Commit | Line | Data |
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0d37f2bc DG |
1 | /* |
2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> | |
3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License, version 2 only, | |
7 | * as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along | |
15 | * with this program; if not, write to the Free Software Foundation, Inc., | |
16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
17 | */ | |
18 | ||
19 | #define _GNU_SOURCE | |
20 | #include <assert.h> | |
21 | #include <limits.h> | |
22 | #include <stdio.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <sys/stat.h> | |
26 | #include <sys/types.h> | |
27 | #include <unistd.h> | |
28 | #include <errno.h> | |
29 | ||
30 | #include <common/defaults.h> | |
31 | #include <common/error.h> | |
32 | ||
33 | #include "unix.h" | |
34 | ||
35 | /* | |
36 | * Connect to unix socket using the path name. | |
37 | */ | |
38 | int lttcomm_connect_unix_sock(const char *pathname) | |
39 | { | |
40 | struct sockaddr_un sun; | |
41 | int fd, ret, closeret; | |
42 | ||
43 | fd = socket(PF_UNIX, SOCK_STREAM, 0); | |
44 | if (fd < 0) { | |
45 | PERROR("socket"); | |
46 | ret = fd; | |
47 | goto error; | |
48 | } | |
49 | ||
50 | memset(&sun, 0, sizeof(sun)); | |
51 | sun.sun_family = AF_UNIX; | |
52 | strncpy(sun.sun_path, pathname, sizeof(sun.sun_path)); | |
53 | sun.sun_path[sizeof(sun.sun_path) - 1] = '\0'; | |
54 | ||
55 | ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun)); | |
56 | if (ret < 0) { | |
57 | /* | |
58 | * Don't print message on connect error, because connect is used in | |
59 | * normal execution to detect if sessiond is alive. | |
60 | */ | |
61 | goto error_connect; | |
62 | } | |
63 | ||
64 | return fd; | |
65 | ||
66 | error_connect: | |
67 | closeret = close(fd); | |
68 | if (closeret) { | |
69 | PERROR("close"); | |
70 | } | |
71 | error: | |
72 | return ret; | |
73 | } | |
74 | ||
75 | /* | |
76 | * Do an accept(2) on the sock and return the new file descriptor. The socket | |
77 | * MUST be bind(2) before. | |
78 | */ | |
79 | int lttcomm_accept_unix_sock(int sock) | |
80 | { | |
81 | int new_fd; | |
82 | struct sockaddr_un sun; | |
83 | socklen_t len = 0; | |
84 | ||
85 | /* Blocking call */ | |
86 | new_fd = accept(sock, (struct sockaddr *) &sun, &len); | |
87 | if (new_fd < 0) { | |
88 | PERROR("accept"); | |
89 | } | |
90 | ||
91 | return new_fd; | |
92 | } | |
93 | ||
94 | /* | |
95 | * Creates a AF_UNIX local socket using pathname bind the socket upon creation | |
96 | * and return the fd. | |
97 | */ | |
98 | int lttcomm_create_unix_sock(const char *pathname) | |
99 | { | |
100 | struct sockaddr_un sun; | |
101 | int fd; | |
102 | int ret = -1; | |
103 | ||
104 | /* Create server socket */ | |
105 | if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) { | |
106 | PERROR("socket"); | |
107 | goto error; | |
108 | } | |
109 | ||
110 | memset(&sun, 0, sizeof(sun)); | |
111 | sun.sun_family = AF_UNIX; | |
112 | strncpy(sun.sun_path, pathname, sizeof(sun.sun_path)); | |
113 | sun.sun_path[sizeof(sun.sun_path) - 1] = '\0'; | |
114 | ||
115 | /* Unlink the old file if present */ | |
116 | (void) unlink(pathname); | |
117 | ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun)); | |
118 | if (ret < 0) { | |
119 | PERROR("bind"); | |
120 | goto error; | |
121 | } | |
122 | ||
123 | return fd; | |
124 | ||
125 | error: | |
126 | return ret; | |
127 | } | |
128 | ||
129 | /* | |
130 | * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN. | |
131 | */ | |
132 | int lttcomm_listen_unix_sock(int sock) | |
133 | { | |
134 | int ret; | |
135 | ||
136 | ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN); | |
137 | if (ret < 0) { | |
