2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * SPDX-License-Identifier: GPL-2.0-only
16 #include <sys/types.h>
20 #include <common/common.h>
21 #include <common/sessiond-comm/sessiond-comm.h>
26 * Connect to unix socket using the path name.
29 int lttcomm_connect_unix_sock(const char *pathname
)
31 struct sockaddr_un s_un
;
32 int fd
, ret
, closeret
;
34 if (strlen(pathname
) >= sizeof(s_un
.sun_path
)) {
35 ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
36 pathname
, strlen(pathname
) + 1,
37 sizeof(s_un
.sun_path
));
42 fd
= socket(PF_UNIX
, SOCK_STREAM
, 0);
49 memset(&s_un
, 0, sizeof(s_un
));
50 s_un
.sun_family
= AF_UNIX
;
51 strncpy(s_un
.sun_path
, pathname
, sizeof(s_un
.sun_path
));
52 s_un
.sun_path
[sizeof(s_un
.sun_path
) - 1] = '\0';
54 ret
= connect(fd
, (struct sockaddr
*) &s_un
, sizeof(s_un
));
57 * Don't print message on connect error, because connect is used in
58 * normal execution to detect if sessiond is alive.
75 * Do an accept(2) on the sock and return the new file descriptor. The socket
76 * MUST be bind(2) before.
79 int lttcomm_accept_unix_sock(int sock
)
82 struct sockaddr_un s_un
;
83 socklen_t len
= sizeof(s_un
);
86 new_fd
= accept(sock
, (struct sockaddr
*) &s_un
, &len
);
95 int lttcomm_create_anon_unix_socketpair(int *fds
)
97 if (socketpair(PF_UNIX
, SOCK_STREAM
, 0, fds
) < 0) {
105 * Creates a AF_UNIX local socket using pathname bind the socket upon creation
109 int lttcomm_create_unix_sock(const char *pathname
)
111 struct sockaddr_un s_un
;
115 if (strlen(pathname
) >= sizeof(s_un
.sun_path
)) {
116 ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
117 pathname
, strlen(pathname
) + 1,
118 sizeof(s_un
.sun_path
));
123 /* Create server socket */
124 if ((fd
= socket(PF_UNIX
, SOCK_STREAM
, 0)) < 0) {
129 memset(&s_un
, 0, sizeof(s_un
));
130 s_un
.sun_family
= AF_UNIX
;
131 strncpy(s_un
.sun_path
, pathname
, sizeof(s_un
.sun_path
));
132 s_un
.sun_path
[sizeof(s_un
.sun_path
) - 1] = '\0';
134 /* Unlink the old file if present */
135 (void) unlink(pathname
);
136 ret
= bind(fd
, (struct sockaddr
*) &s_un
, sizeof(s_un
));
147 PERROR("close create unix sock");
154 * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
157 int lttcomm_listen_unix_sock(int sock
)
161 ret
= listen(sock
, LTTNG_SESSIOND_COMM_MAX_LISTEN
);
170 * Receive data of size len in put that data into the buf param. Using recvmsg
173 * Return the size of received data.
176 ssize_t
lttcomm_recv_unix_sock(int sock
, void *buf
, size_t len
)
183 memset(&msg
, 0, sizeof(msg
));
185 iov
[0].iov_base
= buf
;
186 iov
[0].iov_len
= len
;
191 len_last
= iov
[0].iov_len
;
192 ret
= lttng_recvmsg_nosigpipe(sock
, &msg
);
194 iov
[0].iov_base
+= ret
;
195 iov
[0].iov_len
-= ret
;
196 assert(ret
<= len_last
);
198 } while ((ret
> 0 && ret
< len_last
) || (ret
< 0 && errno
== EINTR
));
201 } else if (ret
> 0) {
204 /* Else ret = 0 meaning an orderly shutdown. */
210 * Receive data of size len in put that data into the buf param. Using recvmsg
211 * API. Only use with sockets set in non-blocking mode.
213 * NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
214 * poll set. The poll loop will handle the EPIPE original cause.
216 * Return the size of received data.
