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varlink: move connection fds > fd2
[thirdparty/systemd.git] / src / shared / varlink.c
CommitLineData
d41bd96f
LP		 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
28typedef enum VarlinkState {
29 /* Client side states */
30 VARLINK_IDLE_CLIENT,
31 VARLINK_AWAITING_REPLY,
45a6c965 32 VARLINK_AWAITING_REPLY_MORE,
d41bd96f
LP		 33 VARLINK_CALLING,
34 VARLINK_CALLED,
35 VARLINK_PROCESSING_REPLY,
36
37 /* Server side states */
38 VARLINK_IDLE_SERVER,
39 VARLINK_PROCESSING_METHOD,
40 VARLINK_PROCESSING_METHOD_MORE,
41 VARLINK_PROCESSING_METHOD_ONEWAY,
42 VARLINK_PROCESSED_METHOD,
d41bd96f
LP		 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, \
45a6c965 66 VARLINK_AWAITING_REPLY_MORE, \
d41bd96f
LP		 67 VARLINK_CALLING, \
68 VARLINK_CALLED, \
69 VARLINK_PROCESSING_REPLY, \
70 VARLINK_IDLE_SERVER, \
71 VARLINK_PROCESSING_METHOD, \
72 VARLINK_PROCESSING_METHOD_MORE, \
73 VARLINK_PROCESSING_METHOD_ONEWAY, \
74 VARLINK_PROCESSED_METHOD, \
d41bd96f
LP		 75 VARLINK_PENDING_METHOD, \
76 VARLINK_PENDING_METHOD_MORE)
77
78struct 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
150typedef struct VarlinkServerSocket VarlinkServerSocket;
151
152struct 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
163struct 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
185static const char* const varlink_state_table[_VARLINK_STATE_MAX] = {
186 [VARLINK_IDLE_CLIENT] = "idle-client",
187 [VARLINK_AWAITING_REPLY] = "awaiting-reply",
45a6c965 188 [VARLINK_AWAITING_REPLY_MORE] = "awaiting-reply-more",
d41bd96f
LP		 189 [VARLINK_CALLING] = "calling",
190 [VARLINK_CALLED] = "called",
191 [VARLINK_PROCESSING_REPLY] = "processing-reply",
192 [VARLINK_IDLE_SERVER] = "idle-server",
193 [VARLINK_PROCESSING_METHOD] = "processing-method",
194 [VARLINK_PROCESSING_METHOD_MORE] = "processing-method-more",
195 [VARLINK_PROCESSING_METHOD_ONEWAY] = "processing-method-oneway",
196 [VARLINK_PROCESSED_METHOD] = "processed-method",
d41bd96f
LP		 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
207DEFINE_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
221static inline const char *varlink_description(Varlink *v) {
222 return strna(v ? v->description : NULL);
223}
224
225static inline const char *varlink_server_description(VarlinkServer *s) {
226 return strna(s ? s->description : NULL);
227}
228
229static void varlink_set_state(Varlink *v, VarlinkState state) {
230 assert(v);
77740b59
ZJS		 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));
d41bd96f
LP		 240
241 v->state = state;
242}
243
244static int varlink_new(Varlink **ret) {
245 Varlink *v;
246
247 assert(ret);
248
a48481dc 249 v = new(Varlink, 1);
d41bd96f
LP		 250 if (!v)
251 return -ENOMEM;
252
253 *v = (Varlink) {
254 .n_ref = 1,
255 .fd = -1,
256
257 .state = _VARLINK_STATE_INVALID,
258
259 .ucred.uid = UID_INVALID,
260 .ucred.gid = GID_INVALID,
261
262 .timestamp = USEC_INFINITY,
263 .timeout = VARLINK_DEFAULT_TIMEOUT_USEC
264 };
265
266 *ret = v;
267 return 0;
268}
269
270int varlink_connect_address(Varlink **ret, const char *address) {
271 _cleanup_(varlink_unrefp) Varlink *v = NULL;
272 union sockaddr_union sockaddr;
273 int r;
274
275 assert_return(ret, -EINVAL);
276 assert_return(address, -EINVAL);
277
278 r = sockaddr_un_set_path(&sockaddr.un, address);
279 if (r < 0)
280 return r;
281
282 r = varlink_new(&v);
283 if (r < 0)
284 return r;
285
286 v->fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
287 if (v->fd < 0)
288 return -errno;
289
a0c41de2
LP		 290 v->fd = fd_move_above_stdio(v->fd);
291
d41bd96f
LP		 292 if (connect(v->fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0) {
293 if (!IN_SET(errno, EAGAIN, EINPROGRESS))
294 return -errno;
295
296 v->connecting = true; /* We are asynchronously connecting, i.e. the connect() is being
297 * processed in the background. As long as that's the case the socket
298 * is in a special state: it's there, we can poll it for EPOLLOUT, but
299 * if we attempt to write() to it before we see EPOLLOUT we'll get
300 * ENOTCONN (and not EAGAIN, like we would for a normal connected
301 * socket that isn't writable at the moment). Since ENOTCONN on write()
302 * hence can mean two different things (i.e. connection not complete
303 * yet vs. already disconnected again), we store as a boolean whether
304 * we are still in connect(). */
305 }
306
307 varlink_set_state(v, VARLINK_IDLE_CLIENT);
308
309 *ret = TAKE_PTR(v);
310 return r;
311}
312
313int varlink_connect_fd(Varlink **ret, int fd) {
314 Varlink *v;
315 int r;
316
317 assert_return(ret, -EINVAL);
318 assert_return(fd >= 0, -EBADF);
319
320 r = fd_nonblock(fd, true);
321 if (r < 0)
322 return r;
323
324 r = varlink_new(&v);
325 if (r < 0)
326 return r;
327
328 v->fd = fd;
329 varlink_set_state(v, VARLINK_IDLE_CLIENT);
330
331 /* Note that if this function is called we assume the passed socket (if it is one) is already
332 * properly connected, i.e. any asynchronous connect() done on it already completed. Because of that
333 * we'll not set the 'connecting' boolean here, i.e. we don't need to avoid write()ing to the socket
334 * until the connection is fully set up. Behaviour here is hence a bit different from
335 * varlink_connect_address() above, as there we do handle asynchronous connections ourselves and
336 * avoid doing write() on it before we saw EPOLLOUT for the first time. */
337
338 *ret = v;
339 return 0;
340}
341
342static void varlink_detach_event_sources(Varlink *v) {
343 assert(v);
344
1d3fe304 345 v->io_event_source = sd_event_source_disable_unref(v->io_event_source);
d41bd96f 346
1d3fe304 347 v->time_event_source = sd_event_source_disable_unref(v->time_event_source);
d41bd96f 348
1d3fe304 349 v->quit_event_source = sd_event_source_disable_unref(v->quit_event_source);
d41bd96f 350
1d3fe304 351 v->defer_event_source = sd_event_source_disable_unref(v->defer_event_source);
d41bd96f
LP		 352}
353
354static void varlink_clear(Varlink *v) {
355 assert(v);
356
357 varlink_detach_event_sources(v);
358
359 v->fd = safe_close(v->fd);
360
361 v->input_buffer = mfree(v->input_buffer);
362 v->output_buffer = mfree(v->output_buffer);
363
364 v->current = json_variant_unref(v->current);
365 v->reply = json_variant_unref(v->reply);
366
367 v->event = sd_event_unref(v->event);
368}
369
370static Varlink* varlink_destroy(Varlink *v) {
371 if (!v)
372 return NULL;
373
374 /* If this is called the server object must already been unreffed here. Why that? because when we
375 * linked up the varlink connection with the server object we took one ref in each direction */
376 assert(!v->server);
377
378 varlink_clear(v);
379
380 free(v->description);
381 return mfree(v);
382}
383
384DEFINE_TRIVIAL_REF_UNREF_FUNC(Varlink, varlink, varlink_destroy);
385
386static int varlink_test_disconnect(Varlink *v) {
387 assert(v);
388
389 /* Tests whether we the the connection has been terminated. We are careful to not stop processing it
390 * prematurely, since we want to handle half-open connections as well as possible and want to flush
391 * out and read data before we close down if we can. */
392
393 /* Already disconnected? */
394 if (!VARLINK_STATE_IS_ALIVE(v->state))
395 return 0;
396
397 /* Wait until connection setup is complete, i.e. until asynchronous connect() completes */
398 if (v->connecting)
399 return 0;
400
401 /* Still something to write and we can write? Stay around */
402 if (v->output_buffer_size > 0 && !v->write_disconnected)
403 return 0;
404
405 /* Both sides gone already? Then there's no need to stick around */
406 if (v->read_disconnected && v->write_disconnected)
