liblttng-ust-ctl/ustctl.c

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; version 2 of the License only.
   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 <string.h>
  21 #include <lttng/ust-ctl.h>
  22 #include <lttng/ust-abi.h>
  23 #include <lttng/ust-events.h>
  24 #include <sys/mman.h>
  25
  26 #include <usterr-signal-safe.h>
  27 #include <ust-comm.h>
  28
  29 #include "../libringbuffer/backend.h"
  30 #include "../libringbuffer/frontend.h"
  31
  32 volatile enum ust_loglevel ust_loglevel;
  33
  34 static
  35 void init_object(struct lttng_ust_object_data *data)
  36 {
  37         data->handle = -1;
  38         data->shm_fd = -1;
  39         data->shm_path = NULL;
  40         data->wait_fd = -1;
  41         data->wait_pipe_path = NULL;
  42         data->memory_map_size = 0;
  43 }
  44
  45 int ustctl_release_handle(int sock, int handle)
  46 {
  47         struct ustcomm_ust_msg lum;
  48         struct ustcomm_ust_reply lur;
  49         int ret;
  50
  51         if (sock >= 0) {
  52                 memset(&lum, 0, sizeof(lum));
  53                 lum.handle = handle;
  54                 lum.cmd = LTTNG_UST_RELEASE;
  55                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
  56                 if (ret < 0) {
  57                         return ret;
  58                 }
  59         }
  60         return 0;
  61 }
  62 /*
  63  * If sock is negative, it means we don't have to notify the other side
  64  * (e.g. application has already vanished).
  65  */
  66 int ustctl_release_object(int sock, struct lttng_ust_object_data *data)
  67 {
  68         int ret;
  69
  70         if (!data)
  71                 return -EINVAL;
  72
  73         if (data->shm_fd >= 0) {
  74                 ret = close(data->shm_fd);
  75                 if (ret < 0) {
  76                         return ret;
  77                 }
  78         }
  79
  80         if (data->shm_path) {
  81                 free(data->shm_path);
  82         }
  83
  84         if (data->wait_fd >= 0) {
  85                 ret = close(data->wait_fd);
  86                 if (ret < 0) {
  87                         return ret;
  88                 }
  89         }
  90
  91         if (data->wait_pipe_path) {
  92                 free(data->wait_pipe_path);
  93         }
  94
  95         return ustctl_release_handle(sock, data->handle);
  96 }
  97
  98 /*
  99  * Send registration done packet to the application.
 100  */
 101 int ustctl_register_done(int sock)
 102 {
 103         struct ustcomm_ust_msg lum;
 104         struct ustcomm_ust_reply lur;
 105         int ret;
 106
 107         DBG("Sending register done command to %d", sock);
 108         memset(&lum, 0, sizeof(lum));
 109         lum.handle = LTTNG_UST_ROOT_HANDLE;
 110         lum.cmd = LTTNG_UST_REGISTER_DONE;
 111         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 112         if (ret)
 113                 return ret;
 114         if (lur.ret_code != USTCOMM_OK) {
 115                 DBG("Return code: %s", ustcomm_get_readable_code(lur.ret_code));
 116                 goto error;
 117         }
 118         return 0;
 119
 120 error:
 121         return -1;
 122 }
 123
 124 /*
 125  * returns session handle.
