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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 | 26 | |
24882e06 | 27 | #include "sd-daemon.h" |
a7e3212d LP |
28 | #include "util.h" |
29 | #include "macro.h" | |
30 | #include "missing.h" | |
2181a7f5 | 31 | #include "utf8.h" |
6482f626 | 32 | #include "formats-util.h" |
24882e06 | 33 | #include "signal-util.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 | ||
aec6d91f LP |
40 | #define SNDBUF_SIZE (8*1024*1024) |
41 | ||
2181a7f5 | 42 | static void iovec_advance(struct iovec iov[], unsigned *idx, size_t size) { |
a7e3212d LP |
43 | |
44 | while (size > 0) { | |
45 | struct iovec *i = iov + *idx; | |
46 | ||
47 | if (i->iov_len > size) { | |
48 | i->iov_base = (uint8_t*) i->iov_base + size; | |
49 | i->iov_len -= size; | |
50 | return; | |
51 | } | |
52 | ||
53 | size -= i->iov_len; | |
54 | ||
55 | i->iov_base = NULL; | |
56 | i->iov_len = 0; | |
57 | ||
58 | (*idx) ++; | |
59 | } | |
60 | } | |
61 | ||
bc7fd8cd | 62 | static int append_iovec(sd_bus_message *m, const void *p, size_t sz) { |
2100fa10 LP |
63 | assert(m); |
64 | assert(p); | |
65 | assert(sz > 0); | |
66 | ||
67 | m->iovec[m->n_iovec].iov_base = (void*) p; | |
68 | m->iovec[m->n_iovec].iov_len = sz; | |
69 | m->n_iovec++; | |
bc7fd8cd LP |
70 | |
71 | return 0; | |
2100fa10 LP |
72 | } |
73 | ||
bc7fd8cd LP |
74 | static int bus_message_setup_iovec(sd_bus_message *m) { |
75 | struct bus_body_part *part; | |
13c299d3 | 76 | unsigned n, i; |
bc7fd8cd LP |
77 | int r; |
78 | ||
2100fa10 LP |
79 | assert(m); |
80 | assert(m->sealed); | |
81 | ||
82 | if (m->n_iovec > 0) | |
bc7fd8cd LP |
83 | return 0; |
84 | ||
85 | assert(!m->iovec); | |
2100fa10 | 86 | |
c91cb83c | 87 | n = 1 + m->n_body_parts; |
bc7fd8cd LP |
88 | if (n < ELEMENTSOF(m->iovec_fixed)) |
89 | m->iovec = m->iovec_fixed; | |
90 | else { | |
91 | m->iovec = new(struct iovec, n); | |
66b26c5c LP |
92 | if (!m->iovec) { |
93 | r = -ENOMEM; | |
94 | goto fail; | |
95 | } | |
bc7fd8cd | 96 | } |
2100fa10 | 97 | |
c91cb83c | 98 | r = append_iovec(m, m->header, BUS_MESSAGE_BODY_BEGIN(m)); |
bc7fd8cd | 99 | if (r < 0) |
66b26c5c | 100 | goto fail; |
2100fa10 | 101 | |
9b29bb68 | 102 | MESSAGE_FOREACH_PART(part, i, m) { |
66b26c5c LP |
103 | r = bus_body_part_map(part); |
104 | if (r < 0) | |
105 | goto fail; | |
106 | ||
bc7fd8cd LP |
107 | r = append_iovec(m, part->data, part->size); |
108 | if (r < 0) | |
66b26c5c | 109 | goto fail; |
bc7fd8cd LP |
110 | } |
111 | ||
112 | assert(n == m->n_iovec); | |
113 | ||
114 | return 0; | |
66b26c5c LP |
115 | |
116 | fail: | |
117 | m->poisoned = true; | |
118 | return r; | |
2100fa10 LP |
119 | } |
120 | ||
2181a7f5 LP |
121 | bool bus_socket_auth_needs_write(sd_bus *b) { |
122 | ||
123 | unsigned i; | |
124 | ||
125 | if (b->auth_index >= ELEMENTSOF(b->auth_iovec)) | |
126 | return false; | |
127 | ||
128 | for (i = b->auth_index; i < ELEMENTSOF(b->auth_iovec); i++) { | |
129 | struct iovec *j = b->auth_iovec + i; | |
130 | ||
131 | if (j->iov_len > 0) | |
132 | return true; | |
133 | } | |
134 | ||
135 | return false; | |
136 | } | |
137 | ||
a7e3212d | 138 | static int bus_socket_write_auth(sd_bus *b) { |
a7e3212d LP |
139 | ssize_t k; |
140 | ||
141 | assert(b); | |
142 | assert(b->state == BUS_AUTHENTICATING); | |
143 | ||
2181a7f5 | 144 | if (!bus_socket_auth_needs_write(b)) |
a7e3212d LP |
145 | return 0; |
146 | ||
15d5af81 LP |
147 | if (b->prefer_writev) |
148 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
149 | else { | |
150 | struct msghdr mh; | |
151 | zero(mh); | |
152 | ||
153 | mh.msg_iov = b->auth_iovec + b->auth_index; | |
154 | mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index; | |
155 | ||
156 | k = sendmsg(b->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
157 | if (k < 0 && errno == ENOTSOCK) { | |
158 | b->prefer_writev = true; | |
159 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
160 | } | |
161 | } | |
a7e3212d | 162 | |
a7e3212d LP |
163 | if (k < 0) |
164 | return errno == EAGAIN ? 0 : -errno; | |
165 | ||
166 | iovec_advance(b->auth_iovec, &b->auth_index, (size_t) k); | |
a7e3212d LP |
167 | return 1; |
168 | } | |
169 | ||
2181a7f5 | 170 | static int bus_socket_auth_verify_client(sd_bus *b) { |
