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a7e3212d LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2013 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <endian.h> | |
23 | #include <assert.h> | |
24 | #include <stdlib.h> | |
25 | #include <unistd.h> | |
26 | #include <sys/poll.h> | |
27 | #include <byteswap.h> | |
28 | ||
29 | #include "util.h" | |
30 | #include "macro.h" | |
31 | #include "missing.h" | |
32 | #include "strv.h" | |
2181a7f5 | 33 | #include "utf8.h" |
a7e3212d LP |
34 | |
35 | #include "sd-bus.h" | |
36 | #include "bus-socket.h" | |
37 | #include "bus-internal.h" | |
38 | #include "bus-message.h" | |
39 | ||
2181a7f5 | 40 | static void iovec_advance(struct iovec iov[], unsigned *idx, size_t size) { |
a7e3212d LP |
41 | |
42 | while (size > 0) { | |
43 | struct iovec *i = iov + *idx; | |
44 | ||
45 | if (i->iov_len > size) { | |
46 | i->iov_base = (uint8_t*) i->iov_base + size; | |
47 | i->iov_len -= size; | |
48 | return; | |
49 | } | |
50 | ||
51 | size -= i->iov_len; | |
52 | ||
53 | i->iov_base = NULL; | |
54 | i->iov_len = 0; | |
55 | ||
56 | (*idx) ++; | |
57 | } | |
58 | } | |
59 | ||
2181a7f5 LP |
60 | bool bus_socket_auth_needs_write(sd_bus *b) { |
61 | ||
62 | unsigned i; | |
63 | ||
64 | if (b->auth_index >= ELEMENTSOF(b->auth_iovec)) | |
65 | return false; | |
66 | ||
67 | for (i = b->auth_index; i < ELEMENTSOF(b->auth_iovec); i++) { | |
68 | struct iovec *j = b->auth_iovec + i; | |
69 | ||
70 | if (j->iov_len > 0) | |
71 | return true; | |
72 | } | |
73 | ||
74 | return false; | |
75 | } | |
76 | ||
a7e3212d LP |
77 | static int bus_socket_write_auth(sd_bus *b) { |
78 | struct msghdr mh; | |
79 | ssize_t k; | |
80 | ||
81 | assert(b); | |
82 | assert(b->state == BUS_AUTHENTICATING); | |
83 | ||
2181a7f5 | 84 | if (!bus_socket_auth_needs_write(b)) |
a7e3212d LP |
85 | return 0; |
86 | ||
a7e3212d LP |
87 | zero(mh); |
88 | mh.msg_iov = b->auth_iovec + b->auth_index; | |
89 | mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index; | |
90 | ||
91 | k = sendmsg(b->fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
92 | if (k < 0) | |
93 | return errno == EAGAIN ? 0 : -errno; | |
94 | ||
95 | iovec_advance(b->auth_iovec, &b->auth_index, (size_t) k); | |
96 | ||
97 | return 1; | |
98 | } | |
99 | ||
2181a7f5 | 100 | static int bus_socket_auth_verify_client(sd_bus *b) { |
a7e3212d LP |
101 | char *e, *f, *start; |
102 | sd_id128_t peer; | |
103 | unsigned i; | |
104 | int r; | |
105 | ||
2181a7f5 LP |
106 | assert(b); |
107 | ||
a7e3212d LP |
108 | /* We expect two response lines: "OK" and possibly |
109 | * "AGREE_UNIX_FD" */ | |
110 | ||
111 | e = memmem(b->rbuffer, b->rbuffer_size, "\r\n", 2); | |
112 | if (!e) | |
113 | return 0; | |
114 | ||
115 | if (b->negotiate_fds) { | |
116 | f = memmem(e + 2, b->rbuffer_size - (e - (char*) b->rbuffer) - 2, "\r\n", 2); | |
117 | if (!f) | |
118 | return 0; | |
119 | ||
120 | start = f + 2; | |
121 | } else { | |
122 | f = NULL; | |
123 | start = e + 2; | |
124 | } | |
125 | ||
126 | /* Nice! We got all the lines we need. First check the OK | |
127 | * line */ | |
128 | ||
129 | if (e - (char*) b->rbuffer != 3 + 32) | |
130 | return -EPERM; | |
131 | ||
132 | if (memcmp(b->rbuffer, "OK ", 3)) | |
133 | return -EPERM; | |
134 | ||
2181a7f5 LP |
135 | b->auth = b->anonymous_auth ? BUS_AUTH_ANONYMOUS : BUS_AUTH_EXTERNAL; |
136 | ||
a7e3212d LP |
137 | for (i = 0; i < 32; i += 2) { |
138 | int x, y; | |
139 | ||
140 | x = unhexchar(((char*) b->rbuffer)[3 + i]); | |
