| 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; only version 2 |
| 8 | * of the License. |
| 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 | #include <sys/mman.h> |
| 39 | #include <assert.h> |
| 40 | |
| 41 | #include <ltt-kconsumerd.h> |
| 42 | #include <lttng-kernel-ctl.h> |
| 43 | #include <lttng-sessiond-comm.h> |
| 44 | #include <lttng/lttng-kconsumerd.h> |
| 45 | #include <lttngerr.h> |
| 46 | |
| 47 | /* the two threads (receive fd and poll) */ |
| 48 | static pthread_t threads[2]; |
| 49 | |
| 50 | /* to count the number of time the user pressed ctrl+c */ |
| 51 | static int sigintcount = 0; |
| 52 | |
| 53 | /* Argument variables */ |
| 54 | int opt_quiet; |
| 55 | int opt_verbose; |
| 56 | static int opt_daemon; |
| 57 | static const char *progname; |
| 58 | static char command_sock_path[PATH_MAX]; /* Global command socket path */ |
| 59 | static char error_sock_path[PATH_MAX]; /* Global error path */ |
| 60 | |
| 61 | /* the liblttngkconsumerd context */ |
| 62 | static struct lttng_kconsumerd_local_data *ctx; |
| 63 | |
| 64 | /* |
| 65 | * Signal handler for the daemon |
| 66 | */ |
| 67 | static void sighandler(int sig) |
| 68 | { |
| 69 | if (sig == SIGINT && sigintcount++ == 0) { |
| 70 | DBG("ignoring first SIGINT"); |
| 71 | return; |
| 72 | } |
| 73 | |
| 74 | lttng_kconsumerd_should_exit(ctx); |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * Setup signal handler for : |
| 79 | * SIGINT, SIGTERM, SIGPIPE |
| 80 | */ |
| 81 | static int set_signal_handler(void) |
| 82 | { |
| 83 | int ret = 0; |
| 84 | struct sigaction sa; |
| 85 | sigset_t sigset; |
| 86 | |
| 87 | if ((ret = sigemptyset(&sigset)) < 0) { |
| 88 | perror("sigemptyset"); |
| 89 | return ret; |
| 90 | } |
| 91 | |
| 92 | sa.sa_handler = sighandler; |
| 93 | sa.sa_mask = sigset; |
| 94 | sa.sa_flags = 0; |
| 95 | if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) { |
| 96 | perror("sigaction"); |
| 97 | return ret; |
| 98 | } |
| 99 | |
| 100 | if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) { |
| 101 | perror("sigaction"); |
| 102 | return ret; |
| 103 | } |
| 104 | |
| 105 | if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) { |
| 106 | perror("sigaction"); |
| 107 | return ret; |
| 108 | } |
| 109 | |
| 110 | return ret; |
| 111 | } |
| 112 | |
| 113 | /* |
| 114 | * usage function on stderr |
| 115 | */ |
| 116 | static void usage(void) |
| 117 | { |
| 118 | fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname); |
| 119 | fprintf(stderr, " -h, --help " |
| 120 | "Display this usage.\n"); |
| 121 | fprintf(stderr, " -c, --kconsumerd-cmd-sock PATH " |
| 122 | "Specify path for the command socket\n"); |
| 123 | fprintf(stderr, " -e, --kconsumerd-err-sock PATH " |
| 124 | "Specify path for the error socket\n"); |
| 125 | fprintf(stderr, " -d, --daemonize " |
| 126 | "Start as a daemon.\n"); |
| 127 | fprintf(stderr, " -q, --quiet " |
| 128 | "No output at all.\n"); |
| 129 | fprintf(stderr, " -v, --verbose " |
