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         if (!cmptr)
 381                 return -EINVAL;
 382         cmptr->cmsg_level = SOL_SOCKET;
 383         cmptr->cmsg_type = SCM_RIGHTS;
 384         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 385         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 386         /* Sum of the length of all control messages in the buffer: */
 387         msg.msg_controllen = cmptr->cmsg_len;
 388
 389         iov[0].iov_base = &dummy;
 390         iov[0].iov_len = 1;
 391         msg.msg_iov = iov;
 392         msg.msg_iovlen = 1;
 393
 394         do {
 395                 ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
 396         } while (ret < 0 && errno == EINTR);
 397         if (ret < 0) {
 398                 /*
 399                  * We consider EPIPE and ECONNRESET as expected.
 400                  */
 401                 if (errno != EPIPE && errno != ECONNRESET) {
 402                         PERROR("sendmsg");
 403                 }
 404                 ret = -errno;
 405                 if (ret == -ECONNRESET)
 406                         ret = -EPIPE;
 407         }
 408         return ret;
 409 }
 410
 411 /*
 412  * Recv a message accompanied by fd(s) from a unix socket.
 413  *
 414  * Returns the size of received data, or negative error value.
 415  *
 416  * Expect at most "nb_fd" file descriptors. Returns the number of fd
 417  * actually received in nb_fd.
 418  * Returns -EPIPE on orderly shutdown.
 419  */
 420 ssize_t ustcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 421 {
 422         struct iovec iov[1];
 423         ssize_t ret = 0;
 424         struct cmsghdr *cmsg;
 425         size_t sizeof_fds = nb_fd * sizeof(int);
 426         char recv_fd[CMSG_SPACE(sizeof_fds)];
 427         struct msghdr msg;
 428         char dummy;
 429
 430         memset(&msg, 0, sizeof(msg));
 431
 432         /* Prepare to receive the structures */
 433         iov[0].iov_base = &dummy;
 434         iov[0].iov_len = 1;
 435         msg.msg_iov = iov;
 436         msg.msg_iovlen = 1;
 437         msg.msg_control = recv_fd;
 438         msg.msg_controllen = sizeof(recv_fd);
 439
 440         do {
 441                 ret = recvmsg(sock, &msg, 0);
 442         } while (ret < 0 && errno == EINTR);
 443         if (ret < 0) {
 444                 if (errno != EPIPE && errno != ECONNRESET) {
 445                         PERROR("recvmsg fds");
 446                 }
 447                 ret = -errno;
 448                 if (ret == -ECONNRESET)
 449                         ret = -EPIPE;
 450                 goto end;
 451         }
 452         if (ret == 0) {
 453                 /* orderly shutdown */
 454                 ret = -EPIPE;
 455                 goto end;
 456         }
 457         if (ret != 1) {
 458                 ERR("Error: Received %zd bytes, expected %d\n",
 459                                 ret, 1);
 460                 goto end;
 461         }
 462         if (msg.msg_flags & MSG_CTRUNC) {
 463                 ERR("Error: Control message truncated.\n");
 464                 ret = -1;
 465                 goto end;
 466         }
 467         cmsg = CMSG_FIRSTHDR(&msg);
 468         if (!cmsg) {
 469                 ERR("Error: Invalid control message header\n");
 470                 ret = -1;
 471                 goto end;
 472         }
 473         if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
 474                 ERR("Didn't received any fd\n");
 475                 ret = -1;
 476                 goto end;
 477         }
 478         if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
 479                 ERR("Error: Received %zu bytes of ancillary data, expected %zu\n",
 480                                 (size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
 481                 ret = -1;
 482                 goto end;
 483         }
 484         memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
 485         ret = sizeof_fds;
 486 end:
 487         return ret;
 488 }
 489
 490 int ustcomm_send_app_msg(int sock, struct ustcomm_ust_msg *lum)
 491 {
 492         ssize_t len;
 493
 494         len = ustcomm_send_unix_sock(sock, lum, sizeof(*lum));
 495         switch (len) {
 496         case sizeof(*lum):
 497                 break;
 498         default:
 499                 if (len < 0) {
 500                         return len;
 501                 } else {
 502                         ERR("incorrect message size: %zd\n", len);
