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 ssize_t ustcomm_recv_event_notifier_notif_fd_from_sessiond(int sock,
 672                 int *_event_notifier_notif_fd)
 673 {
 674         ssize_t nr_fd;
 675         int event_notifier_notif_fd, ret;
 676
 677         /* Receive event_notifier notification fd */
 678         lttng_ust_lock_fd_tracker();
 679         nr_fd = ustcomm_recv_fds_unix_sock(sock, &event_notifier_notif_fd, 1);
 680         if (nr_fd <= 0) {
 681                 lttng_ust_unlock_fd_tracker();
 682                 if (nr_fd < 0) {
 683                         ret = nr_fd;
 684                         goto error;
 685                 } else {
 686                         ret = -EIO;
 687                         goto error;
 688                 }
 689         }
 690
 691         ret = lttng_ust_add_fd_to_tracker(event_notifier_notif_fd);
 692         if (ret < 0) {
 693                 ret = close(event_notifier_notif_fd);
 694                 if (ret) {
 695                         PERROR("close on event_notifier notif fd");
 696                 }
 697                 ret = -EIO;
 698                 lttng_ust_unlock_fd_tracker();
 699                 goto error;
 700         }
 701
 702         *_event_notifier_notif_fd = ret;
 703         lttng_ust_unlock_fd_tracker();
 704
 705         ret = nr_fd;
 706
 707 error:
 708         return ret;
 709 }
 710
 711 int ustcomm_recv_stream_from_sessiond(int sock,
 712                 uint64_t *memory_map_size,
 713                 int *shm_fd, int *wakeup_fd)
 714 {
 715         ssize_t len;
 716         int ret;
 717         int fds[2];
 718
 719         /* recv shm fd and wakeup fd */
 720         lttng_ust_lock_fd_tracker();
 721         len = ustcomm_recv_fds_unix_sock(sock, fds, 2);
 722         if (len <= 0) {
 723                 lttng_ust_unlock_fd_tracker();
 724                 if (len < 0) {
 725                         ret = len;
 726                         goto error;
 727                 } else {
 728                         ret = -EIO;
 729                         goto error;
 730                 }
 731         }
 732
 733         ret = lttng_ust_add_fd_to_tracker(fds[0]);
 734         if (ret < 0) {
 735                 ret = close(fds[0]);
 736                 if (ret) {
 737                         PERROR("close on received shm_fd");
 738                 }
 739                 ret = -EIO;
 740                 lttng_ust_unlock_fd_tracker();
 741                 goto error;
 742         }
 743         *shm_fd = ret;
 744
 745         ret = lttng_ust_add_fd_to_tracker(fds[1]);
 746         if (ret < 0) {
 747                 ret = close(*shm_fd);
 748                 if (ret) {
 749                         PERROR("close on shm_fd");
 750                 }
 751                 *shm_fd = -1;
 752                 ret = close(fds[1]);
 753                 if (ret) {
 754                         PERROR("close on received wakeup_fd");
 755                 }
 756                 ret = -EIO;
 757                 lttng_ust_unlock_fd_tracker();
 758                 goto error;
 759         }
 760         *wakeup_fd = ret;
 761         lttng_ust_unlock_fd_tracker();
 762         return 0;
 763
 764 error:
 765         return ret;
 766 }
 767
 768 /*
 769  * Returns 0 on success, negative error value on error.
 770  */
 771 int ustcomm_send_reg_msg(int sock,
 772                 enum ustctl_socket_type type,
 773                 uint32_t bits_per_long,
 774                 uint32_t uint8_t_alignment,
 775                 uint32_t uint16_t_alignment,
 776                 uint32_t uint32_t_alignment,
 777                 uint32_t uint64_t_alignment,
 778                 uint32_t long_alignment)
 779 {
 780         ssize_t len;
 781         struct ustctl_reg_msg reg_msg;
 782
 783         reg_msg.magic = LTTNG_UST_COMM_MAGIC;
 784         reg_msg.major = LTTNG_UST_ABI_MAJOR_VERSION;
 785         reg_msg.minor = LTTNG_UST_ABI_MINOR_VERSION;
 786         reg_msg.pid = getpid();
 787         reg_msg.ppid = getppid();
 788         reg_msg.uid = getuid();
 789         reg_msg.gid = getgid();
 790         reg_msg.bits_per_long = bits_per_long;
 791         reg_msg.uint8_t_alignment = uint8_t_alignment;
 792         reg_msg.uint16_t_alignment = uint16_t_alignment;
 793         reg_msg.uint32_t_alignment = uint32_t_alignment;
 794         reg_msg.uint64_t_alignment = uint64_t_alignment;
 795         reg_msg.long_alignment = long_alignment;
 796         reg_msg.socket_type = type;
 797         lttng_pthread_getname_np(reg_msg.name, LTTNG_UST_ABI_PROCNAME_LEN);
 798         memset(reg_msg.padding, 0, sizeof(reg_msg.padding));
 799
 800         len = ustcomm_send_unix_sock(sock, &reg_msg, sizeof(reg_msg));
 801         if (len > 0 && len != sizeof(reg_msg))
 802                 return -EIO;
 803         if (len < 0)
 804                 return len;
 805         return 0;
 806 }
 807
 808 static
 809 ssize_t count_one_type(const struct lttng_type *lt)
 810 {
 811         switch (lt->atype) {
