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 <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/socket.h>
  26 #include <sys/stat.h>
  27 #include <sys/types.h>
  28 #include <sys/un.h>
  29 #include <unistd.h>
  30 #include <assert.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33
  34 #include <lttng/ust-ctl.h>
  35 #include <ust-comm.h>
  36 #include <helper.h>
  37 #include <lttng/ust-error.h>
  38 #include <lttng/ust-events.h>
  39 #include <usterr-signal-safe.h>
  40
  41 #include "../liblttng-ust/compat.h"
  42
  43 #define USTCOMM_CODE_OFFSET(code)       \
  44         (code == LTTNG_UST_OK ? 0 : (code - LTTNG_UST_ERR + 1))
  45
  46 #define USTCOMM_MAX_SEND_FDS    4
  47
  48 /*
  49  * Human readable error message.
  50  */
  51 static const char *ustcomm_readable_code[] = {
  52         [ USTCOMM_CODE_OFFSET(LTTNG_UST_OK) ] = "Success",
  53         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR) ] = "Unknown error",
  54         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOENT) ] = "No entry",
  55         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_EXIST) ] = "Object already exists",
  56         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL) ] = "Invalid argument",
  57         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_PERM) ] = "Permission denied",
  58         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOSYS) ] = "Not implemented",
  59         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_EXITING) ] = "Process is exiting",
  60
  61         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL_MAGIC) ] = "Invalid magic number",
  62         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL_SOCKET_TYPE) ] = "Invalid socket type",
  63         [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_UNSUP_MAJOR) ] = "Unsupported major version",
  64 };
  65
  66 /*
  67  * lttng_ust_strerror
  68  *
  69  * Receives positive error value.
  70  * Return ptr to string representing a human readable
  71  * error code from the ustcomm_return_code enum.
  72  */
  73 const char *lttng_ust_strerror(int code)
  74 {
  75         if (code == LTTNG_UST_OK)
  76                 return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)];
  77         if (code < LTTNG_UST_ERR)
  78                 return strerror(code);
  79         if (code >= LTTNG_UST_ERR_NR)
  80                 code = LTTNG_UST_ERR;
  81         return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)];
  82 }
  83
  84 /*
  85  * ustcomm_connect_unix_sock
  86  *
  87  * Connect to unix socket using the path name.
  88  */
  89 int ustcomm_connect_unix_sock(const char *pathname)
  90 {
  91         struct sockaddr_un sun;
  92         int fd, ret;
  93
  94         /*
  95          * libust threads require the close-on-exec flag for all
  96          * resources so it does not leak file descriptors upon exec.
  97          */
  98         fd = socket(PF_UNIX, SOCK_STREAM, 0);
  99         if (fd < 0) {
 100                 PERROR("socket");
 101                 ret = -errno;
 102                 goto error;
 103         }
 104         ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
 105         if (ret < 0) {
 106                 PERROR("fcntl");
 107                 ret = -errno;
 108                 goto error_fcntl;
 109         }
 110
 111         memset(&sun, 0, sizeof(sun));
 112         sun.sun_family = AF_UNIX;
 113         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 114         sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
 115
 116         ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
 117         if (ret < 0) {
 118                 /*
 119                  * Don't print message on connect ENOENT error, because
 120                  * connect is used in normal execution to detect if
 121                  * sessiond is alive. ENOENT is when the unix socket
 122                  * file does not exist, and ECONNREFUSED is when the
 123                  * file exists but no sessiond is listening.
 124                  */
 125                 if (errno != ECONNREFUSED && errno != ECONNRESET
 126                                 && errno != ENOENT && errno != EACCES)
 127                         PERROR("connect");
 128                 ret = -errno;
 129                 if (ret == -ECONNREFUSED || ret == -ECONNRESET)
 130                         ret = -EPIPE;
 131                 goto error_connect;
 132         }
 133
 134         return fd;
 135
 136 error_connect:
 137 error_fcntl:
 138         {
 139                 int closeret;
 140
 141                 closeret = close(fd);
 142                 if (closeret)
 143                         PERROR("close");
 144         }
 145 error:
 146         return ret;
 147 }
 148
 149 /*
 150  * ustcomm_accept_unix_sock
 151  *
 152  * Do an accept(2) on the sock and return the
 153  * new file descriptor. The socket MUST be bind(2) before.
 154  */
 155 int ustcomm_accept_unix_sock(int sock)
 156 {
 157         int new_fd;
 158         struct sockaddr_un sun;
 159         socklen_t len = 0;
 160
 161         /* Blocking call */
 162         new_fd = accept(sock, (struct sockaddr *) &sun, &len);
 163         if (new_fd < 0) {
 164                 if (errno != ECONNABORTED)
 165                         PERROR("accept");
 166                 new_fd = -errno;
 167                 if (new_fd == -ECONNABORTED)
 168                         new_fd = -EPIPE;
 169         }
 170         return new_fd;
 171 }
 172
 173 /*
 174  * ustcomm_create_unix_sock
 175  *
 176  * Creates a AF_UNIX local socket using pathname
 177  * bind the socket upon creation and return the fd.
