src/bin/lttng/utils.c

   1 /*
   2  * Copyright (c)  2011 David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #define _LGPL_SOURCE
  20 #include <assert.h>
  21 #include <stdlib.h>
  22 #include <ctype.h>
  23 #include <limits.h>
  24 #include <sys/types.h>
  25 #include <sys/socket.h>
  26 #include <signal.h>
  27 #include <netinet/in.h>
  28 #include <arpa/inet.h>
  29
  30 #include <common/error.h>
  31 #include <common/utils.h>
  32
  33 #include "conf.h"
  34 #include "utils.h"
  35 #include "command.h"
  36
  37 static const char *str_kernel = "Kernel";
  38 static const char *str_ust = "UST";
  39 static const char *str_jul = "JUL";
  40 static const char *str_log4j = "LOG4J";
  41 static const char *str_python = "Python";
  42
  43 static
  44 char *_get_session_name(int quiet)
  45 {
  46         char *path, *session_name = NULL;
  47
  48         /* Get path to config file */
  49         path = utils_get_home_dir();
  50         if (path == NULL) {
  51                 goto error;
  52         }
  53
  54         /* Get session name from config */
  55         session_name = quiet ? config_read_session_name_quiet(path) :
  56                 config_read_session_name(path);
  57         if (session_name == NULL) {
  58                 goto error;
  59         }
  60
  61         DBG2("Config file path found: %s", path);
  62         DBG("Session name found: %s", session_name);
  63         return session_name;
  64
  65 error:
  66         return NULL;
  67 }
  68
  69 /*
  70  *  get_session_name
  71  *
  72  *  Return allocated string with the session name found in the config
  73  *  directory.
  74  */
  75 char *get_session_name(void)
  76 {
  77         return _get_session_name(0);
  78 }
  79
  80 /*
  81  *  get_session_name_quiet (no warnings/errors emitted)
  82  *
  83  *  Return allocated string with the session name found in the config
  84  *  directory.
  85  */
  86 char *get_session_name_quiet(void)
  87 {
  88         return _get_session_name(1);
  89 }
  90
  91 /*
  92  *  list_commands
  93  *
  94  *  List commands line by line. This is mostly for bash auto completion and to
  95  *  avoid difficult parsing.
  96  */
  97 void list_commands(struct cmd_struct *commands, FILE *ofp)
  98 {
  99         int i = 0;
 100         struct cmd_struct *cmd = NULL;
 101
 102         cmd = &commands[i];
 103         while (cmd->name != NULL) {
 104                 fprintf(ofp, "%s\n", cmd->name);
 105                 i++;
 106                 cmd = &commands[i];
 107         }
 108 }
 109
 110 /*
 111  * list_cmd_options
 112  *
 113  * Prints a simple list of the options available to a command. This is intended
 114  * to be easily parsed for bash completion.
 115  */
 116 void list_cmd_options(FILE *ofp, struct poptOption *options)
 117 {
 118         int i;
 119         struct poptOption *option = NULL;
 120
 121         for (i = 0; options[i].longName != NULL; i++) {
 122                 option = &options[i];
 123
 124                 fprintf(ofp, "--%s\n", option->longName);
 125
 126                 if (isprint(option->shortName)) {
 127                         fprintf(ofp, "-%c\n", option->shortName);
 128                 }
 129         }
 130 }
 131
 132 /*
 133  * fls: returns the position of the most significant bit.
