| 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 <lttng/ust-ctl.h> |
| 22 | #include <poll.h> |
| 23 | #include <pthread.h> |
| 24 | #include <stdlib.h> |
| 25 | #include <string.h> |
| 26 | #include <sys/mman.h> |
| 27 | #include <sys/socket.h> |
| 28 | #include <sys/stat.h> |
| 29 | #include <sys/types.h> |
| 30 | #include <inttypes.h> |
| 31 | #include <unistd.h> |
| 32 | #include <urcu/list.h> |
| 33 | |
| 34 | #include <common/common.h> |
| 35 | #include <common/sessiond-comm/sessiond-comm.h> |
| 36 | #include <common/relayd/relayd.h> |
| 37 | #include <common/compat/fcntl.h> |
| 38 | |
| 39 | #include "ust-consumer.h" |
| 40 | |
| 41 | extern struct lttng_consumer_global_data consumer_data; |
| 42 | extern int consumer_poll_timeout; |
| 43 | extern volatile int consumer_quit; |
| 44 | |
| 45 | /* |
| 46 | * Free channel object and all streams associated with it. This MUST be used |
| 47 | * only and only if the channel has _NEVER_ been added to the global channel |
| 48 | * hash table. |
| 49 | */ |
| 50 | static void destroy_channel(struct lttng_consumer_channel *channel) |
| 51 | { |
| 52 | struct lttng_consumer_stream *stream, *stmp; |
| 53 | |
| 54 | assert(channel); |
| 55 | |
| 56 | DBG("UST consumer cleaning stream list"); |
| 57 | |
| 58 | cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head, |
| 59 | send_node) { |
| 60 | cds_list_del(&stream->send_node); |
| 61 | ustctl_destroy_stream(stream->ustream); |
| 62 | free(stream); |
| 63 | } |
| 64 | |
| 65 | /* |
| 66 | * If a channel is available meaning that was created before the streams |
| 67 | * were, delete it. |
| 68 | */ |
| 69 | if (channel->uchan) { |
| 70 | lttng_ustconsumer_del_channel(channel); |
| 71 | } |
| 72 | free(channel); |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * Add channel to internal consumer state. |
| 77 | * |
| 78 | * Returns 0 on success or else a negative value. |
| 79 | */ |
| 80 | static int add_channel(struct lttng_consumer_channel *channel, |
| 81 | struct lttng_consumer_local_data *ctx) |
| 82 | { |
| 83 | int ret = 0; |
| 84 | |
| 85 | assert(channel); |
| 86 | assert(ctx); |
| 87 | |
| 88 | if (ctx->on_recv_channel != NULL) { |
| 89 | ret = ctx->on_recv_channel(channel); |
| 90 | if (ret == 0) { |
| 91 | ret = consumer_add_channel(channel); |
| 92 | } else if (ret < 0) { |
| 93 | /* Most likely an ENOMEM. */ |
| 94 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); |
| 95 | goto error; |
| 96 | } |
| 97 | } else { |
| 98 | ret = consumer_add_channel(channel); |
| 99 | } |
| 100 | |
| 101 | DBG("UST consumer channel added (key: %u)", channel->key); |
| 102 | |
| 103 | error: |
| 104 | return ret; |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * Allocate and return a consumer channel object. |
| 109 | */ |
| 110 | static struct lttng_consumer_channel *allocate_channel(uint64_t session_id, |
| 111 | const char *pathname, const char *name, uid_t uid, gid_t gid, |
| 112 | int relayd_id, unsigned long key, enum lttng_event_output output) |
| 113 | { |
| 114 | assert(pathname); |
| 115 | assert(name); |
| 116 | |
| 117 | return consumer_allocate_channel(key, session_id, pathname, name, uid, gid, |
| 118 | relayd_id, output); |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the |
| 123 | * error value if applicable is set in it else it is kept untouched. |
| 124 | * |
| 125 | * Return NULL on error else the newly allocated stream object. |
| 126 | */ |
| 127 | static struct lttng_consumer_stream *allocate_stream(int cpu, int key, |
| 128 | struct lttng_consumer_channel *channel, |
| 129 | struct lttng_consumer_local_data *ctx, int *_alloc_ret) |
| 130 | { |
| 131 | int alloc_ret; |
| 132 | struct lttng_consumer_stream *stream = NULL; |
| 133 | |
| 134 | assert(channel); |
| 135 | assert(ctx); |
| 136 | |
| 137 | stream = consumer_allocate_stream(channel->key, |
| 138 | key, |
| 139 | LTTNG_CONSUMER_ACTIVE_STREAM, |
| 140 | channel->name, |
| 141 | channel->uid, |
| 142 | channel->gid, |
| 143 | channel->relayd_id, |
| 144 | channel->session_id, |
| 145 | cpu, |
| 146 | &alloc_ret, |
| 147 | channel->type); |
| 148 | if (stream == NULL) { |
| 149 | switch (alloc_ret) { |
| 150 | case -ENOENT: |
| 151 | /* |
| 152 | * We could not find the channel. Can happen if cpu hotplug |
| 153 | * happens while tearing down. |
| 154 | */ |
