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 * Return the size of received data.
216 ssize_t
lttcomm_recv_unix_sock_non_block(int sock
, void *buf
, size_t len
)
222 memset(&msg
, 0, sizeof(msg
));
224 iov
[0].iov_base
= buf
;
225 iov
[0].iov_len
= len
;
230 ret
= lttng_recvmsg_nosigpipe(sock
, &msg
);
232 if (errno
== EINTR
) {
236 * Only warn about EPIPE when quiet mode is
238 * We consider EPIPE as expected.
240 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
252 * Send buf data of size len. Using sendmsg API.
254 * Return the size of sent data.
257 ssize_t
lttcomm_send_unix_sock(int sock
, const void *buf
, size_t len
)
263 memset(&msg
, 0, sizeof(msg
));
265 iov
[0].iov_base
= (void *) buf
;
266 iov
[0].iov_len
= len
;
270 while (iov
[0].iov_len
) {
271 ret
= sendmsg(sock
, &msg
, 0);
273 if (errno
== EINTR
) {
277 * Only warn about EPIPE when quiet mode is
279 * We consider EPIPE as expected.
281 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
287 iov
[0].iov_len
-= ret
;
288 iov
[0].iov_base
+= ret
;
296 * Send buf data of size len. Using sendmsg API.
297 * Only use with non-blocking sockets. The difference with the blocking version
298 * of the function is that this one does not retry to send on partial sends,
299 * except if the interruption was caused by a signal (EINTR).
301 * Return the size of sent data.
304 ssize_t
lttcomm_send_unix_sock_non_block(int sock
, const void *buf
, size_t len
)
310 memset(&msg
, 0, sizeof(msg
));
312 iov
[0].iov_base
= (void *) buf
;
313 iov
[0].iov_len
= len
;
318 ret
= sendmsg(sock
, &msg
, 0);
320 if (errno
== EINTR
) {
324 * Only warn about EPIPE when quiet mode is
326 * We consider EPIPE as expected.
328 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
340 * Shutdown cleanly a unix socket.
343 int lttcomm_close_unix_sock(int sock
)
347 /* Shutdown receptions and transmissions */
348 ret
= shutdown(sock
, SHUT_RDWR
);
353 closeret
= close(sock
);
362 * Send a message accompanied by fd(s) over a unix socket.
364 * Returns the size of data sent, or negative error value.
367 ssize_t
lttcomm_send_fds_unix_sock(int sock
, const int *fds
, size_t nb_fd
)
370 struct cmsghdr
*cmptr
;
373 unsigned int sizeof_fds
= nb_fd
* sizeof(int);
374 char tmp
[CMSG_SPACE(sizeof_fds
)];
377 memset(&msg
, 0, sizeof(msg
));
378 memset(tmp
, 0, sizeof(tmp
));
380 if (nb_fd
> LTTCOMM_MAX_SEND_FDS
)
383 msg
.msg_control
= (caddr_t
)tmp
;
384 msg
.msg_controllen
= CMSG_LEN(sizeof_fds
);
386 cmptr
= CMSG_FIRSTHDR(&msg
);
391 cmptr
->cmsg_level
= SOL_SOCKET
;
392 cmptr
->cmsg_type
= SCM_RIGHTS
;
393 cmptr
->cmsg_len
= CMSG_LEN(sizeof_fds
);
394 memcpy(CMSG_DATA(cmptr
), fds
, sizeof_fds
);
395 /* Sum of the length of all control messages in the buffer: */
396 msg
.msg_controllen
= cmptr
->cmsg_len
;
398 iov
[0].iov_base
= &dummy
;
404 ret
= sendmsg(sock
, &msg
, 0);
405 } while (ret
< 0 && errno
== EINTR
);
408 * Only warn about EPIPE when quiet mode is deactivated.
409 * We consider EPIPE as expected.
411 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
419 * Recv a message accompanied by fd(s) from a unix socket.
