuration file at %s",
 342                                 override_path);
 343                         ret = -ENOENT;
 344                         goto error;
 345                 }
 346         }
 347
 348         /* Everything went well. */
 349         ret = 0;
 350
 351 error:
 352         return ret;
 353 }
 354
 355 LTTNG_HIDDEN
 356 int config_parse_value(const char *value)
 357 {
 358         int i, ret = 0;
 359         char *endptr, *lower_str;
 360         size_t len;
 361         unsigned long v;
 362
 363         len = strlen(value);
 364         if (!len) {
 365                 ret = -1;
 366                 goto end;
 367         }
 368
 369         v = strtoul(value, &endptr, 10);
 370         if (endptr != value) {
 371                 ret = v;
 372                 goto end;
 373         }
 374
 375         lower_str = zmalloc(len + 1);
 376         if (!lower_str) {
 377                 PERROR("zmalloc");
 378                 ret = -errno;
 379                 goto end;
 380         }
 381
 382         for (i = 0; i < len; i++) {
 383                 lower_str[i] = tolower(value[i]);
 384         }
 385
 386         if (!strcmp(lower_str, config_str_yes) ||
 387                 !strcmp(lower_str, config_str_true) ||
 388                 !strcmp(lower_str, config_str_on)) {
 389                 ret = 1;
 390         } else if (!strcmp(lower_str, config_str_no) ||
 391                 !strcmp(lower_str, config_str_false) ||
 392                 !strcmp(lower_str, config_str_off)) {
 393                 ret = 0;
 394         } else {
 395                 ret = -1;
 396         }
 397
 398         free(lower_str);
 399 end:
 400         return ret;
 401 }
 402
 403 /*
 404  * Returns a xmlChar string which must be released using xmlFree().
 405  */
 406 static xmlChar *encode_string(const char *in_str)
 407 {
 408         xmlChar *out_str = NULL;
 409         xmlCharEncodingHandlerPtr handler;
 410         int out_len, ret, in_len;
 411
 412         assert(in_str);
 413
 414         handler = xmlFindCharEncodingHandler(config_xml_encoding);
 415         if (!handler) {
 416                 ERR("xmlFindCharEncodingHandler return NULL!. Configure issue!");
 417                 goto end;
 418         }
 419
 420         in_len = strlen(in_str);
 421         /*
 422          * Add 1 byte for the NULL terminted character. The factor 4 here is
 423          * used because UTF-8 characters can take up to 4 bytes.
 424          */
 425         out_len = (in_len * 4) + 1;
 426         out_str = xmlMalloc(out_len);
 427         if (!out_str) {
 428                 goto end;
 429         }
 430
 431         ret = handler->input(out_str, &out_len, (const xmlChar *) in_str, &in_len);
 432         if (ret < 0) {
 433                 xmlFree(out_str);
 434                 out_str = NULL;
 435                 goto end;
 436         }
 437
 438         /* out_len is now the size of out_str */
 439         out_str[out_len] = '\0';
 440 end:
 441         return out_str;
 442 }
 443
 444 LTTNG_HIDDEN
 445 struct config_writer *config_writer_create(int fd_output, int indent)
 446 {
 447         int ret;
 448         struct config_writer *writer;
 449         xmlOutputBufferPtr buffer;
 450
 451         writer = zmalloc(sizeof(struct config_writer));
 452         if (!writer) {
 453                 PERROR("zmalloc config_writer_create");
 454                 goto end;
 455         }
 456
 457         buffer = xmlOutputBufferCreateFd(fd_output, NULL);
 458         if (!buffer) {
 459                 goto error_destroy;
 460         }
 461
 462         writer->writer = xmlNewTextWriter(buffer);
 463         ret = xmlTextWriterStartDocument(writer->writer, NULL,
 464                 config_xml_encoding, NULL);
 465         if (ret < 0) {
 466                 goto error_destroy;
 467         }
 468
 469         ret = xmlTextWriterSetIndentString(writer->writer,
 470                 BAD_CAST config_xml_indent_string);
 471         if (ret) {
 472                 goto error_destroy;
 473         }
 474
 475         ret = xmlTextWriterSetIndent(writer->writer, indent);
 476         if (ret) {
 477                 goto error_destroy;
 478         }
 479
 480 end:
 481         return writer;
 482 error_destroy:
 483         config_writer_destroy(writer);
 484         return NULL;
 485 }
 486
 487 LTTNG_HIDDEN
 488 int config_writer_destroy(struct config_writer *writer)
 489 {
 490         int ret = 0;
 491
 492         if (!writer) {
 493                 ret = -EINVAL;
 494                 goto end;
 495         }
 496
 497         if (xmlTextWriterEndDocument(writer->writer) < 0) {
 498                 WARN("Could not close XML document");
 499                 ret = -EIO;
 500         }
 501
 502         if (writer->writer) {
 503                 xmlFreeTextWriter(writer->writer);
 504         }
 505
 506         free(writer);
 507 end:
 508         return ret;
 509 }
 510
 511 LTTNG_HIDDEN
 512 int config_writer_open_element(struct config_writer *writer,
 513         const char *element_name)
 514 {
 515         int ret;
 516         xmlChar *encoded_element_name;
 517
 518         if (!writer || !writer->writer || !element_name || !element_name[0]) {
 519                 ret = -1;
 520                 goto end;
 521         }
 522
 523         encoded_element_name = encode_string(element_name);
 524         if (!encoded_element_name) {
 525                 ret = -1;
 526                 goto end;
 527         }
 528
 529         ret = xmlTextWriterStartElement(writer->writer, encoded_element_name);
 530         xmlFree(encoded_element_name);
 531 end:
 532         return ret >= 0 ? 0 : ret;
 533 }
 534
 535 LTTNG_HIDDEN
 536 int config_writer_write_attribute(struct config_writer *writer,
 537                 const char *name, const char *value)
 538 {
 539         int ret;
 540         xmlChar *encoded_name = NULL;
 541         xmlChar *encoded_value = NULL;
 542
 543         if (!writer || !writer->writer || !name || !name[0]) {
 544                 ret = -1;
 545                 goto end;
 546         }
 547
 548         encoded_name = encode_string(name);
 549         if (!encoded_name) {
 550                 ret = -1;
 551                 goto end;
 552         }
 553
 554         encoded_value = encode_string(value);
 555         if (!encoded_value) {
 556                 ret = -1;
 557                 goto end;
 558         }
 559
 560         ret = xmlTextWriterWriteAttribute(writer->writer, encoded_name,
 561                         encoded_value);
 562 end:
 563         xmlFree(encoded_name);
 564         xmlFree(encoded_value);
 565         return ret >= 0 ? 0 : ret;
 566 }
 567
 568 LTTNG_HIDDEN
 569 int config_writer_close_element(struct config_writer *writer)
 570 {
 571         int ret;
 572
 573         if (!writer || !writer->writer) {
 574                 ret = -1;
 575                 goto end;
 576         }
 577
 578         ret = xmlTextWriterEndElement(writer->writer);
 579 end:
 580         return ret >= 0 ? 0 : ret;
 581 }
 582
 583 LTTNG_HIDDEN
 584 int config_writer_write_element_unsigned_int(struct config_writer *writer,
 585                 const char *element_name, uint64_t value)
 586 {
 587         int ret;
 588         xmlChar *encoded_element_name;
 589
 590         if (!writer || !writer->writer || !element_name || !element_name[0]) {
 591                 ret = -1;
 592                 goto end;
 593         }
 594
 595         encoded_element_name = encode_string(element_name);
 596         if (!encoded_element_name) {
 597                 ret = -1;
 598                 goto end;
 599         }
 600
 601         ret = xmlTextWriterWriteFormatElement(writer->writer,
 602                 encoded_element_name, "%" PRIu64, value);
 603         xmlFree(encoded_element_name);
 604 end:
 605         return ret >= 0 ? 0 : ret;
 606 }
 607
 608 LTTNG_HIDDEN
 609 int config_writer_write_element_signed_int(struct config_writer *writer,
 610                 const char *element_name, int64_t value)
 611 {
 612         int ret;
 613         xmlChar *encoded_element_name;
 614
 615         if (!writer || !writer->writer || !element_name || !element_name[0]) {
 616                 ret = -1;
 617                 goto end;
 618         }
 619
 620         encoded_element_name = encode_string(element_name);
 621         if (!encoded_element_name) {
 622                 ret = -1;
 623                 goto end;
 624         }
 625
 626         ret = xmlTextWriterWriteFormatElement(writer->writer,
 627                 encoded_element_name, "%" PRIi64, value);
 628         xmlFree(encoded_element_name);
 629 end:
 630         return ret >= 0 ? 0 : ret;
 631 }
 632
 633 LTTNG_HIDDEN
 634 int config_writer_write_element_bool(struct config_writer *writer,
 635                 const char *element_name, int value)
 636 {
 637         return config_writer_write_element_string(writer, element_name,
 638                 value ? config_xml_true : config_xml_false);
 639 }
 640
 641 LTTNG_HIDDEN
 642 int config_writer_write_element_string(struct config_writer *writer,
 643                 const char *element_name, const char *value)
 644 {
 645         int ret;
 646         xmlChar *encoded_element_name = NULL;
 647         xmlChar *encoded_value = NULL;
 648
 649         if (!writer || !writer->writer || !element_name || !element_name[0] ||
 650                 !value) {
 651                 ret = -1;
 652                 goto end;
 653         }
 654
 655         encoded_element_name = encode_string(element_name);
 656         if (!encoded_element_name) {
 657                 ret = -1;
 658                 goto end;
 659         }
 660
 661         encoded_value = encode_string(value);
 662         if (!encoded_value) {
 663                 ret = -1;
 664                 goto end;
 665         }
 666
 667         ret = xmlTextWriterWriteElement(writer->writer, encoded_element_name,
 668                         encoded_value);
 669 end:
 670         xmlFree(encoded_element_name);
 671         xmlFree(encoded_value);
 672         return ret >= 0 ? 0 : ret;
 673 }
 674
 675 static
 676 void xml_error_handler(void *ctx, const char *format, ...)
 677 {
 678         char *errMsg;
 679         va_list args;
 680         int ret;
 681
 682         va_start(args, format);
 683         ret = vasprintf(&errMsg, format, args);
 684         va_end(args);
 685         if (ret == -1) {
 686                 ERR("String allocation failed in xml error handler");
 687                 return;
 688         }
 689
 690         fprintf(stderr, "XML Error: %s", errMsg);
 691         free(errMsg);
 692 }
 693
 694 static
 695 void fini_session_config_validation_ctx(
 696         struct session_config_validation_ctx *ctx)
 697 {
 698         if (ctx->parser_ctx) {
 699                 xmlSchemaFreeParserCtxt(ctx->parser_ctx);
 700         }
 701
 702         if (ctx->schema) {
 703                 xmlSchemaFree(ctx->schema);
 704         }
 705
 706         if (ctx->schema_validation_ctx) {
 707                 xmlSchemaFreeValidCtxt(ctx->schema_validation_ctx);
 708         }
 709
 710         memset(ctx, 0, sizeof(struct session_config_validation_ctx));
 711 }
 712
 713 static
 714 char *get_session_config_xsd_path()
 715 {
 716         char *xsd_path;
 717         const char *base_path = lttng_secure_getenv(DEFAULT_SESSION_CONFIG_XSD_PATH_ENV);
 718         size_t base_path_len;
 719         size_t max_path_len;
 720
 721         if (!base_path) {
 722                 base_path = DEFAULT_SESSION_CONFIG_XSD_PATH;
 723         }
 724
 725         base_path_len = strlen(base_path);
 726         max_path_len = base_path_len +
 727                 sizeof(DEFAULT_SESSION_CONFIG_XSD_FILENAME) + 1;
 728         xsd_path = zmalloc(max_path_len);
 729         if (!xsd_path) {
 730                 goto end;
 731         }
 732
 733         strcpy(xsd_path, base_path);
 734         if (xsd_path[base_path_len - 1] != '/') {
 735                 xsd_path[base_path_len++] = '/';
 736         }
 737
 738         strcpy(xsd_path + base_path_len, DEFAULT_SESSION_CONFIG_XSD_FILENAME);
 739 end:
 740         return xsd_path;
 741 }
 742
 743 static
 744 int init_session_config_validation_ctx(
 745         struct session_config_validation_ctx *ctx)
 746 {
 747         int ret;
 748         char *xsd_path = get_session_config_xsd_path();
 749
 750         if (!xsd_path) {
 751                 ret = -LTTNG_ERR_NOMEM;
 752                 goto end;
 753         }
 754
 755         ctx->parser_ctx = xmlSchemaNewParserCtxt(xsd_path);
 756         if (!ctx->parser_ctx) {
 757                 ERR("XSD parser context creation failed");
 758                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
 759                 goto end;
 760         }
 761         xmlSchemaSetParserErrors(ctx->parser_ctx, xml_error_handler,
 762                 xml_error_handler, NULL);
 763
 764         ctx->schema = xmlSchemaParse(ctx->parser_ctx);
 765         if (!ctx->schema) {
 766                 ERR("XSD parsing failed");
 767                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
 768                 goto end;
 769         }
 770
 771         ctx->schema_validation_ctx = xmlSchemaNewValidCtxt(ctx->schema);
 772         if (!ctx->schema_validation_ctx) {
 773                 ERR("XSD validation context creation failed");
 774                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
 775                 goto end;
 776         }
 777
 778         xmlSchemaSetValidErrors(ctx->schema_validation_ctx, xml_error_handler,
 779                         xml_error_handler, NULL);
 780         ret = 0;
 781
 782 end:
 783         if (ret) {
 784                 fini_session_config_validation_ctx(ctx);
 785         }
 786
 787         free(xsd_path);
 788         return ret;
 789 }
 790
 791 static
 792 int parse_uint(xmlChar *str, uint64_t *val)
 793 {
 794         int ret;
 795         char *endptr;
 796
 797         if (!str || !val) {
 798                 ret = -1;
 799                 goto end;
 800         }
 801
 802         *val = strtoull((const char *) str, &endptr, 10);
 803         if (!endptr || *endptr) {
 804                 ret = -1;
 805         } else {
 806                 ret = 0;
 807         }
 808
 809 end:
 810         return ret;
 811 }
 812
 813 static
 814 int parse_int(xmlChar *str, int64_t *val)
 815 {
 816         int ret;
 817         char *endptr;
 818
 819         if (!str || !val) {
 820                 ret = -1;
 821                 goto end;
 822         }
 823
 824         *val = strtoll((const char *) str, &endptr, 10);
 825         if (!endptr || *endptr) {
 826                 ret = -1;
 827         } else {
 828                 ret = 0;
 829         }
 830
 831 end:
 832         return ret;
 833 }
 834
 835 static
 836 int parse_bool(xmlChar *str, int *val)
 837 {
 838         int ret = 0;
 839
 840         if (!str || !val) {
 841                 ret = -1;
 842                 goto end;
 843         }
 844
 845         if (!strcmp((const char *) str, config_xml_true)) {
 846                 *val = 1;
 847         } else if (!strcmp((const char *) str, config_xml_false)) {
 848                 *val = 0;
 849         } else {
 850                 WARN("Invalid boolean value encoutered (%s).",
 851                         (const char *) str);
 852                 ret = -1;
 853         }
 854 end:
 855         return ret;
 856 }
 857
 858 static
 859 int get_domain_type(xmlChar *domain)
 860 {
 861         int ret;
 862
 863         if (!domain) {
 864                 goto error;
 865         }
 866
 867         if (!strcmp((char *) domain, config_domain_type_kernel)) {
 868                 ret = LTTNG_DOMAIN_KERNEL;
 869         } else if (!strcmp((char *) domain, config_domain_type_ust)) {
 870                 ret = LTTNG_DOMAIN_UST;
 871         } else if (!strcmp((char *) domain, config_domain_type_jul)) {
 872                 ret = LTTNG_DOMAIN_JUL;
 873         } else if (!strcmp((char *) domain, config_domain_type_log4j)) {
 874                 ret = LTTNG_DOMAIN_LOG4J;
 875         } else if (!strcmp((char *) domain, config_domain_type_python)) {
 876                 ret = LTTNG_DOMAIN_PYTHON;
 877         } else {
 878                 goto error;
 879         }
 880
 881         return ret;
 882 error:
 883         return -1;
 884 }
 885
 886 static
 887 int get_buffer_type(xmlChar *buffer_type)
 888 {
 889         int ret;
 890
 891         if (!buffer_type) {
 892                 goto error;
 893         }
 894
 895         if (!strcmp((char *) buffer_type, config_buffer_type_global)) {
 896                 ret = LTTNG_BUFFER_GLOBAL;
 897         } else if (!strcmp((char *) buffer_type, config_buffer_type_per_uid)) {
 898                 ret = LTTNG_BUFFER_PER_UID;
 899         } else if (!strcmp((char *) buffer_type, config_buffer_type_per_pid)) {
 900                 ret = LTTNG_BUFFER_PER_PID;
 901         } else {
 902                 goto error;
 903         }
 904
 905         return ret;
 906 error:
 907         return -1;
 908 }
 909
 910 static
 911 int get_overwrite_mode(xmlChar *overwrite_mode)
 912 {
 913         int ret;
 914
 915         if (!overwrite_mode) {
 916                 goto error;
 917         }
 918
 919         if (!strcmp((char *) overwrite_mode, config_overwrite_mode_overwrite)) {
 920                 ret = 1;
 921         } else if (!strcmp((char *) overwrite_mode,
 922                 config_overwrite_mode_discard)) {
 923                 ret = 0;
 924         } else {
 925                 goto error;
 926         }
 927
 928         return ret;
 929 error:
 930         return -1;
 931 }
 932
 933 static
 934 int get_output_type(xmlChar *output_type)
 935 {
 936         int ret;
 937
 938         if (!output_type) {
 939                 goto error;
 940         }
 941
 942         if (!strcmp((char *) output_type, config_output_type_mmap)) {
 943                 ret = LTTNG_EVENT_MMAP;
 944         } else if (!strcmp((char *) output_type, config_output_type_splice)) {
 945                 ret = LTTNG_EVENT_SPLICE;
 946         } else {
 947                 goto error;
 948         }
 949
 950         return ret;
 951 error:
 952         return -1;
 953 }
 954
 955 static
 956 int get_event_type(xmlChar *event_type)
 957 {
 958         int ret;
 959
 960         if (!event_type) {
 961                 goto error;
 962         }
 963
 964         if (!strcmp((char *) event_type, config_event_type_all)) {
 965                 ret = LTTNG_EVENT_ALL;
 966         } else if (!strcmp((char *) event_type, config_event_type_tracepoint)) {
 967                 ret = LTTNG_EVENT_TRACEPOINT;
 968         } else if (!strcmp((char *) event_type, config_event_type_probe)) {
 969                 ret = LTTNG_EVENT_PROBE;
 970         } else if (!strcmp((char *) event_type,
 971                                 config_event_type_userspace_probe)) {
 972                 ret = LTTNG_EVENT_USERSPACE_PROBE;
 973         } else if (!strcmp((char *) event_type, config_event_type_function)) {
 974                 ret = LTTNG_EVENT_FUNCTION;
 975         } else if (!strcmp((char *) event_type,
 976                                 config_event_type_function_entry)) {
 977                 ret = LTTNG_EVENT_FUNCTION_ENTRY;
 978         } else if (!strcmp((char *) event_type, config_event_type_noop)) {
 979                 ret = LTTNG_EVENT_NOOP;
 980         } else if (!strcmp((char *) event_type, config_event_type_syscall)) {
 981                 ret = LTTNG_EVENT_SYSCALL;
 982         } else {
 983                 goto error;
 984         }
 985
 986         return ret;
 987 error:
 988         return -1;
 989 }
 990
 991 static
 992 int get_loglevel_type(xmlChar *loglevel_type)
 993 {
 994         int ret;
 995
 996         if (!loglevel_type) {
 997                 goto error;
 998         }
 999
1000         if (!strcmp((char *) loglevel_type, config_loglevel_type_all)) {
1001                 ret = LTTNG_EVENT_LOGLEVEL_ALL;
1002         } else if (!strcmp((char *) loglevel_type,
1003                 config_loglevel_type_range)) {
1004                 ret = LTTNG_EVENT_LOGLEVEL_RANGE;
1005         } else if (!strcmp((char *) loglevel_type,
1006                 config_loglevel_type_single)) {
1007                 ret = LTTNG_EVENT_LOGLEVEL_SINGLE;
1008         } else {
1009                 goto error;
1010         }
1011
1012         return ret;
1013 error:
1014         return -1;
1015 }
1016
1017 /*
1018  * Return the context type or -1 on error.
