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varlink: add helper for generating errno errors
[thirdparty/systemd.git] / src / shared / varlink.c
1 /* SPDX-License-Identifier: LGPL-2.1+ */
2
3 #include <sys/poll.h>
4
5 #include "alloc-util.h"
6 #include "errno-util.h"
7 #include "fd-util.h"
8 #include "hashmap.h"
9 #include "io-util.h"
10 #include "list.h"
11 #include "process-util.h"
12 #include "set.h"
13 #include "socket-util.h"
14 #include "string-table.h"
15 #include "string-util.h"
16 #include "strv.h"
17 #include "time-util.h"
18 #include "umask-util.h"
19 #include "user-util.h"
20 #include "varlink.h"
21
22 #define VARLINK_DEFAULT_CONNECTIONS_MAX 4096U
23 #define VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX 1024U
24
25 #define VARLINK_DEFAULT_TIMEOUT_USEC (45U*USEC_PER_SEC)
26 #define VARLINK_BUFFER_MAX (16U*1024U*1024U)
27 #define VARLINK_READ_SIZE (64U*1024U)
28
29 typedef enum VarlinkState {
30 /* Client side states */
31 VARLINK_IDLE_CLIENT,
32 VARLINK_AWAITING_REPLY,
33 VARLINK_AWAITING_REPLY_MORE,
34 VARLINK_CALLING,
35 VARLINK_CALLED,
36 VARLINK_PROCESSING_REPLY,
37
38 /* Server side states */
39 VARLINK_IDLE_SERVER,
40 VARLINK_PROCESSING_METHOD,
41 VARLINK_PROCESSING_METHOD_MORE,
42 VARLINK_PROCESSING_METHOD_ONEWAY,
43 VARLINK_PROCESSED_METHOD,
44 VARLINK_PENDING_METHOD,
45 VARLINK_PENDING_METHOD_MORE,
46
47 /* Common states (only during shutdown) */
48 VARLINK_PENDING_DISCONNECT,
49 VARLINK_PENDING_TIMEOUT,
50 VARLINK_PROCESSING_DISCONNECT,
51 VARLINK_PROCESSING_TIMEOUT,
52 VARLINK_PROCESSING_FAILURE,
53 VARLINK_DISCONNECTED,
54
55 _VARLINK_STATE_MAX,
56 _VARLINK_STATE_INVALID = -1
57 } VarlinkState;
58
59 /* Tests whether we are not yet disconnected. Note that this is true during all states where the connection
60 * is still good for something, and false only when it's dead for good. This means: when we are
61 * asynchronously connecting to a peer and the connect() is still pending, then this will return 'true', as
62 * the connection is still good, and we are likely to be able to properly operate on it soon. */
63 #define VARLINK_STATE_IS_ALIVE(state) \
64 IN_SET(state, \
65 VARLINK_IDLE_CLIENT, \
66 VARLINK_AWAITING_REPLY, \
67 VARLINK_AWAITING_REPLY_MORE, \
68 VARLINK_CALLING, \
69 VARLINK_CALLED, \
70 VARLINK_PROCESSING_REPLY, \
71 VARLINK_IDLE_SERVER, \
72 VARLINK_PROCESSING_METHOD, \
73 VARLINK_PROCESSING_METHOD_MORE, \
74 VARLINK_PROCESSING_METHOD_ONEWAY, \
75 VARLINK_PROCESSED_METHOD, \
76 VARLINK_PENDING_METHOD, \
77 VARLINK_PENDING_METHOD_MORE)
78
79 struct Varlink {
80 unsigned n_ref;
81
82 VarlinkServer *server;
83
84 VarlinkState state;
85 bool connecting; /* This boolean indicates whether the socket fd we are operating on is currently
86 * processing an asynchronous connect(). In that state we watch the socket for
87 * EPOLLOUT, but we refrain from calling read() or write() on the socket as that
88 * will trigger ENOTCONN. Note that this boolean is kept separate from the
89 * VarlinkState above on purpose: while the connect() is still not complete we
90 * already want to allow queuing of messages and similar. Thus it's nice to keep
91 * these two state concepts separate: the VarlinkState encodes what our own view of
92 * the connection is, i.e. whether we think it's a server, a client, and has
93 * something queued already, while 'connecting' tells us a detail about the
94 * transport used below, that should have no effect on how we otherwise accept and
95 * process operations from the user.
96 *
97 * Or to say this differently: VARLINK_STATE_IS_ALIVE(state) tells you whether the
98 * connection is good to use, even if it might not be fully connected
99 * yet. connecting=true then informs you that actually we are still connecting, and
100 * the connection is actually not established yet and thus any requests you enqueue
101 * now will still work fine but will be queued only, not sent yet, but that
102 * shouldn't stop you from using the connection, since eventually whatever you queue
103 * *will* be sent.
104 *
105 * Or to say this even differently: 'state' is a high-level ("application layer"
106 * high, if you so will) state, while 'conecting' is a low-level ("transport layer"
107 * low, if you so will) state, and while they are not entirely unrelated and
108 * sometimes propagate effects to each other they are only asynchronously connected
109 * at most. */
110 unsigned n_pending;
111
112 int fd;
113
114 char *input_buffer; /* valid data starts at input_buffer_index, ends at input_buffer_index+input_buffer_size */
115 size_t input_buffer_allocated;
116 size_t input_buffer_index;
117 size_t input_buffer_size;
118 size_t input_buffer_unscanned;
119
120 char *output_buffer; /* valid data starts at output_buffer_index, ends at output_buffer_index+output_buffer_size */
121 size_t output_buffer_allocated;
122 size_t output_buffer_index;
123 size_t output_buffer_size;
124
125 VarlinkReply reply_callback;
126
127 JsonVariant *current;
128 JsonVariant *reply;
129
130 struct ucred ucred;
131 bool ucred_acquired:1;
132
133 bool write_disconnected:1;
134 bool read_disconnected:1;
135 bool prefer_read_write:1;
136 bool got_pollhup:1;
137
138 usec_t timestamp;
139 usec_t timeout;
140
141 void *userdata;
142 char *description;
143
144 sd_event *event;
145 sd_event_source *io_event_source;
146 sd_event_source *time_event_source;
147 sd_event_source *quit_event_source;
148 sd_event_source *defer_event_source;
149 };
150
151 typedef struct VarlinkServerSocket VarlinkServerSocket;
152
153 struct VarlinkServerSocket {
154 VarlinkServer *server;
155
156 int fd;
157 char *address;
158
159 sd_event_source *event_source;
160
161 LIST_FIELDS(VarlinkServerSocket, sockets);
162 };
163
164 struct VarlinkServer {
165 unsigned n_ref;
166 VarlinkServerFlags flags;
167
168 LIST_HEAD(VarlinkServerSocket, sockets);
169
170 Hashmap *methods;
171 VarlinkConnect connect_callback;
172 VarlinkDisconnect disconnect_callback;
173
174 sd_event *event;
175 int64_t event_priority;
176
177 unsigned n_connections;
178 Hashmap *by_uid;
179
180 void *userdata;
181 char *description;
182
183 unsigned connections_max;
184 unsigned connections_per_uid_max;
185 };
186
187 static const char* const varlink_state_table[_VARLINK_STATE_MAX] = {
188 [VARLINK_IDLE_CLIENT] = "idle-client",
189 [VARLINK_AWAITING_REPLY] = "awaiting-reply",
190 [VARLINK_AWAITING_REPLY_MORE] = "awaiting-reply-more",
191 [VARLINK_CALLING] = "calling",
192 [VARLINK_CALLED] = "called",
193 [VARLINK_PROCESSING_REPLY] = "processing-reply",
194 [VARLINK_IDLE_SERVER] = "idle-server",
195 [VARLINK_PROCESSING_METHOD] = "processing-method",
196 [VARLINK_PROCESSING_METHOD_MORE] = "processing-method-more",
197 [VARLINK_PROCESSING_METHOD_ONEWAY] = "processing-method-oneway",
198 [VARLINK_PROCESSED_METHOD] = "processed-method",
199 [VARLINK_PENDING_METHOD] = "pending-method",
200 [VARLINK_PENDING_METHOD_MORE] = "pending-method-more",
201 [VARLINK_PENDING_DISCONNECT] = "pending-disconnect",
202 [VARLINK_PENDING_TIMEOUT] = "pending-timeout",
203 [VARLINK_PROCESSING_DISCONNECT] = "processing-disconnect",
204 [VARLINK_PROCESSING_TIMEOUT] = "processing-timeout",
205 [VARLINK_PROCESSING_FAILURE] = "processing-failure",
206 [VARLINK_DISCONNECTED] = "disconnected",
207 };
208
209 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(varlink_state, VarlinkState);
210
211 #define varlink_log_errno(v, error, fmt, ...) \
212 log_debug_errno(error, "%s: " fmt, varlink_description(v), ##__VA_ARGS__)
213
214 #define varlink_log(v, fmt, ...) \
215 log_debug("%s: " fmt, varlink_description(v), ##__VA_ARGS__)
216
217 #define varlink_server_log_errno(s, error, fmt, ...) \
218 log_debug_errno(error, "%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
219
220 #define varlink_server_log(s, fmt, ...) \
221 log_debug("%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
222
223 static inline const char *varlink_description(Varlink *v) {
224 return strna(v ? v->description : NULL);
225 }
226
227 static inline const char *varlink_server_description(VarlinkServer *s) {
228 return strna(s ? s->description : NULL);
229 }
230
231 static void varlink_set_state(Varlink *v, VarlinkState state) {
232 assert(v);
233 assert(state >= 0 && state < _VARLINK_STATE_MAX);
234
235 if (v->state < 0)
236 varlink_log(v, "varlink: setting state %s",
237 varlink_state_to_string(state));
238 else
