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 #define _GNU_SOURCE
  21 #include <limits.h>
  22 #include <stdint.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <sys/socket.h>
  27 #include <sys/stat.h>
  28 #include <sys/types.h>
  29 #include <sys/un.h>
  30 #include <unistd.h>
  31 #include <assert.h>
  32 #include <errno.h>
  33 #include <fcntl.h>
  34
  35 #include <lttng/ust-ctl.h>
  36 #include <ust-comm.h>
  37 #include <ust-fd.h>
  38 #include <helper.h>
  39 #include <lttng/ust-error.h>
  40 #include <lttng/ust-events.h>
  41 #include <lttng/ust-dynamic-type.h>
  42 #include <usterr-signal-safe.h>
  43
  44 #include "../liblttng-ust/compat.h"
  45
  46 #define USTCOMM_CODE_OFFSET(code)       \
  47         (code == LTTNG_UST_OK ? 0 : (code - LTTNG_UST_ERR + 1))
  48
  49 #define USTCOMM_MAX_SEND_FDS    4
  50
  51 static
  52 ssize_t count_fields_recursive(size_t nr_fields,
  53                 const struct lttng_event_field *lttng_fields);
  54 static
  55 int serialize_one_field(struct lttng_session *session,
  56                 struct ustctl_field *fields, size_t *iter_output,
  57                 const struct lttng_event_field *lf);
  58 static
  59 int serialize_fields(struct lttng_session *session,
  60                 struct ustctl_field *ustctl_fields,
  61                 size_t *iter_output, size_t nr_lttng_fields,
  62                 const struct lttng_event_field *lttng_fields);
  63
  64 /*
  65  * Human readable error message.
  66  */
  67 static const char *ustcomm_readable_code[] = {
  68         [ USTCOMM_CODE_OFFSET(LTTNG_UST_OK) ] = "Success",
  69         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR) ] = "Unknown error",
  70         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOENT) ] = "No entry",
  71         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_EXIST) ] = "Object already exists",
  72         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL) ] = "Invalid argument",
  73         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_PERM) ] = "Permission denied",
  74         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOSYS) ] = "Not implemented",
  75         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_EXITING) ] = "Process is exiting",
  76
  77         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL_MAGIC) ] = "Invalid magic number",
  78         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL_SOCKET_TYPE) ] = "Invalid socket type",
  79         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_UNSUP_MAJOR) ] = "Unsupported major version",
  80 };
  81
  82 /*
  83  * lttng_ust_strerror
  84  *
  85  * Receives positive error value.
  86  * Return ptr to string representing a human readable
  87  * error code from the ustcomm_return_code enum.
  88  */
  89 const char *lttng_ust_strerror(int code)
  90 {
  91         if (code == LTTNG_UST_OK)
  92                 return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)];
  93         if (code < LTTNG_UST_ERR)
  94                 return strerror(code);
  95         if (code >= LTTNG_UST_ERR_NR)
  96                 code = LTTNG_UST_ERR;
  97         return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)];
  98 }
  99
 100 /*
 101  * ustcomm_connect_unix_sock
 102  *
 103  * Connect to unix socket using the path name.
 104  *
 105  * Caller handles FD tracker.
 106  */
 107 int ustcomm_connect_unix_sock(const char *pathname, long timeout)
 108 {
 109         struct sockaddr_un sun;
 110         int fd, ret;
 111
 112         /*
 113          * libust threads require the close-on-exec flag for all
 114          * resources so it does not leak file descriptors upon exec.
 115          * SOCK_CLOEXEC is not used since it is linux specific.
 116          */
 117         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 118         if (fd < 0) {
 119                 PERROR("socket");
 120                 ret = -errno;
 121                 goto error;
 122         }
 123         if (timeout >= 0) {
 124                 /* Give at least 10ms. */
 125                 if (timeout < 10)
 126                         timeout = 10;
 127                 ret = ustcomm_setsockopt_snd_timeout(fd, timeout);
 128                 if (ret < 0) {
 129                         WARN("Error setting connect socket send timeout");
 130                 }
 131         }
 132         ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
 133         if (ret < 0) {
 134                 PERROR("fcntl");
 135                 ret = -errno;
 136                 goto error_fcntl;
 137         }
 138
 139         memset(&sun, 0, sizeof(sun));
 140         sun.sun_family = AF_UNIX;
 141         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 142         sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
 143
 144         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
 145         if (ret < 0) {
 146                 /*
 147                  * Don't print message on connect ENOENT error, because
 148                  * connect is used in normal execution to detect if
 149                  * sessiond is alive. ENOENT is when the unix socket
 150                  * file does not exist, and ECONNREFUSED is when the
 151                  * file exists but no sessiond is listening.
 152                  */
 153                 if (errno != ECONNREFUSED && errno != ECONNRESET
 154                                 && errno != ENOENT && errno != EACCES)
 155                         PERROR("connect");
 156                 ret = -errno;
 157                 if (ret == -ECONNREFUSED || ret == -ECONNRESET)
 158                         ret = -EPIPE;
 159                 goto error_connect;
 160         }
 161
 162         return fd;
 163
 164 error_connect:
 165 error_fcntl:
 166         {
 167                 int closeret;
 168
 169                 closeret = close(fd);
 170                 if (closeret)
 171                         PERROR("close");
 172         }
 173 error:
 174         return ret;
 175 }
 176
 177 /*
 178  * ustcomm_accept_unix_sock
 179  *
 180  * Do an accept(2) on the sock and return the
 181  * new file descriptor. The socket MUST be bind(2) before.
 182  */
 183 int ustcomm_accept_unix_sock(int sock)
 184 {
 185         int new_fd;
 186         struct sockaddr_un sun;
 187         socklen_t len = 0;
 188
 189         /* Blocking call */
 190         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 191         if (new_fd < 0) {
 192                 if (errno != ECONNABORTED)
 193                         PERROR("accept");
 194                 new_fd = -errno;
 195                 if (new_fd == -ECONNABORTED)
 196                         new_fd = -EPIPE;
 197         }
 198         return new_fd;
 199 }
 200
 201 /*
 202  * ustcomm_create_unix_sock
 203  *
 204  * Creates a AF_UNIX local socket using pathname
 205  * bind the socket upon creation and return the fd.
 206  */
 207 int ustcomm_create_unix_sock(const char *pathname)
 208 {
 209         struct sockaddr_un sun;
 210         int fd, ret;
 211
 212         /* Create server socket */
 213         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 214                 PERROR("socket");
 215                 ret = -errno;
 216                 goto error;
 217         }
 218
 219         memset(&sun, 0, sizeof(sun));
 220         sun.sun_family = AF_UNIX;
 221         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 222         sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
 223
 224         /* Unlink the old file if present */
 225         (void) unlink(pathname);
 226         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 227         if (ret < 0) {
 228                 PERROR("bind");
 229                 ret = -errno;
 230                 goto error_close;
 231         }
 232
 233         return fd;
 234
 235 error_close:
 236         {
 237                 int closeret;
 238
 239                 closeret = close(fd);
 240                 if (closeret) {
 241                         PERROR("close");
 242                 }
 243         }
 244 error:
 245         return ret;
 246 }
 247
 248 /*
 249  * ustcomm_listen_unix_sock
 250  *
 251  * Make the socket listen using LTTNG_UST_COMM_MAX_LISTEN.
