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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> | |
a7e3212d LP |
23 | #include <stdlib.h> |
24 | #include <unistd.h> | |
0a6f50c0 | 25 | #include <poll.h> |
a7e3212d LP |
26 | |
27 | #include "util.h" | |
28 | #include "macro.h" | |
29 | #include "missing.h" | |
2181a7f5 | 30 | #include "utf8.h" |
9ab32f9d | 31 | #include "sd-daemon.h" |
a7e3212d LP |
32 | |
33 | #include "sd-bus.h" | |
34 | #include "bus-socket.h" | |
35 | #include "bus-internal.h" | |
36 | #include "bus-message.h" | |
37 | ||
aec6d91f LP |
38 | #define SNDBUF_SIZE (8*1024*1024) |
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 | ||
bc7fd8cd | 60 | static int append_iovec(sd_bus_message *m, const void *p, size_t sz) { |
2100fa10 LP |
61 | assert(m); |
62 | assert(p); | |
63 | assert(sz > 0); | |
64 | ||
65 | m->iovec[m->n_iovec].iov_base = (void*) p; | |
66 | m->iovec[m->n_iovec].iov_len = sz; | |
67 | m->n_iovec++; | |
bc7fd8cd LP |
68 | |
69 | return 0; | |
2100fa10 LP |
70 | } |
71 | ||
bc7fd8cd LP |
72 | static int bus_message_setup_iovec(sd_bus_message *m) { |
73 | struct bus_body_part *part; | |
13c299d3 | 74 | unsigned n, i; |
bc7fd8cd LP |
75 | int r; |
76 | ||
2100fa10 LP |
77 | assert(m); |
78 | assert(m->sealed); | |
79 | ||
80 | if (m->n_iovec > 0) | |
bc7fd8cd LP |
81 | return 0; |
82 | ||
83 | assert(!m->iovec); | |
2100fa10 | 84 | |
c91cb83c | 85 | n = 1 + m->n_body_parts; |
bc7fd8cd LP |
86 | if (n < ELEMENTSOF(m->iovec_fixed)) |
87 | m->iovec = m->iovec_fixed; | |
88 | else { | |
89 | m->iovec = new(struct iovec, n); | |
66b26c5c LP |
90 | if (!m->iovec) { |
91 | r = -ENOMEM; | |
92 | goto fail; | |
93 | } | |
bc7fd8cd | 94 | } |
2100fa10 | 95 | |
c91cb83c | 96 | r = append_iovec(m, m->header, BUS_MESSAGE_BODY_BEGIN(m)); |
bc7fd8cd | 97 | if (r < 0) |
66b26c5c | 98 | goto fail; |
2100fa10 | 99 | |
9b29bb68 | 100 | MESSAGE_FOREACH_PART(part, i, m) { |
66b26c5c LP |
101 | r = bus_body_part_map(part); |
102 | if (r < 0) | |
103 | goto fail; | |
104 | ||
bc7fd8cd LP |
105 | r = append_iovec(m, part->data, part->size); |
106 | if (r < 0) | |
66b26c5c | 107 | goto fail; |
bc7fd8cd LP |
108 | } |
109 | ||
110 | assert(n == m->n_iovec); | |
111 | ||
112 | return 0; | |
66b26c5c LP |
113 | |
114 | fail: | |
115 | m->poisoned = true; | |
116 | return r; | |
2100fa10 LP |
117 | } |
118 | ||
2181a7f5 LP |
119 | bool bus_socket_auth_needs_write(sd_bus *b) { |
120 | ||
121 | unsigned i; | |
122 | ||
123 | if (b->auth_index >= ELEMENTSOF(b->auth_iovec)) | |
124 | return false; | |
125 | ||
126 | for (i = b->auth_index; i < ELEMENTSOF(b->auth_iovec); i++) { | |
127 | struct iovec *j = b->auth_iovec + i; | |
128 | ||
129 | if (j->iov_len > 0) | |
130 | return true; | |
131 | } | |
132 | ||
133 | return false; | |
134 | } | |
135 | ||
a7e3212d | 136 | static int bus_socket_write_auth(sd_bus *b) { |
a7e3212d LP |
137 | ssize_t k; |
138 | ||
139 | assert(b); | |
140 | assert(b->state == BUS_AUTHENTICATING); | |
141 | ||
2181a7f5 | 142 | if (!bus_socket_auth_needs_write(b)) |
a7e3212d LP |
143 | return 0; |
144 | ||
15d5af81 LP |
145 | if (b->prefer_writev) |
146 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
147 | else { | |
148 | struct msghdr mh; | |
149 | zero(mh); | |
150 | ||
151 | mh.msg_iov = b->auth_iovec + b->auth_index; | |
152 | mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index; | |
153 | ||
154 | k = sendmsg(b->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
155 | if (k < 0 && errno == ENOTSOCK) { | |
156 | b->prefer_writev = true; | |
157 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
158 | } | |
159 | } | |
a7e3212d | 160 | |
a7e3212d LP |
161 | if (k < 0) |
162 | return errno == EAGAIN ? 0 : -errno; | |
163 | ||
164 | iovec_advance(b->auth_iovec, &b->auth_index, (size_t) k); | |
a7e3212d LP |
165 | return 1; |
166 | } | |
167 | ||
2181a7f5 | 168 | static int bus_socket_auth_verify_client(sd_bus *b) { |
a7e3212d LP |
169 | char *e, *f, *start; |
170 | sd_id128_t peer; | |
171 | unsigned i; | |
172 | int r; | |
173 | ||
2181a7f5 LP |
174 | assert(b); |
175 | ||
a7e3212d LP |
176 | /* We expect two response lines: "OK" and possibly |
177 | * "AGREE_UNIX_FD" */ | |
