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 */
360 * Shutdown cleanly a unix socket.
363 int lttcomm_close_unix_sock(int sock
)
367 /* Shutdown receptions and transmissions */
368 ret
= shutdown(sock
, SHUT_RDWR
);
373 closeret
= close(sock
);
382 * Send a message accompanied by fd(s) over a unix socket.
384 * Returns the size of data sent, or negative error value.
387 ssize_t
lttcomm_send_fds_unix_sock(int sock
, const int *fds
, size_t nb_fd
)
390 struct cmsghdr
*cmptr
;
393 unsigned int sizeof_fds
= nb_fd
* sizeof(int);
394 char tmp
[CMSG_SPACE(sizeof_fds
)];
397 memset(&msg
, 0, sizeof(msg
));
398 memset(tmp
, 0, sizeof(tmp
));
400 if (nb_fd
> LTTCOMM_MAX_SEND_FDS
)
403 msg
.msg_control
= (caddr_t
)tmp
;
404 msg
.msg_controllen
= CMSG_LEN(sizeof_fds
);
406 cmptr
= CMSG_FIRSTHDR(&msg
);
411 cmptr
->cmsg_level
= SOL_SOCKET
;
412 cmptr
->cmsg_type
= SCM_RIGHTS
;
413 cmptr
->cmsg_len
= CMSG_LEN(sizeof_fds
);
414 memcpy(CMSG_DATA(cmptr
), fds
, sizeof_fds
);
415 /* Sum of the length of all control messages in the buffer: */
416 msg
.msg_controllen
= cmptr
->cmsg_len
;
418 iov
[0].iov_base
= &dummy
;
424 ret
= sendmsg(sock
, &msg
, 0);
425 } while (ret
< 0 && errno
== EINTR
);
428 * Only warn about EPIPE when quiet mode is deactivated.
429 * We consider EPIPE as expected.
431 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
439 * Send a message accompanied by fd(s) over a unix socket.
440 * Only use for non blocking socket.
442 * Returns the size of data sent, or negative error value.
445 ssize_t
lttcomm_send_fds_unix_sock_non_block(int sock
, const int *fds
, size_t nb_fd
)
448 struct cmsghdr
*cmptr
;
451 unsigned int sizeof_fds
= nb_fd
* sizeof(int);
452 char tmp
[CMSG_SPACE(sizeof_fds
)];
455 memset(&msg
, 0, sizeof(msg
));
456 memset(tmp
, 0, sizeof(tmp
));
458 if (nb_fd
> LTTCOMM_MAX_SEND_FDS
)
461 msg
.msg_control
= (caddr_t
)tmp
;
462 msg
.msg_controllen
= CMSG_LEN(sizeof_fds
);
464 cmptr
= CMSG_FIRSTHDR(&msg
);
469 cmptr
->cmsg_level
= SOL_SOCKET
;
470 cmptr
->cmsg_type
= SCM_RIGHTS
;
471 cmptr
->cmsg_len
= CMSG_LEN(sizeof_fds
);
472 memcpy(CMSG_DATA(cmptr
), fds
, sizeof_fds
);
473 /* Sum of the length of all control messages in the buffer: */
474 msg
.msg_controllen
= cmptr
->cmsg_len
;
476 iov
[0].iov_base
= &dummy
;
482 ret
= sendmsg(sock
, &msg
, 0);
484 if (errno
== EINTR
) {
488 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
490 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
) {
492 * This can happen in non blocking mode.
499 if (errno
== EPIPE
) {
500 /* Expected error, pass error to caller */
501 DBG3("EPIPE on sendmsg");
506 /* Unexpected error */
518 * Recv a message accompanied by fd(s) from a unix socket.
520 * Returns the size of received data, or negative error value.
522 * Expect at most "nb_fd" file descriptors. Returns the number of fd
523 * actually received in nb_fd.
