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