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1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ | |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2013 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <endian.h> | |
23 | #include <poll.h> | |
24 | #include <stdlib.h> | |
25 | #include <unistd.h> | |
26 | ||
27 | #include "sd-bus.h" | |
28 | #include "sd-daemon.h" | |
29 | ||
30 | #include "bus-internal.h" | |
31 | #include "bus-message.h" | |
32 | #include "formats-util.h" | |
33 | #include "macro.h" | |
34 | #include "missing.h" | |
35 | #include "signal-util.h" | |
36 | #include "string-util.h" | |
37 | #include "utf8.h" | |
38 | #include "util.h" | |
39 | #include "bus-socket.h" | |
40 | ||
41 | #define SNDBUF_SIZE (8*1024*1024) | |
42 | ||
43 | static void iovec_advance(struct iovec iov[], unsigned *idx, size_t size) { | |
44 | ||
45 | while (size > 0) { | |
46 | struct iovec *i = iov + *idx; | |
47 | ||
48 | if (i->iov_len > size) { | |
49 | i->iov_base = (uint8_t*) i->iov_base + size; | |
50 | i->iov_len -= size; | |
51 | return; | |
52 | } | |
53 | ||
54 | size -= i->iov_len; | |
55 | ||
56 | i->iov_base = NULL; | |
57 | i->iov_len = 0; | |
58 | ||
59 | (*idx) ++; | |
60 | } | |
61 | } | |
62 | ||
63 | static int append_iovec(sd_bus_message *m, const void *p, size_t sz) { | |
64 | assert(m); | |
65 | assert(p); | |
66 | assert(sz > 0); | |
67 | ||
68 | m->iovec[m->n_iovec].iov_base = (void*) p; | |
69 | m->iovec[m->n_iovec].iov_len = sz; | |
70 | m->n_iovec++; | |
71 | ||
72 | return 0; | |
73 | } | |
74 | ||
75 | static int bus_message_setup_iovec(sd_bus_message *m) { | |
76 | struct bus_body_part *part; | |
77 | unsigned n, i; | |
78 | int r; | |
79 | ||
80 | assert(m); | |
81 | assert(m->sealed); | |
82 | ||
83 | if (m->n_iovec > 0) | |
84 | return 0; | |
85 | ||
86 | assert(!m->iovec); | |
87 | ||
88 | n = 1 + m->n_body_parts; | |
89 | if (n < ELEMENTSOF(m->iovec_fixed)) | |
90 | m->iovec = m->iovec_fixed; | |
91 | else { | |
92 | m->iovec = new(struct iovec, n); | |
93 | if (!m->iovec) { | |
94 | r = -ENOMEM; | |
95 | goto fail; | |
96 | } | |
97 | } | |
98 | ||
99 | r = append_iovec(m, m->header, BUS_MESSAGE_BODY_BEGIN(m)); | |
100 | if (r < 0) | |
101 | goto fail; | |
102 | ||
103 | MESSAGE_FOREACH_PART(part, i, m) { | |
104 | r = bus_body_part_map(part); | |
105 | if (r < 0) | |
106 | goto fail; | |
107 | ||
108 | r = append_iovec(m, part->data, part->size); | |
109 | if (r < 0) | |
110 | goto fail; | |
111 | } | |
112 | ||
113 | assert(n == m->n_iovec); | |
114 | ||
115 | return 0; | |
116 | ||
117 | fail: | |
118 | m->poisoned = true; | |
119 | return r; | |
120 | } | |
121 | ||
122 | bool bus_socket_auth_needs_write(sd_bus *b) { | |
123 | ||
124 | unsigned i; | |
125 | ||
126 | if (b->auth_index >= ELEMENTSOF(b->auth_iovec)) | |
127 | return false; | |
128 | ||
129 | for (i = b->auth_index; i < ELEMENTSOF(b->auth_iovec); i++) { | |
130 | struct iovec *j = b->auth_iovec + i; | |
131 | ||
132 | if (j->iov_len > 0) | |
133 | return true; | |
134 | } | |
135 | ||
136 | return false; | |
137 | } | |
138 | ||
139 | static int bus_socket_write_auth(sd_bus *b) { | |
140 | ssize_t k; | |
141 | ||
142 | assert(b); | |
143 | assert(b->state == BUS_AUTHENTICATING); | |
144 | ||
145 | if (!bus_socket_auth_needs_write(b)) | |
146 | return 0; | |
147 | ||
148 | if (b->prefer_writev) | |
149 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
150 | else { | |
151 | struct msghdr mh; | |
152 | zero(mh); | |
153 | ||
154 | mh.msg_iov = b->auth_iovec + b->auth_index; | |
155 | mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index; | |
156 | ||
157 | k = sendmsg(b->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
158 | if (k < 0 && errno == ENOTSOCK) { | |
