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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" |
9ab32f9d | 34 | #include "sd-daemon.h" |
a7e3212d LP |
35 | |
36 | #include "sd-bus.h" | |
37 | #include "bus-socket.h" | |
38 | #include "bus-internal.h" | |
39 | #include "bus-message.h" | |
40 | ||
2181a7f5 | 41 | static void iovec_advance(struct iovec iov[], unsigned *idx, size_t size) { |
a7e3212d LP |
42 | |
43 | while (size > 0) { | |
44 | struct iovec *i = iov + *idx; | |
45 | ||
46 | if (i->iov_len > size) { | |
47 | i->iov_base = (uint8_t*) i->iov_base + size; | |
48 | i->iov_len -= size; | |
49 | return; | |
50 | } | |
51 | ||
52 | size -= i->iov_len; | |
53 | ||
54 | i->iov_base = NULL; | |
55 | i->iov_len = 0; | |
56 | ||
57 | (*idx) ++; | |
58 | } | |
59 | } | |
60 | ||
bc7fd8cd | 61 | static int append_iovec(sd_bus_message *m, const void *p, size_t sz) { |
2100fa10 LP |
62 | assert(m); |
63 | assert(p); | |
64 | assert(sz > 0); | |
65 | ||
66 | m->iovec[m->n_iovec].iov_base = (void*) p; | |
67 | m->iovec[m->n_iovec].iov_len = sz; | |
68 | m->n_iovec++; | |
bc7fd8cd LP |
69 | |
70 | return 0; | |
2100fa10 LP |
71 | } |
72 | ||
bc7fd8cd LP |
73 | static int bus_message_setup_iovec(sd_bus_message *m) { |
74 | struct bus_body_part *part; | |
13c299d3 | 75 | unsigned n, i; |
bc7fd8cd LP |
76 | int r; |
77 | ||
2100fa10 LP |
78 | assert(m); |
79 | assert(m->sealed); | |
80 | ||
81 | if (m->n_iovec > 0) | |
bc7fd8cd LP |
82 | return 0; |
83 | ||
84 | assert(!m->iovec); | |
2100fa10 | 85 | |
bc7fd8cd LP |
86 | n = 1 + !!m->fields + m->n_body_parts; |
87 | if (n < ELEMENTSOF(m->iovec_fixed)) | |
88 | m->iovec = m->iovec_fixed; | |
89 | else { | |
90 | m->iovec = new(struct iovec, n); | |
91 | if (!m->iovec) | |
92 | return -ENOMEM; | |
93 | } | |
2100fa10 | 94 | |
bc7fd8cd LP |
95 | r = append_iovec(m, m->header, sizeof(*m->header)); |
96 | if (r < 0) | |
97 | return r; | |
2100fa10 | 98 | |
bc7fd8cd LP |
99 | if (m->fields) { |
100 | r = append_iovec(m, m->fields, ALIGN8(m->header->fields_size)); | |
101 | if (r < 0) | |
102 | return r; | |
103 | } | |
104 | ||
9b29bb68 | 105 | MESSAGE_FOREACH_PART(part, i, m) { |
bc7fd8cd LP |
106 | r = append_iovec(m, part->data, part->size); |
107 | if (r < 0) | |
108 | return r; | |
109 | } | |
110 | ||
111 | assert(n == m->n_iovec); | |
112 | ||
113 | return 0; | |
2100fa10 LP |
114 | } |
115 | ||
2181a7f5 LP |
116 | bool bus_socket_auth_needs_write(sd_bus *b) { |
117 | ||
118 | unsigned i; | |
119 | ||
120 | if (b->auth_index >= ELEMENTSOF(b->auth_iovec)) | |
121 | return false; | |
122 | ||
123 | for (i = b->auth_index; i < ELEMENTSOF(b->auth_iovec); i++) { | |
124 | struct iovec *j = b->auth_iovec + i; | |
125 | ||
126 | if (j->iov_len > 0) | |
127 | return true; | |
128 | } | |
129 | ||
130 | return false; | |
131 | } | |
132 | ||
a7e3212d | 133 | static int bus_socket_write_auth(sd_bus *b) { |
a7e3212d LP |
134 | ssize_t k; |
135 | ||
136 | assert(b); | |
137 | assert(b->state == BUS_AUTHENTICATING); | |
138 | ||
2181a7f5 | 139 | if (!bus_socket_auth_needs_write(b)) |
a7e3212d LP |
140 | return 0; |
141 | ||
15d5af81 LP |
142 | if (b->prefer_writev) |
143 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
144 | else { | |
145 | struct msghdr mh; | |
146 | zero(mh); | |
147 | ||
148 | mh.msg_iov = b->auth_iovec + b->auth_index; | |
149 | mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index; | |
150 | ||
151 | k = sendmsg(b->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
152 | if (k < 0 && errno == ENOTSOCK) { | |
153 | b->prefer_writev = true; | |
154 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
155 | } | |
156 | } | |
a7e3212d | 157 | |
a7e3212d LP |
158 | if (k < 0) |
159 | return errno == EAGAIN ? 0 : -errno; | |
160 | ||
161 | iovec_advance(b->auth_iovec, &b->auth_index, (size_t) k); | |
a7e3212d LP |
162 | return 1; |
163 | } | |
164 | ||
2181a7f5 | 165 | static int bus_socket_auth_verify_client(sd_bus *b) { |
a7e3212d LP |
166 | char *e, *f, *start; |
167 | sd_id128_t peer; | |
168 | unsigned i; | |
169 | int r; | |
170 | ||
2181a7f5 LP |
171 | assert(b); |