178 | ||
179 | e = memmem(b->rbuffer, b->rbuffer_size, "\r\n", 2); | |
180 | if (!e) | |
181 | return 0; | |
182 | ||
264ad849 | 183 | if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) { |
a7e3212d LP |
184 | f = memmem(e + 2, b->rbuffer_size - (e - (char*) b->rbuffer) - 2, "\r\n", 2); |
185 | if (!f) | |
186 | return 0; | |
187 | ||
188 | start = f + 2; | |
189 | } else { | |
190 | f = NULL; | |
191 | start = e + 2; | |
192 | } | |
193 | ||
194 | /* Nice! We got all the lines we need. First check the OK | |
195 | * line */ | |
196 | ||
197 | if (e - (char*) b->rbuffer != 3 + 32) | |
198 | return -EPERM; | |
199 | ||
200 | if (memcmp(b->rbuffer, "OK ", 3)) | |
201 | return -EPERM; | |
202 | ||
2181a7f5 LP |
203 | b->auth = b->anonymous_auth ? BUS_AUTH_ANONYMOUS : BUS_AUTH_EXTERNAL; |
204 | ||
a7e3212d LP |
205 | for (i = 0; i < 32; i += 2) { |
206 | int x, y; | |
207 | ||
208 | x = unhexchar(((char*) b->rbuffer)[3 + i]); | |
209 | y = unhexchar(((char*) b->rbuffer)[3 + i + 1]); | |
210 | ||
211 | if (x < 0 || y < 0) | |
212 | return -EINVAL; | |
213 | ||
214 | peer.bytes[i/2] = ((uint8_t) x << 4 | (uint8_t) y); | |
215 | } | |
216 | ||
98178d39 LP |
217 | if (!sd_id128_equal(b->server_id, SD_ID128_NULL) && |
218 | !sd_id128_equal(b->server_id, peer)) | |
a7e3212d LP |
219 | return -EPERM; |
220 | ||
98178d39 | 221 | b->server_id = peer; |
a7e3212d LP |
222 | |
223 | /* And possibly check the second line, too */ | |
224 | ||
225 | if (f) | |
226 | b->can_fds = | |
f8294e41 JT |
227 | (f - e == strlen("\r\nAGREE_UNIX_FD")) && |
228 | memcmp(e + 2, "AGREE_UNIX_FD", strlen("AGREE_UNIX_FD")) == 0; | |
a7e3212d LP |
229 | |
230 | b->rbuffer_size -= (start - (char*) b->rbuffer); | |
231 | memmove(b->rbuffer, start, b->rbuffer_size); | |
232 | ||
233 | r = bus_start_running(b); | |
234 | if (r < 0) | |
235 | return r; | |
236 | ||
237 | return 1; | |
238 | } | |
239 | ||
2181a7f5 LP |
240 | static bool line_equals(const char *s, size_t m, const char *line) { |
241 | size_t l; | |
242 | ||
243 | l = strlen(line); | |
244 | if (l != m) | |
245 | return false; | |
246 | ||
247 | return memcmp(s, line, l) == 0; | |
248 | } | |
249 | ||
250 | static bool line_begins(const char *s, size_t m, const char *word) { | |
251 | size_t l; | |
252 | ||
253 | l = strlen(word); | |
254 | if (m < l) | |
255 | return false; | |
256 | ||
257 | if (memcmp(s, word, l) != 0) | |
258 | return false; | |
259 | ||
260 | return m == l || (m > l && s[l] == ' '); | |
261 | } | |
262 | ||
263 | static int verify_anonymous_token(sd_bus *b, const char *p, size_t l) { | |
264 | _cleanup_free_ char *token = NULL; | |
265 | ||
266 | if (!b->anonymous_auth) | |
267 | return 0; | |
268 | ||
269 | if (l <= 0) | |
270 | return 1; | |
271 | ||
272 | assert(p[0] == ' '); | |
273 | p++; l--; | |
274 | ||
275 | if (l % 2 != 0) | |
276 | return 0; | |
277 | token = unhexmem(p, l); | |
278 | if (!token) | |
279 | return -ENOMEM; | |
280 | ||
281 | if (memchr(token, 0, l/2)) | |
282 | return 0; | |
283 | ||
284 | return !!utf8_is_valid(token); | |
285 | } | |
286 | ||
287 | static int verify_external_token(sd_bus *b, const char *p, size_t l) { | |
288 | _cleanup_free_ char *token = NULL; | |
289 | uid_t u; | |
290 | int r; | |
291 | ||
292 | /* We don't do any real authentication here. Instead, we if | |
293 | * the owner of this bus wanted authentication he should have | |
294 | * checked SO_PEERCRED before even creating the bus object. */ | |
295 | ||
8411d2a2 | 296 | if (!b->anonymous_auth && !b->ucred_valid) |
2181a7f5 LP |
297 | return 0; |
298 | ||
299 | if (l <= 0) | |
300 | return 1; | |
301 | ||
302 | assert(p[0] == ' '); | |
303 | p++; l--; | |
304 | ||
305 | if (l % 2 != 0) | |
306 | return 0; | |
307 | ||
308 | token = unhexmem(p, l); | |
309 | if (!token) | |
310 | return -ENOMEM; | |
311 | ||
312 | if (memchr(token, 0, l/2)) | |
313 | return 0; | |
314 | ||
315 | r = parse_uid(token, &u); | |
316 | if (r < 0) | |
317 | return 0; | |
318 | ||
8411d2a2 LP |
319 | /* We ignore the passed value if anonymous authentication is |
320 | * on anyway. */ | |
321 | if (!b->anonymous_auth && u != b->ucred.uid) | |
2181a7f5 LP |
322 | return 0; |
323 | ||
324 | return 1; | |
