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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" |
6482f626 | 32 | #include "formats-util.h" |
a7e3212d LP |
33 | |
34 | #include "sd-bus.h" | |
35 | #include "bus-socket.h" | |
36 | #include "bus-internal.h" | |
37 | #include "bus-message.h" | |
38 | ||
aec6d91f LP |
39 | #define SNDBUF_SIZE (8*1024*1024) |
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 | |
c91cb83c | 86 | n = 1 + m->n_body_parts; |
bc7fd8cd LP |
87 | if (n < ELEMENTSOF(m->iovec_fixed)) |
88 | m->iovec = m->iovec_fixed; | |
89 | else { | |
90 | m->iovec = new(struct iovec, n); | |
66b26c5c LP |
91 | if (!m->iovec) { |
92 | r = -ENOMEM; | |
93 | goto fail; | |
94 | } | |
bc7fd8cd | 95 | } |
2100fa10 | 96 | |
c91cb83c | 97 | r = append_iovec(m, m->header, BUS_MESSAGE_BODY_BEGIN(m)); |
bc7fd8cd | 98 | if (r < 0) |
66b26c5c | 99 | goto fail; |
2100fa10 | 100 | |
9b29bb68 | 101 | MESSAGE_FOREACH_PART(part, i, m) { |
66b26c5c LP |
102 | r = bus_body_part_map(part); |
103 | if (r < 0) | |
104 | goto fail; | |
105 | ||
bc7fd8cd LP |
106 | r = append_iovec(m, part->data, part->size); |
107 | if (r < 0) | |
66b26c5c | 108 | goto fail; |
bc7fd8cd LP |
109 | } |
110 | ||
111 | assert(n == m->n_iovec); | |
112 | ||
113 | return 0; | |
66b26c5c LP |
114 | |
115 | fail: | |
116 | m->poisoned = true; | |
117 | return r; | |
2100fa10 LP |
118 | } |
119 | ||
2181a7f5 LP |
120 | bool bus_socket_auth_needs_write(sd_bus *b) { |
121 | ||
122 | unsigned i; | |
123 | ||
124 | if (b->auth_index >= ELEMENTSOF(b->auth_iovec)) | |
125 | return false; | |
126 | ||
127 | for (i = b->auth_index; i < ELEMENTSOF(b->auth_iovec); i++) { | |
128 | struct iovec *j = b->auth_iovec + i; | |
129 | ||
130 | if (j->iov_len > 0) | |
131 | return true; | |
132 | } | |
133 | ||
134 | return false; | |
135 | } | |
136 | ||
a7e3212d | 137 | static int bus_socket_write_auth(sd_bus *b) { |
a7e3212d LP |
138 | ssize_t k; |
139 | ||
140 | assert(b); | |
141 | assert(b->state == BUS_AUTHENTICATING); | |
142 | ||
2181a7f5 | 143 | if (!bus_socket_auth_needs_write(b)) |
a7e3212d LP |
144 | return 0; |
145 | ||
15d5af81 LP |
146 | if (b->prefer_writev) |
147 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
148 | else { | |
149 | struct msghdr mh; | |
150 | zero(mh); | |
151 | ||
152 | mh.msg_iov = b->auth_iovec + b->auth_index; | |
153 | mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index; | |
154 | ||
155 | k = sendmsg(b->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
156 | if (k < 0 && errno == ENOTSOCK) { | |
157 | b->prefer_writev = true; | |
158 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
159 | } | |
160 | } | |
a7e3212d | 161 | |
a7e3212d LP |
162 | if (k < 0) |
163 | return errno == EAGAIN ? 0 : -errno; | |
164 | ||
165 | iovec_advance(b->auth_iovec, &b->auth_index, (size_t) k); | |
a7e3212d LP |
166 | return 1; |
167 | } | |
168 | ||
2181a7f5 | 169 | static int bus_socket_auth_verify_client(sd_bus *b) { |
a7e3212d LP |
170 | char *e, *f, *start; |
171 | sd_id128_t peer; | |
172 | unsigned i; | |
173 | int r; | |
174 | ||
2181a7f5 LP |
175 | assert(b); |
176 | ||
a7e3212d LP |
177 | /* We expect two response lines: "OK" and possibly |
178 | * "AGREE_UNIX_FD" */ | |
179 | ||
