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

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
   5  * Copyright (C) 2011-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  */
   7
   8 #include <limits.h>
   9 #include <stdint.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <sys/socket.h>
  14 #include <sys/stat.h>
  15 #include <sys/types.h>
  16 #include <sys/un.h>
  17 #include <unistd.h>
  18 #include <assert.h>
  19 #include <errno.h>
  20 #include <fcntl.h>
  21
  22 #include <lttng/ust-ctl.h>
  23 #include <ust-comm.h>
  24 #include <ust-fd.h>
  25 #include <ust-helper.h>
  26 #include <lttng/ust-error.h>
  27 #include <ust-dynamic-type.h>
  28 #include <usterr-signal-safe.h>
  29
  30 #include "../liblttng-ust/ust-events-internal.h"
  31 #include "../liblttng-ust/compat.h"
  32
  33 #define USTCOMM_CODE_OFFSET(code)       \
  34         (code == LTTNG_UST_OK ? 0 : (code - LTTNG_UST_ERR + 1))
  35
  36 #define USTCOMM_MAX_SEND_FDS    4
  37
  38 static
  39 ssize_t count_fields_recursive(size_t nr_fields,
  40                 struct lttng_ust_event_field **lttng_fields);
  41 static
  42 int serialize_one_field(struct lttng_ust_session *session,
  43                 struct ustctl_field *fields, size_t *iter_output,
  44                 struct lttng_ust_event_field *lf);
  45 static
  46 int serialize_fields(struct lttng_ust_session *session,
  47                 struct ustctl_field *ustctl_fields,
  48                 size_t *iter_output, size_t nr_lttng_fields,
  49                 struct lttng_ust_event_field **lttng_fields);
  50
  51 /*
  52  * Human readable error message.
  53  */
  54 static const char *ustcomm_readable_code[] = {
  55         [ USTCOMM_CODE_OFFSET(LTTNG_UST_OK) ] = "Success",
  56         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR) ] = "Unknown error",
  57         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOENT) ] = "No entry",
  58         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_EXIST) ] = "Object already exists",
  59         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL) ] = "Invalid argument",
  60         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_PERM) ] = "Permission denied",
  61         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOSYS) ] = "Not implemented",
  62         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_EXITING) ] = "Process is exiting",
  63
  64         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL_MAGIC) ] = "Invalid magic number",
  65         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL_SOCKET_TYPE) ] = "Invalid socket type",
  66         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_UNSUP_MAJOR) ] = "Unsupported major version",
  67         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_PEERCRED) ] = "Cannot get unix socket peer credentials",
  68         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_PEERCRED_PID) ] = "Peer credentials PID is invalid. Socket appears to belong to a distinct, non-nested pid namespace.",
  69 };
  70
  71 /*
  72  * lttng_ust_strerror
  73  *
  74  * Receives positive error value.
  75  * Return ptr to string representing a human readable
  76  * error code from the ustcomm_return_code enum.
  77  */
  78 const char *lttng_ust_strerror(int code)
  79 {
  80         if (code == LTTNG_UST_OK)
  81                 return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)];
  82         if (code < LTTNG_UST_ERR)
  83                 return strerror(code);
  84         if (code >= LTTNG_UST_ERR_NR)
  85                 code = LTTNG_UST_ERR;
  86         return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)];
  87 }
  88
  89 /*
  90  * ustcomm_connect_unix_sock
  91  *
  92  * Connect to unix socket using the path name.
  93  *
  94  * Caller handles FD tracker.
  95  */
  96 int ustcomm_connect_unix_sock(const char *pathname, long timeout)
  97 {
  98         struct sockaddr_un sun;
  99         int fd, ret;
 100
 101         /*
 102          * libust threads require the close-on-exec flag for all
 103          * resources so it does not leak file descriptors upon exec.
 104          * SOCK_CLOEXEC is not used since it is linux specific.
 105          */
 106         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 107         if (fd < 0) {
 108                 PERROR("socket");
 109                 ret = -errno;
 110                 goto error;
 111         }
 112         if (timeout >= 0) {
 113                 /* Give at least 10ms. */
 114                 if (timeout < 10)
 115                         timeout = 10;
 116                 ret = ustcomm_setsockopt_snd_timeout(fd, timeout);
 117                 if (ret < 0) {
 118                         WARN("Error setting connect socket send timeout");
 119                 }
 120         }
 121         ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
 122         if (ret < 0) {
 123                 PERROR("fcntl");
 124                 ret = -errno;
 125                 goto error_fcntl;
 126         }
 127
 128         memset(&sun, 0, sizeof(sun));
 129         sun.sun_family = AF_UNIX;
 130         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 131         sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
 132
 133         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
 134         if (ret < 0) {
 135                 /*
 136                  * Don't print message on connect ENOENT error, because
 137                  * connect is used in normal execution to detect if
 138                  * sessiond is alive. ENOENT is when the unix socket
 139                  * file does not exist, and ECONNREFUSED is when the
 140                  * file exists but no sessiond is listening.
 141                  */
 142                 if (errno != ECONNREFUSED && errno != ECONNRESET
 143                                 && errno != ENOENT && errno != EACCES)
 144                         PERROR("connect");
 145                 ret = -errno;
 146                 if (ret == -ECONNREFUSED || ret == -ECONNRESET)
 147                         ret = -EPIPE;
 148                 goto error_connect;
 149         }
 150
 151         return fd;
 152
 153 error_connect:
 154 error_fcntl:
 155         {
 156                 int closeret;
 157
 158                 closeret = close(fd);
 159                 if (closeret)
 160                         PERROR("close");
 161         }
 162 error:
 163         return ret;
 164 }
 165
 166 /*
 167  * ustcomm_accept_unix_sock
 168  *
 169  * Do an accept(2) on the sock and return the
 170  * new file descriptor. The socket MUST be bind(2) before.
 171  */
 172 int ustcomm_accept_unix_sock(int sock)
 173 {
 174         int new_fd;
 175         struct sockaddr_un sun;
 176         socklen_t len = 0;
 177
 178         /* Blocking call */
 179         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 180         if (new_fd < 0) {
 181                 if (errno != ECONNABORTED)
 182                         PERROR("accept");
 183                 new_fd = -errno;
 184                 if (new_fd == -ECONNABORTED)
 185                         new_fd = -EPIPE;
 186         }
 187         return new_fd;
 188 }
 189
 190 /*
 191  * ustcomm_create_unix_sock
 192  *
 193  * Creates a AF_UNIX local socket using pathname
 194  * bind the socket upon creation and return the fd.
 195  */
 196 int ustcomm_create_unix_sock(const char *pathname)
 197 {
 198         struct sockaddr_un sun;
 199         int fd, ret;
 200
 201         /* Create server socket */
 202         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 203                 PERROR("socket");
 204                 ret = -errno;
 205                 goto error;
 206         }
 207
 208         memset(&sun, 0, sizeof(sun));
 209         sun.sun_family = AF_UNIX;
 210         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 211         sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
 212
 213         /* Unlink the old file if present */
 214         (void) unlink(pathname);
 215         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 216         if (ret < 0) {
 217                 PERROR("bind");
 218                 ret = -errno;
 219                 goto error_close;
 220         }
 221
 222         return fd;
 223
 224 error_close:
 225         {
 226                 int closeret;
 227
 228                 closeret = close(fd);
 229                 if (closeret) {
 230                         PERROR("close");
 231                 }
 232         }
 233 error:
 234         return ret;
 235 }
 236
 237 /*
 238  * ustcomm_listen_unix_sock
 239  *
 240  * Make the socket listen using LTTNG_UST_COMM_MAX_LISTEN.
