liblttng-ust-comm/lttng-ust-comm.c

   1 /*
   2  * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
   3  * Copyright (C)  2011-2013 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; only
   8  * version 2.1 of the License.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #include <limits.h>
  21 #include <stdint.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/socket.h>
  26 #include <sys/stat.h>
  27 #include <sys/types.h>
  28 #include <sys/un.h>
  29 #include <unistd.h>
  30 #include <assert.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33
  34 #include <lttng/ust-ctl.h>
  35 #include <ust-comm.h>
  36 #include <ust-fd.h>
  37 #include <helper.h>
  38 #include <lttng/ust-error.h>
  39 #include <lttng/ust-events.h>
  40 #include <lttng/ust-dynamic-type.h>
  41 #include <usterr-signal-safe.h>
  42
  43 #include "../liblttng-ust/compat.h"
  44
  45 #define USTCOMM_CODE_OFFSET(code)       \
  46         (code == LTTNG_UST_OK ? 0 : (code - LTTNG_UST_ERR + 1))
  47
  48 #define USTCOMM_MAX_SEND_FDS    4
  49
  50 static
  51 ssize_t count_fields_recursive(size_t nr_fields,
  52                 const struct lttng_event_field *lttng_fields);
  53 static
  54 int serialize_one_field(struct lttng_session *session,
  55                 struct ustctl_field *fields, size_t *iter_output,
  56                 const struct lttng_event_field *lf);
  57 static
  58 int serialize_fields(struct lttng_session *session,
  59                 struct ustctl_field *ustctl_fields,
  60                 size_t *iter_output, size_t nr_lttng_fields,
  61                 const struct lttng_event_field *lttng_fields);
  62
  63 /*
  64  * Human readable error message.
  65  */
  66 static const char *ustcomm_readable_code[] = {
  67         [ USTCOMM_CODE_OFFSET(LTTNG_UST_OK) ] = "Success",
  68         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR) ] = "Unknown error",
  69         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOENT) ] = "No entry",
  70         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_EXIST) ] = "Object already exists",
  71         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL) ] = "Invalid argument",
  72         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_PERM) ] = "Permission denied",
  73         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOSYS) ] = "Not implemented",
  74         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_EXITING) ] = "Process is exiting",
  75
  76         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL_MAGIC) ] = "Invalid magic number",
  77         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL_SOCKET_TYPE) ] = "Invalid socket type",
  78         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_UNSUP_MAJOR) ] = "Unsupported major version",
  79 };
  80
  81 /*
  82  * lttng_ust_strerror
  83  *
  84  * Receives positive error value.
  85  * Return ptr to string representing a human readable
  86  * error code from the ustcomm_return_code enum.
  87  */
  88 const char *lttng_ust_strerror(int code)
  89 {
  90         if (code == LTTNG_UST_OK)
  91                 return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)];
  92         if (code < LTTNG_UST_ERR)
  93                 return strerror(code);
  94         if (code >= LTTNG_UST_ERR_NR)
  95                 code = LTTNG_UST_ERR;
  96         return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)];
  97 }
  98
  99 /*
 100  * ustcomm_connect_unix_sock
 101  *
 102  * Connect to unix socket using the path name.
 103  *
 104  * Caller handles FD tracker.
 105  */
 106 int ustcomm_connect_unix_sock(const char *pathname, long timeout)
 107 {
 108         struct sockaddr_un sun;
 109         int fd, ret;
 110
 111         /*
 112          * libust threads require the close-on-exec flag for all
 113          * resources so it does not leak file descriptors upon exec.
 114          * SOCK_CLOEXEC is not used since it is linux specific.
 115          */
 116         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 117         if (fd < 0) {
 118                 PERROR("socket");
 119                 ret = -errno;
 120                 goto error;
 121         }
 122         if (timeout >= 0) {
 123                 /* Give at least 10ms. */
 124                 if (timeout < 10)
 125                         timeout = 10;
 126                 ret = ustcomm_setsockopt_snd_timeout(fd, timeout);
 127                 if (ret < 0) {
 128                         WARN("Error setting connect socket send timeout");
 129                 }
 130         }
 131         ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
 132         if (ret < 0) {
 133                 PERROR("fcntl");
 134                 ret = -errno;
 135                 goto error_fcntl;
 136         }
 137
 138         memset(&sun, 0, sizeof(sun));
 139         sun.sun_family = AF_UNIX;
 140         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 141         sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
 142
 143         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
 144         if (ret < 0) {
 145                 /*
 146                  * Don't print message on connect ENOENT error, because
 147                  * connect is used in normal execution to detect if
 148                  * sessiond is alive. ENOENT is when the unix socket
 149                  * file does not exist, and ECONNREFUSED is when the
 150                  * file exists but no sessiond is listening.
 151                  */
 152                 if (errno != ECONNREFUSED && errno != ECONNRESET
 153                                 && errno != ENOENT && errno != EACCES)
 154                         PERROR("connect");
 155                 ret = -errno;
 156                 if (ret == -ECONNREFUSED || ret == -ECONNRESET)
 157                         ret = -EPIPE;
 158                 goto error_connect;
 159         }
 160
 161         return fd;
 162
 163 error_connect:
 164 error_fcntl:
 165         {
 166                 int closeret;
 167
 168                 closeret = close(fd);
 169                 if (closeret)
 170                         PERROR("close");
 171         }
 172 error:
 173         return ret;
 174 }
 175
 176 /*
 177  * ustcomm_accept_unix_sock
 178  *
 179  * Do an accept(2) on the sock and return the
 180  * new file descriptor. The socket MUST be bind(2) before.
 181  */
 182 int ustcomm_accept_unix_sock(int sock)
 183 {
 184         int new_fd;
 185         struct sockaddr_un sun;
 186         socklen_t len = 0;
 187
 188         /* Blocking call */
 189         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 190         if (new_fd < 0) {
 191                 if (errno != ECONNABORTED)
 192                         PERROR("accept");
 193                 new_fd = -errno;
 194                 if (new_fd == -ECONNABORTED)
 195                         new_fd = -EPIPE;
 196         }
 197         return new_fd;
 198 }
 199
 200 /*
 201  * ustcomm_create_unix_sock
 202  *
 203  * Creates a AF_UNIX local socket using pathname
 204  * bind the socket upon creation and return the fd.
 205  */
 206 int ustcomm_create_unix_sock(const char *pathname)
 207 {
 208         struct sockaddr_un sun;
 209         int fd, ret;
 210
 211         /* Create server socket */
 212         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 213                 PERROR("socket");
 214                 ret = -errno;
 215                 goto error;
 216         }
 217
 218         memset(&sun, 0, sizeof(sun));
 219         sun.sun_family = AF_UNIX;
 220         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 221         sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
 222
 223         /* Unlink the old file if present */
 224         (void) unlink(pathname);
 225         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 226         if (ret < 0) {
 227                 PERROR("bind");
 228                 ret = -errno;
 229                 goto error_close;
 230         }
 231
 232         return fd;
 233
 234 error_close:
 235         {
 236                 int closeret;
 237
 238                 closeret = close(fd);
 239                 if (closeret) {
 240                         PERROR("close");
 241                 }
 242         }
 243 error:
 244         return ret;
 245 }
 246
 247 /*
 248  * ustcomm_listen_unix_sock
 249  *
 250  * Make the socket listen using LTTNG_UST_COMM_MAX_LISTEN.