180 | e = memmem(b->rbuffer, b->rbuffer_size, "\r\n", 2); | |
181 | if (!e) | |
182 | return 0; | |
183 | ||
264ad849 | 184 | if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) { |
a7e3212d LP |
185 | f = memmem(e + 2, b->rbuffer_size - (e - (char*) b->rbuffer) - 2, "\r\n", 2); |
186 | if (!f) | |
187 | return 0; | |
188 | ||
189 | start = f + 2; | |
190 | } else { | |
191 | f = NULL; | |
192 | start = e + 2; | |
193 | } | |
194 | ||
195 | /* Nice! We got all the lines we need. First check the OK | |
196 | * line */ | |
197 | ||
198 | if (e - (char*) b->rbuffer != 3 + 32) | |
199 | return -EPERM; | |
200 | ||
201 | if (memcmp(b->rbuffer, "OK ", 3)) | |
202 | return -EPERM; | |
203 | ||
2181a7f5 LP |
204 | b->auth = b->anonymous_auth ? BUS_AUTH_ANONYMOUS : BUS_AUTH_EXTERNAL; |
205 | ||
a7e3212d LP |
206 | for (i = 0; i < 32; i += 2) { |
207 | int x, y; | |
208 | ||
209 | x = unhexchar(((char*) b->rbuffer)[3 + i]); | |
210 | y = unhexchar(((char*) b->rbuffer)[3 + i + 1]); | |
211 | ||
212 | if (x < 0 || y < 0) | |
213 | return -EINVAL; | |
214 | ||
215 | peer.bytes[i/2] = ((uint8_t) x << 4 | (uint8_t) y); | |
216 | } | |
217 | ||
98178d39 LP |
218 | if (!sd_id128_equal(b->server_id, SD_ID128_NULL) && |
219 | !sd_id128_equal(b->server_id, peer)) | |
a7e3212d LP |
220 | return -EPERM; |
221 | ||
98178d39 | 222 | b->server_id = peer; |
a7e3212d LP |
223 | |
224 | /* And possibly check the second line, too */ | |
225 | ||
226 | if (f) | |
227 | b->can_fds = | |
f8294e41 JT |
228 | (f - e == strlen("\r\nAGREE_UNIX_FD")) && |
229 | memcmp(e + 2, "AGREE_UNIX_FD", strlen("AGREE_UNIX_FD")) == 0; | |
a7e3212d LP |
230 | |
231 | b->rbuffer_size -= (start - (char*) b->rbuffer); | |
232 | memmove(b->rbuffer, start, b->rbuffer_size); | |
233 | ||
234 | r = bus_start_running(b); | |
235 | if (r < 0) | |
236 | return r; | |
237 | ||
238 | return 1; | |
239 | } | |
240 | ||
2181a7f5 LP |
241 | static bool line_equals(const char *s, size_t m, const char *line) { |
242 | size_t l; | |
243 | ||
244 | l = strlen(line); | |
245 | if (l != m) | |
246 | return false; | |
247 | ||
248 | return memcmp(s, line, l) == 0; | |
249 | } | |
250 | ||
251 | static bool line_begins(const char *s, size_t m, const char *word) { | |
252 | size_t l; | |
253 | ||
254 | l = strlen(word); | |
255 | if (m < l) | |
256 | return false; | |
257 | ||
258 | if (memcmp(s, word, l) != 0) | |
259 | return false; | |
260 | ||
261 | return m == l || (m > l && s[l] == ' '); | |
262 | } | |
263 | ||
264 | static int verify_anonymous_token(sd_bus *b, const char *p, size_t l) { | |
265 | _cleanup_free_ char *token = NULL; | |
266 | ||
267 | if (!b->anonymous_auth) | |
268 | return 0; | |
269 | ||
270 | if (l <= 0) | |
271 | return 1; | |
272 | ||
273 | assert(p[0] == ' '); | |
274 | p++; l--; | |
275 | ||
276 | if (l % 2 != 0) | |
277 | return 0; | |
278 | token = unhexmem(p, l); | |
279 | if (!token) | |
280 | return -ENOMEM; | |
281 | ||
282 | if (memchr(token, 0, l/2)) | |
283 | return 0; | |
284 | ||
285 | return !!utf8_is_valid(token); | |
286 | } | |
287 | ||
288 | static int verify_external_token(sd_bus *b, const char *p, size_t l) { | |
289 | _cleanup_free_ char *token = NULL; | |
290 | uid_t u; | |
291 | int r; | |
292 | ||
293 | /* We don't do any real authentication here. Instead, we if | |
