src/common/unix.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _LGPL_SOURCE
  20 #include <assert.h>
  21 #include <limits.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/stat.h>
  26 #include <sys/types.h>
  27 #include <unistd.h>
  28 #include <errno.h>
  29
  30 #include <common/common.h>
  31 #include <common/sessiond-comm/sessiond-comm.h>
  32
  33 #include "unix.h"
  34
  35 /*
  36  * Connect to unix socket using the path name.
  37  */
  38 LTTNG_HIDDEN
  39 int lttcomm_connect_unix_sock(const char *pathname)
  40 {
  41         struct sockaddr_un s_un;
  42         int fd, ret, closeret;
  43
  44         if (strlen(pathname) >= sizeof(s_un.sun_path)) {
  45                 ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
  46                                 pathname, strlen(pathname) + 1,
  47                                 sizeof(s_un.sun_path));
  48                 ret = -ENAMETOOLONG;
  49                 goto error;
  50         }
  51
  52         fd = socket(PF_UNIX, SOCK_STREAM, 0);
  53         if (fd < 0) {
  54                 PERROR("socket");
  55                 ret = fd;
  56                 goto error;
  57         }
  58
  59         memset(&s_un, 0, sizeof(s_un));
  60         s_un.sun_family = AF_UNIX;
  61         strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
  62         s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
  63
  64         ret = connect(fd, (struct sockaddr *) &s_un, sizeof(s_un));
  65         if (ret < 0) {
  66                 /*
  67                  * Don't print message on connect error, because connect is used in
  68                  * normal execution to detect if sessiond is alive.
  69                  */
  70                 goto error_connect;
  71         }
  72
  73         return fd;
  74
  75 error_connect:
  76         closeret = close(fd);
  77         if (closeret) {
  78                 PERROR("close");
  79         }
  80 error:
  81         return ret;
  82 }
  83
  84 /*
  85  * Do an accept(2) on the sock and return the new file descriptor. The socket
  86  * MUST be bind(2) before.
  87  */
  88 LTTNG_HIDDEN
  89 int lttcomm_accept_unix_sock(int sock)
  90 {
  91         int new_fd;
  92         struct sockaddr_un s_un;
  93         socklen_t len = sizeof(s_un);
  94
  95         /* Blocking call */
  96         new_fd = accept(sock, (struct sockaddr *) &s_un, &len);
  97         if (new_fd < 0) {
  98                 PERROR("accept");
  99         }
 100
 101         return new_fd;
 102 }
 103
 104 LTTNG_HIDDEN
 105 int lttcomm_create_anon_unix_socketpair(int *fds)
 106 {
 107         if (socketpair(PF_UNIX, SOCK_STREAM, 0, fds) < 0) {
 108                 PERROR("socketpair");
 109                 return -1;
 110         }
 111         return 0;
 112 }
 113
 114 /*
 115  * Creates a AF_UNIX local socket using pathname bind the socket upon creation
 116  * and return the fd.
 117  */
 118 LTTNG_HIDDEN
 119 int lttcomm_create_unix_sock(const char *pathname)
 120 {
 121         struct sockaddr_un s_un;
 122         int fd = -1;
 123         int ret = -1;
 124
 125         if (strlen(pathname) >= sizeof(s_un.sun_path)) {
 126                 ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
 127                                 pathname, strlen(pathname) + 1,
 128                                 sizeof(s_un.sun_path));
 129                 ret = -ENAMETOOLONG;
 130                 goto error;
 131         }
 132
 133         /* Create server socket */
 134         if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 135                 PERROR("socket");
 136                 goto error;
 137         }
 138
 139         memset(&s_un, 0, sizeof(s_un));
 140         s_un.sun_family = AF_UNIX;
 141         strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
 142         s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
 143
 144         /* Unlink the old file if present */
 145         (void) unlink(pathname);
 146         ret = bind(fd, (struct sockaddr *) &s_un, sizeof(s_un));
 147         if (ret < 0) {
 148                 PERROR("bind");
 149                 goto error;
 150         }
 151
 152         return fd;
 153
 154 error:
 155         if (fd >= 0) {
 156                 if (close(fd) < 0) {
 157                         PERROR("close create unix sock");
 158                 }
 159         }
 160         return ret;
 161 }
 162
 163 /*
 164  * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
 165  */
 166 LTTNG_HIDDEN
 167 int lttcomm_listen_unix_sock(int sock)
 168 {
 169         int ret;
 170
 171         ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
 172         if (ret < 0) {
 173                 PERROR("listen");
 174         }
 175
 176         return ret;
 177 }
 178
 179 /*
 180  * Receive data of size len in put that data into the buf param. Using recvmsg
 181  * API.
