Commit | Line | Data |
---|---|---|
0d37f2bc | 1 | /* |
ab5be9fa MJ |
2 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> |
3 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
0d37f2bc | 4 | * |
ab5be9fa | 5 | * SPDX-License-Identifier: GPL-2.0-only |
0d37f2bc | 6 | * |
0d37f2bc DG |
7 | */ |
8 | ||
6c1c0768 | 9 | #define _LGPL_SOURCE |
0d37f2bc DG |
10 | #include <assert.h> |
11 | #include <limits.h> | |
12 | #include <stdio.h> | |
13 | #include <stdlib.h> | |
14 | #include <string.h> | |
15 | #include <sys/stat.h> | |
16 | #include <sys/types.h> | |
17 | #include <unistd.h> | |
18 | #include <errno.h> | |
19 | ||
90e535ef | 20 | #include <common/common.h> |
2038dd6c | 21 | #include <common/sessiond-comm/sessiond-comm.h> |
0d37f2bc DG |
22 | |
23 | #include "unix.h" | |
24 | ||
25 | /* | |
26 | * Connect to unix socket using the path name. | |
27 | */ | |
90e535ef | 28 | LTTNG_HIDDEN |
0d37f2bc DG |
29 | int lttcomm_connect_unix_sock(const char *pathname) |
30 | { | |
665886a6 | 31 | struct sockaddr_un s_un; |
0d37f2bc DG |
32 | int fd, ret, closeret; |
33 | ||
7f8bf467 JG |
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)); | |
38 | ret = -ENAMETOOLONG; | |
39 | goto error; | |
40 | } | |
41 | ||
0d37f2bc DG |
42 | fd = socket(PF_UNIX, SOCK_STREAM, 0); |
43 | if (fd < 0) { | |
44 | PERROR("socket"); | |
45 | ret = fd; | |
46 | goto error; | |
47 | } | |
48 | ||
665886a6 MJ |
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'; | |
0d37f2bc | 53 | |
665886a6 | 54 | ret = connect(fd, (struct sockaddr *) &s_un, sizeof(s_un)); |
0d37f2bc DG |
55 | if (ret < 0) { |
56 | /* | |
57 | * Don't print message on connect error, because connect is used in | |
58 | * normal execution to detect if sessiond is alive. | |
59 | */ | |
60 | goto error_connect; | |
61 | } | |
62 | ||
63 | return fd; | |
64 | ||
65 | error_connect: | |
66 | closeret = close(fd); | |
67 | if (closeret) { | |
68 | PERROR("close"); | |
69 | } | |
70 | error: | |
71 | return ret; | |
72 | } | |
73 | ||
74 | /* | |
75 | * Do an accept(2) on the sock and return the new file descriptor. The socket | |
76 | * MUST be bind(2) before. | |
77 | */ | |
90e535ef | 78 | LTTNG_HIDDEN |
0d37f2bc DG |
79 | int lttcomm_accept_unix_sock(int sock) |
80 | { | |
81 | int new_fd; | |
665886a6 | 82 | struct sockaddr_un s_un; |
50786a72 | 83 | socklen_t len = sizeof(s_un); |
0d37f2bc DG |
84 | |
85 | /* Blocking call */ | |
665886a6 | 86 | new_fd = accept(sock, (struct sockaddr *) &s_un, &len); |
0d37f2bc DG |
87 | if (new_fd < 0) { |
88 | PERROR("accept"); | |
89 | } | |
90 | ||
91 | return new_fd; | |
92 | } | |
93 | ||
7567352f MD |
94 | LTTNG_HIDDEN |
95 | int lttcomm_create_anon_unix_socketpair(int *fds) | |
96 | { | |
97 | if (socketpair(PF_UNIX, SOCK_STREAM, 0, fds) < 0) { | |
98 | PERROR("socketpair"); | |
99 | return -1; | |
100 | } | |
101 | return 0; | |
102 | } | |
103 | ||
0d37f2bc DG |
104 | /* |
105 | * Creates a AF_UNIX local socket using pathname bind the socket upon creation | |
106 | * and return the fd. | |
107 | */ | |
90e535ef | 108 | LTTNG_HIDDEN |
0d37f2bc DG |
109 | int lttcomm_create_unix_sock(const char *pathname) |
110 | { | |
665886a6 | 111 | struct sockaddr_un s_un; |
7f8bf467 | 112 | int fd = -1; |
0d37f2bc DG |
113 | int ret = -1; |
114 | ||
7f8bf467 JG |
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)); | |
