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/endian.h>
  54 #include <babeltrace/compat/memstream.h>
  55
  56 #include "lttng-live.h"
  57 #include "lttng-viewer-abi.h"
  58
  59 #define ACTIVE_POLL_DELAY       100     /* ms */
  60
  61 /*
  62  * Memory allocation zeroed
  63  */
  64 #define zmalloc(x) calloc(1, x)
  65
  66 #ifndef max_t
  67 #define max_t(type, a, b)       \
  68         ((type) (a) > (type) (b) ? (type) (a) : (type) (b))
  69 #endif
  70
  71 static void ctf_live_packet_seek(struct bt_stream_pos *stream_pos,
  72                 size_t index, int whence);
  73 static void add_traces(gpointer key, gpointer value, gpointer user_data);
  74 static int del_traces(gpointer key, gpointer value, gpointer user_data);
  75 static int get_new_metadata(struct lttng_live_ctx *ctx,
  76                 struct lttng_live_viewer_stream *viewer_stream,
  77                 char **metadata_buf);
  78
  79 static
  80 ssize_t lttng_live_recv(int fd, void *buf, size_t len)
  81 {
  82         ssize_t ret;
  83         size_t copied = 0, to_copy = len;
  84
  85         do {
  86                 ret = recv(fd, buf + copied, to_copy, 0);
  87                 if (ret > 0) {
  88                         assert(ret <= to_copy);
  89                         copied += ret;
  90                         to_copy -= ret;
  91                 }
  92         } while ((ret > 0 && to_copy > 0)
  93                 || (ret < 0 && errno == EINTR));
  94         if (ret > 0)
  95                 ret = copied;
  96         /* ret = 0 means orderly shutdown, ret < 0 is error. */
  97         return ret;
  98 }
  99
 100 static
 101 ssize_t lttng_live_send(int fd, const void *buf, size_t len)
 102 {
 103         ssize_t ret;
 104
 105         do {
 106                 ret = send(fd, buf, len, MSG_NOSIGNAL);
 107         } while (ret < 0 && errno == EINTR);
 108         return ret;
 109 }
 110
 111 int lttng_live_connect_viewer(struct lttng_live_ctx *ctx)
 112 {
 113         struct hostent *host;
 114         struct sockaddr_in server_addr;
 115         int ret;
 116
 117         if (lttng_live_should_quit()) {
 118                 ret = -1;
 119                 goto end;
 120         }
 121
 122         host = gethostbyname(ctx->relay_hostname);
 123         if (!host) {
 124                 fprintf(stderr, "[error] Cannot lookup hostname %s\n",
 125                         ctx->relay_hostname);
 126                 goto error;
 127         }
 128
 129         if ((ctx->control_sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
 130                 perror("Socket");
 131                 goto error;
 132         }
 133
 134         server_addr.sin_family = AF_INET;
 135         server_addr.sin_port = htons(ctx->port);
 136         server_addr.sin_addr = *((struct in_addr *) host->h_addr);
 137         bzero(&(server_addr.sin_zero), 8);
 138
 139         if (connect(ctx->control_sock, (struct sockaddr *) &server_addr,
 140                                 sizeof(struct sockaddr)) == -1) {
 141                 perror("Connect");
 142                 goto error;
 143         }
 144
 145         ret = 0;
 146
 147 end:
 148         return ret;
 149
 150 error:
 151         fprintf(stderr, "[error] Connection failed\n");
 152         return -1;
 153 }
 154
 155 int lttng_live_establish_connection(struct lttng_live_ctx *ctx)
 156 {
 157         struct lttng_viewer_cmd cmd;
 158         struct lttng_viewer_connect connect;
 159         int ret;
 160         ssize_t ret_len;
 161
 162         if (lttng_live_should_quit()) {
 163                 ret = -1;
 164                 goto end;
 165         }
 166
 167         cmd.cmd = htobe32(LTTNG_VIEWER_CONNECT);
 168         cmd.data_size = sizeof(connect);
 169         cmd.cmd_version = 0;
 170
 171         connect.viewer_session_id = -1ULL;      /* will be set on recv */
 172         connect.major = htobe32(LTTNG_LIVE_MAJOR);
 173         connect.minor = htobe32(LTTNG_LIVE_MINOR);
 174         connect.type = htobe32(LTTNG_VIEWER_CLIENT_COMMAND);
 175
 176         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 177         if (ret_len < 0) {
 178                 perror("[error] Error sending cmd");
 179                 goto error;
 180         }
 181         assert(ret_len == sizeof(cmd));
 182
 183         ret_len = lttng_live_send(ctx->control_sock, &connect, sizeof(connect));
 184         if (ret_len < 0) {
 185                 perror("[error] Error sending version");
 186                 goto error;
 187         }
 188         assert(ret_len == sizeof(connect));
 189
 190         ret_len = lttng_live_recv(ctx->control_sock, &connect, sizeof(connect));
 191         if (ret_len == 0) {
 192                 fprintf(stderr, "[error] Remote side has closed connection\n");
 193                 goto error;
 194         }
 195         if (ret_len < 0) {
 196                 perror("[error] Error receiving version");
 197                 goto error;
 198         }
 199         assert(ret_len == sizeof(connect));
 200
 201         printf_verbose("Received viewer session ID : %" PRIu64 "\n",
 202                         be64toh(connect.viewer_session_id));
 203         printf_verbose("Relayd version : %u.%u\n", be32toh(connect.major),
 204                         be32toh(connect.minor));
 205
 206         if (LTTNG_LIVE_MAJOR != be32toh(connect.major)) {
 207                 fprintf(stderr, "[error] Incompatible lttng-relayd protocol\n");
 208                 goto error;
 209         }
 210         /* Use the smallest protocol version implemented. */
 211         if (LTTNG_LIVE_MINOR > be32toh(connect.minor)) {
 212                 ctx->minor =  be32toh(connect.minor);
 213         } else {
 214                 ctx->minor =  LTTNG_LIVE_MINOR;
 215         }
 216         ctx->major = LTTNG_LIVE_MAJOR;
 217         ret = 0;
 218 end:
 219         return ret;
 220
 221 error:
 222         fprintf(stderr, "[error] Unable to establish connection\n");
 223         return -1;
 224 }
 225
 226 static
 227 void free_session_list(GPtrArray *session_list)
 228 {
 229         int i;
 230         struct lttng_live_relay_session *relay_session;
 231
 232         for (i = 0; i < session_list->len; i++) {
 233                 relay_session = g_ptr_array_index(session_list, i);
 234                 free(relay_session->name);
 235                 free(relay_session->hostname);
 236         }
 237         g_ptr_array_free(session_list, TRUE);
 238 }
 239
 240 static
 241 void print_session_list(GPtrArray *session_list, const char *path)
 242 {
 243         int i;
 244         struct lttng_live_relay_session *relay_session;
 245
 246         for (i = 0; i < session_list->len; i++) {
 247                 relay_session = g_ptr_array_index(session_list, i);
 248                 fprintf(stdout, "%s/host/%s/%s (timer = %u, "
 249                                 "%u stream(s), %u client(s) connected)\n",
 250                                 path, relay_session->hostname,
 251                                 relay_session->name, relay_session->timer,
 252                                 relay_session->streams, relay_session->clients);
 253         }
 254 }
 255
 256 static
 257 void update_session_list(GPtrArray *session_list, char *hostname,
 258                 char *session_name, uint32_t streams, uint32_t clients,
 259                 uint32_t timer)
 260 {
 261         int i, found = 0;
 262         struct lttng_live_relay_session *relay_session;
 263
 264         for (i = 0; i < session_list->len; i++) {
 265                 relay_session = g_ptr_array_index(session_list, i);
 266                 if ((strncmp(relay_session->hostname, hostname, NAME_MAX) == 0) &&
 267                                 strncmp(relay_session->name,
 268                                         session_name, NAME_MAX) == 0) {
 269                         relay_session->streams += streams;
 270                         if (relay_session->clients < clients)
 271                                 relay_session->clients = clients;
 272                         found = 1;
 273                         break;
 274                 }
 275         }
 276         if (found)
 277                 return;
 278
 279         relay_session = g_new0(struct lttng_live_relay_session, 1);
 280         relay_session->hostname = strndup(hostname, NAME_MAX);
 281         relay_session->name = strndup(session_name, NAME_MAX);
 282         relay_session->clients = clients;
 283         relay_session->streams = streams;
 284         relay_session->timer = timer;