219 ssize_t
lttcomm_recv_unix_sock_non_block(int sock
, void *buf
, size_t len
)
225 memset(&msg
, 0, sizeof(msg
));
227 iov
[0].iov_base
= buf
;
228 iov
[0].iov_len
= len
;
233 ret
= lttng_recvmsg_nosigpipe(sock
, &msg
);
235 if (errno
== EINTR
) {
239 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
241 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
||
250 /* Unexpected error */
262 * Send buf data of size len. Using sendmsg API.
264 * Return the size of sent data.
267 ssize_t
lttcomm_send_unix_sock(int sock
, const void *buf
, size_t len
)
273 memset(&msg
, 0, sizeof(msg
));
275 iov
[0].iov_base
= (void *) buf
;
276 iov
[0].iov_len
= len
;
280 while (iov
[0].iov_len
) {
281 ret
= sendmsg(sock
, &msg
, 0);
283 if (errno
== EINTR
) {
287 * Only warn about EPIPE when quiet mode is
289 * We consider EPIPE as expected.
291 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
297 iov
[0].iov_len
-= ret
;
298 iov
[0].iov_base
+= ret
;
306 * Send buf data of size len. Using sendmsg API.
307 * Only use with non-blocking sockets. The difference with the blocking version
308 * of the function is that this one does not retry to send on partial sends,
309 * except if the interruption was caused by a signal (EINTR).
311 * NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
312 * poll set. The poll loop will handle the EPIPE original cause.
314 * Return the size of sent data.
317 ssize_t
lttcomm_send_unix_sock_non_block(int sock
, const void *buf
, size_t len
)
323 memset(&msg
, 0, sizeof(msg
));
325 iov
[0].iov_base
= (void *) buf
;
326 iov
[0].iov_len
= len
;
331 ret
= sendmsg(sock
, &msg
, 0);
333 if (errno
== EINTR
) {
337 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
339 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
||
342 * This can happen in non blocking mode.
349 /* Unexpected error */
361 * Shutdown cleanly a unix socket.
364 int lttcomm_close_unix_sock(int sock
)
368 /* Shutdown receptions and transmissions */
369 ret
= shutdown(sock
, SHUT_RDWR
);
374 closeret
= close(sock
);
383 * Send a message accompanied by fd(s) over a unix socket.
385 * Returns the size of data sent, or negative error value.
388 ssize_t
lttcomm_send_fds_unix_sock(int sock
, const int *fds
, size_t nb_fd
)
391 struct cmsghdr
*cmptr
;
394 unsigned int sizeof_fds
= nb_fd
* sizeof(int);
395 char tmp
[CMSG_SPACE(sizeof_fds
)];
398 memset(&msg
, 0, sizeof(msg
));
399 memset(tmp
, 0, sizeof(tmp
));
401 if (nb_fd
> LTTCOMM_MAX_SEND_FDS
)
404 msg
.msg_control
= (caddr_t
)tmp
;
405 msg
.msg_controllen
= CMSG_LEN(sizeof_fds
);
407 cmptr
= CMSG_FIRSTHDR(&msg
);
412 cmptr
->cmsg_level
= SOL_SOCKET
;
413 cmptr
->cmsg_type
= SCM_RIGHTS
;
414 cmptr
->cmsg_len
= CMSG_LEN(sizeof_fds
);
415 memcpy(CMSG_DATA(cmptr
), fds
, sizeof_fds
);
416 /* Sum of the length of all control messages in the buffer: */
417 msg
.msg_controllen
= cmptr
->cmsg_len
;
419 iov
[0].iov_base
= &dummy
;
425 ret
= sendmsg(sock
, &msg
, 0);
426 } while (ret
< 0 && errno
== EINTR
);
429 * Only warn about EPIPE when quiet mode is deactivated.
430 * We consider EPIPE as expected.
432 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
440 * Send a message accompanied by fd(s) over a unix socket.
441 * Only use for non blocking socket.
443 * Returns the size of data sent, or negative error value.