 178  */
 179 int ustcomm_create_unix_sock(const char *pathname)
 180 {
 181         struct sockaddr_un sun;
 182         int fd, ret;
 183
 184         /* Create server socket */
 185         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 186                 PERROR("socket");
 187                 ret = -errno;
 188                 goto error;
 189         }
 190
 191         memset(&sun, 0, sizeof(sun));
 192         sun.sun_family = AF_UNIX;
 193         strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
 194         sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
 195
 196         /* Unlink the old file if present */
 197         (void) unlink(pathname);
 198         ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
 199         if (ret < 0) {
 200                 PERROR("bind");
 201                 ret = -errno;
 202                 goto error_close;
 203         }
 204
 205         return fd;
 206
 207 error_close:
 208         {
 209                 int closeret;
 210
 211                 closeret = close(fd);
 212                 if (closeret) {
 213                         PERROR("close");
 214                 }
 215         }
 216 error:
 217         return ret;
 218 }
 219
 220 /*
 221  * ustcomm_listen_unix_sock
 222  *
 223  * Make the socket listen using LTTNG_UST_COMM_MAX_LISTEN.
 224  */
 225 int ustcomm_listen_unix_sock(int sock)
 226 {
 227         int ret;
 228
 229         ret = listen(sock, LTTNG_UST_COMM_MAX_LISTEN);
 230         if (ret < 0) {
 231                 ret = -errno;
 232                 PERROR("listen");
 233         }
 234
 235         return ret;
 236 }
 237
 238 /*
 239  * ustcomm_close_unix_sock
 240  *
 241  * Shutdown cleanly a unix socket.
 242  */
 243 int ustcomm_close_unix_sock(int sock)
 244 {
 245         int ret;
 246
 247         ret = close(sock);
 248         if (ret < 0) {
 249                 PERROR("close");
 250                 ret = -errno;
 251         }
 252
 253         return ret;
 254 }
 255
 256 /*
 257  * ustcomm_recv_unix_sock
 258  *
 259  * Receive data of size len in put that data into
 260  * the buf param. Using recvmsg API.
 261  * Return the size of received data.
 262  * Return 0 on orderly shutdown.
 263  */
 264 ssize_t ustcomm_recv_unix_sock(int sock, void *buf, size_t len)
 265 {
 266         struct msghdr msg;
 267         struct iovec iov[1];
 268         ssize_t ret = -1;
 269         size_t len_last;
 270
 271         memset(&msg, 0, sizeof(msg));
 272
 273         iov[0].iov_base = buf;
 274         iov[0].iov_len = len;
 275         msg.msg_iov = iov;
 276         msg.msg_iovlen = 1;
 277
 278         do {
 279                 len_last = iov[0].iov_len;
 280                 ret = recvmsg(sock, &msg, 0);
 281                 if (ret > 0) {
 282                         iov[0].iov_base += ret;
 283                         iov[0].iov_len -= ret;
 284                         assert(ret <= len_last);
 285                 }
 286         } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
 287
 288         if (ret < 0) {
 289                 int shutret;
 290
 291                 if (errno != EPIPE && errno != ECONNRESET && errno != ECONNREFUSED)
 292                         PERROR("recvmsg");
 293                 ret = -errno;
 294                 if (ret == -ECONNRESET || ret == -ECONNREFUSED)
 295                         ret = -EPIPE;
 296
 297                 shutret = shutdown(sock, SHUT_RDWR);
 298                 if (shutret)
 299                         ERR("Socket shutdown error");
 300         } else if (ret > 0) {
 301                 ret = len;
 302         }
 303         /* ret = 0 means an orderly shutdown. */
 304
 305         return ret;
 306 }
 307
 308 /*
 309  * ustcomm_send_unix_sock
 310  *
 311  * Send buf data of size len. Using sendmsg API.
 312  * Return the size of sent data.
 313  */
 314 ssize_t ustcomm_send_unix_sock(int sock, const void *buf, size_t len)
 315 {
 316         struct msghdr msg;
 317         struct iovec iov[1];
 318         ssize_t ret;
 319
 320         memset(&msg, 0, sizeof(msg));
 321
 322         iov[0].iov_base = (void *) buf;
 323         iov[0].iov_len = len;
 324         msg.msg_iov = iov;
 325         msg.msg_iovlen = 1;
 326
 327         /*
 328          * Using the MSG_NOSIGNAL when sending data from sessiond to
 329          * libust, so libust does not receive an unhandled SIGPIPE or
 330          * SIGURG. The sessiond receiver side can be made more resilient
 331          * by ignoring SIGPIPE, but we don't have this luxury on the
 332          * libust side.