141 | y = unhexchar(((char*) b->rbuffer)[3 + i + 1]); | |
142 | ||
143 | if (x < 0 || y < 0) | |
144 | return -EINVAL; | |
145 | ||
146 | peer.bytes[i/2] = ((uint8_t) x << 4 | (uint8_t) y); | |
147 | } | |
148 | ||
149 | if (!sd_id128_equal(b->peer, SD_ID128_NULL) && | |
150 | !sd_id128_equal(b->peer, peer)) | |
151 | return -EPERM; | |
152 | ||
153 | b->peer = peer; | |
154 | ||
155 | /* And possibly check the second line, too */ | |
156 | ||
157 | if (f) | |
158 | b->can_fds = | |
159 | (f - e == sizeof("\r\nAGREE_UNIX_FD") - 1) && | |
160 | memcmp(e + 2, "AGREE_UNIX_FD", sizeof("AGREE_UNIX_FD") - 1) == 0; | |
161 | ||
162 | b->rbuffer_size -= (start - (char*) b->rbuffer); | |
163 | memmove(b->rbuffer, start, b->rbuffer_size); | |
164 | ||
165 | r = bus_start_running(b); | |
166 | if (r < 0) | |
167 | return r; | |
168 | ||
169 | return 1; | |
170 | } | |
171 | ||
2181a7f5 LP |
172 | static bool line_equals(const char *s, size_t m, const char *line) { |
173 | size_t l; | |
174 | ||
175 | l = strlen(line); | |
176 | if (l != m) | |
177 | return false; | |
178 | ||
179 | return memcmp(s, line, l) == 0; | |
180 | } | |
181 | ||
182 | static bool line_begins(const char *s, size_t m, const char *word) { | |
183 | size_t l; | |
184 | ||
185 | l = strlen(word); | |
186 | if (m < l) | |
187 | return false; | |
188 | ||
189 | if (memcmp(s, word, l) != 0) | |
190 | return false; | |
191 | ||
192 | return m == l || (m > l && s[l] == ' '); | |
193 | } | |
194 | ||
195 | static int verify_anonymous_token(sd_bus *b, const char *p, size_t l) { | |
196 | _cleanup_free_ char *token = NULL; | |
197 | ||
198 | if (!b->anonymous_auth) | |
199 | return 0; | |
200 | ||
201 | if (l <= 0) | |
202 | return 1; | |
203 | ||
204 | assert(p[0] == ' '); | |
205 | p++; l--; | |
206 | ||
207 | if (l % 2 != 0) | |
208 | return 0; | |
209 | token = unhexmem(p, l); | |
210 | if (!token) | |
211 | return -ENOMEM; | |
212 | ||
213 | if (memchr(token, 0, l/2)) | |
214 | return 0; | |
215 | ||
216 | return !!utf8_is_valid(token); | |
217 | } | |
218 | ||
219 | static int verify_external_token(sd_bus *b, const char *p, size_t l) { | |
220 | _cleanup_free_ char *token = NULL; | |
221 | uid_t u; | |
222 | int r; | |
223 | ||
224 | /* We don't do any real authentication here. Instead, we if | |
225 | * the owner of this bus wanted authentication he should have | |
226 | * checked SO_PEERCRED before even creating the bus object. */ | |
227 | ||
228 | if (!b->ucred_valid) | |
229 | return 0; | |
230 | ||
231 | if (l <= 0) | |
232 | return 1; | |
233 | ||
234 | assert(p[0] == ' '); | |
235 | p++; l--; | |
236 | ||
237 | if (l % 2 != 0) | |
238 | return 0; | |
239 | ||
240 | token = unhexmem(p, l); | |
241 | if (!token) | |
242 | return -ENOMEM; | |
243 | ||
244 | if (memchr(token, 0, l/2)) | |
245 | return 0; | |
246 | ||
247 | r = parse_uid(token, &u); | |
248 | if (r < 0) | |
249 | return 0; | |
250 | ||
251 | if (u != b->ucred.uid) | |
252 | return 0; | |
253 | ||
254 | return 1; | |
255 | } | |
256 | ||
257 | static int bus_socket_auth_write(sd_bus *b, const char *t) { | |
258 | char *p; | |
259 | size_t l; | |
260 | ||
261 | assert(b); | |
262 | assert(t); | |
263 | ||
264 | /* We only make use of the first iovec */ | |
265 | assert(b->auth_index == 0 || b->auth_index == 1); | |
266 | ||
267 | l = strlen(t); | |
268 | p = malloc(b->auth_iovec[0].iov_len + l); | |
269 | if (!p) | |
270 | return -ENOMEM; | |
271 | ||
272 | memcpy(p, b->auth_iovec[0].iov_base, b->auth_iovec[0].iov_len); | |
