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Merge pull request #12515 from evverx/fix-fuzzers-in-local-mode
[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 "list.h"
10 #include "process-util.h"
11 #include "set.h"
12 #include "socket-util.h"
13 #include "string-table.h"
14 #include "string-util.h"
15 #include "strv.h"
16 #include "time-util.h"
17 #include "umask-util.h"
18 #include "user-util.h"
19 #include "varlink.h"
20
21 #define VARLINK_DEFAULT_CONNECTIONS_MAX 4096U
22 #define VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX 1024U
23
24 #define VARLINK_DEFAULT_TIMEOUT_USEC (45U*USEC_PER_SEC)
25 #define VARLINK_BUFFER_MAX (16U*1024U*1024U)
26 #define VARLINK_READ_SIZE (64U*1024U)
27
28 typedef enum VarlinkState {
29 /* Client side states */
30 VARLINK_IDLE_CLIENT,
31 VARLINK_AWAITING_REPLY,
32 VARLINK_CALLING,
33 VARLINK_CALLED,
34 VARLINK_PROCESSING_REPLY,
35
36 /* Server side states */
37 VARLINK_IDLE_SERVER,
38 VARLINK_PROCESSING_METHOD,
39 VARLINK_PROCESSING_METHOD_MORE,
40 VARLINK_PROCESSING_METHOD_ONEWAY,
41 VARLINK_PROCESSED_METHOD,
42 VARLINK_PROCESSED_METHOD_MORE,
43 VARLINK_PENDING_METHOD,
44 VARLINK_PENDING_METHOD_MORE,
45
46 /* Common states (only during shutdown) */
47 VARLINK_PENDING_DISCONNECT,
48 VARLINK_PENDING_TIMEOUT,
49 VARLINK_PROCESSING_DISCONNECT,
50 VARLINK_PROCESSING_TIMEOUT,
51 VARLINK_PROCESSING_FAILURE,
52 VARLINK_DISCONNECTED,
53
54 _VARLINK_STATE_MAX,
55 _VARLINK_STATE_INVALID = -1
56 } VarlinkState;
57
58 /* Tests whether we are not yet disconnected. Note that this is true during all states where the connection
59 * is still good for something, and false only when it's dead for good. This means: when we are
60 * asynchronously connecting to a peer and the connect() is still pending, then this will return 'true', as
61 * the connection is still good, and we are likely to be able to properly operate on it soon. */
62 #define VARLINK_STATE_IS_ALIVE(state) \
63 IN_SET(state, \
64 VARLINK_IDLE_CLIENT, \
65 VARLINK_AWAITING_REPLY, \
66 VARLINK_CALLING, \
67 VARLINK_CALLED, \
68 VARLINK_PROCESSING_REPLY, \
69 VARLINK_IDLE_SERVER, \
70 VARLINK_PROCESSING_METHOD, \
71 VARLINK_PROCESSING_METHOD_MORE, \
72 VARLINK_PROCESSING_METHOD_ONEWAY, \
73 VARLINK_PROCESSED_METHOD, \
74 VARLINK_PROCESSED_METHOD_MORE, \
75 VARLINK_PENDING_METHOD, \
76 VARLINK_PENDING_METHOD_MORE)
77
78 struct Varlink {
79 unsigned n_ref;
80
81 VarlinkServer *server;
82
83 VarlinkState state;
84 bool connecting; /* This boolean indicates whether the socket fd we are operating on is currently
85 * processing an asynchronous connect(). In that state we watch the socket for
86 * EPOLLOUT, but we refrain from calling read() or write() on the socket as that
87 * will trigger ENOTCONN. Note that this boolean is kept separate from the
88 * VarlinkState above on purpose: while the connect() is still not complete we
89 * already want to allow queuing of messages and similar. Thus it's nice to keep
90 * these two state concepts separate: the VarlinkState encodes what our own view of
91 * the connection is, i.e. whether we think it's a server, a client, and has
92 * something queued already, while 'connecting' tells us a detail about the
93 * transport used below, that should have no effect on how we otherwise accept and
94 * process operations from the user.
95 *
96 * Or to say this differently: VARLINK_STATE_IS_ALIVE(state) tells you whether the
97 * connection is good to use, even if it might not be fully connected
98 * yet. connecting=true then informs you that actually we are still connecting, and
99 * the connection is actually not established yet and thus any requests you enqueue
100 * now will still work fine but will be queued only, not sent yet, but that
101 * shouldn't stop you from using the connection, since eventually whatever you queue
102 * *will* be sent.
103 *
104 * Or to say this even differently: 'state' is a high-level ("application layer"
105 * high, if you so will) state, while 'conecting' is a low-level ("transport layer"
106 * low, if you so will) state, and while they are not entirely unrelated and
107 * sometimes propagate effects to each other they are only asynchronously connected
108 * at most. */
109 unsigned n_pending;
110
111 int fd;
112
113 char *input_buffer; /* valid data starts at input_buffer_index, ends at input_buffer_index+input_buffer_size */
114 size_t input_buffer_allocated;
115 size_t input_buffer_index;
116 size_t input_buffer_size;
117 size_t input_buffer_unscanned;
118
119 char *output_buffer; /* valid data starts at output_buffer_index, ends at output_buffer_index+output_buffer_size */
120 size_t output_buffer_allocated;
121 size_t output_buffer_index;
122 size_t output_buffer_size;
123
124 VarlinkReply reply_callback;
125
126 JsonVariant *current;
127 JsonVariant *reply;
128
129 struct ucred ucred;
130 bool ucred_acquired:1;
131
132 bool write_disconnected:1;
133 bool read_disconnected:1;
134 bool prefer_read_write:1;
135 bool got_pollhup:1;
136
137 usec_t timestamp;
138 usec_t timeout;
139
140 void *userdata;
141 char *description;
142
143 sd_event *event;
144 sd_event_source *io_event_source;
145 sd_event_source *time_event_source;
146 sd_event_source *quit_event_source;
147 sd_event_source *defer_event_source;
148 };
149
150 typedef struct VarlinkServerSocket VarlinkServerSocket;
151
152 struct VarlinkServerSocket {
153 VarlinkServer *server;
154
155 int fd;
156 char *address;
157
158 sd_event_source *event_source;
159
160 LIST_FIELDS(VarlinkServerSocket, sockets);
161 };
162
163 struct VarlinkServer {
164 unsigned n_ref;
165 VarlinkServerFlags flags;
166
167 LIST_HEAD(VarlinkServerSocket, sockets);
168
169 Hashmap *methods;
170 VarlinkConnect connect_callback;
171
172 sd_event *event;
173 int64_t event_priority;
174
175 unsigned n_connections;
176 Hashmap *by_uid;
177
178 void *userdata;
179 char *description;
180
181 unsigned connections_max;
182 unsigned connections_per_uid_max;
183 };
184
185 static const char* const varlink_state_table[_VARLINK_STATE_MAX] = {
186 [VARLINK_IDLE_CLIENT] = "idle-client",
187 [VARLINK_AWAITING_REPLY] = "awaiting-reply",
188 [VARLINK_CALLING] = "calling",
189 [VARLINK_CALLED] = "called",
190 [VARLINK_PROCESSING_REPLY] = "processing-reply",
191 [VARLINK_IDLE_SERVER] = "idle-server",
192 [VARLINK_PROCESSING_METHOD] = "processing-method",
193 [VARLINK_PROCESSING_METHOD_MORE] = "processing-method-more",
194 [VARLINK_PROCESSING_METHOD_ONEWAY] = "processing-method-oneway",
195 [VARLINK_PROCESSED_METHOD] = "processed-method",
196 [VARLINK_PROCESSED_METHOD_MORE] = "processed-method-more",
197 [VARLINK_PENDING_METHOD] = "pending-method",
198 [VARLINK_PENDING_METHOD_MORE] = "pending-method-more",
199 [VARLINK_PENDING_DISCONNECT] = "pending-disconnect",
200 [VARLINK_PENDING_TIMEOUT] = "pending-timeout",
201 [VARLINK_PROCESSING_DISCONNECT] = "processing-disconnect",
202 [VARLINK_PROCESSING_TIMEOUT] = "processing-timeout",
203 [VARLINK_PROCESSING_FAILURE] = "processing-failure",
204 [VARLINK_DISCONNECTED] = "disconnected",
205 };
206
207 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(varlink_state, VarlinkState);
208
209 #define varlink_log_errno(v, error, fmt, ...) \
210 log_debug_errno(error, "%s: " fmt, varlink_description(v), ##__VA_ARGS__)
211
212 #define varlink_log(v, fmt, ...) \
213 log_debug("%s: " fmt, varlink_description(v), ##__VA_ARGS__)
214
215 #define varlink_server_log_errno(s, error, fmt, ...) \
216 log_debug_errno(error, "%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
217
218 #define varlink_server_log(s, fmt, ...) \
219 log_debug("%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
220
221 static inline const char *varlink_description(Varlink *v) {
222 return strna(v ? v->description : NULL);
223 }
224
225 static inline const char *varlink_server_description(VarlinkServer *s) {
226 return strna(s ? s->description : NULL);
227 }
228
229 static void varlink_set_state(Varlink *v, VarlinkState state) {
230 assert(v);
231 assert(state >= 0 && state < _VARLINK_STATE_MAX);