119 | ret = -ENAMETOOLONG; | |
120 | goto error; | |
121 | } | |
122 | ||
0d37f2bc DG |
123 | /* Create server socket */ |
124 | if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) { | |
125 | PERROR("socket"); | |
126 | goto error; | |
127 | } | |
128 | ||
665886a6 MJ |
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'; | |
0d37f2bc DG |
133 | |
134 | /* Unlink the old file if present */ | |
135 | (void) unlink(pathname); | |
665886a6 | 136 | ret = bind(fd, (struct sockaddr *) &s_un, sizeof(s_un)); |
0d37f2bc DG |
137 | if (ret < 0) { |
138 | PERROR("bind"); | |
139 | goto error; | |
140 | } | |
141 | ||
142 | return fd; | |
143 | ||
144 | error: | |
17e75273 DG |
145 | if (fd >= 0) { |
146 | if (close(fd) < 0) { | |
147 | PERROR("close create unix sock"); | |
148 | } | |
149 | } | |
0d37f2bc DG |
150 | return ret; |
151 | } | |
152 | ||
153 | /* | |
154 | * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN. | |
155 | */ | |
90e535ef | 156 | LTTNG_HIDDEN |
0d37f2bc DG |
157 | int lttcomm_listen_unix_sock(int sock) |
158 | { | |
159 | int ret; | |
160 | ||
161 | ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN); | |
162 | if (ret < 0) { | |
163 | PERROR("listen"); | |
164 | } | |
165 | ||
166 | return ret; | |
167 | } | |
168 | ||
169 | /* | |
170 | * Receive data of size len in put that data into the buf param. Using recvmsg | |
171 | * API. | |
172 | * | |
173 | * Return the size of received data. | |
174 | */ | |
90e535ef | 175 | LTTNG_HIDDEN |
0d37f2bc DG |
176 | ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len) |
177 | { | |
178 | struct msghdr msg; | |
179 | struct iovec iov[1]; | |
180 | ssize_t ret = -1; | |
7c5aef62 | 181 | size_t len_last; |
0d37f2bc DG |
182 | |
183 | memset(&msg, 0, sizeof(msg)); | |
184 | ||
185 | iov[0].iov_base = buf; | |
186 | iov[0].iov_len = len; | |
187 | msg.msg_iov = iov; | |
188 | msg.msg_iovlen = 1; | |
189 | ||
190 | do { | |
7c5aef62 | 191 | len_last = iov[0].iov_len; |
fbb1fd3a | 192 | ret = lttng_recvmsg_nosigpipe(sock, &msg); |
7c5aef62 DG |
193 | if (ret > 0) { |
194 | iov[0].iov_base += ret; | |
195 | iov[0].iov_len -= ret; | |
196 | assert(ret <= len_last); | |
197 | } | |
198 | } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR)); | |
0d37f2bc DG |
199 | if (ret < 0) { |
200 | PERROR("recvmsg"); | |
7c5aef62 DG |
201 | } else if (ret > 0) { |
202 | ret = len; | |
0d37f2bc | 203 | } |
7c5aef62 | 204 | /* Else ret = 0 meaning an orderly shutdown. */ |
0d37f2bc DG |
205 | |
206 | return ret; | |
207 | } | |
208 | ||
c72435ad JG |
209 | /* |
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. | |
212 | * | |
44c180ca JR |
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. | |
215 | * | |
c72435ad JG |
216 | * Return the size of received data. |
217 | */ | |
218 | LTTNG_HIDDEN | |
219 | ssize_t lttcomm_recv_unix_sock_non_block(int sock, void *buf, size_t len) | |
220 | { | |
221 | struct msghdr msg; | |
222 | struct iovec iov[1]; | |
223 | ssize_t ret; | |
224 | ||
225 | memset(&msg, 0, sizeof(msg)); | |
226 | ||
227 | iov[0].iov_base = buf; | |
228 | iov[0].iov_len = len; | |
229 | msg.msg_iov = iov; | |
230 | msg.msg_iovlen = 1; | |
231 | ||
232 | retry: | |
233 | ret = lttng_recvmsg_nosigpipe(sock, &msg); | |
234 | if (ret < 0) { | |
235 | if (errno == EINTR) { | |
236 | goto retry; | |
237 | } else { | |
44c180ca JR |
