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license: LGPL-2.1+ -> LGPL-2.1-or-later
[thirdparty/systemd.git] / src / shared / varlink.c
CommitLineData
db9ecf05 1/* SPDX-License-Identifier: LGPL-2.1-or-later */
d41bd96f
LP		 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"
0f2d351f 9#include "io-util.h"
d41bd96f
LP		 10#include "list.h"
11#include "process-util.h"
63e00ccd 12#include "selinux-util.h"
d41bd96f
LP		 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
30typedef enum VarlinkState {
31 /* Client side states */
32 VARLINK_IDLE_CLIENT,
33 VARLINK_AWAITING_REPLY,
45a6c965 34 VARLINK_AWAITING_REPLY_MORE,
d41bd96f
LP		 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,
d41bd96f
LP		 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 = -1
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, \
45a6c965 68 VARLINK_AWAITING_REPLY_MORE, \
d41bd96f
LP		 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, \
d41bd96f
LP		 77 VARLINK_PENDING_METHOD, \
78 VARLINK_PENDING_METHOD_MORE)
79
80struct 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
152typedef struct VarlinkServerSocket VarlinkServerSocket;
153
154struct 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
165struct VarlinkServer {
166 unsigned n_ref;
167 VarlinkServerFlags flags;
168
169 LIST_HEAD(VarlinkServerSocket, sockets);
170
171 Hashmap *methods;
172 VarlinkConnect connect_callback;
6d4d6002 173 VarlinkDisconnect disconnect_callback;
d41bd96f
LP		 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
188static const char* const varlink_state_table[_VARLINK_STATE_MAX] = {
189 [VARLINK_IDLE_CLIENT] = "idle-client",
190 [VARLINK_AWAITING_REPLY] = "awaiting-reply",
45a6c965 191 [VARLINK_AWAITING_REPLY_MORE] = "awaiting-reply-more",
d41bd96f
LP		 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",
d41bd96f
LP		 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
210DEFINE_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
224static inline const char *varlink_description(Varlink *v) {
225 return strna(v ? v->description : NULL);
226}
227
228static inline const char *varlink_server_description(VarlinkServer *s) {
229 return strna(s ? s->description : NULL);
230}
231
232static void varlink_set_state(Varlink *v, VarlinkState state) {
233 assert(v);
77740b59
ZJS		 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));
d41bd96f
LP		 243
244 v->state = state;
245}
246
247static int varlink_new(Varlink **ret) {
248 Varlink *v;
249
250 assert(ret);
251
a48481dc 252 v = new(Varlink, 1);
d41bd96f
LP		 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
273int varlink_connect_address(Varlink **ret, const char *address) {
274 _cleanup_(varlink_unrefp) Varlink *v = NULL;
275 union sockaddr_union sockaddr;
f36a9d59 276 socklen_t sockaddr_len;
d41bd96f
LP		 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 r;
f36a9d59 285 sockaddr_len = r;
d41bd96f
LP		 286
287 r = varlink_new(&v);
288 if (r < 0)
289 return r;
290
291 v->fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
292 if (v->fd < 0)
293 return -errno;
294
a0c41de2
LP		 295 v->fd = fd_move_above_stdio(v->fd);
296
f36a9d59 297 if (connect(v->fd, &sockaddr.sa, sockaddr_len) < 0) {
d41bd96f
LP		 298 if (!IN_SET(errno, EAGAIN, EINPROGRESS))
299 return -errno;
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 r;
316}
317
318int 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 r;
328
329 r = varlink_new(&v);
330 if (r < 0)
331 return r;
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
347static void varlink_detach_event_sources(Varlink *v) {
348 assert(v);
349
1d3fe304 350 v->io_event_source = sd_event_source_disable_unref(v->io_event_source);
1d3fe304 351 v->time_event_source = sd_event_source_disable_unref(v->time_event_source);
1d3fe304 352 v->quit_event_source = sd_event_source_disable_unref(v->quit_event_source);
1d3fe304 353 v->defer_event_source = sd_event_source_disable_unref(v->defer_event_source);
d41bd96f
LP		 354}
355
356static 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
372static 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
386DEFINE_TRIVIAL_REF_UNREF_FUNC(Varlink, varlink, varlink_destroy);
387
388static int varlink_test_disconnect(Varlink *v) {
389 assert(v);
390
37b22b3b 391 /* Tests whether we the connection has been terminated. We are careful to not stop processing it
d41bd96f
LP		 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. */
45a6c965 412 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) && v->read_disconnected)
d41bd96f
LP		 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
e8e9227f
AZ		 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
d41bd96f
LP		 426 return 0;
427
428disconnect:
429 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
430 return 1;
431}
432
433static 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
484static int varlink_read(Varlink *v) {
485 size_t rs;
486 ssize_t n;
487
488 assert(v);
489
45a6c965 490 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER))
d41bd96f
LP		 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
563static 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
77472d06
ZJS		 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. */
d41bd96f 591
d642f640 592 r = json_parse(begin, 0, &v->current, NULL, NULL);
77472d06
ZJS		 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 }
d41bd96f
LP		 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
611static int varlink_test_timeout(Varlink *v) {
612 assert(v);
613
45a6c965 614 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING))
d41bd96f
LP		 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
627static 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
643static 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
656static 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
669static 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
681static 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