 285         g_ptr_array_add(session_list, relay_session);
 286 }
 287
 288 int lttng_live_list_sessions(struct lttng_live_ctx *ctx, const char *path)
 289 {
 290         struct lttng_viewer_cmd cmd;
 291         struct lttng_viewer_list_sessions list;
 292         struct lttng_viewer_session lsession;
 293         int i, ret, sessions_count, print_list = 0;
 294         ssize_t ret_len;
 295         uint64_t session_id;
 296         GPtrArray *session_list = NULL;
 297
 298         if (lttng_live_should_quit()) {
 299                 ret = -1;
 300                 goto end;
 301         }
 302
 303         if (strlen(ctx->session_name) == 0) {
 304                 print_list = 1;
 305                 session_list = g_ptr_array_new();
 306         }
 307
 308         cmd.cmd = htobe32(LTTNG_VIEWER_LIST_SESSIONS);
 309         cmd.data_size = 0;
 310         cmd.cmd_version = 0;
 311
 312         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 313         if (ret_len < 0) {
 314                 perror("[error] Error sending cmd");
 315                 goto error;
 316         }
 317         assert(ret_len == sizeof(cmd));
 318
 319         ret_len = lttng_live_recv(ctx->control_sock, &list, sizeof(list));
 320         if (ret_len == 0) {
 321                 fprintf(stderr, "[error] Remote side has closed connection\n");
 322                 goto error;
 323         }
 324         if (ret_len < 0) {
 325                 perror("[error] Error receiving session list");
 326                 goto error;
 327         }
 328         assert(ret_len == sizeof(list));
 329
 330         sessions_count = be32toh(list.sessions_count);
 331         for (i = 0; i < sessions_count; i++) {
 332                 ret_len = lttng_live_recv(ctx->control_sock, &lsession, sizeof(lsession));
 333                 if (ret_len == 0) {
 334                         fprintf(stderr, "[error] Remote side has closed connection\n");
 335                         goto error;
 336                 }
 337                 if (ret_len < 0) {
 338                         perror("[error] Error receiving session");
 339                         goto error;
 340                 }
 341                 assert(ret_len == sizeof(lsession));
 342                 lsession.hostname[LTTNG_VIEWER_HOST_NAME_MAX - 1] = '\0';
 343                 lsession.session_name[LTTNG_VIEWER_NAME_MAX - 1] = '\0';
 344                 session_id = be64toh(lsession.id);
 345
 346                 if (print_list) {
 347                         update_session_list(session_list,
 348                                         lsession.hostname,
 349                                         lsession.session_name,
 350                                         be32toh(lsession.streams),
 351                                         be32toh(lsession.clients),
 352                                         be32toh(lsession.live_timer));
 353                 } else {
 354                         if ((strncmp(lsession.session_name, ctx->session_name,
 355                                 NAME_MAX) == 0) && (strncmp(lsession.hostname,
 356                                         ctx->traced_hostname, NAME_MAX) == 0)) {
 357                                 printf_verbose("Reading from session %" PRIu64 "\n",
 358                                                 session_id);
 359                                 g_array_append_val(ctx->session_ids,
 360                                                 session_id);
 361                         }
 362                 }
 363         }
 364
 365         if (print_list) {
 366                 print_session_list(session_list, path);
 367                 free_session_list(session_list);
 368         }
 369         ret = 0;
 370 end:
 371         return ret;
 372
 373 error:
 374         fprintf(stderr, "[error] Unable to list sessions\n");
 375         return -1;
 376 }
 377
 378 int lttng_live_ctf_trace_assign(struct lttng_live_viewer_stream *stream,
 379                 uint64_t ctf_trace_id)
 380 {
 381         struct lttng_live_ctf_trace *trace;
 382         int ret = 0;
 383
 384         trace = g_hash_table_lookup(stream->session->ctf_traces,
 385                         (gpointer) ctf_trace_id);
 386         if (!trace) {
 387                 trace = g_new0(struct lttng_live_ctf_trace, 1);
 388                 trace->ctf_trace_id = ctf_trace_id;
 389                 trace->streams = g_ptr_array_new();
 390                 g_hash_table_insert(stream->session->ctf_traces,
 391                                 (gpointer) ctf_trace_id,
 392                                 trace);
 393         }
 394         if (stream->metadata_flag)
 395                 trace->metadata_stream = stream;
 396
 397         stream->ctf_trace = trace;
 398         g_ptr_array_add(trace->streams, stream);
 399
 400         return ret;
 401 }
 402
 403 static
 404 int open_metadata_fp_write(struct lttng_live_viewer_stream *stream,
 405                 char **metadata_buf, size_t *size)
 406 {
 407         int ret = 0;
 408
 409         stream->metadata_fp_write =
 410                 babeltrace_open_memstream(metadata_buf, size);
 411         if (!stream->metadata_fp_write) {
 412                 perror("Metadata open_memstream");
 413                 ret = -1;
 414         }
 415
 416         return ret;
 417 }
 418
 419 int lttng_live_attach_session(struct lttng_live_ctx *ctx, uint64_t id)
 420 {
 421         struct lttng_viewer_cmd cmd;
 422         struct lttng_viewer_attach_session_request rq;
 423         struct lttng_viewer_attach_session_response rp;
 424         struct lttng_viewer_stream stream;
 425         int ret, i;
 426         ssize_t ret_len;
 427
 428         if (lttng_live_should_quit()) {
 429                 ret = -1;
 430                 goto end;
 431         }
 432
 433         cmd.cmd = htobe32(LTTNG_VIEWER_ATTACH_SESSION);
 434         cmd.data_size = sizeof(rq);
 435         cmd.cmd_version = 0;
 436
 437         memset(&rq, 0, sizeof(rq));
 438         rq.session_id = htobe64(id);
 439         // TODO: add cmd line parameter to select seek beginning
 440         // rq.seek = htobe32(LTTNG_VIEWER_SEEK_BEGINNING);
 441         rq.seek = htobe32(LTTNG_VIEWER_SEEK_LAST);
 442
 443         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 444         if (ret_len < 0) {
 445                 perror("[error] Error sending cmd");
 446                 goto error;
 447         }
 448         assert(ret_len == sizeof(cmd));
 449
 450         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
 451         if (ret_len < 0) {
 452                 perror("[error] Error sending attach request");
 453                 goto error;
 454         }
 455         assert(ret_len == sizeof(rq));
 456
 457         ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
 458         if (ret_len == 0) {
 459                 fprintf(stderr, "[error] Remote side has closed connection\n");
 460                 goto error;
 461         }
 462         if (ret_len < 0) {
 463                 perror("[error] Error receiving attach response");
 464                 goto error;
 465         }
 466         assert(ret_len == sizeof(rp));
 467
 468         switch(be32toh(rp.status)) {
 469         case LTTNG_VIEWER_ATTACH_OK:
 470                 break;
 471         case LTTNG_VIEWER_ATTACH_UNK:
 472                 ret = -LTTNG_VIEWER_ATTACH_UNK;
 473                 goto end;
 474         case LTTNG_VIEWER_ATTACH_ALREADY:
 475                 fprintf(stderr, "[error] There is already a viewer attached to this session\n");
 476                 goto error;
 477         case LTTNG_VIEWER_ATTACH_NOT_LIVE:
 478                 fprintf(stderr, "[error] Not a live session\n");
 479                 goto error;
 480         case LTTNG_VIEWER_ATTACH_SEEK_ERR:
 481                 fprintf(stderr, "[error] Wrong seek parameter\n");
 482                 goto error;
 483         default:
 484                 fprintf(stderr, "[error] Unknown attach return code %u\n",
 485                                 be32toh(rp.status));
 486                 goto error;
 487         }
 488         if (be32toh(rp.status) != LTTNG_VIEWER_ATTACH_OK) {
 489                 goto error;
 490         }
 491
 492         ctx->session->stream_count += be32toh(rp.streams_count);
 493         /*
 494          * When the session is created but not started, we do an active wait
 495          * until it starts. It allows the viewer to start processing the trace
 496          * as soon as the session starts.