446 ssize_t
lttcomm_send_fds_unix_sock_non_block(int sock
, const int *fds
, size_t nb_fd
)
449 struct cmsghdr
*cmptr
;
452 unsigned int sizeof_fds
= nb_fd
* sizeof(int);
453 char tmp
[CMSG_SPACE(sizeof_fds
)];
456 memset(&msg
, 0, sizeof(msg
));
457 memset(tmp
, 0, sizeof(tmp
));
459 if (nb_fd
> LTTCOMM_MAX_SEND_FDS
)
462 msg
.msg_control
= (caddr_t
)tmp
;
463 msg
.msg_controllen
= CMSG_LEN(sizeof_fds
);
465 cmptr
= CMSG_FIRSTHDR(&msg
);
470 cmptr
->cmsg_level
= SOL_SOCKET
;
471 cmptr
->cmsg_type
= SCM_RIGHTS
;
472 cmptr
->cmsg_len
= CMSG_LEN(sizeof_fds
);
473 memcpy(CMSG_DATA(cmptr
), fds
, sizeof_fds
);
474 /* Sum of the length of all control messages in the buffer: */
475 msg
.msg_controllen
= cmptr
->cmsg_len
;
477 iov
[0].iov_base
= &dummy
;
483 ret
= sendmsg(sock
, &msg
, 0);
485 if (errno
== EINTR
) {
489 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
491 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
) {
493 * This can happen in non blocking mode.
500 if (errno
== EPIPE
) {
501 /* Expected error, pass error to caller */
502 DBG3("EPIPE on sendmsg");
507 /* Unexpected error */
519 * Recv a message accompanied by fd(s) from a unix socket.
521 * Returns the size of received data, or negative error value.
523 * Expect at most "nb_fd" file descriptors. Returns the number of fd
524 * actually received in nb_fd.
527 ssize_t
lttcomm_recv_fds_unix_sock(int sock
, int *fds
, size_t nb_fd
)
531 struct cmsghdr
*cmsg
;
532 size_t sizeof_fds
= nb_fd
* sizeof(int);
535 /* Account for the struct ucred cmsg in the buffer size */
536 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
538 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
539 #endif /* __linux__ */
541 char recv_buf
[LTTNG_SOCK_RECV_FDS_BUF_SIZE
];
545 memset(&msg
, 0, sizeof(msg
));
547 /* Prepare to receive the structures */
548 iov
[0].iov_base
= &dummy
;
553 cmsg
= (struct cmsghdr
*) recv_buf
;
554 cmsg
->cmsg_len
= CMSG_LEN(sizeof_fds
);
555 cmsg
->cmsg_level
= SOL_SOCKET
;
556 cmsg
->cmsg_type
= SCM_RIGHTS
;
558 msg
.msg_control
= cmsg
;
559 msg
.msg_controllen
= CMSG_LEN(sizeof(recv_buf
));
563 ret
= lttng_recvmsg_nosigpipe(sock
, &msg
);
565 if (errno
== EINTR
) {
568 /* We consider EPIPE and EAGAIN as expected. */
569 if (!lttng_opt_quiet
&&
570 (errno
!= EPIPE
&& errno
!= EAGAIN
)) {
578 fprintf(stderr
, "Error: Received %zd bytes, expected %d\n",
583 if (msg
.msg_flags
& MSG_CTRUNC
) {
584 fprintf(stderr
, "Error: Control message truncated.\n");
590 * If the socket was configured with SO_PASSCRED, the kernel will add a
591 * control message (cmsg) to the ancillary data of the unix socket. We
592 * need to expect a cmsg of the SCM_CREDENTIALS as the first control
595 for (cmsg
= CMSG_FIRSTHDR(&msg
); cmsg
!= NULL
; cmsg
= CMSG_NXTHDR(&msg
, cmsg
)) {
596 if (cmsg
->cmsg_level
!= SOL_SOCKET
) {
597 fprintf(stderr
, "Error: The socket needs to be of type SOL_SOCKET\n");
601 if (cmsg
->cmsg_type
== SCM_RIGHTS
) {
603 * We found the controle message for file descriptors,
604 * now copy the fds to the fds ptr and return success.
606 if (cmsg
->cmsg_len
!= CMSG_LEN(sizeof_fds
)) {
607 fprintf(stderr
, "Error: Received %zu bytes of"
608 "ancillary data for FDs, expected %zu\n",
609 (size_t) cmsg
->cmsg_len
,
610 (size_t) CMSG_LEN(sizeof_fds
));
614 memcpy(fds
, CMSG_DATA(cmsg
), sizeof_fds
);
619 if (cmsg
->cmsg_type
== SCM_CREDENTIALS
) {
621 * Expect credentials to be sent when expecting fds even
622 * if no credential were include in the send(). The
623 * kernel adds them...