 241  */
 242 int ustcomm_listen_unix_sock(int sock)
 243 {
 244         int ret;
 245
 246         ret = listen(sock, LTTNG_UST_COMM_MAX_LISTEN);
 247         if (ret < 0) {
 248                 ret = -errno;
 249                 PERROR("listen");
 250         }
 251
 252         return ret;
 253 }
 254
 255 /*
 256  * ustcomm_close_unix_sock
 257  *
 258  * Shutdown cleanly a unix socket.
 259  *
 260  * Handles fd tracker internally.
 261  */
 262 int ustcomm_close_unix_sock(int sock)
 263 {
 264         int ret;
 265
 266         lttng_ust_lock_fd_tracker();
 267         ret = close(sock);
 268         if (!ret) {
 269                 lttng_ust_delete_fd_from_tracker(sock);
 270         } else {
 271                 PERROR("close");
 272                 ret = -errno;
 273         }
 274         lttng_ust_unlock_fd_tracker();
 275
 276         return ret;
 277 }
 278
 279 /*
 280  * ustcomm_recv_unix_sock
 281  *
 282  * Receive data of size len in put that data into
 283  * the buf param. Using recvmsg API.
 284  * Return the size of received data.
 285  * Return 0 on orderly shutdown.
 286  */
 287 ssize_t ustcomm_recv_unix_sock(int sock, void *buf, size_t len)
 288 {
 289         struct msghdr msg;
 290         struct iovec iov[1];
 291         ssize_t ret = -1;
 292         size_t len_last;
 293
 294         memset(&msg, 0, sizeof(msg));
 295
 296         iov[0].iov_base = buf;
 297         iov[0].iov_len = len;
 298         msg.msg_iov = iov;
 299         msg.msg_iovlen = 1;
 300
 301         do {
 302                 len_last = iov[0].iov_len;
 303                 ret = recvmsg(sock, &msg, 0);
 304                 if (ret > 0) {
 305                         iov[0].iov_base += ret;
 306                         iov[0].iov_len -= ret;
 307                         assert(ret <= len_last);
 308                 }
 309         } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
 310
 311         if (ret < 0) {
 312                 int shutret;
 313
 314                 if (errno != EPIPE && errno != ECONNRESET && errno != ECONNREFUSED)
 315                         PERROR("recvmsg");
 316                 ret = -errno;
 317                 if (ret == -ECONNRESET || ret == -ECONNREFUSED)
 318                         ret = -EPIPE;
 319
 320                 shutret = shutdown(sock, SHUT_RDWR);
 321                 if (shutret)
 322                         ERR("Socket shutdown error");
 323         } else if (ret > 0) {
 324                 ret = len;
 325         }
 326         /* ret = 0 means an orderly shutdown. */
 327
 328         return ret;
 329 }
 330
 331 /*
 332  * ustcomm_send_unix_sock
 333  *
 334  * Send buf data of size len. Using sendmsg API.
 335  * Return the size of sent data.
 336  */
 337 ssize_t ustcomm_send_unix_sock(int sock, const void *buf, size_t len)
 338 {
 339         struct msghdr msg;
 340         struct iovec iov[1];
 341         ssize_t ret;
 342
 343         memset(&msg, 0, sizeof(msg));
 344
 345         iov[0].iov_base = (void *) buf;
 346         iov[0].iov_len = len;
 347         msg.msg_iov = iov;
 348         msg.msg_iovlen = 1;
 349
 350         /*
 351          * Using the MSG_NOSIGNAL when sending data from sessiond to
 352          * libust, so libust does not receive an unhandled SIGPIPE or
 353          * SIGURG. The sessiond receiver side can be made more resilient
 354          * by ignoring SIGPIPE, but we don't have this luxury on the
 355          * libust side.
 356          */
 357         do {
 358                 ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
 359         } while (ret < 0 && errno == EINTR);
 360
 361         if (ret < 0) {
 362                 int shutret;
 363
 364                 if (errno != EPIPE && errno != ECONNRESET)
 365                         PERROR("sendmsg");
 366                 ret = -errno;
 367                 if (ret == -ECONNRESET)
 368                         ret = -EPIPE;
 369
 370                 shutret = shutdown(sock, SHUT_RDWR);
 371                 if (shutret)
 372                         ERR("Socket shutdown error");
 373         }
 374
 375         return ret;
 376 }
 377
 378 /*
 379  * Send a message accompanied by fd(s) over a unix socket.
 380  *
 381  * Returns the size of data sent, or negative error value.
 382  */
 383 ssize_t ustcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 384 {
 385         struct msghdr msg;
 386         struct cmsghdr *cmptr;
 387         struct iovec iov[1];
 388         ssize_t ret = -1;
 389         unsigned int sizeof_fds = nb_fd * sizeof(int);
 390         char tmp[CMSG_SPACE(sizeof_fds)];
 391         char dummy = 0;
 392
 393         memset(&msg, 0, sizeof(msg));
 394         memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));
 395
 396         if (nb_fd > USTCOMM_MAX_SEND_FDS)
 397                 return -EINVAL;
 398
 399         msg.msg_control = (caddr_t)tmp;
 400         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 401
 402         cmptr = CMSG_FIRSTHDR(&msg);
 403         if (!cmptr)
 404                 return -EINVAL;
 405         cmptr->cmsg_level = SOL_SOCKET;
 406         cmptr->cmsg_type = SCM_RIGHTS;
 407         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 408         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 409         /* Sum of the length of all control messages in the buffer: */
 410         msg.msg_controllen = cmptr->cmsg_len;
 411
 412         iov[0].iov_base = &dummy;
 413         iov[0].iov_len = 1;
 414         msg.msg_iov = iov;
 415         msg.msg_iovlen = 1;
 416
 417         do {
 418                 ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
 419         } while (ret < 0 && errno == EINTR);
 420         if (ret < 0) {
 421                 /*
 422                  * We consider EPIPE and ECONNRESET as expected.
 423                  */
 424                 if (errno != EPIPE && errno != ECONNRESET) {
 425                         PERROR("sendmsg");
 426                 }
 427                 ret = -errno;
 428                 if (ret == -ECONNRESET)
 429                         ret = -EPIPE;
 430         }
 431         return ret;
 432 }
 433
 434 /*
 435  * Recv a message accompanied by fd(s) from a unix socket.
 436  *
 437  * Expect at most "nb_fd" file descriptors. Returns the number of fd
 438  * actually received in nb_fd.
 439  * Returns -EPIPE on orderly shutdown.