 812         case atype_integer:
 813         case atype_float:
 814         case atype_string:
 815         case atype_enum:
 816         case atype_array:
 817         case atype_sequence:
 818                 return 1;
 819         case atype_struct:
 820                 return count_fields_recursive(lt->u.legacy._struct.nr_fields,
 821                                 lt->u.legacy._struct.fields) + 1;
 822         case atype_enum_nestable:
 823                 return count_one_type(lt->u.enum_nestable.container_type) + 1;
 824         case atype_array_nestable:
 825                 return count_one_type(lt->u.array_nestable.elem_type) + 1;
 826         case atype_sequence_nestable:
 827                 return count_one_type(lt->u.sequence_nestable.elem_type) + 1;
 828         case atype_struct_nestable:
 829                 return count_fields_recursive(lt->u.struct_nestable.nr_fields,
 830                                 lt->u.struct_nestable.fields) + 1;
 831
 832         case atype_dynamic:
 833         {
 834                 const struct lttng_event_field *choices;
 835                 size_t nr_choices;
 836                 int ret;
 837
 838                 ret = lttng_ust_dynamic_type_choices(&nr_choices,
 839                         &choices);
 840                 if (ret)
 841                         return ret;
 842                 /*
 843                  * Two fields for enum, one field for variant, and
 844                  * one field per choice.
 845                  */
 846                 return count_fields_recursive(nr_choices, choices) + 3;
 847         }
 848
 849         default:
 850                 return -EINVAL;
 851         }
 852         return 0;
 853 }
 854
 855 static
 856 ssize_t count_fields_recursive(size_t nr_fields,
 857                 const struct lttng_event_field *lttng_fields)
 858 {
 859         int i;
 860         ssize_t ret, count = 0;
 861
 862         for (i = 0; i < nr_fields; i++) {
 863                 const struct lttng_event_field *lf;
 864
 865                 lf = &lttng_fields[i];
 866                 /* skip 'nowrite' fields */
 867                 if (lf->nowrite)
 868                         continue;
 869                 ret = count_one_type(&lf->type);
 870                 if (ret < 0)
 871                         return ret;     /* error */
 872                 count += ret;
 873         }
 874         return count;
 875 }
 876
 877 static
 878 ssize_t count_ctx_fields_recursive(size_t nr_fields,
 879                 const struct lttng_ctx_field *lttng_fields)
 880 {
 881         int i;
 882         ssize_t ret, count = 0;
 883
 884         for (i = 0; i < nr_fields; i++) {
 885                 const struct lttng_event_field *lf;
 886
 887                 lf = &lttng_fields[i].event_field;
 888                 /* skip 'nowrite' fields */
 889                 if (lf->nowrite)
 890                         continue;
 891                 ret = count_one_type(&lf->type);
 892                 if (ret < 0)
 893                         return ret;     /* error */
 894                 count += ret;
 895         }
 896         return count;
 897 }
 898
 899 static
 900 int serialize_string_encoding(int32_t *ue,
 901                 enum lttng_string_encodings le)
 902 {
 903         switch (le) {
 904         case lttng_encode_none:
 905                 *ue = ustctl_encode_none;
 906                 break;
 907         case lttng_encode_UTF8:
 908                 *ue = ustctl_encode_UTF8;
 909                 break;
 910         case lttng_encode_ASCII:
 911                 *ue = ustctl_encode_ASCII;
 912                 break;
 913         default:
 914                 return -EINVAL;
 915         }
 916         return 0;
 917 }
 918
 919 static
 920 int serialize_integer_type(struct ustctl_integer_type *uit,
 921                 const struct lttng_integer_type *lit)
 922 {
 923         int32_t encoding;
 924
 925         uit->size = lit->size;
 926         uit->signedness = lit->signedness;
 927         uit->reverse_byte_order = lit->reverse_byte_order;
 928         uit->base = lit->base;
 929         if (serialize_string_encoding(&encoding, lit->encoding))
 930                 return -EINVAL;
 931         uit->encoding = encoding;
 932         uit->alignment = lit->alignment;
 933         return 0;
 934 }
 935
 936 static
 937 int serialize_basic_type(struct lttng_session *session,
 938                 enum ustctl_abstract_types *uatype,
 939                 enum lttng_abstract_types atype,
 940                 union _ustctl_basic_type *ubt,
 941                 const union _lttng_basic_type *lbt)
 942 {
 943         switch (atype) {
 944         case atype_integer:
 945         {
 946                 if (serialize_integer_type(&ubt->integer, &lbt->integer))
 947                         return -EINVAL;
 948                 *uatype = ustctl_atype_integer;
 949                 break;
 950         }
 951         case atype_string:
 952         {
 953                 int32_t encoding;
 954
