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;
 269
 270         memset(&msg, 0, sizeof(msg));
 271
 272         iov[0].iov_base = buf;
 273         iov[0].iov_len = len;
 274         msg.msg_iov = iov;
 275         msg.msg_iovlen = 1;
 276
 277         do {
 278                 ret = recvmsg(sock, &msg, 0);
 279         } while (ret < 0 && errno == EINTR);
 280
 281         if (ret < 0) {
 282                 int shutret;
 283
 284                 if (errno != EPIPE && errno != ECONNRESET && errno != ECONNREFUSED)
 285                         PERROR("recvmsg");
 286                 ret = -errno;
 287                 if (ret == -ECONNRESET || ret == -ECONNREFUSED)
 288                         ret = -EPIPE;
 289
 290                 shutret = shutdown(sock, SHUT_RDWR);
 291                 if (shutret)
 292                         ERR("Socket shutdown error");
 293         }
 294
 295         return ret;
 296 }
 297
 298 /*
 299  * ustcomm_send_unix_sock
 300  *
 301  * Send buf data of size len. Using sendmsg API.
 302  * Return the size of sent data.
 303  */
 304 ssize_t ustcomm_send_unix_sock(int sock, const void *buf, size_t len)
 305 {
 306         struct msghdr msg;
 307         struct iovec iov[1];
 308         ssize_t ret;
 309
 310         memset(&msg, 0, sizeof(msg));
 311
 312         iov[0].iov_base = (void *) buf;
 313         iov[0].iov_len = len;
 314         msg.msg_iov = iov;
 315         msg.msg_iovlen = 1;
 316
 317         /*
 318          * Using the MSG_NOSIGNAL when sending data from sessiond to
 319          * libust, so libust does not receive an unhandled SIGPIPE or
 320          * SIGURG. The sessiond receiver side can be made more resilient
 321          * by ignoring SIGPIPE, but we don't have this luxury on the
 322          * libust side.
 323          */
 324         do {
 325                 ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
 326         } while (ret < 0 && errno == EINTR);
 327
 328         if (ret < 0) {
 329                 int shutret;
 330
 331                 if (errno != EPIPE && errno != ECONNRESET)
 332                         PERROR("sendmsg");
 333                 ret = -errno;
 334                 if (ret == -ECONNRESET)
 335                         ret = -EPIPE;
 336
 337                 shutret = shutdown(sock, SHUT_RDWR);
 338                 if (shutret)
 339                         ERR("Socket shutdown error");
 340         }
 341
 342         return ret;
 343 }
 344
 345 /*
 346  * Send a message accompanied by fd(s) over a unix socket.
 347  *
 348  * Returns the size of data sent, or negative error value.
 349  */
 350 ssize_t ustcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 351 {
 352         struct msghdr msg;
 353         struct cmsghdr *cmptr;
 354         struct iovec iov[1];
 355         ssize_t ret = -1;
 356         unsigned int sizeof_fds = nb_fd * sizeof(int);
 357         char tmp[CMSG_SPACE(sizeof_fds)];
 358         char dummy = 0;
 359
 360         memset(&msg, 0, sizeof(msg));
 361         memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));
 362
 363         if (nb_fd > USTCOMM_MAX_SEND_FDS)
 364                 return -EINVAL;
 365
 366         msg.msg_control = (caddr_t)tmp;
 367         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 368
 369         cmptr = CMSG_FIRSTHDR(&msg);
 370         cmptr->cmsg_level = SOL_SOCKET;
 371         cmptr->cmsg_type = SCM_RIGHTS;
 372         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 373         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 374         /* Sum of the length of all control messages in the buffer: */
 375         msg.msg_controllen = cmptr->cmsg_len;
 376
 377         iov[0].iov_base = &dummy;
 378         iov[0].iov_len = 1;
 379         msg.msg_iov = iov;
 380         msg.msg_iovlen = 1;
 381
 382         do {
 383                 ret = sendmsg(sock, &msg, 0);
 384         } while (ret < 0 && errno == EINTR);
 385         if (ret < 0) {
 386                 /*
 387                  * We consider EPIPE and ECONNRESET as expected.
