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_sock *sock,
  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 = sock->ops->sendmsg(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_sock *sock, void *data, size_t size)
  87 {
  88         int ret;
  89
  90         DBG3("Relayd waiting for reply of size %ld", size);
  91
  92         ret = sock->ops->recvmsg(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", sock->fd);
  97                 } else {
  98                         DBG("Receiving reply failed on sock %d for size %lu with ret %d",
  99                                         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_sock *sock, uint64_t *session_id)
 118 {
 119         int ret;
 120         struct lttcomm_relayd_status_session reply;
 121
 122         assert(sock);
 123         assert(session_id);
 124
 125         DBG("Relayd create session");
 126
 127         /* Send command */
 128         ret = send_command(sock, RELAYD_CREATE_SESSION, NULL, 0, 0);
 129         if (ret < 0) {
 130                 goto error;
 131         }
 132
 133         /* Receive response */
 134         ret = recv_reply(sock, (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_sock *sock, 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(sock);
 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(sock, 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(sock, (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_sock *sock, uint32_t major,
 221                 uint32_t minor, uint32_t *minor_to_use)
 222 {
 223         int ret;
 224         struct lttcomm_relayd_version msg;
 225
 226         /* Code flow error. Safety net. */
 227         assert(sock);
 228
 229         DBG("Relayd version check for major.minor %u.%u", major, minor);
 230
 231         /* Prepare network byte order before transmission. */
 232         msg.major = htobe32(major);
 233         msg.minor = htobe32(minor);
 234
 235         /* Send command */
 236         ret = send_command(sock, RELAYD_VERSION, (void *) &msg, sizeof(msg), 0);
 237         if (ret < 0) {
 238                 goto error;
 239         }
 240
 241         /* Receive response */
 242         ret = recv_reply(sock, (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 != major) {
 258                 /* Not compatible */
 259                 ret = -1;
 260                 DBG2("Relayd version is NOT compatible. Relayd version %u != %u (us)",
 261                                 msg.major, major);
 262                 goto error;
 263         }
 264
 265         /*
 266          * After 2.1.0 release, for the 2.2 release, at this point will have to
 267          * check the minor version in order for the session daemon to know which
 268          * structure to use to communicate with the relayd. If the relayd's minor
 269          * version is higher, it will adapt to our version so we can continue to
 270          * use the latest relayd communication data structure.
 271          */
 272         if (minor <= msg.minor) {
 273                 *minor_to_use = minor;
 274         } else {
 275                 *minor_to_use = msg.minor;
 276         }
 277
 278         /* Version number compatible */
 279         DBG2("Relayd version is compatible, using protocol version %u.%u",
 280                         major, *minor_to_use);
 281         ret = 0;
 282
 283 error:
 284         return ret;
 285 }
 286
 287 /*
 288  * Add stream on the relayd and assign stream handle to the stream_id argument.
 289  *
 290  * On success return 0 else return ret_code negative value.
 291  */
 292 int relayd_send_metadata(struct lttcomm_sock *sock, size_t len)
 293 {
 294         int ret;
 295
 296         /* Code flow error. Safety net. */
 297         assert(sock);
 298
 299         DBG("Relayd sending metadata of size %zu", len);
 300
 301         /* Send command */
 302         ret = send_command(sock, RELAYD_SEND_METADATA, NULL, len, 0);
 303         if (ret < 0) {
 304                 goto error;
 305         }
 306
 307         DBG2("Relayd metadata added successfully");
 308
 309         /*
 310          * After that call, the metadata data MUST be sent to the relayd so the
 311          * receive size on the other end matches the len of the metadata packet
 312          * header. This is why we don't wait for a reply here.
 313          */
 314
 315 error:
 316         return ret;
 317 }
 318
 319 /*
 320  * Connect to relay daemon with an allocated lttcomm_sock.
 321  */
 322 int relayd_connect(struct lttcomm_sock *sock)
 323 {
 324         /* Code flow error. Safety net. */
 325         assert(sock);
 326
 327         DBG3("Relayd connect ...");
 328
 329         return sock->ops->connect(sock);
 330 }
 331
 332 /*
 333  * Close relayd socket with an allocated lttcomm_sock.
 334  *
 335  * If no socket operations are found, simply return 0 meaning that everything
 336  * is fine. Without operations, the socket can not possibly be opened or used.
 337  * This is possible if the socket was allocated but not created. However, the
 338  * caller could simply use it to store a valid file descriptor for instance
 339  * passed over a Unix socket and call this to cleanup but still without a valid
 340  * ops pointer.
