| 1 | /* |
| 2 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License, version 2 only, as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 11 | * more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along with |
| 14 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #define _GNU_SOURCE |
| 19 | #include <assert.h> |
| 20 | #include <urcu/uatomic.h> |
| 21 | |
| 22 | #include <common/common.h> |
| 23 | #include <common/sessiond-comm/agent.h> |
| 24 | |
| 25 | #include <common/compat/endian.h> |
| 26 | |
| 27 | #include "agent.h" |
| 28 | #include "ust-app.h" |
| 29 | #include "utils.h" |
| 30 | |
| 31 | /* |
| 32 | * Match function for the events hash table lookup by name. |
| 33 | */ |
| 34 | static int ht_match_event_by_name(struct cds_lfht_node *node, |
| 35 | const void *_key) |
| 36 | { |
| 37 | struct agent_event *event; |
| 38 | const struct agent_ht_key *key; |
| 39 | |
| 40 | assert(node); |
| 41 | assert(_key); |
| 42 | |
| 43 | event = caa_container_of(node, struct agent_event, node.node); |
| 44 | key = _key; |
| 45 | |
| 46 | /* Match 1 elements of the key: name. */ |
| 47 | |
| 48 | /* Event name */ |
| 49 | if (strncmp(event->name, key->name, sizeof(event->name)) != 0) { |
| 50 | goto no_match; |
| 51 | } |
| 52 | /* Match. */ |
| 53 | return 1; |
| 54 | |
| 55 | no_match: |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | /* |
| 60 | * Match function for the events hash table lookup by name and loglevel. |
| 61 | */ |
| 62 | static int ht_match_event(struct cds_lfht_node *node, |
| 63 | const void *_key) |
| 64 | { |
| 65 | struct agent_event *event; |
| 66 | const struct agent_ht_key *key; |
| 67 | |
| 68 | assert(node); |
| 69 | assert(_key); |
| 70 | |
| 71 | event = caa_container_of(node, struct agent_event, node.node); |
| 72 | key = _key; |
| 73 | |
| 74 | /* Match 2 elements of the key: name and loglevel. */ |
| 75 | |
| 76 | /* Event name */ |
| 77 | if (strncmp(event->name, key->name, sizeof(event->name)) != 0) { |
| 78 | goto no_match; |
| 79 | } |
| 80 | |
| 81 | if (event->loglevel != key->loglevel) { |
| 82 | if (event->loglevel_type == LTTNG_EVENT_LOGLEVEL_ALL && |
| 83 | key->loglevel == 0 && event->loglevel == -1) { |
| 84 | goto match; |
| 85 | } |
| 86 | goto no_match; |
| 87 | } |
| 88 | match: |
| 89 | return 1; |
| 90 | |
| 91 | no_match: |
| 92 | return 0; |
| 93 | } |
| 94 | |
| 95 | /* |
| 96 | * Add unique agent event based on the event name and loglevel. |
| 97 | */ |
| 98 | static void add_unique_agent_event(struct lttng_ht *ht, |
| 99 | struct agent_event *event) |
| 100 | { |
| 101 | struct cds_lfht_node *node_ptr; |
| 102 | struct agent_ht_key key; |
| 103 | |
| 104 | assert(ht); |
| 105 | assert(ht->ht); |
| 106 | assert(event); |
| 107 | |
| 108 | key.name = event->name; |
| 109 | key.loglevel = event->loglevel; |
| 110 | |
| 111 | node_ptr = cds_lfht_add_unique(ht->ht, |
| 112 | ht->hash_fct(event->node.key, lttng_ht_seed), |
| 113 | ht_match_event, &key, &event->node.node); |
| 114 | assert(node_ptr == &event->node.node); |
| 115 | } |
| 116 | |
| 117 | /* |
| 118 | * URCU delayed agent event reclaim. |
| 119 | */ |
| 120 | static void destroy_event_agent_rcu(struct rcu_head *head) |
| 121 | { |
| 122 | struct lttng_ht_node_str *node = |
| 123 | caa_container_of(head, struct lttng_ht_node_str, head); |
| 124 | struct agent_event *event = |
| 125 | caa_container_of(node, struct agent_event, node); |
| 126 | |
| 127 | free(event); |
| 128 | } |
| 129 | |
| 130 | /* |
| 131 | * URCU delayed agent app reclaim. |
| 132 | */ |
| 133 | static void destroy_app_agent_rcu(struct rcu_head *head) |
| 134 | { |
| 135 | struct lttng_ht_node_ulong *node = |
| 136 | caa_container_of(head, struct lttng_ht_node_ulong, head); |