238 | /* |
239 | * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected. | |
240 | */ | |
241 | if (errno == EAGAIN || errno == EWOULDBLOCK || | |
242 | errno == EPIPE) { | |
243 | /* | |
244 | * Nothing was recv. | |
245 | */ | |
246 | ret = 0; | |
247 | goto end; | |
c72435ad | 248 | } |
44c180ca JR |
249 | |
250 | /* Unexpected error */ | |
251 | PERROR("recvmsg"); | |
252 | ret = -1; | |
c72435ad JG |
253 | goto end; |
254 | } | |
255 | } | |
256 | ret = len; | |
257 | end: | |
258 | return ret; | |
259 | } | |
260 | ||
0d37f2bc DG |
261 | /* |
262 | * Send buf data of size len. Using sendmsg API. | |
263 | * | |
264 | * Return the size of sent data. | |
265 | */ | |
90e535ef | 266 | LTTNG_HIDDEN |
c2d69327 | 267 | ssize_t lttcomm_send_unix_sock(int sock, const void *buf, size_t len) |
0d37f2bc DG |
268 | { |
269 | struct msghdr msg; | |
270 | struct iovec iov[1]; | |
c72435ad | 271 | ssize_t ret; |
0d37f2bc DG |
272 | |
273 | memset(&msg, 0, sizeof(msg)); | |
274 | ||
c2d69327 | 275 | iov[0].iov_base = (void *) buf; |
0d37f2bc DG |
276 | iov[0].iov_len = len; |
277 | msg.msg_iov = iov; | |
278 | msg.msg_iovlen = 1; | |
279 | ||
c72435ad JG |
280 | while (iov[0].iov_len) { |
281 | ret = sendmsg(sock, &msg, 0); | |
282 | if (ret < 0) { | |
283 | if (errno == EINTR) { | |
284 | continue; | |
285 | } else { | |
286 | /* | |
287 | * Only warn about EPIPE when quiet mode is | |
288 | * deactivated. | |
289 | * We consider EPIPE as expected. | |
290 | */ | |
291 | if (errno != EPIPE || !lttng_opt_quiet) { | |
292 | PERROR("sendmsg"); | |
293 | } | |
294 | goto end; | |
295 | } | |
296 | } | |
297 | iov[0].iov_len -= ret; | |
298 | iov[0].iov_base += ret; | |
299 | } | |
300 | ret = len; | |
301 | end: | |
302 | return ret; | |
303 | } | |
304 | ||
305 | /* | |
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). | |
310 | * | |
44c180ca JR |
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. | |
313 | * | |
c72435ad JG |
314 | * Return the size of sent data. |
315 | */ | |
316 | LTTNG_HIDDEN | |
317 | ssize_t lttcomm_send_unix_sock_non_block(int sock, const void *buf, size_t len) | |
318 | { | |
319 | struct msghdr msg; | |
320 | struct iovec iov[1]; | |
321 | ssize_t ret; | |
322 | ||
323 | memset(&msg, 0, sizeof(msg)); | |
324 | ||
325 | iov[0].iov_base = (void *) buf; | |
326 | iov[0].iov_len = len; | |
327 | msg.msg_iov = iov; | |
328 | msg.msg_iovlen = 1; | |
329 | ||
330 | retry: | |
0d37f2bc DG |
331 | ret = sendmsg(sock, &msg, 0); |
332 | if (ret < 0) { | |
c72435ad JG |
333 | if (errno == EINTR) { |
334 | goto retry; | |
335 | } else { | |
44c180ca JR |
336 | /* |
337 | * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected. | |
338 | */ | |
339 | if (errno == EAGAIN || errno == EWOULDBLOCK || | |
340 | errno == EPIPE) { | |
341 | /* | |
342 | * This can happen in non blocking mode. | |
343 | * Nothing was sent. | |
344 | */ | |
345 | ret = 0; | |
346 | goto end; | |
c72435ad | 347 | } |
44c180ca JR |
348 | |
349 | /* Unexpected error */ | |
350 | PERROR("sendmsg"); | |
351 | ret = -1; | |
c72435ad | 352 | goto end; |
0d37f2bc DG |
353 | } |
354 | } | |
c72435ad JG |
355 | ret = len; |
356 | end: | |
0d37f2bc DG |
357 | return ret; |
358 | } | |
359 | ||
360 | /* | |
361 | * Shutdown cleanly a unix socket. | |
362 | */ | |
90e535ef | 363 | LTTNG_HIDDEN |
0d37f2bc DG |