407 goto disconnect;
408
409 /* If we are waiting for incoming data but the read side is shut down, disconnect. */
45a6c965 410 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) && v->read_disconnected)
d41bd96f
LP		 411 goto disconnect;
412
413 /* Similar, if are a client that hasn't written anything yet but the write side is dead, also
414 * disconnect. We also explicitly check for POLLHUP here since we likely won't notice the write side
415 * being down if we never wrote anything. */
416 if (IN_SET(v->state, VARLINK_IDLE_CLIENT) && (v->write_disconnected || v->got_pollhup))
417 goto disconnect;
418
419 return 0;
420
421disconnect:
422 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
423 return 1;
424}
425
426static int varlink_write(Varlink *v) {
427 ssize_t n;
428
429 assert(v);
430
431 if (!VARLINK_STATE_IS_ALIVE(v->state))
432 return 0;
433 if (v->connecting) /* Writing while we are still wait for a non-blocking connect() to complete will
434 * result in ENOTCONN, hence exit early here */
435 return 0;
436 if (v->output_buffer_size == 0)
437 return 0;
438 if (v->write_disconnected)
439 return 0;
440
441 assert(v->fd >= 0);
442
443 /* We generally prefer recv()/send() (mostly because of MSG_NOSIGNAL) but also want to be compatible
444 * with non-socket IO, hence fall back automatically */
445 if (!v->prefer_read_write) {
446 n = send(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size, MSG_DONTWAIT|MSG_NOSIGNAL);
447 if (n < 0 && errno == ENOTSOCK)
448 v->prefer_read_write = true;
449 }
450 if (v->prefer_read_write)
451 n = write(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size);
452 if (n < 0) {
453 if (errno == EAGAIN)
454 return 0;
455
456 if (ERRNO_IS_DISCONNECT(errno)) {
457 /* If we get informed about a disconnect on write, then let's remember that, but not
458 * act on it just yet. Let's wait for read() to report the issue first. */
459 v->write_disconnected = true;
460 return 1;
461 }
462
463 return -errno;
464 }
465
466 v->output_buffer_size -= n;
467
468 if (v->output_buffer_size == 0)
469 v->output_buffer_index = 0;
470 else
471 v->output_buffer_index += n;
472
473 v->timestamp = now(CLOCK_MONOTONIC);
474 return 1;
475}
476
477static int varlink_read(Varlink *v) {
478 size_t rs;
479 ssize_t n;
480
481 assert(v);
482
45a6c965 483 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER))
d41bd96f
LP		 484 return 0;
485 if (v->connecting) /* read() on a socket while we are in connect() will fail with EINVAL, hence exit early here */
486 return 0;
487 if (v->current)
488 return 0;
489 if (v->input_buffer_unscanned > 0)
490 return 0;
491 if (v->read_disconnected)
492 return 0;
493
494 if (v->input_buffer_size >= VARLINK_BUFFER_MAX)
495 return -ENOBUFS;
496
497 assert(v->fd >= 0);
498
499 if (v->input_buffer_allocated <= v->input_buffer_index + v->input_buffer_size) {
500 size_t add;
501
502 add = MIN(VARLINK_BUFFER_MAX - v->input_buffer_size, VARLINK_READ_SIZE);
503
504 if (v->input_buffer_index == 0) {
505
506 if (!GREEDY_REALLOC(v->input_buffer, v->input_buffer_allocated, v->input_buffer_size + add))
507 return -ENOMEM;
508
509 } else {
510 char *b;
511
512 b = new(char, v->input_buffer_size + add);
513 if (!b)
514 return -ENOMEM;
515
516 memcpy(b, v->input_buffer + v->input_buffer_index, v->input_buffer_size);
517
518 free_and_replace(v->input_buffer, b);
519
520 v->input_buffer_allocated = v->input_buffer_size + add;
521 v->input_buffer_index = 0;
522 }
523 }
524
525 rs = v->input_buffer_allocated - (v->input_buffer_index + v->input_buffer_size);
526
527 if (!v->prefer_read_write) {
528 n = recv(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs, MSG_DONTWAIT);
529 if (n < 0 && errno == ENOTSOCK)
530 v->prefer_read_write = true;
531 }
532 if (v->prefer_read_write)
533 n = read(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs);
534 if (n < 0) {
535 if (errno == EAGAIN)
536 return 0;
537
538 if (ERRNO_IS_DISCONNECT(errno)) {
539 v->read_disconnected = true;
540 return 1;
541 }
542
543 return -errno;
544 }
545 if (n == 0) { /* EOF */
546 v->read_disconnected = true;
547 return 1;
548 }
549
550 v->input_buffer_size += n;
551 v->input_buffer_unscanned += n;
552
553 return 1;
554}
555
556static int varlink_parse_message(Varlink *v) {
557 const char *e, *begin;
558 size_t sz;
559 int r;
560
561 assert(v);
562
563 if (v->current)
564 return 0;
565 if (v->input_buffer_unscanned <= 0)
566 return 0;
567
568 assert(v->input_buffer_unscanned <= v->input_buffer_size);
569 assert(v->input_buffer_index + v->input_buffer_size <= v->input_buffer_allocated);
570
571 begin = v->input_buffer + v->input_buffer_index;
572
573 e = memchr(begin + v->input_buffer_size - v->input_buffer_unscanned, 0, v->input_buffer_unscanned);
574 if (!e) {
575 v->input_buffer_unscanned = 0;
576 return 0;
577 }
578
579 sz = e - begin + 1;
580
581 varlink_log(v, "New incoming message: %s", begin);
582
583 r = json_parse(begin, &v->current, NULL, NULL);
584 if (r < 0)
585 return r;
586
587 v->input_buffer_size -= sz;
588
589 if (v->input_buffer_size == 0)
590 v->input_buffer_index = 0;
591 else
592 v->input_buffer_index += sz;
593
594 v->input_buffer_unscanned = v->input_buffer_size;
595 return 1;
596}
597
598static int varlink_test_timeout(Varlink *v) {
599 assert(v);
600
45a6c965 601 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING))
d41bd96f
LP		 602 return 0;
603 if (v->timeout == USEC_INFINITY)
604 return 0;
605
606 if (now(CLOCK_MONOTONIC) < usec_add(v->timestamp, v->timeout))
607 return 0;
608
609 varlink_set_state(v, VARLINK_PENDING_TIMEOUT);
610
611 return 1;
612}
613
614static int varlink_dispatch_local_error(Varlink *v, const char *error) {
615 int r;
616
617 assert(v);
618 assert(error);
619
620 if (!v->reply_callback)
621 return 0;
622
623 r = v->reply_callback(v, NULL, error, VARLINK_REPLY_ERROR|VARLINK_REPLY_LOCAL, v->userdata);
624 if (r < 0)
625 log_debug_errno(r, "Reply callback returned error, ignoring: %m");
626
627 return 1;
628}
629
630static int varlink_dispatch_timeout(Varlink *v) {
631 assert(v);
632
633 if (v->state != VARLINK_PENDING_TIMEOUT)
634 return 0;
635
636 varlink_set_state(v, VARLINK_PROCESSING_TIMEOUT);
637 varlink_dispatch_local_error(v, VARLINK_ERROR_TIMEOUT);
638 varlink_close(v);
639
640 return 1;
641}
642
643static int varlink_dispatch_disconnect(Varlink *v) {
644 assert(v);
645
646 if (v->state != VARLINK_PENDING_DISCONNECT)
647 return 0;
648
649 varlink_set_state(v, VARLINK_PROCESSING_DISCONNECT);
650 varlink_dispatch_local_error(v, VARLINK_ERROR_DISCONNECTED);
651 varlink_close(v);
652
653 return 1;
654}
655
656static int varlink_sanitize_parameters(JsonVariant **v) {
657 assert(v);
658
659 /* Varlink always wants a parameters list, hence make one if the caller doesn't want any */
660 if (!*v)
661 return json_variant_new_object(v, NULL, 0);
662 else if (!json_variant_is_object(*v))
663 return -EINVAL;
664
665 return 0;
666}
667
668static int varlink_dispatch_reply(Varlink *v) {
669 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
670 VarlinkReplyFlags flags = 0;
671 const char *error = NULL;
672 JsonVariant *e;
673 const char *k;
674 int r;
675
676 assert(v);
677
45a6c965 678 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING))
d41bd96f
LP		 679 return 0;
680 if (!v->current)
681 return 0;
682
683 assert(v->n_pending > 0);
684
685 if (!json_variant_is_object(v->current))
686 goto invalid;
687
688 JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
689
690 if (streq(k, "error")) {
691 if (error)
692 goto invalid;
693 if (!json_variant_is_string(e))
694 goto invalid;
695
