libustctl/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
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; only version 2
   8  * of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18  */
  19
  20 #include <string.h>
  21 #include <ust/lttng-ust-ctl.h>
  22 #include <ust/lttng-ust-abi.h>
  23 #include <ust/usterr-signal-safe.h>
  24 #include "lttng-ust-comm.h"
  25
  26 #include "../libringbuffer/backend.h"
  27 #include "../libringbuffer/frontend.h"
  28
  29 static
  30 void init_object(struct object_data *data)
  31 {
  32         data->handle = -1;
  33         data->shm_fd = -1;
  34         data->wait_fd = -1;
  35         data->memory_map_size = 0;
  36 }
  37
  38 void release_object(int sock, struct object_data *data)
  39 {
  40         struct ustcomm_ust_msg lum;
  41         struct ustcomm_ust_reply lur;
  42         int ret;
  43
  44         if (data->shm_fd >= 0)
  45                 close(data->shm_fd);
  46         if (data->wait_fd >= 0)
  47                 close(data->wait_fd);
  48         memset(&lum, 0, sizeof(lum));
  49         lum.handle = data->handle;
  50         lum.cmd = LTTNG_UST_RELEASE;
  51         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
  52         assert(!ret);
  53         free(data);
  54 }
  55
  56 /*
  57  * returns session handle.
  58  */
  59 int ustctl_create_session(int sock)
  60 {
  61         struct ustcomm_ust_msg lum;
  62         struct ustcomm_ust_reply lur;
  63         int ret, session_handle;
  64
  65         /* Create session */
  66         memset(&lum, 0, sizeof(lum));
  67         lum.handle = LTTNG_UST_ROOT_HANDLE;
  68         lum.cmd = LTTNG_UST_SESSION;
  69         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
  70         if (ret)
  71                 return ret;
  72         session_handle = lur.ret_val;
  73         DBG("received session handle %u", session_handle);
  74         return session_handle;
  75 }
  76
  77 /* open the metadata global channel */
  78 int ustctl_open_metadata(int sock, int session_handle,
  79                 struct lttng_ust_channel_attr *chops,
  80                 struct object_data **_metadata_data)
  81 {
  82         struct ustcomm_ust_msg lum;
  83         struct ustcomm_ust_reply lur;
  84         struct object_data *metadata_data;
  85         int ret;
  86
  87         metadata_data = malloc(sizeof(*metadata_data));
  88         if (!metadata_data)
  89                 return -ENOMEM;
  90         init_object(metadata_data);
  91         /* Create metadata channel */
  92         memset(&lum, 0, sizeof(lum));
  93         lum.handle = session_handle;
  94         lum.cmd = LTTNG_UST_METADATA;
  95         lum.u.channel.overwrite = chops->overwrite;
  96         lum.u.channel.subbuf_size = chops->subbuf_size;
  97         lum.u.channel.num_subbuf = chops->num_subbuf;
  98         lum.u.channel.switch_timer_interval = chops->switch_timer_interval;
  99         lum.u.channel.read_timer_interval = chops->read_timer_interval;
 100         lum.u.channel.output = chops->output;
 101         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 102         if (ret) {
 103                 free(metadata_data);
 104                 return ret;
 105         }
 106         if (lur.ret_code != USTCOMM_OK) {
 107                 free(metadata_data);
 108                 return lur.ret_code;
 109         }
 110         metadata_data->handle = lur.ret_val;
 111         DBG("received metadata handle %u", metadata_data->handle);
 112         metadata_data->memory_map_size = lur.u.channel.memory_map_size;
 113         /* get shm fd */
 114         ret = ustcomm_recv_fd(sock);
 115         if (ret < 0)
 116                 goto error;
 117         metadata_data->shm_fd = ret;
 118         /* get wait fd */
 119         ret = ustcomm_recv_fd(sock);
 120         if (ret < 0)
 121                 goto error;
 122         metadata_data->wait_fd = ret;
 123         *_metadata_data = metadata_data;
 124         return 0;
 125
 126 error:
 127         release_object(sock, metadata_data);
 128         return -EINVAL;
 129 }
 130