 252  */
 253 int ustcomm_listen_unix_sock(int sock)
 254 {
 255         int ret;
 256
 257         ret = listen(sock, LTTNG_UST_COMM_MAX_LISTEN);
 258         if (ret < 0) {
 259                 ret = -errno;
 260                 PERROR("listen");
 261         }
 262
 263         return ret;
 264 }
 265
 266 /*
 267  * ustcomm_close_unix_sock
 268  *
 269  * Shutdown cleanly a unix socket.
 270  *
 271  * Handles fd tracker internally.
 272  */
 273 int ustcomm_close_unix_sock(int sock)
 274 {
 275         int ret;
 276
 277         lttng_ust_lock_fd_tracker();
 278         ret = close(sock);
 279         if (!ret) {
 280                 lttng_ust_delete_fd_from_tracker(sock);
 281         } else {
 282                 PERROR("close");
 283                 ret = -errno;
 284         }
 285         lttng_ust_unlock_fd_tracker();
 286
 287         return ret;
 288 }
 289
 290 /*
 291  * ustcomm_recv_unix_sock
 292  *
 293  * Receive data of size len in put that data into
 294  * the buf param. Using recvmsg API.
 295  * Return the size of received data.
 296  * Return 0 on orderly shutdown.
 297  */
 298 ssize_t ustcomm_recv_unix_sock(int sock, void *buf, size_t len)
 299 {
 300         struct msghdr msg;
 301         struct iovec iov[1];
 302         ssize_t ret = -1;
 303         size_t len_last;
 304
 305         memset(&msg, 0, sizeof(msg));
 306
 307         iov[0].iov_base = buf;
 308         iov[0].iov_len = len;
 309         msg.msg_iov = iov;
 310         msg.msg_iovlen = 1;
 311
 312         do {
 313                 len_last = iov[0].iov_len;
 314                 ret = recvmsg(sock, &msg, 0);
 315                 if (ret > 0) {
 316                         iov[0].iov_base += ret;
 317                         iov[0].iov_len -= ret;
 318                         assert(ret <= len_last);
 319                 }
 320         } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
 321
 322         if (ret < 0) {
 323                 int shutret;
 324
 325                 if (errno != EPIPE && errno != ECONNRESET && errno != ECONNREFUSED)
 326                         PERROR("recvmsg");
 327                 ret = -errno;
 328                 if (ret == -ECONNRESET || ret == -ECONNREFUSED)
 329                         ret = -EPIPE;
 330
 331                 shutret = shutdown(sock, SHUT_RDWR);
 332                 if (shutret)
 333                         ERR("Socket shutdown error");
 334         } else if (ret > 0) {
 335                 ret = len;
 336         }
 337         /* ret = 0 means an orderly shutdown. */
 338
 339         return ret;
 340 }
 341
 342 /*
 343  * ustcomm_send_unix_sock
 344  *
 345  * Send buf data of size len. Using sendmsg API.
 346  * Return the size of sent data.
 347  */
 348 ssize_t ustcomm_send_unix_sock(int sock, const void *buf, size_t len)
 349 {
 350         struct msghdr msg;
 351         struct iovec iov[1];
 352         ssize_t ret;
 353
 354         memset(&msg, 0, sizeof(msg));
 355
 356         iov[0].iov_base = (void *) buf;
 357         iov[0].iov_len = len;
 358         msg.msg_iov = iov;
 359         msg.msg_iovlen = 1;
 360
 361         /*
 362          * Using the MSG_NOSIGNAL when sending data from sessiond to
 363          * libust, so libust does not receive an unhandled SIGPIPE or
 364          * SIGURG. The sessiond receiver side can be made more resilient
 365          * by ignoring SIGPIPE, but we don't have this luxury on the
 366          * libust side.
 367          */
 368         do {
 369                 ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
 370         } while (ret < 0 && errno == EINTR);
 371
 372         if (ret < 0) {
 373                 int shutret;
 374
 375                 if (errno != EPIPE && errno != ECONNRESET)
 376                         PERROR("sendmsg");
 377                 ret = -errno;
 378                 if (ret == -ECONNRESET)
 379                         ret = -EPIPE;
 380
 381                 shutret = shutdown(sock, SHUT_RDWR);
 382                 if (shutret)
 383                         ERR("Socket shutdown error");
 384         }
 385
 386         return ret;
 387 }
 388
 389 /*
 390  * Send a message accompanied by fd(s) over a unix socket.
 391  *
 392  * Returns the size of data sent, or negative error value.
 393  */
 394 ssize_t ustcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 395 {
 396         struct msghdr msg;
 397         struct cmsghdr *cmptr;
 398         struct iovec iov[1];
 399         ssize_t ret = -1;
 400         unsigned int sizeof_fds = nb_fd * sizeof(int);
 401         char tmp[CMSG_SPACE(sizeof_fds)];
 402         char dummy = 0;
 403
 404         memset(&msg, 0, sizeof(msg));
 405         memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));
 406
 407         if (nb_fd > USTCOMM_MAX_SEND_FDS)
 408                 return -EINVAL;
 409
 410         msg.msg_control = (caddr_t)tmp;
 411         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 412
 413         cmptr = CMSG_FIRSTHDR(&msg);
 414         if (!cmptr)
 415                 return -EINVAL;
 416         cmptr->cmsg_level = SOL_SOCKET;
 417         cmptr->cmsg_type = SCM_RIGHTS;
 418         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 419         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 420         /* Sum of the length of all control messages in the buffer: */
 421         msg.msg_controllen = cmptr->cmsg_len;
 422
 423         iov[0].iov_base = &dummy;
 424         iov[0].iov_len = 1;
 425         msg.msg_iov = iov;
 426         msg.msg_iovlen = 1;
 427
 428         do {
 429                 ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
 430         } while (ret < 0 && errno == EINTR);
 431         if (ret < 0) {
 432                 /*
 433                  * We consider EPIPE and ECONNRESET as expected.
 434                  */
 435                 if (errno != EPIPE && errno != ECONNRESET) {
 436                         PERROR("sendmsg");
 437                 }
 438                 ret = -errno;
 439                 if (ret == -ECONNRESET)
 440                         ret = -EPIPE;
 441         }
 442         return ret;
 443 }
 444
 445 /*
 446  * Recv a message accompanied by fd(s) from a unix socket.
 447  *
 448  * Expect at most "nb_fd" file descriptors. Returns the number of fd
 449  * actually received in nb_fd.
 450  * Returns -EPIPE on orderly shutdown.