 955                 if (serialize_string_encoding(&encoding, lbt->string.encoding))
 956                         return -EINVAL;
 957                 ubt->string.encoding = encoding;
 958                 *uatype = ustctl_atype_string;
 959                 break;
 960         }
 961         case atype_float:
 962         {
 963                 struct ustctl_float_type *uft;
 964                 const struct lttng_float_type *lft;
 965
 966                 uft = &ubt->_float;
 967                 lft = &lbt->_float;
 968                 uft->exp_dig = lft->exp_dig;
 969                 uft->mant_dig = lft->mant_dig;
 970                 uft->alignment = lft->alignment;
 971                 uft->reverse_byte_order = lft->reverse_byte_order;
 972                 *uatype = ustctl_atype_float;
 973                 break;
 974         }
 975         case atype_enum:
 976         {
 977                 strncpy(ubt->enumeration.name, lbt->enumeration.desc->name,
 978                                 LTTNG_UST_SYM_NAME_LEN);
 979                 ubt->enumeration.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 980                 if (serialize_integer_type(&ubt->enumeration.container_type,
 981                                 &lbt->enumeration.container_type))
 982                         return -EINVAL;
 983                 if (session) {
 984                         const struct lttng_enum *_enum;
 985
 986                         _enum = lttng_ust_enum_get_from_desc(session, lbt->enumeration.desc);
 987                         if (!_enum)
 988                                 return -EINVAL;
 989                         ubt->enumeration.id = _enum->id;
 990                 } else {
 991                         ubt->enumeration.id = -1ULL;
 992                 }
 993                 *uatype = ustctl_atype_enum;
 994                 break;
 995         }
 996         case atype_array:
 997         case atype_array_nestable:
 998         case atype_sequence:
 999         case atype_sequence_nestable:
1000         case atype_enum_nestable:
1001         default:
1002                 return -EINVAL;
1003         }
1004         return 0;
1005 }
1006
1007 static
1008 int serialize_dynamic_type(struct lttng_session *session,
1009                 struct ustctl_field *fields, size_t *iter_output,
1010                 const char *field_name)
1011 {
1012         const struct lttng_event_field *choices;
1013         char tag_field_name[LTTNG_UST_SYM_NAME_LEN];
1014         const struct lttng_type *tag_type;
1015         const struct lttng_event_field *tag_field_generic;
1016         struct lttng_event_field tag_field = {
1017                 .name = tag_field_name,
1018                 .nowrite = 0,
1019         };
1020         struct ustctl_field *uf;
1021         size_t nr_choices, i;
1022         int ret;
1023
1024         tag_field_generic = lttng_ust_dynamic_type_tag_field();
1025         tag_type = &tag_field_generic->type;
1026
1027         /* Serialize enum field. */
1028         strncpy(tag_field_name, field_name, LTTNG_UST_SYM_NAME_LEN);
1029         tag_field_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1030         strncat(tag_field_name,
1031                 "_tag",
1032                 LTTNG_UST_SYM_NAME_LEN - strlen(tag_field_name) - 1);
1033         tag_field.type = *tag_type;
1034         ret = serialize_one_field(session, fields, iter_output,
1035                 &tag_field);
1036         if (ret)
1037                 return ret;
1038
1039         /* Serialize variant field. */
1040         uf = &fields[*iter_output];
1041         ret = lttng_ust_dynamic_type_choices(&nr_choices, &choices);
1042         if (ret)
1043                 return ret;
1044
1045         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1046         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1047         uf->type.atype = ustctl_atype_variant;
1048         uf->type.u.variant_nestable.nr_choices = nr_choices;
1049         strncpy(uf->type.u.variant_nestable.tag_name,
1050                 tag_field_name,
1051                 LTTNG_UST_SYM_NAME_LEN);
1052         uf->type.u.variant_nestable.tag_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1053         uf->type.u.variant_nestable.alignment = 0;
1054         (*iter_output)++;
1055
1056         /* Serialize choice fields after variant. */
1057         for (i = 0; i < nr_choices; i++) {
1058                 ret = serialize_one_field(session, fields,
1059                         iter_output, &choices[i]);
1060                 if (ret)
1061                         return ret;
1062         }
1063         return 0;
1064 }
1065
1066 static
1067 int serialize_one_type(struct lttng_session *session,
1068                 struct ustctl_field *fields, size_t *iter_output,
1069                 const char *field_name, const struct lttng_type *lt)
1070 {
1071         int ret;
1072
1073         /*
1074          * Serializing a type (rather than a field) generates a ustctl_field
1075          * entry with 0-length name.