 497          */
 498         if (ctx->session->stream_count == 0) {
 499                 ret = 0;
 500                 goto end;
 501         }
 502         printf_verbose("Waiting for %" PRIu64 " streams:\n",
 503                 ctx->session->stream_count);
 504         ctx->session->streams = g_new0(struct lttng_live_viewer_stream,
 505                         ctx->session->stream_count);
 506         for (i = 0; i < be32toh(rp.streams_count); i++) {
 507                 ret_len = lttng_live_recv(ctx->control_sock, &stream, sizeof(stream));
 508                 if (ret_len == 0) {
 509                         fprintf(stderr, "[error] Remote side has closed connection\n");
 510                         goto error;
 511                 }
 512                 if (ret_len < 0) {
 513                         perror("[error] Error receiving stream");
 514                         goto error;
 515                 }
 516                 assert(ret_len == sizeof(stream));
 517                 stream.path_name[LTTNG_VIEWER_PATH_MAX - 1] = '\0';
 518                 stream.channel_name[LTTNG_VIEWER_NAME_MAX - 1] = '\0';
 519
 520                 printf_verbose("    stream %" PRIu64 " : %s/%s\n",
 521                                 be64toh(stream.id), stream.path_name,
 522                                 stream.channel_name);
 523                 ctx->session->streams[i].id = be64toh(stream.id);
 524                 ctx->session->streams[i].session = ctx->session;
 525
 526                 ctx->session->streams[i].mmap_size = 0;
 527                 ctx->session->streams[i].ctf_stream_id = -1ULL;
 528
 529                 if (be32toh(stream.metadata_flag)) {
 530                         ctx->session->streams[i].metadata_flag = 1;
 531                 }
 532                 ret = lttng_live_ctf_trace_assign(&ctx->session->streams[i],
 533                                 be64toh(stream.ctf_trace_id));
 534                 if (ret < 0) {
 535                         goto error;
 536                 }
 537
 538         }
 539         ret = 0;
 540 end:
 541         return ret;
 542
 543 error:
 544         return -1;
 545 }
 546
 547 /*
 548  * Ask the relay for new streams.
 549  *
 550  * Returns the number of new streams received or a negative value on error.
 551  */
 552 static
 553 int ask_new_streams(struct lttng_live_ctx *ctx)
 554 {
 555         int i, ret = 0, nb_streams = 0;
 556         uint64_t id;
 557
 558 restart:
 559         for (i = 0; i < ctx->session_ids->len; i++) {
 560                 id = g_array_index(ctx->session_ids, uint64_t, i);
 561                 ret = lttng_live_get_new_streams(ctx, id);
 562                 printf_verbose("Asking for new streams returns %d\n", ret);
 563                 if (ret < 0) {
 564                         if (lttng_live_should_quit()) {
 565                                 goto end;
 566                         }
 567                         if (ret == -LTTNG_VIEWER_NEW_STREAMS_HUP) {
 568                                 printf_verbose("Session %" PRIu64 " closed\n",
 569                                                 id);
 570                                 /*
 571                                  * The streams have already been closed during
 572                                  * the reading, so we only need to get rid of
 573                                  * the trace in our internal table of sessions.
 574                                  */
 575                                 g_array_remove_index(ctx->session_ids, i);
 576                                 /*
 577                                  * We can't continue iterating on the g_array
 578                                  * after a remove, we have to start again.
 579                                  */
 580                                 goto restart;
 581                         } else {
 582                                 ret = -1;
 583                                 goto end;
 584                         }
 585                 } else {
 586                         nb_streams += ret;
 587                 }
 588         }
 589         ret = nb_streams;
 590
 591 end:
 592         return ret;
 593 }
 594
 595 static
 596 int append_metadata(struct lttng_live_ctx *ctx,
 597                 struct lttng_live_viewer_stream *viewer_stream)
 598 {
 599         int ret;
 600         struct lttng_live_viewer_stream *metadata;
 601         char *metadata_buf = NULL;
 602
 603         printf_verbose("get_next_index: new metadata needed\n");
 604         ret = get_new_metadata(ctx, viewer_stream, &metadata_buf);
 605         if (ret < 0) {
 606                 free(metadata_buf);
 607                 goto error;
 608         }
 609
 610         metadata = viewer_stream->ctf_trace->metadata_stream;
 611         metadata->ctf_trace->metadata_fp =
 612                 babeltrace_fmemopen(metadata_buf,
 613                                 metadata->metadata_len, "rb");
 614         if (!metadata->ctf_trace->metadata_fp) {
 615                 perror("Metadata fmemopen");
 616                 free(metadata_buf);
 617                 ret = -1;
 618                 goto error;
 619         }
 620         ret = ctf_append_trace_metadata(
 621                         viewer_stream->ctf_trace->handle->td,
 622                         metadata->ctf_trace->metadata_fp);
 623         /* We accept empty metadata packets */
 624         if (ret != 0 && ret != -ENOENT) {
 625                 fprintf(stderr, "[error] Appending metadata\n");
 626                 goto error;
 627         }
 628         ret = 0;
 629
 630 error:
 631         return ret;
 632 }
 633
 634 static
 635 int get_data_packet(struct lttng_live_ctx *ctx,
 636                 struct ctf_stream_pos *pos,
 637                 struct lttng_live_viewer_stream *stream, uint64_t offset,
 638                 uint64_t len)
 639 {
 640         struct lttng_viewer_cmd cmd;
 641         struct lttng_viewer_get_packet rq;
 642         struct lttng_viewer_trace_packet rp;
 643         ssize_t ret_len;
 644         int ret;
 645
 646 retry:
 647         if (lttng_live_should_quit()) {
 648                 ret = -1;
 649                 goto end;
 650         }
 651         cmd.cmd = htobe32(LTTNG_VIEWER_GET_PACKET);
 652         cmd.data_size = sizeof(rq);
 653         cmd.cmd_version = 0;
 654
 655         memset(&rq, 0, sizeof(rq));
 656         rq.stream_id = htobe64(stream->id);
 657         rq.offset = htobe64(offset);
 658         rq.len = htobe32(len);
 659
 660         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 661         if (ret_len < 0) {
 662                 perror("[error] Error sending cmd");
 663                 goto error;
 664         }
 665         assert(ret_len == sizeof(cmd));
 666
 667         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
 668         if (ret_len < 0) {
 669                 perror("[error] Error sending get_data_packet request");
 670                 goto error;
 671         }
 672         assert(ret_len == sizeof(rq));
 673
 674         ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
 675         if (ret_len == 0) {
 676                 fprintf(stderr, "[error] Remote side has closed connection\n");
 677                 goto error;
 678         }
 679         if (ret_len < 0) {
 680                 perror("[error] Error receiving data response");
 681                 goto error;
 682         }
 683         if (ret_len != sizeof(rp)) {
 684                 fprintf(stderr, "[error] get_data_packet: expected %" PRId64
 685                                 ", received %" PRId64 "\n", sizeof(rp),
 686                                 ret_len);
 687                 goto error;
 688         }
 689
 690         rp.flags = be32toh(rp.flags);
 691