 451  */
 452 ssize_t ustcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 453 {
 454         struct iovec iov[1];
 455         ssize_t ret = 0;
 456         struct cmsghdr *cmsg;
 457         size_t sizeof_fds = nb_fd * sizeof(int);
 458         char recv_fd[CMSG_SPACE(sizeof_fds)];
 459         struct msghdr msg;
 460         char dummy;
 461         int i;
 462
 463         memset(&msg, 0, sizeof(msg));
 464
 465         /* Prepare to receive the structures */
 466         iov[0].iov_base = &dummy;
 467         iov[0].iov_len = 1;
 468         msg.msg_iov = iov;
 469         msg.msg_iovlen = 1;
 470         msg.msg_control = recv_fd;
 471         msg.msg_controllen = sizeof(recv_fd);
 472
 473         do {
 474                 ret = recvmsg(sock, &msg, 0);
 475         } while (ret < 0 && errno == EINTR);
 476         if (ret < 0) {
 477                 if (errno != EPIPE && errno != ECONNRESET) {
 478                         PERROR("recvmsg fds");
 479                 }
 480                 ret = -errno;
 481                 if (ret == -ECONNRESET)
 482                         ret = -EPIPE;
 483                 goto end;
 484         }
 485         if (ret == 0) {
 486                 /* orderly shutdown */
 487                 ret = -EPIPE;
 488                 goto end;
 489         }
 490         if (ret != 1) {
 491                 ERR("Error: Received %zd bytes, expected %d\n",
 492                                 ret, 1);
 493                 goto end;
 494         }
 495         if (msg.msg_flags & MSG_CTRUNC) {
 496                 ERR("Error: Control message truncated.\n");
 497                 ret = -1;
 498                 goto end;
 499         }
 500         cmsg = CMSG_FIRSTHDR(&msg);
 501         if (!cmsg) {
 502                 ERR("Error: Invalid control message header\n");
 503                 ret = -1;
 504                 goto end;
 505         }
 506         if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
 507                 ERR("Didn't received any fd\n");
 508                 ret = -1;
 509                 goto end;
 510         }
 511         if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
 512                 ERR("Error: Received %zu bytes of ancillary data, expected %zu\n",
 513                                 (size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
 514                 ret = -1;
 515                 goto end;
 516         }
 517
 518         memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
 519
 520         /* Set FD_CLOEXEC */
 521         for (i = 0; i < nb_fd; i++) {
 522                 ret = fcntl(fds[i], F_SETFD, FD_CLOEXEC);
 523                 if (ret < 0) {
 524                         PERROR("fcntl failed to set FD_CLOEXEC on fd %d",
 525                                fds[i]);
 526                 }
 527         }
 528
 529         ret = nb_fd;
 530 end:
 531         return ret;
 532 }
 533
 534 int ustcomm_send_app_msg(int sock, struct ustcomm_ust_msg *lum)
 535 {
 536         ssize_t len;
 537
 538         len = ustcomm_send_unix_sock(sock, lum, sizeof(*lum));
 539         switch (len) {
 540         case sizeof(*lum):
 541                 break;
 542         default:
 543                 if (len < 0) {
 544                         return len;
 545                 } else {
 546                         ERR("incorrect message size: %zd\n", len);
 547                         return -EINVAL;
 548                 }
 549         }
 550         return 0;
 551 }
 552
 553 int ustcomm_recv_app_reply(int sock, struct ustcomm_ust_reply *lur,
 554                           uint32_t expected_handle, uint32_t expected_cmd)
 555 {
 556         ssize_t len;
 557
 558         memset(lur, 0, sizeof(*lur));
 559         len = ustcomm_recv_unix_sock(sock, lur, sizeof(*lur));
 560         switch (len) {
 561         case 0: /* orderly shutdown */
 562                 return -EPIPE;
 563         case sizeof(*lur):
 564         {
 565                 int err = 0;
 566
 567                 if (lur->handle != expected_handle) {
 568                         ERR("Unexpected result message handle: "
 569                                 "expected: %u vs received: %u\n",
 570                                 expected_handle, lur->handle);
 571                         err = 1;
 572                 }
 573                 if (lur->cmd != expected_cmd) {
 574                         ERR("Unexpected result message command "
 575                                 "expected: %u vs received: %u\n",
 576                                 expected_cmd, lur->cmd);
 577                         err = 1;
 578                 }
 579                 if (err) {
 580                         return -EINVAL;
 581                 } else {
 582                         return lur->ret_code;
 583                 }
 584         }
 585         default:
 586                 if (len >= 0) {
 587                         ERR("incorrect message size: %zd\n", len);
 588                 }
 589                 return len;
 590         }
 591 }
 592
 593 int ustcomm_send_app_cmd(int sock,
 594                         struct ustcomm_ust_msg *lum,
 595                         struct ustcomm_ust_reply *lur)
 596 {
 597         int ret;
 598
 599         ret = ustcomm_send_app_msg(sock, lum);
 600         if (ret)
 601                 return ret;
 602         ret = ustcomm_recv_app_reply(sock, lur, lum->handle, lum->cmd);
 603         if (ret > 0)
 604                 return -EIO;
 605         return ret;
 606 }
 607
 608 /*
 609  * chan_data is allocated internally if this function returns the
 610  * expected var_len.
 611  */
 612 ssize_t ustcomm_recv_channel_from_sessiond(int sock,
 613                 void **_chan_data, uint64_t var_len,
 614                 int *_wakeup_fd)
 615 {
 616         void *chan_data;
 617         ssize_t len, nr_fd;
 618         int wakeup_fd, ret;
 619
 620         if (var_len > LTTNG_UST_CHANNEL_DATA_MAX_LEN) {
 621                 len = -EINVAL;
 622                 goto error_check;
 623         }
 624         /* Receive variable length data */
 625         chan_data = zmalloc(var_len);
 626         if (!chan_data) {
 627                 len = -ENOMEM;
 628                 goto error_alloc;
 629         }
 630         len = ustcomm_recv_unix_sock(sock, chan_data, var_len);
 631         if (len != var_len) {
 632                 goto error_recv;
 633         }
 634         /* recv wakeup fd */
 635         lttng_ust_lock_fd_tracker();
 636         nr_fd = ustcomm_recv_fds_unix_sock(sock, &wakeup_fd, 1);
 637         if (nr_fd <= 0) {
 638                 lttng_ust_unlock_fd_tracker();
 639                 if (nr_fd < 0) {
 640                         len = nr_fd;
 641                         goto error_recv;
 642                 } else {
 643                         len = -EIO;
 644                         goto error_recv;
 645                 }
 646         }
 647
 648         ret = lttng_ust_add_fd_to_tracker(wakeup_fd);
 649         if (ret < 0) {
 650                 ret = close(wakeup_fd);
 651                 if (ret) {
 652                         PERROR("close on wakeup_fd");
 653                 }
 654                 len = -EIO;
 655                 lttng_ust_unlock_fd_tracker();
 656                 goto error_recv;
 657         }
 658
 659         *_wakeup_fd = ret;
 660         lttng_ust_unlock_fd_tracker();
 661
 662         *_chan_data = chan_data;
 663         return len;
 664
 665 error_recv:
 666         free(chan_data);
 667 error_alloc:
 668 error_check:
 669         return len;
 670 }
 671
 672 int ustcomm_recv_stream_from_sessiond(int sock,
 673                 uint64_t *memory_map_size,
 674                 int *shm_fd, int *wakeup_fd)
 675 {
 676         ssize_t len;
 677         int ret;
 678         int fds[2];
 679
 680         /* recv shm fd and wakeup fd */
 681         lttng_ust_lock_fd_tracker();
 682         len = ustcomm_recv_fds_unix_sock(sock, fds, 2);
 683         if (len <= 0) {
 684                 lttng_ust_unlock_fd_tracker();
 685                 if (len < 0) {
 686                         ret = len;
 687                         goto error;
 688                 } else {
 689                         ret = -EIO;
 690                         goto error;
 691                 }
 692         }
 693
 694         ret = lttng_ust_add_fd_to_tracker(fds[0]);
 695         if (ret < 0) {
 696                 ret = close(fds[0]);
 697                 if (ret) {
 698                         PERROR("close on received shm_fd");
 699                 }
 700                 ret = -EIO;
 701                 lttng_ust_unlock_fd_tracker();
 702                 goto error;
 703         }
 704         *shm_fd = ret;
 705
 706         ret = lttng_ust_add_fd_to_tracker(fds[1]);
 707         if (ret < 0) {
 708                 ret = close(*shm_fd);
 709                 if (ret) {
 710                         PERROR("close on shm_fd");
 711                 }
 712                 *shm_fd = -1;
 713                 ret = close(fds[1]);
 714                 if (ret) {
 715                         PERROR("close on received wakeup_fd");
 716                 }
 717                 ret = -EIO;
 718                 lttng_ust_unlock_fd_tracker();
 719                 goto error;
 720         }
 721         *wakeup_fd = ret;
 722         lttng_ust_unlock_fd_tracker();
 723         return 0;
 724
 725 error:
 726         return ret;
 727 }
 728
 729 /*
 730  * Returns 0 on success, negative error value on error.