 251  */
 252 int ustcomm_listen_unix_sock(int sock)
 253 {
 254         int ret;
 255
 256         ret = listen(sock, LTTNG_UST_COMM_MAX_LISTEN);
 257         if (ret < 0) {
 258                 ret = -errno;
 259                 PERROR("listen");
 260         }
 261
 262         return ret;
 263 }
 264
 265 /*
 266  * ustcomm_close_unix_sock
 267  *
 268  * Shutdown cleanly a unix socket.
 269  *
 270  * Handles fd tracker internally.
 271  */
 272 int ustcomm_close_unix_sock(int sock)
 273 {
 274         int ret;
 275
 276         lttng_ust_lock_fd_tracker();
 277         ret = close(sock);
 278         if (!ret) {
 279                 lttng_ust_delete_fd_from_tracker(sock);
 280         } else {
 281                 PERROR("close");
 282                 ret = -errno;
 283         }
 284         lttng_ust_unlock_fd_tracker();
 285
 286         return ret;
 287 }
 288
 289 /*
 290  * ustcomm_recv_unix_sock
 291  *
 292  * Receive data of size len in put that data into
 293  * the buf param. Using recvmsg API.
 294  * Return the size of received data.
 295  * Return 0 on orderly shutdown.
 296  */
 297 ssize_t ustcomm_recv_unix_sock(int sock, void *buf, size_t len)
 298 {
 299         struct msghdr msg;
 300         struct iovec iov[1];
 301         ssize_t ret = -1;
 302         size_t len_last;
 303
 304         memset(&msg, 0, sizeof(msg));
 305
 306         iov[0].iov_base = buf;
 307         iov[0].iov_len = len;
 308         msg.msg_iov = iov;
 309         msg.msg_iovlen = 1;
 310
 311         do {
 312                 len_last = iov[0].iov_len;
 313                 ret = recvmsg(sock, &msg, 0);
 314                 if (ret > 0) {
 315                         iov[0].iov_base += ret;
 316                         iov[0].iov_len -= ret;
 317                         assert(ret <= len_last);
 318                 }
 319         } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
 320
 321         if (ret < 0) {
 322                 int shutret;
 323
 324                 if (errno != EPIPE && errno != ECONNRESET && errno != ECONNREFUSED)
 325                         PERROR("recvmsg");
 326                 ret = -errno;
 327                 if (ret == -ECONNRESET || ret == -ECONNREFUSED)
 328                         ret = -EPIPE;
 329
 330                 shutret = shutdown(sock, SHUT_RDWR);
 331                 if (shutret)
 332                         ERR("Socket shutdown error");
 333         } else if (ret > 0) {
 334                 ret = len;
 335         }
 336         /* ret = 0 means an orderly shutdown. */
 337
 338         return ret;
 339 }
 340
 341 /*
 342  * ustcomm_send_unix_sock
 343  *
 344  * Send buf data of size len. Using sendmsg API.
 345  * Return the size of sent data.
 346  */
 347 ssize_t ustcomm_send_unix_sock(int sock, const void *buf, size_t len)
 348 {
 349         struct msghdr msg;
 350         struct iovec iov[1];
 351         ssize_t ret;
 352
 353         memset(&msg, 0, sizeof(msg));
 354
 355         iov[0].iov_base = (void *) buf;
 356         iov[0].iov_len = len;
 357         msg.msg_iov = iov;
 358         msg.msg_iovlen = 1;
 359
 360         /*
 361          * Using the MSG_NOSIGNAL when sending data from sessiond to
 362          * libust, so libust does not receive an unhandled SIGPIPE or
 363          * SIGURG. The sessiond receiver side can be made more resilient
 364          * by ignoring SIGPIPE, but we don't have this luxury on the
 365          * libust side.
 366          */
 367         do {
 368                 ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
 369         } while (ret < 0 && errno == EINTR);
 370
 371         if (ret < 0) {
 372                 int shutret;
 373
 374                 if (errno != EPIPE && errno != ECONNRESET)
 375                         PERROR("sendmsg");
 376                 ret = -errno;
 377                 if (ret == -ECONNRESET)
 378                         ret = -EPIPE;
 379
 380                 shutret = shutdown(sock, SHUT_RDWR);
 381                 if (shutret)
 382                         ERR("Socket shutdown error");
 383         }
 384
 385         return ret;
 386 }
 387
 388 /*
 389  * Send a message accompanied by fd(s) over a unix socket.
 390  *
 391  * Returns the size of data sent, or negative error value.
 392  */
 393 ssize_t ustcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 394 {
 395         struct msghdr msg;
 396         struct cmsghdr *cmptr;
 397         struct iovec iov[1];
 398         ssize_t ret = -1;
 399         unsigned int sizeof_fds = nb_fd * sizeof(int);
 400         char tmp[CMSG_SPACE(sizeof_fds)];
 401         char dummy = 0;
 402
 403         memset(&msg, 0, sizeof(msg));
 404         memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));
 405
 406         if (nb_fd > USTCOMM_MAX_SEND_FDS)
 407                 return -EINVAL;
 408
 409         msg.msg_control = (caddr_t)tmp;
 410         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 411
 412         cmptr = CMSG_FIRSTHDR(&msg);
 413         if (!cmptr)
 414                 return -EINVAL;
 415         cmptr->cmsg_level = SOL_SOCKET;
 416         cmptr->cmsg_type = SCM_RIGHTS;
 417         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 418         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 419         /* Sum of the length of all control messages in the buffer: */
 420         msg.msg_controllen = cmptr->cmsg_len;
 421
 422         iov[0].iov_base = &dummy;
 423         iov[0].iov_len = 1;
 424         msg.msg_iov = iov;
 425         msg.msg_iovlen = 1;
 426
 427         do {
 428                 ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
 429         } while (ret < 0 && errno == EINTR);
 430         if (ret < 0) {
 431                 /*
 432                  * We consider EPIPE and ECONNRESET as expected.
 433                  */
 434                 if (errno != EPIPE && errno != ECONNRESET) {
 435                         PERROR("sendmsg");
 436                 }
 437                 ret = -errno;
 438                 if (ret == -ECONNRESET)
 439                         ret = -EPIPE;
 440         }
 441         return ret;
 442 }
 443
 444 /*
 445  * Recv a message accompanied by fd(s) from a unix socket.
 446  *
 447  * Expect at most "nb_fd" file descriptors. Returns the number of fd
 448  * actually received in nb_fd.
 449  * Returns -EPIPE on orderly shutdown.