526 ssize_t
lttcomm_recv_fds_unix_sock(int sock
, int *fds
, size_t nb_fd
)
530 struct cmsghdr
*cmsg
;
531 size_t sizeof_fds
= nb_fd
* sizeof(int);
534 /* Account for the struct ucred cmsg in the buffer size */
535 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
537 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
538 #endif /* __linux__ */
540 char recv_buf
[LTTNG_SOCK_RECV_FDS_BUF_SIZE
];
544 memset(&msg
, 0, sizeof(msg
));
546 /* Prepare to receive the structures */
547 iov
[0].iov_base
= &dummy
;
552 cmsg
= (struct cmsghdr
*) recv_buf
;
553 cmsg
->cmsg_len
= CMSG_LEN(sizeof_fds
);
554 cmsg
->cmsg_level
= SOL_SOCKET
;
555 cmsg
->cmsg_type
= SCM_RIGHTS
;
557 msg
.msg_control
= cmsg
;
558 msg
.msg_controllen
= CMSG_LEN(sizeof(recv_buf
));
562 ret
= lttng_recvmsg_nosigpipe(sock
, &msg
);
564 if (errno
== EINTR
) {
567 /* We consider EPIPE and EAGAIN as expected. */
568 if (!lttng_opt_quiet
&&
569 (errno
!= EPIPE
&& errno
!= EAGAIN
)) {
577 fprintf(stderr
, "Error: Received %zd bytes, expected %d\n",
582 if (msg
.msg_flags
& MSG_CTRUNC
) {
583 fprintf(stderr
, "Error: Control message truncated.\n");
589 * If the socket was configured with SO_PASSCRED, the kernel will add a
590 * control message (cmsg) to the ancillary data of the unix socket. We
591 * need to expect a cmsg of the SCM_CREDENTIALS as the first control
594 for (cmsg
= CMSG_FIRSTHDR(&msg
); cmsg
!= NULL
; cmsg
= CMSG_NXTHDR(&msg
, cmsg
)) {
595 if (cmsg
->cmsg_level
!= SOL_SOCKET
) {
596 fprintf(stderr
, "Error: The socket needs to be of type SOL_SOCKET\n");
600 if (cmsg
->cmsg_type
== SCM_RIGHTS
) {
602 * We found the controle message for file descriptors,
603 * now copy the fds to the fds ptr and return success.
605 if (cmsg
->cmsg_len
!= CMSG_LEN(sizeof_fds
)) {
606 fprintf(stderr
, "Error: Received %zu bytes of"
607 "ancillary data for FDs, expected %zu\n",
608 (size_t) cmsg
->cmsg_len
,
609 (size_t) CMSG_LEN(sizeof_fds
));
613 memcpy(fds
, CMSG_DATA(cmsg
), sizeof_fds
);
618 if (cmsg
->cmsg_type
== SCM_CREDENTIALS
) {
620 * Expect credentials to be sent when expecting fds even
621 * if no credential were include in the send(). The
622 * kernel adds them...
626 #endif /* __linux__ */
633 * Recv a message accompanied by fd(s) from a non-blocking unix socket.
634 * Only use with non-blocking sockets.
636 * Returns the size of received data, or negative error value.
638 * Expect at most "nb_fd" file descriptors.
640 * Note that based on our comprehension, partial reception of fds is not
641 * possible since the FDs are actually in the control message. It is all or
642 * nothing, still the sender side can send the wrong number of fds.
645 ssize_t
lttcomm_recv_fds_unix_sock_non_block(int sock
, int *fds
, size_t nb_fd
)
649 struct cmsghdr
*cmsg
;
650 size_t sizeof_fds
= nb_fd
* sizeof(int);
653 /* Account for the struct ucred cmsg in the buffer size */
654 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
656 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
657 #endif /* __linux__ */
659 char recv_buf
[LTTNG_SOCK_RECV_FDS_BUF_SIZE
];
663 memset(&msg
, 0, sizeof(msg
));
665 /* Prepare to receive the structures */
666 iov
[0].iov_base
= &dummy
;
671 cmsg
= (struct cmsghdr
*) recv_buf
;
672 cmsg
->cmsg_len
= CMSG_LEN(sizeof_fds
);
673 cmsg
->cmsg_level
= SOL_SOCKET
;
674 cmsg
->cmsg_type
= SCM_RIGHTS
;
676 msg
.msg_control
= cmsg
;
677 msg
.msg_controllen
= CMSG_LEN(sizeof(recv_buf
));
681 ret
= lttng_recvmsg_nosigpipe(sock
, &msg
);
683 if (errno
== EINTR
) {
687 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
689 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
) {
691 * This can happen in non blocking mode.
698 if (errno
== EPIPE
) {
699 /* Expected error, pass error to caller */
700 DBG3("EPIPE on recvmsg");
705 /* Unexpected error */
713 fprintf(stderr
, "Error: Received %zd bytes, expected %d\n",
718 if (msg
.msg_flags
& MSG_CTRUNC
) {
719 fprintf(stderr
, "Error: Control message truncated.\n");
725 * If the socket was configured with SO_PASSCRED, the kernel will add a
726 * control message (cmsg) to the ancillary data of the unix socket. We
727 * need to expect a cmsg of the SCM_CREDENTIALS as the first control
730 for (cmsg
= CMSG_FIRSTHDR(&msg
); cmsg
!= NULL
; cmsg
= CMSG_NXTHDR(&msg
, cmsg
)) {
731 if (cmsg
->cmsg_level
!= SOL_SOCKET
) {
732 fprintf(stderr
, "Error: The socket needs to be of type SOL_SOCKET\n");
736 if (cmsg
->cmsg_type
== SCM_RIGHTS
) {
738 * We found the controle message for file descriptors,
739 * now copy the fds to the fds ptr and return success.