1019  */
1020 static
1021 int get_context_type(xmlChar *context_type)
1022 {
1023         int ret;
1024
1025         if (!context_type) {
1026                 goto error;
1027         }
1028
1029         if (!strcmp((char *) context_type, config_event_context_pid)) {
1030                 ret = LTTNG_EVENT_CONTEXT_PID;
1031         } else if (!strcmp((char *) context_type,
1032                 config_event_context_procname)) {
1033                 ret = LTTNG_EVENT_CONTEXT_PROCNAME;
1034         } else if (!strcmp((char *) context_type,
1035                 config_event_context_prio)) {
1036                 ret = LTTNG_EVENT_CONTEXT_PRIO;
1037         } else if (!strcmp((char *) context_type,
1038                 config_event_context_nice)) {
1039                 ret = LTTNG_EVENT_CONTEXT_NICE;
1040         } else if (!strcmp((char *) context_type,
1041                 config_event_context_vpid)) {
1042                 ret = LTTNG_EVENT_CONTEXT_VPID;
1043         } else if (!strcmp((char *) context_type,
1044                 config_event_context_tid)) {
1045                 ret = LTTNG_EVENT_CONTEXT_TID;
1046         } else if (!strcmp((char *) context_type,
1047                 config_event_context_vtid)) {
1048                 ret = LTTNG_EVENT_CONTEXT_VTID;
1049         } else if (!strcmp((char *) context_type,
1050                 config_event_context_ppid)) {
1051                 ret = LTTNG_EVENT_CONTEXT_PPID;
1052         } else if (!strcmp((char *) context_type,
1053                 config_event_context_vppid)) {
1054                 ret = LTTNG_EVENT_CONTEXT_VPPID;
1055         } else if (!strcmp((char *) context_type,
1056                 config_event_context_pthread_id)) {
1057                 ret = LTTNG_EVENT_CONTEXT_PTHREAD_ID;
1058         } else if (!strcmp((char *) context_type,
1059                 config_event_context_hostname)) {
1060                 ret = LTTNG_EVENT_CONTEXT_HOSTNAME;
1061         } else if (!strcmp((char *) context_type,
1062                 config_event_context_ip)) {
1063                 ret = LTTNG_EVENT_CONTEXT_IP;
1064         } else if (!strcmp((char *) context_type,
1065                 config_event_context_interruptible)) {
1066                 ret = LTTNG_EVENT_CONTEXT_INTERRUPTIBLE;
1067         } else if (!strcmp((char *) context_type,
1068                 config_event_context_preemptible)) {
1069                 ret = LTTNG_EVENT_CONTEXT_PREEMPTIBLE;
1070         } else if (!strcmp((char *) context_type,
1071                 config_event_context_need_reschedule)) {
1072                 ret = LTTNG_EVENT_CONTEXT_NEED_RESCHEDULE;
1073         } else if (!strcmp((char *) context_type,
1074                 config_event_context_migratable)) {
1075                 ret = LTTNG_EVENT_CONTEXT_MIGRATABLE;
1076         } else if (!strcmp((char *) context_type,
1077                 config_event_context_callstack_user)) {
1078                 ret = LTTNG_EVENT_CONTEXT_CALLSTACK_USER;
1079         } else if (!strcmp((char *) context_type,
1080                 config_event_context_callstack_kernel)) {
1081                 ret = LTTNG_EVENT_CONTEXT_CALLSTACK_KERNEL;
1082         } else if (!strcmp((char *) context_type,
1083                 config_event_context_cgroup_ns)) {
1084                 ret = LTTNG_EVENT_CONTEXT_CGROUP_NS;
1085         } else if (!strcmp((char *) context_type,
1086                 config_event_context_ipc_ns)) {
1087                 ret = LTTNG_EVENT_CONTEXT_IPC_NS;
1088         } else if (!strcmp((char *) context_type,
1089                 config_event_context_mnt_ns)) {
1090                 ret = LTTNG_EVENT_CONTEXT_MNT_NS;
1091         } else if (!strcmp((char *) context_type,
1092                 config_event_context_net_ns)) {
1093                 ret = LTTNG_EVENT_CONTEXT_NET_NS;
1094         } else if (!strcmp((char *) context_type,
1095                 config_event_context_pid_ns)) {
1096                 ret = LTTNG_EVENT_CONTEXT_PID_NS;
1097         } else if (!strcmp((char *) context_type,
1098                 config_event_context_user_ns)) {
1099                 ret = LTTNG_EVENT_CONTEXT_USER_NS;
1100         } else if (!strcmp((char *) context_type,
1101                 config_event_context_uts_ns)) {
1102                 ret = LTTNG_EVENT_CONTEXT_UTS_NS;
1103         } else if (!strcmp((char *) context_type,
1104                 config_event_context_uid)) {
1105                 ret = LTTNG_EVENT_CONTEXT_UID;
1106         } else if (!strcmp((char *) context_type,
1107                 config_event_context_euid)) {
1108                 ret = LTTNG_EVENT_CONTEXT_EUID;
1109         } else if (!strcmp((char *) context_type,
1110                 config_event_context_suid)) {
1111                 ret = LTTNG_EVENT_CONTEXT_SUID;
1112         } else if (!strcmp((char *) context_type,
1113                 config_event_context_gid)) {
1114                 ret = LTTNG_EVENT_CONTEXT_GID;
1115         } else if (!strcmp((char *) context_type,
1116                 config_event_context_egid)) {
1117                 ret = LTTNG_EVENT_CONTEXT_EGID;
1118         } else if (!strcmp((char *) context_type,
1119                 config_event_context_sgid)) {
1120                 ret = LTTNG_EVENT_CONTEXT_SGID;
1121         } else if (!strcmp((char *) context_type,
1122                 config_event_context_vuid)) {
1123                 ret = LTTNG_EVENT_CONTEXT_VUID;
1124         } else if (!strcmp((char *) context_type,
1125                 config_event_context_veuid)) {
1126                 ret = LTTNG_EVENT_CONTEXT_VEUID;
1127         } else if (!strcmp((char *) context_type,
1128                 config_event_context_vsuid)) {
1129                 ret = LTTNG_EVENT_CONTEXT_VSUID;
1130         } else if (!strcmp((char *) context_type,
1131                 config_event_context_vgid)) {
1132                 ret = LTTNG_EVENT_CONTEXT_VGID;
1133         } else if (!strcmp((char *) context_type,
1134                 config_event_context_vegid)) {
1135                 ret = LTTNG_EVENT_CONTEXT_VEGID;
1136         } else if (!strcmp((char *) context_type,
1137                 config_event_context_vsgid)) {
1138                 ret = LTTNG_EVENT_CONTEXT_VSGID;
1139         } else {
1140                 goto error;
1141         }
1142
1143         return ret;
1144 error:
1145         return -1;
1146 }
1147
1148 static
1149 int init_domain(xmlNodePtr domain_node, struct lttng_domain *domain)
1150 {
1151         int ret;
1152         xmlNodePtr node;
1153
1154         for (node = xmlFirstElementChild(domain_node); node;
1155                 node = xmlNextElementSibling(node)) {
1156                 if (!strcmp((const char *) node->name, config_element_type)) {
1157                         /* domain type */
1158                         xmlChar *node_content = xmlNodeGetContent(node);
1159                         if (!node_content) {
1160                                 ret = -LTTNG_ERR_NOMEM;
1161                                 goto end;
1162                         }
1163
1164                         ret = get_domain_type(node_content);
1165                         free(node_content);
1166                         if (ret < 0) {
1167                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1168                                 goto end;
1169                         }
1170
1171                         domain->type = ret;
1172                 } else if (!strcmp((const char *) node->name,
1173                         config_element_buffer_type)) {
1174                         /* buffer type */
1175                         xmlChar *node_content = xmlNodeGetContent(node);
1176                         if (!node_content) {
1177                                 ret = -LTTNG_ERR_NOMEM;
1178                                 goto end;
1179                         }
1180
1181                         ret = get_buffer_type(node_content);
1182                         free(node_content);
1183                         if (ret < 0) {
1184                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1185                                 goto end;
1186                         }
1187
1188                         domain->buf_type = ret;
1189                 }
1190         }
1191         ret = 0;
1192 end:
1193         return ret;
1194 }
1195
1196 static
1197 int get_net_output_uris(xmlNodePtr net_output_node, char **control_uri,
1198         char **data_uri)
1199 {
1200         xmlNodePtr node;
1201
1202         for (node = xmlFirstElementChild(net_output_node); node;
1203                 node = xmlNextElementSibling(node)) {
1204                 if (!strcmp((const char *) node->name, config_element_control_uri)) {
1205                         /* control_uri */
1206                         *control_uri = (char *) xmlNodeGetContent(node);
1207                         if (!*control_uri) {
1208                                 break;
1209                         }
1210                 } else {
1211                         /* data_uri */
1212                         *data_uri = (char *) xmlNodeGetContent(node);
1213                         if (!*data_uri) {
1214                                 break;
1215                         }
1216                 }
1217         }
1218
1219         return *control_uri || *data_uri ? 0 : -LTTNG_ERR_LOAD_INVALID_CONFIG;
1220 }
1221
1222 static
1223 int process_consumer_output(xmlNodePtr consumer_output_node,
1224         struct consumer_output *output)
1225 {
1226         int ret;
1227         xmlNodePtr node;
1228
1229         assert(output);
1230
1231         for (node = xmlFirstElementChild(consumer_output_node); node;
1232                         node = xmlNextElementSibling(node)) {
1233                 if (!strcmp((const char *) node->name, config_element_enabled)) {
1234                         xmlChar *enabled_str = xmlNodeGetContent(node);
1235
1236                         /* enabled */
1237                         if (!enabled_str) {
1238                                 ret = -LTTNG_ERR_NOMEM;
1239                                 goto end;
1240                         }
1241
1242                         ret = parse_bool(enabled_str, &output->enabled);
1243                         free(enabled_str);
1244                         if (ret) {
1245                                 goto end;
1246                         }
1247                 } else {
1248                         xmlNodePtr output_type_node;
1249
1250                         /* destination */
1251                         output_type_node = xmlFirstElementChild(node);
1252                         if (!output_type_node) {
1253                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1254                                 goto end;
1255                         }
1256
1257                         if (!strcmp((const char *) output_type_node->name,
1258                                         config_element_path)) {
1259                                 /* path */
1260                                 output->path = (char *) xmlNodeGetContent(output_type_node);
1261                                 if (!output->path) {
1262                                         ret = -LTTNG_ERR_NOMEM;
1263                                         goto end;
1264                                 }
1265                         } else {
1266                                 /* net_output */
1267                                 ret = get_net_output_uris(output_type_node,
1268                                                 &output->control_uri, &output->data_uri);
1269                                 if (ret) {
1270                                         goto end;
1271                                 }
1272                         }
1273                 }
1274         }
1275         ret = 0;
1276
1277 end:
1278         if (ret) {
1279                 free(output->path);
1280                 free(output->control_uri);
1281                 free(output->data_uri);
1282                 memset(output, 0, sizeof(struct consumer_output));
1283         }
1284         return ret;
1285 }
1286
1287 static
1288 int create_session_net_output(const char *name, const char *control_uri,
1289                 const char *data_uri)
1290 {
1291         int ret;
1292         struct lttng_handle *handle;
1293         const char *uri = NULL;
1294
1295         assert(name);
1296
1297         handle = lttng_create_handle(name, NULL);
1298         if (!handle) {
1299                 ret = -LTTNG_ERR_NOMEM;
1300                 goto end;
1301         }
1302
1303         if (!control_uri || !data_uri) {
1304                 uri = control_uri ? control_uri : data_uri;
1305                 control_uri = uri;
1306                 data_uri = uri;
1307         }
1308
1309         ret = lttng_set_consumer_url(handle, control_uri, data_uri);
1310         lttng_destroy_handle(handle);
1311 end:
1312         return ret;
1313 }
1314
1315 static
1316 int create_snapshot_session(const char *session_name, xmlNodePtr output_node,
1317                 const struct config_load_session_override_attr *overrides)
1318 {
1319         int ret;
1320         xmlNodePtr node = NULL;
1321         xmlNodePtr snapshot_output_list_node;
1322         xmlNodePtr snapshot_output_node;
1323
1324         assert(session_name);
1325
1326         ret = lttng_create_session_snapshot(session_name, NULL);
1327         if (ret) {
1328                 goto end;
1329         }
1330
1331         if (!output_node) {
1332                 goto end;
1333         }
1334
1335         snapshot_output_list_node = xmlFirstElementChild(output_node);
1336
1337         /* Parse and create snapshot outputs */
1338
1339         for (snapshot_output_node =
1340                         xmlFirstElementChild(snapshot_output_list_node);
1341                         snapshot_output_node; snapshot_output_node =
1342                         xmlNextElementSibling(snapshot_output_node)) {
1343                 char *name = NULL;
1344                 uint64_t max_size = UINT64_MAX;
1345                 struct consumer_output output = { 0 };
1346                 struct lttng_snapshot_output *snapshot_output = NULL;
1347                 const char *control_uri = NULL;
1348                 const char *data_uri = NULL;
1349                 const char *path = NULL;
1350
1351                 for (node = xmlFirstElementChild(snapshot_output_node); node;
1352                                 node = xmlNextElementSibling(node)) {
1353                         if (!strcmp((const char *) node->name,
