formats/lttng-live/lttng-live-comm.c

   1 /*
   2  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to deal
   7  * in the Software without restriction, including without limitation the rights
   8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9  * copies of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 #include <sys/socket.h>
  25 #include <sys/types.h>
  26 #include <netinet/in.h>
  27 #include <netdb.h>
  28 #include <stdio.h>
  29 #include <string.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <inttypes.h>
  34 #include <fcntl.h>
  35 #include <sys/mman.h>
  36 #include <poll.h>
  37
  38 #include <babeltrace/ctf/ctf-index.h>
  39
  40 #include <babeltrace/babeltrace.h>
  41 #include <babeltrace/ctf/events.h>
  42 #include <babeltrace/ctf/callbacks.h>
  43 #include <babeltrace/ctf/iterator.h>
  44
  45 /* for packet_index */
  46 #include <babeltrace/ctf/types.h>
  47
  48 #include <babeltrace/ctf/metadata.h>
  49 #include <babeltrace/ctf-text/types.h>
  50 #include <babeltrace/ctf/events-internal.h>
  51 #include <formats/ctf/events-private.h>
  52
  53 #include <babeltrace/compat/memstream.h>
  54
  55 #include "lttng-live.h"
  56 #include "lttng-viewer-abi.h"
  57
  58 #define ACTIVE_POLL_DELAY       100     /* ms */
  59
  60 /*
  61  * Memory allocation zeroed
  62  */
  63 #define zmalloc(x) calloc(1, x)
  64
  65 #ifndef max_t
  66 #define max_t(type, a, b)       \
  67         ((type) (a) > (type) (b) ? (type) (a) : (type) (b))
  68 #endif
  69
  70 static void ctf_live_packet_seek(struct bt_stream_pos *stream_pos,
  71                 size_t index, int whence);
  72 static void add_traces(gpointer key, gpointer value, gpointer user_data);
  73 static int del_traces(gpointer key, gpointer value, gpointer user_data);
  74 static int get_new_metadata(struct lttng_live_ctx *ctx,
  75                 struct lttng_live_viewer_stream *viewer_stream,
  76                 char **metadata_buf);
  77
  78 static
  79 ssize_t lttng_live_recv(int fd, void *buf, size_t len)
  80 {
  81         ssize_t ret;
  82         size_t copied = 0, to_copy = len;
  83
  84         do {
  85                 ret = recv(fd, buf + copied, to_copy, 0);
  86                 if (ret > 0) {
  87                         assert(ret <= to_copy);
  88                         copied += ret;
  89                         to_copy -= ret;
  90                 }
  91         } while ((ret > 0 && to_copy > 0)
  92                 || (ret < 0 && errno == EINTR));
  93         if (ret > 0)
  94                 ret = copied;
  95         /* ret = 0 means orderly shutdown, ret < 0 is error. */
  96         return ret;
  97 }
  98
  99 static
 100 ssize_t lttng_live_send(int fd, const void *buf, size_t len)
 101 {
 102         ssize_t ret;
 103
 104         do {
 105                 ret = send(fd, buf, len, MSG_NOSIGNAL);
 106         } while (ret < 0 && errno == EINTR);
 107         return ret;
 108 }
 109
 110 int lttng_live_connect_viewer(struct lttng_live_ctx *ctx)
 111 {
 112         struct hostent *host;
 113         struct sockaddr_in server_addr;
 114         int ret;
 115
 116         host = gethostbyname(ctx->relay_hostname);
 117         if (!host) {
 118                 ret = -1;
 119                 goto end;
 120         }
 121
 122         if ((ctx->control_sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
 123                 perror("Socket");
 124                 ret = -1;
 125                 goto end;
 126         }
 127
 128         server_addr.sin_family = AF_INET;
 129         server_addr.sin_port = htons(ctx->port);
 130         server_addr.sin_addr = *((struct in_addr *) host->h_addr);
 131         bzero(&(server_addr.sin_zero), 8);
 132
 133         if (connect(ctx->control_sock, (struct sockaddr *) &server_addr,
 134                                 sizeof(struct sockaddr)) == -1) {
 135                 perror("Connect");
 136                 ret = -1;
 137                 goto end;
 138         }
 139
 140         ret = 0;
 141
 142 end:
 143         return ret;
 144 }
 145
 146 int lttng_live_establish_connection(struct lttng_live_ctx *ctx)
 147 {
 148         struct lttng_viewer_cmd cmd;
 149         struct lttng_viewer_connect connect;
 150         int ret;
 151         ssize_t ret_len;
 152
 153         cmd.cmd = htobe32(LTTNG_VIEWER_CONNECT);
 154         cmd.data_size = sizeof(connect);
 155         cmd.cmd_version = 0;
 156
 157         connect.viewer_session_id = -1ULL;      /* will be set on recv */
 158         connect.major = htobe32(LTTNG_LIVE_MAJOR);
 159         connect.minor = htobe32(LTTNG_LIVE_MINOR);
 160         connect.type = htobe32(LTTNG_VIEWER_CLIENT_COMMAND);
 161
 162         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 163         if (ret_len < 0) {
 164                 perror("[error] Error sending cmd");
 165                 ret = ret_len;
 166                 goto error;
 167         }
 168         assert(ret_len == sizeof(cmd));
 169
 170         ret_len = lttng_live_send(ctx->control_sock, &connect, sizeof(connect));
 171         if (ret_len < 0) {
 172                 perror("[error] Error sending version");
 173                 ret = ret_len;
 174                 goto error;
 175         }
 176         assert(ret_len == sizeof(connect));
 177
 178         ret_len = lttng_live_recv(ctx->control_sock, &connect, sizeof(connect));
 179         if (ret_len == 0) {
 180                 fprintf(stderr, "[error] Remote side has closed connection\n");
 181                 ret = -1;
 182                 goto error;
 183         }
 184         if (ret_len < 0) {
 185                 perror("[error] Error receiving version");
 186                 ret = ret_len;
 187                 goto error;
 188         }
 189         assert(ret_len == sizeof(connect));
 190
 191         printf_verbose("Received viewer session ID : %" PRIu64 "\n",
 192                         be64toh(connect.viewer_session_id));
 193         printf_verbose("Relayd version : %u.%u\n", be32toh(connect.major),
 194                         be32toh(connect.minor));
 195
 196         ret = 0;
 197
 198 error:
 199         return ret;
 200 }
 201
 202 static
 203 void free_session_list(GPtrArray *session_list)
 204 {
 205         int i;
 206         struct lttng_live_relay_session *relay_session;
 207
 208         for (i = 0; i < session_list->len; i++) {
 209                 relay_session = g_ptr_array_index(session_list, i);
 210                 free(relay_session->name);
 211                 free(relay_session->hostname);
 212         }
 213         g_ptr_array_free(session_list, TRUE);
 214 }
 215
 216 static
 217 void print_session_list(GPtrArray *session_list, const char *path)
 218 {
 219         int i;
 220         struct lttng_live_relay_session *relay_session;
 221
 222         for (i = 0; i < session_list->len; i++) {
 223                 relay_session = g_ptr_array_index(session_list, i);
 224                 fprintf(stdout, "%s/host/%s/%s (timer = %u, "