 692         switch (be32toh(rp.status)) {
 693         case LTTNG_VIEWER_GET_PACKET_OK:
 694                 len = be32toh(rp.len);
 695                 printf_verbose("get_data_packet: Ok, packet size : %" PRIu64
 696                                 "\n", len);
 697                 break;
 698         case LTTNG_VIEWER_GET_PACKET_RETRY:
 699                 /* Unimplemented by relay daemon */
 700                 printf_verbose("get_data_packet: retry\n");
 701                 goto error;
 702         case LTTNG_VIEWER_GET_PACKET_ERR:
 703                 if (rp.flags & LTTNG_VIEWER_FLAG_NEW_METADATA) {
 704                         printf_verbose("get_data_packet: new metadata needed\n");
 705                         ret = append_metadata(ctx, stream);
 706                         if (ret)
 707                                 goto error;
 708                 }
 709                 if (rp.flags & LTTNG_VIEWER_FLAG_NEW_STREAM) {
 710                         printf_verbose("get_data_packet: new streams needed\n");
 711                         ret = ask_new_streams(ctx);
 712                         if (ret < 0)
 713                                 goto error;
 714                         else if (ret > 0)
 715                                 g_hash_table_foreach(ctx->session->ctf_traces,
 716                                                 add_traces, ctx->bt_ctx);
 717                 }
 718                 if (rp.flags & (LTTNG_VIEWER_FLAG_NEW_METADATA
 719                                 | LTTNG_VIEWER_FLAG_NEW_STREAM)) {
 720                         goto retry;
 721                 }
 722                 fprintf(stderr, "[error] get_data_packet: error\n");
 723                 goto error;
 724         case LTTNG_VIEWER_GET_PACKET_EOF:
 725                 ret = -2;
 726                 goto end;
 727         default:
 728                 printf_verbose("get_data_packet: unknown\n");
 729                 goto error;
 730         }
 731
 732         if (len == 0) {
 733                 goto error;
 734         }
 735
 736         if (len > stream->mmap_size) {
 737                 uint64_t new_size;
 738
 739                 new_size = max_t(uint64_t, len, stream->mmap_size << 1);
 740                 if (pos->base_mma) {
 741                         /* unmap old base */
 742                         ret = munmap_align(pos->base_mma);
 743                         if (ret) {
 744                                 perror("[error] Unable to unmap old base");
 745                                 goto error;
 746                         }
 747                         pos->base_mma = NULL;
 748                 }
 749                 pos->base_mma = mmap_align(new_size,
 750                                 PROT_READ | PROT_WRITE,
 751                                 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 752                 if (pos->base_mma == MAP_FAILED) {
 753                         perror("[error] mmap error");
 754                         pos->base_mma = NULL;
 755                         goto error;
 756                 }
 757
 758                 stream->mmap_size = new_size;
 759                 printf_verbose("Expanding stream mmap size to %" PRIu64 " bytes\n",
 760                                 stream->mmap_size);
 761         }
 762
 763         ret_len = lttng_live_recv(ctx->control_sock,
 764                         mmap_align_addr(pos->base_mma), len);
 765         if (ret_len == 0) {
 766                 fprintf(stderr, "[error] Remote side has closed connection\n");
 767                 goto error;
 768         }
 769         if (ret_len < 0) {
 770                 perror("[error] Error receiving trace packet");
 771                 goto error;
 772         }
 773         assert(ret_len == len);
 774         ret = 0;
 775 end:
 776         return ret;
 777
 778 error:
 779         return -1;
 780 }
 781
 782 static
 783 int get_one_metadata_packet(struct lttng_live_ctx *ctx,
 784                 struct lttng_live_viewer_stream *metadata_stream)
 785 {
 786         uint64_t len = 0;
 787         int ret;
 788         struct lttng_viewer_cmd cmd;
 789         struct lttng_viewer_get_metadata rq;
 790         struct lttng_viewer_metadata_packet rp;
 791         char *data = NULL;
 792         ssize_t ret_len;
 793
 794         if (lttng_live_should_quit()) {
 795                 ret = -1;
 796                 goto end;
 797         }
 798
 799         rq.stream_id = htobe64(metadata_stream->id);
 800         cmd.cmd = htobe32(LTTNG_VIEWER_GET_METADATA);
 801         cmd.data_size = sizeof(rq);
 802         cmd.cmd_version = 0;
 803
 804         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 805         if (ret_len < 0) {
 806                 perror("[error] Error sending cmd");
 807                 goto error;
 808         }
 809         assert(ret_len == sizeof(cmd));
 810
 811         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
 812         if (ret_len < 0) {
 813                 perror("[error] Error sending get_metadata request");
 814                 goto error;
 815         }
 816         assert(ret_len == sizeof(rq));
 817
 818         ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
 819         if (ret_len == 0) {
 820                 fprintf(stderr, "[error] Remote side has closed connection\n");
 821                 goto error;
 822         }
 823         if (ret_len < 0) {
 824                 perror("[error] Error receiving metadata response");
 825                 goto error;
 826         }
 827         assert(ret_len == sizeof(rp));
 828
 829         switch (be32toh(rp.status)) {
 830                 case LTTNG_VIEWER_METADATA_OK:
 831                         printf_verbose("get_metadata : OK\n");
 832                         break;
 833                 case LTTNG_VIEWER_NO_NEW_METADATA:
 834                         printf_verbose("get_metadata : NO NEW\n");
 835                         ret = 0;
 836                         goto end;
 837                 case LTTNG_VIEWER_METADATA_ERR:
 838                         printf_verbose("get_metadata : ERR\n");
 839                         goto error;
 840                 default:
 841                         printf_verbose("get_metadata : UNKNOWN\n");
 842                         goto error;
 843         }
 844
 845         len = be64toh(rp.len);
 846         printf_verbose("Writing %" PRIu64" bytes to metadata\n", len);
 847         if (len <= 0) {
 848                 goto error;
 849         }
 850
 851         data = zmalloc(len);
 852         if (!data) {
 853                 perror("relay data zmalloc");
 854                 goto error;
 855         }
 856         ret_len = lttng_live_recv(ctx->control_sock, data, len);
 857         if (ret_len == 0) {
 858                 fprintf(stderr, "[error] Remote side has closed connection\n");
 859                 goto error_free_data;
 860         }
 861         if (ret_len < 0) {
 862                 perror("[error] Error receiving trace packet");
 863                 goto error_free_data;
 864         }
 865         assert(ret_len == len);
 866
 867         do {
 868                 ret_len = fwrite(data, 1, len,
 869                                 metadata_stream->metadata_fp_write);
 870         } while (ret_len < 0 && errno == EINTR);
 871         if (ret_len < 0) {
 872                 fprintf(stderr, "[error] Writing in the metadata fp\n");
 873                 goto error_free_data;
 874         }
 875         assert(ret_len == len);
 876         metadata_stream->metadata_len += len;
 877         free(data);
 878         ret = len;
 879 end:
 880         return ret;
 881
 882 error_free_data:
 883         free(data);
 884 error:
 885         return -1;
 886 }
 887
 888 /*
 889  * Return 0 on success, a negative value on error.