1076          */
1077
1078         switch (lt->atype) {
1079         case atype_integer:
1080         case atype_float:
1081         case atype_string:
1082         case atype_enum:
1083         {
1084                 struct ustctl_field *uf = &fields[*iter_output];
1085                 struct ustctl_type *ut = &uf->type;
1086                 enum ustctl_abstract_types atype;
1087
1088                 if (field_name) {
1089                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1090                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1091                 } else {
1092                         uf->name[0] = '\0';
1093                 }
1094                 ret = serialize_basic_type(session, &atype, lt->atype,
1095                         &ut->u.legacy.basic, &lt->u.legacy.basic);
1096                 if (ret)
1097                         return ret;
1098                 ut->atype = atype;
1099                 (*iter_output)++;
1100                 break;
1101         }
1102         case atype_array:
1103         {
1104                 struct ustctl_field *uf = &fields[*iter_output];
1105                 struct ustctl_type *ut = &uf->type;
1106                 struct ustctl_basic_type *ubt;
1107                 const struct lttng_basic_type *lbt;
1108                 enum ustctl_abstract_types atype;
1109
1110                 if (field_name) {
1111                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1112                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1113                 } else {
1114                         uf->name[0] = '\0';
1115                 }
1116                 ut->atype = ustctl_atype_array;
1117                 ubt = &ut->u.legacy.array.elem_type;
1118                 lbt = &lt->u.legacy.array.elem_type;
1119                 ut->u.legacy.array.length = lt->u.legacy.array.length;
1120                 ret = serialize_basic_type(session, &atype, lbt->atype,
1121                         &ubt->u.basic, &lbt->u.basic);
1122                 if (ret)
1123                         return -EINVAL;
1124                 ubt->atype = atype;
1125                 (*iter_output)++;
1126                 break;
1127         }
1128         case atype_array_nestable:
1129         {
1130                 struct ustctl_field *uf = &fields[*iter_output];
1131                 struct ustctl_type *ut = &uf->type;
1132
1133                 if (field_name) {
1134                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1135                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1136                 } else {
1137                         uf->name[0] = '\0';
1138                 }
1139                 ut->atype = ustctl_atype_array_nestable;
1140                 ut->u.array_nestable.length = lt->u.array_nestable.length;
1141                 ut->u.array_nestable.alignment = lt->u.array_nestable.alignment;
1142                 (*iter_output)++;
1143
1144                 ret = serialize_one_type(session, fields, iter_output, NULL,
1145                                 lt->u.array_nestable.elem_type);
1146                 if (ret)
1147                         return -EINVAL;
1148                 break;
1149         }
1150         case atype_sequence:
1151         {
1152                 struct ustctl_field *uf = &fields[*iter_output];
1153                 struct ustctl_type *ut = &uf->type;
1154                 struct ustctl_basic_type *ubt;
1155                 const struct lttng_basic_type *lbt;
1156                 enum ustctl_abstract_types atype;
1157
1158                 if (field_name) {
1159                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1160                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1161                 } else {
1162                         uf->name[0] = '\0';
1163                 }
1164                 uf->type.atype = ustctl_atype_sequence;
1165                 ubt = &ut->u.legacy.sequence.length_type;
1166                 lbt = &lt->u.legacy.sequence.length_type;
1167                 ret = serialize_basic_type(session, &atype, lbt->atype,
1168                         &ubt->u.basic, &lbt->u.basic);
1169                 if (ret)
1170                         return -EINVAL;
1171                 ubt->atype = atype;
1172                 ubt = &ut->u.legacy.sequence.elem_type;
1173                 lbt = &lt->u.legacy.sequence.elem_type;
1174                 ret = serialize_basic_type(session, &atype, lbt->atype,
1175                         &ubt->u.basic, &lbt->u.basic);
1176                 if (ret)
1177                         return -EINVAL;
1178                 ubt->atype = atype;
1179                 (*iter_output)++;
1180                 break;
1181         }
1182         case atype_sequence_nestable:
1183         {
1184                 struct ustctl_field *uf = &fields[*iter_output];
1185                 struct ustctl_type *ut = &uf->type;
1186
1187                 if (field_name) {
1188                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1189                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1190                 } else {
1191                         uf->name[0] = '\0';
1192                 }
1193                 ut->atype = ustctl_atype_sequence_nestable;
1194                 strncpy(ut->u.sequence_nestable.length_name,
1195                         lt->u.sequence_nestable.length_name,
1196                         LTTNG_UST_SYM_NAME_LEN);
1197                 ut->u.sequence_nestable.length_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1198                 ut->u.sequence_nestable.alignment = lt->u.sequence_nestable.alignment;
1199                 (*iter_output)++;
1200
1201                 ret = serialize_one_type(session, fields, iter_output, NULL,
1202                                 lt->u.sequence_nestable.elem_type);
1203                 if (ret)
1204                         return -EINVAL;
1205                 break;
1206         }
1207         case atype_dynamic:
1208         {
1209                 ret = serialize_dynamic_type(session, fields, iter_output,
1210                                 field_name);
1211                 if (ret)
