| 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 modify |
| 6 | * it under the terms of the GNU General Public License, version 2 only, |
| 7 | * as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along |
| 15 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #define _GNU_SOURCE |
| 20 | #include <assert.h> |
| 21 | #include <poll.h> |
| 22 | #include <pthread.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <sys/mman.h> |
| 26 | #include <sys/socket.h> |
| 27 | #include <sys/types.h> |
| 28 | #include <unistd.h> |
| 29 | #include <sys/stat.h> |
| 30 | |
| 31 | #include <common/common.h> |
| 32 | #include <common/kernel-ctl/kernel-ctl.h> |
| 33 | #include <common/sessiond-comm/sessiond-comm.h> |
| 34 | #include <common/sessiond-comm/relayd.h> |
| 35 | #include <common/compat/fcntl.h> |
| 36 | #include <common/relayd/relayd.h> |
| 37 | |
| 38 | #include "kernel-consumer.h" |
| 39 | |
| 40 | extern struct lttng_consumer_global_data consumer_data; |
| 41 | extern int consumer_poll_timeout; |
| 42 | extern volatile int consumer_quit; |
| 43 | |
| 44 | /* |
| 45 | * Take a snapshot for a specific fd |
| 46 | * |
| 47 | * Returns 0 on success, < 0 on error |
| 48 | */ |
| 49 | int lttng_kconsumer_take_snapshot(struct lttng_consumer_local_data *ctx, |
| 50 | struct lttng_consumer_stream *stream) |
| 51 | { |
| 52 | int ret = 0; |
| 53 | int infd = stream->wait_fd; |
| 54 | |
| 55 | ret = kernctl_snapshot(infd); |
| 56 | if (ret != 0) { |
| 57 | errno = -ret; |
| 58 | perror("Getting sub-buffer snapshot."); |
| 59 | } |
| 60 | |
| 61 | return ret; |
| 62 | } |
| 63 | |
| 64 | /* |
| 65 | * Get the produced position |
| 66 | * |
| 67 | * Returns 0 on success, < 0 on error |
| 68 | */ |
| 69 | int lttng_kconsumer_get_produced_snapshot( |
| 70 | struct lttng_consumer_local_data *ctx, |
| 71 | struct lttng_consumer_stream *stream, |
| 72 | unsigned long *pos) |
| 73 | { |
| 74 | int ret; |
| 75 | int infd = stream->wait_fd; |
| 76 | |
| 77 | ret = kernctl_snapshot_get_produced(infd, pos); |
| 78 | if (ret != 0) { |
| 79 | errno = -ret; |
| 80 | perror("kernctl_snapshot_get_produced"); |
| 81 | } |
| 82 | |
| 83 | return ret; |
| 84 | } |
| 85 | |
| 86 | int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, |
| 87 | int sock, struct pollfd *consumer_sockpoll) |
| 88 | { |
| 89 | ssize_t ret; |
| 90 | struct lttcomm_consumer_msg msg; |
| 91 | |
| 92 | ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); |
| 93 | if (ret != sizeof(msg)) { |
| 94 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_CMD); |
| 95 | return ret; |
| 96 | } |
| 97 | if (msg.cmd_type == LTTNG_CONSUMER_STOP) { |
| 98 | return -ENOENT; |
| 99 | } |
| 100 | |
| 101 | /* relayd needs RCU read-side protection */ |
| 102 | rcu_read_lock(); |
| 103 | |
| 104 | switch (msg.cmd_type) { |
| 105 | case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: |
| 106 | { |
| 107 | int fd; |
| 108 | struct consumer_relayd_sock_pair *relayd; |
| 109 | |
| 110 | DBG("Consumer adding relayd socket"); |
| 111 | |
| 112 | /* Get relayd reference if exists. */ |
| 113 | relayd = consumer_find_relayd(msg.u.relayd_sock.net_index); |
| 114 | if (relayd == NULL) { |
| 115 | /* Not found. Allocate one. */ |
| 116 | relayd = consumer_allocate_relayd_sock_pair( |
| 117 | msg.u.relayd_sock.net_index); |
| 118 | if (relayd == NULL) { |
| 119 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); |
| 120 | goto end_nosignal; |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | /* Poll on consumer socket. */ |
| 125 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { |
| 126 | return -EINTR; |