273 | memcpy(p + b->auth_iovec[0].iov_len, t, l); | |
274 | ||
275 | b->auth_iovec[0].iov_base = p; | |
276 | b->auth_iovec[0].iov_len += l; | |
277 | ||
278 | free(b->auth_buffer); | |
279 | b->auth_buffer = p; | |
280 | b->auth_index = 0; | |
281 | return 0; | |
282 | } | |
283 | ||
284 | static int bus_socket_auth_write_ok(sd_bus *b) { | |
285 | char t[3 + 32 + 2 + 1]; | |
286 | ||
287 | assert(b); | |
288 | ||
289 | snprintf(t, sizeof(t), "OK " SD_ID128_FORMAT_STR "\r\n", SD_ID128_FORMAT_VAL(b->peer)); | |
290 | char_array_0(t); | |
291 | ||
292 | return bus_socket_auth_write(b, t); | |
293 | } | |
294 | ||
295 | static int bus_socket_auth_verify_server(sd_bus *b) { | |
296 | char *e; | |
297 | const char *line; | |
298 | size_t l; | |
299 | bool processed = false; | |
300 | int r; | |
301 | ||
302 | assert(b); | |
303 | ||
304 | if (b->rbuffer_size < 3) | |
305 | return 0; | |
306 | ||
307 | /* First char must be a NUL byte */ | |
308 | if (*(char*) b->rbuffer != 0) | |
309 | return -EIO; | |
310 | ||
311 | /* Begin with the first line */ | |
312 | if (b->auth_rbegin <= 0) | |
313 | b->auth_rbegin = 1; | |
314 | ||
315 | for (;;) { | |
316 | /* Check if line is complete */ | |
317 | line = (char*) b->rbuffer + b->auth_rbegin; | |
318 | e = memmem(line, b->rbuffer_size - b->auth_rbegin, "\r\n", 2); | |
319 | if (!e) | |
320 | return processed; | |
321 | ||
322 | l = e - line; | |
323 | ||
324 | if (line_begins(line, l, "AUTH ANONYMOUS")) { | |
325 | ||
326 | r = verify_anonymous_token(b, line + 14, l - 14); | |
327 | if (r < 0) | |
328 | return r; | |
329 | if (r == 0) | |
330 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
331 | else { | |
332 | b->auth = BUS_AUTH_ANONYMOUS; | |
333 | r = bus_socket_auth_write_ok(b); | |
334 | } | |
335 | ||
336 | } else if (line_begins(line, l, "AUTH EXTERNAL")) { | |
337 | ||
338 | r = verify_external_token(b, line + 13, l - 13); | |
339 | if (r < 0) | |
340 | return r; | |
341 | if (r == 0) | |
342 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
343 | else { | |
344 | b->auth = BUS_AUTH_EXTERNAL; | |
345 | r = bus_socket_auth_write_ok(b); | |
346 | } | |
347 | ||
348 | } else if (line_begins(line, l, "AUTH")) | |
349 | r = bus_socket_auth_write(b, "REJECTED EXTERNAL ANONYMOUS\r\n"); | |
350 | else if (line_equals(line, l, "CANCEL") || | |
351 | line_begins(line, l, "ERROR")) { | |
352 | ||
353 | b->auth = _BUS_AUTH_INVALID; | |
354 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
355 | ||
356 | } else if (line_equals(line, l, "BEGIN")) { | |
357 | ||
358 | if (b->auth == _BUS_AUTH_INVALID) | |
359 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
360 | else { | |
361 | /* We can't leave from the auth phase | |
362 | * before we haven't written | |
363 | * everything queued, so let's check | |
364 | * that */ | |
365 | ||
366 | if (bus_socket_auth_needs_write(b)) | |
367 | return 1; | |
368 | ||
369 | b->rbuffer_size -= (e + 2 - (char*) b->rbuffer); | |
370 | memmove(b->rbuffer, e + 2, b->rbuffer_size); | |
371 | return bus_start_running(b); | |
372 | } | |
373 | ||
374 | } else if (line_begins(line, l, "DATA")) { | |
375 | ||
376 | if (b->auth == _BUS_AUTH_INVALID) | |
377 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
378 | else { | |
379 | if (b->auth == BUS_AUTH_ANONYMOUS) | |
380 | r = verify_anonymous_token(b, line + 4, l - 4); | |
381 | else | |
382 | r = verify_external_token(b, line + 4, l - 4); | |
383 | ||
384 | if (r < 0) | |
385 | return r; | |
386 | if (r == 0) { | |
387 | b->auth = _BUS_AUTH_INVALID; | |