 440  */
 441 ssize_t ustcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 442 {
 443         struct iovec iov[1];
 444         ssize_t ret = 0;
 445         struct cmsghdr *cmsg;
 446         size_t sizeof_fds = nb_fd * sizeof(int);
 447         char recv_fd[CMSG_SPACE(sizeof_fds)];
 448         struct msghdr msg;
 449         char dummy;
 450         int i;
 451
 452         memset(&msg, 0, sizeof(msg));
 453
 454         /* Prepare to receive the structures */
 455         iov[0].iov_base = &dummy;
 456         iov[0].iov_len = 1;
 457         msg.msg_iov = iov;
 458         msg.msg_iovlen = 1;
 459         msg.msg_control = recv_fd;
 460         msg.msg_controllen = sizeof(recv_fd);
 461
 462         do {
 463                 ret = recvmsg(sock, &msg, 0);
 464         } while (ret < 0 && errno == EINTR);
 465         if (ret < 0) {
 466                 if (errno != EPIPE && errno != ECONNRESET) {
 467                         PERROR("recvmsg fds");
 468                 }
 469                 ret = -errno;
 470                 if (ret == -ECONNRESET)
 471                         ret = -EPIPE;
 472                 goto end;
 473         }
 474         if (ret == 0) {
 475                 /* orderly shutdown */
 476                 ret = -EPIPE;
 477                 goto end;
 478         }
 479         if (ret != 1) {
 480                 ERR("Error: Received %zd bytes, expected %d\n",
 481                                 ret, 1);
 482                 goto end;
 483         }
 484         if (msg.msg_flags & MSG_CTRUNC) {
 485                 ERR("Error: Control message truncated.\n");
 486                 ret = -1;
 487                 goto end;
 488         }
 489         cmsg = CMSG_FIRSTHDR(&msg);
 490         if (!cmsg) {
 491                 ERR("Error: Invalid control message header\n");
 492                 ret = -1;
 493                 goto end;
 494         }
 495         if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
 496                 ERR("Didn't received any fd\n");
 497                 ret = -1;
 498                 goto end;
 499         }
 500         if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
 501                 ERR("Error: Received %zu bytes of ancillary data, expected %zu\n",
 502                                 (size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
 503                 ret = -1;
 504                 goto end;
 505         }
 506
 507         memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
 508
 509         /* Set FD_CLOEXEC */
 510         for (i = 0; i < nb_fd; i++) {
 511                 ret = fcntl(fds[i], F_SETFD, FD_CLOEXEC);
 512                 if (ret < 0) {
 513                         PERROR("fcntl failed to set FD_CLOEXEC on fd %d",
 514                                fds[i]);
 515                 }
 516         }
 517
 518         ret = nb_fd;
 519 end:
 520         return ret;
 521 }
 522
 523 int ustcomm_send_app_msg(int sock, struct ustcomm_ust_msg *lum)
 524 {
 525         ssize_t len;
 526
 527         len = ustcomm_send_unix_sock(sock, lum, sizeof(*lum));
 528         switch (len) {
 529         case sizeof(*lum):
 530                 break;
 531         default:
 532                 if (len < 0) {
 533                         return len;
 534                 } else {
 535                         ERR("incorrect message size: %zd\n", len);
 536                         return -EINVAL;
 537                 }
 538         }
 539         return 0;
 540 }
 541
 542 int ustcomm_recv_app_reply(int sock, struct ustcomm_ust_reply *lur,
 543                           uint32_t expected_handle, uint32_t expected_cmd)
 544 {
 545         ssize_t len;
 546
 547         memset(lur, 0, sizeof(*lur));
 548         len = ustcomm_recv_unix_sock(sock, lur, sizeof(*lur));
 549         switch (len) {
 550         case 0: /* orderly shutdown */
 551                 return -EPIPE;
 552         case sizeof(*lur):
 553         {
 554                 int err = 0;
 555
 556                 if (lur->handle != expected_handle) {
 557                         ERR("Unexpected result message handle: "
 558                                 "expected: %u vs received: %u\n",
 559                                 expected_handle, lur->handle);
 560                         err = 1;
 561                 }
 562                 if (lur->cmd != expected_cmd) {
 563                         ERR("Unexpected result message command "
 564                                 "expected: %u vs received: %u\n",
 565                                 expected_cmd, lur->cmd);
 566                         err = 1;
 567                 }
 568                 if (err) {
 569                         return -EINVAL;
 570                 } else {
 571                         return lur->ret_code;
 572                 }
 573         }
 574         default:
 575                 if (len >= 0) {
 576                         ERR("incorrect message size: %zd\n", len);
 577                 }
 578                 return len;
 579         }
 580 }
 581
 582 int ustcomm_send_app_cmd(int sock,
 583                         struct ustcomm_ust_msg *lum,
 584                         struct ustcomm_ust_reply *lur)
 585 {
 586         int ret;
 587
 588         ret = ustcomm_send_app_msg(sock, lum);
 589         if (ret)
 590                 return ret;
 591         ret = ustcomm_recv_app_reply(sock, lur, lum->handle, lum->cmd);
 592         if (ret > 0)
 593                 return -EIO;
 594         return ret;
 595 }
 596
 597 /*
 598  * chan_data is allocated internally if this function returns the
 599  * expected var_len.
 600  */
 601 ssize_t ustcomm_recv_channel_from_sessiond(int sock,
 602                 void **_chan_data, uint64_t var_len,
 603                 int *_wakeup_fd)
 604 {
 605         void *chan_data;
 606         ssize_t len, nr_fd;
 607         int wakeup_fd, ret;
 608
 609         if (var_len > LTTNG_UST_ABI_CHANNEL_DATA_MAX_LEN) {
 610                 len = -EINVAL;
 611                 goto error_check;
 612         }
 613         /* Receive variable length data */
 614         chan_data = zmalloc(var_len);
 615         if (!chan_data) {
 616                 len = -ENOMEM;
 617                 goto error_alloc;
 618         }
 619         len = ustcomm_recv_unix_sock(sock, chan_data, var_len);
 620         if (len != var_len) {
 621                 goto error_recv;
 622         }
 623         /* recv wakeup fd */
 624         lttng_ust_lock_fd_tracker();
 625         nr_fd = ustcomm_recv_fds_unix_sock(sock, &wakeup_fd, 1);
 626         if (nr_fd <= 0) {
 627                 lttng_ust_unlock_fd_tracker();
 628                 if (nr_fd < 0) {
 629                         len = nr_fd;
 630                         goto error_recv;
 631                 } else {
 632                         len = -EIO;
 633                         goto error_recv;
 634                 }
 635         }
 636
 637         ret = lttng_ust_add_fd_to_tracker(wakeup_fd);
 638         if (ret < 0) {
 639                 ret = close(wakeup_fd);
 640                 if (ret) {
 641                         PERROR("close on wakeup_fd");
 642                 }
 643                 len = -EIO;
 644                 lttng_ust_unlock_fd_tracker();
 645                 goto error_recv;
 646         }
 647
 648         *_wakeup_fd = ret;
 649         lttng_ust_unlock_fd_tracker();
 650
 651         *_chan_data = chan_data;
 652         return len;
 653
 654 error_recv:
 655         free(chan_data);
 656 error_alloc:
 657 error_check:
 658         return len;
 659 }
 660
 661 ssize_t ustcomm_recv_event_notifier_notif_fd_from_sessiond(int sock,
 662                 int *_event_notifier_notif_fd)
 663 {
 664         ssize_t nr_fd;
 665         int event_notifier_notif_fd, ret;
 666
 667         /* Receive event_notifier notification fd */
 668         lttng_ust_lock_fd_tracker();
 669         nr_fd = ustcomm_recv_fds_unix_sock(sock, &event_notifier_notif_fd, 1);