 333          */
 334         do {
 335                 ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
 336         } while (ret < 0 && errno == EINTR);
 337
 338         if (ret < 0) {
 339                 int shutret;
 340
 341                 if (errno != EPIPE && errno != ECONNRESET)
 342                         PERROR("sendmsg");
 343                 ret = -errno;
 344                 if (ret == -ECONNRESET)
 345                         ret = -EPIPE;
 346
 347                 shutret = shutdown(sock, SHUT_RDWR);
 348                 if (shutret)
 349                         ERR("Socket shutdown error");
 350         }
 351
 352         return ret;
 353 }
 354
 355 /*
 356  * Send a message accompanied by fd(s) over a unix socket.
 357  *
 358  * Returns the size of data sent, or negative error value.
 359  */
 360 ssize_t ustcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 361 {
 362         struct msghdr msg;
 363         struct cmsghdr *cmptr;
 364         struct iovec iov[1];
 365         ssize_t ret = -1;
 366         unsigned int sizeof_fds = nb_fd * sizeof(int);
 367         char tmp[CMSG_SPACE(sizeof_fds)];
 368         char dummy = 0;
 369
 370         memset(&msg, 0, sizeof(msg));
 371         memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));
 372
 373         if (nb_fd > USTCOMM_MAX_SEND_FDS)
 374                 return -EINVAL;
 375
 376         msg.msg_control = (caddr_t)tmp;
 377         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 378
 379         cmptr = CMSG_FIRSTHDR(&msg);
 380         cmptr->cmsg_level = SOL_SOCKET;
 381         cmptr->cmsg_type = SCM_RIGHTS;
 382         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 383         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 384         /* Sum of the length of all control messages in the buffer: */
 385         msg.msg_controllen = cmptr->cmsg_len;
 386
 387         iov[0].iov_base = &dummy;
 388         iov[0].iov_len = 1;
 389         msg.msg_iov = iov;
 390         msg.msg_iovlen = 1;
 391
 392         do {
 393                 ret = sendmsg(sock, &msg, 0);
 394         } while (ret < 0 && errno == EINTR);
 395         if (ret < 0) {
 396                 /*
 397                  * We consider EPIPE and ECONNRESET as expected.
 398                  */
 399                 if (errno != EPIPE && errno != ECONNRESET) {
 400                         PERROR("sendmsg");
 401                 }
 402                 ret = -errno;
 403                 if (ret == -ECONNRESET)
 404                         ret = -EPIPE;
 405         }
 406         return ret;
 407 }
 408
 409 /*
 410  * Recv a message accompanied by fd(s) from a unix socket.
 411  *
 412  * Returns the size of received data, or negative error value.
 413  *
 414  * Expect at most "nb_fd" file descriptors. Returns the number of fd
 415  * actually received in nb_fd.
 416  * Returns -EPIPE on orderly shutdown.
 417  */
 418 ssize_t ustcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 419 {
 420         struct iovec iov[1];
 421         ssize_t ret = 0;
 422         struct cmsghdr *cmsg;
 423         size_t sizeof_fds = nb_fd * sizeof(int);
 424         char recv_fd[CMSG_SPACE(sizeof_fds)];
 425         struct msghdr msg;
 426         char dummy;
 427
 428         memset(&msg, 0, sizeof(msg));
 429
 430         /* Prepare to receive the structures */
 431         iov[0].iov_base = &dummy;
 432         iov[0].iov_len = 1;
 433         msg.msg_iov = iov;
 434         msg.msg_iovlen = 1;
 435         msg.msg_control = recv_fd;
 436         msg.msg_controllen = sizeof(recv_fd);
 437
 438         do {
 439                 ret = recvmsg(sock, &msg, 0);
 440         } while (ret < 0 && errno == EINTR);
 441         if (ret < 0) {
 442                 if (errno != EPIPE && errno != ECONNRESET) {
 443                         PERROR("recvmsg fds");
 444                 }
 445                 ret = -errno;
 446                 if (ret == -ECONNRESET)
 447                         ret = -EPIPE;
 448                 goto end;
 449         }
 450         if (ret == 0) {
 451                 /* orderly shutdown */
 452                 ret = -EPIPE;
 453                 goto end;
 454         }
 455         if (ret != 1) {
 456                 ERR("Error: Received %zd bytes, expected %d\n",
 457                                 ret, 1);
 458                 goto end;
 459         }
 460         if (msg.msg_flags & MSG_CTRUNC) {
 461                 ERR("Error: Control message truncated.\n");
 462                 ret = -1;
 463                 goto end;
 464         }
 465         cmsg = CMSG_FIRSTHDR(&msg);
 466         if (!cmsg) {
 467                 ERR("Error: Invalid control message header\n");
 468                 ret = -1;
 469                 goto end;
 470         }
 471         if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
 472                 ERR("Didn't received any fd\n");
 473                 ret = -1;
 474                 goto end;
 475         }
 476         if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
 477                 ERR("Error: Received %zu bytes of ancillary data, expected %zu\n",
 478                                 (size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