45a6c965 691 if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING))
d41bd96f
LP		 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
45a6c965
LP		 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 */
d41bd96f
LP		 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
45a6c965 745 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE)) {
d41bd96f
LP		 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) {
45a6c965 757
d41bd96f 758 assert(v->n_pending > 0);
d41bd96f 759
45a6c965
LP		 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);
d41bd96f
LP		 766 }
767 } else {
768 assert(v->state == VARLINK_CALLING);
d41bd96f
LP		 769 varlink_set_state(v, VARLINK_CALLED);
770 }
771
772 return 1;
773
774invalid:
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
782static 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)) {
7466e94f 877 r = varlink_error_errno(v, r);
d41bd96f
LP		 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
d41bd96f
LP		 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
913invalid:
914 r = -EINVAL;
915
916fail:
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
924int varlink_process(Varlink *v) {
925 int r;
926
927 assert_return(v, -EINVAL);
928
929 if (v->state == VARLINK_DISCONNECTED)
930 return -ENOTCONN;
931
932 varlink_ref(v);
933
934 r = varlink_write(v);
935 if (r != 0)
936 goto finish;
937
938 r = varlink_dispatch_reply(v);
939 if (r != 0)
940 goto finish;
941
942 r = varlink_dispatch_method(v);
943 if (r != 0)
944 goto finish;
945
946 r = varlink_parse_message(v);
947 if (r != 0)
948 goto finish;
949
950 r = varlink_read(v);
951 if (r != 0)
952 goto finish;
953
954 r = varlink_test_disconnect(v);
955 if (r != 0)
956 goto finish;
957
958 r = varlink_dispatch_disconnect(v);
959 if (r != 0)
960 goto finish;
961
962 r = varlink_test_timeout(v);
963 if (r != 0)
964 goto finish;
965
966 r = varlink_dispatch_timeout(v);
967 if (r != 0)
968 goto finish;
969
970finish:
971 if (r >= 0 && v->defer_event_source) {
972 int q;
973
974 /* If we did some processing, make sure we are called again soon */
975 q = sd_event_source_set_enabled(v->defer_event_source, r > 0 ? SD_EVENT_ON : SD_EVENT_OFF);
976 if (q < 0)
977 r = q;
978 }
979
980 if (r < 0) {
981 if (VARLINK_STATE_IS_ALIVE(v->state))
982 /* Initiate disconnection */
983 varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
984 else
985 /* We failed while disconnecting, in that case close right away */
986 varlink_close(v);
987 }
988
989 varlink_unref(v);
990 return r;
991}
992
993static void handle_revents(Varlink *v, int revents) {
994 assert(v);
995
996 if (v->connecting) {
997 /* If we have seen POLLOUT or POLLHUP on a socket we are asynchronously waiting a connect()
998 * to complete on, we know we are ready. We don't read the connection error here though,
999 * we'll get the error on the next read() or write(). */
1000 if ((revents & (POLLOUT|POLLHUP)) == 0)
1001 return;
1002
1003 varlink_log(v, "Anynchronous connection completed.");
1004 v->connecting = false;
1005 } else {
1006 /* Note that we don't care much about POLLIN/POLLOUT here, we'll just try reading and writing
1007 * what we can. However, we do care about POLLHUP to detect connection termination even if we
1008 * momentarily don't want to read nor write anything. */
1009
1010 if (!FLAGS_SET(revents, POLLHUP))
1011 return;
1012
1013 varlink_log(v, "Got POLLHUP from socket.");
1014 v->got_pollhup = true;
1015 }
1016}
1017
1018int varlink_wait(Varlink *v, usec_t timeout) {
d41bd96f
LP		 1019 int r, fd, events;
1020 usec_t t;
1021
1022 assert_return(v, -EINVAL);
d41bd96f
LP		 1023
1024 if (v->state == VARLINK_DISCONNECTED)
1025 return -ENOTCONN;
1026
1027 r = varlink_get_timeout(v, &t);
1028 if (r < 0)
1029 return r;
1030 if (t != USEC_INFINITY) {
1031 usec_t n;
1032
1033 n = now(CLOCK_MONOTONIC);
1034 if (t < n)
1035 t = 0;
1036 else
1037 t = usec_sub_unsigned(t, n);
1038 }
1039
1040 if (timeout != USEC_INFINITY &&
1041 (t == USEC_INFINITY || timeout < t))
1042 t = timeout;
1043
1044 fd = varlink_get_fd(v);
1045 if (fd < 0)
1046 return fd;
1047
1048 events = varlink_get_events(v);
1049 if (events < 0)
1050 return events;
1051
0f2d351f 1052 r = fd_wait_for_event(fd, events, t);
05827831 1053 if (r <= 0)
0f2d351f 1054 return r;
d41bd96f 1055
0f2d351f 1056 handle_revents(v, r);
dad28bff 1057 return 1;
d41bd96f
LP		 1058}
1059
1060int varlink_get_fd(Varlink *v) {
1061
1062 assert_return(v, -EINVAL);
1063
1064 if (v->state == VARLINK_DISCONNECTED)
1065 return -ENOTCONN;
1066 if (v->fd < 0)
1067 return -EBADF;
1068
1069 return v->fd;
1070}
1071
1072int varlink_get_events(Varlink *v) {
1073 int ret = 0;
1074
1075 assert_return(v, -EINVAL);
1076
1077 if (v->state == VARLINK_DISCONNECTED)
1078 return -ENOTCONN;
1079
1080 if (v->connecting) /* When processing an asynchronous connect(), we only wait for EPOLLOUT, which
1081 * tells us that the connection is now complete. Before that we should neither
1082 * write() or read() from the fd. */
1083 return EPOLLOUT;
1084
1085 if (!v->read_disconnected &&
45a6c965 1086 IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) &&
d41bd96f
LP		 1087 !v->current &&
1088 v->input_buffer_unscanned <= 0)
1089 ret |= EPOLLIN;
1090
1091 if (!v->write_disconnected &&
1092 v->output_buffer_size > 0)
1093 ret |= EPOLLOUT;
1094
1095 return ret;
1096}
1097
1098int varlink_get_timeout(Varlink *v, usec_t *ret) {
1099 assert_return(v, -EINVAL);
1100
1101 if (v->state == VARLINK_DISCONNECTED)
1102 return -ENOTCONN;
1103
45a6c965 1104 if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING) &&
d41bd96f
LP		 1105 v->timeout != USEC_INFINITY) {
1106 if (ret)
1107 *ret = usec_add(v->timestamp, v->timeout);
1108 return 1;
1109 } else {
1110 if (ret)
1111 *ret = USEC_INFINITY;
1112 return 0;
1113 }
1114}
1115
1116int varlink_flush(Varlink *v) {
1117 int ret = 0, r;
1118
1119 assert_return(v, -EINVAL);
1120
1121 if (v->state == VARLINK_DISCONNECTED)
1122 return -ENOTCONN;