 670         if (nr_fd <= 0) {
 671                 lttng_ust_unlock_fd_tracker();
 672                 if (nr_fd < 0) {
 673                         ret = nr_fd;
 674                         goto error;
 675                 } else {
 676                         ret = -EIO;
 677                         goto error;
 678                 }
 679         }
 680
 681         ret = lttng_ust_add_fd_to_tracker(event_notifier_notif_fd);
 682         if (ret < 0) {
 683                 ret = close(event_notifier_notif_fd);
 684                 if (ret) {
 685                         PERROR("close on event_notifier notif fd");
 686                 }
 687                 ret = -EIO;
 688                 lttng_ust_unlock_fd_tracker();
 689                 goto error;
 690         }
 691
 692         *_event_notifier_notif_fd = ret;
 693         lttng_ust_unlock_fd_tracker();
 694
 695         ret = nr_fd;
 696
 697 error:
 698         return ret;
 699 }
 700
 701 int ustcomm_recv_stream_from_sessiond(int sock,
 702                 uint64_t *memory_map_size,
 703                 int *shm_fd, int *wakeup_fd)
 704 {
 705         ssize_t len;
 706         int ret;
 707         int fds[2];
 708
 709         /* recv shm fd and wakeup fd */
 710         lttng_ust_lock_fd_tracker();
 711         len = ustcomm_recv_fds_unix_sock(sock, fds, 2);
 712         if (len <= 0) {
 713                 lttng_ust_unlock_fd_tracker();
 714                 if (len < 0) {
 715                         ret = len;
 716                         goto error;
 717                 } else {
 718                         ret = -EIO;
 719                         goto error;
 720                 }
 721         }
 722
 723         ret = lttng_ust_add_fd_to_tracker(fds[0]);
 724         if (ret < 0) {
 725                 ret = close(fds[0]);
 726                 if (ret) {
 727                         PERROR("close on received shm_fd");
 728                 }
 729                 ret = -EIO;
 730                 lttng_ust_unlock_fd_tracker();
 731                 goto error;
 732         }
 733         *shm_fd = ret;
 734
 735         ret = lttng_ust_add_fd_to_tracker(fds[1]);
 736         if (ret < 0) {
 737                 ret = close(*shm_fd);
 738                 if (ret) {
 739                         PERROR("close on shm_fd");
 740                 }
 741                 *shm_fd = -1;
 742                 ret = close(fds[1]);
 743                 if (ret) {
 744                         PERROR("close on received wakeup_fd");
 745                 }
 746                 ret = -EIO;
 747                 lttng_ust_unlock_fd_tracker();
 748                 goto error;
 749         }
 750         *wakeup_fd = ret;
 751         lttng_ust_unlock_fd_tracker();
 752         return 0;
 753
 754 error:
 755         return ret;
 756 }
 757
 758 ssize_t ustcomm_recv_counter_from_sessiond(int sock,
 759                 void **_counter_data, uint64_t var_len)
 760 {
 761         void *counter_data;
 762         ssize_t len;
 763
 764         if (var_len > LTTNG_UST_ABI_COUNTER_DATA_MAX_LEN) {
 765                 len = -EINVAL;
 766                 goto error_check;
 767         }
 768         /* Receive variable length data */
 769         counter_data = zmalloc(var_len);
 770         if (!counter_data) {
 771                 len = -ENOMEM;
 772                 goto error_alloc;
 773         }
 774         len = ustcomm_recv_unix_sock(sock, counter_data, var_len);
 775         if (len != var_len) {
 776                 goto error_recv;
 777         }
 778         *_counter_data = counter_data;
 779         return len;
 780
 781 error_recv:
 782         free(counter_data);
 783 error_alloc:
 784 error_check:
 785         return len;
 786 }
 787
 788 int ustcomm_recv_counter_shm_from_sessiond(int sock,
 789                 int *shm_fd)
 790 {
 791         ssize_t len;
 792         int ret;
 793         int fds[1];
 794
 795         /* recv shm fd fd */
 796         lttng_ust_lock_fd_tracker();
 797         len = ustcomm_recv_fds_unix_sock(sock, fds, 1);
 798         if (len <= 0) {
 799                 lttng_ust_unlock_fd_tracker();
 800                 if (len < 0) {
 801                         ret = len;
 802                         goto error;
 803                 } else {
 804                         ret = -EIO;
 805                         goto error;
 806                 }
 807         }
 808
 809         ret = lttng_ust_add_fd_to_tracker(fds[0]);
 810         if (ret < 0) {
 811                 ret = close(fds[0]);
 812                 if (ret) {
 813                         PERROR("close on received shm_fd");
 814                 }
 815                 ret = -EIO;
 816                 lttng_ust_unlock_fd_tracker();
 817                 goto error;
 818         }
 819         *shm_fd = ret;
 820         lttng_ust_unlock_fd_tracker();
 821         return 0;
 822
 823 error:
 824         return ret;
 825 }
 826
 827 /*
 828  * Returns 0 on success, negative error value on error.
 829  */
 830 int ustcomm_send_reg_msg(int sock,
 831                 enum ustctl_socket_type type,
 832                 uint32_t bits_per_long,
 833                 uint32_t uint8_t_alignment,
 834                 uint32_t uint16_t_alignment,
 835                 uint32_t uint32_t_alignment,
 836                 uint32_t uint64_t_alignment,
 837                 uint32_t long_alignment)
 838 {
 839         ssize_t len;
 840         struct ustctl_reg_msg reg_msg;
 841
 842         reg_msg.magic = LTTNG_UST_ABI_COMM_MAGIC;
 843         reg_msg.major = LTTNG_UST_ABI_MAJOR_VERSION;
 844         reg_msg.minor = LTTNG_UST_ABI_MINOR_VERSION;
 845         reg_msg.pid = getpid();
 846         reg_msg.ppid = getppid();
 847         reg_msg.uid = getuid();
 848         reg_msg.gid = getgid();
 849         reg_msg.bits_per_long = bits_per_long;
 850         reg_msg.uint8_t_alignment = uint8_t_alignment;
 851         reg_msg.uint16_t_alignment = uint16_t_alignment;
 852         reg_msg.uint32_t_alignment = uint32_t_alignment;
 853         reg_msg.uint64_t_alignment = uint64_t_alignment;
 854         reg_msg.long_alignment = long_alignment;
 855         reg_msg.socket_type = type;
 856         lttng_pthread_getname_np(reg_msg.name, LTTNG_UST_ABI_PROCNAME_LEN);
 857         memset(reg_msg.padding, 0, sizeof(reg_msg.padding));
 858
 859         len = ustcomm_send_unix_sock(sock, &reg_msg, sizeof(reg_msg));
 860         if (len > 0 && len != sizeof(reg_msg))
 861                 return -EIO;
 862         if (len < 0)
 863                 return len;
 864         return 0;
 865 }
 866
 867 static
 868 ssize_t count_one_type(struct lttng_ust_type_common *lt)
 869 {
 870         switch (lt->type) {
 871         case lttng_ust_type_integer:
 872         case lttng_ust_type_float:
 873         case lttng_ust_type_string:
 874                 return 1;
 875         case lttng_ust_type_enum:
 876                 return count_one_type(lttng_ust_get_type_enum(lt)->container_type) + 1;
 877         case lttng_ust_type_array:
 878                 return count_one_type(lttng_ust_get_type_array(lt)->elem_type) + 1;
 879         case lttng_ust_type_sequence:
 880                 return count_one_type(lttng_ust_get_type_sequence(lt)->elem_type) + 1;
 881         case lttng_ust_type_struct:
 882                 return count_fields_recursive(lttng_ust_get_type_struct(lt)->nr_fields,
 883                                 lttng_ust_get_type_struct(lt)->fields) + 1;
 884
 885         case lttng_ust_type_dynamic:
 886         {
 887                 struct lttng_ust_event_field **choices;
 888                 size_t nr_choices;
 889                 int ret;
 890
 891                 ret = lttng_ust_dynamic_type_choices(&nr_choices,
 892                         &choices);
 893                 if (ret)
 894                         return ret;
 895                 /*
 896                  * Two fields for enum, one field for variant, and
 897                  * one field per choice.