 890  */
 891 static
 892 int get_new_metadata(struct lttng_live_ctx *ctx,
 893                 struct lttng_live_viewer_stream *viewer_stream,
 894                 char **metadata_buf)
 895 {
 896         int ret = 0;
 897         struct lttng_live_viewer_stream *metadata_stream;
 898         size_t size, len_read = 0;
 899
 900         metadata_stream = viewer_stream->ctf_trace->metadata_stream;
 901         if (!metadata_stream) {
 902                 fprintf(stderr, "[error] No metadata stream\n");
 903                 ret = -1;
 904                 goto error;
 905         }
 906         metadata_stream->metadata_len = 0;
 907         ret = open_metadata_fp_write(metadata_stream, metadata_buf, &size);
 908         if (ret < 0) {
 909                 goto error;
 910         }
 911
 912         do {
 913                 if (lttng_live_should_quit()) {
 914                         ret = -1;
 915                         goto error;
 916                 }
 917                 /*
 918                  * get_one_metadata_packet returns the number of bytes
 919                  * received, 0 when we have received everything, a
 920                  * negative value on error.
 921                  */
 922                 ret = get_one_metadata_packet(ctx, metadata_stream);
 923                 if (ret > 0) {
 924                         len_read += ret;
 925                 }
 926                 if (!len_read) {
 927                         (void) poll(NULL, 0, ACTIVE_POLL_DELAY);
 928                 }
 929         } while (ret > 0 || !len_read);
 930
 931         if (fclose(metadata_stream->metadata_fp_write))
 932                 perror("fclose");
 933         metadata_stream->metadata_fp_write = NULL;
 934
 935 error:
 936         return ret;
 937 }
 938
 939 /*
 940  * Assign the fields from a lttng_viewer_index to a packet_index.
 941  */
 942 static
 943 void lttng_index_to_packet_index(struct lttng_viewer_index *lindex,
 944                 struct packet_index *pindex)
 945 {
 946         assert(lindex);
 947         assert(pindex);
 948
 949         pindex->offset = be64toh(lindex->offset);
 950         pindex->packet_size = be64toh(lindex->packet_size);
 951         pindex->content_size = be64toh(lindex->content_size);
 952         pindex->ts_cycles.timestamp_begin = be64toh(lindex->timestamp_begin);
 953         pindex->ts_cycles.timestamp_end = be64toh(lindex->timestamp_end);
 954         pindex->events_discarded = be64toh(lindex->events_discarded);
 955 }
 956
 957 /*
 958  * Get one index for a stream.
 959  *
 960  * Returns 0 on success or a negative value on error.
 961  */
 962 static
 963 int get_next_index(struct lttng_live_ctx *ctx,
 964                 struct lttng_live_viewer_stream *viewer_stream,
 965                 struct packet_index *index, uint64_t *stream_id)
 966 {
 967         struct lttng_viewer_cmd cmd;
 968         struct lttng_viewer_get_next_index rq;
 969         int ret;
 970         ssize_t ret_len;
 971         struct lttng_viewer_index *rp = &viewer_stream->current_index;
 972
 973         cmd.cmd = htobe32(LTTNG_VIEWER_GET_NEXT_INDEX);
 974         cmd.data_size = sizeof(rq);
 975         cmd.cmd_version = 0;
 976
 977         memset(&rq, 0, sizeof(rq));
 978         rq.stream_id = htobe64(viewer_stream->id);
 979
 980 retry:
 981         if (lttng_live_should_quit()) {
 982                 ret = -1;
 983                 goto end;
 984         }
 985         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
 986         if (ret_len < 0) {
 987                 perror("[error] Error sending cmd");
 988                 goto error;
 989         }
 990         assert(ret_len == sizeof(cmd));
 991
 992         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
 993         if (ret_len < 0) {
 994                 perror("[error] Error sending get_next_index request");
 995                 goto error;
 996         }
 997         assert(ret_len == sizeof(rq));
 998
 999         ret_len = lttng_live_recv(ctx->control_sock, rp, sizeof(*rp));
1000         if (ret_len == 0) {
1001                 fprintf(stderr, "[error] Remote side has closed connection\n");
1002                 goto error;
1003         }
1004         if (ret_len < 0) {
1005                 perror("[error] Error receiving index response");
1006                 goto error;
1007         }
1008         assert(ret_len == sizeof(*rp));
1009
1010         rp->flags = be32toh(rp->flags);
1011
1012         switch (be32toh(rp->status)) {
1013         case LTTNG_VIEWER_INDEX_INACTIVE:
1014                 printf_verbose("get_next_index: inactive\n");
1015                 memset(index, 0, sizeof(struct packet_index));
1016                 index->ts_cycles.timestamp_end = be64toh(rp->timestamp_end);
1017                 *stream_id = be64toh(rp->stream_id);
1018                 break;
1019         case LTTNG_VIEWER_INDEX_OK:
1020                 printf_verbose("get_next_index: Ok, need metadata update : %u\n",
1021                                 rp->flags & LTTNG_VIEWER_FLAG_NEW_METADATA);
1022                 lttng_index_to_packet_index(rp, index);
1023                 *stream_id = be64toh(rp->stream_id);
1024                 viewer_stream->data_pending = 1;
1025
1026                 if (rp->flags & LTTNG_VIEWER_FLAG_NEW_METADATA) {
1027                         ret = append_metadata(ctx, viewer_stream);
1028                         if (ret)
1029                                 goto error;
1030                 }
1031                 if (rp->flags & LTTNG_VIEWER_FLAG_NEW_STREAM) {
1032                         printf_verbose("get_next_index: need new streams\n");
1033                         ret = ask_new_streams(ctx);
1034                         if (ret < 0)
1035                                 goto error;
1036                         else if (ret > 0)
1037                                 g_hash_table_foreach(ctx->session->ctf_traces,
1038                                                 add_traces, ctx->bt_ctx);
1039                 }
1040                 break;
1041         case LTTNG_VIEWER_INDEX_RETRY:
1042                 printf_verbose("get_next_index: retry\n");
1043                 (void) poll(NULL, 0, ACTIVE_POLL_DELAY);
1044                 goto retry;
1045         case LTTNG_VIEWER_INDEX_HUP:
1046                 printf_verbose("get_next_index: stream hung up\n");
1047                 viewer_stream->id = -1ULL;
1048                 index->offset = EOF;
1049                 ctx->session->stream_count--;
1050                 break;
1051         case LTTNG_VIEWER_INDEX_ERR:
1052                 fprintf(stderr, "[error] get_next_index: error\n");
1053                 goto error;
1054         default:
1055                 fprintf(stderr, "[error] get_next_index: unkwown value\n");
1056                 goto error;
1057         }
1058         ret = 0;
1059 end:
1060         return ret;
1061
1062 error:
1063         return -1;
1064 }
1065
1066 static
1067 void read_packet_header(struct ctf_stream_pos *pos,
1068                 struct ctf_file_stream *file_stream)
1069 {
1070         int ret;
1071
1072         /* update trace_packet_header and stream_packet_context */
1073         if (!(pos->prot & PROT_WRITE) &&
1074                 file_stream->parent.trace_packet_header) {
1075                 /* Read packet header */
1076                 ret = generic_rw(&pos->parent,
1077                                 &file_stream->parent.trace_packet_header->p);
1078                 if (ret) {
1079                         pos->offset = EOF;
1080                         fprintf(stderr, "[error] trace packet "
1081                                         "header read failed\n");
1082                         goto end;
1083                 }
1084         }
1085         if (!(pos->prot & PROT_WRITE) &&
1086                 file_stream->parent.stream_packet_context) {
1087                 /* Read packet context */
1088                 ret = generic_rw(&pos->parent,
1089                                 &file_stream->parent.stream_packet_context->p);
1090                 if (ret) {
1091                         pos->offset = EOF;
1092                         fprintf(stderr, "[error] stream packet "
1093                                         "context read failed\n");
1094                         goto end;
1095                 }
1096         }
1097         pos->data_offset = pos->offset;
1098
1099 end:
1100         return;
1101 }
1102
1103 /*
1104  * Handle the seek parameters.
