libustcmd/ustcmd.c

   1 /* Copyright (C) 2009  Pierre-Marc Fournier, Philippe Proulx-Barrette
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library 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 GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <unistd.h>
  21 #include <getopt.h>
  22 #include <stdlib.h>
  23 #include <fcntl.h>
  24 #include <string.h>
  25 #include <dirent.h>
  26
  27 #include "ustcomm.h"
  28 #include "ustcmd.h"
  29 #include "usterr.h"
  30
  31 pid_t *ustcmd_get_online_pids(void)
  32 {
  33         struct dirent *dirent;
  34         DIR *dir;
  35         unsigned int ret_size = 1 * sizeof(pid_t), i = 0;
  36
  37         dir = opendir(SOCK_DIR);
  38         if (!dir) {
  39                 return NULL;
  40         }
  41
  42         pid_t *ret = (pid_t *) malloc(ret_size);
  43
  44         while ((dirent = readdir(dir))) {
  45                 if (!strcmp(dirent->d_name, ".") ||
  46                         !strcmp(dirent->d_name, "..")) {
  47
  48                         continue;
  49                 }
  50
  51                 if (dirent->d_type != DT_DIR &&
  52                         !!strcmp(dirent->d_name, "ustd")) {
  53
  54                         sscanf(dirent->d_name, "%u", (unsigned int *) &ret[i]);
  55                         if (pid_is_online(ret[i])) {
  56                                 ret_size += sizeof(pid_t);
  57                                 ret = (pid_t *) realloc(ret, ret_size);
  58                                 ++i;
  59                         }
  60                 }
  61         }
  62
  63         ret[i] = 0; /* Array end */
  64
  65         if (ret[0] == 0) {
  66                  /* No PID at all */
  67                 free(ret);
  68                 return NULL;
  69         }
  70
  71         closedir(dir);
  72         return ret;
  73 }
  74
  75 /**
  76  * Sets marker state (USTCMD_MS_ON or USTCMD_MS_OFF).
  77  *
  78  * @param mn    Marker name
  79  * @param state Marker's new state
  80  * @param pid   Traced process ID
  81  * @return      0 if successful, or errors {USTCMD_ERR_GEN, USTCMD_ERR_ARG}
  82  */
  83 int ustcmd_set_marker_state(const char *mn, int state, pid_t pid)
  84 {
  85         char *cmd_str [] = {"disable_marker", "enable_marker"};
  86         char *cmd;
  87         int result;
  88
  89         if (mn == NULL) {
  90                 return USTCMD_ERR_ARG;
  91         }
  92
  93         asprintf(&cmd, "%s %s", cmd_str[state], mn);
  94
  95         result = ustcmd_send_cmd(cmd, pid, NULL);
  96         if (result) {
  97                 free(cmd);
  98                 return USTCMD_ERR_GEN;
  99         }
 100
 101         free(cmd);
 102         return 0;
 103 }
 104
 105 /**
 106  * Set subbuffer size.
 107  *
 108  * @param channel_size  Channel name and size
 109  * @param pid           Traced process ID
 110  * @return              0 if successful, or error
 111  */
 112 int ustcmd_set_subbuf_size(const char *channel_size, pid_t pid)
 113 {
 114         char *cmd;
 115         int result;
 116
 117         asprintf(&cmd, "%s %s", "set_subbuf_size", channel_size);
 118
 119         result = ustcmd_send_cmd(cmd, pid, NULL);
 120         if (result != 1) {
 121                 free(cmd);
 122                 return 1;
 123         }
 124
 125         free(cmd);
 126         return 0;
 127 }
 128
 129 /**
 130  * Set subbuffer num.
 131  *
 132  * @param channel_num   Channel name and num
 133  * @param pid           Traced process ID
 134  * @return              0 if successful, or error
 135  */
 136 int ustcmd_set_subbuf_num(const char *channel_size, pid_t pid)
 137 {
 138         char *cmd;
 139         int result;
 140
 141         asprintf(&cmd, "%s %s", "set_subbuf_num", channel_size);
 142
 143         result = ustcmd_send_cmd(cmd, pid, NULL);
 144         if (result != 1) {
 145                 free(cmd);
 146                 return 1;
 147         }
 148
 149         free(cmd);
 150         return 0;
 151 }
 152
 153
 154 /**
 155  * Destroys an UST trace according to a PID.