 898                  */
 899                 return count_fields_recursive(nr_choices, choices) + 3;
 900         }
 901
 902         default:
 903                 return -EINVAL;
 904         }
 905         return 0;
 906 }
 907
 908 static
 909 ssize_t count_fields_recursive(size_t nr_fields,
 910                 struct lttng_ust_event_field **lttng_fields)
 911 {
 912         int i;
 913         ssize_t ret, count = 0;
 914
 915         for (i = 0; i < nr_fields; i++) {
 916                 const struct lttng_ust_event_field *lf;
 917
 918                 lf = lttng_fields[i];
 919                 /* skip 'nowrite' fields */
 920                 if (lf->nowrite)
 921                         continue;
 922                 ret = count_one_type(lf->type);
 923                 if (ret < 0)
 924                         return ret;     /* error */
 925                 count += ret;
 926         }
 927         return count;
 928 }
 929
 930 static
 931 ssize_t count_ctx_fields_recursive(size_t nr_fields,
 932                 struct lttng_ust_ctx_field **lttng_fields)
 933 {
 934         int i;
 935         ssize_t ret, count = 0;
 936
 937         for (i = 0; i < nr_fields; i++) {
 938                 const struct lttng_ust_event_field *lf;
 939
 940                 lf = lttng_fields[i]->event_field;
 941                 /* skip 'nowrite' fields */
 942                 if (lf->nowrite)
 943                         continue;
 944                 ret = count_one_type(lf->type);
 945                 if (ret < 0)
 946                         return ret;     /* error */
 947                 count += ret;
 948         }
 949         return count;
 950 }
 951
 952 static
 953 int serialize_string_encoding(int32_t *ue,
 954                 enum lttng_ust_string_encoding le)
 955 {
 956         switch (le) {
 957         case lttng_ust_string_encoding_none:
 958                 *ue = ustctl_encode_none;
 959                 break;
 960         case lttng_ust_string_encoding_UTF8:
 961                 *ue = ustctl_encode_UTF8;
 962                 break;
 963         case lttng_ust_string_encoding_ASCII:
 964                 *ue = ustctl_encode_ASCII;
 965                 break;
 966         default:
 967                 return -EINVAL;
 968         }
 969         return 0;
 970 }
 971
 972 static
 973 int serialize_integer_type(struct ustctl_integer_type *uit,
 974                 const struct lttng_ust_type_integer *lit,
 975                 enum lttng_ust_string_encoding lencoding)
 976 {
 977         int32_t encoding;
 978
 979         uit->size = lit->size;
 980         uit->signedness = lit->signedness;
 981         uit->reverse_byte_order = lit->reverse_byte_order;
 982         uit->base = lit->base;
 983         if (serialize_string_encoding(&encoding, lencoding))
 984                 return -EINVAL;
 985         uit->encoding = encoding;
 986         uit->alignment = lit->alignment;
 987         return 0;
 988 }
 989
 990 static
 991 int serialize_dynamic_type(struct lttng_ust_session *session,
 992                 struct ustctl_field *fields, size_t *iter_output,
 993                 const char *field_name)
 994 {
 995         struct lttng_ust_event_field **choices;
 996         char tag_field_name[LTTNG_UST_ABI_SYM_NAME_LEN];
 997         struct lttng_ust_type_common *tag_type;
 998         struct lttng_ust_event_field *tag_field_generic;
 999         struct lttng_ust_event_field tag_field = {
1000                 .name = tag_field_name,
1001                 .nowrite = 0,
1002         };
1003         struct ustctl_field *uf;
1004         size_t nr_choices, i;
1005         int ret;
1006
1007         tag_field_generic = lttng_ust_dynamic_type_tag_field();
1008         tag_type = tag_field_generic->type;
1009
1010         /* Serialize enum field. */
1011         strncpy(tag_field_name, field_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1012         tag_field_name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1013         strncat(tag_field_name,
1014                 "_tag",
1015                 LTTNG_UST_ABI_SYM_NAME_LEN - strlen(tag_field_name) - 1);
1016         tag_field.type = tag_type;
1017         ret = serialize_one_field(session, fields, iter_output,
1018                 &tag_field);
1019         if (ret)
1020                 return ret;
1021
1022         /* Serialize variant field. */
1023         uf = &fields[*iter_output];
1024         ret = lttng_ust_dynamic_type_choices(&nr_choices, &choices);
1025         if (ret)
1026                 return ret;
1027
1028         strncpy(uf->name, field_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1029         uf->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1030         uf->type.atype = ustctl_atype_variant;
1031         uf->type.u.variant_nestable.nr_choices = nr_choices;
1032         strncpy(uf->type.u.variant_nestable.tag_name,
1033                 tag_field_name,
1034                 LTTNG_UST_ABI_SYM_NAME_LEN);
1035         uf->type.u.variant_nestable.tag_name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1036         uf->type.u.variant_nestable.alignment = 0;
1037         (*iter_output)++;
1038
1039         /* Serialize choice fields after variant. */
1040         for (i = 0; i < nr_choices; i++) {
1041                 ret = serialize_one_field(session, fields,
1042                         iter_output, choices[i]);
1043                 if (ret)
1044                         return ret;
1045         }
1046         return 0;
1047 }
1048
1049 static
1050 int serialize_one_type(struct lttng_ust_session *session,
1051                 struct ustctl_field *fields, size_t *iter_output,
1052                 const char *field_name, struct lttng_ust_type_common *lt,
1053                 enum lttng_ust_string_encoding parent_encoding)
1054 {
1055         int ret;
1056
1057         /*
1058          * Serializing a type (rather than a field) generates a ustctl_field
1059          * entry with 0-length name.
