1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
6 #include "alloc-util.h"
7 #include "errno-util.h"
9 #include "glyph-util.h"
13 #include "process-util.h"
14 #include "selinux-util.h"
15 #include "serialize.h"
17 #include "socket-util.h"
18 #include "string-table.h"
19 #include "string-util.h"
21 #include "time-util.h"
22 #include "umask-util.h"
23 #include "user-util.h"
25 #include "varlink-internal.h"
27 #define VARLINK_DEFAULT_CONNECTIONS_MAX 4096U
28 #define VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX 1024U
30 #define VARLINK_DEFAULT_TIMEOUT_USEC (45U*USEC_PER_SEC)
31 #define VARLINK_BUFFER_MAX (16U*1024U*1024U)
32 #define VARLINK_READ_SIZE (64U*1024U)
34 typedef enum VarlinkState
{
35 /* Client side states */
37 VARLINK_AWAITING_REPLY
,
38 VARLINK_AWAITING_REPLY_MORE
,
41 VARLINK_PROCESSING_REPLY
,
43 /* Server side states */
45 VARLINK_PROCESSING_METHOD
,
46 VARLINK_PROCESSING_METHOD_MORE
,
47 VARLINK_PROCESSING_METHOD_ONEWAY
,
48 VARLINK_PROCESSED_METHOD
,
49 VARLINK_PENDING_METHOD
,
50 VARLINK_PENDING_METHOD_MORE
,
52 /* Common states (only during shutdown) */
53 VARLINK_PENDING_DISCONNECT
,
54 VARLINK_PENDING_TIMEOUT
,
55 VARLINK_PROCESSING_DISCONNECT
,
56 VARLINK_PROCESSING_TIMEOUT
,
57 VARLINK_PROCESSING_FAILURE
,
61 _VARLINK_STATE_INVALID
= -EINVAL
,
64 /* Tests whether we are not yet disconnected. Note that this is true during all states where the connection
65 * is still good for something, and false only when it's dead for good. This means: when we are
66 * asynchronously connecting to a peer and the connect() is still pending, then this will return 'true', as
67 * the connection is still good, and we are likely to be able to properly operate on it soon. */
68 #define VARLINK_STATE_IS_ALIVE(state) \
70 VARLINK_IDLE_CLIENT, \
71 VARLINK_AWAITING_REPLY, \
72 VARLINK_AWAITING_REPLY_MORE, \
75 VARLINK_PROCESSING_REPLY, \
76 VARLINK_IDLE_SERVER, \
77 VARLINK_PROCESSING_METHOD, \
78 VARLINK_PROCESSING_METHOD_MORE, \
79 VARLINK_PROCESSING_METHOD_ONEWAY, \
80 VARLINK_PROCESSED_METHOD, \
81 VARLINK_PENDING_METHOD, \
82 VARLINK_PENDING_METHOD_MORE)
84 typedef struct VarlinkJsonQueueItem VarlinkJsonQueueItem
;
86 /* A queued message we shall write into the socket, along with the file descriptors to send at the same
87 * time. This queue item binds them together so that message/fd boundaries are maintained throughout the
89 struct VarlinkJsonQueueItem
{
90 LIST_FIELDS(VarlinkJsonQueueItem
, queue
);
99 VarlinkServer
*server
;
102 bool connecting
; /* This boolean indicates whether the socket fd we are operating on is currently
103 * processing an asynchronous connect(). In that state we watch the socket for
104 * EPOLLOUT, but we refrain from calling read() or write() on the socket as that
105 * will trigger ENOTCONN. Note that this boolean is kept separate from the
106 * VarlinkState above on purpose: while the connect() is still not complete we
107 * already want to allow queuing of messages and similar. Thus it's nice to keep
108 * these two state concepts separate: the VarlinkState encodes what our own view of
109 * the connection is, i.e. whether we think it's a server, a client, and has
110 * something queued already, while 'connecting' tells us a detail about the
111 * transport used below, that should have no effect on how we otherwise accept and
112 * process operations from the user.