172 | ||
a7e3212d LP |
173 | /* We expect two response lines: "OK" and possibly |
174 | * "AGREE_UNIX_FD" */ | |
175 | ||
176 | e = memmem(b->rbuffer, b->rbuffer_size, "\r\n", 2); | |
177 | if (!e) | |
178 | return 0; | |
179 | ||
180 | if (b->negotiate_fds) { | |
181 | f = memmem(e + 2, b->rbuffer_size - (e - (char*) b->rbuffer) - 2, "\r\n", 2); | |
182 | if (!f) | |
183 | return 0; | |
184 | ||
185 | start = f + 2; | |
186 | } else { | |
187 | f = NULL; | |
188 | start = e + 2; | |
189 | } | |
190 | ||
191 | /* Nice! We got all the lines we need. First check the OK | |
192 | * line */ | |
193 | ||
194 | if (e - (char*) b->rbuffer != 3 + 32) | |
195 | return -EPERM; | |
196 | ||
197 | if (memcmp(b->rbuffer, "OK ", 3)) | |
198 | return -EPERM; | |
199 | ||
2181a7f5 LP |
200 | b->auth = b->anonymous_auth ? BUS_AUTH_ANONYMOUS : BUS_AUTH_EXTERNAL; |
201 | ||
a7e3212d LP |
202 | for (i = 0; i < 32; i += 2) { |
203 | int x, y; | |
204 | ||
205 | x = unhexchar(((char*) b->rbuffer)[3 + i]); | |
206 | y = unhexchar(((char*) b->rbuffer)[3 + i + 1]); | |
207 | ||
208 | if (x < 0 || y < 0) | |
209 | return -EINVAL; | |
210 | ||
211 | peer.bytes[i/2] = ((uint8_t) x << 4 | (uint8_t) y); | |
212 | } | |
213 | ||
98178d39 LP |
214 | if (!sd_id128_equal(b->server_id, SD_ID128_NULL) && |
215 | !sd_id128_equal(b->server_id, peer)) | |
a7e3212d LP |
216 | return -EPERM; |
217 | ||
98178d39 | 218 | b->server_id = peer; |
a7e3212d LP |
219 | |
220 | /* And possibly check the second line, too */ | |
221 | ||
222 | if (f) | |
223 | b->can_fds = | |
224 | (f - e == sizeof("\r\nAGREE_UNIX_FD") - 1) && | |
225 | memcmp(e + 2, "AGREE_UNIX_FD", sizeof("AGREE_UNIX_FD") - 1) == 0; | |
226 | ||
227 | b->rbuffer_size -= (start - (char*) b->rbuffer); | |
228 | memmove(b->rbuffer, start, b->rbuffer_size); | |
229 | ||
230 | r = bus_start_running(b); | |
231 | if (r < 0) | |
232 | return r; | |
233 | ||
234 | return 1; | |
235 | } | |
236 | ||
2181a7f5 LP |
237 | static bool line_equals(const char *s, size_t m, const char *line) { |
238 | size_t l; | |
239 | ||
240 | l = strlen(line); | |
241 | if (l != m) | |
242 | return false; | |
243 | ||
244 | return memcmp(s, line, l) == 0; | |
245 | } | |
246 | ||
247 | static bool line_begins(const char *s, size_t m, const char *word) { | |
248 | size_t l; | |
249 | ||
250 | l = strlen(word); | |
251 | if (m < l) | |
252 | return false; | |
253 | ||
254 | if (memcmp(s, word, l) != 0) | |
255 | return false; | |
256 | ||
257 | return m == l || (m > l && s[l] == ' '); | |
258 | } | |
259 | ||
260 | static int verify_anonymous_token(sd_bus *b, const char *p, size_t l) { | |
261 | _cleanup_free_ char *token = NULL; | |
262 | ||
263 | if (!b->anonymous_auth) | |
264 | return 0; | |
265 | ||
266 | if (l <= 0) | |
267 | return 1; | |
268 | ||
269 | assert(p[0] == ' '); | |
270 | p++; l--; | |
271 | ||
272 | if (l % 2 != 0) | |
273 | return 0; | |
274 | token = unhexmem(p, l); | |
275 | if (!token) | |
276 | return -ENOMEM; | |
277 | ||
278 | if (memchr(token, 0, l/2)) | |
279 | return 0; | |
280 | ||
281 | return !!utf8_is_valid(token); | |
282 | } | |
283 | ||
284 | static int verify_external_token(sd_bus *b, const char *p, size_t l) { | |
285 | _cleanup_free_ char *token = NULL; | |
286 | uid_t u; | |
287 | int r; | |
288 | ||
289 | /* We don't do any real authentication here. Instead, we if | |
290 | * the owner of this bus wanted authentication he should have | |
291 | * checked SO_PEERCRED before even creating the bus object. */ | |
292 | ||
8411d2a2 | 293 | if (!b->anonymous_auth && !b->ucred_valid) |
2181a7f5 LP |
294 | return 0; |
295 | ||
296 | if (l <= 0) | |
297 | return 1; | |
298 | ||
299 | assert(p[0] == ' '); | |
300 | p++; l--; | |
301 | ||
302 | if (l % 2 != 0) | |
303 | return 0; | |
304 | ||
305 | token = unhexmem(p, l); | |
306 | if (!token) | |
307 | return -ENOMEM; | |
308 | ||
309 | if (memchr(token, 0, l/2)) | |
310 | return 0; | |
311 | ||
312 | r = parse_uid(token, &u); | |
313 | if (r < 0) | |
314 | return 0; | |
315 | ||
8411d2a2 LP |
316 | /* We ignore the passed value if anonymous authentication is |
