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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 | ||
6e6c21c8 | 180 | e = memmem_safe(b->rbuffer, b->rbuffer_size, "\r\n", 2); |
a7e3212d LP |
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; | |
7f4e6a1c | 495 | struct iovec iov = {}; |
a7e3212d LP |
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 | ||
a7e3212d LP |
530 | iov.iov_base = (uint8_t*) b->rbuffer + b->rbuffer_size; |
531 | iov.iov_len = n - b->rbuffer_size; | |
532 | ||
15d5af81 LP |
533 | if (b->prefer_readv) |
534 | k = readv(b->input_fd, &iov, 1); | |
535 | else { | |
536 | zero(mh); | |
537 | mh.msg_iov = &iov; | |
538 | mh.msg_iovlen = 1; | |
539 | mh.msg_control = &control; | |
540 | mh.msg_controllen = sizeof(control); | |
541 | ||
542 | k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
543 | if (k < 0 && errno == ENOTSOCK) { | |
544 | b->prefer_readv = true; | |
545 | k = readv(b->input_fd, &iov, 1); | |
546 | } else | |
547 | handle_cmsg = true; | |
548 | } | |
a7e3212d LP |
549 | if (k < 0) |
550 | return errno == EAGAIN ? 0 : -errno; | |
551 | if (k == 0) | |
552 | return -ECONNRESET; | |
553 | ||
554 | b->rbuffer_size += k; | |
555 | ||
15d5af81 LP |
556 | if (handle_cmsg) { |
557 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
558 | if (cmsg->cmsg_level == SOL_SOCKET && | |
559 | cmsg->cmsg_type == SCM_RIGHTS) { | |
560 | int j; | |
561 | ||
562 | /* Whut? We received fds during the auth | |
563 | * protocol? Somebody is playing games with | |
564 | * us. Close them all, and fail */ | |
565 | j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
566 | close_many((int*) CMSG_DATA(cmsg), j); | |
567 | return -EIO; | |
2181a7f5 | 568 | |
15d5af81 LP |
569 | } else if (cmsg->cmsg_level == SOL_SOCKET && |
570 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
571 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
2181a7f5 | 572 | |
ea8f194f LP |
573 | /* Ignore bogus data, which we might |
574 | * get on socketpair() sockets */ | |
575 | if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { | |
576 | memcpy(&b->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
577 | b->ucred_valid = true; | |
578 | } | |
2181a7f5 | 579 | |
15d5af81 LP |
580 | } else if (cmsg->cmsg_level == SOL_SOCKET && |
581 | cmsg->cmsg_type == SCM_SECURITY) { | |
2181a7f5 | 582 | |
15d5af81 | 583 | size_t l; |
ea8f194f | 584 | |
15d5af81 | 585 | l = cmsg->cmsg_len - CMSG_LEN(0); |
ea8f194f LP |
586 | if (l > 0) { |
587 | memcpy(&b->label, CMSG_DATA(cmsg), l); | |
588 | b->label[l] = 0; | |
589 | } | |
15d5af81 | 590 | } |
2181a7f5 LP |
591 | } |
592 | } | |
593 | ||
a7e3212d LP |
594 | r = bus_socket_auth_verify(b); |
595 | if (r != 0) | |
596 | return r; | |
597 | ||
598 | return 1; | |
599 | } | |
600 | ||
8f04d2eb | 601 | void bus_socket_setup(sd_bus *b) { |
0f4b73c8 | 602 | int enable; |
a7e3212d LP |
603 | |
604 | assert(b); | |
605 | ||
d65ddaa4 LP |
606 | /* Enable SO_PASSCRED + SO_PASSEC. We try this on any |
607 | * socket, just in case. */ | |
0f4b73c8 | 608 | enable = !b->bus_client; |
dc751688 | 609 | (void) setsockopt(b->input_fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(enable)); |
264ad849 | 610 | |