696 error = json_variant_string(e);
697 flags |= VARLINK_REPLY_ERROR;
698
699 } else if (streq(k, "parameters")) {
700 if (parameters)
701 goto invalid;
702 if (!json_variant_is_object(e))
703 goto invalid;
704
705 parameters = json_variant_ref(e);
706
707 } else if (streq(k, "continues")) {
708 if (FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
709 goto invalid;
710
711 if (!json_variant_is_boolean(e))
712 goto invalid;
713
714 if (json_variant_boolean(e))
715 flags |= VARLINK_REPLY_CONTINUES;
716 } else
717 goto invalid;
718 }
719
45a6c965
LP		 720 /* Replies with 'continue' set are only OK if we set 'more' when the method call was initiated */
721 if (v->state != VARLINK_AWAITING_REPLY_MORE && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
722 goto invalid;
723
724 /* An error is final */
d41bd96f
LP		 725 if (error && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
726 goto invalid;
727
728 r = varlink_sanitize_parameters(&parameters);
729 if (r < 0)
730 goto invalid;
731
45a6c965 732 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE)) {
d41bd96f
LP		 733 varlink_set_state(v, VARLINK_PROCESSING_REPLY);
734
735 if (v->reply_callback) {
736 r = v->reply_callback(v, parameters, error, flags, v->userdata);
737 if (r < 0)
738 log_debug_errno(r, "Reply callback returned error, ignoring: %m");
739 }
740
741 v->current = json_variant_unref(v->current);
742
743 if (v->state == VARLINK_PROCESSING_REPLY) {
45a6c965 744
d41bd96f 745 assert(v->n_pending > 0);
d41bd96f 746
45a6c965
LP		 747 if (!FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
748 v->n_pending--;
749
750 varlink_set_state(v,
751 FLAGS_SET(flags, VARLINK_REPLY_CONTINUES) ? VARLINK_AWAITING_REPLY_MORE :
752 v->n_pending == 0 ? VARLINK_IDLE_CLIENT : VARLINK_AWAITING_REPLY);
d41bd96f
LP		 753 }
754 } else {
755 assert(v->state == VARLINK_CALLING);
d41bd96f
LP		 756 varlink_set_state(v, VARLINK_CALLED);
757 }
758
759 return 1;
760
761invalid:
762 varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
763 varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
764 varlink_close(v);
765
766 return 1;
767}
768
769static int varlink_dispatch_method(Varlink *v) {
770 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
771 VarlinkMethodFlags flags = 0;
772 const char *method = NULL, *error;
773 JsonVariant *e;
774 VarlinkMethod callback;
775 const char *k;
776 int r;
777
778 assert(v);
779
780 if (v->state != VARLINK_IDLE_SERVER)
781 return 0;
782 if (!v->current)
783 return 0;
784
785 if (!json_variant_is_object(v->current))
786 goto invalid;
787
788 JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
789
790 if (streq(k, "method")) {
791 if (method)
792 goto invalid;
793 if (!json_variant_is_string(e))
794 goto invalid;
795
796 method = json_variant_string(e);
797
798 } else if (streq(k, "parameters")) {
799 if (parameters)
800 goto invalid;
801 if (!json_variant_is_object(e))
802 goto invalid;
803
804 parameters = json_variant_ref(e);
805
806 } else if (streq(k, "oneway")) {
807
808 if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
809 goto invalid;
810
811 if (!json_variant_is_boolean(e))
812 goto invalid;
813
814 if (json_variant_boolean(e))
815 flags |= VARLINK_METHOD_ONEWAY;
816
817 } else if (streq(k, "more")) {
818
819 if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
820 goto invalid;
821
822 if (!json_variant_is_boolean(e))
823 goto invalid;
824
825 if (json_variant_boolean(e))
826 flags |= VARLINK_METHOD_MORE;
827
828 } else
829 goto invalid;
830 }
831
832 if (!method)
833 goto invalid;
834
835 r = varlink_sanitize_parameters(&parameters);
836 if (r < 0)
837 goto fail;
838
839 varlink_set_state(v, (flags & VARLINK_METHOD_MORE) ? VARLINK_PROCESSING_METHOD_MORE :
840 (flags & VARLINK_METHOD_ONEWAY) ? VARLINK_PROCESSING_METHOD_ONEWAY :
841 VARLINK_PROCESSING_METHOD);
842
843 assert(v->server);
844
845 if (STR_IN_SET(method, "org.varlink.service.GetInfo", "org.varlink.service.GetInterface")) {
846 /* For now, we don't implement a single of varlink's own methods */
847 callback = NULL;
848 error = VARLINK_ERROR_METHOD_NOT_IMPLEMENTED;
849 } else if (startswith(method, "org.varlink.service.")) {
850 callback = NULL;
851 error = VARLINK_ERROR_METHOD_NOT_FOUND;
852 } else {
853 callback = hashmap_get(v->server->methods, method);
854 error = VARLINK_ERROR_METHOD_NOT_FOUND;
855 }
856
857 if (callback) {
858 r = callback(v, parameters, flags, v->userdata);
859 if (r < 0) {
860 log_debug_errno(r, "Callback for %s returned error: %m", method);
861
862 /* We got an error back from the callback. Propagate it to the client if the method call remains unanswered. */
863 if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
864 r = varlink_errorb(v, VARLINK_ERROR_SYSTEM, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("errno", JSON_BUILD_INTEGER(-r))));
865 if (r < 0)
866 return r;
867 }
868 }
869 } else if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
870 assert(error);
871
872 r = varlink_errorb(v, error, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method))));
873 if (r < 0)
874 return r;
875 }
876
877 switch (v->state) {
878
879 case VARLINK_PROCESSED_METHOD: /* Method call is fully processed */
880 case VARLINK_PROCESSING_METHOD_ONEWAY: /* ditto */
881 v->current = json_variant_unref(v->current);
882 varlink_set_state(v, VARLINK_IDLE_SERVER);
883 break;
884
885 case VARLINK_PROCESSING_METHOD: /* Method call wasn't replied to, will be replied to later */
886 varlink_set_state(v, VARLINK_PENDING_METHOD);
887 break;
888
d41bd96f
LP		 889 case VARLINK_PROCESSING_METHOD_MORE: /* No reply for a "more" message was sent, more to come */
890 varlink_set_state(v, VARLINK_PENDING_METHOD_MORE);
891 break;
892
893 default:
894 assert_not_reached("Unexpected state");
895
896 }
897
898 return r;
899
900invalid:
901 r = -EINVAL;
902
903fail:
904 varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
905 varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
906 varlink_close(v);
907
908 return r;
909}
910
911int varlink_process(Varlink *v) {
912 int r;
913
914 assert_return(v, -EINVAL);
915
916 if (v->state == VARLINK_DISCONNECTED)
917 return -ENOTCONN;
918
919 varlink_ref(v);
920
921 r = varlink_write(v);
922 if (r != 0)
923 goto finish;
924
925 r = varlink_dispatch_reply(v);
926 if (r != 0)
927 goto finish;
928
929 r = varlink_dispatch_method(v);
930 if (r != 0)
931 goto finish;
932
933 r = varlink_parse_message(v);
934 if (r != 0)
935 goto finish;
936
937 r = varlink_read(v);
938 if (r != 0)
939 goto finish;
940
941 r = varlink_test_disconnect(v);
942 if (r != 0)
943 goto finish;
944
945 r = varlink_dispatch_disconnect(v);
946 if (r != 0)
947 goto finish;
948
949 r = varlink_test_timeout(v);
950 if (r != 0)
951 goto finish;
952
953 r = varlink_dispatch_timeout(v);
954 if (r != 0)
955 goto finish;
956
957finish:
958 if (r >= 0 && v->defer_event_source) {
959 int q;
960
961 /* If we did some processing, make sure we are called again soon */
962 q = sd_event_source_set_enabled(v->defer_event_source, r > 0 ? SD_EVENT_ON : SD_EVENT_OFF);
963 if (q < 0)
964 r = q;
965 }
966
967 if (r < 0) {
968 if (VARLINK_STATE_IS_ALIVE(v->state))
969 /* Initiate disconnection */
970 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
971 else
972 /* We failed while disconnecting, in that case close right away */
973 varlink_close(v);
974 }
975
976 varlink_unref(v);
977 return r;
978}
979
980static void handle_revents(Varlink *v, int revents) {
981 assert(v);
982
983 if (v->connecting) {
984 /* If we have seen POLLOUT or POLLHUP on a socket we are asynchronously waiting a connect()