294 | * the owner of this bus wanted authentication he should have | |
295 | * checked SO_PEERCRED before even creating the bus object. */ | |
296 | ||
8411d2a2 | 297 | if (!b->anonymous_auth && !b->ucred_valid) |
2181a7f5 LP |
298 | return 0; |
299 | ||
300 | if (l <= 0) | |
301 | return 1; | |
302 | ||
303 | assert(p[0] == ' '); | |
304 | p++; l--; | |
305 | ||
306 | if (l % 2 != 0) | |
307 | return 0; | |
308 | ||
309 | token = unhexmem(p, l); | |
310 | if (!token) | |
311 | return -ENOMEM; | |
312 | ||
313 | if (memchr(token, 0, l/2)) | |
314 | return 0; | |
315 | ||
316 | r = parse_uid(token, &u); | |
317 | if (r < 0) | |
318 | return 0; | |
319 | ||
8411d2a2 LP |
320 | /* We ignore the passed value if anonymous authentication is |
321 | * on anyway. */ | |
322 | if (!b->anonymous_auth && u != b->ucred.uid) | |
2181a7f5 LP |
323 | return 0; |
324 | ||
325 | return 1; | |
326 | } | |
327 | ||
328 | static int bus_socket_auth_write(sd_bus *b, const char *t) { | |
329 | char *p; | |
330 | size_t l; | |
331 | ||
332 | assert(b); | |
333 | assert(t); | |
334 | ||
335 | /* We only make use of the first iovec */ | |
336 | assert(b->auth_index == 0 || b->auth_index == 1); | |
337 | ||
338 | l = strlen(t); | |
339 | p = malloc(b->auth_iovec[0].iov_len + l); | |
340 | if (!p) | |
341 | return -ENOMEM; | |
342 | ||
343 | memcpy(p, b->auth_iovec[0].iov_base, b->auth_iovec[0].iov_len); | |
344 | memcpy(p + b->auth_iovec[0].iov_len, t, l); | |
345 | ||
346 | b->auth_iovec[0].iov_base = p; | |
347 | b->auth_iovec[0].iov_len += l; | |
348 | ||
349 | free(b->auth_buffer); | |
350 | b->auth_buffer = p; | |
351 | b->auth_index = 0; | |
352 | return 0; | |
353 | } | |
354 | ||
355 | static int bus_socket_auth_write_ok(sd_bus *b) { | |
356 | char t[3 + 32 + 2 + 1]; | |
357 | ||
358 | assert(b); | |
359 | ||
5ffa8c81 | 360 | xsprintf(t, "OK " SD_ID128_FORMAT_STR "\r\n", SD_ID128_FORMAT_VAL(b->server_id)); |
2181a7f5 LP |
361 | |
362 | return bus_socket_auth_write(b, t); | |
363 | } | |
364 | ||
365 | static int bus_socket_auth_verify_server(sd_bus *b) { | |
366 | char *e; | |
367 | const char *line; | |
368 | size_t l; | |
369 | bool processed = false; | |
370 | int r; | |
371 | ||
372 | assert(b); | |
373 | ||
2b4ac889 | 374 | if (b->rbuffer_size < 1) |
2181a7f5 LP |
375 | return 0; |
376 | ||
377 | /* First char must be a NUL byte */ | |
378 | if (*(char*) b->rbuffer != 0) | |
379 | return -EIO; | |
380 | ||
2b4ac889 LP |
381 | if (b->rbuffer_size < 3) |
382 | return 0; | |
383 | ||
2181a7f5 LP |
384 | /* Begin with the first line */ |
385 | if (b->auth_rbegin <= 0) | |
386 | b->auth_rbegin = 1; | |
387 | ||
388 | for (;;) { | |
389 | /* Check if line is complete */ | |
390 | line = (char*) b->rbuffer + b->auth_rbegin; | |
391 | e = memmem(line, b->rbuffer_size - b->auth_rbegin, "\r\n", 2); | |
392 | if (!e) | |
393 | return processed; | |
394 | ||
395 | l = e - line; | |
396 | ||
397 | if (line_begins(line, l, "AUTH ANONYMOUS")) { | |
398 | ||
399 | r = verify_anonymous_token(b, line + 14, l - 14); | |
400 | if (r < 0) | |
401 | return r; | |
402 | if (r == 0) | |
403 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
404 | else { | |
405 | b->auth = BUS_AUTH_ANONYMOUS; | |
406 | r = bus_socket_auth_write_ok(b); | |
