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Merge pull request #18007 from fw-strlen/ipv6_masq_and_dnat
[thirdparty/systemd.git] / src / shared / varlink.c
1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3 #include <sys/poll.h>
4
5 #include "alloc-util.h"
6 #include "errno-util.h"
7 #include "fd-util.h"
8 #include "hashmap.h"
9 #include "io-util.h"
10 #include "list.h"
11 #include "process-util.h"
12 #include "selinux-util.h"
13 #include "set.h"
14 #include "socket-util.h"
15 #include "string-table.h"
16 #include "string-util.h"
17 #include "strv.h"
18 #include "time-util.h"
19 #include "umask-util.h"
20 #include "user-util.h"
21 #include "varlink.h"
22
23 #define VARLINK_DEFAULT_CONNECTIONS_MAX 4096U
24 #define VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX 1024U
25
26 #define VARLINK_DEFAULT_TIMEOUT_USEC (45U*USEC_PER_SEC)
27 #define VARLINK_BUFFER_MAX (16U*1024U*1024U)
28 #define VARLINK_READ_SIZE (64U*1024U)
29
30 typedef enum VarlinkState {
31 /* Client side states */
32 VARLINK_IDLE_CLIENT,
33 VARLINK_AWAITING_REPLY,
34 VARLINK_AWAITING_REPLY_MORE,
35 VARLINK_CALLING,
36 VARLINK_CALLED,
37 VARLINK_PROCESSING_REPLY,
38
39 /* Server side states */
40 VARLINK_IDLE_SERVER,
41 VARLINK_PROCESSING_METHOD,
42 VARLINK_PROCESSING_METHOD_MORE,
43 VARLINK_PROCESSING_METHOD_ONEWAY,
44 VARLINK_PROCESSED_METHOD,
45 VARLINK_PENDING_METHOD,
46 VARLINK_PENDING_METHOD_MORE,
47
48 /* Common states (only during shutdown) */
49 VARLINK_PENDING_DISCONNECT,
50 VARLINK_PENDING_TIMEOUT,
51 VARLINK_PROCESSING_DISCONNECT,
52 VARLINK_PROCESSING_TIMEOUT,
53 VARLINK_PROCESSING_FAILURE,
54 VARLINK_DISCONNECTED,
55
56 _VARLINK_STATE_MAX,
57 _VARLINK_STATE_INVALID = -EINVAL,
58 } VarlinkState;
59
60 /* Tests whether we are not yet disconnected. Note that this is true during all states where the connection
61 * is still good for something, and false only when it's dead for good. This means: when we are
62 * asynchronously connecting to a peer and the connect() is still pending, then this will return 'true', as
63 * the connection is still good, and we are likely to be able to properly operate on it soon. */
64 #define VARLINK_STATE_IS_ALIVE(state) \
65 IN_SET(state, \
66 VARLINK_IDLE_CLIENT, \
67 VARLINK_AWAITING_REPLY, \
68 VARLINK_AWAITING_REPLY_MORE, \
69 VARLINK_CALLING, \
70 VARLINK_CALLED, \
71 VARLINK_PROCESSING_REPLY, \
72 VARLINK_IDLE_SERVER, \
73 VARLINK_PROCESSING_METHOD, \
74 VARLINK_PROCESSING_METHOD_MORE, \
75 VARLINK_PROCESSING_METHOD_ONEWAY, \
76 VARLINK_PROCESSED_METHOD, \
77 VARLINK_PENDING_METHOD, \
78 VARLINK_PENDING_METHOD_MORE)
79
80 struct Varlink {
81 unsigned n_ref;
82
83 VarlinkServer *server;
84
85 VarlinkState state;
86 bool connecting; /* This boolean indicates whether the socket fd we are operating on is currently
87 * processing an asynchronous connect(). In that state we watch the socket for
88 * EPOLLOUT, but we refrain from calling read() or write() on the socket as that
89 * will trigger ENOTCONN. Note that this boolean is kept separate from the
90 * VarlinkState above on purpose: while the connect() is still not complete we
91 * already want to allow queuing of messages and similar. Thus it's nice to keep
92 * these two state concepts separate: the VarlinkState encodes what our own view of
93 * the connection is, i.e. whether we think it's a server, a client, and has
94 * something queued already, while 'connecting' tells us a detail about the
95 * transport used below, that should have no effect on how we otherwise accept and
96 * process operations from the user.
97 *
98 * Or to say this differently: VARLINK_STATE_IS_ALIVE(state) tells you whether the
99 * connection is good to use, even if it might not be fully connected
100 * yet. connecting=true then informs you that actually we are still connecting, and
101 * the connection is actually not established yet and thus any requests you enqueue
102 * now will still work fine but will be queued only, not sent yet, but that
103 * shouldn't stop you from using the connection, since eventually whatever you queue
104 * *will* be sent.
105 *
106 * Or to say this even differently: 'state' is a high-level ("application layer"
107 * high, if you so will) state, while 'conecting' is a low-level ("transport layer"
108 * low, if you so will) state, and while they are not entirely unrelated and
109 * sometimes propagate effects to each other they are only asynchronously connected
110 * at most. */
111 unsigned n_pending;
112
113 int fd;
114
115 char *input_buffer; /* valid data starts at input_buffer_index, ends at input_buffer_index+input_buffer_size */
116 size_t input_buffer_allocated;
117 size_t input_buffer_index;
118 size_t input_buffer_size;
119 size_t input_buffer_unscanned;
120
121 char *output_buffer; /* valid data starts at output_buffer_index, ends at output_buffer_index+output_buffer_size */
122 size_t output_buffer_allocated;
123 size_t output_buffer_index;
124 size_t output_buffer_size;
125
126 VarlinkReply reply_callback;
127
128 JsonVariant *current;
129 JsonVariant *reply;
130
131 struct ucred ucred;
132 bool ucred_acquired:1;
133
134 bool write_disconnected:1;
135 bool read_disconnected:1;
136 bool prefer_read_write:1;
137 bool got_pollhup:1;
138
139 usec_t timestamp;
140 usec_t timeout;
141
142 void *userdata;
143 char *description;
144
145 sd_event *event;
146 sd_event_source *io_event_source;
147 sd_event_source *time_event_source;
148 sd_event_source *quit_event_source;
149 sd_event_source *defer_event_source;
150 };
151
152 typedef struct VarlinkServerSocket VarlinkServerSocket;
153
154 struct VarlinkServerSocket {
155 VarlinkServer *server;
156
157 int fd;
158 char *address;
159
160 sd_event_source *event_source;
161
162 LIST_FIELDS(VarlinkServerSocket, sockets);
163 };
164
165 struct VarlinkServer {
166 unsigned n_ref;
167 VarlinkServerFlags flags;
168
169 LIST_HEAD(VarlinkServerSocket, sockets);
170
171 Hashmap *methods;
172 VarlinkConnect connect_callback;
173 VarlinkDisconnect disconnect_callback;
174
175 sd_event *event;
176 int64_t event_priority;
177
178 unsigned n_connections;
179 Hashmap *by_uid;
180
181 void *userdata;
182 char *description;
183
184 unsigned connections_max;
185 unsigned connections_per_uid_max;
186 };
187
188 static const char* const varlink_state_table[_VARLINK_STATE_MAX] = {
189 [VARLINK_IDLE_CLIENT] = "idle-client",
190 [VARLINK_AWAITING_REPLY] = "awaiting-reply",
191 [VARLINK_AWAITING_REPLY_MORE] = "awaiting-reply-more",
192 [VARLINK_CALLING] = "calling",
193 [VARLINK_CALLED] = "called",
194 [VARLINK_PROCESSING_REPLY] = "processing-reply",
195 [VARLINK_IDLE_SERVER] = "idle-server",
196 [VARLINK_PROCESSING_METHOD] = "processing-method",
197 [VARLINK_PROCESSING_METHOD_MORE] = "processing-method-more",
198 [VARLINK_PROCESSING_METHOD_ONEWAY] = "processing-method-oneway",
199 [VARLINK_PROCESSED_METHOD] = "processed-method",
200 [VARLINK_PENDING_METHOD] = "pending-method",
201 [VARLINK_PENDING_METHOD_MORE] = "pending-method-more",
202 [VARLINK_PENDING_DISCONNECT] = "pending-disconnect",
203 [VARLINK_PENDING_TIMEOUT] = "pending-timeout",
204 [VARLINK_PROCESSING_DISCONNECT] = "processing-disconnect",
205 [VARLINK_PROCESSING_TIMEOUT] = "processing-timeout",
206 [VARLINK_PROCESSING_FAILURE] = "processing-failure",
207 [VARLINK_DISCONNECTED] = "disconnected",
208 };
209
210 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(varlink_state, VarlinkState);
211
212 #define varlink_log_errno(v, error, fmt, ...) \
213 log_debug_errno(error, "%s: " fmt, varlink_description(v), ##__VA_ARGS__)
214
215 #define varlink_log(v, fmt, ...) \
216 log_debug("%s: " fmt, varlink_description(v), ##__VA_ARGS__)
217
218 #define varlink_server_log_errno(s, error, fmt, ...) \
219 log_debug_errno(error, "%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
220
221 #define varlink_server_log(s, fmt, ...) \
222 log_debug("%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
223
224 static inline const char *varlink_description(Varlink *v) {
225 return strna(v ? v->description : NULL);
226 }
227
228 static inline const char *varlink_server_description(VarlinkServer *s) {
229 return strna(s ? s->description : NULL);
230 }
231
232 static void varlink_set_state(Varlink *v, VarlinkState state) {
233 assert(v);
234 assert(state >= 0 && state < _VARLINK_STATE_MAX);
235
236 if (v->state < 0)
237 varlink_log(v, "varlink: setting state %s",
238 varlink_state_to_string(state));
239 else
240 varlink_log(v, "varlink: changing state %s → %s",
241 varlink_state_to_string(v->state),
242 varlink_state_to_string(state));
243
244 v->state = state;
245 }
246
247 static int varlink_new(Varlink **ret) {
248 Varlink *v;
249
250 assert(ret);
251
252 v = new(Varlink, 1);
253 if (!v)
254 return -ENOMEM;
255
256 *v = (Varlink) {
257 .n_ref = 1,
258 .fd = -1,
259
260 .state = _VARLINK_STATE_INVALID,
261
262 .ucred.uid = UID_INVALID,
263 .ucred.gid = GID_INVALID,
264
265 .timestamp = USEC_INFINITY,
266 .timeout = VARLINK_DEFAULT_TIMEOUT_USEC
267 };
268
269 *ret = v;
270 return 0;
271 }
272
273 int varlink_connect_address(Varlink **ret, const char *address) {
274 _cleanup_(varlink_unrefp) Varlink *v = NULL;
275 union sockaddr_union sockaddr;
276 socklen_t sockaddr_len;
277 int r;
278
279 assert_return(ret, -EINVAL);
280 assert_return(address, -EINVAL);
281
282 r = sockaddr_un_set_path(&sockaddr.un, address);
283 if (r < 0)
284 return log_debug_errno(r, "Failed to set socket address '%s': %m", address);
285 sockaddr_len = r;
286
287 r = varlink_new(&v);
288 if (r < 0)
289 return log_debug_errno(r, "Failed to create varlink object: %m");