325 | } | |
326 | ||
327 | static int bus_socket_auth_write(sd_bus *b, const char *t) { | |
328 | char *p; | |
329 | size_t l; | |
330 | ||
331 | assert(b); | |
332 | assert(t); | |
333 | ||
334 | /* We only make use of the first iovec */ | |
335 | assert(b->auth_index == 0 || b->auth_index == 1); | |
336 | ||
337 | l = strlen(t); | |
338 | p = malloc(b->auth_iovec[0].iov_len + l); | |
339 | if (!p) | |
340 | return -ENOMEM; | |
341 | ||
342 | memcpy(p, b->auth_iovec[0].iov_base, b->auth_iovec[0].iov_len); | |
343 | memcpy(p + b->auth_iovec[0].iov_len, t, l); | |
344 | ||
345 | b->auth_iovec[0].iov_base = p; | |
346 | b->auth_iovec[0].iov_len += l; | |
347 | ||
348 | free(b->auth_buffer); | |
349 | b->auth_buffer = p; | |
350 | b->auth_index = 0; | |
351 | return 0; | |
352 | } | |
353 | ||
354 | static int bus_socket_auth_write_ok(sd_bus *b) { | |
355 | char t[3 + 32 + 2 + 1]; | |
356 | ||
357 | assert(b); | |
358 | ||
5ffa8c81 | 359 | xsprintf(t, "OK " SD_ID128_FORMAT_STR "\r\n", SD_ID128_FORMAT_VAL(b->server_id)); |
2181a7f5 LP |
360 | |
361 | return bus_socket_auth_write(b, t); | |
362 | } | |
363 | ||
364 | static int bus_socket_auth_verify_server(sd_bus *b) { | |
365 | char *e; | |
366 | const char *line; | |
367 | size_t l; | |
368 | bool processed = false; | |
369 | int r; | |
370 | ||
371 | assert(b); | |
372 | ||
2b4ac889 | 373 | if (b->rbuffer_size < 1) |
2181a7f5 LP |
374 | return 0; |
375 | ||
376 | /* First char must be a NUL byte */ | |
377 | if (*(char*) b->rbuffer != 0) | |
378 | return -EIO; | |
379 | ||
2b4ac889 LP |
380 | if (b->rbuffer_size < 3) |
381 | return 0; | |
382 | ||
2181a7f5 LP |
383 | /* Begin with the first line */ |
384 | if (b->auth_rbegin <= 0) | |
385 | b->auth_rbegin = 1; | |
386 | ||
387 | for (;;) { | |
388 | /* Check if line is complete */ | |
389 | line = (char*) b->rbuffer + b->auth_rbegin; | |
390 | e = memmem(line, b->rbuffer_size - b->auth_rbegin, "\r\n", 2); | |
391 | if (!e) | |
392 | return processed; | |
393 | ||
394 | l = e - line; | |
395 | ||
396 | if (line_begins(line, l, "AUTH ANONYMOUS")) { | |
397 | ||
398 | r = verify_anonymous_token(b, line + 14, l - 14); | |
399 | if (r < 0) | |
400 | return r; | |
401 | if (r == 0) | |
402 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
403 | else { | |
404 | b->auth = BUS_AUTH_ANONYMOUS; | |
405 | r = bus_socket_auth_write_ok(b); | |
406 | } | |
407 | ||
408 | } else if (line_begins(line, l, "AUTH EXTERNAL")) { | |
409 | ||
410 | r = verify_external_token(b, line + 13, l - 13); | |
411 | if (r < 0) | |
412 | return r; | |
413 | if (r == 0) | |
414 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
415 | else { | |
416 | b->auth = BUS_AUTH_EXTERNAL; | |
417 | r = bus_socket_auth_write_ok(b); | |
418 | } | |
419 | ||
420 | } else if (line_begins(line, l, "AUTH")) | |
421 | r = bus_socket_auth_write(b, "REJECTED EXTERNAL ANONYMOUS\r\n"); | |
422 | else if (line_equals(line, l, "CANCEL") || | |
423 | line_begins(line, l, "ERROR")) { | |
424 | ||
425 | b->auth = _BUS_AUTH_INVALID; | |
426 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
427 | ||
428 | } else if (line_equals(line, l, "BEGIN")) { | |
429 | ||
430 | if (b->auth == _BUS_AUTH_INVALID) | |
431 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
432 | else { | |
433 | /* We can't leave from the auth phase | |
434 | * before we haven't written | |
435 | * everything queued, so let's check | |
436 | * that */ | |
437 | ||
438 | if (bus_socket_auth_needs_write(b)) | |
439 | return 1; | |
440 | ||
441 | b->rbuffer_size -= (e + 2 - (char*) b->rbuffer); | |
442 | memmove(b->rbuffer, e + 2, b->rbuffer_size); | |
443 | return bus_start_running(b); | |
444 | } | |
445 | ||
446 | } else if (line_begins(line, l, "DATA")) { | |
447 | ||
448 | if (b->auth == _BUS_AUTH_INVALID) | |
449 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
450 | else { | |
451 | if (b->auth == BUS_AUTH_ANONYMOUS) | |
452 | r = verify_anonymous_token(b, line + 4, l - 4); | |
453 | else | |
454 | r = verify_external_token(b, line + 4, l - 4); | |
455 | ||
456 | if (r < 0) | |
457 | return r; | |
458 | if (r == 0) { | |
459 | b->auth = _BUS_AUTH_INVALID; | |
460 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