| 127 | } |
| 128 | |
| 129 | /* Get relayd socket from session daemon */ |
| 130 | ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); |
| 131 | if (ret != sizeof(fd)) { |
| 132 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); |
| 133 | goto end_nosignal; |
| 134 | } |
| 135 | |
| 136 | /* Copy socket information and received FD */ |
| 137 | switch (msg.u.relayd_sock.type) { |
| 138 | case LTTNG_STREAM_CONTROL: |
| 139 | /* Copy received lttcomm socket */ |
| 140 | lttcomm_copy_sock(&relayd->control_sock, &msg.u.relayd_sock.sock); |
| 141 | |
| 142 | ret = lttcomm_create_sock(&relayd->control_sock); |
| 143 | if (ret < 0) { |
| 144 | goto end_nosignal; |
| 145 | } |
| 146 | |
| 147 | /* Close the created socket fd which is useless */ |
| 148 | close(relayd->control_sock.fd); |
| 149 | |
| 150 | /* Assign new file descriptor */ |
| 151 | relayd->control_sock.fd = fd; |
| 152 | break; |
| 153 | case LTTNG_STREAM_DATA: |
| 154 | /* Copy received lttcomm socket */ |
| 155 | lttcomm_copy_sock(&relayd->data_sock, &msg.u.relayd_sock.sock); |
| 156 | ret = lttcomm_create_sock(&relayd->data_sock); |
| 157 | if (ret < 0) { |
| 158 | goto end_nosignal; |
| 159 | } |
| 160 | |
| 161 | /* Close the created socket fd which is useless */ |
| 162 | close(relayd->data_sock.fd); |
| 163 | |
| 164 | /* Assign new file descriptor */ |
| 165 | relayd->data_sock.fd = fd; |
| 166 | break; |
| 167 | default: |
| 168 | ERR("Unknown relayd socket type"); |
| 169 | goto end_nosignal; |
| 170 | } |
| 171 | |
| 172 | DBG("Consumer %s socket created successfully with net idx %d (fd: %d)", |
| 173 | msg.u.relayd_sock.type == LTTNG_STREAM_CONTROL ? "control" : "data", |
| 174 | relayd->net_seq_idx, fd); |
| 175 | |
| 176 | /* |
| 177 | * Add relayd socket pair to consumer data hashtable. If object already |
| 178 | * exists or on error, the function gracefully returns. |
| 179 | */ |
| 180 | consumer_add_relayd(relayd); |
| 181 | |
| 182 | goto end_nosignal; |
| 183 | } |
| 184 | case LTTNG_CONSUMER_ADD_CHANNEL: |
| 185 | { |
| 186 | struct lttng_consumer_channel *new_channel; |
| 187 | |
| 188 | DBG("consumer_add_channel %d", msg.u.channel.channel_key); |
| 189 | new_channel = consumer_allocate_channel(msg.u.channel.channel_key, |
| 190 | -1, -1, |
| 191 | msg.u.channel.mmap_len, |
| 192 | msg.u.channel.max_sb_size); |
| 193 | if (new_channel == NULL) { |
| 194 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); |
| 195 | goto end_nosignal; |
| 196 | } |
| 197 | if (ctx->on_recv_channel != NULL) { |
| 198 | ret = ctx->on_recv_channel(new_channel); |
| 199 | if (ret == 0) { |
| 200 | consumer_add_channel(new_channel); |
| 201 | } else if (ret < 0) { |
| 202 | goto end_nosignal; |
| 203 | } |
| 204 | } else { |
| 205 | consumer_add_channel(new_channel); |
| 206 | } |
| 207 | goto end_nosignal; |
| 208 | } |
| 209 | case LTTNG_CONSUMER_ADD_STREAM: |
| 210 | { |
| 211 | int fd; |
| 212 | struct consumer_relayd_sock_pair *relayd = NULL; |
| 213 | struct lttng_consumer_stream *new_stream; |
| 214 | |
| 215 | /* block */ |
| 216 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { |
| 217 | return -EINTR; |
| 218 | } |
| 219 | |
| 220 | /* Get stream file descriptor from socket */ |
| 221 | ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); |
| 222 | if (ret != sizeof(fd)) { |
| 223 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); |
| 224 | return ret; |
| 225 | } |
| 226 | |
| 227 | new_stream = consumer_allocate_stream(msg.u.stream.channel_key, |
| 228 | msg.u.stream.stream_key, |
| 229 | fd, fd, |
| 230 | msg.u.stream.state, |
| 231 | msg.u.stream.mmap_len, |