1060          */
1061
1062         switch (lt->type) {
1063         case lttng_ust_type_integer:
1064         {
1065                 struct ustctl_field *uf = &fields[*iter_output];
1066                 struct ustctl_type *ut = &uf->type;
1067
1068                 if (field_name) {
1069                         strncpy(uf->name, field_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1070                         uf->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1071                 } else {
1072                         uf->name[0] = '\0';
1073                 }
1074                 ret = serialize_integer_type(&ut->u.integer, lttng_ust_get_type_integer(lt),
1075                                 parent_encoding);
1076                 if (ret)
1077                         return ret;
1078                 ut->atype = ustctl_atype_integer;
1079                 (*iter_output)++;
1080                 break;
1081         }
1082         case lttng_ust_type_float:
1083         {
1084                 struct ustctl_field *uf = &fields[*iter_output];
1085                 struct ustctl_type *ut = &uf->type;
1086                 struct ustctl_float_type *uft;
1087                 struct lttng_ust_type_float *lft;
1088
1089                 if (field_name) {
1090                         strncpy(uf->name, field_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1091                         uf->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1092                 } else {
1093                         uf->name[0] = '\0';
1094                 }
1095                 uft = &ut->u._float;
1096                 lft = lttng_ust_get_type_float(lt);
1097                 uft->exp_dig = lft->exp_dig;
1098                 uft->mant_dig = lft->mant_dig;
1099                 uft->alignment = lft->alignment;
1100                 uft->reverse_byte_order = lft->reverse_byte_order;
1101                 ut->atype = ustctl_atype_float;
1102                 (*iter_output)++;
1103                 break;
1104         }
1105         case lttng_ust_type_string:
1106         {
1107                 struct ustctl_field *uf = &fields[*iter_output];
1108                 struct ustctl_type *ut = &uf->type;
1109                 int32_t encoding;
1110
1111                 if (field_name) {
1112                         strncpy(uf->name, field_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1113                         uf->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1114                 } else {
1115                         uf->name[0] = '\0';
1116                 }
1117                 ret = serialize_string_encoding(&encoding, lttng_ust_get_type_string(lt)->encoding);
1118                 if (ret)
1119                         return ret;
1120                 ut->u.string.encoding = encoding;
1121                 ut->atype = ustctl_atype_string;
1122                 (*iter_output)++;
1123                 break;
1124         }
1125         case lttng_ust_type_array:
1126         {
1127                 struct ustctl_field *uf = &fields[*iter_output];
1128                 struct ustctl_type *ut = &uf->type;
1129
1130                 if (field_name) {
1131                         strncpy(uf->name, field_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1132                         uf->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1133                 } else {
1134                         uf->name[0] = '\0';
1135                 }
1136                 ut->atype = ustctl_atype_array_nestable;
1137                 ut->u.array_nestable.length = lttng_ust_get_type_array(lt)->length;
1138                 ut->u.array_nestable.alignment = lttng_ust_get_type_array(lt)->alignment;
1139                 (*iter_output)++;
1140
1141                 ret = serialize_one_type(session, fields, iter_output, NULL,
1142                                 lttng_ust_get_type_array(lt)->elem_type,
1143                                 lttng_ust_get_type_array(lt)->encoding);
1144                 if (ret)
1145                         return -EINVAL;
1146                 break;
1147         }
1148         case lttng_ust_type_sequence:
1149         {
1150                 struct ustctl_field *uf = &fields[*iter_output];
1151                 struct ustctl_type *ut = &uf->type;
1152
1153                 if (field_name) {
1154                         strncpy(uf->name, field_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1155                         uf->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1156                 } else {
1157                         uf->name[0] = '\0';
1158                 }
1159                 ut->atype = ustctl_atype_sequence_nestable;
1160                 strncpy(ut->u.sequence_nestable.length_name,
1161                         lttng_ust_get_type_sequence(lt)->length_name,
1162                         LTTNG_UST_ABI_SYM_NAME_LEN);
1163                 ut->u.sequence_nestable.length_name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1164                 ut->u.sequence_nestable.alignment = lttng_ust_get_type_sequence(lt)->alignment;
1165                 (*iter_output)++;
1166
1167                 ret = serialize_one_type(session, fields, iter_output, NULL,
1168                                 lttng_ust_get_type_sequence(lt)->elem_type,
1169                                 lttng_ust_get_type_sequence(lt)->encoding);
1170                 if (ret)
1171                         return -EINVAL;
1172                 break;
1173         }
1174         case lttng_ust_type_dynamic:
1175         {
1176                 ret = serialize_dynamic_type(session, fields, iter_output,
1177                                 field_name);
1178                 if (ret)
1179                         return -EINVAL;
1180                 break;
1181         }
1182         case lttng_ust_type_struct:
1183         {
1184                 struct ustctl_field *uf = &fields[*iter_output];
1185
1186                 if (field_name) {
1187                         strncpy(uf->name, field_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1188                         uf->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1189                 } else {
1190                         uf->name[0] = '\0';
1191                 }
1192                 uf->type.atype = ustctl_atype_struct_nestable;
1193                 uf->type.u.struct_nestable.nr_fields = lttng_ust_get_type_struct(lt)->nr_fields;
1194                 uf->type.u.struct_nestable.alignment = lttng_ust_get_type_struct(lt)->alignment;
1195                 (*iter_output)++;
1196
1197                 ret = serialize_fields(session, fields, iter_output,
1198                                 lttng_ust_get_type_struct(lt)->nr_fields,
1199                                 lttng_ust_get_type_struct(lt)->fields);
1200                 if (ret)
1201                         return -EINVAL;
1202                 break;
1203         }
1204         case lttng_ust_type_enum:
1205         {
1206                 struct ustctl_field *uf = &fields[*iter_output];
1207                 struct ustctl_type *ut = &uf->type;
1208
1209                 if (field_name) {
1210                         strncpy(uf->name, field_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1211                         uf->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1212                 } else {
1213                         uf->name[0] = '\0';
1214                 }
1215                 strncpy(ut->u.enum_nestable.name, lttng_ust_get_type_enum(lt)->desc->name,
1216                                 LTTNG_UST_ABI_SYM_NAME_LEN);
1217                 ut->u.enum_nestable.name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1218                 ut->atype = ustctl_atype_enum_nestable;
1219                 (*iter_output)++;
1220
1221                 ret = serialize_one_type(session, fields, iter_output, NULL,
1222                                 lttng_ust_get_type_enum(lt)->container_type,
1223                                 lttng_ust_string_encoding_none);
1224                 if (ret)
1225                         return -EINVAL;
1226                 if (session) {
1227                         const struct lttng_enum *_enum;
1228
1229                         _enum = lttng_ust_enum_get_from_desc(session, lttng_ust_get_type_enum(lt)->desc);
1230                         if (!_enum)
1231                                 return -EINVAL;
1232                         ut->u.enum_nestable.id = _enum->id;
1233                 } else {
1234                         ut->u.enum_nestable.id = -1ULL;
1235                 }
1236                 break;
1237         }
1238         default:
1239                 return -EINVAL;
1240         }
1241         return 0;
1242 }
1243
1244 static
1245 int serialize_one_field(struct lttng_ust_session *session,
1246                 struct ustctl_field *fields, size_t *iter_output,
1247                 struct lttng_ust_event_field *lf)
1248 {
1249         /* skip 'nowrite' fields */
1250         if (lf->nowrite)
1251                 return 0;
1252
1253         return serialize_one_type(session, fields, iter_output, lf->name, lf->type, lttng_ust_string_encoding_none);
1254 }
1255
1256 static
1257 int serialize_fields(struct lttng_ust_session *session,
1258                 struct ustctl_field *ustctl_fields,
1259                 size_t *iter_output, size_t nr_lttng_fields,
1260                 struct lttng_ust_event_field **lttng_fields)
1261 {
1262         int ret;
1263         size_t i;
1264
1265         for (i = 0; i < nr_lttng_fields; i++) {
1266                 ret = serialize_one_field(session, ustctl_fields,
1267                                 iter_output, lttng_fields[i]);
1268                 if (ret)
1269                         return ret;
