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