| 137 | struct agent_app *app = |
| 138 | caa_container_of(node, struct agent_app, node); |
| 139 | |
| 140 | free(app); |
| 141 | } |
| 142 | |
| 143 | /* |
| 144 | * Communication with the agent. Send the message header to the given socket in |
| 145 | * big endian. |
| 146 | * |
| 147 | * Return 0 on success or else a negative errno message of sendmsg() op. |
| 148 | */ |
| 149 | static int send_header(struct lttcomm_sock *sock, uint64_t data_size, |
| 150 | uint32_t cmd, uint32_t cmd_version) |
| 151 | { |
| 152 | int ret; |
| 153 | ssize_t size; |
| 154 | struct lttcomm_agent_hdr msg; |
| 155 | |
| 156 | assert(sock); |
| 157 | |
| 158 | memset(&msg, 0, sizeof(msg)); |
| 159 | msg.data_size = htobe64(data_size); |
| 160 | msg.cmd = htobe32(cmd); |
| 161 | msg.cmd_version = htobe32(cmd_version); |
| 162 | |
| 163 | size = sock->ops->sendmsg(sock, &msg, sizeof(msg), 0); |
| 164 | if (size < sizeof(msg)) { |
| 165 | ret = -errno; |
| 166 | goto error; |
| 167 | } |
| 168 | ret = 0; |
| 169 | |
| 170 | error: |
| 171 | return ret; |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * Communication call with the agent. Send the payload to the given socket. The |
| 176 | * header MUST be sent prior to this call. |
| 177 | * |
| 178 | * Return 0 on success or else a negative errno value of sendmsg() op. |
| 179 | */ |
| 180 | static int send_payload(struct lttcomm_sock *sock, void *data, |
| 181 | size_t size) |
| 182 | { |
| 183 | int ret; |
| 184 | ssize_t len; |
| 185 | |
| 186 | assert(sock); |
| 187 | assert(data); |
| 188 | |
| 189 | len = sock->ops->sendmsg(sock, data, size, 0); |
| 190 | if (len < size) { |
| 191 | ret = -errno; |
| 192 | goto error; |
| 193 | } |
| 194 | ret = 0; |
| 195 | |
| 196 | error: |
| 197 | return ret; |
| 198 | } |
| 199 | |
| 200 | /* |
| 201 | * Communication call with the agent. Receive reply from the agent using the |
| 202 | * given socket. |
| 203 | * |
| 204 | * Return 0 on success or else a negative errno value from recvmsg() op. |
| 205 | */ |
| 206 | static int recv_reply(struct lttcomm_sock *sock, void *buf, size_t size) |
| 207 | { |
| 208 | int ret; |
| 209 | ssize_t len; |
| 210 | |
| 211 | assert(sock); |
| 212 | assert(buf); |
| 213 | |
| 214 | len = sock->ops->recvmsg(sock, buf, size, 0); |
| 215 | if (len < size) { |
| 216 | ret = -errno; |
| 217 | goto error; |
| 218 | } |
| 219 | ret = 0; |
| 220 | |
| 221 | error: |
| 222 | return ret; |
| 223 | } |
| 224 | |
| 225 | /* |
| 226 | * Internal event listing for a given app. Populate events. |
| 227 | * |
| 228 | * Return number of element in the list or else a negative LTTNG_ERR* code. |
| 229 | * On success, the caller is responsible for freeing the memory |
| 230 | * allocated for "events". |
| 231 | */ |
| 232 | static ssize_t list_events(struct agent_app *app, struct lttng_event **events) |
| 233 | { |
| 234 | int ret, i, len = 0, offset = 0; |
| 235 | uint32_t nb_event; |
| 236 | size_t data_size; |
| 237 | struct lttng_event *tmp_events = NULL; |
| 238 | struct lttcomm_agent_list_reply *reply = NULL; |
| 239 | struct lttcomm_agent_list_reply_hdr reply_hdr; |
| 240 | |
| 241 | assert(app); |
| 242 | assert(app->sock); |
| 243 | assert(events); |
| 244 | |
| 245 | DBG2("Agent listing events for app pid: %d and socket %d", app->pid, |
| 246 | app->sock->fd); |
| 247 | |
| 248 | ret = send_header(app->sock, 0, AGENT_CMD_LIST, 0); |
| 249 | if (ret < 0) { |
| 250 | goto error_io; |
| 251 | } |
| 252 | |
| 253 | /* Get list header so we know how much we'll receive. */ |
| 254 | ret = recv_reply(app->sock, &reply_hdr, sizeof(reply_hdr)); |
| 255 | if (ret < 0) { |
| 256 | goto error_io; |
| 257 | } |
| 258 | |
| 259 | switch (be32toh(reply_hdr.ret_code)) { |
| 260 | case AGENT_RET_CODE_SUCCESS: |