 450  */
 451 ssize_t ustcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 452 {
 453         struct iovec iov[1];
 454         ssize_t ret = 0;
 455         struct cmsghdr *cmsg;
 456         size_t sizeof_fds = nb_fd * sizeof(int);
 457         char recv_fd[CMSG_SPACE(sizeof_fds)];
 458         struct msghdr msg;
 459         char dummy;
 460         int i;
 461
 462         memset(&msg, 0, sizeof(msg));
 463
 464         /* Prepare to receive the structures */
 465         iov[0].iov_base = &dummy;
 466         iov[0].iov_len = 1;
 467         msg.msg_iov = iov;
 468         msg.msg_iovlen = 1;
 469         msg.msg_control = recv_fd;
 470         msg.msg_controllen = sizeof(recv_fd);
 471
 472         do {
 473                 ret = recvmsg(sock, &msg, 0);
 474         } while (ret < 0 && errno == EINTR);
 475         if (ret < 0) {
 476                 if (errno != EPIPE && errno != ECONNRESET) {
 477                         PERROR("recvmsg fds");
 478                 }
 479                 ret = -errno;
 480                 if (ret == -ECONNRESET)
 481                         ret = -EPIPE;
 482                 goto end;
 483         }
 484         if (ret == 0) {
 485                 /* orderly shutdown */
 486                 ret = -EPIPE;
 487                 goto end;
 488         }
 489         if (ret != 1) {
 490                 ERR("Error: Received %zd bytes, expected %d\n",
 491                                 ret, 1);
 492                 goto end;
 493         }
 494         if (msg.msg_flags & MSG_CTRUNC) {
 495                 ERR("Error: Control message truncated.\n");
 496                 ret = -1;
 497                 goto end;
 498         }
 499         cmsg = CMSG_FIRSTHDR(&msg);
 500         if (!cmsg) {
 501                 ERR("Error: Invalid control message header\n");
 502                 ret = -1;
 503                 goto end;
 504         }
 505         if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
 506                 ERR("Didn't received any fd\n");
 507                 ret = -1;
 508                 goto end;
 509         }
 510         if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
 511                 ERR("Error: Received %zu bytes of ancillary data, expected %zu\n",
 512                                 (size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
 513                 ret = -1;
 514                 goto end;
 515         }
 516
 517         memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
 518
 519         /* Set FD_CLOEXEC */
 520         for (i = 0; i < nb_fd; i++) {
 521                 ret = fcntl(fds[i], F_SETFD, FD_CLOEXEC);
 522                 if (ret < 0) {
 523                         PERROR("fcntl failed to set FD_CLOEXEC on fd %d",
 524                                fds[i]);
 525                 }
 526         }
 527
 528         ret = nb_fd;
 529 end:
 530         return ret;
 531 }
 532
 533 int ustcomm_send_app_msg(int sock, struct ustcomm_ust_msg *lum)
 534 {
 535         ssize_t len;
 536
 537         len = ustcomm_send_unix_sock(sock, lum, sizeof(*lum));
 538         switch (len) {
 539         case sizeof(*lum):
 540                 break;
 541         default:
 542                 if (len < 0) {
 543                         return len;
 544                 } else {
 545                         ERR("incorrect message size: %zd\n", len);
 546                         return -EINVAL;
 547                 }
 548         }
 549         return 0;
 550 }
 551
 552 int ustcomm_recv_app_reply(int sock, struct ustcomm_ust_reply *lur,
 553                           uint32_t expected_handle, uint32_t expected_cmd)
 554 {
 555         ssize_t len;
 556
 557         memset(lur, 0, sizeof(*lur));
 558         len = ustcomm_recv_unix_sock(sock, lur, sizeof(*lur));
 559         switch (len) {
 560         case 0: /* orderly shutdown */
 561                 return -EPIPE;
 562         case sizeof(*lur):
 563         {
 564                 int err = 0;
 565
 566                 if (lur->handle != expected_handle) {
 567                         ERR("Unexpected result message handle: "
 568                                 "expected: %u vs received: %u\n",
 569                                 expected_handle, lur->handle);
 570                         err = 1;
 571                 }
 572                 if (lur->cmd != expected_cmd) {
 573                         ERR("Unexpected result message command "
 574                                 "expected: %u vs received: %u\n",
 575                                 expected_cmd, lur->cmd);
 576                         err = 1;
 577                 }
 578                 if (err) {
 579                         return -EINVAL;
 580                 } else {
 581                         return lur->ret_code;
 582                 }
 583         }
 584         default:
 585                 if (len >= 0) {
 586                         ERR("incorrect message size: %zd\n", len);
 587                 }
 588                 return len;
 589         }
 590 }
 591
 592 int ustcomm_send_app_cmd(int sock,
 593                         struct ustcomm_ust_msg *lum,
 594                         struct ustcomm_ust_reply *lur)
 595 {
 596         int ret;
 597
 598         ret = ustcomm_send_app_msg(sock, lum);
 599         if (ret)
 600                 return ret;
 601         ret = ustcomm_recv_app_reply(sock, lur, lum->handle, lum->cmd);
 602         if (ret > 0)
 603                 return -EIO;
 604         return ret;
 605 }
 606
 607 /*
 608  * chan_data is allocated internally if this function returns the
 609  * expected var_len.
 610  */
 611 ssize_t ustcomm_recv_channel_from_sessiond(int sock,
 612                 void **_chan_data, uint64_t var_len,
 613                 int *_wakeup_fd)
 614 {
 615         void *chan_data;
 616         ssize_t len, nr_fd;
 617         int wakeup_fd, ret;
 618
 619         if (var_len > LTTNG_UST_CHANNEL_DATA_MAX_LEN) {
 620                 len = -EINVAL;
 621                 goto error_check;
 622         }
 623         /* Receive variable length data */
 624         chan_data = zmalloc(var_len);
 625         if (!chan_data) {
 626                 len = -ENOMEM;
 627                 goto error_alloc;
 628         }
 629         len = ustcomm_recv_unix_sock(sock, chan_data, var_len);
 630         if (len != var_len) {
 631                 goto error_recv;
 632         }
 633         /* recv wakeup fd */
 634         lttng_ust_lock_fd_tracker();
 635         nr_fd = ustcomm_recv_fds_unix_sock(sock, &wakeup_fd, 1);
 636         if (nr_fd <= 0) {
 637                 lttng_ust_unlock_fd_tracker();
 638                 if (nr_fd < 0) {
 639                         len = nr_fd;
 640                         goto error_recv;
 641                 } else {
 642                         len = -EIO;
 643                         goto error_recv;
 644                 }
 645         }
 646
 647         ret = lttng_ust_add_fd_to_tracker(wakeup_fd);
 648         if (ret < 0) {
 649                 ret = close(wakeup_fd);
 650                 if (ret) {
 651                         PERROR("close on wakeup_fd");
 652                 }
 653                 len = -EIO;
 654                 lttng_ust_unlock_fd_tracker();
 655                 goto error_recv;
 656         }
 657
 658         *_wakeup_fd = ret;
 659         lttng_ust_unlock_fd_tracker();
 660
 661         *_chan_data = chan_data;
 662         return len;
 663
 664 error_recv:
 665         free(chan_data);
 666 error_alloc:
 667 error_check:
 668         return len;
 669 }
 670
 671 int ustcomm_recv_stream_from_sessiond(int sock,
 672                 uint64_t *memory_map_size,
 673                 int *shm_fd, int *wakeup_fd)
 674 {
 675         ssize_t len;
 676         int ret;
 677         int fds[2];
 678
 679         /* recv shm fd and wakeup fd */
 680         lttng_ust_lock_fd_tracker();
 681         len = ustcomm_recv_fds_unix_sock(sock, fds, 2);
 682         if (len <= 0) {
 683                 lttng_ust_unlock_fd_tracker();
 684                 if (len < 0) {
 685                         ret = len;
 686                         goto error;
 687                 } else {
 688                         ret = -EIO;
 689                         goto error;
 690                 }
 691         }
 692
 693         ret = lttng_ust_add_fd_to_tracker(fds[0]);
 694         if (ret < 0) {
 695                 ret = close(fds[0]);
 696                 if (ret) {
 697                         PERROR("close on received shm_fd");
 698                 }
 699                 ret = -EIO;
 700                 lttng_ust_unlock_fd_tracker();
 701                 goto error;
 702         }
 703         *shm_fd = ret;
 704
 705         ret = lttng_ust_add_fd_to_tracker(fds[1]);
 706         if (ret < 0) {
 707                 ret = close(*shm_fd);
 708                 if (ret) {
 709                         PERROR("close on shm_fd");
 710                 }
 711                 *shm_fd = -1;
 712                 ret = close(fds[1]);
 713                 if (ret) {
 714                         PERROR("close on received wakeup_fd");
 715                 }
 716                 ret = -EIO;
 717                 lttng_ust_unlock_fd_tracker();
 718                 goto error;
 719         }
 720         *wakeup_fd = ret;
 721         lttng_ust_unlock_fd_tracker();
 722         return 0;
 723
 724 error:
 725         return ret;
 726 }
 727
 728 /*
 729  * Returns 0 on success, negative error value on error.