 503                         return -EINVAL;
 504                 }
 505         }
 506         return 0;
 507 }
 508
 509 int ustcomm_recv_app_reply(int sock, struct ustcomm_ust_reply *lur,
 510                           uint32_t expected_handle, uint32_t expected_cmd)
 511 {
 512         ssize_t len;
 513
 514         memset(lur, 0, sizeof(*lur));
 515         len = ustcomm_recv_unix_sock(sock, lur, sizeof(*lur));
 516         switch (len) {
 517         case 0: /* orderly shutdown */
 518                 return -EPIPE;
 519         case sizeof(*lur):
 520         {
 521                 int err = 0;
 522
 523                 if (lur->handle != expected_handle) {
 524                         ERR("Unexpected result message handle: "
 525                                 "expected: %u vs received: %u\n",
 526                                 expected_handle, lur->handle);
 527                         err = 1;
 528                 }
 529                 if (lur->cmd != expected_cmd) {
 530                         ERR("Unexpected result message command "
 531                                 "expected: %u vs received: %u\n",
 532                                 expected_cmd, lur->cmd);
 533                         err = 1;
 534                 }
 535                 if (err) {
 536                         return -EINVAL;
 537                 } else {
 538                         return lur->ret_code;
 539                 }
 540         }
 541         default:
 542                 if (len >= 0) {
 543                         ERR("incorrect message size: %zd\n", len);
 544                 }
 545                 return len;
 546         }
 547 }
 548
 549 int ustcomm_send_app_cmd(int sock,
 550                         struct ustcomm_ust_msg *lum,
 551                         struct ustcomm_ust_reply *lur)
 552 {
 553         int ret;
 554
 555         ret = ustcomm_send_app_msg(sock, lum);
 556         if (ret)
 557                 return ret;
 558         ret = ustcomm_recv_app_reply(sock, lur, lum->handle, lum->cmd);
 559         if (ret > 0)
 560                 return -EIO;
 561         return ret;
 562 }
 563
 564 /*
 565  * chan_data is allocated internally if this function returns the
 566  * expected var_len.
 567  */
 568 ssize_t ustcomm_recv_channel_from_sessiond(int sock,
 569                 void **_chan_data, uint64_t var_len,
 570                 int *_wakeup_fd)
 571 {
 572         void *chan_data;
 573         ssize_t len, nr_fd;
 574         int wakeup_fd;
 575
 576         if (var_len > LTTNG_UST_CHANNEL_DATA_MAX_LEN) {
 577                 len = -EINVAL;
 578                 goto error_check;
 579         }
 580         /* Receive variable length data */
 581         chan_data = zmalloc(var_len);
 582         if (!chan_data) {
 583                 len = -ENOMEM;
 584                 goto error_alloc;
 585         }
 586         len = ustcomm_recv_unix_sock(sock, chan_data, var_len);
 587         if (len != var_len) {
 588                 goto error_recv;
 589         }
 590         /* recv wakeup fd */
 591         nr_fd = ustcomm_recv_fds_unix_sock(sock, &wakeup_fd, 1);
 592         if (nr_fd <= 0) {
 593                 if (nr_fd < 0) {
 594                         len = nr_fd;
 595                         goto error_recv;
 596                 } else {
 597                         len = -EIO;
 598                         goto error_recv;
 599                 }
 600         }
 601         *_wakeup_fd = wakeup_fd;
 602         *_chan_data = chan_data;
 603         return len;
 604
 605 error_recv:
 606         free(chan_data);
 607 error_alloc:
 608 error_check:
 609         return len;
 610 }
 611
 612 int ustcomm_recv_stream_from_sessiond(int sock,
 613                 uint64_t *memory_map_size,
 614                 int *shm_fd, int *wakeup_fd)
 615 {
 616         ssize_t len;
 617         int ret;
 618         int fds[2];
 619
 620         /* recv shm fd and wakeup fd */
 621         len = ustcomm_recv_fds_unix_sock(sock, fds, 2);
 622         if (len <= 0) {
 623                 if (len < 0) {
 624                         ret = len;
 625                         goto error;
 626                 } else {
 627                         ret = -EIO;
 628                         goto error;
 629                 }
 630         }
 631         *shm_fd = fds[0];
 632         *wakeup_fd = fds[1];
 633         return 0;
 634
 635 error:
 636         return ret;
 637 }
 638
 639 /*
 640  * Returns 0 on success, negative error value on error.