317 | * on anyway. */ | |
318 | if (!b->anonymous_auth && u != b->ucred.uid) | |
2181a7f5 LP |
319 | return 0; |
320 | ||
321 | return 1; | |
322 | } | |
323 | ||
324 | static int bus_socket_auth_write(sd_bus *b, const char *t) { | |
325 | char *p; | |
326 | size_t l; | |
327 | ||
328 | assert(b); | |
329 | assert(t); | |
330 | ||
331 | /* We only make use of the first iovec */ | |
332 | assert(b->auth_index == 0 || b->auth_index == 1); | |
333 | ||
334 | l = strlen(t); | |
335 | p = malloc(b->auth_iovec[0].iov_len + l); | |
336 | if (!p) | |
337 | return -ENOMEM; | |
338 | ||
339 | memcpy(p, b->auth_iovec[0].iov_base, b->auth_iovec[0].iov_len); | |
340 | memcpy(p + b->auth_iovec[0].iov_len, t, l); | |
341 | ||
342 | b->auth_iovec[0].iov_base = p; | |
343 | b->auth_iovec[0].iov_len += l; | |
344 | ||
345 | free(b->auth_buffer); | |
346 | b->auth_buffer = p; | |
347 | b->auth_index = 0; | |
348 | return 0; | |
349 | } | |
350 | ||
351 | static int bus_socket_auth_write_ok(sd_bus *b) { | |
352 | char t[3 + 32 + 2 + 1]; | |
353 | ||
354 | assert(b); | |
355 | ||
98178d39 | 356 | snprintf(t, sizeof(t), "OK " SD_ID128_FORMAT_STR "\r\n", SD_ID128_FORMAT_VAL(b->server_id)); |
2181a7f5 LP |
357 | char_array_0(t); |
358 | ||
359 | return bus_socket_auth_write(b, t); | |
360 | } | |
361 | ||
362 | static int bus_socket_auth_verify_server(sd_bus *b) { | |
363 | char *e; | |
364 | const char *line; | |
365 | size_t l; | |
366 | bool processed = false; | |
367 | int r; | |
368 | ||
369 | assert(b); | |
370 | ||
2b4ac889 | 371 | if (b->rbuffer_size < 1) |
2181a7f5 LP |
372 | return 0; |
373 | ||
374 | /* First char must be a NUL byte */ | |
375 | if (*(char*) b->rbuffer != 0) | |
376 | return -EIO; | |
377 | ||
2b4ac889 LP |
378 | if (b->rbuffer_size < 3) |
379 | return 0; | |
380 | ||
2181a7f5 LP |
381 | /* Begin with the first line */ |
382 | if (b->auth_rbegin <= 0) | |
383 | b->auth_rbegin = 1; | |
384 | ||
385 | for (;;) { | |
386 | /* Check if line is complete */ | |
387 | line = (char*) b->rbuffer + b->auth_rbegin; | |
388 | e = memmem(line, b->rbuffer_size - b->auth_rbegin, "\r\n", 2); | |
389 | if (!e) | |
390 | return processed; | |
391 | ||
392 | l = e - line; | |
393 | ||
394 | if (line_begins(line, l, "AUTH ANONYMOUS")) { | |
395 | ||
396 | r = verify_anonymous_token(b, line + 14, l - 14); | |
397 | if (r < 0) | |
398 | return r; | |
399 | if (r == 0) | |
400 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
401 | else { | |
402 | b->auth = BUS_AUTH_ANONYMOUS; | |
403 | r = bus_socket_auth_write_ok(b); | |
404 | } | |
405 | ||
406 | } else if (line_begins(line, l, "AUTH EXTERNAL")) { | |
407 | ||
408 | r = verify_external_token(b, line + 13, l - 13); | |
409 | if (r < 0) | |
410 | return r; | |
411 | if (r == 0) | |
412 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
413 | else { | |
414 | b->auth = BUS_AUTH_EXTERNAL; | |
415 | r = bus_socket_auth_write_ok(b); | |
416 | } | |
417 | ||
418 | } else if (line_begins(line, l, "AUTH")) | |
419 | r = bus_socket_auth_write(b, "REJECTED EXTERNAL ANONYMOUS\r\n"); | |
420 | else if (line_equals(line, l, "CANCEL") || | |
421 | line_begins(line, l, "ERROR")) { | |
422 | ||
423 | b->auth = _BUS_AUTH_INVALID; | |
424 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
425 | ||
426 | } else if (line_equals(line, l, "BEGIN")) { | |
427 | ||
428 | if (b->auth == _BUS_AUTH_INVALID) | |
429 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
430 | else { | |
431 | /* We can't leave from the auth phase | |
432 | * before we haven't written | |
433 | * everything queued, so let's check | |
434 | * that */ | |
435 | ||
436 | if (bus_socket_auth_needs_write(b)) | |
437 | return 1; | |
438 | ||
439 | b->rbuffer_size -= (e + 2 - (char*) b->rbuffer); | |
440 | memmove(b->rbuffer, e + 2, b->rbuffer_size); | |
441 | return bus_start_running(b); | |
442 | } | |
443 | ||
444 | } else if (line_begins(line, l, "DATA")) { | |
445 | ||
446 | if (b->auth == _BUS_AUTH_INVALID) | |
447 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
448 | else { | |
449 | if (b->auth == BUS_AUTH_ANONYMOUS) | |