232
233 if (v->state < 0)
234 varlink_log(v, "varlink: setting state %s",
235 varlink_state_to_string(state));
236 else
237 varlink_log(v, "varlink: changing state %s → %s",
238 varlink_state_to_string(v->state),
239 varlink_state_to_string(state));
240
241 v->state = state;
242 }
243
244 static int varlink_new(Varlink **ret) {
245 Varlink *v;
246
247 assert(ret);
248
249 /* Here use new0 as the below structured initializer is nested. */
250 v = new0(Varlink, 1);
251 if (!v)
252 return -ENOMEM;
253
254 *v = (Varlink) {
255 .n_ref = 1,
256 .fd = -1,
257
258 .state = _VARLINK_STATE_INVALID,
259
260 .ucred.uid = UID_INVALID,
261 .ucred.gid = GID_INVALID,
262
263 .timestamp = USEC_INFINITY,
264 .timeout = VARLINK_DEFAULT_TIMEOUT_USEC
265 };
266
267 *ret = v;
268 return 0;
269 }
270
271 int varlink_connect_address(Varlink **ret, const char *address) {
272 _cleanup_(varlink_unrefp) Varlink *v = NULL;
273 union sockaddr_union sockaddr;
274 int r;
275
276 assert_return(ret, -EINVAL);
277 assert_return(address, -EINVAL);
278
279 r = sockaddr_un_set_path(&sockaddr.un, address);
280 if (r < 0)
281 return r;
282
283 r = varlink_new(&v);
284 if (r < 0)
285 return r;
286
287 v->fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
288 if (v->fd < 0)
289 return -errno;
290
291 if (connect(v->fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0) {
292 if (!IN_SET(errno, EAGAIN, EINPROGRESS))
293 return -errno;
294
295 v->connecting = true; /* We are asynchronously connecting, i.e. the connect() is being
296 * processed in the background. As long as that's the case the socket
297 * is in a special state: it's there, we can poll it for EPOLLOUT, but
298 * if we attempt to write() to it before we see EPOLLOUT we'll get
299 * ENOTCONN (and not EAGAIN, like we would for a normal connected
300 * socket that isn't writable at the moment). Since ENOTCONN on write()
301 * hence can mean two different things (i.e. connection not complete
302 * yet vs. already disconnected again), we store as a boolean whether
303 * we are still in connect(). */
304 }
305
306 varlink_set_state(v, VARLINK_IDLE_CLIENT);
307
308 *ret = TAKE_PTR(v);
309 return r;
310 }
311
312 int varlink_connect_fd(Varlink **ret, int fd) {
313 Varlink *v;
314 int r;
315
316 assert_return(ret, -EINVAL);
317 assert_return(fd >= 0, -EBADF);
318
319 r = fd_nonblock(fd, true);
320 if (r < 0)
321 return r;
322
323 r = varlink_new(&v);
324 if (r < 0)
325 return r;
326
327 v->fd = fd;
328 varlink_set_state(v, VARLINK_IDLE_CLIENT);
329
330 /* Note that if this function is called we assume the passed socket (if it is one) is already
331 * properly connected, i.e. any asynchronous connect() done on it already completed. Because of that
332 * we'll not set the 'connecting' boolean here, i.e. we don't need to avoid write()ing to the socket
333 * until the connection is fully set up. Behaviour here is hence a bit different from
334 * varlink_connect_address() above, as there we do handle asynchronous connections ourselves and
335 * avoid doing write() on it before we saw EPOLLOUT for the first time. */
336
337 *ret = v;
338 return 0;
339 }
340
341 static void varlink_detach_event_sources(Varlink *v) {
342 assert(v);
343
344 v->io_event_source = sd_event_source_disable_unref(v->io_event_source);
345
346 v->time_event_source = sd_event_source_disable_unref(v->time_event_source);
347
348 v->quit_event_source = sd_event_source_disable_unref(v->quit_event_source);
349
350 v->defer_event_source = sd_event_source_disable_unref(v->defer_event_source);
351 }
352
353 static void varlink_clear(Varlink *v) {
354 assert(v);
355
356 varlink_detach_event_sources(v);
357
358 v->fd = safe_close(v->fd);
359
360 v->input_buffer = mfree(v->input_buffer);
361 v->output_buffer = mfree(v->output_buffer);
362
363 v->current = json_variant_unref(v->current);
364 v->reply = json_variant_unref(v->reply);
365
366 v->event = sd_event_unref(v->event);
367 }
368
369 static Varlink* varlink_destroy(Varlink *v) {
370 if (!v)
371 return NULL;
372
373 /* If this is called the server object must already been unreffed here. Why that? because when we
374 * linked up the varlink connection with the server object we took one ref in each direction */
375 assert(!v->server);
376
377 varlink_clear(v);
378
379 free(v->description);
380 return mfree(v);
381 }
382
383 DEFINE_TRIVIAL_REF_UNREF_FUNC(Varlink, varlink, varlink_destroy);
384
385 static int varlink_test_disconnect(Varlink *v) {
386 assert(v);
387
388 /* Tests whether we the the connection has been terminated. We are careful to not stop processing it
389 * prematurely, since we want to handle half-open connections as well as possible and want to flush
390 * out and read data before we close down if we can. */
391
392 /* Already disconnected? */
393 if (!VARLINK_STATE_IS_ALIVE(v->state))
394 return 0;
395
396 /* Wait until connection setup is complete, i.e. until asynchronous connect() completes */
397 if (v->connecting)
398 return 0;
399
400 /* Still something to write and we can write? Stay around */
401 if (v->output_buffer_size > 0 && !v->write_disconnected)
402 return 0;
403
404 /* Both sides gone already? Then there's no need to stick around */
405 if (v->read_disconnected && v->write_disconnected)
406 goto disconnect;
407
408 /* If we are waiting for incoming data but the read side is shut down, disconnect. */
409 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING, VARLINK_IDLE_SERVER) && v->read_disconnected)
410 goto disconnect;
411
412 /* Similar, if are a client that hasn't written anything yet but the write side is dead, also
413 * disconnect. We also explicitly check for POLLHUP here since we likely won't notice the write side
414 * being down if we never wrote anything. */
415 if (IN_SET(v->state, VARLINK_IDLE_CLIENT) && (v->write_disconnected || v->got_pollhup))
416 goto disconnect;
417
418 return 0;
419
420 disconnect:
421 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
422 return 1;
423 }
424
425 static int varlink_write(Varlink *v) {
426 ssize_t n;
427
428 assert(v);
429
430 if (!VARLINK_STATE_IS_ALIVE(v->state))
431 return 0;
432 if (v->connecting) /* Writing while we are still wait for a non-blocking connect() to complete will
433 * result in ENOTCONN, hence exit early here */
434 return 0;
435 if (v->output_buffer_size == 0)
436 return 0;
437 if (v->write_disconnected)
438 return 0;
439
440 assert(v->fd >= 0);
441
442 /* We generally prefer recv()/send() (mostly because of MSG_NOSIGNAL) but also want to be compatible
443 * with non-socket IO, hence fall back automatically */
444 if (!v->prefer_read_write) {
445 n = send(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size, MSG_DONTWAIT|MSG_NOSIGNAL);
446 if (n < 0 && errno == ENOTSOCK)
447 v->prefer_read_write = true;
448 }
449 if (v->prefer_read_write)
450 n = write(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size);
451 if (n < 0) {
452 if (errno == EAGAIN)
453 return 0;
454
455 if (ERRNO_IS_DISCONNECT(errno)) {
456 /* If we get informed about a disconnect on write, then let's remember that, but not
457 * act on it just yet. Let's wait for read() to report the issue first. */
458 v->write_disconnected = true;
459 return 1;
460 }
461
462 return -errno;
463 }
464
465 v->output_buffer_size -= n;
466
467 if (v->output_buffer_size == 0)
468 v->output_buffer_index = 0;
469 else
470 v->output_buffer_index += n;
471
472 v->timestamp = now(CLOCK_MONOTONIC);
473 return 1;
474 }
475
476 static int varlink_read(Varlink *v) {
477 size_t rs;
478 ssize_t n;
479
480 assert(v);
481
482 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING, VARLINK_IDLE_SERVER))
483 return 0;
484 if (v->connecting) /* read() on a socket while we are in connect() will fail with EINVAL, hence exit early here */
485 return 0;
486 if (v->current)
487 return 0;
488 if (v->input_buffer_unscanned > 0)
489 return 0;
490 if (v->read_disconnected)
491 return 0;
492
493 if (v->input_buffer_size >= VARLINK_BUFFER_MAX)
494 return -ENOBUFS;
495