388 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
389 | } else | |
390 | r = bus_socket_auth_write_ok(b); | |
391 | } | |
392 | } else if (line_equals(line, l, "NEGOTIATE_UNIX_FD")) { | |
393 | if (b->auth == _BUS_AUTH_INVALID || !b->negotiate_fds) | |
394 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
395 | else { | |
396 | b->can_fds = true; | |
397 | r = bus_socket_auth_write(b, "AGREE_UNIX_FD\r\n"); | |
398 | } | |
399 | } else | |
400 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
401 | ||
402 | if (r < 0) | |
403 | return r; | |
404 | ||
405 | b->auth_rbegin = e + 2 - (char*) b->rbuffer; | |
406 | ||
407 | processed = true; | |
408 | } | |
409 | } | |
410 | ||
411 | static int bus_socket_auth_verify(sd_bus *b) { | |
412 | assert(b); | |
413 | ||
414 | if (b->is_server) | |
415 | return bus_socket_auth_verify_server(b); | |
416 | else | |
417 | return bus_socket_auth_verify_client(b); | |
418 | } | |
419 | ||
a7e3212d LP |
420 | static int bus_socket_read_auth(sd_bus *b) { |
421 | struct msghdr mh; | |
422 | struct iovec iov; | |
423 | size_t n; | |
424 | ssize_t k; | |
425 | int r; | |
426 | void *p; | |
2181a7f5 LP |
427 | union { |
428 | struct cmsghdr cmsghdr; | |
429 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
430 | CMSG_SPACE(sizeof(struct ucred)) + | |
431 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
432 | } control; | |
433 | struct cmsghdr *cmsg; | |
a7e3212d LP |
434 | |
435 | assert(b); | |
2181a7f5 | 436 | assert(b->state == BUS_AUTHENTICATING); |
a7e3212d LP |
437 | |
438 | r = bus_socket_auth_verify(b); | |
439 | if (r != 0) | |
440 | return r; | |
441 | ||
2181a7f5 | 442 | n = MAX(256, b->rbuffer_size * 2); |
a7e3212d LP |
443 | |
444 | if (n > BUS_AUTH_SIZE_MAX) | |
445 | n = BUS_AUTH_SIZE_MAX; | |
446 | ||
447 | if (b->rbuffer_size >= n) | |
448 | return -ENOBUFS; | |
449 | ||
450 | p = realloc(b->rbuffer, n); | |
451 | if (!p) | |
452 | return -ENOMEM; | |
453 | ||
454 | b->rbuffer = p; | |
455 | ||
456 | zero(iov); | |
457 | iov.iov_base = (uint8_t*) b->rbuffer + b->rbuffer_size; | |
458 | iov.iov_len = n - b->rbuffer_size; | |
459 | ||
460 | zero(mh); | |
461 | mh.msg_iov = &iov; | |
462 | mh.msg_iovlen = 1; | |
2181a7f5 LP |
463 | mh.msg_control = &control; |
464 | mh.msg_controllen = sizeof(control); | |
a7e3212d | 465 | |
2181a7f5 | 466 | k = recvmsg(b->fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); |
a7e3212d LP |
467 | if (k < 0) |
468 | return errno == EAGAIN ? 0 : -errno; | |
469 | if (k == 0) | |
470 | return -ECONNRESET; | |
471 | ||
472 | b->rbuffer_size += k; | |
473 | ||
2181a7f5 LP |
474 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { |
475 | if (cmsg->cmsg_level == SOL_SOCKET && | |
476 | cmsg->cmsg_type == SCM_RIGHTS) { | |
477 | int j; | |
478 | ||
479 | /* Whut? We received fds during the auth | |
480 | * protocol? Somebody is playing games with | |
481 | * us. Close them all, and fail */ | |
482 | j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
483 | close_many((int*) CMSG_DATA(cmsg), j); | |
484 | return -EIO; | |
485 | ||
486 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
487 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
488 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
489 | ||
490 | memcpy(&b->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
491 | b->ucred_valid = true; | |
492 | ||
493 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
494 | cmsg->cmsg_type == SCM_SECURITY) { | |
495 | ||
496 | size_t l; | |