 341  *
 342  * Return the close returned value. On error, a negative value is usually
 343  * returned back from close(2).
 344  */
 345 int relayd_close(struct lttcomm_sock *sock)
 346 {
 347         int ret;
 348
 349         /* Code flow error. Safety net. */
 350         assert(sock);
 351
 352         /* An invalid fd is fine, return success. */
 353         if (sock->fd < 0) {
 354                 ret = 0;
 355                 goto end;
 356         }
 357
 358         DBG3("Relayd closing socket %d", sock->fd);
 359
 360         if (sock->ops) {
 361                 ret = sock->ops->close(sock);
 362         } else {
 363                 /* Default call if no specific ops found. */
 364                 ret = close(sock->fd);
 365                 if (ret < 0) {
 366                         PERROR("relayd_close default close");
 367                 }
 368         }
 369
 370 end:
 371         return ret;
 372 }
 373
 374 /*
 375  * Send data header structure to the relayd.
 376  */
 377 int relayd_send_data_hdr(struct lttcomm_sock *sock,
 378                 struct lttcomm_relayd_data_hdr *hdr, size_t size)
 379 {
 380         int ret;
 381
 382         /* Code flow error. Safety net. */
 383         assert(sock);
 384         assert(hdr);
 385
 386         DBG3("Relayd sending data header of size %ld", size);
 387
 388         /* Again, safety net */
 389         if (size == 0) {
 390                 size = sizeof(struct lttcomm_relayd_data_hdr);
 391         }
 392
 393         /* Only send data header. */
 394         ret = sock->ops->sendmsg(sock, hdr, size, 0);
 395         if (ret < 0) {
 396                 ret = -errno;
 397                 goto error;
 398         }
 399
 400         /*
 401          * The data MUST be sent right after that command for the receive on the
 402          * other end to match the size in the header.
 403          */
 404
 405 error:
 406         return ret;
 407 }
 408
 409 /*
 410  * Send close stream command to the relayd.
 411  */
 412 int relayd_send_close_stream(struct lttcomm_sock *sock, uint64_t stream_id,
 413                 uint64_t last_net_seq_num)
 414 {
 415         int ret;
 416         struct lttcomm_relayd_close_stream msg;
 417         struct lttcomm_relayd_generic_reply reply;
 418
 419         /* Code flow error. Safety net. */
 420         assert(sock);
 421
 422         DBG("Relayd closing stream id %" PRIu64, stream_id);
 423
 424         msg.stream_id = htobe64(stream_id);
 425         msg.last_net_seq_num = htobe64(last_net_seq_num);
 426
 427         /* Send command */
 428         ret = send_command(sock, RELAYD_CLOSE_STREAM, (void *) &msg, sizeof(msg), 0);
 429         if (ret < 0) {
 430                 goto error;
 431         }
 432
 433         /* Receive response */
 434         ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 435         if (ret < 0) {
 436                 goto error;
 437         }
 438
 439         reply.ret_code = be32toh(reply.ret_code);
 440
 441         /* Return session id or negative ret code. */
 442         if (reply.ret_code != LTTNG_OK) {
 443                 ret = -1;
 444                 ERR("Relayd close stream replied error %d", reply.ret_code);
 445         } else {
 446                 /* Success */
 447                 ret = 0;
 448         }
 449
 450         DBG("Relayd close stream id %" PRIu64 " successfully", stream_id);
 451
 452 error:
 453         return ret;
 454 }
 455
 456 /*
 457  * Check for data availability for a given stream id.
 458  *
 459  * Return 0 if NOT pending, 1 if so and a negative value on error.
 460  */
 461 int relayd_data_pending(struct lttcomm_sock *sock, uint64_t stream_id,
 462                 uint64_t last_net_seq_num)
 463 {
 464         int ret;
 465         struct lttcomm_relayd_data_pending msg;
 466         struct lttcomm_relayd_generic_reply reply;
 467
 468         /* Code flow error. Safety net. */
 469         assert(sock);
 470
 471         DBG("Relayd data pending for stream id %" PRIu64, stream_id);
 472
 473         msg.stream_id = htobe64(stream_id);
 474         msg.last_net_seq_num = htobe64(last_net_seq_num);
 475
 476         /* Send command */
 477         ret = send_command(sock, RELAYD_DATA_PENDING, (void *) &msg,
 478                         sizeof(msg), 0);
 479         if (ret < 0) {
 480                 goto error;
 481         }
 482
 483         /* Receive response */
 484         ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 485         if (ret < 0) {
 486                 goto error;
 487         }
 488
 489         reply.ret_code = be32toh(reply.ret_code);
 490
 491         /* Return session id or negative ret code. */
 492         if (reply.ret_code >= LTTNG_OK) {
 493                 ERR("Relayd data pending replied error %d", reply.ret_code);
 494         }
 495
 496         /* At this point, the ret code is either 1 or 0 */
 497         ret = reply.ret_code;
 498
 499         DBG("Relayd data is %s pending for stream id %" PRIu64,
 500                         ret == 1 ? "" : "NOT", stream_id);
 501
 502 error:
 503         return ret;
 504 }
 505
 506 /*
 507  * Check on the relayd side for a quiescent state on the control socket.
