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 | } | |
5b86bd5e | 256 | |
c72435ad JG |
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 | 355 | end: |
0d37f2bc DG |
356 | return ret; |
357 | } | |
358 | ||
359 | /* | |
360 | * Shutdown cleanly a unix socket. | |
361 | */ | |
90e535ef | 362 | LTTNG_HIDDEN |
0d37f2bc DG |
363 | int lttcomm_close_unix_sock(int sock) |
364 | { | |
365 | int ret, closeret; | |
366 | ||
367 | /* Shutdown receptions and transmissions */ | |
368 | ret = shutdown(sock, SHUT_RDWR); | |
369 | if (ret < 0) { | |
370 | PERROR("shutdown"); | |
371 | } | |
372 | ||
373 | closeret = close(sock); | |
374 | if (closeret) { | |
375 | PERROR("close"); | |
376 | } | |
377 | ||
378 | return ret; | |
379 | } | |
380 | ||
381 | /* | |
382 | * Send a message accompanied by fd(s) over a unix socket. | |
383 | * | |
384 | * Returns the size of data sent, or negative error value. | |
385 | */ | |
90e535ef | 386 | LTTNG_HIDDEN |
ac2f30af | 387 | ssize_t lttcomm_send_fds_unix_sock(int sock, const int *fds, size_t nb_fd) |
0d37f2bc DG |
388 | { |
389 | struct msghdr msg; | |
390 | struct cmsghdr *cmptr; | |
391 | struct iovec iov[1]; | |
392 | ssize_t ret = -1; | |
393 | unsigned int sizeof_fds = nb_fd * sizeof(int); | |
394 | char tmp[CMSG_SPACE(sizeof_fds)]; | |
395 | char dummy = 0; | |
396 | ||
397 | memset(&msg, 0, sizeof(msg)); | |
b3f35e02 | 398 | memset(tmp, 0, sizeof(tmp)); |
0d37f2bc DG |
399 | |
400 | if (nb_fd > LTTCOMM_MAX_SEND_FDS) | |
401 | return -EINVAL; | |
402 | ||
403 | msg.msg_control = (caddr_t)tmp; | |
404 | msg.msg_controllen = CMSG_LEN(sizeof_fds); | |
405 | ||
406 | cmptr = CMSG_FIRSTHDR(&msg); | |
1d8d0328 MJ |
407 | if (!cmptr) { |
408 | return -1; | |
409 | } | |
b3f35e02 | 410 | |
0d37f2bc DG |
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; | |
417 | ||
418 | iov[0].iov_base = &dummy; | |
419 | iov[0].iov_len = 1; | |
420 | msg.msg_iov = iov; | |
421 | msg.msg_iovlen = 1; | |
422 | ||
423 | do { | |
424 | ret = sendmsg(sock, &msg, 0); | |
425 | } while (ret < 0 && errno == EINTR); | |
426 | if (ret < 0) { | |
427 | /* | |
428 | * Only warn about EPIPE when quiet mode is deactivated. | |
429 | * We consider EPIPE as expected. | |
430 | */ | |
431 | if (errno != EPIPE || !lttng_opt_quiet) { | |
432 | PERROR("sendmsg"); | |
433 | } | |
434 | } | |
435 | return ret; | |
436 | } | |
437 | ||
b72ce630 JR |
438 | /* |
439 | * Send a message accompanied by fd(s) over a unix socket. | |
440 | * Only use for non blocking socket. | |
441 | * | |
442 | * Returns the size of data sent, or negative error value. | |
443 | */ | |
444 | LTTNG_HIDDEN | |
445 | ssize_t lttcomm_send_fds_unix_sock_non_block(int sock, const int *fds, size_t nb_fd) | |
446 | { | |
447 | struct msghdr msg; | |
448 | struct cmsghdr *cmptr; | |
449 | struct iovec iov[1]; | |
450 | ssize_t ret = -1; | |
451 | unsigned int sizeof_fds = nb_fd * sizeof(int); | |
452 | char tmp[CMSG_SPACE(sizeof_fds)]; | |
453 | char dummy = 0; | |
454 | ||
455 | memset(&msg, 0, sizeof(msg)); | |
456 | memset(tmp, 0, sizeof(tmp)); | |
457 | ||
458 | if (nb_fd > LTTCOMM_MAX_SEND_FDS) | |
459 | return -EINVAL; | |
460 | ||
461 | msg.msg_control = (caddr_t)tmp; | |
462 | msg.msg_controllen = CMSG_LEN(sizeof_fds); | |
463 | ||
464 | cmptr = CMSG_FIRSTHDR(&msg); | |
465 | if (!cmptr) { | |
466 | return -1; | |
467 | } | |
468 | ||
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; | |
475 | ||
