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
  28 #include "ustcomm.h"
  29 #include "ustcmd.h"
  30
  31 #define _GNU_SOURCE
  32
  33 pid_t* ustcmd_get_online_pids(void) {
  34         struct dirent* dirent;
  35         DIR* dir;
  36         unsigned int ret_size = 1 * sizeof(pid_t), i = 0;
  37
  38         dir = opendir(SOCK_DIR);
  39         if (!dir) {
  40                 return NULL;
  41         }
  42
  43         pid_t* ret = (pid_t*) malloc(ret_size);
  44
  45         while (dirent = readdir(dir)) {
  46                 if (!strcmp(dirent->d_name, ".") ||
  47                         !strcmp(dirent->d_name, "..")) {
  48
  49                         continue;
  50                 }
  51
  52                 if (dirent->d_type != DT_DIR &&
  53                         !!strcmp(dirent->d_name, "ustd")) {
  54
  55                         sscanf(dirent->d_name, "%u", (unsigned int*) &ret[i]);
  56                         if (pid_is_online(ret[i])) {
  57                                 ret_size += sizeof(pid_t);
  58                                 ret = (pid_t*) realloc(ret, ret_size);
  59                                 ++i;
  60                         }
  61                 }
  62         }
  63
  64         ret[i] = 0; /* Array end */
  65
  66         if (ret[0] == 0) { /* 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_shoot(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  * Destroys an UST trace according to a PID.
 107  *
 108  * @param pid   Traced process ID
 109  * @return      0 if successful, or error USTCMD_ERR_GEN
 110  */
 111 int ustcmd_destroy_trace(pid_t pid) {
 112         int tres;
 113
 114         if (tres = ustcmd_shoot("destroy", pid, NULL)) {
 115                 return USTCMD_ERR_GEN;
 116         }
 117
 118         return 0;
 119 }
 120
 121 /**
 122  * Starts an UST trace (and setups it) according to a PID.
 123  *
 124  * @param pid   Traced process ID
 125  * @return      0 if successful, or error USTCMD_ERR_GEN
 126  */
 127 int ustcmd_setup_and_start(pid_t pid) {
 128         int tres;
 129
 130         if (tres = ustcmd_shoot("start", pid, NULL)) {
 131                 return USTCMD_ERR_GEN;
 132         }
 133
 134         return 0;
 135 }
 136
 137 /**
 138  * Starts an UST trace according to a PID.
 139  *
 140  * @param pid   Traced process ID
 141  * @return      0 if successful, or error USTCMD_ERR_GEN
 142  */
 143 int ustcmd_start_trace(pid_t pid) {
 144         int tres;
 145
 146         if (tres = ustcmd_shoot("trace_start", pid, NULL)) {
 147                 return USTCMD_ERR_GEN;
 148         }
 149
 150         return 0;
 151 }
 152
 153 /**
 154  * Stops an UST trace according to a PID.
 155  *
 156  * @param pid   Traced process ID
 157  * @return      0 if successful, or error USTCMD_ERR_GEN
 158  */
 159 int ustcmd_stop_trace(pid_t pid) {
 160         int tres;
 161
 162         if (tres = ustcmd_shoot("trace_stop", pid, NULL)) {
 163                 return USTCMD_ERR_GEN;
 164         }
 165
 166         return 0;
 167 }
 168
 169 /**
 170  * Counts newlines ('\n') in a string.
 171  *
 172  * @param str   String to search in
 173  * @return      Total newlines count
 174  */
 175 unsigned int ustcmd_count_nl(const char* str) {
 176         unsigned int i = 0, tot = 0;
 177
 178         while (str[i] != '\0') {
 179                 if (str[i] == '\n') {
 180                         ++tot;
 181                 }
 182                 ++i;
 183         }
 184
 185         return tot;
 186 }
 187
 188 /**
 189  * Frees a CMSF array.