290
291 v->fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
292 if (v->fd < 0)
293 return log_debug_errno(errno, "Failed to create AF_UNIX socket: %m");
294
295 v->fd = fd_move_above_stdio(v->fd);
296
297 if (connect(v->fd, &sockaddr.sa, sockaddr_len) < 0) {
298 if (!IN_SET(errno, EAGAIN, EINPROGRESS))
299 return log_debug_errno(errno, "Failed to connect to %s: %m", address);
300
301 v->connecting = true; /* We are asynchronously connecting, i.e. the connect() is being
302 * processed in the background. As long as that's the case the socket
303 * is in a special state: it's there, we can poll it for EPOLLOUT, but
304 * if we attempt to write() to it before we see EPOLLOUT we'll get
305 * ENOTCONN (and not EAGAIN, like we would for a normal connected
306 * socket that isn't writable at the moment). Since ENOTCONN on write()
307 * hence can mean two different things (i.e. connection not complete
308 * yet vs. already disconnected again), we store as a boolean whether
309 * we are still in connect(). */
310 }
311
312 varlink_set_state(v, VARLINK_IDLE_CLIENT);
313
314 *ret = TAKE_PTR(v);
315 return 0;
316 }
317
318 int varlink_connect_fd(Varlink **ret, int fd) {
319 Varlink *v;
320 int r;
321
322 assert_return(ret, -EINVAL);
323 assert_return(fd >= 0, -EBADF);
324
325 r = fd_nonblock(fd, true);
326 if (r < 0)
327 return log_debug_errno(r, "Failed to make fd %d nonblocking: %m", fd);
328
329 r = varlink_new(&v);
330 if (r < 0)
331 return log_debug_errno(r, "Failed to create varlink object: %m");
332
333 v->fd = fd;
334 varlink_set_state(v, VARLINK_IDLE_CLIENT);
335
336 /* Note that if this function is called we assume the passed socket (if it is one) is already
337 * properly connected, i.e. any asynchronous connect() done on it already completed. Because of that
338 * we'll not set the 'connecting' boolean here, i.e. we don't need to avoid write()ing to the socket
339 * until the connection is fully set up. Behaviour here is hence a bit different from
340 * varlink_connect_address() above, as there we do handle asynchronous connections ourselves and
341 * avoid doing write() on it before we saw EPOLLOUT for the first time. */
342
343 *ret = v;
344 return 0;
345 }
346
347 static void varlink_detach_event_sources(Varlink *v) {
348 assert(v);
349
350 v->io_event_source = sd_event_source_disable_unref(v->io_event_source);
351 v->time_event_source = sd_event_source_disable_unref(v->time_event_source);
352 v->quit_event_source = sd_event_source_disable_unref(v->quit_event_source);
353 v->defer_event_source = sd_event_source_disable_unref(v->defer_event_source);
354 }
355
356 static void varlink_clear(Varlink *v) {
357 assert(v);
358
359 varlink_detach_event_sources(v);
360
361 v->fd = safe_close(v->fd);
362
363 v->input_buffer = mfree(v->input_buffer);
364 v->output_buffer = mfree(v->output_buffer);
365
366 v->current = json_variant_unref(v->current);
367 v->reply = json_variant_unref(v->reply);
368
369 v->event = sd_event_unref(v->event);
370 }
371
372 static Varlink* varlink_destroy(Varlink *v) {
373 if (!v)
374 return NULL;
375
376 /* If this is called the server object must already been unreffed here. Why that? because when we
377 * linked up the varlink connection with the server object we took one ref in each direction */
378 assert(!v->server);
379
380 varlink_clear(v);
381
382 free(v->description);
383 return mfree(v);
384 }
385
386 DEFINE_TRIVIAL_REF_UNREF_FUNC(Varlink, varlink, varlink_destroy);
387
388 static int varlink_test_disconnect(Varlink *v) {
389 assert(v);
390
391 /* Tests whether we the connection has been terminated. We are careful to not stop processing it
392 * prematurely, since we want to handle half-open connections as well as possible and want to flush
393 * out and read data before we close down if we can. */
394
395 /* Already disconnected? */
396 if (!VARLINK_STATE_IS_ALIVE(v->state))
397 return 0;
398
399 /* Wait until connection setup is complete, i.e. until asynchronous connect() completes */
400 if (v->connecting)
401 return 0;
402
403 /* Still something to write and we can write? Stay around */
404 if (v->output_buffer_size > 0 && !v->write_disconnected)
405 return 0;
406
407 /* Both sides gone already? Then there's no need to stick around */
408 if (v->read_disconnected && v->write_disconnected)
409 goto disconnect;
410
411 /* If we are waiting for incoming data but the read side is shut down, disconnect. */
412 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) && v->read_disconnected)
413 goto disconnect;
414
415 /* Similar, if are a client that hasn't written anything yet but the write side is dead, also
416 * disconnect. We also explicitly check for POLLHUP here since we likely won't notice the write side
417 * being down if we never wrote anything. */
418 if (IN_SET(v->state, VARLINK_IDLE_CLIENT) && (v->write_disconnected || v->got_pollhup))
419 goto disconnect;
420
421 /* The server is still expecting to write more, but its write end is disconnected and it got a POLLHUP
422 * (i.e. from a disconnected client), so disconnect. */
423 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE) && v->write_disconnected && v->got_pollhup)
424 goto disconnect;
425
426 return 0;
427
428 disconnect:
429 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
430 return 1;
431 }
432
433 static int varlink_write(Varlink *v) {
434 ssize_t n;
435
436 assert(v);
437
438 if (!VARLINK_STATE_IS_ALIVE(v->state))
439 return 0;
440 if (v->connecting) /* Writing while we are still wait for a non-blocking connect() to complete will
441 * result in ENOTCONN, hence exit early here */
442 return 0;
443 if (v->output_buffer_size == 0)
444 return 0;
445 if (v->write_disconnected)
446 return 0;
447
448 assert(v->fd >= 0);
449
450 /* We generally prefer recv()/send() (mostly because of MSG_NOSIGNAL) but also want to be compatible
451 * with non-socket IO, hence fall back automatically */
452 if (!v->prefer_read_write) {
453 n = send(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size, MSG_DONTWAIT|MSG_NOSIGNAL);
454 if (n < 0 && errno == ENOTSOCK)
455 v->prefer_read_write = true;
456 }
457 if (v->prefer_read_write)
458 n = write(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size);
459 if (n < 0) {
460 if (errno == EAGAIN)
461 return 0;
462
463 if (ERRNO_IS_DISCONNECT(errno)) {
464 /* If we get informed about a disconnect on write, then let's remember that, but not
465 * act on it just yet. Let's wait for read() to report the issue first. */
466 v->write_disconnected = true;
467 return 1;
468 }
469
470 return -errno;
471 }
472
473 v->output_buffer_size -= n;
474
475 if (v->output_buffer_size == 0)
476 v->output_buffer_index = 0;
477 else
478 v->output_buffer_index += n;
479
480 v->timestamp = now(CLOCK_MONOTONIC);
481 return 1;
482 }
483
484 static int varlink_read(Varlink *v) {
485 size_t rs;
486 ssize_t n;
487
488 assert(v);
489
490 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER))
491 return 0;
492 if (v->connecting) /* read() on a socket while we are in connect() will fail with EINVAL, hence exit early here */
493 return 0;
494 if (v->current)
495 return 0;
496 if (v->input_buffer_unscanned > 0)
497 return 0;
498 if (v->read_disconnected)
499 return 0;
500
501 if (v->input_buffer_size >= VARLINK_BUFFER_MAX)
502 return -ENOBUFS;
503
504 assert(v->fd >= 0);
505
506 if (v->input_buffer_allocated <= v->input_buffer_index + v->input_buffer_size) {
507 size_t add;
508
509 add = MIN(VARLINK_BUFFER_MAX - v->input_buffer_size, VARLINK_READ_SIZE);
510
511 if (v->input_buffer_index == 0) {
512
513 if (!GREEDY_REALLOC(v->input_buffer, v->input_buffer_allocated, v->input_buffer_size + add))
514 return -ENOMEM;
515
516 } else {
517 char *b;
518
519 b = new(char, v->input_buffer_size + add);
520 if (!b)
521 return -ENOMEM;
522
523 memcpy(b, v->input_buffer + v->input_buffer_index, v->input_buffer_size);
524
525 free_and_replace(v->input_buffer, b);
526
527 v->input_buffer_allocated = v->input_buffer_size + add;
528 v->input_buffer_index = 0;
529 }
530 }
531
532 rs = v->input_buffer_allocated - (v->input_buffer_index + v->input_buffer_size);
533
534 if (!v->prefer_read_write) {
535 n = recv(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs, MSG_DONTWAIT);
536 if (n < 0 && errno == ENOTSOCK)
537 v->prefer_read_write = true;
538 }
539 if (v->prefer_read_write)
540 n = read(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs);
541 if (n < 0) {
542 if (errno == EAGAIN)
543 return 0;
544
545 if (ERRNO_IS_DISCONNECT(errno)) {
546 v->read_disconnected = true;
547 return 1;
548 }
549
550 return -errno;
551 }
552 if (n == 0) { /* EOF */
553 v->read_disconnected = true;
554 return 1;
555 }
556
557 v->input_buffer_size += n;
558 v->input_buffer_unscanned += n;
559
560 return 1;
561 }
562
563 static int varlink_parse_message(Varlink *v) {
564 const char *e, *begin;
565 size_t sz;
566 int r;
567
568 assert(v);
569
570 if (v->current)
571 return 0;
572 if (v->input_buffer_unscanned <= 0)
573 return 0;
574
575 assert(v->input_buffer_unscanned <= v->input_buffer_size);
576 assert(v->input_buffer_index + v->input_buffer_size <= v->input_buffer_allocated);
577
578 begin = v->input_buffer + v->input_buffer_index;
579
580 e = memchr(begin + v->input_buffer_size - v->input_buffer_unscanned, 0, v->input_buffer_unscanned);
581 if (!e) {
582 v->input_buffer_unscanned = 0;
583 return 0;
584 }
585
586 sz = e - begin + 1;
587
588 varlink_log(v, "New incoming message: %s", begin); /* FIXME: should we output the whole message here before validation?
