kconsumerd/kconsumerd.c

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18  */
  19
  20 #define _GNU_SOURCE
  21 #include <fcntl.h>
  22 #include <getopt.h>
  23 #include <grp.h>
  24 #include <limits.h>
  25 #include <pthread.h>
  26 #include <signal.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <sys/ipc.h>
  31 #include <sys/shm.h>
  32 #include <sys/socket.h>
  33 #include <sys/stat.h>
  34 #include <sys/types.h>
  35 #include <urcu/list.h>
  36 #include <poll.h>
  37 #include <unistd.h>
  38
  39 #include "lttngerr.h"
  40 #include "libkernelctl.h"
  41 #include "liblttsessiondcomm.h"
  42 #include "kconsumerd.h"
  43
  44 /* Init the list of FDs */
  45 static struct ltt_kconsumerd_fd_list kconsumerd_fd_list = {
  46         .head = CDS_LIST_HEAD_INIT(kconsumerd_fd_list.head),
  47 };
  48
  49 /* Number of element for the list below. */
  50 static unsigned int fds_count;
  51
  52 /* If the local array of FDs needs update in the poll function */
  53 static unsigned int update_fd_array = 1;
  54
  55 /* lock the fd array and structures */
  56 static pthread_mutex_t kconsumerd_lock_fds;
  57
  58 /* the two threads (receive fd and poll) */
  59 static pthread_t threads[2];
  60
  61 /* communication with splice */
  62 static int thread_pipe[2];
  63
  64 /* socket to communicate errors with sessiond */
  65 static int error_socket = -1;
  66
  67 /* Argument variables */
  68 int opt_quiet;
  69 int opt_verbose;
  70 static int opt_daemon;
  71 static const char *progname;
  72 static char command_sock_path[PATH_MAX]; /* Global command socket path */
  73 static char error_sock_path[PATH_MAX]; /* Global error path */
  74
  75 /*
  76  *  cleanup
  77  *
  78  *  Cleanup the daemon's socket on exit
  79  */
  80 static void cleanup()
  81 {
  82         unlink(command_sock_path);
  83 }
  84
  85 /* send_error
  86  *
  87  * send return code to ltt-sessiond
  88  */
  89 static int send_error(enum lttcomm_return_code cmd)
  90 {
  91         if (error_socket > 0) {
  92                 return lttcomm_send_unix_sock(error_socket, &cmd,
  93                                 sizeof(enum lttcomm_sessiond_command));
  94         } else {
  95                 return 0;
  96         }
  97 }
  98
  99 /*
 100  * cleanup_kconsumerd_fd
 101  *
 102  * Close the FDs and frees a ltt_kconsumerd_fd struct
 103  */
 104 static void cleanup_kconsumerd_fd(struct ltt_kconsumerd_fd *lcf)
 105 {
 106         if (lcf != NULL) {
 107                 close(lcf->out_fd);
 108                 close(lcf->consumerd_fd);
 109                 free(lcf);
 110                 lcf = NULL;
 111         }
 112 }
 113
 114 /*
 115  * add_fd
 116  *
 117  * Add a fd to the global list protected by a mutex
 118  */
 119 static int add_fd(struct lttcomm_kconsumerd_msg *buf, int consumerd_fd)
 120 {
 121         struct ltt_kconsumerd_fd *tmp_fd;
 122         int ret;
 123
 124         tmp_fd = malloc(sizeof(struct ltt_kconsumerd_fd));
 125         tmp_fd->sessiond_fd = buf->fd;
 126         tmp_fd->consumerd_fd = consumerd_fd;
 127         tmp_fd->state = buf->state;
 128         tmp_fd->max_sb_size = buf->max_sb_size;
 129         strncpy(tmp_fd->path_name, buf->path_name, PATH_MAX);
 130
 131         /* Opening the tracefile in write mode */
 132         DBG("Opening %s for writing", tmp_fd->path_name);
 133         ret = open(tmp_fd->path_name,
 134                         O_WRONLY|O_CREAT, S_IRWXU|S_IRWXG|S_IRWXO);
 135         if (ret < 0) {
 136                 ERR("Opening %s", tmp_fd->path_name);
 137                 perror("open");
 138                 goto end;
 139         }
 140         tmp_fd->out_fd = ret;
 141         tmp_fd->out_fd_offset = 0;
 142
 143         DBG("Adding %s (%d, %d, %d)", tmp_fd->path_name,
 144                         tmp_fd->sessiond_fd, tmp_fd->consumerd_fd, tmp_fd->out_fd);
 145
 146         pthread_mutex_lock(&kconsumerd_lock_fds);
 147         cds_list_add(&tmp_fd->list, &kconsumerd_fd_list.head);
 148         fds_count++;
 149         pthread_mutex_unlock(&kconsumerd_lock_fds);
 150
 151 end:
 152         return ret;
 153 }
 154
 155 /*
 156  * del_fd
 157  *
 158  * Remove a fd from the global list protected by a mutex