239 varlink_log(v, "varlink: changing state %s → %s",
240 varlink_state_to_string(v->state),
241 varlink_state_to_string(state));
242
243 v->state = state;
244 }
245
246 static int varlink_new(Varlink **ret) {
247 Varlink *v;
248
249 assert(ret);
250
251 v = new(Varlink, 1);
252 if (!v)
253 return -ENOMEM;
254
255 *v = (Varlink) {
256 .n_ref = 1,
257 .fd = -1,
258
259 .state = _VARLINK_STATE_INVALID,
260
261 .ucred.uid = UID_INVALID,
262 .ucred.gid = GID_INVALID,
263
264 .timestamp = USEC_INFINITY,
265 .timeout = VARLINK_DEFAULT_TIMEOUT_USEC
266 };
267
268 *ret = v;
269 return 0;
270 }
271
272 int varlink_connect_address(Varlink **ret, const char *address) {
273 _cleanup_(varlink_unrefp) Varlink *v = NULL;
274 union sockaddr_union sockaddr;
275 socklen_t sockaddr_len;
276 int r;
277
278 assert_return(ret, -EINVAL);
279 assert_return(address, -EINVAL);
280
281 r = sockaddr_un_set_path(&sockaddr.un, address);
282 if (r < 0)
283 return r;
284 sockaddr_len = r;
285
286 r = varlink_new(&v);
287 if (r < 0)
288 return r;
289
290 v->fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
291 if (v->fd < 0)
292 return -errno;
293
294 v->fd = fd_move_above_stdio(v->fd);
295
296 if (connect(v->fd, &sockaddr.sa, sockaddr_len) < 0) {
297 if (!IN_SET(errno, EAGAIN, EINPROGRESS))
298 return -errno;
299
300 v->connecting = true; /* We are asynchronously connecting, i.e. the connect() is being
301 * processed in the background. As long as that's the case the socket
302 * is in a special state: it's there, we can poll it for EPOLLOUT, but
303 * if we attempt to write() to it before we see EPOLLOUT we'll get
304 * ENOTCONN (and not EAGAIN, like we would for a normal connected
305 * socket that isn't writable at the moment). Since ENOTCONN on write()
306 * hence can mean two different things (i.e. connection not complete
307 * yet vs. already disconnected again), we store as a boolean whether
308 * we are still in connect(). */
309 }
310
311 varlink_set_state(v, VARLINK_IDLE_CLIENT);
312
313 *ret = TAKE_PTR(v);
314 return r;
315 }
316
317 int varlink_connect_fd(Varlink **ret, int fd) {
318 Varlink *v;
319 int r;
320
321 assert_return(ret, -EINVAL);
322 assert_return(fd >= 0, -EBADF);
323
324 r = fd_nonblock(fd, true);
325 if (r < 0)
326 return r;
327
328 r = varlink_new(&v);
329 if (r < 0)
330 return r;
331
332 v->fd = fd;
333 varlink_set_state(v, VARLINK_IDLE_CLIENT);
334
335 /* Note that if this function is called we assume the passed socket (if it is one) is already
336 * properly connected, i.e. any asynchronous connect() done on it already completed. Because of that
337 * we'll not set the 'connecting' boolean here, i.e. we don't need to avoid write()ing to the socket
338 * until the connection is fully set up. Behaviour here is hence a bit different from
339 * varlink_connect_address() above, as there we do handle asynchronous connections ourselves and
340 * avoid doing write() on it before we saw EPOLLOUT for the first time. */
341
342 *ret = v;
343 return 0;
344 }
345
346 static void varlink_detach_event_sources(Varlink *v) {
347 assert(v);
348
349 v->io_event_source = sd_event_source_disable_unref(v->io_event_source);
350 v->time_event_source = sd_event_source_disable_unref(v->time_event_source);
351 v->quit_event_source = sd_event_source_disable_unref(v->quit_event_source);
352 v->defer_event_source = sd_event_source_disable_unref(v->defer_event_source);
353 }
354
355 static void varlink_clear(Varlink *v) {
356 assert(v);
357
358 varlink_detach_event_sources(v);
359
360 v->fd = safe_close(v->fd);
361
362 v->input_buffer = mfree(v->input_buffer);
363 v->output_buffer = mfree(v->output_buffer);
364
365 v->current = json_variant_unref(v->current);
366 v->reply = json_variant_unref(v->reply);
367
368 v->event = sd_event_unref(v->event);
369 }
370
371 static Varlink* varlink_destroy(Varlink *v) {
372 if (!v)
373 return NULL;
374
375 /* If this is called the server object must already been unreffed here. Why that? because when we
376 * linked up the varlink connection with the server object we took one ref in each direction */
377 assert(!v->server);
378
379 varlink_clear(v);
380
381 free(v->description);
382 return mfree(v);
383 }
384
385 DEFINE_TRIVIAL_REF_UNREF_FUNC(Varlink, varlink, varlink_destroy);
386
387 static int varlink_test_disconnect(Varlink *v) {
388 assert(v);
389
390 /* Tests whether we the connection has been terminated. We are careful to not stop processing it
391 * prematurely, since we want to handle half-open connections as well as possible and want to flush
392 * out and read data before we close down if we can. */
393
394 /* Already disconnected? */
395 if (!VARLINK_STATE_IS_ALIVE(v->state))
396 return 0;
397
398 /* Wait until connection setup is complete, i.e. until asynchronous connect() completes */
399 if (v->connecting)
400 return 0;
401
402 /* Still something to write and we can write? Stay around */
403 if (v->output_buffer_size > 0 && !v->write_disconnected)
404 return 0;
405
406 /* Both sides gone already? Then there's no need to stick around */
407 if (v->read_disconnected && v->write_disconnected)
408 goto disconnect;
409
410 /* If we are waiting for incoming data but the read side is shut down, disconnect. */
411 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) && v->read_disconnected)
412 goto disconnect;
413
414 /* Similar, if are a client that hasn't written anything yet but the write side is dead, also
415 * disconnect. We also explicitly check for POLLHUP here since we likely won't notice the write side
416 * being down if we never wrote anything. */
417 if (IN_SET(v->state, VARLINK_IDLE_CLIENT) && (v->write_disconnected || v->got_pollhup))
418 goto disconnect;
419
420 return 0;
421
422 disconnect:
423 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
424 return 1;
425 }
426
427 static int varlink_write(Varlink *v) {
428 ssize_t n;
429
430 assert(v);
431
432 if (!VARLINK_STATE_IS_ALIVE(v->state))
433 return 0;
434 if (v->connecting) /* Writing while we are still wait for a non-blocking connect() to complete will
435 * result in ENOTCONN, hence exit early here */
436 return 0;
437 if (v->output_buffer_size == 0)
438 return 0;
439 if (v->write_disconnected)
440 return 0;
441
442 assert(v->fd >= 0);
443
444 /* We generally prefer recv()/send() (mostly because of MSG_NOSIGNAL) but also want to be compatible
445 * with non-socket IO, hence fall back automatically */
446 if (!v->prefer_read_write) {
447 n = send(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size, MSG_DONTWAIT|MSG_NOSIGNAL);
448 if (n < 0 && errno == ENOTSOCK)
449 v->prefer_read_write = true;
450 }
451 if (v->prefer_read_write)
452 n = write(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size);
453 if (n < 0) {
454 if (errno == EAGAIN)
455 return 0;
456
457 if (ERRNO_IS_DISCONNECT(errno)) {
458 /* If we get informed about a disconnect on write, then let's remember that, but not
459 * act on it just yet. Let's wait for read() to report the issue first. */
460 v->write_disconnected = true;
461 return 1;
462 }
463
464 return -errno;
465 }
466
467 v->output_buffer_size -= n;
468
469 if (v->output_buffer_size == 0)
470 v->output_buffer_index = 0;
471 else
472 v->output_buffer_index += n;
473
474 v->timestamp = now(CLOCK_MONOTONIC);
475 return 1;
476 }
477
478 static int varlink_read(Varlink *v) {
479 size_t rs;
480 ssize_t n;
481
482 assert(v);
483
484 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER))
485 return 0;
486 if (v->connecting) /* read() on a socket while we are in connect() will fail with EINVAL, hence exit early here */
487 return 0;
488 if (v->current)
489 return 0;
490 if (v->input_buffer_unscanned > 0)
491 return 0;
492 if (v->read_disconnected)
493 return 0;
494
495 if (v->input_buffer_size >= VARLINK_BUFFER_MAX)
496 return -ENOBUFS;
497
498 assert(v->fd >= 0);
499
500 if (v->input_buffer_allocated <= v->input_buffer_index + v->input_buffer_size) {
501 size_t add;
502
503 add = MIN(VARLINK_BUFFER_MAX - v->input_buffer_size, VARLINK_READ_SIZE);
504
505 if (v->input_buffer_index == 0) {
506
507 if (!GREEDY_REALLOC(v->input_buffer, v->input_buffer_allocated, v->input_buffer_size + add))
508 return -ENOMEM;
509
510 } else {
511 char *b;
512
513 b = new(char, v->input_buffer_size + add);
514 if (!b)
515 return -ENOMEM;
516
517 memcpy(b, v->input_buffer + v->input_buffer_index, v->input_buffer_size);
518
519 free_and_replace(v->input_buffer, b);