476 | iov[0].iov_base = &dummy; | |
477 | iov[0].iov_len = 1; | |
478 | msg.msg_iov = iov; | |
479 | msg.msg_iovlen = 1; | |
480 | ||
481 | retry: | |
482 | ret = sendmsg(sock, &msg, 0); | |
483 | if (ret < 0) { | |
484 | if (errno == EINTR) { | |
485 | goto retry; | |
486 | } else { | |
487 | /* | |
488 | * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected. | |
489 | */ | |
490 | if (errno == EAGAIN || errno == EWOULDBLOCK) { | |
491 | /* | |
492 | * This can happen in non blocking mode. | |
493 | * Nothing was sent. | |
494 | */ | |
495 | ret = 0; | |
496 | goto end; | |
497 | } | |
498 | ||
499 | if (errno == EPIPE) { | |
500 | /* Expected error, pass error to caller */ | |
501 | DBG3("EPIPE on sendmsg"); | |
502 | ret = -1; | |
503 | goto end; | |
504 | } | |
505 | ||
506 | /* Unexpected error */ | |
507 | PERROR("sendmsg"); | |
508 | ret = -1; | |
509 | goto end; | |
510 | } | |
511 | } | |
512 | ||
513 | end: | |
514 | return ret; | |
515 | } | |
516 | ||
0d37f2bc DG |
517 | /* |
518 | * Recv a message accompanied by fd(s) from a unix socket. | |
519 | * | |
520 | * Returns the size of received data, or negative error value. | |
521 | * | |
522 | * Expect at most "nb_fd" file descriptors. Returns the number of fd | |
523 | * actually received in nb_fd. | |
524 | */ | |
90e535ef | 525 | LTTNG_HIDDEN |
0d37f2bc DG |
526 | ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd) |
527 | { | |
528 | struct iovec iov[1]; | |
529 | ssize_t ret = 0; | |
530 | struct cmsghdr *cmsg; | |
531 | size_t sizeof_fds = nb_fd * sizeof(int); | |
b3f35e02 | 532 | |
ba49ae8c MJ |
533 | #ifdef __linux__ |
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)) | |
536 | #else | |
537 | #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) | |
538 | #endif /* __linux__ */ | |
539 | ||
540 | char recv_buf[LTTNG_SOCK_RECV_FDS_BUF_SIZE]; | |
0d37f2bc DG |
541 | struct msghdr msg; |
542 | char dummy; | |
543 | ||
544 | memset(&msg, 0, sizeof(msg)); | |
545 | ||
546 | /* Prepare to receive the structures */ | |
547 | iov[0].iov_base = &dummy; | |
548 | iov[0].iov_len = 1; | |
549 | msg.msg_iov = iov; | |
550 | msg.msg_iovlen = 1; | |
b3f35e02 FD |
551 | |
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; | |
556 | ||
557 | msg.msg_control = cmsg; | |
558 | msg.msg_controllen = CMSG_LEN(sizeof(recv_buf)); | |
559 | msg.msg_flags = 0; | |
0d37f2bc | 560 | |
b72ce630 JR |
561 | retry: |
562 | ret = lttng_recvmsg_nosigpipe(sock, &msg); | |
0d37f2bc | 563 | if (ret < 0) { |
b72ce630 JR |
564 | if (errno == EINTR) { |
565 | goto retry; | |
566 | } else { | |
567 | /* We consider EPIPE and EAGAIN as expected. */ | |
568 | if (!lttng_opt_quiet && | |
569 | (errno != EPIPE && errno != EAGAIN)) { | |
570 | PERROR("recvmsg"); | |
571 | } | |
572 | goto end; | |
573 | } | |
574 | } | |
575 | ||
576 | if (ret != 1) { | |
577 | fprintf(stderr, "Error: Received %zd bytes, expected %d\n", | |
578 | ret, 1); | |
0d37f2bc DG |
579 | goto end; |
580 | } | |
b3f35e02 | 581 | |
b72ce630 JR |
582 | if (msg.msg_flags & MSG_CTRUNC) { |
583 | fprintf(stderr, "Error: Control message truncated.\n"); | |
584 | ret = -1; | |
585 | goto end; | |
586 | } | |
587 | ||
588 | /* | |
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 | |
592 | * message. | |
593 | */ | |
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"); | |
597 | ret = -1; | |
598 | goto end; | |
599 | } | |
600 | if (cmsg->cmsg_type == SCM_RIGHTS) { | |