364 | int lttcomm_close_unix_sock(int sock) |
365 | { | |
366 | int ret, closeret; | |
367 | ||
368 | /* Shutdown receptions and transmissions */ | |
369 | ret = shutdown(sock, SHUT_RDWR); | |
370 | if (ret < 0) { | |
371 | PERROR("shutdown"); | |
372 | } | |
373 | ||
374 | closeret = close(sock); | |
375 | if (closeret) { | |
376 | PERROR("close"); | |
377 | } | |
378 | ||
379 | return ret; | |
380 | } | |
381 | ||
382 | /* | |
383 | * Send a message accompanied by fd(s) over a unix socket. | |
384 | * | |
385 | * Returns the size of data sent, or negative error value. | |
386 | */ | |
90e535ef | 387 | LTTNG_HIDDEN |
ac2f30af | 388 | ssize_t lttcomm_send_fds_unix_sock(int sock, const int *fds, size_t nb_fd) |
0d37f2bc DG |
389 | { |
390 | struct msghdr msg; | |
391 | struct cmsghdr *cmptr; | |
392 | struct iovec iov[1]; | |
393 | ssize_t ret = -1; | |
394 | unsigned int sizeof_fds = nb_fd * sizeof(int); | |
395 | char tmp[CMSG_SPACE(sizeof_fds)]; | |
396 | char dummy = 0; | |
397 | ||
398 | memset(&msg, 0, sizeof(msg)); | |
b3f35e02 | 399 | memset(tmp, 0, sizeof(tmp)); |
0d37f2bc DG |
400 | |
401 | if (nb_fd > LTTCOMM_MAX_SEND_FDS) | |
402 | return -EINVAL; | |
403 | ||
404 | msg.msg_control = (caddr_t)tmp; | |
405 | msg.msg_controllen = CMSG_LEN(sizeof_fds); | |
406 | ||
407 | cmptr = CMSG_FIRSTHDR(&msg); | |
1d8d0328 MJ |
408 | if (!cmptr) { |
409 | return -1; | |
410 | } | |
b3f35e02 | 411 | |
0d37f2bc DG |
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; | |
418 | ||
419 | iov[0].iov_base = &dummy; | |
420 | iov[0].iov_len = 1; | |
421 | msg.msg_iov = iov; | |
422 | msg.msg_iovlen = 1; | |
423 | ||
424 | do { | |
425 | ret = sendmsg(sock, &msg, 0); | |
426 | } while (ret < 0 && errno == EINTR); | |
427 | if (ret < 0) { | |
428 | /* | |
429 | * Only warn about EPIPE when quiet mode is deactivated. | |
430 | * We consider EPIPE as expected. | |
431 | */ | |
432 | if (errno != EPIPE || !lttng_opt_quiet) { | |
433 | PERROR("sendmsg"); | |
434 | } | |
435 | } | |
436 | return ret; | |
437 | } | |
438 | ||
b72ce630 JR |
439 | /* |
440 | * Send a message accompanied by fd(s) over a unix socket. | |
441 | * Only use for non blocking socket. | |
442 | * | |
443 | * Returns the size of data sent, or negative error value. | |
444 | */ | |
445 | LTTNG_HIDDEN | |
446 | ssize_t lttcomm_send_fds_unix_sock_non_block(int sock, const int *fds, size_t nb_fd) | |
447 | { | |
448 | struct msghdr msg; | |
449 | struct cmsghdr *cmptr; | |
450 | struct iovec iov[1]; | |
451 | ssize_t ret = -1; | |
452 | unsigned int sizeof_fds = nb_fd * sizeof(int); | |
453 | char tmp[CMSG_SPACE(sizeof_fds)]; | |
454 | char dummy = 0; | |
455 | ||
456 | memset(&msg, 0, sizeof(msg)); | |
457 | memset(tmp, 0, sizeof(tmp)); | |
458 | ||
459 | if (nb_fd > LTTCOMM_MAX_SEND_FDS) | |
460 | return -EINVAL; | |
461 | ||
462 | msg.msg_control = (caddr_t)tmp; | |
463 | msg.msg_controllen = CMSG_LEN(sizeof_fds); | |
464 | ||
465 | cmptr = CMSG_FIRSTHDR(&msg); | |
466 | if (!cmptr) { | |
467 | return -1; | |
468 | } | |
469 | ||
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; | |
476 | ||
477 | iov[0].iov_base = &dummy; | |
478 | iov[0].iov_len = 1; | |
479 | msg.msg_iov = iov; | |
480 | msg.msg_iovlen = 1; | |
481 | ||
482 | retry: | |
483 | ret = sendmsg(sock, &msg, 0); | |
484 | if (ret < 0) { | |
485 | if (errno == EINTR) { | |