d21a7bb1 | 611 | enable = !b->bus_client && (b->attach_flags & KDBUS_ATTACH_SECLABEL); |
dc751688 | 612 | (void) setsockopt(b->input_fd, SOL_SOCKET, SO_PASSSEC, &enable, sizeof(enable)); |
a7e3212d | 613 | |
aec6d91f LP |
614 | /* Increase the buffers to 8 MB */ |
615 | fd_inc_rcvbuf(b->input_fd, SNDBUF_SIZE); | |
616 | fd_inc_sndbuf(b->output_fd, SNDBUF_SIZE); | |
a7e3212d | 617 | |
e1d337d4 LP |
618 | b->is_kernel = false; |
619 | b->message_version = 1; | |
0f437184 | 620 | b->message_endian = 0; |
8f04d2eb | 621 | } |
e1d337d4 | 622 | |
8f04d2eb | 623 | static void bus_get_peercred(sd_bus *b) { |
8f04d2eb LP |
624 | assert(b); |
625 | ||
626 | /* Get the peer for socketpair() sockets */ | |
eff05270 | 627 | b->ucred_valid = getpeercred(b->input_fd, &b->ucred) >= 0; |
a7e3212d LP |
628 | } |
629 | ||
2181a7f5 | 630 | static int bus_socket_start_auth_client(sd_bus *b) { |
a7e3212d | 631 | size_t l; |
2181a7f5 | 632 | const char *auth_suffix, *auth_prefix; |
a7e3212d LP |
633 | |
634 | assert(b); | |
635 | ||
2181a7f5 LP |
636 | if (b->anonymous_auth) { |
637 | auth_prefix = "\0AUTH ANONYMOUS "; | |
a7e3212d | 638 | |
2181a7f5 LP |
639 | /* For ANONYMOUS auth we send some arbitrary "trace" string */ |
640 | l = 9; | |
641 | b->auth_buffer = hexmem("anonymous", l); | |
642 | } else { | |
5ffa8c81 | 643 | char text[DECIMAL_STR_MAX(uid_t) + 1]; |
a7e3212d | 644 | |
2181a7f5 | 645 | auth_prefix = "\0AUTH EXTERNAL "; |
a7e3212d | 646 | |
5ffa8c81 | 647 | xsprintf(text, UID_FMT, geteuid()); |
a7e3212d | 648 | |
2181a7f5 LP |
649 | l = strlen(text); |
650 | b->auth_buffer = hexmem(text, l); | |
651 | } | |
652 | ||
653 | if (!b->auth_buffer) | |
a7e3212d LP |
654 | return -ENOMEM; |
655 | ||
264ad849 | 656 | if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) |
2181a7f5 LP |
657 | auth_suffix = "\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n"; |
658 | else | |
659 | auth_suffix = "\r\nBEGIN\r\n"; | |
a7e3212d LP |
660 | |
661 | b->auth_iovec[0].iov_base = (void*) auth_prefix; | |
2181a7f5 LP |
662 | b->auth_iovec[0].iov_len = 1 + strlen(auth_prefix + 1); |
663 | b->auth_iovec[1].iov_base = (void*) b->auth_buffer; | |
a7e3212d LP |
664 | b->auth_iovec[1].iov_len = l * 2; |
665 | b->auth_iovec[2].iov_base = (void*) auth_suffix; | |
666 | b->auth_iovec[2].iov_len = strlen(auth_suffix); | |
a7e3212d LP |
667 | |
668 | return bus_socket_write_auth(b); | |
669 | } | |
670 | ||
a7893c6b | 671 | int bus_socket_start_auth(sd_bus *b) { |
2181a7f5 LP |
672 | assert(b); |
673 | ||
8f04d2eb LP |
674 | bus_get_peercred(b); |
675 | ||
2181a7f5 LP |
676 | b->state = BUS_AUTHENTICATING; |
677 | b->auth_timeout = now(CLOCK_MONOTONIC) + BUS_DEFAULT_TIMEOUT; | |
678 | ||
9ab32f9d | 679 | if (sd_is_socket(b->input_fd, AF_UNIX, 0, 0) <= 0) |
264ad849 | 680 | b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; |
2181a7f5 | 681 | |
9ab32f9d LP |
682 | if (b->output_fd != b->input_fd) |
683 | if (sd_is_socket(b->output_fd, AF_UNIX, 0, 0) <= 0) | |
264ad849 | 684 | b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; |
e82c9509 | 685 | |
2181a7f5 LP |
686 | if (b->is_server) |
687 | return bus_socket_read_auth(b); | |
688 | else | |
689 | return bus_socket_start_auth_client(b); | |