 126  */
 127 int ustctl_create_session(int sock)
 128 {
 129         struct ustcomm_ust_msg lum;
 130         struct ustcomm_ust_reply lur;
 131         int ret, session_handle;
 132
 133         /* Create session */
 134         memset(&lum, 0, sizeof(lum));
 135         lum.handle = LTTNG_UST_ROOT_HANDLE;
 136         lum.cmd = LTTNG_UST_SESSION;
 137         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 138         if (ret)
 139                 return ret;
 140         session_handle = lur.ret_val;
 141         DBG("received session handle %u", session_handle);
 142         return session_handle;
 143 }
 144
 145 /* open the metadata global channel */
 146 int ustctl_open_metadata(int sock, int session_handle,
 147                 struct lttng_ust_channel_attr *chops,
 148                 struct lttng_ust_object_data **_metadata_data)
 149 {
 150         struct ustcomm_ust_msg lum;
 151         struct ustcomm_ust_reply lur;
 152         struct lttng_ust_object_data *metadata_data;
 153         int ret, err = 0;
 154         char *shm_path, *wait_pipe_path;
 155
 156         if (!chops || !_metadata_data)
 157                 return -EINVAL;
 158
 159         metadata_data = malloc(sizeof(*metadata_data));
 160         if (!metadata_data)
 161                 return -ENOMEM;
 162         init_object(metadata_data);
 163         /* Create metadata channel */
 164         memset(&lum, 0, sizeof(lum));
 165         lum.handle = session_handle;
 166         lum.cmd = LTTNG_UST_METADATA;
 167         lum.u.channel.overwrite = chops->overwrite;
 168         lum.u.channel.subbuf_size = chops->subbuf_size;
 169         lum.u.channel.num_subbuf = chops->num_subbuf;
 170         lum.u.channel.switch_timer_interval = chops->switch_timer_interval;
 171         lum.u.channel.read_timer_interval = chops->read_timer_interval;
 172         lum.u.channel.output = chops->output;
 173         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 174         if (ret) {
 175                 free(metadata_data);
 176                 return ret;
 177         }
 178         if (lur.ret_code != USTCOMM_OK) {
 179                 free(metadata_data);
 180                 return lur.ret_code;
 181         }
 182         metadata_data->handle = lur.ret_val;
 183         DBG("received metadata handle %u", metadata_data->handle);
 184         metadata_data->memory_map_size = lur.u.channel.memory_map_size;
 185         /* get shm path */
 186         shm_path = ustcomm_recv_string(sock);
 187         if (!shm_path) {
 188                 err = 1;
 189         } else {
 190                 DBG("Received shm path: %s\n", shm_path);
 191                 metadata_data->shm_fd = -1;
 192                 metadata_data->shm_path = shm_path;
 193         }
 194
 195         /*
 196          * We need to get the second FD even if the first fails, because
 197          * libust expects us to read the two FDs.
 198          */
 199
 200         /* get wait pipe path */
 201         wait_pipe_path = ustcomm_recv_string(sock);
 202         if (!wait_pipe_path) {
 203                 free(shm_path);
 204                 err = 1;
 205         } else {
 206                 DBG("Received wait pipe path: %s\n", wait_pipe_path);
 207                 metadata_data->wait_fd = -1;
 208                 metadata_data->wait_pipe_path = wait_pipe_path;
 209         }
 210
 211
 212         if (err)
 213                 goto error;
 214         *_metadata_data = metadata_data;
 215         return 0;
 216
 217 error:
 218         (void) ustctl_release_object(sock, metadata_data);
 219         free(metadata_data);
 220         return -EINVAL;
 221 }
 222
 223 int ustctl_create_channel(int sock, int session_handle,
 224                 struct lttng_ust_channel_attr *chops,
 225                 struct lttng_ust_object_data **_channel_data)
 226 {
 227         struct ustcomm_ust_msg lum;
 228         struct ustcomm_ust_reply lur;
 229         struct lttng_ust_object_data *channel_data;
 230         int ret, err = 0;
 231         char *shm_path, *wait_pipe_path;
 232
 233         if (!chops || !_channel_data)
 234                 return -EINVAL;
 235
 236         channel_data = malloc(sizeof(*channel_data));
 237         if (!channel_data)
 238                 return -ENOMEM;
 239         init_object(channel_data);
 240         /* Create metadata channel */
 241         memset(&lum, 0, sizeof(lum));
 242         lum.handle = session_handle;
 243         lum.cmd = LTTNG_UST_CHANNEL;
 244         lum.u.channel.overwrite = chops->overwrite;
 245         lum.u.channel.subbuf_size = chops->subbuf_size;
 246         lum.u.channel.num_subbuf = chops->num_subbuf;
 247         lum.u.channel.switch_timer_interval = chops->switch_timer_interval;
 248         lum.u.channel.read_timer_interval = chops->read_timer_interval;
 249         lum.u.channel.output = chops->output;
 250         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 251         if (ret) {
 252                 free(channel_data);
 253                 return ret;
 254         }
 255         if (lur.ret_code != USTCOMM_OK) {
 256                 free(channel_data);
 257                 return lur.ret_code;
 258         }
 259         channel_data->handle = lur.ret_val;
 260         DBG("received channel handle %u", channel_data->handle);
 261         channel_data->memory_map_size = lur.u.channel.memory_map_size;
 262         /* get shm path */
 263         shm_path = ustcomm_recv_string(sock);
 264         if (!shm_path) {
 265                 err = 1;
 266         } else {
 267                 DBG("Received shm path: %s\n", shm_path);
 268                 channel_data->shm_fd = -1;
 269                 channel_data->shm_path = shm_path;
 270         }
 271
 272         /*
 273          * We need to get the second FD even if the first fails, because
 274          * libust expects us to read the two FDs.