985 * to complete on, we know we are ready. We don't read the connection error here though,
986 * we'll get the error on the next read() or write(). */
987 if ((revents & (POLLOUT|POLLHUP)) == 0)
988 return;
989
990 varlink_log(v, "Anynchronous connection completed.");
991 v->connecting = false;
992 } else {
993 /* Note that we don't care much about POLLIN/POLLOUT here, we'll just try reading and writing
994 * what we can. However, we do care about POLLHUP to detect connection termination even if we
995 * momentarily don't want to read nor write anything. */
996
997 if (!FLAGS_SET(revents, POLLHUP))
998 return;
999
1000 varlink_log(v, "Got POLLHUP from socket.");
1001 v->got_pollhup = true;
1002 }
1003}
1004
1005int varlink_wait(Varlink *v, usec_t timeout) {
1006 struct timespec ts;
1007 struct pollfd pfd;
1008 int r, fd, events;
1009 usec_t t;
1010
1011 assert_return(v, -EINVAL);
d41bd96f
LP		 1012
1013 if (v->state == VARLINK_DISCONNECTED)
1014 return -ENOTCONN;
1015
1016 r = varlink_get_timeout(v, &t);
1017 if (r < 0)
1018 return r;
1019 if (t != USEC_INFINITY) {
1020 usec_t n;
1021
1022 n = now(CLOCK_MONOTONIC);
1023 if (t < n)
1024 t = 0;
1025 else
1026 t = usec_sub_unsigned(t, n);
1027 }
1028
1029 if (timeout != USEC_INFINITY &&
1030 (t == USEC_INFINITY || timeout < t))
1031 t = timeout;
1032
1033 fd = varlink_get_fd(v);
1034 if (fd < 0)
1035 return fd;
1036
1037 events = varlink_get_events(v);
1038 if (events < 0)
1039 return events;
1040
1041 pfd = (struct pollfd) {
1042 .fd = fd,
1043 .events = events,
1044 };
1045
1046 r = ppoll(&pfd, 1,
1047 t == USEC_INFINITY ? NULL : timespec_store(&ts, t),
1048 NULL);
1049 if (r < 0)
1050 return -errno;
1051
1052 handle_revents(v, pfd.revents);
1053
1054 return r > 0 ? 1 : 0;
1055}
1056
1057int varlink_get_fd(Varlink *v) {
1058
1059 assert_return(v, -EINVAL);
1060
1061 if (v->state == VARLINK_DISCONNECTED)
1062 return -ENOTCONN;
1063 if (v->fd < 0)
1064 return -EBADF;
1065
1066 return v->fd;
1067}
1068
1069int varlink_get_events(Varlink *v) {
1070 int ret = 0;
1071
1072 assert_return(v, -EINVAL);
1073
1074 if (v->state == VARLINK_DISCONNECTED)
1075 return -ENOTCONN;
1076
1077 if (v->connecting) /* When processing an asynchronous connect(), we only wait for EPOLLOUT, which
1078 * tells us that the connection is now complete. Before that we should neither
1079 * write() or read() from the fd. */
1080 return EPOLLOUT;
1081
1082 if (!v->read_disconnected &&
45a6c965 1083 IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) &&
d41bd96f
LP		 1084 !v->current &&
1085 v->input_buffer_unscanned <= 0)
1086 ret |= EPOLLIN;
1087
1088 if (!v->write_disconnected &&
1089 v->output_buffer_size > 0)
1090 ret |= EPOLLOUT;
1091
1092 return ret;
1093}
1094
1095int varlink_get_timeout(Varlink *v, usec_t *ret) {
1096 assert_return(v, -EINVAL);
1097
1098 if (v->state == VARLINK_DISCONNECTED)
1099 return -ENOTCONN;
1100
45a6c965 1101 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING) &&
d41bd96f
LP		 1102 v->timeout != USEC_INFINITY) {
1103 if (ret)
1104 *ret = usec_add(v->timestamp, v->timeout);
1105 return 1;
1106 } else {
1107 if (ret)
1108 *ret = USEC_INFINITY;
1109 return 0;
1110 }
1111}
1112
1113int varlink_flush(Varlink *v) {
1114 int ret = 0, r;
1115
1116 assert_return(v, -EINVAL);
1117
1118 if (v->state == VARLINK_DISCONNECTED)
1119 return -ENOTCONN;
1120
1121 for (;;) {
1122 struct pollfd pfd;
1123
1124 if (v->output_buffer_size == 0)
1125 break;
1126 if (v->write_disconnected)
1127 return -ECONNRESET;
1128
1129 r = varlink_write(v);
1130 if (r < 0)
1131 return r;
1132 if (r > 0) {
1133 ret = 1;
1134 continue;
1135 }
1136
1137 pfd = (struct pollfd) {
1138 .fd = v->fd,
1139 .events = POLLOUT,
1140 };
1141
1142 if (poll(&pfd, 1, -1) < 0)
1143 return -errno;
1144
1145 handle_revents(v, pfd.revents);
1146 }
1147
1148 return ret;
1149}
1150
1151static void varlink_detach_server(Varlink *v) {
1152 assert(v);
1153
1154 if (!v->server)
1155 return;
1156
1157 if (v->server->by_uid &&
1158 v->ucred_acquired &&
1159 uid_is_valid(v->ucred.uid)) {
1160 unsigned c;
1161
1162 c = PTR_TO_UINT(hashmap_get(v->server->by_uid, UID_TO_PTR(v->ucred.uid)));
1163 assert(c > 0);
1164
1165 if (c == 1)
1166 (void) hashmap_remove(v->server->by_uid, UID_TO_PTR(v->ucred.uid));
1167 else
1168 (void) hashmap_replace(v->server->by_uid, UID_TO_PTR(v->ucred.uid), UINT_TO_PTR(c - 1));
1169 }
1170
1171 assert(v->server->n_connections > 0);
1172 v->server->n_connections--;
1173
1174 /* If this is a connection associated to a server, then let's disconnect the server and the
1175 * connection from each other. This drops the dangling reference that connect_callback() set up. */
1176 v->server = varlink_server_unref(v->server);
1177 varlink_unref(v);
1178}
1179
1180int varlink_close(Varlink *v) {
1181
1182 assert_return(v, -EINVAL);
1183
1184 if (v->state == VARLINK_DISCONNECTED)
1185 return 0;
1186
1187 varlink_set_state(v, VARLINK_DISCONNECTED);
1188
1189 /* Let's take a reference first, since varlink_detach_server() might drop the final (dangling) ref
1190 * which would destroy us before we can call varlink_clear() */
1191 varlink_ref(v);
1192 varlink_detach_server(v);
1193 varlink_clear(v);
1194 varlink_unref(v);
1195
1196 return 1;
1197}
1198
1199Varlink* varlink_flush_close_unref(Varlink *v) {
1200
1201 if (!v)
1202 return NULL;
1203
1204 (void) varlink_flush(v);
1205 (void) varlink_close(v);
1206
1207 return varlink_unref(v);
1208}
1209
1210static int varlink_enqueue_json(Varlink *v, JsonVariant *m) {
1211 _cleanup_free_ char *text = NULL;
1212 int r;
1213
1214 assert(v);
1215 assert(m);
1216
1217 r = json_variant_format(m, 0, &text);
1218 if (r < 0)
1219 return r;
2a04712c 1220 assert(text[r] == '\0');
d41bd96f
LP		 1221
1222 if (v->output_buffer_size + r + 1 > VARLINK_BUFFER_MAX)
1223 return -ENOBUFS;
1224
1225 varlink_log(v, "Sending message: %s", text);
1226
1227 if (v->output_buffer_size == 0) {
1228
1229 free_and_replace(v->output_buffer, text);
1230
1231 v->output_buffer_size = v->output_buffer_allocated = r + 1;
1232 v->output_buffer_index = 0;
1233
1234 } else if (v->output_buffer_index == 0) {
1235
1236 if (!GREEDY_REALLOC(v->output_buffer, v->output_buffer_allocated, v->output_buffer_size + r + 1))
1237 return -ENOMEM;
1238
1239 memcpy(v->output_buffer + v->output_buffer_size, text, r + 1);
1240 v->output_buffer_size += r + 1;
1241
1242 } else {
1243 char *n;
be44e091 1244 const size_t new_size = v->output_buffer_size + r + 1;
d41bd96f 1245
be44e091 1246 n = new(char, new_size);
d41bd96f
LP		 1247 if (!n)
1248 return -ENOMEM;
1249
1250 memcpy(mempcpy(n, v->output_buffer + v->output_buffer_index, v->output_buffer_size), text, r + 1);
1251
1252 free_and_replace(v->output_buffer, n);
be44e091 1253 v->output_buffer_allocated = v->output_buffer_size = new_size;
d41bd96f
LP		 1254 v->output_buffer_index = 0;
1255 }
1256
1257 return 0;
1258}
1259
1260int varlink_send(Varlink *v, const char *method, JsonVariant *parameters) {
1261 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1262 int r;
1263
1264 assert_return(v, -EINVAL);
1265 assert_return(method, -EINVAL);
1266
1267 if (v->state == VARLINK_DISCONNECTED)
1268 return -ENOTCONN;
45a6c965
LP		 1269
1270 /* We allow enqueuing multiple method calls at once! */
d41bd96f
LP		 1271 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1272 return -EBUSY;
1273
1274 r = varlink_sanitize_parameters(&parameters);
1275 if (r < 0)
1276 return r;
1277
1278 r = json_build(&m, JSON_BUILD_OBJECT(
1279 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1280 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1281 JSON_BUILD_PAIR("oneway", JSON_BUILD_BOOLEAN(true))));