1354                                 config_element_name)) {
1355                                 /* name */
1356                                 name = (char *) xmlNodeGetContent(node);
1357                                 if (!name) {
1358                                         ret = -LTTNG_ERR_NOMEM;
1359                                         goto error_snapshot_output;
1360                                 }
1361                         } else if (!strcmp((const char *) node->name,
1362                                 config_element_max_size)) {
1363                                 xmlChar *content = xmlNodeGetContent(node);
1364
1365                                 /* max_size */
1366                                 if (!content) {
1367                                         ret = -LTTNG_ERR_NOMEM;
1368                                         goto error_snapshot_output;
1369                                 }
1370                                 ret = parse_uint(content, &max_size);
1371                                 free(content);
1372                                 if (ret) {
1373                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1374                                         goto error_snapshot_output;
1375                                 }
1376                         } else {
1377                                 /* consumer_output */
1378                                 ret = process_consumer_output(node, &output);
1379                                 if (ret) {
1380                                         goto error_snapshot_output;
1381                                 }
1382                         }
1383                 }
1384
1385                 control_uri = output.control_uri;
1386                 data_uri = output.data_uri;
1387                 path = output.path;
1388
1389                 if (overrides) {
1390                         if (overrides->path_url) {
1391                                 path = overrides->path_url;
1392                                 /* Control/data_uri are null */
1393                                 control_uri = NULL;
1394                                 data_uri = NULL;
1395                         } else {
1396                                 if (overrides->ctrl_url) {
1397                                         control_uri = overrides->ctrl_url;
1398                                         /* path is null */
1399                                         path = NULL;
1400                                 }
1401                                 if (overrides->data_url) {
1402                                         data_uri = overrides->data_url;
1403                                         /* path is null */
1404                                         path = NULL;
1405                                 }
1406                         }
1407                 }
1408
1409                 snapshot_output = lttng_snapshot_output_create();
1410                 if (!snapshot_output) {
1411                         ret = -LTTNG_ERR_NOMEM;
1412                         goto error_snapshot_output;
1413                 }
1414
1415                 ret = lttng_snapshot_output_set_name(name, snapshot_output);
1416                 if (ret) {
1417                         goto error_snapshot_output;
1418                 }
1419
1420                 ret = lttng_snapshot_output_set_size(max_size, snapshot_output);
1421                 if (ret) {
1422                         goto error_snapshot_output;
1423                 }
1424
1425                 if (path) {
1426                         ret = lttng_snapshot_output_set_ctrl_url(path,
1427                                         snapshot_output);
1428                         if (ret) {
1429                                 goto error_snapshot_output;
1430                         }
1431                 } else {
1432                         if (control_uri) {
1433                                 ret = lttng_snapshot_output_set_ctrl_url(control_uri,
1434                                                 snapshot_output);
1435                                 if (ret) {
1436                                         goto error_snapshot_output;
1437                                 }
1438                         }
1439
1440                         if (data_uri) {
1441                                 ret = lttng_snapshot_output_set_data_url(data_uri,
1442                                                 snapshot_output);
1443                                 if (ret) {
1444                                         goto error_snapshot_output;
1445                                 }
1446                         }
1447                 }
1448
1449                 ret = lttng_snapshot_add_output(session_name, snapshot_output);
1450 error_snapshot_output:
1451                 free(name);
1452                 free(output.path);
1453                 free(output.control_uri);
1454                 free(output.data_uri);
1455                 lttng_snapshot_output_destroy(snapshot_output);
1456                 if (ret) {
1457                         goto end;
1458                 }
1459         }
1460 end:
1461         return ret;
1462 }
1463
1464 static
1465 int create_session(const char *name,
1466         xmlNodePtr output_node,
1467         uint64_t live_timer_interval,
1468         const struct config_load_session_override_attr *overrides)
1469 {
1470         int ret;
1471         struct consumer_output output = { 0 };
1472         xmlNodePtr consumer_output_node;
1473         const char *control_uri = NULL;
1474         const char *data_uri = NULL;
1475         const char *path = NULL;
1476
1477         assert(name);
1478
1479         if (output_node) {
1480                 consumer_output_node = xmlFirstElementChild(output_node);
1481                 if (!consumer_output_node) {
1482                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1483                         goto end;
1484                 }
1485
1486                 if (strcmp((const char *) consumer_output_node->name,
1487                         config_element_consumer_output)) {
1488                         WARN("Invalid output type, expected %s node",
1489                                 config_element_consumer_output);
1490                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1491                         goto end;
1492                 }
1493
1494                 ret = process_consumer_output(consumer_output_node, &output);
1495                 if (ret) {
1496                         goto end;
1497                 }
1498         }
1499
1500         control_uri = output.control_uri;
1501         data_uri = output.data_uri;
1502         path = output.path;
1503
1504         /* Check for override and apply them */
1505         if (overrides) {
1506                 if (overrides->path_url) {
1507                         path = overrides->path_url;
1508                         /* control/data_uri are null */;
1509                         control_uri = NULL;
1510                         data_uri = NULL;
1511                 } else {
1512                         if (overrides->ctrl_url) {
1513                                 control_uri = overrides->ctrl_url;
1514                                 /* path is null */
1515                                 path = NULL;
1516                         }
1517                         if (overrides->data_url) {
1518                                 data_uri = overrides->data_url;
1519                                 /* path is null */
1520                                 path = NULL;
1521                         }
1522                 }
1523         }
1524
1525
1526         if (live_timer_interval != UINT64_MAX && !control_uri && !data_uri) {
1527                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1528                 goto end;
1529         }
1530
1531         if (control_uri || data_uri) {
1532                 /* network destination */
1533                 if (live_timer_interval && live_timer_interval != UINT64_MAX) {
1534                         /*
1535                          * URLs are provided for sure since the test above make sure that
1536                          * with a live timer the data and control URIs are provided. So,
1537                          * NULL is passed here and will be set right after.
1538                          */
1539                         ret = lttng_create_session_live(name, NULL, live_timer_interval);
1540                 } else {
1541                         ret = lttng_create_session(name, NULL);
1542                 }
1543                 if (ret) {
1544                         goto end;
1545                 }
1546
1547                 ret = create_session_net_output(name, control_uri, data_uri);
1548                 if (ret) {
1549                         goto end;
1550                 }
1551
1552         } else {
1553                 /* either local output or no output */
1554                 ret = lttng_create_session(name, path);
1555                 if (ret) {
1556                         goto end;
1557                 }
1558         }
1559 end:
1560         free(output.path);
1561         free(output.control_uri);
1562         free(output.data_uri);
1563         return ret;
1564 }
1565
1566 static
1567 struct lttng_userspace_probe_location *
1568 process_userspace_probe_function_attribute_node(
1569                 xmlNodePtr attribute_node)
1570 {
1571         xmlNodePtr function_attribute_node;
1572         char *function_name = NULL, *binary_path = NULL;
1573         struct lttng_userspace_probe_location *location = NULL;
1574         struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL;
1575
1576         /*
1577          * Process userspace probe location function attributes. The order of
1578          * the fields are not guaranteed so we need to iterate over all fields
1579          * and check at the end if everything we need for this location type is
1580          * there.
1581          */
1582         for (function_attribute_node =
1583                         xmlFirstElementChild(attribute_node);
1584                         function_attribute_node;
1585                         function_attribute_node = xmlNextElementSibling(
1586                                 function_attribute_node)) {
1587                 /* Handle function name, binary path and lookup method. */
1588                 if (!strcmp((const char *) function_attribute_node->name,
1589                                         config_element_userspace_probe_function_location_function_name)) {
1590                         function_name = (char *) xmlNodeGetContent(function_attribute_node);
1591                         if (!function_name) {
1592                                 goto error;
1593                         }
1594                 } else if (!strcmp((const char *) function_attribute_node->name,
1595                                         config_element_userspace_probe_location_binary_path)) {
1596                         binary_path = (char *) xmlNodeGetContent(function_attribute_node);
1597                         if (!binary_path) {
1598                                 goto error;
1599                         }
1600                 } else if (!strcmp((const char *) function_attribute_node->name,
1601                                         config_element_userspace_probe_lookup)) {
1602                         char *lookup_method_name;
1603
1604                         lookup_method_name = (char *) xmlNodeGetContent(
1605                                         function_attribute_node);
1606                         if (!lookup_method_name) {
1607                                 goto error;
1608                         }
1609
1610                         /*
1611                          * function_default lookup method defaults to
1612                          * function_elf lookup method at the moment.
1613                          */
1614                         if (!strcmp(lookup_method_name, config_element_userspace_probe_lookup_function_elf)
1615                                         || !strcmp(lookup_method_name, config_element_userspace_probe_lookup_function_default)) {
1616                                 lookup_method = lttng_userspace_probe_location_lookup_method_function_elf_create();
1617                                 if (!lookup_method) {
1618                                         PERROR("Error creating function default/ELF lookup method");
1619                                 }
1620                         } else {
1621                                 WARN("Unknown function lookup method");
1622                         }
1623
1624                         free(lookup_method_name);
1625                         if (!lookup_method) {
1626                                 goto error;
1627                         }
1628                 } else {
1629                         goto error;
1630                 }
1631
1632                 /* Check if all the necessary fields were found. */
1633                 if (binary_path && function_name && lookup_method) {
1634                         /* Ownership of lookup_method is transferred. */
1635                         location =
1636                                 lttng_userspace_probe_location_function_create(
1637                                                 binary_path, function_name,
1638                                                 lookup_method);
1639                         lookup_method = NULL;
1640                         goto error;
1641                 }
1642         }
1643 error:
1644         lttng_userspace_probe_location_lookup_method_destroy(lookup_method);
1645         free(binary_path);
1646         free(function_name);
1647         return location;
1648 }
1649
1650 static
1651 struct lttng_userspace_probe_location *
1652 process_userspace_probe_tracepoint_attribute_node(
1653                 xmlNodePtr attribute_node)
1654 {
1655         xmlNodePtr tracepoint_attribute_node;
1656         char *probe_name = NULL, *provider_name = NULL, *binary_path = NULL;
1657         struct lttng_userspace_probe_location *location = NULL;
1658         struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL;
1659
1660         /*
1661          * Process userspace probe location tracepoint attributes. The order of
1662          * the fields are not guaranteed so we need to iterate over all fields
1663          * and check at the end if everything we need for this location type is
1664          * there.