159 | b->prefer_writev = true; | |
160 | k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); | |
161 | } | |
162 | } | |
163 | ||
164 | if (k < 0) | |
165 | return errno == EAGAIN ? 0 : -errno; | |
166 | ||
167 | iovec_advance(b->auth_iovec, &b->auth_index, (size_t) k); | |
168 | return 1; | |
169 | } | |
170 | ||
171 | static int bus_socket_auth_verify_client(sd_bus *b) { | |
172 | char *e, *f, *start; | |
173 | sd_id128_t peer; | |
174 | unsigned i; | |
175 | int r; | |
176 | ||
177 | assert(b); | |
178 | ||
179 | /* We expect two response lines: "OK" and possibly | |
180 | * "AGREE_UNIX_FD" */ | |
181 | ||
182 | e = memmem_safe(b->rbuffer, b->rbuffer_size, "\r\n", 2); | |
183 | if (!e) | |
184 | return 0; | |
185 | ||
186 | if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) { | |
187 | f = memmem(e + 2, b->rbuffer_size - (e - (char*) b->rbuffer) - 2, "\r\n", 2); | |
188 | if (!f) | |
189 | return 0; | |
190 | ||
191 | start = f + 2; | |
192 | } else { | |
193 | f = NULL; | |
194 | start = e + 2; | |
195 | } | |
196 | ||
197 | /* Nice! We got all the lines we need. First check the OK | |
198 | * line */ | |
199 | ||
200 | if (e - (char*) b->rbuffer != 3 + 32) | |
201 | return -EPERM; | |
202 | ||
203 | if (memcmp(b->rbuffer, "OK ", 3)) | |
204 | return -EPERM; | |
205 | ||
206 | b->auth = b->anonymous_auth ? BUS_AUTH_ANONYMOUS : BUS_AUTH_EXTERNAL; | |
207 | ||
208 | for (i = 0; i < 32; i += 2) { | |
209 | int x, y; | |
210 | ||
211 | x = unhexchar(((char*) b->rbuffer)[3 + i]); | |
212 | y = unhexchar(((char*) b->rbuffer)[3 + i + 1]); | |
213 | ||
214 | if (x < 0 || y < 0) | |
215 | return -EINVAL; | |
216 | ||
217 | peer.bytes[i/2] = ((uint8_t) x << 4 | (uint8_t) y); | |
218 | } | |
219 | ||
220 | if (!sd_id128_equal(b->server_id, SD_ID128_NULL) && | |
221 | !sd_id128_equal(b->server_id, peer)) | |
222 | return -EPERM; | |
223 | ||
224 | b->server_id = peer; | |
225 | ||
226 | /* And possibly check the second line, too */ | |
227 | ||
228 | if (f) | |
229 | b->can_fds = | |
230 | (f - e == strlen("\r\nAGREE_UNIX_FD")) && | |
231 | memcmp(e + 2, "AGREE_UNIX_FD", strlen("AGREE_UNIX_FD")) == 0; | |
232 | ||
233 | b->rbuffer_size -= (start - (char*) b->rbuffer); | |
234 | memmove(b->rbuffer, start, b->rbuffer_size); | |
235 | ||
236 | r = bus_start_running(b); | |
237 | if (r < 0) | |
238 | return r; | |
239 | ||
240 | return 1; | |
241 | } | |
242 | ||
243 | static bool line_equals(const char *s, size_t m, const char *line) { | |
244 | size_t l; | |
245 | ||
246 | l = strlen(line); | |
247 | if (l != m) | |
248 | return false; | |
249 | ||
250 | return memcmp(s, line, l) == 0; | |
251 | } | |
252 | ||
253 | static bool line_begins(const char *s, size_t m, const char *word) { | |
254 | size_t l; | |
255 | ||
256 | l = strlen(word); | |
257 | if (m < l) | |
258 | return false; | |
259 | ||
260 | if (memcmp(s, word, l) != 0) | |
261 | return false; | |
262 | ||
263 | return m == l || (m > l && s[l] == ' '); | |
264 | } | |
265 | ||
266 | static int verify_anonymous_token(sd_bus *b, const char *p, size_t l) { | |
267 | _cleanup_free_ char *token = NULL; | |
268 | size_t len; | |
269 | int r; | |
270 | ||
271 | if (!b->anonymous_auth) | |
272 | return 0; | |
273 | ||
274 | if (l <= 0) | |
275 | return 1; | |
276 | ||
277 | assert(p[0] == ' '); | |
278 | p++; l--; | |
279 | ||
280 | if (l % 2 != 0) | |
281 | return 0; | |
282 | ||
283 | r = unhexmem(p, l, (void **) &token, &len); | |
284 | if (r < 0) | |
285 | return 0; | |
286 | ||
287 | if (memchr(token, 0, len)) | |
288 | return 0; | |
289 | ||
290 | return !!utf8_is_valid(token); | |
291 | } | |
292 | ||
293 | static int verify_external_token(sd_bus *b, const char *p, size_t l) { | |
294 | _cleanup_free_ char *token = NULL; | |