 159  */
 160 static void del_fd(struct ltt_kconsumerd_fd *lcf)
 161 {
 162         pthread_mutex_lock(&kconsumerd_lock_fds);
 163         cds_list_del(&lcf->list);
 164         if (fds_count > 0) {
 165                 fds_count--;
 166                 DBG("Removed ltt_kconsumerd_fd");
 167                 cleanup_kconsumerd_fd(lcf);
 168         }
 169         pthread_mutex_unlock(&kconsumerd_lock_fds);
 170 }
 171
 172 /*
 173  * close_outfds
 174  *
 175  * Close all fds in the previous fd_list
 176  * Must be used with kconsumerd_lock_fds lock held
 177  */
 178 static void close_outfds()
 179 {
 180         struct ltt_kconsumerd_fd *iter;
 181         cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) {
 182                 del_fd(iter);
 183         }
 184 }
 185
 186 /*
 187  *  sighandler
 188  *
 189  *  Signal handler for the daemon
 190  */
 191 static void sighandler(int sig)
 192 {
 193         /* unblock the threads */
 194         pthread_cancel(threads[0]);
 195         pthread_cancel(threads[1]);
 196
 197         close_outfds();
 198         cleanup();
 199
 200         return;
 201 }
 202
 203 /*
 204  *  set_signal_handler
 205  *
 206  *  Setup signal handler for :
 207  *      SIGINT, SIGTERM, SIGPIPE
 208  */
 209 static int set_signal_handler(void)
 210 {
 211         int ret = 0;
 212         struct sigaction sa;
 213         sigset_t sigset;
 214
 215         if ((ret = sigemptyset(&sigset)) < 0) {
 216                 perror("sigemptyset");
 217                 return ret;
 218         }
 219
 220         sa.sa_handler = sighandler;
 221         sa.sa_mask = sigset;
 222         sa.sa_flags = 0;
 223         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 224                 perror("sigaction");
 225                 return ret;
 226         }
 227
 228         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
 229                 perror("sigaction");
 230                 return ret;
 231         }
 232
 233         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
 234                 perror("sigaction");
 235                 return ret;
 236         }
 237
 238         return ret;
 239 }
 240
 241 /*
 242  * on_read_subbuffer
 243  *
 244  * Splice the data from the ring buffer to the tracefile.
 245  * Returns the number of bytes spliced
 246  */
 247 static int on_read_subbuffer(struct ltt_kconsumerd_fd *kconsumerd_fd,
 248                 unsigned long len)
 249 {
 250         long ret = 0;
 251         loff_t offset = 0;
 252         off_t orig_offset = kconsumerd_fd->out_fd_offset;
 253         int fd = kconsumerd_fd->consumerd_fd;
 254         int outfd = kconsumerd_fd->out_fd;
 255
 256         while (len > 0) {
 257                 DBG("splice chan to pipe offset %lu (fd : %d)",
 258                                 (unsigned long)offset, fd);
 259                 ret = splice(fd, &offset, thread_pipe[1], NULL, len,
 260                                 SPLICE_F_MOVE | SPLICE_F_MORE);
 261                 DBG("splice chan to pipe ret %ld", ret);
 262                 if (ret < 0) {
 263                         perror("Error in relay splice");
 264                         goto write_end;
 265                 }
 266
 267                 ret = splice(thread_pipe[0], NULL, outfd, NULL, ret,
 268                                 SPLICE_F_MOVE | SPLICE_F_MORE);
 269                 DBG("splice pipe to file %ld", ret);
 270                 if (ret < 0) {
 271                         perror("Error in file splice");
 272                         goto write_end;
 273                 }
 274                 if (ret >= len) {
 275                         len = 0;
 276                 }
 277                 /* This won't block, but will start writeout asynchronously */
 278                 sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret,
 279                                 SYNC_FILE_RANGE_WRITE);
 280                 kconsumerd_fd->out_fd_offset += ret;
 281         }
 282 write_end:
 283         /*
 284          * This does a blocking write-and-wait on any page that belongs to the
 285          * subbuffer prior to the one we just wrote.