1105  * Returns 0 if the packet_seek can continue, a positive value to
1106  * cleanly exit the packet_seek, a negative value on error.
1107  */
1108 static
1109 int handle_seek_position(size_t index, int whence,
1110                 struct lttng_live_viewer_stream *viewer_stream,
1111                 struct ctf_stream_pos *pos,
1112                 struct ctf_file_stream *file_stream)
1113 {
1114         int ret;
1115
1116         switch (whence) {
1117         case SEEK_CUR:
1118                 ret = 0;
1119                 goto end;
1120         case SEEK_SET:
1121                 /*
1122                  * We only allow to seek to 0.
1123                  */
1124                 if (index != 0) {
1125                         fprintf(stderr, "[error] Arbitrary seek in lttng-live "
1126                                         "trace not supported\n");
1127                         pos->offset = EOF;
1128                         ret = -1;
1129                         goto end;
1130                 }
1131
1132                 ret = 0;
1133                 goto end;
1134
1135         default:
1136                 fprintf(stderr, "[error] Invalid seek parameter\n");
1137                 assert(0);
1138         }
1139
1140 end:
1141         return ret;
1142 }
1143
1144 static
1145 void ctf_live_packet_seek(struct bt_stream_pos *stream_pos, size_t index,
1146                 int whence)
1147 {
1148         struct ctf_stream_pos *pos;
1149         struct ctf_file_stream *file_stream;
1150         struct packet_index *prev_index = NULL, *cur_index;
1151         struct lttng_live_viewer_stream *viewer_stream;
1152         struct lttng_live_session *session;
1153         uint64_t stream_id = -1ULL;
1154         int ret;
1155
1156         pos = ctf_pos(stream_pos);
1157         file_stream = container_of(pos, struct ctf_file_stream, pos);
1158         viewer_stream = (struct lttng_live_viewer_stream *) pos->priv;
1159         session = viewer_stream->session;
1160
1161         ret = handle_seek_position(index, whence, viewer_stream, pos,
1162                         file_stream);
1163         if (ret != 0) {
1164                 return;
1165         }
1166
1167 retry:
1168         switch (pos->packet_index->len) {
1169         case 0:
1170                 g_array_set_size(pos->packet_index, 1);
1171                 cur_index = &g_array_index(pos->packet_index,
1172                                 struct packet_index, 0);
1173                 break;
1174         case 1:
1175                 g_array_set_size(pos->packet_index, 2);
1176                 prev_index = &g_array_index(pos->packet_index,
1177                                 struct packet_index, 0);
1178                 cur_index = &g_array_index(pos->packet_index,
1179                                 struct packet_index, 1);
1180                 break;
1181         case 2:
1182                 g_array_index(pos->packet_index,
1183                         struct packet_index, 0) =
1184                                 g_array_index(pos->packet_index,
1185                                         struct packet_index, 1);
1186                 prev_index = &g_array_index(pos->packet_index,
1187                                 struct packet_index, 0);
1188                 cur_index = &g_array_index(pos->packet_index,
1189                                 struct packet_index, 1);
1190                 break;
1191         default:
1192                 abort();
1193                 break;
1194         }
1195
1196         if (viewer_stream->data_pending) {
1197                 lttng_index_to_packet_index(&viewer_stream->current_index, cur_index);
1198         } else {
1199                 printf_verbose("get_next_index for stream %" PRIu64 "\n", viewer_stream->id);
1200                 ret = get_next_index(session->ctx, viewer_stream, cur_index, &stream_id);
1201                 if (ret < 0) {
1202                         pos->offset = EOF;
1203                         if (!lttng_live_should_quit()) {
1204                                 fprintf(stderr, "[error] get_next_index failed\n");
1205                         }
1206                         return;
1207                 }
1208                 printf_verbose("Index received : packet_size : %" PRIu64
1209                                 ", offset %" PRIu64 ", content_size %" PRIu64
1210                                 ", timestamp_end : %" PRIu64 "\n",
1211                                 cur_index->packet_size, cur_index->offset,
1212                                 cur_index->content_size,
1213                                 cur_index->ts_cycles.timestamp_end);
1214
1215         }
1216
1217         /*
1218          * On the first time we receive an index, the stream_id needs to
1219          * be set for the stream in order to use it, we don't want any
1220          * data at this stage.
1221          */
1222         if (file_stream->parent.stream_id == -1ULL) {
1223                 /*
1224                  * Warning: with lttng-tools < 2.4.2, the beacon does not
1225                  * contain the real stream ID, it is memset to 0, so this
1226                  * might create a problem when a session has multiple
1227                  * channels. We can't detect it at this stage, lttng-tools
1228                  * has to be upgraded to fix this problem.
1229                  */
1230                 printf_verbose("Assigning stream_id %" PRIu64 "\n",
1231                                 stream_id);
1232                 file_stream->parent.stream_id = stream_id;
1233                 viewer_stream->ctf_stream_id = stream_id;
1234
1235                 return;
1236         }
1237
1238         pos->packet_size = cur_index->packet_size;
1239         pos->content_size = cur_index->content_size;
1240         pos->mmap_base_offset = 0;
1241         if (cur_index->offset == EOF) {
1242                 pos->offset = EOF;
1243         } else {
1244                 pos->offset = 0;
1245         }
1246
1247         if (cur_index->content_size == 0) {
1248                 if (file_stream->parent.stream_class) {
1249                         file_stream->parent.cycles_timestamp =
1250                                 cur_index->ts_cycles.timestamp_end;
1251                         file_stream->parent.real_timestamp = ctf_get_real_timestamp(
1252                                         &file_stream->parent,
1253                                         cur_index->ts_cycles.timestamp_end);
1254                 }
1255         } else {
1256                 if (file_stream->parent.stream_class) {
1257                         /* Convert the timestamps and append to the real_index. */
1258                         cur_index->ts_real.timestamp_begin = ctf_get_real_timestamp(
1259                                         &file_stream->parent,
1260                                         cur_index->ts_cycles.timestamp_begin);
1261                         cur_index->ts_real.timestamp_end = ctf_get_real_timestamp(
1262                                         &file_stream->parent,
1263                                         cur_index->ts_cycles.timestamp_end);
1264                 }
1265
1266                 ctf_update_current_packet_index(&file_stream->parent,
1267                                 prev_index, cur_index);
1268
1269                 file_stream->parent.cycles_timestamp =
1270                                 cur_index->ts_cycles.timestamp_begin;
1271                 file_stream->parent.real_timestamp =
1272                                 cur_index->ts_real.timestamp_begin;
1273         }
1274
1275         if (pos->packet_size == 0 || pos->offset == EOF) {
1276                 goto end;
1277         }
1278
1279         printf_verbose("get_data_packet for stream %" PRIu64 "\n",
1280                         viewer_stream->id);
1281         ret = get_data_packet(session->ctx, pos, viewer_stream,
1282                         cur_index->offset,
1283                         cur_index->packet_size / CHAR_BIT);
1284         if (ret == -2) {
1285                 goto retry;
1286         } else if (ret < 0) {
1287                 pos->offset = EOF;
1288                 if (!lttng_live_should_quit()) {
1289                         fprintf(stderr, "[error] get_data_packet failed\n");
1290                 }
1291                 return;
1292         }
1293         viewer_stream->data_pending = 0;
1294
1295         read_packet_header(pos, file_stream);
1296
1297 end:
1298         return;
1299 }
1300
1301 int lttng_live_create_viewer_session(struct lttng_live_ctx *ctx)
1302 {
1303         struct lttng_viewer_cmd cmd;
1304         struct lttng_viewer_create_session_response resp;
1305         int ret;
1306         ssize_t ret_len;
1307