 508  */
 509 int relayd_quiescent_control(struct lttcomm_sock *sock,
 510                 uint64_t metadata_stream_id)
 511 {
 512         int ret;
 513         struct lttcomm_relayd_quiescent_control msg;
 514         struct lttcomm_relayd_generic_reply reply;
 515
 516         /* Code flow error. Safety net. */
 517         assert(sock);
 518
 519         DBG("Relayd checking quiescent control state");
 520
 521         msg.stream_id = htobe64(metadata_stream_id);
 522
 523         /* Send command */
 524         ret = send_command(sock, RELAYD_QUIESCENT_CONTROL, &msg, sizeof(msg), 0);
 525         if (ret < 0) {
 526                 goto error;
 527         }
 528
 529         /* Receive response */
 530         ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 531         if (ret < 0) {
 532                 goto error;
 533         }
 534
 535         reply.ret_code = be32toh(reply.ret_code);
 536
 537         /* Return session id or negative ret code. */
 538         if (reply.ret_code != LTTNG_OK) {
 539                 ret = -1;
 540                 ERR("Relayd quiescent control replied error %d", reply.ret_code);
 541                 goto error;
 542         }
 543
 544         /* Control socket is quiescent */
 545         return 0;
 546
 547 error:
 548         return ret;
 549 }
 550
 551 /*
 552  * Begin a data pending command for a specific session id.
 553  */
 554 int relayd_begin_data_pending(struct lttcomm_sock *sock, uint64_t id)
 555 {
 556         int ret;
 557         struct lttcomm_relayd_begin_data_pending msg;
 558         struct lttcomm_relayd_generic_reply reply;
 559
 560         /* Code flow error. Safety net. */
 561         assert(sock);
 562
 563         DBG("Relayd begin data pending");
 564
 565         msg.session_id = htobe64(id);
 566
 567         /* Send command */
 568         ret = send_command(sock, RELAYD_BEGIN_DATA_PENDING, &msg, sizeof(msg), 0);
 569         if (ret < 0) {
 570                 goto error;
 571         }
 572
 573         /* Receive response */
 574         ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 575         if (ret < 0) {
 576                 goto error;
 577         }
 578
 579         reply.ret_code = be32toh(reply.ret_code);
 580
 581         /* Return session id or negative ret code. */
 582         if (reply.ret_code != LTTNG_OK) {
 583                 ret = -1;
 584                 ERR("Relayd begin data pending replied error %d", reply.ret_code);
 585                 goto error;
 586         }
 587
 588         return 0;
 589
 590 error:
 591         return ret;
 592 }
 593
 594 /*
 595  * End a data pending command for a specific session id.
 596  *
 597  * Return 0 on success and set is_data_inflight to 0 if no data is being
 598  * streamed or 1 if it is the case.
 599  */
 600 int relayd_end_data_pending(struct lttcomm_sock *sock, uint64_t id,
 601                 unsigned int *is_data_inflight)
 602 {
 603         int ret;
 604         struct lttcomm_relayd_end_data_pending msg;
 605         struct lttcomm_relayd_generic_reply reply;
 606
 607         /* Code flow error. Safety net. */
 608         assert(sock);
 609
 610         DBG("Relayd end data pending");
 611
 612         msg.session_id = htobe64(id);
 613
 614         /* Send command */
 615         ret = send_command(sock, RELAYD_END_DATA_PENDING, &msg, sizeof(msg), 0);
 616         if (ret < 0) {
 617                 goto error;
 618         }
 619
 620         /* Receive response */
 621         ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 622         if (ret < 0) {
 623                 goto error;
 624         }
 625
 626         reply.ret_code = be32toh(reply.ret_code);
 627         if (reply.ret_code < 0) {
 628                 ret = reply.ret_code;
 629                 goto error;
 630         }
 631
 632         *is_data_inflight = reply.ret_code;
 633
 634         DBG("Relayd end data pending is data inflight: %d", reply.ret_code);
 635
 636         return 0;
 637
 638 error:
 639         return ret;
 640 }