 731  */
 732 int ustcomm_send_reg_msg(int sock,
 733                 enum ustctl_socket_type type,
 734                 uint32_t bits_per_long,
 735                 uint32_t uint8_t_alignment,
 736                 uint32_t uint16_t_alignment,
 737                 uint32_t uint32_t_alignment,
 738                 uint32_t uint64_t_alignment,
 739                 uint32_t long_alignment)
 740 {
 741         ssize_t len;
 742         struct ustctl_reg_msg reg_msg;
 743
 744         reg_msg.magic = LTTNG_UST_COMM_MAGIC;
 745         reg_msg.major = LTTNG_UST_ABI_MAJOR_VERSION;
 746         reg_msg.minor = LTTNG_UST_ABI_MINOR_VERSION;
 747         reg_msg.pid = getpid();
 748         reg_msg.ppid = getppid();
 749         reg_msg.uid = getuid();
 750         reg_msg.gid = getgid();
 751         reg_msg.bits_per_long = bits_per_long;
 752         reg_msg.uint8_t_alignment = uint8_t_alignment;
 753         reg_msg.uint16_t_alignment = uint16_t_alignment;
 754         reg_msg.uint32_t_alignment = uint32_t_alignment;
 755         reg_msg.uint64_t_alignment = uint64_t_alignment;
 756         reg_msg.long_alignment = long_alignment;
 757         reg_msg.socket_type = type;
 758         lttng_ust_getprocname(reg_msg.name);
 759         memset(reg_msg.padding, 0, sizeof(reg_msg.padding));
 760
 761         len = ustcomm_send_unix_sock(sock, &reg_msg, sizeof(reg_msg));
 762         if (len > 0 && len != sizeof(reg_msg))
 763                 return -EIO;
 764         if (len < 0)
 765                 return len;
 766         return 0;
 767 }
 768
 769 static
 770 ssize_t count_one_type(const struct lttng_type *lt)
 771 {
 772         switch (lt->atype) {
 773         case atype_integer:
 774         case atype_float:
 775         case atype_string:
 776         case atype_enum:
 777         case atype_array:
 778         case atype_sequence:
 779                 return 1;
 780         case atype_struct:
 781                 return count_fields_recursive(lt->u.legacy._struct.nr_fields,
 782                                 lt->u.legacy._struct.fields) + 1;
 783         case atype_enum_nestable:
 784                 return count_one_type(lt->u.enum_nestable.container_type) + 1;
 785         case atype_array_nestable:
 786                 return count_one_type(lt->u.array_nestable.elem_type) + 1;
 787         case atype_sequence_nestable:
 788                 return count_one_type(lt->u.sequence_nestable.elem_type) + 1;
 789         case atype_struct_nestable:
 790                 return count_fields_recursive(lt->u.struct_nestable.nr_fields,
 791                                 lt->u.struct_nestable.fields) + 1;
 792
 793         case atype_dynamic:
 794         {
 795                 const struct lttng_event_field *choices;
 796                 size_t nr_choices;
 797                 int ret;
 798
 799                 ret = lttng_ust_dynamic_type_choices(&nr_choices,
 800                         &choices);
 801                 if (ret)
 802                         return ret;
 803                 /*
 804                  * Two fields for enum, one field for variant, and
 805                  * one field per choice.
 806                  */
 807                 return count_fields_recursive(nr_choices, choices) + 3;
 808         }
 809
 810         default:
 811                 return -EINVAL;
 812         }
 813         return 0;
 814 }
 815
 816 static
 817 ssize_t count_fields_recursive(size_t nr_fields,
 818                 const struct lttng_event_field *lttng_fields)
 819 {
 820         int i;
 821         ssize_t ret, count = 0;
 822
 823         for (i = 0; i < nr_fields; i++) {
 824                 const struct lttng_event_field *lf;
 825
 826                 lf = &lttng_fields[i];
 827                 /* skip 'nowrite' fields */
 828                 if (lf->nowrite)
 829                         continue;
 830                 ret = count_one_type(&lf->type);
 831                 if (ret < 0)
 832                         return ret;     /* error */
 833                 count += ret;
 834         }
 835         return count;
 836 }
 837
 838 static
 839 ssize_t count_ctx_fields_recursive(size_t nr_fields,
 840                 const struct lttng_ctx_field *lttng_fields)
 841 {
 842         int i;
 843         ssize_t ret, count = 0;
 844
 845         for (i = 0; i < nr_fields; i++) {
 846                 const struct lttng_event_field *lf;
 847
 848                 lf = &lttng_fields[i].event_field;
 849                 /* skip 'nowrite' fields */
 850                 if (lf->nowrite)
 851                         continue;
 852                 ret = count_one_type(&lf->type);
 853                 if (ret < 0)
 854                         return ret;     /* error */
 855                 count += ret;
 856         }
 857         return count;
 858 }
 859
 860 static
 861 int serialize_string_encoding(int32_t *ue,
 862                 enum lttng_string_encodings le)
 863 {
 864         switch (le) {
 865         case lttng_encode_none:
 866                 *ue = ustctl_encode_none;
 867                 break;
 868         case lttng_encode_UTF8:
 869                 *ue = ustctl_encode_UTF8;
 870                 break;
 871         case lttng_encode_ASCII:
 872                 *ue = ustctl_encode_ASCII;
 873                 break;
 874         default:
 875                 return -EINVAL;
 876         }
 877         return 0;
 878 }
 879
 880 static
 881 int serialize_integer_type(struct ustctl_integer_type *uit,
 882                 const struct lttng_integer_type *lit)
 883 {
 884         int32_t encoding;
 885
 886         uit->size = lit->size;
 887         uit->signedness = lit->signedness;
 888         uit->reverse_byte_order = lit->reverse_byte_order;
 889         uit->base = lit->base;
 890         if (serialize_string_encoding(&encoding, lit->encoding))
 891                 return -EINVAL;
 892         uit->encoding = encoding;
 893         uit->alignment = lit->alignment;
 894         return 0;
 895 }
 896
 897 static
 898 int serialize_basic_type(struct lttng_session *session,
 899                 enum ustctl_abstract_types *uatype,
 900                 enum lttng_abstract_types atype,
 901                 union _ustctl_basic_type *ubt,
 902                 const union _lttng_basic_type *lbt)
 903 {
 904         switch (atype) {
 905         case atype_integer:
 906         {
 907                 if (serialize_integer_type(&ubt->integer, &lbt->integer))
 908                         return -EINVAL;
 909                 *uatype = ustctl_atype_integer;
 910                 break;
 911         }
 912         case atype_string:
 913         {
 914                 int32_t encoding;
 915
 916                 if (serialize_string_encoding(&encoding, lbt->string.encoding))
 917                         return -EINVAL;
 918                 ubt->string.encoding = encoding;
 919                 *uatype = ustctl_atype_string;
 920                 break;
 921         }
 922         case atype_float:
 923         {
 924                 struct ustctl_float_type *uft;
 925                 const struct lttng_float_type *lft;
 926
 927                 uft = &ubt->_float;
 928                 lft = &lbt->_float;
 929                 uft->exp_dig = lft->exp_dig;
 930                 uft->mant_dig = lft->mant_dig;
 931                 uft->alignment = lft->alignment;
 932                 uft->reverse_byte_order = lft->reverse_byte_order;
 933                 *uatype = ustctl_atype_float;
 934                 break;
 935         }
 936         case atype_enum:
 937         {
 938                 strncpy(ubt->enumeration.name, lbt->enumeration.desc->name,
 939                                 LTTNG_UST_SYM_NAME_LEN);
 940                 ubt->enumeration.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 941                 if (serialize_integer_type(&ubt->enumeration.container_type,
 942                                 &lbt->enumeration.container_type))
 943                         return -EINVAL;
 944                 if (session) {
 945                         const struct lttng_enum *_enum;
 946
 947                         _enum = lttng_ust_enum_get_from_desc(session, lbt->enumeration.desc);
 948                         if (!_enum)
 949                                 return -EINVAL;
 950                         ubt->enumeration.id = _enum->id;
 951                 } else {
 952                         ubt->enumeration.id = -1ULL;
 953                 }
 954                 *uatype = ustctl_atype_enum;
 955                 break;
 956         }
 957         case atype_array:
 958         case atype_array_nestable:
 959         case atype_sequence:
 960         case atype_sequence_nestable:
 961         case atype_enum_nestable:
 962         default:
 963                 return -EINVAL;
 964         }
 965         return 0;
 966 }
 967
 968 static