1123
1124 for (;;) {
d41bd96f
LP		 1125 if (v->output_buffer_size == 0)
1126 break;
1127 if (v->write_disconnected)
1128 return -ECONNRESET;
1129
1130 r = varlink_write(v);
1131 if (r < 0)
1132 return r;
1133 if (r > 0) {
1134 ret = 1;
1135 continue;
1136 }
1137
0f2d351f 1138 r = fd_wait_for_event(v->fd, POLLOUT, USEC_INFINITY);
dad28bff 1139 if (r < 0)
0f2d351f 1140 return r;
d41bd96f 1141
0f2d351f 1142 assert(r != 0);
dad28bff 1143
0f2d351f 1144 handle_revents(v, r);
d41bd96f
LP		 1145 }
1146
1147 return ret;
1148}
1149
1150static void varlink_detach_server(Varlink *v) {
6d4d6002 1151 VarlinkServer *saved_server;
d41bd96f
LP		 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
6d4d6002
LP		 1175 * connection from each other. This drops the dangling reference that connect_callback() set up. But
1176 * before we release the references, let's call the disconnection callback if it is defined. */
1177
1178 saved_server = TAKE_PTR(v->server);
1179
1180 if (saved_server->disconnect_callback)
1181 saved_server->disconnect_callback(saved_server, v, saved_server->userdata);
1182
1183 varlink_server_unref(saved_server);
d41bd96f
LP		 1184 varlink_unref(v);
1185}
1186
1187int varlink_close(Varlink *v) {
1188
1189 assert_return(v, -EINVAL);
1190
1191 if (v->state == VARLINK_DISCONNECTED)
1192 return 0;
1193
1194 varlink_set_state(v, VARLINK_DISCONNECTED);
1195
1196 /* Let's take a reference first, since varlink_detach_server() might drop the final (dangling) ref
1197 * which would destroy us before we can call varlink_clear() */
1198 varlink_ref(v);
1199 varlink_detach_server(v);
1200 varlink_clear(v);
1201 varlink_unref(v);
1202
1203 return 1;
1204}
1205
9652d740
LP		 1206Varlink* varlink_close_unref(Varlink *v) {
1207
1208 if (!v)
1209 return NULL;
1210
1211 (void) varlink_close(v);
1212 return varlink_unref(v);
1213}
1214
d41bd96f
LP		 1215Varlink* varlink_flush_close_unref(Varlink *v) {
1216
1217 if (!v)
1218 return NULL;
1219
1220 (void) varlink_flush(v);
1221 (void) varlink_close(v);
d41bd96f
LP		 1222 return varlink_unref(v);
1223}
1224
1225static int varlink_enqueue_json(Varlink *v, JsonVariant *m) {
1226 _cleanup_free_ char *text = NULL;
1227 int r;
1228
1229 assert(v);
1230 assert(m);
1231
1232 r = json_variant_format(m, 0, &text);
1233 if (r < 0)
1234 return r;
2a04712c 1235 assert(text[r] == '\0');
d41bd96f
LP		 1236
1237 if (v->output_buffer_size + r + 1 > VARLINK_BUFFER_MAX)
1238 return -ENOBUFS;
1239
1240 varlink_log(v, "Sending message: %s", text);
1241
1242 if (v->output_buffer_size == 0) {
1243
1244 free_and_replace(v->output_buffer, text);
1245
1246 v->output_buffer_size = v->output_buffer_allocated = r + 1;
1247 v->output_buffer_index = 0;
1248
1249 } else if (v->output_buffer_index == 0) {
1250
1251 if (!GREEDY_REALLOC(v->output_buffer, v->output_buffer_allocated, v->output_buffer_size + r + 1))
1252 return -ENOMEM;
1253
1254 memcpy(v->output_buffer + v->output_buffer_size, text, r + 1);
1255 v->output_buffer_size += r + 1;
1256
1257 } else {
1258 char *n;
be44e091 1259 const size_t new_size = v->output_buffer_size + r + 1;
d41bd96f 1260
be44e091 1261 n = new(char, new_size);
d41bd96f
LP		 1262 if (!n)
1263 return -ENOMEM;
1264
1265 memcpy(mempcpy(n, v->output_buffer + v->output_buffer_index, v->output_buffer_size), text, r + 1);
1266
1267 free_and_replace(v->output_buffer, n);
be44e091 1268 v->output_buffer_allocated = v->output_buffer_size = new_size;
d41bd96f
LP		 1269 v->output_buffer_index = 0;
1270 }
1271
1272 return 0;
1273}
1274
1275int varlink_send(Varlink *v, const char *method, JsonVariant *parameters) {
1276 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1277 int r;
1278
1279 assert_return(v, -EINVAL);
1280 assert_return(method, -EINVAL);
1281
1282 if (v->state == VARLINK_DISCONNECTED)
1283 return -ENOTCONN;
45a6c965
LP		 1284
1285 /* We allow enqueuing multiple method calls at once! */
d41bd96f
LP		 1286 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1287 return -EBUSY;
1288
1289 r = varlink_sanitize_parameters(&parameters);
1290 if (r < 0)
1291 return r;
1292
1293 r = json_build(&m, JSON_BUILD_OBJECT(
1294 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1295 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1296 JSON_BUILD_PAIR("oneway", JSON_BUILD_BOOLEAN(true))));
1297 if (r < 0)
1298 return r;
1299
1300 r = varlink_enqueue_json(v, m);
1301 if (r < 0)
1302 return r;
1303
1304 /* No state change here, this is one-way only after all */
1305 v->timestamp = now(CLOCK_MONOTONIC);
1306 return 0;
1307}
1308
1309int varlink_sendb(Varlink *v, const char *method, ...) {
1310 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1311 va_list ap;
1312 int r;
1313
1314 assert_return(v, -EINVAL);
1315
1316 va_start(ap, method);
1317 r = json_buildv(&parameters, ap);
1318 va_end(ap);
1319
1320 if (r < 0)
1321 return r;
1322
1323 return varlink_send(v, method, parameters);
1324}
1325
1326int varlink_invoke(Varlink *v, const char *method, JsonVariant *parameters) {
1327 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1328 int r;
1329
1330 assert_return(v, -EINVAL);
1331 assert_return(method, -EINVAL);
1332
1333 if (v->state == VARLINK_DISCONNECTED)
1334 return -ENOTCONN;
45a6c965 1335
86b52a39 1336 /* We allow enqueuing multiple method calls at once! */
d41bd96f
LP		 1337 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
1338 return -EBUSY;
1339
1340 r = varlink_sanitize_parameters(&parameters);
1341 if (r < 0)
1342 return r;
1343
1344 r = json_build(&m, JSON_BUILD_OBJECT(
1345 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1346 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1347 if (r < 0)
1348 return r;
1349
1350 r = varlink_enqueue_json(v, m);
1351 if (r < 0)
1352 return r;
1353
1354 varlink_set_state(v, VARLINK_AWAITING_REPLY);
1355 v->n_pending++;
1356 v->timestamp = now(CLOCK_MONOTONIC);
1357
1358 return 0;
1359}
1360
1361int varlink_invokeb(Varlink *v, const char *method, ...) {