138 | PERROR("listen"); | |
139 | } | |
140 | ||
141 | return ret; | |
142 | } | |
143 | ||
144 | /* | |
145 | * Receive data of size len in put that data into the buf param. Using recvmsg | |
146 | * API. | |
147 | * | |
148 | * Return the size of received data. | |
149 | */ | |
150 | ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len) | |
151 | { | |
152 | struct msghdr msg; | |
153 | struct iovec iov[1]; | |
154 | ssize_t ret = -1; | |
155 | ||
156 | memset(&msg, 0, sizeof(msg)); | |
157 | ||
158 | iov[0].iov_base = buf; | |
159 | iov[0].iov_len = len; | |
160 | msg.msg_iov = iov; | |
161 | msg.msg_iovlen = 1; | |
162 | ||
163 | do { | |
164 | ret = recvmsg(sock, &msg, MSG_WAITALL); | |
165 | } while (ret < 0 && errno == EINTR); | |
166 | if (ret < 0) { | |
167 | PERROR("recvmsg"); | |
168 | } | |
169 | ||
170 | return ret; | |
171 | } | |
172 | ||
173 | /* | |
174 | * Send buf data of size len. Using sendmsg API. | |
175 | * | |
176 | * Return the size of sent data. | |
177 | */ | |
178 | ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len) | |
179 | { | |
180 | struct msghdr msg; | |
181 | struct iovec iov[1]; | |
182 | ssize_t ret = -1; | |
183 | ||
184 | memset(&msg, 0, sizeof(msg)); | |
185 | ||
186 | iov[0].iov_base = buf; | |
187 | iov[0].iov_len = len; | |
188 | msg.msg_iov = iov; | |
189 | msg.msg_iovlen = 1; | |
190 | ||
191 | ret = sendmsg(sock, &msg, 0); | |
192 | if (ret < 0) { | |
193 | /* | |
194 | * Only warn about EPIPE when quiet mode is deactivated. | |
195 | * We consider EPIPE as expected. | |
196 | */ | |
197 | if (errno != EPIPE || !lttng_opt_quiet) { | |
198 | PERROR("sendmsg"); | |
199 | } | |
200 | } | |
201 | ||
202 | return ret; | |
203 | } | |
204 | ||
205 | /* | |
206 | * Shutdown cleanly a unix socket. | |
207 | */ | |
208 | int lttcomm_close_unix_sock(int sock) | |
209 | { | |
210 | int ret, closeret; | |
211 | ||
212 | /* Shutdown receptions and transmissions */ | |
213 | ret = shutdown(sock, SHUT_RDWR); | |
214 | if (ret < 0) { | |
215 | PERROR("shutdown"); | |
216 | } | |
217 | ||
218 | closeret = close(sock); | |
219 | if (closeret) { | |
220 | PERROR("close"); | |
221 | } | |
222 | ||
223 | return ret; | |
224 | } | |
225 | ||
226 | /* | |
227 | * Send a message accompanied by fd(s) over a unix socket. | |
228 | * | |
229 | * Returns the size of data sent, or negative error value. | |
230 | */ | |
231 | ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd) | |
232 | { | |
233 | struct msghdr msg; | |
234 | struct cmsghdr *cmptr; | |
235 | struct iovec iov[1]; | |
236 | ssize_t ret = -1; | |
237 | unsigned int sizeof_fds = nb_fd * sizeof(int); | |
238 | char tmp[CMSG_SPACE(sizeof_fds)]; | |
239 | char dummy = 0; | |
240 | ||
241 | memset(&msg, 0, sizeof(msg)); | |
242 | ||
243 | if (nb_fd > LTTCOMM_MAX_SEND_FDS) | |
244 | return -EINVAL; | |
245 | ||
246 | msg.msg_control = (caddr_t)tmp; | |
247 | msg.msg_controllen = CMSG_LEN(sizeof_fds); | |
248 | ||
249 | cmptr = CMSG_FIRSTHDR(&msg); | |
250 | cmptr->cmsg_level = SOL_SOCKET; | |
251 | cmptr->cmsg_type = SCM_RIGHTS; | |
252 | cmptr->cmsg_len = CMSG_LEN(sizeof_fds); | |
253 | memcpy(CMSG_DATA(cmptr), fds, sizeof_fds); | |
254 | /* Sum of the length of all control messages in the buffer: */ | |
255 | msg.msg_controllen = cmptr->cmsg_len; | |
256 | ||
257 | iov[0].iov_base = &dummy; | |
258 | iov[0].iov_len = 1; | |
259 | msg.msg_iov = iov; | |
260 | msg.msg_iovlen = 1; | |
261 | ||
262 | do { | |
263 | ret = sendmsg(sock, &msg, 0); | |
264 | } while (ret < 0 && errno == EINTR); | |
265 | if (ret < 0) { | |
266 | /* | |
267 | * Only warn about EPIPE when quiet mode is deactivated. | |
268 | * We consider EPIPE as expected. | |
269 | */ | |
270 | if (errno != EPIPE || !lttng_opt_quiet) { | |
