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 "ust/ustcmd.h"
  29 #include "usterr.h"
  30
  31 static int do_cmd(const pid_t pid,
  32                   const struct ustcomm_header *req_header,
  33                   const char *req_data,
  34                   struct ustcomm_header *res_header,
  35                   char **res_data)
  36 {
  37         int app_fd, result, saved_errno = 0;
  38         char *recv_buf;
  39
  40         if (ustcomm_connect_app(pid, &app_fd)) {
  41                 ERR("could not connect to PID %u", (unsigned int) pid);
  42                 errno = ENOTCONN;
  43                 return -1;
  44         }
  45
  46         recv_buf = zmalloc(USTCOMM_BUFFER_SIZE);
  47         if (!recv_buf) {
  48                 saved_errno = ENOMEM;
  49                 goto close_app_fd;
  50         }
  51
  52         result = ustcomm_req(app_fd, req_header, req_data, res_header, recv_buf);
  53         if (result > 0) {
  54                 saved_errno = -res_header->result;
  55                 if (res_header->size == 0 || saved_errno > 0) {
  56                         free(recv_buf);
  57                 } else {
  58                         if (res_data) {
  59                                 *res_data = recv_buf;
  60                         } else {
  61                                 free(recv_buf);
  62                         }
  63                 }
  64         } else {
  65                 ERR("ustcomm req failed");
  66                 if (result == 0) {
  67                         saved_errno = ENOTCONN;
  68                 } else {
  69                         saved_errno = -result;
  70                 }
  71                 free(recv_buf);
  72         }
  73
  74 close_app_fd:
  75         close(app_fd);
  76
  77         errno = saved_errno;
  78
  79         if (errno) {
  80                 return -1;
  81         }
  82
  83         return 0;
  84 }
  85
  86 pid_t *ustcmd_get_online_pids(void)
  87 {
  88         struct dirent *dirent;
  89         DIR *dir;
  90         unsigned int ret_size = 1 * sizeof(pid_t), i = 0;
  91
  92         dir = opendir(SOCK_DIR);
  93         if (!dir) {
  94                 return NULL;
  95         }
  96
  97         pid_t *ret = (pid_t *) malloc(ret_size);
  98
  99         while ((dirent = readdir(dir))) {
 100                 if (!strcmp(dirent->d_name, ".") ||
 101                     !strcmp(dirent->d_name, "..")) {
 102
 103                         continue;
 104                 }
 105
 106                 if (dirent->d_type != DT_DIR &&
 107                     !!strcmp(dirent->d_name, "ustd")) {
 108
 109                         sscanf(dirent->d_name, "%u", (unsigned int *) &ret[i]);
 110                         /* FIXME: Here we previously called pid_is_online, which
 111                          * always returned 1, now I replaced it with just 1.
 112                          * We need to figure out an intelligent way of solving
 113                          * this, maybe connect-disconnect.
 114                          */
 115                         if (1) {
 116                                 ret_size += sizeof(pid_t);
 117                                 ret = (pid_t *) realloc(ret, ret_size);
 118                                 ++i;
 119                         }
 120                 }
 121         }
 122
 123         ret[i] = 0; /* Array end */
 124
 125         if (ret[0] == 0) {
 126                 /* No PID at all */
 127                 free(ret);
 128                 return NULL;
 129         }
 130
 131         closedir(dir);
 132         return ret;
 133 }
 134
 135 /**
 136  * Sets marker state (USTCMD_MS_ON or USTCMD_MS_OFF).
 137  *
 138  * @param mn    Marker name
 139  * @param state Marker's new state
 140  * @param pid   Traced process ID
 141  * @return      0 if successful, or errors {USTCMD_ERR_GEN, USTCMD_ERR_ARG}
 142  */
 143 int ustcmd_set_marker_state(const char *trace, const char *channel,
 144                             const char *marker, int state, pid_t pid)
 145 {
 146         struct ustcomm_header req_header, res_header;
 147         struct ustcomm_marker_info marker_inf;
 148         int result;
 149
 150         result = ustcomm_pack_marker_info(&req_header,
 151                                           &marker_inf,
 152                                           trace,
 153                                           channel,
 154                                           marker);
 155         if (result < 0) {
 156                 errno = -result;
 157                 return -1;
 158         }
 159
 160         req_header.command = state ? ENABLE_MARKER : DISABLE_MARKER;
 161
 162         return do_cmd(pid, &req_header, (char *)&marker_inf,
 163                       &res_header, NULL);
 164 }
 165
 166 /**
 167  * Set subbuffer size.