| 232 | msg.u.stream.output, |
| 233 | msg.u.stream.path_name, |
| 234 | msg.u.stream.uid, |
| 235 | msg.u.stream.gid, |
| 236 | msg.u.stream.net_index, |
| 237 | msg.u.stream.metadata_flag); |
| 238 | if (new_stream == NULL) { |
| 239 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); |
| 240 | goto end; |
| 241 | } |
| 242 | |
| 243 | /* The stream is not metadata. Get relayd reference if exists. */ |
| 244 | relayd = consumer_find_relayd(msg.u.stream.net_index); |
| 245 | if (relayd != NULL) { |
| 246 | /* Add stream on the relayd */ |
| 247 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); |
| 248 | ret = relayd_add_stream(&relayd->control_sock, |
| 249 | msg.u.stream.name, msg.u.stream.path_name, |
| 250 | &new_stream->relayd_stream_id); |
| 251 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); |
| 252 | if (ret < 0) { |
| 253 | goto end; |
| 254 | } |
| 255 | } else if (msg.u.stream.net_index != -1) { |
| 256 | ERR("Network sequence index %d unknown. Not adding stream.", |
| 257 | msg.u.stream.net_index); |
| 258 | free(new_stream); |
| 259 | goto end; |
| 260 | } |
| 261 | |
| 262 | if (ctx->on_recv_stream != NULL) { |
| 263 | ret = ctx->on_recv_stream(new_stream); |
| 264 | if (ret == 0) { |
| 265 | consumer_add_stream(new_stream); |
| 266 | } else if (ret < 0) { |
| 267 | goto end; |
| 268 | } |
| 269 | } else { |
| 270 | consumer_add_stream(new_stream); |
| 271 | } |
| 272 | |
| 273 | DBG("Kernel consumer_add_stream (%d)", fd); |
| 274 | break; |
| 275 | } |
| 276 | case LTTNG_CONSUMER_UPDATE_STREAM: |
| 277 | { |
| 278 | if (ctx->on_update_stream != NULL) { |
| 279 | ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state); |
| 280 | if (ret == 0) { |
| 281 | consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state); |
| 282 | } else if (ret < 0) { |
| 283 | goto end; |
| 284 | } |
| 285 | } else { |
| 286 | consumer_change_stream_state(msg.u.stream.stream_key, |
| 287 | msg.u.stream.state); |
| 288 | } |
| 289 | break; |
| 290 | } |
| 291 | default: |
| 292 | break; |
| 293 | } |
| 294 | end: |
| 295 | /* |
| 296 | * Wake-up the other end by writing a null byte in the pipe |
| 297 | * (non-blocking). Important note: Because writing into the |
| 298 | * pipe is non-blocking (and therefore we allow dropping wakeup |
| 299 | * data, as long as there is wakeup data present in the pipe |
| 300 | * buffer to wake up the other end), the other end should |
| 301 | * perform the following sequence for waiting: |
| 302 | * 1) empty the pipe (reads). |
| 303 | * 2) perform update operation. |
| 304 | * 3) wait on the pipe (poll). |
| 305 | */ |
| 306 | do { |
| 307 | ret = write(ctx->consumer_poll_pipe[1], "", 1); |
| 308 | } while (ret < 0 && errno == EINTR); |
| 309 | end_nosignal: |
| 310 | rcu_read_unlock(); |
| 311 | return 0; |
| 312 | } |
| 313 | |
| 314 | /* |
| 315 | * Consume data on a file descriptor and write it on a trace file. |
| 316 | */ |
| 317 | ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream, |
| 318 | struct lttng_consumer_local_data *ctx) |
| 319 | { |
| 320 | unsigned long len; |
| 321 | int err; |
| 322 | ssize_t ret = 0; |
| 323 | int infd = stream->wait_fd; |
| 324 | |
| 325 | DBG("In read_subbuffer (infd : %d)", infd); |
| 326 | /* Get the next subbuffer */ |
| 327 | err = kernctl_get_next_subbuf(infd); |
| 328 | if (err != 0) { |
| 329 | /* |
| 330 | * This is a debug message even for single-threaded consumer, |
| 331 | * because poll() have more relaxed criterions than get subbuf, |
| 332 | * so get_subbuf may fail for short race windows where poll() |
| 333 | * would issue wakeups. |
| 334 | */ |