461 | } else | |
462 | r = bus_socket_auth_write_ok(b); | |
463 | } | |
464 | } else if (line_equals(line, l, "NEGOTIATE_UNIX_FD")) { | |
264ad849 | 465 | if (b->auth == _BUS_AUTH_INVALID || !(b->hello_flags & KDBUS_HELLO_ACCEPT_FD)) |
2181a7f5 LP |
466 | r = bus_socket_auth_write(b, "ERROR\r\n"); |
467 | else { | |
468 | b->can_fds = true; | |
469 | r = bus_socket_auth_write(b, "AGREE_UNIX_FD\r\n"); | |
470 | } | |
471 | } else | |
472 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
473 | ||
474 | if (r < 0) | |
475 | return r; | |
476 | ||
477 | b->auth_rbegin = e + 2 - (char*) b->rbuffer; | |
478 | ||
479 | processed = true; | |
480 | } | |
481 | } | |
482 | ||
483 | static int bus_socket_auth_verify(sd_bus *b) { | |
484 | assert(b); | |
485 | ||
486 | if (b->is_server) | |
487 | return bus_socket_auth_verify_server(b); | |
488 | else | |
489 | return bus_socket_auth_verify_client(b); | |
490 | } | |
491 | ||
a7e3212d LP |
492 | static int bus_socket_read_auth(sd_bus *b) { |
493 | struct msghdr mh; | |
494 | struct iovec iov; | |
495 | size_t n; | |
496 | ssize_t k; | |
497 | int r; | |
498 | void *p; | |
2181a7f5 LP |
499 | union { |
500 | struct cmsghdr cmsghdr; | |
501 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
502 | CMSG_SPACE(sizeof(struct ucred)) + | |
503 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
504 | } control; | |
505 | struct cmsghdr *cmsg; | |
15d5af81 | 506 | bool handle_cmsg = false; |
a7e3212d LP |
507 | |
508 | assert(b); | |
2181a7f5 | 509 | assert(b->state == BUS_AUTHENTICATING); |
a7e3212d LP |
510 | |
511 | r = bus_socket_auth_verify(b); | |
512 | if (r != 0) | |
513 | return r; | |
514 | ||
9607d947 | 515 | n = MAX(256u, b->rbuffer_size * 2); |
a7e3212d LP |
516 | |
517 | if (n > BUS_AUTH_SIZE_MAX) | |
518 | n = BUS_AUTH_SIZE_MAX; | |
519 | ||
520 | if (b->rbuffer_size >= n) | |
521 | return -ENOBUFS; | |
522 | ||
523 | p = realloc(b->rbuffer, n); | |
524 | if (!p) | |
525 | return -ENOMEM; | |
526 | ||
527 | b->rbuffer = p; | |
528 | ||
529 | zero(iov); | |
530 | iov.iov_base = (uint8_t*) b->rbuffer + b->rbuffer_size; | |
531 | iov.iov_len = n - b->rbuffer_size; | |
532 | ||
15d5af81 LP |
533 | if (b->prefer_readv) |
534 | k = readv(b->input_fd, &iov, 1); | |
535 | else { | |
536 | zero(mh); | |
537 | mh.msg_iov = &iov; | |
538 | mh.msg_iovlen = 1; | |
539 | mh.msg_control = &control; | |
540 | mh.msg_controllen = sizeof(control); | |
541 | ||
542 | k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
543 | if (k < 0 && errno == ENOTSOCK) { | |
544 | b->prefer_readv = true; | |
545 | k = readv(b->input_fd, &iov, 1); | |
546 | } else | |
547 | handle_cmsg = true; | |
548 | } | |
a7e3212d LP |
549 | if (k < 0) |
550 | return errno == EAGAIN ? 0 : -errno; | |
551 | if (k == 0) | |
552 | return -ECONNRESET; | |
553 | ||
554 | b->rbuffer_size += k; | |
555 | ||
15d5af81 LP |
556 | if (handle_cmsg) { |
557 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
558 | if (cmsg->cmsg_level == SOL_SOCKET && | |
559 | cmsg->cmsg_type == SCM_RIGHTS) { | |
560 | int j; | |
561 | ||
562 | /* Whut? We received fds during the auth | |
563 | * protocol? Somebody is playing games with | |
564 | * us. Close them all, and fail */ | |
565 | j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
566 | close_many((int*) CMSG_DATA(cmsg), j); | |
567 | return -EIO; | |
2181a7f5 | 568 | |
15d5af81 LP |
569 | } else if (cmsg->cmsg_level == SOL_SOCKET && |
570 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
571 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
2181a7f5 | 572 | |
ea8f194f LP |
573 | /* Ignore bogus data, which we might |
574 | * get on socketpair() sockets */ | |
575 | if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { | |
576 | memcpy(&b->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
577 | b->ucred_valid = true; | |
578 | } | |
2181a7f5 | 579 | |
15d5af81 LP |
580 | } else if (cmsg->cmsg_level == SOL_SOCKET && |
581 | cmsg->cmsg_type == SCM_SECURITY) { | |
2181a7f5 | 582 | |
15d5af81 | 583 | size_t l; |
ea8f194f | 584 | |
15d5af81 | 585 | l = cmsg->cmsg_len - CMSG_LEN(0); |
ea8f194f LP |
586 | if (l > 0) { |
587 | memcpy(&b->label, CMSG_DATA(cmsg), l); | |