 225                                 "%u stream(s), %u client(s) connected)\n",
 226                                 path, relay_session->hostname,
 227                                 relay_session->name, relay_session->timer,
 228                                 relay_session->streams, relay_session->clients);
 229         }
 230 }
 231
 232 static
 233 void update_session_list(GPtrArray *session_list, char *hostname,
 234                 char *session_name, uint32_t streams, uint32_t clients,
 235                 uint32_t timer)
 236 {
 237         int i, found = 0;
 238         struct lttng_live_relay_session *relay_session;
 239
 240         for (i = 0; i < session_list->len; i++) {
 241                 relay_session = g_ptr_array_index(session_list, i);
 242                 if ((strncmp(relay_session->hostname, hostname, NAME_MAX) == 0) &&
 243                                 strncmp(relay_session->name,
 244                                         session_name, NAME_MAX) == 0) {
 245                         relay_session->streams += streams;
 246                         if (relay_session->clients < clients)
 247                                 relay_session->clients = clients;
 248                         found = 1;
 249                         break;
 250                 }
 251         }
 252         if (found)
 253                 return;
 254
 255         relay_session = g_new0(struct lttng_live_relay_session, 1);
 256         relay_session->hostname = strndup(hostname, NAME_MAX);
 257         relay_session->name = strndup(session_name, NAME_MAX);
 258         relay_session->clients = clients;
 259         relay_session->streams = streams;
 260         relay_session->timer = timer;
 261         g_ptr_array_add(session_list, relay_session);
 262 }
 263
 264 int lttng_live_list_sessions(struct lttng_live_ctx *ctx, const char *path)
 265 {
 266         struct lttng_viewer_cmd cmd;
 267         struct lttng_viewer_list_sessions list;
 268         struct lttng_viewer_session lsession;
 269         int i, ret, sessions_count, print_list = 0;
 270         ssize_t ret_len;
 271         uint64_t session_id;
 272         GPtrArray *session_list = NULL;
 273
 274         if (strlen(ctx->session_name) == 0) {
 275                 print_list = 1;
 276                 session_list = g_ptr_array_new();
 277         }
 278
 279         cmd.cmd = htobe32(LTTNG_VIEWER_LIST_SESSIONS);
 280         cmd.data_size = 0;
 281         cmd.cmd_version = 0;
 282
 283         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 284         if (ret_len < 0) {
 285                 perror("[error] Error sending cmd");
 286                 ret = ret_len;
 287                 goto error;
 288         }
 289         assert(ret_len == sizeof(cmd));
 290
 291         ret_len = lttng_live_recv(ctx->control_sock, &list, sizeof(list));
 292         if (ret_len == 0) {
 293                 fprintf(stderr, "[error] Remote side has closed connection\n");
 294                 ret = -1;
 295                 goto error;
 296         }
 297         if (ret_len < 0) {
 298                 perror("[error] Error receiving session list");
 299                 ret = ret_len;
 300                 goto error;
 301         }
 302         assert(ret_len == sizeof(list));
 303
 304         sessions_count = be32toh(list.sessions_count);
 305         for (i = 0; i < sessions_count; i++) {
 306                 ret_len = lttng_live_recv(ctx->control_sock, &lsession, sizeof(lsession));
 307                 if (ret_len == 0) {
 308                         fprintf(stderr, "[error] Remote side has closed connection\n");
 309                         ret = -1;
 310                         goto error;
 311                 }
 312                 if (ret_len < 0) {
 313                         perror("[error] Error receiving session");
 314                         ret = ret_len;
 315                         goto error;
 316                 }
 317                 assert(ret_len == sizeof(lsession));
 318                 lsession.hostname[LTTNG_VIEWER_HOST_NAME_MAX - 1] = '\0';
 319                 lsession.session_name[LTTNG_VIEWER_NAME_MAX - 1] = '\0';
 320                 session_id = be64toh(lsession.id);
 321
 322                 if (print_list) {
 323                         update_session_list(session_list,
 324                                         lsession.hostname,
 325                                         lsession.session_name,
 326                                         be32toh(lsession.streams),
 327                                         be32toh(lsession.clients),
 328                                         be32toh(lsession.live_timer));
 329                 } else {
 330                         if ((strncmp(lsession.session_name, ctx->session_name,
 331                                 NAME_MAX) == 0) && (strncmp(lsession.hostname,
 332                                         ctx->traced_hostname, NAME_MAX) == 0)) {
 333                                 printf_verbose("Reading from session %" PRIu64 "\n",
 334                                                 session_id);
 335                                 g_array_append_val(ctx->session_ids,
 336                                                 session_id);
 337                         }
 338                 }
 339         }
 340
 341         if (print_list) {
 342                 print_session_list(session_list, path);
 343                 free_session_list(session_list);
 344         }
 345
 346         ret = 0;
 347
 348 error:
 349         return ret;
 350 }
 351
 352 int lttng_live_ctf_trace_assign(struct lttng_live_viewer_stream *stream,
 353                 uint64_t ctf_trace_id)
 354 {
 355         struct lttng_live_ctf_trace *trace;
 356         int ret = 0;
 357
 358         trace = g_hash_table_lookup(stream->session->ctf_traces,
 359                         (gpointer) ctf_trace_id);
 360         if (!trace) {
 361                 trace = g_new0(struct lttng_live_ctf_trace, 1);
 362                 trace->ctf_trace_id = ctf_trace_id;
 363                 trace->streams = g_ptr_array_new();
 364                 g_hash_table_insert(stream->session->ctf_traces,
 365                                 (gpointer) ctf_trace_id,
 366                                 trace);
 367         }
 368         if (stream->metadata_flag)
 369                 trace->metadata_stream = stream;
 370
 371         stream->ctf_trace = trace;
 372         g_ptr_array_add(trace->streams, stream);
 373
 374         return ret;
 375 }
 376
 377 static
 378 int open_metadata_fp_write(struct lttng_live_viewer_stream *stream,
 379                 char **metadata_buf, size_t *size)
 380 {
 381         int ret = 0;
 382
 383         stream->metadata_fp_write =
 384                 babeltrace_open_memstream(metadata_buf, size);
 385         if (!stream->metadata_fp_write) {
 386                 perror("Metadata open_memstream");
