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_sessiond_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) {
  94                 ret = -errno;
  95                 goto error;
  96         }
  97
  98 error:
  99         return ret;
 100 }
 101
 102 /*
 103  * Add stream on the relayd and assign stream handle to the stream_id argument.
 104  *
 105  * On success return 0 else return ret_code negative value.
 106  */
 107 int relayd_add_stream(struct lttcomm_sock *sock, const char *channel_name,
 108                 const char *pathname, uint64_t *stream_id)
 109 {
 110         int ret;
 111         struct lttcomm_relayd_add_stream msg;
 112         struct lttcomm_relayd_status_stream reply;
 113
 114         /* Code flow error. Safety net. */
 115         assert(sock);
 116         assert(channel_name);
 117         assert(pathname);
 118
 119         DBG("Relayd adding stream for channel name %s", channel_name);
 120
 121         strncpy(msg.channel_name, channel_name, sizeof(msg.channel_name));
 122         strncpy(msg.pathname, pathname, sizeof(msg.pathname));
 123
 124         /* Send command */
 125         ret = send_command(sock, RELAYD_ADD_STREAM, (void *) &msg, sizeof(msg), 0);
 126         if (ret < 0) {
 127                 goto error;
 128         }
 129
 130         /* Waiting for reply */
 131         ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 132         if (ret < 0) {
 133                 goto error;
 134         }
 135
 136         /* Back to host bytes order. */
 137         reply.handle = be64toh(reply.handle);
 138         reply.ret_code = be32toh(reply.ret_code);
 139
 140         /* Return session id or negative ret code. */
 141         if (reply.ret_code != LTTNG_OK) {
 142                 ret = -reply.ret_code;
 143                 ERR("Relayd add stream replied error %d", ret);
 144         } else {
 145                 /* Success */
 146                 ret = 0;
 147                 *stream_id = reply.handle;
 148         }
 149
 150         DBG("Relayd stream added successfully with handle %" PRIu64,
 151                 reply.handle);
 152
 153 error:
 154         return ret;
 155 }
 156
 157 /*
 158  * Check version numbers on the relayd.
 159  *
 160  * Return 0 if compatible else negative value.
 161  */
 162 int relayd_version_check(struct lttcomm_sock *sock, uint32_t major,
 163                 uint32_t minor)
 164 {
 165         int ret;
 166         struct lttcomm_relayd_version msg;
 167
 168         /* Code flow error. Safety net. */
 169         assert(sock);
 170
 171         DBG("Relayd version check for major.minor %u.%u", major, minor);
 172
 173         /* Prepare network byte order before transmission. */
 174         msg.major = htobe32(major);
 175         msg.minor = htobe32(minor);
 176
 177         /* Send command */
 178         ret = send_command(sock, RELAYD_VERSION, (void *) &msg, sizeof(msg), 0);
 179         if (ret < 0) {
 180                 goto error;
 181         }
 182
 183         /* Recevie response */
 184         ret = recv_reply(sock, (void *) &msg, sizeof(msg));
 185         if (ret < 0) {
 186                 goto error;
 187         }
 188
 189         /* Set back to host bytes order */
 190         msg.major = be32toh(msg.major);
 191         msg.minor = be32toh(msg.minor);
 192
 193         /*
 194          * Only validate the major version. If the other side is higher,
 195          * communication is not possible. Only major version equal can talk to each
 196          * other. If the minor version differs, the lowest version is used by both
 197          * sides.
 198          *
 199          * For now, before 2.1.0 stable release, we don't have to check the minor
 200          * because this new mechanism with the relayd will only be available with
 201          * 2.1 and NOT 2.0.x.
 202          */
 203         if (msg.major == major) {
 204                 /* Compatible */
 205                 ret = 0;
 206                 DBG2("Relayd version is compatible");
 207                 goto error;
 208         }
 209
 210         /*
 211          * After 2.1.0 release, for the 2.2 release, at this point will have to
 212          * check the minor version in order for the session daemon to know which
 213          * structure to use to communicate with the relayd. If the relayd's minor
 214          * version is higher, it will adapt to our version so we can continue to
 215          * use the latest relayd communication data structure.