 182  *
 183  * Return the size of received data.
 184  */
 185 LTTNG_HIDDEN
 186 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 187 {
 188         struct msghdr msg;
 189         struct iovec iov[1];
 190         ssize_t ret = -1;
 191         size_t len_last;
 192
 193         memset(&msg, 0, sizeof(msg));
 194
 195         iov[0].iov_base = buf;
 196         iov[0].iov_len = len;
 197         msg.msg_iov = iov;
 198         msg.msg_iovlen = 1;
 199
 200         do {
 201                 len_last = iov[0].iov_len;
 202                 ret = lttng_recvmsg_nosigpipe(sock, &msg);
 203                 if (ret > 0) {
 204                         iov[0].iov_base += ret;
 205                         iov[0].iov_len -= ret;
 206                         assert(ret <= len_last);
 207                 }
 208         } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
 209         if (ret < 0) {
 210                 PERROR("recvmsg");
 211         } else if (ret > 0) {
 212                 ret = len;
 213         }
 214         /* Else ret = 0 meaning an orderly shutdown. */
 215
 216         return ret;
 217 }
 218
 219 /*
 220  * Receive data of size len in put that data into the buf param. Using recvmsg
 221  * API. Only use with sockets set in non-blocking mode.
 222  *
 223  * Return the size of received data.
 224  */
 225 LTTNG_HIDDEN
 226 ssize_t lttcomm_recv_unix_sock_non_block(int sock, void *buf, size_t len)
 227 {
 228         struct msghdr msg;
 229         struct iovec iov[1];
 230         ssize_t ret;
 231
 232         memset(&msg, 0, sizeof(msg));
 233
 234         iov[0].iov_base = buf;
 235         iov[0].iov_len = len;
 236         msg.msg_iov = iov;
 237         msg.msg_iovlen = 1;
 238
 239 retry:
 240         ret = lttng_recvmsg_nosigpipe(sock, &msg);
 241         if (ret < 0) {
 242                 if (errno == EINTR) {
 243                         goto retry;
 244                 } else {
 245                         /* We consider EPIPE and EAGAIN as expected. */
 246                         if (!lttng_opt_quiet &&
 247                                         (errno != EPIPE && errno != EAGAIN)) {
 248                                 PERROR("recvmsg");
 249                         }
 250                         goto end;
 251                 }
 252         }
 253         ret = len;
 254 end:
 255         return ret;
 256 }
 257
 258 /*
 259  * Send buf data of size len. Using sendmsg API.
 260  *
 261  * Return the size of sent data.
 262  */
 263 LTTNG_HIDDEN
 264 ssize_t lttcomm_send_unix_sock(int sock, const 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 = (void *) buf;
 273         iov[0].iov_len = len;
 274         msg.msg_iov = iov;
 275         msg.msg_iovlen = 1;
 276
 277         while (iov[0].iov_len) {
 278                 ret = sendmsg(sock, &msg, 0);
 279                 if (ret < 0) {
 280                         if (errno == EINTR) {
 281                                 continue;
 282                         } else {
 283                                 /*
 284                                  * Only warn about EPIPE when quiet mode is
 285                                  * deactivated.
 286                                  * We consider EPIPE as expected.
 287                                  */
 288                                 if (errno != EPIPE || !lttng_opt_quiet) {
 289                                         PERROR("sendmsg");
 290                                 }
 291                                 goto end;
 292                         }
 293                 }
 294                 iov[0].iov_len -= ret;
 295                 iov[0].iov_base += ret;
 296         }
 297         ret = len;
 298 end:
 299         return ret;
 300 }
 301
 302 /*
 303  * Send buf data of size len. Using sendmsg API.
 304  * Only use with non-blocking sockets. The difference with the blocking version
 305  * of the function is that this one does not retry to send on partial sends,
 306  * except if the interruption was caused by a signal (EINTR).
 307  *
 308  * Return the size of sent data.