690 | } | |
691 | ||
a7e3212d LP |
692 | int bus_socket_connect(sd_bus *b) { |
693 | int r; | |
694 | ||
695 | assert(b); | |
e82c9509 LP |
696 | assert(b->input_fd < 0); |
697 | assert(b->output_fd < 0); | |
a7e3212d LP |
698 | assert(b->sockaddr.sa.sa_family != AF_UNSPEC); |
699 | ||
e82c9509 LP |
700 | b->input_fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
701 | if (b->input_fd < 0) | |
a7e3212d LP |
702 | return -errno; |
703 | ||
e82c9509 LP |
704 | b->output_fd = b->input_fd; |
705 | ||
8f04d2eb | 706 | bus_socket_setup(b); |
a7e3212d | 707 | |
e82c9509 | 708 | r = connect(b->input_fd, &b->sockaddr.sa, b->sockaddr_size); |
a7e3212d LP |
709 | if (r < 0) { |
710 | if (errno == EINPROGRESS) | |
711 | return 1; | |
712 | ||
713 | return -errno; | |
714 | } | |
715 | ||
716 | return bus_socket_start_auth(b); | |
717 | } | |
718 | ||
719 | int bus_socket_exec(sd_bus *b) { | |
e82c9509 | 720 | int s[2], r; |
a7e3212d LP |
721 | pid_t pid; |
722 | ||
723 | assert(b); | |
e82c9509 LP |
724 | assert(b->input_fd < 0); |
725 | assert(b->output_fd < 0); | |
a7e3212d LP |
726 | assert(b->exec_path); |
727 | ||
e82c9509 LP |
728 | r = socketpair(AF_UNIX, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, s); |
729 | if (r < 0) | |
a7e3212d LP |
730 | return -errno; |
731 | ||
732 | pid = fork(); | |
733 | if (pid < 0) { | |
3d94f76c | 734 | safe_close_pair(s); |
a7e3212d LP |
735 | return -errno; |
736 | } | |
737 | if (pid == 0) { | |
738 | /* Child */ | |
739 | ||
e82c9509 LP |
740 | reset_all_signal_handlers(); |
741 | ||
742 | close_all_fds(s+1, 1); | |
a7e3212d LP |
743 | |
744 | assert_se(dup3(s[1], STDIN_FILENO, 0) == STDIN_FILENO); | |
745 | assert_se(dup3(s[1], STDOUT_FILENO, 0) == STDOUT_FILENO); | |
746 | ||
747 | if (s[1] != STDIN_FILENO && s[1] != STDOUT_FILENO) | |
03e334a1 | 748 | safe_close(s[1]); |
a7e3212d LP |
749 | |
750 | fd_cloexec(STDIN_FILENO, false); | |
751 | fd_cloexec(STDOUT_FILENO, false); | |
752 | fd_nonblock(STDIN_FILENO, false); | |
753 | fd_nonblock(STDOUT_FILENO, false); | |
754 | ||
755 | if (b->exec_argv) | |
756 | execvp(b->exec_path, b->exec_argv); | |
757 | else { | |
758 | const char *argv[] = { b->exec_path, NULL }; | |
759 | execvp(b->exec_path, (char**) argv); | |
760 | } | |
761 | ||
762 | _exit(EXIT_FAILURE); | |
763 | } | |
764 | ||
03e334a1 | 765 | safe_close(s[1]); |
e82c9509 | 766 | b->output_fd = b->input_fd = s[0]; |
a7e3212d | 767 | |
8f04d2eb | 768 | bus_socket_setup(b); |
e1d337d4 | 769 | |
a7e3212d LP |
770 | return bus_socket_start_auth(b); |
771 | } | |
772 | ||
773 | int bus_socket_take_fd(sd_bus *b) { | |
a7e3212d LP |
774 | assert(b); |
775 | ||
8f04d2eb | 776 | bus_socket_setup(b); |
a7e3212d LP |
777 | |
778 | return bus_socket_start_auth(b); | |
779 | } | |
780 | ||
781 | int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) { | |
a7e3212d LP |
782 | struct iovec *iov; |
783 | ssize_t k; | |
784 | size_t n; | |
785 | unsigned j; | |
bc7fd8cd | 786 | int r; |
a7e3212d LP |
787 | |
788 | assert(bus); | |
789 | assert(m); | |
790 | assert(idx); | |
791 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
792 | ||
6629161f | 793 | if (*idx >= BUS_MESSAGE_SIZE(m)) |
a7e3212d | 794 | return 0; |