114 * Or to say this differently: VARLINK_STATE_IS_ALIVE(state) tells you whether the
115 * connection is good to use, even if it might not be fully connected
116 * yet. connecting=true then informs you that actually we are still connecting, and
117 * the connection is actually not established yet and thus any requests you enqueue
118 * now will still work fine but will be queued only, not sent yet, but that
119 * shouldn't stop you from using the connection, since eventually whatever you queue
122 * Or to say this even differently: 'state' is a high-level ("application layer"
123 * high, if you so will) state, while 'conecting' is a low-level ("transport layer"
124 * low, if you so will) state, and while they are not entirely unrelated and
125 * sometimes propagate effects to each other they are only asynchronously connected
131 char *input_buffer
; /* valid data starts at input_buffer_index, ends at input_buffer_index+input_buffer_size */
132 size_t input_buffer_index
;
133 size_t input_buffer_size
;
134 size_t input_buffer_unscanned
;
136 char *output_buffer
; /* valid data starts at output_buffer_index, ends at output_buffer_index+output_buffer_size */
137 size_t output_buffer_index
;
138 size_t output_buffer_size
;
140 int *input_fds
; /* file descriptors associated with the data in input_buffer (for fd passing) */
143 int *output_fds
; /* file descriptors associated with the data in output_buffer (for fd passing) */
146 /* Further messages to output not yet formatted into text, and thus not included in output_buffer
147 * yet. We keep them separate from output_buffer, to not violate fd message boundaries: we want that
148 * each fd that is sent is associated with its fds, and that fds cannot be accidentally associated
149 * with preceding or following messages. */
150 LIST_HEAD(VarlinkJsonQueueItem
, output_queue
);
151 VarlinkJsonQueueItem
*output_queue_tail
;
153 /* The fds to associate with the next message that is about to be enqueued. The user first pushes the
154 * fds it intends to send via varlink_push_fd() into this queue, and then once the message data is
155 * submitted we'll combine the fds and the message data into one. */
159 VarlinkReply reply_callback
;
161 JsonVariant
*current
;
164 bool ucred_acquired
:1;
166 bool write_disconnected
:1;
167 bool read_disconnected
:1;
168 bool prefer_read_write
:1;
171 bool allow_fd_passing_input
:1;
172 bool allow_fd_passing_output
:1;
174 bool output_buffer_sensitive
:1; /* whether to erase the output buffer after writing it to the socket */
176 int af
; /* address family if socket; AF_UNSPEC if not socket; negative if not known */
185 sd_event_source
*io_event_source
;
186 sd_event_source
*time_event_source
;
187 sd_event_source
*quit_event_source
;
188 sd_event_source
*defer_event_source
;
191 typedef struct VarlinkServerSocket VarlinkServerSocket
;
193 struct VarlinkServerSocket
{
194 VarlinkServer
*server
;
199 sd_event_source
*event_source
;
201 LIST_FIELDS(VarlinkServerSocket
, sockets
);
204 struct VarlinkServer
{
206 VarlinkServerFlags flags
;
208 LIST_HEAD(VarlinkServerSocket
, sockets
);
211 VarlinkConnect connect_callback
;
212 VarlinkDisconnect disconnect_callback
;
215 int64_t event_priority
;
217 unsigned n_connections
;
223 unsigned connections_max
;
224 unsigned connections_per_uid_max
;
227 static const char* const varlink_state_table
[_VARLINK_STATE_MAX
] = {
228 [VARLINK_IDLE_CLIENT
] = "idle-client",
229 [VARLINK_AWAITING_REPLY
] = "awaiting-reply",
230 [VARLINK_AWAITING_REPLY_MORE
] = "awaiting-reply-more",
231 [VARLINK_CALLING
] = "calling",
232 [VARLINK_CALLED
] = "called",
233 [VARLINK_PROCESSING_REPLY
] = "processing-reply",
234 [VARLINK_IDLE_SERVER
] = "idle-server",
235 [VARLINK_PROCESSING_METHOD
] = "processing-method",
236 [VARLINK_PROCESSING_METHOD_MORE
] = "processing-method-more",
237 [VARLINK_PROCESSING_METHOD_ONEWAY
] = "processing-method-oneway",
238 [VARLINK_PROCESSED_METHOD
] = "processed-method",
239 [VARLINK_PENDING_METHOD
] = "pending-method",
240 [VARLINK_PENDING_METHOD_MORE
] = "pending-method-more",
241 [VARLINK_PENDING_DISCONNECT
] = "pending-disconnect",
242 [VARLINK_PENDING_TIMEOUT
] = "pending-timeout",
243 [VARLINK_PROCESSING_DISCONNECT
] = "processing-disconnect",
244 [VARLINK_PROCESSING_TIMEOUT
] = "processing-timeout",
245 [VARLINK_PROCESSING_FAILURE
] = "processing-failure",
246 [VARLINK_DISCONNECTED
] = "disconnected",
249 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(varlink_state
, VarlinkState
);
251 #define varlink_log_errno(v, error, fmt, ...) \
252 log_debug_errno(error, "%s: " fmt, varlink_description(v), ##__VA_ARGS__)