 309  */
 310 LTTNG_HIDDEN
 311 ssize_t lttcomm_send_unix_sock_non_block(int sock, const void *buf, size_t len)
 312 {
 313         struct msghdr msg;
 314         struct iovec iov[1];
 315         ssize_t ret;
 316
 317         memset(&msg, 0, sizeof(msg));
 318
 319         iov[0].iov_base = (void *) buf;
 320         iov[0].iov_len = len;
 321         msg.msg_iov = iov;
 322         msg.msg_iovlen = 1;
 323
 324 retry:
 325         ret = sendmsg(sock, &msg, 0);
 326         if (ret < 0) {
 327                 if (errno == EINTR) {
 328                         goto retry;
 329                 } else {
 330                         /* We consider EPIPE and EAGAIN as expected. */
 331                         if (!lttng_opt_quiet &&
 332                                         (errno != EPIPE && errno != EAGAIN)) {
 333                                 PERROR("sendmsg");
 334                         }
 335                         goto end;
 336                 }
 337         }
 338         ret = len;
 339 end:
 340         return ret;
 341 }
 342
 343 /*
 344  * Shutdown cleanly a unix socket.
 345  */
 346 LTTNG_HIDDEN
 347 int lttcomm_close_unix_sock(int sock)
 348 {
 349         int ret, closeret;
 350
 351         /* Shutdown receptions and transmissions */
 352         ret = shutdown(sock, SHUT_RDWR);
 353         if (ret < 0) {
 354                 PERROR("shutdown");
 355         }
 356
 357         closeret = close(sock);
 358         if (closeret) {
 359                 PERROR("close");
 360         }
 361
 362         return ret;
 363 }
 364
 365 /*
 366  * Send a message accompanied by fd(s) over a unix socket.
 367  *
 368  * Returns the size of data sent, or negative error value.
 369  */
 370 LTTNG_HIDDEN
 371 ssize_t lttcomm_send_fds_unix_sock(int sock, const int *fds, size_t nb_fd)
 372 {
 373         struct msghdr msg;
 374         struct cmsghdr *cmptr;
 375         struct iovec iov[1];
 376         ssize_t ret = -1;
 377         unsigned int sizeof_fds = nb_fd * sizeof(int);
 378         char tmp[CMSG_SPACE(sizeof_fds)];
 379         char dummy = 0;
 380
 381         memset(&msg, 0, sizeof(msg));
 382         memset(tmp, 0, sizeof(tmp));
 383
 384         if (nb_fd > LTTCOMM_MAX_SEND_FDS)
 385                 return -EINVAL;
 386
 387         msg.msg_control = (caddr_t)tmp;
 388         msg.msg_controllen = CMSG_LEN(sizeof_fds);
 389
 390         cmptr = CMSG_FIRSTHDR(&msg);
 391         if (!cmptr) {
 392                 return -1;
 393         }
 394
 395         cmptr->cmsg_level = SOL_SOCKET;
 396         cmptr->cmsg_type = SCM_RIGHTS;
 397         cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
 398         memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
 399         /* Sum of the length of all control messages in the buffer: */
 400         msg.msg_controllen = cmptr->cmsg_len;
 401
 402         iov[0].iov_base = &dummy;
 403         iov[0].iov_len = 1;
 404         msg.msg_iov = iov;
 405         msg.msg_iovlen = 1;
 406
 407         do {
 408                 ret = sendmsg(sock, &msg, 0);
 409         } while (ret < 0 && errno == EINTR);
 410         if (ret < 0) {
 411                 /*
 412                  * Only warn about EPIPE when quiet mode is deactivated.
 413                  * We consider EPIPE as expected.
 414                  */
 415                 if (errno != EPIPE || !lttng_opt_quiet) {
 416                         PERROR("sendmsg");
 417                 }
 418         }
 419         return ret;
 420 }
 421
 422 /*
 423  * Recv a message accompanied by fd(s) from a unix socket.
 424  *
 425  * Returns the size of received data, or negative error value.
 426  *
 427  * Expect at most "nb_fd" file descriptors. Returns the number of fd
 428  * actually received in nb_fd.