 156  *
 157  * @param pid   Traced process ID
 158  * @return      0 if successful, or error USTCMD_ERR_GEN
 159  */
 160 int ustcmd_destroy_trace(pid_t pid)
 161 {
 162         int result;
 163
 164         result = ustcmd_send_cmd("trace_destroy", pid, NULL);
 165         if (result != 1) {
 166                 return USTCMD_ERR_GEN;
 167         }
 168
 169         return 0;
 170 }
 171
 172 /**
 173  * Starts an UST trace (and setups it) according to a PID.
 174  *
 175  * @param pid   Traced process ID
 176  * @return      0 if successful, or error USTCMD_ERR_GEN
 177  */
 178 int ustcmd_setup_and_start(pid_t pid)
 179 {
 180         int result;
 181
 182         result = ustcmd_send_cmd("start", pid, NULL);
 183         if (result != 1) {
 184                 return USTCMD_ERR_GEN;
 185         }
 186
 187         return 0;
 188 }
 189
 190 /**
 191  * Creates an UST trace according to a PID.
 192  *
 193  * @param pid   Traced process ID
 194  * @return      0 if successful, or error USTCMD_ERR_GEN
 195  */
 196 int ustcmd_create_trace(pid_t pid)
 197 {
 198         int result;
 199
 200         result = ustcmd_send_cmd("trace_create", pid, NULL);
 201         if (result != 1) {
 202                 return USTCMD_ERR_GEN;
 203         }
 204
 205         return 0;
 206 }
 207
 208 /**
 209  * Starts an UST trace according to a PID.
 210  *
 211  * @param pid   Traced process ID
 212  * @return      0 if successful, or error USTCMD_ERR_GEN
 213  */
 214 int ustcmd_start_trace(pid_t pid)
 215 {
 216         int result;
 217
 218         result = ustcmd_send_cmd("trace_start", pid, NULL);
 219         if (result != 1) {
 220                 return USTCMD_ERR_GEN;
 221         }
 222
 223         return 0;
 224 }
 225
 226 /**
 227  * Alloc an UST trace according to a PID.
 228  *
 229  * @param pid   Traced process ID
 230  * @return      0 if successful, or error USTCMD_ERR_GEN
 231  */
 232 int ustcmd_alloc_trace(pid_t pid)
 233 {
 234         int result;
 235
 236         result = ustcmd_send_cmd("trace_alloc", pid, NULL);
 237         if (result != 1) {
 238                 return USTCMD_ERR_GEN;
 239         }
 240
 241         return 0;
 242 }
 243
 244 /**
 245  * Stops an UST trace according to a PID.
 246  *
 247  * @param pid   Traced process ID
 248  * @return      0 if successful, or error USTCMD_ERR_GEN
 249  */
 250 int ustcmd_stop_trace(pid_t pid)
 251 {
 252         int result;
 253
 254         result = ustcmd_send_cmd("trace_stop", pid, NULL);
 255         if (result != 1) {
 256                 return USTCMD_ERR_GEN;
 257         }
 258
 259         return 0;
 260 }
 261
 262 /**
 263  * Counts newlines ('\n') in a string.
 264  *
 265  * @param str   String to search in
 266  * @return      Total newlines count
 267  */
 268 unsigned int ustcmd_count_nl(const char *str)
 269 {
 270         unsigned int i = 0, tot = 0;
 271
 272         while (str[i] != '\0') {
 273                 if (str[i] == '\n') {
 274                         ++tot;
 275                 }
 276                 ++i;
 277         }
 278
 279         return tot;
 280 }
 281
 282 /**
 283  * Frees a CMSF array.