407 | } | |
408 | ||
409 | } else if (line_begins(line, l, "AUTH EXTERNAL")) { | |
410 | ||
411 | r = verify_external_token(b, line + 13, l - 13); | |
412 | if (r < 0) | |
413 | return r; | |
414 | if (r == 0) | |
415 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
416 | else { | |
417 | b->auth = BUS_AUTH_EXTERNAL; | |
418 | r = bus_socket_auth_write_ok(b); | |
419 | } | |
420 | ||
421 | } else if (line_begins(line, l, "AUTH")) | |
422 | r = bus_socket_auth_write(b, "REJECTED EXTERNAL ANONYMOUS\r\n"); | |
423 | else if (line_equals(line, l, "CANCEL") || | |
424 | line_begins(line, l, "ERROR")) { | |
425 | ||
426 | b->auth = _BUS_AUTH_INVALID; | |
427 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
428 | ||
429 | } else if (line_equals(line, l, "BEGIN")) { | |
430 | ||
431 | if (b->auth == _BUS_AUTH_INVALID) | |
432 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
433 | else { | |
434 | /* We can't leave from the auth phase | |
435 | * before we haven't written | |
436 | * everything queued, so let's check | |
437 | * that */ | |
438 | ||
439 | if (bus_socket_auth_needs_write(b)) | |
440 | return 1; | |
441 | ||
442 | b->rbuffer_size -= (e + 2 - (char*) b->rbuffer); | |
443 | memmove(b->rbuffer, e + 2, b->rbuffer_size); | |
444 | return bus_start_running(b); | |
445 | } | |
446 | ||
447 | } else if (line_begins(line, l, "DATA")) { | |
448 | ||
449 | if (b->auth == _BUS_AUTH_INVALID) | |
450 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
451 | else { | |
452 | if (b->auth == BUS_AUTH_ANONYMOUS) | |
453 | r = verify_anonymous_token(b, line + 4, l - 4); | |
454 | else | |
455 | r = verify_external_token(b, line + 4, l - 4); | |
456 | ||
457 | if (r < 0) | |
458 | return r; | |
459 | if (r == 0) { | |
460 | b->auth = _BUS_AUTH_INVALID; | |
461 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
462 | } else | |
463 | r = bus_socket_auth_write_ok(b); | |
464 | } | |
465 | } else if (line_equals(line, l, "NEGOTIATE_UNIX_FD")) { | |
264ad849 | 466 | if (b->auth == _BUS_AUTH_INVALID || !(b->hello_flags & KDBUS_HELLO_ACCEPT_FD)) |
2181a7f5 LP |
467 | r = bus_socket_auth_write(b, "ERROR\r\n"); |
468 | else { | |
469 | b->can_fds = true; | |
470 | r = bus_socket_auth_write(b, "AGREE_UNIX_FD\r\n"); | |
471 | } | |
472 | } else | |
473 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
474 | ||
475 | if (r < 0) | |
476 | return r; | |
477 | ||
478 | b->auth_rbegin = e + 2 - (char*) b->rbuffer; | |
479 | ||
480 | processed = true; | |
481 | } | |
482 | } | |
483 | ||
484 | static int bus_socket_auth_verify(sd_bus *b) { | |
485 | assert(b); | |
486 | ||
487 | if (b->is_server) | |
488 | return bus_socket_auth_verify_server(b); | |
489 | else | |
490 | return bus_socket_auth_verify_client(b); | |
491 | } | |
492 | ||
a7e3212d LP |
493 | static int bus_socket_read_auth(sd_bus *b) { |
494 | struct msghdr mh; | |
495 | struct iovec iov; | |
496 | size_t n; | |
497 | ssize_t k; | |
498 | int r; | |
499 | void *p; | |
2181a7f5 LP |
500 | union { |
501 | struct cmsghdr cmsghdr; | |
502 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
503 | CMSG_SPACE(sizeof(struct ucred)) + | |
504 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
505 | } control; | |
506 | struct cmsghdr *cmsg; | |
