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 * Recv a message accompanied by fd(s) from a unix socket.
442 * Returns the size of received data, or negative error value.
444 * Expect at most "nb_fd" file descriptors. Returns the number of fd
445 * actually received in nb_fd.
448 ssize_t
lttcomm_recv_fds_unix_sock(int sock
, int *fds
, size_t nb_fd
)
452 struct cmsghdr
*cmsg
;
453 size_t sizeof_fds
= nb_fd
* sizeof(int);
456 /* Account for the struct ucred cmsg in the buffer size */
457 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
459 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
460 #endif /* __linux__ */
462 char recv_buf
[LTTNG_SOCK_RECV_FDS_BUF_SIZE
];
466 memset(&msg
, 0, sizeof(msg
));
468 /* Prepare to receive the structures */
469 iov
[0].iov_base
= &dummy
;
474 cmsg
= (struct cmsghdr
*) recv_buf
;
475 cmsg
->cmsg_len
= CMSG_LEN(sizeof_fds
);
476 cmsg
->cmsg_level
= SOL_SOCKET
;
477 cmsg
->cmsg_type
= SCM_RIGHTS
;
479 msg
.msg_control
= cmsg
;
480 msg
.msg_controllen
= CMSG_LEN(sizeof(recv_buf
));
484 ret
= recvmsg(sock
, &msg
, 0);
485 } while (ret
< 0 && errno
== EINTR
);
487 PERROR("recvmsg fds");
492 fprintf(stderr
, "Error: Received %zd bytes, expected %d\n",
497 if (msg
.msg_flags
& MSG_CTRUNC
) {
498 fprintf(stderr
, "Error: Control message truncated.\n");
504 * If the socket was configured with SO_PASSCRED, the kernel will add a
505 * control message (cmsg) to the ancillary data of the unix socket. We
506 * need to expect a cmsg of the SCM_CREDENTIALS as the first control
509 for (cmsg
= CMSG_FIRSTHDR(&msg
); cmsg
!= NULL
; cmsg
= CMSG_NXTHDR(&msg
, cmsg
)) {
510 if (cmsg
->cmsg_level
!= SOL_SOCKET
) {
511 fprintf(stderr
, "Error: The socket needs to be of type SOL_SOCKET\n");
515 if (cmsg
->cmsg_type
== SCM_RIGHTS
) {
517 * We found the controle message for file descriptors,
518 * now copy the fds to the fds ptr and return success.
520 if (cmsg
->cmsg_len
!= CMSG_LEN(sizeof_fds
)) {
521 fprintf(stderr
, "Error: Received %zu bytes of"
522 "ancillary data for FDs, expected %zu\n",
523 (size_t) cmsg
->cmsg_len
,
524 (size_t) CMSG_LEN(sizeof_fds
));
528 memcpy(fds
, CMSG_DATA(cmsg
), sizeof_fds
);
533 if (cmsg
->cmsg_type
== SCM_CREDENTIALS
) {
535 * Expect credentials to be sent when expecting fds even
536 * if no credential were include in the send(). The
537 * kernel adds them...
541 #endif /* __linux__ */
548 * Send a message with credentials over a unix socket.
550 * Returns the size of data sent, or negative error value.
553 ssize_t
lttcomm_send_creds_unix_sock(int sock
, void *buf
, size_t len
)
559 struct cmsghdr
*cmptr
;
560 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
561 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
562 lttng_sock_cred
*creds
;
564 memset(anc_buf
, 0, CMSG_SPACE(sizeof_cred
) * sizeof(char));
565 #endif /* __linux__ */
567 memset(&msg
, 0, sizeof(msg
));
569 iov
[0].iov_base
= buf
;
570 iov
[0].iov_len
= len
;
575 msg
.msg_control
= (caddr_t
) anc_buf
;
576 msg
.msg_controllen
= CMSG_LEN(sizeof_cred
);
578 cmptr
= CMSG_FIRSTHDR(&msg
);
582 cmptr
->cmsg_level
= SOL_SOCKET
;
583 cmptr
->cmsg_type
= LTTNG_SOCK_CREDS
;
584 cmptr
->cmsg_len
= CMSG_LEN(sizeof_cred
);
586 creds
= (lttng_sock_cred
*) CMSG_DATA(cmptr
);
588 LTTNG_SOCK_SET_UID_CRED(creds
, geteuid());
589 LTTNG_SOCK_SET_GID_CRED(creds
, getegid());
590 LTTNG_SOCK_SET_PID_CRED(creds
, getpid());
591 #endif /* __linux__ */
594 ret
= sendmsg(sock
, &msg
, 0);
595 } while (ret
< 0 && errno
== EINTR
);
598 * Only warn about EPIPE when quiet mode is deactivated.
599 * We consider EPIPE as expected.
601 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
609 * Recv a message accompanied with credentials from a unix socket.
611 * Returns the size of received data, or negative error value.
614 ssize_t
lttcomm_recv_creds_unix_sock(int sock
, void *buf
, size_t len
,
615 lttng_sock_cred
*creds
)
622 struct cmsghdr
*cmptr
;
623 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
624 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
625 #endif /* __linux__ */
627 memset(&msg
, 0, sizeof(msg
));
635 /* Prepare to receive the structures */
636 iov
[0].iov_base
= buf
;
637 iov
[0].iov_len
= len
;
642 msg
.msg_control
= anc_buf
;
643 msg
.msg_controllen
= sizeof(anc_buf
);
644 #endif /* __linux__ */
647 len_last
= iov
[0].iov_len
;
648 ret
= recvmsg(sock
, &msg
, 0);
650 iov
[0].iov_base
+= ret
;
651 iov
[0].iov_len
-= ret
;
652 assert(ret
<= len_last
);
654 } while ((ret
> 0 && ret
< len_last
) || (ret
< 0 && errno
== EINTR
));
656 PERROR("recvmsg fds");
658 } else if (ret
> 0) {
661 /* Else ret = 0 meaning an orderly shutdown. */
664 if (msg
.msg_flags
& MSG_CTRUNC
) {
665 fprintf(stderr
, "Error: Control message truncated.\n");
670 cmptr
= CMSG_FIRSTHDR(&msg
);
672 fprintf(stderr
, "Error: Invalid control message header\n");
677 if (cmptr
->cmsg_level
!= SOL_SOCKET
||
678 cmptr
->cmsg_type
!= LTTNG_SOCK_CREDS
) {
679 fprintf(stderr
, "Didn't received any credentials\n");
684 if (cmptr
->cmsg_len
!= CMSG_LEN(sizeof_cred
)) {
685 fprintf(stderr
, "Error: Received %zu bytes of ancillary data, expected %zu\n",
686 (size_t) cmptr
->cmsg_len
, (size_t) CMSG_LEN(sizeof_cred
));
691 memcpy(creds
, CMSG_DATA(cmptr
), sizeof_cred
);
692 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
696 peer_ret
= getpeereid(sock
, &creds
->uid
, &creds
->gid
);
702 #error "Please implement credential support for your OS."
703 #endif /* __linux__ */
710 * Set socket option to use credentials passing.
714 int lttcomm_setsockopt_creds_unix_sock(int sock
)
718 /* Set socket for credentials retrieval */
719 ret
= setsockopt(sock
, SOL_SOCKET
, SO_PASSCRED
, &on
, sizeof(on
));
721 PERROR("setsockopt creds unix sock");
725 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
727 int lttcomm_setsockopt_creds_unix_sock(int sock
)
732 #error "Please implement credential support for your OS."
733 #endif /* __linux__ */