 168  *
 169  * @param channel_size  Channel name and size
 170  * @param pid           Traced process ID
 171  * @return              0 if successful, or error
 172  */
 173 int ustcmd_set_subbuf_size(const char *trace, const char *channel,
 174                            unsigned int subbuf_size, pid_t pid)
 175 {
 176         struct ustcomm_header req_header, res_header;
 177         struct ustcomm_channel_info ch_inf;
 178         int result;
 179
 180         result = ustcomm_pack_channel_info(&req_header,
 181                                            &ch_inf,
 182                                            trace,
 183                                            channel);
 184         if (result < 0) {
 185                 errno = -result;
 186                 return -1;
 187         }
 188
 189         req_header.command = SET_SUBBUF_SIZE;
 190         ch_inf.subbuf_size = subbuf_size;
 191
 192         return do_cmd(pid, &req_header, (char *)&ch_inf,
 193                       &res_header, NULL);
 194 }
 195
 196 /**
 197  * Set subbuffer num.
 198  *
 199  * @param channel_num   Channel name and num
 200  * @param pid           Traced process ID
 201  * @return              0 if successful, or error
 202  */
 203 int ustcmd_set_subbuf_num(const char *trace, const char *channel,
 204                           unsigned int num, pid_t pid)
 205 {
 206         struct ustcomm_header req_header, res_header;
 207         struct ustcomm_channel_info ch_inf;
 208         int result;
 209
 210         result = ustcomm_pack_channel_info(&req_header,
 211                                            &ch_inf,
 212                                            trace,
 213                                            channel);
 214         if (result < 0) {
 215                 errno = -result;
 216                 return -1;
 217         }
 218
 219         req_header.command = SET_SUBBUF_NUM;
 220         ch_inf.subbuf_num = num;
 221
 222         return do_cmd(pid, &req_header, (char *)&ch_inf,
 223                       &res_header, NULL);
 224
 225 }
 226
 227 static int ustcmd_get_subbuf_num_size(const char *trace, const char *channel,
 228                                       pid_t pid, int *num, int *size)
 229 {
 230         struct ustcomm_header req_header, res_header;
 231         struct ustcomm_channel_info ch_inf, *ch_inf_res;
 232         int result;
 233
 234
 235         result = ustcomm_pack_channel_info(&req_header,
 236                                            &ch_inf,
 237                                            trace,
 238                                            channel);
 239         if (result < 0) {
 240                 errno = -result;
 241                 return -1;
 242         }
 243
 244         req_header.command = GET_SUBBUF_NUM_SIZE;
 245
 246         result = do_cmd(pid, &req_header, (char *)&ch_inf,
 247                         &res_header, (char **)&ch_inf_res);
 248         if (result < 0) {
 249                 return -1;
 250         }
 251
 252         *num = ch_inf_res->subbuf_num;
 253         *size = ch_inf_res->subbuf_size;
 254
 255         free(ch_inf_res);
 256
 257         return 0;
 258 }
 259
 260 /**
 261  * Get subbuffer num.
 262  *
 263  * @param channel       Channel name
 264  * @param pid           Traced process ID
 265  * @return              subbuf cnf if successful, or error
 266  */
 267 int ustcmd_get_subbuf_num(const char *trace, const char *channel, pid_t pid)
 268 {
 269         int num, size, result;
 270
 271         result = ustcmd_get_subbuf_num_size(trace, channel, pid,
 272                                             &num, &size);
 273         if (result < 0) {
 274                 errno = -result;
 275                 return -1;
 276         }
 277
 278         return num;
 279 }
 280
 281 /**
 282  * Get subbuffer size.