627 #endif /* __linux__ */
634 * Recv a message accompanied by fd(s) from a non-blocking unix socket.
635 * Only use with non-blocking sockets.
637 * Returns the size of received data, or negative error value.
639 * Expect at most "nb_fd" file descriptors.
641 * Note that based on our comprehension, partial reception of fds is not
642 * possible since the FDs are actually in the control message. It is all or
643 * nothing, still the sender side can send the wrong number of fds.
646 ssize_t
lttcomm_recv_fds_unix_sock_non_block(int sock
, int *fds
, size_t nb_fd
)
650 struct cmsghdr
*cmsg
;
651 size_t sizeof_fds
= nb_fd
* sizeof(int);
654 /* Account for the struct ucred cmsg in the buffer size */
655 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
657 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
658 #endif /* __linux__ */
660 char recv_buf
[LTTNG_SOCK_RECV_FDS_BUF_SIZE
];
664 memset(&msg
, 0, sizeof(msg
));
666 /* Prepare to receive the structures */
667 iov
[0].iov_base
= &dummy
;
672 cmsg
= (struct cmsghdr
*) recv_buf
;
673 cmsg
->cmsg_len
= CMSG_LEN(sizeof_fds
);
674 cmsg
->cmsg_level
= SOL_SOCKET
;
675 cmsg
->cmsg_type
= SCM_RIGHTS
;
677 msg
.msg_control
= cmsg
;
678 msg
.msg_controllen
= CMSG_LEN(sizeof(recv_buf
));
682 ret
= lttng_recvmsg_nosigpipe(sock
, &msg
);
684 if (errno
== EINTR
) {
688 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
690 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
) {
692 * This can happen in non blocking mode.
699 if (errno
== EPIPE
) {
700 /* Expected error, pass error to caller */
701 DBG3("EPIPE on recvmsg");
706 /* Unexpected error */
714 fprintf(stderr
, "Error: Received %zd bytes, expected %d\n",
719 if (msg
.msg_flags
& MSG_CTRUNC
) {
720 fprintf(stderr
, "Error: Control message truncated.\n");
726 * If the socket was configured with SO_PASSCRED, the kernel will add a
727 * control message (cmsg) to the ancillary data of the unix socket. We
728 * need to expect a cmsg of the SCM_CREDENTIALS as the first control
731 for (cmsg
= CMSG_FIRSTHDR(&msg
); cmsg
!= NULL
; cmsg
= CMSG_NXTHDR(&msg
, cmsg
)) {
732 if (cmsg
->cmsg_level
!= SOL_SOCKET
) {
733 fprintf(stderr
, "Error: The socket needs to be of type SOL_SOCKET\n");
737 if (cmsg
->cmsg_type
== SCM_RIGHTS
) {
739 * We found the controle message for file descriptors,
740 * now copy the fds to the fds ptr and return success.
742 if (cmsg
->cmsg_len
!= CMSG_LEN(sizeof_fds
)) {
743 fprintf(stderr
, "Error: Received %zu bytes of"
744 "ancillary data for FDs, expected %zu\n",
745 (size_t) cmsg
->cmsg_len
,
746 (size_t) CMSG_LEN(sizeof_fds
));
750 memcpy(fds
, CMSG_DATA(cmsg
), sizeof_fds
);
755 if (cmsg
->cmsg_type
== SCM_CREDENTIALS
) {
757 * Expect credentials to be sent when expecting fds even
758 * if no credential were include in the send(). The
759 * kernel adds them...
763 #endif /* __linux__ */
770 * Send a message with credentials over a unix socket.
772 * Returns the size of data sent, or negative error value.
