src/common/relayd/relayd.c

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <assert.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <inttypes.h>
  25
  26 #include <common/common.h>
  27 #include <common/defaults.h>
  28 #include <common/sessiond-comm/relayd.h>
  29
  30 #include "relayd.h"
  31
  32 /*
  33  * Send command. Fill up the header and append the data.
  34  */
  35 static int send_command(struct lttcomm_relayd_sock *rsock,
  36                 enum lttcomm_relayd_command cmd, void *data, size_t size,
  37                 int flags)
  38 {
  39         int ret;
  40         struct lttcomm_relayd_hdr header;
  41         char *buf;
  42         uint64_t buf_size = sizeof(header);
  43
  44         if (data) {
  45                 buf_size += size;
  46         }
  47
  48         buf = zmalloc(buf_size);
  49         if (buf == NULL) {
  50                 PERROR("zmalloc relayd send command buf");
  51                 ret = -1;
  52                 goto alloc_error;
  53         }
  54
  55         header.cmd = htobe32(cmd);
  56         header.data_size = htobe64(size);
  57
  58         /* Zeroed for now since not used. */
  59         header.cmd_version = 0;
  60         header.circuit_id = 0;
  61
  62         /* Prepare buffer to send. */
  63         memcpy(buf, &header, sizeof(header));
  64         if (data) {
  65                 memcpy(buf + sizeof(header), data, size);
  66         }
  67
  68         ret = rsock->sock.ops->sendmsg(&rsock->sock, buf, buf_size, flags);
  69         if (ret < 0) {
  70                 ret = -errno;
  71                 goto error;
  72         }
  73
  74         DBG3("Relayd sending command %d of size %" PRIu64, cmd, buf_size);
  75
  76 error:
  77         free(buf);
  78 alloc_error:
  79         return ret;
  80 }
  81
  82 /*
  83  * Receive reply data on socket. This MUST be call after send_command or else
  84  * could result in unexpected behavior(s).
  85  */
  86 static int recv_reply(struct lttcomm_relayd_sock *rsock, void *data, size_t size)
  87 {
  88         int ret;
  89
  90         DBG3("Relayd waiting for reply of size %ld", size);
  91
  92         ret = rsock->sock.ops->recvmsg(&rsock->sock, data, size, 0);
  93         if (ret <= 0 || ret != size) {
  94                 if (ret == 0) {
  95                         /* Orderly shutdown. */
  96                         DBG("Socket %d has performed an orderly shutdown", rsock->sock.fd);
  97                 } else {
  98                         DBG("Receiving reply failed on sock %d for size %lu with ret %d",
  99                                         rsock->sock.fd, size, ret);
 100                 }
 101                 /* Always return -1 here and the caller can use errno. */
 102                 ret = -1;
 103                 goto error;
 104         }
 105
 106 error:
 107         return ret;
 108 }
 109
 110 /*
 111  * Send a RELAYD_CREATE_SESSION command to the relayd with the given socket and
 112  * set session_id of the relayd if we have a successful reply from the relayd.
 113  *
 114  * On success, return 0 else a negative value which is either an errno error or
 115  * a lttng error code from the relayd.
 116  */
 117 int relayd_create_session(struct lttcomm_relayd_sock *rsock, uint64_t *session_id)
 118 {
 119         int ret;
 120         struct lttcomm_relayd_status_session reply;
 121
 122         assert(rsock);
 123         assert(session_id);
 124
 125         DBG("Relayd create session");
 126
 127         /* Send command */
 128         ret = send_command(rsock, RELAYD_CREATE_SESSION, NULL, 0, 0);
 129         if (ret < 0) {
 130                 goto error;
 131         }
 132
 133         /* Receive response */
 134         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 135         if (ret < 0) {
 136                 goto error;
 137         }
 138
 139         reply.session_id = be64toh(reply.session_id);
 140         reply.ret_code = be32toh(reply.ret_code);
 141
 142         /* Return session id or negative ret code. */
 143         if (reply.ret_code != LTTNG_OK) {
 144                 ret = -1;
 145                 ERR("Relayd create session replied error %d", reply.ret_code);
 146                 goto error;
 147         } else {
 148                 ret = 0;
 149                 *session_id = reply.session_id;
 150         }
 151
 152         DBG("Relayd session created with id %" PRIu64, reply.session_id);
 153
 154 error:
 155         return ret;
 156 }
 157
 158 /*
 159  * Add stream on the relayd and assign stream handle to the stream_id argument.