 429  */
 430 LTTNG_HIDDEN
 431 ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 432 {
 433         struct iovec iov[1];
 434         ssize_t ret = 0;
 435         struct cmsghdr *cmsg;
 436         size_t sizeof_fds = nb_fd * sizeof(int);
 437
 438 #ifdef __linux__
 439 /* Account for the struct ucred cmsg in the buffer size */
 440 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
 441 #else
 442 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
 443 #endif /* __linux__ */
 444
 445         char recv_buf[LTTNG_SOCK_RECV_FDS_BUF_SIZE];
 446         struct msghdr msg;
 447         char dummy;
 448
 449         memset(&msg, 0, sizeof(msg));
 450
 451         /* Prepare to receive the structures */
 452         iov[0].iov_base = &dummy;
 453         iov[0].iov_len = 1;
 454         msg.msg_iov = iov;
 455         msg.msg_iovlen = 1;
 456
 457         cmsg = (struct cmsghdr *) recv_buf;
 458         cmsg->cmsg_len = CMSG_LEN(sizeof_fds);
 459         cmsg->cmsg_level = SOL_SOCKET;
 460         cmsg->cmsg_type = SCM_RIGHTS;
 461
 462         msg.msg_control = cmsg;
 463         msg.msg_controllen = CMSG_LEN(sizeof(recv_buf));
 464         msg.msg_flags = 0;
 465
 466         do {
 467                 ret = recvmsg(sock, &msg, 0);
 468         } while (ret < 0 && errno == EINTR);
 469         if (ret < 0) {
 470                 PERROR("recvmsg fds");
 471                 goto end;
 472         }
 473
 474         if (ret != 1) {
 475                 fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
 476                                 ret, 1);
 477                 goto end;
 478         }
 479
 480         if (msg.msg_flags & MSG_CTRUNC) {
 481                 fprintf(stderr, "Error: Control message truncated.\n");
 482                 ret = -1;
 483                 goto end;
 484         }
 485
 486         /*
 487          * If the socket was configured with SO_PASSCRED, the kernel will add a
 488          * control message (cmsg) to the ancillary data of the unix socket. We
 489          * need to expect a cmsg of the SCM_CREDENTIALS as the first control
 490          * message.
 491          */
 492         for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
 493                 if (cmsg->cmsg_level != SOL_SOCKET) {
 494                         fprintf(stderr, "Error: The socket needs to be of type SOL_SOCKET\n");
 495                         ret = -1;
 496                         goto end;
 497                 }
 498                 if (cmsg->cmsg_type == SCM_RIGHTS) {
 499                         /*
 500                          * We found the controle message for file descriptors,
 501                          * now copy the fds to the fds ptr and return success.
 502                          */
 503                         if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
 504                                 fprintf(stderr, "Error: Received %zu bytes of"
 505                                         "ancillary data for FDs, expected %zu\n",
 506                                         (size_t) cmsg->cmsg_len,
 507                                         (size_t) CMSG_LEN(sizeof_fds));
 508                                 ret = -1;
 509                                 goto end;
 510                         }
 511                         memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
 512                         ret = sizeof_fds;
 513                         goto end;
 514                 }
 515 #ifdef __linux__
 516                 if (cmsg->cmsg_type == SCM_CREDENTIALS) {
 517                         /*
 518                          * Expect credentials to be sent when expecting fds even
 519                          * if no credential were include in the send(). The
 520                          * kernel adds them...
 521                          */
 522                         ret = -1;
 523                 }
 524 #endif /* __linux__ */
 525         }
 526 end:
 527         return ret;
 528 }
 529
 530 /*
 531  * Send a message with credentials over a unix socket.
 532  *
 533  * Returns the size of data sent, or negative error value.
 534  */
 535 LTTNG_HIDDEN
 536 ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len)
 537 {
 538         struct msghdr msg;
 539         struct iovec iov[1];
 540         ssize_t ret = -1;
 541 #ifdef __linux__
 542         struct cmsghdr *cmptr;
 543         size_t sizeof_cred = sizeof(lttng_sock_cred);
 544         char anc_buf[CMSG_SPACE(sizeof_cred)];
 545         lttng_sock_cred *creds;
 546
 547         memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char));
 548 #endif /* __linux__ */
 549
 550         memset(&msg, 0, sizeof(msg));
 551
 552         iov[0].iov_base = buf;
 553         iov[0].iov_len = len;
 554         msg.msg_iov = iov;
 555         msg.msg_iovlen = 1;
 556
 557 #ifdef __linux__
 558         msg.msg_control = (caddr_t) anc_buf;
 559         msg.msg_controllen = CMSG_LEN(sizeof_cred);
 560
 561         cmptr = CMSG_FIRSTHDR(&msg);
 562         if (!cmptr) {
 563                 return -1;
 564         }
 565         cmptr->cmsg_level = SOL_SOCKET;
 566         cmptr->cmsg_type = LTTNG_SOCK_CREDS;
 567         cmptr->cmsg_len = CMSG_LEN(sizeof_cred);
 568
 569         creds = (lttng_sock_cred*) CMSG_DATA(cmptr);
 570
 571         LTTNG_SOCK_SET_UID_CRED(creds, geteuid());
 572         LTTNG_SOCK_SET_GID_CRED(creds, getegid());
 573         LTTNG_SOCK_SET_PID_CRED(creds, getpid());
 574 #endif /* __linux__ */
 575
 576         do {
 577                 ret = sendmsg(sock, &msg, 0);
 578         } while (ret < 0 && errno == EINTR);
 579         if (ret < 0) {
 580                 /*
 581                  * Only warn about EPIPE when quiet mode is deactivated.