 275          */
 276         /* get wait pipe path */
 277         wait_pipe_path = ustcomm_recv_string(sock);
 278         if (!wait_pipe_path) {
 279                 free(shm_path);
 280                 err = 1;
 281         } else {
 282                 DBG("Received wait pipe path: %s\n", wait_pipe_path);
 283                 channel_data->wait_fd = -1;
 284                 channel_data->wait_pipe_path = wait_pipe_path;
 285         }
 286
 287         if (err)
 288                 goto error;
 289         *_channel_data = channel_data;
 290         return 0;
 291
 292 error:
 293         (void) ustctl_release_object(sock, channel_data);
 294         free(channel_data);
 295         return -EINVAL;
 296 }
 297
 298 /*
 299  * Return -ENOENT if no more stream is available for creation.
 300  * Return 0 on success.
 301  * Return negative error value on error.
 302  */
 303 int ustctl_create_stream(int sock, struct lttng_ust_object_data *channel_data,
 304                 struct lttng_ust_object_data **_stream_data)
 305 {
 306         struct ustcomm_ust_msg lum;
 307         struct ustcomm_ust_reply lur;
 308         struct lttng_ust_object_data *stream_data;
 309         int ret, err = 0;
 310         char *shm_path, *wait_pipe_path;
 311
 312         if (!channel_data || !_stream_data)
 313                 return -EINVAL;
 314
 315         stream_data = malloc(sizeof(*stream_data));
 316         if (!stream_data)
 317                 return -ENOMEM;
 318         init_object(stream_data);
 319         memset(&lum, 0, sizeof(lum));
 320         lum.handle = channel_data->handle;
 321         lum.cmd = LTTNG_UST_STREAM;
 322         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 323         if (ret) {
 324                 free(stream_data);
 325                 return ret;
 326         }
 327         if (lur.ret_code != USTCOMM_OK) {
 328                 free(stream_data);
 329                 return lur.ret_code;
 330         }
 331
 332         stream_data->handle = lur.ret_val;
 333         DBG("received stream handle %u", stream_data->handle);
 334         stream_data->memory_map_size = lur.u.stream.memory_map_size;
 335         /* get shm path */
 336         shm_path = ustcomm_recv_string(sock);
 337         if (!shm_path) {
 338                 err = 1;
 339         } else {
 340                 DBG("Received shm path: %s\n", shm_path);
 341                 stream_data->shm_fd = -1;
 342                 stream_data->shm_path = shm_path;
 343         }
 344
 345         /*
 346          * We need to get the second FD even if the first fails, because
 347          * libust expects us to read the two FDs.