601 | /* | |
602 | * We found the controle message for file descriptors, | |
603 | * now copy the fds to the fds ptr and return success. | |
604 | */ | |
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)); | |
610 | ret = -1; | |
611 | goto end; | |
612 | } | |
613 | memcpy(fds, CMSG_DATA(cmsg), sizeof_fds); | |
614 | ret = sizeof_fds; | |
615 | goto end; | |
616 | } | |
617 | #ifdef __linux__ | |
618 | if (cmsg->cmsg_type == SCM_CREDENTIALS) { | |
619 | /* | |
620 | * Expect credentials to be sent when expecting fds even | |
621 | * if no credential were include in the send(). The | |
622 | * kernel adds them... | |
623 | */ | |
624 | ret = -1; | |
625 | } | |
626 | #endif /* __linux__ */ | |
627 | } | |
628 | end: | |
629 | return ret; | |
630 | } | |
631 | ||
632 | /* | |
633 | * Recv a message accompanied by fd(s) from a non-blocking unix socket. | |
634 | * Only use with non-blocking sockets. | |
635 | * | |
636 | * Returns the size of received data, or negative error value. | |
637 | * | |
638 | * Expect at most "nb_fd" file descriptors. | |
639 | * | |
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. | |
643 | */ | |
644 | LTTNG_HIDDEN | |
645 | ssize_t lttcomm_recv_fds_unix_sock_non_block(int sock, int *fds, size_t nb_fd) | |
646 | { | |
647 | struct iovec iov[1]; | |
648 | ssize_t ret = 0; | |
649 | struct cmsghdr *cmsg; | |
650 | size_t sizeof_fds = nb_fd * sizeof(int); | |
651 | ||
652 | #ifdef __linux__ | |
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)) | |
655 | #else | |
656 | #define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) | |
657 | #endif /* __linux__ */ | |
658 | ||
659 | char recv_buf[LTTNG_SOCK_RECV_FDS_BUF_SIZE]; | |
660 | struct msghdr msg; | |
661 | char dummy; | |
662 | ||
663 | memset(&msg, 0, sizeof(msg)); | |
664 | ||
665 | /* Prepare to receive the structures */ | |
666 | iov[0].iov_base = &dummy; | |
667 | iov[0].iov_len = 1; | |
668 | msg.msg_iov = iov; | |
669 | msg.msg_iovlen = 1; | |
670 | ||
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; | |
675 | ||
676 | msg.msg_control = cmsg; | |
677 | msg.msg_controllen = CMSG_LEN(sizeof(recv_buf)); | |
678 | msg.msg_flags = 0; | |
679 | ||
680 | retry: | |
681 | ret = lttng_recvmsg_nosigpipe(sock, &msg); | |
682 | if (ret < 0) { | |
683 | if (errno == EINTR) { | |
684 | goto retry; | |
685 | } else { | |
686 | /* | |
687 | * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected. | |
688 | */ | |
689 | if (errno == EAGAIN || errno == EWOULDBLOCK) { | |
690 | /* | |
691 | * This can happen in non blocking mode. | |
692 | * Nothing was recv. | |
693 | */ | |
694 | ret = 0; | |
695 | goto end; | |
696 | } | |
697 | ||
698 | if (errno == EPIPE) { | |
699 | /* Expected error, pass error to caller */ | |
700 | DBG3("EPIPE on recvmsg"); | |
701 | ret = -1; | |
702 | goto end; | |
703 | } | |
704 | ||
705 | /* Unexpected error */ | |
706 | PERROR("recvmsg"); | |
707 | ret = -1; | |
708 | goto end; | |
709 | } | |
710 | } | |
711 | ||
0d37f2bc DG |
712 | if (ret != 1) { |
713 | fprintf(stderr, "Error: Received %zd bytes, expected %d\n", | |
714 | ret, 1); | |
715 | goto end; | |
716 | } | |
b3f35e02 | 717 | |
0d37f2bc DG |
718 | if (msg.msg_flags & MSG_CTRUNC) { |
719 | fprintf(stderr, "Error: Control message truncated.\n"); | |
720 | ret = -1; | |
721 | goto end; | |
722 | } | |
b3f35e02 FD |
723 | |
724 | /* | |
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 | |