497 | l = cmsg->cmsg_len - CMSG_LEN(0); | |
498 | memcpy(&b->label, CMSG_DATA(cmsg), l); | |
499 | b->label[l] = 0; | |
500 | } | |
501 | } | |
502 | ||
a7e3212d LP |
503 | r = bus_socket_auth_verify(b); |
504 | if (r != 0) | |
505 | return r; | |
506 | ||
507 | return 1; | |
508 | } | |
509 | ||
510 | static int bus_socket_setup(sd_bus *b) { | |
0f4b73c8 | 511 | int enable; |
a7e3212d LP |
512 | |
513 | assert(b); | |
514 | ||
d65ddaa4 LP |
515 | /* Enable SO_PASSCRED + SO_PASSEC. We try this on any |
516 | * socket, just in case. */ | |
0f4b73c8 LP |
517 | enable = !b->bus_client; |
518 | setsockopt(b->fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(enable)); | |
519 | setsockopt(b->fd, SOL_SOCKET, SO_PASSSEC, &enable, sizeof(enable)); | |
a7e3212d LP |
520 | |
521 | /* Increase the buffers to a MB */ | |
522 | fd_inc_rcvbuf(b->fd, 1024*1024); | |
523 | fd_inc_sndbuf(b->fd, 1024*1024); | |
524 | ||
525 | return 0; | |
526 | } | |
527 | ||
2181a7f5 | 528 | static int bus_socket_start_auth_client(sd_bus *b) { |
a7e3212d | 529 | size_t l; |
2181a7f5 | 530 | const char *auth_suffix, *auth_prefix; |
a7e3212d LP |
531 | |
532 | assert(b); | |
533 | ||
2181a7f5 LP |
534 | if (b->anonymous_auth) { |
535 | auth_prefix = "\0AUTH ANONYMOUS "; | |
a7e3212d | 536 | |
2181a7f5 LP |
537 | /* For ANONYMOUS auth we send some arbitrary "trace" string */ |
538 | l = 9; | |
539 | b->auth_buffer = hexmem("anonymous", l); | |
540 | } else { | |
541 | char text[20 + 1]; /* enough space for a 64bit integer plus NUL */ | |
a7e3212d | 542 | |
2181a7f5 | 543 | auth_prefix = "\0AUTH EXTERNAL "; |
a7e3212d | 544 | |
2181a7f5 LP |
545 | snprintf(text, sizeof(text), "%lu", (unsigned long) geteuid()); |
546 | char_array_0(text); | |
a7e3212d | 547 | |
2181a7f5 LP |
548 | l = strlen(text); |
549 | b->auth_buffer = hexmem(text, l); | |
550 | } | |
551 | ||
552 | if (!b->auth_buffer) | |
a7e3212d LP |
553 | return -ENOMEM; |
554 | ||
2181a7f5 LP |
555 | if (b->negotiate_fds) |
556 | auth_suffix = "\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n"; | |
557 | else | |
558 | auth_suffix = "\r\nBEGIN\r\n"; | |
a7e3212d LP |
559 | |
560 | b->auth_iovec[0].iov_base = (void*) auth_prefix; | |
2181a7f5 LP |
561 | b->auth_iovec[0].iov_len = 1 + strlen(auth_prefix + 1); |
562 | b->auth_iovec[1].iov_base = (void*) b->auth_buffer; | |
a7e3212d LP |
563 | b->auth_iovec[1].iov_len = l * 2; |
564 | b->auth_iovec[2].iov_base = (void*) auth_suffix; | |
565 | b->auth_iovec[2].iov_len = strlen(auth_suffix); | |
a7e3212d LP |
566 | |
567 | return bus_socket_write_auth(b); | |
568 | } | |
569 | ||
2181a7f5 LP |
570 | static int bus_socket_start_auth(sd_bus *b) { |
571 | int domain = 0, r; | |
572 | socklen_t sl; | |
573 | ||
574 | assert(b); | |
575 | ||
576 | b->state = BUS_AUTHENTICATING; | |
577 | b->auth_timeout = now(CLOCK_MONOTONIC) + BUS_DEFAULT_TIMEOUT; | |
578 | ||
579 | sl = sizeof(domain); | |
580 | r = getsockopt(b->fd, SOL_SOCKET, SO_DOMAIN, &domain, &sl); | |
581 | if (r < 0) | |
582 | return -errno; | |
583 | ||
584 | if (domain != AF_UNIX) | |
585 | b->negotiate_fds = false; | |
586 | ||
587 | if (b->is_server) | |
588 | return bus_socket_read_auth(b); | |
589 | else | |
590 | return bus_socket_start_auth_client(b); | |
591 | } | |
592 | ||
a7e3212d LP |
593 | int bus_socket_connect(sd_bus *b) { |
594 | int r; | |
595 | ||
596 | assert(b); | |
597 | assert(b->fd < 0); | |
598 | assert(b->sockaddr.sa.sa_family != AF_UNSPEC); | |
599 | ||
600 | b->fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); | |