a7e3212d LP |
171 | char *e, *f, *start; |
172 | sd_id128_t peer; | |
173 | unsigned i; | |
174 | int r; | |
175 | ||
2181a7f5 LP |
176 | assert(b); |
177 | ||
a7e3212d LP |
178 | /* We expect two response lines: "OK" and possibly |
179 | * "AGREE_UNIX_FD" */ | |
180 | ||
6e6c21c8 | 181 | e = memmem_safe(b->rbuffer, b->rbuffer_size, "\r\n", 2); |
a7e3212d LP |
182 | if (!e) |
183 | return 0; | |
184 | ||
264ad849 | 185 | if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) { |
a7e3212d LP |
186 | f = memmem(e + 2, b->rbuffer_size - (e - (char*) b->rbuffer) - 2, "\r\n", 2); |
187 | if (!f) | |
188 | return 0; | |
189 | ||
190 | start = f + 2; | |
191 | } else { | |
192 | f = NULL; | |
193 | start = e + 2; | |
194 | } | |
195 | ||
196 | /* Nice! We got all the lines we need. First check the OK | |
197 | * line */ | |
198 | ||
199 | if (e - (char*) b->rbuffer != 3 + 32) | |
200 | return -EPERM; | |
201 | ||
202 | if (memcmp(b->rbuffer, "OK ", 3)) | |
203 | return -EPERM; | |
204 | ||
2181a7f5 LP |
205 | b->auth = b->anonymous_auth ? BUS_AUTH_ANONYMOUS : BUS_AUTH_EXTERNAL; |
206 | ||
a7e3212d LP |
207 | for (i = 0; i < 32; i += 2) { |
208 | int x, y; | |
209 | ||
210 | x = unhexchar(((char*) b->rbuffer)[3 + i]); | |
211 | y = unhexchar(((char*) b->rbuffer)[3 + i + 1]); | |
212 | ||
213 | if (x < 0 || y < 0) | |
214 | return -EINVAL; | |
215 | ||
216 | peer.bytes[i/2] = ((uint8_t) x << 4 | (uint8_t) y); | |
217 | } | |
218 | ||
98178d39 LP |
219 | if (!sd_id128_equal(b->server_id, SD_ID128_NULL) && |
220 | !sd_id128_equal(b->server_id, peer)) | |
a7e3212d LP |
221 | return -EPERM; |
222 | ||
98178d39 | 223 | b->server_id = peer; |
a7e3212d LP |
224 | |
225 | /* And possibly check the second line, too */ | |
226 | ||
227 | if (f) | |
228 | b->can_fds = | |
f8294e41 JT |
229 | (f - e == strlen("\r\nAGREE_UNIX_FD")) && |
230 | memcmp(e + 2, "AGREE_UNIX_FD", strlen("AGREE_UNIX_FD")) == 0; | |
a7e3212d LP |
231 | |
232 | b->rbuffer_size -= (start - (char*) b->rbuffer); | |
233 | memmove(b->rbuffer, start, b->rbuffer_size); | |
234 | ||
235 | r = bus_start_running(b); | |
236 | if (r < 0) | |
237 | return r; | |
238 | ||
239 | return 1; | |
240 | } | |
241 | ||
2181a7f5 LP |
242 | static bool line_equals(const char *s, size_t m, const char *line) { |
243 | size_t l; | |
244 | ||
245 | l = strlen(line); | |
246 | if (l != m) | |
247 | return false; | |
248 | ||
249 | return memcmp(s, line, l) == 0; | |
250 | } | |
251 | ||
252 | static bool line_begins(const char *s, size_t m, const char *word) { | |
253 | size_t l; | |
254 | ||
255 | l = strlen(word); | |
256 | if (m < l) | |
257 | return false; | |
258 | ||
259 | if (memcmp(s, word, l) != 0) | |
260 | return false; | |
261 | ||
262 | return m == l || (m > l && s[l] == ' '); | |
263 | } | |
264 | ||
265 | static int verify_anonymous_token(sd_bus *b, const char *p, size_t l) { | |
266 | _cleanup_free_ char *token = NULL; | |
267 | ||
268 | if (!b->anonymous_auth) | |
269 | return 0; | |
270 | ||
271 | if (l <= 0) | |
272 | return 1; | |
273 | ||
274 | assert(p[0] == ' '); | |
275 | p++; l--; | |
276 | ||
277 | if (l % 2 != 0) | |
278 | return 0; | |
279 | token = unhexmem(p, l); | |
280 | if (!token) | |
281 | return -ENOMEM; | |
282 | ||
283 | if (memchr(token, 0, l/2)) | |
284 | return 0; | |
285 | ||
286 | return !!utf8_is_valid(token); | |
287 | } | |
288 | ||
289 | static int verify_external_token(sd_bus *b, const char *p, size_t l) { | |
290 | _cleanup_free_ char *token = NULL; | |
291 | uid_t u; | |
292 | int r; | |
293 | ||
294 | /* We don't do any real authentication here. Instead, we if | |
295 | * the owner of this bus wanted authentication he should have | |
296 | * checked SO_PEERCRED before even creating the bus object. */ | |
297 | ||
8411d2a2 | 298 | if (!b->anonymous_auth && !b->ucred_valid) |
2181a7f5 LP |
299 | return 0; |
300 | ||
301 | if (l <= 0) | |
302 | return 1; | |
303 | ||
304 | assert(p[0] == ' '); | |
305 | p++; l--; | |
306 | ||
307 | if (l % 2 != 0) | |
308 | return 0; | |
309 | ||
310 | token = unhexmem(p, l); | |
311 | if (!token) | |
312 | return -ENOMEM; | |
313 | ||
314 | if (memchr(token, 0, l/2)) | |
315 | return 0; | |
316 | ||
317 | r = parse_uid(token, &u); | |