15d5af81 | 507 | bool handle_cmsg = false; |
a7e3212d LP |
508 | |
509 | assert(b); | |
2181a7f5 | 510 | assert(b->state == BUS_AUTHENTICATING); |
a7e3212d LP |
511 | |
512 | r = bus_socket_auth_verify(b); | |
513 | if (r != 0) | |
514 | return r; | |
515 | ||
9607d947 | 516 | n = MAX(256u, b->rbuffer_size * 2); |
a7e3212d LP |
517 | |
518 | if (n > BUS_AUTH_SIZE_MAX) | |
519 | n = BUS_AUTH_SIZE_MAX; | |
520 | ||
521 | if (b->rbuffer_size >= n) | |
522 | return -ENOBUFS; | |
523 | ||
524 | p = realloc(b->rbuffer, n); | |
525 | if (!p) | |
526 | return -ENOMEM; | |
527 | ||
528 | b->rbuffer = p; | |
529 | ||
530 | zero(iov); | |
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 { | |
811 | struct msghdr mh; | |
812 | zero(mh); | |
813 | ||
814 | if (m->n_fds > 0) { | |
815 | struct cmsghdr *control; | |
816 | control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds)); | |
817 | ||
818 | mh.msg_control = control; | |
819 | control->cmsg_level = SOL_SOCKET; | |
820 | control->cmsg_type = SCM_RIGHTS; | |
821 | mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds); | |
822 | memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds); | |
823 | } | |
824 | ||
825 | mh.msg_iov = iov; | |
826 | mh.msg_iovlen = m->n_iovec; | |
827 | ||
828 | k = sendmsg(bus->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
829 | if (k < 0 && errno == ENOTSOCK) { | |
830 | bus->prefer_writev = true; | |
831 | k = writev(bus->output_fd, iov, m->n_iovec); | |
832 | } | |
833 | } | |
a7e3212d | 834 | |
a7e3212d LP |
835 | if (k < 0) |
836 | return errno == EAGAIN ? 0 : -errno; | |
837 | ||
838 | *idx += (size_t) k; | |
839 | return 1; | |
840 | } | |
841 | ||
842 | static int bus_socket_read_message_need(sd_bus *bus, size_t *need) { | |
843 | uint32_t a, b; | |
844 | uint8_t e; | |
845 | uint64_t sum; | |
846 | ||
847 | assert(bus); | |
848 | assert(need); | |
849 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
850 | ||
851 | if (bus->rbuffer_size < sizeof(struct bus_header)) { | |
852 | *need = sizeof(struct bus_header) + 8; | |
853 | ||
854 | /* Minimum message size: | |
855 | * | |
856 | * Header + | |
857 | * | |
858 | * Method Call: +2 string headers | |
859 | * Signal: +3 string headers | |
860 | * Method Error: +1 string headers | |
861 | * +1 uint32 headers | |
862 | * Method Reply: +1 uint32 headers | |
863 | * | |
864 | * A string header is at least 9 bytes | |
865 | * A uint32 header is at least 8 bytes | |
866 | * | |
867 | * Hence the minimum message size of a valid message | |
868 | * is header + 8 bytes */ | |
869 | ||
870 | return 0; | |
871 | } | |
872 | ||
873 | a = ((const uint32_t*) bus->rbuffer)[1]; | |
874 | b = ((const uint32_t*) bus->rbuffer)[3]; | |
875 | ||
876 | e = ((const uint8_t*) bus->rbuffer)[0]; | |
0461f8cd | 877 | if (e == BUS_LITTLE_ENDIAN) { |
a7e3212d LP |
878 | a = le32toh(a); |
879 | b = le32toh(b); | |
0461f8cd | 880 | } else if (e == BUS_BIG_ENDIAN) { |
a7e3212d LP |
881 | a = be32toh(a); |
882 | b = be32toh(b); | |
883 | } else | |
884 | return -EBADMSG; | |
885 | ||
886 | sum = (uint64_t) sizeof(struct bus_header) + (uint64_t) ALIGN_TO(b, 8) + (uint64_t) a; | |
887 | if (sum >= BUS_MESSAGE_SIZE_MAX) | |
888 | return -ENOBUFS; | |
889 | ||
890 | *need = (size_t) sum; | |
891 | return 0; | |