 969 int serialize_dynamic_type(struct lttng_session *session,
 970                 struct ustctl_field *fields, size_t *iter_output,
 971                 const char *field_name)
 972 {
 973         const struct lttng_event_field *choices;
 974         char tag_field_name[LTTNG_UST_SYM_NAME_LEN];
 975         const struct lttng_type *tag_type;
 976         const struct lttng_event_field *tag_field_generic;
 977         struct lttng_event_field tag_field = {
 978                 .name = tag_field_name,
 979                 .nowrite = 0,
 980         };
 981         struct ustctl_field *uf;
 982         size_t nr_choices, i;
 983         int ret;
 984
 985         tag_field_generic = lttng_ust_dynamic_type_tag_field();
 986         tag_type = &tag_field_generic->type;
 987
 988         /* Serialize enum field. */
 989         strncpy(tag_field_name, field_name, LTTNG_UST_SYM_NAME_LEN);
 990         tag_field_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 991         strncat(tag_field_name,
 992                 "_tag",
 993                 LTTNG_UST_SYM_NAME_LEN - strlen(tag_field_name) - 1);
 994         tag_field.type = *tag_type;
 995         ret = serialize_one_field(session, fields, iter_output,
 996                 &tag_field);
 997         if (ret)
 998                 return ret;
 999
1000         /* Serialize variant field. */
1001         uf = &fields[*iter_output];
1002         ret = lttng_ust_dynamic_type_choices(&nr_choices, &choices);
1003         if (ret)
1004                 return ret;
1005
1006         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1007         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1008         uf->type.atype = ustctl_atype_variant;
1009         uf->type.u.variant_nestable.nr_choices = nr_choices;
1010         strncpy(uf->type.u.variant_nestable.tag_name,
1011                 tag_field_name,
1012                 LTTNG_UST_SYM_NAME_LEN);
1013         uf->type.u.variant_nestable.tag_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1014         uf->type.u.variant_nestable.alignment = 0;
1015         (*iter_output)++;
1016
1017         /* Serialize choice fields after variant. */
1018         for (i = 0; i < nr_choices; i++) {
1019                 ret = serialize_one_field(session, fields,
1020                         iter_output, &choices[i]);
1021                 if (ret)
1022                         return ret;
1023         }
1024         return 0;
1025 }
1026
1027 static
1028 int serialize_one_type(struct lttng_session *session,
1029                 struct ustctl_field *fields, size_t *iter_output,
1030                 const char *field_name, const struct lttng_type *lt)
1031 {
1032         int ret;
1033
1034         /*
1035          * Serializing a type (rather than a field) generates a ustctl_field
1036          * entry with 0-length name.
1037          */
1038
1039         switch (lt->atype) {
1040         case atype_integer:
1041         case atype_float:
1042         case atype_string:
1043         case atype_enum:
1044         {
1045                 struct ustctl_field *uf = &fields[*iter_output];
1046                 struct ustctl_type *ut = &uf->type;
1047                 enum ustctl_abstract_types atype;
1048
1049                 if (field_name) {
1050                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1051                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1052                 } else {
1053                         uf->name[0] = '\0';
1054                 }
1055                 ret = serialize_basic_type(session, &atype, lt->atype,
1056                         &ut->u.legacy.basic, &lt->u.legacy.basic);
1057                 if (ret)
1058                         return ret;
1059                 ut->atype = atype;
1060                 (*iter_output)++;
1061                 break;
1062         }
1063         case atype_array:
1064         {
1065                 struct ustctl_field *uf = &fields[*iter_output];
1066                 struct ustctl_type *ut = &uf->type;
1067                 struct ustctl_basic_type *ubt;
1068                 const struct lttng_basic_type *lbt;
1069                 enum ustctl_abstract_types atype;
1070
1071                 if (field_name) {
1072                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1073                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1074                 } else {
1075                         uf->name[0] = '\0';
1076                 }
1077                 ut->atype = ustctl_atype_array;
1078                 ubt = &ut->u.legacy.array.elem_type;
1079                 lbt = &lt->u.legacy.array.elem_type;
1080                 ut->u.legacy.array.length = lt->u.legacy.array.length;
1081                 ret = serialize_basic_type(session, &atype, lbt->atype,
1082                         &ubt->u.basic, &lbt->u.basic);
1083                 if (ret)
1084                         return -EINVAL;
1085                 ubt->atype = atype;
1086                 (*iter_output)++;
1087                 break;
1088         }
1089         case atype_array_nestable:
1090         {
1091                 struct ustctl_field *uf = &fields[*iter_output];
1092                 struct ustctl_type *ut = &uf->type;
1093
1094                 if (field_name) {
1095                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1096                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1097                 } else {
1098                         uf->name[0] = '\0';
1099                 }
1100                 ut->atype = ustctl_atype_array_nestable;
1101                 ut->u.array_nestable.length = lt->u.array_nestable.length;
1102                 ut->u.array_nestable.alignment = lt->u.array_nestable.alignment;
1103                 (*iter_output)++;
1104
1105                 ret = serialize_one_type(session, fields, iter_output, NULL,
1106                                 lt->u.array_nestable.elem_type);
1107                 if (ret)
1108                         return -EINVAL;
1109                 break;
1110         }
1111         case atype_sequence:
1112         {
1113                 struct ustctl_field *uf = &fields[*iter_output];
1114                 struct ustctl_type *ut = &uf->type;
1115                 struct ustctl_basic_type *ubt;
1116                 const struct lttng_basic_type *lbt;
1117                 enum ustctl_abstract_types atype;
1118
1119                 if (field_name) {
1120                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1121                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1122                 } else {
1123                         uf->name[0] = '\0';
1124                 }
1125                 uf->type.atype = ustctl_atype_sequence;
1126                 ubt = &ut->u.legacy.sequence.length_type;
1127                 lbt = &lt->u.legacy.sequence.length_type;
1128                 ret = serialize_basic_type(session, &atype, lbt->atype,
1129                         &ubt->u.basic, &lbt->u.basic);
1130                 if (ret)
1131                         return -EINVAL;
1132                 ubt->atype = atype;
1133                 ubt = &ut->u.legacy.sequence.elem_type;
1134                 lbt = &lt->u.legacy.sequence.elem_type;
1135                 ret = serialize_basic_type(session, &atype, lbt->atype,
1136                         &ubt->u.basic, &lbt->u.basic);
1137                 if (ret)
1138                         return -EINVAL;
1139                 ubt->atype = atype;
1140                 (*iter_output)++;
1141                 break;
1142         }
1143         case atype_sequence_nestable:
1144         {
1145                 struct ustctl_field *uf = &fields[*iter_output];
1146                 struct ustctl_type *ut = &uf->type;
1147
1148                 if (field_name) {
1149                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1150                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1151                 } else {
1152                         uf->name[0] = '\0';
1153                 }
1154                 ut->atype = ustctl_atype_sequence_nestable;
1155                 strncpy(ut->u.sequence_nestable.length_name,
1156                         lt->u.sequence_nestable.length_name,
1157                         LTTNG_UST_SYM_NAME_LEN);
1158                 ut->u.sequence_nestable.length_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1159                 ut->u.sequence_nestable.alignment = lt->u.sequence_nestable.alignment;
1160                 (*iter_output)++;
1161
1162                 ret = serialize_one_type(session, fields, iter_output, NULL,
1163                                 lt->u.sequence_nestable.elem_type);
1164                 if (ret)
1165                         return -EINVAL;
1166                 break;
1167         }
1168         case atype_dynamic:
1169         {