 131 int ustctl_create_channel(int sock, int session_handle,
 132                 struct lttng_ust_channel_attr *chops,
 133                 struct object_data **_channel_data)
 134 {
 135         struct ustcomm_ust_msg lum;
 136         struct ustcomm_ust_reply lur;
 137         struct object_data *channel_data;
 138         int ret;
 139
 140         channel_data = malloc(sizeof(*channel_data));
 141         if (!channel_data)
 142                 return -ENOMEM;
 143         init_object(channel_data);
 144         /* Create metadata channel */
 145         memset(&lum, 0, sizeof(lum));
 146         lum.handle = session_handle;
 147         lum.cmd = LTTNG_UST_CHANNEL;
 148         lum.u.channel.overwrite = chops->overwrite;
 149         lum.u.channel.subbuf_size = chops->subbuf_size;
 150         lum.u.channel.num_subbuf = chops->num_subbuf;
 151         lum.u.channel.switch_timer_interval = chops->switch_timer_interval;
 152         lum.u.channel.read_timer_interval = chops->read_timer_interval;
 153         lum.u.channel.output = chops->output;
 154         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 155         if (ret) {
 156                 free(channel_data);
 157                 return ret;
 158         }
 159         if (lur.ret_code != USTCOMM_OK) {
 160                 free(channel_data);
 161                 return lur.ret_code;
 162         }
 163         channel_data->handle = lur.ret_val;
 164         DBG("received channel handle %u", channel_data->handle);
 165         channel_data->memory_map_size = lur.u.channel.memory_map_size;
 166         /* get shm fd */
 167         ret = ustcomm_recv_fd(sock);
 168         if (ret < 0)
 169                 goto error;
 170         channel_data->shm_fd = ret;
 171         /* get wait fd */
 172         ret = ustcomm_recv_fd(sock);
 173         if (ret < 0)
 174                 goto error;
 175         channel_data->wait_fd = ret;
 176         *_channel_data = channel_data;
 177         return 0;
 178
 179 error:
 180         release_object(sock, channel_data);
 181         return -EINVAL;
 182 }
 183
 184 /*
 185  * Return -ENOENT if no more stream is available for creation.
 186  * Return 0 on success.
 187  * Return negative error value on error.
 188  */
 189 int ustctl_create_stream(int sock, struct object_data *channel_data,
 190                 struct object_data **_stream_data)
 191 {
 192         struct ustcomm_ust_msg lum;
 193         struct ustcomm_ust_reply lur;
 194         struct object_data *stream_data;
 195         int ret, fd;
 196
 197         stream_data = malloc(sizeof(*stream_data));
 198         if (!stream_data)
 199                 return -ENOMEM;
 200         init_object(stream_data);
 201         memset(&lum, 0, sizeof(lum));
 202         lum.handle = channel_data->handle;
 203         lum.cmd = LTTNG_UST_STREAM;
 204         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 205         if (ret) {
 206                 free(stream_data);
 207                 return ret;
 208         }
 209         if (lur.ret_code != USTCOMM_OK) {
 210                 free(stream_data);
 211                 return lur.ret_code;
 212         }
 213
 214         stream_data->handle = lur.ret_val;
 215         DBG("received stream handle %u", stream_data->handle);
 216         stream_data->memory_map_size = lur.u.stream.memory_map_size;
 217         /* get shm fd */
 218         fd = ustcomm_recv_fd(sock);
 219         if (fd < 0)
 220                 goto error;
 221         stream_data->shm_fd = fd;
 222         /* get wait fd */
 223         fd = ustcomm_recv_fd(sock);
 224         if (fd < 0)
 225                 goto error;
 226         stream_data->wait_fd = fd;
 227         *_stream_data = stream_data;
 228         return ret;
 229
 230 error:
 231         release_object(sock, stream_data);
 232         return -EINVAL;
 233 }
 234
 235 int ustctl_create_event(int sock, struct lttng_ust_event *ev,
 236                 struct object_data *channel_data,
 237                 struct object_data **_event_data)
 238 {
 239         struct ustcomm_ust_msg lum;
 240         struct ustcomm_ust_reply lur;