1270         }
1271         return 0;
1272 }
1273
1274 static
1275 int alloc_serialize_fields(struct lttng_ust_session *session,
1276                 size_t *_nr_write_fields,
1277                 struct ustctl_field **ustctl_fields,
1278                 size_t nr_fields,
1279                 struct lttng_ust_event_field **lttng_fields)
1280 {
1281         struct ustctl_field *fields;
1282         int ret;
1283         size_t iter_output = 0;
1284         ssize_t nr_write_fields;
1285
1286         nr_write_fields = count_fields_recursive(nr_fields, lttng_fields);
1287         if (nr_write_fields < 0) {
1288                 return (int) nr_write_fields;
1289         }
1290
1291         fields = zmalloc(nr_write_fields * sizeof(*fields));
1292         if (!fields)
1293                 return -ENOMEM;
1294
1295         ret = serialize_fields(session, fields, &iter_output, nr_fields,
1296                         lttng_fields);
1297         if (ret)
1298                 goto error_type;
1299
1300         *_nr_write_fields = nr_write_fields;
1301         *ustctl_fields = fields;
1302         return 0;
1303
1304 error_type:
1305         free(fields);
1306         return ret;
1307 }
1308
1309 static
1310 int serialize_entries(struct ustctl_enum_entry **_entries,
1311                 size_t nr_entries,
1312                 struct lttng_ust_enum_entry **lttng_entries)
1313 {
1314         struct ustctl_enum_entry *entries;
1315         int i;
1316
1317         /* Serialize the entries */
1318         entries = zmalloc(nr_entries * sizeof(*entries));
1319         if (!entries)
1320                 return -ENOMEM;
1321         for (i = 0; i < nr_entries; i++) {
1322                 struct ustctl_enum_entry *uentry;
1323                 const struct lttng_ust_enum_entry *lentry;
1324
1325                 uentry = &entries[i];
1326                 lentry = lttng_entries[i];
1327
1328                 uentry->start.value = lentry->start.value;
1329                 uentry->start.signedness = lentry->start.signedness;
1330                 uentry->end.value = lentry->end.value;
1331                 uentry->end.signedness = lentry->end.signedness;
1332                 strncpy(uentry->string, lentry->string, LTTNG_UST_ABI_SYM_NAME_LEN);
1333                 uentry->string[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1334
1335                 if (lentry->options & LTTNG_ENUM_ENTRY_OPTION_IS_AUTO) {
1336                         uentry->u.extra.options |=
1337                                 USTCTL_UST_ENUM_ENTRY_OPTION_IS_AUTO;
1338                 }
1339         }
1340         *_entries = entries;
1341         return 0;
1342 }
1343
1344 static
1345 int serialize_ctx_fields(struct lttng_ust_session *session,
1346                 size_t *_nr_write_fields,
1347                 struct ustctl_field **ustctl_fields,
1348                 size_t nr_fields,
1349                 struct lttng_ust_ctx_field **lttng_fields)
1350 {
1351         struct ustctl_field *fields;
1352         int ret;
1353         size_t i, iter_output = 0;
1354         ssize_t nr_write_fields;
1355
1356         nr_write_fields = count_ctx_fields_recursive(nr_fields,
1357                         lttng_fields);
1358         if (nr_write_fields < 0) {
1359                 return (int) nr_write_fields;
1360         }
1361
1362         fields = zmalloc(nr_write_fields * sizeof(*fields));
1363         if (!fields)
1364                 return -ENOMEM;
1365
1366         for (i = 0; i < nr_fields; i++) {
1367                 ret = serialize_one_field(session, fields, &iter_output,
1368                                 lttng_fields[i]->event_field);
1369                 if (ret)
1370                         goto error_type;
1371         }
1372
1373         *_nr_write_fields = nr_write_fields;
1374         *ustctl_fields = fields;
1375         return 0;
1376
1377 error_type:
1378         free(fields);
1379         return ret;
1380 }
1381
1382 /*
1383  * Returns 0 on success, negative error value on error.
1384  */
1385 int ustcomm_register_event(int sock,
1386         struct lttng_ust_session *session,
1387         int session_objd,               /* session descriptor */
1388         int channel_objd,               /* channel descriptor */
1389         const char *event_name,         /* event name (input) */
1390         int loglevel,
1391         const char *signature,          /* event signature (input) */
1392         size_t nr_fields,               /* fields */
1393         struct lttng_ust_event_field **lttng_fields,
1394         const char *model_emf_uri,
1395         uint32_t *id)                   /* event id (output) */
1396 {
1397         ssize_t len;
1398         struct {
1399                 struct ustcomm_notify_hdr header;
1400                 struct ustcomm_notify_event_msg m;
1401         } msg;
1402         struct {
1403                 struct ustcomm_notify_hdr header;
1404                 struct ustcomm_notify_event_reply r;
1405         } reply;
1406         size_t signature_len, fields_len, model_emf_uri_len;
1407         struct ustctl_field *fields = NULL;
1408         size_t nr_write_fields = 0;
1409         int ret;
1410
1411         memset(&msg, 0, sizeof(msg));
1412         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
1413         msg.m.session_objd = session_objd;
1414         msg.m.channel_objd = channel_objd;
1415         strncpy(msg.m.event_name, event_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1416         msg.m.event_name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1417         msg.m.loglevel = loglevel;
1418         signature_len = strlen(signature) + 1;
1419         msg.m.signature_len = signature_len;
1420
1421         /* Calculate fields len, serialize fields. */
1422         if (nr_fields > 0) {
1423                 ret = alloc_serialize_fields(session, &nr_write_fields, &fields,
1424                                 nr_fields, lttng_fields);
1425                 if (ret)
1426                         return ret;
1427         }
1428
1429         fields_len = sizeof(*fields) * nr_write_fields;
1430         msg.m.fields_len = fields_len;
1431         if (model_emf_uri) {
1432                 model_emf_uri_len = strlen(model_emf_uri) + 1;
1433         } else {
1434                 model_emf_uri_len = 0;
1435         }
1436         msg.m.model_emf_uri_len = model_emf_uri_len;
1437
1438         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1439         if (len > 0 && len != sizeof(msg)) {
1440                 ret = -EIO;
1441                 goto error_fields;
1442         }
1443         if (len < 0) {
1444                 ret = len;
1445                 goto error_fields;
1446         }
1447
1448         /* send signature */
1449         len = ustcomm_send_unix_sock(sock, signature, signature_len);
1450         if (len > 0 && len != signature_len) {
1451                 ret = -EIO;
1452                 goto error_fields;
1453         }
1454         if (len < 0) {
1455                 ret = len;
1456                 goto error_fields;
1457         }
1458
1459         /* send fields */
1460         if (fields_len > 0) {
1461                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1462                 if (len > 0 && len != fields_len) {
1463                         ret = -EIO;
1464                         goto error_fields;
1465                 }
1466                 if (len < 0) {
1467                         ret = len;
1468                         goto error_fields;
1469                 }
1470         }
1471         free(fields);
1472
1473         if (model_emf_uri_len) {
1474                 /* send model_emf_uri */
1475                 len = ustcomm_send_unix_sock(sock, model_emf_uri,
1476                                 model_emf_uri_len);
1477                 if (len > 0 && len != model_emf_uri_len) {
1478                         return -EIO;
1479                 }
1480                 if (len < 0) {
1481                         return len;
1482                 }
1483         }
1484
1485         /* receive reply */
1486         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1487         switch (len) {
1488         case 0: /* orderly shutdown */
1489                 return -EPIPE;
1490         case sizeof(reply):
1491                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1492                         ERR("Unexpected result message command "
1493                                 "expected: %u vs received: %u\n",
1494                                 msg.header.notify_cmd, reply.header.notify_cmd);
1495                         return -EINVAL;
1496                 }
1497                 if (reply.r.ret_code > 0)
1498                         return -EINVAL;
1499                 if (reply.r.ret_code < 0)
1500                         return reply.r.ret_code;
1501                 *id = reply.r.event_id;
1502                 DBG("Sent register event notification for name \"%s\": ret_code %d, event_id %u\n",
1503                         event_name, reply.r.ret_code, reply.r.event_id);
1504                 return 0;
1505         default:
1506                 if (len < 0) {
1507                         /* Transport level error */
1508                         if (errno == EPIPE || errno == ECONNRESET)
1509                                 len = -errno;
1510                         return len;
1511                 } else {
1512                         ERR("incorrect message size: %zd\n", len);
1513                         return len;
1514                 }
1515         }
1516         /* Unreached. */
1517
1518         /* Error path only. */
1519 error_fields:
1520         free(fields);
1521         return ret;
1522 }
1523
1524 /*
1525  * Returns 0 on success, negative error value on error.