| 261 | data_size = be32toh(reply_hdr.data_size) + sizeof(*reply); |
| 262 | break; |
| 263 | default: |
| 264 | ERR("Agent returned an unknown code: %" PRIu32, |
| 265 | be32toh(reply_hdr.ret_code)); |
| 266 | ret = LTTNG_ERR_FATAL; |
| 267 | goto error; |
| 268 | } |
| 269 | |
| 270 | reply = zmalloc(data_size); |
| 271 | if (!reply) { |
| 272 | ret = LTTNG_ERR_NOMEM; |
| 273 | goto error; |
| 274 | } |
| 275 | |
| 276 | /* Get the list with the appropriate data size. */ |
| 277 | ret = recv_reply(app->sock, reply, data_size); |
| 278 | if (ret < 0) { |
| 279 | goto error_io; |
| 280 | } |
| 281 | |
| 282 | nb_event = be32toh(reply->nb_event); |
| 283 | tmp_events = zmalloc(sizeof(*tmp_events) * nb_event); |
| 284 | if (!tmp_events) { |
| 285 | ret = LTTNG_ERR_NOMEM; |
| 286 | goto error; |
| 287 | } |
| 288 | |
| 289 | for (i = 0; i < nb_event; i++) { |
| 290 | offset += len; |
| 291 | strncpy(tmp_events[i].name, reply->payload + offset, |
| 292 | sizeof(tmp_events[i].name)); |
| 293 | tmp_events[i].pid = app->pid; |
| 294 | tmp_events[i].enabled = -1; |
| 295 | len = strlen(reply->payload + offset) + 1; |
| 296 | } |
| 297 | |
| 298 | *events = tmp_events; |
| 299 | |
| 300 | free(reply); |
| 301 | return nb_event; |
| 302 | |
| 303 | error_io: |
| 304 | ret = LTTNG_ERR_UST_LIST_FAIL; |
| 305 | error: |
| 306 | free(reply); |
| 307 | free(tmp_events); |
| 308 | return -ret; |
| 309 | |
| 310 | } |
| 311 | |
| 312 | /* |
| 313 | * Internal enable agent event on a agent application. This function |
| 314 | * communicates with the agent to enable a given event. |
| 315 | * |
| 316 | * Return LTTNG_OK on success or else a LTTNG_ERR* code. |
| 317 | */ |
| 318 | static int enable_event(struct agent_app *app, struct agent_event *event) |
| 319 | { |
| 320 | int ret; |
| 321 | uint64_t data_size; |
| 322 | struct lttcomm_agent_enable msg; |
| 323 | struct lttcomm_agent_generic_reply reply; |
| 324 | |
| 325 | assert(app); |
| 326 | assert(app->sock); |
| 327 | assert(event); |
| 328 | |
| 329 | DBG2("Agent enabling event %s for app pid: %d and socket %d", event->name, |
| 330 | app->pid, app->sock->fd); |
| 331 | |
| 332 | data_size = sizeof(msg); |
| 333 | |
| 334 | ret = send_header(app->sock, data_size, AGENT_CMD_ENABLE, 0); |
| 335 | if (ret < 0) { |
| 336 | goto error_io; |
| 337 | } |
| 338 | |
| 339 | memset(&msg, 0, sizeof(msg)); |
| 340 | msg.loglevel = event->loglevel; |
| 341 | msg.loglevel_type = event->loglevel_type; |
| 342 | strncpy(msg.name, event->name, sizeof(msg.name)); |
| 343 | ret = send_payload(app->sock, &msg, sizeof(msg)); |
| 344 | if (ret < 0) { |
| 345 | goto error_io; |
| 346 | } |
| 347 | |
| 348 | ret = recv_reply(app->sock, &reply, sizeof(reply)); |
| 349 | if (ret < 0) { |
| 350 | goto error_io; |
| 351 | } |
| 352 | |
| 353 | switch (be32toh(reply.ret_code)) { |
| 354 | case AGENT_RET_CODE_SUCCESS: |
| 355 | break; |
| 356 | case AGENT_RET_CODE_UNKNOWN_NAME: |
| 357 | ret = LTTNG_ERR_UST_EVENT_NOT_FOUND; |
| 358 | goto error; |
| 359 | default: |
| 360 | ERR("Agent returned an unknown code: %" PRIu32, |
| 361 | be32toh(reply.ret_code)); |
| 362 | ret = LTTNG_ERR_FATAL; |
| 363 | goto error; |
| 364 | } |
| 365 | |
| 366 | return LTTNG_OK; |
| 367 | |
| 368 | error_io: |
| 369 | ret = LTTNG_ERR_UST_ENABLE_FAIL; |
| 370 | error: |
| 371 | return ret; |
| 372 | } |
| 373 | |
| 374 | /* |
| 375 | * Internal disable agent event call on a agent application. This function |
| 376 | * communicates with the agent to disable a given event. |
| 377 | * |
| 378 | * Return LTTNG_OK on success or else a LTTNG_ERR* code. |
| 379 | */ |
| 380 | static int disable_event(struct agent_app *app, struct agent_event *event) |
| 381 | { |
| 382 | int ret; |
| 383 | uint64_t data_size; |