589 * This may produce a non-printable journal entry if the message
590 * is invalid. We may also expose privileged information. */
591
592 r = json_parse(begin, 0, &v->current, NULL, NULL);
593 if (r < 0) {
594 /* If we encounter a parse failure flush all data. We cannot possibly recover from this,
595 * hence drop all buffered data now. */
596 v->input_buffer_index = v->input_buffer_size = v->input_buffer_unscanned = 0;
597 return varlink_log_errno(v, r, "Failed to parse JSON: %m");
598 }
599
600 v->input_buffer_size -= sz;
601
602 if (v->input_buffer_size == 0)
603 v->input_buffer_index = 0;
604 else
605 v->input_buffer_index += sz;
606
607 v->input_buffer_unscanned = v->input_buffer_size;
608 return 1;
609 }
610
611 static int varlink_test_timeout(Varlink *v) {
612 assert(v);
613
614 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING))
615 return 0;
616 if (v->timeout == USEC_INFINITY)
617 return 0;
618
619 if (now(CLOCK_MONOTONIC) < usec_add(v->timestamp, v->timeout))
620 return 0;
621
622 varlink_set_state(v, VARLINK_PENDING_TIMEOUT);
623
624 return 1;
625 }
626
627 static int varlink_dispatch_local_error(Varlink *v, const char *error) {
628 int r;
629
630 assert(v);
631 assert(error);
632
633 if (!v->reply_callback)
634 return 0;
635
636 r = v->reply_callback(v, NULL, error, VARLINK_REPLY_ERROR|VARLINK_REPLY_LOCAL, v->userdata);
637 if (r < 0)
638 log_debug_errno(r, "Reply callback returned error, ignoring: %m");
639
640 return 1;
641 }
642
643 static int varlink_dispatch_timeout(Varlink *v) {
644 assert(v);
645
646 if (v->state != VARLINK_PENDING_TIMEOUT)
647 return 0;
648
649 varlink_set_state(v, VARLINK_PROCESSING_TIMEOUT);
650 varlink_dispatch_local_error(v, VARLINK_ERROR_TIMEOUT);
651 varlink_close(v);
652
653 return 1;
654 }
655
656 static int varlink_dispatch_disconnect(Varlink *v) {
657 assert(v);
658
659 if (v->state != VARLINK_PENDING_DISCONNECT)
660 return 0;
661
662 varlink_set_state(v, VARLINK_PROCESSING_DISCONNECT);
663 varlink_dispatch_local_error(v, VARLINK_ERROR_DISCONNECTED);
664 varlink_close(v);
665
666 return 1;
667 }
668
669 static int varlink_sanitize_parameters(JsonVariant **v) {
670 assert(v);
671
672 /* Varlink always wants a parameters list, hence make one if the caller doesn't want any */
673 if (!*v)
674 return json_variant_new_object(v, NULL, 0);
675 else if (!json_variant_is_object(*v))
676 return -EINVAL;
677
678 return 0;
679 }
680
681 static int varlink_dispatch_reply(Varlink *v) {
682 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
683 VarlinkReplyFlags flags = 0;
684 const char *error = NULL;
685 JsonVariant *e;
686 const char *k;
687 int r;
688
689 assert(v);
690
691 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING))
692 return 0;
693 if (!v->current)
694 return 0;
695
696 assert(v->n_pending > 0);
697
698 if (!json_variant_is_object(v->current))
699 goto invalid;
700
701 JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
702
703 if (streq(k, "error")) {
704 if (error)
705 goto invalid;
706 if (!json_variant_is_string(e))
707 goto invalid;
708
709 error = json_variant_string(e);
710 flags |= VARLINK_REPLY_ERROR;
711
712 } else if (streq(k, "parameters")) {
713 if (parameters)
714 goto invalid;
715 if (!json_variant_is_object(e))
716 goto invalid;
717
718 parameters = json_variant_ref(e);
719
720 } else if (streq(k, "continues")) {
721 if (FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
722 goto invalid;
723
724 if (!json_variant_is_boolean(e))
725 goto invalid;
726
727 if (json_variant_boolean(e))
728 flags |= VARLINK_REPLY_CONTINUES;
729 } else
730 goto invalid;
731 }
732
733 /* Replies with 'continue' set are only OK if we set 'more' when the method call was initiated */
734 if (v->state != VARLINK_AWAITING_REPLY_MORE && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
735 goto invalid;
736
737 /* An error is final */
738 if (error && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
739 goto invalid;
740
741 r = varlink_sanitize_parameters(&parameters);
742 if (r < 0)
743 goto invalid;
744
745 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE)) {
746 varlink_set_state(v, VARLINK_PROCESSING_REPLY);
747
748 if (v->reply_callback) {
749 r = v->reply_callback(v, parameters, error, flags, v->userdata);
750 if (r < 0)
751 log_debug_errno(r, "Reply callback returned error, ignoring: %m");
752 }
753
754 v->current = json_variant_unref(v->current);
755
756 if (v->state == VARLINK_PROCESSING_REPLY) {
757
758 assert(v->n_pending > 0);
759
760 if (!FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
761 v->n_pending--;
762
763 varlink_set_state(v,
764 FLAGS_SET(flags, VARLINK_REPLY_CONTINUES) ? VARLINK_AWAITING_REPLY_MORE :
765 v->n_pending == 0 ? VARLINK_IDLE_CLIENT : VARLINK_AWAITING_REPLY);
766 }
767 } else {
768 assert(v->state == VARLINK_CALLING);
769 varlink_set_state(v, VARLINK_CALLED);
770 }
771
772 return 1;
773
774 invalid:
775 varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
776 varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
777 varlink_close(v);
778
779 return 1;
780 }
781
782 static int varlink_dispatch_method(Varlink *v) {
783 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
784 VarlinkMethodFlags flags = 0;
785 const char *method = NULL, *error;
786 JsonVariant *e;
787 VarlinkMethod callback;
788 const char *k;
789 int r;
790
791 assert(v);
792
793 if (v->state != VARLINK_IDLE_SERVER)
794 return 0;
795 if (!v->current)
796 return 0;
797
798 if (!json_variant_is_object(v->current))
799 goto invalid;
800
801 JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
802
803 if (streq(k, "method")) {
804 if (method)
805 goto invalid;
806 if (!json_variant_is_string(e))
807 goto invalid;
808
809 method = json_variant_string(e);
810
811 } else if (streq(k, "parameters")) {
812 if (parameters)
813 goto invalid;
814 if (!json_variant_is_object(e))
815 goto invalid;
816
817 parameters = json_variant_ref(e);
818
819 } else if (streq(k, "oneway")) {
820
821 if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
822 goto invalid;
823
824 if (!json_variant_is_boolean(e))
825 goto invalid;
826
827 if (json_variant_boolean(e))
828 flags |= VARLINK_METHOD_ONEWAY;
829
830 } else if (streq(k, "more")) {
831
832 if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
833 goto invalid;
834
835 if (!json_variant_is_boolean(e))
836 goto invalid;
837
838 if (json_variant_boolean(e))
839 flags |= VARLINK_METHOD_MORE;
840
841 } else
842 goto invalid;
843 }
844
845 if (!method)
846 goto invalid;
847
848 r = varlink_sanitize_parameters(&parameters);
849 if (r < 0)
850 goto fail;
851
852 varlink_set_state(v, (flags & VARLINK_METHOD_MORE) ? VARLINK_PROCESSING_METHOD_MORE :
853 (flags & VARLINK_METHOD_ONEWAY) ? VARLINK_PROCESSING_METHOD_ONEWAY :
854 VARLINK_PROCESSING_METHOD);
855
856 assert(v->server);
857
858 if (STR_IN_SET(method, "org.varlink.service.GetInfo", "org.varlink.service.GetInterface")) {
859 /* For now, we don't implement a single of varlink's own methods */
860 callback = NULL;
861 error = VARLINK_ERROR_METHOD_NOT_IMPLEMENTED;
862 } else if (startswith(method, "org.varlink.service.")) {
863 callback = NULL;
864 error = VARLINK_ERROR_METHOD_NOT_FOUND;
865 } else {
866 callback = hashmap_get(v->server->methods, method);
867 error = VARLINK_ERROR_METHOD_NOT_FOUND;
868 }
869
870 if (callback) {
871 r = callback(v, parameters, flags, v->userdata);
872 if (r < 0) {
873 log_debug_errno(r, "Callback for %s returned error: %m", method);
874
875 /* We got an error back from the callback. Propagate it to the client if the method call remains unanswered. */
876 if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
877 r = varlink_error_errno(v, r);
878 if (r < 0)
879 return r;
880 }
881 }
882 } else if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
883 assert(error);
884
885 r = varlink_errorb(v, error, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method))));
886 if (r < 0)
887 return r;
888 }
889
890 switch (v->state) {
891
892 case VARLINK_PROCESSED_METHOD: /* Method call is fully processed */
893 case VARLINK_PROCESSING_METHOD_ONEWAY: /* ditto */
894 v->current = json_variant_unref(v->current);
895 varlink_set_state(v, VARLINK_IDLE_SERVER);
896 break;
897
898 case VARLINK_PROCESSING_METHOD: /* Method call wasn't replied to, will be replied to later */
899 varlink_set_state(v, VARLINK_PENDING_METHOD);
900 break;
901
902 case VARLINK_PROCESSING_METHOD_MORE: /* No reply for a "more" message was sent, more to come */
903 varlink_set_state(v, VARLINK_PENDING_METHOD_MORE);
904 break;
905
906 default:
907 assert_not_reached("Unexpected state");
908
909 }
910
911 return r;
912
913 invalid:
914 r = -EINVAL;
915
916 fail:
917 varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
918 varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
919 varlink_close(v);
920
921 return r;
922 }
923