588 | b->label[l] = 0; | |
589 | } | |
15d5af81 | 590 | } |
2181a7f5 LP |
591 | } |
592 | } | |
593 | ||
a7e3212d LP |
594 | r = bus_socket_auth_verify(b); |
595 | if (r != 0) | |
596 | return r; | |
597 | ||
598 | return 1; | |
599 | } | |
600 | ||
8f04d2eb | 601 | void bus_socket_setup(sd_bus *b) { |
0f4b73c8 | 602 | int enable; |
a7e3212d LP |
603 | |
604 | assert(b); | |
605 | ||
d65ddaa4 LP |
606 | /* Enable SO_PASSCRED + SO_PASSEC. We try this on any |
607 | * socket, just in case. */ | |
0f4b73c8 | 608 | enable = !b->bus_client; |
3aeaee97 | 609 | (void)setsockopt(b->input_fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(enable)); |
264ad849 | 610 | |
d21a7bb1 | 611 | enable = !b->bus_client && (b->attach_flags & KDBUS_ATTACH_SECLABEL); |
3aeaee97 | 612 | (void)setsockopt(b->input_fd, SOL_SOCKET, SO_PASSSEC, &enable, sizeof(enable)); |
a7e3212d | 613 | |
aec6d91f LP |
614 | /* Increase the buffers to 8 MB */ |
615 | fd_inc_rcvbuf(b->input_fd, SNDBUF_SIZE); | |
616 | fd_inc_sndbuf(b->output_fd, SNDBUF_SIZE); | |
a7e3212d | 617 | |
e1d337d4 LP |
618 | b->is_kernel = false; |
619 | b->message_version = 1; | |
0f437184 | 620 | b->message_endian = 0; |
8f04d2eb | 621 | } |
e1d337d4 | 622 | |
8f04d2eb | 623 | static void bus_get_peercred(sd_bus *b) { |
8f04d2eb LP |
624 | assert(b); |
625 | ||
626 | /* Get the peer for socketpair() sockets */ | |
eff05270 | 627 | b->ucred_valid = getpeercred(b->input_fd, &b->ucred) >= 0; |
a7e3212d LP |
628 | } |
629 | ||
2181a7f5 | 630 | static int bus_socket_start_auth_client(sd_bus *b) { |
a7e3212d | 631 | size_t l; |
2181a7f5 | 632 | const char *auth_suffix, *auth_prefix; |
a7e3212d LP |
633 | |
634 | assert(b); | |
635 | ||
2181a7f5 LP |
636 | if (b->anonymous_auth) { |
637 | auth_prefix = "\0AUTH ANONYMOUS "; | |
a7e3212d | 638 | |
2181a7f5 LP |
639 | /* For ANONYMOUS auth we send some arbitrary "trace" string */ |
640 | l = 9; | |
641 | b->auth_buffer = hexmem("anonymous", l); | |
642 | } else { | |
5ffa8c81 | 643 | char text[DECIMAL_STR_MAX(uid_t) + 1]; |
a7e3212d | 644 | |
2181a7f5 | 645 | auth_prefix = "\0AUTH EXTERNAL "; |
a7e3212d | 646 | |
5ffa8c81 | 647 | xsprintf(text, UID_FMT, geteuid()); |
a7e3212d | 648 | |
2181a7f5 LP |
649 | l = strlen(text); |
650 | b->auth_buffer = hexmem(text, l); | |
651 | } | |
652 | ||
653 | if (!b->auth_buffer) | |
a7e3212d LP |
654 | return -ENOMEM; |
655 | ||
264ad849 | 656 | if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) |
2181a7f5 LP |
657 | auth_suffix = "\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n"; |
658 | else | |
659 | auth_suffix = "\r\nBEGIN\r\n"; | |
a7e3212d LP |
660 | |
661 | b->auth_iovec[0].iov_base = (void*) auth_prefix; | |
2181a7f5 LP |
662 | b->auth_iovec[0].iov_len = 1 + strlen(auth_prefix + 1); |
663 | b->auth_iovec[1].iov_base = (void*) b->auth_buffer; | |
a7e3212d LP |
664 | b->auth_iovec[1].iov_len = l * 2; |
665 | b->auth_iovec[2].iov_base = (void*) auth_suffix; | |
666 | b->auth_iovec[2].iov_len = strlen(auth_suffix); | |
a7e3212d LP |
667 | |
668 | return bus_socket_write_auth(b); | |
669 | } | |
670 | ||
a7893c6b | 671 | int bus_socket_start_auth(sd_bus *b) { |
2181a7f5 LP |
672 | assert(b); |
673 | ||
8f04d2eb LP |
674 | bus_get_peercred(b); |
675 | ||
2181a7f5 LP |
676 | b->state = BUS_AUTHENTICATING; |
677 | b->auth_timeout = now(CLOCK_MONOTONIC) + BUS_DEFAULT_TIMEOUT; | |
678 | ||
9ab32f9d | 679 | if (sd_is_socket(b->input_fd, AF_UNIX, 0, 0) <= 0) |
264ad849 | 680 | b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; |
2181a7f5 | 681 | |
9ab32f9d LP |
682 | if (b->output_fd != b->input_fd) |
683 | if (sd_is_socket(b->output_fd, AF_UNIX, 0, 0) <= 0) | |
264ad849 | 684 | b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; |
e82c9509 | 685 | |
2181a7f5 LP |
686 | if (b->is_server) |
687 | return bus_socket_read_auth(b); | |
688 | else | |
689 | return bus_socket_start_auth_client(b); | |
690 | } | |
691 | ||
a7e3212d LP |
692 | int bus_socket_connect(sd_bus *b) { |
693 | int r; | |
694 | ||
695 | assert(b); | |
e82c9509 LP |
696 | assert(b->input_fd < 0); |
697 | assert(b->output_fd < 0); | |
a7e3212d LP |
698 | assert(b->sockaddr.sa.sa_family != AF_UNSPEC); |
699 | ||