 134  * Returns 0 if no bit is set, else returns the position of the most
 135  * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
 136  */
 137 #if defined(__i386) || defined(__x86_64)
 138 static inline
 139 unsigned int fls_u32(uint32_t x)
 140 {
 141         int r;
 142
 143         asm("bsrl %1,%0\n\t"
 144             "jnz 1f\n\t"
 145             "movl $-1,%0\n\t"
 146             "1:\n\t"
 147             : "=r" (r) : "rm" (x));
 148         return r + 1;
 149 }
 150 #define HAS_FLS_U32
 151 #endif
 152
 153 #if defined(__x86_64)
 154 static inline
 155 unsigned int fls_u64(uint64_t x)
 156 {
 157         long r;
 158
 159         asm("bsrq %1,%0\n\t"
 160             "jnz 1f\n\t"
 161             "movq $-1,%0\n\t"
 162             "1:\n\t"
 163             : "=r" (r) : "rm" (x));
 164         return r + 1;
 165 }
 166 #define HAS_FLS_U64
 167 #endif
 168
 169 #ifndef HAS_FLS_U64
 170 static __attribute__((unused))
 171 unsigned int fls_u64(uint64_t x)
 172 {
 173         unsigned int r = 64;
 174
 175         if (!x)
 176                 return 0;
 177
 178         if (!(x & 0xFFFFFFFF00000000ULL)) {
 179                 x <<= 32;
 180                 r -= 32;
 181         }
 182         if (!(x & 0xFFFF000000000000ULL)) {
 183                 x <<= 16;
 184                 r -= 16;
 185         }
 186         if (!(x & 0xFF00000000000000ULL)) {
 187                 x <<= 8;
 188                 r -= 8;
 189         }
 190         if (!(x & 0xF000000000000000ULL)) {
 191                 x <<= 4;
 192                 r -= 4;
 193         }
 194         if (!(x & 0xC000000000000000ULL)) {
 195                 x <<= 2;
 196                 r -= 2;
 197         }
 198         if (!(x & 0x8000000000000000ULL)) {
 199                 x <<= 1;
 200                 r -= 1;
 201         }
 202         return r;
 203 }
 204 #endif
 205
 206 #ifndef HAS_FLS_U32
 207 static __attribute__((unused))
 208 unsigned int fls_u32(uint32_t x)
 209 {
 210         unsigned int r = 32;
 211
 212         if (!x)
 213                 return 0;
 214         if (!(x & 0xFFFF0000U)) {
 215                 x <<= 16;
 216                 r -= 16;
 217         }
 218         if (!(x & 0xFF000000U)) {
 219                 x <<= 8;
 220                 r -= 8;
 221         }
 222         if (!(x & 0xF0000000U)) {
 223                 x <<= 4;
 224                 r -= 4;
 225         }
 226         if (!(x & 0xC0000000U)) {
 227                 x <<= 2;
 228                 r -= 2;
 229         }
 230         if (!(x & 0x80000000U)) {
 231                 x <<= 1;
 232                 r -= 1;
 233         }
 234         return r;
 235 }
 236 #endif
 237
 238 static
 239 unsigned int fls_ulong(unsigned long x)
 240 {
 241 #if (CAA_BITS_PER_LONG == 32)
 242         return fls_u32(x);
 243 #else
 244         return fls_u64(x);
 245 #endif
 246 }
 247
 248 /*
 249  * Return the minimum order for which x <= (1UL << order).
 250  * Return -1 if x is 0.
 251  */
 252 int get_count_order_u32(uint32_t x)
 253 {
 254         if (!x)
 255                 return -1;
 256
 257         return fls_u32(x - 1);
 258 }
 259
 260 /*
 261  * Return the minimum order for which x <= (1UL << order).
 262  * Return -1 if x is 0.
 263  */
 264 int get_count_order_u64(uint64_t x)
 265 {
 266         if (!x)
 267                 return -1;
 268
 269         return fls_u64(x - 1);
 270 }
 271
 272 /*
 273  * Return the minimum order for which x <= (1UL << order).
 274  * Return -1 if x is 0.