 479                 ret = -1;
 480                 goto end;
 481         }
 482         memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
 483         ret = sizeof_fds;
 484 end:
 485         return ret;
 486 }
 487
 488 int ustcomm_send_app_msg(int sock, struct ustcomm_ust_msg *lum)
 489 {
 490         ssize_t len;
 491
 492         len = ustcomm_send_unix_sock(sock, lum, sizeof(*lum));
 493         switch (len) {
 494         case sizeof(*lum):
 495                 break;
 496         default:
 497                 if (len < 0) {
 498                         return len;
 499                 } else {
 500                         ERR("incorrect message size: %zd\n", len);
 501                         return -EINVAL;
 502                 }
 503         }
 504         return 0;
 505 }
 506
 507 int ustcomm_recv_app_reply(int sock, struct ustcomm_ust_reply *lur,
 508                           uint32_t expected_handle, uint32_t expected_cmd)
 509 {
 510         ssize_t len;
 511
 512         memset(lur, 0, sizeof(*lur));
 513         len = ustcomm_recv_unix_sock(sock, lur, sizeof(*lur));
 514         switch (len) {
 515         case 0: /* orderly shutdown */
 516                 return -EPIPE;
 517         case sizeof(*lur):
 518         {
 519                 int err = 0;
 520
 521                 if (lur->handle != expected_handle) {
 522                         ERR("Unexpected result message handle: "
 523                                 "expected: %u vs received: %u\n",
 524                                 expected_handle, lur->handle);
 525                         err = 1;
 526                 }
 527                 if (lur->cmd != expected_cmd) {
 528                         ERR("Unexpected result message command "
 529                                 "expected: %u vs received: %u\n",
 530                                 expected_cmd, lur->cmd);
 531                         err = 1;
 532                 }
 533                 if (err) {
 534                         return -EINVAL;
 535                 } else {
 536                         return lur->ret_code;
 537                 }
 538         }
 539         default:
 540                 if (len >= 0) {
 541                         ERR("incorrect message size: %zd\n", len);
 542                 }
 543                 return len;
 544         }
 545 }
 546
 547 int ustcomm_send_app_cmd(int sock,
 548                         struct ustcomm_ust_msg *lum,
 549                         struct ustcomm_ust_reply *lur)
 550 {
 551         int ret;
 552
 553         ret = ustcomm_send_app_msg(sock, lum);
 554         if (ret)
 555                 return ret;
 556         ret = ustcomm_recv_app_reply(sock, lur, lum->handle, lum->cmd);
 557         if (ret > 0)
 558                 return -EIO;
 559         return ret;
 560 }
 561
 562 /*
 563  * chan_data is allocated internally if this function returns the
 564  * expected var_len.
 565  */
 566 ssize_t ustcomm_recv_channel_from_sessiond(int sock,
 567                 void **_chan_data, uint64_t var_len,
 568                 int *_wakeup_fd)
 569 {
 570         void *chan_data;
 571         ssize_t len, nr_fd;
 572         int wakeup_fd;
 573
 574         if (var_len > LTTNG_UST_CHANNEL_DATA_MAX_LEN) {
 575                 len = -EINVAL;
 576                 goto error_check;
 577         }
 578         /* Receive variable length data */
 579         chan_data = zmalloc(var_len);
 580         if (!chan_data) {
 581                 len = -ENOMEM;
 582                 goto error_alloc;
 583         }
 584         len = ustcomm_recv_unix_sock(sock, chan_data, var_len);
 585         if (len != var_len) {
 586                 goto error_recv;
 587         }
 588         /* recv wakeup fd */
 589         nr_fd = ustcomm_recv_fds_unix_sock(sock, &wakeup_fd, 1);
 590         if (nr_fd <= 0) {
 591                 if (nr_fd < 0) {
 592                         len = nr_fd;
 593                         goto error_recv;
 594                 } else {
 595                         len = -EIO;
 596                         goto error_recv;
 597                 }
 598         }
 599         *_wakeup_fd = wakeup_fd;
 600         *_chan_data = chan_data;
 601         return len;
 602
 603 error_recv:
 604         free(chan_data);
 605 error_alloc:
 606 error_check:
 607         return len;
 608 }
 609
 610 int ustcomm_recv_stream_from_sessiond(int sock,
 611                 uint64_t *memory_map_size,
 612                 int *shm_fd, int *wakeup_fd)
 613 {
 614         ssize_t len;
 615         int ret;
 616         int fds[2];
 617
 618         /* recv shm fd and wakeup fd */
 619         len = ustcomm_recv_fds_unix_sock(sock, fds, 2);
 620         if (len <= 0) {
 621                 if (len < 0) {
 622                         ret = len;
 623                         goto error;
 624                 } else {
 625                         ret = -EIO;
 626                         goto error;
 627                 }
 628         }
 629         *shm_fd = fds[0];
 630         *wakeup_fd = fds[1];
 631         return 0;
 632
 633 error:
 634         return ret;
 635 }
 636
 637 /*
 638  * Returns 0 on success, negative error value on error.