421 * Returns the size of received data, or negative error value.
423 * Expect at most "nb_fd" file descriptors. Returns the number of fd
424 * actually received in nb_fd.
427 ssize_t
lttcomm_recv_fds_unix_sock(int sock
, int *fds
, size_t nb_fd
)
431 struct cmsghdr
*cmsg
;
432 size_t sizeof_fds
= nb_fd
* sizeof(int);
435 /* Account for the struct ucred cmsg in the buffer size */
436 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
438 #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
439 #endif /* __linux__ */
441 char recv_buf
[LTTNG_SOCK_RECV_FDS_BUF_SIZE
];
445 memset(&msg
, 0, sizeof(msg
));
447 /* Prepare to receive the structures */
448 iov
[0].iov_base
= &dummy
;
453 cmsg
= (struct cmsghdr
*) recv_buf
;
454 cmsg
->cmsg_len
= CMSG_LEN(sizeof_fds
);
455 cmsg
->cmsg_level
= SOL_SOCKET
;
456 cmsg
->cmsg_type
= SCM_RIGHTS
;
458 msg
.msg_control
= cmsg
;
459 msg
.msg_controllen
= CMSG_LEN(sizeof(recv_buf
));
463 ret
= recvmsg(sock
, &msg
, 0);
464 } while (ret
< 0 && errno
== EINTR
);
466 PERROR("recvmsg fds");
471 fprintf(stderr
, "Error: Received %zd bytes, expected %d\n",
476 if (msg
.msg_flags
& MSG_CTRUNC
) {
477 fprintf(stderr
, "Error: Control message truncated.\n");
483 * If the socket was configured with SO_PASSCRED, the kernel will add a
484 * control message (cmsg) to the ancillary data of the unix socket. We
485 * need to expect a cmsg of the SCM_CREDENTIALS as the first control
488 for (cmsg
= CMSG_FIRSTHDR(&msg
); cmsg
!= NULL
; cmsg
= CMSG_NXTHDR(&msg
, cmsg
)) {
489 if (cmsg
->cmsg_level
!= SOL_SOCKET
) {
490 fprintf(stderr
, "Error: The socket needs to be of type SOL_SOCKET\n");
494 if (cmsg
->cmsg_type
== SCM_RIGHTS
) {
496 * We found the controle message for file descriptors,
497 * now copy the fds to the fds ptr and return success.
499 if (cmsg
->cmsg_len
!= CMSG_LEN(sizeof_fds
)) {
500 fprintf(stderr
, "Error: Received %zu bytes of"
501 "ancillary data for FDs, expected %zu\n",
502 (size_t) cmsg
->cmsg_len
,
503 (size_t) CMSG_LEN(sizeof_fds
));
507 memcpy(fds
, CMSG_DATA(cmsg
), sizeof_fds
);
512 if (cmsg
->cmsg_type
== SCM_CREDENTIALS
) {
514 * Expect credentials to be sent when expecting fds even
515 * if no credential were include in the send(). The
516 * kernel adds them...
520 #endif /* __linux__ */
527 * Send a message with credentials over a unix socket.
529 * Returns the size of data sent, or negative error value.