| 130 | "Verbose mode. Activate DBG() macro.\n"); |
| 131 | fprintf(stderr, " -V, --version " |
| 132 | "Show version number.\n"); |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | * daemon argument parsing |
| 137 | */ |
| 138 | static void parse_args(int argc, char **argv) |
| 139 | { |
| 140 | int c; |
| 141 | |
| 142 | static struct option long_options[] = { |
| 143 | { "kconsumerd-cmd-sock", 1, 0, 'c' }, |
| 144 | { "kconsumerd-err-sock", 1, 0, 'e' }, |
| 145 | { "daemonize", 0, 0, 'd' }, |
| 146 | { "help", 0, 0, 'h' }, |
| 147 | { "quiet", 0, 0, 'q' }, |
| 148 | { "verbose", 0, 0, 'v' }, |
| 149 | { "version", 0, 0, 'V' }, |
| 150 | { NULL, 0, 0, 0 } |
| 151 | }; |
| 152 | |
| 153 | while (1) { |
| 154 | int option_index = 0; |
| 155 | c = getopt_long(argc, argv, "dhqvV" "c:e:", long_options, &option_index); |
| 156 | if (c == -1) { |
| 157 | break; |
| 158 | } |
| 159 | |
| 160 | switch (c) { |
| 161 | case 0: |
| 162 | fprintf(stderr, "option %s", long_options[option_index].name); |
| 163 | if (optarg) { |
| 164 | fprintf(stderr, " with arg %s\n", optarg); |
| 165 | } |
| 166 | break; |
| 167 | case 'c': |
| 168 | snprintf(command_sock_path, PATH_MAX, "%s", optarg); |
| 169 | break; |
| 170 | case 'e': |
| 171 | snprintf(error_sock_path, PATH_MAX, "%s", optarg); |
| 172 | break; |
| 173 | case 'd': |
| 174 | opt_daemon = 1; |
| 175 | break; |
| 176 | case 'h': |
| 177 | usage(); |
| 178 | exit(EXIT_FAILURE); |
| 179 | case 'q': |
| 180 | opt_quiet = 1; |
| 181 | break; |
| 182 | case 'v': |
| 183 | opt_verbose = 1; |
| 184 | break; |
| 185 | case 'V': |
| 186 | fprintf(stdout, "%s\n", VERSION); |
| 187 | exit(EXIT_SUCCESS); |
| 188 | default: |
| 189 | usage(); |
| 190 | exit(EXIT_FAILURE); |
| 191 | } |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | /* |
| 196 | * Consume data on a file descriptor and write it on a trace file. |
| 197 | */ |
| 198 | static int read_subbuffer(struct lttng_kconsumerd_fd *kconsumerd_fd) |
| 199 | { |
| 200 | unsigned long len; |
| 201 | int err; |
| 202 | long ret = 0; |
| 203 | int infd = kconsumerd_fd->consumerd_fd; |
| 204 | |
| 205 | DBG("In kconsumerd_read_subbuffer (infd : %d)", infd); |
| 206 | /* Get the next subbuffer */ |
| 207 | err = kernctl_get_next_subbuf(infd); |
| 208 | if (err != 0) { |
| 209 | ret = errno; |
| 210 | /* |
| 211 | * This is a debug message even for single-threaded consumer, |
| 212 | * because poll() have more relaxed criterions than get subbuf, |
| 213 | * so get_subbuf may fail for short race windows where poll() |
| 214 | * would issue wakeups. |
| 215 | */ |
| 216 | DBG("Reserving sub buffer failed (everything is normal, " |
| 217 | "it is due to concurrency)"); |
| 218 | goto end; |
| 219 | } |
| 220 | |
| 221 | switch (kconsumerd_fd->output) { |
| 222 | case LTTNG_EVENT_SPLICE: |
| 223 | /* read the whole subbuffer */ |
| 224 | err = kernctl_get_padded_subbuf_size(infd, &len); |
| 225 | if (err != 0) { |
| 226 | ret = errno; |