924 int varlink_process(Varlink *v) {
925 int r;
926
927 assert_return(v, -EINVAL);
928
929 if (v->state == VARLINK_DISCONNECTED)
930 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
931
932 varlink_ref(v);
933
934 r = varlink_write(v);
935 if (r < 0)
936 varlink_log_errno(v, r, "Write failed: %m");
937 if (r != 0)
938 goto finish;
939
940 r = varlink_dispatch_reply(v);
941 if (r < 0)
942 varlink_log_errno(v, r, "Reply dispatch failed: %m");
943 if (r != 0)
944 goto finish;
945
946 r = varlink_dispatch_method(v);
947 if (r < 0)
948 varlink_log_errno(v, r, "Method dispatch failed: %m");
949 if (r != 0)
950 goto finish;
951
952 r = varlink_parse_message(v);
953 if (r < 0)
954 varlink_log_errno(v, r, "Message parsing failed: %m");
955 if (r != 0)
956 goto finish;
957
958 r = varlink_read(v);
959 if (r < 0)
960 varlink_log_errno(v, r, "Read failed: %m");
961 if (r != 0)
962 goto finish;
963
964 r = varlink_test_disconnect(v);
965 assert(r >= 0);
966 if (r != 0)
967 goto finish;
968
969 r = varlink_dispatch_disconnect(v);
970 assert(r >= 0);
971 if (r != 0)
972 goto finish;
973
974 r = varlink_test_timeout(v);
975 assert(r >= 0);
976 if (r != 0)
977 goto finish;
978
979 r = varlink_dispatch_timeout(v);
980 assert(r >= 0);
981 if (r != 0)
982 goto finish;
983
984 finish:
985 if (r >= 0 && v->defer_event_source) {
986 int q;
987
988 /* If we did some processing, make sure we are called again soon */
989 q = sd_event_source_set_enabled(v->defer_event_source, r > 0 ? SD_EVENT_ON : SD_EVENT_OFF);
990 if (q < 0)
991 r = varlink_log_errno(v, q, "Failed to enable deferred event source: %m");
992 }
993
994 if (r < 0) {
995 if (VARLINK_STATE_IS_ALIVE(v->state))
996 /* Initiate disconnection */
997 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
998 else
999 /* We failed while disconnecting, in that case close right away */
1000 varlink_close(v);
1001 }
1002
1003 varlink_unref(v);
1004 return r;
1005 }
1006
1007 static void handle_revents(Varlink *v, int revents) {
1008 assert(v);
1009
1010 if (v->connecting) {
1011 /* If we have seen POLLOUT or POLLHUP on a socket we are asynchronously waiting a connect()
1012 * to complete on, we know we are ready. We don't read the connection error here though,
1013 * we'll get the error on the next read() or write(). */
1014 if ((revents & (POLLOUT|POLLHUP)) == 0)
1015 return;
1016
1017 varlink_log(v, "Anynchronous connection completed.");
1018 v->connecting = false;
1019 } else {
1020 /* Note that we don't care much about POLLIN/POLLOUT here, we'll just try reading and writing
1021 * what we can. However, we do care about POLLHUP to detect connection termination even if we
1022 * momentarily don't want to read nor write anything. */
1023
1024 if (!FLAGS_SET(revents, POLLHUP))
1025 return;
1026
1027 varlink_log(v, "Got POLLHUP from socket.");
1028 v->got_pollhup = true;
1029 }
1030 }
1031
1032 int varlink_wait(Varlink *v, usec_t timeout) {
1033 int r, fd, events;
1034 usec_t t;
1035
1036 assert_return(v, -EINVAL);
1037
1038 if (v->state == VARLINK_DISCONNECTED)
1039 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1040
1041 r = varlink_get_timeout(v, &t);
1042 if (r < 0)
1043 return r;
1044 if (t != USEC_INFINITY) {
1045 usec_t n;
1046
1047 n = now(CLOCK_MONOTONIC);
1048 if (t < n)
1049 t = 0;
1050 else
1051 t = usec_sub_unsigned(t, n);
1052 }
1053
1054 if (timeout != USEC_INFINITY &&
1055 (t == USEC_INFINITY || timeout < t))
1056 t = timeout;
1057
1058 fd = varlink_get_fd(v);
1059 if (fd < 0)
1060 return fd;
1061
1062 events = varlink_get_events(v);
1063 if (events < 0)
1064 return events;
1065
1066 r = fd_wait_for_event(fd, events, t);
1067 if (r <= 0)
1068 return r;
1069
1070 handle_revents(v, r);
1071 return 1;
1072 }
1073
1074 int varlink_get_fd(Varlink *v) {
1075
1076 assert_return(v, -EINVAL);
1077
1078 if (v->state == VARLINK_DISCONNECTED)
1079 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1080 if (v->fd < 0)
1081 return varlink_log_errno(v, SYNTHETIC_ERRNO(EBADF), "No valid fd.");
1082
1083 return v->fd;
1084 }
1085
1086 int varlink_get_events(Varlink *v) {
1087 int ret = 0;
1088
1089 assert_return(v, -EINVAL);
1090
1091 if (v->state == VARLINK_DISCONNECTED)
1092 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1093
1094 if (v->connecting) /* When processing an asynchronous connect(), we only wait for EPOLLOUT, which
1095 * tells us that the connection is now complete. Before that we should neither
1096 * write() or read() from the fd. */
1097 return EPOLLOUT;
1098
1099 if (!v->read_disconnected &&
1100 IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) &&
1101 !v->current &&
1102 v->input_buffer_unscanned <= 0)
1103 ret |= EPOLLIN;
1104
1105 if (!v->write_disconnected &&
1106 v->output_buffer_size > 0)
1107 ret |= EPOLLOUT;
1108
1109 return ret;
1110 }
1111
1112 int varlink_get_timeout(Varlink *v, usec_t *ret) {
1113 assert_return(v, -EINVAL);
1114
1115 if (v->state == VARLINK_DISCONNECTED)
1116 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1117
1118 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING) &&
1119 v->timeout != USEC_INFINITY) {
1120 if (ret)
1121 *ret = usec_add(v->timestamp, v->timeout);
1122 return 1;
1123 } else {
1124 if (ret)
1125 *ret = USEC_INFINITY;
1126 return 0;
1127 }
1128 }
1129
1130 int varlink_flush(Varlink *v) {
1131 int ret = 0, r;
1132
1133 assert_return(v, -EINVAL);
1134
1135 if (v->state == VARLINK_DISCONNECTED)
1136 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1137
1138 for (;;) {
1139 if (v->output_buffer_size == 0)
1140 break;
1141 if (v->write_disconnected)
1142 return -ECONNRESET;
1143
1144 r = varlink_write(v);
1145 if (r < 0)
1146 return r;
1147 if (r > 0) {
1148 ret = 1;
1149 continue;
1150 }
1151
1152 r = fd_wait_for_event(v->fd, POLLOUT, USEC_INFINITY);
1153 if (r < 0)
1154 return varlink_log_errno(v, r, "Poll failed on fd: %m");
1155
1156 assert(r != 0);
1157
1158 handle_revents(v, r);
1159 }
1160
1161 return ret;
1162 }
1163
1164 static void varlink_detach_server(Varlink *v) {
1165 VarlinkServer *saved_server;
1166 assert(v);
1167
1168 if (!v->server)
1169 return;
1170
1171 if (v->server->by_uid &&
1172 v->ucred_acquired &&
1173 uid_is_valid(v->ucred.uid)) {
1174 unsigned c;
1175
1176 c = PTR_TO_UINT(hashmap_get(v->server->by_uid, UID_TO_PTR(v->ucred.uid)));
1177 assert(c > 0);
1178
1179 if (c == 1)
1180 (void) hashmap_remove(v->server->by_uid, UID_TO_PTR(v->ucred.uid));
1181 else
1182 (void) hashmap_replace(v->server->by_uid, UID_TO_PTR(v->ucred.uid), UINT_TO_PTR(c - 1));
1183 }
1184
1185 assert(v->server->n_connections > 0);
1186 v->server->n_connections--;
1187
1188 /* If this is a connection associated to a server, then let's disconnect the server and the
1189 * connection from each other. This drops the dangling reference that connect_callback() set up. But
1190 * before we release the references, let's call the disconnection callback if it is defined. */
1191
1192 saved_server = TAKE_PTR(v->server);
1193
1194 if (saved_server->disconnect_callback)
1195 saved_server->disconnect_callback(saved_server, v, saved_server->userdata);
1196
1197 varlink_server_unref(saved_server);
1198 varlink_unref(v);
1199 }
1200
1201 int varlink_close(Varlink *v) {
1202 assert_return(v, -EINVAL);
1203
1204 if (v->state == VARLINK_DISCONNECTED)
1205 return 0;
1206
1207 varlink_set_state(v, VARLINK_DISCONNECTED);
1208
1209 /* Let's take a reference first, since varlink_detach_server() might drop the final (dangling) ref
1210 * which would destroy us before we can call varlink_clear() */
1211 varlink_ref(v);
1212 varlink_detach_server(v);
1213 varlink_clear(v);
1214 varlink_unref(v);
1215
1216 return 1;
1217 }
1218
1219 Varlink* varlink_close_unref(Varlink *v) {
1220 if (!v)
1221 return NULL;
1222
1223 (void) varlink_close(v);
1224 return varlink_unref(v);
1225 }
1226
1227 Varlink* varlink_flush_close_unref(Varlink *v) {
1228 if (!v)
1229 return NULL;
1230
1231 (void) varlink_flush(v);
1232 (void) varlink_close(v);
1233 return varlink_unref(v);
1234 }
1235
1236 static int varlink_enqueue_json(Varlink *v, JsonVariant *m) {
1237 _cleanup_free_ char *text = NULL;
1238 int r;
1239
1240 assert(v);
1241 assert(m);
1242
1243 r = json_variant_format(m, 0, &text);
1244 if (r < 0)
1245 return r;
1246 assert(text[r] == '\0');
1247
1248 if (v->output_buffer_size + r + 1 > VARLINK_BUFFER_MAX)
1249 return -ENOBUFS;
1250
1251 varlink_log(v, "Sending message: %s", text);
1252
1253 if (v->output_buffer_size == 0) {
1254
1255 free_and_replace(v->output_buffer, text);
1256
1257 v->output_buffer_size = v->output_buffer_allocated = r + 1;
1258 v->output_buffer_index = 0;
1259
1260 } else if (v->output_buffer_index == 0) {
1261
1262 if (!GREEDY_REALLOC(v->output_buffer, v->output_buffer_allocated, v->output_buffer_size + r + 1))
1263 return -ENOMEM;
1264
1265 memcpy(v->output_buffer + v->output_buffer_size, text, r + 1);
1266 v->output_buffer_size += r + 1;