 160  *
 161  * On success return 0 else return ret_code negative value.
 162  */
 163 int relayd_add_stream(struct lttcomm_relayd_sock *rsock, const char *channel_name,
 164                 const char *pathname, uint64_t *stream_id)
 165 {
 166         int ret;
 167         struct lttcomm_relayd_add_stream msg;
 168         struct lttcomm_relayd_status_stream reply;
 169
 170         /* Code flow error. Safety net. */
 171         assert(rsock);
 172         assert(channel_name);
 173         assert(pathname);
 174
 175         DBG("Relayd adding stream for channel name %s", channel_name);
 176
 177         strncpy(msg.channel_name, channel_name, sizeof(msg.channel_name));
 178         strncpy(msg.pathname, pathname, sizeof(msg.pathname));
 179
 180         /* Send command */
 181         ret = send_command(rsock, RELAYD_ADD_STREAM, (void *) &msg, sizeof(msg), 0);
 182         if (ret < 0) {
 183                 goto error;
 184         }
 185
 186         /* Waiting for reply */
 187         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 188         if (ret < 0) {
 189                 goto error;
 190         }
 191
 192         /* Back to host bytes order. */
 193         reply.handle = be64toh(reply.handle);
 194         reply.ret_code = be32toh(reply.ret_code);
 195
 196         /* Return session id or negative ret code. */
 197         if (reply.ret_code != LTTNG_OK) {
 198                 ret = -1;
 199                 ERR("Relayd add stream replied error %d", reply.ret_code);
 200         } else {
 201                 /* Success */
 202                 ret = 0;
 203                 *stream_id = reply.handle;
 204         }
 205
 206         DBG("Relayd stream added successfully with handle %" PRIu64,
 207                 reply.handle);
 208
 209 error:
 210         return ret;
 211 }
 212
 213 /*
 214  * Check version numbers on the relayd.
 215  * If major versions are compatible, we assign minor_to_use to the
 216  * minor version of the procotol we are going to use for this session.
 217  *
 218  * Return 0 if compatible else negative value.
 219  */
 220 int relayd_version_check(struct lttcomm_relayd_sock *rsock)
 221 {
 222         int ret;
 223         struct lttcomm_relayd_version msg;
 224
 225         /* Code flow error. Safety net. */
 226         assert(rsock);
 227
 228         DBG("Relayd version check for major.minor %u.%u", rsock->major,
 229                         rsock->minor);
 230
 231         /* Prepare network byte order before transmission. */
 232         msg.major = htobe32(rsock->major);
 233         msg.minor = htobe32(rsock->minor);
 234
 235         /* Send command */
 236         ret = send_command(rsock, RELAYD_VERSION, (void *) &msg, sizeof(msg), 0);
 237         if (ret < 0) {
 238                 goto error;
 239         }
 240
 241         /* Receive response */
 242         ret = recv_reply(rsock, (void *) &msg, sizeof(msg));
 243         if (ret < 0) {
 244                 goto error;
 245         }
 246
 247         /* Set back to host bytes order */
 248         msg.major = be32toh(msg.major);
 249         msg.minor = be32toh(msg.minor);
 250
 251         /*
 252          * Only validate the major version. If the other side is higher,
 253          * communication is not possible. Only major version equal can talk to each
 254          * other. If the minor version differs, the lowest version is used by both
 255          * sides.