1665          */
1666         for (tracepoint_attribute_node =
1667                 xmlFirstElementChild(attribute_node); tracepoint_attribute_node;
1668                 tracepoint_attribute_node = xmlNextElementSibling(
1669                                 tracepoint_attribute_node)) {
1670                 if (!strcmp((const char *) tracepoint_attribute_node->name,
1671                                         config_element_userspace_probe_tracepoint_location_probe_name)) {
1672                         probe_name = (char *) xmlNodeGetContent(tracepoint_attribute_node);
1673                         if (!probe_name) {
1674                                 goto error;
1675                         }
1676                 } else if (!strcmp((const char *) tracepoint_attribute_node->name,
1677                                         config_element_userspace_probe_tracepoint_location_provider_name)) {
1678                         provider_name = (char *) xmlNodeGetContent(tracepoint_attribute_node);
1679                         if (!provider_name) {
1680                                 goto error;
1681                         }
1682                 } else if (!strcmp((const char *) tracepoint_attribute_node->name,
1683                                         config_element_userspace_probe_location_binary_path)) {
1684                         binary_path = (char *) xmlNodeGetContent(tracepoint_attribute_node);
1685                         if (!binary_path) {
1686                                 goto error;
1687                         }
1688                 } else if (!strcmp((const char *) tracepoint_attribute_node->name,
1689                                         config_element_userspace_probe_lookup)) {
1690                         char *lookup_method_name;
1691
1692                         lookup_method_name = (char *) xmlNodeGetContent(
1693                                         tracepoint_attribute_node);
1694                         if (!lookup_method_name) {
1695                                 goto error;
1696                         }
1697
1698                         if (!strcmp(lookup_method_name,
1699                                                 config_element_userspace_probe_lookup_tracepoint_sdt)) {
1700                                 lookup_method =
1701                                         lttng_userspace_probe_location_lookup_method_tracepoint_sdt_create();
1702                                 if (!lookup_method) {
1703                                         PERROR("Error creating tracepoint SDT lookup method");
1704                                 }
1705                         } else {
1706                                 WARN("Unknown tracepoint lookup method");
1707                         }
1708
1709                         free(lookup_method_name);
1710                         if (!lookup_method) {
1711                                 goto error;
1712                         }
1713                 } else {
1714                         WARN("Unknown tracepoint attribute");
1715                         goto error;
1716                 }
1717
1718                 /* Check if all the necessary fields were found. */
1719                 if (binary_path && provider_name && probe_name && lookup_method) {
1720                         /* Ownership of lookup_method is transferred. */
1721                         location =
1722                                 lttng_userspace_probe_location_tracepoint_create(
1723                                                 binary_path, provider_name,
1724                                                 probe_name, lookup_method);
1725                         lookup_method = NULL;
1726                         goto error;
1727                 }
1728         }
1729 error:
1730         lttng_userspace_probe_location_lookup_method_destroy(lookup_method);
1731         free(binary_path);
1732         free(provider_name);
1733         free(probe_name);
1734         return location;
1735 }
1736
1737 static
1738 int process_probe_attribute_node(xmlNodePtr probe_attribute_node,
1739         struct lttng_event_probe_attr *attr)
1740 {
1741         int ret;
1742
1743         assert(probe_attribute_node);
1744         assert(attr);
1745
1746         if (!strcmp((const char *) probe_attribute_node->name,
1747                 config_element_address)) {
1748                 xmlChar *content;
1749                 uint64_t addr = 0;
1750
1751                 /* addr */
1752                 content = xmlNodeGetContent(probe_attribute_node);
1753                 if (!content) {
1754                         ret = -LTTNG_ERR_NOMEM;
1755                         goto end;
1756                 }
1757
1758                 ret = parse_uint(content, &addr);
1759                 free(content);
1760                 if (ret) {
1761                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1762                         goto end;
1763                 }
1764
1765                 attr->addr = addr;
1766         } else if (!strcmp((const char *) probe_attribute_node->name,
1767                 config_element_offset)) {
1768                 xmlChar *content;
1769                 uint64_t offset = 0;
1770
1771                 /* offset */
1772                 content = xmlNodeGetContent(probe_attribute_node);
1773                 if (!content) {
1774                         ret = -LTTNG_ERR_NOMEM;
1775                         goto end;
1776                 }
1777
1778                 ret = parse_uint(content, &offset);
1779                 free(content);
1780                 if (ret) {
1781                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1782                         goto end;
1783                 }
1784
1785                 attr->offset = offset;
1786         } else if (!strcmp((const char *) probe_attribute_node->name,
1787                 config_element_symbol_name)) {
1788                 xmlChar *content;
1789
1790                 /* symbol_name */
1791                 content = xmlNodeGetContent(probe_attribute_node);
1792                 if (!content) {
1793                         ret = -LTTNG_ERR_NOMEM;
1794                         goto end;
1795                 }
1796
1797                 ret = lttng_strncpy(attr->symbol_name,
1798                                 (const char *) content,
1799                                 LTTNG_SYMBOL_NAME_LEN);
1800                 if (ret == -1) {
1801                         ERR("symbol name \"%s\"'s length (%zu) exceeds the maximal permitted length (%d) in session configuration",
1802                                         (const char *) content,
1803                                         strlen((const char *) content),
1804                                         LTTNG_SYMBOL_NAME_LEN);
1805                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1806                         free(content);
1807                         goto end;
1808                 }
1809                 free(content);
1810         }
1811         ret = 0;
1812 end:
1813         return ret;
1814 }
1815
1816 static
1817 int process_event_node(xmlNodePtr event_node, struct lttng_handle *handle,
1818         const char *channel_name, const enum process_event_node_phase phase)
1819 {
1820         int ret = 0, i;
1821         xmlNodePtr node;
1822         struct lttng_event *event;
1823         char **exclusions = NULL;
1824         unsigned long exclusion_count = 0;
1825         char *filter_expression = NULL;
1826
1827         assert(event_node);
1828         assert(handle);
1829         assert(channel_name);
1830
1831         event = lttng_event_create();
1832         if (!event) {
1833                 ret = -LTTNG_ERR_NOMEM;
1834                 goto end;
1835         }
1836
1837         /* Initialize default log level which varies by domain */
1838         switch (handle->domain.type)
1839         {
1840         case LTTNG_DOMAIN_JUL:
1841                 event->loglevel = LTTNG_LOGLEVEL_JUL_ALL;
1842                 break;
1843         case LTTNG_DOMAIN_LOG4J:
1844                 event->loglevel = LTTNG_LOGLEVEL_LOG4J_ALL;
1845                 break;
1846         case LTTNG_DOMAIN_PYTHON:
1847                 event->loglevel = LTTNG_LOGLEVEL_PYTHON_DEBUG;
1848                 break;
1849         case LTTNG_DOMAIN_UST:
1850         case LTTNG_DOMAIN_KERNEL:
1851                 event->loglevel = LTTNG_LOGLEVEL_DEBUG;
1852                 break;
1853         default:
1854                 assert(0);
1855         }
1856
1857         for (node = xmlFirstElementChild(event_node); node;
1858                 node = xmlNextElementSibling(node)) {
1859                 if (!strcmp((const char *) node->name, config_element_name)) {
1860                         xmlChar *content;
1861
1862                         /* name */
1863                         content = xmlNodeGetContent(node);
1864                         if (!content) {
1865                                 ret = -LTTNG_ERR_NOMEM;
1866                                 goto end;
1867                         }
1868
1869                         ret = lttng_strncpy(event->name,
1870                                         (const char *) content,
1871                                         LTTNG_SYMBOL_NAME_LEN);
1872                         if (ret == -1) {
1873                                 WARN("Event \"%s\"'s name length (%zu) exceeds the maximal permitted length (%d) in session configuration",
1874                                                 (const char *) content,
1875                                                 strlen((const char *) content),
1876                                                 LTTNG_SYMBOL_NAME_LEN);
1877                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1878                                 free(content);
1879                                 goto end;
1880                         }
1881                         free(content);
1882                 } else if (!strcmp((const char *) node->name,
1883                         config_element_enabled)) {
1884                         xmlChar *content = xmlNodeGetContent(node);
1885
1886                         /* enabled */
1887                         if (!content) {
1888                                 ret = -LTTNG_ERR_NOMEM;
1889                                 goto end;
1890                         }
1891
1892                         ret = parse_bool(content, &event->enabled);
1893                         free(content);
1894                         if (ret) {
1895                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1896                                 goto end;
1897                         }
1898                 } else if (!strcmp((const char *) node->name,
1899                         config_element_type)) {
1900                         xmlChar *content = xmlNodeGetContent(node);
1901
1902                         /* type */
1903                         if (!content) {
1904                                 ret = -LTTNG_ERR_NOMEM;
1905                                 goto end;
1906                         }
1907
1908                         ret = get_event_type(content);
1909                         free(content);
1910                         if (ret < 0) {
1911                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1912                                 goto end;
1913                         }
1914
1915                         event->type = ret;
1916                 } else if (!strcmp((const char *) node->name,
1917                         config_element_loglevel_type)) {
1918                         xmlChar *content = xmlNodeGetContent(node);
1919
1920                         /* loglevel_type */
1921                         if (!content) {
1922                                 ret = -LTTNG_ERR_NOMEM;
1923                                 goto end;
1924                         }
1925
1926                         ret = get_loglevel_type(content);
1927                         free(content);
1928                         if (ret < 0) {
1929                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1930                                 goto end;
1931                         }
1932
1933                         event->loglevel_type = ret;
1934                 } else if (!strcmp((const char *) node->name,
1935                         config_element_loglevel)) {
1936                         xmlChar *content;
1937                         int64_t loglevel = 0;
1938
1939                         /* loglevel */
1940                         content = xmlNodeGetContent(node);
1941                         if (!content) {
1942                                 ret = -LTTNG_ERR_NOMEM;
1943                                 goto end;
1944                         }
1945
1946                         ret = parse_int(content, &loglevel);
1947                         free(content);
1948                         if (ret) {
1949                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1950                                 goto end;
1951                         }
1952
1953                         if (loglevel > INT_MAX || loglevel < INT_MIN) {
1954                                 WARN("loglevel out of range.");
1955                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1956                                 goto end;
1957                         }
1958
1959                         event->loglevel = loglevel;
1960                 } else if (!strcmp((const char *) node->name,
1961                         config_element_filter)) {
1962                         xmlChar *content =
1963                                 xmlNodeGetContent(node);
1964
1965                         /* filter */
1966                         if (!content) {
1967                                 ret = -LTTNG_ERR_NOMEM;
1968                                 goto end;
1969                         }
1970
1971                         free(filter_expression);
1972                         filter_expression = strdup((char *) content);
1973                         free(content);
1974                         if (!filter_expression) {
1975                                 ret = -LTTNG_ERR_NOMEM;
1976                                 goto end;
1977                         }
1978                 } else if (!strcmp((const char *) node->name,
1979                         config_element_exclusions)) {
1980                         xmlNodePtr exclusion_node;
1981                         int exclusion_index = 0;
1982
1983                         /* exclusions */
1984                         if (exclusions) {
1985                                 /*
1986                                  * Exclusions has already been initialized,
1987                                  * invalid file.
1988                                  */
1989                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
1990                                 goto end;
1991                         }
1992
1993                         exclusion_count = xmlChildElementCount(node);
1994                         if (!exclusion_count) {
1995                                 continue;
1996                         }
1997
1998                         exclusions = zmalloc(exclusion_count * sizeof(char *));
1999                         if (!exclusions) {
2000                                 exclusion_count = 0;
2001                                 ret = -LTTNG_ERR_NOMEM;
2002                                 goto end;
2003                         }
2004
2005                         for (exclusion_node = xmlFirstElementChild(node); exclusion_node;
2006                                         exclusion_node = xmlNextElementSibling(exclusion_node)) {
2007                                 xmlChar *content =
2008                                         xmlNodeGetContent(exclusion_node);
2009
2010                                 if (!content) {
2011                                         ret = -LTTNG_ERR_NOMEM;
2012                                         goto end;
2013                                 }
2014
2015                                 exclusions[exclusion_index] = strdup((const char *) content);
2016                                 free(content);
2017                                 if (!exclusions[exclusion_index]) {
2018                                         ret = -LTTNG_ERR_NOMEM;
2019                                         goto end;
2020                                 }
2021                                 exclusion_index++;
2022                         }
2023
2024                         event->exclusion = 1;
2025                 } else if (!strcmp((const char *) node->name,
2026                         config_element_attributes)) {
2027                         xmlNodePtr attribute_node = xmlFirstElementChild(node);
2028
2029                         /* attributes */
2030                         if (!attribute_node) {
2031                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2032                                 goto end;
2033                         }
2034
2035                         if (!strcmp((const char *) attribute_node->name,
2036                                                 config_element_probe_attributes)) {
2037                                 xmlNodePtr probe_attribute_node;
2038
2039                                 /* probe_attributes */
2040                                 for (probe_attribute_node =
2041                                         xmlFirstElementChild(attribute_node); probe_attribute_node;
2042                                         probe_attribute_node = xmlNextElementSibling(
2043                                                         probe_attribute_node)) {
2044
2045                                         ret = process_probe_attribute_node(probe_attribute_node,
2046                                                         &event->attr.probe);
2047                                         if (ret) {
2048                                                 goto end;
2049                                         }
2050                                 }
2051                         } else if (!strcmp((const char *) attribute_node->name,
2052                                                 config_element_function_attributes)) {
2053                                 size_t sym_len;
2054                                 xmlChar *content;
2055                                 xmlNodePtr symbol_node = xmlFirstElementChild(attribute_node);
2056
2057                                 /* function_attributes */
2058                                 content = xmlNodeGetContent(symbol_node);
2059                                 if (!content) {
2060                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2061                                         goto end;
2062                                 }
2063
2064                                 sym_len = strlen((char *) content);
2065                                 if (sym_len >= LTTNG_SYMBOL_NAME_LEN) {
2066                                         WARN("Function name too long.");
2067                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2068                                         free(content);
2069                                         goto end;
2070                                 }
2071
2072                                 ret = lttng_strncpy(
2073                                                 event->attr.ftrace.symbol_name,
2074                                                 (char *) content, sym_len);
2075                                 if (ret == -1) {
2076                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2077                                         free(content);
2078                                         goto end;
2079                                 }
2080                                 free(content);
2081                         } else if (!strcmp((const char *) attribute_node->name,
2082                                                 config_element_userspace_probe_tracepoint_attributes)) {
2083                                 struct lttng_userspace_probe_location *location;
2084
2085                                 location = process_userspace_probe_tracepoint_attribute_node(attribute_node);
2086                                 if (!location) {
2087                                         WARN("Error processing userspace probe tracepoint attribute");
2088                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2089                                         goto end;
2090                                 }
2091                                 ret = lttng_event_set_userspace_probe_location(
2092                                                 event, location);
2093                                 if (ret) {
2094                                         WARN("Error setting userspace probe location field");
2095                                         lttng_userspace_probe_location_destroy(
2096                                                         location);
2097                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2098                                         goto end;
2099                                 }
2100                         } else if (!strcmp((const char *) attribute_node->name,
2101                                                 config_element_userspace_probe_function_attributes)) {
2102                                 struct lttng_userspace_probe_location *location;
2103
2104                                 location =
2105                                         process_userspace_probe_function_attribute_node(
2106                                                         attribute_node);
2107                                 if (!location) {
2108                                         WARN("Error processing userspace probe function attribute");
2109                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2110                                         goto end;
2111                                 }
2112
2113                                 ret = lttng_event_set_userspace_probe_location(
2114                                                 event, location);
2115                                 if (ret) {
2116                                         WARN("Error setting userspace probe location field");
2117                                         lttng_userspace_probe_location_destroy(
2118                                                         location);
2119                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2120                                         goto end;
2121                                 }
2122                         } else {
2123                                 /* Unknown event attribute. */
2124                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2125                                 goto end;
2126                         }
2127                 }
2128         }
2129
2130         if ((event->enabled && phase == ENABLE) || phase == CREATION) {
2131                 ret = lttng_enable_event_with_exclusions(handle, event, channel_name,
2132                                 filter_expression, exclusion_count, exclusions);
2133                 if (ret < 0) {
2134                         WARN("Enabling event (name:%s) on load failed.", event->name);
2135                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2136                         goto end;
2137                 }
2138         }
2139         ret = 0;
2140 end:
2141         for (i = 0; i < exclusion_count; i++) {
2142                 free(exclusions[i]);
2143         }
2144
2145         lttng_event_destroy(event);
2146         free(exclusions);
2147         free(filter_expression);
2148         return ret;
2149 }
2150
2151 static
2152 int process_events_node(xmlNodePtr events_node, struct lttng_handle *handle,
2153         const char *channel_name)
2154 {
2155         int ret = 0;
2156         struct lttng_event event;
2157         xmlNodePtr node;
2158
2159         assert(events_node);
2160         assert(handle);
2161         assert(channel_name);
2162
2163         for (node = xmlFirstElementChild(events_node); node;
2164                 node = xmlNextElementSibling(node)) {
2165                 ret = process_event_node(node, handle, channel_name, CREATION);
2166                 if (ret) {
2167                         goto end;
2168                 }
2169         }
2170
2171         /*
2172          * Disable all events to enable only the necessary events.
2173          * Limitations regarding lttng_disable_events and tuple descriptor
2174          * force this approach.