254 #define varlink_log(v, fmt, ...) \
255 log_debug("%s: " fmt, varlink_description(v), ##__VA_ARGS__)
257 #define varlink_server_log_errno(s, error, fmt, ...) \
258 log_debug_errno(error, "%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
260 #define varlink_server_log(s, fmt, ...) \
261 log_debug("%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
263 static int varlink_format_queue(Varlink
*v
);
265 static inline const char *varlink_description(Varlink
*v
) {
266 return (v
? v
->description
: NULL
) ?: "varlink";
269 static inline const char *varlink_server_description(VarlinkServer
*s
) {
270 return (s
? s
->description
: NULL
) ?: "varlink";
273 static VarlinkJsonQueueItem
*varlink_json_queue_item_free(VarlinkJsonQueueItem
*q
) {
277 json_variant_unref(q
->data
);
278 close_many(q
->fds
, q
->n_fds
);
283 static VarlinkJsonQueueItem
*varlink_json_queue_item_new(JsonVariant
*m
, const int fds
[], size_t n_fds
) {
284 VarlinkJsonQueueItem
*q
;
287 assert(fds
|| n_fds
== 0);
289 q
= malloc(offsetof(VarlinkJsonQueueItem
, fds
) + sizeof(int) * n_fds
);
293 *q
= (VarlinkJsonQueueItem
) {
294 .data
= json_variant_ref(m
),
298 memcpy_safe(q
->fds
, fds
, n_fds
* sizeof(int));
303 static void varlink_set_state(Varlink
*v
, VarlinkState state
) {
305 assert(state
>= 0 && state
< _VARLINK_STATE_MAX
);
308 varlink_log(v
, "Setting state %s",
309 varlink_state_to_string(state
));
311 varlink_log(v
, "Changing state %s %s %s",
312 varlink_state_to_string(v
->state
),
313 special_glyph(SPECIAL_GLYPH_ARROW_RIGHT
),
314 varlink_state_to_string(state
));
319 static int varlink_new(Varlink
**ret
) {
332 .state
= _VARLINK_STATE_INVALID
,
334 .ucred
= UCRED_INVALID
,
336 .timestamp
= USEC_INFINITY
,
337 .timeout
= VARLINK_DEFAULT_TIMEOUT_USEC
,
346 int varlink_connect_address(Varlink
**ret
, const char *address
) {
347 _cleanup_(varlink_unrefp
) Varlink
*v
= NULL
;
348 union sockaddr_union sockaddr
;
351 assert_return(ret
, -EINVAL
);
352 assert_return(address
, -EINVAL
);
356 return log_debug_errno(r
, "Failed to create varlink object: %m");
358 v
->fd
= socket(AF_UNIX
, SOCK_STREAM
|SOCK_CLOEXEC
|SOCK_NONBLOCK
, 0);
360 return log_debug_errno(errno
, "Failed to create AF_UNIX socket: %m");
362 v
->fd
= fd_move_above_stdio(v
->fd
);
365 r
= sockaddr_un_set_path(&sockaddr
.un
, address
);
367 if (r
!= -ENAMETOOLONG
)
368 return log_debug_errno(r
, "Failed to set socket address '%s': %m", address
);
370 /* This is a file system path, and too long to fit into sockaddr_un. Let's connect via O_PATH
373 r
= connect_unix_path(v
->fd
, AT_FDCWD
, address
);
375 r
= RET_NERRNO(connect(v
->fd
, &sockaddr
.sa
, r
));
378 if (!IN_SET(r
, -EAGAIN
, -EINPROGRESS
))
379 return log_debug_errno(r
, "Failed to connect to %s: %m", address
);
381 v
->connecting
= true; /* We are asynchronously connecting, i.e. the connect() is being
382 * processed in the background. As long as that's the case the socket
383 * is in a special state: it's there, we can poll it for EPOLLOUT, but
384 * if we attempt to write() to it before we see EPOLLOUT we'll get
385 * ENOTCONN (and not EAGAIN, like we would for a normal connected
386 * socket that isn't writable at the moment). Since ENOTCONN on write()
387 * hence can mean two different things (i.e. connection not complete
388 * yet vs. already disconnected again), we store as a boolean whether
389 * we are still in connect(). */
392 varlink_set_state(v
, VARLINK_IDLE_CLIENT
);
398 int varlink_connect_fd(Varlink
**ret
, int fd
) {
402 assert_return(ret
, -EINVAL
);
403 assert_return(fd
>= 0, -EBADF
);
405 r
= fd_nonblock(fd
, true);
407 return log_debug_errno(r
, "Failed to make fd %d nonblocking: %m", fd
);
411 return log_debug_errno(r
, "Failed to create varlink object: %m");
415 varlink_set_state(v
, VARLINK_IDLE_CLIENT
);
417 /* Note that if this function is called we assume the passed socket (if it is one) is already
418 * properly connected, i.e. any asynchronous connect() done on it already completed. Because of that
419 * we'll not set the 'connecting' boolean here, i.e. we don't need to avoid write()ing to the socket
420 * until the connection is fully set up. Behaviour here is hence a bit different from
421 * varlink_connect_address() above, as there we do handle asynchronous connections ourselves and
422 * avoid doing write() on it before we saw EPOLLOUT for the first time. */
428 static void varlink_detach_event_sources(Varlink
*v
) {
431 v
->io_event_source
= sd_event_source_disable_unref(v
->io_event_source
);
432 v
->time_event_source
= sd_event_source_disable_unref(v
->time_event_source