| 155 | DBG3("Could not find channel"); |
| 156 | break; |
| 157 | case -ENOMEM: |
| 158 | case -EINVAL: |
| 159 | default: |
| 160 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); |
| 161 | break; |
| 162 | } |
| 163 | goto error; |
| 164 | } |
| 165 | |
| 166 | stream->chan = channel; |
| 167 | |
| 168 | error: |
| 169 | if (_alloc_ret) { |
| 170 | *_alloc_ret = alloc_ret; |
| 171 | } |
| 172 | return stream; |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * Send the given stream pointer to the corresponding thread. |
| 177 | * |
| 178 | * Returns 0 on success else a negative value. |
| 179 | */ |
| 180 | static int send_stream_to_thread(struct lttng_consumer_stream *stream, |
| 181 | struct lttng_consumer_local_data *ctx) |
| 182 | { |
| 183 | int ret, stream_pipe; |
| 184 | |
| 185 | /* Get the right pipe where the stream will be sent. */ |
| 186 | if (stream->metadata_flag) { |
| 187 | stream_pipe = ctx->consumer_metadata_pipe[1]; |
| 188 | } else { |
| 189 | stream_pipe = ctx->consumer_data_pipe[1]; |
| 190 | } |
| 191 | |
| 192 | do { |
| 193 | ret = write(stream_pipe, &stream, sizeof(stream)); |
| 194 | } while (ret < 0 && errno == EINTR); |
| 195 | if (ret < 0) { |
| 196 | PERROR("Consumer write %s stream to pipe %d", |
| 197 | stream->metadata_flag ? "metadata" : "data", stream_pipe); |
| 198 | } |
| 199 | |
| 200 | return ret; |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * Search for a relayd object related to the stream. If found, send the stream |
| 205 | * to the relayd. |
| 206 | * |
| 207 | * On success, returns 0 else a negative value. |
| 208 | */ |
| 209 | static int send_stream_to_relayd(struct lttng_consumer_stream *stream) |
| 210 | { |
| 211 | int ret = 0; |
| 212 | struct consumer_relayd_sock_pair *relayd; |
| 213 | |
| 214 | assert(stream); |
| 215 | |
| 216 | relayd = consumer_find_relayd(stream->net_seq_idx); |
| 217 | if (relayd != NULL) { |
| 218 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); |
| 219 | /* Add stream on the relayd */ |
| 220 | ret = relayd_add_stream(&relayd->control_sock, stream->name, |
| 221 | stream->chan->pathname, &stream->relayd_stream_id); |
| 222 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); |
| 223 | if (ret < 0) { |
| 224 | goto error; |
| 225 | } |
| 226 | } else if (stream->net_seq_idx != -1) { |
| 227 | ERR("Network sequence index %d unknown. Not adding stream.", |
| 228 | stream->net_seq_idx); |
| 229 | ret = -1; |
| 230 | goto error; |
| 231 | } |
| 232 | |
| 233 | error: |
| 234 | return ret; |
| 235 | } |
| 236 | |
| 237 | static int create_ust_streams(struct lttng_consumer_channel *channel, |
| 238 | struct lttng_consumer_local_data *ctx) |
| 239 | { |
| 240 | int ret, cpu = 0; |
| 241 | struct ustctl_consumer_stream *ustream; |
| 242 | struct lttng_consumer_stream *stream; |
| 243 | |
| 244 | assert(channel); |
| 245 | assert(ctx); |
| 246 | |
| 247 | /* |
| 248 | * While a stream is available from ustctl. When NULL is returned, we've |
| 249 | * reached the end of the possible stream for the channel. |
| 250 | */ |
| 251 | while ((ustream = ustctl_create_stream(channel->uchan, cpu))) { |
| 252 | int wait_fd; |
| 253 | |
| 254 | wait_fd = ustctl_get_wait_fd(ustream); |
| 255 | |
| 256 | /* Allocate consumer stream object. */ |
| 257 | stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret); |
| 258 | if (!stream) { |
| 259 | goto error_alloc; |
| 260 | } |
| 261 | stream->ustream = ustream; |
| 262 | /* |
| 263 | * Store it so we can save multiple function calls afterwards since |
| 264 | * this value is used heavily in the stream threads. This is UST |
| 265 | * specific so this is why it's done after allocation. |
| 266 | */ |
| 267 | stream->wait_fd = wait_fd; |
| 268 | |
| 269 | /* |
| 270 | * Order is important this is why a list is used. On error, the caller |
| 271 | * should clean this list. |
| 272 | */ |
| 273 | cds_list_add_tail(&stream->send_node, &channel->streams.head); |
| 274 | |
| 275 | ret = ustctl_get_max_subbuf_size(stream->ustream, |
| 276 | &stream->max_sb_size); |
| 277 | if (ret < 0) { |
| 278 | ERR("ustctl_get_max_subbuf_size failed for stream %s", |
| 279 | stream->name); |
| 280 | goto error; |
| 281 | } |
| 282 | |
| 283 | /* Do actions once stream has been received. */ |
| 284 | if (ctx->on_recv_stream) { |
| 285 | ret = ctx->on_recv_stream(stream); |