 730  */
 731 int ustcomm_send_reg_msg(int sock,
 732                 enum ustctl_socket_type type,
 733                 uint32_t bits_per_long,
 734                 uint32_t uint8_t_alignment,
 735                 uint32_t uint16_t_alignment,
 736                 uint32_t uint32_t_alignment,
 737                 uint32_t uint64_t_alignment,
 738                 uint32_t long_alignment)
 739 {
 740         ssize_t len;
 741         struct ustctl_reg_msg reg_msg;
 742
 743         reg_msg.magic = LTTNG_UST_COMM_MAGIC;
 744         reg_msg.major = LTTNG_UST_ABI_MAJOR_VERSION;
 745         reg_msg.minor = LTTNG_UST_ABI_MINOR_VERSION;
 746         reg_msg.pid = getpid();
 747         reg_msg.ppid = getppid();
 748         reg_msg.uid = getuid();
 749         reg_msg.gid = getgid();
 750         reg_msg.bits_per_long = bits_per_long;
 751         reg_msg.uint8_t_alignment = uint8_t_alignment;
 752         reg_msg.uint16_t_alignment = uint16_t_alignment;
 753         reg_msg.uint32_t_alignment = uint32_t_alignment;
 754         reg_msg.uint64_t_alignment = uint64_t_alignment;
 755         reg_msg.long_alignment = long_alignment;
 756         reg_msg.socket_type = type;
 757         lttng_pthread_getname_np(reg_msg.name, LTTNG_UST_ABI_PROCNAME_LEN);
 758         memset(reg_msg.padding, 0, sizeof(reg_msg.padding));
 759
 760         len = ustcomm_send_unix_sock(sock, &reg_msg, sizeof(reg_msg));
 761         if (len > 0 && len != sizeof(reg_msg))
 762                 return -EIO;
 763         if (len < 0)
 764                 return len;
 765         return 0;
 766 }
 767
 768 static
 769 ssize_t count_one_type(const struct lttng_type *lt)
 770 {
 771         switch (lt->atype) {
 772         case atype_integer:
 773         case atype_float:
 774         case atype_string:
 775         case atype_enum:
 776         case atype_array:
 777         case atype_sequence:
 778                 return 1;
 779         case atype_struct:
 780                 return count_fields_recursive(lt->u.legacy._struct.nr_fields,
 781                                 lt->u.legacy._struct.fields) + 1;
 782         case atype_enum_nestable:
 783                 return count_one_type(lt->u.enum_nestable.container_type) + 1;
 784         case atype_array_nestable:
 785                 return count_one_type(lt->u.array_nestable.elem_type) + 1;
 786         case atype_sequence_nestable:
 787                 return count_one_type(lt->u.sequence_nestable.elem_type) + 1;
 788         case atype_struct_nestable:
 789                 return count_fields_recursive(lt->u.struct_nestable.nr_fields,
 790                                 lt->u.struct_nestable.fields) + 1;
 791
 792         case atype_dynamic:
 793         {
 794                 const struct lttng_event_field *choices;
 795                 size_t nr_choices;
 796                 int ret;
 797
 798                 ret = lttng_ust_dynamic_type_choices(&nr_choices,
 799                         &choices);
 800                 if (ret)
 801                         return ret;
 802                 /*
 803                  * Two fields for enum, one field for variant, and
 804                  * one field per choice.
 805                  */
 806                 return count_fields_recursive(nr_choices, choices) + 3;
 807         }
 808
 809         default:
 810                 return -EINVAL;
 811         }
 812         return 0;
 813 }
 814
 815 static
 816 ssize_t count_fields_recursive(size_t nr_fields,
 817                 const struct lttng_event_field *lttng_fields)
 818 {
 819         int i;
 820         ssize_t ret, count = 0;
 821
 822         for (i = 0; i < nr_fields; i++) {
 823                 const struct lttng_event_field *lf;
 824
 825                 lf = &lttng_fields[i];
 826                 /* skip 'nowrite' fields */
 827                 if (lf->nowrite)
 828                         continue;
 829                 ret = count_one_type(&lf->type);
 830                 if (ret < 0)
 831                         return ret;     /* error */
 832                 count += ret;
 833         }
 834         return count;
 835 }
 836
 837 static
 838 ssize_t count_ctx_fields_recursive(size_t nr_fields,
 839                 const struct lttng_ctx_field *lttng_fields)
 840 {
 841         int i;
 842         ssize_t ret, count = 0;
 843
 844         for (i = 0; i < nr_fields; i++) {
 845                 const struct lttng_event_field *lf;
 846
 847                 lf = &lttng_fields[i].event_field;
 848                 /* skip 'nowrite' fields */
 849                 if (lf->nowrite)
 850                         continue;
 851                 ret = count_one_type(&lf->type);
 852                 if (ret < 0)
 853                         return ret;     /* error */
 854                 count += ret;
 855         }
 856         return count;
 857 }
 858
 859 static
 860 int serialize_string_encoding(int32_t *ue,
 861                 enum lttng_string_encodings le)
 862 {
 863         switch (le) {
 864         case lttng_encode_none:
 865                 *ue = ustctl_encode_none;
 866                 break;
 867         case lttng_encode_UTF8:
 868                 *ue = ustctl_encode_UTF8;
 869                 break;
 870         case lttng_encode_ASCII:
 871                 *ue = ustctl_encode_ASCII;
 872                 break;
 873         default:
 874                 return -EINVAL;
 875         }
 876         return 0;
 877 }
 878
 879 static
 880 int serialize_integer_type(struct ustctl_integer_type *uit,
 881                 const struct lttng_integer_type *lit)
 882 {
 883         int32_t encoding;
 884
 885         uit->size = lit->size;
 886         uit->signedness = lit->signedness;
 887         uit->reverse_byte_order = lit->reverse_byte_order;
 888         uit->base = lit->base;
 889         if (serialize_string_encoding(&encoding, lit->encoding))
 890                 return -EINVAL;
 891         uit->encoding = encoding;
 892         uit->alignment = lit->alignment;
 893         return 0;
 894 }
 895
 896 static
 897 int serialize_basic_type(struct lttng_session *session,
 898                 enum ustctl_abstract_types *uatype,
 899                 enum lttng_abstract_types atype,
 900                 union _ustctl_basic_type *ubt,
 901                 const union _lttng_basic_type *lbt)
 902 {
 903         switch (atype) {
 904         case atype_integer:
 905         {
 906                 if (serialize_integer_type(&ubt->integer, &lbt->integer))
 907                         return -EINVAL;
 908                 *uatype = ustctl_atype_integer;
 909                 break;
 910         }
 911         case atype_string:
 912         {
 913                 int32_t encoding;
 914
 915                 if (serialize_string_encoding(&encoding, lbt->string.encoding))
 916                         return -EINVAL;
 917                 ubt->string.encoding = encoding;
 918                 *uatype = ustctl_atype_string;
 919                 break;
 920         }
 921         case atype_float:
 922         {
 923                 struct ustctl_float_type *uft;
 924                 const struct lttng_float_type *lft;
 925
 926                 uft = &ubt->_float;
 927                 lft = &lbt->_float;
 928                 uft->exp_dig = lft->exp_dig;
 929                 uft->mant_dig = lft->mant_dig;
 930                 uft->alignment = lft->alignment;
 931                 uft->reverse_byte_order = lft->reverse_byte_order;
 932                 *uatype = ustctl_atype_float;
 933                 break;
 934         }
 935         case atype_enum:
 936         {
 937                 strncpy(ubt->enumeration.name, lbt->enumeration.desc->name,
 938                                 LTTNG_UST_SYM_NAME_LEN);
 939                 ubt->enumeration.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 940                 if (serialize_integer_type(&ubt->enumeration.container_type,
 941                                 &lbt->enumeration.container_type))
 942                         return -EINVAL;
 943                 if (session) {
 944                         const struct lttng_enum *_enum;
 945
 946                         _enum = lttng_ust_enum_get_from_desc(session, lbt->enumeration.desc);
 947                         if (!_enum)
 948                                 return -EINVAL;
 949                         ubt->enumeration.id = _enum->id;
 950                 } else {
 951                         ubt->enumeration.id = -1ULL;
 952                 }
 953                 *uatype = ustctl_atype_enum;
 954                 break;
 955         }
 956         case atype_array:
 957         case atype_array_nestable:
 958         case atype_sequence:
 959         case atype_sequence_nestable:
 960         case atype_enum_nestable:
 961         default:
 962                 return -EINVAL;
 963         }
 964         return 0;
 965 }
 966