601 | if (b->fd < 0) | |
602 | return -errno; | |
603 | ||
604 | r = bus_socket_setup(b); | |
605 | if (r < 0) | |
606 | return r; | |
607 | ||
608 | r = connect(b->fd, &b->sockaddr.sa, b->sockaddr_size); | |
609 | if (r < 0) { | |
610 | if (errno == EINPROGRESS) | |
611 | return 1; | |
612 | ||
613 | return -errno; | |
614 | } | |
615 | ||
616 | return bus_socket_start_auth(b); | |
617 | } | |
618 | ||
619 | int bus_socket_exec(sd_bus *b) { | |
620 | int s[2]; | |
621 | pid_t pid; | |
622 | ||
623 | assert(b); | |
624 | assert(b->fd < 0); | |
625 | assert(b->exec_path); | |
626 | ||
627 | b->fd = socketpair(AF_UNIX, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, s); | |
628 | if (b->fd < 0) | |
629 | return -errno; | |
630 | ||
631 | pid = fork(); | |
632 | if (pid < 0) { | |
633 | close_pipe(s); | |
634 | return -errno; | |
635 | } | |
636 | if (pid == 0) { | |
637 | /* Child */ | |
638 | ||
639 | close_all_fds(s, 2); | |
640 | close_nointr_nofail(s[0]); | |
641 | ||
642 | assert_se(dup3(s[1], STDIN_FILENO, 0) == STDIN_FILENO); | |
643 | assert_se(dup3(s[1], STDOUT_FILENO, 0) == STDOUT_FILENO); | |
644 | ||
645 | if (s[1] != STDIN_FILENO && s[1] != STDOUT_FILENO) | |
646 | close_nointr_nofail(s[1]); | |
647 | ||
648 | fd_cloexec(STDIN_FILENO, false); | |
649 | fd_cloexec(STDOUT_FILENO, false); | |
650 | fd_nonblock(STDIN_FILENO, false); | |
651 | fd_nonblock(STDOUT_FILENO, false); | |
652 | ||
653 | if (b->exec_argv) | |
654 | execvp(b->exec_path, b->exec_argv); | |
655 | else { | |
656 | const char *argv[] = { b->exec_path, NULL }; | |
657 | execvp(b->exec_path, (char**) argv); | |
658 | } | |
659 | ||
660 | _exit(EXIT_FAILURE); | |
661 | } | |
662 | ||
663 | close_nointr_nofail(s[1]); | |
664 | b->fd = s[0]; | |
665 | ||
666 | return bus_socket_start_auth(b); | |
667 | } | |
668 | ||
669 | int bus_socket_take_fd(sd_bus *b) { | |
670 | int r; | |
671 | assert(b); | |
672 | ||
673 | r = bus_socket_setup(b); | |
674 | if (r < 0) | |
675 | return r; | |
676 | ||
677 | return bus_socket_start_auth(b); | |
678 | } | |
679 | ||
680 | int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) { | |
681 | struct msghdr mh; | |
682 | struct iovec *iov; | |
683 | ssize_t k; | |
684 | size_t n; | |
685 | unsigned j; | |
686 | ||
687 | assert(bus); | |
688 | assert(m); | |
689 | assert(idx); | |
690 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
691 | ||
692 | if (*idx >= m->size) | |
693 | return 0; | |
694 | zero(mh); | |
695 | ||
696 | if (m->n_fds > 0) { | |
697 | struct cmsghdr *control; | |
698 | control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds)); | |
699 | ||
700 | mh.msg_control = control; | |
701 | control->cmsg_level = SOL_SOCKET; | |
702 | control->cmsg_type = SCM_RIGHTS; | |
703 | mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds); | |
704 | memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds); | |
705 | } | |
706 | ||
707 | n = m->n_iovec * sizeof(struct iovec); | |
708 | iov = alloca(n); | |
709 | memcpy(iov, m->iovec, n); | |
710 | ||
711 | j = 0; | |
712 | iovec_advance(iov, &j, *idx); | |
713 | ||
714 | mh.msg_iov = iov; | |
715 | mh.msg_iovlen = m->n_iovec; | |
716 | ||
717 | k = sendmsg(bus->fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
718 | if (k < 0) | |
719 | return errno == EAGAIN ? 0 : -errno; | |
720 | ||
721 | *idx += (size_t) k; | |
722 | return 1; | |
723 | } | |
724 | ||
725 | static int bus_socket_read_message_need(sd_bus *bus, size_t *need) { | |
726 | uint32_t a, b; | |