 348          */
 349         /* get wait pipe path */
 350         wait_pipe_path = ustcomm_recv_string(sock);
 351         if (!wait_pipe_path) {
 352                 free(shm_path);
 353                 err = 1;
 354         } else {
 355                 DBG("Received wait pipe path: %s\n", wait_pipe_path);
 356                 stream_data->wait_fd = -1;
 357                 stream_data->wait_pipe_path = wait_pipe_path;
 358         }
 359
 360         if (err)
 361                 goto error;
 362         *_stream_data = stream_data;
 363         return ret;
 364
 365 error:
 366         (void) ustctl_release_object(sock, stream_data);
 367         free(stream_data);
 368         return -EINVAL;
 369 }
 370
 371 int ustctl_create_event(int sock, struct lttng_ust_event *ev,
 372                 struct lttng_ust_object_data *channel_data,
 373                 struct lttng_ust_object_data **_event_data)
 374 {
 375         struct ustcomm_ust_msg lum;
 376         struct ustcomm_ust_reply lur;
 377         struct lttng_ust_object_data *event_data;
 378         int ret;
 379
 380         if (!channel_data || !_event_data)
 381                 return -EINVAL;
 382
 383         event_data = malloc(sizeof(*event_data));
 384         if (!event_data)
 385                 return -ENOMEM;
 386         init_object(event_data);
 387         memset(&lum, 0, sizeof(lum));
 388         lum.handle = channel_data->handle;
 389         lum.cmd = LTTNG_UST_EVENT;
 390         strncpy(lum.u.event.name, ev->name,
 391                 LTTNG_UST_SYM_NAME_LEN);
 392         lum.u.event.instrumentation = ev->instrumentation;
 393         lum.u.event.loglevel_type = ev->loglevel_type;
 394         lum.u.event.loglevel = ev->loglevel;
 395         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 396         if (ret) {
 397                 free(event_data);
 398                 return ret;
 399         }
 400         event_data->handle = lur.ret_val;
 401         DBG("received event handle %u", event_data->handle);
 402         *_event_data = event_data;
 403         return 0;
 404 }
 405
 406 int ustctl_add_context(int sock, struct lttng_ust_context *ctx,
 407                 struct lttng_ust_object_data *obj_data,
 408                 struct lttng_ust_object_data **_context_data)
 409 {
 410         struct ustcomm_ust_msg lum;
 411         struct ustcomm_ust_reply lur;
 412         struct lttng_ust_object_data *context_data;
 413         int ret;
 414
 415         if (!obj_data || !_context_data)
 416                 return -EINVAL;
 417
 418         context_data = malloc(sizeof(*context_data));
 419         if (!context_data)
 420                 return -ENOMEM;
 421         init_object(context_data);
 422         memset(&lum, 0, sizeof(lum));
 423         lum.handle = obj_data->handle;
 424         lum.cmd = LTTNG_UST_CONTEXT;
 425         lum.u.context.ctx = ctx->ctx;
 426         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 427         if (ret) {
 428                 free(context_data);
 429                 return ret;
 430         }
 431         context_data->handle = lur.ret_val;
 432         DBG("received context handle %u", context_data->handle);
 433         *_context_data = context_data;
 434         return ret;
 435 }
 436
 437 /* Enable event, channel and session ioctl */
 438 int ustctl_enable(int sock, struct lttng_ust_object_data *object)
 439 {
 440         struct ustcomm_ust_msg lum;
 441         struct ustcomm_ust_reply lur;
 442         int ret;
 443
 444         if (!object)
 445                 return -EINVAL;
 446
 447         memset(&lum, 0, sizeof(lum));
 448         lum.handle = object->handle;
 449         lum.cmd = LTTNG_UST_ENABLE;
 450         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 451         if (ret)
 452                 return ret;
 453         DBG("enabled handle %u", object->handle);
 454         return 0;
 455 }
 456
 457 /* Disable event, channel and session ioctl */
 458 int ustctl_disable(int sock, struct lttng_ust_object_data *object)
 459 {
 460         struct ustcomm_ust_msg lum;
 461         struct ustcomm_ust_reply lur;
 462         int ret;
 463
 464         if (!object)
 465                 return -EINVAL;
 466
 467         memset(&lum, 0, sizeof(lum));
 468         lum.handle = object->handle;
 469         lum.cmd = LTTNG_UST_DISABLE;
 470         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 471         if (ret)
 472                 return ret;
 473         DBG("disable handle %u", object->handle);
 474         return 0;
 475 }
 476
 477 int ustctl_start_session(int sock, int handle)
 478 {