 967 static
 968 int serialize_dynamic_type(struct lttng_session *session,
 969                 struct ustctl_field *fields, size_t *iter_output,
 970                 const char *field_name)
 971 {
 972         const struct lttng_event_field *choices;
 973         char tag_field_name[LTTNG_UST_SYM_NAME_LEN];
 974         const struct lttng_type *tag_type;
 975         const struct lttng_event_field *tag_field_generic;
 976         struct lttng_event_field tag_field = {
 977                 .name = tag_field_name,
 978                 .nowrite = 0,
 979         };
 980         struct ustctl_field *uf;
 981         size_t nr_choices, i;
 982         int ret;
 983
 984         tag_field_generic = lttng_ust_dynamic_type_tag_field();
 985         tag_type = &tag_field_generic->type;
 986
 987         /* Serialize enum field. */
 988         strncpy(tag_field_name, field_name, LTTNG_UST_SYM_NAME_LEN);
 989         tag_field_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 990         strncat(tag_field_name,
 991                 "_tag",
 992                 LTTNG_UST_SYM_NAME_LEN - strlen(tag_field_name) - 1);
 993         tag_field.type = *tag_type;
 994         ret = serialize_one_field(session, fields, iter_output,
 995                 &tag_field);
 996         if (ret)
 997                 return ret;
 998
 999         /* Serialize variant field. */
1000         uf = &fields[*iter_output];
1001         ret = lttng_ust_dynamic_type_choices(&nr_choices, &choices);
1002         if (ret)
1003                 return ret;
1004
1005         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1006         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1007         uf->type.atype = ustctl_atype_variant;
1008         uf->type.u.variant_nestable.nr_choices = nr_choices;
1009         strncpy(uf->type.u.variant_nestable.tag_name,
1010                 tag_field_name,
1011                 LTTNG_UST_SYM_NAME_LEN);
1012         uf->type.u.variant_nestable.tag_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1013         uf->type.u.variant_nestable.alignment = 0;
1014         (*iter_output)++;
1015
1016         /* Serialize choice fields after variant. */
1017         for (i = 0; i < nr_choices; i++) {
1018                 ret = serialize_one_field(session, fields,
1019                         iter_output, &choices[i]);
1020                 if (ret)
1021                         return ret;
1022         }
1023         return 0;
1024 }
1025
1026 static
1027 int serialize_one_type(struct lttng_session *session,
1028                 struct ustctl_field *fields, size_t *iter_output,
1029                 const char *field_name, const struct lttng_type *lt)
1030 {
1031         int ret;
1032
1033         /*
1034          * Serializing a type (rather than a field) generates a ustctl_field
1035          * entry with 0-length name.
1036          */
1037
1038         switch (lt->atype) {
1039         case atype_integer:
1040         case atype_float:
1041         case atype_string:
1042         case atype_enum:
1043         {
1044                 struct ustctl_field *uf = &fields[*iter_output];
1045                 struct ustctl_type *ut = &uf->type;
1046                 enum ustctl_abstract_types atype;
1047
1048                 if (field_name) {
1049                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1050                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1051                 } else {
1052                         uf->name[0] = '\0';
1053                 }
1054                 ret = serialize_basic_type(session, &atype, lt->atype,
1055                         &ut->u.legacy.basic, &lt->u.legacy.basic);
1056                 if (ret)
1057                         return ret;
1058                 ut->atype = atype;
1059                 (*iter_output)++;
1060                 break;
1061         }
1062         case atype_array:
1063         {
1064                 struct ustctl_field *uf = &fields[*iter_output];
1065                 struct ustctl_type *ut = &uf->type;
1066                 struct ustctl_basic_type *ubt;
1067                 const struct lttng_basic_type *lbt;
1068                 enum ustctl_abstract_types atype;
1069
1070                 if (field_name) {
1071                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1072                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1073                 } else {
1074                         uf->name[0] = '\0';
1075                 }
1076                 ut->atype = ustctl_atype_array;
1077                 ubt = &ut->u.legacy.array.elem_type;
1078                 lbt = &lt->u.legacy.array.elem_type;
1079                 ut->u.legacy.array.length = lt->u.legacy.array.length;
1080                 ret = serialize_basic_type(session, &atype, lbt->atype,
1081                         &ubt->u.basic, &lbt->u.basic);
1082                 if (ret)
1083                         return -EINVAL;
1084                 ubt->atype = atype;
1085                 (*iter_output)++;
1086                 break;
1087         }
1088         case atype_array_nestable:
1089         {
1090                 struct ustctl_field *uf = &fields[*iter_output];
1091                 struct ustctl_type *ut = &uf->type;
1092
1093                 if (field_name) {
1094                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1095                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1096                 } else {
1097                         uf->name[0] = '\0';
1098                 }
1099                 ut->atype = ustctl_atype_array_nestable;
1100                 ut->u.array_nestable.length = lt->u.array_nestable.length;
1101                 ut->u.array_nestable.alignment = lt->u.array_nestable.alignment;
1102                 (*iter_output)++;
1103
1104                 ret = serialize_one_type(session, fields, iter_output, NULL,
1105                                 lt->u.array_nestable.elem_type);
1106                 if (ret)
1107                         return -EINVAL;
1108                 break;
1109         }
1110         case atype_sequence:
1111         {
1112                 struct ustctl_field *uf = &fields[*iter_output];
1113                 struct ustctl_type *ut = &uf->type;
1114                 struct ustctl_basic_type *ubt;
1115                 const struct lttng_basic_type *lbt;
1116                 enum ustctl_abstract_types atype;
1117
1118                 if (field_name) {
1119                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1120                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1121                 } else {
1122                         uf->name[0] = '\0';
1123                 }
1124                 uf->type.atype = ustctl_atype_sequence;
1125                 ubt = &ut->u.legacy.sequence.length_type;
1126                 lbt = &lt->u.legacy.sequence.length_type;
1127                 ret = serialize_basic_type(session, &atype, lbt->atype,
1128                         &ubt->u.basic, &lbt->u.basic);
1129                 if (ret)
1130                         return -EINVAL;
1131                 ubt->atype = atype;
1132                 ubt = &ut->u.legacy.sequence.elem_type;
1133                 lbt = &lt->u.legacy.sequence.elem_type;
1134                 ret = serialize_basic_type(session, &atype, lbt->atype,
1135                         &ubt->u.basic, &lbt->u.basic);
1136                 if (ret)
1137                         return -EINVAL;
1138                 ubt->atype = atype;
1139                 (*iter_output)++;
1140                 break;
1141         }
1142         case atype_sequence_nestable:
1143         {
1144                 struct ustctl_field *uf = &fields[*iter_output];
1145                 struct ustctl_type *ut = &uf->type;
1146
1147                 if (field_name) {
1148                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1149                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1150                 } else {
1151                         uf->name[0] = '\0';
1152                 }
1153                 ut->atype = ustctl_atype_sequence_nestable;
1154                 strncpy(ut->u.sequence_nestable.length_name,
1155                         lt->u.sequence_nestable.length_name,
1156                         LTTNG_UST_SYM_NAME_LEN);
1157                 ut->u.sequence_nestable.length_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1158                 ut->u.sequence_nestable.alignment = lt->u.sequence_nestable.alignment;
1159                 (*iter_output)++;
1160
1161                 ret = serialize_one_type(session, fields, iter_output, NULL,
1162                                 lt->u.sequence_nestable.elem_type);
1163                 if (ret)
1164                         return -EINVAL;
1165                 break;
1166         }
1167         case atype_dynamic:
1168         {