1362 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1363 va_list ap;
1364 int r;
1365
1366 assert_return(v, -EINVAL);
1367
1368 va_start(ap, method);
1369 r = json_buildv(&parameters, ap);
1370 va_end(ap);
1371
1372 if (r < 0)
1373 return r;
1374
1375 return varlink_invoke(v, method, parameters);
45a6c965
LP		 1376}
1377
1378int varlink_observe(Varlink *v, const char *method, JsonVariant *parameters) {
1379 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1380 int r;
1381
1382 assert_return(v, -EINVAL);
1383 assert_return(method, -EINVAL);
1384
1385 if (v->state == VARLINK_DISCONNECTED)
1386 return -ENOTCONN;
1387 /* Note that we don't allow enqueuing multiple method calls when we are in more/continues mode! We
1388 * thus insist on an idle client here. */
1389 if (v->state != VARLINK_IDLE_CLIENT)
1390 return -EBUSY;
1391
1392 r = varlink_sanitize_parameters(&parameters);
1393 if (r < 0)
1394 return r;
1395
1396 r = json_build(&m, JSON_BUILD_OBJECT(
1397 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1398 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1399 JSON_BUILD_PAIR("more", JSON_BUILD_BOOLEAN(true))));
1400 if (r < 0)
1401 return r;
1402
1403 r = varlink_enqueue_json(v, m);
1404 if (r < 0)
1405 return r;
1406
1407
1408 varlink_set_state(v, VARLINK_AWAITING_REPLY_MORE);
1409 v->n_pending++;
1410 v->timestamp = now(CLOCK_MONOTONIC);
1411
1412 return 0;
1413}
1414
1415int varlink_observeb(Varlink *v, const char *method, ...) {
1416 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1417 va_list ap;
1418 int r;
1419
1420 assert_return(v, -EINVAL);
1421
1422 va_start(ap, method);
1423 r = json_buildv(&parameters, ap);
1424 va_end(ap);
1425
1426 if (r < 0)
1427 return r;
1428
1429 return varlink_observe(v, method, parameters);
d41bd96f
LP		 1430}
1431
1432int varlink_call(
1433 Varlink *v,
1434 const char *method,
1435 JsonVariant *parameters,
1436 JsonVariant **ret_parameters,
1437 const char **ret_error_id,
1438 VarlinkReplyFlags *ret_flags) {
1439
1440 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1441 int r;
1442
1443 assert_return(v, -EINVAL);
1444 assert_return(method, -EINVAL);
1445
1446 if (v->state == VARLINK_DISCONNECTED)
1447 return -ENOTCONN;
1448 if (!IN_SET(v->state, VARLINK_IDLE_CLIENT))
1449 return -EBUSY;
1450
1451 assert(v->n_pending == 0); /* n_pending can't be > 0 if we are in VARLINK_IDLE_CLIENT state */
1452
1453 r = varlink_sanitize_parameters(&parameters);
1454 if (r < 0)
1455 return r;
1456
1457 r = json_build(&m, JSON_BUILD_OBJECT(
1458 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
1459 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1460 if (r < 0)
1461 return r;
1462
1463 r = varlink_enqueue_json(v, m);
1464 if (r < 0)
1465 return r;
1466
1467 varlink_set_state(v, VARLINK_CALLING);
1468 v->n_pending++;
1469 v->timestamp = now(CLOCK_MONOTONIC);
1470
1471 while (v->state == VARLINK_CALLING) {
1472
1473 r = varlink_process(v);
1474 if (r < 0)
1475 return r;
1476 if (r > 0)
1477 continue;
1478
1479 r = varlink_wait(v, USEC_INFINITY);
1480 if (r < 0)
1481 return r;
1482 }
1483
1484 switch (v->state) {
1485
1486 case VARLINK_CALLED:
1487 assert(v->current);
1488
1489 json_variant_unref(v->reply);
1490 v->reply = TAKE_PTR(v->current);
1491
1492 varlink_set_state(v, VARLINK_IDLE_CLIENT);
1493 assert(v->n_pending == 1);
1494 v->n_pending--;
1495
1496 if (ret_parameters)
1497 *ret_parameters = json_variant_by_key(v->reply, "parameters");
1498 if (ret_error_id)
1499 *ret_error_id = json_variant_string(json_variant_by_key(v->reply, "error"));
1500 if (ret_flags)
1501 *ret_flags = 0;
1502
1503 return 1;
1504
1505 case VARLINK_PENDING_DISCONNECT:
1506 case VARLINK_DISCONNECTED:
1507 return -ECONNRESET;
1508
1509 case VARLINK_PENDING_TIMEOUT:
1510 return -ETIME;
1511
1512 default:
1513 assert_not_reached("Unexpected state after method call.");
1514 }
1515}
1516
1517int varlink_callb(
1518 Varlink *v,
1519 const char *method,
1520 JsonVariant **ret_parameters,
1521 const char **ret_error_id,
1522 VarlinkReplyFlags *ret_flags, ...) {
1523
1524 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1525 va_list ap;
1526 int r;
1527
1528 assert_return(v, -EINVAL);
1529
1530 va_start(ap, ret_flags);
1531 r = json_buildv(&parameters, ap);
1532 va_end(ap);
1533
1534 if (r < 0)
1535 return r;
1536
1537 return varlink_call(v, method, parameters, ret_parameters, ret_error_id, ret_flags);
1538}
1539
1540int varlink_reply(Varlink *v, JsonVariant *parameters) {
1541 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1542 int r;
1543
1544 assert_return(v, -EINVAL);
1545
1546 if (v->state == VARLINK_DISCONNECTED)
1547 return -ENOTCONN;
1548 if (!IN_SET(v->state,
1549 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1550 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1551 return -EBUSY;
1552
1553 r = varlink_sanitize_parameters(&parameters);
1554 if (r < 0)
1555 return r;
1556
1557 r = json_build(&m, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1558 if (r < 0)
1559 return r;
1560
1561 r = varlink_enqueue_json(v, m);
1562 if (r < 0)
1563 return r;
1564
1565 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1566 /* We just replied to a method call that was let hanging for a while (i.e. we were outside of
1567 * the varlink_dispatch_method() stack frame), which means with this reply we are ready to
1568 * process further messages. */
1569 v->current = json_variant_unref(v->current);
1570 varlink_set_state(v, VARLINK_IDLE_SERVER);
1571 } else
1572 /* We replied to a method call from within the varlink_dispatch_method() stack frame), which
1573 * means we should it handle the rest of the state engine. */
1574 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1575
1576 return 1;
1577}
1578
1579int varlink_replyb(Varlink *v, ...) {
1580 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1581 va_list ap;
1582 int r;
1583
1584 assert_return(v, -EINVAL);
1585
1586 va_start(ap, v);