 479         struct lttng_ust_object_data obj;
 480
 481         obj.handle = handle;
 482         return ustctl_enable(sock, &obj);
 483 }
 484
 485 int ustctl_stop_session(int sock, int handle)
 486 {
 487         struct lttng_ust_object_data obj;
 488
 489         obj.handle = handle;
 490         return ustctl_disable(sock, &obj);
 491 }
 492
 493 int ustctl_tracepoint_list(int sock)
 494 {
 495         struct ustcomm_ust_msg lum;
 496         struct ustcomm_ust_reply lur;
 497         int ret, tp_list_handle;
 498
 499         memset(&lum, 0, sizeof(lum));
 500         lum.handle = LTTNG_UST_ROOT_HANDLE;
 501         lum.cmd = LTTNG_UST_TRACEPOINT_LIST;
 502         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 503         if (ret)
 504                 return ret;
 505         tp_list_handle = lur.ret_val;
 506         DBG("received tracepoint list handle %u", tp_list_handle);
 507         return tp_list_handle;
 508 }
 509
 510 int ustctl_tracepoint_list_get(int sock, int tp_list_handle,
 511                 struct lttng_ust_tracepoint_iter *iter)
 512 {
 513         struct ustcomm_ust_msg lum;
 514         struct ustcomm_ust_reply lur;
 515         int ret;
 516
 517         if (!iter)
 518                 return -EINVAL;
 519
 520         memset(&lum, 0, sizeof(lum));
 521         lum.handle = tp_list_handle;
 522         lum.cmd = LTTNG_UST_TRACEPOINT_LIST_GET;
 523         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 524         if (ret)
 525                 return ret;
 526         DBG("received tracepoint list entry name %s loglevel %d",
 527                 lur.u.tracepoint.name,
 528                 lur.u.tracepoint.loglevel);
 529         memcpy(iter, &lur.u.tracepoint, sizeof(*iter));
 530         return 0;
 531 }
 532
 533 int ustctl_tracer_version(int sock, struct lttng_ust_tracer_version *v)
 534 {
 535         struct ustcomm_ust_msg lum;
 536         struct ustcomm_ust_reply lur;
 537         int ret;
 538
 539         if (!v)
 540                 return -EINVAL;
 541
 542         memset(&lum, 0, sizeof(lum));
 543         lum.handle = LTTNG_UST_ROOT_HANDLE;
 544         lum.cmd = LTTNG_UST_TRACER_VERSION;
 545         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 546         if (ret)
 547                 return ret;
 548         memcpy(v, &lur.u.version, sizeof(*v));
 549         DBG("received tracer version");
 550         return 0;
 551 }
 552
 553 int ustctl_wait_quiescent(int sock)
 554 {
 555         struct ustcomm_ust_msg lum;
 556         struct ustcomm_ust_reply lur;
 557         int ret;
 558
 559         memset(&lum, 0, sizeof(lum));
 560         lum.handle = LTTNG_UST_ROOT_HANDLE;
 561         lum.cmd = LTTNG_UST_WAIT_QUIESCENT;
 562         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 563         if (ret)
 564                 return ret;
 565         DBG("waited for quiescent state");
 566         return 0;
 567 }
 568
 569 int ustctl_calibrate(int sock, struct lttng_ust_calibrate *calibrate)
 570 {
 571         if (!calibrate)
 572                 return -EINVAL;
 573
 574         return -ENOSYS;
 575 }
 576
 577 int ustctl_sock_flush_buffer(int sock, struct lttng_ust_object_data *object)
 578 {
 579         struct ustcomm_ust_msg lum;
 580         struct ustcomm_ust_reply lur;
 581         int ret;
 582
 583         if (!object)
 584                 return -EINVAL;
 585
 586         memset(&lum, 0, sizeof(lum));
 587         lum.handle = object->handle;
 588         lum.cmd = LTTNG_UST_FLUSH_BUFFER;
 589         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 590         if (ret)
 591                 return ret;
 592         DBG("flushed buffer handle %u", object->handle);
 593         return 0;
 594 }
 595
 596 /* Buffer operations */
 597
 598 /* Map channel shm into process memory */
 599 struct lttng_ust_shm_handle *ustctl_map_channel(struct lttng_ust_object_data *chan_data)
 600 {
 601         struct lttng_ust_shm_handle *handle;
 602         struct channel *chan;
 603         size_t chan_size;
 604         struct lttng_ust_lib_ring_buffer_config *config;
 605         int ret;
 606
 607         if (!chan_data)
 608                 return NULL;
 609
 610         handle = channel_handle_create(chan_data->shm_fd,
 611                 chan_data->wait_fd,
 612                 chan_data->memory_map_size);
 613         if (!handle) {
 614                 ERR("create handle error");
 615                 return NULL;
 616         }
 617         /*
 618          * Set to -1, and then close the shm fd, and set the handle shm
 619          * fd to -1 too. We don't need the shm fds after they have been
 620          * mapped.