1169                 ret = serialize_dynamic_type(session, fields, iter_output,
1170                                 field_name);
1171                 if (ret)
1172                         return -EINVAL;
1173                 break;
1174         }
1175         case atype_struct:
1176         {
1177                 struct ustctl_field *uf = &fields[*iter_output];
1178
1179                 if (field_name) {
1180                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1181                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1182                 } else {
1183                         uf->name[0] = '\0';
1184                 }
1185                 uf->type.atype = ustctl_atype_struct;
1186                 uf->type.u.legacy._struct.nr_fields = lt->u.legacy._struct.nr_fields;
1187                 (*iter_output)++;
1188
1189                 ret = serialize_fields(session, fields, iter_output,
1190                                 lt->u.legacy._struct.nr_fields,
1191                                 lt->u.legacy._struct.fields);
1192                 if (ret)
1193                         return -EINVAL;
1194                 break;
1195         }
1196         case atype_struct_nestable:
1197         {
1198                 struct ustctl_field *uf = &fields[*iter_output];
1199
1200                 if (field_name) {
1201                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1202                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1203                 } else {
1204                         uf->name[0] = '\0';
1205                 }
1206                 uf->type.atype = ustctl_atype_struct_nestable;
1207                 uf->type.u.struct_nestable.nr_fields = lt->u.struct_nestable.nr_fields;
1208                 uf->type.u.struct_nestable.alignment = lt->u.struct_nestable.alignment;
1209                 (*iter_output)++;
1210
1211                 ret = serialize_fields(session, fields, iter_output,
1212                                 lt->u.struct_nestable.nr_fields,
1213                                 lt->u.struct_nestable.fields);
1214                 if (ret)
1215                         return -EINVAL;
1216                 break;
1217         }
1218         case atype_enum_nestable:
1219         {
1220                 struct ustctl_field *uf = &fields[*iter_output];
1221                 struct ustctl_type *ut = &uf->type;
1222
1223                 if (field_name) {
1224                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1225                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1226                 } else {
1227                         uf->name[0] = '\0';
1228                 }
1229                 strncpy(ut->u.enum_nestable.name, lt->u.enum_nestable.desc->name,
1230                                 LTTNG_UST_SYM_NAME_LEN);
1231                 ut->u.enum_nestable.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1232                 ut->atype = ustctl_atype_enum_nestable;
1233                 (*iter_output)++;
1234
1235                 ret = serialize_one_type(session, fields, iter_output, NULL,
1236                                 lt->u.enum_nestable.container_type);
1237                 if (ret)
1238                         return -EINVAL;
1239                 if (session) {
1240                         const struct lttng_enum *_enum;
1241
1242                         _enum = lttng_ust_enum_get_from_desc(session, lt->u.enum_nestable.desc);
1243                         if (!_enum)
1244                                 return -EINVAL;
1245                         ut->u.enum_nestable.id = _enum->id;
1246                 } else {
1247                         ut->u.enum_nestable.id = -1ULL;
1248                 }
1249                 break;
1250         }
1251         default:
1252                 return -EINVAL;
1253         }
1254         return 0;
1255 }
1256
1257 static
1258 int serialize_one_field(struct lttng_session *session,
1259                 struct ustctl_field *fields, size_t *iter_output,
1260                 const struct lttng_event_field *lf)
1261 {
1262         /* skip 'nowrite' fields */
1263         if (lf->nowrite)
1264                 return 0;
1265
1266         return serialize_one_type(session, fields, iter_output, lf->name, &lf->type);
1267 }
1268
1269 static
1270 int serialize_fields(struct lttng_session *session,
1271                 struct ustctl_field *ustctl_fields,
1272                 size_t *iter_output, size_t nr_lttng_fields,
1273                 const struct lttng_event_field *lttng_fields)
1274 {
1275         int ret;
1276         size_t i;
1277
1278         for (i = 0; i < nr_lttng_fields; i++) {
1279                 ret = serialize_one_field(session, ustctl_fields,
1280                                 iter_output, &lttng_fields[i]);
1281                 if (ret)
1282                         return ret;
1283         }
1284         return 0;
1285 }
1286
1287 static
1288 int alloc_serialize_fields(struct lttng_session *session,
1289                 size_t *_nr_write_fields,
1290                 struct ustctl_field **ustctl_fields,
1291                 size_t nr_fields,
1292                 const struct lttng_event_field *lttng_fields)
1293 {
1294         struct ustctl_field *fields;
1295         int ret;
1296         size_t iter_output = 0;
1297         ssize_t nr_write_fields;
1298
1299         nr_write_fields = count_fields_recursive(nr_fields, lttng_fields);
1300         if (nr_write_fields < 0) {
1301                 return (int) nr_write_fields;
1302         }
1303
1304         fields = zmalloc(nr_write_fields * sizeof(*fields));
1305         if (!fields)
1306                 return -ENOMEM;
1307
1308         ret = serialize_fields(session, fields, &iter_output, nr_fields,
1309                         lttng_fields);
1310         if (ret)
1311                 goto error_type;
1312
1313         *_nr_write_fields = nr_write_fields;
1314         *ustctl_fields = fields;
1315         return 0;
1316
1317 error_type:
1318         free(fields);
1319         return ret;
1320 }
1321
1322 static
1323 int serialize_entries(struct ustctl_enum_entry **_entries,
1324                 size_t nr_entries,
1325                 const struct lttng_enum_entry *lttng_entries)
1326 {
1327         struct ustctl_enum_entry *entries;
1328         int i;
1329
1330         /* Serialize the entries */
1331         entries = zmalloc(nr_entries * sizeof(*entries));
1332         if (!entries)
1333                 return -ENOMEM;
1334         for (i = 0; i < nr_entries; i++) {
1335                 struct ustctl_enum_entry *uentry;
1336                 const struct lttng_enum_entry *lentry;
1337
1338                 uentry = &entries[i];
1339                 lentry = &lttng_entries[i];
1340
1341                 uentry->start.value = lentry->start.value;
1342                 uentry->start.signedness = lentry->start.signedness;
1343                 uentry->end.value = lentry->end.value;
1344                 uentry->end.signedness = lentry->end.signedness;
1345                 strncpy(uentry->string, lentry->string, LTTNG_UST_SYM_NAME_LEN);
1346                 uentry->string[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1347
1348                 if (lentry->u.extra.options & LTTNG_ENUM_ENTRY_OPTION_IS_AUTO) {
1349                         uentry->u.extra.options |=
1350                                 USTCTL_UST_ENUM_ENTRY_OPTION_IS_AUTO;
1351                 }
1352         }
1353         *_entries = entries;
1354         return 0;
1355 }
1356
1357 static
1358 int serialize_ctx_fields(struct lttng_session *session,
1359                 size_t *_nr_write_fields,
1360                 struct ustctl_field **ustctl_fields,
1361                 size_t nr_fields,
1362                 const struct lttng_ctx_field *lttng_fields)
1363 {
1364         struct ustctl_field *fields;
1365         int ret;
1366         size_t i, iter_output = 0;
1367         ssize_t nr_write_fields;
1368
1369         nr_write_fields = count_ctx_fields_recursive(nr_fields,
1370                         lttng_fields);
1371         if (nr_write_fields < 0) {
1372                 return (int) nr_write_fields;
1373         }
1374
1375         fields = zmalloc(nr_write_fields * sizeof(*fields));
1376         if (!fields)
1377                 return -ENOMEM;
1378
1379         for (i = 0; i < nr_fields; i++) {
1380                 ret = serialize_one_field(session, fields, &iter_output,
1381                                 &lttng_fields[i].event_field);
1382                 if (ret)
1383                         goto error_type;
1384         }
1385
1386         *_nr_write_fields = nr_write_fields;
1387         *ustctl_fields = fields;
1388         return 0;
1389
1390 error_type:
1391         free(fields);
1392         return ret;
1393 }
1394
1395 /*
1396  * Returns 0 on success, negative error value on error.