1267
1268 } else {
1269 char *n;
1270 const size_t new_size = v->output_buffer_size + r + 1;
1271
1272 n = new(char, new_size);
1273 if (!n)
1274 return -ENOMEM;
1275
1276 memcpy(mempcpy(n, v->output_buffer + v->output_buffer_index, v->output_buffer_size), text, r + 1);
1277
1278 free_and_replace(v->output_buffer, n);
1279 v->output_buffer_allocated = v->output_buffer_size = new_size;
1280 v->output_buffer_index = 0;
1281 }
1282
1283 return 0;
1284 }
1285
1286 int varlink_send(Varlink *v, const char *method, JsonVariant *parameters) {
1287 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1288 int r;
1289
1290 assert_return(v, -EINVAL);
1291 assert_return(method, -EINVAL);
1292
1293 if (v->state == VARLINK_DISCONNECTED)
1294 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1295
1296 /* We allow enqueuing multiple method calls at once! */
1297 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1298 return varlink_log_errno(v, SYNTHETIC_ERRNO(EBUSY), "Connection busy.");
1299
1300 r = varlink_sanitize_parameters(&parameters);
1301 if (r < 0)
1302 return varlink_log_errno(v, r, "Failed to sanitize parameters: %m");
1303
1304 r = json_build(&m, JSON_BUILD_OBJECT(
1305 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1306 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1307 JSON_BUILD_PAIR("oneway", JSON_BUILD_BOOLEAN(true))));
1308 if (r < 0)
1309 return varlink_log_errno(v, r, "Failed to build json message: %m");
1310
1311 r = varlink_enqueue_json(v, m);
1312 if (r < 0)
1313 return varlink_log_errno(v, r, "Failed to enqueue json message: %m");
1314
1315 /* No state change here, this is one-way only after all */
1316 v->timestamp = now(CLOCK_MONOTONIC);
1317 return 0;
1318 }
1319
1320 int varlink_sendb(Varlink *v, const char *method, ...) {
1321 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1322 va_list ap;
1323 int r;
1324
1325 assert_return(v, -EINVAL);
1326
1327 va_start(ap, method);
1328 r = json_buildv(&parameters, ap);
1329 va_end(ap);
1330
1331 if (r < 0)
1332 return varlink_log_errno(v, r, "Failed to build json message: %m");
1333
1334 return varlink_send(v, method, parameters);
1335 }
1336
1337 int varlink_invoke(Varlink *v, const char *method, JsonVariant *parameters) {
1338 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1339 int r;
1340
1341 assert_return(v, -EINVAL);
1342 assert_return(method, -EINVAL);
1343
1344 if (v->state == VARLINK_DISCONNECTED)
1345 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1346
1347 /* We allow enqueuing multiple method calls at once! */
1348 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1349 return varlink_log_errno(v, SYNTHETIC_ERRNO(EBUSY), "Connection busy.");
1350
1351 r = varlink_sanitize_parameters(&parameters);
1352 if (r < 0)
1353 return varlink_log_errno(v, r, "Failed to sanitize parameters: %m");
1354
1355 r = json_build(&m, JSON_BUILD_OBJECT(
1356 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1357 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1358 if (r < 0)
1359 return varlink_log_errno(v, r, "Failed to build json message: %m");
1360
1361 r = varlink_enqueue_json(v, m);
1362 if (r < 0)
1363 return varlink_log_errno(v, r, "Failed to enqueue json message: %m");
1364
1365 varlink_set_state(v, VARLINK_AWAITING_REPLY);
1366 v->n_pending++;
1367 v->timestamp = now(CLOCK_MONOTONIC);
1368
1369 return 0;
1370 }
1371
1372 int varlink_invokeb(Varlink *v, const char *method, ...) {
1373 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1374 va_list ap;
1375 int r;
1376
1377 assert_return(v, -EINVAL);
1378
1379 va_start(ap, method);
1380 r = json_buildv(&parameters, ap);
1381 va_end(ap);
1382
1383 if (r < 0)
1384 return varlink_log_errno(v, r, "Failed to build json message: %m");
1385
1386 return varlink_invoke(v, method, parameters);
1387 }
1388
1389 int varlink_observe(Varlink *v, const char *method, JsonVariant *parameters) {
1390 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1391 int r;
1392
1393 assert_return(v, -EINVAL);
1394 assert_return(method, -EINVAL);
1395
1396 if (v->state == VARLINK_DISCONNECTED)
1397 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1398
1399 /* Note that we don't allow enqueuing multiple method calls when we are in more/continues mode! We
1400 * thus insist on an idle client here. */
1401 if (v->state != VARLINK_IDLE_CLIENT)
1402 return varlink_log_errno(v, SYNTHETIC_ERRNO(EBUSY), "Connection busy.");
1403
1404 r = varlink_sanitize_parameters(&parameters);
1405 if (r < 0)
1406 return varlink_log_errno(v, r, "Failed to sanitize parameters: %m");
1407
1408 r = json_build(&m, JSON_BUILD_OBJECT(
1409 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1410 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1411 JSON_BUILD_PAIR("more", JSON_BUILD_BOOLEAN(true))));
1412 if (r < 0)
1413 return varlink_log_errno(v, r, "Failed to build json message: %m");
1414
1415 r = varlink_enqueue_json(v, m);
1416 if (r < 0)
1417 return varlink_log_errno(v, r, "Failed to enqueue json message: %m");
1418
1419 varlink_set_state(v, VARLINK_AWAITING_REPLY_MORE);
1420 v->n_pending++;
1421 v->timestamp = now(CLOCK_MONOTONIC);
1422
1423 return 0;
1424 }
1425
1426 int varlink_observeb(Varlink *v, const char *method, ...) {
1427 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1428 va_list ap;
1429 int r;
1430
1431 assert_return(v, -EINVAL);
1432
1433 va_start(ap, method);
1434 r = json_buildv(&parameters, ap);
1435 va_end(ap);
1436
1437 if (r < 0)
1438 return varlink_log_errno(v, r, "Failed to build json message: %m");
1439
1440 return varlink_observe(v, method, parameters);
1441 }
1442
1443 int varlink_call(
1444 Varlink *v,
1445 const char *method,
1446 JsonVariant *parameters,
1447 JsonVariant **ret_parameters,
1448 const char **ret_error_id,
1449 VarlinkReplyFlags *ret_flags) {
1450
1451 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1452 int r;
1453
1454 assert_return(v, -EINVAL);
1455 assert_return(method, -EINVAL);
1456
1457 if (v->state == VARLINK_DISCONNECTED)
1458 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1459 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT))
1460 return varlink_log_errno(v, SYNTHETIC_ERRNO(EBUSY), "Connection busy.");
1461
1462 assert(v->n_pending == 0); /* n_pending can't be > 0 if we are in VARLINK_IDLE_CLIENT state */
1463
1464 r = varlink_sanitize_parameters(&parameters);
1465 if (r < 0)
1466 return varlink_log_errno(v, r, "Failed to sanitize parameters: %m");
1467
1468 r = json_build(&m, JSON_BUILD_OBJECT(
1469 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1470 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1471 if (r < 0)
1472 return varlink_log_errno(v, r, "Failed to build json message: %m");
1473
1474 r = varlink_enqueue_json(v, m);
1475 if (r < 0)
1476 return varlink_log_errno(v, r, "Failed to enqueue json message: %m");
1477
1478 varlink_set_state(v, VARLINK_CALLING);
1479 v->n_pending++;
1480 v->timestamp = now(CLOCK_MONOTONIC);
1481
1482 while (v->state == VARLINK_CALLING) {
1483
1484 r = varlink_process(v);
1485 if (r < 0)
1486 return r;
1487 if (r > 0)
1488 continue;
1489
1490 r = varlink_wait(v, USEC_INFINITY);
1491 if (r < 0)
1492 return r;
1493 }
1494
1495 switch (v->state) {
1496
1497 case VARLINK_CALLED:
1498 assert(v->current);
1499
1500 json_variant_unref(v->reply);
1501 v->reply = TAKE_PTR(v->current);
1502
1503 varlink_set_state(v, VARLINK_IDLE_CLIENT);
1504 assert(v->n_pending == 1);
1505 v->n_pending--;
1506
1507 if (ret_parameters)
1508 *ret_parameters = json_variant_by_key(v->reply, "parameters");
1509 if (ret_error_id)
1510 *ret_error_id = json_variant_string(json_variant_by_key(v->reply, "error"));
1511 if (ret_flags)
1512 *ret_flags = 0;
1513
1514 return 1;
1515
1516 case VARLINK_PENDING_DISCONNECT:
1517 case VARLINK_DISCONNECTED:
1518 return varlink_log_errno(v, SYNTHETIC_ERRNO(ECONNRESET), "Connection was closed.");
1519
1520 case VARLINK_PENDING_TIMEOUT:
1521 return varlink_log_errno(v, SYNTHETIC_ERRNO(ETIME), "Connection timed out.");
1522
1523 default:
1524 assert_not_reached("Unexpected state after method call.");
1525 }
1526 }
1527
1528 int varlink_callb(
1529 Varlink *v,
1530 const char *method,
1531 JsonVariant **ret_parameters,
1532 const char **ret_error_id,
1533 VarlinkReplyFlags *ret_flags, ...) {
1534
1535 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1536 va_list ap;
1537 int r;
1538
1539 assert_return(v, -EINVAL);
1540
1541 va_start(ap, ret_flags);
1542 r = json_buildv(&parameters, ap);
1543 va_end(ap);
1544
1545 if (r < 0)
1546 return varlink_log_errno(v, r, "Failed to build json message: %m");
1547
1548 return varlink_call(v, method, parameters, ret_parameters, ret_error_id, ret_flags);
1549 }
1550
1551 int varlink_reply(Varlink *v, JsonVariant *parameters) {
1552 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1553 int r;
1554
1555 assert_return(v, -EINVAL);