 388                  */
 389                 if (errno != EPIPE && errno != ECONNRESET) {
 390                         PERROR("sendmsg");
 391                 }
 392                 ret = -errno;
 393                 if (ret == -ECONNRESET)
 394                         ret = -EPIPE;
 395         }
 396         return ret;
 397 }
 398
 399 /*
 400  * Recv a message accompanied by fd(s) from a unix socket.
 401  *
 402  * Returns the size of received data, or negative error value.
 403  *
 404  * Expect at most "nb_fd" file descriptors. Returns the number of fd
 405  * actually received in nb_fd.
 406  * Returns -EPIPE on orderly shutdown.
 407  */
 408 ssize_t ustcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 409 {
 410         struct iovec iov[1];
 411         ssize_t ret = 0;
 412         struct cmsghdr *cmsg;
 413         size_t sizeof_fds = nb_fd * sizeof(int);
 414         char recv_fd[CMSG_SPACE(sizeof_fds)];
 415         struct msghdr msg;
 416         char dummy;
 417
 418         memset(&msg, 0, sizeof(msg));
 419
 420         /* Prepare to receive the structures */
 421         iov[0].iov_base = &dummy;
 422         iov[0].iov_len = 1;
 423         msg.msg_iov = iov;
 424         msg.msg_iovlen = 1;
 425         msg.msg_control = recv_fd;
 426         msg.msg_controllen = sizeof(recv_fd);
 427
 428         do {
 429                 ret = recvmsg(sock, &msg, 0);
 430         } while (ret < 0 && errno == EINTR);
 431         if (ret < 0) {
 432                 if (errno != EPIPE && errno != ECONNRESET) {
 433                         PERROR("recvmsg fds");
 434                 }
 435                 ret = -errno;
 436                 if (ret == -ECONNRESET)
 437                         ret = -EPIPE;
 438                 goto end;
 439         }
 440         if (ret == 0) {
 441                 /* orderly shutdown */
 442                 ret = -EPIPE;
 443                 goto end;
 444         }
 445         if (ret != 1) {
 446                 ERR("Error: Received %zd bytes, expected %d\n",
 447                                 ret, 1);
 448                 goto end;
 449         }
 450         if (msg.msg_flags & MSG_CTRUNC) {
 451                 ERR("Error: Control message truncated.\n");
 452                 ret = -1;
 453                 goto end;
 454         }
 455         cmsg = CMSG_FIRSTHDR(&msg);
 456         if (!cmsg) {
 457                 ERR("Error: Invalid control message header\n");
 458                 ret = -1;
 459                 goto end;
 460         }
 461         if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
 462                 ERR("Didn't received any fd\n");
 463                 ret = -1;
 464                 goto end;
 465         }
 466         if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
 467                 ERR("Error: Received %zu bytes of ancillary data, expected %zu\n",
 468                                 (size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
 469                 ret = -1;
 470                 goto end;
 471         }
 472         memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
 473         ret = sizeof_fds;
 474 end:
 475         return ret;
 476 }
 477
 478 int ustcomm_send_app_msg(int sock, struct ustcomm_ust_msg *lum)
 479 {
 480         ssize_t len;
 481
 482         len = ustcomm_send_unix_sock(sock, lum, sizeof(*lum));
 483         switch (len) {
 484         case sizeof(*lum):
 485                 break;
 486         default:
 487                 if (len < 0) {
 488                         return len;
 489                 } else {
 490                         ERR("incorrect message size: %zd\n", len);
 491                         return -EINVAL;
 492                 }
 493         }
 494         return 0;
 495 }
 496
 497 int ustcomm_recv_app_reply(int sock, struct ustcomm_ust_reply *lur,
 498                           uint32_t expected_handle, uint32_t expected_cmd)
 499 {
 500         ssize_t len;
 501
 502         memset(lur, 0, sizeof(*lur));
 503         len = ustcomm_recv_unix_sock(sock, lur, sizeof(*lur));
 504         switch (len) {
 505         case 0: /* orderly shutdown */
 506                 return -EPIPE;
 507         case sizeof(*lur):
 508                 if (lur->handle != expected_handle) {
 509                         ERR("Unexpected result message handle: "
 510                                 "expected: %u vs received: %u\n",
 511                                 expected_handle, lur->handle);
 512                         return -EINVAL;
 513                 }
 514                 if (lur->cmd != expected_cmd) {
 515                         ERR("Unexpected result message command "
 516                                 "expected: %u vs received: %u\n",
 517                                 expected_cmd, lur->cmd);
 518                         return -EINVAL;
 519                 }
 520                 return lur->ret_code;
 521         default:
 522                 if (len >= 0) {
 523                         ERR("incorrect message size: %zd\n", len);
 524                 }
 525                 return len;
 526         }
 527 }
 528
 529 int ustcomm_send_app_cmd(int sock,
 530                         struct ustcomm_ust_msg *lum,
 531                         struct ustcomm_ust_reply *lur)
 532 {
 533         int ret;
 534
 535         ret = ustcomm_send_app_msg(sock, lum);
 536         if (ret)
 537                 return ret;
 538         ret = ustcomm_recv_app_reply(sock, lur, lum->handle, lum->cmd);
 539         if (ret > 0)
 540                 return -EIO;
 541         return ret;
 542 }
 543
 544 /*
 545  * chan_data is allocated internally if this function returns the
 546  * expected var_len.