450 | r = verify_anonymous_token(b, line + 4, l - 4); | |
451 | else | |
452 | r = verify_external_token(b, line + 4, l - 4); | |
453 | ||
454 | if (r < 0) | |
455 | return r; | |
456 | if (r == 0) { | |
457 | b->auth = _BUS_AUTH_INVALID; | |
458 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
459 | } else | |
460 | r = bus_socket_auth_write_ok(b); | |
461 | } | |
462 | } else if (line_equals(line, l, "NEGOTIATE_UNIX_FD")) { | |
463 | if (b->auth == _BUS_AUTH_INVALID || !b->negotiate_fds) | |
464 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
465 | else { | |
466 | b->can_fds = true; | |
467 | r = bus_socket_auth_write(b, "AGREE_UNIX_FD\r\n"); | |
468 | } | |
469 | } else | |
470 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
471 | ||
472 | if (r < 0) | |
473 | return r; | |
474 | ||
475 | b->auth_rbegin = e + 2 - (char*) b->rbuffer; | |
476 | ||
477 | processed = true; | |
478 | } | |
479 | } | |
480 | ||
481 | static int bus_socket_auth_verify(sd_bus *b) { | |
482 | assert(b); | |
483 | ||
484 | if (b->is_server) | |
485 | return bus_socket_auth_verify_server(b); | |
486 | else | |
487 | return bus_socket_auth_verify_client(b); | |
488 | } | |
489 | ||
a7e3212d LP |
490 | static int bus_socket_read_auth(sd_bus *b) { |
491 | struct msghdr mh; | |
492 | struct iovec iov; | |
493 | size_t n; | |
494 | ssize_t k; | |
495 | int r; | |
496 | void *p; | |
2181a7f5 LP |
497 | union { |
498 | struct cmsghdr cmsghdr; | |
499 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
500 | CMSG_SPACE(sizeof(struct ucred)) + | |
501 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
502 | } control; | |
503 | struct cmsghdr *cmsg; | |
15d5af81 | 504 | bool handle_cmsg = false; |
a7e3212d LP |
505 | |
506 | assert(b); | |
2181a7f5 | 507 | assert(b->state == BUS_AUTHENTICATING); |
a7e3212d LP |
508 | |
509 | r = bus_socket_auth_verify(b); | |
510 | if (r != 0) | |
511 | return r; | |
512 | ||
9607d947 | 513 | n = MAX(256u, b->rbuffer_size * 2); |
a7e3212d LP |
514 | |
515 | if (n > BUS_AUTH_SIZE_MAX) | |
516 | n = BUS_AUTH_SIZE_MAX; | |
517 | ||
518 | if (b->rbuffer_size >= n) | |
519 | return -ENOBUFS; | |
520 | ||
521 | p = realloc(b->rbuffer, n); | |
522 | if (!p) | |
523 | return -ENOMEM; | |
524 | ||
525 | b->rbuffer = p; | |
526 | ||
527 | zero(iov); | |
528 | iov.iov_base = (uint8_t*) b->rbuffer + b->rbuffer_size; | |
529 | iov.iov_len = n - b->rbuffer_size; | |
530 | ||
15d5af81 LP |
531 | if (b->prefer_readv) |
532 | k = readv(b->input_fd, &iov, 1); | |
533 | else { | |
534 | zero(mh); | |
535 | mh.msg_iov = &iov; | |
536 | mh.msg_iovlen = 1; | |
537 | mh.msg_control = &control; | |
538 | mh.msg_controllen = sizeof(control); | |
539 | ||
540 | k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
541 | if (k < 0 && errno == ENOTSOCK) { | |
542 | b->prefer_readv = true; | |
543 | k = readv(b->input_fd, &iov, 1); | |
544 | } else | |
545 | handle_cmsg = true; | |
546 | } | |
a7e3212d LP |
547 | if (k < 0) |
548 | return errno == EAGAIN ? 0 : -errno; | |
549 | if (k == 0) | |
550 | return -ECONNRESET; | |
551 | ||
552 | b->rbuffer_size += k; | |
553 | ||
15d5af81 LP |
554 | if (handle_cmsg) { |
555 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
556 | if (cmsg->cmsg_level == SOL_SOCKET && | |
557 | cmsg->cmsg_type == SCM_RIGHTS) { | |
558 | int j; | |
559 | ||
560 | /* Whut? We received fds during the auth | |
561 | * protocol? Somebody is playing games with | |
562 | * us. Close them all, and fail */ | |
563 | j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
564 | close_many((int*) CMSG_DATA(cmsg), j); | |
565 | return -EIO; | |
2181a7f5 | 566 | |
15d5af81 LP |
567 | } else if (cmsg->cmsg_level == SOL_SOCKET && |
568 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
569 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
2181a7f5 | 570 | |
ea8f194f LP |
571 | /* Ignore bogus data, which we might |
572 | * get on socketpair() sockets */ | |
573 | if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { | |
574 | memcpy(&b->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
575 | b->ucred_valid = true; | |
576 | } | |