 387                 ret = -1;
 388         }
 389
 390         return ret;
 391 }
 392
 393 int lttng_live_attach_session(struct lttng_live_ctx *ctx, uint64_t id)
 394 {
 395         struct lttng_viewer_cmd cmd;
 396         struct lttng_viewer_attach_session_request rq;
 397         struct lttng_viewer_attach_session_response rp;
 398         struct lttng_viewer_stream stream;
 399         int ret, i;
 400         ssize_t ret_len;
 401
 402         cmd.cmd = htobe32(LTTNG_VIEWER_ATTACH_SESSION);
 403         cmd.data_size = sizeof(rq);
 404         cmd.cmd_version = 0;
 405
 406         memset(&rq, 0, sizeof(rq));
 407         rq.session_id = htobe64(id);
 408         // TODO: add cmd line parameter to select seek beginning
 409         // rq.seek = htobe32(LTTNG_VIEWER_SEEK_BEGINNING);
 410         rq.seek = htobe32(LTTNG_VIEWER_SEEK_LAST);
 411
 412         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 413         if (ret_len < 0) {
 414                 perror("[error] Error sending cmd");
 415                 ret = ret_len;
 416                 goto error;
 417         }
 418         assert(ret_len == sizeof(cmd));
 419
 420         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
 421         if (ret_len < 0) {
 422                 perror("[error] Error sending attach request");
 423                 ret = ret_len;
 424                 goto error;
 425         }
 426         assert(ret_len == sizeof(rq));
 427
 428         ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
 429         if (ret_len == 0) {
 430                 fprintf(stderr, "[error] Remote side has closed connection\n");
 431                 ret = -1;
 432                 goto error;
 433         }
 434         if (ret_len < 0) {
 435                 perror("[error] Error receiving attach response");
 436                 ret = ret_len;
 437                 goto error;
 438         }
 439         assert(ret_len == sizeof(rp));
 440
 441         switch(be32toh(rp.status)) {
 442         case LTTNG_VIEWER_ATTACH_OK:
 443                 break;
 444         case LTTNG_VIEWER_ATTACH_UNK:
 445                 ret = -LTTNG_VIEWER_ATTACH_UNK;
 446                 goto end;
 447         case LTTNG_VIEWER_ATTACH_ALREADY:
 448                 fprintf(stderr, "[error] There is already a viewer attached to this session\n");
 449                 ret = -1;
 450                 goto end;
 451         case LTTNG_VIEWER_ATTACH_NOT_LIVE:
 452                 fprintf(stderr, "[error] Not a live session\n");
 453                 ret = -1;
 454                 goto end;
 455         case LTTNG_VIEWER_ATTACH_SEEK_ERR:
 456                 fprintf(stderr, "[error] Wrong seek parameter\n");
 457                 ret = -1;
 458                 goto end;
 459         default:
 460                 fprintf(stderr, "[error] Unknown attach return code %u\n",
 461                                 be32toh(rp.status));
 462                 ret = -1;
 463                 goto end;
 464         }
 465         if (be32toh(rp.status) != LTTNG_VIEWER_ATTACH_OK) {
 466                 ret = -1;
 467                 goto end;
 468         }
 469
 470         ctx->session->stream_count += be32toh(rp.streams_count);
 471         /*
 472          * When the session is created but not started, we do an active wait
 473          * until it starts. It allows the viewer to start processing the trace
 474          * as soon as the session starts.
 475          */
 476         if (ctx->session->stream_count == 0) {
 477                 ret = 0;
 478                 goto end;
 479         }
 480         printf_verbose("Waiting for %" PRIu64 " streams:\n",
 481                 ctx->session->stream_count);
 482         ctx->session->streams = g_new0(struct lttng_live_viewer_stream,
 483                         ctx->session->stream_count);
 484         for (i = 0; i < be32toh(rp.streams_count); i++) {
 485                 ret_len = lttng_live_recv(ctx->control_sock, &stream, sizeof(stream));
 486                 if (ret_len == 0) {
 487                         fprintf(stderr, "[error] Remote side has closed connection\n");
 488                         ret = -1;
 489                         goto error;
 490                 }
 491                 if (ret_len < 0) {
 492                         perror("[error] Error receiving stream");
 493                         ret = ret_len;
 494                         goto error;
 495                 }
 496                 assert(ret_len == sizeof(stream));
 497                 stream.path_name[LTTNG_VIEWER_PATH_MAX - 1] = '\0';
 498                 stream.channel_name[LTTNG_VIEWER_NAME_MAX - 1] = '\0';
 499
 500                 printf_verbose("    stream %" PRIu64 " : %s/%s\n",
 501                                 be64toh(stream.id), stream.path_name,
 502                                 stream.channel_name);
 503                 ctx->session->streams[i].id = be64toh(stream.id);
 504                 ctx->session->streams[i].session = ctx->session;
 505
 506                 ctx->session->streams[i].first_read = 1;
 507                 ctx->session->streams[i].mmap_size = 0;
 508
 509                 if (be32toh(stream.metadata_flag)) {
 510                         ctx->session->streams[i].metadata_flag = 1;
 511                 }
 512                 ret = lttng_live_ctf_trace_assign(&ctx->session->streams[i],
 513                                 be64toh(stream.ctf_trace_id));
 514                 if (ret < 0) {
 515                         goto error;
 516                 }
 517
 518         }
 519         ret = 0;
 520
 521 end:
 522 error:
 523         return ret;
 524 }
 525
 526 static
 527 int ask_new_streams(struct lttng_live_ctx *ctx)
 528 {
 529         int i, ret = 0;
 530         uint64_t id;
 531
 532 restart:
 533         for (i = 0; i < ctx->session_ids->len; i++) {
 534                 id = g_array_index(ctx->session_ids, uint64_t, i);
 535                 ret = lttng_live_get_new_streams(ctx, id);
 536                 printf_verbose("Asking for new streams returns %d\n",
 537                                 ret);
 538                 if (ret < 0) {
 539                         if (ret == -LTTNG_VIEWER_NEW_STREAMS_HUP) {
 540                                 printf_verbose("Session %" PRIu64 " closed\n",
 541                                                 id);
 542                                 /*
 543                                  * The streams have already been closed during
 544                                  * the reading, so we only need to get rid of
 545                                  * the trace in our internal table of sessions.
 546                                  */
 547                                 g_array_remove_index(ctx->session_ids, i);
 548                                 /*
 549                                  * We can't continue iterating on the g_array
 550                                  * after a remove, we have to start again.