496 assert(v->fd >= 0);
497
498 if (v->input_buffer_allocated <= v->input_buffer_index + v->input_buffer_size) {
499 size_t add;
500
501 add = MIN(VARLINK_BUFFER_MAX - v->input_buffer_size, VARLINK_READ_SIZE);
502
503 if (v->input_buffer_index == 0) {
504
505 if (!GREEDY_REALLOC(v->input_buffer, v->input_buffer_allocated, v->input_buffer_size + add))
506 return -ENOMEM;
507
508 } else {
509 char *b;
510
511 b = new(char, v->input_buffer_size + add);
512 if (!b)
513 return -ENOMEM;
514
515 memcpy(b, v->input_buffer + v->input_buffer_index, v->input_buffer_size);
516
517 free_and_replace(v->input_buffer, b);
518
519 v->input_buffer_allocated = v->input_buffer_size + add;
520 v->input_buffer_index = 0;
521 }
522 }
523
524 rs = v->input_buffer_allocated - (v->input_buffer_index + v->input_buffer_size);
525
526 if (!v->prefer_read_write) {
527 n = recv(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs, MSG_DONTWAIT);
528 if (n < 0 && errno == ENOTSOCK)
529 v->prefer_read_write = true;
530 }
531 if (v->prefer_read_write)
532 n = read(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs);
533 if (n < 0) {
534 if (errno == EAGAIN)
535 return 0;
536
537 if (ERRNO_IS_DISCONNECT(errno)) {
538 v->read_disconnected = true;
539 return 1;
540 }
541
542 return -errno;
543 }
544 if (n == 0) { /* EOF */
545 v->read_disconnected = true;
546 return 1;
547 }
548
549 v->input_buffer_size += n;
550 v->input_buffer_unscanned += n;
551
552 return 1;
553 }
554
555 static int varlink_parse_message(Varlink *v) {
556 const char *e, *begin;
557 size_t sz;
558 int r;
559
560 assert(v);
561
562 if (v->current)
563 return 0;
564 if (v->input_buffer_unscanned <= 0)
565 return 0;
566
567 assert(v->input_buffer_unscanned <= v->input_buffer_size);
568 assert(v->input_buffer_index + v->input_buffer_size <= v->input_buffer_allocated);
569
570 begin = v->input_buffer + v->input_buffer_index;
571
572 e = memchr(begin + v->input_buffer_size - v->input_buffer_unscanned, 0, v->input_buffer_unscanned);
573 if (!e) {
574 v->input_buffer_unscanned = 0;
575 return 0;
576 }
577
578 sz = e - begin + 1;
579
580 varlink_log(v, "New incoming message: %s", begin);
581
582 r = json_parse(begin, &v->current, NULL, NULL);
583 if (r < 0)
584 return r;
585
586 v->input_buffer_size -= sz;
587
588 if (v->input_buffer_size == 0)
589 v->input_buffer_index = 0;
590 else
591 v->input_buffer_index += sz;
592
593 v->input_buffer_unscanned = v->input_buffer_size;
594 return 1;
595 }
596
597 static int varlink_test_timeout(Varlink *v) {
598 assert(v);
599
600 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING))
601 return 0;
602 if (v->timeout == USEC_INFINITY)
603 return 0;
604
605 if (now(CLOCK_MONOTONIC) < usec_add(v->timestamp, v->timeout))
606 return 0;
607
608 varlink_set_state(v, VARLINK_PENDING_TIMEOUT);
609
610 return 1;
611 }
612
613 static int varlink_dispatch_local_error(Varlink *v, const char *error) {
614 int r;
615
616 assert(v);
617 assert(error);
618
619 if (!v->reply_callback)
620 return 0;
621
622 r = v->reply_callback(v, NULL, error, VARLINK_REPLY_ERROR|VARLINK_REPLY_LOCAL, v->userdata);
623 if (r < 0)
624 log_debug_errno(r, "Reply callback returned error, ignoring: %m");
625
626 return 1;
627 }
628
629 static int varlink_dispatch_timeout(Varlink *v) {
630 assert(v);
631
632 if (v->state != VARLINK_PENDING_TIMEOUT)
633 return 0;
634
635 varlink_set_state(v, VARLINK_PROCESSING_TIMEOUT);
636 varlink_dispatch_local_error(v, VARLINK_ERROR_TIMEOUT);
637 varlink_close(v);
638
639 return 1;
640 }
641
642 static int varlink_dispatch_disconnect(Varlink *v) {
643 assert(v);
644
645 if (v->state != VARLINK_PENDING_DISCONNECT)
646 return 0;
647
648 varlink_set_state(v, VARLINK_PROCESSING_DISCONNECT);
649 varlink_dispatch_local_error(v, VARLINK_ERROR_DISCONNECTED);
650 varlink_close(v);
651
652 return 1;
653 }
654
655 static int varlink_sanitize_parameters(JsonVariant **v) {
656 assert(v);
657
658 /* Varlink always wants a parameters list, hence make one if the caller doesn't want any */
659 if (!*v)
660 return json_variant_new_object(v, NULL, 0);
661 else if (!json_variant_is_object(*v))
662 return -EINVAL;
663
664 return 0;
665 }
666
667 static int varlink_dispatch_reply(Varlink *v) {
668 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
669 VarlinkReplyFlags flags = 0;
670 const char *error = NULL;
671 JsonVariant *e;
672 const char *k;
673 int r;
674
675 assert(v);
676
677 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING))
678 return 0;
679 if (!v->current)
680 return 0;
681
682 assert(v->n_pending > 0);
683
684 if (!json_variant_is_object(v->current))
685 goto invalid;
686
687 JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
688
689 if (streq(k, "error")) {
690 if (error)
691 goto invalid;
692 if (!json_variant_is_string(e))
693 goto invalid;
694
695 error = json_variant_string(e);
696 flags |= VARLINK_REPLY_ERROR;
697
698 } else if (streq(k, "parameters")) {
699 if (parameters)
700 goto invalid;
701 if (!json_variant_is_object(e))
702 goto invalid;
703
704 parameters = json_variant_ref(e);
705
706 } else if (streq(k, "continues")) {
707 if (FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
708 goto invalid;
709
710 if (!json_variant_is_boolean(e))
711 goto invalid;
712
713 if (json_variant_boolean(e))
714 flags |= VARLINK_REPLY_CONTINUES;
715 } else
716 goto invalid;
717 }
718
719 if (error && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
720 goto invalid;
721
722 r = varlink_sanitize_parameters(&parameters);
723 if (r < 0)
724 goto invalid;
725
726 if (v->state == VARLINK_AWAITING_REPLY) {
727 varlink_set_state(v, VARLINK_PROCESSING_REPLY);
728
729 if (v->reply_callback) {
730 r = v->reply_callback(v, parameters, error, flags, v->userdata);
731 if (r < 0)
732 log_debug_errno(r, "Reply callback returned error, ignoring: %m");
733 }
734
735 v->current = json_variant_unref(v->current);
736
737 if (v->state == VARLINK_PROCESSING_REPLY) {
738 assert(v->n_pending > 0);
739 v->n_pending--;
740
741 varlink_set_state(v, v->n_pending == 0 ? VARLINK_IDLE_CLIENT : VARLINK_AWAITING_REPLY);
742 }
743 } else {
744 assert(v->state == VARLINK_CALLING);
745
746 if (FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
747 goto invalid;
748
749 varlink_set_state(v, VARLINK_CALLED);
750 }
751
752 return 1;
753
754 invalid:
755 varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
756 varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
757 varlink_close(v);
758
759 return 1;
760 }
761
762 static int varlink_dispatch_method(Varlink *v) {
763 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
764 VarlinkMethodFlags flags = 0;
765 const char *method = NULL, *error;
766 JsonVariant *e;
767 VarlinkMethod callback;
768 const char *k;
769 int r;
770
771 assert(v);
772
773 if (v->state != VARLINK_IDLE_SERVER)
774 return 0;
775 if (!v->current)
776 return 0;
777
778 if (!json_variant_is_object(v->current))
779 goto invalid;
780
781 JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
782
783 if (streq(k, "method")) {
784 if (method)
785 goto invalid;
786 if (!json_variant_is_string(e))
787 goto invalid;
788
789 method = json_variant_string(e);
790
791 } else if (streq(k, "parameters")) {
792 if (parameters)
793 goto invalid;
794 if (!json_variant_is_object(e))
795 goto invalid;
796
797 parameters = json_variant_ref(e);
798
799 } else if (streq(k, "oneway")) {
800
801 if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
802 goto invalid;
803
804 if (!json_variant_is_boolean(e))
805 goto invalid;
806
807 if (json_variant_boolean(e))
808 flags |= VARLINK_METHOD_ONEWAY;
809
810 } else if (streq(k, "more")) {
811
812 if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
813 goto invalid;
814
815 if (!json_variant_is_boolean(e))
816 goto invalid;
817
818 if (json_variant_boolean(e))
819 flags |= VARLINK_METHOD_MORE;
820
821 } else
822 goto invalid;
823 }
824
825 if (!method)
826 goto invalid;
827
828 r = varlink_sanitize_parameters(&parameters);
829 if (r < 0)
830 goto fail;
831