 621          * The wait_fd is set to -1 in chan_data because it is now owned
 622          * by the handle.
 623          */
 624         chan_data->shm_fd = -1;
 625         chan_data->wait_fd = -1;
 626
 627         /* chan is object 0. This is hardcoded. */
 628         if (handle->table->objects[0].shm_fd >= 0) {
 629                 ret = close(handle->table->objects[0].shm_fd);
 630                 if (ret) {
 631                         perror("Error closing shm_fd");
 632                 }
 633                 handle->table->objects[0].shm_fd = -1;
 634         }
 635
 636         /*
 637          * TODO: add consistency checks to be resilient if the
 638          * application try to feed us with incoherent channel structure
 639          * values.
 640          */
 641         chan = shmp(handle, handle->chan);
 642         /* chan is object 0. This is hardcoded. */
 643         chan_size = handle->table->objects[0].allocated_len;
 644         handle->shadow_chan = malloc(chan_size);
 645         if (!handle->shadow_chan) {
 646                 channel_destroy(chan, handle, 1);
 647                 return NULL;
 648         }
 649         memcpy(handle->shadow_chan, chan, chan_size);
 650         /*
 651          * The callback pointers in the producer are invalid in the
 652          * consumer. We need to look them up here.
 653          */
 654         config = &handle->shadow_chan->backend.config;
 655         switch (config->client_type) {
 656         case LTTNG_CLIENT_METADATA:
 657                 memcpy(&config->cb, lttng_client_callbacks_metadata,
 658                         sizeof(config->cb));
 659                 break;
 660         case LTTNG_CLIENT_DISCARD:
 661                 memcpy(&config->cb, lttng_client_callbacks_discard,
 662                         sizeof(config->cb));
 663                 break;
 664         case LTTNG_CLIENT_OVERWRITE:
 665                 memcpy(&config->cb, lttng_client_callbacks_overwrite,
 666                         sizeof(config->cb));
 667                 break;
 668         default:
 669                 ERR("Unknown client type %d", config->client_type);
 670                 channel_destroy(chan, handle, 1);
 671                 return NULL;
 672         }
 673         /* Replace the object table pointer. */
 674         ret = munmap(handle->table->objects[0].memory_map,
 675                 handle->table->objects[0].memory_map_size);
 676         if (ret) {
 677                 perror("munmap");
 678                 assert(0);
 679         }
 680         handle->table->objects[0].memory_map = (char *) handle->shadow_chan;
 681         handle->table->objects[0].is_shadow = 1;
 682         return handle;
 683 }
 684
 685 /* Add stream to channel shm and map its shm into process memory */
 686 int ustctl_add_stream(struct lttng_ust_shm_handle *handle,
 687                 struct lttng_ust_object_data *stream_data)
 688 {
 689         int ret;
 690
 691         if (!handle || !stream_data)
 692                 return -EINVAL;
 693
 694         if (!stream_data->handle)
 695                 return -ENOENT;
 696         /* map stream */
 697         ret = channel_handle_add_stream(handle,
 698                 stream_data->shm_fd,
 699                 stream_data->wait_fd,
 700                 stream_data->memory_map_size);
 701         if (ret) {
 702                 ERR("add stream error\n");
 703                 return ret;
 704         }
 705         /*
 706          * Set to -1 because the lttng_ust_shm_handle destruction will take care
 707          * of closing shm_fd and wait_fd.
 708          */
 709         stream_data->shm_fd = -1;
 710         stream_data->wait_fd = -1;
 711         return 0;
 712 }
 713
 714 void ustctl_unmap_channel(struct lttng_ust_shm_handle *handle)
 715 {
 716         struct channel *chan;
 717
 718         assert(handle);
 719         chan = shmp(handle, handle->chan);
 720         channel_destroy(chan, handle, 1);
 721 }
 722
 723 /*
 724  * ustctl closes the shm_fd fds after mapping it.