295 | size_t len; | |
296 | uid_t u; | |
297 | int r; | |
298 | ||
299 | /* We don't do any real authentication here. Instead, we if | |
300 | * the owner of this bus wanted authentication he should have | |
301 | * checked SO_PEERCRED before even creating the bus object. */ | |
302 | ||
303 | if (!b->anonymous_auth && !b->ucred_valid) | |
304 | return 0; | |
305 | ||
306 | if (l <= 0) | |
307 | return 1; | |
308 | ||
309 | assert(p[0] == ' '); | |
310 | p++; l--; | |
311 | ||
312 | if (l % 2 != 0) | |
313 | return 0; | |
314 | ||
315 | r = unhexmem(p, l, (void**) &token, &len); | |
316 | if (r < 0) | |
317 | return 0; | |
318 | ||
319 | if (memchr(token, 0, len)) | |
320 | return 0; | |
321 | ||
322 | r = parse_uid(token, &u); | |
323 | if (r < 0) | |
324 | return 0; | |
325 | ||
326 | /* We ignore the passed value if anonymous authentication is | |
327 | * on anyway. */ | |
328 | if (!b->anonymous_auth && u != b->ucred.uid) | |
329 | return 0; | |
330 | ||
331 | return 1; | |
332 | } | |
333 | ||
334 | static int bus_socket_auth_write(sd_bus *b, const char *t) { | |
335 | char *p; | |
336 | size_t l; | |
337 | ||
338 | assert(b); | |
339 | assert(t); | |
340 | ||
341 | /* We only make use of the first iovec */ | |
342 | assert(b->auth_index == 0 || b->auth_index == 1); | |
343 | ||
344 | l = strlen(t); | |
345 | p = malloc(b->auth_iovec[0].iov_len + l); | |
346 | if (!p) | |
347 | return -ENOMEM; | |
348 | ||
349 | memcpy(p, b->auth_iovec[0].iov_base, b->auth_iovec[0].iov_len); | |
350 | memcpy(p + b->auth_iovec[0].iov_len, t, l); | |
351 | ||
352 | b->auth_iovec[0].iov_base = p; | |
353 | b->auth_iovec[0].iov_len += l; | |
354 | ||
355 | free(b->auth_buffer); | |
356 | b->auth_buffer = p; | |
357 | b->auth_index = 0; | |
358 | return 0; | |
359 | } | |
360 | ||
361 | static int bus_socket_auth_write_ok(sd_bus *b) { | |
362 | char t[3 + 32 + 2 + 1]; | |
363 | ||
364 | assert(b); | |
365 | ||
366 | xsprintf(t, "OK " SD_ID128_FORMAT_STR "\r\n", SD_ID128_FORMAT_VAL(b->server_id)); | |
367 | ||
368 | return bus_socket_auth_write(b, t); | |
369 | } | |
370 | ||
371 | static int bus_socket_auth_verify_server(sd_bus *b) { | |
372 | char *e; | |
373 | const char *line; | |
374 | size_t l; | |
375 | bool processed = false; | |
376 | int r; | |
377 | ||
378 | assert(b); | |
379 | ||
380 | if (b->rbuffer_size < 1) | |
381 | return 0; | |
382 | ||
383 | /* First char must be a NUL byte */ | |
384 | if (*(char*) b->rbuffer != 0) | |
385 | return -EIO; | |
386 | ||
387 | if (b->rbuffer_size < 3) | |
388 | return 0; | |
389 | ||
390 | /* Begin with the first line */ | |
391 | if (b->auth_rbegin <= 0) | |
392 | b->auth_rbegin = 1; | |
393 | ||
394 | for (;;) { | |
395 | /* Check if line is complete */ | |
396 | line = (char*) b->rbuffer + b->auth_rbegin; | |
397 | e = memmem(line, b->rbuffer_size - b->auth_rbegin, "\r\n", 2); | |
398 | if (!e) | |
399 | return processed; | |
400 | ||
401 | l = e - line; | |
402 | ||
403 | if (line_begins(line, l, "AUTH ANONYMOUS")) { | |
404 | ||
405 | r = verify_anonymous_token(b, line + 14, l - 14); | |
406 | if (r < 0) | |
407 | return r; | |
408 | if (r == 0) | |
409 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
410 | else { | |
411 | b->auth = BUS_AUTH_ANONYMOUS; | |
412 | r = bus_socket_auth_write_ok(b); | |
413 | } | |
414 | ||
415 | } else if (line_begins(line, l, "AUTH EXTERNAL")) { | |
416 | ||
417 | r = verify_external_token(b, line + 13, l - 13); | |
418 | if (r < 0) | |
419 | return r; | |
420 | if (r == 0) | |
421 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
422 | else { | |
423 | b->auth = BUS_AUTH_EXTERNAL; | |
424 | r = bus_socket_auth_write_ok(b); | |
425 | } | |
426 | ||
427 | } else if (line_begins(line, l, "AUTH")) | |