1587 r = json_buildv(&parameters, ap);
1588 va_end(ap);
1589
1590 if (r < 0)
1591 return r;
1592
1593 return varlink_reply(v, parameters);
1594}
1595
1596int varlink_error(Varlink *v, const char *error_id, JsonVariant *parameters) {
1597 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1598 int r;
1599
1600 assert_return(v, -EINVAL);
1601 assert_return(error_id, -EINVAL);
1602
1603 if (v->state == VARLINK_DISCONNECTED)
1604 return -ENOTCONN;
1605 if (!IN_SET(v->state,
1606 VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
1607 VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
1608 return -EBUSY;
1609
1610 r = varlink_sanitize_parameters(&parameters);
1611 if (r < 0)
1612 return r;
1613
1614 r = json_build(&m, JSON_BUILD_OBJECT(
1615 JSON_BUILD_PAIR("error", JSON_BUILD_STRING(error_id)),
1616 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
1617 if (r < 0)
1618 return r;
1619
1620 r = varlink_enqueue_json(v, m);
1621 if (r < 0)
1622 return r;
1623
1624 if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
1625 v->current = json_variant_unref(v->current);
1626 varlink_set_state(v, VARLINK_IDLE_SERVER);
1627 } else
1628 varlink_set_state(v, VARLINK_PROCESSED_METHOD);
1629
1630 return 1;
1631}
1632
1633int varlink_errorb(Varlink *v, const char *error_id, ...) {
1634 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1635 va_list ap;
1636 int r;
1637
1638 assert_return(v, -EINVAL);
1639 assert_return(error_id, -EINVAL);
1640
1641 va_start(ap, error_id);
1642 r = json_buildv(&parameters, ap);
1643 va_end(ap);
1644
1645 if (r < 0)
1646 return r;
1647
1648 return varlink_error(v, error_id, parameters);
1649}
1650
1651int varlink_error_invalid_parameter(Varlink *v, JsonVariant *parameters) {
1652
1653 assert_return(v, -EINVAL);
1654 assert_return(parameters, -EINVAL);
1655
1656 /* We expect to be called in one of two ways: the 'parameters' argument is a string variant in which
1657 * case it is the parameter key name that is invalid. Or the 'parameters' argument is an object
1658 * variant in which case we'll pull out the first key. The latter mode is useful in functions that
1659 * don't expect any arguments. */
1660
1661 if (json_variant_is_string(parameters))
1662 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER, parameters);
1663
1664 if (json_variant_is_object(parameters) &&
1665 json_variant_elements(parameters) > 0)
1666 return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER,
1667 json_variant_by_index(parameters, 0));
1668
1669 return -EINVAL;
1670}
1671
7466e94f
LP		 1672int varlink_error_errno(Varlink *v, int error) {
1673 return varlink_errorb(
1674 v,
1675 VARLINK_ERROR_SYSTEM,
1676 JSON_BUILD_OBJECT(JSON_BUILD_PAIR("errno", JSON_BUILD_INTEGER(abs(error)))));
1677}
1678
d41bd96f
LP		 1679int varlink_notify(Varlink *v, JsonVariant *parameters) {
1680 _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
1681 int r;
1682
1683 assert_return(v, -EINVAL);
1684
1685 if (v->state == VARLINK_DISCONNECTED)
1686 return -ENOTCONN;
1687 if (!IN_SET(v->state, VARLINK_PROCESSING_METHOD_MORE, VARLINK_PENDING_METHOD_MORE))
1688 return -EBUSY;
1689
1690 r = varlink_sanitize_parameters(&parameters);
1691 if (r < 0)
1692 return r;
1693
1694 r = json_build(&m, JSON_BUILD_OBJECT(
1695 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
1696 JSON_BUILD_PAIR("continues", JSON_BUILD_BOOLEAN(true))));
1697 if (r < 0)
1698 return r;
1699
1700 r = varlink_enqueue_json(v, m);
1701 if (r < 0)
1702 return r;
1703
1704 /* No state change, as more is coming */
1705 return 1;
1706}
1707
1708int varlink_notifyb(Varlink *v, ...) {
1709 _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
1710 va_list ap;
1711 int r;
1712
1713 assert_return(v, -EINVAL);
1714
1715 va_start(ap, v);
1716 r = json_buildv(&parameters, ap);
1717 va_end(ap);
1718
1719 if (r < 0)
1720 return r;
1721
1722 return varlink_notify(v, parameters);
1723}
1724
1725int varlink_bind_reply(Varlink *v, VarlinkReply callback) {
1726 assert_return(v, -EINVAL);
1727
1728 if (callback && v->reply_callback && callback != v->reply_callback)
1729 return -EBUSY;
1730
1731 v->reply_callback = callback;
1732
1733 return 0;
1734}
1735
1736void* varlink_set_userdata(Varlink *v, void *userdata) {
1737 void *old;
1738
1739 assert_return(v, NULL);
1740
1741 old = v->userdata;
1742 v->userdata = userdata;
1743
1744 return old;
1745}
1746
1747void* varlink_get_userdata(Varlink *v) {
1748 assert_return(v, NULL);
1749
1750 return v->userdata;
1751}
1752
1753static int varlink_acquire_ucred(Varlink *v) {
1754 int r;
1755
1756 assert(v);
1757
1758 if (v->ucred_acquired)
1759 return 0;
1760
1761 r = getpeercred(v->fd, &v->ucred);
1762 if (r < 0)
1763 return r;
1764
1765 v->ucred_acquired = true;
1766 return 0;
1767}
1768
1769int varlink_get_peer_uid(Varlink *v, uid_t *ret) {
1770 int r;
1771
1772 assert_return(v, -EINVAL);
1773 assert_return(ret, -EINVAL);
1774
1775 r = varlink_acquire_ucred(v);
1776 if (r < 0)
1777 return r;
1778
1779 if (!uid_is_valid(v->ucred.uid))
1780 return -ENODATA;
1781
1782 *ret = v->ucred.uid;
1783 return 0;
1784}
1785
1786int varlink_get_peer_pid(Varlink *v, pid_t *ret) {
1787 int r;
1788
1789 assert_return(v, -EINVAL);
1790 assert_return(ret, -EINVAL);
1791
1792 r = varlink_acquire_ucred(v);
1793 if (r < 0)
1794 return r;
1795
1796 if (!pid_is_valid(v->ucred.pid))
1797 return -ENODATA;
1798
1799 *ret = v->ucred.pid;
1800 return 0;
1801}
1802
1803int varlink_set_relative_timeout(Varlink *v, usec_t timeout) {
1804 assert_return(v, -EINVAL);
1805 assert_return(timeout > 0, -EINVAL);
1806
1807 v->timeout = timeout;
1808 return 0;
1809}
1810
1811VarlinkServer *varlink_get_server(Varlink *v) {
1812 assert_return(v, NULL);
1813
1814 return v->server;
1815}
1816
1817int varlink_set_description(Varlink *v, const char *description) {
1818 assert_return(v, -EINVAL);
1819
1820 return free_and_strdup(&v->description, description);
1821}
1822
1823static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