2175          */
2176         memset(&event, 0, sizeof(event));
2177         event.loglevel = -1;
2178         event.type = LTTNG_EVENT_ALL;
2179         ret = lttng_disable_event_ext(handle, &event, channel_name, NULL);
2180         if (ret) {
2181                 goto end;
2182         }
2183
2184         for (node = xmlFirstElementChild(events_node); node;
2185                         node = xmlNextElementSibling(node)) {
2186                 ret = process_event_node(node, handle, channel_name, ENABLE);
2187                 if (ret) {
2188                         goto end;
2189                 }
2190         }
2191
2192 end:
2193         return ret;
2194 }
2195
2196 static
2197 int process_channel_attr_node(xmlNodePtr attr_node,
2198                 struct lttng_channel *channel, xmlNodePtr *contexts_node,
2199                 xmlNodePtr *events_node)
2200 {
2201         int ret;
2202
2203         assert(attr_node);
2204         assert(channel);
2205         assert(contexts_node);
2206         assert(events_node);
2207
2208         if (!strcmp((const char *) attr_node->name, config_element_name)) {
2209                 xmlChar *content;
2210
2211                 /* name */
2212                 content = xmlNodeGetContent(attr_node);
2213                 if (!content) {
2214                         ret = -LTTNG_ERR_NOMEM;
2215                         goto end;
2216                 }
2217
2218                 ret = lttng_strncpy(channel->name,
2219                                 (const char *) content,
2220                                 LTTNG_SYMBOL_NAME_LEN);
2221                 if (ret == -1) {
2222                         WARN("Channel \"%s\"'s name length (%zu) exceeds the maximal permitted length (%d) in session configuration",
2223                                         (const char *) content,
2224                                         strlen((const char *) content),
2225                                         LTTNG_SYMBOL_NAME_LEN);
2226                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2227                         free(content);
2228                         goto end;
2229                 }
2230                 free(content);
2231         } else if (!strcmp((const char *) attr_node->name,
2232                         config_element_enabled)) {
2233                 xmlChar *content;
2234                 int enabled;
2235
2236                 /* enabled */
2237                 content = xmlNodeGetContent(attr_node);
2238                 if (!content) {
2239                         ret = -LTTNG_ERR_NOMEM;
2240                         goto end;
2241                 }
2242
2243                 ret = parse_bool(content, &enabled);
2244                 free(content);
2245                 if (ret) {
2246                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2247                         goto end;
2248                 }
2249
2250                 channel->enabled = enabled;
2251         } else if (!strcmp((const char *) attr_node->name,
2252                         config_element_overwrite_mode)) {
2253                 xmlChar *content;
2254
2255                 /* overwrite_mode */
2256                 content = xmlNodeGetContent(attr_node);
2257                 if (!content) {
2258                         ret = -LTTNG_ERR_NOMEM;
2259                         goto end;
2260                 }
2261
2262                 ret = get_overwrite_mode(content);
2263                 free(content);
2264                 if (ret < 0) {
2265                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2266                         goto end;
2267                 }
2268
2269                 channel->attr.overwrite = ret;
2270         } else if (!strcmp((const char *) attr_node->name,
2271                         config_element_subbuf_size)) {
2272                 xmlChar *content;
2273
2274                 /* subbuffer_size */
2275                 content = xmlNodeGetContent(attr_node);
2276                 if (!content) {
2277                         ret = -LTTNG_ERR_NOMEM;
2278                         goto end;
2279                 }
2280
2281                 ret = parse_uint(content, &channel->attr.subbuf_size);
2282                 free(content);
2283                 if (ret) {
2284                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2285                         goto end;
2286                 }
2287         } else if (!strcmp((const char *) attr_node->name,
2288                         config_element_num_subbuf)) {
2289                 xmlChar *content;
2290
2291                 /* subbuffer_count */
2292                 content = xmlNodeGetContent(attr_node);
2293                 if (!content) {
2294                         ret = -LTTNG_ERR_NOMEM;
2295                         goto end;
2296                 }
2297
2298                 ret = parse_uint(content, &channel->attr.num_subbuf);
2299                 free(content);
2300                 if (ret) {
2301                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2302                         goto end;
2303                 }
2304         } else if (!strcmp((const char *) attr_node->name,
2305                         config_element_switch_timer_interval)) {
2306                 xmlChar *content;
2307                 uint64_t switch_timer_interval = 0;
2308
2309                 /* switch_timer_interval */
2310                 content = xmlNodeGetContent(attr_node);
2311                 if (!content) {
2312                         ret = -LTTNG_ERR_NOMEM;
2313                         goto end;
2314                 }
2315
2316                 ret = parse_uint(content, &switch_timer_interval);
2317                 free(content);
2318                 if (ret) {
2319                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2320                         goto end;
2321                 }
2322
2323                 if (switch_timer_interval > UINT_MAX) {
2324                         WARN("switch_timer_interval out of range.");
2325                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2326                         goto end;
2327                 }
2328
2329                 channel->attr.switch_timer_interval =
2330                         switch_timer_interval;
2331         } else if (!strcmp((const char *) attr_node->name,
2332                         config_element_read_timer_interval)) {
2333                 xmlChar *content;
2334                 uint64_t read_timer_interval = 0;
2335
2336                 /* read_timer_interval */
2337                 content = xmlNodeGetContent(attr_node);
2338                 if (!content) {
2339                         ret = -LTTNG_ERR_NOMEM;
2340                         goto end;
2341                 }
2342
2343                 ret = parse_uint(content, &read_timer_interval);
2344                 free(content);
2345                 if (ret) {
2346                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2347                         goto end;
2348                 }
2349
2350                 if (read_timer_interval > UINT_MAX) {
2351                         WARN("read_timer_interval out of range.");
2352                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2353                         goto end;
2354                 }
2355
2356                 channel->attr.read_timer_interval =
2357                         read_timer_interval;
2358         } else if (!strcmp((const char *) attr_node->name,
2359                         config_element_output_type)) {
2360                 xmlChar *content;
2361
2362                 /* output_type */
2363                 content = xmlNodeGetContent(attr_node);
2364                 if (!content) {
2365                         ret = -LTTNG_ERR_NOMEM;
2366                         goto end;
2367                 }
2368
2369                 ret = get_output_type(content);
2370                 free(content);
2371                 if (ret < 0) {
2372                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2373                         goto end;
2374                 }
2375
2376                 channel->attr.output = ret;
2377         } else if (!strcmp((const char *) attr_node->name,
2378                         config_element_tracefile_size)) {
2379                 xmlChar *content;
2380
2381                 /* tracefile_size */
2382                 content = xmlNodeGetContent(attr_node);
2383                 if (!content) {
2384                         ret = -LTTNG_ERR_NOMEM;
2385                         goto end;
2386                 }
2387
2388                 ret = parse_uint(content, &channel->attr.tracefile_size);
2389                 free(content);
2390                 if (ret) {
2391                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2392                         goto end;
2393                 }
2394         } else if (!strcmp((const char *) attr_node->name,
2395                         config_element_tracefile_count)) {
2396                 xmlChar *content;
2397
2398                 /* tracefile_count */
2399                 content = xmlNodeGetContent(attr_node);
2400                 if (!content) {
2401                         ret = -LTTNG_ERR_NOMEM;
2402                         goto end;
2403                 }
2404
2405                 ret = parse_uint(content, &channel->attr.tracefile_count);
2406                 free(content);
2407                 if (ret) {
2408                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2409                         goto end;
2410                 }
2411         } else if (!strcmp((const char *) attr_node->name,
2412                         config_element_live_timer_interval)) {
2413                 xmlChar *content;
2414                 uint64_t live_timer_interval = 0;
2415
2416                 /* live_timer_interval */
2417                 content = xmlNodeGetContent(attr_node);
2418                 if (!content) {
2419                         ret = -LTTNG_ERR_NOMEM;
2420                         goto end;
2421                 }
2422
2423                 ret = parse_uint(content, &live_timer_interval);
2424                 free(content);
2425                 if (ret) {
2426                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2427                         goto end;
2428                 }
2429
2430                 if (live_timer_interval > UINT_MAX) {
2431                         WARN("live_timer_interval out of range.");
2432                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2433                         goto end;
2434                 }
2435
2436                 channel->attr.live_timer_interval =
2437                         live_timer_interval;
2438         } else if (!strcmp((const char *) attr_node->name,
2439                         config_element_monitor_timer_interval)) {
2440                 xmlChar *content;
2441                 uint64_t monitor_timer_interval = 0;
2442
2443                 /* monitor_timer_interval */
2444                 content = xmlNodeGetContent(attr_node);
2445                 if (!content) {
2446                         ret = -LTTNG_ERR_NOMEM;
2447                         goto end;
2448                 }
2449
2450                 ret = parse_uint(content, &monitor_timer_interval);
2451                 free(content);
2452                 if (ret) {
2453                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2454                         goto end;
2455                 }
2456
2457                 ret = lttng_channel_set_monitor_timer_interval(channel,
2458                         monitor_timer_interval);
2459                 if (ret) {
2460                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2461                         goto end;
2462                 }
2463         } else if (!strcmp((const char *) attr_node->name,
2464                         config_element_blocking_timeout)) {
2465                 xmlChar *content;
2466                 int64_t blocking_timeout = 0;
2467
2468                 /* blocking_timeout */
2469                 content = xmlNodeGetContent(attr_node);
2470                 if (!content) {
2471                         ret = -LTTNG_ERR_NOMEM;
2472                         goto end;
2473                 }
2474
2475                 ret = parse_int(content, &blocking_timeout);
2476                 free(content);
2477                 if (ret) {
2478                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2479                         goto end;
2480                 }
2481
2482                 ret = lttng_channel_set_blocking_timeout(channel,
2483                         blocking_timeout);
2484                 if (ret) {
2485                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2486                         goto end;
2487                 }
2488         } else if (!strcmp((const char *) attr_node->name,
2489                         config_element_events)) {
2490                 /* events */
2491                 *events_node = attr_node;
2492         } else {
2493                 /* contexts */
2494                 *contexts_node = attr_node;
2495         }
2496         ret = 0;
2497 end:
2498         return ret;
2499 }
2500
2501 static
2502 int process_context_node(xmlNodePtr context_node,
2503         struct lttng_handle *handle, const char *channel_name)
2504 {
2505         int ret;
2506         struct lttng_event_context context;
2507         xmlNodePtr context_child_node = xmlFirstElementChild(context_node);
2508
2509         assert(handle);
2510         assert(channel_name);
2511
2512         if (!context_child_node) {
2513                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2514                 goto end;
2515         }
2516
2517         memset(&context, 0, sizeof(context));
2518
2519         if (!strcmp((const char *) context_child_node->name,
2520                 config_element_type)) {
2521                 /* type */
2522                 xmlChar *content = xmlNodeGetContent(context_child_node);
2523
2524                 if (!content) {
2525                         ret = -LTTNG_ERR_NOMEM;
2526                         goto end;
2527                 }
2528
2529                 ret = get_context_type(content);
2530                 free(content);
2531                 if (ret < 0) {
2532                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2533                         goto end;
2534                 }
2535
2536                 context.ctx = ret;
2537         } else if (!strcmp((const char *) context_child_node->name,
2538                 config_element_context_perf)) {
2539                 /* perf */
2540                 xmlNodePtr perf_attr_node;
2541
2542                 context.ctx = handle->domain.type == LTTNG_DOMAIN_KERNEL ?
2543                         LTTNG_EVENT_CONTEXT_PERF_CPU_COUNTER :
2544                         LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER;
2545                 for (perf_attr_node = xmlFirstElementChild(context_child_node);
2546                         perf_attr_node; perf_attr_node =
2547                                 xmlNextElementSibling(perf_attr_node)) {
2548                         if (!strcmp((const char *) perf_attr_node->name,
2549                                 config_element_type)) {
2550                                 xmlChar *content;
2551                                 uint64_t type = 0;
2552
2553                                 /* type */
2554                                 content = xmlNodeGetContent(perf_attr_node);
2555                                 if (!content) {
2556                                         ret = -LTTNG_ERR_NOMEM;
2557                                         goto end;
2558                                 }
2559
2560                                 ret = parse_uint(content, &type);
2561                                 free(content);
2562                                 if (ret) {
2563                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2564                                         goto end;
2565                                 }
2566
2567                                 if (type > UINT32_MAX) {
2568                                         WARN("perf context type out of range.");
2569                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2570                                         goto end;
2571                                 }
2572
2573                                 context.u.perf_counter.type = type;
2574                         } else if (!strcmp((const char *) perf_attr_node->name,
2575                                 config_element_config)) {
2576                                 xmlChar *content;
2577                                 uint64_t config = 0;
2578
2579                                 /* config */
2580                                 content = xmlNodeGetContent(perf_attr_node);
2581                                 if (!content) {
2582                                         ret = -LTTNG_ERR_NOMEM;
2583                                         goto end;
2584                                 }
2585
2586                                 ret = parse_uint(content, &config);
2587                                 free(content);
2588                                 if (ret) {
2589                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2590                                         goto end;
2591                                 }
2592
2593                                 context.u.perf_counter.config = config;
2594                         } else if (!strcmp((const char *) perf_attr_node->name,
2595                                 config_element_name)) {
2596                                 xmlChar *content;
2597
2598                                 /* name */
2599                                 content = xmlNodeGetContent(perf_attr_node);
2600                                 if (!content) {
2601                                         ret = -LTTNG_ERR_NOMEM;
2602                                         goto end;
2603                                 }
2604
2605                                 ret = lttng_strncpy(context.u.perf_counter.name,
2606                                                 (const char *) content,
2607                                                 LTTNG_SYMBOL_NAME_LEN);
2608                                 if (ret == -1) {
2609                                         WARN("Perf counter \"%s\"'s name length (%zu) exceeds the maximal permitted length (%d) in session configuration",
2610                                                         (const char *) content,
2611                                                         strlen((const char *) content),
2612                                                         LTTNG_SYMBOL_NAME_LEN);
2613                                         ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2614                                         free(content);
2615                                         goto end;
2616                                 }
2617                                 free(content);
2618                         }
2619                 }
2620         } else if (!strcmp((const char *) context_child_node->name,
2621                 config_element_context_app)) {
2622                 /* application context */
2623                 xmlNodePtr app_ctx_node;
2624
2625                 context.ctx = LTTNG_EVENT_CONTEXT_APP_CONTEXT;
2626                 for (app_ctx_node = xmlFirstElementChild(context_child_node);
2627                                 app_ctx_node; app_ctx_node =
2628                                 xmlNextElementSibling(app_ctx_node)) {
2629                         xmlChar *content;
2630                         char **target = strcmp(
2631                                 (const char *) app_ctx_node->name,
2632                                 config_element_context_app_provider_name) == 0 ?
2633                                         &context.u.app_ctx.provider_name :
2634                                         &context.u.app_ctx.ctx_name;
2635
2636                         content = xmlNodeGetContent(app_ctx_node);
2637                         if (!content) {
2638                                 ret = -LTTNG_ERR_NOMEM;
2639                                 goto end;
2640                         }
2641
2642                         *target = (char *) content;
2643                 }
2644         } else {
2645                 /* Unrecognized context type */
2646                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
2647                 goto end;
2648         }
2649
2650         ret = lttng_add_context(handle, &context, NULL, channel_name);
2651         if (context.ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
2652                 free(context.u.app_ctx.provider_name);
2653                 free(context.u.app_ctx.ctx_name);
2654         }
2655 end:
2656         return ret;
2657 }
2658
2659 static
2660 int process_contexts_node(xmlNodePtr contexts_node,
2661         struct lttng_handle *handle, const char *channel_name)
2662 {
2663         int ret = 0;
2664         xmlNodePtr context_node;
2665
2666         for (context_node = xmlFirstElementChild(contexts_node); context_node;
2667                         context_node = xmlNextElementSibling(context_node)) {
2668                 ret = process_context_node(context_node, handle, channel_name);
2669                 if (ret) {
2670                         goto end;
2671                 }
2672         }
2673 end:
2674         return ret;
2675 }
2676
2677 static int get_tracker_elements(enum lttng_process_attr process_attr,
2678                 const char **element_id_tracker,
2679                 const char **element_value_type,
2680                 const char **element_value,
2681                 const char **element_value_alias,
2682                 const char **element_name)
2683 {
2684         int ret = 0;
2685
2686         switch (process_attr) {
2687         case LTTNG_PROCESS_ATTR_PROCESS_ID:
2688                 *element_id_tracker = config_element_process_attr_tracker_pid;
2689                 *element_value_type = config_element_process_attr_pid_value;
2690                 *element_value = config_element_process_attr_id;
2691                 *element_value_alias = config_element_process_attr_id;
2692                 *element_name = NULL;
2693                 break;
2694         case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
2695                 *element_id_tracker = config_element_process_attr_tracker_vpid;
2696                 *element_value_type = config_element_process_attr_vpid_value;
2697                 *element_value = config_element_process_attr_id;
2698                 *element_value_alias = NULL;
2699                 *element_name = NULL;
2700                 break;
2701         case LTTNG_PROCESS_ATTR_USER_ID:
2702                 *element_id_tracker = config_element_process_attr_tracker_uid;
2703                 *element_value_type = config_element_process_attr_uid_value;
2704                 *element_value = config_element_process_attr_id;
2705                 *element_value_alias = NULL;
2706                 *element_name = config_element_name;
2707                 break;
2708         case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
2709                 *element_id_tracker = config_element_process_attr_tracker_vuid;
2710                 *element_value_type = config_element_process_attr_vuid_value;
2711                 *element_value = config_element_process_attr_id;
2712                 *element_value_alias = NULL;
2713                 *element_name = config_element_name;
2714                 break;
2715         case LTTNG_PROCESS_ATTR_GROUP_ID:
2716                 *element_id_tracker = config_element_process_attr_tracker_gid;
2717                 *element_value_type = config_element_process_attr_gid_value;
2718                 *element_value = config_element_process_attr_id;
2719                 *element_value_alias = NULL;
2720                 *element_name = config_element_name;
2721                 break;
2722         case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
2723                 *element_id_tracker = config_element_process_attr_tracker_vgid;
2724                 *element_value_type = config_element_process_attr_vgid_value;
2725                 *element_value = config_element_process_attr_id;
2726                 *element_value_alias = NULL;
2727                 *element_name = config_element_name;
2728                 break;
2729         default:
2730                 ret = LTTNG_ERR_INVALID;
2731         }
2732         return ret;
2733 }
2734
2735 static int process_legacy_pid_tracker_node(
2736                 xmlNodePtr trackers_node, struct lttng_handle *handle)
2737 {
2738         int ret = 0, child_count;
2739         xmlNodePtr targets_node = NULL;
2740         xmlNodePtr node;
2741         const char *element_id_tracker;
2742         const char *element_target_id;
2743         const char *element_id;
2744         const char *element_id_alias;
2745         const char *element_name;
2746         enum lttng_error_code tracker_handle_ret_code;
2747         struct lttng_process_attr_tracker_handle *tracker_handle = NULL;
2748         enum lttng_process_attr_tracker_handle_status status;
2749         const enum lttng_process_attr process_attr =
2750                         handle->domain.type == LTTNG_DOMAIN_UST ?