 639  */
 640 int ustcomm_send_reg_msg(int sock,
 641                 enum ustctl_socket_type type,
 642                 uint32_t bits_per_long,
 643                 uint32_t uint8_t_alignment,
 644                 uint32_t uint16_t_alignment,
 645                 uint32_t uint32_t_alignment,
 646                 uint32_t uint64_t_alignment,
 647                 uint32_t long_alignment)
 648 {
 649         ssize_t len;
 650         struct ustctl_reg_msg reg_msg;
 651
 652         reg_msg.magic = LTTNG_UST_COMM_MAGIC;
 653         reg_msg.major = LTTNG_UST_ABI_MAJOR_VERSION;
 654         reg_msg.minor = LTTNG_UST_ABI_MINOR_VERSION;
 655         reg_msg.pid = getpid();
 656         reg_msg.ppid = getppid();
 657         reg_msg.uid = getuid();
 658         reg_msg.gid = getgid();
 659         reg_msg.bits_per_long = bits_per_long;
 660         reg_msg.uint8_t_alignment = uint8_t_alignment;
 661         reg_msg.uint16_t_alignment = uint16_t_alignment;
 662         reg_msg.uint32_t_alignment = uint32_t_alignment;
 663         reg_msg.uint64_t_alignment = uint64_t_alignment;
 664         reg_msg.long_alignment = long_alignment;
 665         reg_msg.socket_type = type;
 666         lttng_ust_getprocname(reg_msg.name);
 667         memset(reg_msg.padding, 0, sizeof(reg_msg.padding));
 668
 669         len = ustcomm_send_unix_sock(sock, &reg_msg, sizeof(reg_msg));
 670         if (len > 0 && len != sizeof(reg_msg))
 671                 return -EIO;
 672         if (len < 0)
 673                 return len;
 674         return 0;
 675 }
 676
 677 static
 678 int serialize_string_encoding(enum ustctl_string_encodings *ue,
 679                 enum lttng_string_encodings le)
 680 {
 681         switch (le) {
 682         case lttng_encode_none:
 683                 *ue = ustctl_encode_none;
 684                 break;
 685         case lttng_encode_UTF8:
 686                 *ue = ustctl_encode_UTF8;
 687                 break;
 688         case lttng_encode_ASCII:
 689                 *ue = ustctl_encode_ASCII;
 690                 break;
 691         default:
 692                 return -EINVAL;
 693         }
 694         return 0;
 695 }
 696
 697 static
 698 int serialize_basic_type(enum ustctl_abstract_types *uatype,
 699                 enum lttng_abstract_types atype,
 700                 union _ustctl_basic_type *ubt,
 701                 const union _lttng_basic_type *lbt)
 702 {
 703         switch (atype) {
 704         case atype_integer:
 705         {
 706                 struct ustctl_integer_type *uit;
 707                 const struct lttng_integer_type *lit;
 708
 709                 uit = &ubt->integer;
 710                 lit = &lbt->integer;
 711                 uit->size = lit->size;
 712                 uit->signedness = lit->signedness;
 713                 uit->reverse_byte_order = lit->reverse_byte_order;
 714                 uit->base = lit->base;
 715                 if (serialize_string_encoding(&uit->encoding, lit->encoding))
 716                         return -EINVAL;
 717                 uit->alignment = lit->alignment;
 718                 *uatype = ustctl_atype_integer;
 719                 break;
 720         }
 721         case atype_string:
 722         {
 723                 if (serialize_string_encoding(&ubt->string.encoding,
 724                                 lbt->string.encoding))
 725                         return -EINVAL;
 726                 *uatype = ustctl_atype_string;
 727                 break;
 728         }
 729         case atype_float:
 730         {
 731                 struct ustctl_float_type *uft;
 732                 const struct lttng_float_type *lft;
 733
 734                 uft = &ubt->_float;
 735                 lft = &lbt->_float;
 736                 uft->exp_dig = lft->exp_dig;
 737                 uft->mant_dig = lft->mant_dig;
 738                 uft->alignment = lft->alignment;
 739                 uft->reverse_byte_order = lft->reverse_byte_order;
 740                 *uatype = ustctl_atype_float;
 741                 break;
 742         }
 743         case atype_enum:
 744         case atype_array:
 745         case atype_sequence:
 746         default:
 747                 return -EINVAL;
 748         }
 749         return 0;
 750 }
 751
 752 static
 753 int serialize_one_type(struct ustctl_type *ut, const struct lttng_type *lt)
 754 {
 755         int ret;
 756
 757         switch (lt->atype) {
 758         case atype_integer:
 759         case atype_float:
 760         case atype_string:
 761                 ret = serialize_basic_type(&ut->atype, lt->atype,
 762                         &ut->u.basic, &lt->u.basic);
 763                 if (ret)