428 | r = bus_socket_auth_write(b, "REJECTED EXTERNAL ANONYMOUS\r\n"); | |
429 | else if (line_equals(line, l, "CANCEL") || | |
430 | line_begins(line, l, "ERROR")) { | |
431 | ||
432 | b->auth = _BUS_AUTH_INVALID; | |
433 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
434 | ||
435 | } else if (line_equals(line, l, "BEGIN")) { | |
436 | ||
437 | if (b->auth == _BUS_AUTH_INVALID) | |
438 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
439 | else { | |
440 | /* We can't leave from the auth phase | |
441 | * before we haven't written | |
442 | * everything queued, so let's check | |
443 | * that */ | |
444 | ||
445 | if (bus_socket_auth_needs_write(b)) | |
446 | return 1; | |
447 | ||
448 | b->rbuffer_size -= (e + 2 - (char*) b->rbuffer); | |
449 | memmove(b->rbuffer, e + 2, b->rbuffer_size); | |
450 | return bus_start_running(b); | |
451 | } | |
452 | ||
453 | } else if (line_begins(line, l, "DATA")) { | |
454 | ||
455 | if (b->auth == _BUS_AUTH_INVALID) | |
456 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
457 | else { | |
458 | if (b->auth == BUS_AUTH_ANONYMOUS) | |
459 | r = verify_anonymous_token(b, line + 4, l - 4); | |
460 | else | |
461 | r = verify_external_token(b, line + 4, l - 4); | |
462 | ||
463 | if (r < 0) | |
464 | return r; | |
465 | if (r == 0) { | |
466 | b->auth = _BUS_AUTH_INVALID; | |
467 | r = bus_socket_auth_write(b, "REJECTED\r\n"); | |
468 | } else | |
469 | r = bus_socket_auth_write_ok(b); | |
470 | } | |
471 | } else if (line_equals(line, l, "NEGOTIATE_UNIX_FD")) { | |
472 | if (b->auth == _BUS_AUTH_INVALID || !(b->hello_flags & KDBUS_HELLO_ACCEPT_FD)) | |
473 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
474 | else { | |
475 | b->can_fds = true; | |
476 | r = bus_socket_auth_write(b, "AGREE_UNIX_FD\r\n"); | |
477 | } | |
478 | } else | |
479 | r = bus_socket_auth_write(b, "ERROR\r\n"); | |
480 | ||
481 | if (r < 0) | |
482 | return r; | |
483 | ||
484 | b->auth_rbegin = e + 2 - (char*) b->rbuffer; | |
485 | ||
486 | processed = true; | |
487 | } | |
488 | } | |
489 | ||
490 | static int bus_socket_auth_verify(sd_bus *b) { | |
491 | assert(b); | |
492 | ||
493 | if (b->is_server) | |
494 | return bus_socket_auth_verify_server(b); | |
495 | else | |
496 | return bus_socket_auth_verify_client(b); | |
497 | } | |
498 | ||
499 | static int bus_socket_read_auth(sd_bus *b) { | |
500 | struct msghdr mh; | |
501 | struct iovec iov = {}; | |
502 | size_t n; | |
503 | ssize_t k; | |
504 | int r; | |
505 | void *p; | |
506 | union { | |
507 | struct cmsghdr cmsghdr; | |
508 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX)]; | |
509 | } control; | |
510 | bool handle_cmsg = false; | |
511 | ||
512 | assert(b); | |
513 | assert(b->state == BUS_AUTHENTICATING); | |
514 | ||
515 | r = bus_socket_auth_verify(b); | |
516 | if (r != 0) | |
517 | return r; | |
518 | ||
519 | n = MAX(256u, b->rbuffer_size * 2); | |
520 | ||
521 | if (n > BUS_AUTH_SIZE_MAX) | |
522 | n = BUS_AUTH_SIZE_MAX; | |
523 | ||
524 | if (b->rbuffer_size >= n) | |
525 | return -ENOBUFS; | |
526 | ||
527 | p = realloc(b->rbuffer, n); | |
528 | if (!p) | |
529 | return -ENOMEM; | |
530 | ||
531 | b->rbuffer = p; | |
532 | ||
533 | iov.iov_base = (uint8_t*) b->rbuffer + b->rbuffer_size; | |
534 | iov.iov_len = n - b->rbuffer_size; | |
535 | ||
536 | if (b->prefer_readv) | |
537 | k = readv(b->input_fd, &iov, 1); | |
538 | else { | |
539 | zero(mh); | |
540 | mh.msg_iov = &iov; | |
541 | mh.msg_iovlen = 1; | |
542 | mh.msg_control = &control; | |
543 | mh.msg_controllen = sizeof(control); | |
544 | ||
545 | k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
546 | if (k < 0 && errno == ENOTSOCK) { | |
547 | b->prefer_readv = true; | |
548 | k = readv(b->input_fd, &iov, 1); | |
549 | } else | |