1212                         return -EINVAL;
1213                 break;
1214         }
1215         case atype_struct:
1216         {
1217                 struct ustctl_field *uf = &fields[*iter_output];
1218
1219                 if (field_name) {
1220                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1221                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1222                 } else {
1223                         uf->name[0] = '\0';
1224                 }
1225                 uf->type.atype = ustctl_atype_struct;
1226                 uf->type.u.legacy._struct.nr_fields = lt->u.legacy._struct.nr_fields;
1227                 (*iter_output)++;
1228
1229                 ret = serialize_fields(session, fields, iter_output,
1230                                 lt->u.legacy._struct.nr_fields,
1231                                 lt->u.legacy._struct.fields);
1232                 if (ret)
1233                         return -EINVAL;
1234                 break;
1235         }
1236         case atype_struct_nestable:
1237         {
1238                 struct ustctl_field *uf = &fields[*iter_output];
1239
1240                 if (field_name) {
1241                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1242                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1243                 } else {
1244                         uf->name[0] = '\0';
1245                 }
1246                 uf->type.atype = ustctl_atype_struct_nestable;
1247                 uf->type.u.struct_nestable.nr_fields = lt->u.struct_nestable.nr_fields;
1248                 uf->type.u.struct_nestable.alignment = lt->u.struct_nestable.alignment;
1249                 (*iter_output)++;
1250
1251                 ret = serialize_fields(session, fields, iter_output,
1252                                 lt->u.struct_nestable.nr_fields,
1253                                 lt->u.struct_nestable.fields);
1254                 if (ret)
1255                         return -EINVAL;
1256                 break;
1257         }
1258         case atype_enum_nestable:
1259         {
1260                 struct ustctl_field *uf = &fields[*iter_output];
1261                 struct ustctl_type *ut = &uf->type;
1262
1263                 if (field_name) {
1264                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1265                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1266                 } else {
1267                         uf->name[0] = '\0';
1268                 }
1269                 strncpy(ut->u.enum_nestable.name, lt->u.enum_nestable.desc->name,
1270                                 LTTNG_UST_SYM_NAME_LEN);
1271                 ut->u.enum_nestable.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1272                 ut->atype = ustctl_atype_enum_nestable;
1273                 (*iter_output)++;
1274
1275                 ret = serialize_one_type(session, fields, iter_output, NULL,
1276                                 lt->u.enum_nestable.container_type);
1277                 if (ret)
1278                         return -EINVAL;
1279                 if (session) {
1280                         const struct lttng_enum *_enum;
1281
1282                         _enum = lttng_ust_enum_get_from_desc(session, lt->u.enum_nestable.desc);
1283                         if (!_enum)
1284                                 return -EINVAL;
1285                         ut->u.enum_nestable.id = _enum->id;
1286                 } else {
1287                         ut->u.enum_nestable.id = -1ULL;
1288                 }
1289                 break;
1290         }
1291         default:
1292                 return -EINVAL;
1293         }
1294         return 0;
1295 }
1296
1297 static
1298 int serialize_one_field(struct lttng_session *session,
1299                 struct ustctl_field *fields, size_t *iter_output,
1300                 const struct lttng_event_field *lf)
1301 {
1302         /* skip 'nowrite' fields */
1303         if (lf->nowrite)
1304                 return 0;
1305
1306         return serialize_one_type(session, fields, iter_output, lf->name, &lf->type);
1307 }
1308
1309 static
1310 int serialize_fields(struct lttng_session *session,
1311                 struct ustctl_field *ustctl_fields,
1312                 size_t *iter_output, size_t nr_lttng_fields,
1313                 const struct lttng_event_field *lttng_fields)
1314 {
1315         int ret;
1316         size_t i;
1317
1318         for (i = 0; i < nr_lttng_fields; i++) {
1319                 ret = serialize_one_field(session, ustctl_fields,
1320                                 iter_output, &lttng_fields[i]);
1321                 if (ret)
1322                         return ret;
1323         }
1324         return 0;
1325 }
1326
1327 static
1328 int alloc_serialize_fields(struct lttng_session *session,
1329                 size_t *_nr_write_fields,
1330                 struct ustctl_field **ustctl_fields,
1331                 size_t nr_fields,
1332                 const struct lttng_event_field *lttng_fields)
1333 {
1334         struct ustctl_field *fields;
1335         int ret;
1336         size_t iter_output = 0;
1337         ssize_t nr_write_fields;
1338
1339         nr_write_fields = count_fields_recursive(nr_fields, lttng_fields);
1340         if (nr_write_fields < 0) {
1341                 return (int) nr_write_fields;
1342         }
1343
1344         fields = zmalloc(nr_write_fields * sizeof(*fields));
1345         if (!fields)
1346                 return -ENOMEM;
1347
1348         ret = serialize_fields(session, fields, &iter_output, nr_fields,
1349                         lttng_fields);
1350         if (ret)
1351                 goto error_type;
1352
1353         *_nr_write_fields = nr_write_fields;
1354         *ustctl_fields = fields;
1355         return 0;
1356
1357 error_type:
1358         free(fields);
1359         return ret;
1360 }
1361
1362 static
1363 int serialize_entries(struct ustctl_enum_entry **_entries,
1364                 size_t nr_entries,
1365                 const struct lttng_enum_entry *lttng_entries)
1366 {
1367         struct ustctl_enum_entry *entries;
1368         int i;
1369