 190  *
 191  * @param cmsf  CMSF array to free
 192  * @return      0 if successful, or error USTCMD_ERR_ARG
 193  */
 194 int ustcmd_free_cmsf(struct USTcmd_cmsf* cmsf) {
 195         if (cmsf == NULL) {
 196                 return USTCMD_ERR_ARG;
 197         }
 198
 199         unsigned int i = 0;
 200         while (cmsf[i].channel != NULL) {
 201                 free(cmsf[i].channel);
 202                 free(cmsf[i].marker);
 203                 free(cmsf[i].fs);
 204                 ++i;
 205         }
 206         free(cmsf);
 207
 208         return 0;
 209 }
 210
 211 /**
 212  * Gets channel/marker/state/format string for a given PID.
 213  *
 214  * @param cmsf  Pointer to CMSF array to be filled (callee allocates, caller
 215  *              frees with `ustcmd_free_cmsf')
 216  * @param pid   Targeted PID
 217  * @return      0 if successful, or errors {USTCMD_ERR_ARG, USTCMD_ERR_GEN}
 218  */
 219 int ustcmd_get_cmsf(struct USTcmd_cmsf** cmsf, const pid_t pid) {
 220         char* big_str = NULL;
 221         int result;
 222         struct USTcmd_cmsf* tmp_cmsf = NULL;
 223         unsigned int i = 0, cmsf_ind = 0;
 224
 225         if (cmsf == NULL) {
 226                 return USTCMD_ERR_ARG;
 227         }
 228         result = ustcmd_shoot("list_markers", pid, &big_str);
 229         if (result) {
 230                 return USTCMD_ERR_GEN;
 231         }
 232
 233         if (big_str == NULL) {
 234                 fprintf(stderr, "ustcmd: error while getting markers list\n");
 235                 return USTCMD_ERR_GEN;
 236         }
 237
 238         tmp_cmsf = (struct USTcmd_cmsf*) malloc(sizeof(struct USTcmd_cmsf) *
 239                 (ustcmd_count_nl(big_str) + 1));
 240         if (tmp_cmsf == NULL) {
 241                 return USTCMD_ERR_GEN;
 242         }
 243
 244         /* Parse received reply string (format: "[chan]/[mark] [st] [fs]"): */
 245         while (big_str[i] != '\0') {
 246                 char state;
 247
 248                 sscanf(big_str + i, "%a[^/]/%a[^ ] %c %a[^\n]",
 249                         &tmp_cmsf[cmsf_ind].channel,
 250                         &tmp_cmsf[cmsf_ind].marker,
 251                         &state,
 252                         &tmp_cmsf[cmsf_ind].fs);
 253                 tmp_cmsf[cmsf_ind].state = (state == USTCMD_MS_CHR_ON ?
 254                         USTCMD_MS_ON : USTCMD_MS_OFF); /* Marker state */
 255
 256                 while (big_str[i] != '\n') {
 257                         ++i; /* Go to next '\n' */
 258                 }
 259                 ++i; /* Skip current pointed '\n' */
 260                 ++cmsf_ind;
 261         }
 262         tmp_cmsf[cmsf_ind].channel = NULL;
 263         tmp_cmsf[cmsf_ind].marker = NULL;
 264         tmp_cmsf[cmsf_ind].fs = NULL;
 265
 266         *cmsf = tmp_cmsf;
 267
 268         free(big_str);
 269         return 0;
 270 }
 271
 272 /**
 273  * Shoots a given command using ustcomm.
 274  *
 275  * @param cmd   Null-terminated command to shoot
 276  * @param pid   Targeted PID
 277  * @param reply Pointer to string to be filled with a reply string (must
 278  *              be NULL if no reply is needed for the given command).
 279  * @return      0 if successful, or errors {USTCMD_ERR_ARG, USTCMD_ERR_CONN}
 280  */
 281 int ustcmd_shoot(const char* cmd, const pid_t pid, char** reply) {
 282         if (cmd == NULL) {
 283                 return USTCMD_ERR_ARG;
 284         }
 285
 286         if (ustcomm_connect_app(pid, &conn)) {
 287                 fprintf(stderr, "ustcmd_shoot: could not connect to PID %u\n",
 288                         (unsigned int) pid);
 289                 return USTCMD_ERR_CONN;
 290         }
 291
 292         ustcomm_send_request(&conn, cmd, reply);
 293
 294         return 0;
 295 }