271 | PERROR("sendmsg"); | |
272 | } | |
273 | } | |
274 | return ret; | |
275 | } | |
276 | ||
277 | /* | |
278 | * Recv a message accompanied by fd(s) from a unix socket. | |
279 | * | |
280 | * Returns the size of received data, or negative error value. | |
281 | * | |
282 | * Expect at most "nb_fd" file descriptors. Returns the number of fd | |
283 | * actually received in nb_fd. | |
284 | */ | |
285 | ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd) | |
286 | { | |
287 | struct iovec iov[1]; | |
288 | ssize_t ret = 0; | |
289 | struct cmsghdr *cmsg; | |
290 | size_t sizeof_fds = nb_fd * sizeof(int); | |
291 | char recv_fd[CMSG_SPACE(sizeof_fds)]; | |
292 | struct msghdr msg; | |
293 | char dummy; | |
294 | ||
295 | memset(&msg, 0, sizeof(msg)); | |
296 | ||
297 | /* Prepare to receive the structures */ | |
298 | iov[0].iov_base = &dummy; | |
299 | iov[0].iov_len = 1; | |
300 | msg.msg_iov = iov; | |
301 | msg.msg_iovlen = 1; | |
302 | msg.msg_control = recv_fd; | |
303 | msg.msg_controllen = sizeof(recv_fd); | |
304 | ||
305 | do { | |
306 | ret = recvmsg(sock, &msg, 0); | |
307 | } while (ret < 0 && errno == EINTR); | |
308 | if (ret < 0) { | |
309 | PERROR("recvmsg fds"); | |
310 | goto end; | |
311 | } | |
312 | if (ret != 1) { | |
313 | fprintf(stderr, "Error: Received %zd bytes, expected %d\n", | |
314 | ret, 1); | |
315 | goto end; | |
316 | } | |
317 | if (msg.msg_flags & MSG_CTRUNC) { | |
318 | fprintf(stderr, "Error: Control message truncated.\n"); | |
319 | ret = -1; | |
320 | goto end; | |
321 | } | |
322 | cmsg = CMSG_FIRSTHDR(&msg); | |
323 | if (!cmsg) { | |
324 | fprintf(stderr, "Error: Invalid control message header\n"); | |
325 | ret = -1; | |
326 | goto end; | |
327 | } | |
328 | if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) { | |
329 | fprintf(stderr, "Didn't received any fd\n"); | |
330 | ret = -1; | |
331 | goto end; | |
332 | } | |
333 | if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) { | |
334 | fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n", | |
335 | (size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds)); | |
336 | ret = -1; | |
337 | goto end; | |
338 | } | |
339 | memcpy(fds, CMSG_DATA(cmsg), sizeof_fds); | |
340 | ret = sizeof_fds; | |
341 | end: | |
342 | return ret; | |
343 | } | |
344 | ||
345 | /* | |
346 | * Send a message with credentials over a unix socket. | |
347 | * | |
348 | * Returns the size of data sent, or negative error value. | |
349 | */ | |
350 | ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len) | |
351 | { | |
352 | struct msghdr msg; | |
353 | struct iovec iov[1]; | |
354 | ssize_t ret = -1; | |
355 | #ifdef __linux__ | |
356 | struct cmsghdr *cmptr; | |
357 | size_t sizeof_cred = sizeof(lttng_sock_cred); | |
358 | char anc_buf[CMSG_SPACE(sizeof_cred)]; | |
359 | lttng_sock_cred *creds; | |
360 | #endif /* __linux__ */ | |
361 | ||
362 | memset(&msg, 0, sizeof(msg)); | |
363 | ||
364 | iov[0].iov_base = buf; | |
365 | iov[0].iov_len = len; | |
366 | msg.msg_iov = iov; | |
367 | msg.msg_iovlen = 1; | |
368 | ||
369 | #ifdef __linux__ | |
370 | msg.msg_control = (caddr_t) anc_buf; | |
371 | msg.msg_controllen = CMSG_LEN(sizeof_cred); | |
372 | ||
373 | cmptr = CMSG_FIRSTHDR(&msg); | |
374 | cmptr->cmsg_level = SOL_SOCKET; | |
375 | cmptr->cmsg_type = LTTNG_SOCK_CREDS; | |
376 | cmptr->cmsg_len = CMSG_LEN(sizeof_cred); | |
377 | ||
378 | creds = (lttng_sock_cred*) CMSG_DATA(cmptr); | |
379 | ||
380 | LTTNG_SOCK_SET_UID_CRED(creds, geteuid()); | |
381 | LTTNG_SOCK_SET_GID_CRED(creds, getegid()); | |
382 | LTTNG_SOCK_SET_PID_CRED(creds, getpid()); | |
383 | #endif /* __linux__ */ | |
384 | ||
385 | do { | |
386 | ret = sendmsg(sock, &msg, 0); | |