832 varlink_set_state(v, (flags & VARLINK_METHOD_MORE) ? VARLINK_PROCESSING_METHOD_MORE :
833 (flags & VARLINK_METHOD_ONEWAY) ? VARLINK_PROCESSING_METHOD_ONEWAY :
834 VARLINK_PROCESSING_METHOD);
835
836 assert(v->server);
837
838 if (STR_IN_SET(method, "org.varlink.service.GetInfo", "org.varlink.service.GetInterface")) {
839 /* For now, we don't implement a single of varlink's own methods */
840 callback = NULL;
841 error = VARLINK_ERROR_METHOD_NOT_IMPLEMENTED;
842 } else if (startswith(method, "org.varlink.service.")) {
843 callback = NULL;
844 error = VARLINK_ERROR_METHOD_NOT_FOUND;
845 } else {
846 callback = hashmap_get(v->server->methods, method);
847 error = VARLINK_ERROR_METHOD_NOT_FOUND;
848 }
849
850 if (callback) {
851 r = callback(v, parameters, flags, v->userdata);
852 if (r < 0) {
853 log_debug_errno(r, "Callback for %s returned error: %m", method);
854
855 /* We got an error back from the callback. Propagate it to the client if the method call remains unanswered. */
856 if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
857 r = varlink_errorb(v, VARLINK_ERROR_SYSTEM, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("errno", JSON_BUILD_INTEGER(-r))));
858 if (r < 0)
859 return r;
860 }
861 }
862 } else if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
863 assert(error);
864
865 r = varlink_errorb(v, error, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method))));
866 if (r < 0)
867 return r;
868 }
869
870 switch (v->state) {
871
872 case VARLINK_PROCESSED_METHOD: /* Method call is fully processed */
873 case VARLINK_PROCESSING_METHOD_ONEWAY: /* ditto */
874 v->current = json_variant_unref(v->current);
875 varlink_set_state(v, VARLINK_IDLE_SERVER);
876 break;
877
878 case VARLINK_PROCESSING_METHOD: /* Method call wasn't replied to, will be replied to later */
879 varlink_set_state(v, VARLINK_PENDING_METHOD);
880 break;
881
882 case VARLINK_PROCESSED_METHOD_MORE: /* One reply for a "more" message was sent, more to come */
883 case VARLINK_PROCESSING_METHOD_MORE: /* No reply for a "more" message was sent, more to come */
884 varlink_set_state(v, VARLINK_PENDING_METHOD_MORE);
885 break;
886
887 default:
888 assert_not_reached("Unexpected state");
889
890 }
891
892 return r;
893
894 invalid:
895 r = -EINVAL;
896
897 fail:
898 varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
899 varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
900 varlink_close(v);
901
902 return r;
903 }
904
905 int varlink_process(Varlink *v) {
906 int r;
907
908 assert_return(v, -EINVAL);
909
910 if (v->state == VARLINK_DISCONNECTED)
911 return -ENOTCONN;
912
913 varlink_ref(v);
914
915 r = varlink_write(v);
916 if (r != 0)
917 goto finish;
918
919 r = varlink_dispatch_reply(v);
920 if (r != 0)
921 goto finish;
922
923 r = varlink_dispatch_method(v);
924 if (r != 0)
925 goto finish;
926
927 r = varlink_parse_message(v);
928 if (r != 0)
929 goto finish;
930
931 r = varlink_read(v);
932 if (r != 0)
933 goto finish;
934
935 r = varlink_test_disconnect(v);
936 if (r != 0)
937 goto finish;
938
939 r = varlink_dispatch_disconnect(v);
940 if (r != 0)
941 goto finish;
942
943 r = varlink_test_timeout(v);
944 if (r != 0)
945 goto finish;
946
947 r = varlink_dispatch_timeout(v);
948 if (r != 0)
949 goto finish;
950
951 finish:
952 if (r >= 0 && v->defer_event_source) {
953 int q;
954
955 /* If we did some processing, make sure we are called again soon */
956 q = sd_event_source_set_enabled(v->defer_event_source, r > 0 ? SD_EVENT_ON : SD_EVENT_OFF);
957 if (q < 0)
958 r = q;
959 }
960
961 if (r < 0) {
962 if (VARLINK_STATE_IS_ALIVE(v->state))
963 /* Initiate disconnection */
964 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
965 else
966 /* We failed while disconnecting, in that case close right away */
967 varlink_close(v);
968 }
969
970 varlink_unref(v);
971 return r;
972 }
973
974 static void handle_revents(Varlink *v, int revents) {
975 assert(v);
976
977 if (v->connecting) {
978 /* If we have seen POLLOUT or POLLHUP on a socket we are asynchronously waiting a connect()
979 * to complete on, we know we are ready. We don't read the connection error here though,
980 * we'll get the error on the next read() or write(). */
981 if ((revents & (POLLOUT|POLLHUP)) == 0)
982 return;
983
984 varlink_log(v, "Anynchronous connection completed.");
985 v->connecting = false;
986 } else {
987 /* Note that we don't care much about POLLIN/POLLOUT here, we'll just try reading and writing
988 * what we can. However, we do care about POLLHUP to detect connection termination even if we
989 * momentarily don't want to read nor write anything. */
990
991 if (!FLAGS_SET(revents, POLLHUP))
992 return;
993
994 varlink_log(v, "Got POLLHUP from socket.");
995 v->got_pollhup = true;
996 }
997 }
998
999 int varlink_wait(Varlink *v, usec_t timeout) {
1000 struct timespec ts;
1001 struct pollfd pfd;
1002 int r, fd, events;
1003 usec_t t;
1004
1005 assert_return(v, -EINVAL);
1006 assert_return(!v->server, -ENOTTY);
1007
1008 if (v->state == VARLINK_DISCONNECTED)
1009 return -ENOTCONN;
1010
1011 r = varlink_get_timeout(v, &t);
1012 if (r < 0)
1013 return r;
1014 if (t != USEC_INFINITY) {
1015 usec_t n;
1016
1017 n = now(CLOCK_MONOTONIC);
1018 if (t < n)
1019 t = 0;
1020 else
1021 t = usec_sub_unsigned(t, n);
1022 }
1023
1024 if (timeout != USEC_INFINITY &&
1025 (t == USEC_INFINITY || timeout < t))
1026 t = timeout;
1027
1028 fd = varlink_get_fd(v);
1029 if (fd < 0)
1030 return fd;
1031
1032 events = varlink_get_events(v);
1033 if (events < 0)
1034 return events;
1035
1036 pfd = (struct pollfd) {
1037 .fd = fd,
1038 .events = events,
1039 };
1040
1041 r = ppoll(&pfd, 1,
1042 t == USEC_INFINITY ? NULL : timespec_store(&ts, t),
1043 NULL);
1044 if (r < 0)
1045 return -errno;
1046
1047 handle_revents(v, pfd.revents);
1048
1049 return r > 0 ? 1 : 0;
1050 }
1051
1052 int varlink_get_fd(Varlink *v) {
1053
1054 assert_return(v, -EINVAL);
1055
1056 if (v->state == VARLINK_DISCONNECTED)
1057 return -ENOTCONN;
1058 if (v->fd < 0)
1059 return -EBADF;
1060
1061 return v->fd;
1062 }
1063
1064 int varlink_get_events(Varlink *v) {
1065 int ret = 0;
1066
1067 assert_return(v, -EINVAL);
1068
1069 if (v->state == VARLINK_DISCONNECTED)
1070 return -ENOTCONN;
1071
1072 if (v->connecting) /* When processing an asynchronous connect(), we only wait for EPOLLOUT, which
1073 * tells us that the connection is now complete. Before that we should neither
1074 * write() or read() from the fd. */
1075 return EPOLLOUT;
1076
1077 if (!v->read_disconnected &&
1078 IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING, VARLINK_IDLE_SERVER) &&
1079 !v->current &&
1080 v->input_buffer_unscanned <= 0)
1081 ret |= EPOLLIN;
1082
1083 if (!v->write_disconnected &&
1084 v->output_buffer_size > 0)
1085 ret |= EPOLLOUT;
1086
1087 return ret;
1088 }
1089
1090 int varlink_get_timeout(Varlink *v, usec_t *ret) {
1091 assert_return(v, -EINVAL);
1092
1093 if (v->state == VARLINK_DISCONNECTED)
1094 return -ENOTCONN;
1095
1096 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING) &&
1097 v->timeout != USEC_INFINITY) {
1098 if (ret)
1099 *ret = usec_add(v->timestamp, v->timeout);
1100 return 1;
1101 } else {
1102 if (ret)
1103 *ret = USEC_INFINITY;
1104 return 0;
1105 }
1106 }
1107
1108 int varlink_flush(Varlink *v) {
1109 int ret = 0, r;
1110
1111 assert_return(v, -EINVAL);
1112
1113 if (v->state == VARLINK_DISCONNECTED)
1114 return -ENOTCONN;
1115
1116 for (;;) {
1117 struct pollfd pfd;
1118
1119 if (v->output_buffer_size == 0)
1120 break;
1121 if (v->write_disconnected)
1122 return -ECONNRESET;
1123
1124 r = varlink_write(v);
1125 if (r < 0)
1126 return r;
1127 if (r > 0) {
1128 ret = 1;
1129 continue;
1130 }
1131
1132 pfd = (struct pollfd) {
1133 .fd = v->fd,
1134 .events = POLLOUT,
1135 };
1136
1137 if (poll(&pfd, 1, -1) < 0)
1138 return -errno;
1139
1140 handle_revents(v, pfd.revents);
1141 }
1142
1143 return ret;
1144 }
1145
1146 static void varlink_detach_server(Varlink *v) {
1147 assert(v);
1148
1149 if (!v->server)
1150 return;
1151