| 286 | if (ret < 0) { |
| 287 | goto error; |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | DBG("UST consumer add stream %s (key: %d) with relayd id %" PRIu64, |
| 292 | stream->name, stream->key, stream->relayd_stream_id); |
| 293 | |
| 294 | /* Set next CPU stream. */ |
| 295 | channel->streams.count = ++cpu; |
| 296 | } |
| 297 | |
| 298 | return 0; |
| 299 | |
| 300 | error: |
| 301 | error_alloc: |
| 302 | return ret; |
| 303 | } |
| 304 | |
| 305 | /* |
| 306 | * Create an UST channel with the given attributes and send it to the session |
| 307 | * daemon using the ust ctl API. |
| 308 | * |
| 309 | * Return 0 on success or else a negative value. |
| 310 | */ |
| 311 | static int create_ust_channel(struct ustctl_consumer_channel_attr *attr, |
| 312 | struct ustctl_consumer_channel **chanp) |
| 313 | { |
| 314 | int ret; |
| 315 | struct ustctl_consumer_channel *channel; |
| 316 | |
| 317 | assert(attr); |
| 318 | assert(chanp); |
| 319 | |
| 320 | DBG3("Creating channel to ustctl with attr: [overwrite: %d, " |
| 321 | "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", " |
| 322 | "switch_timer_interval: %u, read_timer_interval: %u, " |
| 323 | "output: %d, type: %d", attr->overwrite, attr->subbuf_size, |
| 324 | attr->num_subbuf, attr->switch_timer_interval, |
| 325 | attr->read_timer_interval, attr->output, attr->type); |
| 326 | |
| 327 | channel = ustctl_create_channel(attr); |
| 328 | if (!channel) { |
| 329 | ret = -1; |
| 330 | goto error_create; |
| 331 | } |
| 332 | |
| 333 | *chanp = channel; |
| 334 | |
| 335 | return 0; |
| 336 | |
| 337 | error_create: |
| 338 | return ret; |
| 339 | } |
| 340 | |
| 341 | static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream) |
| 342 | { |
| 343 | int ret; |
| 344 | |
| 345 | assert(stream); |
| 346 | assert(sock >= 0); |
| 347 | |
| 348 | DBG2("UST consumer sending stream %d to sessiond", stream->key); |
| 349 | |
| 350 | /* Send stream to session daemon. */ |
| 351 | ret = ustctl_send_stream_to_sessiond(sock, stream->ustream); |
| 352 | if (ret < 0) { |
| 353 | goto error; |
| 354 | } |
| 355 | |
| 356 | ret = ustctl_stream_close_wakeup_fd(stream->ustream); |
| 357 | if (ret < 0) { |
| 358 | goto error; |
| 359 | } |
| 360 | |
| 361 | error: |
| 362 | return ret; |
| 363 | } |
| 364 | |
| 365 | /* |
| 366 | * Send channel to sessiond. |
| 367 | * |
| 368 | * Return 0 on success or else a negative value. On error, the channel is |
| 369 | * destroy using ustctl. |
| 370 | */ |
| 371 | static int send_sessiond_channel(int sock, |
| 372 | struct lttng_consumer_channel *channel, |
| 373 | struct lttng_consumer_local_data *ctx, int *relayd_error) |
| 374 | { |
| 375 | int ret; |
| 376 | struct lttng_consumer_stream *stream; |
| 377 | |
| 378 | assert(channel); |
| 379 | assert(ctx); |
| 380 | assert(sock >= 0); |
| 381 | |
| 382 | DBG("UST consumer sending channel %s to sessiond", channel->name); |
| 383 | |
| 384 | /* Send channel to sessiond. */ |
| 385 | ret = ustctl_send_channel_to_sessiond(sock, channel->uchan); |
| 386 | if (ret < 0) { |
| 387 | goto error; |
| 388 | } |
| 389 | |
| 390 | /* The channel was sent successfully to the sessiond at this point. */ |
| 391 | cds_list_for_each_entry(stream, &channel->streams.head, send_node) { |
| 392 | /* Try to send the stream to the relayd if one is available. */ |
| 393 | ret = send_stream_to_relayd(stream); |
| 394 | if (ret < 0) { |
| 395 | /* |
| 396 | * Flag that the relayd was the problem here probably due to a |
| 397 | * communicaton error on the socket. |
| 398 | */ |
| 399 | if (relayd_error) { |
| 400 | *relayd_error = 1; |
| 401 | } |
| 402 | goto error; |
| 403 | } |
| 404 | |
| 405 | /* Send stream to session daemon. */ |
| 406 | ret = send_sessiond_stream(sock, stream); |
| 407 | if (ret < 0) { |
| 408 | goto error; |
| 409 | } |
| 410 | } |
| 411 | |
| 412 | /* Tell sessiond there is no more stream. */ |
| 413 | ret = ustctl_send_stream_to_sessiond(sock, NULL); |
| 414 | if (ret < 0) { |
| 415 | goto error; |
| 416 | } |
| 417 | |
| 418 | DBG("UST consumer NULL stream sent to sessiond"); |
| 419 | |
| 420 | return 0; |
| 421 | |
| 422 | error: |
| 423 | return ret; |
| 424 | } |
| 425 | |
| 426 | /* |
| 427 | * Creates a channel and streams and add the channel it to the channel internal |