1526  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1527  */
1528 int ustcomm_register_enum(int sock,
1529         int session_objd,               /* session descriptor */
1530         const char *enum_name,          /* enum name (input) */
1531         size_t nr_entries,              /* entries */
1532         struct lttng_ust_enum_entry **lttng_entries,
1533         uint64_t *id)
1534 {
1535         ssize_t len;
1536         struct {
1537                 struct ustcomm_notify_hdr header;
1538                 struct ustcomm_notify_enum_msg m;
1539         } msg;
1540         struct {
1541                 struct ustcomm_notify_hdr header;
1542                 struct ustcomm_notify_enum_reply r;
1543         } reply;
1544         size_t entries_len;
1545         struct ustctl_enum_entry *entries = NULL;
1546         int ret;
1547
1548         memset(&msg, 0, sizeof(msg));
1549         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_ENUM;
1550         msg.m.session_objd = session_objd;
1551         strncpy(msg.m.enum_name, enum_name, LTTNG_UST_ABI_SYM_NAME_LEN);
1552         msg.m.enum_name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1553
1554         /* Calculate entries len, serialize entries. */
1555         if (nr_entries > 0) {
1556                 ret = serialize_entries(&entries,
1557                                 nr_entries, lttng_entries);
1558                 if (ret)
1559                         return ret;
1560         }
1561
1562         entries_len = sizeof(*entries) * nr_entries;
1563         msg.m.entries_len = entries_len;
1564
1565         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1566         if (len > 0 && len != sizeof(msg)) {
1567                 ret = -EIO;
1568                 goto error_entries;
1569         }
1570         if (len < 0) {
1571                 ret = len;
1572                 goto error_entries;
1573         }
1574
1575         /* send entries */
1576         if (entries_len > 0) {
1577                 len = ustcomm_send_unix_sock(sock, entries, entries_len);
1578                 if (len > 0 && len != entries_len) {
1579                         ret = -EIO;
1580                         goto error_entries;
1581                 }
1582                 if (len < 0) {
1583                         ret = len;
1584                         goto error_entries;
1585                 }
1586         }
1587         free(entries);
1588         entries = NULL;
1589
1590         /* receive reply */
1591         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1592         switch (len) {
1593         case 0: /* orderly shutdown */
1594                 return -EPIPE;
1595         case sizeof(reply):
1596                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1597                         ERR("Unexpected result message command "
1598                                 "expected: %u vs received: %u\n",
1599                                 msg.header.notify_cmd, reply.header.notify_cmd);
1600                         return -EINVAL;
1601                 }
1602                 if (reply.r.ret_code > 0)
1603                         return -EINVAL;
1604                 if (reply.r.ret_code < 0)
1605                         return reply.r.ret_code;
1606                 *id = reply.r.enum_id;
1607                 DBG("Sent register enum notification for name \"%s\": ret_code %d\n",
1608                         enum_name, reply.r.ret_code);
1609                 return 0;
1610         default:
1611                 if (len < 0) {
1612                         /* Transport level error */
1613                         if (errno == EPIPE || errno == ECONNRESET)
1614                                 len = -errno;
1615                         return len;
1616                 } else {
1617                         ERR("incorrect message size: %zd\n", len);
1618                         return len;
1619                 }
1620         }
1621         return ret;
1622
1623 error_entries:
1624         free(entries);
1625         return ret;
1626 }
1627
1628 /*
1629  * Returns 0 on success, negative error value on error.
1630  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1631  */
1632 int ustcomm_register_channel(int sock,
1633         struct lttng_ust_session *session,
1634         int session_objd,               /* session descriptor */
1635         int channel_objd,               /* channel descriptor */
1636         size_t nr_ctx_fields,
1637         struct lttng_ust_ctx_field **ctx_fields,
1638         uint32_t *chan_id,              /* channel id (output) */
1639         int *header_type)               /* header type (output) */
1640 {
1641         ssize_t len;
1642         struct {
1643                 struct ustcomm_notify_hdr header;
1644                 struct ustcomm_notify_channel_msg m;
1645         } msg;
1646         struct {
1647                 struct ustcomm_notify_hdr header;
1648                 struct ustcomm_notify_channel_reply r;
1649         } reply;
1650         size_t fields_len;
1651         struct ustctl_field *fields = NULL;
1652         int ret;
1653         size_t nr_write_fields = 0;
1654
1655         memset(&msg, 0, sizeof(msg));
1656         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1657         msg.m.session_objd = session_objd;
1658         msg.m.channel_objd = channel_objd;
1659
1660         /* Calculate fields len, serialize fields. */
1661         if (nr_ctx_fields > 0) {
1662                 ret = serialize_ctx_fields(session, &nr_write_fields, &fields,
1663                                 nr_ctx_fields, ctx_fields);
1664                 if (ret)
1665                         return ret;
1666         }
1667
1668         fields_len = sizeof(*fields) * nr_write_fields;
1669         msg.m.ctx_fields_len = fields_len;
1670         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1671         if (len > 0 && len != sizeof(msg)) {
1672                 free(fields);
1673                 return -EIO;
1674         }
1675         if (len < 0) {
1676                 free(fields);
1677                 return len;
1678         }
1679
1680         /* send fields */
1681         if (fields_len > 0) {
1682                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1683                 free(fields);
1684                 if (len > 0 && len != fields_len) {
1685                         return -EIO;
1686                 }
1687                 if (len < 0) {
1688                         return len;
1689                 }
1690         } else {
1691                 free(fields);
1692         }
1693
1694         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1695         switch (len) {
1696         case 0: /* orderly shutdown */
1697                 return -EPIPE;
1698         case sizeof(reply):
1699                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1700                         ERR("Unexpected result message command "
1701                                 "expected: %u vs received: %u\n",
1702                                 msg.header.notify_cmd, reply.header.notify_cmd);
1703                         return -EINVAL;
1704                 }
1705                 if (reply.r.ret_code > 0)
1706                         return -EINVAL;
1707                 if (reply.r.ret_code < 0)
1708                         return reply.r.ret_code;
1709                 *chan_id = reply.r.chan_id;
1710                 switch (reply.r.header_type) {
1711                 case 1:
1712                 case 2:
1713                         *header_type = reply.r.header_type;
1714                         break;
1715                 default:
1716                         ERR("Unexpected channel header type %u\n",
1717                                 reply.r.header_type);
1718                         return -EINVAL;
1719                 }
1720                 DBG("Sent register channel notification: chan_id %d, header_type %d\n",
1721                         reply.r.chan_id, reply.r.header_type);
1722                 return 0;
1723         default:
1724                 if (len < 0) {
1725                         /* Transport level error */
1726                         if (errno == EPIPE || errno == ECONNRESET)
1727                                 len = -errno;
1728                         return len;
1729                 } else {
1730                         ERR("incorrect message size: %zd\n", len);
1731                         return len;
1732                 }
1733         }
1734 }
1735
1736 /*
1737  * Set socket reciving timeout.
1738  */
1739 int ustcomm_setsockopt_rcv_timeout(int sock, unsigned int msec)
1740 {
1741         int ret;
1742         struct timeval tv;
1743
1744         tv.tv_sec = msec / 1000;
1745         tv.tv_usec = (msec * 1000 % 1000000);
1746
1747         ret = setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
1748         if (ret < 0) {
1749                 PERROR("setsockopt SO_RCVTIMEO");
1750                 ret = -errno;
1751         }
1752
1753         return ret;
1754 }
1755
1756 /*
1757  * Set socket sending timeout.
1758  */
1759 int ustcomm_setsockopt_snd_timeout(int sock, unsigned int msec)
1760 {
1761         int ret;
1762         struct timeval tv;
1763
1764         tv.tv_sec = msec / 1000;
1765         tv.tv_usec = (msec * 1000) % 1000000;
1766
1767         ret = setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
1768         if (ret < 0) {
1769                 PERROR("setsockopt SO_SNDTIMEO");
1770                 ret = -errno;
1771         }
1772
1773         return ret;
1774 }