 641  */
 642 int ustcomm_send_reg_msg(int sock,
 643                 enum ustctl_socket_type type,
 644                 uint32_t bits_per_long,
 645                 uint32_t uint8_t_alignment,
 646                 uint32_t uint16_t_alignment,
 647                 uint32_t uint32_t_alignment,
 648                 uint32_t uint64_t_alignment,
 649                 uint32_t long_alignment)
 650 {
 651         ssize_t len;
 652         struct ustctl_reg_msg reg_msg;
 653
 654         reg_msg.magic = LTTNG_UST_COMM_MAGIC;
 655         reg_msg.major = LTTNG_UST_ABI_MAJOR_VERSION;
 656         reg_msg.minor = LTTNG_UST_ABI_MINOR_VERSION;
 657         reg_msg.pid = getpid();
 658         reg_msg.ppid = getppid();
 659         reg_msg.uid = getuid();
 660         reg_msg.gid = getgid();
 661         reg_msg.bits_per_long = bits_per_long;
 662         reg_msg.uint8_t_alignment = uint8_t_alignment;
 663         reg_msg.uint16_t_alignment = uint16_t_alignment;
 664         reg_msg.uint32_t_alignment = uint32_t_alignment;
 665         reg_msg.uint64_t_alignment = uint64_t_alignment;
 666         reg_msg.long_alignment = long_alignment;
 667         reg_msg.socket_type = type;
 668         lttng_ust_getprocname(reg_msg.name);
 669         memset(reg_msg.padding, 0, sizeof(reg_msg.padding));
 670
 671         len = ustcomm_send_unix_sock(sock, &reg_msg, sizeof(reg_msg));
 672         if (len > 0 && len != sizeof(reg_msg))
 673                 return -EIO;
 674         if (len < 0)
 675                 return len;
 676         return 0;
 677 }
 678
 679 static
 680 int serialize_string_encoding(enum ustctl_string_encodings *ue,
 681                 enum lttng_string_encodings le)
 682 {
 683         switch (le) {
 684         case lttng_encode_none:
 685                 *ue = ustctl_encode_none;
 686                 break;
 687         case lttng_encode_UTF8:
 688                 *ue = ustctl_encode_UTF8;
 689                 break;
 690         case lttng_encode_ASCII:
 691                 *ue = ustctl_encode_ASCII;
 692                 break;
 693         default:
 694                 return -EINVAL;
 695         }
 696         return 0;
 697 }
 698
 699 static
 700 int serialize_basic_type(enum ustctl_abstract_types *uatype,
 701                 enum lttng_abstract_types atype,
 702                 union _ustctl_basic_type *ubt,
 703                 const union _lttng_basic_type *lbt)
 704 {
 705         switch (atype) {
 706         case atype_integer:
 707         {
 708                 struct ustctl_integer_type *uit;
 709                 const struct lttng_integer_type *lit;
 710
 711                 uit = &ubt->integer;
 712                 lit = &lbt->integer;
 713                 uit->size = lit->size;
 714                 uit->signedness = lit->signedness;
 715                 uit->reverse_byte_order = lit->reverse_byte_order;
 716                 uit->base = lit->base;
 717                 if (serialize_string_encoding(&uit->encoding, lit->encoding))
 718                         return -EINVAL;
 719                 uit->alignment = lit->alignment;
 720                 *uatype = ustctl_atype_integer;
 721                 break;
 722         }
 723         case atype_string:
 724         {
 725                 if (serialize_string_encoding(&ubt->string.encoding,
 726                                 lbt->string.encoding))
 727                         return -EINVAL;
 728                 *uatype = ustctl_atype_string;
 729                 break;
 730         }
 731         case atype_float:
 732         {
 733                 struct ustctl_float_type *uft;
 734                 const struct lttng_float_type *lft;
 735
 736                 uft = &ubt->_float;