741 if (cmsg
->cmsg_len
!= CMSG_LEN(sizeof_fds
)) {
742 fprintf(stderr
, "Error: Received %zu bytes of"
743 "ancillary data for FDs, expected %zu\n",
744 (size_t) cmsg
->cmsg_len
,
745 (size_t) CMSG_LEN(sizeof_fds
));
749 memcpy(fds
, CMSG_DATA(cmsg
), sizeof_fds
);
754 if (cmsg
->cmsg_type
== SCM_CREDENTIALS
) {
756 * Expect credentials to be sent when expecting fds even
757 * if no credential were include in the send(). The
758 * kernel adds them...
762 #endif /* __linux__ */
769 * Send a message with credentials over a unix socket.
771 * Returns the size of data sent, or negative error value.
774 ssize_t
lttcomm_send_creds_unix_sock(int sock
, void *buf
, size_t len
)
780 struct cmsghdr
*cmptr
;
781 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
782 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
783 lttng_sock_cred
*creds
;
785 memset(anc_buf
, 0, CMSG_SPACE(sizeof_cred
) * sizeof(char));
786 #endif /* __linux__ */
788 memset(&msg
, 0, sizeof(msg
));
790 iov
[0].iov_base
= buf
;
791 iov
[0].iov_len
= len
;
796 msg
.msg_control
= (caddr_t
) anc_buf
;
797 msg
.msg_controllen
= CMSG_LEN(sizeof_cred
);
799 cmptr
= CMSG_FIRSTHDR(&msg
);
803 cmptr
->cmsg_level
= SOL_SOCKET
;
804 cmptr
->cmsg_type
= LTTNG_SOCK_CREDS
;
805 cmptr
->cmsg_len
= CMSG_LEN(sizeof_cred
);
807 creds
= (lttng_sock_cred
*) CMSG_DATA(cmptr
);
809 LTTNG_SOCK_SET_UID_CRED(creds
, geteuid());
810 LTTNG_SOCK_SET_GID_CRED(creds
, getegid());
811 LTTNG_SOCK_SET_PID_CRED(creds
, getpid());
812 #endif /* __linux__ */
815 ret
= sendmsg(sock
, &msg
, 0);
816 } while (ret
< 0 && errno
== EINTR
);
819 * Only warn about EPIPE when quiet mode is deactivated.
820 * We consider EPIPE as expected.
822 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
830 * Recv a message accompanied with credentials from a unix socket.
832 * Returns the size of received data, or negative error value.
835 ssize_t
lttcomm_recv_creds_unix_sock(int sock
, void *buf
, size_t len
,
836 lttng_sock_cred
*creds
)
843 struct cmsghdr
*cmptr
;
844 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
845 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
846 #endif /* __linux__ */
848 memset(&msg
, 0, sizeof(msg
));
856 /* Prepare to receive the structures */
857 iov
[0].iov_base
= buf
;
858 iov
[0].iov_len
= len
;
863 msg
.msg_control
= anc_buf
;
864 msg
.msg_controllen
= sizeof(anc_buf
);
865 #endif /* __linux__ */
868 len_last
= iov
[0].iov_len
;
869 ret
= recvmsg(sock
, &msg
, 0);
871 iov
[0].iov_base
+= ret
;
872 iov
[0].iov_len
-= ret
;
873 assert(ret
<= len_last
);
875 } while ((ret
> 0 && ret
< len_last
) || (ret
< 0 && errno
== EINTR
));
877 PERROR("recvmsg fds");
879 } else if (ret
> 0) {
882 /* Else ret = 0 meaning an orderly shutdown. */
885 if (msg
.msg_flags
& MSG_CTRUNC
) {
886 fprintf(stderr
, "Error: Control message truncated.\n");
891 cmptr
= CMSG_FIRSTHDR(&msg
);
893 fprintf(stderr
, "Error: Invalid control message header\n");
898 if (cmptr
->cmsg_level
!= SOL_SOCKET
||
899 cmptr
->cmsg_type
!= LTTNG_SOCK_CREDS
) {
900 fprintf(stderr
, "Didn't received any credentials\n");
905 if (cmptr
->cmsg_len
!= CMSG_LEN(sizeof_cred
)) {
906 fprintf(stderr
, "Error: Received %zu bytes of ancillary data, expected %zu\n",
907 (size_t) cmptr
->cmsg_len
, (size_t) CMSG_LEN(sizeof_cred
));
912 memcpy(creds
, CMSG_DATA(cmptr
), sizeof_cred
);
913 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
917 peer_ret
= getpeereid(sock
, &creds
->uid
, &creds
->gid
);
923 #error "Please implement credential support for your OS."
924 #endif /* __linux__ */
931 * Set socket option to use credentials passing.
935 int lttcomm_setsockopt_creds_unix_sock(int sock
)
939 /* Set socket for credentials retrieval */
940 ret
= setsockopt(sock
, SOL_SOCKET
, SO_PASSCRED
, &on
, sizeof(on
));
942 PERROR("setsockopt creds unix sock");
946 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
948 int lttcomm_setsockopt_creds_unix_sock(int sock
)
953 #error "Please implement credential support for your OS."
954 #endif /* __linux__ */