520
521 v->input_buffer_allocated = v->input_buffer_size + add;
522 v->input_buffer_index = 0;
523 }
524 }
525
526 rs = v->input_buffer_allocated - (v->input_buffer_index + v->input_buffer_size);
527
528 if (!v->prefer_read_write) {
529 n = recv(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs, MSG_DONTWAIT);
530 if (n < 0 && errno == ENOTSOCK)
531 v->prefer_read_write = true;
532 }
533 if (v->prefer_read_write)
534 n = read(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs);
535 if (n < 0) {
536 if (errno == EAGAIN)
537 return 0;
538
539 if (ERRNO_IS_DISCONNECT(errno)) {
540 v->read_disconnected = true;
541 return 1;
542 }
543
544 return -errno;
545 }
546 if (n == 0) { /* EOF */
547 v->read_disconnected = true;
548 return 1;
549 }
550
551 v->input_buffer_size += n;
552 v->input_buffer_unscanned += n;
553
554 return 1;
555 }
556
557 static int varlink_parse_message(Varlink *v) {
558 const char *e, *begin;
559 size_t sz;
560 int r;
561
562 assert(v);
563
564 if (v->current)
565 return 0;
566 if (v->input_buffer_unscanned <= 0)
567 return 0;
568
569 assert(v->input_buffer_unscanned <= v->input_buffer_size);
570 assert(v->input_buffer_index + v->input_buffer_size <= v->input_buffer_allocated);
571
572 begin = v->input_buffer + v->input_buffer_index;
573
574 e = memchr(begin + v->input_buffer_size - v->input_buffer_unscanned, 0, v->input_buffer_unscanned);
575 if (!e) {
576 v->input_buffer_unscanned = 0;
577 return 0;
578 }
579
580 sz = e - begin + 1;
581
582 varlink_log(v, "New incoming message: %s", begin);
583
584 r = json_parse(begin, 0, &v->current, NULL, NULL);
585 if (r < 0)
586 return r;
587
588 v->input_buffer_size -= sz;
589
590 if (v->input_buffer_size == 0)
591 v->input_buffer_index = 0;
592 else
593 v->input_buffer_index += sz;
594
595 v->input_buffer_unscanned = v->input_buffer_size;
596 return 1;
597 }
598
599 static int varlink_test_timeout(Varlink *v) {
600 assert(v);
601
602 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING))
603 return 0;
604 if (v->timeout == USEC_INFINITY)
605 return 0;
606
607 if (now(CLOCK_MONOTONIC) < usec_add(v->timestamp, v->timeout))
608 return 0;
609
610 varlink_set_state(v, VARLINK_PENDING_TIMEOUT);
611
612 return 1;
613 }
614
615 static int varlink_dispatch_local_error(Varlink *v, const char *error) {
616 int r;
617
618 assert(v);
619 assert(error);
620
621 if (!v->reply_callback)
622 return 0;
623
624 r = v->reply_callback(v, NULL, error, VARLINK_REPLY_ERROR|VARLINK_REPLY_LOCAL, v->userdata);
625 if (r < 0)
626 log_debug_errno(r, "Reply callback returned error, ignoring: %m");
627
628 return 1;
629 }
630
631 static int varlink_dispatch_timeout(Varlink *v) {
632 assert(v);
633
634 if (v->state != VARLINK_PENDING_TIMEOUT)
635 return 0;
636
637 varlink_set_state(v, VARLINK_PROCESSING_TIMEOUT);
638 varlink_dispatch_local_error(v, VARLINK_ERROR_TIMEOUT);
639 varlink_close(v);
640
641 return 1;
642 }
643
644 static int varlink_dispatch_disconnect(Varlink *v) {
645 assert(v);
646
647 if (v->state != VARLINK_PENDING_DISCONNECT)
648 return 0;
649
650 varlink_set_state(v, VARLINK_PROCESSING_DISCONNECT);
651 varlink_dispatch_local_error(v, VARLINK_ERROR_DISCONNECTED);
652 varlink_close(v);
653
654 return 1;
655 }
656
657 static int varlink_sanitize_parameters(JsonVariant **v) {
658 assert(v);
659
660 /* Varlink always wants a parameters list, hence make one if the caller doesn't want any */
661 if (!*v)
662 return json_variant_new_object(v, NULL, 0);
663 else if (!json_variant_is_object(*v))
664 return -EINVAL;
665
666 return 0;
667 }
668
669 static int varlink_dispatch_reply(Varlink *v) {
670 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
671 VarlinkReplyFlags flags = 0;
672 const char *error = NULL;
673 JsonVariant *e;
674 const char *k;
675 int r;
676
677 assert(v);
678
679 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING))
680 return 0;
681 if (!v->current)
682 return 0;
683
684 assert(v->n_pending > 0);
685
686 if (!json_variant_is_object(v->current))
687 goto invalid;
688
689 JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
690
691 if (streq(k, "error")) {
692 if (error)
693 goto invalid;
694 if (!json_variant_is_string(e))
695 goto invalid;
696
697 error = json_variant_string(e);
698 flags |= VARLINK_REPLY_ERROR;
699
700 } else if (streq(k, "parameters")) {
701 if (parameters)
702 goto invalid;
703 if (!json_variant_is_object(e))
704 goto invalid;
705
706 parameters = json_variant_ref(e);
707
708 } else if (streq(k, "continues")) {
709 if (FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
710 goto invalid;
711
712 if (!json_variant_is_boolean(e))
713 goto invalid;
714
715 if (json_variant_boolean(e))
716 flags |= VARLINK_REPLY_CONTINUES;
717 } else
718 goto invalid;
719 }
720
721 /* Replies with 'continue' set are only OK if we set 'more' when the method call was initiated */
722 if (v->state != VARLINK_AWAITING_REPLY_MORE && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
723 goto invalid;
724
725 /* An error is final */
726 if (error && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
727 goto invalid;
728
729 r = varlink_sanitize_parameters(&parameters);
730 if (r < 0)
731 goto invalid;
732
733 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE)) {
734 varlink_set_state(v, VARLINK_PROCESSING_REPLY);
735
736 if (v->reply_callback) {
737 r = v->reply_callback(v, parameters, error, flags, v->userdata);
738 if (r < 0)
739 log_debug_errno(r, "Reply callback returned error, ignoring: %m");
740 }
741
742 v->current = json_variant_unref(v->current);
743
744 if (v->state == VARLINK_PROCESSING_REPLY) {
745
746 assert(v->n_pending > 0);
747
748 if (!FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
749 v->n_pending--;
750
751 varlink_set_state(v,
752 FLAGS_SET(flags, VARLINK_REPLY_CONTINUES) ? VARLINK_AWAITING_REPLY_MORE :
753 v->n_pending == 0 ? VARLINK_IDLE_CLIENT : VARLINK_AWAITING_REPLY);
754 }
755 } else {
756 assert(v->state == VARLINK_CALLING);
757 varlink_set_state(v, VARLINK_CALLED);
758 }
759
760 return 1;
761
762 invalid:
763 varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
764 varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
765 varlink_close(v);
766
767 return 1;
768 }
769
770 static int varlink_dispatch_method(Varlink *v) {
771 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
772 VarlinkMethodFlags flags = 0;
773 const char *method = NULL, *error;
774 JsonVariant *e;
775 VarlinkMethod callback;
776 const char *k;
777 int r;
778
779 assert(v);
780
781 if (v->state != VARLINK_IDLE_SERVER)
782 return 0;
783 if (!v->current)
784 return 0;
785
786 if (!json_variant_is_object(v->current))
787 goto invalid;
788
789 JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
790
791 if (streq(k, "method")) {
792 if (method)
793 goto invalid;
794 if (!json_variant_is_string(e))
795 goto invalid;
796
797 method = json_variant_string(e);
798
799 } else if (streq(k, "parameters")) {
800 if (parameters)
801 goto invalid;
802 if (!json_variant_is_object(e))
803 goto invalid;
804
805 parameters = json_variant_ref(e);
806
807 } else if (streq(k, "oneway")) {
808
809 if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
810 goto invalid;
811
812 if (!json_variant_is_boolean(e))
813 goto invalid;
814
815 if (json_variant_boolean(e))
816 flags |= VARLINK_METHOD_ONEWAY;
817
818 } else if (streq(k, "more")) {
819
820 if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
821 goto invalid;
822
823 if (!json_variant_is_boolean(e))
824 goto invalid;
825
826 if (json_variant_boolean(e))
827 flags |= VARLINK_METHOD_MORE;
828
829 } else
830 goto invalid;
831 }
832
833 if (!method)
834 goto invalid;
835
836 r = varlink_sanitize_parameters(&parameters);
837 if (r < 0)
838 goto fail;
839
840 varlink_set_state(v, (flags & VARLINK_METHOD_MORE) ? VARLINK_PROCESSING_METHOD_MORE :
841 (flags & VARLINK_METHOD_ONEWAY) ? VARLINK_PROCESSING_METHOD_ONEWAY :
842 VARLINK_PROCESSING_METHOD);
843
844 assert(v->server);
845
846 if (STR_IN_SET(method, "org.varlink.service.GetInfo", "org.varlink.service.GetInterface")) {
847 /* For now, we don't implement a single of varlink's own methods */
848 callback = NULL;
849 error = VARLINK_ERROR_METHOD_NOT_IMPLEMENTED;
850 } else if (startswith(method, "org.varlink.service.")) {
851 callback = NULL;
852 error = VARLINK_ERROR_METHOD_NOT_FOUND;
853 } else {
854 callback = hashmap_get(v->server->methods, method);