 286          * Don't care about error values, as these are just hints and ways to
 287          * limit the amount of page cache used.
 288          */
 289         if (orig_offset >= kconsumerd_fd->max_sb_size) {
 290                 sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size,
 291                                 kconsumerd_fd->max_sb_size,
 292                                 SYNC_FILE_RANGE_WAIT_BEFORE
 293                                 | SYNC_FILE_RANGE_WRITE
 294                                 | SYNC_FILE_RANGE_WAIT_AFTER);
 295                 /*
 296                  * Give hints to the kernel about how we access the file:
 297                  * POSIX_FADV_DONTNEED : we won't re-access data in a near
 298                  * future after we write it.
 299                  * We need to call fadvise again after the file grows because
 300                  * the kernel does not seem to apply fadvise to non-existing
 301                  * parts of the file.
 302                  * Call fadvise _after_ having waited for the page writeback to
 303                  * complete because the dirty page writeback semantic is not
 304                  * well defined. So it can be expected to lead to lower
 305                  * throughput in streaming.
 306                  */
 307                 posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size,
 308                                 kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED);
 309         }
 310         return ret;
 311 }
 312
 313 /*
 314  * read_subbuffer
 315  *
 316  * Consume data on a file descriptor and write it on a trace file
 317  */
 318 static int read_subbuffer(struct ltt_kconsumerd_fd *kconsumerd_fd)
 319 {
 320         unsigned long len;
 321         int err;
 322         long ret = 0;
 323         int infd = kconsumerd_fd->consumerd_fd;
 324
 325         DBG("In read_subbuffer");
 326         /* Get the next subbuffer */
 327         err = kernctl_get_next_subbuf(infd);
 328         if (err != 0) {
 329                 ret = errno;
 330                 perror("Reserving sub buffer failed (everything is normal, "
 331                                 "it is due to concurrency)");
 332                 goto end;
 333         }
 334
 335         /* read the whole subbuffer */
 336         err = kernctl_get_padded_subbuf_size(infd, &len);
 337         if (err != 0) {
 338                 ret = errno;
 339                 perror("Getting sub-buffer len failed.");
 340                 goto end;
 341         }
 342
 343         /* splice the subbuffer to the tracefile */
 344         ret = on_read_subbuffer(kconsumerd_fd, len);
 345         if (ret < 0) {
 346                 /*
 347                  * display the error but continue processing to try
 348                  * to release the subbuffer
 349                  */
 350                 ERR("Error splicing to tracefile");
 351         }
 352
 353         err = kernctl_put_next_subbuf(infd);
 354         if (err != 0) {
 355                 ret = errno;
 356                 if (errno == EFAULT) {
 357                         perror("Error in unreserving sub buffer\n");
 358                 } else if (errno == EIO) {
 359                         /* Should never happen with newer LTTng versions */
 360                         perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
 361                 }
 362                 goto end;
 363         }
 364
 365 end:
 366         return ret;
 367 }
 368
 369 /*
 370  * change_fd_state
 371  *
 372  * Update a fd according to what we just received
 373  */
 374 static void change_fd_state(int sessiond_fd,
 375                 enum lttcomm_kconsumerd_fd_state state)
 376 {
 377         struct ltt_kconsumerd_fd *iter;
 378         cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) {
 379                 if (iter->sessiond_fd == sessiond_fd) {
 380                         iter->state = state;
 381                         break;
 382                 }
 383         }
 384 }
 385
 386 /*
 387  * consumerd_recv_fd
 388  *
 389  * Receives an array of file descriptors and the associated
 390  * structures describing each fd (path name).