1370         /* Serialize the entries */
1371         entries = zmalloc(nr_entries * sizeof(*entries));
1372         if (!entries)
1373                 return -ENOMEM;
1374         for (i = 0; i < nr_entries; i++) {
1375                 struct ustctl_enum_entry *uentry;
1376                 const struct lttng_enum_entry *lentry;
1377
1378                 uentry = &entries[i];
1379                 lentry = &lttng_entries[i];
1380
1381                 uentry->start.value = lentry->start.value;
1382                 uentry->start.signedness = lentry->start.signedness;
1383                 uentry->end.value = lentry->end.value;
1384                 uentry->end.signedness = lentry->end.signedness;
1385                 strncpy(uentry->string, lentry->string, LTTNG_UST_SYM_NAME_LEN);
1386                 uentry->string[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1387
1388                 if (lentry->u.extra.options & LTTNG_ENUM_ENTRY_OPTION_IS_AUTO) {
1389                         uentry->u.extra.options |=
1390                                 USTCTL_UST_ENUM_ENTRY_OPTION_IS_AUTO;
1391                 }
1392         }
1393         *_entries = entries;
1394         return 0;
1395 }
1396
1397 static
1398 int serialize_ctx_fields(struct lttng_session *session,
1399                 size_t *_nr_write_fields,
1400                 struct ustctl_field **ustctl_fields,
1401                 size_t nr_fields,
1402                 const struct lttng_ctx_field *lttng_fields)
1403 {
1404         struct ustctl_field *fields;
1405         int ret;
1406         size_t i, iter_output = 0;
1407         ssize_t nr_write_fields;
1408
1409         nr_write_fields = count_ctx_fields_recursive(nr_fields,
1410                         lttng_fields);
1411         if (nr_write_fields < 0) {
1412                 return (int) nr_write_fields;
1413         }
1414
1415         fields = zmalloc(nr_write_fields * sizeof(*fields));
1416         if (!fields)
1417                 return -ENOMEM;
1418
1419         for (i = 0; i < nr_fields; i++) {
1420                 ret = serialize_one_field(session, fields, &iter_output,
1421                                 &lttng_fields[i].event_field);
1422                 if (ret)
1423                         goto error_type;
1424         }
1425
1426         *_nr_write_fields = nr_write_fields;
1427         *ustctl_fields = fields;
1428         return 0;
1429
1430 error_type:
1431         free(fields);
1432         return ret;
1433 }
1434
1435 /*
1436  * Returns 0 on success, negative error value on error.
1437  */
1438 int ustcomm_register_event(int sock,
1439         struct lttng_session *session,
1440         int session_objd,               /* session descriptor */
1441         int channel_objd,               /* channel descriptor */
1442         const char *event_name,         /* event name (input) */
1443         int loglevel,
1444         const char *signature,          /* event signature (input) */
1445         size_t nr_fields,               /* fields */
1446         const struct lttng_event_field *lttng_fields,
1447         const char *model_emf_uri,
1448         uint32_t *id)                   /* event id (output) */
1449 {
1450         ssize_t len;
1451         struct {
1452                 struct ustcomm_notify_hdr header;
1453                 struct ustcomm_notify_event_msg m;
1454         } msg;
1455         struct {
1456                 struct ustcomm_notify_hdr header;
1457                 struct ustcomm_notify_event_reply r;
1458         } reply;
1459         size_t signature_len, fields_len, model_emf_uri_len;
1460         struct ustctl_field *fields = NULL;
1461         size_t nr_write_fields = 0;
1462         int ret;
1463
1464         memset(&msg, 0, sizeof(msg));
1465         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
1466         msg.m.session_objd = session_objd;
1467         msg.m.channel_objd = channel_objd;
1468         strncpy(msg.m.event_name, event_name, LTTNG_UST_SYM_NAME_LEN);
1469         msg.m.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1470         msg.m.loglevel = loglevel;
1471         signature_len = strlen(signature) + 1;
1472         msg.m.signature_len = signature_len;
1473
1474         /* Calculate fields len, serialize fields. */
1475         if (nr_fields > 0) {
1476                 ret = alloc_serialize_fields(session, &nr_write_fields, &fields,
1477                                 nr_fields, lttng_fields);
1478                 if (ret)
1479                         return ret;
1480         }
1481
1482         fields_len = sizeof(*fields) * nr_write_fields;
1483         msg.m.fields_len = fields_len;
1484         if (model_emf_uri) {
1485                 model_emf_uri_len = strlen(model_emf_uri) + 1;
1486         } else {
1487                 model_emf_uri_len = 0;
1488         }
1489         msg.m.model_emf_uri_len = model_emf_uri_len;
1490
1491         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1492         if (len > 0 && len != sizeof(msg)) {
1493                 ret = -EIO;
1494                 goto error_fields;
1495         }
1496         if (len < 0) {
1497                 ret = len;
1498                 goto error_fields;
1499         }
1500
1501         /* send signature */
1502         len = ustcomm_send_unix_sock(sock, signature, signature_len);
1503         if (len > 0 && len != signature_len) {
1504                 ret = -EIO;
1505                 goto error_fields;
1506         }
1507         if (len < 0) {
1508                 ret = len;
1509                 goto error_fields;
1510         }
1511
1512         /* send fields */
1513         if (fields_len > 0) {
1514                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1515                 if (len > 0 && len != fields_len) {
1516                         ret = -EIO;
1517                         goto error_fields;
1518                 }
1519                 if (len < 0) {
1520                         ret = len;
1521                         goto error_fields;
1522                 }
1523         }
1524         free(fields);
1525
1526         if (model_emf_uri_len) {
1527                 /* send model_emf_uri */