2181a7f5 | 577 | |
15d5af81 LP |
578 | } else if (cmsg->cmsg_level == SOL_SOCKET && |
579 | cmsg->cmsg_type == SCM_SECURITY) { | |
2181a7f5 | 580 | |
15d5af81 | 581 | size_t l; |
ea8f194f | 582 | |
15d5af81 | 583 | l = cmsg->cmsg_len - CMSG_LEN(0); |
ea8f194f LP |
584 | if (l > 0) { |
585 | memcpy(&b->label, CMSG_DATA(cmsg), l); | |
586 | b->label[l] = 0; | |
587 | } | |
15d5af81 | 588 | } |
2181a7f5 LP |
589 | } |
590 | } | |
591 | ||
a7e3212d LP |
592 | r = bus_socket_auth_verify(b); |
593 | if (r != 0) | |
594 | return r; | |
595 | ||
596 | return 1; | |
597 | } | |
598 | ||
599 | static int bus_socket_setup(sd_bus *b) { | |
0f4b73c8 | 600 | int enable; |
ea8f194f | 601 | socklen_t l; |
a7e3212d LP |
602 | |
603 | assert(b); | |
604 | ||
d65ddaa4 LP |
605 | /* Enable SO_PASSCRED + SO_PASSEC. We try this on any |
606 | * socket, just in case. */ | |
0f4b73c8 | 607 | enable = !b->bus_client; |
e82c9509 LP |
608 | setsockopt(b->input_fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(enable)); |
609 | setsockopt(b->input_fd, SOL_SOCKET, SO_PASSSEC, &enable, sizeof(enable)); | |
a7e3212d LP |
610 | |
611 | /* Increase the buffers to a MB */ | |
e82c9509 LP |
612 | fd_inc_rcvbuf(b->input_fd, 1024*1024); |
613 | fd_inc_sndbuf(b->output_fd, 1024*1024); | |
a7e3212d | 614 | |
ea8f194f LP |
615 | /* Get the peer for socketpair() sockets */ |
616 | l = sizeof(b->ucred); | |
617 | if (getsockopt(b->input_fd, SOL_SOCKET, SO_PEERCRED, &b->ucred, &l) >= 0 && l >= sizeof(b->ucred)) | |
618 | b->ucred_valid = b->ucred.pid > 0; | |
619 | ||
a7e3212d LP |
620 | return 0; |
621 | } | |
622 | ||
2181a7f5 | 623 | static int bus_socket_start_auth_client(sd_bus *b) { |
a7e3212d | 624 | size_t l; |
2181a7f5 | 625 | const char *auth_suffix, *auth_prefix; |
a7e3212d LP |
626 | |
627 | assert(b); | |
628 | ||
2181a7f5 LP |
629 | if (b->anonymous_auth) { |
630 | auth_prefix = "\0AUTH ANONYMOUS "; | |
a7e3212d | 631 | |
2181a7f5 LP |
632 | /* For ANONYMOUS auth we send some arbitrary "trace" string */ |
633 | l = 9; | |
634 | b->auth_buffer = hexmem("anonymous", l); | |
635 | } else { | |
636 | char text[20 + 1]; /* enough space for a 64bit integer plus NUL */ | |
a7e3212d | 637 | |
2181a7f5 | 638 | auth_prefix = "\0AUTH EXTERNAL "; |
a7e3212d | 639 | |
2181a7f5 LP |
640 | snprintf(text, sizeof(text), "%lu", (unsigned long) geteuid()); |
641 | char_array_0(text); | |
a7e3212d | 642 | |
2181a7f5 LP |
643 | l = strlen(text); |
644 | b->auth_buffer = hexmem(text, l); | |
645 | } | |
646 | ||
647 | if (!b->auth_buffer) | |
a7e3212d LP |
648 | return -ENOMEM; |
649 | ||
2181a7f5 LP |
650 | if (b->negotiate_fds) |
651 | auth_suffix = "\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n"; | |
652 | else | |
653 | auth_suffix = "\r\nBEGIN\r\n"; | |
a7e3212d LP |
654 | |
655 | b->auth_iovec[0].iov_base = (void*) auth_prefix; | |
2181a7f5 LP |
656 | b->auth_iovec[0].iov_len = 1 + strlen(auth_prefix + 1); |
657 | b->auth_iovec[1].iov_base = (void*) b->auth_buffer; | |
a7e3212d LP |
658 | b->auth_iovec[1].iov_len = l * 2; |
659 | b->auth_iovec[2].iov_base = (void*) auth_suffix; | |
660 | b->auth_iovec[2].iov_len = strlen(auth_suffix); | |
a7e3212d LP |
661 | |
662 | return bus_socket_write_auth(b); | |
663 | } | |
664 | ||
2181a7f5 | 665 | static int bus_socket_start_auth(sd_bus *b) { |
2181a7f5 LP |
666 | assert(b); |
667 | ||
668 | b->state = BUS_AUTHENTICATING; | |
669 | b->auth_timeout = now(CLOCK_MONOTONIC) + BUS_DEFAULT_TIMEOUT; | |
670 | ||
9ab32f9d | 671 | if (sd_is_socket(b->input_fd, AF_UNIX, 0, 0) <= 0) |
2181a7f5 LP |
672 | b->negotiate_fds = false; |
673 | ||
9ab32f9d LP |
674 | if (b->output_fd != b->input_fd) |
675 | if (sd_is_socket(b->output_fd, AF_UNIX, 0, 0) <= 0) | |
e82c9509 | 676 | b->negotiate_fds = false; |
e82c9509 | 677 | |
2181a7f5 LP |
678 | if (b->is_server) |
679 | return bus_socket_read_auth(b); | |
680 | else | |
681 | return bus_socket_start_auth_client(b); | |
682 | } | |
683 | ||
a7e3212d LP |
684 | int bus_socket_connect(sd_bus *b) { |
685 | int r; | |
686 | ||
687 | assert(b); | |
e82c9509 LP |
688 | assert(b->input_fd < 0); |