1282 if (r < 0)
1283 return r;
1284
1285 r = varlink_enqueue_json(v, m);
1286 if (r < 0)
1287 return r;
1288
1289 /* No state change here, this is one-way only after all */
1290 v->timestamp = now(CLOCK_MONOTONIC);
1291 return 0;
1292}
1293
1294int varlink_sendb(Varlink *v, const char *method, ...) {
1295 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1296 va_list ap;
1297 int r;
1298
1299 assert_return(v, -EINVAL);
1300
1301 va_start(ap, method);
1302 r = json_buildv(&parameters, ap);
1303 va_end(ap);
1304
1305 if (r < 0)
1306 return r;
1307
1308 return varlink_send(v, method, parameters);
1309}
1310
1311int varlink_invoke(Varlink *v, const char *method, JsonVariant *parameters) {
1312 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1313 int r;
1314
1315 assert_return(v, -EINVAL);
1316 assert_return(method, -EINVAL);
1317
1318 if (v->state == VARLINK_DISCONNECTED)
1319 return -ENOTCONN;
45a6c965
LP		 1320
1321 /* We allow enqueing multiple method calls at once! */
d41bd96f
LP		 1322 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1323 return -EBUSY;
1324
1325 r = varlink_sanitize_parameters(&parameters);
1326 if (r < 0)
1327 return r;
1328
1329 r = json_build(&m, JSON_BUILD_OBJECT(
1330 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1331 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1332 if (r < 0)
1333 return r;
1334
1335 r = varlink_enqueue_json(v, m);
1336 if (r < 0)
1337 return r;
1338
1339 varlink_set_state(v, VARLINK_AWAITING_REPLY);
1340 v->n_pending++;
1341 v->timestamp = now(CLOCK_MONOTONIC);
1342
1343 return 0;
1344}
1345
1346int varlink_invokeb(Varlink *v, const char *method, ...) {
1347 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1348 va_list ap;
1349 int r;
1350
1351 assert_return(v, -EINVAL);
1352
1353 va_start(ap, method);
1354 r = json_buildv(&parameters, ap);
1355 va_end(ap);
1356
1357 if (r < 0)
1358 return r;
1359
1360 return varlink_invoke(v, method, parameters);
45a6c965
LP		 1361}
1362
1363int varlink_observe(Varlink *v, const char *method, JsonVariant *parameters) {
1364 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1365 int r;
1366
1367 assert_return(v, -EINVAL);
1368 assert_return(method, -EINVAL);
1369
1370 if (v->state == VARLINK_DISCONNECTED)
1371 return -ENOTCONN;
1372 /* Note that we don't allow enqueuing multiple method calls when we are in more/continues mode! We
1373 * thus insist on an idle client here. */
1374 if (v->state != VARLINK_IDLE_CLIENT)
1375 return -EBUSY;
1376
1377 r = varlink_sanitize_parameters(&parameters);
1378 if (r < 0)
1379 return r;
1380
1381 r = json_build(&m, JSON_BUILD_OBJECT(
1382 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1383 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1384 JSON_BUILD_PAIR("more", JSON_BUILD_BOOLEAN(true))));
1385 if (r < 0)
1386 return r;
1387
1388 r = varlink_enqueue_json(v, m);
1389 if (r < 0)
1390 return r;
1391
1392
1393 varlink_set_state(v, VARLINK_AWAITING_REPLY_MORE);
1394 v->n_pending++;
1395 v->timestamp = now(CLOCK_MONOTONIC);
1396
1397 return 0;
1398}
1399
1400int varlink_observeb(Varlink *v, const char *method, ...) {
1401 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1402 va_list ap;
1403 int r;
1404
1405 assert_return(v, -EINVAL);
1406
1407 va_start(ap, method);
1408 r = json_buildv(&parameters, ap);
1409 va_end(ap);
1410
1411 if (r < 0)
1412 return r;
1413
1414 return varlink_observe(v, method, parameters);
d41bd96f
LP		 1415}
1416
1417int varlink_call(
1418 Varlink *v,
1419 const char *method,
1420 JsonVariant *parameters,
1421 JsonVariant **ret_parameters,
1422 const char **ret_error_id,
1423 VarlinkReplyFlags *ret_flags) {
1424
1425 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1426 int r;
1427
1428 assert_return(v, -EINVAL);
1429 assert_return(method, -EINVAL);
1430
1431 if (v->state == VARLINK_DISCONNECTED)
1432 return -ENOTCONN;
1433 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT))
1434 return -EBUSY;
1435
1436 assert(v->n_pending == 0); /* n_pending can't be > 0 if we are in VARLINK_IDLE_CLIENT state */
1437
1438 r = varlink_sanitize_parameters(&parameters);
1439 if (r < 0)
1440 return r;
1441
1442 r = json_build(&m, JSON_BUILD_OBJECT(
1443 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1444 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1445 if (r < 0)
1446 return r;
1447
1448 r = varlink_enqueue_json(v, m);
1449 if (r < 0)
1450 return r;
1451
1452 varlink_set_state(v, VARLINK_CALLING);
1453 v->n_pending++;
1454 v->timestamp = now(CLOCK_MONOTONIC);
1455
1456 while (v->state == VARLINK_CALLING) {
1457
1458 r = varlink_process(v);
1459 if (r < 0)
1460 return r;
1461 if (r > 0)
1462 continue;
1463
1464 r = varlink_wait(v, USEC_INFINITY);
1465 if (r < 0)
1466 return r;
1467 }
1468
1469 switch (v->state) {
1470
1471 case VARLINK_CALLED:
1472 assert(v->current);
1473
1474 json_variant_unref(v->reply);
1475 v->reply = TAKE_PTR(v->current);
1476
1477 varlink_set_state(v, VARLINK_IDLE_CLIENT);
1478 assert(v->n_pending == 1);
1479 v->n_pending--;
1480
1481 if (ret_parameters)
1482 *ret_parameters = json_variant_by_key(v->reply, "parameters");
1483 if (ret_error_id)
1484 *ret_error_id = json_variant_string(json_variant_by_key(v->reply, "error"));
1485 if (ret_flags)
1486 *ret_flags = 0;
1487
1488 return 1;
1489
1490 case VARLINK_PENDING_DISCONNECT:
1491 case VARLINK_DISCONNECTED:
1492 return -ECONNRESET;
1493
1494 case VARLINK_PENDING_TIMEOUT:
1495 return -ETIME;
1496
1497 default:
1498 assert_not_reached("Unexpected state after method call.");
1499 }
1500}
1501
1502int varlink_callb(
1503 Varlink *v,
1504 const char *method,
1505 JsonVariant **ret_parameters,
1506 const char **ret_error_id,
1507 VarlinkReplyFlags *ret_flags, ...) {
1508
1509 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1510 va_list ap;
1511 int r;
1512
1513 assert_return(v, -EINVAL);
1514
1515 va_start(ap, ret_flags);
1516 r = json_buildv(&parameters, ap);
1517 va_end(ap);
1518
1519 if (r < 0)
1520 return r;
1521
1522 return varlink_call(v, method, parameters, ret_parameters, ret_error_id, ret_flags);
1523}
1524
1525int varlink_reply(Varlink *v, JsonVariant *parameters) {
1526 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1527 int r;
1528
1529 assert_return(v, -EINVAL);
1530
1531 if (v->state == VARLINK_DISCONNECTED)
1532 return -ENOTCONN;
1533 if (!IN_SET(v->state,
1534 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1535 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1536 return -EBUSY;
1537
1538 r = varlink_sanitize_parameters(&parameters);
1539 if (r < 0)
1540 return r;
1541
1542 r = json_build(&m, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1543 if (r < 0)
1544 return r;
1545
1546 r = varlink_enqueue_json(v, m);
1547 if (r < 0)
1548 return r;
1549
1550 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1551 /* We just replied to a method call that was let hanging for a while (i.e. we were outside of
1552 * the varlink_dispatch_method() stack frame), which means with this reply we are ready to
1553 * process further messages. */
1554 v->current = json_variant_unref(v->current);
1555 varlink_set_state(v, VARLINK_IDLE_SERVER);
1556 } else
1557 /* We replied to a method call from within the varlink_dispatch_method() stack frame), which
1558 * means we should it handle the rest of the state engine. */
1559 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1560
1561 return 1;
1562}
1563
1564int varlink_replyb(Varlink *v, ...) {
1565 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1566 va_list ap;
1567 int r;
1568