 241         struct object_data *event_data;
 242         int ret;
 243
 244         event_data = malloc(sizeof(*event_data));
 245         if (!event_data)
 246                 return -ENOMEM;
 247         init_object(event_data);
 248         memset(&lum, 0, sizeof(lum));
 249         lum.handle = channel_data->handle;
 250         lum.cmd = LTTNG_UST_EVENT;
 251         strncpy(lum.u.event.name, ev->name,
 252                 LTTNG_UST_SYM_NAME_LEN);
 253         lum.u.event.instrumentation = ev->instrumentation;
 254         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 255         if (ret) {
 256                 free(event_data);
 257                 return ret;
 258         }
 259         event_data->handle = lur.ret_val;
 260         DBG("received event handle %u", event_data->handle);
 261         *_event_data = event_data;
 262         return 0;
 263 }
 264
 265 int ustctl_add_context(int sock, struct lttng_ust_context *ctx,
 266                 struct object_data *channel_data,
 267                 struct object_data **_context_data)
 268 {
 269         struct ustcomm_ust_msg lum;
 270         struct ustcomm_ust_reply lur;
 271         struct object_data *context_data;
 272         int ret;
 273
 274         context_data = malloc(sizeof(*context_data));
 275         if (!context_data)
 276                 return -ENOMEM;
 277         init_object(context_data);
 278         memset(&lum, 0, sizeof(lum));
 279         lum.handle = channel_data->handle;
 280         lum.cmd = LTTNG_UST_CONTEXT;
 281         lum.u.context.ctx = ctx->ctx;
 282         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 283         if (ret) {
 284                 free(context_data);
 285                 return ret;
 286         }
 287         context_data->handle = lur.ret_val;
 288         DBG("received context handle %u", context_data->handle);
 289         *_context_data = context_data;
 290         return ret;
 291 }
 292
 293 /* Enable event, channel and session ioctl */
 294 int ustctl_enable(int sock, struct object_data *object)
 295 {
 296         struct ustcomm_ust_msg lum;
 297         struct ustcomm_ust_reply lur;
 298         int ret;
 299
 300         memset(&lum, 0, sizeof(lum));
 301         lum.handle = object->handle;
 302         lum.cmd = LTTNG_UST_ENABLE;
 303         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 304         if (ret)
 305                 return ret;
 306         DBG("enabled handle %u", object->handle);
 307         return 0;
 308 }
 309
 310 /* Disable event, channel and session ioctl */
 311 int ustctl_disable(int sock, struct object_data *object)
 312 {
 313         struct ustcomm_ust_msg lum;
 314         struct ustcomm_ust_reply lur;
 315         int ret;
 316
 317         memset(&lum, 0, sizeof(lum));
 318         lum.handle = object->handle;
 319         lum.cmd = LTTNG_UST_DISABLE;
 320         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 321         if (ret)
 322                 return ret;
 323         DBG("disable handle %u", object->handle);
 324         return 0;
 325 }
 326
 327 int ustctl_start_session(int sock, struct object_data *object)
 328 {
 329         return ustctl_enable(sock, object);
 330 }
 331
 332 int ustctl_stop_session(int sock, struct object_data *object)
 333 {
 334         return ustctl_disable(sock, object);
 335 }
 336
 337
 338 int ustctl_tracepoint_list(int sock)
 339 {
 340         return -ENOSYS; /* not implemented */
 341 }
 342
 343 int ustctl_tracer_version(int sock, struct lttng_ust_tracer_version *v)
 344 {
 345         struct ustcomm_ust_msg lum;
 346         struct ustcomm_ust_reply lur;
 347         int ret;
 348
 349         memset(&lum, 0, sizeof(lum));
 350         lum.handle = LTTNG_UST_ROOT_HANDLE;
 351         lum.cmd = LTTNG_UST_TRACER_VERSION;
 352         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 353         if (ret)
 354                 return ret;
 355         memcpy(v, &lur.u.version, sizeof(*v));
 356         DBG("received tracer version");
 357         return 0;
 358 }
 359
 360 int ustctl_wait_quiescent(int sock)
 361 {
 362         struct ustcomm_ust_msg lum;