 283  *
 284  * @param channel       Channel name
 285  * @param pid           Traced process ID
 286  * @return              subbuf size if successful, or error
 287  */
 288 int ustcmd_get_subbuf_size(const char *trace, const char *channel, pid_t pid)
 289 {
 290         int num, size, result;
 291
 292         result = ustcmd_get_subbuf_num_size(trace, channel, pid,
 293                                             &num, &size);
 294         if (result < 0) {
 295                 errno = -result;
 296                 return -1;
 297         }
 298
 299         return size;
 300 }
 301
 302
 303 static int do_trace_cmd(const char *trace, pid_t pid, int command)
 304 {
 305         struct ustcomm_header req_header, res_header;
 306         struct ustcomm_single_field trace_inf;
 307         int result;
 308
 309         result = ustcomm_pack_single_field(&req_header,
 310                                            &trace_inf,
 311                                            trace);
 312         if (result < 0) {
 313                 errno = -result;
 314                 return -1;
 315         }
 316
 317         req_header.command = command;
 318
 319         return do_cmd(pid, &req_header, (char *)&trace_inf, &res_header, NULL);
 320 }
 321
 322 /**
 323  * Destroys an UST trace according to a PID.
 324  *
 325  * @param pid   Traced process ID
 326  * @return      0 if successful, or error USTCMD_ERR_GEN
 327  */
 328 int ustcmd_destroy_trace(const char *trace, pid_t pid)
 329 {
 330         return do_trace_cmd(trace, pid, DESTROY_TRACE);
 331 }
 332
 333 /**
 334  * Starts an UST trace (and setups it) according to a PID.
 335  *
 336  * @param pid   Traced process ID
 337  * @return      0 if successful, or error USTCMD_ERR_GEN
 338  */
 339 int ustcmd_setup_and_start(const char *trace, pid_t pid)
 340 {
 341         return do_trace_cmd(trace, pid, START);
 342 }
 343
 344 /**
 345  * Creates an UST trace according to a PID.
 346  *
 347  * @param pid   Traced process ID
 348  * @return      0 if successful, or error USTCMD_ERR_GEN
 349  */
 350 int ustcmd_create_trace(const char *trace, pid_t pid)
 351 {
 352         return do_trace_cmd(trace, pid, CREATE_TRACE);
 353 }
 354
 355 /**
 356  * Starts an UST trace according to a PID.
 357  *
 358  * @param pid   Traced process ID
 359  * @return      0 if successful, or error USTCMD_ERR_GEN
 360  */
 361 int ustcmd_start_trace(const char *trace, pid_t pid)
 362 {
 363         return do_trace_cmd(trace, pid, START_TRACE);
 364 }
 365
 366 /**
 367  * Alloc an UST trace according to a PID.
 368  *
 369  * @param pid   Traced process ID
 370  * @return      0 if successful, or error USTCMD_ERR_GEN
 371  */
 372 int ustcmd_alloc_trace(const char *trace, pid_t pid)
 373 {
 374         return do_trace_cmd(trace, pid, ALLOC_TRACE);
 375 }
 376
 377 /**
 378  * Stops an UST trace according to a PID.
 379  *
 380  * @param pid   Traced process ID
 381  * @return      0 if successful, or error USTCMD_ERR_GEN
 382  */
 383 int ustcmd_stop_trace(const char *trace, pid_t pid)
 384 {
 385         return do_trace_cmd(trace, pid, STOP_TRACE);
 386 }
 387
 388 /**
 389  * Counts newlines ('\n') in a string.
 390  *
 391  * @param str   String to search in
 392  * @return      Total newlines count
 393  */
 394 unsigned int ustcmd_count_nl(const char *str)
 395 {
 396         unsigned int i = 0, tot = 0;
 397
 398         while (str[i] != '\0') {
 399                 if (str[i] == '\n') {
 400                         ++tot;
 401                 }
 402                 ++i;
 403         }
 404
 405         return tot;
 406 }
 407
 408 /**
 409  * Frees a CMSF array.
 410  *
 411  * @param cmsf  CMSF array to free
 412  * @return      0 if successful, or error USTCMD_ERR_ARG
 413  */
 414 int ustcmd_free_cmsf(struct marker_status *cmsf)
 415 {
 416         if (cmsf == NULL) {
 417                 return USTCMD_ERR_ARG;
 418         }
 419
 420         unsigned int i = 0;
 421         while (cmsf[i].channel != NULL) {
 422                 free(cmsf[i].channel);
 423                 free(cmsf[i].marker);
 424                 free(cmsf[i].fs);
 425                 ++i;
 426         }
 427         free(cmsf);
 428
 429         return 0;
 430 }
 431
 432 /**
 433  * Gets channel/marker/state/format string for a given PID.