892 | } | |
893 | ||
7d22c717 | 894 | static int bus_socket_make_message(sd_bus *bus, size_t size) { |
a7e3212d LP |
895 | sd_bus_message *t; |
896 | void *b; | |
897 | int r; | |
898 | ||
899 | assert(bus); | |
a7e3212d LP |
900 | assert(bus->rbuffer_size >= size); |
901 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
902 | ||
7adc46fc LP |
903 | r = bus_rqueue_make_room(bus); |
904 | if (r < 0) | |
905 | return r; | |
906 | ||
a7e3212d LP |
907 | if (bus->rbuffer_size > size) { |
908 | b = memdup((const uint8_t*) bus->rbuffer + size, | |
909 | bus->rbuffer_size - size); | |
910 | if (!b) | |
911 | return -ENOMEM; | |
912 | } else | |
913 | b = NULL; | |
914 | ||
df2d202e LP |
915 | r = bus_message_from_malloc(bus, |
916 | bus->rbuffer, size, | |
a7e3212d | 917 | bus->fds, bus->n_fds, |
038f9863 LP |
918 | NULL, |
919 | NULL, | |
a7e3212d LP |
920 | &t); |
921 | if (r < 0) { | |
922 | free(b); | |
923 | return r; | |
924 | } | |
925 | ||
926 | bus->rbuffer = b; | |
927 | bus->rbuffer_size -= size; | |
928 | ||
929 | bus->fds = NULL; | |
930 | bus->n_fds = 0; | |
931 | ||
7adc46fc | 932 | bus->rqueue[bus->rqueue_size++] = t; |
7d22c717 | 933 | |
a7e3212d LP |
934 | return 1; |
935 | } | |
936 | ||
7d22c717 | 937 | int bus_socket_read_message(sd_bus *bus) { |
a7e3212d LP |
938 | struct msghdr mh; |
939 | struct iovec iov; | |
940 | ssize_t k; | |
941 | size_t need; | |
942 | int r; | |
943 | void *b; | |
944 | union { | |
945 | struct cmsghdr cmsghdr; | |
946 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
947 | CMSG_SPACE(sizeof(struct ucred)) + | |
948 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
949 | } control; | |
950 | struct cmsghdr *cmsg; | |
4d3a5b10 | 951 | bool handle_cmsg = false; |
a7e3212d LP |
952 | |
953 | assert(bus); | |
a7e3212d LP |
954 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); |
955 | ||
956 | r = bus_socket_read_message_need(bus, &need); | |
957 | if (r < 0) | |
958 | return r; | |
959 | ||
960 | if (bus->rbuffer_size >= need) | |
7d22c717 | 961 | return bus_socket_make_message(bus, need); |
a7e3212d LP |
962 | |
963 | b = realloc(bus->rbuffer, need); | |
964 | if (!b) | |
965 | return -ENOMEM; | |
966 | ||
967 | bus->rbuffer = b; | |
968 | ||
969 | zero(iov); | |
970 | iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size; | |
971 | iov.iov_len = need - bus->rbuffer_size; | |
972 | ||
15d5af81 LP |
973 | if (bus->prefer_readv) |
974 | k = readv(bus->input_fd, &iov, 1); | |
975 | else { | |
976 | zero(mh); | |
977 | mh.msg_iov = &iov; | |
978 | mh.msg_iovlen = 1; | |
979 | mh.msg_control = &control; | |
980 | mh.msg_controllen = sizeof(control); | |
981 | ||
982 | k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
983 | if (k < 0 && errno == ENOTSOCK) { | |
984 | bus->prefer_readv = true; | |
985 | k = readv(bus->input_fd, &iov, 1); | |
986 | } else | |
987 | handle_cmsg = true; | |
988 | } | |
a7e3212d LP |
989 | if (k < 0) |
990 | return errno == EAGAIN ? 0 : -errno; | |
991 | if (k == 0) | |
992 | return -ECONNRESET; | |
993 | ||
994 | bus->rbuffer_size += k; | |
995 | ||
15d5af81 LP |
996 | if (handle_cmsg) { |
997 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
998 | if (cmsg->cmsg_level == SOL_SOCKET && | |
999 | cmsg->cmsg_type == SCM_RIGHTS) { | |