 737                 lft = &lbt->_float;
 738                 uft->exp_dig = lft->exp_dig;
 739                 uft->mant_dig = lft->mant_dig;
 740                 uft->alignment = lft->alignment;
 741                 uft->reverse_byte_order = lft->reverse_byte_order;
 742                 *uatype = ustctl_atype_float;
 743                 break;
 744         }
 745         case atype_enum:
 746         case atype_array:
 747         case atype_sequence:
 748         default:
 749                 return -EINVAL;
 750         }
 751         return 0;
 752 }
 753
 754 static
 755 int serialize_one_type(struct ustctl_type *ut, const struct lttng_type *lt)
 756 {
 757         int ret;
 758
 759         switch (lt->atype) {
 760         case atype_integer:
 761         case atype_float:
 762         case atype_string:
 763                 ret = serialize_basic_type(&ut->atype, lt->atype,
 764                         &ut->u.basic, &lt->u.basic);
 765                 if (ret)
 766                         return ret;
 767                 break;
 768         case atype_array:
 769         {
 770                 struct ustctl_basic_type *ubt;
 771                 const struct lttng_basic_type *lbt;
 772                 int ret;
 773
 774                 ubt = &ut->u.array.elem_type;
 775                 lbt = &lt->u.array.elem_type;
 776                 ut->u.array.length = lt->u.array.length;
 777                 ret = serialize_basic_type(&ubt->atype, lbt->atype,
 778                         &ubt->u.basic, &lbt->u.basic);
 779                 if (ret)
 780                         return -EINVAL;
 781                 ut->atype = ustctl_atype_array;
 782                 break;
 783         }
 784         case atype_sequence:
 785         {
 786                 struct ustctl_basic_type *ubt;
 787                 const struct lttng_basic_type *lbt;
 788                 int ret;
 789
 790                 ubt = &ut->u.sequence.length_type;
 791                 lbt = &lt->u.sequence.length_type;
 792                 ret = serialize_basic_type(&ubt->atype, lbt->atype,
 793                         &ubt->u.basic, &lbt->u.basic);
 794                 if (ret)
 795                         return -EINVAL;
 796                 ubt = &ut->u.sequence.elem_type;
 797                 lbt = &lt->u.sequence.elem_type;
 798                 ret = serialize_basic_type(&ubt->atype, lbt->atype,
 799                         &ubt->u.basic, &lbt->u.basic);
 800                 if (ret)
 801                         return -EINVAL;
 802                 ut->atype = ustctl_atype_sequence;
 803                 break;
 804         }
 805         case atype_enum:
 806         default:
 807                 return -EINVAL;
 808         }
 809         return 0;
 810 }
 811
 812 static
 813 int serialize_fields(size_t *_nr_write_fields,
 814                 struct ustctl_field **ustctl_fields,
 815                 size_t nr_fields,
 816                 const struct lttng_event_field *lttng_fields)
 817 {
 818         struct ustctl_field *fields;
 819         int i, ret;
 820         size_t nr_write_fields = 0;
 821
 822         fields = zmalloc(nr_fields * sizeof(*fields));
 823         if (!fields)
 824                 return -ENOMEM;
 825
 826         for (i = 0; i < nr_fields; i++) {
 827                 struct ustctl_field *f;
 828                 const struct lttng_event_field *lf;
 829
 830                 f = &fields[nr_write_fields];
 831                 lf = &lttng_fields[i];
 832
 833                 /* skip 'nowrite' fields */
 834                 if (lf->nowrite)
 835                         continue;
 836                 strncpy(f->name, lf->name, LTTNG_UST_SYM_NAME_LEN);