 284  *
 285  * @param cmsf  CMSF array to free
 286  * @return      0 if successful, or error USTCMD_ERR_ARG
 287  */
 288 int ustcmd_free_cmsf(struct marker_status *cmsf)
 289 {
 290         if (cmsf == NULL) {
 291                 return USTCMD_ERR_ARG;
 292         }
 293
 294         unsigned int i = 0;
 295         while (cmsf[i].channel != NULL) {
 296                 free(cmsf[i].channel);
 297                 free(cmsf[i].marker);
 298                 free(cmsf[i].fs);
 299                 ++i;
 300         }
 301         free(cmsf);
 302
 303         return 0;
 304 }
 305
 306 /**
 307  * Gets channel/marker/state/format string for a given PID.
 308  *
 309  * @param cmsf  Pointer to CMSF array to be filled (callee allocates, caller
 310  *              frees with `ustcmd_free_cmsf')
 311  * @param pid   Targeted PID
 312  * @return      0 if successful, or -1 on error
 313  */
 314 int ustcmd_get_cmsf(struct marker_status **cmsf, const pid_t pid)
 315 {
 316         char *big_str = NULL;
 317         int result;
 318         struct marker_status *tmp_cmsf = NULL;
 319         unsigned int i = 0, cmsf_ind = 0;
 320
 321         if (cmsf == NULL) {
 322                 return -1;
 323         }
 324         result = ustcmd_send_cmd("list_markers", pid, &big_str);
 325         if (result != 1) {
 326                 return -1;
 327         }
 328
 329         if (result != 1) {
 330                 ERR("error while getting markers list");
 331                 return -1;
 332         }
 333
 334         tmp_cmsf = (struct marker_status *) malloc(sizeof(struct marker_status) *
 335                 (ustcmd_count_nl(big_str) + 1));
 336         if (tmp_cmsf == NULL) {
 337                 return -1;
 338         }
 339
 340         /* Parse received reply string (format: "[chan]/[mark] [st] [fs]"): */
 341         while (big_str[i] != '\0') {
 342                 char state;
 343
 344                 sscanf(big_str + i, "marker: %a[^/]/%a[^ ] %c %a[^\n]",
 345                         &tmp_cmsf[cmsf_ind].channel,
 346                         &tmp_cmsf[cmsf_ind].marker,
 347                         &state,
 348                         &tmp_cmsf[cmsf_ind].fs);
 349                 tmp_cmsf[cmsf_ind].state = (state == USTCMD_MS_CHR_ON ?
 350                         USTCMD_MS_ON : USTCMD_MS_OFF); /* Marker state */
 351
 352                 while (big_str[i] != '\n') {
 353                         ++i; /* Go to next '\n' */
 354                 }
 355                 ++i; /* Skip current pointed '\n' */
 356                 ++cmsf_ind;
 357         }
 358         tmp_cmsf[cmsf_ind].channel = NULL;
 359         tmp_cmsf[cmsf_ind].marker = NULL;
 360         tmp_cmsf[cmsf_ind].fs = NULL;
 361
 362         *cmsf = tmp_cmsf;
 363
 364         free(big_str);
 365         return 0;
 366 }
 367
 368 /**
 369  * Sends a given command to a traceable process
 370  *
 371  * @param cmd   Null-terminated command to send
 372  * @param pid   Targeted PID
 373  * @param reply Pointer to string to be filled with a reply string (must
 374  *              be NULL if no reply is needed for the given command).
 375  * @return      -1 if successful, 0 on EOT, 1 on success
 376  */
 377
 378 int ustcmd_send_cmd(const char *cmd, const pid_t pid, char **reply)
 379 {
 380         struct ustcomm_connection conn;
 381         int retval;
 382
 383         if (ustcomm_connect_app(pid, &conn)) {
 384                 ERR("could not connect to PID %u", (unsigned int) pid);
 385                 return -1;
 386         }
 387
 388         retval = ustcomm_send_request(&conn, cmd, reply);
 389
 390         ustcomm_close_app(&conn);
 391
 392         return retval;
 393 }