| 227 | perror("Getting sub-buffer len failed."); |
| 228 | goto end; |
| 229 | } |
| 230 | |
| 231 | /* splice the subbuffer to the tracefile */ |
| 232 | ret = lttng_kconsumerd_on_read_subbuffer_splice(ctx, kconsumerd_fd, len); |
| 233 | if (ret < 0) { |
| 234 | /* |
| 235 | * display the error but continue processing to try |
| 236 | * to release the subbuffer |
| 237 | */ |
| 238 | ERR("Error splicing to tracefile"); |
| 239 | } |
| 240 | break; |
| 241 | case LTTNG_EVENT_MMAP: |
| 242 | /* read the used subbuffer size */ |
| 243 | err = kernctl_get_padded_subbuf_size(infd, &len); |
| 244 | if (err != 0) { |
| 245 | ret = errno; |
| 246 | perror("Getting sub-buffer len failed."); |
| 247 | goto end; |
| 248 | } |
| 249 | /* write the subbuffer to the tracefile */ |
| 250 | ret = lttng_kconsumerd_on_read_subbuffer_mmap(ctx, kconsumerd_fd, len); |
| 251 | if (ret < 0) { |
| 252 | /* |
| 253 | * display the error but continue processing to try |
| 254 | * to release the subbuffer |
| 255 | */ |
| 256 | ERR("Error writing to tracefile"); |
| 257 | } |
| 258 | break; |
| 259 | default: |
| 260 | ERR("Unknown output method"); |
| 261 | ret = -1; |
| 262 | } |
| 263 | |
| 264 | err = kernctl_put_next_subbuf(infd); |
| 265 | if (err != 0) { |
| 266 | ret = errno; |
| 267 | if (errno == EFAULT) { |
| 268 | perror("Error in unreserving sub buffer\n"); |
| 269 | } else if (errno == EIO) { |
| 270 | /* Should never happen with newer LTTng versions */ |
| 271 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); |
| 272 | } |
| 273 | goto end; |
| 274 | } |
| 275 | |
| 276 | end: |
| 277 | return ret; |
| 278 | } |
| 279 | |
| 280 | static int on_recv_fd(struct lttng_kconsumerd_fd *kconsumerd_fd) |
| 281 | { |
| 282 | int ret; |
| 283 | |
| 284 | /* Opening the tracefile in write mode */ |
| 285 | if (kconsumerd_fd->path_name != NULL) { |
| 286 | ret = open(kconsumerd_fd->path_name, |
| 287 | O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO); |
| 288 | if (ret < 0) { |
| 289 | ERR("Opening %s", kconsumerd_fd->path_name); |
| 290 | perror("open"); |
| 291 | goto error; |
| 292 | } |
| 293 | kconsumerd_fd->out_fd = ret; |
| 294 | } |
| 295 | |
| 296 | if (kconsumerd_fd->output == LTTNG_EVENT_MMAP) { |
| 297 | /* get the len of the mmap region */ |
| 298 | unsigned long mmap_len; |
| 299 | |
| 300 | ret = kernctl_get_mmap_len(kconsumerd_fd->consumerd_fd, &mmap_len); |
| 301 | if (ret != 0) { |
| 302 | ret = errno; |
| 303 | perror("kernctl_get_mmap_len"); |
| 304 | goto error_close_fd; |
| 305 | } |
| 306 | kconsumerd_fd->mmap_len = (size_t) mmap_len; |
| 307 | |
| 308 | kconsumerd_fd->mmap_base = mmap(NULL, kconsumerd_fd->mmap_len, |
| 309 | PROT_READ, MAP_PRIVATE, kconsumerd_fd->consumerd_fd, 0); |
| 310 | if (kconsumerd_fd->mmap_base == MAP_FAILED) { |
| 311 | perror("Error mmaping"); |
| 312 | ret = -1; |
| 313 | goto error_close_fd; |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | /* we return 0 to let the library handle the FD internally */ |