);
433 v
->quit_event_source
= sd_event_source_disable_unref(v
->quit_event_source
);
434 v
->defer_event_source
= sd_event_source_disable_unref(v
->defer_event_source
);
437 static void varlink_clear_current(Varlink
*v
) {
440 /* Clears the currently processed incoming message */
441 v
->current
= json_variant_unref(v
->current
);
443 close_many(v
->input_fds
, v
->n_input_fds
);
444 v
->input_fds
= mfree(v
->input_fds
);
448 static void varlink_clear(Varlink
*v
) {
451 varlink_detach_event_sources(v
);
453 v
->fd
= safe_close(v
->fd
);
455 varlink_clear_current(v
);
457 v
->input_buffer
= mfree(v
->input_buffer
);
458 v
->output_buffer
= v
->output_buffer_sensitive
? erase_and_free(v
->output_buffer
) : mfree(v
->output_buffer
);
460 varlink_clear_current(v
);
462 close_many(v
->output_fds
, v
->n_output_fds
);
463 v
->output_fds
= mfree(v
->output_fds
);
466 close_many(v
->pushed_fds
, v
->n_pushed_fds
);
467 v
->pushed_fds
= mfree(v
->pushed_fds
);
470 while (v
->output_queue
) {
471 VarlinkJsonQueueItem
*q
= v
->output_queue
;
473 LIST_REMOVE(queue
, v
->output_queue
, q
);
474 varlink_json_queue_item_free(q
);
476 v
->output_queue_tail
= NULL
;
478 v
->event
= sd_event_unref(v
->event
);
481 static Varlink
* varlink_destroy(Varlink
*v
) {
485 /* If this is called the server object must already been unreffed here. Why that? because when we
486 * linked up the varlink connection with the server object we took one ref in each direction */
491 free(v
->description
);
495 DEFINE_TRIVIAL_REF_UNREF_FUNC(Varlink
, varlink
, varlink_destroy
);
497 static int varlink_test_disconnect(Varlink
*v
) {
500 /* Tests whether we the connection has been terminated. We are careful to not stop processing it
501 * prematurely, since we want to handle half-open connections as well as possible and want to flush
502 * out and read data before we close down if we can. */
504 /* Already disconnected? */
505 if (!VARLINK_STATE_IS_ALIVE(v
->state
))
508 /* Wait until connection setup is complete, i.e. until asynchronous connect() completes */
512 /* Still something to write and we can write? Stay around */
513 if (v
->output_buffer_size
> 0 && !v
->write_disconnected
)
516 /* Both sides gone already? Then there's no need to stick around */
517 if (v
->read_disconnected
&& v
->write_disconnected
)
520 /* If we are waiting for incoming data but the read side is shut down, disconnect. */
521 if (IN_SET(v
->state
, VARLINK_AWAITING_REPLY
, VARLINK_AWAITING_REPLY_MORE
, VARLINK_CALLING
, VARLINK_IDLE_SERVER
) && v
->read_disconnected
)
524 /* Similar, if are a client that hasn't written anything yet but the write side is dead, also
525 * disconnect. We also explicitly check for POLLHUP here since we likely won't notice the write side
526 * being down if we never wrote anything. */
527 if (v
->state
== VARLINK_IDLE_CLIENT
&& (v
->write_disconnected
|| v
->got_pollhup
))
530 /* We are on the server side and still want to send out more replies, but we saw POLLHUP already, and
531 * either got no buffered bytes to write anymore or already saw a write error. In that case we should
532 * shut down the varlink link. */
533 if (IN_SET(v
->state
, VARLINK_PENDING_METHOD
, VARLINK_PENDING_METHOD_MORE
) && (v
->write_disconnected
|| v
->output_buffer_size
== 0) && v
->got_pollhup
)
539 varlink_set_state(v
, VARLINK_PENDING_DISCONNECT
);
543 static int varlink_write(Varlink
*v
) {
549 if (!VARLINK_STATE_IS_ALIVE(v
->state
))
551 if (v
->connecting
) /* Writing while we are still wait for a non-blocking connect() to complete will
552 * result in ENOTCONN, hence exit early here */
554 if (v
->write_disconnected
)
557 /* If needed let's convert some output queue json variants into text form */
558 r
= varlink_format_queue(v
);
562 if (v
->output_buffer_size
== 0)
567 if (v
->n_output_fds
> 0) { /* If we shall send fds along, we must use sendmsg() */
569 .iov_base
= v
->output_buffer
+ v
->output_buffer_index
,
570 .iov_len
= v
->output_buffer_size
,
575 .msg_controllen
= CMSG_SPACE(sizeof(int) * v
->n_output_fds
),
578 mh
.msg_control
= alloca0(mh
.msg_controllen
);
580 struct cmsghdr
*control
= CMSG_FIRSTHDR(&mh
);
581 control
->cmsg_len
= CMSG_LEN(sizeof(int) * v
->n_output_fds
);
582 control
->cmsg_level
= SOL_SOCKET
;
583 control
->cmsg_type
= SCM_RIGHTS
;
584 memcpy(CMSG_DATA(control
), v
->output_fds
, sizeof(int) * v
->n_output_fds
);
586 n
= sendmsg(v
->fd
, &mh
, MSG_DONTWAIT
|MSG_NOSIGNAL
);
588 /* We generally prefer recv()/send() (mostly because of MSG_NOSIGNAL) but also want to be compatible
589 * with non-socket IO, hence fall back automatically.