1308         if (lttng_live_should_quit()) {
1309                 ret = -1;
1310                 goto end;
1311         }
1312
1313         cmd.cmd = htobe32(LTTNG_VIEWER_CREATE_SESSION);
1314         cmd.data_size = 0;
1315         cmd.cmd_version = 0;
1316
1317         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
1318         if (ret_len < 0) {
1319                 perror("[error] Error sending cmd");
1320                 goto error;
1321         }
1322         assert(ret_len == sizeof(cmd));
1323
1324         ret_len = lttng_live_recv(ctx->control_sock, &resp, sizeof(resp));
1325         if (ret_len == 0) {
1326                 fprintf(stderr, "[error] Remote side has closed connection\n");
1327                 goto error;
1328         }
1329         if (ret_len < 0) {
1330                 perror("[error] Error receiving create session reply");
1331                 goto error;
1332         }
1333         assert(ret_len == sizeof(resp));
1334
1335         if (be32toh(resp.status) != LTTNG_VIEWER_CREATE_SESSION_OK) {
1336                 fprintf(stderr, "[error] Error creating viewer session\n");
1337                 goto error;
1338         }
1339         ret = 0;
1340 end:
1341         return ret;
1342
1343 error:
1344         return -1;
1345 }
1346
1347 static
1348 int del_traces(gpointer key, gpointer value, gpointer user_data)
1349 {
1350         struct bt_context *bt_ctx = user_data;
1351         struct lttng_live_ctf_trace *trace = value;
1352         int ret;
1353
1354         ret = bt_context_remove_trace(bt_ctx, trace->trace_id);
1355         if (ret < 0)
1356                 fprintf(stderr, "[error] removing trace from context\n");
1357
1358         /* remove the key/value pair from the HT. */
1359         return 1;
1360 }
1361
1362 static
1363 void add_traces(gpointer key, gpointer value, gpointer user_data)
1364 {
1365         int i, ret;
1366         struct bt_context *bt_ctx = user_data;
1367         struct lttng_live_ctf_trace *trace = value;
1368         struct lttng_live_viewer_stream *stream;
1369         struct bt_mmap_stream *new_mmap_stream;
1370         struct bt_mmap_stream_list mmap_list;
1371         struct lttng_live_ctx *ctx = NULL;
1372         struct bt_trace_descriptor *td;
1373         struct bt_trace_handle *handle;
1374
1375         /*
1376          * We don't know how many streams we will receive for a trace, so
1377          * once we are done receiving the traces, we add all the traces
1378          * received to the bt_context.
1379          * We can receive streams during the attach command or the
1380          * get_new_streams, so we have to make sure not to add multiple
1381          * times the same traces.
1382          * If a trace is already in the context, we just skip this function.
1383          */
1384         if (trace->in_use)
1385                 return;
1386
1387         BT_INIT_LIST_HEAD(&mmap_list.head);
1388
1389         for (i = 0; i < trace->streams->len; i++) {
1390                 stream = g_ptr_array_index(trace->streams, i);
1391                 ctx = stream->session->ctx;
1392
1393                 if (!stream->metadata_flag) {
1394                         new_mmap_stream = zmalloc(sizeof(struct bt_mmap_stream));
1395                         new_mmap_stream->priv = (void *) stream;
1396                         new_mmap_stream->fd = -1;
1397                         bt_list_add(&new_mmap_stream->list, &mmap_list.head);
1398                 } else {
1399                         char *metadata_buf = NULL;
1400
1401                         /* Get all possible metadata before starting */
1402                         ret = get_new_metadata(ctx, stream, &metadata_buf);
1403                         if (ret) {
1404                                 free(metadata_buf);
1405                                 goto end_free;
1406                         }
1407                         if (!stream->metadata_len) {
1408                                 fprintf(stderr, "[error] empty metadata\n");
1409                                 ret = -1;
1410                                 free(metadata_buf);
1411                                 goto end_free;
1412                         }
1413
1414                         trace->metadata_fp = babeltrace_fmemopen(metadata_buf,
1415                                         stream->metadata_len, "rb");
1416                         if (!trace->metadata_fp) {
1417                                 perror("Metadata fmemopen");
1418                                 ret = -1;
1419                                 free(metadata_buf);
1420                                 goto end_free;
1421                         }
1422                 }
1423         }
1424
1425         if (!trace->metadata_fp) {
1426                 fprintf(stderr, "[error] No metadata stream opened\n");
1427                 goto end_free;
1428         }
1429
1430         ret = bt_context_add_trace(bt_ctx, NULL, "ctf",
1431                         ctf_live_packet_seek, &mmap_list, trace->metadata_fp);
1432         if (ret < 0) {
1433                 fprintf(stderr, "[error] Error adding trace\n");
1434                 goto end_free;
1435         }
1436         trace->metadata_stream->metadata_len = 0;
1437
1438         handle = (struct bt_trace_handle *) g_hash_table_lookup(
1439                         bt_ctx->trace_handles,
1440                         (gpointer) (unsigned long) ret);
1441         td = handle->td;
1442         trace->handle = handle;
1443         if (bt_ctx->current_iterator) {
1444                 bt_iter_add_trace(bt_ctx->current_iterator, td);
1445         }
1446
1447         trace->trace_id = ret;
1448         trace->in_use = 1;
1449
1450         goto end;
1451
1452 end_free:
1453         bt_context_put(bt_ctx);
1454 end:
1455         return;
1456 }
1457
1458 /*
1459  * Request new streams for a session.
1460  * Returns the number of streams received or a negative value on error.
1461  */
1462 int lttng_live_get_new_streams(struct lttng_live_ctx *ctx, uint64_t id)
1463 {
1464         struct lttng_viewer_cmd cmd;
1465         struct lttng_viewer_new_streams_request rq;
1466         struct lttng_viewer_new_streams_response rp;
1467         struct lttng_viewer_stream stream;
1468         int ret, i, nb_streams = 0;
1469         ssize_t ret_len;
1470         uint32_t stream_count;
1471
1472         if (lttng_live_should_quit()) {
1473                 ret = -1;
1474                 goto end;
1475         }
1476
1477         cmd.cmd = htobe32(LTTNG_VIEWER_GET_NEW_STREAMS);
1478         cmd.data_size = sizeof(rq);
1479         cmd.cmd_version = 0;
1480
1481         memset(&rq, 0, sizeof(rq));
1482         rq.session_id = htobe64(id);
1483
1484         ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
1485         if (ret_len < 0) {
1486                 perror("[error] Error sending cmd");
1487                 goto error;
1488         }
1489         assert(ret_len == sizeof(cmd));
1490
1491         ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
1492         if (ret_len < 0) {
1493                 perror("[error] Error sending get_new_streams request");
1494                 goto error;
1495         }
1496         assert(ret_len == sizeof(rq));
1497
1498         ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
1499         if (ret_len == 0) {
1500                 fprintf(stderr, "[error] Remote side has closed connection\n");
1501                 goto error;
1502         }
1503         if (ret_len < 0) {
1504                 perror("[error] Error receiving get_new_streams response");
1505                 goto error;
1506         }
1507         assert(ret_len == sizeof(rp));
1508
1509         switch(be32toh(rp.status)) {
1510         case LTTNG_VIEWER_NEW_STREAMS_OK:
1511                 break;
1512         case LTTNG_VIEWER_NEW_STREAMS_NO_NEW:
1513                 ret = 0;
1514                 goto end;
1515         case LTTNG_VIEWER_NEW_STREAMS_HUP:
1516                 ret = -LTTNG_VIEWER_NEW_STREAMS_HUP;
1517                 goto end;
1518         case LTTNG_VIEWER_NEW_STREAMS_ERR:
1519                 fprintf(stderr, "[error] get_new_streams error\n");
1520                 goto error;
1521         default:
1522                 fprintf(stderr, "[error] Unknown return code %u\n",
1523                                 be32toh(rp.status));
1524                 goto error;
1525         }
1526
1527         stream_count = be32toh(rp.streams_count);
1528         ctx->session->stream_count += stream_count;
1529         /*
1530          * When the session is created but not started, we do an active wait
1531          * until it starts. It allows the viewer to start processing the trace
1532          * as soon as the session starts.