| 384 | struct lttcomm_agent_disable msg; |
| 385 | struct lttcomm_agent_generic_reply reply; |
| 386 | |
| 387 | assert(app); |
| 388 | assert(app->sock); |
| 389 | assert(event); |
| 390 | |
| 391 | DBG2("Agent disabling event %s for app pid: %d and socket %d", event->name, |
| 392 | app->pid, app->sock->fd); |
| 393 | |
| 394 | data_size = sizeof(msg); |
| 395 | |
| 396 | ret = send_header(app->sock, data_size, AGENT_CMD_DISABLE, 0); |
| 397 | if (ret < 0) { |
| 398 | goto error_io; |
| 399 | } |
| 400 | |
| 401 | memset(&msg, 0, sizeof(msg)); |
| 402 | strncpy(msg.name, event->name, sizeof(msg.name)); |
| 403 | ret = send_payload(app->sock, &msg, sizeof(msg)); |
| 404 | if (ret < 0) { |
| 405 | goto error_io; |
| 406 | } |
| 407 | |
| 408 | ret = recv_reply(app->sock, &reply, sizeof(reply)); |
| 409 | if (ret < 0) { |
| 410 | goto error_io; |
| 411 | } |
| 412 | |
| 413 | switch (be32toh(reply.ret_code)) { |
| 414 | case AGENT_RET_CODE_SUCCESS: |
| 415 | break; |
| 416 | case AGENT_RET_CODE_UNKNOWN_NAME: |
| 417 | ret = LTTNG_ERR_UST_EVENT_NOT_FOUND; |
| 418 | goto error; |
| 419 | default: |
| 420 | ERR("Agent returned an unknown code: %" PRIu32, |
| 421 | be32toh(reply.ret_code)); |
| 422 | ret = LTTNG_ERR_FATAL; |
| 423 | goto error; |
| 424 | } |
| 425 | |
| 426 | return LTTNG_OK; |
| 427 | |
| 428 | error_io: |
| 429 | ret = LTTNG_ERR_UST_DISABLE_FAIL; |
| 430 | error: |
| 431 | return ret; |
| 432 | } |
| 433 | |
| 434 | /* |
| 435 | * Send back the registration DONE command to a given agent application. |
| 436 | * |
| 437 | * Return 0 on success or else a negative value. |
| 438 | */ |
| 439 | int agent_send_registration_done(struct agent_app *app) |
| 440 | { |
| 441 | assert(app); |
| 442 | assert(app->sock); |
| 443 | |
| 444 | DBG("Agent sending registration done to app socket %d", app->sock->fd); |
| 445 | |
| 446 | return send_header(app->sock, 0, AGENT_CMD_REG_DONE, 0); |
| 447 | } |
| 448 | |
| 449 | /* |
| 450 | * Enable agent event on every agent applications registered with the session |
| 451 | * daemon. |
| 452 | * |
| 453 | * Return LTTNG_OK on success or else a LTTNG_ERR* code. |
| 454 | */ |
| 455 | int agent_enable_event(struct agent_event *event, |
| 456 | enum lttng_domain_type domain) |
| 457 | { |
| 458 | int ret; |
| 459 | struct agent_app *app; |
| 460 | struct lttng_ht_iter iter; |
| 461 | |
| 462 | assert(event); |
| 463 | |
| 464 | rcu_read_lock(); |
| 465 | |
| 466 | cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app, |
| 467 | node.node) { |
| 468 | if (app->domain != domain) { |
| 469 | continue; |
| 470 | } |
| 471 | |
| 472 | /* Enable event on agent application through TCP socket. */ |
| 473 | ret = enable_event(app, event); |
| 474 | if (ret != LTTNG_OK) { |
| 475 | goto error; |
| 476 | } |
| 477 | } |
| 478 | |
| 479 | event->enabled = 1; |
| 480 | ret = LTTNG_OK; |
| 481 | |
| 482 | error: |
| 483 | rcu_read_unlock(); |
| 484 | return ret; |
| 485 | } |
| 486 | |
| 487 | /* |
| 488 | * Disable agent event on every agent applications registered with the session |
| 489 | * daemon. |
| 490 | * |
| 491 | * Return LTTNG_OK on success or else a LTTNG_ERR* code. |
| 492 | */ |
| 493 | int agent_disable_event(struct agent_event *event, |
| 494 | enum lttng_domain_type domain) |
| 495 | { |
| 496 | int ret; |
| 497 | struct agent_app *app; |
| 498 | struct lttng_ht_iter iter; |
| 499 | |
| 500 | assert(event); |
| 501 | |
| 502 | rcu_read_lock(); |
| 503 | |
| 504 | cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app, |
| 505 | node.node) { |
| 506 | if (app->domain != domain) { |
| 507 | continue; |
| 508 | } |
| 509 | |
| 510 | /* Enable event on agent application through TCP socket. */ |
| 511 | ret = disable_event(app, event); |