689 | assert(b->output_fd < 0); | |
a7e3212d LP |
690 | assert(b->sockaddr.sa.sa_family != AF_UNSPEC); |
691 | ||
e82c9509 LP |
692 | b->input_fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
693 | if (b->input_fd < 0) | |
a7e3212d LP |
694 | return -errno; |
695 | ||
e82c9509 LP |
696 | b->output_fd = b->input_fd; |
697 | ||
a7e3212d LP |
698 | r = bus_socket_setup(b); |
699 | if (r < 0) | |
700 | return r; | |
701 | ||
e82c9509 | 702 | r = connect(b->input_fd, &b->sockaddr.sa, b->sockaddr_size); |
a7e3212d LP |
703 | if (r < 0) { |
704 | if (errno == EINPROGRESS) | |
705 | return 1; | |
706 | ||
707 | return -errno; | |
708 | } | |
709 | ||
710 | return bus_socket_start_auth(b); | |
711 | } | |
712 | ||
713 | int bus_socket_exec(sd_bus *b) { | |
e82c9509 | 714 | int s[2], r; |
a7e3212d LP |
715 | pid_t pid; |
716 | ||
717 | assert(b); | |
e82c9509 LP |
718 | assert(b->input_fd < 0); |
719 | assert(b->output_fd < 0); | |
a7e3212d LP |
720 | assert(b->exec_path); |
721 | ||
e82c9509 LP |
722 | r = socketpair(AF_UNIX, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, s); |
723 | if (r < 0) | |
a7e3212d LP |
724 | return -errno; |
725 | ||
726 | pid = fork(); | |
727 | if (pid < 0) { | |
728 | close_pipe(s); | |
729 | return -errno; | |
730 | } | |
731 | if (pid == 0) { | |
732 | /* Child */ | |
733 | ||
e82c9509 LP |
734 | reset_all_signal_handlers(); |
735 | ||
736 | close_all_fds(s+1, 1); | |
a7e3212d LP |
737 | |
738 | assert_se(dup3(s[1], STDIN_FILENO, 0) == STDIN_FILENO); | |
739 | assert_se(dup3(s[1], STDOUT_FILENO, 0) == STDOUT_FILENO); | |
740 | ||
741 | if (s[1] != STDIN_FILENO && s[1] != STDOUT_FILENO) | |
742 | close_nointr_nofail(s[1]); | |
743 | ||
744 | fd_cloexec(STDIN_FILENO, false); | |
745 | fd_cloexec(STDOUT_FILENO, false); | |
746 | fd_nonblock(STDIN_FILENO, false); | |
747 | fd_nonblock(STDOUT_FILENO, false); | |
748 | ||
749 | if (b->exec_argv) | |
750 | execvp(b->exec_path, b->exec_argv); | |
751 | else { | |
752 | const char *argv[] = { b->exec_path, NULL }; | |
753 | execvp(b->exec_path, (char**) argv); | |
754 | } | |
755 | ||
756 | _exit(EXIT_FAILURE); | |
757 | } | |
758 | ||
759 | close_nointr_nofail(s[1]); | |
e82c9509 | 760 | b->output_fd = b->input_fd = s[0]; |
a7e3212d LP |
761 | |
762 | return bus_socket_start_auth(b); | |
763 | } | |
764 | ||
765 | int bus_socket_take_fd(sd_bus *b) { | |
766 | int r; | |
767 | assert(b); | |
768 | ||
769 | r = bus_socket_setup(b); | |
770 | if (r < 0) | |
771 | return r; | |
772 | ||
773 | return bus_socket_start_auth(b); | |
774 | } | |
775 | ||
776 | int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) { | |
a7e3212d LP |
777 | struct iovec *iov; |
778 | ssize_t k; | |
779 | size_t n; | |
780 | unsigned j; | |
bc7fd8cd | 781 | int r; |
a7e3212d LP |
782 | |
783 | assert(bus); | |
784 | assert(m); | |
785 | assert(idx); | |
786 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
787 | ||
6629161f | 788 | if (*idx >= BUS_MESSAGE_SIZE(m)) |
a7e3212d | 789 | return 0; |
a7e3212d | 790 | |
bc7fd8cd LP |
791 | r = bus_message_setup_iovec(m); |
792 | if (r < 0) | |
793 | return r; | |
2100fa10 | 794 | |
a7e3212d LP |
795 | n = m->n_iovec * sizeof(struct iovec); |
796 | iov = alloca(n); | |
797 | memcpy(iov, m->iovec, n); | |
798 | ||
799 | j = 0; | |
800 | iovec_advance(iov, &j, *idx); | |
801 | ||
15d5af81 LP |
802 | if (bus->prefer_writev) |
803 | k = writev(bus->output_fd, iov, m->n_iovec); | |
804 | else { | |
805 | struct msghdr mh; | |
806 | zero(mh); | |
807 | ||
808 | if (m->n_fds > 0) { | |
809 | struct cmsghdr *control; | |
810 | control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds)); | |
811 | ||
812 | mh.msg_control = control; | |
813 | control->cmsg_level = SOL_SOCKET; | |
814 | control->cmsg_type = SCM_RIGHTS; | |
815 | mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds); | |
816 | memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds); | |
817 | } | |
818 | ||
819 | mh.msg_iov = iov; | |
820 | mh.msg_iovlen = m->n_iovec; | |
821 | ||
822 | k = sendmsg(bus->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
823 | if (k < 0 && errno == ENOTSOCK) { | |