 391  * Returns the size of received data
 392  */
 393 static int consumerd_recv_fd(int sfd, int size,
 394                 enum lttcomm_consumerd_command cmd_type)
 395 {
 396         struct msghdr msg;
 397         struct iovec iov[1];
 398         int ret, i;
 399         struct cmsghdr *cmsg;
 400         int nb_fd;
 401         char tmp[CMSG_SPACE(size)];
 402         struct lttcomm_kconsumerd_msg *buf;
 403         /* the number of fds we are about to receive */
 404         nb_fd = size/sizeof(struct lttcomm_kconsumerd_msg);
 405
 406         buf = malloc(size);
 407
 408         memset(&msg, 0, sizeof(msg));
 409
 410         /* Prepare to receive the structures */
 411         iov[0].iov_base = buf;
 412         iov[0].iov_len = size;
 413         msg.msg_iov = iov;
 414         msg.msg_iovlen = 1;
 415
 416         msg.msg_control = tmp;
 417         msg.msg_controllen = sizeof(tmp);
 418
 419         DBG("Waiting to receive fds");
 420         if ((ret = recvmsg(sfd, &msg, 0)) < 0) {
 421                 perror("recvmsg");
 422         }
 423         if (ret != size) {
 424                 ERR("Received only %d, expected %d", ret, size);
 425                 send_error(KCONSUMERD_ERROR_RECV_FD);
 426                 goto end;
 427         }
 428
 429         cmsg = CMSG_FIRSTHDR(&msg);
 430         if (!cmsg) {
 431                 ERR("Invalid control message header");
 432                 ret = -1;
 433                 send_error(KCONSUMERD_ERROR_RECV_FD);
 434                 goto end;
 435         }
 436
 437         /* if we received fds */
 438         if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
 439                 DBG("Receive : expecting %d fds", nb_fd);
 440                 for (i = 0; i < nb_fd; i++) {
 441                         switch (cmd_type) {
 442                                 case LTTCOMM_ADD_STREAM:
 443                                         DBG("add_fd %s (%d)", buf[i].path_name, ((int *)CMSG_DATA(cmsg))[i]);
 444                                         ret = add_fd(&buf[i], ((int *)CMSG_DATA(cmsg))[i]);
 445                                         if (ret < 0) {
 446                                                 send_error(KCONSUMERD_OUTFD_ERROR);
 447                                                 goto end;
 448                                         }
 449                                         break;
 450                                 case LTTCOMM_UPDATE_STREAM:
 451                                         change_fd_state(buf[i].fd, buf[i].state);
 452                                         break;
 453                                 default:
 454                                         break;
 455                         }
 456                 }
 457                 /* flag to tell the polling thread to update its fd array */
 458                 update_fd_array = 1;
 459                 send_error(KCONSUMERD_SUCCESS_RECV_FD);
 460         } else {
 461                 ERR("Didn't received any fd");
 462                 send_error(KCONSUMERD_ERROR_RECV_FD);
 463                 ret = -1;
 464                 goto end;
 465         }
 466
 467 end:
 468         if (buf != NULL) {
 469                 free(buf);
 470                 buf = NULL;
 471         }
 472         return ret;
 473 }
 474
 475 /*
 476  *  thread_receive_fds
 477  *
 478  *  This thread listens on the consumerd socket and
 479  *  receives the file descriptors from ltt-sessiond
 480  */
 481 static void *thread_receive_fds(void *data)
 482 {
 483         int sock, client_socket, ret;
 484         struct lttcomm_kconsumerd_header tmp;
 485
 486         DBG("Creating command socket %s", command_sock_path);
 487         unlink(command_sock_path);
 488         client_socket = lttcomm_create_unix_sock(command_sock_path);
 489         if (client_socket < 0) {
 490                 ERR("Cannot create command socket");
 491                 goto error;
 492         }
 493
 494         ret = lttcomm_listen_unix_sock(client_socket);
 495         if (ret < 0) {
 496                 goto error;
 497         }
 498
 499         DBG("Sending ready command to ltt-sessiond");
 500         ret = send_error(KCONSUMERD_COMMAND_SOCK_READY);
 501         if (ret < 0) {
 502                 ERR("Error sending ready command to ltt-sessiond");
 503                 goto error;
 504         }
 505
 506         while (1) {
 507                 /* Blocking call, waiting for transmission */
 508                 sock = lttcomm_accept_unix_sock(client_socket);
 509                 if (sock <= 0) {
 510                         continue;
 511                 }
 512
 513                 /* We first get the number of fd we are about to receive */
 514                 ret = lttcomm_recv_unix_sock(sock, &tmp,
 515                                 sizeof(struct lttcomm_kconsumerd_header));
 516                 if (ret < 0) {
 517                         ERR("Receiving the lttcomm_kconsumerd_header");
 518                         continue;
 519                 }
 520                 ret = consumerd_recv_fd(sock, tmp.payload_size, tmp.cmd_type);
 521                 if (ret < 0) {
 522                         continue;
 523                 }
 524         }
 525
 526 error:
 527         return NULL;
 528 }
 529
 530 /*
 531  * update_poll_array
 532  *
 533  * Allocate the pollfd structure and the local view of the out fds
 534  * to avoid doing a lookup in the linked list and concurrency issues
 535  * when writing is needed.