 256          */
 257         if (msg.major != rsock->major) {
 258                 /* Not compatible */
 259                 ret = -1;
 260                 DBG2("Relayd version is NOT compatible. Relayd version %u != %u (us)",
 261                                 msg.major, rsock->major);
 262                 goto error;
 263         }
 264
 265         /*
 266          * If the relayd's minor version is higher, it will adapt to our version so
 267          * we can continue to use the latest relayd communication data structure.
 268          * If the received minor version is higher, the relayd should adapt to us.
 269          */
 270         if (rsock->minor > msg.minor) {
 271                 rsock->minor = msg.minor;
 272         }
 273
 274         /* Version number compatible */
 275         DBG2("Relayd version is compatible, using protocol version %u.%u",
 276                         rsock->major, rsock->minor);
 277         ret = 0;
 278
 279 error:
 280         return ret;
 281 }
 282
 283 /*
 284  * Add stream on the relayd and assign stream handle to the stream_id argument.
 285  *
 286  * On success return 0 else return ret_code negative value.
 287  */
 288 int relayd_send_metadata(struct lttcomm_relayd_sock *rsock, size_t len)
 289 {
 290         int ret;
 291
 292         /* Code flow error. Safety net. */
 293         assert(rsock);
 294
 295         DBG("Relayd sending metadata of size %zu", len);
 296
 297         /* Send command */
 298         ret = send_command(rsock, RELAYD_SEND_METADATA, NULL, len, 0);
 299         if (ret < 0) {
 300                 goto error;
 301         }
 302
 303         DBG2("Relayd metadata added successfully");
 304
 305         /*
 306          * After that call, the metadata data MUST be sent to the relayd so the
 307          * receive size on the other end matches the len of the metadata packet
 308          * header. This is why we don't wait for a reply here.
 309          */
 310
 311 error:
 312         return ret;
 313 }
 314
 315 /*
 316  * Connect to relay daemon with an allocated lttcomm_relayd_sock.
 317  */
 318 int relayd_connect(struct lttcomm_relayd_sock *rsock)
 319 {
 320         /* Code flow error. Safety net. */
 321         assert(rsock);
 322
 323         DBG3("Relayd connect ...");
 324
 325         return rsock->sock.ops->connect(&rsock->sock);
 326 }
 327
 328 /*
 329  * Close relayd socket with an allocated lttcomm_relayd_sock.
 330  *
 331  * If no socket operations are found, simply return 0 meaning that everything
 332  * is fine. Without operations, the socket can not possibly be opened or used.
 333  * This is possible if the socket was allocated but not created. However, the
 334  * caller could simply use it to store a valid file descriptor for instance
 335  * passed over a Unix socket and call this to cleanup but still without a valid
 336  * ops pointer.
 337  *
 338  * Return the close returned value. On error, a negative value is usually
 339  * returned back from close(2).
 340  */
 341 int relayd_close(struct lttcomm_relayd_sock *rsock)
 342 {
 343         int ret;
 344
 345         /* Code flow error. Safety net. */
 346         assert(rsock);
 347
 348         /* An invalid fd is fine, return success. */
 349         if (rsock->sock.fd < 0) {
 350                 ret = 0;
 351                 goto end;
 352         }
 353
 354         DBG3("Relayd closing socket %d", rsock->sock.fd);
 355
 356         if (rsock->sock.ops) {
 357                 ret = rsock->sock.ops->close(&rsock->sock);
 358         } else {
 359                 /* Default call if no specific ops found. */
 360                 ret = close(rsock->sock.fd);
 361                 if (ret < 0) {
 362                         PERROR("relayd_close default close");
 363                 }
 364         }
 365
 366 end:
 367         return ret;
 368 }
 369
 370 /*
 371  * Send data header structure to the relayd.