1556
1557 if (v->state == VARLINK_DISCONNECTED)
1558 return -ENOTCONN;
1559 if (!IN_SET(v->state,
1560 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1561 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1562 return -EBUSY;
1563
1564 r = varlink_sanitize_parameters(&parameters);
1565 if (r < 0)
1566 return varlink_log_errno(v, r, "Failed to sanitize parameters: %m");
1567
1568 r = json_build(&m, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1569 if (r < 0)
1570 return varlink_log_errno(v, r, "Failed to build json message: %m");
1571
1572 r = varlink_enqueue_json(v, m);
1573 if (r < 0)
1574 return varlink_log_errno(v, r, "Failed to enqueue json message: %m");
1575
1576 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1577 /* We just replied to a method call that was let hanging for a while (i.e. we were outside of
1578 * the varlink_dispatch_method() stack frame), which means with this reply we are ready to
1579 * process further messages. */
1580 v->current = json_variant_unref(v->current);
1581 varlink_set_state(v, VARLINK_IDLE_SERVER);
1582 } else
1583 /* We replied to a method call from within the varlink_dispatch_method() stack frame), which
1584 * means we should it handle the rest of the state engine. */
1585 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1586
1587 return 1;
1588 }
1589
1590 int varlink_replyb(Varlink *v, ...) {
1591 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1592 va_list ap;
1593 int r;
1594
1595 assert_return(v, -EINVAL);
1596
1597 va_start(ap, v);
1598 r = json_buildv(&parameters, ap);
1599 va_end(ap);
1600
1601 if (r < 0)
1602 return r;
1603
1604 return varlink_reply(v, parameters);
1605 }
1606
1607 int varlink_error(Varlink *v, const char *error_id, JsonVariant *parameters) {
1608 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1609 int r;
1610
1611 assert_return(v, -EINVAL);
1612 assert_return(error_id, -EINVAL);
1613
1614 if (v->state == VARLINK_DISCONNECTED)
1615 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1616 if (!IN_SET(v->state,
1617 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1618 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1619 return varlink_log_errno(v, SYNTHETIC_ERRNO(EBUSY), "Connection busy.");
1620
1621 r = varlink_sanitize_parameters(&parameters);
1622 if (r < 0)
1623 return varlink_log_errno(v, r, "Failed to sanitize parameters: %m");
1624
1625 r = json_build(&m, JSON_BUILD_OBJECT(
1626 JSON_BUILD_PAIR("error", JSON_BUILD_STRING(error_id)),
1627 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1628 if (r < 0)
1629 return varlink_log_errno(v, r, "Failed to build json message: %m");
1630
1631 r = varlink_enqueue_json(v, m);
1632 if (r < 0)
1633 return varlink_log_errno(v, r, "Failed to enqueue json message: %m");
1634
1635 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1636 v->current = json_variant_unref(v->current);
1637 varlink_set_state(v, VARLINK_IDLE_SERVER);
1638 } else
1639 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1640
1641 return 1;
1642 }
1643
1644 int varlink_errorb(Varlink *v, const char *error_id, ...) {
1645 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1646 va_list ap;
1647 int r;
1648
1649 assert_return(v, -EINVAL);
1650 assert_return(error_id, -EINVAL);
1651
1652 va_start(ap, error_id);
1653 r = json_buildv(&parameters, ap);
1654 va_end(ap);
1655
1656 if (r < 0)
1657 return varlink_log_errno(v, r, "Failed to build json message: %m");
1658
1659 return varlink_error(v, error_id, parameters);
1660 }
1661
1662 int varlink_error_invalid_parameter(Varlink *v, JsonVariant *parameters) {
1663
1664 assert_return(v, -EINVAL);
1665 assert_return(parameters, -EINVAL);
1666
1667 /* We expect to be called in one of two ways: the 'parameters' argument is a string variant in which
1668 * case it is the parameter key name that is invalid. Or the 'parameters' argument is an object
1669 * variant in which case we'll pull out the first key. The latter mode is useful in functions that
1670 * don't expect any arguments. */
1671
1672 if (json_variant_is_string(parameters))
1673 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER, parameters);
1674
1675 if (json_variant_is_object(parameters) &&
1676 json_variant_elements(parameters) > 0)
1677 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER,
1678 json_variant_by_index(parameters, 0));
1679
1680 return -EINVAL;
1681 }
1682
1683 int varlink_error_errno(Varlink *v, int error) {
1684 return varlink_errorb(
1685 v,
1686 VARLINK_ERROR_SYSTEM,
1687 JSON_BUILD_OBJECT(JSON_BUILD_PAIR("errno", JSON_BUILD_INTEGER(abs(error)))));
1688 }
1689
1690 int varlink_notify(Varlink *v, JsonVariant *parameters) {
1691 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1692 int r;
1693
1694 assert_return(v, -EINVAL);
1695
1696 if (v->state == VARLINK_DISCONNECTED)
1697 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENOTCONN), "Not connected.");
1698 if (!IN_SET(v->state, VARLINK_PROCESSING_METHOD_MORE, VARLINK_PENDING_METHOD_MORE))
1699 return varlink_log_errno(v, SYNTHETIC_ERRNO(EBUSY), "Connection busy.");
1700
1701 r = varlink_sanitize_parameters(&parameters);
1702 if (r < 0)
1703 return varlink_log_errno(v, r, "Failed to sanitize parameters: %m");
1704
1705 r = json_build(&m, JSON_BUILD_OBJECT(
1706 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1707 JSON_BUILD_PAIR("continues", JSON_BUILD_BOOLEAN(true))));
1708 if (r < 0)
1709 return varlink_log_errno(v, r, "Failed to build json message: %m");
1710
1711 r = varlink_enqueue_json(v, m);
1712 if (r < 0)
1713 return varlink_log_errno(v, r, "Failed to enqueue json message: %m");
1714
1715 /* No state change, as more is coming */
1716 return 1;
1717 }
1718
1719 int varlink_notifyb(Varlink *v, ...) {
1720 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1721 va_list ap;
1722 int r;
1723
1724 assert_return(v, -EINVAL);
1725
1726 va_start(ap, v);
1727 r = json_buildv(&parameters, ap);
1728 va_end(ap);
1729
1730 if (r < 0)
1731 return varlink_log_errno(v, r, "Failed to build json message: %m");
1732
1733 return varlink_notify(v, parameters);
1734 }
1735
1736 int varlink_bind_reply(Varlink *v, VarlinkReply callback) {
1737 assert_return(v, -EINVAL);
1738
1739 if (callback && v->reply_callback && callback != v->reply_callback)
1740 return varlink_log_errno(v, SYNTHETIC_ERRNO(EBUSY), "A different callback was already set.");
1741
1742 v->reply_callback = callback;
1743
1744 return 0;
1745 }
1746
1747 void* varlink_set_userdata(Varlink *v, void *userdata) {
1748 void *old;
1749
1750 assert_return(v, NULL);
1751
1752 old = v->userdata;
1753 v->userdata = userdata;
1754
1755 return old;
1756 }
1757
1758 void* varlink_get_userdata(Varlink *v) {
1759 assert_return(v, NULL);
1760
1761 return v->userdata;
1762 }
1763
1764 static int varlink_acquire_ucred(Varlink *v) {
1765 int r;
1766
1767 assert(v);
1768
1769 if (v->ucred_acquired)
1770 return 0;
1771
1772 r = getpeercred(v->fd, &v->ucred);
1773 if (r < 0)
1774 return r;
1775
1776 v->ucred_acquired = true;
1777 return 0;
1778 }
1779
1780 int varlink_get_peer_uid(Varlink *v, uid_t *ret) {
1781 int r;
1782
1783 assert_return(v, -EINVAL);
1784 assert_return(ret, -EINVAL);
1785
1786 r = varlink_acquire_ucred(v);
1787 if (r < 0)
1788 return varlink_log_errno(v, r, "Failed to acquire credentials: %m");
1789
1790 if (!uid_is_valid(v->ucred.uid))
1791 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENODATA), "Peer uid is invalid.");
1792
1793 *ret = v->ucred.uid;
1794 return 0;
1795 }
1796
1797 int varlink_get_peer_pid(Varlink *v, pid_t *ret) {
1798 int r;
1799
1800 assert_return(v, -EINVAL);
1801 assert_return(ret, -EINVAL);
1802
1803 r = varlink_acquire_ucred(v);
1804 if (r < 0)
1805 return varlink_log_errno(v, r, "Failed to acquire credentials: %m");
1806
1807 if (!pid_is_valid(v->ucred.pid))
1808 return varlink_log_errno(v, SYNTHETIC_ERRNO(ENODATA), "Peer uid is invalid.");
1809
1810 *ret = v->ucred.pid;
1811 return 0;
1812 }
1813
1814 int varlink_set_relative_timeout(Varlink *v, usec_t timeout) {
1815 assert_return(v, -EINVAL);
1816 assert_return(timeout > 0, -EINVAL);
1817
1818 v->timeout = timeout;
1819 return 0;
1820 }
1821
1822 VarlinkServer *varlink_get_server(Varlink *v) {
1823 assert_return(v, NULL);
1824
1825 return v->server;
1826 }
1827
1828 int varlink_set_description(Varlink *v, const char *description) {
1829 assert_return(v, -EINVAL);
1830
1831 return free_and_strdup(&v->description, description);
1832 }
1833
1834 static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
1835 Varlink *v = userdata;
1836
1837 assert(s);
1838 assert(v);
1839
1840 handle_revents(v, revents);
1841 (void) varlink_process(v);
1842
1843 return 1;
1844 }
1845
1846 static int time_callback(sd_event_source *s, uint64_t usec, void *userdata) {
1847 Varlink *v = userdata;
1848
1849 assert(s);
1850 assert(v);
1851
1852 (void) varlink_process(v);