| 512 | if (ret != LTTNG_OK) { |
| 513 | goto error; |
| 514 | } |
| 515 | } |
| 516 | |
| 517 | event->enabled = 0; |
| 518 | ret = LTTNG_OK; |
| 519 | |
| 520 | error: |
| 521 | rcu_read_unlock(); |
| 522 | return ret; |
| 523 | } |
| 524 | |
| 525 | /* |
| 526 | * Ask every agent for the list of possible event. Events is allocated with the |
| 527 | * events of every agent application. |
| 528 | * |
| 529 | * Return the number of events or else a negative value. |
| 530 | */ |
| 531 | int agent_list_events(struct lttng_event **events, |
| 532 | enum lttng_domain_type domain) |
| 533 | { |
| 534 | int ret; |
| 535 | size_t nbmem, count = 0; |
| 536 | struct agent_app *app; |
| 537 | struct lttng_event *tmp_events = NULL; |
| 538 | struct lttng_ht_iter iter; |
| 539 | |
| 540 | assert(events); |
| 541 | |
| 542 | nbmem = UST_APP_EVENT_LIST_SIZE; |
| 543 | tmp_events = zmalloc(nbmem * sizeof(*tmp_events)); |
| 544 | if (!tmp_events) { |
| 545 | PERROR("zmalloc agent list events"); |
| 546 | ret = -ENOMEM; |
| 547 | goto error; |
| 548 | } |
| 549 | |
| 550 | rcu_read_lock(); |
| 551 | cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app, |
| 552 | node.node) { |
| 553 | ssize_t nb_ev; |
| 554 | struct lttng_event *agent_events; |
| 555 | |
| 556 | /* Skip domain not asked by the list. */ |
| 557 | if (app->domain != domain) { |
| 558 | continue; |
| 559 | } |
| 560 | |
| 561 | nb_ev = list_events(app, &agent_events); |
| 562 | if (nb_ev < 0) { |
| 563 | ret = nb_ev; |
| 564 | goto error_unlock; |
| 565 | } |
| 566 | |
| 567 | if (count + nb_ev > nbmem) { |
| 568 | /* In case the realloc fails, we free the memory */ |
| 569 | struct lttng_event *new_tmp_events; |
| 570 | size_t new_nbmem; |
| 571 | |
| 572 | new_nbmem = max_t(size_t, count + nb_ev, nbmem << 1); |
| 573 | DBG2("Reallocating agent event list from %zu to %zu entries", |
| 574 | nbmem, new_nbmem); |
| 575 | new_tmp_events = realloc(tmp_events, |
| 576 | new_nbmem * sizeof(*new_tmp_events)); |
| 577 | if (!new_tmp_events) { |
| 578 | PERROR("realloc agent events"); |
| 579 | ret = -ENOMEM; |
| 580 | free(agent_events); |
| 581 | goto error_unlock; |
| 582 | } |
| 583 | /* Zero the new memory */ |
| 584 | memset(new_tmp_events + nbmem, 0, |
| 585 | (new_nbmem - nbmem) * sizeof(*new_tmp_events)); |
| 586 | nbmem = new_nbmem; |
| 587 | tmp_events = new_tmp_events; |
| 588 | } |
| 589 | memcpy(tmp_events + count, agent_events, |
| 590 | nb_ev * sizeof(*tmp_events)); |
| 591 | free(agent_events); |
| 592 | count += nb_ev; |
| 593 | } |
| 594 | rcu_read_unlock(); |
| 595 | |
| 596 | ret = count; |
| 597 | *events = tmp_events; |
| 598 | return ret; |
| 599 | |
| 600 | error_unlock: |
| 601 | rcu_read_unlock(); |
| 602 | error: |
| 603 | free(tmp_events); |
| 604 | return ret; |
| 605 | } |
| 606 | |
| 607 | /* |
| 608 | * Create a agent app object using the given PID. |
| 609 | * |
| 610 | * Return newly allocated object or else NULL on error. |
| 611 | */ |
| 612 | struct agent_app *agent_create_app(pid_t pid, enum lttng_domain_type domain, |
| 613 | struct lttcomm_sock *sock) |
| 614 | { |
| 615 | struct agent_app *app; |
| 616 | |
| 617 | assert(sock); |
| 618 | |
| 619 | app = zmalloc(sizeof(*app)); |
| 620 | if (!app) { |
| 621 | PERROR("zmalloc agent create"); |
| 622 | goto error; |
| 623 | } |
| 624 | |
| 625 | app->pid = pid; |
| 626 | app->domain = domain; |
| 627 | app->sock = sock; |
| 628 | lttng_ht_node_init_ulong(&app->node, (unsigned long) app->sock->fd); |
| 629 | |
| 630 | error: |
| 631 | return app; |
| 632 | } |
| 633 | |
| 634 | /* |
| 635 | * Lookup agent app by socket in the global hash table. |
| 636 | * |
| 637 | * RCU read side lock MUST be acquired. |
| 638 | * |
| 639 | * Return object if found else NULL. |