1397  */
1398 int ustcomm_register_event(int sock,
1399         struct lttng_session *session,
1400         int session_objd,               /* session descriptor */
1401         int channel_objd,               /* channel descriptor */
1402         const char *event_name,         /* event name (input) */
1403         int loglevel,
1404         const char *signature,          /* event signature (input) */
1405         size_t nr_fields,               /* fields */
1406         const struct lttng_event_field *lttng_fields,
1407         const char *model_emf_uri,
1408         uint32_t *id)                   /* event id (output) */
1409 {
1410         ssize_t len;
1411         struct {
1412                 struct ustcomm_notify_hdr header;
1413                 struct ustcomm_notify_event_msg m;
1414         } msg;
1415         struct {
1416                 struct ustcomm_notify_hdr header;
1417                 struct ustcomm_notify_event_reply r;
1418         } reply;
1419         size_t signature_len, fields_len, model_emf_uri_len;
1420         struct ustctl_field *fields = NULL;
1421         size_t nr_write_fields = 0;
1422         int ret;
1423
1424         memset(&msg, 0, sizeof(msg));
1425         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
1426         msg.m.session_objd = session_objd;
1427         msg.m.channel_objd = channel_objd;
1428         strncpy(msg.m.event_name, event_name, LTTNG_UST_SYM_NAME_LEN);
1429         msg.m.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1430         msg.m.loglevel = loglevel;
1431         signature_len = strlen(signature) + 1;
1432         msg.m.signature_len = signature_len;
1433
1434         /* Calculate fields len, serialize fields. */
1435         if (nr_fields > 0) {
1436                 ret = alloc_serialize_fields(session, &nr_write_fields, &fields,
1437                                 nr_fields, lttng_fields);
1438                 if (ret)
1439                         return ret;
1440         }
1441
1442         fields_len = sizeof(*fields) * nr_write_fields;
1443         msg.m.fields_len = fields_len;
1444         if (model_emf_uri) {
1445                 model_emf_uri_len = strlen(model_emf_uri) + 1;
1446         } else {
1447                 model_emf_uri_len = 0;
1448         }
1449         msg.m.model_emf_uri_len = model_emf_uri_len;
1450
1451         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1452         if (len > 0 && len != sizeof(msg)) {
1453                 ret = -EIO;
1454                 goto error_fields;
1455         }
1456         if (len < 0) {
1457                 ret = len;
1458                 goto error_fields;
1459         }
1460
1461         /* send signature */
1462         len = ustcomm_send_unix_sock(sock, signature, signature_len);
1463         if (len > 0 && len != signature_len) {
1464                 ret = -EIO;
1465                 goto error_fields;
1466         }
1467         if (len < 0) {
1468                 ret = len;
1469                 goto error_fields;
1470         }
1471
1472         /* send fields */
1473         if (fields_len > 0) {
1474                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1475                 if (len > 0 && len != fields_len) {
1476                         ret = -EIO;
1477                         goto error_fields;
1478                 }
1479                 if (len < 0) {
1480                         ret = len;
1481                         goto error_fields;
1482                 }
1483         }
1484         free(fields);
1485
1486         if (model_emf_uri_len) {
1487                 /* send model_emf_uri */
1488                 len = ustcomm_send_unix_sock(sock, model_emf_uri,
1489                                 model_emf_uri_len);
1490                 if (len > 0 && len != model_emf_uri_len) {
1491                         return -EIO;
1492                 }
1493                 if (len < 0) {
1494                         return len;
1495                 }
1496         }
1497
1498         /* receive reply */
1499         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1500         switch (len) {
1501         case 0: /* orderly shutdown */
1502                 return -EPIPE;
1503         case sizeof(reply):
1504                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1505                         ERR("Unexpected result message command "
1506                                 "expected: %u vs received: %u\n",
1507                                 msg.header.notify_cmd, reply.header.notify_cmd);
1508                         return -EINVAL;
1509                 }
1510                 if (reply.r.ret_code > 0)
1511                         return -EINVAL;
1512                 if (reply.r.ret_code < 0)
1513                         return reply.r.ret_code;
1514                 *id = reply.r.event_id;
1515                 DBG("Sent register event notification for name \"%s\": ret_code %d, event_id %u\n",
1516                         event_name, reply.r.ret_code, reply.r.event_id);
1517                 return 0;
1518         default:
1519                 if (len < 0) {
1520                         /* Transport level error */
1521                         if (errno == EPIPE || errno == ECONNRESET)
1522                                 len = -errno;
1523                         return len;
1524                 } else {
1525                         ERR("incorrect message size: %zd\n", len);
1526                         return len;
1527                 }
1528         }
1529         /* Unreached. */
1530
1531         /* Error path only. */
1532 error_fields:
1533         free(fields);
1534         return ret;
1535 }
1536
1537 /*
1538  * Returns 0 on success, negative error value on error.