1824 Varlink *v = userdata;
1825
1826 assert(s);
1827 assert(v);
1828
1829 handle_revents(v, revents);
1830 (void) varlink_process(v);
1831
1832 return 1;
1833}
1834
1835static int time_callback(sd_event_source *s, uint64_t usec, void *userdata) {
1836 Varlink *v = userdata;
1837
1838 assert(s);
1839 assert(v);
1840
1841 (void) varlink_process(v);
1842 return 1;
1843}
1844
1845static int defer_callback(sd_event_source *s, void *userdata) {
1846 Varlink *v = userdata;
1847
1848 assert(s);
1849 assert(v);
1850
1851 (void) varlink_process(v);
1852 return 1;
1853}
1854
1855static int prepare_callback(sd_event_source *s, void *userdata) {
1856 Varlink *v = userdata;
1857 int r, e;
1858 usec_t until;
f1194f5d 1859 bool have_timeout;
d41bd96f
LP		 1860
1861 assert(s);
1862 assert(v);
1863
1864 e = varlink_get_events(v);
1865 if (e < 0)
1866 return e;
1867
1868 r = sd_event_source_set_io_events(v->io_event_source, e);
1869 if (r < 0)
1870 return r;
1871
1872 r = varlink_get_timeout(v, &until);
1873 if (r < 0)
1874 return r;
f1194f5d
LP		 1875 have_timeout = r > 0;
1876
1877 if (have_timeout) {
d41bd96f
LP		 1878 r = sd_event_source_set_time(v->time_event_source, until);
1879 if (r < 0)
1880 return r;
1881 }
1882
f1194f5d 1883 r = sd_event_source_set_enabled(v->time_event_source, have_timeout ? SD_EVENT_ON : SD_EVENT_OFF);
d41bd96f
LP		 1884 if (r < 0)
1885 return r;
1886
1887 return 1;
1888}
1889
1890static int quit_callback(sd_event_source *event, void *userdata) {
1891 Varlink *v = userdata;
1892
1893 assert(event);
1894 assert(v);
1895
1896 varlink_flush(v);
1897 varlink_close(v);
1898
1899 return 1;
1900}
1901
1902int varlink_attach_event(Varlink *v, sd_event *e, int64_t priority) {
1903 int r;
1904
1905 assert_return(v, -EINVAL);
1906 assert_return(!v->event, -EBUSY);
1907
1908 if (e)
1909 v->event = sd_event_ref(e);
1910 else {
1911 r = sd_event_default(&v->event);
1912 if (r < 0)
1913 return r;
1914 }
1915
1916 r = sd_event_add_time(v->event, &v->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, v);
1917 if (r < 0)
1918 goto fail;
1919
1920 r = sd_event_source_set_priority(v->time_event_source, priority);
1921 if (r < 0)
1922 goto fail;
1923
1924 (void) sd_event_source_set_description(v->time_event_source, "varlink-time");
1925
1926 r = sd_event_add_exit(v->event, &v->quit_event_source, quit_callback, v);
1927 if (r < 0)
1928 goto fail;
1929
1930 r = sd_event_source_set_priority(v->quit_event_source, priority);
1931 if (r < 0)
1932 goto fail;
1933
1934 (void) sd_event_source_set_description(v->quit_event_source, "varlink-quit");
1935
1936 r = sd_event_add_io(v->event, &v->io_event_source, v->fd, 0, io_callback, v);
1937 if (r < 0)
1938 goto fail;
1939
1940 r = sd_event_source_set_prepare(v->io_event_source, prepare_callback);
1941 if (r < 0)
1942 goto fail;
1943
1944 r = sd_event_source_set_priority(v->io_event_source, priority);
1945 if (r < 0)
1946 goto fail;
1947
1948 (void) sd_event_source_set_description(v->io_event_source, "varlink-io");
1949
1950 r = sd_event_add_defer(v->event, &v->defer_event_source, defer_callback, v);
1951 if (r < 0)
1952 goto fail;
1953
1954 r = sd_event_source_set_priority(v->defer_event_source, priority);
1955 if (r < 0)
1956 goto fail;
1957
1958 (void) sd_event_source_set_description(v->defer_event_source, "varlink-defer");
1959
1960 return 0;
1961
1962fail:
1963 varlink_detach_event(v);
1964 return r;
1965}
1966
d41bd96f
LP		 1967void varlink_detach_event(Varlink *v) {
1968 if (!v)
1969 return;
1970
1971 varlink_detach_event_sources(v);
1972
1973 v->event = sd_event_unref(v->event);
1974}
1975
1976sd_event *varlink_get_event(Varlink *v) {
1977 assert_return(v, NULL);
1978
1979 return v->event;
1980}
1981
1982int varlink_server_new(VarlinkServer **ret, VarlinkServerFlags flags) {
1983 VarlinkServer *s;
1984
1985 assert_return(ret, -EINVAL);
1986 assert_return((flags & ~_VARLINK_SERVER_FLAGS_ALL) == 0, -EINVAL);
1987
1988 s = new(VarlinkServer, 1);
1989 if (!s)
1990 return -ENOMEM;
1991
1992 *s = (VarlinkServer) {
1993 .n_ref = 1,
1994 .flags = flags,
1995 .connections_max = varlink_server_connections_max(NULL),
1996 .connections_per_uid_max = varlink_server_connections_per_uid_max(NULL),
1997 };
1998
1999 *ret = s;
2000 return 0;
2001}
2002
2003static VarlinkServer* varlink_server_destroy(VarlinkServer *s) {
2004 char *m;
2005
2006 if (!s)
2007 return NULL;
2008
2009 varlink_server_shutdown(s);
2010
2011 while ((m = hashmap_steal_first_key(s->methods)))
2012 free(m);
2013
2014 hashmap_free(s->methods);
2015 hashmap_free(s->by_uid);
2016
2017 sd_event_unref(s->event);
2018
2019 free(s->description);
2020
2021 return mfree(s);
2022}
2023
2024DEFINE_TRIVIAL_REF_UNREF_FUNC(VarlinkServer, varlink_server, varlink_server_destroy);
2025
2026static int validate_connection(VarlinkServer *server, const struct ucred *ucred) {
2027 int allowed = -1;
2028
2029 assert(server);
2030 assert(ucred);
2031
2032 if (FLAGS_SET(server->flags, VARLINK_SERVER_ROOT_ONLY))
2033 allowed = ucred->uid == 0;
2034
2035 if (FLAGS_SET(server->flags, VARLINK_SERVER_MYSELF_ONLY))
2036 allowed = allowed > 0 || ucred->uid == getuid();
2037
2038 if (allowed == 0) { /* Allow access when it is explicitly allowed or when neither
2039 * VARLINK_SERVER_ROOT_ONLY nor VARLINK_SERVER_MYSELF_ONLY are specified. */
2040 varlink_server_log(server, "Unprivileged client attempted connection, refusing.");
2041 return 0;
2042 }
2043
2044 if (server->n_connections >= server->connections_max) {
2045 varlink_server_log(server, "Connection limit of %u reached, refusing.", server->connections_max);
2046 return 0;
2047 }
2048
2049 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
2050 unsigned c;
2051
2052 if (!uid_is_valid(ucred->uid)) {
2053 varlink_server_log(server, "Client with invalid UID attempted connection, refusing.");
2054 return 0;
2055 }
2056
2057 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
2058 if (c >= server->connections_per_uid_max) {