728 | * message. | |
729 | */ | |
730 | for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { | |
b3f35e02 FD |
731 | if (cmsg->cmsg_level != SOL_SOCKET) { |
732 | fprintf(stderr, "Error: The socket needs to be of type SOL_SOCKET\n"); | |
733 | ret = -1; | |
734 | goto end; | |
735 | } | |
736 | if (cmsg->cmsg_type == SCM_RIGHTS) { | |
737 | /* | |
738 | * We found the controle message for file descriptors, | |
739 | * now copy the fds to the fds ptr and return success. | |
740 | */ | |
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)); | |
746 | ret = -1; | |
747 | goto end; | |
748 | } | |
749 | memcpy(fds, CMSG_DATA(cmsg), sizeof_fds); | |
750 | ret = sizeof_fds; | |
751 | goto end; | |
752 | } | |
ba49ae8c | 753 | #ifdef __linux__ |
b3f35e02 FD |
754 | if (cmsg->cmsg_type == SCM_CREDENTIALS) { |
755 | /* | |
756 | * Expect credentials to be sent when expecting fds even | |
757 | * if no credential were include in the send(). The | |
758 | * kernel adds them... | |
759 | */ | |
b3f35e02 FD |
760 | ret = -1; |
761 | } | |
ba49ae8c | 762 | #endif /* __linux__ */ |
0d37f2bc | 763 | } |
0d37f2bc DG |
764 | end: |
765 | return ret; | |
766 | } | |
767 | ||
768 | /* | |
769 | * Send a message with credentials over a unix socket. | |
770 | * | |
771 | * Returns the size of data sent, or negative error value. | |
772 | */ | |
90e535ef | 773 | LTTNG_HIDDEN |
e368fb43 | 774 | ssize_t lttcomm_send_creds_unix_sock(int sock, const void *buf, size_t len) |
0d37f2bc DG |
775 | { |
776 | struct msghdr msg; | |
777 | struct iovec iov[1]; | |
778 | ssize_t ret = -1; | |
779 | #ifdef __linux__ | |
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; | |
8bbffd54 MJ |
784 | |
785 | memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char)); | |
0d37f2bc DG |
786 | #endif /* __linux__ */ |
787 | ||
788 | memset(&msg, 0, sizeof(msg)); | |
789 | ||
e368fb43 | 790 | iov[0].iov_base = (void *) buf; |
0d37f2bc DG |
791 | iov[0].iov_len = len; |
792 | msg.msg_iov = iov; | |
793 | msg.msg_iovlen = 1; | |
794 | ||
795 | #ifdef __linux__ | |
796 | msg.msg_control = (caddr_t) anc_buf; | |
797 | msg.msg_controllen = CMSG_LEN(sizeof_cred); | |
798 | ||
799 | cmptr = CMSG_FIRSTHDR(&msg); | |
1d8d0328 MJ |
800 | if (!cmptr) { |
801 | return -1; | |
802 | } | |
0d37f2bc DG |
803 | cmptr->cmsg_level = SOL_SOCKET; |
804 | cmptr->cmsg_type = LTTNG_SOCK_CREDS; | |
805 | cmptr->cmsg_len = CMSG_LEN(sizeof_cred); | |
806 | ||
807 | creds = (lttng_sock_cred*) CMSG_DATA(cmptr); | |
808 | ||
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__ */ | |
813 | ||
814 | do { | |
815 | ret = sendmsg(sock, &msg, 0); | |
816 | } while (ret < 0 && errno == EINTR); | |
817 | if (ret < 0) { | |
818 | /* | |
819 | * Only warn about EPIPE when quiet mode is deactivated. | |
820 | * We consider EPIPE as expected. | |
821 | */ | |
822 | if (errno != EPIPE || !lttng_opt_quiet) { | |
823 | PERROR("sendmsg"); | |
824 | } | |
825 | } | |
826 | return ret; | |
827 | } | |
828 | ||
829 | /* | |
830 | * Recv a message accompanied with credentials from a unix socket. | |
831 | * | |
832 | * Returns the size of received data, or negative error value. | |
833 | */ | |
90e535ef | 834 | LTTNG_HIDDEN |
0d37f2bc DG |
835 | ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len, |
836 | lttng_sock_cred *creds) | |
837 | { | |
838 | struct msghdr msg; | |
839 | struct iovec iov[1]; | |
840 | ssize_t ret; | |
4100e49a | 841 | size_t len_last; |