1853 return 1;
1854 }
1855
1856 static int defer_callback(sd_event_source *s, void *userdata) {
1857 Varlink *v = userdata;
1858
1859 assert(s);
1860 assert(v);
1861
1862 (void) varlink_process(v);
1863 return 1;
1864 }
1865
1866 static int prepare_callback(sd_event_source *s, void *userdata) {
1867 Varlink *v = userdata;
1868 int r, e;
1869 usec_t until;
1870 bool have_timeout;
1871
1872 assert(s);
1873 assert(v);
1874
1875 e = varlink_get_events(v);
1876 if (e < 0)
1877 return e;
1878
1879 r = sd_event_source_set_io_events(v->io_event_source, e);
1880 if (r < 0)
1881 return varlink_log_errno(v, r, "Failed to set source events: %m");
1882
1883 r = varlink_get_timeout(v, &until);
1884 if (r < 0)
1885 return r;
1886 have_timeout = r > 0;
1887
1888 if (have_timeout) {
1889 r = sd_event_source_set_time(v->time_event_source, until);
1890 if (r < 0)
1891 return varlink_log_errno(v, r, "Failed to set source time: %m");
1892 }
1893
1894 r = sd_event_source_set_enabled(v->time_event_source, have_timeout ? SD_EVENT_ON : SD_EVENT_OFF);
1895 if (r < 0)
1896 return varlink_log_errno(v, r, "Failed to enable event source: %m");
1897
1898 return 1;
1899 }
1900
1901 static int quit_callback(sd_event_source *event, void *userdata) {
1902 Varlink *v = userdata;
1903
1904 assert(event);
1905 assert(v);
1906
1907 varlink_flush(v);
1908 varlink_close(v);
1909
1910 return 1;
1911 }
1912
1913 int varlink_attach_event(Varlink *v, sd_event *e, int64_t priority) {
1914 int r;
1915
1916 assert_return(v, -EINVAL);
1917 assert_return(!v->event, -EBUSY);
1918
1919 if (e)
1920 v->event = sd_event_ref(e);
1921 else {
1922 r = sd_event_default(&v->event);
1923 if (r < 0)
1924 return varlink_log_errno(v, r, "Failed to create event source: %m");
1925 }
1926
1927 r = sd_event_add_time(v->event, &v->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, v);
1928 if (r < 0)
1929 goto fail;
1930
1931 r = sd_event_source_set_priority(v->time_event_source, priority);
1932 if (r < 0)
1933 goto fail;
1934
1935 (void) sd_event_source_set_description(v->time_event_source, "varlink-time");
1936
1937 r = sd_event_add_exit(v->event, &v->quit_event_source, quit_callback, v);
1938 if (r < 0)
1939 goto fail;
1940
1941 r = sd_event_source_set_priority(v->quit_event_source, priority);
1942 if (r < 0)
1943 goto fail;
1944
1945 (void) sd_event_source_set_description(v->quit_event_source, "varlink-quit");
1946
1947 r = sd_event_add_io(v->event, &v->io_event_source, v->fd, 0, io_callback, v);
1948 if (r < 0)
1949 goto fail;
1950
1951 r = sd_event_source_set_prepare(v->io_event_source, prepare_callback);
1952 if (r < 0)
1953 goto fail;
1954
1955 r = sd_event_source_set_priority(v->io_event_source, priority);
1956 if (r < 0)
1957 goto fail;
1958
1959 (void) sd_event_source_set_description(v->io_event_source, "varlink-io");
1960
1961 r = sd_event_add_defer(v->event, &v->defer_event_source, defer_callback, v);
1962 if (r < 0)
1963 goto fail;
1964
1965 r = sd_event_source_set_priority(v->defer_event_source, priority);
1966 if (r < 0)
1967 goto fail;
1968
1969 (void) sd_event_source_set_description(v->defer_event_source, "varlink-defer");
1970
1971 return 0;
1972
1973 fail:
1974 varlink_log_errno(v, r, "Failed to setup event source: %m");
1975 varlink_detach_event(v);
1976 return r;
1977 }
1978
1979 void varlink_detach_event(Varlink *v) {
1980 if (!v)
1981 return;
1982
1983 varlink_detach_event_sources(v);
1984
1985 v->event = sd_event_unref(v->event);
1986 }
1987
1988 sd_event *varlink_get_event(Varlink *v) {
1989 assert_return(v, NULL);
1990
1991 return v->event;
1992 }
1993
1994 int varlink_server_new(VarlinkServer **ret, VarlinkServerFlags flags) {
1995 VarlinkServer *s;
1996
1997 assert_return(ret, -EINVAL);
1998 assert_return((flags & ~_VARLINK_SERVER_FLAGS_ALL) == 0, -EINVAL);
1999
2000 s = new(VarlinkServer, 1);
2001 if (!s)
2002 return log_oom_debug();
2003
2004 *s = (VarlinkServer) {
2005 .n_ref = 1,
2006 .flags = flags,
2007 .connections_max = varlink_server_connections_max(NULL),
2008 .connections_per_uid_max = varlink_server_connections_per_uid_max(NULL),
2009 };
2010
2011 *ret = s;
2012 return 0;
2013 }
2014
2015 static VarlinkServer* varlink_server_destroy(VarlinkServer *s) {
2016 char *m;
2017
2018 if (!s)
2019 return NULL;
2020
2021 varlink_server_shutdown(s);
2022
2023 while ((m = hashmap_steal_first_key(s->methods)))
2024 free(m);
2025
2026 hashmap_free(s->methods);
2027 hashmap_free(s->by_uid);
2028
2029 sd_event_unref(s->event);
2030
2031 free(s->description);
2032
2033 return mfree(s);
2034 }
2035
2036 DEFINE_TRIVIAL_REF_UNREF_FUNC(VarlinkServer, varlink_server, varlink_server_destroy);
2037
2038 static int validate_connection(VarlinkServer *server, const struct ucred *ucred) {
2039 int allowed = -1;
2040
2041 assert(server);
2042 assert(ucred);
2043
2044 if (FLAGS_SET(server->flags, VARLINK_SERVER_ROOT_ONLY))
2045 allowed = ucred->uid == 0;
2046
2047 if (FLAGS_SET(server->flags, VARLINK_SERVER_MYSELF_ONLY))
2048 allowed = allowed > 0 || ucred->uid == getuid();
2049
2050 if (allowed == 0) { /* Allow access when it is explicitly allowed or when neither
2051 * VARLINK_SERVER_ROOT_ONLY nor VARLINK_SERVER_MYSELF_ONLY are specified. */
2052 varlink_server_log(server, "Unprivileged client attempted connection, refusing.");
2053 return 0;
2054 }
2055
2056 if (server->n_connections >= server->connections_max) {
2057 varlink_server_log(server, "Connection limit of %u reached, refusing.", server->connections_max);
2058 return 0;
2059 }
2060
2061 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
2062 unsigned c;
2063
2064 if (!uid_is_valid(ucred->uid)) {
2065 varlink_server_log(server, "Client with invalid UID attempted connection, refusing.");
2066 return 0;
2067 }
2068
2069 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
2070 if (c >= server->connections_per_uid_max) {
2071 varlink_server_log(server, "Per-UID connection limit of %u reached, refusing.",
2072 server->connections_per_uid_max);
2073 return 0;
2074 }
2075 }
2076
2077 return 1;
2078 }
2079
2080 static int count_connection(VarlinkServer *server, struct ucred *ucred) {
2081 unsigned c;
2082 int r;
2083
2084 assert(server);
2085 assert(ucred);
2086
2087 server->n_connections++;
2088
2089 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
2090 r = hashmap_ensure_allocated(&server->by_uid, NULL);
2091 if (r < 0)
2092 return log_debug_errno(r, "Failed to allocate UID hash table: %m");
2093
2094 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
2095
2096 varlink_server_log(server, "Connections of user " UID_FMT ": %u (of %u max)",
2097 ucred->uid, c, server->connections_per_uid_max);
2098
2099 r = hashmap_replace(server->by_uid, UID_TO_PTR(ucred->uid), UINT_TO_PTR(c + 1));
2100 if (r < 0)
2101 return log_debug_errno(r, "Failed to increment counter in UID hash table: %m");
2102 }
2103
2104 return 0;
2105 }
2106
2107 int varlink_server_add_connection(VarlinkServer *server, int fd, Varlink **ret) {
2108 _cleanup_(varlink_unrefp) Varlink *v = NULL;
2109 bool ucred_acquired;
2110 struct ucred ucred;
2111 int r;
2112
2113 assert_return(server, -EINVAL);
2114 assert_return(fd >= 0, -EBADF);
2115
2116 if ((server->flags & (VARLINK_SERVER_ROOT_ONLY|VARLINK_SERVER_ACCOUNT_UID)) != 0) {
2117 r = getpeercred(fd, &ucred);
2118 if (r < 0)
2119 return varlink_server_log_errno(server, r, "Failed to acquire peer credentials of incoming socket, refusing: %m");
2120
2121 ucred_acquired = true;
2122
2123 r = validate_connection(server, &ucred);
2124 if (r < 0)
2125 return r;
2126 if (r == 0)
2127 return -EPERM;
2128 } else
2129 ucred_acquired = false;
2130
2131 r = varlink_new(&v);
2132 if (r < 0)
2133 return varlink_server_log_errno(server, r, "Failed to allocate connection object: %m");
2134
2135 r = count_connection(server, &ucred);
2136 if (r < 0)
2137 return r;
2138
2139 v->fd = fd;
2140 if (server->flags & VARLINK_SERVER_INHERIT_USERDATA)
2141 v->userdata = server->userdata;
2142
2143 if (ucred_acquired) {
2144 v->ucred = ucred;
2145 v->ucred_acquired = true;
2146 }
2147
2148 (void) asprintf(&v->description, "%s-%i", server->description ?: "varlink", v->fd);
2149
2150 /* Link up the server and the connection, and take reference in both directions. Note that the
2151 * reference on the connection is left dangling. It will be dropped when the connection is closed,
2152 * which happens in varlink_close(), including in the event loop quit callback. */
2153 v->server = varlink_server_ref(server);
2154 varlink_ref(v);
2155
2156 varlink_set_state(v, VARLINK_IDLE_SERVER);
2157
2158 if (server->event) {
2159 r = varlink_attach_event(v, server->event, server->event_priority);
2160 if (r < 0) {
2161 varlink_log_errno(v, r, "Failed to attach new connection: %m");
2162 v->fd = -1; /* take the fd out of the connection again */
2163 varlink_close(v);
2164 return r;
2165 }
2166 }
2167
2168 if (ret)
2169 *ret = v;