855 error = VARLINK_ERROR_METHOD_NOT_FOUND;
856 }
857
858 if (callback) {
859 r = callback(v, parameters, flags, v->userdata);
860 if (r < 0) {
861 log_debug_errno(r, "Callback for %s returned error: %m", method);
862
863 /* We got an error back from the callback. Propagate it to the client if the method call remains unanswered. */
864 if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
865 r = varlink_error_errno(v, r);
866 if (r < 0)
867 return r;
868 }
869 }
870 } else if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
871 assert(error);
872
873 r = varlink_errorb(v, error, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method))));
874 if (r < 0)
875 return r;
876 }
877
878 switch (v->state) {
879
880 case VARLINK_PROCESSED_METHOD: /* Method call is fully processed */
881 case VARLINK_PROCESSING_METHOD_ONEWAY: /* ditto */
882 v->current = json_variant_unref(v->current);
883 varlink_set_state(v, VARLINK_IDLE_SERVER);
884 break;
885
886 case VARLINK_PROCESSING_METHOD: /* Method call wasn't replied to, will be replied to later */
887 varlink_set_state(v, VARLINK_PENDING_METHOD);
888 break;
889
890 case VARLINK_PROCESSING_METHOD_MORE: /* No reply for a "more" message was sent, more to come */
891 varlink_set_state(v, VARLINK_PENDING_METHOD_MORE);
892 break;
893
894 default:
895 assert_not_reached("Unexpected state");
896
897 }
898
899 return r;
900
901 invalid:
902 r = -EINVAL;
903
904 fail:
905 varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
906 varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
907 varlink_close(v);
908
909 return r;
910 }
911
912 int varlink_process(Varlink *v) {
913 int r;
914
915 assert_return(v, -EINVAL);
916
917 if (v->state == VARLINK_DISCONNECTED)
918 return -ENOTCONN;
919
920 varlink_ref(v);
921
922 r = varlink_write(v);
923 if (r != 0)
924 goto finish;
925
926 r = varlink_dispatch_reply(v);
927 if (r != 0)
928 goto finish;
929
930 r = varlink_dispatch_method(v);
931 if (r != 0)
932 goto finish;
933
934 r = varlink_parse_message(v);
935 if (r != 0)
936 goto finish;
937
938 r = varlink_read(v);
939 if (r != 0)
940 goto finish;
941
942 r = varlink_test_disconnect(v);
943 if (r != 0)
944 goto finish;
945
946 r = varlink_dispatch_disconnect(v);
947 if (r != 0)
948 goto finish;
949
950 r = varlink_test_timeout(v);
951 if (r != 0)
952 goto finish;
953
954 r = varlink_dispatch_timeout(v);
955 if (r != 0)
956 goto finish;
957
958 finish:
959 if (r >= 0 && v->defer_event_source) {
960 int q;
961
962 /* If we did some processing, make sure we are called again soon */
963 q = sd_event_source_set_enabled(v->defer_event_source, r > 0 ? SD_EVENT_ON : SD_EVENT_OFF);
964 if (q < 0)
965 r = q;
966 }
967
968 if (r < 0) {
969 if (VARLINK_STATE_IS_ALIVE(v->state))
970 /* Initiate disconnection */
971 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
972 else
973 /* We failed while disconnecting, in that case close right away */
974 varlink_close(v);
975 }
976
977 varlink_unref(v);
978 return r;
979 }
980
981 static void handle_revents(Varlink *v, int revents) {
982 assert(v);
983
984 if (v->connecting) {
985 /* If we have seen POLLOUT or POLLHUP on a socket we are asynchronously waiting a connect()
986 * to complete on, we know we are ready. We don't read the connection error here though,
987 * we'll get the error on the next read() or write(). */
988 if ((revents & (POLLOUT|POLLHUP)) == 0)
989 return;
990
991 varlink_log(v, "Anynchronous connection completed.");
992 v->connecting = false;
993 } else {
994 /* Note that we don't care much about POLLIN/POLLOUT here, we'll just try reading and writing
995 * what we can. However, we do care about POLLHUP to detect connection termination even if we
996 * momentarily don't want to read nor write anything. */
997
998 if (!FLAGS_SET(revents, POLLHUP))
999 return;
1000
1001 varlink_log(v, "Got POLLHUP from socket.");
1002 v->got_pollhup = true;
1003 }
1004 }
1005
1006 int varlink_wait(Varlink *v, usec_t timeout) {
1007 int r, fd, events;
1008 usec_t t;
1009
1010 assert_return(v, -EINVAL);
1011
1012 if (v->state == VARLINK_DISCONNECTED)
1013 return -ENOTCONN;
1014
1015 r = varlink_get_timeout(v, &t);
1016 if (r < 0)
1017 return r;
1018 if (t != USEC_INFINITY) {
1019 usec_t n;
1020
1021 n = now(CLOCK_MONOTONIC);
1022 if (t < n)
1023 t = 0;
1024 else
1025 t = usec_sub_unsigned(t, n);
1026 }
1027
1028 if (timeout != USEC_INFINITY &&
1029 (t == USEC_INFINITY || timeout < t))
1030 t = timeout;
1031
1032 fd = varlink_get_fd(v);
1033 if (fd < 0)
1034 return fd;
1035
1036 events = varlink_get_events(v);
1037 if (events < 0)
1038 return events;
1039
1040 r = fd_wait_for_event(fd, events, t);
1041 if (r < 0)
1042 return r;
1043 if (r == 0)
1044 return 0;
1045
1046 handle_revents(v, r);
1047 return 1;
1048 }
1049
1050 int varlink_get_fd(Varlink *v) {
1051
1052 assert_return(v, -EINVAL);
1053
1054 if (v->state == VARLINK_DISCONNECTED)
1055 return -ENOTCONN;
1056 if (v->fd < 0)
1057 return -EBADF;
1058
1059 return v->fd;
1060 }
1061
1062 int varlink_get_events(Varlink *v) {
1063 int ret = 0;
1064
1065 assert_return(v, -EINVAL);
1066
1067 if (v->state == VARLINK_DISCONNECTED)
1068 return -ENOTCONN;
1069
1070 if (v->connecting) /* When processing an asynchronous connect(), we only wait for EPOLLOUT, which
1071 * tells us that the connection is now complete. Before that we should neither
1072 * write() or read() from the fd. */
1073 return EPOLLOUT;
1074
1075 if (!v->read_disconnected &&
1076 IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) &&
1077 !v->current &&
1078 v->input_buffer_unscanned <= 0)
1079 ret |= EPOLLIN;
1080
1081 if (!v->write_disconnected &&
1082 v->output_buffer_size > 0)
1083 ret |= EPOLLOUT;
1084
1085 return ret;
1086 }
1087
1088 int varlink_get_timeout(Varlink *v, usec_t *ret) {
1089 assert_return(v, -EINVAL);
1090
1091 if (v->state == VARLINK_DISCONNECTED)
1092 return -ENOTCONN;
1093
1094 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING) &&
1095 v->timeout != USEC_INFINITY) {
1096 if (ret)
1097 *ret = usec_add(v->timestamp, v->timeout);
1098 return 1;
1099 } else {
1100 if (ret)
1101 *ret = USEC_INFINITY;
1102 return 0;
1103 }
1104 }
1105
1106 int varlink_flush(Varlink *v) {
1107 int ret = 0, r;
1108
1109 assert_return(v, -EINVAL);
1110
1111 if (v->state == VARLINK_DISCONNECTED)
1112 return -ENOTCONN;
1113
1114 for (;;) {
1115 if (v->output_buffer_size == 0)
1116 break;
1117 if (v->write_disconnected)
1118 return -ECONNRESET;
1119
1120 r = varlink_write(v);
1121 if (r < 0)
1122 return r;
1123 if (r > 0) {
1124 ret = 1;
1125 continue;
1126 }
1127
1128 r = fd_wait_for_event(v->fd, POLLOUT, USEC_INFINITY);
1129 if (r < 0)
1130 return r;
1131
1132 assert(r != 0);
1133
1134 handle_revents(v, r);
1135 }
1136
1137 return ret;
1138 }
1139
1140 static void varlink_detach_server(Varlink *v) {
1141 VarlinkServer *saved_server;
1142 assert(v);
1143
1144 if (!v->server)
1145 return;
1146
1147 if (v->server->by_uid &&
1148 v->ucred_acquired &&
1149 uid_is_valid(v->ucred.uid)) {
1150 unsigned c;
1151
1152 c = PTR_TO_UINT(hashmap_get(v->server->by_uid, UID_TO_PTR(v->ucred.uid)));
1153 assert(c > 0);
1154
1155 if (c == 1)
1156 (void) hashmap_remove(v->server->by_uid, UID_TO_PTR(v->ucred.uid));
1157 else
1158 (void) hashmap_replace(v->server->by_uid, UID_TO_PTR(v->ucred.uid), UINT_TO_PTR(c - 1));
1159 }
1160
1161 assert(v->server->n_connections > 0);
1162 v->server->n_connections--;
1163
1164 /* If this is a connection associated to a server, then let's disconnect the server and the
1165 * connection from each other. This drops the dangling reference that connect_callback() set up. But
1166 * before we release the references, let's call the disconnection callback if it is defined. */
1167
1168 saved_server = TAKE_PTR(v->server);
1169
1170 if (saved_server->disconnect_callback)
1171 saved_server->disconnect_callback(saved_server, v, saved_server->userdata);
1172
1173 varlink_server_unref(saved_server);
1174 varlink_unref(v);
1175 }
1176
1177 int varlink_close(Varlink *v) {
1178
1179 assert_return(v, -EINVAL);
1180
1181 if (v->state == VARLINK_DISCONNECTED)
1182 return 0;
1183
1184 varlink_set_state(v, VARLINK_DISCONNECTED);
1185
1186 /* Let's take a reference first, since varlink_detach_server() might drop the final (dangling) ref
1187 * which would destroy us before we can call varlink_clear() */
1188 varlink_ref(v);