824 | bus->prefer_writev = true; | |
825 | k = writev(bus->output_fd, iov, m->n_iovec); | |
826 | } | |
827 | } | |
a7e3212d | 828 | |
a7e3212d LP |
829 | if (k < 0) |
830 | return errno == EAGAIN ? 0 : -errno; | |
831 | ||
832 | *idx += (size_t) k; | |
833 | return 1; | |
834 | } | |
835 | ||
836 | static int bus_socket_read_message_need(sd_bus *bus, size_t *need) { | |
837 | uint32_t a, b; | |
838 | uint8_t e; | |
839 | uint64_t sum; | |
840 | ||
841 | assert(bus); | |
842 | assert(need); | |
843 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
844 | ||
845 | if (bus->rbuffer_size < sizeof(struct bus_header)) { | |
846 | *need = sizeof(struct bus_header) + 8; | |
847 | ||
848 | /* Minimum message size: | |
849 | * | |
850 | * Header + | |
851 | * | |
852 | * Method Call: +2 string headers | |
853 | * Signal: +3 string headers | |
854 | * Method Error: +1 string headers | |
855 | * +1 uint32 headers | |
856 | * Method Reply: +1 uint32 headers | |
857 | * | |
858 | * A string header is at least 9 bytes | |
859 | * A uint32 header is at least 8 bytes | |
860 | * | |
861 | * Hence the minimum message size of a valid message | |
862 | * is header + 8 bytes */ | |
863 | ||
864 | return 0; | |
865 | } | |
866 | ||
867 | a = ((const uint32_t*) bus->rbuffer)[1]; | |
868 | b = ((const uint32_t*) bus->rbuffer)[3]; | |
869 | ||
870 | e = ((const uint8_t*) bus->rbuffer)[0]; | |
871 | if (e == SD_BUS_LITTLE_ENDIAN) { | |
872 | a = le32toh(a); | |
873 | b = le32toh(b); | |
874 | } else if (e == SD_BUS_BIG_ENDIAN) { | |
875 | a = be32toh(a); | |
876 | b = be32toh(b); | |
877 | } else | |
878 | return -EBADMSG; | |
879 | ||
880 | sum = (uint64_t) sizeof(struct bus_header) + (uint64_t) ALIGN_TO(b, 8) + (uint64_t) a; | |
881 | if (sum >= BUS_MESSAGE_SIZE_MAX) | |
882 | return -ENOBUFS; | |
883 | ||
884 | *need = (size_t) sum; | |
885 | return 0; | |
886 | } | |
887 | ||
888 | static int bus_socket_make_message(sd_bus *bus, size_t size, sd_bus_message **m) { | |
889 | sd_bus_message *t; | |
890 | void *b; | |
891 | int r; | |
892 | ||
893 | assert(bus); | |
894 | assert(m); | |
895 | assert(bus->rbuffer_size >= size); | |
896 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
897 | ||
898 | if (bus->rbuffer_size > size) { | |
899 | b = memdup((const uint8_t*) bus->rbuffer + size, | |
900 | bus->rbuffer_size - size); | |
901 | if (!b) | |
902 | return -ENOMEM; | |
903 | } else | |
904 | b = NULL; | |
905 | ||
906 | r = bus_message_from_malloc(bus->rbuffer, size, | |
907 | bus->fds, bus->n_fds, | |
0f4b73c8 LP |
908 | bus->ucred_valid ? &bus->ucred : NULL, |
909 | bus->label[0] ? bus->label : NULL, | |
a7e3212d LP |
910 | &t); |
911 | if (r < 0) { | |
912 | free(b); | |
913 | return r; | |
914 | } | |
915 | ||
916 | bus->rbuffer = b; | |
917 | bus->rbuffer_size -= size; | |
918 | ||
919 | bus->fds = NULL; | |
920 | bus->n_fds = 0; | |
921 | ||
922 | *m = t; | |
923 | return 1; | |
924 | } | |
925 | ||
926 | int bus_socket_read_message(sd_bus *bus, sd_bus_message **m) { | |
927 | struct msghdr mh; | |
928 | struct iovec iov; | |
929 | ssize_t k; | |
930 | size_t need; | |
931 | int r; | |
932 | void *b; | |
933 | union { | |
934 | struct cmsghdr cmsghdr; | |
935 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
936 | CMSG_SPACE(sizeof(struct ucred)) + | |
937 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
938 | } control; | |
939 | struct cmsghdr *cmsg; | |
4d3a5b10 | 940 | bool handle_cmsg = false; |
a7e3212d LP |
941 | |
942 | assert(bus); | |
943 | assert(m); | |
944 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
945 | ||
946 | r = bus_socket_read_message_need(bus, &need); | |
947 | if (r < 0) | |
948 | return r; | |
949 | ||
950 | if (bus->rbuffer_size >= need) | |
951 | return bus_socket_make_message(bus, need, m); | |
952 | ||
953 | b = realloc(bus->rbuffer, need); | |
954 | if (!b) | |
955 | return -ENOMEM; | |
956 | ||
957 | bus->rbuffer = b; | |
958 | ||
959 | zero(iov); | |
960 | iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size; | |
961 | iov.iov_len = need - bus->rbuffer_size; | |
962 | ||
15d5af81 LP |