2751                                         LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID :
2752                                         LTTNG_PROCESS_ATTR_PROCESS_ID;
2753
2754         assert(handle);
2755
2756         tracker_handle_ret_code = lttng_session_get_tracker_handle(
2757                         handle->session_name, handle->domain.type,
2758                         process_attr,
2759                         &tracker_handle);
2760         if (tracker_handle_ret_code != LTTNG_OK) {
2761                 ret = LTTNG_ERR_INVALID;
2762                 goto end;
2763         }
2764
2765         ret = get_tracker_elements(process_attr, &element_id_tracker,
2766                         &element_target_id, &element_id, &element_id_alias,
2767                         &element_name);
2768         if (ret) {
2769                 goto end;
2770         }
2771
2772         /* Get the targets node */
2773         for (node = xmlFirstElementChild(trackers_node); node;
2774                         node = xmlNextElementSibling(node)) {
2775                 if (!strcmp((const char *) node->name,
2776                                 config_element_tracker_targets_legacy)) {
2777                         targets_node = node;
2778                         break;
2779                 }
2780         }
2781
2782         if (!targets_node) {
2783                 ret = LTTNG_ERR_INVALID;
2784                 goto end;
2785         }
2786
2787         /* Go through all id target node */
2788         child_count = xmlChildElementCount(targets_node);
2789         status = lttng_process_attr_tracker_handle_set_tracking_policy(
2790                         tracker_handle,
2791                         child_count == 0 ? LTTNG_TRACKING_POLICY_EXCLUDE_ALL :
2792                                            LTTNG_TRACKING_POLICY_INCLUDE_SET);
2793         if (status != LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_OK) {
2794                 ret = LTTNG_ERR_UNK;
2795                 goto end;
2796         }
2797
2798         /* Add all tracked values. */
2799         for (node = xmlFirstElementChild(targets_node); node;
2800                         node = xmlNextElementSibling(node)) {
2801                 xmlNodePtr pid_target_node = node;
2802
2803                 /* get pid_target node and track it */
2804                 for (node = xmlFirstElementChild(pid_target_node); node;
2805                                 node = xmlNextElementSibling(node)) {
2806                         if (!strcmp((const char *) node->name,
2807                                             config_element_tracker_pid_legacy)) {
2808                                 int64_t id;
2809                                 xmlChar *content = xmlNodeGetContent(node);
2810
2811                                 if (!content) {
2812                                         ret = LTTNG_ERR_LOAD_INVALID_CONFIG;
2813                                         goto end;
2814                                 }
2815
2816                                 ret = parse_int(content, &id);
2817                                 free(content);
2818                                 if (ret) {
2819                                         ret = LTTNG_ERR_LOAD_INVALID_CONFIG;
2820                                         goto end;
2821                                 }
2822
2823                                 switch (process_attr) {
2824                                 case LTTNG_PROCESS_ATTR_PROCESS_ID:
2825                                         status = lttng_process_attr_process_id_tracker_handle_add_pid(
2826                                                         tracker_handle,
2827                                                         (pid_t) id);
2828                                         break;
2829                                 case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
2830                                         status = lttng_process_attr_virtual_process_id_tracker_handle_add_pid(
2831                                                         tracker_handle,
2832                                                         (pid_t) id);
2833                                         break;
2834                                 default:
2835                                         ret = LTTNG_ERR_INVALID;
2836                                         goto end;
2837                                 }
2838                         }
2839                         switch (status) {
2840                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_OK:
2841                                 continue;
2842                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_INVALID:
2843                                 ret = LTTNG_ERR_INVALID;
2844                                 break;
2845                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_EXISTS:
2846                                 ret = LTTNG_ERR_PROCESS_ATTR_EXISTS;
2847                                 break;
2848                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_MISSING:
2849                                 ret = LTTNG_ERR_PROCESS_ATTR_MISSING;
2850                                 break;
2851                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_ERROR:
2852                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_COMMUNICATION_ERROR:
2853                         default:
2854                                 ret = LTTNG_ERR_UNK;
2855                                 goto end;
2856                         }
2857                 }
2858                 node = pid_target_node;
2859         }
2860
2861 end:
2862         lttng_process_attr_tracker_handle_destroy(tracker_handle);
2863         return ret;
2864  }
2865
2866 static int process_id_tracker_node(xmlNodePtr id_tracker_node,
2867                 struct lttng_handle *handle,
2868                 enum lttng_process_attr process_attr)
2869 {
2870         int ret = 0, child_count;
2871         xmlNodePtr values_node = NULL;
2872         xmlNodePtr node;
2873         const char *element_id_tracker;
2874         const char *element_target_id;
2875         const char *element_id;
2876         const char *element_id_alias;
2877         const char *element_name;
2878         enum lttng_error_code tracker_handle_ret_code;
2879         struct lttng_process_attr_tracker_handle *tracker_handle = NULL;
2880         enum lttng_process_attr_tracker_handle_status status;
2881
2882         assert(handle);
2883         assert(id_tracker_node);
2884
2885         tracker_handle_ret_code = lttng_session_get_tracker_handle(
2886                         handle->session_name, handle->domain.type, process_attr,
2887                         &tracker_handle);
2888         if (tracker_handle_ret_code != LTTNG_OK) {
2889                 ret = LTTNG_ERR_INVALID;
2890                 goto end;
2891         }
2892
2893         ret = get_tracker_elements(process_attr, &element_id_tracker,
2894                         &element_target_id, &element_id, &element_id_alias,
2895                         &element_name);
2896         if (ret) {
2897                 goto end;
2898         }
2899
2900         /* get the values node */
2901         for (node = xmlFirstElementChild(id_tracker_node); node;
2902                         node = xmlNextElementSibling(node)) {
2903                 if (!strcmp((const char *) node->name,
2904                                 config_element_process_attr_values)) {
2905                         values_node = node;
2906                         break;
2907                 }
2908         }
2909
2910         if (!values_node) {
2911                 ret = LTTNG_ERR_INVALID;
2912                 goto end;
2913         }
2914
2915         /* Go through all id target node */
2916         child_count = xmlChildElementCount(values_node);
2917         status = lttng_process_attr_tracker_handle_set_tracking_policy(
2918                         tracker_handle,
2919                         child_count == 0 ? LTTNG_TRACKING_POLICY_EXCLUDE_ALL :
2920                                            LTTNG_TRACKING_POLICY_INCLUDE_SET);
2921         if (status != LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_OK) {
2922                 ret = LTTNG_ERR_UNK;
2923                 goto end;
2924         }
2925
2926         /* Add all tracked values. */
2927         for (node = xmlFirstElementChild(values_node); node;
2928                         node = xmlNextElementSibling(node)) {
2929                 xmlNodePtr id_target_node = node;
2930
2931                 /* get id node and track it */
2932                 for (node = xmlFirstElementChild(id_target_node); node;
2933                                 node = xmlNextElementSibling(node)) {
2934                         if (!strcmp((const char *) node->name, element_id) ||
2935                                         (element_id_alias &&
2936                                                         !strcmp((const char *) node->name,
2937                                                                         element_id_alias))) {
2938                                 int64_t id;
2939                                 xmlChar *content = xmlNodeGetContent(node);
2940
2941                                 if (!content) {
2942                                         ret = LTTNG_ERR_LOAD_INVALID_CONFIG;
2943                                         goto end;
2944                                 }
2945
2946                                 ret = parse_int(content, &id);
2947                                 free(content);
2948                                 if (ret) {
2949                                         ret = LTTNG_ERR_LOAD_INVALID_CONFIG;
2950                                         goto end;
2951                                 }
2952
2953                                 switch (process_attr) {
2954                                 case LTTNG_PROCESS_ATTR_PROCESS_ID:
2955                                         status = lttng_process_attr_process_id_tracker_handle_add_pid(
2956                                                         tracker_handle,
2957                                                         (pid_t) id);
2958                                         break;
2959                                 case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
2960                                         status = lttng_process_attr_virtual_process_id_tracker_handle_add_pid(
2961                                                         tracker_handle,
2962                                                         (pid_t) id);
2963                                         break;
2964                                 case LTTNG_PROCESS_ATTR_USER_ID:
2965                                         status = lttng_process_attr_user_id_tracker_handle_add_uid(
2966                                                         tracker_handle,
2967                                                         (uid_t) id);
2968                                         break;
2969                                 case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
2970                                         status = lttng_process_attr_virtual_user_id_tracker_handle_add_uid(
2971                                                         tracker_handle,
2972                                                         (uid_t) id);
2973                                         break;
2974                                 case LTTNG_PROCESS_ATTR_GROUP_ID:
2975                                         status = lttng_process_attr_group_id_tracker_handle_add_gid(
2976                                                         tracker_handle,
2977                                                         (gid_t) id);
2978                                         break;
2979                                 case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
2980                                         status = lttng_process_attr_virtual_group_id_tracker_handle_add_gid(
2981                                                         tracker_handle,
2982                                                         (gid_t) id);
2983                                         break;
2984                                 default:
2985                                         ret = LTTNG_ERR_INVALID;
2986                                         goto end;
2987                                 }
2988                         } else if (element_name &&
2989                                         !strcmp((const char *) node->name,
2990                                                         element_name)) {
2991                                 xmlChar *content = xmlNodeGetContent(node);
2992
2993                                 if (!content) {
2994                                         ret = LTTNG_ERR_LOAD_INVALID_CONFIG;
2995                                         goto end;
2996                                 }
2997
2998                                 switch (process_attr) {
2999                                 case LTTNG_PROCESS_ATTR_USER_ID:
3000                                         status = lttng_process_attr_user_id_tracker_handle_add_user_name(
3001                                                         tracker_handle,
3002                                                         (const char *) content);
3003                                         break;
3004                                 case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
3005                                         status = lttng_process_attr_virtual_user_id_tracker_handle_add_user_name(
3006                                                         tracker_handle,
3007                                                         (const char *) content);
3008                                         break;
3009                                 case LTTNG_PROCESS_ATTR_GROUP_ID:
3010                                         status = lttng_process_attr_group_id_tracker_handle_add_group_name(
3011                                                         tracker_handle,
3012                                                         (const char *) content);
3013                                         break;
3014                                 case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
3015                                         status = lttng_process_attr_virtual_group_id_tracker_handle_add_group_name(
3016                                                         tracker_handle,
3017                                                         (const char *) content);
3018                                         break;
3019                                 default:
3020                                         free(content);
3021                                         ret = LTTNG_ERR_INVALID;
3022                                         goto end;
3023                                 }
3024                                 free(content);
3025                         }
3026                         switch (status) {
3027                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_OK:
3028                                 continue;
3029                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_INVALID:
3030                                 ret = LTTNG_ERR_INVALID;
3031                                 break;
3032                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_EXISTS:
3033                                 ret = LTTNG_ERR_PROCESS_ATTR_EXISTS;
3034                                 break;
3035                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_MISSING:
3036                                 ret = LTTNG_ERR_PROCESS_ATTR_MISSING;
3037                                 break;
3038                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_ERROR:
3039                         case LTTNG_PROCESS_ATTR_TRACKER_HANDLE_STATUS_COMMUNICATION_ERROR:
3040                         default:
3041                                 ret = LTTNG_ERR_UNK;
3042                                 goto end;
3043                         }
3044                 }
3045                 node = id_target_node;
3046         }
3047
3048 end:
3049         lttng_process_attr_tracker_handle_destroy(tracker_handle);
3050         return ret;
3051 }
3052
3053 static
3054 int process_domain_node(xmlNodePtr domain_node, const char *session_name)
3055 {
3056         int ret;
3057         struct lttng_domain domain = { 0 };
3058         struct lttng_handle *handle = NULL;
3059         struct lttng_channel *channel = NULL;
3060         xmlNodePtr channels_node = NULL;
3061         xmlNodePtr trackers_node = NULL;
3062         xmlNodePtr pid_tracker_node = NULL;
3063         xmlNodePtr vpid_tracker_node = NULL;
3064         xmlNodePtr uid_tracker_node = NULL;
3065         xmlNodePtr vuid_tracker_node = NULL;
3066         xmlNodePtr gid_tracker_node = NULL;
3067         xmlNodePtr vgid_tracker_node = NULL;
3068         xmlNodePtr node;
3069
3070         assert(session_name);
3071
3072         ret = init_domain(domain_node, &domain);
3073         if (ret) {
3074                 goto end;
3075         }
3076
3077         handle = lttng_create_handle(session_name, &domain);
3078         if (!handle) {
3079                 ret = -LTTNG_ERR_NOMEM;
3080                 goto end;
3081         }
3082
3083         /* get the channels node */
3084         for (node = xmlFirstElementChild(domain_node); node;
3085                 node = xmlNextElementSibling(node)) {
3086                 if (!strcmp((const char *) node->name,
3087                         config_element_channels)) {
3088                         channels_node = node;
3089                         break;
3090                 }
3091         }
3092
3093         if (!channels_node) {
3094                 goto end;
3095         }
3096
3097         /* create all channels */
3098         for (node = xmlFirstElementChild(channels_node); node;
3099                 node = xmlNextElementSibling(node)) {
3100                 const enum lttng_domain_type original_domain = domain.type;
3101                 xmlNodePtr contexts_node = NULL;
3102                 xmlNodePtr events_node = NULL;
3103                 xmlNodePtr channel_attr_node;
3104
3105                 /*
3106                  * Channels of the "agent" types cannot be created directly.
3107                  * They are meant to be created implicitly through the
3108                  * activation of events in their domain. However, a user
3109                  * can override the default channel configuration attributes
3110                  * by creating the underlying UST channel _before_ enabling
3111                  * an agent domain event.
3112                  *
3113                  * Hence, the channel's type is substituted before the creation
3114                  * and restored by the time the events are created.