1569 assert_return(v, -EINVAL);
1570
1571 va_start(ap, v);
1572 r = json_buildv(&parameters, ap);
1573 va_end(ap);
1574
1575 if (r < 0)
1576 return r;
1577
1578 return varlink_reply(v, parameters);
1579}
1580
1581int varlink_error(Varlink *v, const char *error_id, JsonVariant *parameters) {
1582 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1583 int r;
1584
1585 assert_return(v, -EINVAL);
1586 assert_return(error_id, -EINVAL);
1587
1588 if (v->state == VARLINK_DISCONNECTED)
1589 return -ENOTCONN;
1590 if (!IN_SET(v->state,
1591 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1592 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1593 return -EBUSY;
1594
1595 r = varlink_sanitize_parameters(&parameters);
1596 if (r < 0)
1597 return r;
1598
1599 r = json_build(&m, JSON_BUILD_OBJECT(
1600 JSON_BUILD_PAIR("error", JSON_BUILD_STRING(error_id)),
1601 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1602 if (r < 0)
1603 return r;
1604
1605 r = varlink_enqueue_json(v, m);
1606 if (r < 0)
1607 return r;
1608
1609 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1610 v->current = json_variant_unref(v->current);
1611 varlink_set_state(v, VARLINK_IDLE_SERVER);
1612 } else
1613 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1614
1615 return 1;
1616}
1617
1618int varlink_errorb(Varlink *v, const char *error_id, ...) {
1619 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1620 va_list ap;
1621 int r;
1622
1623 assert_return(v, -EINVAL);
1624 assert_return(error_id, -EINVAL);
1625
1626 va_start(ap, error_id);
1627 r = json_buildv(&parameters, ap);
1628 va_end(ap);
1629
1630 if (r < 0)
1631 return r;
1632
1633 return varlink_error(v, error_id, parameters);
1634}
1635
1636int varlink_error_invalid_parameter(Varlink *v, JsonVariant *parameters) {
1637
1638 assert_return(v, -EINVAL);
1639 assert_return(parameters, -EINVAL);
1640
1641 /* We expect to be called in one of two ways: the 'parameters' argument is a string variant in which
1642 * case it is the parameter key name that is invalid. Or the 'parameters' argument is an object
1643 * variant in which case we'll pull out the first key. The latter mode is useful in functions that
1644 * don't expect any arguments. */
1645
1646 if (json_variant_is_string(parameters))
1647 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER, parameters);
1648
1649 if (json_variant_is_object(parameters) &&
1650 json_variant_elements(parameters) > 0)
1651 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER,
1652 json_variant_by_index(parameters, 0));
1653
1654 return -EINVAL;
1655}
1656
1657int varlink_notify(Varlink *v, JsonVariant *parameters) {
1658 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1659 int r;
1660
1661 assert_return(v, -EINVAL);
1662
1663 if (v->state == VARLINK_DISCONNECTED)
1664 return -ENOTCONN;
1665 if (!IN_SET(v->state, VARLINK_PROCESSING_METHOD_MORE, VARLINK_PENDING_METHOD_MORE))
1666 return -EBUSY;
1667
1668 r = varlink_sanitize_parameters(&parameters);
1669 if (r < 0)
1670 return r;
1671
1672 r = json_build(&m, JSON_BUILD_OBJECT(
1673 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1674 JSON_BUILD_PAIR("continues", JSON_BUILD_BOOLEAN(true))));
1675 if (r < 0)
1676 return r;
1677
1678 r = varlink_enqueue_json(v, m);
1679 if (r < 0)
1680 return r;
1681
1682 /* No state change, as more is coming */
1683 return 1;
1684}
1685
1686int varlink_notifyb(Varlink *v, ...) {
1687 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1688 va_list ap;
1689 int r;
1690
1691 assert_return(v, -EINVAL);
1692
1693 va_start(ap, v);
1694 r = json_buildv(&parameters, ap);
1695 va_end(ap);
1696
1697 if (r < 0)
1698 return r;
1699
1700 return varlink_notify(v, parameters);
1701}
1702
1703int varlink_bind_reply(Varlink *v, VarlinkReply callback) {
1704 assert_return(v, -EINVAL);
1705
1706 if (callback && v->reply_callback && callback != v->reply_callback)
1707 return -EBUSY;
1708
1709 v->reply_callback = callback;
1710
1711 return 0;
1712}
1713
1714void* varlink_set_userdata(Varlink *v, void *userdata) {
1715 void *old;
1716
1717 assert_return(v, NULL);
1718
1719 old = v->userdata;
1720 v->userdata = userdata;
1721
1722 return old;
1723}
1724
1725void* varlink_get_userdata(Varlink *v) {
1726 assert_return(v, NULL);
1727
1728 return v->userdata;
1729}
1730
1731static int varlink_acquire_ucred(Varlink *v) {
1732 int r;
1733
1734 assert(v);
1735
1736 if (v->ucred_acquired)
1737 return 0;
1738
1739 r = getpeercred(v->fd, &v->ucred);
1740 if (r < 0)
1741 return r;
1742
1743 v->ucred_acquired = true;
1744 return 0;
1745}
1746
1747int varlink_get_peer_uid(Varlink *v, uid_t *ret) {
1748 int r;
1749
1750 assert_return(v, -EINVAL);
1751 assert_return(ret, -EINVAL);
1752
1753 r = varlink_acquire_ucred(v);
1754 if (r < 0)
1755 return r;
1756
1757 if (!uid_is_valid(v->ucred.uid))
1758 return -ENODATA;
1759
1760 *ret = v->ucred.uid;
1761 return 0;
1762}
1763
1764int varlink_get_peer_pid(Varlink *v, pid_t *ret) {
1765 int r;
1766
1767 assert_return(v, -EINVAL);
1768 assert_return(ret, -EINVAL);
1769
1770 r = varlink_acquire_ucred(v);
1771 if (r < 0)
1772 return r;
1773
1774 if (!pid_is_valid(v->ucred.pid))
1775 return -ENODATA;
1776
1777 *ret = v->ucred.pid;
1778 return 0;
1779}
1780
1781int varlink_set_relative_timeout(Varlink *v, usec_t timeout) {
1782 assert_return(v, -EINVAL);
1783 assert_return(timeout > 0, -EINVAL);
1784
1785 v->timeout = timeout;
1786 return 0;
1787}
1788
1789VarlinkServer *varlink_get_server(Varlink *v) {
1790 assert_return(v, NULL);
1791
1792 return v->server;
1793}
1794
1795int varlink_set_description(Varlink *v, const char *description) {
1796 assert_return(v, -EINVAL);
1797
1798 return free_and_strdup(&v->description, description);
1799}
1800
1801static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
1802 Varlink *v = userdata;
1803
1804 assert(s);
1805 assert(v);
1806
1807 handle_revents(v, revents);
1808 (void) varlink_process(v);
1809
1810 return 1;
1811}
1812
1813static int time_callback(sd_event_source *s, uint64_t usec, void *userdata) {
1814 Varlink *v = userdata;
1815
1816 assert(s);
1817 assert(v);
1818
1819 (void) varlink_process(v);
1820 return 1;
1821}
1822
1823static int defer_callback(sd_event_source *s, void *userdata) {
1824 Varlink *v = userdata;
1825
1826 assert(s);
1827 assert(v);
1828
1829 (void) varlink_process(v);
1830 return 1;
1831}
1832
1833static int prepare_callback(sd_event_source *s, void *userdata) {
1834 Varlink *v = userdata;
1835 int r, e;
1836 usec_t until;
1837
1838 assert(s);
1839 assert(v);
1840
1841 e = varlink_get_events(v);
1842 if (e < 0)
1843 return e;
1844
1845 r = sd_event_source_set_io_events(v->io_event_source, e);
1846 if (r < 0)
1847 return r;
1848
1849 r = varlink_get_timeout(v, &until);
1850 if (r < 0)
1851 return r;
1852 if (r > 0) {
1853 r = sd_event_source_set_time(v->time_event_source, until);
1854 if (r < 0)
1855 return r;
1856 }
1857
1858 r = sd_event_source_set_enabled(v->time_event_source, r > 0 ? SD_EVENT_ON : SD_EVENT_OFF);
1859 if (r < 0)
1860 return r;
1861
1862 return 1;
1863}
1864
1865static int quit_callback(sd_event_source *event, void *userdata) {
1866 Varlink *v = userdata;
1867
1868 assert(event);
1869 assert(v);
1870
1871 varlink_flush(v);
1872 varlink_close(v);
1873
1874 return 1;
1875}
1876
1877int varlink_attach_event(Varlink *v, sd_event *e, int64_t priority) {
1878 int r;
1879
1880 assert_return(v, -EINVAL);
1881 assert_return(!v->event, -EBUSY);
1882
1883 if (e)
1884 v->event = sd_event_ref(e);
1885 else {
1886 r = sd_event_default(&v->event);
1887 if (r < 0)
1888 return r;
1889 }
1890