 837                 f->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 838                 ret = serialize_one_type(&f->type, &lf->type);
 839                 if (ret)
 840                         goto error_type;
 841                 nr_write_fields++;
 842         }
 843
 844         *_nr_write_fields = nr_write_fields;
 845         *ustctl_fields = fields;
 846         return 0;
 847
 848 error_type:
 849         free(fields);
 850         return ret;
 851 }
 852
 853 static
 854 int serialize_ctx_fields(size_t *_nr_write_fields,
 855                 struct ustctl_field **ustctl_fields,
 856                 size_t nr_fields,
 857                 const struct lttng_ctx_field *lttng_fields)
 858 {
 859         struct ustctl_field *fields;
 860         int i, ret;
 861         size_t nr_write_fields = 0;
 862
 863         fields = zmalloc(nr_fields * sizeof(*fields));
 864         if (!fields)
 865                 return -ENOMEM;
 866
 867         for (i = 0; i < nr_fields; i++) {
 868                 struct ustctl_field *f;
 869                 const struct lttng_event_field *lf;
 870
 871                 f = &fields[nr_write_fields];
 872                 lf = &lttng_fields[i].event_field;
 873
 874                 /* skip 'nowrite' fields */
 875                 if (lf->nowrite)
 876                         continue;
 877                 strncpy(f->name, lf->name, LTTNG_UST_SYM_NAME_LEN);
 878                 f->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 879                 ret = serialize_one_type(&f->type, &lf->type);
 880                 if (ret)
 881                         goto error_type;
 882                 nr_write_fields++;
 883         }
 884
 885         *_nr_write_fields = nr_write_fields;
 886         *ustctl_fields = fields;
 887         return 0;
 888
 889 error_type:
 890         free(fields);
 891         return ret;
 892 }
 893
 894 /*
 895  * Returns 0 on success, negative error value on error.
 896  */
 897 int ustcomm_register_event(int sock,
 898         int session_objd,               /* session descriptor */
 899         int channel_objd,               /* channel descriptor */
 900         const char *event_name,         /* event name (input) */
 901         int loglevel,
 902         const char *signature,          /* event signature (input) */
 903         size_t nr_fields,               /* fields */
 904         const struct lttng_event_field *lttng_fields,
 905         const char *model_emf_uri,
 906         uint32_t *id)                   /* event id (output) */
 907 {
 908         ssize_t len;
 909         struct {
 910                 struct ustcomm_notify_hdr header;
 911                 struct ustcomm_notify_event_msg m;
 912         } msg;
 913         struct {
 914                 struct ustcomm_notify_hdr header;
 915                 struct ustcomm_notify_event_reply r;
 916         } reply;
 917         size_t signature_len, fields_len, model_emf_uri_len;
 918         struct ustctl_field *fields = NULL;
 919         size_t nr_write_fields = 0;
 920         int ret;
 921
 922         memset(&msg, 0, sizeof(msg));
 923         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
 924         msg.m.session_objd = session_objd;
 925         msg.m.channel_objd = channel_objd;
 926         strncpy(msg.m.event_name, event_name, LTTNG_UST_SYM_NAME_LEN);
 927         msg.m.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 928         msg.m.loglevel = loglevel;
 929         signature_len = strlen(signature) + 1;
 930         msg.m.signature_len = signature_len;
 931
 932         /* Calculate fields len, serialize fields. */
 933         if (nr_fields > 0) {
 934                 ret = serialize_fields(&nr_write_fields, &fields,