 547  */
 548 ssize_t ustcomm_recv_channel_from_sessiond(int sock,
 549                 void **_chan_data, uint64_t var_len,
 550                 int *_wakeup_fd)
 551 {
 552         void *chan_data;
 553         ssize_t len, nr_fd;
 554         int wakeup_fd;
 555
 556         if (var_len > LTTNG_UST_CHANNEL_DATA_MAX_LEN) {
 557                 len = -EINVAL;
 558                 goto error_check;
 559         }
 560         /* Receive variable length data */
 561         chan_data = zmalloc(var_len);
 562         if (!chan_data) {
 563                 len = -ENOMEM;
 564                 goto error_alloc;
 565         }
 566         len = ustcomm_recv_unix_sock(sock, chan_data, var_len);
 567         if (len != var_len) {
 568                 goto error_recv;
 569         }
 570         /* recv wakeup fd */
 571         nr_fd = ustcomm_recv_fds_unix_sock(sock, &wakeup_fd, 1);
 572         if (nr_fd <= 0) {
 573                 if (nr_fd < 0) {
 574                         len = nr_fd;
 575                         goto error_recv;
 576                 } else {
 577                         len = -EIO;
 578                         goto error_recv;
 579                 }
 580         }
 581         *_wakeup_fd = wakeup_fd;
 582         *_chan_data = chan_data;
 583         return len;
 584
 585 error_recv:
 586         free(chan_data);
 587 error_alloc:
 588 error_check:
 589         return len;
 590 }
 591
 592 int ustcomm_recv_stream_from_sessiond(int sock,
 593                 uint64_t *memory_map_size,
 594                 int *shm_fd, int *wakeup_fd)
 595 {
 596         ssize_t len;
 597         int ret;
 598         int fds[2];
 599
 600         /* recv shm fd and wakeup fd */
 601         len = ustcomm_recv_fds_unix_sock(sock, fds, 2);
 602         if (len <= 0) {
 603                 if (len < 0) {
 604                         ret = len;
 605                         goto error;
 606                 } else {
 607                         ret = -EIO;
 608                         goto error;
 609                 }
 610         }
 611         *shm_fd = fds[0];
 612         *wakeup_fd = fds[1];
 613         return 0;
 614
 615 error:
 616         return ret;
 617 }
 618
 619 /*
 620  * Returns 0 on success, negative error value on error.