1170                 ret = serialize_dynamic_type(session, fields, iter_output,
1171                                 field_name);
1172                 if (ret)
1173                         return -EINVAL;
1174                 break;
1175         }
1176         case atype_struct:
1177         {
1178                 struct ustctl_field *uf = &fields[*iter_output];
1179
1180                 if (field_name) {
1181                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1182                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1183                 } else {
1184                         uf->name[0] = '\0';
1185                 }
1186                 uf->type.atype = ustctl_atype_struct;
1187                 uf->type.u.legacy._struct.nr_fields = lt->u.legacy._struct.nr_fields;
1188                 (*iter_output)++;
1189
1190                 ret = serialize_fields(session, fields, iter_output,
1191                                 lt->u.legacy._struct.nr_fields,
1192                                 lt->u.legacy._struct.fields);
1193                 if (ret)
1194                         return -EINVAL;
1195                 break;
1196         }
1197         case atype_struct_nestable:
1198         {
1199                 struct ustctl_field *uf = &fields[*iter_output];
1200
1201                 if (field_name) {
1202                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1203                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1204                 } else {
1205                         uf->name[0] = '\0';
1206                 }
1207                 uf->type.atype = ustctl_atype_struct_nestable;
1208                 uf->type.u.struct_nestable.nr_fields = lt->u.struct_nestable.nr_fields;
1209                 uf->type.u.struct_nestable.alignment = lt->u.struct_nestable.alignment;
1210                 (*iter_output)++;
1211
1212                 ret = serialize_fields(session, fields, iter_output,
1213                                 lt->u.struct_nestable.nr_fields,
1214                                 lt->u.struct_nestable.fields);
1215                 if (ret)
1216                         return -EINVAL;
1217                 break;
1218         }
1219         case atype_enum_nestable:
1220         {
1221                 struct ustctl_field *uf = &fields[*iter_output];
1222                 struct ustctl_type *ut = &uf->type;
1223
1224                 if (field_name) {
1225                         strncpy(uf->name, field_name, LTTNG_UST_SYM_NAME_LEN);
1226                         uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1227                 } else {
1228                         uf->name[0] = '\0';
1229                 }
1230                 strncpy(ut->u.enum_nestable.name, lt->u.enum_nestable.desc->name,
1231                                 LTTNG_UST_SYM_NAME_LEN);
1232                 ut->u.enum_nestable.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1233                 ut->atype = ustctl_atype_enum_nestable;
1234                 (*iter_output)++;
1235
1236                 ret = serialize_one_type(session, fields, iter_output, NULL,
1237                                 lt->u.enum_nestable.container_type);
1238                 if (ret)
1239                         return -EINVAL;
1240                 if (session) {
1241                         const struct lttng_enum *_enum;
1242
1243                         _enum = lttng_ust_enum_get_from_desc(session, lt->u.enum_nestable.desc);
1244                         if (!_enum)
1245                                 return -EINVAL;
1246                         ut->u.enum_nestable.id = _enum->id;
1247                 } else {
1248                         ut->u.enum_nestable.id = -1ULL;
1249                 }
1250                 break;
1251         }
1252         default:
1253                 return -EINVAL;
1254         }
1255         return 0;
1256 }
1257
1258 static
1259 int serialize_one_field(struct lttng_session *session,
1260                 struct ustctl_field *fields, size_t *iter_output,
1261                 const struct lttng_event_field *lf)
1262 {
1263         /* skip 'nowrite' fields */
1264         if (lf->nowrite)
1265                 return 0;
1266
1267         return serialize_one_type(session, fields, iter_output, lf->name, &lf->type);
1268 }
1269
1270 static
1271 int serialize_fields(struct lttng_session *session,
1272                 struct ustctl_field *ustctl_fields,
1273                 size_t *iter_output, size_t nr_lttng_fields,
1274                 const struct lttng_event_field *lttng_fields)
1275 {
1276         int ret;
1277         size_t i;
1278
1279         for (i = 0; i < nr_lttng_fields; i++) {
1280                 ret = serialize_one_field(session, ustctl_fields,
1281                                 iter_output, &lttng_fields[i]);
1282                 if (ret)
1283                         return ret;
1284         }
1285         return 0;
1286 }
1287
1288 static
1289 int alloc_serialize_fields(struct lttng_session *session,
1290                 size_t *_nr_write_fields,
1291                 struct ustctl_field **ustctl_fields,
1292                 size_t nr_fields,
1293                 const struct lttng_event_field *lttng_fields)
1294 {
1295         struct ustctl_field *fields;
1296         int ret;
1297         size_t iter_output = 0;
1298         ssize_t nr_write_fields;
1299
1300         nr_write_fields = count_fields_recursive(nr_fields, lttng_fields);
1301         if (nr_write_fields < 0) {
1302                 return (int) nr_write_fields;
1303         }
1304
1305         fields = zmalloc(nr_write_fields * sizeof(*fields));
1306         if (!fields)
1307                 return -ENOMEM;
1308
1309         ret = serialize_fields(session, fields, &iter_output, nr_fields,
1310                         lttng_fields);
1311         if (ret)
1312                 goto error_type;
1313
1314         *_nr_write_fields = nr_write_fields;
1315         *ustctl_fields = fields;
1316         return 0;
1317
1318 error_type:
1319         free(fields);
1320         return ret;
1321 }
1322
1323 static
1324 int serialize_entries(struct ustctl_enum_entry **_entries,
1325                 size_t nr_entries,
1326                 const struct lttng_enum_entry *lttng_entries)
1327 {
1328         struct ustctl_enum_entry *entries;
1329         int i;
1330
1331         /* Serialize the entries */
1332         entries = zmalloc(nr_entries * sizeof(*entries));
1333         if (!entries)
1334                 return -ENOMEM;
1335         for (i = 0; i < nr_entries; i++) {
1336                 struct ustctl_enum_entry *uentry;
1337                 const struct lttng_enum_entry *lentry;
1338
1339                 uentry = &entries[i];
1340                 lentry = &lttng_entries[i];
1341
1342                 uentry->start.value = lentry->start.value;
1343                 uentry->start.signedness = lentry->start.signedness;
1344                 uentry->end.value = lentry->end.value;
1345                 uentry->end.signedness = lentry->end.signedness;
1346                 strncpy(uentry->string, lentry->string, LTTNG_UST_SYM_NAME_LEN);
1347                 uentry->string[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1348
1349                 if (lentry->u.extra.options & LTTNG_ENUM_ENTRY_OPTION_IS_AUTO) {
1350                         uentry->u.extra.options |=
1351                                 USTCTL_UST_ENUM_ENTRY_OPTION_IS_AUTO;
1352                 }
1353         }
1354         *_entries = entries;
1355         return 0;
1356 }
1357
1358 static
1359 int serialize_ctx_fields(struct lttng_session *session,
1360                 size_t *_nr_write_fields,
1361                 struct ustctl_field **ustctl_fields,
1362                 size_t nr_fields,
1363                 const struct lttng_ctx_field *lttng_fields)
1364 {
1365         struct ustctl_field *fields;
1366         int ret;
1367         size_t i, iter_output = 0;
1368         ssize_t nr_write_fields;
1369
1370         nr_write_fields = count_ctx_fields_recursive(nr_fields,
1371                         lttng_fields);
1372         if (nr_write_fields < 0) {
1373                 return (int) nr_write_fields;
1374         }
1375
1376         fields = zmalloc(nr_write_fields * sizeof(*fields));
1377         if (!fields)
1378                 return -ENOMEM;
1379
1380         for (i = 0; i < nr_fields; i++) {
1381                 ret = serialize_one_field(session, fields, &iter_output,
1382                                 &lttng_fields[i].event_field);
1383                 if (ret)
1384                         goto error_type;
1385         }
1386
1387         *_nr_write_fields = nr_write_fields;
1388         *ustctl_fields = fields;
1389         return 0;
1390
1391 error_type:
1392         free(fields);
1393         return ret;
1394 }
1395
1396 /*
1397  * Returns 0 on success, negative error value on error.