318 | if (r < 0) | |
319 | return 0; | |
320 | ||
8411d2a2 LP |
321 | /* We ignore the passed value if anonymous authentication is |
322 | * on anyway. */ | |
323 | if (!b->anonymous_auth && u != b->ucred.uid) | |
2181a7f5 LP |
324 | return 0; |
325 | ||
326 | return 1; | |
327 | } | |
328 | ||
329 | static int bus_socket_auth_write(sd_bus *b, const char *t) { | |
330 | char *p; | |
331 | size_t l; | |
332 | ||
333 | assert(b); | |
334 | assert(t); | |
335 | ||
336 | /* We only make use of the first iovec */ | |
337 | assert(b->auth_index == 0 || b->auth_index == 1); | |
338 | ||
339 | l = strlen(t); | |
340 | p = malloc(b->auth_iovec[0].iov_len + l); | |
341 | if (!p) | |
342 | return -ENOMEM; | |
343 | ||
344 | memcpy(p, b->auth_iovec[0].iov_base, b->auth_iovec[0].iov_len); | |
345 | memcpy(p + b->auth_iovec[0].iov_len, t, l); | |
346 | ||
347 | b->auth_iovec[0].iov_base = p; | |
348 | b->auth_iovec[0].iov_len += l; | |
349 | ||
350 | free(b->auth_buffer); | |
351 | b->auth_buffer = p; | |
352 | b->auth_index = 0; | |
353 | return 0; | |
354 | } | |
355 | ||
356 | static int bus_socket_auth_write_ok(sd_bus *b) { | |
357 | char t[3 + 32 + 2 + 1]; | |
358 | ||
359 | assert(b); | |
360 | ||
5ffa8c81 | 361 | xsprintf(t, "OK " SD_ID128_FORMAT_STR "\r\n", SD_ID128_FORMAT_VAL(b->server_id)); |
2181a7f5 LP |
362 | |
363 | return bus_socket_auth_write(b, t); | |
364 | } | |
365 | ||
366 | static int bus_socket_auth_verify_server(sd_bus *b) { | |
367 | char *e; | |
368 | const char *line; | |
369 | size_t l; | |
370 | bool processed = false; | |
371 | int r; | |
372 | ||
373 | assert(b); | |
374 | ||
2b4ac889 | 375 | if (b->rbuffer_size < 1) |
2181a7f5 LP |
376 | return 0; |
377 | ||
378 | /* First char must be a NUL byte */ | |
379 | if (*(char*) b->rbuffer != 0) | |
380 | return -EIO; | |
381 | ||
2b4ac889 LP |
382 | if (b->rbuffer_size < 3) |
383 | return 0; | |
384 | ||
2181a7f5 LP |
385 | /* Begin with the first line */ |
386 | if (b->auth_rbegin <= 0) | |
387 | b->auth_rbegin = 1; | |
388 | ||
389 | for (;;) { | |
390 | /* Check if line is complete */ | |
391 | line = (char*) b->rbuffer + b->auth_rbegin; | |
392 | e = memmem(line, b->rbuffer_size - b->auth_rbegin, "\r\n", 2); | |
393 | if (!e) | |
394 | return processed; | |
395 | ||
396 | l = e - line; | |
397 | ||
398 | if (line_begins(line, l, "AUTH ANONYMOUS")) { | |
399 | ||
400 | r = verify_anonymous_token(b, line + 14, l - 14); | |
401 | if (r < 0) | |
402 | return r; | |
403 | if (r == 0) | |
404 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
405 | else { | |
406 | b->auth = BUS_AUTH_ANONYMOUS; | |
407 | r = bus_socket_auth_write_ok(b); | |
408 | } | |
409 | ||
410 | } else if (line_begins(line, l, "AUTH EXTERNAL")) { | |
411 | ||
412 | r = verify_external_token(b, line + 13, l - 13); | |
413 | if (r < 0) | |
414 | return r; | |
415 | if (r == 0) | |
416 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
417 | else { | |
418 | b->auth = BUS_AUTH_EXTERNAL; | |
419 | r = bus_socket_auth_write_ok(b); | |
420 | } | |
421 | ||
422 | } else if (line_begins(line, l, "AUTH")) | |
423 | r = bus_socket_auth_write(b, "REJECTED EXTERNAL ANONYMOUS\r\n"); | |
424 | else if (line_equals(line, l, "CANCEL") || | |
425 | line_begins(line, l, "ERROR")) { | |
426 | ||
427 | b->auth = _BUS_AUTH_INVALID; | |
428 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
429 | ||
430 | } else if (line_equals(line, l, "BEGIN")) { | |
431 | ||
432 | if (b->auth == _BUS_AUTH_INVALID) | |
433 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
434 | else { | |
435 | /* We can't leave from the auth phase | |
436 | * before we haven't written | |
437 | * everything queued, so let's check | |
438 | * that */ | |
439 | ||
440 | if (bus_socket_auth_needs_write(b)) | |
441 | return 1; | |
442 | ||
443 | b->rbuffer_size -= (e + 2 - (char*) b->rbuffer); | |
444 | memmove(b->rbuffer, e + 2, b->rbuffer_size); | |
445 | return bus_start_running(b); | |
446 | } | |
447 | ||
448 | } else if (line_begins(line, l, "DATA")) { | |
449 | ||
450 | if (b->auth == _BUS_AUTH_INVALID) | |
451 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
452 | else { | |
453 | if (b->auth == BUS_AUTH_ANONYMOUS) | |
454 | r = verify_anonymous_token(b, line + 4, l - 4); | |