1528                 len = ustcomm_send_unix_sock(sock, model_emf_uri,
1529                                 model_emf_uri_len);
1530                 if (len > 0 && len != model_emf_uri_len) {
1531                         return -EIO;
1532                 }
1533                 if (len < 0) {
1534                         return len;
1535                 }
1536         }
1537
1538         /* receive reply */
1539         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1540         switch (len) {
1541         case 0: /* orderly shutdown */
1542                 return -EPIPE;
1543         case sizeof(reply):
1544                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1545                         ERR("Unexpected result message command "
1546                                 "expected: %u vs received: %u\n",
1547                                 msg.header.notify_cmd, reply.header.notify_cmd);
1548                         return -EINVAL;
1549                 }
1550                 if (reply.r.ret_code > 0)
1551                         return -EINVAL;
1552                 if (reply.r.ret_code < 0)
1553                         return reply.r.ret_code;
1554                 *id = reply.r.event_id;
1555                 DBG("Sent register event notification for name \"%s\": ret_code %d, event_id %u\n",
1556                         event_name, reply.r.ret_code, reply.r.event_id);
1557                 return 0;
1558         default:
1559                 if (len < 0) {
1560                         /* Transport level error */
1561                         if (errno == EPIPE || errno == ECONNRESET)
1562                                 len = -errno;
1563                         return len;
1564                 } else {
1565                         ERR("incorrect message size: %zd\n", len);
1566                         return len;
1567                 }
1568         }
1569         /* Unreached. */
1570
1571         /* Error path only. */
1572 error_fields:
1573         free(fields);
1574         return ret;
1575 }
1576
1577 /*
1578  * Returns 0 on success, negative error value on error.
1579  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1580  */
1581 int ustcomm_register_enum(int sock,
1582         int session_objd,               /* session descriptor */
1583         const char *enum_name,          /* enum name (input) */
1584         size_t nr_entries,              /* entries */
1585         const struct lttng_enum_entry *lttng_entries,
1586         uint64_t *id)
1587 {
1588         ssize_t len;
1589         struct {
1590                 struct ustcomm_notify_hdr header;
1591                 struct ustcomm_notify_enum_msg m;
1592         } msg;
1593         struct {
1594                 struct ustcomm_notify_hdr header;
1595                 struct ustcomm_notify_enum_reply r;
1596         } reply;
1597         size_t entries_len;
1598         struct ustctl_enum_entry *entries = NULL;
1599         int ret;
1600
1601         memset(&msg, 0, sizeof(msg));
1602         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_ENUM;
1603         msg.m.session_objd = session_objd;
1604         strncpy(msg.m.enum_name, enum_name, LTTNG_UST_SYM_NAME_LEN);
1605         msg.m.enum_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1606
1607         /* Calculate entries len, serialize entries. */
1608         if (nr_entries > 0) {
1609                 ret = serialize_entries(&entries,
1610                                 nr_entries, lttng_entries);
1611                 if (ret)
1612                         return ret;
1613         }
1614
1615         entries_len = sizeof(*entries) * nr_entries;
1616         msg.m.entries_len = entries_len;
1617
1618         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1619         if (len > 0 && len != sizeof(msg)) {
1620                 ret = -EIO;
1621                 goto error_entries;
1622         }
1623         if (len < 0) {
1624                 ret = len;
1625                 goto error_entries;
1626         }
1627
1628         /* send entries */
1629         if (entries_len > 0) {
1630                 len = ustcomm_send_unix_sock(sock, entries, entries_len);
1631                 if (len > 0 && len != entries_len) {
1632                         ret = -EIO;
1633                         goto error_entries;
1634                 }
1635                 if (len < 0) {
1636                         ret = len;
1637                         goto error_entries;
1638                 }
1639         }
1640         free(entries);
1641         entries = NULL;
1642
1643         /* receive reply */
1644         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1645         switch (len) {
1646         case 0: /* orderly shutdown */
1647                 return -EPIPE;
1648         case sizeof(reply):
1649                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1650                         ERR("Unexpected result message command "
1651                                 "expected: %u vs received: %u\n",
1652                                 msg.header.notify_cmd, reply.header.notify_cmd);
1653                         return -EINVAL;
1654                 }
1655                 if (reply.r.ret_code > 0)
1656                         return -EINVAL;
1657                 if (reply.r.ret_code < 0)
1658                         return reply.r.ret_code;
1659                 *id = reply.r.enum_id;
1660                 DBG("Sent register enum notification for name \"%s\": ret_code %d\n",
1661                         enum_name, reply.r.ret_code);
1662                 return 0;
1663         default:
1664                 if (len < 0) {
1665                         /* Transport level error */
1666                         if (errno == EPIPE || errno == ECONNRESET)
1667                                 len = -errno;
1668                         return len;
1669                 } else {
1670                         ERR("incorrect message size: %zd\n", len);
1671                         return len;
1672                 }
1673         }
1674         return ret;
1675
1676 error_entries:
1677         free(entries);
1678         return ret;
1679 }
1680
1681 /*
1682  * Returns 0 on success, negative error value on error.