727 | uint8_t e; | |
728 | uint64_t sum; | |
729 | ||
730 | assert(bus); | |
731 | assert(need); | |
732 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
733 | ||
734 | if (bus->rbuffer_size < sizeof(struct bus_header)) { | |
735 | *need = sizeof(struct bus_header) + 8; | |
736 | ||
737 | /* Minimum message size: | |
738 | * | |
739 | * Header + | |
740 | * | |
741 | * Method Call: +2 string headers | |
742 | * Signal: +3 string headers | |
743 | * Method Error: +1 string headers | |
744 | * +1 uint32 headers | |
745 | * Method Reply: +1 uint32 headers | |
746 | * | |
747 | * A string header is at least 9 bytes | |
748 | * A uint32 header is at least 8 bytes | |
749 | * | |
750 | * Hence the minimum message size of a valid message | |
751 | * is header + 8 bytes */ | |
752 | ||
753 | return 0; | |
754 | } | |
755 | ||
756 | a = ((const uint32_t*) bus->rbuffer)[1]; | |
757 | b = ((const uint32_t*) bus->rbuffer)[3]; | |
758 | ||
759 | e = ((const uint8_t*) bus->rbuffer)[0]; | |
760 | if (e == SD_BUS_LITTLE_ENDIAN) { | |
761 | a = le32toh(a); | |
762 | b = le32toh(b); | |
763 | } else if (e == SD_BUS_BIG_ENDIAN) { | |
764 | a = be32toh(a); | |
765 | b = be32toh(b); | |
766 | } else | |
767 | return -EBADMSG; | |
768 | ||
769 | sum = (uint64_t) sizeof(struct bus_header) + (uint64_t) ALIGN_TO(b, 8) + (uint64_t) a; | |
770 | if (sum >= BUS_MESSAGE_SIZE_MAX) | |
771 | return -ENOBUFS; | |
772 | ||
773 | *need = (size_t) sum; | |
774 | return 0; | |
775 | } | |
776 | ||
777 | static int bus_socket_make_message(sd_bus *bus, size_t size, sd_bus_message **m) { | |
778 | sd_bus_message *t; | |
779 | void *b; | |
780 | int r; | |
781 | ||
782 | assert(bus); | |
783 | assert(m); | |
784 | assert(bus->rbuffer_size >= size); | |
785 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
786 | ||
787 | if (bus->rbuffer_size > size) { | |
788 | b = memdup((const uint8_t*) bus->rbuffer + size, | |
789 | bus->rbuffer_size - size); | |
790 | if (!b) | |
791 | return -ENOMEM; | |
792 | } else | |
793 | b = NULL; | |
794 | ||
795 | r = bus_message_from_malloc(bus->rbuffer, size, | |
796 | bus->fds, bus->n_fds, | |
0f4b73c8 LP |
797 | bus->ucred_valid ? &bus->ucred : NULL, |
798 | bus->label[0] ? bus->label : NULL, | |
a7e3212d LP |
799 | &t); |
800 | if (r < 0) { | |
801 | free(b); | |
802 | return r; | |
803 | } | |
804 | ||
805 | bus->rbuffer = b; | |
806 | bus->rbuffer_size -= size; | |
807 | ||
808 | bus->fds = NULL; | |
809 | bus->n_fds = 0; | |
810 | ||
811 | *m = t; | |
812 | return 1; | |
813 | } | |
814 | ||
815 | int bus_socket_read_message(sd_bus *bus, sd_bus_message **m) { | |
816 | struct msghdr mh; | |
817 | struct iovec iov; | |
818 | ssize_t k; | |
819 | size_t need; | |
820 | int r; | |
821 | void *b; | |
822 | union { | |
823 | struct cmsghdr cmsghdr; | |
824 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
825 | CMSG_SPACE(sizeof(struct ucred)) + | |
826 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
827 | } control; | |
828 | struct cmsghdr *cmsg; | |
829 | ||
830 | assert(bus); | |
831 | assert(m); | |
832 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
833 | ||
834 | r = bus_socket_read_message_need(bus, &need); | |
835 | if (r < 0) | |
836 | return r; | |
837 | ||
838 | if (bus->rbuffer_size >= need) | |
839 | return bus_socket_make_message(bus, need, m); | |
840 | ||
841 | b = realloc(bus->rbuffer, need); | |
842 | if (!b) | |
843 | return -ENOMEM; | |
844 | ||
845 | bus->rbuffer = b; | |
846 | ||
847 | zero(iov); | |