 372  */
 373 int relayd_send_data_hdr(struct lttcomm_relayd_sock *rsock,
 374                 struct lttcomm_relayd_data_hdr *hdr, size_t size)
 375 {
 376         int ret;
 377
 378         /* Code flow error. Safety net. */
 379         assert(rsock);
 380         assert(hdr);
 381
 382         DBG3("Relayd sending data header of size %ld", size);
 383
 384         /* Again, safety net */
 385         if (size == 0) {
 386                 size = sizeof(struct lttcomm_relayd_data_hdr);
 387         }
 388
 389         /* Only send data header. */
 390         ret = rsock->sock.ops->sendmsg(&rsock->sock, hdr, size, 0);
 391         if (ret < 0) {
 392                 ret = -errno;
 393                 goto error;
 394         }
 395
 396         /*
 397          * The data MUST be sent right after that command for the receive on the
 398          * other end to match the size in the header.
 399          */
 400
 401 error:
 402         return ret;
 403 }
 404
 405 /*
 406  * Send close stream command to the relayd.
 407  */
 408 int relayd_send_close_stream(struct lttcomm_relayd_sock *rsock, uint64_t stream_id,
 409                 uint64_t last_net_seq_num)
 410 {
 411         int ret;
 412         struct lttcomm_relayd_close_stream msg;
 413         struct lttcomm_relayd_generic_reply reply;
 414
 415         /* Code flow error. Safety net. */
 416         assert(rsock);
 417
 418         DBG("Relayd closing stream id %" PRIu64, stream_id);
 419
 420         msg.stream_id = htobe64(stream_id);
 421         msg.last_net_seq_num = htobe64(last_net_seq_num);
 422
 423         /* Send command */
 424         ret = send_command(rsock, RELAYD_CLOSE_STREAM, (void *) &msg, sizeof(msg), 0);
 425         if (ret < 0) {
 426                 goto error;
 427         }
 428
 429         /* Receive response */
 430         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 431         if (ret < 0) {
 432                 goto error;
 433         }
 434
 435         reply.ret_code = be32toh(reply.ret_code);
 436
 437         /* Return session id or negative ret code. */
 438         if (reply.ret_code != LTTNG_OK) {
 439                 ret = -1;
 440                 ERR("Relayd close stream replied error %d", reply.ret_code);
 441         } else {
 442                 /* Success */
 443                 ret = 0;
 444         }
 445
 446         DBG("Relayd close stream id %" PRIu64 " successfully", stream_id);
 447
 448 error:
 449         return ret;
 450 }
 451
 452 /*
 453  * Check for data availability for a given stream id.
 454  *
 455  * Return 0 if NOT pending, 1 if so and a negative value on error.
 456  */
 457 int relayd_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t stream_id,
 458                 uint64_t last_net_seq_num)
 459 {
 460         int ret;
 461         struct lttcomm_relayd_data_pending msg;
 462         struct lttcomm_relayd_generic_reply reply;
 463
 464         /* Code flow error. Safety net. */
 465         assert(rsock);
 466
 467         DBG("Relayd data pending for stream id %" PRIu64, stream_id);
 468
 469         msg.stream_id = htobe64(stream_id);
 470         msg.last_net_seq_num = htobe64(last_net_seq_num);
 471
 472         /* Send command */
 473         ret = send_command(rsock, RELAYD_DATA_PENDING, (void *) &msg,
 474                         sizeof(msg), 0);
 475         if (ret < 0) {
 476                 goto error;
 477         }
 478
 479         /* Receive response */
 480         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 481         if (ret < 0) {
 482                 goto error;
 483         }
 484
 485         reply.ret_code = be32toh(reply.ret_code);
 486
 487         /* Return session id or negative ret code. */
 488         if (reply.ret_code >= LTTNG_OK) {
 489                 ERR("Relayd data pending replied error %d", reply.ret_code);
 490         }
 491
 492         /* At this point, the ret code is either 1 or 0 */
 493         ret = reply.ret_code;
 494
 495         DBG("Relayd data is %s pending for stream id %" PRIu64,
 496                         ret == 1 ? "" : "NOT", stream_id);
 497
 498 error:
 499         return ret;
 500 }
 501
 502 /*
 503  * Check on the relayd side for a quiescent state on the control socket.