1533          */
1534         if (ctx->session->stream_count == 0) {
1535                 ret = 0;
1536                 goto end;
1537         }
1538         printf_verbose("Waiting for %" PRIu64 " streams:\n",
1539                 ctx->session->stream_count);
1540         ctx->session->streams = g_new0(struct lttng_live_viewer_stream,
1541                         ctx->session->stream_count);
1542         for (i = 0; i < stream_count; i++) {
1543                 ret_len = lttng_live_recv(ctx->control_sock, &stream, sizeof(stream));
1544                 if (ret_len == 0) {
1545                         fprintf(stderr, "[error] Remote side has closed connection\n");
1546                         goto error;
1547                 }
1548                 if (ret_len < 0) {
1549                         perror("[error] Error receiving stream");
1550                         goto error;
1551                 }
1552                 assert(ret_len == sizeof(stream));
1553                 stream.path_name[LTTNG_VIEWER_PATH_MAX - 1] = '\0';
1554                 stream.channel_name[LTTNG_VIEWER_NAME_MAX - 1] = '\0';
1555
1556                 printf_verbose("    stream %" PRIu64 " : %s/%s\n",
1557                                 be64toh(stream.id), stream.path_name,
1558                                 stream.channel_name);
1559                 ctx->session->streams[i].id = be64toh(stream.id);
1560                 ctx->session->streams[i].session = ctx->session;
1561
1562                 ctx->session->streams[i].mmap_size = 0;
1563                 ctx->session->streams[i].ctf_stream_id = -1ULL;
1564
1565                 if (be32toh(stream.metadata_flag)) {
1566                         ctx->session->streams[i].metadata_flag = 1;
1567                 }
1568                 ret = lttng_live_ctf_trace_assign(&ctx->session->streams[i],
1569                                 be64toh(stream.ctf_trace_id));
1570                 if (ret < 0) {
1571                         goto error;
1572                 }
1573                 nb_streams++;
1574
1575         }
1576         ret = nb_streams;
1577 end:
1578         return ret;
1579
1580 error:
1581         return -1;
1582 }
1583
1584 int lttng_live_read(struct lttng_live_ctx *ctx)
1585 {
1586         int ret = -1;
1587         int i;
1588         struct bt_ctf_iter *iter;
1589         const struct bt_ctf_event *event;
1590         struct bt_iter_pos begin_pos;
1591         struct bt_trace_descriptor *td_write;
1592         struct bt_format *fmt_write;
1593         struct ctf_text_stream_pos *sout;
1594         uint64_t id;
1595
1596         ctx->bt_ctx = bt_context_create();
1597         if (!ctx->bt_ctx) {
1598                 fprintf(stderr, "[error] bt_context_create allocation\n");
1599                 goto end;
1600         }
1601
1602         fmt_write = bt_lookup_format(g_quark_from_static_string("text"));
1603         if (!fmt_write) {
1604                 fprintf(stderr, "[error] ctf-text error\n");
1605                 goto end;
1606         }
1607
1608         td_write = fmt_write->open_trace(NULL, O_RDWR, NULL, NULL);
1609         if (!td_write) {
1610                 fprintf(stderr, "[error] Error opening output trace\n");
1611                 goto end_free;
1612         }
1613
1614         sout = container_of(td_write, struct ctf_text_stream_pos,
1615                         trace_descriptor);
1616         if (!sout->parent.event_cb) {
1617                 goto end_free;
1618         }
1619
1620         ret = lttng_live_create_viewer_session(ctx);
1621         if (ret < 0) {
1622                 goto end_free;
1623         }
1624
1625         for (i = 0; i < ctx->session_ids->len; i++) {
1626                 id = g_array_index(ctx->session_ids, uint64_t, i);
1627                 printf_verbose("Attaching to session %lu\n", id);
1628                 ret = lttng_live_attach_session(ctx, id);
1629                 printf_verbose("Attaching session returns %d\n", ret);
1630                 if (ret < 0) {
1631                         if (ret == -LTTNG_VIEWER_ATTACH_UNK) {
1632                                 fprintf(stderr, "[error] Unknown session ID\n");
1633                         }
1634                         goto end_free;
1635                 }
1636         }
1637
1638         /*
1639          * As long as the session is active, we try to get new streams.
1640          */
1641         for (;;) {
1642                 int flags;
1643
1644                 if (lttng_live_should_quit()) {
1645                         ret = 0;
1646                         goto end_free;
1647                 }
1648
1649                 while (!ctx->session->stream_count) {
1650                         if (lttng_live_should_quit()
1651                                         || ctx->session_ids->len == 0) {
1652                                 ret = 0;
1653                                 goto end_free;
1654                         }
1655                         ret = ask_new_streams(ctx);
1656                         if (ret < 0) {
1657                                 goto end_free;
1658                         }
1659                         if (!ctx->session->stream_count) {
1660                                 (void) poll(NULL, 0, ACTIVE_POLL_DELAY);
1661                         }
1662                 }
1663
1664                 g_hash_table_foreach(ctx->session->ctf_traces, add_traces,
1665                                 ctx->bt_ctx);
1666
1667                 begin_pos.type = BT_SEEK_BEGIN;
1668                 iter = bt_ctf_iter_create(ctx->bt_ctx, &begin_pos, NULL);
1669                 if (!iter) {
1670                         if (lttng_live_should_quit()) {
1671                                 ret = 0;
1672                                 goto end;
1673                         }
1674                         fprintf(stderr, "[error] Iterator creation error\n");
1675                         goto end;
1676                 }
1677                 for (;;) {
1678                         if (lttng_live_should_quit()) {
1679                                 ret = 0;
1680                                 goto end_free;
1681                         }
1682                         event = bt_ctf_iter_read_event_flags(iter, &flags);
1683                         if (!(flags & BT_ITER_FLAG_RETRY)) {
1684                                 if (!event) {
1685                                         /* End of trace */
1686                                         break;
1687                                 }
1688                                 ret = sout->parent.event_cb(&sout->parent,
1689                                                 event->parent->stream);
1690                                 if (ret) {
1691                                         fprintf(stderr, "[error] Writing "
1692                                                         "event failed.\n");
1693                                         goto end_free;
1694                                 }
1695                         }
1696                         ret = bt_iter_next(bt_ctf_get_iter(iter));
1697                         if (ret < 0) {
1698                                 goto end_free;
1699                         }
1700                 }
1701                 bt_ctf_iter_destroy(iter);
1702                 g_hash_table_foreach_remove(ctx->session->ctf_traces,
1703                                 del_traces, ctx->bt_ctx);
1704                 ctx->session->stream_count = 0;
1705         }
1706
1707 end_free:
1708         bt_context_put(ctx->bt_ctx);
1709 end:
1710         if (lttng_live_should_quit()) {
1711                 ret = 0;
1712         }
1713         return ret;
1714 }