0d37f2bc DG |
842 | #ifdef __linux__ |
843 | struct cmsghdr *cmptr; | |
844 | size_t sizeof_cred = sizeof(lttng_sock_cred); | |
845 | char anc_buf[CMSG_SPACE(sizeof_cred)]; | |
846 | #endif /* __linux__ */ | |
847 | ||
848 | memset(&msg, 0, sizeof(msg)); | |
849 | ||
850 | /* Not allowed */ | |
851 | if (creds == NULL) { | |
852 | ret = -1; | |
853 | goto end; | |
854 | } | |
855 | ||
856 | /* Prepare to receive the structures */ | |
857 | iov[0].iov_base = buf; | |
858 | iov[0].iov_len = len; | |
859 | msg.msg_iov = iov; | |
860 | msg.msg_iovlen = 1; | |
861 | ||
862 | #ifdef __linux__ | |
863 | msg.msg_control = anc_buf; | |
864 | msg.msg_controllen = sizeof(anc_buf); | |
865 | #endif /* __linux__ */ | |
866 | ||
867 | do { | |
4100e49a | 868 | len_last = iov[0].iov_len; |
0d37f2bc | 869 | ret = recvmsg(sock, &msg, 0); |
4100e49a DG |
870 | if (ret > 0) { |
871 | iov[0].iov_base += ret; | |
872 | iov[0].iov_len -= ret; | |
873 | assert(ret <= len_last); | |
874 | } | |
875 | } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR)); | |
0d37f2bc DG |
876 | if (ret < 0) { |
877 | PERROR("recvmsg fds"); | |
878 | goto end; | |
4100e49a DG |
879 | } else if (ret > 0) { |
880 | ret = len; | |
0d37f2bc | 881 | } |
4100e49a | 882 | /* Else ret = 0 meaning an orderly shutdown. */ |
0d37f2bc DG |
883 | |
884 | #ifdef __linux__ | |
885 | if (msg.msg_flags & MSG_CTRUNC) { | |
886 | fprintf(stderr, "Error: Control message truncated.\n"); | |
887 | ret = -1; | |
888 | goto end; | |
889 | } | |
890 | ||
891 | cmptr = CMSG_FIRSTHDR(&msg); | |
892 | if (cmptr == NULL) { | |
893 | fprintf(stderr, "Error: Invalid control message header\n"); | |
894 | ret = -1; | |
895 | goto end; | |
896 | } | |
897 | ||
898 | if (cmptr->cmsg_level != SOL_SOCKET || | |
899 | cmptr->cmsg_type != LTTNG_SOCK_CREDS) { | |
900 | fprintf(stderr, "Didn't received any credentials\n"); | |
901 | ret = -1; | |
902 | goto end; | |
903 | } | |
904 | ||
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)); | |
908 | ret = -1; | |
909 | goto end; | |
910 | } | |
911 | ||
912 | memcpy(creds, CMSG_DATA(cmptr), sizeof_cred); | |
bfa419e4 | 913 | #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__)) |
0d37f2bc DG |
914 | { |
915 | int peer_ret; | |
916 | ||
917 | peer_ret = getpeereid(sock, &creds->uid, &creds->gid); | |
918 | if (peer_ret != 0) { | |
919 | return peer_ret; | |
920 | } | |
921 | } | |
922 | #else | |
923 | #error "Please implement credential support for your OS." | |
924 | #endif /* __linux__ */ | |
925 | ||
926 | end: | |
927 | return ret; | |
928 | } | |
929 | ||
930 | /* | |
931 | * Set socket option to use credentials passing. | |
932 | */ | |
933 | #ifdef __linux__ | |
90e535ef | 934 | LTTNG_HIDDEN |
0d37f2bc DG |
935 | int lttcomm_setsockopt_creds_unix_sock(int sock) |
936 | { | |
937 | int ret, on = 1; | |
938 | ||
939 | /* Set socket for credentials retrieval */ | |
940 | ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); | |
941 | if (ret < 0) { | |
942 | PERROR("setsockopt creds unix sock"); | |
943 | } | |
944 | return ret; | |
945 | } | |
bfa419e4 | 946 | #elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__)) |
90e535ef | 947 | LTTNG_HIDDEN |
0d37f2bc DG |
948 | int lttcomm_setsockopt_creds_unix_sock(int sock) |
949 | { | |
950 | return 0; | |
951 | } | |
952 | #else | |
953 | #error "Please implement credential support for your OS." | |
954 | #endif /* __linux__ */ |