2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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.
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
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.
26 #include <sys/types.h>
30 #include <common/common.h>
31 #include <common/sessiond-comm/sessiond-comm.h>
36 * Connect to unix socket using the path name.
39 int lttcomm_connect_unix_sock(const char *pathname
)
41 struct sockaddr_un s_un
;
42 int fd
, ret
, closeret
;
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
));
52 fd
= socket(PF_UNIX
, SOCK_STREAM
, 0);
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';
64 ret
= connect(fd
, (struct sockaddr
*) &s_un
, sizeof(s_un
));
67 * Don't print message on connect error, because connect is used in
68 * normal execution to detect if sessiond is alive.
85 * Do an accept(2) on the sock and return the new file descriptor. The socket
86 * MUST be bind(2) before.
89 int lttcomm_accept_unix_sock(int sock
)
92 struct sockaddr_un s_un
;
93 socklen_t len
= sizeof(s_un
);
96 new_fd
= accept(sock
, (struct sockaddr
*) &s_un
, &len
);
105 int lttcomm_create_anon_unix_socketpair(int *fds
)
107 if (socketpair(PF_UNIX
, SOCK_STREAM
, 0, fds
) < 0) {
108 PERROR("socketpair");
115 * Creates a AF_UNIX local socket using pathname bind the socket upon creation
119 int lttcomm_create_unix_sock(const char *pathname
)
121 struct sockaddr_un s_un
;
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
));
133 /* Create server socket */
134 if ((fd
= socket(PF_UNIX
, SOCK_STREAM
, 0)) < 0) {
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';
144 /* Unlink the old file if present */
145 (void) unlink(pathname
);
146 ret
= bind(fd
, (struct sockaddr
*) &s_un
, sizeof(s_un
));
157 PERROR("close create unix sock");
164 * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
167 int lttcomm_listen_unix_sock(int sock
)
171 ret
= listen(sock
, LTTNG_SESSIOND_COMM_MAX_LISTEN
);
180 * Receive data of size len in put that data into the buf param. Using recvmsg
183 * Return the size of received data.
186 ssize_t
lttcomm_recv_unix_sock(int sock
, void *buf
, size_t len
)
193 memset(&msg
, 0, sizeof(msg
));
195 iov
[0].iov_base
= buf
;
196 iov
[0].iov_len
= len
;
201 len_last
= iov
[0].iov_len
;
202 ret
= lttng_recvmsg_nosigpipe(sock
, &msg
);
204 iov
[0].iov_base
+= ret
;
205 iov
[0].iov_len
-= ret
;
206 assert(ret
<= len_last
);
208 } while ((ret
> 0 && ret
< len_last
) || (ret
< 0 && errno
== EINTR
));
211 } else if (ret
> 0) {
214 /* Else ret = 0 meaning an orderly shutdown. */
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.
223 * NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
224 * poll set. The poll loop will handle the EPIPE original cause.
226 * Return the size of received data.
229 ssize_t
lttcomm_recv_unix_sock_non_block(int sock
, void *buf
, size_t len
)
235 memset(&msg
, 0, sizeof(msg
));
237 iov
[0].iov_base
= buf
;
238 iov
[0].iov_len
= len
;
243 ret
= lttng_recvmsg_nosigpipe(sock
, &msg
);
245 if (errno
== EINTR
) {
249 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
251 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
||
260 /* Unexpected error */
272 * Send buf data of size len. Using sendmsg API.
274 * Return the size of sent data.
277 ssize_t
lttcomm_send_unix_sock(int sock
, const void *buf
, size_t len
)
283 memset(&msg
, 0, sizeof(msg
));
285 iov
[0].iov_base
= (void *) buf
;
286 iov
[0].iov_len
= len
;
290 while (iov
[0].iov_len
) {
291 ret
= sendmsg(sock
, &msg
, 0);
293 if (errno
== EINTR
) {
297 * Only warn about EPIPE when quiet mode is
299 * We consider EPIPE as expected.
301 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
307 iov
[0].iov_len
-= ret
;
308 iov
[0].iov_base
+= ret
;
316 * Send buf data of size len. Using sendmsg API.
317 * Only use with non-blocking sockets. The difference with the blocking version
318 * of the function is that this one does not retry to send on partial sends,
319 * except if the interruption was caused by a signal (EINTR).
321 * NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
322 * poll set. The poll loop will handle the EPIPE original cause.
324 * Return the size of sent data.
327 ssize_t
lttcomm_send_unix_sock_non_block(int sock
, const void *buf
, size_t len
)
333 memset(&msg
, 0, sizeof(msg
));
335 iov
[0].iov_base
= (void *) buf
;
336 iov
[0].iov_len
= len
;
341 ret
= sendmsg(sock
, &msg
, 0);
343 if (errno
== EINTR
) {
347 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
349 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
||
352 * This can happen in non blocking mode.