2170
2171 return 0;
2172 }
2173
2174 static int connect_callback(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
2175 VarlinkServerSocket *ss = userdata;
2176 _cleanup_close_ int cfd = -1;
2177 Varlink *v = NULL;
2178 int r;
2179
2180 assert(source);
2181 assert(ss);
2182
2183 varlink_server_log(ss->server, "New incoming connection.");
2184
2185 cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
2186 if (cfd < 0) {
2187 if (ERRNO_IS_ACCEPT_AGAIN(errno))
2188 return 0;
2189
2190 return varlink_server_log_errno(ss->server, errno, "Failed to accept incoming socket: %m");
2191 }
2192
2193 r = varlink_server_add_connection(ss->server, cfd, &v);
2194 if (r < 0)
2195 return 0;
2196
2197 TAKE_FD(cfd);
2198
2199 if (ss->server->connect_callback) {
2200 r = ss->server->connect_callback(ss->server, v, ss->server->userdata);
2201 if (r < 0) {
2202 varlink_log_errno(v, r, "Connection callback returned error, disconnecting client: %m");
2203 varlink_close(v);
2204 return 0;
2205 }
2206 }
2207
2208 return 0;
2209 }
2210
2211 int varlink_server_listen_fd(VarlinkServer *s, int fd) {
2212 _cleanup_free_ VarlinkServerSocket *ss = NULL;
2213 int r;
2214
2215 assert_return(s, -EINVAL);
2216 assert_return(fd >= 0, -EBADF);
2217
2218 r = fd_nonblock(fd, true);
2219 if (r < 0)
2220 return r;
2221
2222 ss = new(VarlinkServerSocket, 1);
2223 if (!ss)
2224 return log_oom_debug();
2225
2226 *ss = (VarlinkServerSocket) {
2227 .server = s,
2228 .fd = fd,
2229 };
2230
2231 if (s->event) {
2232 r = sd_event_add_io(s->event, &ss->event_source, fd, EPOLLIN, connect_callback, ss);
2233 if (r < 0)
2234 return r;
2235
2236 r = sd_event_source_set_priority(ss->event_source, s->event_priority);
2237 if (r < 0)
2238 return r;
2239 }
2240
2241 LIST_PREPEND(sockets, s->sockets, TAKE_PTR(ss));
2242 return 0;
2243 }
2244
2245 int varlink_server_listen_address(VarlinkServer *s, const char *address, mode_t m) {
2246 union sockaddr_union sockaddr;
2247 socklen_t sockaddr_len;
2248 _cleanup_close_ int fd = -1;
2249 int r;
2250
2251 assert_return(s, -EINVAL);
2252 assert_return(address, -EINVAL);
2253 assert_return((m & ~0777) == 0, -EINVAL);
2254
2255 r = sockaddr_un_set_path(&sockaddr.un, address);
2256 if (r < 0)
2257 return r;
2258 sockaddr_len = r;
2259
2260 fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
2261 if (fd < 0)
2262 return -errno;
2263
2264 fd = fd_move_above_stdio(fd);
2265
2266 (void) sockaddr_un_unlink(&sockaddr.un);
2267
2268 RUN_WITH_UMASK(~m & 0777) {
2269 r = mac_selinux_bind(fd, &sockaddr.sa, sockaddr_len);
2270 if (r < 0)
2271 return r;
2272 }
2273
2274 if (listen(fd, SOMAXCONN) < 0)
2275 return -errno;
2276
2277 r = varlink_server_listen_fd(s, fd);
2278 if (r < 0)
2279 return r;
2280
2281 TAKE_FD(fd);
2282 return 0;
2283 }
2284
2285 void* varlink_server_set_userdata(VarlinkServer *s, void *userdata) {
2286 void *ret;
2287
2288 assert_return(s, NULL);
2289
2290 ret = s->userdata;
2291 s->userdata = userdata;
2292
2293 return ret;
2294 }
2295
2296 void* varlink_server_get_userdata(VarlinkServer *s) {
2297 assert_return(s, NULL);
2298
2299 return s->userdata;
2300 }
2301
2302 static VarlinkServerSocket* varlink_server_socket_destroy(VarlinkServerSocket *ss) {
2303 if (!ss)
2304 return NULL;
2305
2306 if (ss->server)
2307 LIST_REMOVE(sockets, ss->server->sockets, ss);
2308
2309 sd_event_source_disable_unref(ss->event_source);
2310
2311 free(ss->address);
2312 safe_close(ss->fd);
2313
2314 return mfree(ss);
2315 }
2316
2317 int varlink_server_shutdown(VarlinkServer *s) {
2318 assert_return(s, -EINVAL);
2319
2320 while (s->sockets)
2321 varlink_server_socket_destroy(s->sockets);
2322
2323 return 0;
2324 }
2325
2326 int varlink_server_attach_event(VarlinkServer *s, sd_event *e, int64_t priority) {
2327 VarlinkServerSocket *ss;
2328 int r;
2329
2330 assert_return(s, -EINVAL);
2331 assert_return(!s->event, -EBUSY);
2332
2333 if (e)
2334 s->event = sd_event_ref(e);
2335 else {
2336 r = sd_event_default(&s->event);
2337 if (r < 0)
2338 return r;
2339 }
2340
2341 LIST_FOREACH(sockets, ss, s->sockets) {
2342 assert(!ss->event_source);
2343
2344 r = sd_event_add_io(s->event, &ss->event_source, ss->fd, EPOLLIN, connect_callback, ss);
2345 if (r < 0)
2346 goto fail;
2347
2348 r = sd_event_source_set_priority(ss->event_source, priority);
2349 if (r < 0)
2350 goto fail;
2351 }
2352
2353 s->event_priority = priority;
2354 return 0;
2355
2356 fail:
2357 varlink_server_detach_event(s);
2358 return r;
2359 }
2360
2361 int varlink_server_detach_event(VarlinkServer *s) {
2362 VarlinkServerSocket *ss;
2363
2364 assert_return(s, -EINVAL);
2365
2366 LIST_FOREACH(sockets, ss, s->sockets) {
2367
2368 if (!ss->event_source)
2369 continue;
2370
2371 (void) sd_event_source_set_enabled(ss->event_source, SD_EVENT_OFF);
2372 ss->event_source = sd_event_source_unref(ss->event_source);
2373 }
2374
2375 sd_event_unref(s->event);
2376 return 0;
2377 }
2378
2379 sd_event *varlink_server_get_event(VarlinkServer *s) {
2380 assert_return(s, NULL);
2381
2382 return s->event;
2383 }
2384
2385 int varlink_server_bind_method(VarlinkServer *s, const char *method, VarlinkMethod callback) {
2386 _cleanup_free_ char *m = NULL;
2387 int r;
2388
2389 assert_return(s, -EINVAL);
2390 assert_return(method, -EINVAL);
2391 assert_return(callback, -EINVAL);
2392
2393 if (startswith(method, "org.varlink.service."))
2394 return log_debug_errno(SYNTHETIC_ERRNO(EEXIST), "Cannot bind server to '%s'.", method);
2395
2396 m = strdup(method);
2397 if (!m)
2398 return log_oom_debug();
2399
2400 r = hashmap_ensure_put(&s->methods, &string_hash_ops, m, callback);
2401 if (r == -ENOMEM)
2402 return log_oom_debug();
2403 if (r < 0)
2404 return log_debug_errno(r, "Failed to register callback: %m");
2405 if (r > 0)
2406 TAKE_PTR(m);
2407
2408 return 0;
2409 }
2410
2411 int varlink_server_bind_method_many_internal(VarlinkServer *s, ...) {
2412 va_list ap;
2413 int r = 0;
2414
2415 assert_return(s, -EINVAL);
2416
2417 va_start(ap, s);
2418 for (;;) {
2419 VarlinkMethod callback;
2420 const char *method;
2421
2422 method = va_arg(ap, const char *);
2423 if (!method)
2424 break;
2425
2426 callback = va_arg(ap, VarlinkMethod);
2427
2428 r = varlink_server_bind_method(s, method, callback);
2429 if (r < 0)
2430 break;
2431 }
2432 va_end(ap);
2433
2434 return r;
2435 }
2436
2437 int varlink_server_bind_connect(VarlinkServer *s, VarlinkConnect callback) {
2438 assert_return(s, -EINVAL);
2439
2440 if (callback && s->connect_callback && callback != s->connect_callback)
2441 return log_debug_errno(SYNTHETIC_ERRNO(EBUSY), "A different callback was already set.");
2442
2443 s->connect_callback = callback;
2444 return 0;
2445 }
2446
2447 int varlink_server_bind_disconnect(VarlinkServer *s, VarlinkDisconnect callback) {
2448 assert_return(s, -EINVAL);
2449
2450 if (callback && s->disconnect_callback && callback != s->disconnect_callback)
2451 return log_debug_errno(SYNTHETIC_ERRNO(EBUSY), "A different callback was already set.");
2452
2453 s->disconnect_callback = callback;
2454 return 0;
2455 }
2456
2457 unsigned varlink_server_connections_max(VarlinkServer *s) {
2458 int dts;
2459
2460 /* If a server is specified, return the setting for that server, otherwise the default value */
2461 if (s)
2462 return s->connections_max;
2463
2464 dts = getdtablesize();
2465 assert_se(dts > 0);
2466
2467 /* Make sure we never use up more than ¾th of RLIMIT_NOFILE for IPC */
2468 if (VARLINK_DEFAULT_CONNECTIONS_MAX > (unsigned) dts / 4 * 3)
2469 return dts / 4 * 3;
2470
2471 return VARLINK_DEFAULT_CONNECTIONS_MAX;
2472 }
2473
2474 unsigned varlink_server_connections_per_uid_max(VarlinkServer *s) {
2475 unsigned m;
2476
2477 if (s)
2478 return s->connections_per_uid_max;
2479
2480 /* Make sure to never use up more than ¾th of available connections for a single user */
2481 m = varlink_server_connections_max(NULL);
2482 if (VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX > m)
2483 return m / 4 * 3;
2484
2485 return VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX;
2486 }
2487
2488 int varlink_server_set_connections_per_uid_max(VarlinkServer *s, unsigned m) {
2489 assert_return(s, -EINVAL);
2490 assert_return(m > 0, -EINVAL);
2491
2492 s->connections_per_uid_max = m;
2493 return 0;
2494 }
2495
2496 int varlink_server_set_connections_max(VarlinkServer *s, unsigned m) {
2497 assert_return(s, -EINVAL);
2498 assert_return(m > 0, -EINVAL);
2499
2500 s->connections_max = m;
2501 return 0;
2502 }
2503
2504 unsigned varlink_server_current_connections(VarlinkServer *s) {
2505 assert_return(s, UINT_MAX);
2506
2507 return s->n_connections;
2508 }
2509
2510 int varlink_server_set_description(VarlinkServer *s, const char *description) {
2511 assert_return(s, -EINVAL);
2512
2513 return free_and_strdup(&s->description, description);
2514 }
Unnamed repository; edit this file 'description' to name the repository.