 551                                  */
 552                                 goto restart;
 553                         } else {
 554                                 ret = -1;
 555                                 goto end;
 556                         }
 557                 }
 558         }
 559
 560 end:
 561         return ret;
 562 }
 563
 564 static
 565 int append_metadata(struct lttng_live_ctx *ctx,
 566                 struct lttng_live_viewer_stream *viewer_stream)
 567 {
 568         int ret;
 569         struct lttng_live_viewer_stream *metadata;
 570         char *metadata_buf = NULL;
 571
 572         printf_verbose("get_next_index: new metadata needed\n");
 573         ret = get_new_metadata(ctx, viewer_stream, &metadata_buf);
 574         if (ret < 0) {
 575                 free(metadata_buf);
 576                 goto error;
 577         }
 578
 579         metadata = viewer_stream->ctf_trace->metadata_stream;
 580         metadata->ctf_trace->metadata_fp =
 581                 babeltrace_fmemopen(metadata_buf,
 582                                 metadata->metadata_len, "rb");
 583         if (!metadata->ctf_trace->metadata_fp) {
 584                 perror("Metadata fmemopen");
 585                 free(metadata_buf);
 586                 ret = -1;
 587                 goto error;
 588         }
 589         ret = ctf_append_trace_metadata(
 590                         viewer_stream->ctf_trace->handle->td,
 591                         metadata->ctf_trace->metadata_fp);
 592         if (ret != 0) {
 593                 fprintf(stderr, "[error] Appending metadata\n");
 594                 goto error;
 595         }
 596
 597 error:
 598         return ret;
 599 }
 600
 601 static
 602 int get_data_packet(struct lttng_live_ctx *ctx,
 603                 struct ctf_stream_pos *pos,
 604                 struct lttng_live_viewer_stream *stream, uint64_t offset,
 605                 uint64_t len)
 606 {
 607         struct lttng_viewer_cmd cmd;
 608         struct lttng_viewer_get_packet rq;
 609         struct lttng_viewer_trace_packet rp;
 610         ssize_t ret_len;
 611         int ret;
 612
 613 retry:
 614         cmd.cmd = htobe32(LTTNG_VIEWER_GET_PACKET);
 615         cmd.data_size = sizeof(rq);
 616         cmd.cmd_version = 0;
 617
 618         memset(&rq, 0, sizeof(rq));
 619         rq.stream_id = htobe64(stream->id);
 620         /* Already in big endian. */
 621         rq.offset = offset;
 622         rq.len = htobe32(len);
 623
 624         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 625         if (ret_len < 0) {
 626                 perror("[error] Error sending cmd");
 627                 ret = ret_len;
 628                 goto error;
 629         }
 630         assert(ret_len == sizeof(cmd));
 631
 632         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
 633         if (ret_len < 0) {
 634                 perror("[error] Error sending get_data_packet request");
 635                 ret = ret_len;
 636                 goto error;
 637         }
 638         assert(ret_len == sizeof(rq));
 639
 640         ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
 641         if (ret_len == 0) {
 642                 fprintf(stderr, "[error] Remote side has closed connection\n");
 643                 ret = -1;
 644                 goto error;
 645         }
 646         if (ret_len < 0) {
 647                 perror("[error] Error receiving data response");
 648                 ret = ret_len;
 649                 goto error;
 650         }
 651         if (ret_len != sizeof(rp)) {
 652                 fprintf(stderr, "[error] get_data_packet: expected %" PRId64
 653                                 ", received %" PRId64 "\n", ret_len,
 654                                 sizeof(rp));
 655                 ret = -1;
 656                 goto error;
 657         }
 658
 659         rp.flags = be32toh(rp.flags);
 660
 661         switch (be32toh(rp.status)) {
 662         case LTTNG_VIEWER_GET_PACKET_OK:
 663                 len = be32toh(rp.len);
 664                 printf_verbose("get_data_packet: Ok, packet size : %" PRIu64
 665                                 "\n", len);
 666                 break;
 667         case LTTNG_VIEWER_GET_PACKET_RETRY:
 668                 printf_verbose("get_data_packet: retry\n");
 669                 ret = -1;
 670                 goto end;
 671         case LTTNG_VIEWER_GET_PACKET_ERR:
 672                 if (rp.flags & LTTNG_VIEWER_FLAG_NEW_METADATA) {
 673                         printf_verbose("get_data_packet: new metadata needed\n");
 674                         ret = append_metadata(ctx, stream);
 675                         if (ret)
 676                                 goto error;
 677                         goto retry;
 678                 }
 679                 if (rp.flags & LTTNG_VIEWER_FLAG_NEW_STREAM) {
 680                         ret = ask_new_streams(ctx);
 681                         if (ret < 0)
 682                                 goto error;
 683                         g_hash_table_foreach(ctx->session->ctf_traces, add_traces,
 684                                         ctx->bt_ctx);
 685                 }
 686                 fprintf(stderr, "[error] get_data_packet: error\n");
 687                 ret = -1;
 688                 goto end;
 689         case LTTNG_VIEWER_GET_PACKET_EOF:
 690                 ret = -2;
 691                 goto error;
 692         default:
 693                 printf_verbose("get_data_packet: unknown\n");
 694                 assert(0);
 695                 ret = -1;
 696                 goto end;
 697         }
 698
 699         if (len <= 0) {
 700                 ret = -1;
 701                 goto end;
 702         }
 703
 704         if (len > stream->mmap_size) {
 705                 uint64_t new_size;
 706
 707                 new_size = max_t(uint64_t, len, stream->mmap_size << 1);
 708                 if (pos->base_mma) {
 709                         /* unmap old base */
 710                         ret = munmap_align(pos->base_mma);
 711                         if (ret) {
 712                                 perror("[error] Unable to unmap old base");
 713                                 ret = -1;
 714                                 goto error;
 715                         }
 716                         pos->base_mma = NULL;
 717                 }
 718                 pos->base_mma = mmap_align(new_size,
 719                                 PROT_READ | PROT_WRITE,
 720                                 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 721                 if (pos->base_mma == MAP_FAILED) {
 722                         perror("[error] mmap error");
 723                         pos->base_mma = NULL;
 724                         ret = -1;
 725                         goto error;
 726                 }
 727
 728                 stream->mmap_size = new_size;
 729                 printf_verbose("Expanding stream mmap size to %" PRIu64 " bytes\n",
 730                                 stream->mmap_size);
 731         }
 732
 733         ret_len = lttng_live_recv(ctx->control_sock,
 734                         mmap_align_addr(pos->base_mma), len);
 735         if (ret_len == 0) {
 736                 fprintf(stderr, "[error] Remote side has closed connection\n");
 737                 ret = -1;
 738                 goto error;
 739         }
 740         if (ret_len < 0) {
 741                 perror("[error] Error receiving trace packet");
 742                 ret = ret_len;
 743                 goto error;
 744         }
 745         assert(ret_len == len);
 746
 747 end:
 748 error:
 749         return ret;
 750 }
 751
 752 static
 753 int get_one_metadata_packet(struct lttng_live_ctx *ctx,
 754                 struct lttng_live_viewer_stream *metadata_stream)
 755 {
 756         uint64_t len = 0;
 757         int ret;
 758         struct lttng_viewer_cmd cmd;
 759         struct lttng_viewer_get_metadata rq;
 760         struct lttng_viewer_metadata_packet rp;
 761         char *data = NULL;
 762         ssize_t ret_len;
 763
 764         rq.stream_id = htobe64(metadata_stream->id);
 765         cmd.cmd = htobe32(LTTNG_VIEWER_GET_METADATA);
 766         cmd.data_size = sizeof(rq);