 621  */
 622 int ustcomm_send_reg_msg(int sock,
 623                 enum ustctl_socket_type type,
 624                 uint32_t bits_per_long,
 625                 uint32_t uint8_t_alignment,
 626                 uint32_t uint16_t_alignment,
 627                 uint32_t uint32_t_alignment,
 628                 uint32_t uint64_t_alignment,
 629                 uint32_t long_alignment)
 630 {
 631         ssize_t len;
 632         struct ustctl_reg_msg reg_msg;
 633
 634         reg_msg.magic = LTTNG_UST_COMM_MAGIC;
 635         reg_msg.major = LTTNG_UST_ABI_MAJOR_VERSION;
 636         reg_msg.minor = LTTNG_UST_ABI_MINOR_VERSION;
 637         reg_msg.pid = getpid();
 638         reg_msg.ppid = getppid();
 639         reg_msg.uid = getuid();
 640         reg_msg.gid = getgid();
 641         reg_msg.bits_per_long = bits_per_long;
 642         reg_msg.uint8_t_alignment = uint8_t_alignment;
 643         reg_msg.uint16_t_alignment = uint16_t_alignment;
 644         reg_msg.uint32_t_alignment = uint32_t_alignment;
 645         reg_msg.uint64_t_alignment = uint64_t_alignment;
 646         reg_msg.long_alignment = long_alignment;
 647         reg_msg.socket_type = type;
 648         lttng_ust_getprocname(reg_msg.name);
 649         memset(reg_msg.padding, 0, sizeof(reg_msg.padding));
 650
 651         len = ustcomm_send_unix_sock(sock, &reg_msg, sizeof(reg_msg));
 652         if (len > 0 && len != sizeof(reg_msg))
 653                 return -EIO;
 654         if (len < 0)
 655                 return len;
 656         return 0;
 657 }
 658
 659 static
 660 int serialize_string_encoding(enum ustctl_string_encodings *ue,
 661                 enum lttng_string_encodings le)
 662 {
 663         switch (le) {
 664         case lttng_encode_none:
 665                 *ue = ustctl_encode_none;
 666                 break;
 667         case lttng_encode_UTF8:
 668                 *ue = ustctl_encode_UTF8;
 669                 break;
 670         case lttng_encode_ASCII:
 671                 *ue = ustctl_encode_ASCII;
 672                 break;
 673         default:
 674                 return -EINVAL;
 675         }
 676         return 0;
 677 }
 678
 679 static
 680 int serialize_basic_type(enum ustctl_abstract_types *uatype,
 681                 enum lttng_abstract_types atype,
 682                 union _ustctl_basic_type *ubt,
 683                 const union _lttng_basic_type *lbt)
 684 {
 685         switch (atype) {
 686         case atype_integer:
 687         {
 688                 struct ustctl_integer_type *uit;
 689                 const struct lttng_integer_type *lit;
 690
 691                 uit = &ubt->integer;
 692                 lit = &lbt->integer;
 693                 uit->size = lit->size;
 694                 uit->signedness = lit->signedness;
 695                 uit->reverse_byte_order = lit->reverse_byte_order;
 696                 uit->base = lit->base;
 697                 if (serialize_string_encoding(&uit->encoding, lit->encoding))
 698                         return -EINVAL;
 699                 uit->alignment = lit->alignment;
 700                 *uatype = ustctl_atype_integer;
 701                 break;
 702         }
 703         case atype_string:
 704         {
 705                 if (serialize_string_encoding(&ubt->string.encoding,
 706                                 lbt->string.encoding))
 707                         return -EINVAL;
 708                 *uatype = ustctl_atype_string;
 709                 break;
 710         }
 711         case atype_float:
 712         {
 713                 struct ustctl_float_type *uft;
 714                 const struct lttng_float_type *lft;
 715
 716                 uft = &ubt->_float;
 717                 lft = &lbt->_float;
 718                 uft->exp_dig = lft->exp_dig;
 719                 uft->mant_dig = lft->mant_dig;
 720                 uft->alignment = lft->alignment;
 721                 uft->reverse_byte_order = lft->reverse_byte_order;