848 | iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size; | |
849 | iov.iov_len = need - bus->rbuffer_size; | |
850 | ||
851 | zero(mh); | |
852 | mh.msg_iov = &iov; | |
853 | mh.msg_iovlen = 1; | |
854 | mh.msg_control = &control; | |
855 | mh.msg_controllen = sizeof(control); | |
856 | ||
857 | k = recvmsg(bus->fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
858 | if (k < 0) | |
859 | return errno == EAGAIN ? 0 : -errno; | |
860 | if (k == 0) | |
861 | return -ECONNRESET; | |
862 | ||
863 | bus->rbuffer_size += k; | |
864 | ||
865 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
866 | if (cmsg->cmsg_level == SOL_SOCKET && | |
867 | cmsg->cmsg_type == SCM_RIGHTS) { | |
868 | int n, *f; | |
869 | ||
870 | n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
871 | ||
5384d4b3 LP |
872 | if (!bus->can_fds) { |
873 | /* Whut? We received fds but this | |
874 | * isn't actually enabled? Close them, | |
875 | * and fail */ | |
876 | ||
877 | close_many((int*) CMSG_DATA(cmsg), n); | |
878 | return -EIO; | |
879 | } | |
880 | ||
a7e3212d LP |
881 | f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n)); |
882 | if (!f) { | |
883 | close_many((int*) CMSG_DATA(cmsg), n); | |
884 | return -ENOMEM; | |
885 | } | |
886 | ||
887 | memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int)); | |
888 | bus->fds = f; | |
889 | bus->n_fds += n; | |
890 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
891 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
892 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
893 | ||
894 | memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
895 | bus->ucred_valid = true; | |
896 | ||
897 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
898 | cmsg->cmsg_type == SCM_SECURITY) { | |
899 | ||
900 | size_t l; | |
901 | l = cmsg->cmsg_len - CMSG_LEN(0); | |
902 | memcpy(&bus->label, CMSG_DATA(cmsg), l); | |
903 | bus->label[l] = 0; | |
904 | } | |
905 | } | |
906 | ||
907 | r = bus_socket_read_message_need(bus, &need); | |
908 | if (r < 0) | |
909 | return r; | |
910 | ||
911 | if (bus->rbuffer_size >= need) | |
912 | return bus_socket_make_message(bus, need, m); | |
913 | ||
914 | return 1; | |
915 | } | |
916 | ||
917 | int bus_socket_process_opening(sd_bus *b) { | |
918 | int error = 0; | |
919 | socklen_t slen = sizeof(error); | |
920 | struct pollfd p; | |
921 | int r; | |
922 | ||
923 | assert(b); | |
924 | assert(b->state == BUS_OPENING); | |
925 | ||
926 | zero(p); | |
927 | p.fd = b->fd; | |
928 | p.events = POLLOUT; | |
929 | ||
930 | r = poll(&p, 1, 0); | |
931 | if (r < 0) | |
932 | return -errno; | |
933 | ||
934 | if (!(p.revents & (POLLOUT|POLLERR|POLLHUP))) | |
935 | return 0; | |
936 | ||
937 | r = getsockopt(b->fd, SOL_SOCKET, SO_ERROR, &error, &slen); | |
938 | if (r < 0) | |
939 | b->last_connect_error = errno; | |
940 | else if (error != 0) | |
941 | b->last_connect_error = error; | |
942 | else if (p.revents & (POLLERR|POLLHUP)) | |
943 | b->last_connect_error = ECONNREFUSED; | |
944 | else | |
945 | return bus_socket_start_auth(b); | |
946 | ||
947 | return bus_next_address(b); | |
948 | } | |
949 | ||
950 | int bus_socket_process_authenticating(sd_bus *b) { | |
951 | int r; | |
952 | ||
953 | assert(b); | |
954 | assert(b->state == BUS_AUTHENTICATING); | |
955 | ||
956 | if (now(CLOCK_MONOTONIC) >= b->auth_timeout) | |
957 | return -ETIMEDOUT; | |
958 | ||
959 | r = bus_socket_write_auth(b); | |
960 | if (r != 0) | |
961 | return r; | |
962 | ||
963 | return bus_socket_read_auth(b); | |
964 | } |