 767         cmd.cmd_version = 0;
 768
 769         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 770         if (ret_len < 0) {
 771                 perror("[error] Error sending cmd");
 772                 ret = ret_len;
 773                 goto error;
 774         }
 775         assert(ret_len == sizeof(cmd));
 776
 777         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
 778         if (ret_len < 0) {
 779                 perror("[error] Error sending get_metadata request");
 780                 ret = ret_len;
 781                 goto error;
 782         }
 783         assert(ret_len == sizeof(rq));
 784
 785         ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
 786         if (ret_len == 0) {
 787                 fprintf(stderr, "[error] Remote side has closed connection\n");
 788                 ret = -1;
 789                 goto error;
 790         }
 791         if (ret_len < 0) {
 792                 perror("[error] Error receiving metadata response");
 793                 ret = ret_len;
 794                 goto error;
 795         }
 796         assert(ret_len == sizeof(rp));
 797
 798         switch (be32toh(rp.status)) {
 799                 case LTTNG_VIEWER_METADATA_OK:
 800                         printf_verbose("get_metadata : OK\n");
 801                         break;
 802                 case LTTNG_VIEWER_NO_NEW_METADATA:
 803                         printf_verbose("get_metadata : NO NEW\n");
 804                         ret = 0;
 805                         goto end;
 806                 case LTTNG_VIEWER_METADATA_ERR:
 807                         printf_verbose("get_metadata : ERR\n");
 808                         ret = -1;
 809                         goto end;
 810                 default:
 811                         printf_verbose("get_metadata : UNKNOWN\n");
 812                         ret = -1;
 813                         goto end;
 814         }
 815
 816         len = be64toh(rp.len);
 817         printf_verbose("Writing %" PRIu64" bytes to metadata\n", len);
 818         if (len <= 0) {
 819                 ret = -1;
 820                 goto end;
 821         }
 822
 823         data = zmalloc(len);
 824         if (!data) {
 825                 perror("relay data zmalloc");
 826                 ret = -1;
 827                 goto error;
 828         }
 829         ret_len = lttng_live_recv(ctx->control_sock, data, len);
 830         if (ret_len == 0) {
 831                 fprintf(stderr, "[error] Remote side has closed connection\n");
 832                 ret = -1;
 833                 free(data);
 834                 goto error;
 835         }
 836         if (ret_len < 0) {
 837                 perror("[error] Error receiving trace packet");
 838                 ret = ret_len;
 839                 free(data);
 840                 goto error;
 841         }
 842         assert(ret_len == len);
 843
 844         do {
 845                 ret_len = fwrite(data, 1, len,
 846                                 metadata_stream->metadata_fp_write);
 847         } while (ret_len < 0 && errno == EINTR);
 848         if (ret_len < 0) {
 849                 fprintf(stderr, "[error] Writing in the metadata fp\n");
 850                 free(data);
 851                 ret = ret_len;
 852                 goto error;
 853         }
 854         assert(ret_len == len);
 855         metadata_stream->metadata_len += len;
 856         ret = len;
 857
 858         free(data);
 859
 860 end:
 861 error:
 862         return ret;
 863 }
 864
 865 /*
 866  * Return 0 on success, a negative value on error.
 867  */
 868 static
 869 int get_new_metadata(struct lttng_live_ctx *ctx,
 870                 struct lttng_live_viewer_stream *viewer_stream,
 871                 char **metadata_buf)
 872 {
 873         int ret = 0;
 874         struct lttng_live_viewer_stream *metadata_stream;
 875         size_t size, len_read = 0;;
 876
 877         metadata_stream = viewer_stream->ctf_trace->metadata_stream;
 878         if (!metadata_stream) {
 879                 fprintf(stderr, "[error] No metadata stream\n");
 880                 ret = -1;
 881                 goto error;
 882         }
 883         metadata_stream->metadata_len = 0;
 884         ret = open_metadata_fp_write(metadata_stream, metadata_buf, &size);
 885         if (ret < 0) {
 886                 goto error;
 887         }
 888
 889         do {
 890                 /*
 891                  * get_one_metadata_packet returns the number of bytes
 892                  * received, 0 when we have received everything, a
 893                  * negative value on error.
 894                  */
 895                 ret = get_one_metadata_packet(ctx, metadata_stream);
 896                 if (ret > 0) {
 897                         len_read += ret;
 898                 }
 899                 if (!len_read) {
 900                         (void) poll(NULL, 0, ACTIVE_POLL_DELAY);
 901                 }
 902         } while (ret > 0 || !len_read);
 903
 904         if (fclose(metadata_stream->metadata_fp_write))
 905                 perror("fclose");
 906         metadata_stream->metadata_fp_write = NULL;
 907
 908 error:
 909         return ret;
 910 }
 911
 912 /*
 913  * Get one index for a stream.
 914  *
 915  * Returns 0 on success or a negative value on error.
 916  */
 917 static
 918 int get_next_index(struct lttng_live_ctx *ctx,
 919                 struct lttng_live_viewer_stream *viewer_stream,
 920                 struct packet_index *index)
 921 {
 922         struct lttng_viewer_cmd cmd;
 923         struct lttng_viewer_get_next_index rq;
 924         struct lttng_viewer_index rp;
 925         int ret;
 926         ssize_t ret_len;
 927
 928         cmd.cmd = htobe32(LTTNG_VIEWER_GET_NEXT_INDEX);
 929         cmd.data_size = sizeof(rq);
 930         cmd.cmd_version = 0;
 931
 932         memset(&rq, 0, sizeof(rq));
 933         rq.stream_id = htobe64(viewer_stream->id);
 934
 935 retry:
 936         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 937         if (ret_len < 0) {
 938                 perror("[error] Error sending cmd");
 939                 ret = ret_len;
 940                 goto error;
 941         }
 942         assert(ret_len == sizeof(cmd));
 943
 944         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
 945         if (ret_len < 0) {
 946                 perror("[error] Error sending get_next_index request");
 947                 ret = ret_len;
 948                 goto error;
 949         }
 950         assert(ret_len == sizeof(rq));
 951
 952         ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
 953         if (ret_len == 0) {
 954                 fprintf(stderr, "[error] Remote side has closed connection\n");
 955                 ret = -1;
 956                 goto error;
 957         }
 958         if (ret_len < 0) {
 959                 perror("[error] Error receiving index response");
 960                 ret = ret_len;
 961                 goto error;
 962         }
 963         assert(ret_len == sizeof(rp));
 964
 965         rp.flags = be32toh(rp.flags);
 966
 967         switch (be32toh(rp.status)) {
 968         case LTTNG_VIEWER_INDEX_INACTIVE:
 969                 printf_verbose("get_next_index: inactive\n");
 970                 memset(index, 0, sizeof(struct packet_index));
 971                 index->ts_cycles.timestamp_end = be64toh(rp.timestamp_end);
 972                 break;
 973         case LTTNG_VIEWER_INDEX_OK:
 974                 printf_verbose("get_next_index: Ok, need metadata update : %u\n",
 975                                 rp.flags & LTTNG_VIEWER_FLAG_NEW_METADATA);
 976                 index->offset = be64toh(rp.offset);
 977                 index->packet_size = be64toh(rp.packet_size);
 978                 index->content_size = be64toh(rp.content_size);
 979                 index->ts_cycles.timestamp_begin = be64toh(rp.timestamp_begin);
 980                 index->ts_cycles.timestamp_end = be64toh(rp.timestamp_end);
 981                 index->events_discarded = be64toh(rp.events_discarded);
 982
 983                 if (rp.flags & LTTNG_VIEWER_FLAG_NEW_METADATA) {
 984                         ret = append_metadata(ctx, viewer_stream);