963 | if (bus->prefer_readv) |
964 | k = readv(bus->input_fd, &iov, 1); | |
965 | else { | |
966 | zero(mh); | |
967 | mh.msg_iov = &iov; | |
968 | mh.msg_iovlen = 1; | |
969 | mh.msg_control = &control; | |
970 | mh.msg_controllen = sizeof(control); | |
971 | ||
972 | k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
973 | if (k < 0 && errno == ENOTSOCK) { | |
974 | bus->prefer_readv = true; | |
975 | k = readv(bus->input_fd, &iov, 1); | |
976 | } else | |
977 | handle_cmsg = true; | |
978 | } | |
a7e3212d LP |
979 | if (k < 0) |
980 | return errno == EAGAIN ? 0 : -errno; | |
981 | if (k == 0) | |
982 | return -ECONNRESET; | |
983 | ||
984 | bus->rbuffer_size += k; | |
985 | ||
15d5af81 LP |
986 | if (handle_cmsg) { |
987 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
988 | if (cmsg->cmsg_level == SOL_SOCKET && | |
989 | cmsg->cmsg_type == SCM_RIGHTS) { | |
990 | int n, *f; | |
991 | ||
992 | n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
993 | ||
994 | if (!bus->can_fds) { | |
995 | /* Whut? We received fds but this | |
996 | * isn't actually enabled? Close them, | |
997 | * and fail */ | |
998 | ||
999 | close_many((int*) CMSG_DATA(cmsg), n); | |
1000 | return -EIO; | |
1001 | } | |
1002 | ||
1003 | f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n)); | |
1004 | if (!f) { | |
1005 | close_many((int*) CMSG_DATA(cmsg), n); | |
1006 | return -ENOMEM; | |
1007 | } | |
1008 | ||
1009 | memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int)); | |
1010 | bus->fds = f; | |
1011 | bus->n_fds += n; | |
1012 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1013 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
1014 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
1015 | ||
ea8f194f LP |
1016 | /* Ignore bogus data, which we might |
1017 | * get on socketpair() sockets */ | |
1018 | if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { | |
1019 | memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
1020 | bus->ucred_valid = true; | |
1021 | } | |
15d5af81 LP |
1022 | |
1023 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1024 | cmsg->cmsg_type == SCM_SECURITY) { | |
1025 | ||
1026 | size_t l; | |
1027 | l = cmsg->cmsg_len - CMSG_LEN(0); | |
ea8f194f LP |
1028 | if (l > 0) { |
1029 | memcpy(&bus->label, CMSG_DATA(cmsg), l); | |
1030 | bus->label[l] = 0; | |
1031 | } | |
a7e3212d | 1032 | } |
a7e3212d LP |
1033 | } |
1034 | } | |
1035 | ||
1036 | r = bus_socket_read_message_need(bus, &need); | |
1037 | if (r < 0) | |
1038 | return r; | |
1039 | ||
1040 | if (bus->rbuffer_size >= need) | |
1041 | return bus_socket_make_message(bus, need, m); | |
1042 | ||
1043 | return 1; | |
1044 | } | |
1045 | ||
1046 | int bus_socket_process_opening(sd_bus *b) { | |
1047 | int error = 0; | |
1048 | socklen_t slen = sizeof(error); | |
b92bea5d ZJS |
1049 | struct pollfd p = { |
1050 | .fd = b->output_fd, | |
1051 | .events = POLLOUT, | |
1052 | }; | |
a7e3212d LP |
1053 | int r; |
1054 | ||
a7e3212d LP |
1055 | assert(b->state == BUS_OPENING); |
1056 | ||
a7e3212d LP |
1057 | r = poll(&p, 1, 0); |
1058 | if (r < 0) | |
1059 | return -errno; | |
1060 | ||
1061 | if (!(p.revents & (POLLOUT|POLLERR|POLLHUP))) | |
1062 | return 0; | |
1063 | ||
e82c9509 | 1064 | r = getsockopt(b->output_fd, SOL_SOCKET, SO_ERROR, &error, &slen); |
a7e3212d LP |
1065 | if (r < 0) |
1066 | b->last_connect_error = errno; | |
1067 | else if (error != 0) | |
1068 | b->last_connect_error = error; | |
1069 | else if (p.revents & (POLLERR|POLLHUP)) | |
1070 | b->last_connect_error = ECONNREFUSED; | |
1071 | else | |
1072 | return bus_socket_start_auth(b); | |
1073 | ||
1074 | return bus_next_address(b); | |
1075 | } | |
1076 | ||
1077 | int bus_socket_process_authenticating(sd_bus *b) { | |
1078 | int r; | |
1079 | ||
1080 | assert(b); | |
1081 | assert(b->state == BUS_AUTHENTICATING); | |
1082 | ||
1083 | if (now(CLOCK_MONOTONIC) >= b->auth_timeout) | |
1084 | return -ETIMEDOUT; | |
1085 | ||
1086 | r = bus_socket_write_auth(b); | |
1087 | if (r != 0) | |
1088 | return r; | |
1089 | ||
1090 | return bus_socket_read_auth(b); | |
1091 | } |