591 * Use a local variable to help gcc figure out that we set 'n' in all cases. */
592 bool prefer_write
= v
->prefer_read_write
;
594 n
= send(v
->fd
, v
->output_buffer
+ v
->output_buffer_index
, v
->output_buffer_size
, MSG_DONTWAIT
|MSG_NOSIGNAL
);
595 if (n
< 0 && errno
== ENOTSOCK
)
596 prefer_write
= v
->prefer_read_write
= true;
599 n
= write(v
->fd
, v
->output_buffer
+ v
->output_buffer_index
, v
->output_buffer_size
);
605 if (ERRNO_IS_DISCONNECT(errno
)) {
606 /* If we get informed about a disconnect on write, then let's remember that, but not
607 * act on it just yet. Let's wait for read() to report the issue first. */
608 v
->write_disconnected
= true;
615 if (v
->output_buffer_sensitive
)
616 explicit_bzero_safe(v
->output_buffer
+ v
->output_buffer_index
, n
);
618 v
->output_buffer_size
-= n
;
620 if (v
->output_buffer_size
== 0) {
621 v
->output_buffer_index
= 0;
622 v
->output_buffer_sensitive
= false; /* We can reset the sensitive flag once the buffer is empty */
624 v
->output_buffer_index
+= n
;
626 close_many(v
->output_fds
, v
->n_output_fds
);
629 v
->timestamp
= now(CLOCK_MONOTONIC
);
633 #define VARLINK_FDS_MAX (16U*1024U)
635 static int varlink_read(Varlink
*v
) {
636 CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(int) * VARLINK_FDS_MAX
)) control
;
645 if (!IN_SET(v
->state
, VARLINK_AWAITING_REPLY
, VARLINK_AWAITING_REPLY_MORE
, VARLINK_CALLING
, VARLINK_IDLE_SERVER
))
647 if (v
->connecting
) /* read() on a socket while we are in connect() will fail with EINVAL, hence exit early here */
651 if (v
->input_buffer_unscanned
> 0)
653 if (v
->read_disconnected
)
656 if (v
->input_buffer_size
>= VARLINK_BUFFER_MAX
)
661 if (MALLOC_SIZEOF_SAFE(v
->input_buffer
) <= v
->input_buffer_index
+ v
->input_buffer_size
) {
664 add
= MIN(VARLINK_BUFFER_MAX
- v
->input_buffer_size
, VARLINK_READ_SIZE
);
666 if (v
->input_buffer_index
== 0) {
668 if (!GREEDY_REALLOC(v
->input_buffer
, v
->input_buffer_size
+ add
))
674 b
= new(char, v
->input_buffer_size
+ add
);
678 memcpy(b
, v
->input_buffer
+ v
->input_buffer_index
, v
->input_buffer_size
);
680 free_and_replace(v
->input_buffer
, b
);
681 v
->input_buffer_index
= 0;
685 p
= v
->input_buffer
+ v
->input_buffer_index
+ v
->input_buffer_size
;
686 rs
= MALLOC_SIZEOF_SAFE(v
->input_buffer
) - (v
->input_buffer_index
+ v
->input_buffer_size
);
688 if (v
->allow_fd_passing_input
) {
689 iov
= (struct iovec
) {
693 mh
= (struct msghdr
) {
696 .msg_control
= &control
,
697 .msg_controllen
= sizeof(control
),
699 n
= recvmsg_safe(v
->fd
, &mh
, MSG_DONTWAIT
|MSG_CMSG_CLOEXEC
);
701 bool prefer_read
= v
->prefer_read_write
;
703 n
= recv(v
->fd
, p
, rs
, MSG_DONTWAIT
);
704 if (n
< 0 && errno
== ENOTSOCK
)
705 prefer_read
= v
->prefer_read_write
= true;
708 n
= read(v
->fd
, p
, rs
);
714 if (ERRNO_IS_DISCONNECT(errno
)) {
715 v
->read_disconnected
= true;
721 if (n
== 0) { /* EOF */
723 if (v
->allow_fd_passing_input
)
726 v
->read_disconnected
= true;
730 if (v
->allow_fd_passing_input
) {
731 struct cmsghdr
* cmsg
;
733 cmsg
= cmsg_find(&mh
, SOL_SOCKET
, SCM_RIGHTS
, (socklen_t
) -1);
737 /* We only allow file descriptors to be passed along with the first byte of a
738 * message. If they are passed with any other byte this is a protocol violation. */
739 if (v
->input_buffer_size
!= 0) {
744 add
= (cmsg
->cmsg_len
- CMSG_LEN(0)) / sizeof(int);
745 if (add
> INT_MAX
- v
->n_input_fds
) {
750 if (!GREEDY_REALLOC(v
->input_fds
, v
->n_input_fds
+ add
)) {
755 memcpy_safe(v
->input_fds
+ v
->n_input_fds
, CMSG_TYPED_DATA(cmsg
, int), add
* sizeof(int));
756 v
->n_input_fds
+= add
;
760 v
->input_buffer_size
+= n
;
761 v
->input_buffer_unscanned
+= n
;
766 static int varlink_parse_message(Varlink
*v
) {
767 const char *e
, *begin
;
775 if (v
->input_buffer_unscanned
<= 0)
778 assert(v
->input_buffer_unscanned
<= v
->input_buffer_size
);
779 assert(v
->input_buffer_index
+ v
->input_buffer_size
<= MALLOC_SIZEOF_SAFE(v
->input_buffer
));
781 begin
= v
->input_buffer
+ v
->input_buffer_index
;
783 e
= memchr(begin
+ v
->input_buffer_size
- v
->input_buffer_unscanned
, 0, v
->input_buffer_unscanned
);
785 v
->input_buffer_unscanned
= 0;
791 varlink_log(v
, "New incoming message: %s", begin
); /* FIXME: should we output the whole message here before validation?