 582                  * We consider EPIPE as expected.
 583                  */
 584                 if (errno != EPIPE || !lttng_opt_quiet) {
 585                         PERROR("sendmsg");
 586                 }
 587         }
 588         return ret;
 589 }
 590
 591 /*
 592  * Recv a message accompanied with credentials from a unix socket.
 593  *
 594  * Returns the size of received data, or negative error value.
 595  */
 596 LTTNG_HIDDEN
 597 ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
 598                 lttng_sock_cred *creds)
 599 {
 600         struct msghdr msg;
 601         struct iovec iov[1];
 602         ssize_t ret;
 603         size_t len_last;
 604 #ifdef __linux__
 605         struct cmsghdr *cmptr;
 606         size_t sizeof_cred = sizeof(lttng_sock_cred);
 607         char anc_buf[CMSG_SPACE(sizeof_cred)];
 608 #endif  /* __linux__ */
 609
 610         memset(&msg, 0, sizeof(msg));
 611
 612         /* Not allowed */
 613         if (creds == NULL) {
 614                 ret = -1;
 615                 goto end;
 616         }
 617
 618         /* Prepare to receive the structures */
 619         iov[0].iov_base = buf;
 620         iov[0].iov_len = len;
 621         msg.msg_iov = iov;
 622         msg.msg_iovlen = 1;
 623
 624 #ifdef __linux__
 625         msg.msg_control = anc_buf;
 626         msg.msg_controllen = sizeof(anc_buf);
 627 #endif /* __linux__ */
 628
 629         do {
 630                 len_last = iov[0].iov_len;
 631                 ret = recvmsg(sock, &msg, 0);
 632                 if (ret > 0) {
 633                         iov[0].iov_base += ret;
 634                         iov[0].iov_len -= ret;
 635                         assert(ret <= len_last);
 636                 }
 637         } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
 638         if (ret < 0) {
 639                 PERROR("recvmsg fds");
 640                 goto end;
 641         } else if (ret > 0) {
 642                 ret = len;
 643         }
 644         /* Else ret = 0 meaning an orderly shutdown. */
 645
 646 #ifdef __linux__
 647         if (msg.msg_flags & MSG_CTRUNC) {
 648                 fprintf(stderr, "Error: Control message truncated.\n");
 649                 ret = -1;
 650                 goto end;
 651         }
 652
 653         cmptr = CMSG_FIRSTHDR(&msg);
 654         if (cmptr == NULL) {
 655                 fprintf(stderr, "Error: Invalid control message header\n");
 656                 ret = -1;
 657                 goto end;
 658         }
 659
 660         if (cmptr->cmsg_level != SOL_SOCKET ||
 661                         cmptr->cmsg_type != LTTNG_SOCK_CREDS) {
 662                 fprintf(stderr, "Didn't received any credentials\n");
 663                 ret = -1;
 664                 goto end;
 665         }
 666
 667         if (cmptr->cmsg_len != CMSG_LEN(sizeof_cred)) {
 668                 fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
 669                                 (size_t) cmptr->cmsg_len, (size_t) CMSG_LEN(sizeof_cred));
 670                 ret = -1;
 671                 goto end;
 672         }
 673
 674         memcpy(creds, CMSG_DATA(cmptr), sizeof_cred);
 675 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
 676         {
 677                 int peer_ret;
 678
 679                 peer_ret = getpeereid(sock, &creds->uid, &creds->gid);
 680                 if (peer_ret != 0) {
 681                         return peer_ret;
 682                 }
 683         }
 684 #else
 685 #error "Please implement credential support for your OS."
 686 #endif  /* __linux__ */
 687
 688 end:
 689         return ret;
 690 }
 691
 692 /*
 693  * Set socket option to use credentials passing.
 694  */
 695 #ifdef __linux__
 696 LTTNG_HIDDEN
 697 int lttcomm_setsockopt_creds_unix_sock(int sock)
 698 {
 699         int ret, on = 1;
 700
 701         /* Set socket for credentials retrieval */
 702         ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
 703         if (ret < 0) {
 704                 PERROR("setsockopt creds unix sock");
 705         }
 706         return ret;
 707 }
 708 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
 709 LTTNG_HIDDEN
 710 int lttcomm_setsockopt_creds_unix_sock(int sock)
 711 {
 712         return 0;
 713 }
 714 #else
 715 #error "Please implement credential support for your OS."
 716 #endif /* __linux__ */