 722                 *uatype = ustctl_atype_float;
 723                 break;
 724         }
 725         case atype_enum:
 726         case atype_array:
 727         case atype_sequence:
 728         default:
 729                 return -EINVAL;
 730         }
 731         return 0;
 732 }
 733
 734 static
 735 int serialize_one_type(struct ustctl_type *ut, const struct lttng_type *lt)
 736 {
 737         int ret;
 738
 739         switch (lt->atype) {
 740         case atype_integer:
 741         case atype_float:
 742         case atype_string:
 743                 ret = serialize_basic_type(&ut->atype, lt->atype,
 744                         &ut->u.basic, &lt->u.basic);
 745                 if (ret)
 746                         return ret;
 747                 break;
 748         case atype_array:
 749         {
 750                 struct ustctl_basic_type *ubt;
 751                 const struct lttng_basic_type *lbt;
 752                 int ret;
 753
 754                 ubt = &ut->u.array.elem_type;
 755                 lbt = &lt->u.array.elem_type;
 756                 ut->u.array.length = lt->u.array.length;
 757                 ret = serialize_basic_type(&ubt->atype, lbt->atype,
 758                         &ubt->u.basic, &lbt->u.basic);
 759                 if (ret)
 760                         return -EINVAL;
 761                 ut->atype = ustctl_atype_array;
 762                 break;
 763         }
 764         case atype_sequence:
 765         {
 766                 struct ustctl_basic_type *ubt;
 767                 const struct lttng_basic_type *lbt;
 768                 int ret;
 769
 770                 ubt = &ut->u.sequence.length_type;
 771                 lbt = &lt->u.sequence.length_type;
 772                 ret = serialize_basic_type(&ubt->atype, lbt->atype,
 773                         &ubt->u.basic, &lbt->u.basic);
 774                 if (ret)
 775                         return -EINVAL;
 776                 ubt = &ut->u.sequence.elem_type;
 777                 lbt = &lt->u.sequence.elem_type;
 778                 ret = serialize_basic_type(&ubt->atype, lbt->atype,
 779                         &ubt->u.basic, &lbt->u.basic);
 780                 if (ret)
 781                         return -EINVAL;
 782                 ut->atype = ustctl_atype_sequence;
 783                 break;
 784         }
 785         case atype_enum:
 786         default:
 787                 return -EINVAL;
 788         }
 789         return 0;
 790 }
 791
 792 static
 793 int serialize_fields(size_t *_nr_write_fields,
 794                 struct ustctl_field **ustctl_fields,
 795                 size_t nr_fields,
 796                 const struct lttng_event_field *lttng_fields)
 797 {
 798         struct ustctl_field *fields;
 799         int i, ret;
 800         size_t nr_write_fields = 0;
 801
 802         fields = zmalloc(nr_fields * sizeof(*fields));
 803         if (!fields)
 804                 return -ENOMEM;
 805
 806         for (i = 0; i < nr_fields; i++) {
 807                 struct ustctl_field *f;
 808                 const struct lttng_event_field *lf;
 809
 810                 f = &fields[nr_write_fields];
 811                 lf = &lttng_fields[i];
 812
 813                 /* skip 'nowrite' fields */
 814                 if (lf->nowrite)
 815                         continue;
 816                 strncpy(f->name, lf->name, LTTNG_UST_SYM_NAME_LEN);
 817                 f->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 818                 ret = serialize_one_type(&f->type, &lf->type);
 819                 if (ret)
 820                         goto error_type;
 821                 nr_write_fields++;
 822         }
 823
 824         *_nr_write_fields = nr_write_fields;
 825         *ustctl_fields = fields;
 826         return 0;
 827
 828 error_type:
 829         free(fields);
 830         return ret;
 831 }
 832
 833 /*
 834  * Returns 0 on success, negative error value on error.