359 /* Unexpected error */
371 * Shutdown cleanly a unix socket.
374 int lttcomm_close_unix_sock(int sock
)
378 /* Shutdown receptions and transmissions */
379 ret
= shutdown(sock
, SHUT_RDWR
);
384 closeret
= close(sock
);
393 * Send a message accompanied by fd(s) over a unix socket.
395 * Returns the size of data sent, or negative error value.
398 ssize_t
lttcomm_send_fds_unix_sock(int sock
, const int *fds
, size_t nb_fd
)
401 struct cmsghdr
*cmptr
;
404 unsigned int sizeof_fds
= nb_fd
* sizeof(int);
405 char tmp
[CMSG_SPACE(sizeof_fds
)];
408 memset(&msg
, 0, sizeof(msg
));
409 memset(tmp
, 0, sizeof(tmp
));
411 if (nb_fd
> LTTCOMM_MAX_SEND_FDS
)
414 msg
.msg_control
= (caddr_t
)tmp
;
415 msg
.msg_controllen
= CMSG_LEN(sizeof_fds
);
417 cmptr
= CMSG_FIRSTHDR(&msg
);
422 cmptr
->cmsg_level
= SOL_SOCKET
;
423 cmptr
->cmsg_type
= SCM_RIGHTS
;
424 cmptr
->cmsg_len
= CMSG_LEN(sizeof_fds
);
425 memcpy(CMSG_DATA(cmptr
), fds
, sizeof_fds
);
426 /* Sum of the length of all control messages in the buffer: */
427 msg
.msg_controllen
= cmptr
->cmsg_len
;
429 iov
[0].iov_base
= &dummy
;
435 ret
= sendmsg(sock
, &msg
, 0);
436 } while (ret
< 0 && errno
== EINTR
);
439 * Only warn about EPIPE when quiet mode is deactivated.
440 * We consider EPIPE as expected.
442 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
450 * Recv a message accompanied by fd(s) from a unix socket.
452 * Returns the size of received data, or negative error value.
454 * Expect at most "nb_fd" file descriptors. Returns the number of fd
455 * actually received in nb_fd.
458 ssize_t
lttcomm_recv_fds_unix_sock(int sock
, int *fds
, size_t nb_fd
)
462 struct cmsghdr
*cmsg
;
463 size_t sizeof_fds
= nb_fd
* sizeof(int);
466 /* Account for the struct ucred cmsg in the buffer size */
467 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
469 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
470 #endif /* __linux__ */
472 char recv_buf
[LTTNG_SOCK_RECV_FDS_BUF_SIZE
];
476 memset(&msg
, 0, sizeof(msg
));
478 /* Prepare to receive the structures */
479 iov
[0].iov_base
= &dummy
;
484 cmsg
= (struct cmsghdr
*) recv_buf
;
485 cmsg
->cmsg_len
= CMSG_LEN(sizeof_fds
);
486 cmsg
->cmsg_level
= SOL_SOCKET
;
487 cmsg
->cmsg_type
= SCM_RIGHTS
;
489 msg
.msg_control
= cmsg
;
490 msg
.msg_controllen
= CMSG_LEN(sizeof(recv_buf
));
494 ret
= recvmsg(sock
, &msg
, 0);
495 } while (ret
< 0 && errno
== EINTR
);
497 PERROR("recvmsg fds");
502 fprintf(stderr
, "Error: Received %zd bytes, expected %d\n",
507 if (msg
.msg_flags
& MSG_CTRUNC
) {
508 fprintf(stderr
, "Error: Control message truncated.\n");
514 * If the socket was configured with SO_PASSCRED, the kernel will add a
515 * control message (cmsg) to the ancillary data of the unix socket. We
516 * need to expect a cmsg of the SCM_CREDENTIALS as the first control
519 for (cmsg
= CMSG_FIRSTHDR(&msg
); cmsg
!= NULL
; cmsg
= CMSG_NXTHDR(&msg
, cmsg
)) {
520 if (cmsg
->cmsg_level
!= SOL_SOCKET
) {
521 fprintf(stderr
, "Error: The socket needs to be of type SOL_SOCKET\n");
525 if (cmsg
->cmsg_type
== SCM_RIGHTS
) {
527 * We found the controle message for file descriptors,
528 * now copy the fds to the fds ptr and return success.
530 if (cmsg
->cmsg_len
!= CMSG_LEN(sizeof_fds
)) {
531 fprintf(stderr
, "Error: Received %zu bytes of"
532 "ancillary data for FDs, expected %zu\n",
533 (size_t) cmsg
->cmsg_len
,
534 (size_t) CMSG_LEN(sizeof_fds
));
538 memcpy(fds
, CMSG_DATA(cmsg
), sizeof_fds
);
543 if (cmsg
->cmsg_type
== SCM_CREDENTIALS
) {
545 * Expect credentials to be sent when expecting fds even
546 * if no credential were include in the send(). The
547 * kernel adds them...