1152 if (v->server->by_uid &&
1153 v->ucred_acquired &&
1154 uid_is_valid(v->ucred.uid)) {
1155 unsigned c;
1156
1157 c = PTR_TO_UINT(hashmap_get(v->server->by_uid, UID_TO_PTR(v->ucred.uid)));
1158 assert(c > 0);
1159
1160 if (c == 1)
1161 (void) hashmap_remove(v->server->by_uid, UID_TO_PTR(v->ucred.uid));
1162 else
1163 (void) hashmap_replace(v->server->by_uid, UID_TO_PTR(v->ucred.uid), UINT_TO_PTR(c - 1));
1164 }
1165
1166 assert(v->server->n_connections > 0);
1167 v->server->n_connections--;
1168
1169 /* If this is a connection associated to a server, then let's disconnect the server and the
1170 * connection from each other. This drops the dangling reference that connect_callback() set up. */
1171 v->server = varlink_server_unref(v->server);
1172 varlink_unref(v);
1173 }
1174
1175 int varlink_close(Varlink *v) {
1176
1177 assert_return(v, -EINVAL);
1178
1179 if (v->state == VARLINK_DISCONNECTED)
1180 return 0;
1181
1182 varlink_set_state(v, VARLINK_DISCONNECTED);
1183
1184 /* Let's take a reference first, since varlink_detach_server() might drop the final (dangling) ref
1185 * which would destroy us before we can call varlink_clear() */
1186 varlink_ref(v);
1187 varlink_detach_server(v);
1188 varlink_clear(v);
1189 varlink_unref(v);
1190
1191 return 1;
1192 }
1193
1194 Varlink* varlink_flush_close_unref(Varlink *v) {
1195
1196 if (!v)
1197 return NULL;
1198
1199 (void) varlink_flush(v);
1200 (void) varlink_close(v);
1201
1202 return varlink_unref(v);
1203 }
1204
1205 static int varlink_enqueue_json(Varlink *v, JsonVariant *m) {
1206 _cleanup_free_ char *text = NULL;
1207 int r;
1208
1209 assert(v);
1210 assert(m);
1211
1212 r = json_variant_format(m, 0, &text);
1213 if (r < 0)
1214 return r;
1215
1216 if (v->output_buffer_size + r + 1 > VARLINK_BUFFER_MAX)
1217 return -ENOBUFS;
1218
1219 varlink_log(v, "Sending message: %s", text);
1220
1221 if (v->output_buffer_size == 0) {
1222
1223 free_and_replace(v->output_buffer, text);
1224
1225 v->output_buffer_size = v->output_buffer_allocated = r + 1;
1226 v->output_buffer_index = 0;
1227
1228 } else if (v->output_buffer_index == 0) {
1229
1230 if (!GREEDY_REALLOC(v->output_buffer, v->output_buffer_allocated, v->output_buffer_size + r + 1))
1231 return -ENOMEM;
1232
1233 memcpy(v->output_buffer + v->output_buffer_size, text, r + 1);
1234 v->output_buffer_size += r + 1;
1235
1236 } else {
1237 char *n;
1238
1239 n = new(char, v->output_buffer_size + r + 1);
1240 if (!n)
1241 return -ENOMEM;
1242
1243 memcpy(mempcpy(n, v->output_buffer + v->output_buffer_index, v->output_buffer_size), text, r + 1);
1244
1245 free_and_replace(v->output_buffer, n);
1246 v->output_buffer_size += r + 1;
1247 v->output_buffer_index = 0;
1248 }
1249
1250 return 0;
1251 }
1252
1253 int varlink_send(Varlink *v, const char *method, JsonVariant *parameters) {
1254 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1255 int r;
1256
1257 assert_return(v, -EINVAL);
1258 assert_return(method, -EINVAL);
1259
1260 if (v->state == VARLINK_DISCONNECTED)
1261 return -ENOTCONN;
1262 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1263 return -EBUSY;
1264
1265 r = varlink_sanitize_parameters(&parameters);
1266 if (r < 0)
1267 return r;
1268
1269 r = json_build(&m, JSON_BUILD_OBJECT(
1270 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1271 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1272 JSON_BUILD_PAIR("oneway", JSON_BUILD_BOOLEAN(true))));
1273 if (r < 0)
1274 return r;
1275
1276 r = varlink_enqueue_json(v, m);
1277 if (r < 0)
1278 return r;
1279
1280 /* No state change here, this is one-way only after all */
1281 v->timestamp = now(CLOCK_MONOTONIC);
1282 return 0;
1283 }
1284
1285 int varlink_sendb(Varlink *v, const char *method, ...) {
1286 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1287 va_list ap;
1288 int r;
1289
1290 assert_return(v, -EINVAL);
1291
1292 va_start(ap, method);
1293 r = json_buildv(&parameters, ap);
1294 va_end(ap);
1295
1296 if (r < 0)
1297 return r;
1298
1299 return varlink_send(v, method, parameters);
1300 }
1301
1302 int varlink_invoke(Varlink *v, const char *method, JsonVariant *parameters) {
1303 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1304 int r;
1305
1306 assert_return(v, -EINVAL);
1307 assert_return(method, -EINVAL);
1308
1309 if (v->state == VARLINK_DISCONNECTED)
1310 return -ENOTCONN;
1311 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1312 return -EBUSY;
1313
1314 r = varlink_sanitize_parameters(&parameters);
1315 if (r < 0)
1316 return r;
1317
1318 r = json_build(&m, JSON_BUILD_OBJECT(
1319 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1320 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1321 if (r < 0)
1322 return r;
1323
1324 r = varlink_enqueue_json(v, m);
1325 if (r < 0)
1326 return r;
1327
1328 varlink_set_state(v, VARLINK_AWAITING_REPLY);
1329 v->n_pending++;
1330 v->timestamp = now(CLOCK_MONOTONIC);
1331
1332 return 0;
1333 }
1334
1335 int varlink_invokeb(Varlink *v, const char *method, ...) {
1336 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1337 va_list ap;
1338 int r;
1339
1340 assert_return(v, -EINVAL);
1341
1342 va_start(ap, method);
1343 r = json_buildv(&parameters, ap);
1344 va_end(ap);
1345
1346 if (r < 0)
1347 return r;
1348
1349 return varlink_invoke(v, method, parameters);
1350 }
1351
1352 int varlink_call(
1353 Varlink *v,
1354 const char *method,
1355 JsonVariant *parameters,
1356 JsonVariant **ret_parameters,
1357 const char **ret_error_id,
1358 VarlinkReplyFlags *ret_flags) {
1359
1360 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1361 int r;
1362
1363 assert_return(v, -EINVAL);
1364 assert_return(method, -EINVAL);
1365
1366 if (v->state == VARLINK_DISCONNECTED)
1367 return -ENOTCONN;
1368 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT))
1369 return -EBUSY;
1370
1371 assert(v->n_pending == 0); /* n_pending can't be > 0 if we are in VARLINK_IDLE_CLIENT state */
1372
1373 r = varlink_sanitize_parameters(&parameters);
1374 if (r < 0)
1375 return r;
1376
1377 r = json_build(&m, JSON_BUILD_OBJECT(
1378 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1379 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1380 if (r < 0)
1381 return r;
1382
1383 r = varlink_enqueue_json(v, m);
1384 if (r < 0)
1385 return r;
1386
1387 varlink_set_state(v, VARLINK_CALLING);
1388 v->n_pending++;
1389 v->timestamp = now(CLOCK_MONOTONIC);
1390
1391 while (v->state == VARLINK_CALLING) {
1392
1393 r = varlink_process(v);
1394 if (r < 0)
1395 return r;
1396 if (r > 0)
1397 continue;
1398
1399 r = varlink_wait(v, USEC_INFINITY);
1400 if (r < 0)
1401 return r;
1402 }
1403
1404 switch (v->state) {
1405
1406 case VARLINK_CALLED:
1407 assert(v->current);
1408
1409 json_variant_unref(v->reply);
1410 v->reply = TAKE_PTR(v->current);
1411
1412 varlink_set_state(v, VARLINK_IDLE_CLIENT);
1413 assert(v->n_pending == 1);
1414 v->n_pending--;
1415
1416 if (ret_parameters)
1417 *ret_parameters = json_variant_by_key(v->reply, "parameters");
1418 if (ret_error_id)
1419 *ret_error_id = json_variant_string(json_variant_by_key(v->reply, "error"));
1420 if (ret_flags)
1421 *ret_flags = 0;
1422
1423 return 1;
1424
1425 case VARLINK_PENDING_DISCONNECT:
1426 case VARLINK_DISCONNECTED:
1427 return -ECONNRESET;
1428
1429 case VARLINK_PENDING_TIMEOUT:
1430 return -ETIME;
1431
1432 default:
1433 assert_not_reached("Unexpected state after method call.");
1434 }
1435 }
1436
1437 int varlink_callb(
1438 Varlink *v,
1439 const char *method,
1440 JsonVariant **ret_parameters,
1441 const char **ret_error_id,
1442 VarlinkReplyFlags *ret_flags, ...) {
1443
1444 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1445 va_list ap;
1446 int r;
1447
1448 assert_return(v, -EINVAL);
1449
1450 va_start(ap, ret_flags);
1451 r = json_buildv(&parameters, ap);
1452 va_end(ap);
1453
1454 if (r < 0)
1455 return r;
1456
1457 return varlink_call(v, method, parameters, ret_parameters, ret_error_id, ret_flags);
1458 }
1459
1460 int varlink_reply(Varlink *v, JsonVariant *parameters) {