 536  * Returns the number of fds in the structures
 537  */
 538 static int update_poll_array(struct pollfd **pollfd,
 539                 struct ltt_kconsumerd_fd **local_kconsumerd_fd)
 540 {
 541         struct ltt_kconsumerd_fd *iter;
 542         int i = 0;
 543
 544         if (*pollfd != NULL) {
 545                 free(*pollfd);
 546                 *pollfd = NULL;
 547         }
 548
 549         if (*local_kconsumerd_fd != NULL) {
 550                 free(*local_kconsumerd_fd);
 551                 *local_kconsumerd_fd = NULL;
 552         }
 553
 554         *pollfd = malloc(fds_count * sizeof(struct pollfd));
 555         if (*pollfd == NULL) {
 556                 perror("pollfd malloc");
 557                 goto error_mem;
 558         }
 559
 560         *local_kconsumerd_fd = malloc(fds_count * sizeof(struct ltt_kconsumerd_fd));
 561         if (*local_kconsumerd_fd == NULL) {
 562                 perror("local_kconsumerd_fd malloc");
 563                 goto error_mem;
 564         }
 565
 566         DBG("Updating poll fd array");
 567         pthread_mutex_lock(&kconsumerd_lock_fds);
 568
 569         cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) {
 570                 DBG("Inside for each");
 571                 if (iter->state == ACTIVE_FD) {
 572                         DBG("Active FD %d", iter->consumerd_fd);
 573                         pollfd[i]->fd = iter->consumerd_fd;
 574                         pollfd[i]->events = POLLIN | POLLPRI;
 575                         local_kconsumerd_fd[i] = iter;
 576                         i++;
 577                 } else if (iter->state == DELETE_FD) {
 578                         del_fd(iter);
 579                 }
 580         }
 581         update_fd_array = 0;
 582         pthread_mutex_unlock(&kconsumerd_lock_fds);
 583         return i;
 584
 585 error_mem:
 586         return -ENOMEM;
 587 }
 588
 589 /*
 590  *  thread_poll_fds
 591  *
 592  *  This thread polls the fds in the ltt_fd_list to consume the data
 593  *  and write it to tracefile if necessary.