1189 varlink_detach_server(v);
1190 varlink_clear(v);
1191 varlink_unref(v);
1192
1193 return 1;
1194 }
1195
1196 Varlink* varlink_close_unref(Varlink *v) {
1197
1198 if (!v)
1199 return NULL;
1200
1201 (void) varlink_close(v);
1202 return varlink_unref(v);
1203 }
1204
1205 Varlink* varlink_flush_close_unref(Varlink *v) {
1206
1207 if (!v)
1208 return NULL;
1209
1210 (void) varlink_flush(v);
1211 (void) varlink_close(v);
1212 return varlink_unref(v);
1213 }
1214
1215 static int varlink_enqueue_json(Varlink *v, JsonVariant *m) {
1216 _cleanup_free_ char *text = NULL;
1217 int r;
1218
1219 assert(v);
1220 assert(m);
1221
1222 r = json_variant_format(m, 0, &text);
1223 if (r < 0)
1224 return r;
1225 assert(text[r] == '\0');
1226
1227 if (v->output_buffer_size + r + 1 > VARLINK_BUFFER_MAX)
1228 return -ENOBUFS;
1229
1230 varlink_log(v, "Sending message: %s", text);
1231
1232 if (v->output_buffer_size == 0) {
1233
1234 free_and_replace(v->output_buffer, text);
1235
1236 v->output_buffer_size = v->output_buffer_allocated = r + 1;
1237 v->output_buffer_index = 0;
1238
1239 } else if (v->output_buffer_index == 0) {
1240
1241 if (!GREEDY_REALLOC(v->output_buffer, v->output_buffer_allocated, v->output_buffer_size + r + 1))
1242 return -ENOMEM;
1243
1244 memcpy(v->output_buffer + v->output_buffer_size, text, r + 1);
1245 v->output_buffer_size += r + 1;
1246
1247 } else {
1248 char *n;
1249 const size_t new_size = v->output_buffer_size + r + 1;
1250
1251 n = new(char, new_size);
1252 if (!n)
1253 return -ENOMEM;
1254
1255 memcpy(mempcpy(n, v->output_buffer + v->output_buffer_index, v->output_buffer_size), text, r + 1);
1256
1257 free_and_replace(v->output_buffer, n);
1258 v->output_buffer_allocated = v->output_buffer_size = new_size;
1259 v->output_buffer_index = 0;
1260 }
1261
1262 return 0;
1263 }
1264
1265 int varlink_send(Varlink *v, const char *method, JsonVariant *parameters) {
1266 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1267 int r;
1268
1269 assert_return(v, -EINVAL);
1270 assert_return(method, -EINVAL);
1271
1272 if (v->state == VARLINK_DISCONNECTED)
1273 return -ENOTCONN;
1274
1275 /* We allow enqueuing multiple method calls at once! */
1276 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1277 return -EBUSY;
1278
1279 r = varlink_sanitize_parameters(&parameters);
1280 if (r < 0)
1281 return r;
1282
1283 r = json_build(&m, JSON_BUILD_OBJECT(
1284 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1285 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1286 JSON_BUILD_PAIR("oneway", JSON_BUILD_BOOLEAN(true))));
1287 if (r < 0)
1288 return r;
1289
1290 r = varlink_enqueue_json(v, m);
1291 if (r < 0)
1292 return r;
1293
1294 /* No state change here, this is one-way only after all */
1295 v->timestamp = now(CLOCK_MONOTONIC);
1296 return 0;
1297 }
1298
1299 int varlink_sendb(Varlink *v, const char *method, ...) {
1300 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1301 va_list ap;
1302 int r;
1303
1304 assert_return(v, -EINVAL);
1305
1306 va_start(ap, method);
1307 r = json_buildv(&parameters, ap);
1308 va_end(ap);
1309
1310 if (r < 0)
1311 return r;
1312
1313 return varlink_send(v, method, parameters);
1314 }
1315
1316 int varlink_invoke(Varlink *v, const char *method, JsonVariant *parameters) {
1317 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1318 int r;
1319
1320 assert_return(v, -EINVAL);
1321 assert_return(method, -EINVAL);
1322
1323 if (v->state == VARLINK_DISCONNECTED)
1324 return -ENOTCONN;
1325
1326 /* We allow enqueuing multiple method calls at once! */
1327 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1328 return -EBUSY;
1329
1330 r = varlink_sanitize_parameters(&parameters);
1331 if (r < 0)
1332 return r;
1333
1334 r = json_build(&m, JSON_BUILD_OBJECT(
1335 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1336 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1337 if (r < 0)
1338 return r;
1339
1340 r = varlink_enqueue_json(v, m);
1341 if (r < 0)
1342 return r;
1343
1344 varlink_set_state(v, VARLINK_AWAITING_REPLY);
1345 v->n_pending++;
1346 v->timestamp = now(CLOCK_MONOTONIC);
1347
1348 return 0;
1349 }
1350
1351 int varlink_invokeb(Varlink *v, const char *method, ...) {
1352 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1353 va_list ap;
1354 int r;
1355
1356 assert_return(v, -EINVAL);
1357
1358 va_start(ap, method);
1359 r = json_buildv(&parameters, ap);
1360 va_end(ap);
1361
1362 if (r < 0)
1363 return r;
1364
1365 return varlink_invoke(v, method, parameters);
1366 }
1367
1368 int varlink_observe(Varlink *v, const char *method, JsonVariant *parameters) {
1369 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1370 int r;
1371
1372 assert_return(v, -EINVAL);
1373 assert_return(method, -EINVAL);
1374
1375 if (v->state == VARLINK_DISCONNECTED)
1376 return -ENOTCONN;
1377 /* Note that we don't allow enqueuing multiple method calls when we are in more/continues mode! We
1378 * thus insist on an idle client here. */
1379 if (v->state != VARLINK_IDLE_CLIENT)
1380 return -EBUSY;
1381
1382 r = varlink_sanitize_parameters(&parameters);
1383 if (r < 0)
1384 return r;
1385
1386 r = json_build(&m, JSON_BUILD_OBJECT(
1387 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1388 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1389 JSON_BUILD_PAIR("more", JSON_BUILD_BOOLEAN(true))));
1390 if (r < 0)
1391 return r;
1392
1393 r = varlink_enqueue_json(v, m);
1394 if (r < 0)
1395 return r;
1396
1397
1398 varlink_set_state(v, VARLINK_AWAITING_REPLY_MORE);
1399 v->n_pending++;
1400 v->timestamp = now(CLOCK_MONOTONIC);
1401
1402 return 0;
1403 }
1404
1405 int varlink_observeb(Varlink *v, const char *method, ...) {
1406 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1407 va_list ap;
1408 int r;
1409
1410 assert_return(v, -EINVAL);
1411
1412 va_start(ap, method);
1413 r = json_buildv(&parameters, ap);
1414 va_end(ap);
1415
1416 if (r < 0)
1417 return r;
1418
1419 return varlink_observe(v, method, parameters);
1420 }
1421
1422 int varlink_call(
1423 Varlink *v,
1424 const char *method,
1425 JsonVariant *parameters,
1426 JsonVariant **ret_parameters,
1427 const char **ret_error_id,
1428 VarlinkReplyFlags *ret_flags) {
1429
1430 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1431 int r;
1432
1433 assert_return(v, -EINVAL);
1434 assert_return(method, -EINVAL);
1435
1436 if (v->state == VARLINK_DISCONNECTED)
1437 return -ENOTCONN;
1438 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT))
1439 return -EBUSY;
1440
1441 assert(v->n_pending == 0); /* n_pending can't be > 0 if we are in VARLINK_IDLE_CLIENT state */
1442
1443 r = varlink_sanitize_parameters(&parameters);
1444 if (r < 0)
1445 return r;
1446
1447 r = json_build(&m, JSON_BUILD_OBJECT(
1448 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1449 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1450 if (r < 0)
1451 return r;
1452
1453 r = varlink_enqueue_json(v, m);
1454 if (r < 0)
1455 return r;
1456
1457 varlink_set_state(v, VARLINK_CALLING);
1458 v->n_pending++;
1459 v->timestamp = now(CLOCK_MONOTONIC);
1460
1461 while (v->state == VARLINK_CALLING) {
1462
1463 r = varlink_process(v);
1464 if (r < 0)
1465 return r;
1466 if (r > 0)
1467 continue;
1468
1469 r = varlink_wait(v, USEC_INFINITY);
1470 if (r < 0)
1471 return r;
1472 }
1473
1474 switch (v->state) {
1475
1476 case VARLINK_CALLED:
1477 assert(v->current);
1478
1479 json_variant_unref(v->reply);
1480 v->reply = TAKE_PTR(v->current);
1481
1482 varlink_set_state(v, VARLINK_IDLE_CLIENT);
1483 assert(v->n_pending == 1);
1484 v->n_pending--;
1485
1486 if (ret_parameters)
1487 *ret_parameters = json_variant_by_key(v->reply, "parameters");
1488 if (ret_error_id)
1489 *ret_error_id = json_variant_string(json_variant_by_key(v->reply, "error"));
1490 if (ret_flags)
1491 *ret_flags = 0;
1492
1493 return 1;
1494
1495 case VARLINK_PENDING_DISCONNECT:
1496 case VARLINK_DISCONNECTED:
1497 return -ECONNRESET;
1498
1499 case VARLINK_PENDING_TIMEOUT:
1500 return -ETIME;
1501
1502 default:
1503 assert_not_reached("Unexpected state after method call.");
1504 }
1505 }
1506
1507 int varlink_callb(
1508 Varlink *v,
1509 const char *method,
1510 JsonVariant **ret_parameters,
1511 const char **ret_error_id,
1512 VarlinkReplyFlags *ret_flags, ...) {
1513
1514 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1515 va_list ap;
1516 int r;
1517
1518 assert_return(v, -EINVAL);
1519