455 | else | |
456 | r = verify_external_token(b, line + 4, l - 4); | |
457 | ||
458 | if (r < 0) | |
459 | return r; | |
460 | if (r == 0) { | |
461 | b->auth = _BUS_AUTH_INVALID; | |
462 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
463 | } else | |
464 | r = bus_socket_auth_write_ok(b); | |
465 | } | |
466 | } else if (line_equals(line, l, "NEGOTIATE_UNIX_FD")) { | |
264ad849 | 467 | if (b->auth == _BUS_AUTH_INVALID || !(b->hello_flags & KDBUS_HELLO_ACCEPT_FD)) |
2181a7f5 LP |
468 | r = bus_socket_auth_write(b, "ERROR\r\n"); |
469 | else { | |
470 | b->can_fds = true; | |
471 | r = bus_socket_auth_write(b, "AGREE_UNIX_FD\r\n"); | |
472 | } | |
473 | } else | |
474 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
475 | ||
476 | if (r < 0) | |
477 | return r; | |
478 | ||
479 | b->auth_rbegin = e + 2 - (char*) b->rbuffer; | |
480 | ||
481 | processed = true; | |
482 | } | |
483 | } | |
484 | ||
485 | static int bus_socket_auth_verify(sd_bus *b) { | |
486 | assert(b); | |
487 | ||
488 | if (b->is_server) | |
489 | return bus_socket_auth_verify_server(b); | |
490 | else | |
491 | return bus_socket_auth_verify_client(b); | |
492 | } | |
493 | ||
a7e3212d LP |
494 | static int bus_socket_read_auth(sd_bus *b) { |
495 | struct msghdr mh; | |
7f4e6a1c | 496 | struct iovec iov = {}; |
a7e3212d LP |
497 | size_t n; |
498 | ssize_t k; | |
499 | int r; | |
500 | void *p; | |
2181a7f5 LP |
501 | union { |
502 | struct cmsghdr cmsghdr; | |
503 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
504 | CMSG_SPACE(sizeof(struct ucred)) + | |
505 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
506 | } control; | |
507 | struct cmsghdr *cmsg; | |
15d5af81 | 508 | bool handle_cmsg = false; |
a7e3212d LP |
509 | |
510 | assert(b); | |
2181a7f5 | 511 | assert(b->state == BUS_AUTHENTICATING); |
a7e3212d LP |
512 | |
513 | r = bus_socket_auth_verify(b); | |
514 | if (r != 0) | |
515 | return r; | |
516 | ||
9607d947 | 517 | n = MAX(256u, b->rbuffer_size * 2); |
a7e3212d LP |
518 | |
519 | if (n > BUS_AUTH_SIZE_MAX) | |
520 | n = BUS_AUTH_SIZE_MAX; | |
521 | ||
522 | if (b->rbuffer_size >= n) | |
523 | return -ENOBUFS; | |
524 | ||
525 | p = realloc(b->rbuffer, n); | |
526 | if (!p) | |
527 | return -ENOMEM; | |
528 | ||
529 | b->rbuffer = p; | |
530 | ||
a7e3212d LP |
531 | iov.iov_base = (uint8_t*) b->rbuffer + b->rbuffer_size; |
532 | iov.iov_len = n - b->rbuffer_size; | |
533 | ||
15d5af81 LP |
534 | if (b->prefer_readv) |
535 | k = readv(b->input_fd, &iov, 1); | |
536 | else { | |
537 | zero(mh); | |
538 | mh.msg_iov = &iov; | |
539 | mh.msg_iovlen = 1; | |
540 | mh.msg_control = &control; | |
541 | mh.msg_controllen = sizeof(control); | |
542 | ||
543 | k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
544 | if (k < 0 && errno == ENOTSOCK) { | |
545 | b->prefer_readv = true; | |
546 | k = readv(b->input_fd, &iov, 1); | |
547 | } else | |
548 | handle_cmsg = true; | |
549 | } | |
a7e3212d LP |
550 | if (k < 0) |
551 | return errno == EAGAIN ? 0 : -errno; | |
552 | if (k == 0) | |
553 | return -ECONNRESET; | |
554 | ||
555 | b->rbuffer_size += k; | |
556 | ||
15d5af81 LP |
557 | if (handle_cmsg) { |
558 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
559 | if (cmsg->cmsg_level == SOL_SOCKET && | |
560 | cmsg->cmsg_type == SCM_RIGHTS) { | |
561 | int j; | |
562 | ||
563 | /* Whut? We received fds during the auth | |
564 | * protocol? Somebody is playing games with | |
565 | * us. Close them all, and fail */ | |
566 | j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
567 | close_many((int*) CMSG_DATA(cmsg), j); | |
568 | return -EIO; | |
2181a7f5 | 569 | |
15d5af81 LP |
570 | } else if (cmsg->cmsg_level == SOL_SOCKET && |
571 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
572 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
2181a7f5 | 573 | |
ea8f194f LP |
574 | /* Ignore bogus data, which we might |
575 | * get on socketpair() sockets */ | |
576 | if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { | |
577 | memcpy(&b->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
578 | b->ucred_valid = true; | |
579 | } | |
2181a7f5 | 580 | |
15d5af81 LP |
581 | } else if (cmsg->cmsg_level == SOL_SOCKET && |
582 | cmsg->cmsg_type == SCM_SECURITY) { | |