 594  */
 595 static void *thread_poll_fds(void *data)
 596 {
 597         int num_rdy, num_hup, high_prio, ret, i;
 598         struct pollfd *pollfd = NULL;
 599         /* local view of the fds */
 600         struct ltt_kconsumerd_fd *local_kconsumerd_fd = NULL;
 601         /* local view of fds_count */
 602         int nb_fd = 0;
 603
 604         ret = pipe(thread_pipe);
 605         if (ret < 0) {
 606                 perror("Error creating pipe");
 607                 goto end;
 608         }
 609
 610         while (1) {
 611                 high_prio = 0;
 612                 num_hup = 0;
 613
 614                 /*
 615                  * the ltt_fd_list has been updated, we need to update our
 616                  * local array as well
 617                  */
 618                 if (update_fd_array) {
 619                         ret = update_poll_array(&pollfd, &local_kconsumerd_fd);
 620                         if (ret < 0) {
 621                                 ERR("Error in allocating pollfd or local_outfds");
 622                                 send_error(KCONSUMERD_POLL_ERROR);
 623                                 goto end;
 624                         }
 625                         nb_fd = ret;
 626                 }
 627
 628                 /* poll on the array of fds */
 629                 DBG("polling on %d fd", nb_fd);
 630                 num_rdy = poll(pollfd, nb_fd, POLL_TIMEOUT);
 631                 DBG("poll num_rdy : %d", num_rdy);
 632                 if (num_rdy == -1) {
 633                         perror("Poll error");
 634                         send_error(KCONSUMERD_POLL_ERROR);
 635                         goto end;
 636                 }
 637
 638                 /* Take care of high priority channels first. */
 639                 for (i = 0; i < nb_fd; i++) {
 640                         switch(pollfd[i].revents) {
 641                                 case POLLERR:
 642                                         ERR("Error returned in polling fd %d.", pollfd[i].fd);
 643                                         num_hup++;
 644                                         send_error(KCONSUMERD_POLL_ERROR);
 645                                         break;
 646                                 case POLLHUP:
 647                                         ERR("Polling fd %d tells it has hung up.", pollfd[i].fd);
 648                                         num_hup++;
 649                                         break;
 650                                 case POLLNVAL:
 651                                         ERR("Polling fd %d tells fd is not open.", pollfd[i].fd);
 652                                         send_error(KCONSUMERD_POLL_NVAL);
 653                                         num_hup++;
 654                                         break;
 655                                 case POLLPRI:
 656                                         DBG("Urgent read on fd %d", pollfd[i].fd);
 657                                         high_prio = 1;
 658                                         ret = read_subbuffer(&local_kconsumerd_fd[i]);
 659                                         /* it's ok to have an unavailable sub-buffer (FIXME : is it ?) */
 660                                         if (ret == EAGAIN) {
 661                                                 ret = 0;
 662                                         }
 663                                         break;
 664                         }
 665                 }
 666
 667                 /* If every buffer FD has hung up, we end the read loop here */
 668                 if (nb_fd > 0 && num_hup == nb_fd) {
 669                         DBG("every buffer FD has hung up\n");
 670                         send_error(KCONSUMERD_POLL_HUP);
 671                         continue;
 672                 }
 673
 674                 /* Take care of low priority channels. */
 675                 if (!high_prio) {
 676                         for (i = 0; i < nb_fd; i++) {
 677                                 switch(pollfd[i].revents) {
 678                                         case POLLIN:
 679                                                 DBG("Normal read on fd %d", pollfd[i].fd);
 680                                                 ret = read_subbuffer(&local_kconsumerd_fd[i]);
 681                                                 /* it's ok to have an unavailable subbuffer (FIXME : is it ?) */
 682                                                 if (ret == EAGAIN) {
 683                                                         ret = 0;
 684                                                 }
 685                                                 break;
 686                                 }
 687                         }
 688                 }
 689         }
 690 end:
 691         if (pollfd != NULL) {
 692                 free(pollfd);
 693                 pollfd = NULL;
 694         }
 695         if (local_kconsumerd_fd != NULL) {
 696                 free(local_kconsumerd_fd);
 697                 local_kconsumerd_fd = NULL;
 698         }
 699         return NULL;
 700 }
 701
 702 /*
 703  * usage function on stderr
 704  */
 705 static void usage(void)
 706 {
 707         fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
 708         fprintf(stderr, "  -h, --help                         "
 709                         "Display this usage.\n");
 710         fprintf(stderr, "  -c, --kconsumerd-cmd-sock PATH     "
 711                         "Specify path for the command socket\n");
 712         fprintf(stderr, "  -e, --kconsumerd-err-sock PATH     "