a7e3212d | 795 | |
bc7fd8cd LP |
796 | r = bus_message_setup_iovec(m); |
797 | if (r < 0) | |
798 | return r; | |
2100fa10 | 799 | |
a7e3212d LP |
800 | n = m->n_iovec * sizeof(struct iovec); |
801 | iov = alloca(n); | |
802 | memcpy(iov, m->iovec, n); | |
803 | ||
804 | j = 0; | |
805 | iovec_advance(iov, &j, *idx); | |
806 | ||
15d5af81 LP |
807 | if (bus->prefer_writev) |
808 | k = writev(bus->output_fd, iov, m->n_iovec); | |
809 | else { | |
7f4e6a1c ZJS |
810 | struct msghdr mh = { |
811 | .msg_iov = iov, | |
812 | .msg_iovlen = m->n_iovec, | |
813 | }; | |
15d5af81 LP |
814 | |
815 | if (m->n_fds > 0) { | |
816 | struct cmsghdr *control; | |
15d5af81 | 817 | |
7f4e6a1c ZJS |
818 | mh.msg_control = control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds)); |
819 | mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds); | |
15d5af81 LP |
820 | control->cmsg_level = SOL_SOCKET; |
821 | control->cmsg_type = SCM_RIGHTS; | |
15d5af81 LP |
822 | memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds); |
823 | } | |
824 | ||
15d5af81 LP |
825 | k = sendmsg(bus->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); |
826 | if (k < 0 && errno == ENOTSOCK) { | |
827 | bus->prefer_writev = true; | |
828 | k = writev(bus->output_fd, iov, m->n_iovec); | |
829 | } | |
830 | } | |
a7e3212d | 831 | |
a7e3212d LP |
832 | if (k < 0) |
833 | return errno == EAGAIN ? 0 : -errno; | |
834 | ||
835 | *idx += (size_t) k; | |
836 | return 1; | |
837 | } | |
838 | ||
839 | static int bus_socket_read_message_need(sd_bus *bus, size_t *need) { | |
840 | uint32_t a, b; | |
841 | uint8_t e; | |
842 | uint64_t sum; | |
843 | ||
844 | assert(bus); | |
845 | assert(need); | |
846 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
847 | ||
848 | if (bus->rbuffer_size < sizeof(struct bus_header)) { | |
849 | *need = sizeof(struct bus_header) + 8; | |
850 | ||
851 | /* Minimum message size: | |
852 | * | |
853 | * Header + | |
854 | * | |
855 | * Method Call: +2 string headers | |
856 | * Signal: +3 string headers | |
857 | * Method Error: +1 string headers | |
858 | * +1 uint32 headers | |
859 | * Method Reply: +1 uint32 headers | |
860 | * | |
861 | * A string header is at least 9 bytes | |
862 | * A uint32 header is at least 8 bytes | |
863 | * | |
864 | * Hence the minimum message size of a valid message | |
865 | * is header + 8 bytes */ | |
866 | ||
867 | return 0; | |
868 | } | |
869 | ||
870 | a = ((const uint32_t*) bus->rbuffer)[1]; | |
871 | b = ((const uint32_t*) bus->rbuffer)[3]; | |
872 | ||
873 | e = ((const uint8_t*) bus->rbuffer)[0]; | |
0461f8cd | 874 | if (e == BUS_LITTLE_ENDIAN) { |
a7e3212d LP |
875 | a = le32toh(a); |
876 | b = le32toh(b); | |
0461f8cd | 877 | } else if (e == BUS_BIG_ENDIAN) { |
a7e3212d LP |
878 | a = be32toh(a); |
879 | b = be32toh(b); | |
880 | } else | |
881 | return -EBADMSG; | |
882 | ||
883 | sum = (uint64_t) sizeof(struct bus_header) + (uint64_t) ALIGN_TO(b, 8) + (uint64_t) a; | |
884 | if (sum >= BUS_MESSAGE_SIZE_MAX) | |
885 | return -ENOBUFS; | |
886 | ||
887 | *need = (size_t) sum; | |
888 | return 0; | |
889 | } | |
890 | ||
7d22c717 | 891 | static int bus_socket_make_message(sd_bus *bus, size_t size) { |
a7e3212d LP |