2181a7f5 | 583 | |
15d5af81 | 584 | size_t l; |
ea8f194f | 585 | |
15d5af81 | 586 | l = cmsg->cmsg_len - CMSG_LEN(0); |
ea8f194f LP |
587 | if (l > 0) { |
588 | memcpy(&b->label, CMSG_DATA(cmsg), l); | |
589 | b->label[l] = 0; | |
590 | } | |
15d5af81 | 591 | } |
2181a7f5 LP |
592 | } |
593 | } | |
594 | ||
a7e3212d LP |
595 | r = bus_socket_auth_verify(b); |
596 | if (r != 0) | |
597 | return r; | |
598 | ||
599 | return 1; | |
600 | } | |
601 | ||
8f04d2eb | 602 | void bus_socket_setup(sd_bus *b) { |
0f4b73c8 | 603 | int enable; |
a7e3212d LP |
604 | |
605 | assert(b); | |
606 | ||
d65ddaa4 LP |
607 | /* Enable SO_PASSCRED + SO_PASSEC. We try this on any |
608 | * socket, just in case. */ | |
0f4b73c8 | 609 | enable = !b->bus_client; |
dc751688 | 610 | (void) setsockopt(b->input_fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(enable)); |
264ad849 | 611 | |
d21a7bb1 | 612 | enable = !b->bus_client && (b->attach_flags & KDBUS_ATTACH_SECLABEL); |
dc751688 | 613 | (void) setsockopt(b->input_fd, SOL_SOCKET, SO_PASSSEC, &enable, sizeof(enable)); |
a7e3212d | 614 | |
aec6d91f LP |
615 | /* Increase the buffers to 8 MB */ |
616 | fd_inc_rcvbuf(b->input_fd, SNDBUF_SIZE); | |
617 | fd_inc_sndbuf(b->output_fd, SNDBUF_SIZE); | |
a7e3212d | 618 | |
e1d337d4 LP |
619 | b->is_kernel = false; |
620 | b->message_version = 1; | |
0f437184 | 621 | b->message_endian = 0; |
8f04d2eb | 622 | } |
e1d337d4 | 623 | |
8f04d2eb | 624 | static void bus_get_peercred(sd_bus *b) { |
8f04d2eb LP |
625 | assert(b); |
626 | ||
627 | /* Get the peer for socketpair() sockets */ | |
eff05270 | 628 | b->ucred_valid = getpeercred(b->input_fd, &b->ucred) >= 0; |
a7e3212d LP |
629 | } |
630 | ||
2181a7f5 | 631 | static int bus_socket_start_auth_client(sd_bus *b) { |
a7e3212d | 632 | size_t l; |
2181a7f5 | 633 | const char *auth_suffix, *auth_prefix; |
a7e3212d LP |
634 | |
635 | assert(b); | |
636 | ||
2181a7f5 LP |
637 | if (b->anonymous_auth) { |
638 | auth_prefix = "\0AUTH ANONYMOUS "; | |
a7e3212d | 639 | |
2181a7f5 LP |
640 | /* For ANONYMOUS auth we send some arbitrary "trace" string */ |
641 | l = 9; | |
642 | b->auth_buffer = hexmem("anonymous", l); | |
643 | } else { | |
5ffa8c81 | 644 | char text[DECIMAL_STR_MAX(uid_t) + 1]; |
a7e3212d | 645 | |
2181a7f5 | 646 | auth_prefix = "\0AUTH EXTERNAL "; |
a7e3212d | 647 | |
5ffa8c81 | 648 | xsprintf(text, UID_FMT, geteuid()); |
a7e3212d | 649 | |
2181a7f5 LP |
650 | l = strlen(text); |
651 | b->auth_buffer = hexmem(text, l); | |
652 | } | |
653 | ||
654 | if (!b->auth_buffer) | |
a7e3212d LP |
655 | return -ENOMEM; |
656 | ||
264ad849 | 657 | if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) |
2181a7f5 LP |
658 | auth_suffix = "\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n"; |
659 | else | |
660 | auth_suffix = "\r\nBEGIN\r\n"; | |
a7e3212d LP |
661 | |
662 | b->auth_iovec[0].iov_base = (void*) auth_prefix; | |
2181a7f5 LP |
663 | b->auth_iovec[0].iov_len = 1 + strlen(auth_prefix + 1); |
664 | b->auth_iovec[1].iov_base = (void*) b->auth_buffer; | |
a7e3212d LP |
665 | b->auth_iovec[1].iov_len = l * 2; |
666 | b->auth_iovec[2].iov_base = (void*) auth_suffix; | |
667 | b->auth_iovec[2].iov_len = strlen(auth_suffix); | |
a7e3212d LP |
668 | |
669 | return bus_socket_write_auth(b); | |
670 | } | |
671 | ||
a7893c6b | 672 | int bus_socket_start_auth(sd_bus *b) { |
2181a7f5 LP |
673 | assert(b); |
674 | ||
8f04d2eb LP |
675 | bus_get_peercred(b); |
676 | ||
2181a7f5 LP |
677 | b->state = BUS_AUTHENTICATING; |
678 | b->auth_timeout = now(CLOCK_MONOTONIC) + BUS_DEFAULT_TIMEOUT; | |
679 | ||
9ab32f9d | 680 | if (sd_is_socket(b->input_fd, AF_UNIX, 0, 0) <= 0) |
264ad849 | 681 | b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; |
2181a7f5 | 682 | |
9ab32f9d LP |
683 | if (b->output_fd != b->input_fd) |
684 | if (sd_is_socket(b->output_fd, AF_UNIX, 0, 0) <= 0) | |
264ad849 | 685 | b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; |
e82c9509 | 686 | |
2181a7f5 LP |
687 | if (b->is_server) |
688 | return bus_socket_read_auth(b); | |
689 | else | |
690 | return bus_socket_start_auth_client(b); | |
691 | } | |
692 | ||
a7e3212d LP |
693 | int bus_socket_connect(sd_bus *b) { |
694 | int r; | |
695 | ||
696 | assert(b); | |