1891 r = sd_event_add_time(v->event, &v->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, v);
1892 if (r < 0)
1893 goto fail;
1894
1895 r = sd_event_source_set_priority(v->time_event_source, priority);
1896 if (r < 0)
1897 goto fail;
1898
1899 (void) sd_event_source_set_description(v->time_event_source, "varlink-time");
1900
1901 r = sd_event_add_exit(v->event, &v->quit_event_source, quit_callback, v);
1902 if (r < 0)
1903 goto fail;
1904
1905 r = sd_event_source_set_priority(v->quit_event_source, priority);
1906 if (r < 0)
1907 goto fail;
1908
1909 (void) sd_event_source_set_description(v->quit_event_source, "varlink-quit");
1910
1911 r = sd_event_add_io(v->event, &v->io_event_source, v->fd, 0, io_callback, v);
1912 if (r < 0)
1913 goto fail;
1914
1915 r = sd_event_source_set_prepare(v->io_event_source, prepare_callback);
1916 if (r < 0)
1917 goto fail;
1918
1919 r = sd_event_source_set_priority(v->io_event_source, priority);
1920 if (r < 0)
1921 goto fail;
1922
1923 (void) sd_event_source_set_description(v->io_event_source, "varlink-io");
1924
1925 r = sd_event_add_defer(v->event, &v->defer_event_source, defer_callback, v);
1926 if (r < 0)
1927 goto fail;
1928
1929 r = sd_event_source_set_priority(v->defer_event_source, priority);
1930 if (r < 0)
1931 goto fail;
1932
1933 (void) sd_event_source_set_description(v->defer_event_source, "varlink-defer");
1934
1935 return 0;
1936
1937fail:
1938 varlink_detach_event(v);
1939 return r;
1940}
1941
d41bd96f
LP		 1942void varlink_detach_event(Varlink *v) {
1943 if (!v)
1944 return;
1945
1946 varlink_detach_event_sources(v);
1947
1948 v->event = sd_event_unref(v->event);
1949}
1950
1951sd_event *varlink_get_event(Varlink *v) {
1952 assert_return(v, NULL);
1953
1954 return v->event;
1955}
1956
1957int varlink_server_new(VarlinkServer **ret, VarlinkServerFlags flags) {
1958 VarlinkServer *s;
1959
1960 assert_return(ret, -EINVAL);
1961 assert_return((flags & ~_VARLINK_SERVER_FLAGS_ALL) == 0, -EINVAL);
1962
1963 s = new(VarlinkServer, 1);
1964 if (!s)
1965 return -ENOMEM;
1966
1967 *s = (VarlinkServer) {
1968 .n_ref = 1,
1969 .flags = flags,
1970 .connections_max = varlink_server_connections_max(NULL),
1971 .connections_per_uid_max = varlink_server_connections_per_uid_max(NULL),
1972 };
1973
1974 *ret = s;
1975 return 0;
1976}
1977
1978static VarlinkServer* varlink_server_destroy(VarlinkServer *s) {
1979 char *m;
1980
1981 if (!s)
1982 return NULL;
1983
1984 varlink_server_shutdown(s);
1985
1986 while ((m = hashmap_steal_first_key(s->methods)))
1987 free(m);
1988
1989 hashmap_free(s->methods);
1990 hashmap_free(s->by_uid);
1991
1992 sd_event_unref(s->event);
1993
1994 free(s->description);
1995
1996 return mfree(s);
1997}
1998
1999DEFINE_TRIVIAL_REF_UNREF_FUNC(VarlinkServer, varlink_server, varlink_server_destroy);
2000
2001static int validate_connection(VarlinkServer *server, const struct ucred *ucred) {
2002 int allowed = -1;
2003
2004 assert(server);
2005 assert(ucred);
2006
2007 if (FLAGS_SET(server->flags, VARLINK_SERVER_ROOT_ONLY))
2008 allowed = ucred->uid == 0;
2009
2010 if (FLAGS_SET(server->flags, VARLINK_SERVER_MYSELF_ONLY))
2011 allowed = allowed > 0 || ucred->uid == getuid();
2012
2013 if (allowed == 0) { /* Allow access when it is explicitly allowed or when neither
2014 * VARLINK_SERVER_ROOT_ONLY nor VARLINK_SERVER_MYSELF_ONLY are specified. */
2015 varlink_server_log(server, "Unprivileged client attempted connection, refusing.");
2016 return 0;
2017 }
2018
2019 if (server->n_connections >= server->connections_max) {
2020 varlink_server_log(server, "Connection limit of %u reached, refusing.", server->connections_max);
2021 return 0;
2022 }
2023
2024 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
2025 unsigned c;
2026
2027 if (!uid_is_valid(ucred->uid)) {
2028 varlink_server_log(server, "Client with invalid UID attempted connection, refusing.");
2029 return 0;
2030 }
2031
2032 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
2033 if (c >= server->connections_per_uid_max) {
2034 varlink_server_log(server, "Per-UID connection limit of %u reached, refusing.",
2035 server->connections_per_uid_max);
2036 return 0;
2037 }
2038 }
2039
2040 return 1;
2041}
2042
2043static int count_connection(VarlinkServer *server, struct ucred *ucred) {
2044 unsigned c;
2045 int r;
2046
2047 assert(server);
2048 assert(ucred);
2049
2050 server->n_connections++;
2051
2052 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
2053 r = hashmap_ensure_allocated(&server->by_uid, NULL);
2054 if (r < 0)
2055 return log_debug_errno(r, "Failed to allocate UID hash table: %m");
2056
2057 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
2058
2059 varlink_server_log(server, "Connections of user " UID_FMT ": %u (of %u max)",
2060 ucred->uid, c, server->connections_per_uid_max);
2061
2062 r = hashmap_replace(server->by_uid, UID_TO_PTR(ucred->uid), UINT_TO_PTR(c + 1));
2063 if (r < 0)
2064 return log_debug_errno(r, "Failed to increment counter in UID hash table: %m");
2065 }
2066
2067 return 0;
2068}
2069
2070int varlink_server_add_connection(VarlinkServer *server, int fd, Varlink **ret) {
2071 _cleanup_(varlink_unrefp) Varlink *v = NULL;
2072 bool ucred_acquired;
2073 struct ucred ucred;
2074 int r;
2075
2076 assert_return(server, -EINVAL);
2077 assert_return(fd >= 0, -EBADF);
2078
2079 if ((server->flags & (VARLINK_SERVER_ROOT_ONLY|VARLINK_SERVER_ACCOUNT_UID)) != 0) {
2080 r = getpeercred(fd, &ucred);
2081 if (r < 0)
2082 return varlink_server_log_errno(server, r, "Failed to acquire peer credentials of incoming socket, refusing: %m");
2083
2084 ucred_acquired = true;
2085
2086 r = validate_connection(server, &ucred);
2087 if (r < 0)
2088 return r;
2089 if (r == 0)
2090 return -EPERM;
2091 } else
2092 ucred_acquired = false;
2093
2094 r = varlink_new(&v);
2095 if (r < 0)
2096 return varlink_server_log_errno(server, r, "Failed to allocate connection object: %m");
2097
2098 r = count_connection(server, &ucred);
2099 if (r < 0)
2100 return r;
2101
2102 v->fd = fd;
2103 v->userdata = server->userdata;
2104 if (ucred_acquired) {
2105 v->ucred = ucred;
2106 v->ucred_acquired = true;
2107 }
2108
2109 (void) asprintf(&v->description, "%s-%i", server->description ?: "varlink", v->fd);
2110
2111 /* Link up the server and the connection, and take reference in both directions. Note that the
2112 * reference on the connection is left dangling. It will be dropped when the connection is closed,
2113 * which happens in varlink_close(), including in the event loop quit callback. */
2114 v->server = varlink_server_ref(server);
2115 varlink_ref(v);
2116
2117 varlink_set_state(v, VARLINK_IDLE_SERVER);
2118
7e69d90c
LP		 2119 if (server->event) {
2120 r = varlink_attach_event(v, server->event, server->event_priority);
2121 if (r < 0) {
2122 varlink_log_errno(v, r, "Failed to attach new connection: %m");
2123 v->fd = -1; /* take the fd out of the connection again */
2124 varlink_close(v);
2125 return r;
2126 }
d41bd96f
LP		 2127 }
2128
2129 if (ret)
2130 *ret = v;
2131
2132 return 0;
2133}
2134
2135static int connect_callback(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
2136 VarlinkServerSocket *ss = userdata;
2137 _cleanup_close_ int cfd = -1;
2138 Varlink *v = NULL;
2139 int r;
2140
2141 assert(source);
2142 assert(ss);
2143
2144 varlink_server_log(ss->server, "New incoming connection.");
2145
2146 cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
2147 if (cfd < 0) {
2148 if (ERRNO_IS_ACCEPT_AGAIN(errno))
2149 return 0;
2150
2151 return varlink_server_log_errno(ss->server, errno, "Failed to accept incoming socket: %m");
2152 }
2153