| 428 | * state. The created stream must ONLY be sent once the GET_CHANNEL command is |
| 429 | * received. |
| 430 | * |
| 431 | * Return 0 on success or else, a negative value is returned and the channel |
| 432 | * MUST be destroyed by consumer_del_channel(). |
| 433 | */ |
| 434 | static int ask_channel(struct lttng_consumer_local_data *ctx, int sock, |
| 435 | struct lttng_consumer_channel *channel, |
| 436 | struct ustctl_consumer_channel_attr *attr) |
| 437 | { |
| 438 | int ret; |
| 439 | |
| 440 | assert(ctx); |
| 441 | assert(channel); |
| 442 | assert(attr); |
| 443 | |
| 444 | /* |
| 445 | * This value is still used by the kernel consumer since for the kernel, |
| 446 | * the stream ownership is not IN the consumer so we need to have the |
| 447 | * number of left stream that needs to be initialized so we can know when |
| 448 | * to delete the channel (see consumer.c). |
| 449 | * |
| 450 | * As for the user space tracer now, the consumer creates and sends the |
| 451 | * stream to the session daemon which only sends them to the application |
| 452 | * once every stream of a channel is received making this value useless |
| 453 | * because we they will be added to the poll thread before the application |
| 454 | * receives them. This ensures that a stream can not hang up during |
| 455 | * initilization of a channel. |
| 456 | */ |
| 457 | channel->nb_init_stream_left = 0; |
| 458 | |
| 459 | /* The reply msg status is handled in the following call. */ |
| 460 | ret = create_ust_channel(attr, &channel->uchan); |
| 461 | if (ret < 0) { |
| 462 | goto error; |
| 463 | } |
| 464 | |
| 465 | /* Open all streams for this channel. */ |
| 466 | ret = create_ust_streams(channel, ctx); |
| 467 | if (ret < 0) { |
| 468 | goto error; |
| 469 | } |
| 470 | |
| 471 | error: |
| 472 | return ret; |
| 473 | } |
| 474 | |
| 475 | /* |
| 476 | * Receive command from session daemon and process it. |
| 477 | * |
| 478 | * Return 1 on success else a negative value or 0. |
| 479 | */ |
| 480 | int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, |
| 481 | int sock, struct pollfd *consumer_sockpoll) |
| 482 | { |
| 483 | ssize_t ret; |
| 484 | enum lttng_error_code ret_code = LTTNG_OK; |
| 485 | struct lttcomm_consumer_msg msg; |
| 486 | struct lttng_consumer_channel *channel = NULL; |
| 487 | |
| 488 | ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); |
| 489 | if (ret != sizeof(msg)) { |
| 490 | DBG("Consumer received unexpected message size %zd (expects %zu)", |
| 491 | ret, sizeof(msg)); |
| 492 | lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD); |
| 493 | /* |
| 494 | * The ret value might 0 meaning an orderly shutdown but this is ok |
| 495 | * since the caller handles this. |
| 496 | */ |
| 497 | return ret; |
| 498 | } |
| 499 | if (msg.cmd_type == LTTNG_CONSUMER_STOP) { |
| 500 | /* |
| 501 | * Notify the session daemon that the command is completed. |
| 502 | * |
| 503 | * On transport layer error, the function call will print an error |
| 504 | * message so handling the returned code is a bit useless since we |
| 505 | * return an error code anyway. |
| 506 | */ |
| 507 | (void) consumer_send_status_msg(sock, ret_code); |
| 508 | return -ENOENT; |
| 509 | } |
| 510 | |
| 511 | /* relayd needs RCU read-side lock */ |
| 512 | rcu_read_lock(); |
| 513 | |
| 514 | switch (msg.cmd_type) { |
| 515 | case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: |
| 516 | { |
| 517 | /* Session daemon status message are handled in the following call. */ |
| 518 | ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index, |
| 519 | msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll, |
| 520 | &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id); |
| 521 | goto end_nosignal; |
| 522 | } |
| 523 | case LTTNG_CONSUMER_DESTROY_RELAYD: |
| 524 | { |
| 525 | uint64_t index = msg.u.destroy_relayd.net_seq_idx; |
| 526 | struct consumer_relayd_sock_pair *relayd; |
| 527 | |
| 528 | DBG("UST consumer destroying relayd %" PRIu64, index); |
| 529 | |
| 530 | /* Get relayd reference if exists. */ |
| 531 | relayd = consumer_find_relayd(index); |
| 532 | if (relayd == NULL) { |
| 533 | DBG("Unable to find relayd %" PRIu64, index); |
| 534 | ret_code = LTTNG_ERR_NO_CONSUMER; |
| 535 | } |
| 536 | |
| 537 | /* |
| 538 | * Each relayd socket pair has a refcount of stream attached to it |