| 640 | */ |
| 641 | struct agent_app *agent_find_app_by_sock(int sock) |
| 642 | { |
| 643 | struct lttng_ht_node_ulong *node; |
| 644 | struct lttng_ht_iter iter; |
| 645 | struct agent_app *app; |
| 646 | |
| 647 | assert(sock >= 0); |
| 648 | |
| 649 | lttng_ht_lookup(agent_apps_ht_by_sock, (void *)((unsigned long) sock), &iter); |
| 650 | node = lttng_ht_iter_get_node_ulong(&iter); |
| 651 | if (node == NULL) { |
| 652 | goto error; |
| 653 | } |
| 654 | app = caa_container_of(node, struct agent_app, node); |
| 655 | |
| 656 | DBG3("Agent app pid %d found by sock %d.", app->pid, sock); |
| 657 | return app; |
| 658 | |
| 659 | error: |
| 660 | DBG3("Agent app NOT found by sock %d.", sock); |
| 661 | return NULL; |
| 662 | } |
| 663 | |
| 664 | /* |
| 665 | * Add agent application object to the global hash table. |
| 666 | */ |
| 667 | void agent_add_app(struct agent_app *app) |
| 668 | { |
| 669 | assert(app); |
| 670 | |
| 671 | DBG3("Agent adding app sock: %d and pid: %d to ht", app->sock->fd, app->pid); |
| 672 | |
| 673 | rcu_read_lock(); |
| 674 | lttng_ht_add_unique_ulong(agent_apps_ht_by_sock, &app->node); |
| 675 | rcu_read_unlock(); |
| 676 | } |
| 677 | |
| 678 | /* |
| 679 | * Delete agent application from the global hash table. |
| 680 | */ |
| 681 | void agent_delete_app(struct agent_app *app) |
| 682 | { |
| 683 | int ret; |
| 684 | struct lttng_ht_iter iter; |
| 685 | |
| 686 | assert(app); |
| 687 | |
| 688 | DBG3("Agent deleting app pid: %d and sock: %d", app->pid, app->sock->fd); |
| 689 | |
| 690 | iter.iter.node = &app->node.node; |
| 691 | rcu_read_lock(); |
| 692 | ret = lttng_ht_del(agent_apps_ht_by_sock, &iter); |
| 693 | rcu_read_unlock(); |
| 694 | assert(!ret); |
| 695 | } |
| 696 | |
| 697 | /* |
| 698 | * Destroy a agent application object by detaching it from its corresponding |
| 699 | * UST app if one is connected by closing the socket. Finally, perform a |
| 700 | * delayed memory reclaim. |
| 701 | */ |
| 702 | void agent_destroy_app(struct agent_app *app) |
| 703 | { |
| 704 | assert(app); |
| 705 | |
| 706 | if (app->sock) { |
| 707 | app->sock->ops->close(app->sock); |
| 708 | lttcomm_destroy_sock(app->sock); |
| 709 | } |
| 710 | |
| 711 | call_rcu(&app->node.head, destroy_app_agent_rcu); |
| 712 | } |
| 713 | |
| 714 | /* |
| 715 | * Initialize an already allocated agent object. |
| 716 | * |
| 717 | * Return 0 on success or else a negative errno value. |
| 718 | */ |
| 719 | int agent_init(struct agent *agt) |
| 720 | { |
| 721 | int ret; |
| 722 | |
| 723 | assert(agt); |
| 724 | |
| 725 | agt->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING); |
| 726 | if (!agt->events) { |
| 727 | ret = -ENOMEM; |
| 728 | goto error; |
| 729 | } |
| 730 | lttng_ht_node_init_u64(&agt->node, agt->domain); |
| 731 | |
| 732 | return 0; |
| 733 | |
| 734 | error: |
| 735 | return ret; |
| 736 | } |
| 737 | |
| 738 | /* |
| 739 | * Add agent object to the given hash table. |
| 740 | */ |
| 741 | void agent_add(struct agent *agt, struct lttng_ht *ht) |
| 742 | { |
| 743 | assert(agt); |
| 744 | assert(ht); |
| 745 | |
| 746 | DBG3("Agent adding from domain %d", agt->domain); |
| 747 | |
| 748 | rcu_read_lock(); |
| 749 | lttng_ht_add_unique_u64(ht, &agt->node); |
| 750 | rcu_read_unlock(); |
| 751 | } |
| 752 | |
| 753 | /* |
| 754 | * Create an agent object for the given domain. |
| 755 | * |
| 756 | * Return the allocated agent or NULL on error. |
| 757 | */ |
| 758 | struct agent *agent_create(enum lttng_domain_type domain) |
| 759 | { |
| 760 | int ret; |
| 761 | struct agent *agt; |
| 762 | |
| 763 | agt = zmalloc(sizeof(*agt)); |
| 764 | if (!agt) { |
| 765 | goto error; |
| 766 | } |
| 767 | agt->domain = domain; |
| 768 | |
| 769 | ret = agent_init(agt); |