1398  */
1399 int ustcomm_register_event(int sock,
1400         struct lttng_session *session,
1401         int session_objd,               /* session descriptor */
1402         int channel_objd,               /* channel descriptor */
1403         const char *event_name,         /* event name (input) */
1404         int loglevel,
1405         const char *signature,          /* event signature (input) */
1406         size_t nr_fields,               /* fields */
1407         const struct lttng_event_field *lttng_fields,
1408         const char *model_emf_uri,
1409         uint32_t *id)                   /* event id (output) */
1410 {
1411         ssize_t len;
1412         struct {
1413                 struct ustcomm_notify_hdr header;
1414                 struct ustcomm_notify_event_msg m;
1415         } msg;
1416         struct {
1417                 struct ustcomm_notify_hdr header;
1418                 struct ustcomm_notify_event_reply r;
1419         } reply;
1420         size_t signature_len, fields_len, model_emf_uri_len;
1421         struct ustctl_field *fields = NULL;
1422         size_t nr_write_fields = 0;
1423         int ret;
1424
1425         memset(&msg, 0, sizeof(msg));
1426         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
1427         msg.m.session_objd = session_objd;
1428         msg.m.channel_objd = channel_objd;
1429         strncpy(msg.m.event_name, event_name, LTTNG_UST_SYM_NAME_LEN);
1430         msg.m.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1431         msg.m.loglevel = loglevel;
1432         signature_len = strlen(signature) + 1;
1433         msg.m.signature_len = signature_len;
1434
1435         /* Calculate fields len, serialize fields. */
1436         if (nr_fields > 0) {
1437                 ret = alloc_serialize_fields(session, &nr_write_fields, &fields,
1438                                 nr_fields, lttng_fields);
1439                 if (ret)
1440                         return ret;
1441         }
1442
1443         fields_len = sizeof(*fields) * nr_write_fields;
1444         msg.m.fields_len = fields_len;
1445         if (model_emf_uri) {
1446                 model_emf_uri_len = strlen(model_emf_uri) + 1;
1447         } else {
1448                 model_emf_uri_len = 0;
1449         }
1450         msg.m.model_emf_uri_len = model_emf_uri_len;
1451
1452         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1453         if (len > 0 && len != sizeof(msg)) {
1454                 ret = -EIO;
1455                 goto error_fields;
1456         }
1457         if (len < 0) {
1458                 ret = len;
1459                 goto error_fields;
1460         }
1461
1462         /* send signature */
1463         len = ustcomm_send_unix_sock(sock, signature, signature_len);
1464         if (len > 0 && len != signature_len) {
1465                 ret = -EIO;
1466                 goto error_fields;
1467         }
1468         if (len < 0) {
1469                 ret = len;
1470                 goto error_fields;
1471         }
1472
1473         /* send fields */
1474         if (fields_len > 0) {
1475                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1476                 if (len > 0 && len != fields_len) {
1477                         ret = -EIO;
1478                         goto error_fields;
1479                 }
1480                 if (len < 0) {
1481                         ret = len;
1482                         goto error_fields;
1483                 }
1484         }
1485         free(fields);
1486
1487         if (model_emf_uri_len) {
1488                 /* send model_emf_uri */
1489                 len = ustcomm_send_unix_sock(sock, model_emf_uri,
1490                                 model_emf_uri_len);
1491                 if (len > 0 && len != model_emf_uri_len) {
1492                         return -EIO;
1493                 }
1494                 if (len < 0) {
1495                         return len;
1496                 }
1497         }
1498
1499         /* receive reply */
1500         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1501         switch (len) {
1502         case 0: /* orderly shutdown */
1503                 return -EPIPE;
1504         case sizeof(reply):
1505                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1506                         ERR("Unexpected result message command "
1507                                 "expected: %u vs received: %u\n",
1508                                 msg.header.notify_cmd, reply.header.notify_cmd);
1509                         return -EINVAL;
1510                 }
1511                 if (reply.r.ret_code > 0)
1512                         return -EINVAL;
1513                 if (reply.r.ret_code < 0)
1514                         return reply.r.ret_code;
1515                 *id = reply.r.event_id;
1516                 DBG("Sent register event notification for name \"%s\": ret_code %d, event_id %u\n",
1517                         event_name, reply.r.ret_code, reply.r.event_id);
1518                 return 0;
1519         default:
1520                 if (len < 0) {
1521                         /* Transport level error */
1522                         if (errno == EPIPE || errno == ECONNRESET)
1523                                 len = -errno;
1524                         return len;
1525                 } else {
1526                         ERR("incorrect message size: %zd\n", len);
1527                         return len;
1528                 }
1529         }
1530         /* Unreached. */
1531
1532         /* Error path only. */
1533 error_fields:
1534         free(fields);
1535         return ret;
1536 }
1537
1538 /*
1539  * Returns 0 on success, negative error value on error.