550 | handle_cmsg = true; | |
551 | } | |
552 | if (k < 0) | |
553 | return errno == EAGAIN ? 0 : -errno; | |
554 | if (k == 0) | |
555 | return -ECONNRESET; | |
556 | ||
557 | b->rbuffer_size += k; | |
558 | ||
559 | if (handle_cmsg) { | |
560 | struct cmsghdr *cmsg; | |
561 | ||
562 | CMSG_FOREACH(cmsg, &mh) | |
563 | if (cmsg->cmsg_level == SOL_SOCKET && | |
564 | cmsg->cmsg_type == SCM_RIGHTS) { | |
565 | int j; | |
566 | ||
567 | /* Whut? We received fds during the auth | |
568 | * protocol? Somebody is playing games with | |
569 | * us. Close them all, and fail */ | |
570 | j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
571 | close_many((int*) CMSG_DATA(cmsg), j); | |
572 | return -EIO; | |
573 | } else | |
574 | log_debug("Got unexpected auxiliary data with level=%d and type=%d", | |
575 | cmsg->cmsg_level, cmsg->cmsg_type); | |
576 | } | |
577 | ||
578 | r = bus_socket_auth_verify(b); | |
579 | if (r != 0) | |
580 | return r; | |
581 | ||
582 | return 1; | |
583 | } | |
584 | ||
585 | void bus_socket_setup(sd_bus *b) { | |
586 | assert(b); | |
587 | ||
588 | /* Increase the buffers to 8 MB */ | |
589 | fd_inc_rcvbuf(b->input_fd, SNDBUF_SIZE); | |
590 | fd_inc_sndbuf(b->output_fd, SNDBUF_SIZE); | |
591 | ||
592 | b->is_kernel = false; | |
593 | b->message_version = 1; | |
594 | b->message_endian = 0; | |
595 | } | |
596 | ||
597 | static void bus_get_peercred(sd_bus *b) { | |
598 | int r; | |
599 | ||
600 | assert(b); | |
601 | ||
602 | /* Get the peer for socketpair() sockets */ | |
603 | b->ucred_valid = getpeercred(b->input_fd, &b->ucred) >= 0; | |
604 | ||
605 | /* Get the SELinux context of the peer */ | |
606 | r = getpeersec(b->input_fd, &b->label); | |
607 | if (r < 0 && r != -EOPNOTSUPP) | |
608 | log_debug_errno(r, "Failed to determine peer security context: %m"); | |
609 | } | |
610 | ||
611 | static int bus_socket_start_auth_client(sd_bus *b) { | |
612 | size_t l; | |
613 | const char *auth_suffix, *auth_prefix; | |
614 | ||
615 | assert(b); | |
616 | ||
617 | if (b->anonymous_auth) { | |
618 | auth_prefix = "\0AUTH ANONYMOUS "; | |
619 | ||
620 | /* For ANONYMOUS auth we send some arbitrary "trace" string */ | |
621 | l = 9; | |
622 | b->auth_buffer = hexmem("anonymous", l); | |
623 | } else { | |
624 | char text[DECIMAL_STR_MAX(uid_t) + 1]; | |
625 | ||
626 | auth_prefix = "\0AUTH EXTERNAL "; | |
627 | ||
628 | xsprintf(text, UID_FMT, geteuid()); | |
629 | ||
630 | l = strlen(text); | |
631 | b->auth_buffer = hexmem(text, l); | |
632 | } | |
633 | ||
634 | if (!b->auth_buffer) | |
635 | return -ENOMEM; | |
636 | ||
637 | if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) | |
638 | auth_suffix = "\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n"; | |
639 | else | |
640 | auth_suffix = "\r\nBEGIN\r\n"; | |
641 | ||
642 | b->auth_iovec[0].iov_base = (void*) auth_prefix; | |
643 | b->auth_iovec[0].iov_len = 1 + strlen(auth_prefix + 1); | |
644 | b->auth_iovec[1].iov_base = (void*) b->auth_buffer; | |
645 | b->auth_iovec[1].iov_len = l * 2; | |
646 | b->auth_iovec[2].iov_base = (void*) auth_suffix; | |
647 | b->auth_iovec[2].iov_len = strlen(auth_suffix); | |
648 | ||
649 | return bus_socket_write_auth(b); | |
650 | } | |
651 | ||
652 | int bus_socket_start_auth(sd_bus *b) { | |
653 | assert(b); | |
654 | ||
655 | bus_get_peercred(b); | |
656 | ||
657 | b->state = BUS_AUTHENTICATING; | |
658 | b->auth_timeout = now(CLOCK_MONOTONIC) + BUS_DEFAULT_TIMEOUT; | |
659 | ||
660 | if (sd_is_socket(b->input_fd, AF_UNIX, 0, 0) <= 0) | |
661 | b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; | |
662 | ||
663 | if (b->output_fd != b->input_fd) | |
664 | if (sd_is_socket(b->output_fd, AF_UNIX, 0, 0) <= 0) | |
665 | b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; | |