1520 va_start(ap, ret_flags);
1521 r = json_buildv(&parameters, ap);
1522 va_end(ap);
1523
1524 if (r < 0)
1525 return r;
1526
1527 return varlink_call(v, method, parameters, ret_parameters, ret_error_id, ret_flags);
1528 }
1529
1530 int varlink_reply(Varlink *v, JsonVariant *parameters) {
1531 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1532 int r;
1533
1534 assert_return(v, -EINVAL);
1535
1536 if (v->state == VARLINK_DISCONNECTED)
1537 return -ENOTCONN;
1538 if (!IN_SET(v->state,
1539 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1540 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1541 return -EBUSY;
1542
1543 r = varlink_sanitize_parameters(&parameters);
1544 if (r < 0)
1545 return r;
1546
1547 r = json_build(&m, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1548 if (r < 0)
1549 return r;
1550
1551 r = varlink_enqueue_json(v, m);
1552 if (r < 0)
1553 return r;
1554
1555 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1556 /* We just replied to a method call that was let hanging for a while (i.e. we were outside of
1557 * the varlink_dispatch_method() stack frame), which means with this reply we are ready to
1558 * process further messages. */
1559 v->current = json_variant_unref(v->current);
1560 varlink_set_state(v, VARLINK_IDLE_SERVER);
1561 } else
1562 /* We replied to a method call from within the varlink_dispatch_method() stack frame), which
1563 * means we should it handle the rest of the state engine. */
1564 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1565
1566 return 1;
1567 }
1568
1569 int varlink_replyb(Varlink *v, ...) {
1570 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1571 va_list ap;
1572 int r;
1573
1574 assert_return(v, -EINVAL);
1575
1576 va_start(ap, v);
1577 r = json_buildv(&parameters, ap);
1578 va_end(ap);
1579
1580 if (r < 0)
1581 return r;
1582
1583 return varlink_reply(v, parameters);
1584 }
1585
1586 int varlink_error(Varlink *v, const char *error_id, JsonVariant *parameters) {
1587 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1588 int r;
1589
1590 assert_return(v, -EINVAL);
1591 assert_return(error_id, -EINVAL);
1592
1593 if (v->state == VARLINK_DISCONNECTED)
1594 return -ENOTCONN;
1595 if (!IN_SET(v->state,
1596 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1597 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1598 return -EBUSY;
1599
1600 r = varlink_sanitize_parameters(&parameters);
1601 if (r < 0)
1602 return r;
1603
1604 r = json_build(&m, JSON_BUILD_OBJECT(
1605 JSON_BUILD_PAIR("error", JSON_BUILD_STRING(error_id)),
1606 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1607 if (r < 0)
1608 return r;
1609
1610 r = varlink_enqueue_json(v, m);
1611 if (r < 0)
1612 return r;
1613
1614 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1615 v->current = json_variant_unref(v->current);
1616 varlink_set_state(v, VARLINK_IDLE_SERVER);
1617 } else
1618 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1619
1620 return 1;
1621 }
1622
1623 int varlink_errorb(Varlink *v, const char *error_id, ...) {
1624 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1625 va_list ap;
1626 int r;
1627
1628 assert_return(v, -EINVAL);
1629 assert_return(error_id, -EINVAL);
1630
1631 va_start(ap, error_id);
1632 r = json_buildv(&parameters, ap);
1633 va_end(ap);
1634
1635 if (r < 0)
1636 return r;
1637
1638 return varlink_error(v, error_id, parameters);
1639 }
1640
1641 int varlink_error_invalid_parameter(Varlink *v, JsonVariant *parameters) {
1642
1643 assert_return(v, -EINVAL);
1644 assert_return(parameters, -EINVAL);
1645
1646 /* We expect to be called in one of two ways: the 'parameters' argument is a string variant in which
1647 * case it is the parameter key name that is invalid. Or the 'parameters' argument is an object
1648 * variant in which case we'll pull out the first key. The latter mode is useful in functions that
1649 * don't expect any arguments. */
1650
1651 if (json_variant_is_string(parameters))
1652 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER, parameters);
1653
1654 if (json_variant_is_object(parameters) &&
1655 json_variant_elements(parameters) > 0)
1656 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER,
1657 json_variant_by_index(parameters, 0));
1658
1659 return -EINVAL;
1660 }
1661
1662 int varlink_error_errno(Varlink *v, int error) {
1663 return varlink_errorb(
1664 v,
1665 VARLINK_ERROR_SYSTEM,
1666 JSON_BUILD_OBJECT(JSON_BUILD_PAIR("errno", JSON_BUILD_INTEGER(abs(error)))));
1667 }
1668
1669 int varlink_notify(Varlink *v, JsonVariant *parameters) {
1670 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1671 int r;
1672
1673 assert_return(v, -EINVAL);
1674
1675 if (v->state == VARLINK_DISCONNECTED)
1676 return -ENOTCONN;
1677 if (!IN_SET(v->state, VARLINK_PROCESSING_METHOD_MORE, VARLINK_PENDING_METHOD_MORE))
1678 return -EBUSY;
1679
1680 r = varlink_sanitize_parameters(&parameters);
1681 if (r < 0)
1682 return r;
1683
1684 r = json_build(&m, JSON_BUILD_OBJECT(
1685 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1686 JSON_BUILD_PAIR("continues", JSON_BUILD_BOOLEAN(true))));
1687 if (r < 0)
1688 return r;
1689
1690 r = varlink_enqueue_json(v, m);
1691 if (r < 0)
1692 return r;
1693
1694 /* No state change, as more is coming */
1695 return 1;
1696 }
1697
1698 int varlink_notifyb(Varlink *v, ...) {
1699 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1700 va_list ap;
1701 int r;
1702
1703 assert_return(v, -EINVAL);
1704
1705 va_start(ap, v);
1706 r = json_buildv(&parameters, ap);
1707 va_end(ap);
1708
1709 if (r < 0)
1710 return r;
1711
1712 return varlink_notify(v, parameters);
1713 }
1714
1715 int varlink_bind_reply(Varlink *v, VarlinkReply callback) {
1716 assert_return(v, -EINVAL);
1717
1718 if (callback && v->reply_callback && callback != v->reply_callback)
1719 return -EBUSY;
1720
1721 v->reply_callback = callback;
1722
1723 return 0;
1724 }
1725
1726 void* varlink_set_userdata(Varlink *v, void *userdata) {
1727 void *old;
1728
1729 assert_return(v, NULL);
1730
1731 old = v->userdata;
1732 v->userdata = userdata;
1733
1734 return old;
1735 }
1736
1737 void* varlink_get_userdata(Varlink *v) {
1738 assert_return(v, NULL);
1739
1740 return v->userdata;
1741 }
1742
1743 static int varlink_acquire_ucred(Varlink *v) {
1744 int r;
1745
1746 assert(v);
1747
1748 if (v->ucred_acquired)
1749 return 0;
1750
1751 r = getpeercred(v->fd, &v->ucred);
1752 if (r < 0)
1753 return r;
1754
1755 v->ucred_acquired = true;
1756 return 0;
1757 }
1758
1759 int varlink_get_peer_uid(Varlink *v, uid_t *ret) {
1760 int r;
1761
1762 assert_return(v, -EINVAL);
1763 assert_return(ret, -EINVAL);
1764
1765 r = varlink_acquire_ucred(v);
1766 if (r < 0)
1767 return r;
1768
1769 if (!uid_is_valid(v->ucred.uid))
1770 return -ENODATA;
1771
1772 *ret = v->ucred.uid;
1773 return 0;
1774 }
1775
1776 int varlink_get_peer_pid(Varlink *v, pid_t *ret) {
1777 int r;
1778
1779 assert_return(v, -EINVAL);
1780 assert_return(ret, -EINVAL);
1781
1782 r = varlink_acquire_ucred(v);
1783 if (r < 0)
1784 return r;
1785
1786 if (!pid_is_valid(v->ucred.pid))
1787 return -ENODATA;
1788
1789 *ret = v->ucred.pid;
1790 return 0;
1791 }
1792
1793 int varlink_set_relative_timeout(Varlink *v, usec_t timeout) {
1794 assert_return(v, -EINVAL);
1795 assert_return(timeout > 0, -EINVAL);
1796
1797 v->timeout = timeout;
1798 return 0;
1799 }
1800
1801 VarlinkServer *varlink_get_server(Varlink *v) {
1802 assert_return(v, NULL);
1803
1804 return v->server;
1805 }
1806
1807 int varlink_set_description(Varlink *v, const char *description) {
1808 assert_return(v, -EINVAL);
1809
1810 return free_and_strdup(&v->description, description);
1811 }
1812
1813 static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
1814 Varlink *v = userdata;
1815
1816 assert(s);
1817 assert(v);
1818
1819 handle_revents(v, revents);
1820 (void) varlink_process(v);
1821
1822 return 1;
1823 }
1824
1825 static int time_callback(sd_event_source *s, uint64_t usec, void *userdata) {
1826 Varlink *v = userdata;
1827
1828 assert(s);
1829 assert(v);
1830
1831 (void) varlink_process(v);
1832 return 1;
1833 }
1834
1835 static int defer_callback(sd_event_source *s, void *userdata) {
1836 Varlink *v = userdata;
1837
1838 assert(s);
1839 assert(v);
1840
1841 (void) varlink_process(v);
1842 return 1;
1843 }
1844
1845 static int prepare_callback(sd_event_source *s, void *userdata) {
1846 Varlink *v = userdata;