 985                         if (ret)
 986                                 goto error;
 987                 }
 988                 if (rp.flags & LTTNG_VIEWER_FLAG_NEW_STREAM) {
 989                         ret = ask_new_streams(ctx);
 990                         if (ret < 0)
 991                                 goto error;
 992                         g_hash_table_foreach(ctx->session->ctf_traces, add_traces,
 993                                         ctx->bt_ctx);
 994                 }
 995                 break;
 996         case LTTNG_VIEWER_INDEX_RETRY:
 997                 printf_verbose("get_next_index: retry\n");
 998                 (void) poll(NULL, 0, ACTIVE_POLL_DELAY);
 999                 goto retry;
1000         case LTTNG_VIEWER_INDEX_HUP:
1001                 printf_verbose("get_next_index: stream hung up\n");
1002                 viewer_stream->id = -1ULL;
1003                 index->offset = EOF;
1004                 ctx->session->stream_count--;
1005                 break;
1006         case LTTNG_VIEWER_INDEX_ERR:
1007                 fprintf(stderr, "[error] get_next_index: error\n");
1008                 ret = -1;
1009                 goto error;
1010         default:
1011                 fprintf(stderr, "[error] get_next_index: unkwown value\n");
1012                 ret = -1;
1013                 goto error;
1014         }
1015
1016         ret = 0;
1017
1018 error:
1019         return ret;
1020 }
1021
1022 static
1023 void ctf_live_packet_seek(struct bt_stream_pos *stream_pos, size_t index,
1024                 int whence)
1025 {
1026         struct ctf_stream_pos *pos;
1027         struct ctf_file_stream *file_stream;
1028         struct packet_index *prev_index = NULL, *cur_index;
1029         struct lttng_live_viewer_stream *viewer_stream;
1030         struct lttng_live_session *session;
1031         int ret;
1032
1033 retry:
1034         pos = ctf_pos(stream_pos);
1035         file_stream = container_of(pos, struct ctf_file_stream, pos);
1036         viewer_stream = (struct lttng_live_viewer_stream *) pos->priv;
1037         session = viewer_stream->session;
1038
1039         switch (pos->packet_index->len) {
1040         case 0:
1041                 g_array_set_size(pos->packet_index, 1);
1042                 cur_index = &g_array_index(pos->packet_index,
1043                                 struct packet_index, 0);
1044                 break;
1045         case 1:
1046                 g_array_set_size(pos->packet_index, 2);
1047                 prev_index = &g_array_index(pos->packet_index,
1048                                 struct packet_index, 0);
1049                 cur_index = &g_array_index(pos->packet_index,
1050                                 struct packet_index, 1);
1051                 break;
1052         case 2:
1053                 g_array_index(pos->packet_index,
1054                         struct packet_index, 0) =
1055                                 g_array_index(pos->packet_index,
1056                                         struct packet_index, 1);
1057                 prev_index = &g_array_index(pos->packet_index,
1058                                 struct packet_index, 0);
1059                 cur_index = &g_array_index(pos->packet_index,
1060                                 struct packet_index, 1);
1061                 break;
1062         default:
1063                 abort();
1064                 break;
1065         }
1066         printf_verbose("get_next_index for stream %" PRIu64 "\n", viewer_stream->id);
1067         ret = get_next_index(session->ctx, viewer_stream, cur_index);
1068         if (ret < 0) {
1069                 pos->offset = EOF;
1070                 fprintf(stderr, "[error] get_next_index failed\n");
1071                 return;
1072         }
1073
1074         pos->packet_size = cur_index->packet_size;
1075         pos->content_size = cur_index->content_size;
1076         pos->mmap_base_offset = 0;
1077         if (cur_index->offset == EOF) {
1078                 pos->offset = EOF;
1079         } else {
1080                 pos->offset = 0;
1081         }
1082
1083         if (cur_index->content_size == 0) {
1084                 file_stream->parent.cycles_timestamp =
1085                                 cur_index->ts_cycles.timestamp_end;
1086                 file_stream->parent.real_timestamp = ctf_get_real_timestamp(
1087                                 &file_stream->parent,
1088                                 cur_index->ts_cycles.timestamp_end);
1089         } else {
1090                 /* Convert the timestamps and append to the real_index. */
1091                 cur_index->ts_real.timestamp_begin = ctf_get_real_timestamp(
1092                                 &file_stream->parent,
1093                                 cur_index->ts_cycles.timestamp_begin);
1094                 cur_index->ts_real.timestamp_end = ctf_get_real_timestamp(
1095                                 &file_stream->parent,
1096                                 cur_index->ts_cycles.timestamp_end);
1097
1098                 ctf_update_current_packet_index(&file_stream->parent,
1099                                 prev_index, cur_index);
1100
1101                 file_stream->parent.cycles_timestamp =
1102                                 cur_index->ts_cycles.timestamp_begin;
1103                 file_stream->parent.real_timestamp =
1104                                 cur_index->ts_real.timestamp_begin;
1105         }
1106
1107         if (pos->packet_size == 0 || pos->offset == EOF) {
1108                 goto end;
1109         }
1110
1111         printf_verbose("get_data_packet for stream %" PRIu64 "\n",
1112                         viewer_stream->id);
1113         ret = get_data_packet(session->ctx, pos, viewer_stream,
1114                         be64toh(cur_index->offset),
1115                         cur_index->packet_size / CHAR_BIT);
1116         if (ret == -2) {
1117                 goto retry;
1118         } else if (ret < 0) {
1119                 pos->offset = EOF;
1120                 fprintf(stderr, "[error] get_data_packet failed\n");
1121                 return;
1122         }
1123
1124         printf_verbose("Index received : packet_size : %" PRIu64
1125                         ", offset %" PRIu64 ", content_size %" PRIu64
1126                         ", timestamp_end : %" PRIu64 "\n",
1127                         cur_index->packet_size, cur_index->offset,
1128                         cur_index->content_size,
1129                         cur_index->ts_cycles.timestamp_end);
1130
1131         /* update trace_packet_header and stream_packet_context */
1132         if (pos->prot != PROT_WRITE && file_stream->parent.trace_packet_header) {
1133                 /* Read packet header */
1134                 ret = generic_rw(&pos->parent, &file_stream->parent.trace_packet_header->p);
1135                 if (ret) {
1136                         pos->offset = EOF;
1137                         fprintf(stderr, "[error] trace packet header read failed\n");
1138                         goto end;
1139                 }
1140         }
1141         if (pos->prot != PROT_WRITE && file_stream->parent.stream_packet_context) {
1142                 /* Read packet context */
1143                 ret = generic_rw(&pos->parent, &file_stream->parent.stream_packet_context->p);
1144                 if (ret) {
1145                         pos->offset = EOF;
1146                         fprintf(stderr, "[error] stream packet context read failed\n");
1147                         goto end;
1148                 }
1149         }
1150         pos->data_offset = pos->offset;
1151
1152 end:
1153         return;
1154 }
1155
1156 int lttng_live_create_viewer_session(struct lttng_live_ctx *ctx)
1157 {
1158         struct lttng_viewer_cmd cmd;
1159         struct lttng_viewer_create_session_response resp;
1160         int ret;
1161         ssize_t ret_len;
1162
1163         cmd.cmd = htobe32(LTTNG_VIEWER_CREATE_SESSION);
1164         cmd.data_size = 0;
1165         cmd.cmd_version = 0;
1166
1167         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
1168         if (ret_len < 0) {
1169                 perror("[error] Error sending cmd");
1170                 ret = ret_len;
1171                 goto error;
1172         }