2059 varlink_server_log(server, "Per-UID connection limit of %u reached, refusing.",
2060 server->connections_per_uid_max);
2061 return 0;
2062 }
2063 }
2064
2065 return 1;
2066}
2067
2068static int count_connection(VarlinkServer *server, struct ucred *ucred) {
2069 unsigned c;
2070 int r;
2071
2072 assert(server);
2073 assert(ucred);
2074
2075 server->n_connections++;
2076
2077 if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
2078 r = hashmap_ensure_allocated(&server->by_uid, NULL);
2079 if (r < 0)
2080 return log_debug_errno(r, "Failed to allocate UID hash table: %m");
2081
2082 c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
2083
2084 varlink_server_log(server, "Connections of user " UID_FMT ": %u (of %u max)",
2085 ucred->uid, c, server->connections_per_uid_max);
2086
2087 r = hashmap_replace(server->by_uid, UID_TO_PTR(ucred->uid), UINT_TO_PTR(c + 1));
2088 if (r < 0)
2089 return log_debug_errno(r, "Failed to increment counter in UID hash table: %m");
2090 }
2091
2092 return 0;
2093}
2094
2095int varlink_server_add_connection(VarlinkServer *server, int fd, Varlink **ret) {
2096 _cleanup_(varlink_unrefp) Varlink *v = NULL;
2097 bool ucred_acquired;
2098 struct ucred ucred;
2099 int r;
2100
2101 assert_return(server, -EINVAL);
2102 assert_return(fd >= 0, -EBADF);
2103
2104 if ((server->flags & (VARLINK_SERVER_ROOT_ONLY|VARLINK_SERVER_ACCOUNT_UID)) != 0) {
2105 r = getpeercred(fd, &ucred);
2106 if (r < 0)
2107 return varlink_server_log_errno(server, r, "Failed to acquire peer credentials of incoming socket, refusing: %m");
2108
2109 ucred_acquired = true;
2110
2111 r = validate_connection(server, &ucred);
2112 if (r < 0)
2113 return r;
2114 if (r == 0)
2115 return -EPERM;
2116 } else
2117 ucred_acquired = false;
2118
2119 r = varlink_new(&v);
2120 if (r < 0)
2121 return varlink_server_log_errno(server, r, "Failed to allocate connection object: %m");
2122
2123 r = count_connection(server, &ucred);
2124 if (r < 0)
2125 return r;
2126
2127 v->fd = fd;
2128 v->userdata = server->userdata;
2129 if (ucred_acquired) {
2130 v->ucred = ucred;
2131 v->ucred_acquired = true;
2132 }
2133
2134 (void) asprintf(&v->description, "%s-%i", server->description ?: "varlink", v->fd);
2135
2136 /* Link up the server and the connection, and take reference in both directions. Note that the
2137 * reference on the connection is left dangling. It will be dropped when the connection is closed,
2138 * which happens in varlink_close(), including in the event loop quit callback. */
2139 v->server = varlink_server_ref(server);
2140 varlink_ref(v);
2141
2142 varlink_set_state(v, VARLINK_IDLE_SERVER);
2143
7e69d90c
LP		 2144 if (server->event) {
2145 r = varlink_attach_event(v, server->event, server->event_priority);
2146 if (r < 0) {
2147 varlink_log_errno(v, r, "Failed to attach new connection: %m");
2148 v->fd = -1; /* take the fd out of the connection again */
2149 varlink_close(v);
2150 return r;
2151 }
d41bd96f
LP		 2152 }
2153
2154 if (ret)
2155 *ret = v;
2156
2157 return 0;
2158}
2159
2160static int connect_callback(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
2161 VarlinkServerSocket *ss = userdata;
2162 _cleanup_close_ int cfd = -1;
2163 Varlink *v = NULL;
2164 int r;
2165
2166 assert(source);
2167 assert(ss);
2168
2169 varlink_server_log(ss->server, "New incoming connection.");
2170
2171 cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
2172 if (cfd < 0) {
2173 if (ERRNO_IS_ACCEPT_AGAIN(errno))
2174 return 0;
2175
2176 return varlink_server_log_errno(ss->server, errno, "Failed to accept incoming socket: %m");
2177 }
2178
2179 r = varlink_server_add_connection(ss->server, cfd, &v);
2180 if (r < 0)
2181 return 0;
2182
2183 TAKE_FD(cfd);
2184
2185 if (ss->server->connect_callback) {
2186 r = ss->server->connect_callback(ss->server, v, ss->server->userdata);
2187 if (r < 0) {
2188 varlink_log_errno(v, r, "Connection callback returned error, disconnecting client: %m");
2189 varlink_close(v);
2190 return 0;
2191 }
2192 }
2193
2194 return 0;
2195}
2196
2197int varlink_server_listen_fd(VarlinkServer *s, int fd) {
2198 _cleanup_free_ VarlinkServerSocket *ss = NULL;
2199 int r;
2200
2201 assert_return(s, -EINVAL);
2202 assert_return(fd >= 0, -EBADF);
2203
2204 r = fd_nonblock(fd, true);
2205 if (r < 0)
2206 return r;
2207
2208 ss = new(VarlinkServerSocket, 1);
2209 if (!ss)
2210 return -ENOMEM;
2211
2212 *ss = (VarlinkServerSocket) {
2213 .server = s,
2214 .fd = fd,
2215 };
2216
2217 if (s->event) {
8d91b220 2218 r = sd_event_add_io(s->event, &ss->event_source, fd, EPOLLIN, connect_callback, ss);
d41bd96f
LP		 2219 if (r < 0)
2220 return r;
2221
2222 r = sd_event_source_set_priority(ss->event_source, s->event_priority);
2223 if (r < 0)
2224 return r;
2225 }
2226
2227 LIST_PREPEND(sockets, s->sockets, TAKE_PTR(ss));
2228 return 0;
2229}
2230
2231int varlink_server_listen_address(VarlinkServer *s, const char *address, mode_t m) {
2232 union sockaddr_union sockaddr;
f36a9d59 2233 socklen_t sockaddr_len;
d41bd96f
LP		 2234 _cleanup_close_ int fd = -1;
2235 int r;
2236
2237 assert_return(s, -EINVAL);
2238 assert_return(address, -EINVAL);
2239 assert_return((m & ~0777) == 0, -EINVAL);
2240
2241 r = sockaddr_un_set_path(&sockaddr.un, address);
2242 if (r < 0)
2243 return r;
f36a9d59 2244 sockaddr_len = r;
d41bd96f
LP		 2245
2246 fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
2247 if (fd < 0)
2248 return -errno;
2249
a0c41de2
LP		 2250 fd = fd_move_above_stdio(fd);
2251
d41bd96f
LP		 2252 (void) sockaddr_un_unlink(&sockaddr.un);
2253
63e00ccd
CG		 2254 RUN_WITH_UMASK(~m & 0777) {
2255 r = mac_selinux_bind(fd, &sockaddr.sa, sockaddr_len);
2256 if (r < 0)
2257 return r;
2258 }
d41bd96f
LP		 2259
2260 if (listen(fd, SOMAXCONN) < 0)
2261 return -errno;
2262
2263 r = varlink_server_listen_fd(s, fd);
2264 if (r < 0)
2265 return r;
2266
2267 TAKE_FD(fd);
2268 return 0;
2269}
2270
2271void* varlink_server_set_userdata(VarlinkServer *s, void *userdata) {