e82c9509 LP |
700 | b->input_fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
701 | if (b->input_fd < 0) | |
a7e3212d LP |
702 | return -errno; |
703 | ||
e82c9509 LP |
704 | b->output_fd = b->input_fd; |
705 | ||
8f04d2eb | 706 | bus_socket_setup(b); |
a7e3212d | 707 | |
e82c9509 | 708 | r = connect(b->input_fd, &b->sockaddr.sa, b->sockaddr_size); |
a7e3212d LP |
709 | if (r < 0) { |
710 | if (errno == EINPROGRESS) | |
711 | return 1; | |
712 | ||
713 | return -errno; | |
714 | } | |
715 | ||
716 | return bus_socket_start_auth(b); | |
717 | } | |
718 | ||
719 | int bus_socket_exec(sd_bus *b) { | |
e82c9509 | 720 | int s[2], r; |
a7e3212d LP |
721 | pid_t pid; |
722 | ||
723 | assert(b); | |
e82c9509 LP |
724 | assert(b->input_fd < 0); |
725 | assert(b->output_fd < 0); | |
a7e3212d LP |
726 | assert(b->exec_path); |
727 | ||
e82c9509 LP |
728 | r = socketpair(AF_UNIX, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, s); |
729 | if (r < 0) | |
a7e3212d LP |
730 | return -errno; |
731 | ||
732 | pid = fork(); | |
733 | if (pid < 0) { | |
3d94f76c | 734 | safe_close_pair(s); |
a7e3212d LP |
735 | return -errno; |
736 | } | |
737 | if (pid == 0) { | |
738 | /* Child */ | |
739 | ||
e82c9509 LP |
740 | reset_all_signal_handlers(); |
741 | ||
742 | close_all_fds(s+1, 1); | |
a7e3212d LP |
743 | |
744 | assert_se(dup3(s[1], STDIN_FILENO, 0) == STDIN_FILENO); | |
745 | assert_se(dup3(s[1], STDOUT_FILENO, 0) == STDOUT_FILENO); | |
746 | ||
747 | if (s[1] != STDIN_FILENO && s[1] != STDOUT_FILENO) | |
03e334a1 | 748 | safe_close(s[1]); |
a7e3212d LP |
749 | |
750 | fd_cloexec(STDIN_FILENO, false); | |
751 | fd_cloexec(STDOUT_FILENO, false); | |
752 | fd_nonblock(STDIN_FILENO, false); | |
753 | fd_nonblock(STDOUT_FILENO, false); | |
754 | ||
755 | if (b->exec_argv) | |
756 | execvp(b->exec_path, b->exec_argv); | |
757 | else { | |
758 | const char *argv[] = { b->exec_path, NULL }; | |
759 | execvp(b->exec_path, (char**) argv); | |
760 | } | |
761 | ||
762 | _exit(EXIT_FAILURE); | |
763 | } | |
764 | ||
03e334a1 | 765 | safe_close(s[1]); |
e82c9509 | 766 | b->output_fd = b->input_fd = s[0]; |
a7e3212d | 767 | |
8f04d2eb | 768 | bus_socket_setup(b); |
e1d337d4 | 769 | |
a7e3212d LP |
770 | return bus_socket_start_auth(b); |
771 | } | |
772 | ||
773 | int bus_socket_take_fd(sd_bus *b) { | |
a7e3212d LP |
774 | assert(b); |
775 | ||
8f04d2eb | 776 | bus_socket_setup(b); |
a7e3212d LP |
777 | |
778 | return bus_socket_start_auth(b); | |
779 | } | |
780 | ||
781 | int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) { | |
a7e3212d LP |
782 | struct iovec *iov; |
783 | ssize_t k; | |
784 | size_t n; | |
785 | unsigned j; | |
bc7fd8cd | 786 | int r; |
a7e3212d LP |
787 | |
788 | assert(bus); | |
789 | assert(m); | |
790 | assert(idx); | |
791 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
792 | ||
6629161f | 793 | if (*idx >= BUS_MESSAGE_SIZE(m)) |
a7e3212d | 794 | return 0; |
a7e3212d | 795 | |
bc7fd8cd LP |
796 | r = bus_message_setup_iovec(m); |
797 | if (r < 0) | |
798 | return r; | |
2100fa10 | 799 | |
a7e3212d LP |
800 | n = m->n_iovec * sizeof(struct iovec); |
801 | iov = alloca(n); | |
802 | memcpy(iov, m->iovec, n); | |
803 | ||
804 | j = 0; | |
805 | iovec_advance(iov, &j, *idx); | |
806 | ||
15d5af81 LP |
807 | if (bus->prefer_writev) |
808 | k = writev(bus->output_fd, iov, m->n_iovec); | |
809 | else { | |
810 | struct msghdr mh; | |
811 | zero(mh); | |
812 | ||
813 | if (m->n_fds > 0) { | |
814 | struct cmsghdr *control; | |
815 | control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds)); | |
816 | ||
817 | mh.msg_control = control; | |
818 | control->cmsg_level = SOL_SOCKET; | |
819 | control->cmsg_type = SCM_RIGHTS; | |
820 | mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds); | |
821 | memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds); | |
822 | } | |
823 | ||
824 | mh.msg_iov = iov; | |
825 | mh.msg_iovlen = m->n_iovec; | |
826 | ||
827 | k = sendmsg(bus->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
828 | if (k < 0 && errno == ENOTSOCK) { | |
829 | bus->prefer_writev = true; | |
830 | k = writev(bus->output_fd, iov, m->n_iovec); | |
831 | } | |
832 | } | |
a7e3212d | 833 | |