 764                         return ret;
 765                 break;
 766         case atype_array:
 767         {
 768                 struct ustctl_basic_type *ubt;
 769                 const struct lttng_basic_type *lbt;
 770                 int ret;
 771
 772                 ubt = &ut->u.array.elem_type;
 773                 lbt = &lt->u.array.elem_type;
 774                 ut->u.array.length = lt->u.array.length;
 775                 ret = serialize_basic_type(&ubt->atype, lbt->atype,
 776                         &ubt->u.basic, &lbt->u.basic);
 777                 if (ret)
 778                         return -EINVAL;
 779                 ut->atype = ustctl_atype_array;
 780                 break;
 781         }
 782         case atype_sequence:
 783         {
 784                 struct ustctl_basic_type *ubt;
 785                 const struct lttng_basic_type *lbt;
 786                 int ret;
 787
 788                 ubt = &ut->u.sequence.length_type;
 789                 lbt = &lt->u.sequence.length_type;
 790                 ret = serialize_basic_type(&ubt->atype, lbt->atype,
 791                         &ubt->u.basic, &lbt->u.basic);
 792                 if (ret)
 793                         return -EINVAL;
 794                 ubt = &ut->u.sequence.elem_type;
 795                 lbt = &lt->u.sequence.elem_type;
 796                 ret = serialize_basic_type(&ubt->atype, lbt->atype,
 797                         &ubt->u.basic, &lbt->u.basic);
 798                 if (ret)
 799                         return -EINVAL;
 800                 ut->atype = ustctl_atype_sequence;
 801                 break;
 802         }
 803         case atype_enum:
 804         default:
 805                 return -EINVAL;
 806         }
 807         return 0;
 808 }
 809
 810 static
 811 int serialize_fields(size_t *_nr_write_fields,
 812                 struct ustctl_field **ustctl_fields,
 813                 size_t nr_fields,
 814                 const struct lttng_event_field *lttng_fields)
 815 {
 816         struct ustctl_field *fields;
 817         int i, ret;
 818         size_t nr_write_fields = 0;
 819
 820         fields = zmalloc(nr_fields * sizeof(*fields));
 821         if (!fields)
 822                 return -ENOMEM;
 823
 824         for (i = 0; i < nr_fields; i++) {
 825                 struct ustctl_field *f;
 826                 const struct lttng_event_field *lf;
 827
 828                 f = &fields[nr_write_fields];
 829                 lf = &lttng_fields[i];
 830
 831                 /* skip 'nowrite' fields */
 832                 if (lf->nowrite)
 833                         continue;
 834                 strncpy(f->name, lf->name, LTTNG_UST_SYM_NAME_LEN);
 835                 f->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 836                 ret = serialize_one_type(&f->type, &lf->type);
 837                 if (ret)
 838                         goto error_type;
 839                 nr_write_fields++;
 840         }
 841
 842         *_nr_write_fields = nr_write_fields;
 843         *ustctl_fields = fields;
 844         return 0;
 845
 846 error_type:
 847         free(fields);
 848         return ret;
 849 }
 850
 851 static
 852 int serialize_ctx_fields(size_t *_nr_write_fields,
 853                 struct ustctl_field **ustctl_fields,
 854                 size_t nr_fields,
 855                 const struct lttng_ctx_field *lttng_fields)
 856 {
 857         struct ustctl_field *fields;
 858         int i, ret;
 859         size_t nr_write_fields = 0;
 860
 861         fields = zmalloc(nr_fields * sizeof(*fields));
 862         if (!fields)
 863                 return -ENOMEM;
 864
 865         for (i = 0; i < nr_fields; i++) {
 866                 struct ustctl_field *f;
 867                 const struct lttng_event_field *lf;
 868
 869                 f = &fields[nr_write_fields];
 870                 lf = &lttng_fields[i].event_field;
 871
 872                 /* skip 'nowrite' fields */
 873                 if (lf->nowrite)
 874                         continue;
 875                 strncpy(f->name, lf->name, LTTNG_UST_SYM_NAME_LEN);
 876                 f->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 877                 ret = serialize_one_type(&f->type, &lf->type);
 878                 if (ret)
 879                         goto error_type;
 880                 nr_write_fields++;
 881         }
 882
 883         *_nr_write_fields = nr_write_fields;
 884         *ustctl_fields = fields;
 885         return 0;
 886
 887 error_type:
 888         free(fields);
 889         return ret;
 890 }
 891
 892 /*
 893  * Returns 0 on success, negative error value on error.