3115                  */
3116                 switch (domain.type) {
3117                 case LTTNG_DOMAIN_JUL:
3118                 case LTTNG_DOMAIN_LOG4J:
3119                 case LTTNG_DOMAIN_PYTHON:
3120                         domain.type = LTTNG_DOMAIN_UST;
3121                 default:
3122                         break;
3123                 }
3124
3125                 channel = lttng_channel_create(&domain);
3126                 if (!channel) {
3127                         ret = -1;
3128                         goto end;
3129                 }
3130
3131                 for (channel_attr_node = xmlFirstElementChild(node);
3132                         channel_attr_node; channel_attr_node =
3133                         xmlNextElementSibling(channel_attr_node)) {
3134                         ret = process_channel_attr_node(channel_attr_node,
3135                                 channel, &contexts_node, &events_node);
3136                         if (ret) {
3137                                 goto end;
3138                         }
3139                 }
3140
3141                 ret = lttng_enable_channel(handle, channel);
3142                 if (ret < 0) {
3143                         goto end;
3144                 }
3145
3146                 /* Restore the original channel domain. */
3147                 domain.type = original_domain;
3148
3149                 ret = process_events_node(events_node, handle, channel->name);
3150                 if (ret) {
3151                         goto end;
3152                 }
3153
3154                 ret = process_contexts_node(contexts_node, handle,
3155                         channel->name);
3156                 if (ret) {
3157                         goto end;
3158                 }
3159
3160                 lttng_channel_destroy(channel);
3161         }
3162         channel = NULL;
3163
3164         /* get the trackers node */
3165         for (node = xmlFirstElementChild(domain_node); node;
3166                         node = xmlNextElementSibling(node)) {
3167                 if (!strcmp((const char *) node->name,
3168                                     config_element_process_attr_trackers) ||
3169                                 !strcmp((const char *) node->name,
3170                                                 config_element_trackers_legacy)) {
3171                         if (trackers_node) {
3172                                 ERR("Only one instance of `%s` or `%s` is allowed in a session configuration",
3173                                                 config_element_process_attr_trackers,
3174                                                 config_element_trackers_legacy);
3175                                 ret = -1;
3176                                 goto end;
3177                         }
3178                         trackers_node = node;
3179                         break;
3180                 }
3181         }
3182
3183         if (!trackers_node) {
3184                 goto end;
3185         }
3186
3187         for (node = xmlFirstElementChild(trackers_node); node;
3188                         node = xmlNextElementSibling(node)) {
3189                 if (!strcmp((const char *) node->name,
3190                                     config_element_process_attr_tracker_pid)) {
3191                         pid_tracker_node = node;
3192                         ret = process_id_tracker_node(pid_tracker_node, handle,
3193                                         LTTNG_PROCESS_ATTR_PROCESS_ID);
3194                         if (ret) {
3195                                 goto end;
3196                         }
3197                 }
3198                 if (!strcmp((const char *) node->name,
3199                                     config_element_process_attr_tracker_vpid)) {
3200                         vpid_tracker_node = node;
3201                         ret = process_id_tracker_node(vpid_tracker_node, handle,
3202                                         LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID);
3203                         if (ret) {
3204                                 goto end;
3205                         }
3206                 }
3207                 if (!strcmp((const char *) node->name,
3208                                     config_element_process_attr_tracker_uid)) {
3209                         uid_tracker_node = node;
3210                         ret = process_id_tracker_node(uid_tracker_node, handle,
3211                                         LTTNG_PROCESS_ATTR_USER_ID);
3212                         if (ret) {
3213                                 goto end;
3214                         }
3215                 }
3216                 if (!strcmp((const char *) node->name,
3217                                     config_element_process_attr_tracker_vuid)) {
3218                         vuid_tracker_node = node;
3219                         ret = process_id_tracker_node(vuid_tracker_node, handle,
3220                                         LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID);
3221                         if (ret) {
3222                                 goto end;
3223                         }
3224                 }
3225                 if (!strcmp((const char *) node->name,
3226                                     config_element_process_attr_tracker_gid)) {
3227                         gid_tracker_node = node;
3228                         ret = process_id_tracker_node(gid_tracker_node, handle,
3229                                         LTTNG_PROCESS_ATTR_GROUP_ID);
3230                         if (ret) {
3231                                 goto end;
3232                         }
3233                 }
3234                 if (!strcmp((const char *) node->name,
3235                                     config_element_process_attr_tracker_vgid)) {
3236                         vgid_tracker_node = node;
3237                         ret = process_id_tracker_node(vgid_tracker_node, handle,
3238                                         LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID);
3239                         if (ret) {
3240                                 goto end;
3241                         }
3242                 }
3243                 if (!strcmp((const char *) node->name,
3244                                     config_element_pid_tracker_legacy)) {
3245                         ret = process_legacy_pid_tracker_node(node, handle);
3246                         if (ret) {
3247                                 goto end;
3248                         }
3249                 }
3250         }
3251
3252 end:
3253         lttng_channel_destroy(channel);
3254         lttng_destroy_handle(handle);
3255         return ret;
3256 }
3257
3258 static
3259 int add_periodic_rotation(const char *name, uint64_t time_us)
3260 {
3261         int ret;
3262         enum lttng_rotation_status status;
3263         struct lttng_rotation_schedule *periodic =
3264                         lttng_rotation_schedule_periodic_create();
3265
3266         if (!periodic) {
3267                 ret = -LTTNG_ERR_NOMEM;
3268                 goto error;
3269         }
3270
3271         status = lttng_rotation_schedule_periodic_set_period(periodic,
3272                         time_us);
3273         if (status != LTTNG_ROTATION_STATUS_OK) {
3274                 ret = -LTTNG_ERR_INVALID;
3275                 goto error;
3276         }
3277
3278         status = lttng_session_add_rotation_schedule(name, periodic);
3279         switch (status) {
3280         case LTTNG_ROTATION_STATUS_OK:
3281                 ret = 0;
3282                 break;
3283         case LTTNG_ROTATION_STATUS_SCHEDULE_ALREADY_SET:
3284         case LTTNG_ROTATION_STATUS_INVALID:
3285                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3286                 break;
3287         default:
3288                 ret = -LTTNG_ERR_UNK;
3289                 break;
3290         }
3291 error:
3292         lttng_rotation_schedule_destroy(periodic);
3293         return ret;
3294 }
3295
3296 static
3297 int add_size_rotation(const char *name, uint64_t size_bytes)
3298 {
3299         int ret;
3300         enum lttng_rotation_status status;
3301         struct lttng_rotation_schedule *size =
3302                         lttng_rotation_schedule_size_threshold_create();
3303
3304         if (!size) {
3305                 ret = -LTTNG_ERR_NOMEM;
3306                 goto error;
3307         }
3308
3309         status = lttng_rotation_schedule_size_threshold_set_threshold(size,
3310                         size_bytes);
3311         if (status != LTTNG_ROTATION_STATUS_OK) {
3312                 ret = -LTTNG_ERR_INVALID;
3313                 goto error;
3314         }
3315
3316         status = lttng_session_add_rotation_schedule(name, size);
3317         switch (status) {
3318         case LTTNG_ROTATION_STATUS_OK:
3319                 ret = 0;
3320                 break;
3321         case LTTNG_ROTATION_STATUS_SCHEDULE_ALREADY_SET:
3322         case LTTNG_ROTATION_STATUS_INVALID:
3323                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3324                 break;
3325         default:
3326                 ret = -LTTNG_ERR_UNK;
3327                 break;
3328         }
3329 error:
3330         lttng_rotation_schedule_destroy(size);
3331         return ret;
3332 }
3333
3334 static
3335 int process_session_rotation_schedules_node(
3336                 xmlNodePtr schedules_node,
3337                 uint64_t *rotation_timer_interval,
3338                 uint64_t *rotation_size)
3339 {
3340         int ret = 0;
3341         xmlNodePtr child;
3342
3343         for (child = xmlFirstElementChild(schedules_node);
3344                         child;
3345                         child = xmlNextElementSibling(child)) {
3346                 if (!strcmp((const char *) child->name,
3347                                 config_element_rotation_schedule_periodic)) {
3348                         xmlChar *content;
3349                         xmlNodePtr time_us_node;
3350
3351                         /* periodic rotation schedule */
3352                         time_us_node = xmlFirstElementChild(child);
3353                         if (!time_us_node ||
3354                                         strcmp((const char *) time_us_node->name,
3355                                                 config_element_rotation_schedule_periodic_time_us)) {
3356                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3357                                 goto end;
3358                         }
3359
3360                         /* time_us child */
3361                         content = xmlNodeGetContent(time_us_node);
3362                         if (!content) {
3363                                 ret = -LTTNG_ERR_NOMEM;
3364                                 goto end;
3365                         }
3366                         ret = parse_uint(content, rotation_timer_interval);
3367                         free(content);
3368                         if (ret) {
3369                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3370                                 goto end;
3371                         }
3372                 } else if (!strcmp((const char *) child->name,
3373                                 config_element_rotation_schedule_size_threshold)) {
3374                         xmlChar *content;
3375                         xmlNodePtr bytes_node;
3376
3377                         /* size_threshold rotation schedule */
3378                         bytes_node = xmlFirstElementChild(child);
3379                         if (!bytes_node ||
3380                                         strcmp((const char *) bytes_node->name,
3381                                                 config_element_rotation_schedule_size_threshold_bytes)) {
3382                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3383                                 goto end;
3384                         }
3385
3386                         /* bytes child */
3387                         content = xmlNodeGetContent(bytes_node);
3388                         if (!content) {
3389                                 ret = -LTTNG_ERR_NOMEM;
3390                                 goto end;
3391                         }
3392                         ret = parse_uint(content, rotation_size);
3393                         free(content);
3394                         if (ret) {
3395                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3396                                 goto end;
3397                         }
3398                 }
3399         }
3400
3401 end:
3402         return ret;
3403 }
3404
3405 static
3406 int process_session_node(xmlNodePtr session_node, const char *session_name,
3407                 int overwrite,
3408                 const struct config_load_session_override_attr *overrides)
3409 {
3410         int ret, started = -1, snapshot_mode = -1;
3411         uint64_t live_timer_interval = UINT64_MAX,
3412                          rotation_timer_interval = 0,
3413                          rotation_size = 0;
3414         xmlChar *name = NULL;
3415         xmlChar *shm_path = NULL;
3416         xmlNodePtr domains_node = NULL;
3417         xmlNodePtr output_node = NULL;
3418         xmlNodePtr node;
3419         xmlNodePtr attributes_child;
3420         struct lttng_domain *kernel_domain = NULL;
3421         struct lttng_domain *ust_domain = NULL;
3422         struct lttng_domain *jul_domain = NULL;
3423         struct lttng_domain *log4j_domain = NULL;
3424         struct lttng_domain *python_domain = NULL;
3425
3426         for (node = xmlFirstElementChild(session_node); node;
3427                 node = xmlNextElementSibling(node)) {
3428                 if (!name && !strcmp((const char *) node->name,
3429                         config_element_name)) {
3430                         /* name */
3431                         xmlChar *node_content = xmlNodeGetContent(node);
3432                         if (!node_content) {
3433                                 ret = -LTTNG_ERR_NOMEM;
3434                                 goto error;
3435                         }
3436
3437                         name = node_content;
3438                 } else if (!domains_node && !strcmp((const char *) node->name,
3439                         config_element_domains)) {
3440                         /* domains */
3441                         domains_node = node;
3442                 } else if (started == -1 && !strcmp((const char *) node->name,
3443                         config_element_started)) {
3444                         /* started */
3445                         xmlChar *node_content = xmlNodeGetContent(node);
3446                         if (!node_content) {
3447                                 ret = -LTTNG_ERR_NOMEM;
3448                                 goto error;
3449                         }
3450
3451                         ret = parse_bool(node_content, &started);
3452                         free(node_content);
3453                         if (ret) {
3454                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3455                                 goto error;
3456                         }
3457                 } else if (!output_node && !strcmp((const char *) node->name,
3458                         config_element_output)) {
3459                         /* output */
3460                         output_node = node;
3461                 } else if (!shm_path && !strcmp((const char *) node->name,
3462                         config_element_shared_memory_path)) {
3463                         /* shared memory path */
3464                         xmlChar *node_content = xmlNodeGetContent(node);
3465                         if (!node_content) {
3466                                 ret = -LTTNG_ERR_NOMEM;
3467                                 goto error;
3468                         }
3469
3470                         shm_path = node_content;
3471                 } else {
3472                         /*
3473                          * attributes, snapshot_mode, live_timer_interval, rotation_size,
3474                          * rotation_timer_interval.
3475                          */
3476                         for (attributes_child = xmlFirstElementChild(node); attributes_child;
3477                                         attributes_child = xmlNextElementSibling(attributes_child)) {
3478                                 if (!strcmp((const char *) attributes_child->name,
3479                                                         config_element_snapshot_mode)) {
3480                                         /* snapshot_mode */
3481                                         xmlChar *snapshot_mode_content =
3482                                                 xmlNodeGetContent(attributes_child);
3483                                         if (!snapshot_mode_content) {
3484                                                 ret = -LTTNG_ERR_NOMEM;
3485                                                 goto error;
3486                                         }
3487
3488                                         ret = parse_bool(snapshot_mode_content, &snapshot_mode);
3489                                         free(snapshot_mode_content);
3490                                         if (ret) {
3491                                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3492                                                 goto error;
3493                                         }
3494                                 } else if (!strcmp((const char *) attributes_child->name,
3495                                                         config_element_live_timer_interval)) {
3496                                         /* live_timer_interval */
3497                                         xmlChar *timer_interval_content =
3498                                                 xmlNodeGetContent(attributes_child);
3499                                         if (!timer_interval_content) {
3500                                                 ret = -LTTNG_ERR_NOMEM;
3501                                                 goto error;
3502                                         }
3503
3504                                         ret = parse_uint(timer_interval_content, &live_timer_interval);
3505                                         free(timer_interval_content);
3506                                         if (ret) {
3507                                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3508                                                 goto error;
3509                                         }
3510                                 } else if (!strcmp((const char *) attributes_child->name,
3511                                                         config_element_rotation_schedules)) {
3512                                         ret = process_session_rotation_schedules_node(
3513                                                         attributes_child,
3514                                                         &rotation_timer_interval,
3515                                                         &rotation_size);
3516                                         if (ret) {
3517                                                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3518                                                 goto error;
3519                                         }
3520
3521                                 }
3522                         }
3523                 }
3524         }
3525
3526         if (!name) {
3527                 /* Mandatory attribute, as defined in the session XSD */
3528                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3529                 goto error;
3530         }
3531
3532         if (session_name && strcmp((char *) name, session_name)) {
3533                 /* This is not the session we are looking for */
3534                 ret = -LTTNG_ERR_NO_SESSION;
3535                 goto error;
3536         }
3537
3538         /* Init domains to create the session handles */
3539         for (node = xmlFirstElementChild(domains_node); node;
3540                 node = xmlNextElementSibling(node)) {
3541                 struct lttng_domain *domain;
3542
3543                 domain = zmalloc(sizeof(*domain));
3544                 if (!domain) {
3545                         ret = -LTTNG_ERR_NOMEM;
3546                         goto error;
3547                 }
3548
3549                 ret = init_domain(node, domain);
3550                 if (ret) {
3551                         goto domain_init_error;
3552                 }
3553
3554                 switch (domain->type) {
3555                 case LTTNG_DOMAIN_KERNEL:
3556                         if (kernel_domain) {
3557                                 /* Same domain seen twice, invalid! */
3558                                 goto domain_init_error;
3559                         }
3560                         kernel_domain = domain;
3561                         break;
3562                 case LTTNG_DOMAIN_UST:
3563                         if (ust_domain) {
3564                                 /* Same domain seen twice, invalid! */
3565                                 goto domain_init_error;
3566                         }
3567                         ust_domain = domain;
3568                         break;
3569                 case LTTNG_DOMAIN_JUL:
3570                         if (jul_domain) {
3571                                 /* Same domain seen twice, invalid! */
3572                                 goto domain_init_error;
3573                         }
3574                         jul_domain = domain;
3575                         break;
3576                 case LTTNG_DOMAIN_LOG4J:
3577                         if (log4j_domain) {
3578                                 /* Same domain seen twice, invalid! */
3579                                 goto domain_init_error;
3580                         }
3581                         log4j_domain = domain;
3582                         break;
3583                 case LTTNG_DOMAIN_PYTHON:
3584                         if (python_domain) {
3585                                 /* Same domain seen twice, invalid! */
3586                                 goto domain_init_error;
3587                         }
3588                         python_domain = domain;
3589                         break;
3590                 default:
3591                         WARN("Invalid domain type");
3592                         goto domain_init_error;
3593                 }
3594                 continue;
3595 domain_init_error:
3596                 free(domain);
3597                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3598                 goto error;
3599         }
3600
3601         /* Apply overrides */
3602         if (overrides) {
3603                 if (overrides->session_name) {
3604                         xmlChar *name_override = xmlStrdup(BAD_CAST(overrides->session_name));
3605                         if (!name_override) {
3606                                 ret = -LTTNG_ERR_NOMEM;
3607                                 goto error;
3608                         }
3609
3610                         /* Overrides the session name to the provided name */
3611                         xmlFree(name);
3612                         name = name_override;
3613                 }
3614         }
3615
3616         if (overwrite) {
3617                 /* Destroy session if it exists */
3618                 ret = lttng_destroy_session((const char *) name);
3619                 if (ret && ret != -LTTNG_ERR_SESS_NOT_FOUND) {
3620                         ERR("Failed to destroy existing session.");
3621                         goto error;
3622                 }
3623         }
3624
3625         /* Create session type depending on output type */
3626         if (snapshot_mode && snapshot_mode != -1) {
3627                 ret = create_snapshot_session((const char *) name, output_node,
3628                                 overrides);
3629         } else if (live_timer_interval &&
3630                 live_timer_interval != UINT64_MAX) {
3631                 ret = create_session((const char *) name,
3632                                 output_node, live_timer_interval, overrides);
3633         } else {
3634                 /* regular session */
3635                 ret = create_session((const char *) name,
3636                                 output_node, UINT64_MAX, overrides);
3637         }
3638         if (ret) {
3639                 goto error;
3640         }
3641
3642         if (shm_path) {
3643                 ret = lttng_set_session_shm_path((const char *) name,
3644                                 (const char *) shm_path);
3645                 if (ret) {
3646                         goto error;
3647                 }
3648         }
3649
3650         for (node = xmlFirstElementChild(domains_node); node;
3651                 node = xmlNextElementSibling(node)) {
3652                 ret = process_domain_node(node, (const char *) name);
3653                 if (ret) {
3654                         goto end;
3655                 }
3656         }
3657
3658         if (rotation_timer_interval) {
3659                 ret = add_periodic_rotation((const char *) name,
3660                                 rotation_timer_interval);
3661                 if (ret < 0) {
3662                         goto error;
3663                 }
3664         }
3665         if (rotation_size) {
3666                 ret = add_size_rotation((const char *) name,
3667                                 rotation_size);
3668                 if (ret < 0) {
3669                         goto error;
3670                 }
3671         }
3672
3673         if (started) {
3674                 ret = lttng_start_tracing((const char *) name);
3675                 if (ret) {
3676                         goto end;
3677                 }
3678         }
3679
3680 end:
3681         if (ret < 0) {
3682                 ERR("Failed to load session %s: %s", (const char *) name,
3683                         lttng_strerror(ret));
3684                 lttng_destroy_session((const char *) name);
3685         }
3686
3687 error:
3688         free(kernel_domain);
3689         free(ust_domain);
3690         free(jul_domain);
3691         free(log4j_domain);
3692         free(python_domain);
3693         xmlFree(name);
3694         xmlFree(shm_path);
3695         return ret;
3696 }
3697
3698 /*
3699  * Return 1 if the given path is readable by the current UID or 0 if not.