 275  */
 276 int get_count_order_ulong(unsigned long x)
 277 {
 278         if (!x)
 279                 return -1;
 280
 281         return fls_ulong(x - 1);
 282 }
 283
 284 const char *get_domain_str(enum lttng_domain_type domain)
 285 {
 286         const char *str_dom;
 287
 288         switch (domain) {
 289         case LTTNG_DOMAIN_KERNEL:
 290                 str_dom = str_kernel;
 291                 break;
 292         case LTTNG_DOMAIN_UST:
 293                 str_dom = str_ust;
 294                 break;
 295         case LTTNG_DOMAIN_JUL:
 296                 str_dom = str_jul;
 297                 break;
 298         case LTTNG_DOMAIN_LOG4J:
 299                 str_dom = str_log4j;
 300                 break;
 301         case LTTNG_DOMAIN_PYTHON:
 302                 str_dom = str_python;
 303                 break;
 304         default:
 305                 /* Should not have an unknown domain or else define it. */
 306                 assert(0);
 307         }
 308
 309         return str_dom;
 310 }
 311
 312 /*
 313  * Spawn a lttng relayd daemon by forking and execv.
 314  */
 315 int spawn_relayd(const char *pathname, int port)
 316 {
 317         int ret = 0;
 318         pid_t pid;
 319         char url[255];
 320
 321         if (!port) {
 322                 port = DEFAULT_NETWORK_VIEWER_PORT;
 323         }
 324
 325         ret = snprintf(url, sizeof(url), "tcp://localhost:%d", port);
 326         if (ret < 0) {
 327                 goto end;
 328         }
 329
 330         MSG("Spawning a relayd daemon");
 331         pid = fork();
 332         if (pid == 0) {
 333                 /*
 334                  * Spawn session daemon and tell
 335                  * it to signal us when ready.
 336                  */
 337                 execlp(pathname, "lttng-relayd", "-L", url, NULL);
 338                 /* execlp only returns if error happened */
 339                 if (errno == ENOENT) {
 340                         ERR("No relayd found. Use --relayd-path.");
 341                 } else {
 342                         PERROR("execlp");
 343                 }
 344                 kill(getppid(), SIGTERM);       /* wake parent */
 345                 exit(EXIT_FAILURE);
 346         } else if (pid > 0) {
 347                 goto end;
 348         } else {
 349                 PERROR("fork");
 350                 ret = -1;
 351                 goto end;
 352         }
 353
 354 end:
 355         return ret;
 356 }
 357
 358 /*
 359  * Check if relayd is alive.
 360  *
 361  * Return 1 if found else 0 if NOT found. Negative value on error.
 362  */
 363 int check_relayd(void)
 364 {
 365         int ret, fd;
 366         struct sockaddr_in sin;
 367
 368         fd = socket(AF_INET, SOCK_STREAM, 0);
 369         if (fd < 0) {
 370                 PERROR("socket check relayd");
 371                 ret = -1;
 372                 goto error_socket;
 373         }
 374
 375         sin.sin_family = AF_INET;
 376         sin.sin_port = htons(DEFAULT_NETWORK_VIEWER_PORT);
 377         ret = inet_pton(sin.sin_family, "127.0.0.1", &sin.sin_addr);
 378         if (ret < 1) {
 379                 PERROR("inet_pton check relayd");
 380                 ret = -1;
 381                 goto error;
 382         }
 383
 384         /*
 385          * A successful connect means the relayd exists thus returning 0 else a
 386          * negative value means it does NOT exists.
 387          */
 388         ret = connect(fd, &sin, sizeof(sin));
 389         if (ret < 0) {
 390                 /* Not found. */
 391                 ret = 0;
 392         } else {
 393                 /* Already spawned. */
 394                 ret = 1;
 395         }
 396
 397 error:
 398         if (close(fd) < 0) {
 399                 PERROR("close relayd fd");
 400         }
 401 error_socket:
 402         return ret;
 403 }
 404
 405 int print_missing_or_multiple_domains(unsigned int sum)
 406 {
 407         int ret = 0;
 408
 409         if (sum == 0) {
 410                 ERR("Please specify a domain (-k/-u/-j).");
 411                 ret = -1;
 412         } else if (sum > 1) {
 413                 ERR("Multiple domains specified.");
 414                 ret = -1;
 415         }
 416
 417         return ret;
 418 }