1000 | int n, *f; | |
1001 | ||
1002 | n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
1003 | ||
1004 | if (!bus->can_fds) { | |
1005 | /* Whut? We received fds but this | |
1006 | * isn't actually enabled? Close them, | |
1007 | * and fail */ | |
1008 | ||
1009 | close_many((int*) CMSG_DATA(cmsg), n); | |
1010 | return -EIO; | |
1011 | } | |
1012 | ||
1013 | f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n)); | |
1014 | if (!f) { | |
1015 | close_many((int*) CMSG_DATA(cmsg), n); | |
1016 | return -ENOMEM; | |
1017 | } | |
1018 | ||
1019 | memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int)); | |
1020 | bus->fds = f; | |
1021 | bus->n_fds += n; | |
1022 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1023 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
1024 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
1025 | ||
ea8f194f LP |
1026 | /* Ignore bogus data, which we might |
1027 | * get on socketpair() sockets */ | |
1028 | if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { | |
1029 | memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
1030 | bus->ucred_valid = true; | |
1031 | } | |
15d5af81 LP |
1032 | |
1033 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1034 | cmsg->cmsg_type == SCM_SECURITY) { | |
1035 | ||
1036 | size_t l; | |
1037 | l = cmsg->cmsg_len - CMSG_LEN(0); | |
ea8f194f LP |
1038 | if (l > 0) { |
1039 | memcpy(&bus->label, CMSG_DATA(cmsg), l); | |
1040 | bus->label[l] = 0; | |
1041 | } | |
a7e3212d | 1042 | } |
a7e3212d LP |
1043 | } |
1044 | } | |
1045 | ||
1046 | r = bus_socket_read_message_need(bus, &need); | |
1047 | if (r < 0) | |
1048 | return r; | |
1049 | ||
1050 | if (bus->rbuffer_size >= need) | |
7d22c717 | 1051 | return bus_socket_make_message(bus, need); |
a7e3212d LP |
1052 | |
1053 | return 1; | |
1054 | } | |
1055 | ||
1056 | int bus_socket_process_opening(sd_bus *b) { | |
1057 | int error = 0; | |
1058 | socklen_t slen = sizeof(error); | |
b92bea5d ZJS |
1059 | struct pollfd p = { |
1060 | .fd = b->output_fd, | |
1061 | .events = POLLOUT, | |
1062 | }; | |
a7e3212d LP |
1063 | int r; |
1064 | ||
a7e3212d LP |
1065 | assert(b->state == BUS_OPENING); |
1066 | ||
a7e3212d LP |
1067 | r = poll(&p, 1, 0); |
1068 | if (r < 0) | |
1069 | return -errno; | |
1070 | ||
1071 | if (!(p.revents & (POLLOUT|POLLERR|POLLHUP))) | |
1072 | return 0; | |
1073 | ||
e82c9509 | 1074 | r = getsockopt(b->output_fd, SOL_SOCKET, SO_ERROR, &error, &slen); |
a7e3212d LP |
1075 | if (r < 0) |
1076 | b->last_connect_error = errno; | |
1077 | else if (error != 0) | |
1078 | b->last_connect_error = error; | |
1079 | else if (p.revents & (POLLERR|POLLHUP)) | |
1080 | b->last_connect_error = ECONNREFUSED; | |
1081 | else | |
1082 | return bus_socket_start_auth(b); | |
1083 | ||
1084 | return bus_next_address(b); | |
1085 | } | |
1086 | ||
1087 | int bus_socket_process_authenticating(sd_bus *b) { | |
1088 | int r; | |
1089 | ||
1090 | assert(b); | |
1091 | assert(b->state == BUS_AUTHENTICATING); | |
1092 | ||
1093 | if (now(CLOCK_MONOTONIC) >= b->auth_timeout) | |
1094 | return -ETIMEDOUT; | |
1095 | ||
1096 | r = bus_socket_write_auth(b); | |
1097 | if (r != 0) | |
1098 | return r; | |
1099 | ||
1100 | return bus_socket_read_auth(b); | |
1101 | } |