 504  */
 505 int relayd_quiescent_control(struct lttcomm_relayd_sock *rsock,
 506                 uint64_t metadata_stream_id)
 507 {
 508         int ret;
 509         struct lttcomm_relayd_quiescent_control msg;
 510         struct lttcomm_relayd_generic_reply reply;
 511
 512         /* Code flow error. Safety net. */
 513         assert(rsock);
 514
 515         DBG("Relayd checking quiescent control state");
 516
 517         msg.stream_id = htobe64(metadata_stream_id);
 518
 519         /* Send command */
 520         ret = send_command(rsock, RELAYD_QUIESCENT_CONTROL, &msg, sizeof(msg), 0);
 521         if (ret < 0) {
 522                 goto error;
 523         }
 524
 525         /* Receive response */
 526         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 527         if (ret < 0) {
 528                 goto error;
 529         }
 530
 531         reply.ret_code = be32toh(reply.ret_code);
 532
 533         /* Return session id or negative ret code. */
 534         if (reply.ret_code != LTTNG_OK) {
 535                 ret = -1;
 536                 ERR("Relayd quiescent control replied error %d", reply.ret_code);
 537                 goto error;
 538         }
 539
 540         /* Control socket is quiescent */
 541         return 0;
 542
 543 error:
 544         return ret;
 545 }
 546
 547 /*
 548  * Begin a data pending command for a specific session id.
 549  */
 550 int relayd_begin_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t id)
 551 {
 552         int ret;
 553         struct lttcomm_relayd_begin_data_pending msg;
 554         struct lttcomm_relayd_generic_reply reply;
 555
 556         /* Code flow error. Safety net. */
 557         assert(rsock);
 558
 559         DBG("Relayd begin data pending");
 560
 561         msg.session_id = htobe64(id);
 562
 563         /* Send command */
 564         ret = send_command(rsock, RELAYD_BEGIN_DATA_PENDING, &msg, sizeof(msg), 0);
 565         if (ret < 0) {
 566                 goto error;
 567         }
 568
 569         /* Receive response */
 570         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 571         if (ret < 0) {
 572                 goto error;
 573         }
 574
 575         reply.ret_code = be32toh(reply.ret_code);
 576
 577         /* Return session id or negative ret code. */
 578         if (reply.ret_code != LTTNG_OK) {
 579                 ret = -1;
 580                 ERR("Relayd begin data pending replied error %d", reply.ret_code);
 581                 goto error;
 582         }
 583
 584         return 0;
 585
 586 error:
 587         return ret;
 588 }
 589
 590 /*
 591  * End a data pending command for a specific session id.
 592  *
 593  * Return 0 on success and set is_data_inflight to 0 if no data is being
 594  * streamed or 1 if it is the case.
 595  */
 596 int relayd_end_data_pending(struct lttcomm_relayd_sock *rsock, uint64_t id,
 597                 unsigned int *is_data_inflight)
 598 {
 599         int ret;
 600         struct lttcomm_relayd_end_data_pending msg;
 601         struct lttcomm_relayd_generic_reply reply;
 602
 603         /* Code flow error. Safety net. */
 604         assert(rsock);
 605
 606         DBG("Relayd end data pending");
 607
 608         msg.session_id = htobe64(id);
 609
 610         /* Send command */
 611         ret = send_command(rsock, RELAYD_END_DATA_PENDING, &msg, sizeof(msg), 0);
 612         if (ret < 0) {
 613                 goto error;
 614         }
 615
 616         /* Receive response */
 617         ret = recv_reply(rsock, (void *) &reply, sizeof(reply));
 618         if (ret < 0) {
 619                 goto error;
 620         }
 621
 622         reply.ret_code = be32toh(reply.ret_code);
 623         if (reply.ret_code < 0) {
 624                 ret = reply.ret_code;
 625                 goto error;
 626         }
 627
 628         *is_data_inflight = reply.ret_code;
 629
 630         DBG("Relayd end data pending is data inflight: %d", reply.ret_code);
 631
 632         return 0;
 633
 634 error:
 635         return ret;
 636 }