532 ssize_t
lttcomm_send_creds_unix_sock(int sock
, void *buf
, size_t len
)
538 struct cmsghdr
*cmptr
;
539 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
540 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
541 lttng_sock_cred
*creds
;
543 memset(anc_buf
, 0, CMSG_SPACE(sizeof_cred
) * sizeof(char));
544 #endif /* __linux__ */
546 memset(&msg
, 0, sizeof(msg
));
548 iov
[0].iov_base
= buf
;
549 iov
[0].iov_len
= len
;
554 msg
.msg_control
= (caddr_t
) anc_buf
;
555 msg
.msg_controllen
= CMSG_LEN(sizeof_cred
);
557 cmptr
= CMSG_FIRSTHDR(&msg
);
561 cmptr
->cmsg_level
= SOL_SOCKET
;
562 cmptr
->cmsg_type
= LTTNG_SOCK_CREDS
;
563 cmptr
->cmsg_len
= CMSG_LEN(sizeof_cred
);
565 creds
= (lttng_sock_cred
*) CMSG_DATA(cmptr
);
567 LTTNG_SOCK_SET_UID_CRED(creds
, geteuid());
568 LTTNG_SOCK_SET_GID_CRED(creds
, getegid());
569 LTTNG_SOCK_SET_PID_CRED(creds
, getpid());
570 #endif /* __linux__ */
573 ret
= sendmsg(sock
, &msg
, 0);
574 } while (ret
< 0 && errno
== EINTR
);
577 * Only warn about EPIPE when quiet mode is deactivated.
578 * We consider EPIPE as expected.
580 if (errno
!= EPIPE
|| !lttng_opt_quiet
) {
588 * Recv a message accompanied with credentials from a unix socket.
590 * Returns the size of received data, or negative error value.
593 ssize_t
lttcomm_recv_creds_unix_sock(int sock
, void *buf
, size_t len
,
594 lttng_sock_cred
*creds
)
601 struct cmsghdr
*cmptr
;
602 size_t sizeof_cred
= sizeof(lttng_sock_cred
);
603 char anc_buf
[CMSG_SPACE(sizeof_cred
)];
604 #endif /* __linux__ */
606 memset(&msg
, 0, sizeof(msg
));
614 /* Prepare to receive the structures */
615 iov
[0].iov_base
= buf
;
616 iov
[0].iov_len
= len
;
621 msg
.msg_control
= anc_buf
;
622 msg
.msg_controllen
= sizeof(anc_buf
);
623 #endif /* __linux__ */
626 len_last
= iov
[0].iov_len
;
627 ret
= recvmsg(sock
, &msg
, 0);
629 iov
[0].iov_base
+= ret
;
630 iov
[0].iov_len
-= ret
;
631 assert(ret
<= len_last
);
633 } while ((ret
> 0 && ret
< len_last
) || (ret
< 0 && errno
== EINTR
));
635 PERROR("recvmsg fds");
637 } else if (ret
> 0) {
640 /* Else ret = 0 meaning an orderly shutdown. */
643 if (msg
.msg_flags
& MSG_CTRUNC
) {
644 fprintf(stderr
, "Error: Control message truncated.\n");
649 cmptr
= CMSG_FIRSTHDR(&msg
);
651 fprintf(stderr
, "Error: Invalid control message header\n");
656 if (cmptr
->cmsg_level
!= SOL_SOCKET
||
657 cmptr
->cmsg_type
!= LTTNG_SOCK_CREDS
) {
658 fprintf(stderr
, "Didn't received any credentials\n");
663 if (cmptr
->cmsg_len
!= CMSG_LEN(sizeof_cred
)) {
664 fprintf(stderr
, "Error: Received %zu bytes of ancillary data, expected %zu\n",
665 (size_t) cmptr
->cmsg_len
, (size_t) CMSG_LEN(sizeof_cred
));
670 memcpy(creds
, CMSG_DATA(cmptr
), sizeof_cred
);
671 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
675 peer_ret
= getpeereid(sock
, &creds
->uid
, &creds
->gid
);
681 #error "Please implement credential support for your OS."
682 #endif /* __linux__ */
689 * Set socket option to use credentials passing.
693 int lttcomm_setsockopt_creds_unix_sock(int sock
)
697 /* Set socket for credentials retrieval */
698 ret
= setsockopt(sock
, SOL_SOCKET
, SO_PASSCRED
, &on
, sizeof(on
));
700 PERROR("setsockopt creds unix sock");
704 #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
706 int lttcomm_setsockopt_creds_unix_sock(int sock
)
711 #error "Please implement credential support for your OS."
712 #endif /* __linux__ */