 894  */
 895 int ustcomm_register_event(int sock,
 896         int session_objd,               /* session descriptor */
 897         int channel_objd,               /* channel descriptor */
 898         const char *event_name,         /* event name (input) */
 899         int loglevel,
 900         const char *signature,          /* event signature (input) */
 901         size_t nr_fields,               /* fields */
 902         const struct lttng_event_field *lttng_fields,
 903         const char *model_emf_uri,
 904         uint32_t *id)                   /* event id (output) */
 905 {
 906         ssize_t len;
 907         struct {
 908                 struct ustcomm_notify_hdr header;
 909                 struct ustcomm_notify_event_msg m;
 910         } msg;
 911         struct {
 912                 struct ustcomm_notify_hdr header;
 913                 struct ustcomm_notify_event_reply r;
 914         } reply;
 915         size_t signature_len, fields_len, model_emf_uri_len;
 916         struct ustctl_field *fields = NULL;
 917         size_t nr_write_fields = 0;
 918         int ret;
 919
 920         memset(&msg, 0, sizeof(msg));
 921         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
 922         msg.m.session_objd = session_objd;
 923         msg.m.channel_objd = channel_objd;
 924         strncpy(msg.m.event_name, event_name, LTTNG_UST_SYM_NAME_LEN);
 925         msg.m.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 926         msg.m.loglevel = loglevel;
 927         signature_len = strlen(signature) + 1;
 928         msg.m.signature_len = signature_len;
 929
 930         /* Calculate fields len, serialize fields. */
 931         if (nr_fields > 0) {
 932                 ret = serialize_fields(&nr_write_fields, &fields,
 933                                 nr_fields, lttng_fields);
 934                 if (ret)
 935                         return ret;
 936         }
 937
 938         fields_len = sizeof(*fields) * nr_write_fields;
 939         msg.m.fields_len = fields_len;
 940         if (model_emf_uri) {
 941                 model_emf_uri_len = strlen(model_emf_uri) + 1;
 942         } else {
 943                 model_emf_uri_len = 0;
 944         }
 945         msg.m.model_emf_uri_len = model_emf_uri_len;
 946         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
 947         if (len > 0 && len != sizeof(msg)) {
 948                 free(fields);
 949                 return -EIO;
 950         }
 951         if (len < 0) {
 952                 free(fields);
 953                 return len;
 954         }
 955
 956         /* send signature */
 957         len = ustcomm_send_unix_sock(sock, signature, signature_len);
 958         if (len > 0 && len != signature_len) {
 959                 free(fields);
 960                 return -EIO;
 961         }
 962         if (len < 0) {
 963                 free(fields);
 964                 return len;
 965         }
 966
 967         /* send fields */
 968         if (fields_len > 0) {
 969                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
 970                 free(fields);
 971                 if (len > 0 && len != fields_len) {
 972                         return -EIO;
 973                 }
 974                 if (len < 0) {
 975                         return len;
 976                 }
 977         } else {
 978                 free(fields);
 979         }
 980
 981         if (model_emf_uri_len) {
 982                 /* send model_emf_uri */
 983                 len = ustcomm_send_unix_sock(sock, model_emf_uri,
 984                                 model_emf_uri_len);
 985                 if (len > 0 && len != model_emf_uri_len)
 986                         return -EIO;
 987                 if (len < 0)
 988                         return len;
 989         }
 990
 991         /* receive reply */
 992         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
 993         switch (len) {
 994         case 0: /* orderly shutdown */
 995                 return -EPIPE;
 996         case sizeof(reply):
 997                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
 998                         ERR("Unexpected result message command "
 999                                 "expected: %u vs received: %u\n",
1000                                 msg.header.notify_cmd, reply.header.notify_cmd);
1001                         return -EINVAL;
1002                 }
1003                 if (reply.r.ret_code > 0)
1004                         return -EINVAL;
1005                 if (reply.r.ret_code < 0)
1006                         return reply.r.ret_code;
1007                 *id = reply.r.event_id;
1008                 DBG("Sent register event notification for name \"%s\": ret_code %d, event_id %u\n",
1009                         event_name, reply.r.ret_code, reply.r.event_id);
1010                 return 0;
1011         default:
1012                 if (len < 0) {
1013                         /* Transport level error */
1014                         if (errno == EPIPE || errno == ECONNRESET)
1015                                 len = -errno;
1016                         return len;
1017                 } else {
1018                         ERR("incorrect message size: %zd\n", len);
1019                         return len;
1020                 }
1021         }
1022 }
1023
1024 /*
1025  * Returns 0 on success, negative error value on error.