892 | sd_bus_message *t; |
893 | void *b; | |
894 | int r; | |
895 | ||
896 | assert(bus); | |
a7e3212d LP |
897 | assert(bus->rbuffer_size >= size); |
898 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
899 | ||
7adc46fc LP |
900 | r = bus_rqueue_make_room(bus); |
901 | if (r < 0) | |
902 | return r; | |
903 | ||
a7e3212d LP |
904 | if (bus->rbuffer_size > size) { |
905 | b = memdup((const uint8_t*) bus->rbuffer + size, | |
906 | bus->rbuffer_size - size); | |
907 | if (!b) | |
908 | return -ENOMEM; | |
909 | } else | |
910 | b = NULL; | |
911 | ||
df2d202e LP |
912 | r = bus_message_from_malloc(bus, |
913 | bus->rbuffer, size, | |
a7e3212d | 914 | bus->fds, bus->n_fds, |
038f9863 LP |
915 | NULL, |
916 | NULL, | |
a7e3212d LP |
917 | &t); |
918 | if (r < 0) { | |
919 | free(b); | |
920 | return r; | |
921 | } | |
922 | ||
923 | bus->rbuffer = b; | |
924 | bus->rbuffer_size -= size; | |
925 | ||
926 | bus->fds = NULL; | |
927 | bus->n_fds = 0; | |
928 | ||
7adc46fc | 929 | bus->rqueue[bus->rqueue_size++] = t; |
7d22c717 | 930 | |
a7e3212d LP |
931 | return 1; |
932 | } | |
933 | ||
7d22c717 | 934 | int bus_socket_read_message(sd_bus *bus) { |
a7e3212d | 935 | struct msghdr mh; |
7f4e6a1c | 936 | struct iovec iov = {}; |
a7e3212d LP |
937 | ssize_t k; |
938 | size_t need; | |
939 | int r; | |
940 | void *b; | |
941 | union { | |
942 | struct cmsghdr cmsghdr; | |
943 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + | |
944 | CMSG_SPACE(sizeof(struct ucred)) + | |
945 | CMSG_SPACE(NAME_MAX)]; /*selinux label */ | |
946 | } control; | |
947 | struct cmsghdr *cmsg; | |
4d3a5b10 | 948 | bool handle_cmsg = false; |
a7e3212d LP |
949 | |
950 | assert(bus); | |
a7e3212d LP |
951 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); |
952 | ||
953 | r = bus_socket_read_message_need(bus, &need); | |
954 | if (r < 0) | |
955 | return r; | |
956 | ||
957 | if (bus->rbuffer_size >= need) | |
7d22c717 | 958 | return bus_socket_make_message(bus, need); |
a7e3212d LP |
959 | |
960 | b = realloc(bus->rbuffer, need); | |
961 | if (!b) | |
962 | return -ENOMEM; | |
963 | ||
964 | bus->rbuffer = b; | |
965 | ||
a7e3212d LP |
966 | iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size; |
967 | iov.iov_len = need - bus->rbuffer_size; | |
968 | ||
15d5af81 LP |
969 | if (bus->prefer_readv) |
970 | k = readv(bus->input_fd, &iov, 1); | |
971 | else { | |
972 | zero(mh); | |
973 | mh.msg_iov = &iov; | |
974 | mh.msg_iovlen = 1; | |
975 | mh.msg_control = &control; | |
976 | mh.msg_controllen = sizeof(control); | |
977 | ||
978 | k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
979 | if (k < 0 && errno == ENOTSOCK) { | |
980 | bus->prefer_readv = true; | |
981 | k = readv(bus->input_fd, &iov, 1); | |
982 | } else | |
983 | handle_cmsg = true; | |
984 | } | |
a7e3212d LP |
985 | if (k < 0) |
986 | return errno == EAGAIN ? 0 : -errno; | |
987 | if (k == 0) | |
988 | return -ECONNRESET; | |
989 | ||
990 | bus->rbuffer_size += k; | |
991 | ||
15d5af81 LP |
992 | if (handle_cmsg) { |
993 | for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { | |
994 | if (cmsg->cmsg_level == SOL_SOCKET && | |
995 | cmsg->cmsg_type == SCM_RIGHTS) { | |
996 | int n, *f; | |
997 | ||