2154 r = varlink_server_add_connection(ss->server, cfd, &v);
2155 if (r < 0)
2156 return 0;
2157
2158 TAKE_FD(cfd);
2159
2160 if (ss->server->connect_callback) {
2161 r = ss->server->connect_callback(ss->server, v, ss->server->userdata);
2162 if (r < 0) {
2163 varlink_log_errno(v, r, "Connection callback returned error, disconnecting client: %m");
2164 varlink_close(v);
2165 return 0;
2166 }
2167 }
2168
2169 return 0;
2170}
2171
2172int varlink_server_listen_fd(VarlinkServer *s, int fd) {
2173 _cleanup_free_ VarlinkServerSocket *ss = NULL;
2174 int r;
2175
2176 assert_return(s, -EINVAL);
2177 assert_return(fd >= 0, -EBADF);
2178
2179 r = fd_nonblock(fd, true);
2180 if (r < 0)
2181 return r;
2182
2183 ss = new(VarlinkServerSocket, 1);
2184 if (!ss)
2185 return -ENOMEM;
2186
2187 *ss = (VarlinkServerSocket) {
2188 .server = s,
2189 .fd = fd,
2190 };
2191
2192 if (s->event) {
2193 _cleanup_(sd_event_source_unrefp) sd_event_source *es = NULL;
2194
2195 r = sd_event_add_io(s->event, &es, fd, EPOLLIN, connect_callback, ss);
2196 if (r < 0)
2197 return r;
2198
2199 r = sd_event_source_set_priority(ss->event_source, s->event_priority);
2200 if (r < 0)
2201 return r;
2202 }
2203
2204 LIST_PREPEND(sockets, s->sockets, TAKE_PTR(ss));
2205 return 0;
2206}
2207
2208int varlink_server_listen_address(VarlinkServer *s, const char *address, mode_t m) {
2209 union sockaddr_union sockaddr;
2210 _cleanup_close_ int fd = -1;
2211 int r;
2212
2213 assert_return(s, -EINVAL);
2214 assert_return(address, -EINVAL);
2215 assert_return((m & ~0777) == 0, -EINVAL);
2216
2217 r = sockaddr_un_set_path(&sockaddr.un, address);
2218 if (r < 0)
2219 return r;
2220
2221 fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
2222 if (fd < 0)
2223 return -errno;
2224
a0c41de2
LP		 2225 fd = fd_move_above_stdio(fd);
2226
d41bd96f
LP		 2227 (void) sockaddr_un_unlink(&sockaddr.un);
2228
2229 RUN_WITH_UMASK(~m & 0777)
2230 if (bind(fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0)
2231 return -errno;
2232
2233 if (listen(fd, SOMAXCONN) < 0)
2234 return -errno;
2235
2236 r = varlink_server_listen_fd(s, fd);
2237 if (r < 0)
2238 return r;
2239
2240 TAKE_FD(fd);
2241 return 0;
2242}
2243
2244void* varlink_server_set_userdata(VarlinkServer *s, void *userdata) {
2245 void *ret;
2246
2247 assert_return(s, NULL);
2248
2249 ret = s->userdata;
2250 s->userdata = userdata;
2251
2252 return ret;
2253}
2254
2255void* varlink_server_get_userdata(VarlinkServer *s) {
2256 assert_return(s, NULL);
2257
2258 return s->userdata;
2259}
2260
2261static VarlinkServerSocket* varlink_server_socket_destroy(VarlinkServerSocket *ss) {
2262 if (!ss)
2263 return NULL;
2264
2265 if (ss->server)
2266 LIST_REMOVE(sockets, ss->server->sockets, ss);
2267
1d3fe304 2268 sd_event_source_disable_unref(ss->event_source);
d41bd96f
LP		 2269
2270 free(ss->address);
2271 safe_close(ss->fd);
2272
2273 return mfree(ss);
2274}
2275
2276int varlink_server_shutdown(VarlinkServer *s) {
2277 assert_return(s, -EINVAL);
2278
2279 while (s->sockets)
2280 varlink_server_socket_destroy(s->sockets);
2281
2282 return 0;
2283}
2284
2285int varlink_server_attach_event(VarlinkServer *s, sd_event *e, int64_t priority) {
2286 VarlinkServerSocket *ss;
2287 int r;
2288
2289 assert_return(s, -EINVAL);
2290 assert_return(!s->event, -EBUSY);
2291
2292 if (e)
2293 s->event = sd_event_ref(e);
2294 else {
2295 r = sd_event_default(&s->event);
2296 if (r < 0)
2297 return r;
2298 }
2299
2300 LIST_FOREACH(sockets, ss, s->sockets) {
2301 assert(!ss->event_source);
2302
2303 r = sd_event_add_io(s->event, &ss->event_source, ss->fd, EPOLLIN, connect_callback, ss);
2304 if (r < 0)
2305 goto fail;
2306
2307 r = sd_event_source_set_priority(ss->event_source, priority);
2308 if (r < 0)
2309 goto fail;
2310 }
2311
2312 s->event_priority = priority;
2313 return 0;
2314
2315fail:
2316 varlink_server_detach_event(s);
2317 return r;
2318}
2319
2320int varlink_server_detach_event(VarlinkServer *s) {
2321 VarlinkServerSocket *ss;
2322
2323 assert_return(s, -EINVAL);
2324
2325 LIST_FOREACH(sockets, ss, s->sockets) {
2326
2327 if (!ss->event_source)
2328 continue;
2329
2330 (void) sd_event_source_set_enabled(ss->event_source, SD_EVENT_OFF);
2331 ss->event_source = sd_event_source_unref(ss->event_source);
2332 }
2333
2334 sd_event_unref(s->event);
2335 return 0;
2336}
2337
2338sd_event *varlink_server_get_event(VarlinkServer *s) {
2339 assert_return(s, NULL);
2340
2341 return s->event;
2342}
2343
2344int varlink_server_bind_method(VarlinkServer *s, const char *method, VarlinkMethod callback) {
2345 char *m;
2346 int r;
2347
2348 assert_return(s, -EINVAL);
2349 assert_return(method, -EINVAL);
2350 assert_return(callback, -EINVAL);
2351
2352 if (startswith(method, "org.varlink.service."))
2353 return -EEXIST;
2354
2355 r = hashmap_ensure_allocated(&s->methods, &string_hash_ops);
2356 if (r < 0)
2357 return r;
2358
2359 m = strdup(method);
2360 if (!m)
2361 return -ENOMEM;
2362
2363 r = hashmap_put(s->methods, m, callback);
2364 if (r < 0) {
2365 free(m);
2366 return r;
2367 }
2368
2369 return 0;
2370}
2371
2372int varlink_server_bind_method_many_internal(VarlinkServer *s, ...) {
2373 va_list ap;
e7b93f97 2374 int r = 0;
d41bd96f
LP		 2375
2376 assert_return(s, -EINVAL);
2377
2378 va_start(ap, s);
2379 for (;;) {
2380 VarlinkMethod callback;
2381 const char *method;
2382
2383 method = va_arg(ap, const char *);
2384 if (!method)
2385 break;
2386
2387 callback = va_arg(ap, VarlinkMethod);
2388
2389 r = varlink_server_bind_method(s, method, callback);
2390 if (r < 0)
e7b93f97 2391 break;
d41bd96f 2392 }
e7b93f97 2393 va_end(ap);
d41bd96f 2394
e7b93f97 2395 return r;
d41bd96f
LP		 2396}
2397
2398int varlink_server_bind_connect(VarlinkServer *s, VarlinkConnect callback) {
2399 assert_return(s, -EINVAL);
2400
2401 if (callback && s->connect_callback && callback != s->connect_callback)
2402 return -EBUSY;
2403
2404 s->connect_callback = callback;
2405 return 0;
2406}
2407
2408unsigned varlink_server_connections_max(VarlinkServer *s) {
2409 struct rlimit rl;
2410
2411 /* If a server is specified, return the setting for that server, otherwise the default value */
2412 if (s)
2413 return s->connections_max;
2414
2415 assert_se(getrlimit(RLIMIT_NOFILE, &rl) >= 0);
2416
2417 /* Make sure we never use up more than ¾th of RLIMIT_NOFILE for IPC */
2418 if (VARLINK_DEFAULT_CONNECTIONS_MAX > rl.rlim_cur / 4 * 3)
2419 return rl.rlim_cur / 4 * 3;
2420
2421 return VARLINK_DEFAULT_CONNECTIONS_MAX;
2422}
2423
2424unsigned varlink_server_connections_per_uid_max(VarlinkServer *s) {
2425 unsigned m;
2426
2427 if (s)
2428 return s->connections_per_uid_max;
2429
2430 /* Make sure to never use up more than ¾th of available connections for a single user */
2431 m = varlink_server_connections_max(NULL);
2432 if (VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX > m)
2433 return m / 4 * 3;
2434
2435 return VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX;
2436}
2437
2438int varlink_server_set_connections_per_uid_max(VarlinkServer *s, unsigned m) {
2439 assert_return(s, -EINVAL);
2440 assert_return(m > 0, -EINVAL);
2441
2442 s->connections_per_uid_max = m;
2443 return 0;
2444}
2445
2446int varlink_server_set_connections_max(VarlinkServer *s, unsigned m) {
2447 assert_return(s, -EINVAL);
2448 assert_return(m > 0, -EINVAL);
2449
2450 s->connections_max = m;
2451 return 0;
2452}
2453
2454int varlink_server_set_description(VarlinkServer *s, const char *description) {
2455 assert_return(s, -EINVAL);
2456
2457 return free_and_strdup(&s->description, description);
2458}
Unnamed repository; edit this file 'description' to name the repository.