1026  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1027  */
1028 int ustcomm_register_channel(int sock,
1029         int session_objd,               /* session descriptor */
1030         int channel_objd,               /* channel descriptor */
1031         size_t nr_ctx_fields,
1032         const struct lttng_ctx_field *ctx_fields,
1033         uint32_t *chan_id,              /* channel id (output) */
1034         int *header_type)               /* header type (output) */
1035 {
1036         ssize_t len;
1037         struct {
1038                 struct ustcomm_notify_hdr header;
1039                 struct ustcomm_notify_channel_msg m;
1040         } msg;
1041         struct {
1042                 struct ustcomm_notify_hdr header;
1043                 struct ustcomm_notify_channel_reply r;
1044         } reply;
1045         size_t fields_len;
1046         struct ustctl_field *fields = NULL;
1047         int ret;
1048         size_t nr_write_fields = 0;
1049
1050         memset(&msg, 0, sizeof(msg));
1051         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1052         msg.m.session_objd = session_objd;
1053         msg.m.channel_objd = channel_objd;
1054
1055         /* Calculate fields len, serialize fields. */
1056         if (nr_ctx_fields > 0) {
1057                 ret = serialize_ctx_fields(&nr_write_fields, &fields,
1058                                 nr_ctx_fields, ctx_fields);
1059                 if (ret)
1060                         return ret;
1061         }
1062
1063         fields_len = sizeof(*fields) * nr_write_fields;
1064         msg.m.ctx_fields_len = fields_len;
1065         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1066         if (len > 0 && len != sizeof(msg)) {
1067                 free(fields);
1068                 return -EIO;
1069         }
1070         if (len < 0) {
1071                 free(fields);
1072                 return len;
1073         }
1074
1075         /* send fields */
1076         if (fields_len > 0) {
1077                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1078                 free(fields);
1079                 if (len > 0 && len != fields_len) {
1080                         return -EIO;
1081                 }
1082                 if (len < 0) {
1083                         return len;
1084                 }
1085         } else {
1086                 free(fields);
1087         }
1088
1089         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1090         switch (len) {
1091         case 0: /* orderly shutdown */
1092                 return -EPIPE;
1093         case sizeof(reply):
1094                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1095                         ERR("Unexpected result message command "
1096                                 "expected: %u vs received: %u\n",
1097                                 msg.header.notify_cmd, reply.header.notify_cmd);
1098                         return -EINVAL;
1099                 }
1100                 if (reply.r.ret_code > 0)
1101                         return -EINVAL;
1102                 if (reply.r.ret_code < 0)
1103                         return reply.r.ret_code;
1104                 *chan_id = reply.r.chan_id;
1105                 switch (reply.r.header_type) {
1106                 case 1:
1107                 case 2:
1108                         *header_type = reply.r.header_type;
1109                         break;
1110                 default:
1111                         ERR("Unexpected channel header type %u\n",
1112                                 reply.r.header_type);
1113                         return -EINVAL;
1114                 }
1115                 DBG("Sent register channel notification: chan_id %d, header_type %d\n",
1116                         reply.r.chan_id, reply.r.header_type);
1117                 return 0;
1118         default:
1119                 if (len < 0) {
1120                         /* Transport level error */
1121                         if (errno == EPIPE || errno == ECONNRESET)
1122                                 len = -errno;
1123                         return len;
1124                 } else {
1125                         ERR("incorrect message size: %zd\n", len);
1126                         return len;
1127                 }
1128         }
1129 }
1130
1131 /*
1132  * Set socket reciving timeout.
1133  */
1134 int ustcomm_setsockopt_rcv_timeout(int sock, unsigned int msec)
1135 {
1136         int ret;
1137         struct timeval tv;
1138
1139         tv.tv_sec = msec / 1000;
1140         tv.tv_usec = (msec * 1000 % 1000000);
1141
1142         ret = setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
1143         if (ret < 0) {
1144                 PERROR("setsockopt SO_RCVTIMEO");
1145                 ret = -errno;
1146         }
1147
1148         return ret;
1149 }
1150
1151 /*
1152  * Set socket sending timeout.
1153  */
1154 int ustcomm_setsockopt_snd_timeout(int sock, unsigned int msec)
1155 {
1156         int ret;
1157         struct timeval tv;
1158
1159         tv.tv_sec = msec / 1000;
1160         tv.tv_usec = (msec * 1000) % 1000000;
1161
1162         ret = setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
1163         if (ret < 0) {
1164                 PERROR("setsockopt SO_SNDTIMEO");
1165                 ret = -errno;
1166         }
1167
1168         return ret;
1169 }