 725  */
 726 struct lttng_ust_lib_ring_buffer *ustctl_open_stream_read(struct lttng_ust_shm_handle *handle,
 727         int cpu)
 728 {
 729         struct channel *chan;
 730         int *shm_fd, *wait_fd;
 731         char *shm_path, *wait_pipe_path;
 732         uint64_t *memory_map_size;
 733         struct lttng_ust_lib_ring_buffer *buf;
 734         int ret;
 735
 736         if (!handle)
 737                 return NULL;
 738
 739         chan = handle->shadow_chan;
 740         buf = channel_get_ring_buffer(&chan->backend.config,
 741                                       chan, cpu, handle,
 742                                       &shm_fd, &shm_path,
 743                                       &wait_fd, &wait_pipe_path,
 744                                       &memory_map_size);
 745         if (!buf)
 746                 return NULL;
 747         ret = lib_ring_buffer_open_read(buf, handle, 1);
 748         if (ret)
 749                 return NULL;
 750         /*
 751          * We can close shm_fd early, right after is has been mapped.
 752          */
 753         if (*shm_fd >= 0) {
 754                 ret = close(*shm_fd);
 755                 if (ret) {
 756                         perror("Error closing shm_fd");
 757                 }
 758                 *shm_fd = -1;
 759         }
 760         return buf;
 761 }
 762
 763 void ustctl_close_stream_read(struct lttng_ust_shm_handle *handle,
 764                 struct lttng_ust_lib_ring_buffer *buf)
 765 {
 766         assert(handle && buf);
 767         lib_ring_buffer_release_read(buf, handle, 1);
 768 }
 769
 770 /* For mmap mode, readable without "get" operation */
 771
 772 void *ustctl_get_mmap_base(struct lttng_ust_shm_handle *handle,
 773                 struct lttng_ust_lib_ring_buffer *buf)
 774 {
 775         if (!handle || !buf)
 776                 return NULL;
 777         return shmp(handle, buf->backend.memory_map);
 778 }
 779
 780 /* returns the length to mmap. */
 781 int ustctl_get_mmap_len(struct lttng_ust_shm_handle *handle,
 782                 struct lttng_ust_lib_ring_buffer *buf,
 783                 unsigned long *len)
 784 {
 785         unsigned long mmap_buf_len;
 786         struct channel *chan;
 787
 788         if (!handle || !buf || !len)
 789                 return -EINVAL;
 790
 791         chan = handle->shadow_chan;
 792         if (chan->backend.config.output != RING_BUFFER_MMAP)
 793                 return -EINVAL;
 794         mmap_buf_len = chan->backend.buf_size;
 795         if (chan->backend.extra_reader_sb)
 796                 mmap_buf_len += chan->backend.subbuf_size;
 797         if (mmap_buf_len > INT_MAX)
 798                 return -EFBIG;
 799         *len = mmap_buf_len;
 800         return 0;
 801 }
 802
 803 /* returns the maximum size for sub-buffers. */
 804 int ustctl_get_max_subbuf_size(struct lttng_ust_shm_handle *handle,
 805                 struct lttng_ust_lib_ring_buffer *buf,
 806                 unsigned long *len)
 807 {
 808         struct channel *chan;
 809
 810         if (!handle || !buf || !len)
 811                 return -EINVAL;
 812
 813         chan = handle->shadow_chan;
 814         *len = chan->backend.subbuf_size;
 815         return 0;
 816 }
 817
 818 /*
 819  * For mmap mode, operate on the current packet (between get/put or
 820  * get_next/put_next).