775 ssize_t
lttcomm_send_creds_unix_sock(int sock
, void *buf
, size_t len
)
781 struct cmsghdr
*cmptr
;
782 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
783 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
784 lttng_sock_cred
*creds
;
786 memset(anc_buf
, 0, CMSG_SPACE(sizeof_cred
) * sizeof(char));
787 #endif /* __linux__ */
789 memset(&msg
, 0, sizeof(msg
));
791 iov
[0].iov_base
= buf
;
792 iov
[0].iov_len
= len
;
797 msg
.msg_control
= (caddr_t
) anc_buf
;
798 msg
.msg_controllen
= CMSG_LEN(sizeof_cred
);
800 cmptr
= CMSG_FIRSTHDR(&msg
);
804 cmptr
->cmsg_level
= SOL_SOCKET
;
805 cmptr
->cmsg_type
= LTTNG_SOCK_CREDS
;
806 cmptr
->cmsg_len
= CMSG_LEN(sizeof_cred
);
808 creds
= (lttng_sock_cred
*) CMSG_DATA(cmptr
);
810 LTTNG_SOCK_SET_UID_CRED(creds
, geteuid());
811 LTTNG_SOCK_SET_GID_CRED(creds
, getegid());
812 LTTNG_SOCK_SET_PID_CRED(creds
, getpid());
813 #endif /* __linux__ */
816 ret
= sendmsg(sock
, &msg
, 0);
817 } while (ret
< 0 && errno
== EINTR
);
820 * Only warn about EPIPE when quiet mode is deactivated.
821 * We consider EPIPE as expected.
823 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
831 * Recv a message accompanied with credentials from a unix socket.
833 * Returns the size of received data, or negative error value.
836 ssize_t
lttcomm_recv_creds_unix_sock(int sock
, void *buf
, size_t len
,
837 lttng_sock_cred
*creds
)
844 struct cmsghdr
*cmptr
;
845 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
846 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
847 #endif /* __linux__ */
849 memset(&msg
, 0, sizeof(msg
));
857 /* Prepare to receive the structures */
858 iov
[0].iov_base
= buf
;
859 iov
[0].iov_len
= len
;
864 msg
.msg_control
= anc_buf
;
865 msg
.msg_controllen
= sizeof(anc_buf
);
866 #endif /* __linux__ */
869 len_last
= iov
[0].iov_len
;
870 ret
= recvmsg(sock
, &msg
, 0);
872 iov
[0].iov_base
+= ret
;
873 iov
[0].iov_len
-= ret
;
874 assert(ret
<= len_last
);
876 } while ((ret
> 0 && ret
< len_last
) || (ret
< 0 && errno
== EINTR
));
878 PERROR("recvmsg fds");
880 } else if (ret
> 0) {
883 /* Else ret = 0 meaning an orderly shutdown. */
886 if (msg
.msg_flags
& MSG_CTRUNC
) {
887 fprintf(stderr
, "Error: Control message truncated.\n");
892 cmptr
= CMSG_FIRSTHDR(&msg
);
894 fprintf(stderr
, "Error: Invalid control message header\n");
899 if (cmptr
->cmsg_level
!= SOL_SOCKET
||
900 cmptr
->cmsg_type
!= LTTNG_SOCK_CREDS
) {
901 fprintf(stderr
, "Didn't received any credentials\n");
906 if (cmptr
->cmsg_len
!= CMSG_LEN(sizeof_cred
)) {
907 fprintf(stderr
, "Error: Received %zu bytes of ancillary data, expected %zu\n",
908 (size_t) cmptr
->cmsg_len
, (size_t) CMSG_LEN(sizeof_cred
));
913 memcpy(creds
, CMSG_DATA(cmptr
), sizeof_cred
);
914 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
918 peer_ret
= getpeereid(sock
, &creds
->uid
, &creds
->gid
);
924 #error "Please implement credential support for your OS."
925 #endif /* __linux__ */
932 * Set socket option to use credentials passing.
936 int lttcomm_setsockopt_creds_unix_sock(int sock
)
940 /* Set socket for credentials retrieval */
941 ret
= setsockopt(sock
, SOL_SOCKET
, SO_PASSCRED
, &on
, sizeof(on
));
943 PERROR("setsockopt creds unix sock");
947 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
949 int lttcomm_setsockopt_creds_unix_sock(int sock
)
954 #error "Please implement credential support for your OS."
955 #endif /* __linux__ */