| 539 | * which tells if the relayd is still active or not depending on the |
| 540 | * refcount value. |
| 541 | * |
| 542 | * This will set the destroy flag of the relayd object and destroy it |
| 543 | * if the refcount reaches zero when called. |
| 544 | * |
| 545 | * The destroy can happen either here or when a stream fd hangs up. |
| 546 | */ |
| 547 | if (relayd) { |
| 548 | consumer_flag_relayd_for_destroy(relayd); |
| 549 | } |
| 550 | |
| 551 | ret = consumer_send_status_msg(sock, ret_code); |
| 552 | if (ret < 0) { |
| 553 | /* Somehow, the session daemon is not responding anymore. */ |
| 554 | goto end_nosignal; |
| 555 | } |
| 556 | |
| 557 | goto end_nosignal; |
| 558 | } |
| 559 | case LTTNG_CONSUMER_UPDATE_STREAM: |
| 560 | { |
| 561 | rcu_read_unlock(); |
| 562 | return -ENOSYS; |
| 563 | } |
| 564 | case LTTNG_CONSUMER_DATA_PENDING: |
| 565 | { |
| 566 | int ret, is_data_pending; |
| 567 | uint64_t id = msg.u.data_pending.session_id; |
| 568 | |
| 569 | DBG("UST consumer data pending command for id %" PRIu64, id); |
| 570 | |
| 571 | is_data_pending = consumer_data_pending(id); |
| 572 | |
| 573 | /* Send back returned value to session daemon */ |
| 574 | ret = lttcomm_send_unix_sock(sock, &is_data_pending, |
| 575 | sizeof(is_data_pending)); |
| 576 | if (ret < 0) { |
| 577 | DBG("Error when sending the data pending ret code: %d", ret); |
| 578 | } |
| 579 | |
| 580 | /* |
| 581 | * No need to send back a status message since the data pending |
| 582 | * returned value is the response. |
| 583 | */ |
| 584 | break; |
| 585 | } |
| 586 | case LTTNG_CONSUMER_ASK_CHANNEL_CREATION: |
| 587 | { |
| 588 | int ret; |
| 589 | struct ustctl_consumer_channel_attr attr; |
| 590 | |
| 591 | /* Create a plain object and reserve a channel key. */ |
| 592 | channel = allocate_channel(msg.u.ask_channel.session_id, |
| 593 | msg.u.ask_channel.pathname, msg.u.ask_channel.name, |
| 594 | msg.u.ask_channel.uid, msg.u.ask_channel.gid, |
| 595 | msg.u.ask_channel.relayd_id, msg.u.ask_channel.key, |
| 596 | (enum lttng_event_output) msg.u.ask_channel.output); |
| 597 | if (!channel) { |
| 598 | goto end_channel_error; |
| 599 | } |
| 600 | |
| 601 | /* Build channel attributes from received message. */ |
| 602 | attr.subbuf_size = msg.u.ask_channel.subbuf_size; |
| 603 | attr.num_subbuf = msg.u.ask_channel.num_subbuf; |
| 604 | attr.overwrite = msg.u.ask_channel.overwrite; |
| 605 | attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval; |
| 606 | attr.read_timer_interval = msg.u.ask_channel.read_timer_interval; |
| 607 | memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid)); |
| 608 | |
| 609 | /* Translate the event output type to UST. */ |
| 610 | switch (channel->output) { |
| 611 | case LTTNG_EVENT_SPLICE: |
| 612 | /* Splice not supported so fallback on mmap(). */ |
| 613 | case LTTNG_EVENT_MMAP: |
| 614 | default: |
| 615 | attr.output = CONSUMER_CHANNEL_MMAP; |
| 616 | break; |
| 617 | }; |
| 618 | |
| 619 | /* Translate and save channel type. */ |
| 620 | switch (msg.u.ask_channel.type) { |
| 621 | case LTTNG_UST_CHAN_PER_CPU: |
| 622 | channel->type = CONSUMER_CHANNEL_TYPE_DATA; |
| 623 | attr.type = LTTNG_UST_CHAN_PER_CPU; |
| 624 | break; |
| 625 | case LTTNG_UST_CHAN_METADATA: |
| 626 | channel->type = CONSUMER_CHANNEL_TYPE_METADATA; |
| 627 | attr.type = LTTNG_UST_CHAN_METADATA; |
| 628 | break; |
| 629 | default: |
| 630 | assert(0); |
| 631 | goto error_fatal; |
| 632 | }; |
| 633 | |
| 634 | ret = ask_channel(ctx, sock, channel, &attr); |
| 635 | if (ret < 0) { |
| 636 | goto end_channel_error; |
| 637 | } |
| 638 | |
| 639 | /* |
| 640 | * Add the channel to the internal state AFTER all streams were created |
| 641 | * and successfully sent to session daemon. This way, all streams must |
| 642 | * be ready before this channel is visible to the threads. |
| 643 | */ |
| 644 | ret = add_channel(channel, ctx); |
| 645 | if (ret < 0) { |
| 646 | goto end_channel_error; |
| 647 | } |
| 648 | |
| 649 | /* |
| 650 | * Channel and streams are now created. Inform the session daemon that |
| 651 | * everything went well and should wait to receive the channel and |
| 652 | * streams with ustctl API. |
| 653 | */ |
| 654 | ret = consumer_send_status_channel(sock, channel); |
| 655 | if (ret < 0) { |
| 656 | /* |