1847 int r, e;
1848 usec_t until;
1849 bool have_timeout;
1850
1851 assert(s);
1852 assert(v);
1853
1854 e = varlink_get_events(v);
1855 if (e < 0)
1856 return e;
1857
1858 r = sd_event_source_set_io_events(v->io_event_source, e);
1859 if (r < 0)
1860 return r;
1861
1862 r = varlink_get_timeout(v, &until);
1863 if (r < 0)
1864 return r;
1865 have_timeout = r > 0;
1866
1867 if (have_timeout) {
1868 r = sd_event_source_set_time(v->time_event_source, until);
1869 if (r < 0)
1870 return r;
1871 }
1872
1873 r = sd_event_source_set_enabled(v->time_event_source, have_timeout ? SD_EVENT_ON : SD_EVENT_OFF);
1874 if (r < 0)
1875 return r;
1876
1877 return 1;
1878 }
1879
1880 static int quit_callback(sd_event_source *event, void *userdata) {
1881 Varlink *v = userdata;
1882
1883 assert(event);
1884 assert(v);
1885
1886 varlink_flush(v);
1887 varlink_close(v);
1888
1889 return 1;
1890 }
1891
1892 int varlink_attach_event(Varlink *v, sd_event *e, int64_t priority) {
1893 int r;
1894
1895 assert_return(v, -EINVAL);
1896 assert_return(!v->event, -EBUSY);
1897
1898 if (e)
1899 v->event = sd_event_ref(e);
1900 else {
1901 r = sd_event_default(&v->event);
1902 if (r < 0)
1903 return r;
1904 }
1905
1906 r = sd_event_add_time(v->event, &v->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, v);
1907 if (r < 0)
1908 goto fail;
1909
1910 r = sd_event_source_set_priority(v->time_event_source, priority);
1911 if (r < 0)
1912 goto fail;
1913
1914 (void) sd_event_source_set_description(v->time_event_source, "varlink-time");
1915
1916 r = sd_event_add_exit(v->event, &v->quit_event_source, quit_callback, v);
1917 if (r < 0)
1918 goto fail;
1919
1920 r = sd_event_source_set_priority(v->quit_event_source, priority);
1921 if (r < 0)
1922 goto fail;
1923
1924 (void) sd_event_source_set_description(v->quit_event_source, "varlink-quit");
1925
1926 r = sd_event_add_io(v->event, &v->io_event_source, v->fd, 0, io_callback, v);
1927 if (r < 0)
1928 goto fail;
1929
1930 r = sd_event_source_set_prepare(v->io_event_source, prepare_callback);
1931 if (r < 0)
1932 goto fail;
1933
1934 r = sd_event_source_set_priority(v->io_event_source, priority);
1935 if (r < 0)
1936 goto fail;
1937
1938 (void) sd_event_source_set_description(v->io_event_source, "varlink-io");
1939
1940 r = sd_event_add_defer(v->event, &v->defer_event_source, defer_callback, v);
1941 if (r < 0)
1942 goto fail;
1943
1944 r = sd_event_source_set_priority(v->defer_event_source, priority);
1945 if (r < 0)
1946 goto fail;
1947
1948 (void) sd_event_source_set_description(v->defer_event_source, "varlink-defer");
1949
1950 return 0;
1951
1952 fail:
1953 varlink_detach_event(v);
1954 return r;
1955 }
1956
1957 void varlink_detach_event(Varlink *v) {
1958 if (!v)
1959 return;
1960
1961 varlink_detach_event_sources(v);
1962
1963 v->event = sd_event_unref(v->event);
1964 }
1965
1966 sd_event *varlink_get_event(Varlink *v) {
1967 assert_return(v, NULL);
1968
1969 return v->event;
1970 }
1971
1972 int varlink_server_new(VarlinkServer **ret, VarlinkServerFlags flags) {
1973 VarlinkServer *s;
1974
1975 assert_return(ret, -EINVAL);
1976 assert_return((flags & ~_VARLINK_SERVER_FLAGS_ALL) == 0, -EINVAL);
1977
1978 s = new(VarlinkServer, 1);
1979 if (!s)
1980 return -ENOMEM;
1981
1982 *s = (VarlinkServer) {
1983 .n_ref = 1,
1984 .flags = flags,
1985 .connections_max = varlink_server_connections_max(NULL),
1986 .connections_per_uid_max = varlink_server_connections_per_uid_max(NULL),
1987 };
1988
1989 *ret = s;
1990 return 0;
1991 }
1992
1993 static VarlinkServer* varlink_server_destroy(VarlinkServer *s) {
1994 char *m;
1995
1996 if (!s)
1997 return NULL;
1998
1999 varlink_server_shutdown(s);
2000
2001 while ((m = hashmap_steal_first_key(s->methods)))
2002 free(m);
2003
2004 hashmap_free(s->methods);
2005 hashmap_free(s->by_uid);
2006
2007 sd_event_unref(s->event);
2008
2009 free(s->description);
2010
2011 return mfree(s);
2012 }
2013
2014 DEFINE_TRIVIAL_REF_UNREF_FUNC(VarlinkServer, varlink_server, varlink_server_destroy);
2015
2016 static int validate_connection(VarlinkServer *server, const struct ucred *ucred) {
2017 int allowed = -1;
2018
2019 assert(server);
2020 assert(ucred);
2021
2022 if (FLAGS_SET(server->flags, VARLINK_SERVER_ROOT_ONLY))
2023 allowed = ucred->uid == 0;
2024
2025 if (FLAGS_SET(server->flags, VARLINK_SERVER_MYSELF_ONLY))
2026 allowed = allowed > 0 || ucred->uid == getuid();
2027
2028 if (allowed == 0) { /* Allow access when it is explicitly allowed or when neither
2029 * VARLINK_SERVER_ROOT_ONLY nor VARLINK_SERVER_MYSELF_ONLY are specified. */
2030 varlink_server_log(server, "Unprivileged client attempted connection, refusing.");
2031 return 0;
2032 }
2033
2034 if (server->n_connections >= server->connections_max) {
2035 varlink_server_log(server, "Connection limit of %u reached, refusing.", server->connections_max);
2036 return 0;
2037 }
2038
2039 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
2040 unsigned c;
2041
2042 if (!uid_is_valid(ucred->uid)) {
2043 varlink_server_log(server, "Client with invalid UID attempted connection, refusing.");
2044 return 0;
2045 }
2046
2047 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
2048 if (c >= server->connections_per_uid_max) {
2049 varlink_server_log(server, "Per-UID connection limit of %u reached, refusing.",
2050 server->connections_per_uid_max);
2051 return 0;
2052 }
2053 }
2054
2055 return 1;
2056 }
2057
2058 static int count_connection(VarlinkServer *server, struct ucred *ucred) {
2059 unsigned c;
2060 int r;
2061
2062 assert(server);
2063 assert(ucred);
2064
2065 server->n_connections++;
2066
2067 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
2068 r = hashmap_ensure_allocated(&server->by_uid, NULL);
2069 if (r < 0)
2070 return log_debug_errno(r, "Failed to allocate UID hash table: %m");
2071
2072 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
2073
2074 varlink_server_log(server, "Connections of user " UID_FMT ": %u (of %u max)",
2075 ucred->uid, c, server->connections_per_uid_max);
2076
2077 r = hashmap_replace(server->by_uid, UID_TO_PTR(ucred->uid), UINT_TO_PTR(c + 1));
2078 if (r < 0)
2079 return log_debug_errno(r, "Failed to increment counter in UID hash table: %m");
2080 }
2081
2082 return 0;
2083 }
2084
2085 int varlink_server_add_connection(VarlinkServer *server, int fd, Varlink **ret) {
2086 _cleanup_(varlink_unrefp) Varlink *v = NULL;
2087 bool ucred_acquired;
2088 struct ucred ucred;
2089 int r;
2090
2091 assert_return(server, -EINVAL);
2092 assert_return(fd >= 0, -EBADF);
2093
2094 if ((server->flags & (VARLINK_SERVER_ROOT_ONLY|VARLINK_SERVER_ACCOUNT_UID)) != 0) {
2095 r = getpeercred(fd, &ucred);
2096 if (r < 0)
2097 return varlink_server_log_errno(server, r, "Failed to acquire peer credentials of incoming socket, refusing: %m");
2098
2099 ucred_acquired = true;
2100
2101 r = validate_connection(server, &ucred);
2102 if (r < 0)
2103 return r;
2104 if (r == 0)
2105 return -EPERM;
2106 } else
2107 ucred_acquired = false;
2108
2109 r = varlink_new(&v);
2110 if (r < 0)
2111 return varlink_server_log_errno(server, r, "Failed to allocate connection object: %m");
2112
2113 r = count_connection(server, &ucred);
2114 if (r < 0)
2115 return r;
2116
2117 v->fd = fd;
2118 v->userdata = server->userdata;
2119 if (ucred_acquired) {
2120 v->ucred = ucred;
2121 v->ucred_acquired = true;
2122 }
2123
2124 (void) asprintf(&v->description, "%s-%i", server->description ?: "varlink", v->fd);
2125
2126 /* Link up the server and the connection, and take reference in both directions. Note that the
2127 * reference on the connection is left dangling. It will be dropped when the connection is closed,
2128 * which happens in varlink_close(), including in the event loop quit callback. */
2129 v->server = varlink_server_ref(server);
2130 varlink_ref(v);
2131
2132 varlink_set_state(v, VARLINK_IDLE_SERVER);
2133
2134 if (server->event) {
2135 r = varlink_attach_event(v, server->event, server->event_priority);
2136 if (r < 0) {
2137 varlink_log_errno(v, r, "Failed to attach new connection: %m");
2138 v->fd = -1; /* take the fd out of the connection again */
2139 varlink_close(v);
2140 return r;
2141 }
2142 }
2143
2144 if (ret)
2145 *ret = v;
2146
2147 return 0;
2148 }
2149
2150 static int connect_callback(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
2151 VarlinkServerSocket *ss = userdata;
2152 _cleanup_close_ int cfd = -1;