792 * This may produce a non-printable journal entry if the message
793 * is invalid. We may also expose privileged information. */
795 r
= json_parse(begin
, 0, &v
->current
, NULL
, NULL
);
797 /* If we encounter a parse failure flush all data. We cannot possibly recover from this,
798 * hence drop all buffered data now. */
799 v
->input_buffer_index
= v
->input_buffer_size
= v
->input_buffer_unscanned
= 0;
800 return varlink_log_errno(v
, r
, "Failed to parse JSON: %m");
803 v
->input_buffer_size
-= sz
;
805 if (v
->input_buffer_size
== 0)
806 v
->input_buffer_index
= 0;
808 v
->input_buffer_index
+= sz
;
810 v
->input_buffer_unscanned
= v
->input_buffer_size
;
814 static int varlink_test_timeout(Varlink
*v
) {
817 if (!IN_SET(v
->state
, VARLINK_AWAITING_REPLY
, VARLINK_AWAITING_REPLY_MORE
, VARLINK_CALLING
))
819 if (v
->timeout
== USEC_INFINITY
)
822 if (now(CLOCK_MONOTONIC
) < usec_add(v
->timestamp
, v
->timeout
))
825 varlink_set_state(v
, VARLINK_PENDING_TIMEOUT
);
830 static int varlink_dispatch_local_error(Varlink
*v
, const char *error
) {
836 if (!v
->reply_callback
)
839 r
= v
->reply_callback(v
, NULL
, error
, VARLINK_REPLY_ERROR
|VARLINK_REPLY_LOCAL
, v
->userdata
);
841 log_debug_errno(r
, "Reply callback returned error, ignoring: %m");
846 static int varlink_dispatch_timeout(Varlink
*v
) {
849 if (v
->state
!= VARLINK_PENDING_TIMEOUT
)
852 varlink_set_state(v
, VARLINK_PROCESSING_TIMEOUT
);
853 varlink_dispatch_local_error(v
, VARLINK_ERROR_TIMEOUT
);
859 static int varlink_dispatch_disconnect(Varlink
*v
) {
862 if (v
->state
!= VARLINK_PENDING_DISCONNECT
)
865 varlink_set_state(v
, VARLINK_PROCESSING_DISCONNECT
);
866 varlink_dispatch_local_error(v
, VARLINK_ERROR_DISCONNECTED
);
872 static int varlink_sanitize_parameters(JsonVariant
**v
) {
875 /* Varlink always wants a parameters list, hence make one if the caller doesn't want any */
877 return json_variant_new_object(v
, NULL
, 0);
878 else if (!json_variant_is_object(*v
))
884 static int varlink_dispatch_reply(Varlink
*v
) {
885 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters
= NULL
;
886 VarlinkReplyFlags flags
= 0;
887 const char *error
= NULL
;
894 if (!IN_SET(v
->state
, VARLINK_AWAITING_REPLY
, VARLINK_AWAITING_REPLY_MORE
, VARLINK_CALLING
))
899 assert(v
->n_pending
> 0);
901 if (!json_variant_is_object(v
->current
))
904 JSON_VARIANT_OBJECT_FOREACH(k
, e
, v
->current
) {
906 if (streq(k
, "error")) {
909 if (!json_variant_is_string(e
))
912 error
= json_variant_string(e
);
913 flags
|= VARLINK_REPLY_ERROR
;
915 } else if (streq(k
, "parameters")) {
918 if (!json_variant_is_object(e
))
921 parameters
= json_variant_ref(e
);
923 } else if (streq(k
, "continues")) {
924 if (FLAGS_SET(flags
, VARLINK_REPLY_CONTINUES
))
927 if (!json_variant_is_boolean(e
))
930 if (json_variant_boolean(e
))
931 flags
|= VARLINK_REPLY_CONTINUES
;
936 /* Replies with 'continue' set are only OK if we set 'more' when the method call was initiated */
937 if (v
->state
!= VARLINK_AWAITING_REPLY_MORE
&& FLAGS_SET(flags
, VARLINK_REPLY_CONTINUES
))
940 /* An error is final */
941 if (error
&& FLAGS_SET(flags
, VARLINK_REPLY_CONTINUES
))
944 r
= varlink_sanitize_parameters(¶meters
);
948 if (IN_SET(v
->state
, VARLINK_AWAITING_REPLY
, VARLINK_AWAITING_REPLY_MORE
)) {
949 varlink_set_state(v
, VARLINK_PROCESSING_REPLY
);
951 if (v
->reply_callback
) {
952 r
= v
->reply_callback(v
, parameters
, error
, flags
, v
->userdata
);
954 log_debug_errno(r
, "Reply callback returned error, ignoring: %m");
957 varlink_clear_current(v
);
959 if (v
->state
== VARLINK_PROCESSING_REPLY
) {
961 assert(v
->n_pending
> 0);
963 if (!FLAGS_SET(flags
, VARLINK_REPLY_CONTINUES
))
967 FLAGS_SET(flags
, VARLINK_REPLY_CONTINUES
) ? VARLINK_AWAITING_REPLY_MORE
:
968 v
->n_pending
== 0 ? VARLINK_IDLE_CLIENT
: VARLINK_AWAITING_REPLY
);
971 assert(v
->state
== VARLINK_CALLING
);
972 varlink_set_state(v
, VARLINK_CALLED
);
978 varlink_set_state(v
, VARLINK_PROCESSING_FAILURE
);
979 varlink_dispatch_local_error(v