 216          */
 217
 218         /* Version number not compatible */
 219         DBG2("Relayd version is NOT compatible. Relayd version %u != %u (us)",
 220                         msg.major, major);
 221         ret = -1;
 222
 223 error:
 224         return ret;
 225 }
 226
 227 /*
 228  * Add stream on the relayd and assign stream handle to the stream_id argument.
 229  *
 230  * On success return 0 else return ret_code negative value.
 231  */
 232 int relayd_send_metadata(struct lttcomm_sock *sock, size_t len)
 233 {
 234         int ret;
 235
 236         /* Code flow error. Safety net. */
 237         assert(sock);
 238
 239         DBG("Relayd sending metadata of size %zu", len);
 240
 241         /* Send command */
 242         ret = send_command(sock, RELAYD_SEND_METADATA, NULL, len, 0);
 243         if (ret < 0) {
 244                 goto error;
 245         }
 246
 247         DBG2("Relayd metadata added successfully");
 248
 249         /*
 250          * After that call, the metadata data MUST be sent to the relayd so the
 251          * receive size on the other end matches the len of the metadata packet
 252          * header. This is why we don't wait for a reply here.
 253          */
 254
 255 error:
 256         return ret;
 257 }
 258
 259 /*
 260  * Connect to relay daemon with an allocated lttcomm_sock.
 261  */
 262 int relayd_connect(struct lttcomm_sock *sock)
 263 {
 264         /* Code flow error. Safety net. */
 265         assert(sock);
 266
 267         DBG3("Relayd connect ...");
 268
 269         return sock->ops->connect(sock);
 270 }
 271
 272 /*
 273  * Close relayd socket with an allocated lttcomm_sock.
 274  */
 275 int relayd_close(struct lttcomm_sock *sock)
 276 {
 277         /* Code flow error. Safety net. */
 278         assert(sock);
 279
 280         DBG3("Relayd closing socket %d", sock->fd);
 281
 282         return sock->ops->close(sock);
 283 }
 284
 285 /*
 286  * Send data header structure to the relayd.
 287  */
 288 int relayd_send_data_hdr(struct lttcomm_sock *sock,
 289                 struct lttcomm_relayd_data_hdr *hdr, size_t size)
 290 {
 291         int ret;
 292
 293         /* Code flow error. Safety net. */
 294         assert(sock);
 295         assert(hdr);
 296
 297         DBG3("Relayd sending data header of size %ld", size);
 298
 299         /* Again, safety net */
 300         if (size == 0) {
 301                 size = sizeof(struct lttcomm_relayd_data_hdr);
 302         }
 303
 304         /* Only send data header. */
 305         ret = sock->ops->sendmsg(sock, hdr, size, 0);
 306         if (ret < 0) {
 307                 ret = -errno;
 308                 goto error;
 309         }
 310
 311         /*
 312          * The data MUST be sent right after that command for the receive on the
 313          * other end to match the size in the header.
 314          */
 315
 316 error:
 317         return ret;
 318 }
 319
 320 /*
 321  * Send close stream command to the relayd.