2153 Varlink *v = NULL;
2154 int r;
2155
2156 assert(source);
2157 assert(ss);
2158
2159 varlink_server_log(ss->server, "New incoming connection.");
2160
2161 cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
2162 if (cfd < 0) {
2163 if (ERRNO_IS_ACCEPT_AGAIN(errno))
2164 return 0;
2165
2166 return varlink_server_log_errno(ss->server, errno, "Failed to accept incoming socket: %m");
2167 }
2168
2169 r = varlink_server_add_connection(ss->server, cfd, &v);
2170 if (r < 0)
2171 return 0;
2172
2173 TAKE_FD(cfd);
2174
2175 if (ss->server->connect_callback) {
2176 r = ss->server->connect_callback(ss->server, v, ss->server->userdata);
2177 if (r < 0) {
2178 varlink_log_errno(v, r, "Connection callback returned error, disconnecting client: %m");
2179 varlink_close(v);
2180 return 0;
2181 }
2182 }
2183
2184 return 0;
2185 }
2186
2187 int varlink_server_listen_fd(VarlinkServer *s, int fd) {
2188 _cleanup_free_ VarlinkServerSocket *ss = NULL;
2189 int r;
2190
2191 assert_return(s, -EINVAL);
2192 assert_return(fd >= 0, -EBADF);
2193
2194 r = fd_nonblock(fd, true);
2195 if (r < 0)
2196 return r;
2197
2198 ss = new(VarlinkServerSocket, 1);
2199 if (!ss)
2200 return -ENOMEM;
2201
2202 *ss = (VarlinkServerSocket) {
2203 .server = s,
2204 .fd = fd,
2205 };
2206
2207 if (s->event) {
2208 _cleanup_(sd_event_source_unrefp) sd_event_source *es = NULL;
2209
2210 r = sd_event_add_io(s->event, &es, fd, EPOLLIN, connect_callback, ss);
2211 if (r < 0)
2212 return r;
2213
2214 r = sd_event_source_set_priority(ss->event_source, s->event_priority);
2215 if (r < 0)
2216 return r;
2217 }
2218
2219 LIST_PREPEND(sockets, s->sockets, TAKE_PTR(ss));
2220 return 0;
2221 }
2222
2223 int varlink_server_listen_address(VarlinkServer *s, const char *address, mode_t m) {
2224 union sockaddr_union sockaddr;
2225 socklen_t sockaddr_len;
2226 _cleanup_close_ int fd = -1;
2227 int r;
2228
2229 assert_return(s, -EINVAL);
2230 assert_return(address, -EINVAL);
2231 assert_return((m & ~0777) == 0, -EINVAL);
2232
2233 r = sockaddr_un_set_path(&sockaddr.un, address);
2234 if (r < 0)
2235 return r;
2236 sockaddr_len = r;
2237
2238 fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
2239 if (fd < 0)
2240 return -errno;
2241
2242 fd = fd_move_above_stdio(fd);
2243
2244 (void) sockaddr_un_unlink(&sockaddr.un);
2245
2246 RUN_WITH_UMASK(~m & 0777)
2247 if (bind(fd, &sockaddr.sa, sockaddr_len) < 0)
2248 return -errno;
2249
2250 if (listen(fd, SOMAXCONN) < 0)
2251 return -errno;
2252
2253 r = varlink_server_listen_fd(s, fd);
2254 if (r < 0)
2255 return r;
2256
2257 TAKE_FD(fd);
2258 return 0;
2259 }
2260
2261 void* varlink_server_set_userdata(VarlinkServer *s, void *userdata) {
2262 void *ret;
2263
2264 assert_return(s, NULL);
2265
2266 ret = s->userdata;
2267 s->userdata = userdata;
2268
2269 return ret;
2270 }
2271
2272 void* varlink_server_get_userdata(VarlinkServer *s) {
2273 assert_return(s, NULL);
2274
2275 return s->userdata;
2276 }
2277
2278 static VarlinkServerSocket* varlink_server_socket_destroy(VarlinkServerSocket *ss) {
2279 if (!ss)
2280 return NULL;
2281
2282 if (ss->server)
2283 LIST_REMOVE(sockets, ss->server->sockets, ss);
2284
2285 sd_event_source_disable_unref(ss->event_source);
2286
2287 free(ss->address);
2288 safe_close(ss->fd);
2289
2290 return mfree(ss);
2291 }
2292
2293 int varlink_server_shutdown(VarlinkServer *s) {
2294 assert_return(s, -EINVAL);
2295
2296 while (s->sockets)
2297 varlink_server_socket_destroy(s->sockets);
2298
2299 return 0;
2300 }
2301
2302 int varlink_server_attach_event(VarlinkServer *s, sd_event *e, int64_t priority) {
2303 VarlinkServerSocket *ss;
2304 int r;
2305
2306 assert_return(s, -EINVAL);
2307 assert_return(!s->event, -EBUSY);
2308
2309 if (e)
2310 s->event = sd_event_ref(e);
2311 else {
2312 r = sd_event_default(&s->event);
2313 if (r < 0)
2314 return r;
2315 }
2316
2317 LIST_FOREACH(sockets, ss, s->sockets) {
2318 assert(!ss->event_source);
2319
2320 r = sd_event_add_io(s->event, &ss->event_source, ss->fd, EPOLLIN, connect_callback, ss);
2321 if (r < 0)
2322 goto fail;
2323
2324 r = sd_event_source_set_priority(ss->event_source, priority);
2325 if (r < 0)
2326 goto fail;
2327 }
2328
2329 s->event_priority = priority;
2330 return 0;
2331
2332 fail:
2333 varlink_server_detach_event(s);
2334 return r;
2335 }
2336
2337 int varlink_server_detach_event(VarlinkServer *s) {
2338 VarlinkServerSocket *ss;
2339
2340 assert_return(s, -EINVAL);
2341
2342 LIST_FOREACH(sockets, ss, s->sockets) {
2343
2344 if (!ss->event_source)
2345 continue;
2346
2347 (void) sd_event_source_set_enabled(ss->event_source, SD_EVENT_OFF);
2348 ss->event_source = sd_event_source_unref(ss->event_source);
2349 }
2350
2351 sd_event_unref(s->event);
2352 return 0;
2353 }
2354
2355 sd_event *varlink_server_get_event(VarlinkServer *s) {
2356 assert_return(s, NULL);
2357
2358 return s->event;
2359 }
2360
2361 int varlink_server_bind_method(VarlinkServer *s, const char *method, VarlinkMethod callback) {
2362 char *m;
2363 int r;
2364
2365 assert_return(s, -EINVAL);
2366 assert_return(method, -EINVAL);
2367 assert_return(callback, -EINVAL);
2368
2369 if (startswith(method, "org.varlink.service."))
2370 return -EEXIST;
2371
2372 r = hashmap_ensure_allocated(&s->methods, &string_hash_ops);
2373 if (r < 0)
2374 return r;
2375
2376 m = strdup(method);
2377 if (!m)
2378 return -ENOMEM;
2379
2380 r = hashmap_put(s->methods, m, callback);
2381 if (r < 0) {
2382 free(m);
2383 return r;
2384 }
2385
2386 return 0;
2387 }
2388
2389 int varlink_server_bind_method_many_internal(VarlinkServer *s, ...) {
2390 va_list ap;
2391 int r = 0;
2392
2393 assert_return(s, -EINVAL);
2394
2395 va_start(ap, s);
2396 for (;;) {
2397 VarlinkMethod callback;
2398 const char *method;
2399
2400 method = va_arg(ap, const char *);
2401 if (!method)
2402 break;
2403
2404 callback = va_arg(ap, VarlinkMethod);
2405
2406 r = varlink_server_bind_method(s, method, callback);
2407 if (r < 0)
2408 break;
2409 }
2410 va_end(ap);
2411
2412 return r;
2413 }
2414
2415 int varlink_server_bind_connect(VarlinkServer *s, VarlinkConnect callback) {
2416 assert_return(s, -EINVAL);
2417
2418 if (callback && s->connect_callback && callback != s->connect_callback)
2419 return -EBUSY;
2420
2421 s->connect_callback = callback;
2422 return 0;
2423 }
2424
2425 int varlink_server_bind_disconnect(VarlinkServer *s, VarlinkDisconnect callback) {
2426 assert_return(s, -EINVAL);
2427
2428 if (callback && s->disconnect_callback && callback != s->disconnect_callback)
2429 return -EBUSY;
2430
2431 s->disconnect_callback = callback;
2432 return 0;
2433 }
2434
2435 unsigned varlink_server_connections_max(VarlinkServer *s) {
2436 int dts;
2437
2438 /* If a server is specified, return the setting for that server, otherwise the default value */
2439 if (s)
2440 return s->connections_max;
2441
2442 dts = getdtablesize();
2443 assert_se(dts > 0);
2444
2445 /* Make sure we never use up more than ¾th of RLIMIT_NOFILE for IPC */
2446 if (VARLINK_DEFAULT_CONNECTIONS_MAX > (unsigned) dts / 4 * 3)
2447 return dts / 4 * 3;
2448
2449 return VARLINK_DEFAULT_CONNECTIONS_MAX;
2450 }
2451
2452 unsigned varlink_server_connections_per_uid_max(VarlinkServer *s) {
2453 unsigned m;
2454
2455 if (s)
2456 return s->connections_per_uid_max;
2457
2458 /* Make sure to never use up more than ¾th of available connections for a single user */
2459 m = varlink_server_connections_max(NULL);
2460 if (VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX > m)
2461 return m / 4 * 3;
2462
2463 return VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX;
2464 }
2465
2466 int varlink_server_set_connections_per_uid_max(VarlinkServer *s, unsigned m) {
2467 assert_return(s, -EINVAL);
2468 assert_return(m > 0, -EINVAL);
2469
2470 s->connections_per_uid_max = m;
2471 return 0;
2472 }
2473
2474 int varlink_server_set_connections_max(VarlinkServer *s, unsigned m) {
2475 assert_return(s, -EINVAL);
2476 assert_return(m > 0, -EINVAL);
2477
2478 s->connections_max = m;
2479 return 0;
2480 }
2481
2482 unsigned varlink_server_current_connections(VarlinkServer *s) {
2483 assert_return(s, UINT_MAX);
2484
2485 return s->n_connections;
2486 }
2487
2488 int varlink_server_set_description(VarlinkServer *s, const char *description) {
2489 assert_return(s, -EINVAL);
2490
2491 return free_and_strdup(&s->description, description);
2492 }
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