, VARLINK_ERROR_PROTOCOL
);
985 static int varlink_dispatch_method(Varlink
*v
) {
986 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters
= NULL
;
987 VarlinkMethodFlags flags
= 0;
988 const char *method
= NULL
, *error
;
990 VarlinkMethod callback
;
996 if (v
->state
!= VARLINK_IDLE_SERVER
)
1001 if (!json_variant_is_object(v
->current
))
1004 JSON_VARIANT_OBJECT_FOREACH(k
, e
, v
->current
) {
1006 if (streq(k
, "method")) {
1009 if (!json_variant_is_string(e
))
1012 method
= json_variant_string(e
);
1014 } else if (streq(k
, "parameters")) {
1017 if (!json_variant_is_object(e
))
1020 parameters
= json_variant_ref(e
);
1022 } else if (streq(k
, "oneway")) {
1024 if ((flags
& (VARLINK_METHOD_ONEWAY
|VARLINK_METHOD_MORE
)) != 0)
1027 if (!json_variant_is_boolean(e
))
1030 if (json_variant_boolean(e
))
1031 flags
|= VARLINK_METHOD_ONEWAY
;
1033 } else if (streq(k
, "more")) {
1035 if ((flags
& (VARLINK_METHOD_ONEWAY
|VARLINK_METHOD_MORE
)) != 0)
1038 if (!json_variant_is_boolean(e
))
1041 if (json_variant_boolean(e
))
1042 flags
|= VARLINK_METHOD_MORE
;
1051 r
= varlink_sanitize_parameters(¶meters
);
1055 varlink_set_state(v
, (flags
& VARLINK_METHOD_MORE
) ? VARLINK_PROCESSING_METHOD_MORE
:
1056 (flags
& VARLINK_METHOD_ONEWAY
) ? VARLINK_PROCESSING_METHOD_ONEWAY
:
1057 VARLINK_PROCESSING_METHOD
);
1061 if (STR_IN_SET(method
, "org.varlink.service.GetInfo", "org.varlink.service.GetInterface")) {
1062 /* For now, we don't implement a single of varlink's own methods */
1064 error
= VARLINK_ERROR_METHOD_NOT_IMPLEMENTED
;
1065 } else if (startswith(method
, "org.varlink.service.")) {
1067 error
= VARLINK_ERROR_METHOD_NOT_FOUND
;
1069 callback
= hashmap_get(v
->server
->methods
, method
);
1070 error
= VARLINK_ERROR_METHOD_NOT_FOUND
;
1074 r
= callback(v
, parameters
, flags
, v
->userdata
);
1076 log_debug_errno(r
, "Callback for %s returned error: %m", method
);
1078 /* We got an error back from the callback. Propagate it to the client if the method call remains unanswered. */
1079 if (!FLAGS_SET(flags
, VARLINK_METHOD_ONEWAY
)) {
1080 r
= varlink_error_errno(v
, r
);
1085 } else if (!FLAGS_SET(flags
, VARLINK_METHOD_ONEWAY
)) {
1088 r
= varlink_errorb(v
, error
, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method
))));
1095 case VARLINK_PROCESSED_METHOD
: /* Method call is fully processed */
1096 case VARLINK_PROCESSING_METHOD_ONEWAY
: /* ditto */
1097 varlink_clear_current(v
);
1098 varlink_set_state(v
, VARLINK_IDLE_SERVER
);
1101 case VARLINK_PROCESSING_METHOD
: /* Method call wasn't replied to, will be replied to later */
1102 varlink_set_state(v
, VARLINK_PENDING_METHOD
);
1105 case VARLINK_PROCESSING_METHOD_MORE
: /* No reply for a "more" message was sent, more to come */
1106 varlink_set_state(v
, VARLINK_PENDING_METHOD_MORE
);
1110 assert_not_reached();
1120 varlink_set_state(v
, VARLINK_PROCESSING_FAILURE
);
1121 varlink_dispatch_local_error(v
, VARLINK_ERROR_PROTOCOL
);
1127 int varlink_process(Varlink
*v
) {
1130 assert_return(v
, -EINVAL
);
1132 if (v
->state
== VARLINK_DISCONNECTED
)
1133 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1137 r
= varlink_write(v
);
1139 varlink_log_errno(v
, r
, "Write failed: %m");
1143 r
= varlink_dispatch_reply(v
);
1145 varlink_log_errno(v
, r
, "Reply dispatch failed: %m");
1149 r
= varlink_dispatch_method(v
);
1151 varlink_log_errno(v
, r
, "Method dispatch failed: %m");
1155 r
= varlink_parse_message(v
);
1157 varlink_log_errno(v
, r
, "Message parsing failed: %m");
1161 r
= varlink_read(v
);
1163 varlink_log_errno(v
, r
, "Read failed: %m");
1167 r
= varlink_test_disconnect(v
);
1172 r
= varlink_dispatch_disconnect(v
);
1177 r
= varlink_test_timeout(v
);
1182 r
= varlink_dispatch_timeout(v
);
1188 if (r
>= 0 && v
->defer_event_source
) {
1191 /* If we did some processing, make sure we are called again soon */
1192 q
= sd_event_source_set_enabled(v
->defer_event_source
, r
> 0 ? SD_EVENT_ON
: SD_EVENT_OFF
);
1194 r
= varlink_log_errno(v
, q
, "Failed to enable deferred event source: %m");