1539  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1540  */
1541 int ustcomm_register_enum(int sock,
1542         int session_objd,               /* session descriptor */
1543         const char *enum_name,          /* enum name (input) */
1544         size_t nr_entries,              /* entries */
1545         const struct lttng_enum_entry *lttng_entries,
1546         uint64_t *id)
1547 {
1548         ssize_t len;
1549         struct {
1550                 struct ustcomm_notify_hdr header;
1551                 struct ustcomm_notify_enum_msg m;
1552         } msg;
1553         struct {
1554                 struct ustcomm_notify_hdr header;
1555                 struct ustcomm_notify_enum_reply r;
1556         } reply;
1557         size_t entries_len;
1558         struct ustctl_enum_entry *entries = NULL;
1559         int ret;
1560
1561         memset(&msg, 0, sizeof(msg));
1562         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_ENUM;
1563         msg.m.session_objd = session_objd;
1564         strncpy(msg.m.enum_name, enum_name, LTTNG_UST_SYM_NAME_LEN);
1565         msg.m.enum_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1566
1567         /* Calculate entries len, serialize entries. */
1568         if (nr_entries > 0) {
1569                 ret = serialize_entries(&entries,
1570                                 nr_entries, lttng_entries);
1571                 if (ret)
1572                         return ret;
1573         }
1574
1575         entries_len = sizeof(*entries) * nr_entries;
1576         msg.m.entries_len = entries_len;
1577
1578         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1579         if (len > 0 && len != sizeof(msg)) {
1580                 ret = -EIO;
1581                 goto error_entries;
1582         }
1583         if (len < 0) {
1584                 ret = len;
1585                 goto error_entries;
1586         }
1587
1588         /* send entries */
1589         if (entries_len > 0) {
1590                 len = ustcomm_send_unix_sock(sock, entries, entries_len);
1591                 if (len > 0 && len != entries_len) {
1592                         ret = -EIO;
1593                         goto error_entries;
1594                 }
1595                 if (len < 0) {
1596                         ret = len;
1597                         goto error_entries;
1598                 }
1599         }
1600         free(entries);
1601         entries = NULL;
1602
1603         /* receive reply */
1604         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1605         switch (len) {
1606         case 0: /* orderly shutdown */
1607                 return -EPIPE;
1608         case sizeof(reply):
1609                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1610                         ERR("Unexpected result message command "
1611                                 "expected: %u vs received: %u\n",
1612                                 msg.header.notify_cmd, reply.header.notify_cmd);
1613                         return -EINVAL;
1614                 }
1615                 if (reply.r.ret_code > 0)
1616                         return -EINVAL;
1617                 if (reply.r.ret_code < 0)
1618                         return reply.r.ret_code;
1619                 *id = reply.r.enum_id;
1620                 DBG("Sent register enum notification for name \"%s\": ret_code %d\n",
1621                         enum_name, reply.r.ret_code);
1622                 return 0;
1623         default:
1624                 if (len < 0) {
1625                         /* Transport level error */
1626                         if (errno == EPIPE || errno == ECONNRESET)
1627                                 len = -errno;
1628                         return len;
1629                 } else {
1630                         ERR("incorrect message size: %zd\n", len);
1631                         return len;
1632                 }
1633         }
1634         return ret;
1635
1636 error_entries:
1637         free(entries);
1638         return ret;
1639 }
1640
1641 /*
1642  * Returns 0 on success, negative error value on error.
1643  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1644  */
1645 int ustcomm_register_channel(int sock,
1646         struct lttng_session *session,
1647         int session_objd,               /* session descriptor */
1648         int channel_objd,               /* channel descriptor */
1649         size_t nr_ctx_fields,
1650         const struct lttng_ctx_field *ctx_fields,
1651         uint32_t *chan_id,              /* channel id (output) */
1652         int *header_type)               /* header type (output) */
1653 {
1654         ssize_t len;
1655         struct {
1656                 struct ustcomm_notify_hdr header;
1657                 struct ustcomm_notify_channel_msg m;
1658         } msg;
1659         struct {
1660                 struct ustcomm_notify_hdr header;
1661                 struct ustcomm_notify_channel_reply r;
1662         } reply;
1663         size_t fields_len;
1664         struct ustctl_field *fields = NULL;
1665         int ret;
1666         size_t nr_write_fields = 0;
1667
1668         memset(&msg, 0, sizeof(msg));
1669         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1670         msg.m.session_objd = session_objd;
1671         msg.m.channel_objd = channel_objd;
1672
1673         /* Calculate fields len, serialize fields. */
1674         if (nr_ctx_fields > 0) {
1675                 ret = serialize_ctx_fields(session, &nr_write_fields, &fields,
1676                                 nr_ctx_fields, ctx_fields);
1677                 if (ret)
1678                         return ret;
1679         }
1680
1681         fields_len = sizeof(*fields) * nr_write_fields;
1682         msg.m.ctx_fields_len = fields_len;
1683         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1684         if (len > 0 && len != sizeof(msg)) {
1685                 free(fields);
1686                 return -EIO;
1687         }
1688         if (len < 0) {
1689                 free(fields);
1690                 return len;
1691         }
1692
1693         /* send fields */
1694         if (fields_len > 0) {
1695                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1696                 free(fields);
1697                 if (len > 0 && len != fields_len) {
1698                         return -EIO;
1699                 }
1700                 if (len < 0) {
1701                         return len;
1702                 }
1703         } else {
1704                 free(fields);
1705         }
1706
1707         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1708         switch (len) {
1709         case 0: /* orderly shutdown */
1710                 return -EPIPE;
1711         case sizeof(reply):
1712                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1713                         ERR("Unexpected result message command "
1714                                 "expected: %u vs received: %u\n",
1715                                 msg.header.notify_cmd, reply.header.notify_cmd);
1716                         return -EINVAL;
1717                 }
1718                 if (reply.r.ret_code > 0)
1719                         return -EINVAL;
1720                 if (reply.r.ret_code < 0)
1721                         return reply.r.ret_code;
1722                 *chan_id = reply.r.chan_id;
1723                 switch (reply.r.header_type) {
1724                 case 1:
1725                 case 2:
1726                         *header_type = reply.r.header_type;
1727                         break;
1728                 default:
1729                         ERR("Unexpected channel header type %u\n",
1730                                 reply.r.header_type);
1731                         return -EINVAL;
1732                 }
1733                 DBG("Sent register channel notification: chan_id %d, header_type %d\n",
1734                         reply.r.chan_id, reply.r.header_type);
1735                 return 0;
1736         default:
1737                 if (len < 0) {
1738                         /* Transport level error */
1739                         if (errno == EPIPE || errno == ECONNRESET)
1740                                 len = -errno;
1741                         return len;
1742                 } else {
1743                         ERR("incorrect message size: %zd\n", len);
1744                         return len;
1745                 }
1746         }
1747 }
1748
1749 /*
1750  * Set socket reciving timeout.
1751  */
1752 int ustcomm_setsockopt_rcv_timeout(int sock, unsigned int msec)
1753 {
1754         int ret;
1755         struct timeval tv;
1756
1757         tv.tv_sec = msec / 1000;
1758         tv.tv_usec = (msec * 1000 % 1000000);
1759
1760         ret = setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
1761         if (ret < 0) {
1762                 PERROR("setsockopt SO_RCVTIMEO");
1763                 ret = -errno;
1764         }
1765
1766         return ret;
1767 }
1768
1769 /*
1770  * Set socket sending timeout.
1771  */
1772 int ustcomm_setsockopt_snd_timeout(int sock, unsigned int msec)
1773 {
1774         int ret;
1775         struct timeval tv;
1776
1777         tv.tv_sec = msec / 1000;
1778         tv.tv_usec = (msec * 1000) % 1000000;
1779
1780         ret = setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
1781         if (ret < 0) {
1782                 PERROR("setsockopt SO_SNDTIMEO");
1783                 ret = -errno;
1784         }
1785
1786         return ret;
1787 }