e82c9509 LP |
697 | assert(b->input_fd < 0); |
698 | assert(b->output_fd < 0); | |
a7e3212d LP |
699 | assert(b->sockaddr.sa.sa_family != AF_UNSPEC); |
700 | ||
e82c9509 LP |
701 | b->input_fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
702 | if (b->input_fd < 0) | |
a7e3212d LP |
703 | return -errno; |
704 | ||
e82c9509 LP |
705 | b->output_fd = b->input_fd; |
706 | ||
8f04d2eb | 707 | bus_socket_setup(b); |
a7e3212d | 708 | |
e82c9509 | 709 | r = connect(b->input_fd, &b->sockaddr.sa, b->sockaddr_size); |
a7e3212d LP |
710 | if (r < 0) { |
711 | if (errno == EINPROGRESS) | |
712 | return 1; | |
713 | ||
714 | return -errno; | |
715 | } | |
716 | ||
717 | return bus_socket_start_auth(b); | |
718 | } | |
719 | ||
720 | int bus_socket_exec(sd_bus *b) { | |
e82c9509 | 721 | int s[2], r; |
a7e3212d LP |
722 | pid_t pid; |
723 | ||
724 | assert(b); | |
e82c9509 LP |
725 | assert(b->input_fd < 0); |
726 | assert(b->output_fd < 0); | |
a7e3212d LP |
727 | assert(b->exec_path); |
728 | ||
e82c9509 LP |
729 | r = socketpair(AF_UNIX, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, s); |
730 | if (r < 0) | |
a7e3212d LP |
731 | return -errno; |
732 | ||
733 | pid = fork(); | |
734 | if (pid < 0) { | |
3d94f76c | 735 | safe_close_pair(s); |
a7e3212d LP |
736 | return -errno; |
737 | } | |
738 | if (pid == 0) { | |
739 | /* Child */ | |
740 | ||
e82c9509 LP |
741 | reset_all_signal_handlers(); |
742 | ||
743 | close_all_fds(s+1, 1); | |
a7e3212d LP |
744 | |
745 | assert_se(dup3(s[1], STDIN_FILENO, 0) == STDIN_FILENO); | |
746 | assert_se(dup3(s[1], STDOUT_FILENO, 0) == STDOUT_FILENO); | |
747 | ||
748 | if (s[1] != STDIN_FILENO && s[1] != STDOUT_FILENO) | |
03e334a1 | 749 | safe_close(s[1]); |
a7e3212d LP |
750 | |
751 | fd_cloexec(STDIN_FILENO, false); | |
752 | fd_cloexec(STDOUT_FILENO, false); | |
753 | fd_nonblock(STDIN_FILENO, false); | |
754 | fd_nonblock(STDOUT_FILENO, false); | |
755 | ||
756 | if (b->exec_argv) | |
757 | execvp(b->exec_path, b->exec_argv); | |
758 | else { | |
759 | const char *argv[] = { b->exec_path, NULL }; | |
760 | execvp(b->exec_path, (char**) argv); | |
761 | } | |
762 | ||
763 | _exit(EXIT_FAILURE); | |
764 | } | |
765 | ||
03e334a1 | 766 | safe_close(s[1]); |
e82c9509 | 767 | b->output_fd = b->input_fd = s[0]; |
a7e3212d | 768 | |
8f04d2eb | 769 | bus_socket_setup(b); |
e1d337d4 | 770 | |
a7e3212d LP |
771 | return bus_socket_start_auth(b); |
772 | } | |
773 | ||
774 | int bus_socket_take_fd(sd_bus *b) { | |
a7e3212d LP |
775 | assert(b); |
776 | ||
8f04d2eb | 777 | bus_socket_setup(b); |
a7e3212d LP |
778 | |
779 | return bus_socket_start_auth(b); | |
780 | } | |
781 | ||
782 | int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) { | |
a7e3212d LP |
783 | struct iovec *iov; |
784 | ssize_t k; | |
785 | size_t n; | |
786 | unsigned j; | |
bc7fd8cd | 787 | int r; |
a7e3212d LP |
788 | |
789 | assert(bus); | |
790 | assert(m); | |
791 | assert(idx); | |
792 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
793 | ||
6629161f | 794 | if (*idx >= BUS_MESSAGE_SIZE(m)) |
a7e3212d | 795 | return 0; |
a7e3212d | 796 | |
bc7fd8cd LP |
797 | r = bus_message_setup_iovec(m); |
798 | if (r < 0) | |
799 | return r; | |
2100fa10 | 800 | |
a7e3212d LP |
801 | n = m->n_iovec * sizeof(struct iovec); |
802 | iov = alloca(n); | |
803 | memcpy(iov, m->iovec, n); | |
804 | ||
805 | j = 0; | |
806 | iovec_advance(iov, &j, *idx); | |
807 | ||
15d5af81 LP |
808 | if (bus->prefer_writev) |
809 | k = writev(bus->output_fd, iov, m->n_iovec); | |
810 | else { | |
7f4e6a1c ZJS |
811 | struct msghdr mh = { |
812 | .msg_iov = iov, | |
813 | .msg_iovlen = m->n_iovec, | |
814 | }; | |
15d5af81 LP |
815 | |
816 | if (m->n_fds > 0) { | |
817 | struct cmsghdr *control; | |
15d5af81 | 818 | |
7f4e6a1c ZJS |
819 | mh.msg_control = control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds)); |
820 | mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds); | |
15d5af81 LP |
821 | control->cmsg_level = SOL_SOCKET; |
822 | control->cmsg_type = SCM_RIGHTS; | |
15d5af81 LP |
823 | memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds); |
824 | } | |
825 | ||
15d5af81 LP |
826 | k = sendmsg(bus->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); |