486 | goto retry; | |
487 | } else { | |
488 | /* | |
489 | * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected. | |
490 | */ | |
491 | if (errno == EAGAIN || errno == EWOULDBLOCK) { | |
492 | /* | |
493 | * This can happen in non blocking mode. | |
494 | * Nothing was sent. | |
495 | */ | |
496 | ret = 0; | |
497 | goto end; | |
498 | } | |
499 | ||
500 | if (errno == EPIPE) { | |
501 | /* Expected error, pass error to caller */ | |
502 | DBG3("EPIPE on sendmsg"); | |
503 | ret = -1; | |
504 | goto end; | |
505 | } | |
506 | ||
507 | /* Unexpected error */ | |
508 | PERROR("sendmsg"); | |
509 | ret = -1; | |
510 | goto end; | |
511 | } | |
512 | } | |
513 | ||
514 | end: | |
515 | return ret; | |
516 | } | |
517 | ||
0d37f2bc DG |
518 | /* |
519 | * Recv a message accompanied by fd(s) from a unix socket. | |
520 | * | |
521 | * Returns the size of received data, or negative error value. | |
522 | * | |
523 | * Expect at most "nb_fd" file descriptors. Returns the number of fd | |
524 | * actually received in nb_fd. | |
525 | */ | |
90e535ef | 526 | LTTNG_HIDDEN |
0d37f2bc DG |
527 | ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd) |
528 | { | |
529 | struct iovec iov[1]; | |
530 | ssize_t ret = 0; | |
531 | struct cmsghdr *cmsg; | |
532 | size_t sizeof_fds = nb_fd * sizeof(int); | |
b3f35e02 | 533 | |
ba49ae8c MJ |
534 | #ifdef __linux__ |
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)) | |
537 | #else | |
538 | #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) | |
539 | #endif /* __linux__ */ | |
540 | ||
541 | char recv_buf[LTTNG_SOCK_RECV_FDS_BUF_SIZE]; | |
0d37f2bc DG |
542 | struct msghdr msg; |
543 | char dummy; | |
544 | ||
545 | memset(&msg, 0, sizeof(msg)); | |
546 | ||
547 | /* Prepare to receive the structures */ | |
548 | iov[0].iov_base = &dummy; | |
549 | iov[0].iov_len = 1; | |
550 | msg.msg_iov = iov; | |
551 | msg.msg_iovlen = 1; | |
b3f35e02 FD |
552 | |
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; | |
557 | ||
558 | msg.msg_control = cmsg; | |
559 | msg.msg_controllen = CMSG_LEN(sizeof(recv_buf)); | |
560 | msg.msg_flags = 0; | |
0d37f2bc | 561 | |
b72ce630 JR |
562 | retry: |
563 | ret = lttng_recvmsg_nosigpipe(sock, &msg); | |
0d37f2bc | 564 | if (ret < 0) { |
b72ce630 JR |
565 | if (errno == EINTR) { |
566 | goto retry; | |
567 | } else { | |
568 | /* We consider EPIPE and EAGAIN as expected. */ | |
569 | if (!lttng_opt_quiet && | |
570 | (errno != EPIPE && errno != EAGAIN)) { | |
571 | PERROR("recvmsg"); | |
572 | } | |
573 | goto end; | |
574 | } | |
575 | } | |
576 | ||
577 | if (ret != 1) { | |
578 | fprintf(stderr, "Error: Received %zd bytes, expected %d\n", | |
579 | ret, 1); | |
0d37f2bc DG |
580 | goto end; |
581 | } | |
b3f35e02 | 582 | |
b72ce630 JR |
583 | if (msg.msg_flags & MSG_CTRUNC) { |
584 | fprintf(stderr, "Error: Control message truncated.\n"); | |
585 | ret = -1; | |
586 | goto end; | |
587 | } | |
588 | ||
589 | /* | |
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 | |
593 | * message. | |
594 | */ | |
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"); | |
598 | ret = -1; | |
599 | goto end; | |
600 | } | |
601 | if (cmsg->cmsg_type == SCM_RIGHTS) { | |
602 | /* | |
603 | * We found the controle message for file descriptors, | |
604 | * now copy the fds to the fds ptr and return success. | |
605 | */ | |