| 318 | return 0; |
| 319 | |
| 320 | error_close_fd: |
| 321 | { |
| 322 | int err; |
| 323 | |
| 324 | err = close(kconsumerd_fd->out_fd); |
| 325 | assert(!err); |
| 326 | } |
| 327 | error: |
| 328 | return ret; |
| 329 | } |
| 330 | |
| 331 | /* |
| 332 | * main |
| 333 | */ |
| 334 | int main(int argc, char **argv) |
| 335 | { |
| 336 | int i; |
| 337 | int ret = 0; |
| 338 | void *status; |
| 339 | |
| 340 | /* Parse arguments */ |
| 341 | progname = argv[0]; |
| 342 | parse_args(argc, argv); |
| 343 | |
| 344 | /* Daemonize */ |
| 345 | if (opt_daemon) { |
| 346 | ret = daemon(0, 0); |
| 347 | if (ret < 0) { |
| 348 | perror("daemon"); |
| 349 | goto error; |
| 350 | } |
| 351 | } |
| 352 | |
| 353 | if (strlen(command_sock_path) == 0) { |
| 354 | snprintf(command_sock_path, PATH_MAX, |
| 355 | KCONSUMERD_CMD_SOCK_PATH); |
| 356 | } |
| 357 | /* create the consumer instance with and assign the callbacks */ |
| 358 | ctx = lttng_kconsumerd_create(read_subbuffer, on_recv_fd, NULL); |
| 359 | if (ctx == NULL) { |
| 360 | goto error; |
| 361 | } |
| 362 | |
| 363 | lttng_kconsumerd_set_command_sock_path(ctx, command_sock_path); |
| 364 | if (strlen(error_sock_path) == 0) { |
| 365 | snprintf(error_sock_path, PATH_MAX, |
| 366 | KCONSUMERD_ERR_SOCK_PATH); |
| 367 | } |
| 368 | |
| 369 | if (set_signal_handler() < 0) { |
| 370 | goto error; |
| 371 | } |
| 372 | |
| 373 | /* Connect to the socket created by ltt-sessiond to report errors */ |
| 374 | DBG("Connecting to error socket %s", error_sock_path); |
| 375 | ret = lttcomm_connect_unix_sock(error_sock_path); |
| 376 | /* not a fatal error, but all communication with ltt-sessiond will fail */ |
| 377 | if (ret < 0) { |
| 378 | WARN("Cannot connect to error socket, is ltt-sessiond started ?"); |
| 379 | } |
| 380 | lttng_kconsumerd_set_error_sock(ctx, ret); |
| 381 | |
| 382 | /* Create the thread to manage the receive of fd */ |
| 383 | ret = pthread_create(&threads[0], NULL, lttng_kconsumerd_thread_receive_fds, |
| 384 | (void *) ctx); |
| 385 | if (ret != 0) { |
| 386 | perror("pthread_create"); |
| 387 | goto error; |
| 388 | } |
| 389 | |
| 390 | /* Create thread to manage the polling/writing of traces */ |
| 391 | ret = pthread_create(&threads[1], NULL, lttng_kconsumerd_thread_poll_fds, |
| 392 | (void *) ctx); |
| 393 | if (ret != 0) { |
| 394 | perror("pthread_create"); |
| 395 | goto error; |
| 396 | } |
| 397 | |
| 398 | for (i = 0; i < 2; i++) { |
| 399 | ret = pthread_join(threads[i], &status); |
| 400 | if (ret != 0) { |
| 401 | perror("pthread_join"); |
| 402 | goto error; |
| 403 | } |
| 404 | } |
| 405 | ret = EXIT_SUCCESS; |
| 406 | lttng_kconsumerd_send_error(ctx, KCONSUMERD_EXIT_SUCCESS); |
| 407 | goto end; |
| 408 | |
| 409 | error: |
| 410 | ret = EXIT_FAILURE; |
| 411 | lttng_kconsumerd_send_error(ctx, KCONSUMERD_EXIT_FAILURE); |
| 412 | |
| 413 | end: |
| 414 | lttng_kconsumerd_destroy(ctx); |
| 415 | lttng_kconsumerd_cleanup(); |
| 416 | |
| 417 | return ret; |
| 418 | } |