998 | n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
999 | ||
1000 | if (!bus->can_fds) { | |
1001 | /* Whut? We received fds but this | |
1002 | * isn't actually enabled? Close them, | |
1003 | * and fail */ | |
1004 | ||
1005 | close_many((int*) CMSG_DATA(cmsg), n); | |
1006 | return -EIO; | |
1007 | } | |
1008 | ||
1009 | f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n)); | |
1010 | if (!f) { | |
1011 | close_many((int*) CMSG_DATA(cmsg), n); | |
1012 | return -ENOMEM; | |
1013 | } | |
1014 | ||
1015 | memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int)); | |
1016 | bus->fds = f; | |
1017 | bus->n_fds += n; | |
1018 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1019 | cmsg->cmsg_type == SCM_CREDENTIALS && | |
1020 | cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { | |
1021 | ||
ea8f194f LP |
1022 | /* Ignore bogus data, which we might |
1023 | * get on socketpair() sockets */ | |
1024 | if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { | |
1025 | memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); | |
1026 | bus->ucred_valid = true; | |
1027 | } | |
15d5af81 LP |
1028 | |
1029 | } else if (cmsg->cmsg_level == SOL_SOCKET && | |
1030 | cmsg->cmsg_type == SCM_SECURITY) { | |
1031 | ||
1032 | size_t l; | |
1033 | l = cmsg->cmsg_len - CMSG_LEN(0); | |
ea8f194f LP |
1034 | if (l > 0) { |
1035 | memcpy(&bus->label, CMSG_DATA(cmsg), l); | |
1036 | bus->label[l] = 0; | |
1037 | } | |
a7e3212d | 1038 | } |
a7e3212d LP |
1039 | } |
1040 | } | |
1041 | ||
1042 | r = bus_socket_read_message_need(bus, &need); | |
1043 | if (r < 0) | |
1044 | return r; | |
1045 | ||
1046 | if (bus->rbuffer_size >= need) | |
7d22c717 | 1047 | return bus_socket_make_message(bus, need); |
a7e3212d LP |
1048 | |
1049 | return 1; | |
1050 | } | |
1051 | ||
1052 | int bus_socket_process_opening(sd_bus *b) { | |
1053 | int error = 0; | |
1054 | socklen_t slen = sizeof(error); | |
b92bea5d ZJS |
1055 | struct pollfd p = { |
1056 | .fd = b->output_fd, | |
1057 | .events = POLLOUT, | |
1058 | }; | |
a7e3212d LP |
1059 | int r; |
1060 | ||
a7e3212d LP |
1061 | assert(b->state == BUS_OPENING); |
1062 | ||
a7e3212d LP |
1063 | r = poll(&p, 1, 0); |
1064 | if (r < 0) | |
1065 | return -errno; | |
1066 | ||
1067 | if (!(p.revents & (POLLOUT|POLLERR|POLLHUP))) | |
1068 | return 0; | |
1069 | ||
e82c9509 | 1070 | r = getsockopt(b->output_fd, SOL_SOCKET, SO_ERROR, &error, &slen); |
a7e3212d LP |
1071 | if (r < 0) |
1072 | b->last_connect_error = errno; | |
1073 | else if (error != 0) | |
1074 | b->last_connect_error = error; | |
1075 | else if (p.revents & (POLLERR|POLLHUP)) | |
1076 | b->last_connect_error = ECONNREFUSED; | |
1077 | else | |
1078 | return bus_socket_start_auth(b); | |
1079 | ||
1080 | return bus_next_address(b); | |
1081 | } | |
1082 | ||
1083 | int bus_socket_process_authenticating(sd_bus *b) { | |
1084 | int r; | |
1085 | ||
1086 | assert(b); | |
1087 | assert(b->state == BUS_AUTHENTICATING); | |
1088 | ||
1089 | if (now(CLOCK_MONOTONIC) >= b->auth_timeout) | |
1090 | return -ETIMEDOUT; | |
1091 | ||
1092 | r = bus_socket_write_auth(b); | |
1093 | if (r != 0) | |
1094 | return r; | |
1095 | ||
1096 | return bus_socket_read_auth(b); | |
1097 | } |