1173         assert(ret_len == sizeof(cmd));
1174
1175         ret_len = lttng_live_recv(ctx->control_sock, &resp, sizeof(resp));
1176         if (ret_len == 0) {
1177                 fprintf(stderr, "[error] Remote side has closed connection\n");
1178                 ret = -1;
1179                 goto error;
1180         }
1181         if (ret_len < 0) {
1182                 perror("[error] Error receiving create session reply");
1183                 ret = ret_len;
1184                 goto error;
1185         }
1186         assert(ret_len == sizeof(resp));
1187
1188         if (be32toh(resp.status) != LTTNG_VIEWER_CREATE_SESSION_OK) {
1189                 fprintf(stderr, "[error] Error creating viewer session\n");
1190                 ret = -1;
1191                 goto error;
1192         }
1193         ret = 0;
1194
1195 error:
1196         return ret;
1197 }
1198
1199 static
1200 int del_traces(gpointer key, gpointer value, gpointer user_data)
1201 {
1202         struct bt_context *bt_ctx = user_data;
1203         struct lttng_live_ctf_trace *trace = value;
1204         int ret;
1205
1206         ret = bt_context_remove_trace(bt_ctx, trace->trace_id);
1207         if (ret < 0)
1208                 fprintf(stderr, "[error] removing trace from context\n");
1209
1210         /* remove the key/value pair from the HT. */
1211         return 1;
1212 }
1213
1214 static
1215 void add_traces(gpointer key, gpointer value, gpointer user_data)
1216 {
1217         int i, ret;
1218         struct bt_context *bt_ctx = user_data;
1219         struct lttng_live_ctf_trace *trace = value;
1220         struct lttng_live_viewer_stream *stream;
1221         struct bt_mmap_stream *new_mmap_stream;
1222         struct bt_mmap_stream_list mmap_list;
1223         struct lttng_live_ctx *ctx = NULL;
1224         struct bt_trace_descriptor *td;
1225         struct bt_trace_handle *handle;
1226
1227         /*
1228          * We don't know how many streams we will receive for a trace, so
1229          * once we are done receiving the traces, we add all the traces
1230          * received to the bt_context.
1231          * We can receive streams during the attach command or the
1232          * get_new_streams, so we have to make sure not to add multiple
1233          * times the same traces.
1234          * If a trace is already in the context, we just skip this function.
1235          */
1236         if (trace->in_use)
1237                 return;
1238
1239         BT_INIT_LIST_HEAD(&mmap_list.head);
1240
1241         for (i = 0; i < trace->streams->len; i++) {
1242                 stream = g_ptr_array_index(trace->streams, i);
1243                 ctx = stream->session->ctx;
1244
1245                 if (!stream->metadata_flag) {
1246                         new_mmap_stream = zmalloc(sizeof(struct bt_mmap_stream));
1247                         new_mmap_stream->priv = (void *) stream;
1248                         new_mmap_stream->fd = -1;
1249                         bt_list_add(&new_mmap_stream->list, &mmap_list.head);
1250                 } else {
1251                         char *metadata_buf = NULL;
1252
1253                         /* Get all possible metadata before starting */
1254                         ret = get_new_metadata(ctx, stream, &metadata_buf);
1255                         if (ret) {
1256                                 free(metadata_buf);
1257                                 goto end_free;
1258                         }
1259                         if (!stream->metadata_len) {
1260                                 fprintf(stderr, "[error] empty metadata\n");
1261                                 ret = -1;
1262                                 free(metadata_buf);
1263                                 goto end_free;
1264                         }
1265
1266                         trace->metadata_fp = babeltrace_fmemopen(metadata_buf,
1267                                         stream->metadata_len, "rb");
1268                         if (!trace->metadata_fp) {
1269                                 perror("Metadata fmemopen");
1270                                 ret = -1;
1271                                 free(metadata_buf);
1272                                 goto end_free;
1273                         }
1274                 }
1275         }
1276
1277         if (!trace->metadata_fp) {
1278                 fprintf(stderr, "[error] No metadata stream opened\n");
1279                 goto end_free;
1280         }
1281
1282         ret = bt_context_add_trace(bt_ctx, NULL, "ctf",
1283                         ctf_live_packet_seek, &mmap_list, trace->metadata_fp);
1284         if (ret < 0) {
1285                 fprintf(stderr, "[error] Error adding trace\n");
1286                 goto end_free;
1287         }
1288         trace->metadata_stream->metadata_len = 0;
1289
1290         handle = (struct bt_trace_handle *) g_hash_table_lookup(
1291                         bt_ctx->trace_handles,
1292                         (gpointer) (unsigned long) ret);
1293         td = handle->td;
1294         trace->handle = handle;
1295         if (bt_ctx->current_iterator) {
1296                 bt_iter_add_trace(bt_ctx->current_iterator, td);
1297         }
1298
1299         trace->trace_id = ret;
1300         trace->in_use = 1;
1301
1302         goto end;
1303
1304 end_free:
1305         bt_context_put(bt_ctx);
1306 end:
1307         return;
1308 }
1309
1310 int lttng_live_get_new_streams(struct lttng_live_ctx *ctx, uint64_t id)
1311 {
1312         struct lttng_viewer_cmd cmd;
1313         struct lttng_viewer_new_streams_request rq;
1314         struct lttng_viewer_new_streams_response rp;
1315         struct lttng_viewer_stream stream;
1316         int ret, i;
1317         ssize_t ret_len;
1318         uint32_t stream_count;
1319
1320         cmd.cmd = htobe32(LTTNG_VIEWER_GET_NEW_STREAMS);
1321         cmd.data_size = sizeof(rq);
1322         cmd.cmd_version = 0;
1323
1324         memset(&rq, 0, sizeof(rq));
1325         rq.session_id = htobe64(id);
1326
1327         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
1328         if (ret_len < 0) {
1329                 perror("[error] Error sending cmd");
1330                 ret = ret_len;
1331                 goto error;
1332         }
1333         assert(ret_len == sizeof(cmd));
1334
1335         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
1336         if (ret_len < 0) {
1337                 perror("[error] Error sending get_new_streams request");
1338                 ret = ret_len;
1339                 goto error;
1340         }
1341         assert(ret_len == sizeof(rq));
1342
1343         ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
1344         if (ret_len == 0) {
1345                 fprintf(stderr, "[error] Remote side has closed connection\n");
1346                 ret = -1;
1347                 goto error;
1348         }
1349         if (ret_len < 0) {
1350                 perror("[error] Error receiving get_new_streams response");
1351                 ret = ret_len;
1352                 goto error;
1353         }
1354         assert(ret_len == sizeof(rp));
1355
1356         switch(be32toh(rp.status)) {
1357         case LTTNG_VIEWER_NEW_STREAMS_OK:
1358                 break;
1359         case LTTNG_VIEWER_NEW_STREAMS_NO_NEW:
1360                 ret = 0;
1361                 goto end;
1362         case LTTNG_VIEWER_NEW_STREAMS_HUP:
1363                 ret = -LTTNG_VIEWER_NEW_STREAMS_HUP;
1364                 goto end;
1365         case LTTNG_VIEWER_NEW_STREAMS_ERR:
1366                 fprintf(stderr, "[error] get_new_streams error\n");
1367                 ret = -1;
1368                 goto end;
1369         default:
1370                 fprintf(stderr, "[error] Unknown return code %u\n",
1371                                 be32toh(rp.status));
1372                 ret = -1;
1373                 goto end;
1374         }
1375
1376         stream_count = be32toh(rp.streams_count);
1377         ctx->session->stream_count += stream_count;
1378         /*
1379          * When the session is created but not started, we do an active wait
1380          * until it starts. It allows the viewer to start processing the trace
1381          * as soon as the session starts.