827 | if (k < 0 && errno == ENOTSOCK) { | |
828 | bus->prefer_writev = true; | |
829 | k = writev(bus->output_fd, iov, m->n_iovec); | |
830 | } | |
831 | } | |
a7e3212d | 832 | |
a7e3212d LP |
833 | if (k < 0) |
834 | return errno == EAGAIN ? 0 : -errno; | |
835 | ||
836 | *idx += (size_t) k; | |
837 | return 1; | |
838 | } | |
839 | ||
840 | static int bus_socket_read_message_need(sd_bus *bus, size_t *need) { | |
841 | uint32_t a, b; | |
842 | uint8_t e; | |
843 | uint64_t sum; | |
844 | ||
845 | assert(bus); | |
846 | assert(need); | |
847 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
848 | ||
849 | if (bus->rbuffer_size < sizeof(struct bus_header)) { | |
850 | *need = sizeof(struct bus_header) + 8; | |
851 | ||
852 | /* Minimum message size: | |
853 | * | |
854 | * Header + | |
855 | * | |
856 | * Method Call: +2 string headers | |
857 | * Signal: +3 string headers | |
858 | * Method Error: +1 string headers | |
859 | * +1 uint32 headers | |
860 | * Method Reply: +1 uint32 headers | |
861 | * | |
862 | * A string header is at least 9 bytes | |
863 | * A uint32 header is at least 8 bytes | |
864 | * | |
865 | * Hence the minimum message size of a valid message | |
866 | * is header + 8 bytes */ | |
867 | ||
868 | return 0; | |
869 | } | |
870 | ||
871 | a = ((const uint32_t*) bus->rbuffer)[1]; | |
872 | b = ((const uint32_t*) bus->rbuffer)[3]; | |
873 | ||
874 | e = ((const uint8_t*) bus->rbuffer)[0]; | |
0461f8cd | 875 | if (e == BUS_LITTLE_ENDIAN) { |
a7e3212d LP |
876 | a = le32toh(a); |
877 | b = le32toh(b); | |
0461f8cd | 878 | } else if (e == BUS_BIG_ENDIAN) { |
a7e3212d LP |
879 | a = be32toh(a); |
880 | b = be32toh(b); | |
881 | } else | |
882 | return -EBADMSG; | |
883 | ||
884 | sum = (uint64_t) sizeof(struct bus_header) + (uint64_t) ALIGN_TO(b, 8) + (uint64_t) a; | |
885 | if (sum >= BUS_MESSAGE_SIZE_MAX) | |
886 | return -ENOBUFS; | |
887 | ||
888 | *need = (size_t) sum; | |
889 | return 0; | |
890 | } | |
891 | ||
7d22c717 | 892 | static int bus_socket_make_message(sd_bus *bus, size_t size) { |
a7e3212d LP |
893 | sd_bus_message *t; |
894 | void *b; | |
895 | int r; | |
896 | ||
897 | assert(bus); | |
a7e3212d LP |
898 | assert(bus->rbuffer_size >= size); |
899 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
900 | ||
7adc46fc LP |
901 | r = bus_rqueue_make_room(bus); |
902 | if (r < 0) | |
903 | return r; | |
904 | ||
a7e3212d LP |
905 | if (bus->rbuffer_size > size) { |
906 | b = memdup((const uint8_t*) bus->rbuffer + size, | |
907 | bus->rbuffer_size - size); | |
908 | if (!b) | |
909 | return -ENOMEM; | |
910 | } else | |
911 | b = NULL; | |
912 | ||
df2d202e LP |
913 | r = bus_message_from_malloc(bus, |
914 | bus->rbuffer, size, | |
a7e3212d | 915 | bus->fds, bus->n_fds, |
038f9863 LP |
916 | NULL, |
917 | NULL, | |
a7e3212d LP |
918 | &t); |
919 | if (r < 0) { | |
920 | free(b); | |
921 | return r; | |
922 | } | |
923 | ||
924 | bus->rbuffer = b; | |
925 | bus->rbuffer_size -= size; | |
926 | ||
927 | bus->fds = NULL; | |
928 | bus->n_fds = 0; | |
929 | ||
7adc46fc | 930 | bus->rqueue[bus->rqueue_size++] = t; |
7d22c717 | 931 | |
a7e3212d LP |
932 | return 1; |
933 | } | |
934 | ||
7d22c717 | 935 | int bus_socket_read_message(sd_bus *bus) { |
a7e3212d | 936 | struct msghdr mh; |
7f4e6a1c | 937 | struct iovec iov = {}; |
a7e3212d LP |
938 | ssize_t k; |
939 | size_t need; | |
940 | int r; | |
941 | void *b; | |
942 | union { | |
943 | struct cmsghdr cmsghdr; | |
944 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
945 | CMSG_SPACE(sizeof(struct ucred)) + | |
946 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
947 | } control; | |
948 | struct cmsghdr *cmsg; | |
4d3a5b10 | 949 | bool handle_cmsg = false; |
a7e3212d LP |
950 | |
951 | assert(bus); | |
a7e3212d LP |
952 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); |
953 | ||
954 | r = bus_socket_read_message_need(bus, &need); | |
955 | if (r < 0) | |
956 | return r; | |
957 | ||
958 | if (bus->rbuffer_size >= need) | |
7d22c717 | 959 | return bus_socket_make_message(bus, need); |
a7e3212d LP |
960 | |
961 | b = realloc(bus->rbuffer, need); | |
962 | if (!b) | |
963 | return -ENOMEM; | |
964 | ||
965 | bus->rbuffer = b; | |
966 | ||
a7e3212d LP |
967 | iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size; |