551 #endif /* __linux__ */
558 * Send a message with credentials over a unix socket.
560 * Returns the size of data sent, or negative error value.
563 ssize_t
lttcomm_send_creds_unix_sock(int sock
, void *buf
, size_t len
)
569 struct cmsghdr
*cmptr
;
570 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
571 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
572 lttng_sock_cred
*creds
;
574 memset(anc_buf
, 0, CMSG_SPACE(sizeof_cred
) * sizeof(char));
575 #endif /* __linux__ */
577 memset(&msg
, 0, sizeof(msg
));
579 iov
[0].iov_base
= buf
;
580 iov
[0].iov_len
= len
;
585 msg
.msg_control
= (caddr_t
) anc_buf
;
586 msg
.msg_controllen
= CMSG_LEN(sizeof_cred
);
588 cmptr
= CMSG_FIRSTHDR(&msg
);
592 cmptr
->cmsg_level
= SOL_SOCKET
;
593 cmptr
->cmsg_type
= LTTNG_SOCK_CREDS
;
594 cmptr
->cmsg_len
= CMSG_LEN(sizeof_cred
);
596 creds
= (lttng_sock_cred
*) CMSG_DATA(cmptr
);
598 LTTNG_SOCK_SET_UID_CRED(creds
, geteuid());
599 LTTNG_SOCK_SET_GID_CRED(creds
, getegid());
600 LTTNG_SOCK_SET_PID_CRED(creds
, getpid());
601 #endif /* __linux__ */
604 ret
= sendmsg(sock
, &msg
, 0);
605 } while (ret
< 0 && errno
== EINTR
);
608 * Only warn about EPIPE when quiet mode is deactivated.
609 * We consider EPIPE as expected.
611 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
619 * Recv a message accompanied with credentials from a unix socket.
621 * Returns the size of received data, or negative error value.
624 ssize_t
lttcomm_recv_creds_unix_sock(int sock
, void *buf
, size_t len
,
625 lttng_sock_cred
*creds
)
632 struct cmsghdr
*cmptr
;
633 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
634 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
635 #endif /* __linux__ */
637 memset(&msg
, 0, sizeof(msg
));
645 /* Prepare to receive the structures */
646 iov
[0].iov_base
= buf
;
647 iov
[0].iov_len
= len
;
652 msg
.msg_control
= anc_buf
;
653 msg
.msg_controllen
= sizeof(anc_buf
);
654 #endif /* __linux__ */
657 len_last
= iov
[0].iov_len
;
658 ret
= recvmsg(sock
, &msg
, 0);
660 iov
[0].iov_base
+= ret
;
661 iov
[0].iov_len
-= ret
;
662 assert(ret
<= len_last
);
664 } while ((ret
> 0 && ret
< len_last
) || (ret
< 0 && errno
== EINTR
));
666 PERROR("recvmsg fds");
668 } else if (ret
> 0) {
671 /* Else ret = 0 meaning an orderly shutdown. */
674 if (msg
.msg_flags
& MSG_CTRUNC
) {
675 fprintf(stderr
, "Error: Control message truncated.\n");
680 cmptr
= CMSG_FIRSTHDR(&msg
);
682 fprintf(stderr
, "Error: Invalid control message header\n");
687 if (cmptr
->cmsg_level
!= SOL_SOCKET
||
688 cmptr
->cmsg_type
!= LTTNG_SOCK_CREDS
) {
689 fprintf(stderr
, "Didn't received any credentials\n");
694 if (cmptr
->cmsg_len
!= CMSG_LEN(sizeof_cred
)) {
695 fprintf(stderr
, "Error: Received %zu bytes of ancillary data, expected %zu\n",
696 (size_t) cmptr
->cmsg_len
, (size_t) CMSG_LEN(sizeof_cred
));
701 memcpy(creds
, CMSG_DATA(cmptr
), sizeof_cred
);
702 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
706 peer_ret
= getpeereid(sock
, &creds
->uid
, &creds
->gid
);
712 #error "Please implement credential support for your OS."
713 #endif /* __linux__ */
720 * Set socket option to use credentials passing.
724 int lttcomm_setsockopt_creds_unix_sock(int sock
)
728 /* Set socket for credentials retrieval */
729 ret
= setsockopt(sock
, SOL_SOCKET
, SO_PASSCRED
, &on
, sizeof(on
));
731 PERROR("setsockopt creds unix sock");
735 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
737 int lttcomm_setsockopt_creds_unix_sock(int sock
)
742 #error "Please implement credential support for your OS."
743 #endif /* __linux__ */