1461 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1462 int r;
1463
1464 assert_return(v, -EINVAL);
1465
1466 if (v->state == VARLINK_DISCONNECTED)
1467 return -ENOTCONN;
1468 if (!IN_SET(v->state,
1469 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1470 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1471 return -EBUSY;
1472
1473 r = varlink_sanitize_parameters(&parameters);
1474 if (r < 0)
1475 return r;
1476
1477 r = json_build(&m, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1478 if (r < 0)
1479 return r;
1480
1481 r = varlink_enqueue_json(v, m);
1482 if (r < 0)
1483 return r;
1484
1485 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1486 /* We just replied to a method call that was let hanging for a while (i.e. we were outside of
1487 * the varlink_dispatch_method() stack frame), which means with this reply we are ready to
1488 * process further messages. */
1489 v->current = json_variant_unref(v->current);
1490 varlink_set_state(v, VARLINK_IDLE_SERVER);
1491 } else
1492 /* We replied to a method call from within the varlink_dispatch_method() stack frame), which
1493 * means we should it handle the rest of the state engine. */
1494 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1495
1496 return 1;
1497 }
1498
1499 int varlink_replyb(Varlink *v, ...) {
1500 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1501 va_list ap;
1502 int r;
1503
1504 assert_return(v, -EINVAL);
1505
1506 va_start(ap, v);
1507 r = json_buildv(&parameters, ap);
1508 va_end(ap);
1509
1510 if (r < 0)
1511 return r;
1512
1513 return varlink_reply(v, parameters);
1514 }
1515
1516 int varlink_error(Varlink *v, const char *error_id, JsonVariant *parameters) {
1517 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1518 int r;
1519
1520 assert_return(v, -EINVAL);
1521 assert_return(error_id, -EINVAL);
1522
1523 if (v->state == VARLINK_DISCONNECTED)
1524 return -ENOTCONN;
1525 if (!IN_SET(v->state,
1526 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1527 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1528 return -EBUSY;
1529
1530 r = varlink_sanitize_parameters(&parameters);
1531 if (r < 0)
1532 return r;
1533
1534 r = json_build(&m, JSON_BUILD_OBJECT(
1535 JSON_BUILD_PAIR("error", JSON_BUILD_STRING(error_id)),
1536 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1537 if (r < 0)
1538 return r;
1539
1540 r = varlink_enqueue_json(v, m);
1541 if (r < 0)
1542 return r;
1543
1544 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1545 v->current = json_variant_unref(v->current);
1546 varlink_set_state(v, VARLINK_IDLE_SERVER);
1547 } else
1548 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1549
1550 return 1;
1551 }
1552
1553 int varlink_errorb(Varlink *v, const char *error_id, ...) {
1554 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1555 va_list ap;
1556 int r;
1557
1558 assert_return(v, -EINVAL);
1559 assert_return(error_id, -EINVAL);
1560
1561 va_start(ap, error_id);
1562 r = json_buildv(&parameters, ap);
1563 va_end(ap);
1564
1565 if (r < 0)
1566 return r;
1567
1568 return varlink_error(v, error_id, parameters);
1569 }
1570
1571 int varlink_error_invalid_parameter(Varlink *v, JsonVariant *parameters) {
1572
1573 assert_return(v, -EINVAL);
1574 assert_return(parameters, -EINVAL);
1575
1576 /* We expect to be called in one of two ways: the 'parameters' argument is a string variant in which
1577 * case it is the parameter key name that is invalid. Or the 'parameters' argument is an object
1578 * variant in which case we'll pull out the first key. The latter mode is useful in functions that
1579 * don't expect any arguments. */
1580
1581 if (json_variant_is_string(parameters))
1582 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER, parameters);
1583
1584 if (json_variant_is_object(parameters) &&
1585 json_variant_elements(parameters) > 0)
1586 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER,
1587 json_variant_by_index(parameters, 0));
1588
1589 return -EINVAL;
1590 }
1591
1592 int varlink_notify(Varlink *v, JsonVariant *parameters) {
1593 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1594 int r;
1595
1596 assert_return(v, -EINVAL);
1597
1598 if (v->state == VARLINK_DISCONNECTED)
1599 return -ENOTCONN;
1600 if (!IN_SET(v->state, VARLINK_PROCESSING_METHOD_MORE, VARLINK_PENDING_METHOD_MORE))
1601 return -EBUSY;
1602
1603 r = varlink_sanitize_parameters(&parameters);
1604 if (r < 0)
1605 return r;
1606
1607 r = json_build(&m, JSON_BUILD_OBJECT(
1608 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1609 JSON_BUILD_PAIR("continues", JSON_BUILD_BOOLEAN(true))));
1610 if (r < 0)
1611 return r;
1612
1613 r = varlink_enqueue_json(v, m);
1614 if (r < 0)
1615 return r;
1616
1617 /* No state change, as more is coming */
1618 return 1;
1619 }
1620
1621 int varlink_notifyb(Varlink *v, ...) {
1622 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1623 va_list ap;
1624 int r;
1625
1626 assert_return(v, -EINVAL);
1627
1628 va_start(ap, v);
1629 r = json_buildv(&parameters, ap);
1630 va_end(ap);
1631
1632 if (r < 0)
1633 return r;
1634
1635 return varlink_notify(v, parameters);
1636 }
1637
1638 int varlink_bind_reply(Varlink *v, VarlinkReply callback) {
1639 assert_return(v, -EINVAL);
1640
1641 if (callback && v->reply_callback && callback != v->reply_callback)
1642 return -EBUSY;
1643
1644 v->reply_callback = callback;
1645
1646 return 0;
1647 }
1648
1649 void* varlink_set_userdata(Varlink *v, void *userdata) {
1650 void *old;
1651
1652 assert_return(v, NULL);
1653
1654 old = v->userdata;
1655 v->userdata = userdata;
1656
1657 return old;
1658 }
1659
1660 void* varlink_get_userdata(Varlink *v) {
1661 assert_return(v, NULL);
1662
1663 return v->userdata;
1664 }
1665
1666 static int varlink_acquire_ucred(Varlink *v) {
1667 int r;
1668
1669 assert(v);
1670
1671 if (v->ucred_acquired)
1672 return 0;
1673
1674 r = getpeercred(v->fd, &v->ucred);
1675 if (r < 0)
1676 return r;
1677
1678 v->ucred_acquired = true;
1679 return 0;
1680 }
1681
1682 int varlink_get_peer_uid(Varlink *v, uid_t *ret) {
1683 int r;
1684
1685 assert_return(v, -EINVAL);
1686 assert_return(ret, -EINVAL);
1687
1688 r = varlink_acquire_ucred(v);
1689 if (r < 0)
1690 return r;
1691
1692 if (!uid_is_valid(v->ucred.uid))
1693 return -ENODATA;
1694
1695 *ret = v->ucred.uid;
1696 return 0;
1697 }
1698
1699 int varlink_get_peer_pid(Varlink *v, pid_t *ret) {
1700 int r;
1701
1702 assert_return(v, -EINVAL);
1703 assert_return(ret, -EINVAL);
1704
1705 r = varlink_acquire_ucred(v);
1706 if (r < 0)
1707 return r;
1708
1709 if (!pid_is_valid(v->ucred.pid))
1710 return -ENODATA;
1711
1712 *ret = v->ucred.pid;
1713 return 0;
1714 }
1715
1716 int varlink_set_relative_timeout(Varlink *v, usec_t timeout) {
1717 assert_return(v, -EINVAL);
1718 assert_return(timeout > 0, -EINVAL);
1719
1720 v->timeout = timeout;
1721 return 0;
1722 }
1723
1724 VarlinkServer *varlink_get_server(Varlink *v) {
1725 assert_return(v, NULL);
1726
1727 return v->server;
1728 }
1729
1730 int varlink_set_description(Varlink *v, const char *description) {
1731 assert_return(v, -EINVAL);
1732
1733 return free_and_strdup(&v->description, description);
1734 }
1735
1736 static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
1737 Varlink *v = userdata;
1738
1739 assert(s);
1740 assert(v);
1741
1742 handle_revents(v, revents);
1743 (void) varlink_process(v);
1744
1745 return 1;
1746 }
1747
1748 static int time_callback(sd_event_source *s, uint64_t usec, void *userdata) {
1749 Varlink *v = userdata;
1750
1751 assert(s);
1752 assert(v);
1753
1754 (void) varlink_process(v);
1755 return 1;
1756 }
1757
1758 static int defer_callback(sd_event_source *s, void *userdata) {
1759 Varlink *v = userdata;
1760
1761 assert(s);
1762 assert(v);
1763
1764 (void) varlink_process(v);
1765 return 1;
1766 }
1767
1768 static int prepare_callback(sd_event_source *s, void *userdata) {
1769 Varlink *v = userdata;
1770 int r, e;
1771 usec_t until;
1772
1773 assert(s);
1774 assert(v);
1775
1776 e = varlink_get_events(v);