 821  */
 822
 823 /* returns the offset of the subbuffer belonging to the mmap reader. */
 824 int ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle,
 825                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *off)
 826 {
 827         struct channel *chan;
 828         unsigned long sb_bindex;
 829
 830         if (!handle || !buf || !off)
 831                 return -EINVAL;
 832
 833         chan = handle->shadow_chan;
 834         if (chan->backend.config.output != RING_BUFFER_MMAP)
 835                 return -EINVAL;
 836         sb_bindex = subbuffer_id_get_index(&chan->backend.config,
 837                                            buf->backend.buf_rsb.id);
 838         *off = shmp(handle, shmp_index(handle, buf->backend.array, sb_bindex)->shmp)->mmap_offset;
 839         return 0;
 840 }
 841
 842 /* returns the size of the current sub-buffer, without padding (for mmap). */
 843 int ustctl_get_subbuf_size(struct lttng_ust_shm_handle *handle,
 844                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *len)
 845 {
 846         struct channel *chan;
 847
 848         if (!handle || !buf || !len)
 849                 return -EINVAL;
 850
 851         chan = handle->shadow_chan;
 852         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
 853                 handle);
 854         return 0;
 855 }
 856
 857 /* returns the size of the current sub-buffer, without padding (for mmap). */
 858 int ustctl_get_padded_subbuf_size(struct lttng_ust_shm_handle *handle,
 859                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *len)
 860 {
 861         struct channel *chan;
 862
 863         if (!handle || !buf || !len)
 864                 return -EINVAL;
 865
 866         chan = handle->shadow_chan;
 867         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
 868                 handle);
 869         *len = PAGE_ALIGN(*len);
 870         return 0;
 871 }
 872
 873 /* Get exclusive read access to the next sub-buffer that can be read. */
 874 int ustctl_get_next_subbuf(struct lttng_ust_shm_handle *handle,
 875                 struct lttng_ust_lib_ring_buffer *buf)
 876 {
 877         if (!handle || !buf)
 878                 return -EINVAL;
 879
 880         return lib_ring_buffer_get_next_subbuf(buf, handle);
 881 }
 882
 883
 884 /* Release exclusive sub-buffer access, move consumer forward. */
 885 int ustctl_put_next_subbuf(struct lttng_ust_shm_handle *handle,
 886                 struct lttng_ust_lib_ring_buffer *buf)
 887 {
 888         if (!handle || !buf)
 889                 return -EINVAL;
 890
 891         lib_ring_buffer_put_next_subbuf(buf, handle);
 892         return 0;
 893 }
 894
 895 /* snapshot */
 896
 897 /* Get a snapshot of the current ring buffer producer and consumer positions */
 898 int ustctl_snapshot(struct lttng_ust_shm_handle *handle,
 899                 struct lttng_ust_lib_ring_buffer *buf)
 900 {
 901         if (!handle || !buf)
 902                 return -EINVAL;
 903
 904         return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
 905                         &buf->prod_snapshot, handle);
 906 }
 907
 908 /* Get the consumer position (iteration start) */
 909 int ustctl_snapshot_get_consumed(struct lttng_ust_shm_handle *handle,
 910                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *pos)
 911 {
 912         if (!handle || !buf || !pos)
 913                 return -EINVAL;
 914
 915         *pos = buf->cons_snapshot;
 916         return 0;
 917 }
 918
 919 /* Get the producer position (iteration end) */
 920 int ustctl_snapshot_get_produced(struct lttng_ust_shm_handle *handle,
 921                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *pos)
 922 {
 923         if (!handle || !buf || !pos)
 924                 return -EINVAL;
 925
 926         *pos = buf->prod_snapshot;
 927         return 0;
 928 }
 929
 930 /* Get exclusive read access to the specified sub-buffer position */
 931 int ustctl_get_subbuf(struct lttng_ust_shm_handle *handle,
 932                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *pos)
 933 {
 934         if (!handle || !buf || !pos)
 935                 return -EINVAL;
 936
 937         return lib_ring_buffer_get_subbuf(buf, *pos, handle);
 938 }
 939
 940 /* Release exclusive sub-buffer access */
 941 int ustctl_put_subbuf(struct lttng_ust_shm_handle *handle,
 942                 struct lttng_ust_lib_ring_buffer *buf)
 943 {
 944         if (!handle || !buf)
 945                 return -EINVAL;
 946
 947         lib_ring_buffer_put_subbuf(buf, handle);
 948         return 0;
 949 }
 950
 951 void ustctl_flush_buffer(struct lttng_ust_shm_handle *handle,
 952                 struct lttng_ust_lib_ring_buffer *buf,
 953                 int producer_active)
 954 {
 955         assert(handle && buf);
 956         lib_ring_buffer_switch_slow(buf,
 957                 producer_active ? SWITCH_ACTIVE : SWITCH_FLUSH,
 958                 handle);
 959 }