1683  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1684  */
1685 int ustcomm_register_channel(int sock,
1686         struct lttng_session *session,
1687         int session_objd,               /* session descriptor */
1688         int channel_objd,               /* channel descriptor */
1689         size_t nr_ctx_fields,
1690         const struct lttng_ctx_field *ctx_fields,
1691         uint32_t *chan_id,              /* channel id (output) */
1692         int *header_type)               /* header type (output) */
1693 {
1694         ssize_t len;
1695         struct {
1696                 struct ustcomm_notify_hdr header;
1697                 struct ustcomm_notify_channel_msg m;
1698         } msg;
1699         struct {
1700                 struct ustcomm_notify_hdr header;
1701                 struct ustcomm_notify_channel_reply r;
1702         } reply;
1703         size_t fields_len;
1704         struct ustctl_field *fields = NULL;
1705         int ret;
1706         size_t nr_write_fields = 0;
1707
1708         memset(&msg, 0, sizeof(msg));
1709         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1710         msg.m.session_objd = session_objd;
1711         msg.m.channel_objd = channel_objd;
1712
1713         /* Calculate fields len, serialize fields. */
1714         if (nr_ctx_fields > 0) {
1715                 ret = serialize_ctx_fields(session, &nr_write_fields, &fields,
1716                                 nr_ctx_fields, ctx_fields);
1717                 if (ret)
1718                         return ret;
1719         }
1720
1721         fields_len = sizeof(*fields) * nr_write_fields;
1722         msg.m.ctx_fields_len = fields_len;
1723         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1724         if (len > 0 && len != sizeof(msg)) {
1725                 free(fields);
1726                 return -EIO;
1727         }
1728         if (len < 0) {
1729                 free(fields);
1730                 return len;
1731         }
1732
1733         /* send fields */
1734         if (fields_len > 0) {
1735                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1736                 free(fields);
1737                 if (len > 0 && len != fields_len) {
1738                         return -EIO;
1739                 }
1740                 if (len < 0) {
1741                         return len;
1742                 }
1743         } else {
1744                 free(fields);
1745         }
1746
1747         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1748         switch (len) {
1749         case 0: /* orderly shutdown */
1750                 return -EPIPE;
1751         case sizeof(reply):
1752                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1753                         ERR("Unexpected result message command "
1754                                 "expected: %u vs received: %u\n",
1755                                 msg.header.notify_cmd, reply.header.notify_cmd);
1756                         return -EINVAL;
1757                 }
1758                 if (reply.r.ret_code > 0)
1759                         return -EINVAL;
1760                 if (reply.r.ret_code < 0)
1761                         return reply.r.ret_code;
1762                 *chan_id = reply.r.chan_id;
1763                 switch (reply.r.header_type) {
1764                 case 1:
1765                 case 2:
1766                         *header_type = reply.r.header_type;
1767                         break;
1768                 default:
1769                         ERR("Unexpected channel header type %u\n",
1770                                 reply.r.header_type);
1771                         return -EINVAL;
1772                 }
1773                 DBG("Sent register channel notification: chan_id %d, header_type %d\n",
1774                         reply.r.chan_id, reply.r.header_type);
1775                 return 0;
1776         default:
1777                 if (len < 0) {
1778                         /* Transport level error */
1779                         if (errno == EPIPE || errno == ECONNRESET)
1780                                 len = -errno;
1781                         return len;
1782                 } else {
1783                         ERR("incorrect message size: %zd\n", len);
1784                         return len;
1785                 }
1786         }
1787 }
1788
1789 /*
1790  * Set socket reciving timeout.
1791  */
1792 int ustcomm_setsockopt_rcv_timeout(int sock, unsigned int msec)
1793 {
1794         int ret;
1795         struct timeval tv;
1796
1797         tv.tv_sec = msec / 1000;
1798         tv.tv_usec = (msec * 1000 % 1000000);
1799
1800         ret = setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
1801         if (ret < 0) {
1802                 PERROR("setsockopt SO_RCVTIMEO");
1803                 ret = -errno;
1804         }
1805
1806         return ret;
1807 }
1808
1809 /*
1810  * Set socket sending timeout.
1811  */
1812 int ustcomm_setsockopt_snd_timeout(int sock, unsigned int msec)
1813 {
1814         int ret;
1815         struct timeval tv;
1816
1817         tv.tv_sec = msec / 1000;
1818         tv.tv_usec = (msec * 1000) % 1000000;
1819
1820         ret = setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
1821         if (ret < 0) {
1822                 PERROR("setsockopt SO_SNDTIMEO");
1823                 ret = -errno;
1824         }
1825
1826         return ret;
1827 }