 935                                 nr_fields, lttng_fields);
 936                 if (ret)
 937                         return ret;
 938         }
 939
 940         fields_len = sizeof(*fields) * nr_write_fields;
 941         msg.m.fields_len = fields_len;
 942         if (model_emf_uri) {
 943                 model_emf_uri_len = strlen(model_emf_uri) + 1;
 944         } else {
 945                 model_emf_uri_len = 0;
 946         }
 947         msg.m.model_emf_uri_len = model_emf_uri_len;
 948         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
 949         if (len > 0 && len != sizeof(msg)) {
 950                 free(fields);
 951                 return -EIO;
 952         }
 953         if (len < 0) {
 954                 free(fields);
 955                 return len;
 956         }
 957
 958         /* send signature */
 959         len = ustcomm_send_unix_sock(sock, signature, signature_len);
 960         if (len > 0 && len != signature_len) {
 961                 free(fields);
 962                 return -EIO;
 963         }
 964         if (len < 0) {
 965                 free(fields);
 966                 return len;
 967         }
 968
 969         /* send fields */
 970         if (fields_len > 0) {
 971                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
 972                 free(fields);
 973                 if (len > 0 && len != fields_len) {
 974                         return -EIO;
 975                 }
 976                 if (len < 0) {
 977                         return len;
 978                 }
 979         } else {
 980                 free(fields);
 981         }
 982
 983         if (model_emf_uri_len) {
 984                 /* send model_emf_uri */
 985                 len = ustcomm_send_unix_sock(sock, model_emf_uri,
 986                                 model_emf_uri_len);
 987                 if (len > 0 && len != model_emf_uri_len)
 988                         return -EIO;
 989                 if (len < 0)
 990                         return len;
 991         }
 992
 993         /* receive reply */
 994         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
 995         switch (len) {
 996         case 0: /* orderly shutdown */
 997                 return -EPIPE;
 998         case sizeof(reply):
 999                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1000                         ERR("Unexpected result message command "
1001                                 "expected: %u vs received: %u\n",
1002                                 msg.header.notify_cmd, reply.header.notify_cmd);
1003                         return -EINVAL;
1004                 }
1005                 if (reply.r.ret_code > 0)
1006                         return -EINVAL;
1007                 if (reply.r.ret_code < 0)
1008                         return reply.r.ret_code;
1009                 *id = reply.r.event_id;
1010                 DBG("Sent register event notification for name \"%s\": ret_code %d, event_id %u\n",
1011                         event_name, reply.r.ret_code, reply.r.event_id);
1012                 return 0;
1013         default:
1014                 if (len < 0) {
1015                         /* Transport level error */
1016                         if (errno == EPIPE || errno == ECONNRESET)
1017                                 len = -errno;
1018                         return len;
1019                 } else {
1020                         ERR("incorrect message size: %zd\n", len);
1021                         return len;
1022                 }
1023         }
1024 }
1025
1026 /*
1027  * Returns 0 on success, negative error value on error.
1028  * Returns -EPIPE or -ECONNRESET if other end has hung up.