 835  */
 836 int ustcomm_register_event(int sock,
 837         int session_objd,               /* session descriptor */
 838         int channel_objd,               /* channel descriptor */
 839         const char *event_name,         /* event name (input) */
 840         int loglevel,
 841         const char *signature,          /* event signature (input) */
 842         size_t nr_fields,               /* fields */
 843         const struct lttng_event_field *lttng_fields,
 844         const char *model_emf_uri,
 845         uint32_t *id)                   /* event id (output) */
 846 {
 847         ssize_t len;
 848         struct {
 849                 struct ustcomm_notify_hdr header;
 850                 struct ustcomm_notify_event_msg m;
 851         } msg;
 852         struct {
 853                 struct ustcomm_notify_hdr header;
 854                 struct ustcomm_notify_event_reply r;
 855         } reply;
 856         size_t signature_len, fields_len, model_emf_uri_len;
 857         struct ustctl_field *fields = NULL;
 858         size_t nr_write_fields = 0;
 859         int ret;
 860
 861         memset(&msg, 0, sizeof(msg));
 862         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
 863         msg.m.session_objd = session_objd;
 864         msg.m.channel_objd = channel_objd;
 865         strncpy(msg.m.event_name, event_name, LTTNG_UST_SYM_NAME_LEN);
 866         msg.m.event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 867         msg.m.loglevel = loglevel;
 868         signature_len = strlen(signature) + 1;
 869         msg.m.signature_len = signature_len;
 870
 871         /* Calculate fields len, serialize fields. */
 872         if (nr_fields > 0) {
 873                 ret = serialize_fields(&nr_write_fields, &fields,
 874                                 nr_fields, lttng_fields);
 875                 if (ret)
 876                         return ret;
 877         }
 878
 879         fields_len = sizeof(*fields) * nr_write_fields;
 880         msg.m.fields_len = fields_len;
 881         if (model_emf_uri) {
 882                 model_emf_uri_len = strlen(model_emf_uri) + 1;
 883         } else {
 884                 model_emf_uri_len = 0;
 885         }
 886         msg.m.model_emf_uri_len = model_emf_uri_len;
 887         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
 888         if (len > 0 && len != sizeof(msg)) {
 889                 free(fields);
 890                 return -EIO;
 891         }
 892         if (len < 0) {
 893                 free(fields);
 894                 return len;
 895         }
 896
 897         /* send signature */
 898         len = ustcomm_send_unix_sock(sock, signature, signature_len);
 899         if (len > 0 && len != signature_len) {
 900                 free(fields);
 901                 return -EIO;
 902         }
 903         if (len < 0) {
 904                 free(fields);
 905                 return len;
 906         }
 907
 908         /* send fields */
 909         if (fields_len > 0) {
 910                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
 911                 free(fields);
 912                 if (len > 0 && len != fields_len) {
 913                         return -EIO;
 914                 }
 915                 if (len < 0) {
 916                         return len;
 917                 }
 918         }
 919
 920         if (model_emf_uri_len) {
 921                 /* send model_emf_uri */
 922                 len = ustcomm_send_unix_sock(sock, model_emf_uri,
 923                                 model_emf_uri_len);
 924                 if (len > 0 && len != model_emf_uri_len)
 925                         return -EIO;
 926                 if (len < 0)
 927                         return len;
 928         }
 929
 930         /* receive reply */
 931         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
 932         switch (len) {
 933         case 0: /* orderly shutdown */
 934                 return -EPIPE;
 935         case sizeof(reply):
 936                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
 937                         ERR("Unexpected result message command "
 938                                 "expected: %u vs received: %u\n",
 939                                 msg.header.notify_cmd, reply.header.notify_cmd);
 940                         return -EINVAL;
 941                 }
 942                 if (reply.r.ret_code > 0)
 943                         return -EINVAL;
 944                 if (reply.r.ret_code < 0)
 945                         return reply.r.ret_code;
 946                 *id = reply.r.event_id;
 947                 DBG("Sent register event notification for name \"%s\": ret_code %d, event_id %u\n",
 948                         event_name, reply.r.ret_code, reply.r.event_id);
 949                 return 0;
 950         default:
 951                 if (len < 0) {
 952                         /* Transport level error */
 953                         if (errno == EPIPE || errno == ECONNRESET)
 954                                 len = -errno;
 955                         return len;
 956                 } else {
 957                         ERR("incorrect message size: %zd\n", len);
 958                         return len;
 959                 }
 960         }
 961 }
 962
 963 /*
 964  * Returns 0 on success, negative error value on error.
 965  * Returns -EPIPE or -ECONNRESET if other end has hung up.