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)); | |
611 | ret = -1; | |
612 | goto end; | |
613 | } | |
614 | memcpy(fds, CMSG_DATA(cmsg), sizeof_fds); | |
615 | ret = sizeof_fds; | |
616 | goto end; | |
617 | } | |
618 | #ifdef __linux__ | |
619 | if (cmsg->cmsg_type == SCM_CREDENTIALS) { | |
620 | /* | |
621 | * Expect credentials to be sent when expecting fds even | |
622 | * if no credential were include in the send(). The | |
623 | * kernel adds them... | |
624 | */ | |
625 | ret = -1; | |
626 | } | |
627 | #endif /* __linux__ */ | |
628 | } | |
629 | end: | |
630 | return ret; | |
631 | } | |
632 | ||
633 | /* | |
634 | * Recv a message accompanied by fd(s) from a non-blocking unix socket. | |
635 | * Only use with non-blocking sockets. | |
636 | * | |
637 | * Returns the size of received data, or negative error value. | |
638 | * | |
639 | * Expect at most "nb_fd" file descriptors. | |
640 | * | |
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. | |
644 | */ | |
645 | LTTNG_HIDDEN | |
646 | ssize_t lttcomm_recv_fds_unix_sock_non_block(int sock, int *fds, size_t nb_fd) | |
647 | { | |
648 | struct iovec iov[1]; | |
649 | ssize_t ret = 0; | |
650 | struct cmsghdr *cmsg; | |
651 | size_t sizeof_fds = nb_fd * sizeof(int); | |
652 | ||
653 | #ifdef __linux__ | |
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)) | |
656 | #else | |
657 | #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) | |
658 | #endif /* __linux__ */ | |
659 | ||
660 | char recv_buf[LTTNG_SOCK_RECV_FDS_BUF_SIZE]; | |
661 | struct msghdr msg; | |
662 | char dummy; | |
663 | ||
664 | memset(&msg, 0, sizeof(msg)); | |
665 | ||
666 | /* Prepare to receive the structures */ | |
667 | iov[0].iov_base = &dummy; | |
668 | iov[0].iov_len = 1; | |
669 | msg.msg_iov = iov; | |
670 | msg.msg_iovlen = 1; | |
671 | ||
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; | |
676 | ||
677 | msg.msg_control = cmsg; | |
678 | msg.msg_controllen = CMSG_LEN(sizeof(recv_buf)); | |
679 | msg.msg_flags = 0; | |
680 | ||
681 | retry: | |
682 | ret = lttng_recvmsg_nosigpipe(sock, &msg); | |
683 | if (ret < 0) { | |
684 | if (errno == EINTR) { | |
685 | goto retry; | |
686 | } else { | |
687 | /* | |
688 | * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected. | |
689 | */ | |
690 | if (errno == EAGAIN || errno == EWOULDBLOCK) { | |
691 | /* | |
692 | * This can happen in non blocking mode. | |
693 | * Nothing was recv. | |
694 | */ | |
695 | ret = 0; | |
696 | goto end; | |
697 | } | |
698 | ||
699 | if (errno == EPIPE) { | |
700 | /* Expected error, pass error to caller */ | |
701 | DBG3("EPIPE on recvmsg"); | |
702 | ret = -1; | |
703 | goto end; | |
704 | } | |
705 | ||
706 | /* Unexpected error */ | |
707 | PERROR("recvmsg"); | |
708 | ret = -1; | |
709 | goto end; | |
710 | } | |
711 | } | |
712 | ||
0d37f2bc DG |
713 | if (ret != 1) { |
714 | fprintf(stderr, "Error: Received %zd bytes, expected %d\n", | |
715 | ret, 1); | |
716 | goto end; | |
717 | } | |
b3f35e02 | 718 | |
0d37f2bc DG |
719 | if (msg.msg_flags & MSG_CTRUNC) { |
720 | fprintf(stderr, "Error: Control message truncated.\n"); | |
721 | ret = -1; | |
722 | goto end; | |
723 | } | |
b3f35e02 FD |
724 | |
725 | /* | |
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 | |
729 | * message. | |
730 | */ | |
731 | for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { | |
b3f35e02 FD |
732 | if (cmsg->cmsg_level != SOL_SOCKET) { |
733 | fprintf(stderr, "Error: The socket needs to be of type SOL_SOCKET\n"); | |
734 | ret = -1; | |
735 | goto end; | |
736 | } | |
737 | if (cmsg->cmsg_type == SCM_RIGHTS) { | |
738 | /* | |
739 | * We found the controle message for file descriptors, | |
740 | * now copy the fds to the fds ptr and return success. | |
741 | */ | |
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)); | |
747 | ret = -1; | |
748 | goto end; | |
749 | } | |
750 | memcpy(fds, CMSG_DATA(cmsg), sizeof_fds); | |
751 | ret = sizeof_fds; | |
752 | goto end; | |
753 | } | |
ba49ae8c | 754 | #ifdef __linux__ |
b3f35e02 FD |
755 | if (cmsg->cmsg_type == SCM_CREDENTIALS) { |
756 | /* | |
757 | * Expect credentials to be sent when expecting fds even | |
758 | * if no credential were include in the send(). The | |
759 | * kernel adds them... | |
760 | */ | |
b3f35e02 FD |
761 | ret = -1; |
762 | } | |
ba49ae8c | 763 | #endif /* __linux__ */ |
0d37f2bc | 764 | } |
0d37f2bc DG |
765 | end: |
766 | return ret; | |
767 | } | |
768 | ||
769 | /* | |
770 | * Send a message with credentials over a unix socket. | |
771 | * | |
772 | * Returns the size of data sent, or negative error value. | |
773 | */ | |
90e535ef | 774 | LTTNG_HIDDEN |
0d37f2bc DG |
775 | ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len) |
776 | { | |
777 | struct msghdr msg; | |
778 | struct iovec iov[1]; | |
779 | ssize_t ret = -1; | |
780 | #ifdef __linux__ | |
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; | |
8bbffd54 MJ |
785 | |
786 | memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char)); | |
0d37f2bc DG |
787 | #endif /* __linux__ */ |
788 | ||
789 | memset(&msg, 0, sizeof(msg)); | |
790 | ||
791 | iov[0].iov_base = buf; | |
792 | iov[0].iov_len = len; | |
793 | msg.msg_iov = iov; | |
794 | msg.msg_iovlen = 1; | |
795 | ||
796 | #ifdef __linux__ | |
797 | msg.msg_control = (caddr_t) anc_buf; | |
798 | msg.msg_controllen = CMSG_LEN(sizeof_cred); | |
799 | ||
800 | cmptr = CMSG_FIRSTHDR(&msg); | |
1d8d0328 MJ |
801 | if (!cmptr) { |
802 | return -1; | |
803 | } | |
0d37f2bc DG |
804 | cmptr->cmsg_level = SOL_SOCKET; |
805 | cmptr->cmsg_type = LTTNG_SOCK_CREDS; | |
806 | cmptr->cmsg_len = CMSG_LEN(sizeof_cred); | |
807 | ||
808 | creds = (lttng_sock_cred*) CMSG_DATA(cmptr); | |
809 | ||
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__ */ | |
814 | ||
815 | do { | |
816 | ret = sendmsg(sock, &msg, 0); | |
817 | } while (ret < 0 && errno == EINTR); | |
818 | if (ret < 0) { | |
819 | /* | |
820 | * Only warn about EPIPE when quiet mode is deactivated. | |
821 | * We consider EPIPE as expected. | |
822 | */ | |
823 | if (errno != EPIPE || !lttng_opt_quiet) { | |
824 | PERROR("sendmsg"); | |
825 | } | |
826 | } | |
827 | return ret; | |
828 | } | |
829 | ||
830 | /* | |
831 | * Recv a message accompanied with credentials from a unix socket. | |
832 | * | |
833 | * Returns the size of received data, or negative error value. | |
834 | */ | |
90e535ef | 835 | LTTNG_HIDDEN |
0d37f2bc DG |
836 | ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len, |
837 | lttng_sock_cred *creds) | |
838 | { | |
839 | struct msghdr msg; | |
840 | struct iovec iov[1]; | |
841 | ssize_t ret; | |
4100e49a | 842 | size_t len_last; |
0d37f2bc DG |
843 | #ifdef __linux__ |
844 | struct cmsghdr *cmptr; | |