666 | ||
667 | if (b->is_server) | |
668 | return bus_socket_read_auth(b); | |
669 | else | |
670 | return bus_socket_start_auth_client(b); | |
671 | } | |
672 | ||
673 | int bus_socket_connect(sd_bus *b) { | |
674 | int r; | |
675 | ||
676 | assert(b); | |
677 | assert(b->input_fd < 0); | |
678 | assert(b->output_fd < 0); | |
679 | assert(b->sockaddr.sa.sa_family != AF_UNSPEC); | |
680 | ||
681 | b->input_fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); | |
682 | if (b->input_fd < 0) | |
683 | return -errno; | |
684 | ||
685 | b->output_fd = b->input_fd; | |
686 | ||
687 | bus_socket_setup(b); | |
688 | ||
689 | r = connect(b->input_fd, &b->sockaddr.sa, b->sockaddr_size); | |
690 | if (r < 0) { | |
691 | if (errno == EINPROGRESS) | |
692 | return 1; | |
693 | ||
694 | return -errno; | |
695 | } | |
696 | ||
697 | return bus_socket_start_auth(b); | |
698 | } | |
699 | ||
700 | int bus_socket_exec(sd_bus *b) { | |
701 | int s[2], r; | |
702 | pid_t pid; | |
703 | ||
704 | assert(b); | |
705 | assert(b->input_fd < 0); | |
706 | assert(b->output_fd < 0); | |
707 | assert(b->exec_path); | |
708 | ||
709 | r = socketpair(AF_UNIX, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, s); | |
710 | if (r < 0) | |
711 | return -errno; | |
712 | ||
713 | pid = fork(); | |
714 | if (pid < 0) { | |
715 | safe_close_pair(s); | |
716 | return -errno; | |
717 | } | |
718 | if (pid == 0) { | |
719 | /* Child */ | |
720 | ||
721 | (void) reset_all_signal_handlers(); | |
722 | (void) reset_signal_mask(); | |
723 | ||
724 | close_all_fds(s+1, 1); | |
725 | ||
726 | assert_se(dup3(s[1], STDIN_FILENO, 0) == STDIN_FILENO); | |
727 | assert_se(dup3(s[1], STDOUT_FILENO, 0) == STDOUT_FILENO); | |
728 | ||
729 | if (s[1] != STDIN_FILENO && s[1] != STDOUT_FILENO) | |
730 | safe_close(s[1]); | |
731 | ||
732 | fd_cloexec(STDIN_FILENO, false); | |
733 | fd_cloexec(STDOUT_FILENO, false); | |
734 | fd_nonblock(STDIN_FILENO, false); | |
735 | fd_nonblock(STDOUT_FILENO, false); | |
736 | ||
737 | if (b->exec_argv) | |
738 | execvp(b->exec_path, b->exec_argv); | |
739 | else { | |
740 | const char *argv[] = { b->exec_path, NULL }; | |
741 | execvp(b->exec_path, (char**) argv); | |
742 | } | |
743 | ||
744 | _exit(EXIT_FAILURE); | |
745 | } | |
746 | ||
747 | safe_close(s[1]); | |
748 | b->output_fd = b->input_fd = s[0]; | |
749 | ||
750 | bus_socket_setup(b); | |
751 | ||
752 | return bus_socket_start_auth(b); | |
753 | } | |
754 | ||
755 | int bus_socket_take_fd(sd_bus *b) { | |
756 | assert(b); | |
757 | ||
758 | bus_socket_setup(b); | |
759 | ||
760 | return bus_socket_start_auth(b); | |
761 | } | |
762 | ||
763 | int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) { | |
764 | struct iovec *iov; | |
765 | ssize_t k; | |
766 | size_t n; | |
767 | unsigned j; | |
768 | int r; | |
769 | ||
770 | assert(bus); | |
771 | assert(m); | |
772 | assert(idx); | |
773 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
774 | ||
775 | if (*idx >= BUS_MESSAGE_SIZE(m)) | |
776 | return 0; | |
777 | ||
778 | r = bus_message_setup_iovec(m); | |
779 | if (r < 0) | |
780 | return r; | |
781 | ||
782 | n = m->n_iovec * sizeof(struct iovec); | |
783 | iov = alloca(n); | |
784 | memcpy(iov, m->iovec, n); | |
785 | ||
786 | j = 0; | |
787 | iovec_advance(iov, &j, *idx); | |
788 | ||
789 | if (bus->prefer_writev) | |
790 | k = writev(bus->output_fd, iov, m->n_iovec); | |
791 | else { | |
792 | struct msghdr mh = { | |
793 | .msg_iov = iov, | |
794 | .msg_iovlen = m->n_iovec, | |
795 | }; | |
796 | ||
797 | if (m->n_fds > 0) { | |
798 | struct cmsghdr *control; | |
799 | ||
800 | mh.msg_control = control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds)); | |
801 | mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds); | |