 966  */
 967 int ustcomm_register_channel(int sock,
 968         int session_objd,               /* session descriptor */
 969         int channel_objd,               /* channel descriptor */
 970         size_t nr_ctx_fields,
 971         const struct lttng_event_field *ctx_fields,
 972         uint32_t *chan_id,              /* channel id (output) */
 973         int *header_type)               /* header type (output) */
 974 {
 975         ssize_t len;
 976         struct {
 977                 struct ustcomm_notify_hdr header;
 978                 struct ustcomm_notify_channel_msg m;
 979         } msg;
 980         struct {
 981                 struct ustcomm_notify_hdr header;
 982                 struct ustcomm_notify_channel_reply r;
 983         } reply;
 984         size_t fields_len;
 985         struct ustctl_field *fields;
 986         int ret;
 987         size_t nr_write_fields = 0;
 988
 989         memset(&msg, 0, sizeof(msg));
 990         msg.header.notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
 991         msg.m.session_objd = session_objd;
 992         msg.m.channel_objd = channel_objd;
 993
 994         /* Calculate fields len, serialize fields. */
 995         if (nr_ctx_fields > 0) {
 996                 ret = serialize_fields(&nr_write_fields, &fields,
 997                                 nr_ctx_fields, ctx_fields);
 998                 if (ret)
 999                         return ret;
1000         }
1001
1002         fields_len = sizeof(*fields) * nr_write_fields;
1003         msg.m.ctx_fields_len = fields_len;
1004         len = ustcomm_send_unix_sock(sock, &msg, sizeof(msg));
1005         if (len > 0 && len != sizeof(msg)) {
1006                 free(fields);
1007                 return -EIO;
1008         }
1009         if (len < 0) {
1010                 free(fields);
1011                 return len;
1012         }
1013
1014         /* send fields */
1015         if (fields_len > 0) {
1016                 len = ustcomm_send_unix_sock(sock, fields, fields_len);
1017                 free(fields);
1018                 if (len > 0 && len != fields_len) {
1019                         return -EIO;
1020                 }
1021                 if (len < 0) {
1022                         return len;
1023                 }
1024         }
1025
1026         len = ustcomm_recv_unix_sock(sock, &reply, sizeof(reply));
1027         switch (len) {
1028         case 0: /* orderly shutdown */
1029                 return -EPIPE;
1030         case sizeof(reply):
1031                 if (reply.header.notify_cmd != msg.header.notify_cmd) {
1032                         ERR("Unexpected result message command "
1033                                 "expected: %u vs received: %u\n",
1034                                 msg.header.notify_cmd, reply.header.notify_cmd);
1035                         return -EINVAL;
1036                 }
1037                 if (reply.r.ret_code > 0)
1038                         return -EINVAL;
1039                 if (reply.r.ret_code < 0)
1040                         return reply.r.ret_code;
1041                 *chan_id = reply.r.chan_id;
1042                 switch (reply.r.header_type) {
1043                 case 1:
1044                 case 2:
1045                         *header_type = reply.r.header_type;
1046                         break;
1047                 default:
1048                         ERR("Unexpected channel header type %u\n",
1049                                 reply.r.header_type);
1050                         return -EINVAL;
1051                 }
1052                 DBG("Sent register channel notification: chan_id %d, header_type %d\n",
1053                         reply.r.chan_id, reply.r.header_type);
1054                 return 0;
1055         default:
1056                 if (len < 0) {
1057                         /* Transport level error */
1058                         if (errno == EPIPE || errno == ECONNRESET)
1059                                 len = -errno;
1060                         return len;
1061                 } else {
1062                         ERR("incorrect message size: %zd\n", len);
1063                         return len;
1064                 }
1065         }
1066 }
1067
1068 /*
1069  * Set socket reciving timeout.
1070  */
1071 int ustcomm_setsockopt_rcv_timeout(int sock, unsigned int msec)
1072 {
1073         int ret;
1074         struct timeval tv;
1075
1076         tv.tv_sec = msec / 1000;
1077         tv.tv_usec = (msec * 1000 % 1000000);
1078
1079         ret = setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
1080         if (ret < 0) {
1081                 PERROR("setsockopt SO_RCVTIMEO");
1082                 ret = -errno;
1083         }
1084
1085         return ret;
1086 }
1087
1088 /*
1089  * Set socket sending timeout.
1090  */
1091 int ustcomm_setsockopt_snd_timeout(int sock, unsigned int msec)
1092 {
1093         int ret;
1094         struct timeval tv;
1095
1096         tv.tv_sec = msec / 1000;
1097         tv.tv_usec = (msec * 1000) % 1000000;
1098
1099         ret = setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
1100         if (ret < 0) {
1101                 PERROR("setsockopt SO_SNDTIMEO");
1102                 ret = -errno;
1103         }
1104
1105         return ret;
1106 }