387 | } while (ret < 0 && errno == EINTR); | |
388 | if (ret < 0) { | |
389 | /* | |
390 | * Only warn about EPIPE when quiet mode is deactivated. | |
391 | * We consider EPIPE as expected. | |
392 | */ | |
393 | if (errno != EPIPE || !lttng_opt_quiet) { | |
394 | PERROR("sendmsg"); | |
395 | } | |
396 | } | |
397 | return ret; | |
398 | } | |
399 | ||
400 | /* | |
401 | * Recv a message accompanied with credentials from a unix socket. | |
402 | * | |
403 | * Returns the size of received data, or negative error value. | |
404 | */ | |
405 | ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len, | |
406 | lttng_sock_cred *creds) | |
407 | { | |
408 | struct msghdr msg; | |
409 | struct iovec iov[1]; | |
410 | ssize_t ret; | |
411 | #ifdef __linux__ | |
412 | struct cmsghdr *cmptr; | |
413 | size_t sizeof_cred = sizeof(lttng_sock_cred); | |
414 | char anc_buf[CMSG_SPACE(sizeof_cred)]; | |
415 | #endif /* __linux__ */ | |
416 | ||
417 | memset(&msg, 0, sizeof(msg)); | |
418 | ||
419 | /* Not allowed */ | |
420 | if (creds == NULL) { | |
421 | ret = -1; | |
422 | goto end; | |
423 | } | |
424 | ||
425 | /* Prepare to receive the structures */ | |
426 | iov[0].iov_base = buf; | |
427 | iov[0].iov_len = len; | |
428 | msg.msg_iov = iov; | |
429 | msg.msg_iovlen = 1; | |
430 | ||
431 | #ifdef __linux__ | |
432 | msg.msg_control = anc_buf; | |
433 | msg.msg_controllen = sizeof(anc_buf); | |
434 | #endif /* __linux__ */ | |
435 | ||
436 | do { | |
437 | ret = recvmsg(sock, &msg, 0); | |
438 | } while (ret < 0 && errno == EINTR); | |
439 | if (ret < 0) { | |
440 | PERROR("recvmsg fds"); | |
441 | goto end; | |
442 | } | |
443 | ||
444 | #ifdef __linux__ | |
445 | if (msg.msg_flags & MSG_CTRUNC) { | |
446 | fprintf(stderr, "Error: Control message truncated.\n"); | |
447 | ret = -1; | |
448 | goto end; | |
449 | } | |
450 | ||
451 | cmptr = CMSG_FIRSTHDR(&msg); | |
452 | if (cmptr == NULL) { | |
453 | fprintf(stderr, "Error: Invalid control message header\n"); | |
454 | ret = -1; | |
455 | goto end; | |
456 | } | |
457 | ||
458 | if (cmptr->cmsg_level != SOL_SOCKET || | |
459 | cmptr->cmsg_type != LTTNG_SOCK_CREDS) { | |
460 | fprintf(stderr, "Didn't received any credentials\n"); | |
461 | ret = -1; | |
462 | goto end; | |
463 | } | |
464 | ||
465 | if (cmptr->cmsg_len != CMSG_LEN(sizeof_cred)) { | |
466 | fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n", | |
467 | (size_t) cmptr->cmsg_len, (size_t) CMSG_LEN(sizeof_cred)); | |
468 | ret = -1; | |
469 | goto end; | |
470 | } | |
471 | ||
472 | memcpy(creds, CMSG_DATA(cmptr), sizeof_cred); | |
473 | #elif (defined(__FreeBSD__) || defined(__CYGWIN__)) | |
474 | { | |
475 | int peer_ret; | |
476 | ||
477 | peer_ret = getpeereid(sock, &creds->uid, &creds->gid); | |
478 | if (peer_ret != 0) { | |
479 | return peer_ret; | |
480 | } | |
481 | } | |
482 | #else | |
483 | #error "Please implement credential support for your OS." | |
484 | #endif /* __linux__ */ | |
485 | ||
486 | end: | |
487 | return ret; | |
488 | } | |
489 | ||
490 | /* | |
491 | * Set socket option to use credentials passing. | |
492 | */ | |
493 | #ifdef __linux__ | |
494 | int lttcomm_setsockopt_creds_unix_sock(int sock) | |
495 | { | |
496 | int ret, on = 1; | |
497 | ||
498 | /* Set socket for credentials retrieval */ | |
499 | ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); | |
500 | if (ret < 0) { | |
501 | PERROR("setsockopt creds unix sock"); | |
502 | } | |
503 | return ret; | |
504 | } | |
505 | #elif (defined(__FreeBSD__) || defined(__CYGWIN__)) | |
506 | int lttcomm_setsockopt_creds_unix_sock(int sock) | |
507 | { | |
508 | return 0; | |
509 | } | |
510 | #else | |
511 | #error "Please implement credential support for your OS." | |
512 | #endif /* __linux__ */ |