 713                         "Specify path for the error socket\n");
 714         fprintf(stderr, "  -d, --daemonize                    "
 715                         "Start as a daemon.\n");
 716         fprintf(stderr, "  -q, --quiet                        "
 717                         "No output at all.\n");
 718         fprintf(stderr, "  -v, --verbose                      "
 719                         "Verbose mode. Activate DBG() macro.\n");
 720         fprintf(stderr, "  -V, --version                      "
 721                         "Show version number.\n");
 722 }
 723
 724 /*
 725  * daemon argument parsing
 726  */
 727 static void parse_args(int argc, char **argv)
 728 {
 729         int c;
 730
 731         static struct option long_options[] = {
 732                 { "kconsumerd-cmd-sock", 1, 0, 'c' },
 733                 { "kconsumerd-err-sock", 1, 0, 'e' },
 734                 { "daemonize", 0, 0, 'd' },
 735                 { "help", 0, 0, 'h' },
 736                 { "quiet", 0, 0, 'q' },
 737                 { "verbose", 0, 0, 'v' },
 738                 { "version", 0, 0, 'V' },
 739                 { NULL, 0, 0, 0 }
 740         };
 741
 742         while (1) {
 743                 int option_index = 0;
 744                 c = getopt_long(argc, argv, "dhqvV" "c:e:", long_options, &option_index);
 745                 if (c == -1) {
 746                         break;
 747                 }
 748
 749                 switch (c) {
 750                         case 0:
 751                                 fprintf(stderr, "option %s", long_options[option_index].name);
 752                                 if (optarg) {
 753                                         fprintf(stderr, " with arg %s\n", optarg);
 754                                 }
 755                                 break;
 756                         case 'c':
 757                                 snprintf(command_sock_path, PATH_MAX, "%s", optarg);
 758                                 break;
 759                         case 'e':
 760                                 snprintf(error_sock_path, PATH_MAX, "%s", optarg);
 761                                 break;
 762                         case 'd':
 763                                 opt_daemon = 1;
 764                                 break;
 765                         case 'h':
 766                                 usage();
 767                                 exit(EXIT_FAILURE);
 768                         case 'q':
 769                                 opt_quiet = 1;
 770                                 break;
 771                         case 'v':
 772                                 opt_verbose = 1;
 773                                 break;
 774                         case 'V':
 775                                 fprintf(stdout, "%s\n", VERSION);
 776                                 exit(EXIT_SUCCESS);
 777                         default:
 778                                 usage();
 779                                 exit(EXIT_FAILURE);
 780                 }
 781         }
 782 }
 783
 784
 785 /*
 786  * main
 787  */
 788 int main(int argc, char **argv)
 789 {
 790         int i;
 791         int ret = 0;
 792         void *status;
 793
 794         /* Parse arguments */
 795         progname = argv[0];
 796         parse_args(argc, argv);
 797
 798         /* Daemonize */
 799         if (opt_daemon) {
 800                 ret = daemon(0, 0);
 801                 if (ret < 0) {
 802                         perror("daemon");
 803                         goto error;
 804                 }
 805         }
 806
 807         if (strlen(command_sock_path) == 0) {
 808                 snprintf(command_sock_path, PATH_MAX,
 809                                 KCONSUMERD_CMD_SOCK_PATH);
 810         }
 811         if (strlen(error_sock_path) == 0) {
 812                 snprintf(error_sock_path, PATH_MAX,
 813                                 KCONSUMERD_ERR_SOCK_PATH);
 814         }
 815
 816         if (set_signal_handler() < 0) {
 817                 goto error;
 818         }
 819
 820         /* Connect to the socket created by ltt-sessiond to report errors */
 821         DBG("Connecting to error socket %s", error_sock_path);
 822         error_socket = lttcomm_connect_unix_sock(error_sock_path);
 823         /* not a fatal error, but all communication with ltt-sessiond will fail */
 824         if (error_socket < 0) {
 825                 WARN("Cannot connect to error socket, is ltt-sessiond started ?");
 826         }
 827
 828         /* Create the thread to manage the receive of fd */
 829         ret = pthread_create(&threads[0], NULL, thread_receive_fds, (void *) NULL);
 830         if (ret != 0) {
 831                 perror("pthread_create");
 832                 goto error;
 833         }
 834
 835         /* Create thread to manage the polling/writing of traces */
 836         ret = pthread_create(&threads[1], NULL, thread_poll_fds, (void *) NULL);
 837         if (ret != 0) {
 838                 perror("pthread_create");
 839                 goto error;
 840         }
 841
 842         for (i = 0; i < 2; i++) {
 843                 ret = pthread_join(threads[i], &status);
 844                 if (ret != 0) {
 845                         perror("pthread_join");
 846                         goto error;
 847                 }
 848         }
 849         ret = EXIT_SUCCESS;
 850         send_error(KCONSUMERD_EXIT_SUCCESS);
 851         goto end;
 852
 853 error:
 854         ret = EXIT_FAILURE;
 855         send_error(KCONSUMERD_EXIT_FAILURE);
 856
 857 end:
 858         cleanup();
 859
 860         return ret;
 861 }