2272 void *ret;
2273
2274 assert_return(s, NULL);
2275
2276 ret = s->userdata;
2277 s->userdata = userdata;
2278
2279 return ret;
2280}
2281
2282void* varlink_server_get_userdata(VarlinkServer *s) {
2283 assert_return(s, NULL);
2284
2285 return s->userdata;
2286}
2287
2288static VarlinkServerSocket* varlink_server_socket_destroy(VarlinkServerSocket *ss) {
2289 if (!ss)
2290 return NULL;
2291
2292 if (ss->server)
2293 LIST_REMOVE(sockets, ss->server->sockets, ss);
2294
1d3fe304 2295 sd_event_source_disable_unref(ss->event_source);
d41bd96f
LP		 2296
2297 free(ss->address);
2298 safe_close(ss->fd);
2299
2300 return mfree(ss);
2301}
2302
2303int varlink_server_shutdown(VarlinkServer *s) {
2304 assert_return(s, -EINVAL);
2305
2306 while (s->sockets)
2307 varlink_server_socket_destroy(s->sockets);
2308
2309 return 0;
2310}
2311
2312int varlink_server_attach_event(VarlinkServer *s, sd_event *e, int64_t priority) {
2313 VarlinkServerSocket *ss;
2314 int r;
2315
2316 assert_return(s, -EINVAL);
2317 assert_return(!s->event, -EBUSY);
2318
2319 if (e)
2320 s->event = sd_event_ref(e);
2321 else {
2322 r = sd_event_default(&s->event);
2323 if (r < 0)
2324 return r;
2325 }
2326
2327 LIST_FOREACH(sockets, ss, s->sockets) {
2328 assert(!ss->event_source);
2329
2330 r = sd_event_add_io(s->event, &ss->event_source, ss->fd, EPOLLIN, connect_callback, ss);
2331 if (r < 0)
2332 goto fail;
2333
2334 r = sd_event_source_set_priority(ss->event_source, priority);
2335 if (r < 0)
2336 goto fail;
2337 }
2338
2339 s->event_priority = priority;
2340 return 0;
2341
2342fail:
2343 varlink_server_detach_event(s);
2344 return r;
2345}
2346
2347int varlink_server_detach_event(VarlinkServer *s) {
2348 VarlinkServerSocket *ss;
2349
2350 assert_return(s, -EINVAL);
2351
2352 LIST_FOREACH(sockets, ss, s->sockets) {
2353
2354 if (!ss->event_source)
2355 continue;
2356
2357 (void) sd_event_source_set_enabled(ss->event_source, SD_EVENT_OFF);
2358 ss->event_source = sd_event_source_unref(ss->event_source);
2359 }
2360
2361 sd_event_unref(s->event);
2362 return 0;
2363}
2364
2365sd_event *varlink_server_get_event(VarlinkServer *s) {
2366 assert_return(s, NULL);
2367
2368 return s->event;
2369}
2370
2371int varlink_server_bind_method(VarlinkServer *s, const char *method, VarlinkMethod callback) {
2372 char *m;
2373 int r;
2374
2375 assert_return(s, -EINVAL);
2376 assert_return(method, -EINVAL);
2377 assert_return(callback, -EINVAL);
2378
2379 if (startswith(method, "org.varlink.service."))
2380 return -EEXIST;
2381
2382 r = hashmap_ensure_allocated(&s->methods, &string_hash_ops);
2383 if (r < 0)
2384 return r;
2385
2386 m = strdup(method);
2387 if (!m)
2388 return -ENOMEM;
2389
2390 r = hashmap_put(s->methods, m, callback);
2391 if (r < 0) {
2392 free(m);
2393 return r;
2394 }
2395
2396 return 0;
2397}
2398
2399int varlink_server_bind_method_many_internal(VarlinkServer *s, ...) {
2400 va_list ap;
e7b93f97 2401 int r = 0;
d41bd96f
LP		 2402
2403 assert_return(s, -EINVAL);
2404
2405 va_start(ap, s);
2406 for (;;) {
2407 VarlinkMethod callback;
2408 const char *method;
2409
2410 method = va_arg(ap, const char *);
2411 if (!method)
2412 break;
2413
2414 callback = va_arg(ap, VarlinkMethod);
2415
2416 r = varlink_server_bind_method(s, method, callback);
2417 if (r < 0)
e7b93f97 2418 break;
d41bd96f 2419 }
e7b93f97 2420 va_end(ap);
d41bd96f 2421
e7b93f97 2422 return r;
d41bd96f
LP		 2423}
2424
2425int varlink_server_bind_connect(VarlinkServer *s, VarlinkConnect callback) {
2426 assert_return(s, -EINVAL);
2427
2428 if (callback && s->connect_callback && callback != s->connect_callback)
2429 return -EBUSY;
2430
2431 s->connect_callback = callback;
2432 return 0;
2433}
2434
6d4d6002
LP		 2435int varlink_server_bind_disconnect(VarlinkServer *s, VarlinkDisconnect callback) {
2436 assert_return(s, -EINVAL);
2437
2438 if (callback && s->disconnect_callback && callback != s->disconnect_callback)
2439 return -EBUSY;
2440
2441 s->disconnect_callback = callback;
2442 return 0;
2443}
2444
d41bd96f 2445unsigned varlink_server_connections_max(VarlinkServer *s) {
88a36d36 2446 int dts;
d41bd96f
LP		 2447
2448 /* If a server is specified, return the setting for that server, otherwise the default value */
2449 if (s)
2450 return s->connections_max;
2451
88a36d36
LP		 2452 dts = getdtablesize();
2453 assert_se(dts > 0);
d41bd96f
LP		 2454
2455 /* Make sure we never use up more than ¾th of RLIMIT_NOFILE for IPC */
88a36d36
LP		 2456 if (VARLINK_DEFAULT_CONNECTIONS_MAX > (unsigned) dts / 4 * 3)
2457 return dts / 4 * 3;
d41bd96f
LP		 2458
2459 return VARLINK_DEFAULT_CONNECTIONS_MAX;
2460}
2461
2462unsigned varlink_server_connections_per_uid_max(VarlinkServer *s) {
2463 unsigned m;
2464
2465 if (s)
2466 return s->connections_per_uid_max;
2467
2468 /* Make sure to never use up more than ¾th of available connections for a single user */
2469 m = varlink_server_connections_max(NULL);
2470 if (VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX > m)
2471 return m / 4 * 3;
2472
2473 return VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX;
2474}
2475
2476int varlink_server_set_connections_per_uid_max(VarlinkServer *s, unsigned m) {
2477 assert_return(s, -EINVAL);
2478 assert_return(m > 0, -EINVAL);
2479
2480 s->connections_per_uid_max = m;
2481 return 0;
2482}
2483
2484int varlink_server_set_connections_max(VarlinkServer *s, unsigned m) {
2485 assert_return(s, -EINVAL);
2486 assert_return(m > 0, -EINVAL);
2487
2488 s->connections_max = m;
2489 return 0;
2490}
2491
c4f601f2
LP		 2492unsigned varlink_server_current_connections(VarlinkServer *s) {
2493 assert_return(s, UINT_MAX);
2494
2495 return s->n_connections;
2496}
2497
d41bd96f
LP		 2498int varlink_server_set_description(VarlinkServer *s, const char *description) {
2499 assert_return(s, -EINVAL);
2500
2501 return free_and_strdup(&s->description, description);
2502}
Unnamed repository; edit this file 'description' to name the repository.