| 770 | if (ret < 0) { |
| 771 | free(agt); |
| 772 | agt = NULL; |
| 773 | goto error; |
| 774 | } |
| 775 | |
| 776 | error: |
| 777 | return agt; |
| 778 | } |
| 779 | |
| 780 | /* |
| 781 | * Create a newly allocated agent event data structure. If name is valid, it's |
| 782 | * copied into the created event. |
| 783 | * |
| 784 | * Return a new object else NULL on error. |
| 785 | */ |
| 786 | struct agent_event *agent_create_event(const char *name, |
| 787 | struct lttng_filter_bytecode *filter) |
| 788 | { |
| 789 | struct agent_event *event; |
| 790 | |
| 791 | DBG3("Agent create new event with name %s", name); |
| 792 | |
| 793 | event = zmalloc(sizeof(*event)); |
| 794 | if (!event) { |
| 795 | goto error; |
| 796 | } |
| 797 | |
| 798 | if (name) { |
| 799 | strncpy(event->name, name, sizeof(event->name)); |
| 800 | event->name[sizeof(event->name) - 1] = '\0'; |
| 801 | lttng_ht_node_init_str(&event->node, event->name); |
| 802 | } |
| 803 | |
| 804 | if (filter) { |
| 805 | event->filter = filter; |
| 806 | } |
| 807 | |
| 808 | error: |
| 809 | return event; |
| 810 | } |
| 811 | |
| 812 | /* |
| 813 | * Unique add of a agent event to an agent object. |
| 814 | */ |
| 815 | void agent_add_event(struct agent_event *event, struct agent *agt) |
| 816 | { |
| 817 | assert(event); |
| 818 | assert(agt); |
| 819 | assert(agt->events); |
| 820 | |
| 821 | DBG3("Agent adding event %s", event->name); |
| 822 | |
| 823 | rcu_read_lock(); |
| 824 | add_unique_agent_event(agt->events, event); |
| 825 | rcu_read_unlock(); |
| 826 | agt->being_used = 1; |
| 827 | } |
| 828 | |
| 829 | /* |
| 830 | * Find a agent event in the given agent using name. |
| 831 | * |
| 832 | * RCU read side lock MUST be acquired. |
| 833 | * |
| 834 | * Return object if found else NULL. |
| 835 | */ |
| 836 | struct agent_event *agent_find_event_by_name(const char *name, |
| 837 | struct agent *agt) |
| 838 | { |
| 839 | struct lttng_ht_node_str *node; |
| 840 | struct lttng_ht_iter iter; |
| 841 | struct lttng_ht *ht; |
| 842 | struct agent_ht_key key; |
| 843 | |
| 844 | assert(name); |
| 845 | assert(agt); |
| 846 | assert(agt->events); |
| 847 | |
| 848 | ht = agt->events; |
| 849 | key.name = name; |
| 850 | |
| 851 | cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed), |
| 852 | ht_match_event_by_name, &key, &iter.iter); |
| 853 | node = lttng_ht_iter_get_node_str(&iter); |
| 854 | if (node == NULL) { |
| 855 | goto error; |
| 856 | } |
| 857 | |
| 858 | DBG3("Agent event found %s by name.", name); |
| 859 | return caa_container_of(node, struct agent_event, node); |
| 860 | |
| 861 | error: |
| 862 | DBG3("Agent NOT found by name %s.", name); |
| 863 | return NULL; |
| 864 | } |
| 865 | |
| 866 | /* |
| 867 | * Find a agent event in the given agent using name and loglevel. |
| 868 | * |
| 869 | * RCU read side lock MUST be acquired. |
| 870 | * |
| 871 | * Return object if found else NULL. |
| 872 | */ |
| 873 | struct agent_event *agent_find_event(const char *name, int loglevel, |
| 874 | struct agent *agt) |
| 875 | { |
| 876 | struct lttng_ht_node_str *node; |
| 877 | struct lttng_ht_iter iter; |
| 878 | struct lttng_ht *ht; |
| 879 | struct agent_ht_key key; |
| 880 | |
| 881 | assert(name); |
| 882 | assert(agt); |
| 883 | assert(agt->events); |
| 884 | |
| 885 | ht = agt->events; |
| 886 | key.name = name; |
| 887 | key.loglevel = loglevel; |
| 888 | |
| 889 | cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed), |
| 890 | ht_match_event, &key, &iter.iter); |
| 891 | node = lttng_ht_iter_get_node_str(&iter); |
| 892 | if (node == NULL) { |
| 893 | goto error; |
| 894 | } |
| 895 | |
| 896 | DBG3("Agent event found %s.", name); |
| 897 | return caa_container_of(node, struct agent_event, node); |