 322  */
 323 int relayd_send_close_stream(struct lttcomm_sock *sock, uint64_t stream_id,
 324                 uint64_t last_net_seq_num)
 325 {
 326         int ret;
 327         struct lttcomm_relayd_close_stream msg;
 328         struct lttcomm_relayd_generic_reply reply;
 329
 330         /* Code flow error. Safety net. */
 331         assert(sock);
 332
 333         DBG("Relayd closing stream id %" PRIu64, stream_id);
 334
 335         msg.stream_id = htobe64(stream_id);
 336         msg.last_net_seq_num = htobe64(last_net_seq_num);
 337
 338         /* Send command */
 339         ret = send_command(sock, RELAYD_CLOSE_STREAM, (void *) &msg, sizeof(msg), 0);
 340         if (ret < 0) {
 341                 goto error;
 342         }
 343
 344         /* Recevie response */
 345         ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 346         if (ret < 0) {
 347                 goto error;
 348         }
 349
 350         reply.ret_code = be32toh(reply.ret_code);
 351
 352         /* Return session id or negative ret code. */
 353         if (reply.ret_code != LTTNG_OK) {
 354                 ret = -reply.ret_code;
 355                 ERR("Relayd close stream replied error %d", ret);
 356         } else {
 357                 /* Success */
 358                 ret = 0;
 359         }
 360
 361         DBG("Relayd close stream id %" PRIu64 " successfully", stream_id);
 362
 363 error:
 364         return ret;
 365 }
 366
 367 /*
 368  * Check for data availability for a given stream id.
 369  *
 370  * Return 0 if NOT pending, 1 if so and a negative value on error.
 371  */
 372 int relayd_data_pending(struct lttcomm_sock *sock, uint64_t stream_id,
 373                 uint64_t last_net_seq_num)
 374 {
 375         int ret;
 376         struct lttcomm_relayd_data_pending msg;
 377         struct lttcomm_relayd_generic_reply reply;
 378
 379         /* Code flow error. Safety net. */
 380         assert(sock);
 381
 382         DBG("Relayd data pending for stream id %" PRIu64, stream_id);
 383
 384         msg.stream_id = htobe64(stream_id);
 385         msg.last_net_seq_num = htobe64(last_net_seq_num);
 386
 387         /* Send command */
 388         ret = send_command(sock, RELAYD_DATA_PENDING, (void *) &msg,
 389                         sizeof(msg), 0);
 390         if (ret < 0) {
 391                 goto error;
 392         }
 393
 394         /* Recevie response */
 395         ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 396         if (ret < 0) {
 397                 goto error;
 398         }
 399
 400         reply.ret_code = be32toh(reply.ret_code);
 401
 402         /* Return session id or negative ret code. */
 403         if (reply.ret_code >= LTTNG_OK) {
 404                 ret = -reply.ret_code;
 405                 ERR("Relayd data pending replied error %d", ret);
 406         }
 407
 408         /* At this point, the ret code is either 1 or 0 */
 409         ret = reply.ret_code;
 410
 411         DBG("Relayd data is %s pending for stream id %" PRIu64,
 412                         ret == 1 ? "NOT" : "", stream_id);
 413
 414 error:
 415         return ret;
 416 }
 417
 418 /*
 419  * Check on the relayd side for a quiescent state on the control socket.
 420  */
 421 int relayd_quiescent_control(struct lttcomm_sock *sock)
 422 {
 423         int ret;
 424         struct lttcomm_relayd_generic_reply reply;
 425
 426         /* Code flow error. Safety net. */
 427         assert(sock);
 428
 429         DBG("Relayd checking quiescent control state");
 430
 431         /* Send command */
 432         ret = send_command(sock, RELAYD_QUIESCENT_CONTROL, NULL, 0, 0);
 433         if (ret < 0) {
 434                 goto error;
 435         }
 436
 437         /* Recevie response */
 438         ret = recv_reply(sock, (void *) &reply, sizeof(reply));
 439         if (ret < 0) {
 440                 goto error;
 441         }
 442
 443         reply.ret_code = be32toh(reply.ret_code);
 444
 445         /* Return session id or negative ret code. */
 446         if (reply.ret_code != LTTNG_OK) {
 447                 ret = -reply.ret_code;
 448                 ERR("Relayd quiescent control replied error %d", ret);
 449                 goto error;
 450         }
 451
 452         /* Control socket is quiescent */
 453         return 0;
 454
 455 error:
 456         return ret;
 457 }