 363         struct ustcomm_ust_reply lur;
 364         int ret;
 365
 366         memset(&lum, 0, sizeof(lum));
 367         lum.handle = LTTNG_UST_ROOT_HANDLE;
 368         lum.cmd = LTTNG_UST_WAIT_QUIESCENT;
 369         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 370         if (ret)
 371                 return ret;
 372         DBG("waited for quiescent state");
 373         return 0;
 374 }
 375
 376 int ustctl_calibrate(int sock, struct lttng_ust_calibrate *calibrate)
 377 {
 378         return -ENOSYS;
 379 }
 380
 381 /* Buffer operations */
 382
 383 /* Map channel shm into process memory */
 384 struct shm_handle *ustctl_map_channel(struct object_data *chan_data)
 385 {
 386         struct shm_handle *handle;
 387         struct channel *chan;
 388         size_t chan_size;
 389
 390         handle = channel_handle_create(chan_data->shm_fd,
 391                 chan_data->wait_fd,
 392                 chan_data->memory_map_size);
 393         if (!handle) {
 394                 ERR("create handle error");
 395                 return NULL;
 396         }
 397         /*
 398          * Set to -1 because the shm_handle destruction will take care
 399          * of closing shm_fd and wait_fd.
 400          */
 401         chan_data->shm_fd = -1;
 402         chan_data->wait_fd = -1;
 403
 404         /*
 405          * TODO: add consistency checks to be resilient if the
 406          * application try to feed us with incoherent channel structure
 407          * values.
 408          */
 409         chan = shmp(handle, handle->chan);
 410         /* chan is object 0. This is hardcoded. */
 411         chan_size = handle->table->objects[0].allocated_len;
 412         handle->shadow_chan = malloc(chan_size);
 413         if (!handle->shadow_chan) {
 414                 channel_destroy(chan, handle, 1);
 415                 return NULL;
 416         }
 417         memcpy(handle->shadow_chan, chan, chan_size);
 418         return handle;
 419 }
 420
 421 /* Add stream to channel shm and map its shm into process memory */
 422 int ustctl_add_stream(struct shm_handle *handle,
 423                 struct object_data *stream_data)
 424 {
 425         int ret;
 426
 427         if (!stream_data->handle)
 428                 return -ENOENT;
 429         /* map stream */
 430         ret = channel_handle_add_stream(handle,
 431                 stream_data->shm_fd,
 432                 stream_data->wait_fd,
 433                 stream_data->memory_map_size);
 434         if (ret) {
 435                 ERR("add stream error\n");
 436                 return ret;
 437         }
 438         /*
 439          * Set to -1 because the shm_handle destruction will take care
 440          * of closing shm_fd and wait_fd.
 441          */
 442         stream_data->shm_fd = -1;
 443         stream_data->wait_fd = -1;
 444         return 0;
 445 }
 446
 447 /* For mmap mode, readable without "get" operation */
 448
 449 /* returns the length to mmap. */
 450 int ustctl_get_mmap_len(struct shm_handle *handle,
 451                 struct lib_ring_buffer *buf,
 452                 unsigned long *len)
 453 {
 454         unsigned long mmap_buf_len;
 455         struct channel *chan = handle->shadow_chan;
 456
 457         if (chan->backend.config.output != RING_BUFFER_MMAP)
 458                 return -EINVAL;
 459         mmap_buf_len = chan->backend.buf_size;
 460         if (chan->backend.extra_reader_sb)
 461                 mmap_buf_len += chan->backend.subbuf_size;
 462         if (mmap_buf_len > INT_MAX)
 463                 return -EFBIG;
 464         *len = mmap_buf_len;
 465         return 0;
 466 }
 467
 468 /* returns the maximum size for sub-buffers. */
 469 int ustctl_get_max_subbuf_size(struct shm_handle *handle,
 470                 struct lib_ring_buffer *buf,
 471                 unsigned long *len)
 472 {
 473         struct channel *chan = handle->shadow_chan;
 474
 475         *len = chan->backend.subbuf_size;
 476         return 0;
 477 }
 478
 479 /*
 480  * For mmap mode, operate on the current packet (between get/put or
 481  * get_next/put_next).