1029  */
1030 int ustcomm_register_channel(int sock,
1031         int session_objd,               /* session descriptor */
1032         int channel_objd,               /* channel descriptor */
1033         size_t nr_ctx_fields,
1034         const struct lttng_ctx_field *ctx_fields,
1035         uint32_t *chan_id,              /* channel id (output) */
1036         int *header_type)               /* header type (output) */
1037 {
1038         ssize_t len;
1039         struct {
1040                 struct ustcomm_notify_hdr header;
1041                 struct ustcomm_notify_channel_msg m;
1042         } msg;
1043         struct {
1044                 struct ustcomm_notify_hdr header;
1045                 struct ustcomm_notify_channel_reply r;
1046         } reply;
1047         size_t fields_len;
1048         struct ustctl_field *fields = NULL;
1049         int ret;
1050         size_t nr_write_fields = 0;
1051
1052         memset(&msg, 0, sizeof(msg));
1053         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1054         msg.m.session_objd = session_objd;
1055         msg.m.channel_objd = channel_objd;
1056
1057         /* Calculate fields len, serialize fields. */
1058         if (nr_ctx_fields > 0) {
1059                 ret = serialize_ctx_fields(&nr_write_fields, &fields,
1060                                 nr_ctx_fields, ctx_fields);
1061                 if (ret)
1062                         return ret;
1063         }
1064
1065         fields_len = sizeof(*fields) * nr_write_fields;
1066         msg.m.ctx_fields_len = fields_len;
1067         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1068         if (len > 0 && len != sizeof(msg)) {
1069                 free(fields);
1070                 return -EIO;
1071         }
1072         if (len < 0) {
1073                 free(fields);
1074                 return len;
1075         }
1076
1077         /* send fields */
1078         if (fields_len > 0) {
1079                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1080                 free(fields);
1081                 if (len > 0 && len != fields_len) {
1082                         return -EIO;
1083                 }
1084                 if (len < 0) {
1085                         return len;
1086                 }
1087         } else {
1088                 free(fields);
1089         }
1090
1091         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1092         switch (len) {
1093         case 0: /* orderly shutdown */
1094                 return -EPIPE;
1095         case sizeof(reply):
1096                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1097                         ERR("Unexpected result message command "
1098                                 "expected: %u vs received: %u\n",
1099                                 msg.header.notify_cmd, reply.header.notify_cmd);
1100                         return -EINVAL;
1101                 }
1102                 if (reply.r.ret_code > 0)
1103                         return -EINVAL;
1104                 if (reply.r.ret_code < 0)
1105                         return reply.r.ret_code;
1106                 *chan_id = reply.r.chan_id;
1107                 switch (reply.r.header_type) {
1108                 case 1:
1109                 case 2:
1110                         *header_type = reply.r.header_type;
1111                         break;
1112                 default:
1113                         ERR("Unexpected channel header type %u\n",
1114                                 reply.r.header_type);
1115                         return -EINVAL;
1116                 }
1117                 DBG("Sent register channel notification: chan_id %d, header_type %d\n",
1118                         reply.r.chan_id, reply.r.header_type);
1119                 return 0;
1120         default:
1121                 if (len < 0) {
1122                         /* Transport level error */
1123                         if (errno == EPIPE || errno == ECONNRESET)
1124                                 len = -errno;
1125                         return len;
1126                 } else {
1127                         ERR("incorrect message size: %zd\n", len);
1128                         return len;
1129                 }
1130         }
1131 }
1132
1133 /*
1134  * Set socket reciving timeout.
1135  */
1136 int ustcomm_setsockopt_rcv_timeout(int sock, unsigned int msec)
1137 {
1138         int ret;
1139         struct timeval tv;
1140
1141         tv.tv_sec = msec / 1000;
1142         tv.tv_usec = (msec * 1000 % 1000000);
1143
1144         ret = setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
1145         if (ret < 0) {
1146                 PERROR("setsockopt SO_RCVTIMEO");
1147                 ret = -errno;
1148         }
1149
1150         return ret;
1151 }
1152
1153 /*
1154  * Set socket sending timeout.
1155  */
1156 int ustcomm_setsockopt_snd_timeout(int sock, unsigned int msec)
1157 {
1158         int ret;
1159         struct timeval tv;
1160
1161         tv.tv_sec = msec / 1000;
1162         tv.tv_usec = (msec * 1000) % 1000000;
1163
1164         ret = setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
1165         if (ret < 0) {
1166                 PERROR("setsockopt SO_SNDTIMEO");
1167                 ret = -errno;
1168         }
1169
1170         return ret;
1171 }