 434  *
 435  * @param cmsf  Pointer to CMSF array to be filled (callee allocates, caller
 436  *              frees with `ustcmd_free_cmsf')
 437  * @param pid   Targeted PID
 438  * @return      0 if successful, or -1 on error
 439  */
 440 int ustcmd_get_cmsf(struct marker_status **cmsf, const pid_t pid)
 441 {
 442         struct ustcomm_header req_header, res_header;
 443         char *big_str = NULL;
 444         int result, app_fd;
 445         struct marker_status *tmp_cmsf = NULL;
 446         unsigned int i = 0, cmsf_ind = 0;
 447
 448         if (cmsf == NULL) {
 449                 return -1;
 450         }
 451
 452         if (ustcomm_connect_app(pid, &app_fd)) {
 453                 ERR("could not connect to PID %u", (unsigned int) pid);
 454                 return -1;
 455         }
 456
 457         req_header.command = LIST_MARKERS;
 458         req_header.size = 0;
 459
 460         result = ustcomm_send(app_fd, &req_header, NULL);
 461         if (result <= 0) {
 462                 PERROR("error while requesting markers list for process %d", pid);
 463                 return -1;
 464         }
 465
 466         result = ustcomm_recv_alloc(app_fd, &res_header, &big_str);
 467         if (result <= 0) {
 468                 ERR("error while receiving markers list");
 469                 return -1;
 470         }
 471
 472         close(app_fd);
 473
 474         tmp_cmsf = (struct marker_status *) zmalloc(sizeof(struct marker_status) *
 475                                                     (ustcmd_count_nl(big_str) + 1));
 476         if (tmp_cmsf == NULL) {
 477                 ERR("Failed to allocate CMSF array");
 478                 return -1;
 479         }
 480
 481         /* Parse received reply string (format: "[chan]/[mark] [st] [fs]"): */
 482         while (big_str[i] != '\0') {
 483                 char state;
 484
 485                 sscanf(big_str + i, "marker: %a[^/]/%a[^ ] %c %a[^\n]",
 486                        &tmp_cmsf[cmsf_ind].channel,
 487                        &tmp_cmsf[cmsf_ind].marker,
 488                        &state,
 489                        &tmp_cmsf[cmsf_ind].fs);
 490                 tmp_cmsf[cmsf_ind].state = (state == USTCMD_MS_CHR_ON ?
 491                                             USTCMD_MS_ON : USTCMD_MS_OFF); /* Marker state */
 492
 493                 while (big_str[i] != '\n') {
 494                         ++i; /* Go to next '\n' */
 495                 }
 496                 ++i; /* Skip current pointed '\n' */
 497                 ++cmsf_ind;
 498         }
 499         tmp_cmsf[cmsf_ind].channel = NULL;
 500         tmp_cmsf[cmsf_ind].marker = NULL;
 501         tmp_cmsf[cmsf_ind].fs = NULL;
 502
 503         *cmsf = tmp_cmsf;
 504
 505         free(big_str);
 506         return 0;
 507 }
 508
 509
 510 /**
 511  * Frees a TES array.
 512  *
 513  * @param tes   TES array to free
 514  * @return      0 if successful, or error USTCMD_ERR_ARG
 515  */
 516 int ustcmd_free_tes(struct trace_event_status *tes)
 517 {
 518         if (tes == NULL) {
 519                 return USTCMD_ERR_ARG;
 520         }
 521
 522         unsigned int i = 0;
 523         while (tes[i].name != NULL) {
 524                 free(tes[i].name);
 525                 ++i;
 526         }
 527         free(tes);
 528
 529         return 0;
 530 }
 531
 532 /**
 533  * Gets trace_events string for a given PID.