| 335 | DBG("Reserving sub buffer failed (everything is normal, " |
| 336 | "it is due to concurrency)"); |
| 337 | goto end; |
| 338 | } |
| 339 | |
| 340 | switch (stream->output) { |
| 341 | case LTTNG_EVENT_SPLICE: |
| 342 | /* read the whole subbuffer */ |
| 343 | err = kernctl_get_padded_subbuf_size(infd, &len); |
| 344 | if (err != 0) { |
| 345 | errno = -ret; |
| 346 | perror("Getting sub-buffer len failed."); |
| 347 | goto end; |
| 348 | } |
| 349 | |
| 350 | /* splice the subbuffer to the tracefile */ |
| 351 | ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, len); |
| 352 | if (ret != len) { |
| 353 | /* |
| 354 | * display the error but continue processing to try |
| 355 | * to release the subbuffer |
| 356 | */ |
| 357 | ERR("Error splicing to tracefile (ret: %ld != len: %ld)", |
| 358 | ret, len); |
| 359 | } |
| 360 | |
| 361 | break; |
| 362 | case LTTNG_EVENT_MMAP: |
| 363 | /* read the used subbuffer size */ |
| 364 | err = kernctl_get_padded_subbuf_size(infd, &len); |
| 365 | if (err != 0) { |
| 366 | errno = -ret; |
| 367 | perror("Getting sub-buffer len failed."); |
| 368 | goto end; |
| 369 | } |
| 370 | /* write the subbuffer to the tracefile */ |
| 371 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len); |
| 372 | if (ret != len) { |
| 373 | /* |
| 374 | * display the error but continue processing to try |
| 375 | * to release the subbuffer |
| 376 | */ |
| 377 | ERR("Error writing to tracefile"); |
| 378 | } |
| 379 | break; |
| 380 | default: |
| 381 | ERR("Unknown output method"); |
| 382 | ret = -1; |
| 383 | } |
| 384 | |
| 385 | err = kernctl_put_next_subbuf(infd); |
| 386 | if (err != 0) { |
| 387 | errno = -ret; |
| 388 | if (errno == EFAULT) { |
| 389 | perror("Error in unreserving sub buffer\n"); |
| 390 | } else if (errno == EIO) { |
| 391 | /* Should never happen with newer LTTng versions */ |
| 392 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); |
| 393 | } |
| 394 | goto end; |
| 395 | } |
| 396 | |
| 397 | end: |
| 398 | return ret; |
| 399 | } |
| 400 | |
| 401 | int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream) |
| 402 | { |
| 403 | int ret; |
| 404 | |
| 405 | /* Opening the tracefile in write mode */ |
| 406 | if (strlen(stream->path_name) > 0 && stream->net_seq_idx == -1) { |
| 407 | ret = run_as_open(stream->path_name, |
| 408 | O_WRONLY|O_CREAT|O_TRUNC, |
| 409 | S_IRWXU|S_IRWXG|S_IRWXO, |
| 410 | stream->uid, stream->gid); |
| 411 | if (ret < 0) { |
| 412 | ERR("Opening %s", stream->path_name); |
| 413 | perror("open"); |
| 414 | goto error; |
| 415 | } |
| 416 | stream->out_fd = ret; |
| 417 | } |
| 418 | |
| 419 | if (stream->output == LTTNG_EVENT_MMAP) { |
| 420 | /* get the len of the mmap region */ |
| 421 | unsigned long mmap_len; |
| 422 | |
| 423 | ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len); |
| 424 | if (ret != 0) { |
| 425 | errno = -ret; |
| 426 | perror("kernctl_get_mmap_len"); |
| 427 | goto error_close_fd; |
| 428 | } |
| 429 | stream->mmap_len = (size_t) mmap_len; |
| 430 | |
| 431 | stream->mmap_base = mmap(NULL, stream->mmap_len, |
| 432 | PROT_READ, MAP_PRIVATE, stream->wait_fd, 0); |
| 433 | if (stream->mmap_base == MAP_FAILED) { |
| 434 | perror("Error mmaping"); |
| 435 | ret = -1; |
| 436 | goto error_close_fd; |
| 437 | } |
| 438 | } |
| 439 | |
| 440 | /* we return 0 to let the library handle the FD internally */ |
| 441 | return 0; |
| 442 | |
| 443 | error_close_fd: |
| 444 | { |
| 445 | int err; |
| 446 | |
| 447 | err = close(stream->out_fd); |
| 448 | assert(!err); |
| 449 | } |
| 450 | error: |
| 451 | return ret; |
| 452 | } |
| 453 | |