 482  */
 483
 484 /* returns the offset of the subbuffer belonging to the mmap reader. */
 485 int ustctl_get_mmap_read_offset(struct shm_handle *handle,
 486                 struct lib_ring_buffer *buf, unsigned long *off)
 487 {
 488         struct channel *chan = handle->shadow_chan;
 489         unsigned long sb_bindex;
 490
 491         if (chan->backend.config.output != RING_BUFFER_MMAP)
 492                 return -EINVAL;
 493         sb_bindex = subbuffer_id_get_index(&chan->backend.config,
 494                                            buf->backend.buf_rsb.id);
 495         *off = shmp(handle, shmp_index(handle, buf->backend.array, sb_bindex)->shmp)->mmap_offset;
 496         return 0;
 497 }
 498
 499 /* returns the size of the current sub-buffer, without padding (for mmap). */
 500 int ustctl_get_subbuf_size(struct shm_handle *handle,
 501                 struct lib_ring_buffer *buf, unsigned long *len)
 502 {
 503         struct channel *chan = handle->shadow_chan;
 504
 505         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
 506                 handle);
 507         return 0;
 508 }
 509
 510 /* returns the size of the current sub-buffer, without padding (for mmap). */
 511 int ustctl_get_padded_subbuf_size(struct shm_handle *handle,
 512                 struct lib_ring_buffer *buf, unsigned long *len)
 513 {
 514         struct channel *chan = handle->shadow_chan;
 515
 516         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
 517                 handle);
 518         *len = PAGE_ALIGN(*len);
 519         return 0;
 520 }
 521
 522 /* Get exclusive read access to the next sub-buffer that can be read. */
 523 int ustctl_get_next_subbuf(struct shm_handle *handle,
 524                 struct lib_ring_buffer *buf)
 525 {
 526         return lib_ring_buffer_get_next_subbuf(buf, handle);
 527 }
 528
 529
 530 /* Release exclusive sub-buffer access, move consumer forward. */
 531 int ustctl_put_next_subbuf(struct shm_handle *handle,
 532                 struct lib_ring_buffer *buf)
 533 {
 534         lib_ring_buffer_put_next_subbuf(buf, handle);
 535         return 0;
 536 }
 537
 538 /* snapshot */
 539
 540 /* Get a snapshot of the current ring buffer producer and consumer positions */
 541 int ustctl_snapshot(struct shm_handle *handle,
 542                 struct lib_ring_buffer *buf)
 543 {
 544         return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
 545                         &buf->prod_snapshot, handle);
 546 }
 547
 548 /* Get the consumer position (iteration start) */
 549 int ustctl_snapshot_get_consumed(struct shm_handle *handle,
 550                 struct lib_ring_buffer *buf, unsigned long *pos)
 551 {
 552         *pos = buf->cons_snapshot;
 553         return 0;
 554 }
 555
 556 /* Get the producer position (iteration end) */
 557 int ustctl_snapshot_get_produced(struct shm_handle *handle,
 558                 struct lib_ring_buffer *buf, unsigned long *pos)
 559 {
 560         *pos = buf->prod_snapshot;
 561         return 0;
 562 }
 563
 564 /* Get exclusive read access to the specified sub-buffer position */
 565 int ustctl_get_subbuf(struct shm_handle *handle,
 566                 struct lib_ring_buffer *buf, unsigned long *pos)
 567 {
 568         return lib_ring_buffer_get_subbuf(buf, *pos, handle);
 569 }
 570
 571 /* Release exclusive sub-buffer access */
 572 int ustctl_put_subbuf(struct shm_handle *handle,
 573                 struct lib_ring_buffer *buf)
 574 {
 575         lib_ring_buffer_put_subbuf(buf, handle);
 576         return 0;
 577 }
 578
 579 int ustctl_buffer_flush(struct shm_handle *handle,
 580                 struct lib_ring_buffer *buf)
 581 {
 582         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE, handle);
 583         return 0;
 584 }