 534  *
 535  * @param tes   Pointer to TES array to be filled (callee allocates, caller
 536  *              frees with `ustcmd_free_tes')
 537  * @param pid   Targeted PID
 538  * @return      0 if successful, or -1 on error
 539  */
 540 int ustcmd_get_tes(struct trace_event_status **tes,
 541                    const pid_t pid)
 542 {
 543         struct ustcomm_header req_header, res_header;
 544         char *big_str = NULL;
 545         int result, app_fd;
 546         struct trace_event_status *tmp_tes = NULL;
 547         unsigned int i = 0, tes_ind = 0;
 548
 549         if (tes == NULL) {
 550                 return -1;
 551         }
 552
 553         if (ustcomm_connect_app(pid, &app_fd)) {
 554                 ERR("could not connect to PID %u", (unsigned int) pid);
 555                 return -1;
 556         }
 557
 558         req_header.command = LIST_TRACE_EVENTS;
 559         req_header.size = 0;
 560
 561         result = ustcomm_send(app_fd, &req_header, NULL);
 562         if (result != 1) {
 563                 ERR("error while requesting trace_event list");
 564                 return -1;
 565         }
 566
 567         result = ustcomm_recv_alloc(app_fd, &res_header, &big_str);
 568         if (result != 1) {
 569                 ERR("error while receiving markers list");
 570                 return -1;
 571         }
 572
 573         close(app_fd);
 574
 575         tmp_tes = (struct trace_event_status *)
 576                 zmalloc(sizeof(struct trace_event_status) *
 577                         (ustcmd_count_nl(big_str) + 1));
 578         if (tmp_tes == NULL) {
 579                 ERR("Failed to allocate TES array");
 580                 return -1;
 581         }
 582
 583         /* Parse received reply string (format: "[name]"): */
 584         while (big_str[i] != '\0') {
 585                 sscanf(big_str + i, "trace_event: %a[^\n]",
 586                        &tmp_tes[tes_ind].name);
 587                 while (big_str[i] != '\n') {
 588                         ++i; /* Go to next '\n' */
 589                 }
 590                 ++i; /* Skip current pointed '\n' */
 591                 ++tes_ind;
 592         }
 593         tmp_tes[tes_ind].name = NULL;
 594
 595         *tes = tmp_tes;
 596
 597         free(big_str);
 598         return 0;
 599 }
 600
 601 /**
 602  * Set socket path
 603  *
 604  * @param sock_path     Socket path
 605  * @param pid           Traced process ID
 606  * @return              0 if successful, or error
 607  */
 608 int ustcmd_set_sock_path(const char *sock_path, pid_t pid)
 609 {
 610         int result;
 611         struct ustcomm_header req_header, res_header;
 612         struct ustcomm_single_field sock_path_msg;
 613
 614         result = ustcomm_pack_single_field(&req_header,
 615                                            &sock_path_msg,
 616                                            sock_path);
 617         if (result < 0) {
 618                 errno = -result;
 619                 return -1;
 620         }
 621
 622         req_header.command = SET_SOCK_PATH;
 623
 624         return do_cmd(pid, &req_header, (char *)&sock_path_msg,
 625                       &res_header, NULL);
 626 }
 627
 628 /**
 629  * Get socket path
 630  *
 631  * @param sock_path     Pointer to where the socket path will be returned
 632  * @param pid           Traced process ID
 633  * @return              0 if successful, or error
 634  */
 635 int ustcmd_get_sock_path(char **sock_path, pid_t pid)
 636 {
 637         int result;
 638         struct ustcomm_header req_header, res_header;
 639         struct ustcomm_single_field *sock_path_msg;
 640
 641         req_header.command = GET_SOCK_PATH;
 642         req_header.size = 0;
 643
 644         result = do_cmd(pid, &req_header, NULL, &res_header,
 645                         (char **)&sock_path_msg);
 646         if (result < 0) {
 647                 return -1;
 648         }
 649
 650         result = ustcomm_unpack_single_field(sock_path_msg);
 651         if (result < 0) {
 652                 return result;
 653         }
 654
 655         *sock_path = strdup(sock_path_msg->field);
 656
 657         free(sock_path_msg);
 658
 659         return 0;
 660 }
 661
 662 int ustcmd_force_switch(pid_t pid)
 663 {
 664         struct ustcomm_header req_header, res_header;
 665
 666         req_header.command = FORCE_SUBBUF_SWITCH;
 667         req_header.size = 0;
 668
 669         return do_cmd(pid, &req_header, NULL, &res_header, NULL);
 670 }
 671