1540  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1541  */
1542 int ustcomm_register_enum(int sock,
1543         int session_objd,               /* session descriptor */
1544         const char *enum_name,          /* enum name (input) */
1545         size_t nr_entries,              /* entries */
1546         const struct lttng_enum_entry *lttng_entries,
1547         uint64_t *id)
1548 {
1549         ssize_t len;
1550         struct {
1551                 struct ustcomm_notify_hdr header;
1552                 struct ustcomm_notify_enum_msg m;
1553         } msg;
1554         struct {
1555                 struct ustcomm_notify_hdr header;
1556                 struct ustcomm_notify_enum_reply r;
1557         } reply;
1558         size_t entries_len;
1559         struct ustctl_enum_entry *entries = NULL;
1560         int ret;
1561
1562         memset(&msg, 0, sizeof(msg));
1563         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_ENUM;
1564         msg.m.session_objd = session_objd;
1565         strncpy(msg.m.enum_name, enum_name, LTTNG_UST_SYM_NAME_LEN);
1566         msg.m.enum_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1567
1568         /* Calculate entries len, serialize entries. */
1569         if (nr_entries > 0) {
1570                 ret = serialize_entries(&entries,
1571                                 nr_entries, lttng_entries);
1572                 if (ret)
1573                         return ret;
1574         }
1575
1576         entries_len = sizeof(*entries) * nr_entries;
1577         msg.m.entries_len = entries_len;
1578
1579         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1580         if (len > 0 && len != sizeof(msg)) {
1581                 ret = -EIO;
1582                 goto error_entries;
1583         }
1584         if (len < 0) {
1585                 ret = len;
1586                 goto error_entries;
1587         }
1588
1589         /* send entries */
1590         if (entries_len > 0) {
1591                 len = ustcomm_send_unix_sock(sock, entries, entries_len);
1592                 if (len > 0 && len != entries_len) {
1593                         ret = -EIO;
1594                         goto error_entries;
1595                 }
1596                 if (len < 0) {
1597                         ret = len;
1598                         goto error_entries;
1599                 }
1600         }
1601         free(entries);
1602         entries = NULL;
1603
1604         /* receive reply */
1605         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1606         switch (len) {
1607         case 0: /* orderly shutdown */
1608                 return -EPIPE;
1609         case sizeof(reply):
1610                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1611                         ERR("Unexpected result message command "
1612                                 "expected: %u vs received: %u\n",
1613                                 msg.header.notify_cmd, reply.header.notify_cmd);
1614                         return -EINVAL;
1615                 }
1616                 if (reply.r.ret_code > 0)
1617                         return -EINVAL;
1618                 if (reply.r.ret_code < 0)
1619                         return reply.r.ret_code;
1620                 *id = reply.r.enum_id;
1621                 DBG("Sent register enum notification for name \"%s\": ret_code %d\n",
1622                         enum_name, reply.r.ret_code);
1623                 return 0;
1624         default:
1625                 if (len < 0) {
1626                         /* Transport level error */
1627                         if (errno == EPIPE || errno == ECONNRESET)
1628                                 len = -errno;
1629                         return len;
1630                 } else {
1631                         ERR("incorrect message size: %zd\n", len);
1632                         return len;
1633                 }
1634         }
1635         return ret;
1636
1637 error_entries:
1638         free(entries);
1639         return ret;
1640 }
1641
1642 /*
1643  * Returns 0 on success, negative error value on error.
1644  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1645  */
1646 int ustcomm_register_channel(int sock,
1647         struct lttng_session *session,
1648         int session_objd,               /* session descriptor */
1649         int channel_objd,               /* channel descriptor */
1650         size_t nr_ctx_fields,
1651         const struct lttng_ctx_field *ctx_fields,
1652         uint32_t *chan_id,              /* channel id (output) */
1653         int *header_type)               /* header type (output) */
1654 {
1655         ssize_t len;
1656         struct {
1657                 struct ustcomm_notify_hdr header;
1658                 struct ustcomm_notify_channel_msg m;
1659         } msg;
1660         struct {
1661                 struct ustcomm_notify_hdr header;
1662                 struct ustcomm_notify_channel_reply r;
1663         } reply;
1664         size_t fields_len;
1665         struct ustctl_field *fields = NULL;
1666         int ret;
1667         size_t nr_write_fields = 0;
1668
1669         memset(&msg, 0, sizeof(msg));
1670         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1671         msg.m.session_objd = session_objd;
1672         msg.m.channel_objd = channel_objd;
1673
1674         /* Calculate fields len, serialize fields. */
1675         if (nr_ctx_fields > 0) {
1676                 ret = serialize_ctx_fields(session, &nr_write_fields, &fields,
1677                                 nr_ctx_fields, ctx_fields);
1678                 if (ret)
1679                         return ret;
1680         }
1681
1682         fields_len = sizeof(*fields) * nr_write_fields;
1683         msg.m.ctx_fields_len = fields_len;
1684         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1685         if (len > 0 && len != sizeof(msg)) {
1686                 free(fields);
1687                 return -EIO;
1688         }
1689         if (len < 0) {
1690                 free(fields);
1691                 return len;
1692         }
1693
1694         /* send fields */
1695         if (fields_len > 0) {
1696                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1697                 free(fields);
1698                 if (len > 0 && len != fields_len) {
1699                         return -EIO;
1700                 }
1701                 if (len < 0) {
1702                         return len;
1703                 }
1704         } else {
1705                 free(fields);
1706         }
1707
1708         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1709         switch (len) {
1710         case 0: /* orderly shutdown */
1711                 return -EPIPE;
1712         case sizeof(reply):
1713                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1714                         ERR("Unexpected result message command "
1715                                 "expected: %u vs received: %u\n",
1716                                 msg.header.notify_cmd, reply.header.notify_cmd);
1717                         return -EINVAL;
1718                 }
1719                 if (reply.r.ret_code > 0)
1720                         return -EINVAL;
1721                 if (reply.r.ret_code < 0)
1722                         return reply.r.ret_code;
1723                 *chan_id = reply.r.chan_id;
1724                 switch (reply.r.header_type) {
1725                 case 1:
1726                 case 2:
1727                         *header_type = reply.r.header_type;
1728                         break;
1729                 default:
1730                         ERR("Unexpected channel header type %u\n",
1731                                 reply.r.header_type);
1732                         return -EINVAL;
1733                 }
1734                 DBG("Sent register channel notification: chan_id %d, header_type %d\n",
1735                         reply.r.chan_id, reply.r.header_type);
1736                 return 0;
1737         default:
1738                 if (len < 0) {
1739                         /* Transport level error */
1740                         if (errno == EPIPE || errno == ECONNRESET)
1741                                 len = -errno;
1742                         return len;
1743                 } else {
1744                         ERR("incorrect message size: %zd\n", len);
1745                         return len;
1746                 }
1747         }
1748 }
1749
1750 /*
1751  * Set socket reciving timeout.
1752  */
1753 int ustcomm_setsockopt_rcv_timeout(int sock, unsigned int msec)
1754 {
1755         int ret;
1756         struct timeval tv;
1757
1758         tv.tv_sec = msec / 1000;
1759         tv.tv_usec = (msec * 1000 % 1000000);
1760
1761         ret = setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
1762         if (ret < 0) {
1763                 PERROR("setsockopt SO_RCVTIMEO");
1764                 ret = -errno;
1765         }
1766
1767         return ret;
1768 }
1769
1770 /*
1771  * Set socket sending timeout.
1772  */
1773 int ustcomm_setsockopt_snd_timeout(int sock, unsigned int msec)
1774 {
1775         int ret;
1776         struct timeval tv;
1777
1778         tv.tv_sec = msec / 1000;
1779         tv.tv_usec = (msec * 1000) % 1000000;
1780
1781         ret = setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
1782         if (ret < 0) {
1783                 PERROR("setsockopt SO_SNDTIMEO");
1784                 ret = -errno;
1785         }
1786
1787         return ret;
1788 }