| 898 | |
| 899 | error: |
| 900 | DBG3("Agent NOT found %s.", name); |
| 901 | return NULL; |
| 902 | } |
| 903 | |
| 904 | /* |
| 905 | * Free given agent event. This event must not be globally visible at this |
| 906 | * point (only expected to be used on failure just after event creation). After |
| 907 | * this call, the pointer is not usable anymore. |
| 908 | */ |
| 909 | void agent_destroy_event(struct agent_event *event) |
| 910 | { |
| 911 | assert(event); |
| 912 | |
| 913 | free(event); |
| 914 | } |
| 915 | |
| 916 | /* |
| 917 | * Destroy an agent completely. Note that the given pointer is NOT freed |
| 918 | * thus a reference to static or stack data can be passed to this function. |
| 919 | */ |
| 920 | void agent_destroy(struct agent *agt) |
| 921 | { |
| 922 | struct lttng_ht_node_str *node; |
| 923 | struct lttng_ht_iter iter; |
| 924 | |
| 925 | assert(agt); |
| 926 | |
| 927 | DBG3("Agent destroy"); |
| 928 | |
| 929 | /* |
| 930 | * Just ignore if no events hash table exists. This is possible if for |
| 931 | * instance an agent object was allocated but not initialized. |
| 932 | */ |
| 933 | if (!agt->events) { |
| 934 | return; |
| 935 | } |
| 936 | |
| 937 | rcu_read_lock(); |
| 938 | cds_lfht_for_each_entry(agt->events->ht, &iter.iter, node, node) { |
| 939 | int ret; |
| 940 | struct agent_event *event; |
| 941 | |
| 942 | /* |
| 943 | * When destroying an event, we have to try to disable it on the agent |
| 944 | * side so the event stops generating data. The return value is not |
| 945 | * important since we have to continue anyway destroying the object. |
| 946 | */ |
| 947 | event = caa_container_of(node, struct agent_event, node); |
| 948 | (void) agent_disable_event(event, agt->domain); |
| 949 | |
| 950 | ret = lttng_ht_del(agt->events, &iter); |
| 951 | assert(!ret); |
| 952 | call_rcu(&node->head, destroy_event_agent_rcu); |
| 953 | } |
| 954 | rcu_read_unlock(); |
| 955 | |
| 956 | lttng_ht_destroy(agt->events); |
| 957 | } |
| 958 | |
| 959 | /* |
| 960 | * Initialize agent subsystem. |
| 961 | */ |
| 962 | int agent_setup(void) |
| 963 | { |
| 964 | agent_apps_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); |
| 965 | if (!agent_apps_ht_by_sock) { |
| 966 | return -1; |
| 967 | } |
| 968 | |
| 969 | return 0; |
| 970 | } |
| 971 | |
| 972 | /* |
| 973 | * Update a agent application (given socket) using the given agent. |
| 974 | * |
| 975 | * Note that this function is most likely to be used with a tracing session |
| 976 | * thus the caller should make sure to hold the appropriate lock(s). |
| 977 | */ |
| 978 | void agent_update(struct agent *agt, int sock) |
| 979 | { |
| 980 | int ret; |
| 981 | struct agent_app *app; |
| 982 | struct agent_event *event; |
| 983 | struct lttng_ht_iter iter; |
| 984 | |
| 985 | assert(agt); |
| 986 | assert(sock >= 0); |
| 987 | |
| 988 | DBG("Agent updating app socket %d", sock); |
| 989 | |
| 990 | rcu_read_lock(); |
| 991 | cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) { |
| 992 | /* Skip event if disabled. */ |
| 993 | if (!event->enabled) { |
| 994 | continue; |
| 995 | } |
| 996 | |
| 997 | app = agent_find_app_by_sock(sock); |
| 998 | /* |
| 999 | * We are in the registration path thus if the application is gone, |
| 1000 | * there is a serious code flow error. |
| 1001 | */ |
| 1002 | assert(app); |
| 1003 | |
| 1004 | ret = enable_event(app, event); |
| 1005 | if (ret != LTTNG_OK) { |
| 1006 | DBG2("Agent update unable to enable event %s on app pid: %d sock %d", |
| 1007 | event->name, app->pid, app->sock->fd); |
| 1008 | /* Let's try the others here and don't assume the app is dead. */ |
| 1009 | continue; |
| 1010 | } |
| 1011 | } |
| 1012 | rcu_read_unlock(); |
| 1013 | } |