1777 if (e < 0)
1778 return e;
1779
1780 r = sd_event_source_set_io_events(v->io_event_source, e);
1781 if (r < 0)
1782 return r;
1783
1784 r = varlink_get_timeout(v, &until);
1785 if (r < 0)
1786 return r;
1787 if (r > 0) {
1788 r = sd_event_source_set_time(v->time_event_source, until);
1789 if (r < 0)
1790 return r;
1791 }
1792
1793 r = sd_event_source_set_enabled(v->time_event_source, r > 0 ? SD_EVENT_ON : SD_EVENT_OFF);
1794 if (r < 0)
1795 return r;
1796
1797 return 1;
1798 }
1799
1800 static int quit_callback(sd_event_source *event, void *userdata) {
1801 Varlink *v = userdata;
1802
1803 assert(event);
1804 assert(v);
1805
1806 varlink_flush(v);
1807 varlink_close(v);
1808
1809 return 1;
1810 }
1811
1812 int varlink_attach_event(Varlink *v, sd_event *e, int64_t priority) {
1813 int r;
1814
1815 assert_return(v, -EINVAL);
1816 assert_return(!v->event, -EBUSY);
1817
1818 if (e)
1819 v->event = sd_event_ref(e);
1820 else {
1821 r = sd_event_default(&v->event);
1822 if (r < 0)
1823 return r;
1824 }
1825
1826 r = sd_event_add_time(v->event, &v->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, v);
1827 if (r < 0)
1828 goto fail;
1829
1830 r = sd_event_source_set_priority(v->time_event_source, priority);
1831 if (r < 0)
1832 goto fail;
1833
1834 (void) sd_event_source_set_description(v->time_event_source, "varlink-time");
1835
1836 r = sd_event_add_exit(v->event, &v->quit_event_source, quit_callback, v);
1837 if (r < 0)
1838 goto fail;
1839
1840 r = sd_event_source_set_priority(v->quit_event_source, priority);
1841 if (r < 0)
1842 goto fail;
1843
1844 (void) sd_event_source_set_description(v->quit_event_source, "varlink-quit");
1845
1846 r = sd_event_add_io(v->event, &v->io_event_source, v->fd, 0, io_callback, v);
1847 if (r < 0)
1848 goto fail;
1849
1850 r = sd_event_source_set_prepare(v->io_event_source, prepare_callback);
1851 if (r < 0)
1852 goto fail;
1853
1854 r = sd_event_source_set_priority(v->io_event_source, priority);
1855 if (r < 0)
1856 goto fail;
1857
1858 (void) sd_event_source_set_description(v->io_event_source, "varlink-io");
1859
1860 r = sd_event_add_defer(v->event, &v->defer_event_source, defer_callback, v);
1861 if (r < 0)
1862 goto fail;
1863
1864 r = sd_event_source_set_priority(v->defer_event_source, priority);
1865 if (r < 0)
1866 goto fail;
1867
1868 (void) sd_event_source_set_description(v->defer_event_source, "varlink-defer");
1869
1870 return 0;
1871
1872 fail:
1873 varlink_detach_event(v);
1874 return r;
1875 }
1876
1877
1878 void varlink_detach_event(Varlink *v) {
1879 if (!v)
1880 return;
1881
1882 varlink_detach_event_sources(v);
1883
1884 v->event = sd_event_unref(v->event);
1885 }
1886
1887 sd_event *varlink_get_event(Varlink *v) {
1888 assert_return(v, NULL);
1889
1890 return v->event;
1891 }
1892
1893 int varlink_server_new(VarlinkServer **ret, VarlinkServerFlags flags) {
1894 VarlinkServer *s;
1895
1896 assert_return(ret, -EINVAL);
1897 assert_return((flags & ~_VARLINK_SERVER_FLAGS_ALL) == 0, -EINVAL);
1898
1899 s = new(VarlinkServer, 1);
1900 if (!s)
1901 return -ENOMEM;
1902
1903 *s = (VarlinkServer) {
1904 .n_ref = 1,
1905 .flags = flags,
1906 .connections_max = varlink_server_connections_max(NULL),
1907 .connections_per_uid_max = varlink_server_connections_per_uid_max(NULL),
1908 };
1909
1910 *ret = s;
1911 return 0;
1912 }
1913
1914 static VarlinkServer* varlink_server_destroy(VarlinkServer *s) {
1915 char *m;
1916
1917 if (!s)
1918 return NULL;
1919
1920 varlink_server_shutdown(s);
1921
1922 while ((m = hashmap_steal_first_key(s->methods)))
1923 free(m);
1924
1925 hashmap_free(s->methods);
1926 hashmap_free(s->by_uid);
1927
1928 sd_event_unref(s->event);
1929
1930 free(s->description);
1931
1932 return mfree(s);
1933 }
1934
1935 DEFINE_TRIVIAL_REF_UNREF_FUNC(VarlinkServer, varlink_server, varlink_server_destroy);
1936
1937 static int validate_connection(VarlinkServer *server, const struct ucred *ucred) {
1938 int allowed = -1;
1939
1940 assert(server);
1941 assert(ucred);
1942
1943 if (FLAGS_SET(server->flags, VARLINK_SERVER_ROOT_ONLY))
1944 allowed = ucred->uid == 0;
1945
1946 if (FLAGS_SET(server->flags, VARLINK_SERVER_MYSELF_ONLY))
1947 allowed = allowed > 0 || ucred->uid == getuid();
1948
1949 if (allowed == 0) { /* Allow access when it is explicitly allowed or when neither
1950 * VARLINK_SERVER_ROOT_ONLY nor VARLINK_SERVER_MYSELF_ONLY are specified. */
1951 varlink_server_log(server, "Unprivileged client attempted connection, refusing.");
1952 return 0;
1953 }
1954
1955 if (server->n_connections >= server->connections_max) {
1956 varlink_server_log(server, "Connection limit of %u reached, refusing.", server->connections_max);
1957 return 0;
1958 }
1959
1960 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
1961 unsigned c;
1962
1963 if (!uid_is_valid(ucred->uid)) {
1964 varlink_server_log(server, "Client with invalid UID attempted connection, refusing.");
1965 return 0;
1966 }
1967
1968 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
1969 if (c >= server->connections_per_uid_max) {
1970 varlink_server_log(server, "Per-UID connection limit of %u reached, refusing.",
1971 server->connections_per_uid_max);
1972 return 0;
1973 }
1974 }
1975
1976 return 1;
1977 }
1978
1979 static int count_connection(VarlinkServer *server, struct ucred *ucred) {
1980 unsigned c;
1981 int r;
1982
1983 assert(server);
1984 assert(ucred);
1985
1986 server->n_connections++;
1987
1988 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
1989 r = hashmap_ensure_allocated(&server->by_uid, NULL);
1990 if (r < 0)
1991 return log_debug_errno(r, "Failed to allocate UID hash table: %m");
1992
1993 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
1994
1995 varlink_server_log(server, "Connections of user " UID_FMT ": %u (of %u max)",
1996 ucred->uid, c, server->connections_per_uid_max);
1997
1998 r = hashmap_replace(server->by_uid, UID_TO_PTR(ucred->uid), UINT_TO_PTR(c + 1));
1999 if (r < 0)
2000 return log_debug_errno(r, "Failed to increment counter in UID hash table: %m");
2001 }
2002
2003 return 0;
2004 }
2005
2006 int varlink_server_add_connection(VarlinkServer *server, int fd, Varlink **ret) {
2007 _cleanup_(varlink_unrefp) Varlink *v = NULL;
2008 bool ucred_acquired;
2009 struct ucred ucred;
2010 int r;
2011
2012 assert_return(server, -EINVAL);
2013 assert_return(fd >= 0, -EBADF);
2014
2015 if ((server->flags & (VARLINK_SERVER_ROOT_ONLY|VARLINK_SERVER_ACCOUNT_UID)) != 0) {
2016 r = getpeercred(fd, &ucred);
2017 if (r < 0)
2018 return varlink_server_log_errno(server, r, "Failed to acquire peer credentials of incoming socket, refusing: %m");
2019
2020 ucred_acquired = true;
2021
2022 r = validate_connection(server, &ucred);
2023 if (r < 0)
2024 return r;
2025 if (r == 0)
2026 return -EPERM;
2027 } else
2028 ucred_acquired = false;
2029
2030 r = varlink_new(&v);
2031 if (r < 0)
2032 return varlink_server_log_errno(server, r, "Failed to allocate connection object: %m");
2033
2034 r = count_connection(server, &ucred);
2035 if (r < 0)
2036 return r;
2037
2038 v->fd = fd;
2039 v->userdata = server->userdata;
2040 if (ucred_acquired) {
2041 v->ucred = ucred;
2042 v->ucred_acquired = true;
2043 }
2044
2045 (void) asprintf(&v->description, "%s-%i", server->description ?: "varlink", v->fd);
2046
2047 /* Link up the server and the connection, and take reference in both directions. Note that the
2048 * reference on the connection is left dangling. It will be dropped when the connection is closed,
2049 * which happens in varlink_close(), including in the event loop quit callback. */
2050 v->server = varlink_server_ref(server);
2051 varlink_ref(v);
2052
2053 varlink_set_state(v, VARLINK_IDLE_SERVER);
2054
2055 r = varlink_attach_event(v, server->event, server->event_priority);
2056 if (r < 0) {
2057 varlink_log_errno(v, r, "Failed to attach new connection: %m");
2058 v->fd = -1; /* take the fd out of the connection again */
2059 varlink_close(v);
2060 return r;
2061 }
2062
2063 if (ret)
2064 *ret = v;
2065
2066 return 0;
2067 }
2068