3700  * Return -1 if the path is EPERM.
3701  */
3702 static int validate_file_read_creds(const char *path)
3703 {
3704         int ret;
3705
3706         assert(path);
3707
3708         /* Can we read the file. */
3709         ret = access(path, R_OK);
3710         if (!ret) {
3711                 goto valid;
3712         }
3713         if (errno == EACCES) {
3714                 return -1;
3715         } else {
3716                 /* Invalid. */
3717                 return 0;
3718         }
3719 valid:
3720         return 1;
3721 }
3722
3723 static
3724 int load_session_from_file(const char *path, const char *session_name,
3725         struct session_config_validation_ctx *validation_ctx, int overwrite,
3726         const struct config_load_session_override_attr *overrides)
3727 {
3728         int ret, session_found = !session_name;
3729         xmlDocPtr doc = NULL;
3730         xmlNodePtr sessions_node;
3731         xmlNodePtr session_node;
3732
3733         assert(path);
3734         assert(validation_ctx);
3735
3736         ret = validate_file_read_creds(path);
3737         if (ret != 1) {
3738                 if (ret == -1) {
3739                         ret = -LTTNG_ERR_EPERM;
3740                 } else {
3741                         ret = -LTTNG_ERR_LOAD_SESSION_NOENT;
3742                 }
3743                 goto end;
3744         }
3745
3746         doc = xmlParseFile(path);
3747         if (!doc) {
3748                 ret = -LTTNG_ERR_LOAD_IO_FAIL;
3749                 goto end;
3750         }
3751
3752         ret = xmlSchemaValidateDoc(validation_ctx->schema_validation_ctx, doc);
3753         if (ret) {
3754                 ERR("Session configuration file validation failed");
3755                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3756                 goto end;
3757         }
3758
3759         sessions_node = xmlDocGetRootElement(doc);
3760         if (!sessions_node) {
3761                 ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
3762                 goto end;
3763         }
3764
3765         for (session_node = xmlFirstElementChild(sessions_node);
3766                 session_node; session_node =
3767                         xmlNextElementSibling(session_node)) {
3768                 ret = process_session_node(session_node,
3769                         session_name, overwrite, overrides);
3770                 if (session_name && ret == 0) {
3771                         /* Target session found and loaded */
3772                         session_found = 1;
3773                         break;
3774                 }
3775         }
3776 end:
3777         xmlFreeDoc(doc);
3778         if (!ret) {
3779                 ret = session_found ? 0 : -LTTNG_ERR_LOAD_SESSION_NOENT;
3780         }
3781         if (ret == -LTTNG_ERR_NO_SESSION) {
3782                 ret = -LTTNG_ERR_LOAD_SESSION_NOENT;
3783         }
3784         return ret;
3785 }
3786
3787 static
3788 int load_session_from_path(const char *path, const char *session_name,
3789         struct session_config_validation_ctx *validation_ctx, int overwrite,
3790         const struct config_load_session_override_attr *overrides)
3791 {
3792         int ret, session_found = !session_name;
3793         DIR *directory = NULL;
3794         struct lttng_dynamic_buffer file_path;
3795         size_t path_len;
3796
3797         assert(path);
3798         assert(validation_ctx);
3799         path_len = strlen(path);
3800         lttng_dynamic_buffer_init(&file_path);
3801         if (path_len >= LTTNG_PATH_MAX) {
3802                 ERR("Session configuration load path \"%s\" length (%zu) exceeds the maximal length allowed (%d)",
3803                                 path, path_len, LTTNG_PATH_MAX);
3804                 ret = -LTTNG_ERR_INVALID;
3805                 goto end;
3806         }
3807
3808         directory = opendir(path);
3809         if (!directory) {
3810                 switch (errno) {
3811                 case ENOTDIR:
3812                         /* Try the file loading. */
3813                         break;
3814                 case ENOENT:
3815                         ret = -LTTNG_ERR_LOAD_SESSION_NOENT;
3816                         goto end;
3817                 default:
3818                         ret = -LTTNG_ERR_LOAD_IO_FAIL;
3819                         goto end;
3820                 }
3821         }
3822         if (directory) {
3823                 size_t file_path_root_len;
3824
3825                 ret = lttng_dynamic_buffer_set_capacity(&file_path,
3826                                 LTTNG_PATH_MAX);
3827                 if (ret) {
3828                         ret = -LTTNG_ERR_NOMEM;
3829                         goto end;
3830                 }
3831
3832                 ret = lttng_dynamic_buffer_append(&file_path, path, path_len);
3833                 if (ret) {
3834                         ret = -LTTNG_ERR_NOMEM;
3835                         goto end;
3836                 }
3837
3838                 if (file_path.data[file_path.size - 1] != '/') {
3839                         ret = lttng_dynamic_buffer_append(&file_path, "/", 1);
3840                         if (ret) {
3841                                 ret = -LTTNG_ERR_NOMEM;
3842                                 goto end;
3843                         }
3844                 }
3845                 file_path_root_len = file_path.size;
3846
3847                 /* Search for *.lttng files */
3848                 for (;;) {
3849                         size_t file_name_len;
3850                         struct dirent *result;
3851
3852                         /*
3853                          * When the end of the directory stream is reached, NULL
3854                          * is returned and errno is kept unchanged. When an
3855                          * error occurs, NULL is returned and errno is set
3856                          * accordingly. To distinguish between the two, set
3857                          * errno to zero before calling readdir().
3858                          *
3859                          * On success, readdir() returns a pointer to a dirent
3860                          * structure. This structure may be statically
3861                          * allocated, do not attempt to free(3) it.
3862                          */
3863                         errno = 0;
3864                         result = readdir(directory);
3865
3866                         /* Reached end of dir stream or error out. */
3867                         if (!result) {
3868                                 if (errno) {
3869                                         PERROR("Failed to enumerate the contents of path \"%s\" while loading session, readdir returned", path);
3870                                         ret = -LTTNG_ERR_LOAD_IO_FAIL;
3871                                         goto end;
3872                                 }
3873                                 break;
3874                         }
3875
3876                         file_name_len = strlen(result->d_name);
3877
3878                         if (file_name_len <=
3879                                 sizeof(DEFAULT_SESSION_CONFIG_FILE_EXTENSION)) {
3880                                 continue;
3881                         }
3882
3883                         if (file_path.size + file_name_len >= LTTNG_PATH_MAX) {
3884                                 WARN("Ignoring file \"%s\" since the path's length (%zu) would exceed the maximal permitted size (%d)",
3885                                                 result->d_name,
3886                                                 /* +1 to account for NULL terminator. */
3887                                                 file_path.size + file_name_len + 1,
3888                                                 LTTNG_PATH_MAX);
3889                                 continue;
3890                         }
3891
3892                         /* Does the file end with .lttng? */
3893                         if (strcmp(DEFAULT_SESSION_CONFIG_FILE_EXTENSION,
3894                                         result->d_name + file_name_len - sizeof(
3895                                         DEFAULT_SESSION_CONFIG_FILE_EXTENSION) + 1)) {
3896                                 continue;
3897                         }
3898
3899                         ret = lttng_dynamic_buffer_append(&file_path, result->d_name,
3900                                         file_name_len + 1);
3901                         if (ret) {
3902                                 ret = -LTTNG_ERR_NOMEM;
3903                                 goto end;
3904                         }
3905
3906                         ret = load_session_from_file(file_path.data, session_name,
3907                                 validation_ctx, overwrite, overrides);
3908                         if (session_name &&
3909                                         (!ret || ret != -LTTNG_ERR_LOAD_SESSION_NOENT)) {
3910                                 session_found = 1;
3911                                 break;
3912                         }
3913                         if (ret && ret != -LTTNG_ERR_LOAD_SESSION_NOENT) {
3914                                 goto end;
3915                         }
3916                         /*
3917                          * Reset the buffer's size to the location of the
3918                          * path's trailing '/'.
3919                          */
3920                         ret = lttng_dynamic_buffer_set_size(&file_path,
3921                                         file_path_root_len);
3922                         if (ret) {
3923                                 ret = -LTTNG_ERR_UNK;
3924                                 goto end;
3925                         }
3926                 }
3927         } else {
3928                 ret = load_session_from_file(path, session_name,
3929                         validation_ctx, overwrite, overrides);
3930                 if (ret) {
3931                         goto end;
3932                 }
3933                 session_found = 1;
3934         }
3935
3936         ret = 0;
3937 end:
3938         if (directory) {
3939                 if (closedir(directory)) {
3940                         PERROR("closedir");
3941                 }
3942         }
3943         if (!ret && !session_found) {
3944                 ret = -LTTNG_ERR_LOAD_SESSION_NOENT;
3945         }
3946         lttng_dynamic_buffer_reset(&file_path);
3947         return ret;
3948 }
3949
3950 /*
3951  * Validate that the given path's credentials and the current process have the
3952  * same UID. If so, return 1 else return 0 if it does NOT match.
3953  */
3954 static int validate_path_creds(const char *path)
3955 {
3956         int ret, uid = getuid();
3957         struct stat buf;
3958
3959         assert(path);
3960
3961         if (uid == 0) {
3962                 goto valid;
3963         }
3964
3965         ret = stat(path, &buf);
3966         if (ret < 0) {
3967                 if (errno != ENOENT) {
3968                         PERROR("stat");
3969                 }
3970                 goto valid;
3971         }
3972
3973         if (buf.st_uid != uid) {
3974                 goto invalid;
3975         }
3976
3977 valid:
3978         return 1;
3979 invalid:
3980         return 0;
3981 }
3982
3983 LTTNG_HIDDEN
3984 int config_load_session(const char *path, const char *session_name,
3985                 int overwrite, unsigned int autoload,
3986                 const struct config_load_session_override_attr *overrides)
3987 {
3988         int ret;
3989         bool session_loaded = false;
3990         const char *path_ptr = NULL;
3991         struct session_config_validation_ctx validation_ctx = { 0 };
3992
3993         ret = init_session_config_validation_ctx(&validation_ctx);
3994         if (ret) {
3995                 goto end;
3996         }
3997
3998         if (!path) {
3999                 const char *home_path;
4000                 const char *sys_path;
4001
4002                 /* Try home path */
4003                 home_path = utils_get_home_dir();
4004                 if (home_path) {
4005                         char path[PATH_MAX];
4006
4007                         /*
4008                          * Try user session configuration path. Ignore error here so we can
4009                          * continue loading the system wide sessions.
4010                          */
4011                         if (autoload) {
4012                                 ret = snprintf(path, sizeof(path),
4013                                                 DEFAULT_SESSION_HOME_CONFIGPATH "/"
4014                                                 DEFAULT_SESSION_CONFIG_AUTOLOAD, home_path);
4015                                 if (ret < 0) {
4016                                         PERROR("snprintf session autoload home config path");
4017                                         ret = -LTTNG_ERR_INVALID;
4018                                         goto end;
4019                                 }
4020
4021                                 /*
4022                                  * Credentials are only validated for the autoload in order to
4023                                  * avoid any user session daemon to try to load kernel sessions
4024                                  * automatically and failing all the times.
4025                                  */
4026                                 ret = validate_path_creds(path);
4027                                 if (ret) {
4028                                         path_ptr = path;
4029                                 }
4030                         } else {
4031                                 ret = snprintf(path, sizeof(path),
4032                                                 DEFAULT_SESSION_HOME_CONFIGPATH, home_path);
4033                                 if (ret < 0) {
4034                                         PERROR("snprintf session home config path");
4035                                         ret = -LTTNG_ERR_INVALID;
4036                                         goto end;
4037                                 }
4038                                 path_ptr = path;
4039                         }
4040                         if (path_ptr) {
4041                                 ret = load_session_from_path(path_ptr, session_name,
4042                                                 &validation_ctx, overwrite, overrides);
4043                                 if (ret && ret != -LTTNG_ERR_LOAD_SESSION_NOENT) {
4044                                         goto end;
4045                                 }
4046                                 /*
4047                                  * Continue even if the session was found since we have to try
4048                                  * the system wide sessions.
4049                                  */
4050                                 session_loaded = true;
4051                         }
4052                 }
4053
4054                 /* Reset path pointer for the system wide dir. */
4055                 path_ptr = NULL;
4056
4057                 /* Try system wide configuration directory. */
4058                 if (autoload) {
4059                         sys_path = DEFAULT_SESSION_SYSTEM_CONFIGPATH "/"
4060                                 DEFAULT_SESSION_CONFIG_AUTOLOAD;
4061                         ret = validate_path_creds(sys_path);
4062                         if (ret) {
4063                                 path_ptr = sys_path;
4064                         }
4065                 } else {
4066                         sys_path = DEFAULT_SESSION_SYSTEM_CONFIGPATH;
4067                         path_ptr = sys_path;
4068                 }
4069
4070                 if (path_ptr) {
4071                         ret = load_session_from_path(path_ptr, session_name,
4072                                         &validation_ctx, overwrite, overrides);
4073                         if (!ret) {
4074                                 session_loaded = true;
4075                         }
4076                 } else {
4077                         ret = 0;
4078                 }
4079         } else {
4080                 ret = access(path, F_OK);
4081                 if (ret < 0) {
4082                         PERROR("access");
4083                         switch (errno) {
4084                         case ENOENT:
4085                                 ret = -LTTNG_ERR_INVALID;
4086                                 WARN("Session configuration path does not exist.");
4087                                 break;
4088                         case EACCES:
4089                                 ret = -LTTNG_ERR_EPERM;
4090                                 break;
4091                         default:
4092                                 ret = -LTTNG_ERR_UNK;
4093                                 break;
4094                         }
4095                         goto end;
4096                 }
4097
4098                 ret = load_session_from_path(path, session_name,
4099                         &validation_ctx, overwrite, overrides);
4100         }
4101 end:
4102         fini_session_config_validation_ctx(&validation_ctx);
4103         if (ret == -LTTNG_ERR_LOAD_SESSION_NOENT && !session_name && !path) {
4104                 /*
4105                  * Don't report an error if no sessions are found when called
4106                  * without a session_name or a search path.
4107                  */
4108                 ret = 0;
4109         }
4110
4111         if (session_loaded && ret == -LTTNG_ERR_LOAD_SESSION_NOENT) {
4112                 /* A matching session was found in one of the search paths. */
4113                 ret = 0;
4114         }
4115         return ret;
4116 }
4117
4118 static
4119 void __attribute__((destructor)) session_config_exit(void)
4120 {
4121         xmlCleanupParser();
4122 }