968 | iov.iov_len = need - bus->rbuffer_size; | |
969 | ||
15d5af81 LP |
970 | if (bus->prefer_readv) |
971 | k = readv(bus->input_fd, &iov, 1); | |
972 | else { | |
973 | zero(mh); | |
974 | mh.msg_iov = &iov; | |
975 | mh.msg_iovlen = 1; | |
976 | mh.msg_control = &control; | |
977 | mh.msg_controllen = sizeof(control); | |
978 | ||
979 | k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
980 | if (k < 0 && errno == ENOTSOCK) { | |
981 | bus->prefer_readv = true; | |
982 | k = readv(bus->input_fd, &iov, 1); | |
983 | } else | |
984 | handle_cmsg = true; | |
985 | } | |
a7e3212d LP |
986 | if (k < 0) |
987 | return errno == EAGAIN ? 0 : -errno; | |
988 | if (k == 0) | |
989 | return -ECONNRESET; | |
990 | ||
991 | bus->rbuffer_size += k; | |
992 | ||
15d5af81 LP |
993 | if (handle_cmsg) { |
994 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
995 | if (cmsg->cmsg_level == SOL_SOCKET && | |
996 | cmsg->cmsg_type == SCM_RIGHTS) { | |
997 | int n, *f; | |
998 | ||
999 | n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
1000 | ||
1001 | if (!bus->can_fds) { | |
1002 | /* Whut? We received fds but this | |
1003 | * isn't actually enabled? Close them, | |
1004 | * and fail */ | |
1005 | ||
1006 | close_many((int*) CMSG_DATA(cmsg), n); | |
1007 | return -EIO; | |
1008 | } | |
1009 | ||
1010 | f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n)); | |
1011 | if (!f) { | |
1012 | close_many((int*) CMSG_DATA(cmsg), n); | |
1013 | return -ENOMEM; | |
1014 | } | |
1015 | ||
1016 | memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int)); | |
1017 | bus->fds = f; | |
1018 | bus->n_fds += n; | |
1019 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1020 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
1021 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
1022 | ||
ea8f194f LP |
1023 | /* Ignore bogus data, which we might |
1024 | * get on socketpair() sockets */ | |
1025 | if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { | |
1026 | memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
1027 | bus->ucred_valid = true; | |
1028 | } | |
15d5af81 LP |
1029 | |
1030 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1031 | cmsg->cmsg_type == SCM_SECURITY) { | |
1032 | ||
1033 | size_t l; | |
1034 | l = cmsg->cmsg_len - CMSG_LEN(0); | |
ea8f194f LP |
1035 | if (l > 0) { |
1036 | memcpy(&bus->label, CMSG_DATA(cmsg), l); | |
1037 | bus->label[l] = 0; | |
1038 | } | |
a7e3212d | 1039 | } |
a7e3212d LP |
1040 | } |
1041 | } | |
1042 | ||
1043 | r = bus_socket_read_message_need(bus, &need); | |
1044 | if (r < 0) | |
1045 | return r; | |
1046 | ||
1047 | if (bus->rbuffer_size >= need) | |
7d22c717 | 1048 | return bus_socket_make_message(bus, need); |
a7e3212d LP |
1049 | |
1050 | return 1; | |
1051 | } | |
1052 | ||
1053 | int bus_socket_process_opening(sd_bus *b) { | |
1054 | int error = 0; | |
1055 | socklen_t slen = sizeof(error); | |
b92bea5d ZJS |
1056 | struct pollfd p = { |
1057 | .fd = b->output_fd, | |
1058 | .events = POLLOUT, | |
1059 | }; | |
a7e3212d LP |
1060 | int r; |
1061 | ||
a7e3212d LP |
1062 | assert(b->state == BUS_OPENING); |
1063 | ||
a7e3212d LP |
1064 | r = poll(&p, 1, 0); |
1065 | if (r < 0) | |
1066 | return -errno; | |
1067 | ||
1068 | if (!(p.revents & (POLLOUT|POLLERR|POLLHUP))) | |
1069 | return 0; | |
1070 | ||
e82c9509 | 1071 | r = getsockopt(b->output_fd, SOL_SOCKET, SO_ERROR, &error, &slen); |
a7e3212d LP |
1072 | if (r < 0) |
1073 | b->last_connect_error = errno; | |
1074 | else if (error != 0) | |
1075 | b->last_connect_error = error; | |
1076 | else if (p.revents & (POLLERR|POLLHUP)) | |
1077 | b->last_connect_error = ECONNREFUSED; | |
1078 | else | |
1079 | return bus_socket_start_auth(b); | |
1080 | ||
1081 | return bus_next_address(b); | |
1082 | } | |
1083 | ||
1084 | int bus_socket_process_authenticating(sd_bus *b) { | |
1085 | int r; | |
1086 | ||
1087 | assert(b); | |
1088 | assert(b->state == BUS_AUTHENTICATING); | |
1089 | ||
1090 | if (now(CLOCK_MONOTONIC) >= b->auth_timeout) | |
1091 | return -ETIMEDOUT; | |
1092 | ||
1093 | r = bus_socket_write_auth(b); | |
1094 | if (r != 0) | |
1095 | return r; | |
1096 | ||
1097 | return bus_socket_read_auth(b); | |
1098 | } |