845 | size_t sizeof_cred = sizeof(lttng_sock_cred); | |
846 | char anc_buf[CMSG_SPACE(sizeof_cred)]; | |
847 | #endif /* __linux__ */ | |
848 | ||
849 | memset(&msg, 0, sizeof(msg)); | |
850 | ||
851 | /* Not allowed */ | |
852 | if (creds == NULL) { | |
853 | ret = -1; | |
854 | goto end; | |
855 | } | |
856 | ||
857 | /* Prepare to receive the structures */ | |
858 | iov[0].iov_base = buf; | |
859 | iov[0].iov_len = len; | |
860 | msg.msg_iov = iov; | |
861 | msg.msg_iovlen = 1; | |
862 | ||
863 | #ifdef __linux__ | |
864 | msg.msg_control = anc_buf; | |
865 | msg.msg_controllen = sizeof(anc_buf); | |
866 | #endif /* __linux__ */ | |
867 | ||
868 | do { | |
4100e49a | 869 | len_last = iov[0].iov_len; |
0d37f2bc | 870 | ret = recvmsg(sock, &msg, 0); |
4100e49a DG |
871 | if (ret > 0) { |
872 | iov[0].iov_base += ret; | |
873 | iov[0].iov_len -= ret; | |
874 | assert(ret <= len_last); | |
875 | } | |
876 | } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR)); | |
0d37f2bc DG |
877 | if (ret < 0) { |
878 | PERROR("recvmsg fds"); | |
879 | goto end; | |
4100e49a DG |
880 | } else if (ret > 0) { |
881 | ret = len; | |
0d37f2bc | 882 | } |
4100e49a | 883 | /* Else ret = 0 meaning an orderly shutdown. */ |
0d37f2bc DG |
884 | |
885 | #ifdef __linux__ | |
886 | if (msg.msg_flags & MSG_CTRUNC) { | |
887 | fprintf(stderr, "Error: Control message truncated.\n"); | |
888 | ret = -1; | |
889 | goto end; | |
890 | } | |
891 | ||
892 | cmptr = CMSG_FIRSTHDR(&msg); | |
893 | if (cmptr == NULL) { | |
894 | fprintf(stderr, "Error: Invalid control message header\n"); | |
895 | ret = -1; | |
896 | goto end; | |
897 | } | |
898 | ||
899 | if (cmptr->cmsg_level != SOL_SOCKET || | |
900 | cmptr->cmsg_type != LTTNG_SOCK_CREDS) { | |
901 | fprintf(stderr, "Didn't received any credentials\n"); | |
902 | ret = -1; | |
903 | goto end; | |
904 | } | |
905 | ||
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)); | |
909 | ret = -1; | |
910 | goto end; | |
911 | } | |
912 | ||
913 | memcpy(creds, CMSG_DATA(cmptr), sizeof_cred); | |
bfa419e4 | 914 | #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__)) |
0d37f2bc DG |
915 | { |
916 | int peer_ret; | |
917 | ||
918 | peer_ret = getpeereid(sock, &creds->uid, &creds->gid); | |
919 | if (peer_ret != 0) { | |
920 | return peer_ret; | |
921 | } | |
922 | } | |
923 | #else | |
924 | #error "Please implement credential support for your OS." | |
925 | #endif /* __linux__ */ | |
926 | ||
927 | end: | |
928 | return ret; | |
929 | } | |
930 | ||
931 | /* | |
932 | * Set socket option to use credentials passing. | |
933 | */ | |
934 | #ifdef __linux__ | |
90e535ef | 935 | LTTNG_HIDDEN |
0d37f2bc DG |
936 | int lttcomm_setsockopt_creds_unix_sock(int sock) |
937 | { | |
938 | int ret, on = 1; | |
939 | ||
940 | /* Set socket for credentials retrieval */ | |
941 | ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); | |
942 | if (ret < 0) { | |
943 | PERROR("setsockopt creds unix sock"); | |
944 | } | |
945 | return ret; | |
946 | } | |
bfa419e4 | 947 | #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__)) |
90e535ef | 948 | LTTNG_HIDDEN |
0d37f2bc DG |
949 | int lttcomm_setsockopt_creds_unix_sock(int sock) |
950 | { | |
951 | return 0; | |
952 | } | |
953 | #else | |
954 | #error "Please implement credential support for your OS." | |
955 | #endif /* __linux__ */ |