a7e3212d LP |
834 | if (k < 0) |
835 | return errno == EAGAIN ? 0 : -errno; | |
836 | ||
837 | *idx += (size_t) k; | |
838 | return 1; | |
839 | } | |
840 | ||
841 | static int bus_socket_read_message_need(sd_bus *bus, size_t *need) { | |
842 | uint32_t a, b; | |
843 | uint8_t e; | |
844 | uint64_t sum; | |
845 | ||
846 | assert(bus); | |
847 | assert(need); | |
848 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
849 | ||
850 | if (bus->rbuffer_size < sizeof(struct bus_header)) { | |
851 | *need = sizeof(struct bus_header) + 8; | |
852 | ||
853 | /* Minimum message size: | |
854 | * | |
855 | * Header + | |
856 | * | |
857 | * Method Call: +2 string headers | |
858 | * Signal: +3 string headers | |
859 | * Method Error: +1 string headers | |
860 | * +1 uint32 headers | |
861 | * Method Reply: +1 uint32 headers | |
862 | * | |
863 | * A string header is at least 9 bytes | |
864 | * A uint32 header is at least 8 bytes | |
865 | * | |
866 | * Hence the minimum message size of a valid message | |
867 | * is header + 8 bytes */ | |
868 | ||
869 | return 0; | |
870 | } | |
871 | ||
872 | a = ((const uint32_t*) bus->rbuffer)[1]; | |
873 | b = ((const uint32_t*) bus->rbuffer)[3]; | |
874 | ||
875 | e = ((const uint8_t*) bus->rbuffer)[0]; | |
0461f8cd | 876 | if (e == BUS_LITTLE_ENDIAN) { |
a7e3212d LP |
877 | a = le32toh(a); |
878 | b = le32toh(b); | |
0461f8cd | 879 | } else if (e == BUS_BIG_ENDIAN) { |
a7e3212d LP |
880 | a = be32toh(a); |
881 | b = be32toh(b); | |
882 | } else | |
883 | return -EBADMSG; | |
884 | ||
885 | sum = (uint64_t) sizeof(struct bus_header) + (uint64_t) ALIGN_TO(b, 8) + (uint64_t) a; | |
886 | if (sum >= BUS_MESSAGE_SIZE_MAX) | |
887 | return -ENOBUFS; | |
888 | ||
889 | *need = (size_t) sum; | |
890 | return 0; | |
891 | } | |
892 | ||
7d22c717 | 893 | static int bus_socket_make_message(sd_bus *bus, size_t size) { |
a7e3212d LP |
894 | sd_bus_message *t; |
895 | void *b; | |
896 | int r; | |
897 | ||
898 | assert(bus); | |
a7e3212d LP |
899 | assert(bus->rbuffer_size >= size); |
900 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
901 | ||
7adc46fc LP |
902 | r = bus_rqueue_make_room(bus); |
903 | if (r < 0) | |
904 | return r; | |
905 | ||
a7e3212d LP |
906 | if (bus->rbuffer_size > size) { |
907 | b = memdup((const uint8_t*) bus->rbuffer + size, | |
908 | bus->rbuffer_size - size); | |
909 | if (!b) | |
910 | return -ENOMEM; | |
911 | } else | |
912 | b = NULL; | |
913 | ||
df2d202e LP |
914 | r = bus_message_from_malloc(bus, |
915 | bus->rbuffer, size, | |
a7e3212d | 916 | bus->fds, bus->n_fds, |
e7f7a1b0 LP |
917 | !bus->bus_client && bus->ucred_valid ? &bus->ucred : NULL, |
918 | !bus->bus_client && bus->label[0] ? bus->label : NULL, | |
a7e3212d LP |
919 | &t); |
920 | if (r < 0) { | |
921 | free(b); | |
922 | return r; | |
923 | } | |
924 | ||
925 | bus->rbuffer = b; | |
926 | bus->rbuffer_size -= size; | |
927 | ||
928 | bus->fds = NULL; | |
929 | bus->n_fds = 0; | |
930 | ||
7adc46fc | 931 | bus->rqueue[bus->rqueue_size++] = t; |
7d22c717 | 932 | |
a7e3212d LP |
933 | return 1; |
934 | } | |
935 | ||
7d22c717 | 936 | int bus_socket_read_message(sd_bus *bus) { |
a7e3212d LP |
937 | struct msghdr mh; |
938 | struct iovec iov; | |
939 | ssize_t k; | |
940 | size_t need; | |
941 | int r; | |
942 | void *b; | |
943 | union { | |
944 | struct cmsghdr cmsghdr; | |
945 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
946 | CMSG_SPACE(sizeof(struct ucred)) + | |
947 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
948 | } control; | |
949 | struct cmsghdr *cmsg; | |
4d3a5b10 | 950 | bool handle_cmsg = false; |
a7e3212d LP |
951 | |
952 | assert(bus); | |
a7e3212d LP |
953 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); |
954 | ||
955 | r = bus_socket_read_message_need(bus, &need); | |
956 | if (r < 0) | |
957 | return r; | |
958 | ||
959 | if (bus->rbuffer_size >= need) | |
7d22c717 | 960 | return bus_socket_make_message(bus, need); |
a7e3212d LP |
961 | |
962 | b = realloc(bus->rbuffer, need); | |
963 | if (!b) | |
964 | return -ENOMEM; | |
965 | ||
966 | bus->rbuffer = b; | |
967 | ||
968 | zero(iov); | |
969 | iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size; | |