802 | control->cmsg_level = SOL_SOCKET; | |
803 | control->cmsg_type = SCM_RIGHTS; | |
804 | memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds); | |
805 | } | |
806 | ||
807 | k = sendmsg(bus->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); | |
808 | if (k < 0 && errno == ENOTSOCK) { | |
809 | bus->prefer_writev = true; | |
810 | k = writev(bus->output_fd, iov, m->n_iovec); | |
811 | } | |
812 | } | |
813 | ||
814 | if (k < 0) | |
815 | return errno == EAGAIN ? 0 : -errno; | |
816 | ||
817 | *idx += (size_t) k; | |
818 | return 1; | |
819 | } | |
820 | ||
821 | static int bus_socket_read_message_need(sd_bus *bus, size_t *need) { | |
822 | uint32_t a, b; | |
823 | uint8_t e; | |
824 | uint64_t sum; | |
825 | ||
826 | assert(bus); | |
827 | assert(need); | |
828 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
829 | ||
830 | if (bus->rbuffer_size < sizeof(struct bus_header)) { | |
831 | *need = sizeof(struct bus_header) + 8; | |
832 | ||
833 | /* Minimum message size: | |
834 | * | |
835 | * Header + | |
836 | * | |
837 | * Method Call: +2 string headers | |
838 | * Signal: +3 string headers | |
839 | * Method Error: +1 string headers | |
840 | * +1 uint32 headers | |
841 | * Method Reply: +1 uint32 headers | |
842 | * | |
843 | * A string header is at least 9 bytes | |
844 | * A uint32 header is at least 8 bytes | |
845 | * | |
846 | * Hence the minimum message size of a valid message | |
847 | * is header + 8 bytes */ | |
848 | ||
849 | return 0; | |
850 | } | |
851 | ||
852 | a = ((const uint32_t*) bus->rbuffer)[1]; | |
853 | b = ((const uint32_t*) bus->rbuffer)[3]; | |
854 | ||
855 | e = ((const uint8_t*) bus->rbuffer)[0]; | |
856 | if (e == BUS_LITTLE_ENDIAN) { | |
857 | a = le32toh(a); | |
858 | b = le32toh(b); | |
859 | } else if (e == BUS_BIG_ENDIAN) { | |
860 | a = be32toh(a); | |
861 | b = be32toh(b); | |
862 | } else | |
863 | return -EBADMSG; | |
864 | ||
865 | sum = (uint64_t) sizeof(struct bus_header) + (uint64_t) ALIGN_TO(b, 8) + (uint64_t) a; | |
866 | if (sum >= BUS_MESSAGE_SIZE_MAX) | |
867 | return -ENOBUFS; | |
868 | ||
869 | *need = (size_t) sum; | |
870 | return 0; | |
871 | } | |
872 | ||
873 | static int bus_socket_make_message(sd_bus *bus, size_t size) { | |
874 | sd_bus_message *t; | |
875 | void *b; | |
876 | int r; | |
877 | ||
878 | assert(bus); | |
879 | assert(bus->rbuffer_size >= size); | |
880 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
881 | ||
882 | r = bus_rqueue_make_room(bus); | |
883 | if (r < 0) | |
884 | return r; | |
885 | ||
886 | if (bus->rbuffer_size > size) { | |
887 | b = memdup((const uint8_t*) bus->rbuffer + size, | |
888 | bus->rbuffer_size - size); | |
889 | if (!b) | |
890 | return -ENOMEM; | |
891 | } else | |
892 | b = NULL; | |
893 | ||
894 | r = bus_message_from_malloc(bus, | |
895 | bus->rbuffer, size, | |
896 | bus->fds, bus->n_fds, | |
897 | NULL, | |
898 | &t); | |
899 | if (r < 0) { | |
900 | free(b); | |
901 | return r; | |
902 | } | |
903 | ||
904 | bus->rbuffer = b; | |
905 | bus->rbuffer_size -= size; | |
906 | ||
907 | bus->fds = NULL; | |
908 | bus->n_fds = 0; | |
909 | ||
910 | bus->rqueue[bus->rqueue_size++] = t; | |
911 | ||
912 | return 1; | |
913 | } | |
914 | ||
915 | int bus_socket_read_message(sd_bus *bus) { | |
916 | struct msghdr mh; | |
917 | struct iovec iov = {}; | |
918 | ssize_t k; | |
919 | size_t need; | |
920 | int r; | |
921 | void *b; | |
922 | union { | |
923 | struct cmsghdr cmsghdr; | |
924 | uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX)]; | |
925 | } control; | |
926 | bool handle_cmsg = false; | |
927 | ||
928 | assert(bus); | |
929 | assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); | |
930 | ||
931 | r = bus_socket_read_message_need(bus, &need); | |