1382          */
1383         if (ctx->session->stream_count == 0) {
1384                 ret = 0;
1385                 goto end;
1386         }
1387         printf_verbose("Waiting for %" PRIu64 " streams:\n",
1388                 ctx->session->stream_count);
1389         ctx->session->streams = g_new0(struct lttng_live_viewer_stream,
1390                         ctx->session->stream_count);
1391         for (i = 0; i < stream_count; i++) {
1392                 ret_len = lttng_live_recv(ctx->control_sock, &stream, sizeof(stream));
1393                 if (ret_len == 0) {
1394                         fprintf(stderr, "[error] Remote side has closed connection\n");
1395                         ret = -1;
1396                         goto error;
1397                 }
1398                 if (ret_len < 0) {
1399                         perror("[error] Error receiving stream");
1400                         ret = ret_len;
1401                         goto error;
1402                 }
1403                 assert(ret_len == sizeof(stream));
1404                 stream.path_name[LTTNG_VIEWER_PATH_MAX - 1] = '\0';
1405                 stream.channel_name[LTTNG_VIEWER_NAME_MAX - 1] = '\0';
1406
1407                 printf_verbose("    stream %" PRIu64 " : %s/%s\n",
1408                                 be64toh(stream.id), stream.path_name,
1409                                 stream.channel_name);
1410                 ctx->session->streams[i].id = be64toh(stream.id);
1411                 ctx->session->streams[i].session = ctx->session;
1412
1413                 ctx->session->streams[i].first_read = 1;
1414                 ctx->session->streams[i].mmap_size = 0;
1415
1416                 if (be32toh(stream.metadata_flag)) {
1417                         ctx->session->streams[i].metadata_flag = 1;
1418                 }
1419                 ret = lttng_live_ctf_trace_assign(&ctx->session->streams[i],
1420                                 be64toh(stream.ctf_trace_id));
1421                 if (ret < 0) {
1422                         goto error;
1423                 }
1424
1425         }
1426         ret = 0;
1427
1428 end:
1429 error:
1430         return ret;
1431 }
1432
1433 void lttng_live_read(struct lttng_live_ctx *ctx)
1434 {
1435         int ret, i;
1436         struct bt_ctf_iter *iter;
1437         const struct bt_ctf_event *event;
1438         struct bt_iter_pos begin_pos;
1439         struct bt_trace_descriptor *td_write;
1440         struct bt_format *fmt_write;
1441         struct ctf_text_stream_pos *sout;
1442         uint64_t id;
1443
1444         ctx->bt_ctx = bt_context_create();
1445         if (!ctx->bt_ctx) {
1446                 fprintf(stderr, "[error] bt_context_create allocation\n");
1447                 goto end;
1448         }
1449
1450         fmt_write = bt_lookup_format(g_quark_from_static_string("text"));
1451         if (!fmt_write) {
1452                 fprintf(stderr, "[error] ctf-text error\n");
1453                 goto end;
1454         }
1455
1456         td_write = fmt_write->open_trace(NULL, O_RDWR, NULL, NULL);
1457         if (!td_write) {
1458                 fprintf(stderr, "[error] Error opening output trace\n");
1459                 goto end_free;
1460         }
1461
1462         sout = container_of(td_write, struct ctf_text_stream_pos,
1463                         trace_descriptor);
1464         if (!sout->parent.event_cb)
1465                 goto end_free;
1466
1467         ret = lttng_live_create_viewer_session(ctx);
1468         if (ret < 0) {
1469                 goto end_free;
1470         }
1471
1472         for (i = 0; i < ctx->session_ids->len; i++) {
1473                 id = g_array_index(ctx->session_ids, uint64_t, i);
1474                 printf_verbose("Attaching to session %lu\n", id);
1475                 ret = lttng_live_attach_session(ctx, id);
1476                 printf_verbose("Attaching session returns %d\n", ret);
1477                 if (ret < 0) {
1478                         if (ret == -LTTNG_VIEWER_ATTACH_UNK) {
1479                                 fprintf(stderr, "[error] Unknown session ID\n");
1480                         }
1481                         goto end_free;
1482                 }
1483         }
1484
1485         /*
1486          * As long as the session is active, we try to get new streams.
1487          */
1488         for (;;) {
1489                 int flags;
1490
1491                 while (!ctx->session->stream_count) {
1492                         if (ctx->session_ids->len == 0)
1493                                 goto end_free;
1494                         ret = ask_new_streams(ctx);
1495                         if (ret < 0)
1496                                 goto end_free;
1497                         if (!ctx->session->stream_count)
1498                                 (void) poll(NULL, 0, ACTIVE_POLL_DELAY);
1499                 }
1500
1501                 g_hash_table_foreach(ctx->session->ctf_traces, add_traces,
1502                                 ctx->bt_ctx);
1503
1504                 begin_pos.type = BT_SEEK_BEGIN;
1505                 iter = bt_ctf_iter_create(ctx->bt_ctx, &begin_pos, NULL);
1506                 if (!iter) {
1507                         fprintf(stderr, "[error] Iterator creation error\n");
1508                         goto end;
1509                 }
1510                 for (;;) {
1511                         event = bt_ctf_iter_read_event_flags(iter, &flags);
1512                         if (!(flags & BT_ITER_FLAG_RETRY)) {
1513                                 if (!event) {
1514                                         /* End of trace */
1515                                         break;
1516                                 }
1517                                 ret = sout->parent.event_cb(&sout->parent,
1518                                                 event->parent->stream);
1519                                 if (ret) {
1520                                         fprintf(stderr, "[error] Writing "
1521                                                         "event failed.\n");
1522                                         goto end_free;
1523                                 }
1524                         }
1525                         ret = bt_iter_next(bt_ctf_get_iter(iter));
1526                         if (ret < 0) {
1527                                 goto end_free;
1528                         }
1529                 }
1530                 bt_ctf_iter_destroy(iter);
1531                 g_hash_table_foreach_remove(ctx->session->ctf_traces,
1532                                 del_traces, ctx->bt_ctx);
1533                 ctx->session->stream_count = 0;
1534         }
1535
1536 end_free:
1537         bt_context_put(ctx->bt_ctx);
1538 end:
1539         return;
1540 }