970 | iov.iov_len = need - bus->rbuffer_size; | |
971 | ||
15d5af81 LP |
972 | if (bus->prefer_readv) |
973 | k = readv(bus->input_fd, &iov, 1); | |
974 | else { | |
975 | zero(mh); | |
976 | mh.msg_iov = &iov; | |
977 | mh.msg_iovlen = 1; | |
978 | mh.msg_control = &control; | |
979 | mh.msg_controllen = sizeof(control); | |
980 | ||
981 | k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
982 | if (k < 0 && errno == ENOTSOCK) { | |
983 | bus->prefer_readv = true; | |
984 | k = readv(bus->input_fd, &iov, 1); | |
985 | } else | |
986 | handle_cmsg = true; | |
987 | } | |
a7e3212d LP |
988 | if (k < 0) |
989 | return errno == EAGAIN ? 0 : -errno; | |
990 | if (k == 0) | |
991 | return -ECONNRESET; | |
992 | ||
993 | bus->rbuffer_size += k; | |
994 | ||
15d5af81 LP |
995 | if (handle_cmsg) { |
996 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
997 | if (cmsg->cmsg_level == SOL_SOCKET && | |
998 | cmsg->cmsg_type == SCM_RIGHTS) { | |
999 | int n, *f; | |
1000 | ||
1001 | n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
1002 | ||
1003 | if (!bus->can_fds) { | |
1004 | /* Whut? We received fds but this | |
1005 | * isn't actually enabled? Close them, | |
1006 | * and fail */ | |
1007 | ||
1008 | close_many((int*) CMSG_DATA(cmsg), n); | |
1009 | return -EIO; | |
1010 | } | |
1011 | ||
1012 | f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n)); | |
1013 | if (!f) { | |
1014 | close_many((int*) CMSG_DATA(cmsg), n); | |
1015 | return -ENOMEM; | |
1016 | } | |
1017 | ||
1018 | memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int)); | |
1019 | bus->fds = f; | |
1020 | bus->n_fds += n; | |
1021 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1022 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
1023 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
1024 | ||
ea8f194f LP |
1025 | /* Ignore bogus data, which we might |
1026 | * get on socketpair() sockets */ | |
1027 | if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { | |
1028 | memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
1029 | bus->ucred_valid = true; | |
1030 | } | |
15d5af81 LP |
1031 | |
1032 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1033 | cmsg->cmsg_type == SCM_SECURITY) { | |
1034 | ||
1035 | size_t l; | |
1036 | l = cmsg->cmsg_len - CMSG_LEN(0); | |
ea8f194f LP |
1037 | if (l > 0) { |
1038 | memcpy(&bus->label, CMSG_DATA(cmsg), l); | |
1039 | bus->label[l] = 0; | |
1040 | } | |
a7e3212d | 1041 | } |
a7e3212d LP |
1042 | } |
1043 | } | |
1044 | ||
1045 | r = bus_socket_read_message_need(bus, &need); | |
1046 | if (r < 0) | |
1047 | return r; | |
1048 | ||
1049 | if (bus->rbuffer_size >= need) | |
7d22c717 | 1050 | return bus_socket_make_message(bus, need); |
a7e3212d LP |
1051 | |
1052 | return 1; | |
1053 | } | |
1054 | ||
1055 | int bus_socket_process_opening(sd_bus *b) { | |
1056 | int error = 0; | |
1057 | socklen_t slen = sizeof(error); | |
b92bea5d ZJS |
1058 | struct pollfd p = { |
1059 | .fd = b->output_fd, | |
1060 | .events = POLLOUT, | |
1061 | }; | |
a7e3212d LP |
1062 | int r; |
1063 | ||
a7e3212d LP |
1064 | assert(b->state == BUS_OPENING); |
1065 | ||
a7e3212d LP |
1066 | r = poll(&p, 1, 0); |
1067 | if (r < 0) | |
1068 | return -errno; | |
1069 | ||
1070 | if (!(p.revents & (POLLOUT|POLLERR|POLLHUP))) | |
1071 | return 0; | |
1072 | ||
e82c9509 | 1073 | r = getsockopt(b->output_fd, SOL_SOCKET, SO_ERROR, &error, &slen); |
a7e3212d LP |
1074 | if (r < 0) |
1075 | b->last_connect_error = errno; | |
1076 | else if (error != 0) | |
1077 | b->last_connect_error = error; | |
1078 | else if (p.revents & (POLLERR|POLLHUP)) | |
1079 | b->last_connect_error = ECONNREFUSED; | |
1080 | else | |
1081 | return bus_socket_start_auth(b); | |
1082 | ||
1083 | return bus_next_address(b); | |
1084 | } | |
1085 | ||
1086 | int bus_socket_process_authenticating(sd_bus *b) { | |
1087 | int r; | |
1088 | ||
1089 | assert(b); | |
1090 | assert(b->state == BUS_AUTHENTICATING); | |
1091 | ||
1092 | if (now(CLOCK_MONOTONIC) >= b->auth_timeout) | |
1093 | return -ETIMEDOUT; | |
1094 | ||
1095 | r = bus_socket_write_auth(b); | |
1096 | if (r != 0) | |
1097 | return r; | |
1098 | ||
1099 | return bus_socket_read_auth(b); | |
1100 | } |