| 657 | * There is probably a problem on the socket so the poll will get |
| 658 | * it and clean everything up. |
| 659 | */ |
| 660 | goto end_nosignal; |
| 661 | } |
| 662 | |
| 663 | break; |
| 664 | } |
| 665 | case LTTNG_CONSUMER_GET_CHANNEL: |
| 666 | { |
| 667 | int ret, relayd_err = 0; |
| 668 | unsigned long key = msg.u.get_channel.key; |
| 669 | struct lttng_consumer_channel *channel; |
| 670 | struct lttng_consumer_stream *stream, *stmp; |
| 671 | |
| 672 | channel = consumer_find_channel(key); |
| 673 | if (!channel) { |
| 674 | ERR("UST consumer get channel key %lu not found", key); |
| 675 | ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND; |
| 676 | goto end_msg_sessiond; |
| 677 | } |
| 678 | |
| 679 | /* Inform sessiond that we are about to send channel and streams. */ |
| 680 | ret = consumer_send_status_msg(sock, LTTNG_OK); |
| 681 | if (ret < 0) { |
| 682 | /* Somehow, the session daemon is not responding anymore. */ |
| 683 | goto end_nosignal; |
| 684 | } |
| 685 | |
| 686 | /* Send everything to sessiond. */ |
| 687 | ret = send_sessiond_channel(sock, channel, ctx, &relayd_err); |
| 688 | if (ret < 0) { |
| 689 | if (relayd_err) { |
| 690 | /* |
| 691 | * We were unable to send to the relayd the stream so avoid |
| 692 | * sending back a fatal error to the thread since this is OK |
| 693 | * and the consumer can continue its work. |
| 694 | */ |
| 695 | ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL; |
| 696 | goto end_msg_sessiond; |
| 697 | } |
| 698 | /* |
| 699 | * The communicaton was broken hence there is a bad state between |
| 700 | * the consumer and sessiond so stop everything. |
| 701 | */ |
| 702 | goto error_fatal; |
| 703 | } |
| 704 | |
| 705 | /* Send streams to the corresponding thread. */ |
| 706 | cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head, |
| 707 | send_node) { |
| 708 | /* Sending the stream to the thread. */ |
| 709 | ret = send_stream_to_thread(stream, ctx); |
| 710 | if (ret < 0) { |
| 711 | /* |
| 712 | * If we are unable to send the stream to the thread, there is |
| 713 | * a big problem so just stop everything. |
| 714 | */ |
| 715 | goto error_fatal; |
| 716 | } |
| 717 | |
| 718 | /* Remove node from the channel stream list. */ |
| 719 | cds_list_del(&stream->send_node); |
| 720 | } |
| 721 | |
| 722 | /* List MUST be empty after or else it could be reused. */ |
| 723 | assert(cds_list_empty(&channel->streams.head)); |
| 724 | |
| 725 | /* Inform sessiond that everything is done and OK on our side. */ |
| 726 | ret = consumer_send_status_msg(sock, LTTNG_OK); |
| 727 | if (ret < 0) { |
| 728 | /* Somehow, the session daemon is not responding anymore. */ |
| 729 | goto end_nosignal; |
| 730 | } |
| 731 | |
| 732 | break; |
| 733 | } |
| 734 | case LTTNG_CONSUMER_DESTROY_CHANNEL: |
| 735 | { |
| 736 | int ret; |
| 737 | unsigned long key = msg.u.destroy_channel.key; |
| 738 | struct lttng_consumer_channel *channel; |
| 739 | |
| 740 | DBG("UST consumer destroy channel key %lu", key); |
| 741 | |
| 742 | channel = consumer_find_channel(key); |
| 743 | if (!channel) { |
| 744 | ERR("UST consumer destroy channel %lu not found", key); |
| 745 | ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND; |
| 746 | } else { |
| 747 | /* Protocol error if the stream list is NOT empty. */ |
| 748 | assert(!cds_list_empty(&channel->streams.head)); |
| 749 | consumer_del_channel(channel); |
| 750 | } |
| 751 | |
| 752 | ret = consumer_send_status_msg(sock, LTTNG_OK); |
| 753 | if (ret < 0) { |
| 754 | /* Somehow, the session daemon is not responding anymore. */ |
| 755 | goto end_nosignal; |
| 756 | } |
| 757 | } |
| 758 | default: |
| 759 | break; |
| 760 | } |
| 761 | |
| 762 | end_nosignal: |
| 763 | rcu_read_unlock(); |
| 764 | |
| 765 | /* |
| 766 | * Return 1 to indicate success since the 0 value can be a socket |
| 767 | * shutdown during the recv() or send() call. |
| 768 | */ |
| 769 | return 1; |
| 770 | |
| 771 | end_msg_sessiond: |
| 772 | /* |
| 773 | * The returned value here is not useful since either way we'll return 1 to |
| 774 | * the caller because the session daemon socket management is done |
| 775 | * elsewhere. Returning a negative code or 0 will shutdown the consumer. |
| 776 | */ |
| 777 | (void) consumer_send_status_msg(sock, ret_code); |
| 778 | rcu_read_unlock(); |
| 779 | return 1; |