2069 static int connect_callback(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
2070 VarlinkServerSocket *ss = userdata;
2071 _cleanup_close_ int cfd = -1;
2072 Varlink *v = NULL;
2073 int r;
2074
2075 assert(source);
2076 assert(ss);
2077
2078 varlink_server_log(ss->server, "New incoming connection.");
2079
2080 cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
2081 if (cfd < 0) {
2082 if (ERRNO_IS_ACCEPT_AGAIN(errno))
2083 return 0;
2084
2085 return varlink_server_log_errno(ss->server, errno, "Failed to accept incoming socket: %m");
2086 }
2087
2088 r = varlink_server_add_connection(ss->server, cfd, &v);
2089 if (r < 0)
2090 return 0;
2091
2092 TAKE_FD(cfd);
2093
2094 if (ss->server->connect_callback) {
2095 r = ss->server->connect_callback(ss->server, v, ss->server->userdata);
2096 if (r < 0) {
2097 varlink_log_errno(v, r, "Connection callback returned error, disconnecting client: %m");
2098 varlink_close(v);
2099 return 0;
2100 }
2101 }
2102
2103 return 0;
2104 }
2105
2106 int varlink_server_listen_fd(VarlinkServer *s, int fd) {
2107 _cleanup_free_ VarlinkServerSocket *ss = NULL;
2108 int r;
2109
2110 assert_return(s, -EINVAL);
2111 assert_return(fd >= 0, -EBADF);
2112
2113 r = fd_nonblock(fd, true);
2114 if (r < 0)
2115 return r;
2116
2117 ss = new(VarlinkServerSocket, 1);
2118 if (!ss)
2119 return -ENOMEM;
2120
2121 *ss = (VarlinkServerSocket) {
2122 .server = s,
2123 .fd = fd,
2124 };
2125
2126 if (s->event) {
2127 _cleanup_(sd_event_source_unrefp) sd_event_source *es = NULL;
2128
2129 r = sd_event_add_io(s->event, &es, fd, EPOLLIN, connect_callback, ss);
2130 if (r < 0)
2131 return r;
2132
2133 r = sd_event_source_set_priority(ss->event_source, s->event_priority);
2134 if (r < 0)
2135 return r;
2136 }
2137
2138 LIST_PREPEND(sockets, s->sockets, TAKE_PTR(ss));
2139 return 0;
2140 }
2141
2142 int varlink_server_listen_address(VarlinkServer *s, const char *address, mode_t m) {
2143 union sockaddr_union sockaddr;
2144 _cleanup_close_ int fd = -1;
2145 int r;
2146
2147 assert_return(s, -EINVAL);
2148 assert_return(address, -EINVAL);
2149 assert_return((m & ~0777) == 0, -EINVAL);
2150
2151 r = sockaddr_un_set_path(&sockaddr.un, address);
2152 if (r < 0)
2153 return r;
2154
2155 fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
2156 if (fd < 0)
2157 return -errno;
2158
2159 (void) sockaddr_un_unlink(&sockaddr.un);
2160
2161 RUN_WITH_UMASK(~m & 0777)
2162 if (bind(fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0)
2163 return -errno;
2164
2165 if (listen(fd, SOMAXCONN) < 0)
2166 return -errno;
2167
2168 r = varlink_server_listen_fd(s, fd);
2169 if (r < 0)
2170 return r;
2171
2172 TAKE_FD(fd);
2173 return 0;
2174 }
2175
2176 void* varlink_server_set_userdata(VarlinkServer *s, void *userdata) {
2177 void *ret;
2178
2179 assert_return(s, NULL);
2180
2181 ret = s->userdata;
2182 s->userdata = userdata;
2183
2184 return ret;
2185 }
2186
2187 void* varlink_server_get_userdata(VarlinkServer *s) {
2188 assert_return(s, NULL);
2189
2190 return s->userdata;
2191 }
2192
2193 static VarlinkServerSocket* varlink_server_socket_destroy(VarlinkServerSocket *ss) {
2194 if (!ss)
2195 return NULL;
2196
2197 if (ss->server)
2198 LIST_REMOVE(sockets, ss->server->sockets, ss);
2199
2200 sd_event_source_disable_unref(ss->event_source);
2201
2202 free(ss->address);
2203 safe_close(ss->fd);
2204
2205 return mfree(ss);
2206 }
2207
2208 int varlink_server_shutdown(VarlinkServer *s) {
2209 assert_return(s, -EINVAL);
2210
2211 while (s->sockets)
2212 varlink_server_socket_destroy(s->sockets);
2213
2214 return 0;
2215 }
2216
2217 int varlink_server_attach_event(VarlinkServer *s, sd_event *e, int64_t priority) {
2218 VarlinkServerSocket *ss;
2219 int r;
2220
2221 assert_return(s, -EINVAL);
2222 assert_return(!s->event, -EBUSY);
2223
2224 if (e)
2225 s->event = sd_event_ref(e);
2226 else {
2227 r = sd_event_default(&s->event);
2228 if (r < 0)
2229 return r;
2230 }
2231
2232 LIST_FOREACH(sockets, ss, s->sockets) {
2233 assert(!ss->event_source);
2234
2235 r = sd_event_add_io(s->event, &ss->event_source, ss->fd, EPOLLIN, connect_callback, ss);
2236 if (r < 0)
2237 goto fail;
2238
2239 r = sd_event_source_set_priority(ss->event_source, priority);
2240 if (r < 0)
2241 goto fail;
2242 }
2243
2244 s->event_priority = priority;
2245 return 0;
2246
2247 fail:
2248 varlink_server_detach_event(s);
2249 return r;
2250 }
2251
2252 int varlink_server_detach_event(VarlinkServer *s) {
2253 VarlinkServerSocket *ss;
2254
2255 assert_return(s, -EINVAL);
2256
2257 LIST_FOREACH(sockets, ss, s->sockets) {
2258
2259 if (!ss->event_source)
2260 continue;
2261
2262 (void) sd_event_source_set_enabled(ss->event_source, SD_EVENT_OFF);
2263 ss->event_source = sd_event_source_unref(ss->event_source);
2264 }
2265
2266 sd_event_unref(s->event);
2267 return 0;
2268 }
2269
2270 sd_event *varlink_server_get_event(VarlinkServer *s) {
2271 assert_return(s, NULL);
2272
2273 return s->event;
2274 }
2275
2276 int varlink_server_bind_method(VarlinkServer *s, const char *method, VarlinkMethod callback) {
2277 char *m;
2278 int r;
2279
2280 assert_return(s, -EINVAL);
2281 assert_return(method, -EINVAL);
2282 assert_return(callback, -EINVAL);
2283
2284 if (startswith(method, "org.varlink.service."))
2285 return -EEXIST;
2286
2287 r = hashmap_ensure_allocated(&s->methods, &string_hash_ops);
2288 if (r < 0)
2289 return r;
2290
2291 m = strdup(method);
2292 if (!m)
2293 return -ENOMEM;
2294
2295 r = hashmap_put(s->methods, m, callback);
2296 if (r < 0) {
2297 free(m);
2298 return r;
2299 }
2300
2301 return 0;
2302 }
2303
2304 int varlink_server_bind_method_many_internal(VarlinkServer *s, ...) {
2305 va_list ap;
2306 int r;
2307
2308 assert_return(s, -EINVAL);
2309
2310 va_start(ap, s);
2311 for (;;) {
2312 VarlinkMethod callback;
2313 const char *method;
2314
2315 method = va_arg(ap, const char *);
2316 if (!method)
2317 break;
2318
2319 callback = va_arg(ap, VarlinkMethod);
2320
2321 r = varlink_server_bind_method(s, method, callback);
2322 if (r < 0)
2323 return r;
2324 }
2325
2326 return 0;
2327 }
2328
2329 int varlink_server_bind_connect(VarlinkServer *s, VarlinkConnect callback) {
2330 assert_return(s, -EINVAL);
2331
2332 if (callback && s->connect_callback && callback != s->connect_callback)
2333 return -EBUSY;
2334
2335 s->connect_callback = callback;
2336 return 0;
2337 }
2338
2339 unsigned varlink_server_connections_max(VarlinkServer *s) {
2340 struct rlimit rl;
2341
2342 /* If a server is specified, return the setting for that server, otherwise the default value */
2343 if (s)
2344 return s->connections_max;
2345
2346 assert_se(getrlimit(RLIMIT_NOFILE, &rl) >= 0);
2347
2348 /* Make sure we never use up more than ¾th of RLIMIT_NOFILE for IPC */
2349 if (VARLINK_DEFAULT_CONNECTIONS_MAX > rl.rlim_cur / 4 * 3)
2350 return rl.rlim_cur / 4 * 3;
2351
2352 return VARLINK_DEFAULT_CONNECTIONS_MAX;
2353 }
2354
2355 unsigned varlink_server_connections_per_uid_max(VarlinkServer *s) {
2356 unsigned m;
2357
2358 if (s)
2359 return s->connections_per_uid_max;
2360
2361 /* Make sure to never use up more than ¾th of available connections for a single user */
2362 m = varlink_server_connections_max(NULL);
2363 if (VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX > m)
2364 return m / 4 * 3;
2365
2366 return VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX;
2367 }
2368
2369 int varlink_server_set_connections_per_uid_max(VarlinkServer *s, unsigned m) {
2370 assert_return(s, -EINVAL);
2371 assert_return(m > 0, -EINVAL);
2372
2373 s->connections_per_uid_max = m;
2374 return 0;
2375 }
2376
2377 int varlink_server_set_connections_max(VarlinkServer *s, unsigned m) {
2378 assert_return(s, -EINVAL);
2379 assert_return(m > 0, -EINVAL);
2380
2381 s->connections_max = m;
2382 return 0;
2383 }
2384
2385 int varlink_server_set_description(VarlinkServer *s, const char *description) {
2386 assert_return(s, -EINVAL);
2387
2388 return free_and_strdup(&s->description, description);
2389 }
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