932 | if (r < 0) | |
933 | return r; | |
934 | ||
935 | if (bus->rbuffer_size >= need) | |
936 | return bus_socket_make_message(bus, need); | |
937 | ||
938 | b = realloc(bus->rbuffer, need); | |
939 | if (!b) | |
940 | return -ENOMEM; | |
941 | ||
942 | bus->rbuffer = b; | |
943 | ||
944 | iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size; | |
945 | iov.iov_len = need - bus->rbuffer_size; | |
946 | ||
947 | if (bus->prefer_readv) | |
948 | k = readv(bus->input_fd, &iov, 1); | |
949 | else { | |
950 | zero(mh); | |
951 | mh.msg_iov = &iov; | |
952 | mh.msg_iovlen = 1; | |
953 | mh.msg_control = &control; | |
954 | mh.msg_controllen = sizeof(control); | |
955 | ||
956 | k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); | |
957 | if (k < 0 && errno == ENOTSOCK) { | |
958 | bus->prefer_readv = true; | |
959 | k = readv(bus->input_fd, &iov, 1); | |
960 | } else | |
961 | handle_cmsg = true; | |
962 | } | |
963 | if (k < 0) | |
964 | return errno == EAGAIN ? 0 : -errno; | |
965 | if (k == 0) | |
966 | return -ECONNRESET; | |
967 | ||
968 | bus->rbuffer_size += k; | |
969 | ||
970 | if (handle_cmsg) { | |
971 | struct cmsghdr *cmsg; | |
972 | ||
973 | CMSG_FOREACH(cmsg, &mh) | |
974 | if (cmsg->cmsg_level == SOL_SOCKET && | |
975 | cmsg->cmsg_type == SCM_RIGHTS) { | |
976 | int n, *f; | |
977 | ||
978 | n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); | |
979 | ||
980 | if (!bus->can_fds) { | |
981 | /* Whut? We received fds but this | |
982 | * isn't actually enabled? Close them, | |
983 | * and fail */ | |
984 | ||
985 | close_many((int*) CMSG_DATA(cmsg), n); | |
986 | return -EIO; | |
987 | } | |
988 | ||
989 | f = realloc(bus->fds, sizeof(int) * (bus->n_fds + n)); | |
990 | if (!f) { | |
991 | close_many((int*) CMSG_DATA(cmsg), n); | |
992 | return -ENOMEM; | |
993 | } | |
994 | ||
995 | memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int)); | |
996 | bus->fds = f; | |
997 | bus->n_fds += n; | |
998 | } else | |
999 | log_debug("Got unexpected auxiliary data with level=%d and type=%d", | |
1000 | cmsg->cmsg_level, cmsg->cmsg_type); | |
1001 | } | |
1002 | ||
1003 | r = bus_socket_read_message_need(bus, &need); | |
1004 | if (r < 0) | |
1005 | return r; | |
1006 | ||
1007 | if (bus->rbuffer_size >= need) | |
1008 | return bus_socket_make_message(bus, need); | |
1009 | ||
1010 | return 1; | |
1011 | } | |
1012 | ||
1013 | int bus_socket_process_opening(sd_bus *b) { | |
1014 | int error = 0; | |
1015 | socklen_t slen = sizeof(error); | |
1016 | struct pollfd p = { | |
1017 | .fd = b->output_fd, | |
1018 | .events = POLLOUT, | |
1019 | }; | |
1020 | int r; | |
1021 | ||
1022 | assert(b->state == BUS_OPENING); | |
1023 | ||
1024 | r = poll(&p, 1, 0); | |
1025 | if (r < 0) | |
1026 | return -errno; | |
1027 | ||
1028 | if (!(p.revents & (POLLOUT|POLLERR|POLLHUP))) | |
1029 | return 0; | |
1030 | ||
1031 | r = getsockopt(b->output_fd, SOL_SOCKET, SO_ERROR, &error, &slen); | |
1032 | if (r < 0) | |
1033 | b->last_connect_error = errno; | |
1034 | else if (error != 0) | |
1035 | b->last_connect_error = error; | |
1036 | else if (p.revents & (POLLERR|POLLHUP)) | |
1037 | b->last_connect_error = ECONNREFUSED; | |
1038 | else | |
1039 | return bus_socket_start_auth(b); | |
1040 | ||
1041 | return bus_next_address(b); | |
1042 | } | |
1043 | ||
1044 | int bus_socket_process_authenticating(sd_bus *b) { | |
1045 | int r; | |
1046 | ||
1047 | assert(b); | |
1048 | assert(b->state == BUS_AUTHENTICATING); | |
1049 | ||
1050 | if (now(CLOCK_MONOTONIC) >= b->auth_timeout) | |
1051 | return -ETIMEDOUT; | |
1052 | ||
1053 | r = bus_socket_write_auth(b); | |
1054 | if (r != 0) | |
1055 | return r; | |
1056 | ||
1057 | return bus_socket_read_auth(b); | |
1058 | } |