| 780 | end_channel_error: |
| 781 | if (channel) { |
| 782 | /* |
| 783 | * Free channel here since no one has a reference to it. We don't |
| 784 | * free after that because a stream can store this pointer. |
| 785 | */ |
| 786 | destroy_channel(channel); |
| 787 | } |
| 788 | /* We have to send a status channel message indicating an error. */ |
| 789 | ret = consumer_send_status_channel(sock, NULL); |
| 790 | if (ret < 0) { |
| 791 | /* Stop everything if session daemon can not be notified. */ |
| 792 | goto error_fatal; |
| 793 | } |
| 794 | rcu_read_unlock(); |
| 795 | return 1; |
| 796 | error_fatal: |
| 797 | rcu_read_unlock(); |
| 798 | /* This will issue a consumer stop. */ |
| 799 | return -1; |
| 800 | } |
| 801 | |
| 802 | /* |
| 803 | * Wrapper over the mmap() read offset from ust-ctl library. Since this can be |
| 804 | * compiled out, we isolate it in this library. |
| 805 | */ |
| 806 | int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream, |
| 807 | unsigned long *off) |
| 808 | { |
| 809 | assert(stream); |
| 810 | assert(stream->ustream); |
| 811 | |
| 812 | return ustctl_get_mmap_read_offset(stream->ustream, off); |
| 813 | } |
| 814 | |
| 815 | /* |
| 816 | * Wrapper over the mmap() read offset from ust-ctl library. Since this can be |
| 817 | * compiled out, we isolate it in this library. |
| 818 | */ |
| 819 | void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream) |
| 820 | { |
| 821 | assert(stream); |
| 822 | assert(stream->ustream); |
| 823 | |
| 824 | return ustctl_get_mmap_base(stream->ustream); |
| 825 | } |
| 826 | |
| 827 | /* |
| 828 | * Take a snapshot for a specific fd |
| 829 | * |
| 830 | * Returns 0 on success, < 0 on error |
| 831 | */ |
| 832 | int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream) |
| 833 | { |
| 834 | assert(stream); |
| 835 | assert(stream->ustream); |
| 836 | |
| 837 | return ustctl_snapshot(stream->ustream); |
| 838 | } |
| 839 | |
| 840 | /* |
| 841 | * Get the produced position |
| 842 | * |
| 843 | * Returns 0 on success, < 0 on error |
| 844 | */ |
| 845 | int lttng_ustconsumer_get_produced_snapshot( |
| 846 | struct lttng_consumer_stream *stream, unsigned long *pos) |
| 847 | { |
| 848 | assert(stream); |
| 849 | assert(stream->ustream); |
| 850 | assert(pos); |
| 851 | |
| 852 | return ustctl_snapshot_get_produced(stream->ustream, pos); |
| 853 | } |
| 854 | |
| 855 | /* |
| 856 | * Called when the stream signal the consumer that it has hang up. |
| 857 | */ |
| 858 | void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream) |
| 859 | { |
| 860 | assert(stream); |
| 861 | assert(stream->ustream); |
| 862 | |
| 863 | ustctl_flush_buffer(stream->ustream, 0); |
| 864 | stream->hangup_flush_done = 1; |
| 865 | } |
| 866 | |
| 867 | void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan) |
| 868 | { |
| 869 | assert(chan); |
| 870 | assert(chan->uchan); |
| 871 | |
| 872 | ustctl_destroy_channel(chan->uchan); |
| 873 | } |
| 874 | |
| 875 | void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream) |
| 876 | { |
| 877 | assert(stream); |
| 878 | assert(stream->ustream); |
| 879 | |
| 880 | ustctl_destroy_stream(stream->ustream); |
| 881 | } |
| 882 | |
| 883 | int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream, |
| 884 | struct lttng_consumer_local_data *ctx) |
| 885 | { |
| 886 | unsigned long len, subbuf_size, padding; |
| 887 | int err; |
| 888 | long ret = 0; |
| 889 | char dummy; |
| 890 | struct ustctl_consumer_stream *ustream; |
| 891 | |
| 892 | assert(stream); |
| 893 | assert(stream->ustream); |
| 894 | assert(ctx); |
| 895 | |
| 896 | DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd, |
| 897 | stream->name); |
| 898 | |
| 899 | /* Ease our life for what's next. */ |
| 900 | ustream = stream->ustream; |
| 901 | |
| 902 | /* We can consume the 1 byte written into the wait_fd by UST */ |
| 903 | if (!stream->hangup_flush_done) { |
| 904 | ssize_t readlen; |
| 905 | |
| 906 | do { |
| 907 | readlen = read(stream->wait_fd, &dummy, 1); |
| 908 | } while (readlen == -1 && errno == EINTR); |
| 909 | if (readlen == -1) { |
| 910 | ret = readlen; |
| 911 | goto end; |
| 912 | } |
| 913 | } |
| 914 | |
| 915 | /* Get the next subbuffer */ |
| 916 | err = ustctl_get_next_subbuf(ustream); |
| 917 | if (err != 0) { |
| 918 | ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */ |
| 919 | /* |
| 920 | * This is a debug message even for single-threaded consumer, |
| 921 | * because poll() have more relaxed criterions than get subbuf, |
| 922 | * so get_subbuf may fail for short race windows where poll() |
| 923 | * would issue wakeups. |
| 924 | */ |
| 925 | DBG("Reserving sub buffer failed (everything is normal, " |
| 926 | "it is due to concurrency) [ret: %d]", err); |
| 927 | goto end; |
| 928 | } |
| 929 | assert(stream->chan->output == CONSUMER_CHANNEL_MMAP); |
| 930 | /* Get the full padded subbuffer size */ |
| 931 | err = ustctl_get_padded_subbuf_size(ustream, &len); |
| 932 | assert(err == 0); |
| 933 | |
| 934 | /* Get subbuffer data size (without padding) */ |
| 935 | err = ustctl_get_subbuf_size(ustream, &subbuf_size); |
| 936 | assert(err == 0); |
| 937 | |
| 938 | /* Make sure we don't get a subbuffer size bigger than the padded */ |
| 939 | assert(len >= subbuf_size); |
| 940 | |
| 941 | padding = len - subbuf_size; |
| 942 | /* write the subbuffer to the tracefile */ |
| 943 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding); |
| 944 | /* |
| 945 | * The mmap operation should write subbuf_size amount of data when network |
| 946 | * streaming or the full padding (len) size when we are _not_ streaming. |
| 947 | */ |
| 948 | if ((ret != subbuf_size && stream->net_seq_idx != -1) || |
| 949 | (ret != len && stream->net_seq_idx == -1)) { |
| 950 | /* |
| 951 | * Display the error but continue processing to try to release the |
| 952 | * subbuffer. This is a DBG statement since any unexpected kill or |
| 953 | * signal, the application gets unregistered, relayd gets closed or |
| 954 | * anything that affects the buffer lifetime will trigger this error. |
| 955 | * So, for the sake of the user, don't print this error since it can |
| 956 | * happen and it is OK with the code flow. |
| 957 | */ |
| 958 | DBG("Error writing to tracefile " |
| 959 | "(ret: %zd != len: %lu != subbuf_size: %lu)", |
| 960 | ret, len, subbuf_size); |
| 961 | } |
| 962 | err = ustctl_put_next_subbuf(ustream); |
| 963 | assert(err == 0); |
| 964 | end: |
| 965 | return ret; |
| 966 | } |
| 967 | |
| 968 | /* |
| 969 | * Called when a stream is created. |
| 970 | */ |
| 971 | int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream) |
| 972 | { |
| 973 | int ret; |
| 974 | char full_path[PATH_MAX]; |
| 975 | |
| 976 | /* Opening the tracefile in write mode */ |
| 977 | if (stream->net_seq_idx != -1) { |
| 978 | goto end; |
| 979 | } |
| 980 | |
| 981 | ret = snprintf(full_path, sizeof(full_path), "%s/%s", |
| 982 | stream->chan->pathname, stream->name); |
| 983 | if (ret < 0) { |
| 984 | PERROR("snprintf on_recv_stream"); |
| 985 | goto error; |
| 986 | } |
| 987 | |
| 988 | ret = run_as_open(full_path, O_WRONLY | O_CREAT | O_TRUNC, |
| 989 | S_IRWXU | S_IRWXG | S_IRWXO, stream->uid, stream->gid); |
| 990 | if (ret < 0) { |
| 991 | PERROR("open stream path %s", full_path); |
| 992 | goto error; |
| 993 | } |
| 994 | stream->out_fd = ret; |
| 995 | |
| 996 | end: |
| 997 | /* we return 0 to let the library handle the FD internally */ |
| 998 | return 0; |
| 999 | |
| 1000 | error: |
| 1001 | return ret; |
| 1002 | } |
| 1003 | |
| 1004 | /* |
| 1005 | * Check if data is still being extracted from the buffers for a specific |
| 1006 | * stream. Consumer data lock MUST be acquired before calling this function |
| 1007 | * and the stream lock. |
| 1008 | * |
| 1009 | * Return 1 if the traced data are still getting read else 0 meaning that the |
| 1010 | * data is available for trace viewer reading. |
| 1011 | */ |
| 1012 | int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream) |
| 1013 | { |
| 1014 | int ret; |
| 1015 | |
| 1016 | assert(stream); |
| 1017 | assert(stream->ustream); |
| 1018 | |
| 1019 | DBG("UST consumer checking data pending"); |
| 1020 | |
| 1021 | ret = ustctl_get_next_subbuf(stream->ustream); |
| 1022 | if (ret == 0) { |
| 1023 | /* There is still data so let's put back this subbuffer. */ |
| 1024 | ret = ustctl_put_subbuf(stream->ustream); |
| 1025 | assert(ret == 0); |
| 1026 | ret = 1; /* Data is pending */ |
| 1027 | goto end; |
| 1028 | } |
| 1029 | |
| 1030 | /* Data is NOT pending so ready to be read. */ |
| 1031 | ret = 0; |
| 1032 | |
| 1033 | end: |
| 1034 | return ret; |
| 1035 | } |