1198 if (VARLINK_STATE_IS_ALIVE(v
->state
))
1199 /* Initiate disconnection */
1200 varlink_set_state(v
, VARLINK_PENDING_DISCONNECT
);
1202 /* We failed while disconnecting, in that case close right away */
1210 static void handle_revents(Varlink
*v
, int revents
) {
1213 if (v
->connecting
) {
1214 /* If we have seen POLLOUT or POLLHUP on a socket we are asynchronously waiting a connect()
1215 * to complete on, we know we are ready. We don't read the connection error here though,
1216 * we'll get the error on the next read() or write(). */
1217 if ((revents
& (POLLOUT
|POLLHUP
)) == 0)
1220 varlink_log(v
, "Asynchronous connection completed.");
1221 v
->connecting
= false;
1223 /* Note that we don't care much about POLLIN/POLLOUT here, we'll just try reading and writing
1224 * what we can. However, we do care about POLLHUP to detect connection termination even if we
1225 * momentarily don't want to read nor write anything. */
1227 if (!FLAGS_SET(revents
, POLLHUP
))
1230 varlink_log(v
, "Got POLLHUP from socket.");
1231 v
->got_pollhup
= true;
1235 int varlink_wait(Varlink
*v
, usec_t timeout
) {
1239 assert_return(v
, -EINVAL
);
1241 if (v
->state
== VARLINK_DISCONNECTED
)
1242 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1244 r
= varlink_get_timeout(v
, &t
);
1247 if (t
!= USEC_INFINITY
) {
1250 n
= now(CLOCK_MONOTONIC
);
1254 t
= usec_sub_unsigned(t
, n
);
1257 if (timeout
!= USEC_INFINITY
&&
1258 (t
== USEC_INFINITY
|| timeout
< t
))
1261 fd
= varlink_get_fd(v
);
1265 events
= varlink_get_events(v
);
1269 r
= fd_wait_for_event(fd
, events
, t
);
1270 if (r
< 0 && ERRNO_IS_TRANSIENT(r
)) /* Treat EINTR as not a timeout, but also nothing happened, and
1271 * the caller gets a chance to call back into us */
1276 handle_revents(v
, r
);
1280 int varlink_get_fd(Varlink
*v
) {
1282 assert_return(v
, -EINVAL
);
1284 if (v
->state
== VARLINK_DISCONNECTED
)
1285 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1287 return varlink_log_errno(v
, SYNTHETIC_ERRNO(EBADF
), "No valid fd.");
1292 int varlink_get_events(Varlink
*v
) {
1295 assert_return(v
, -EINVAL
);
1297 if (v
->state
== VARLINK_DISCONNECTED
)
1298 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1300 if (v
->connecting
) /* When processing an asynchronous connect(), we only wait for EPOLLOUT, which
1301 * tells us that the connection is now complete. Before that we should neither
1302 * write() or read() from the fd. */
1305 if (!v
->read_disconnected
&&
1306 IN_SET(v
->state
, VARLINK_AWAITING_REPLY
, VARLINK_AWAITING_REPLY_MORE
, VARLINK_CALLING
, VARLINK_IDLE_SERVER
) &&
1308 v
->input_buffer_unscanned
<= 0)
1311 if (!v
->write_disconnected
&&
1312 v
->output_buffer_size
> 0)
1318 int varlink_get_timeout(Varlink
*v
, usec_t
*ret
) {
1319 assert_return(v
, -EINVAL
);
1321 if (v
->state
== VARLINK_DISCONNECTED
)
1322 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1324 if (IN_SET(v
->state
, VARLINK_AWAITING_REPLY
, VARLINK_AWAITING_REPLY_MORE
, VARLINK_CALLING
) &&
1325 v
->timeout
!= USEC_INFINITY
) {
1327 *ret
= usec_add(v
->timestamp
, v
->timeout
);
1331 *ret
= USEC_INFINITY
;
1336 int varlink_flush(Varlink
*v
) {
1339 assert_return(v
, -EINVAL
);
1341 if (v
->state
== VARLINK_DISCONNECTED
)
1342 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1345 if (v
->output_buffer_size
== 0)
1347 if (v
->write_disconnected
)
1350 r
= varlink_write(v
);
1358 r
= fd_wait_for_event(v
->fd
, POLLOUT
, USEC_INFINITY
);
1360 if (ERRNO_IS_TRANSIENT(r
))
1363 return varlink_log_errno(v
, r
, "Poll failed on fd: %m");
1368 handle_revents(v
, r
);
1374 static void varlink_detach_server(Varlink
*v
) {
1375 VarlinkServer
*saved_server
;
1381 if (v
->server
->by_uid
&&
1382 v
->ucred_acquired
&&
1383 uid_is_valid(v
->ucred
.uid
)) {
1386 c
= PTR_TO_UINT(hashmap_get(v
->server
->by_uid
, UID_TO_PTR(v
->ucred
.uid
)));
1390 (void) hashmap_remove(v
->server
->by_uid
, UID_TO_PTR(v
->ucred
.uid
));
1392 (void) hashmap_replace(v
->server
->by_uid
, UID_TO_PTR(v
->ucred
.uid
), UINT_TO_PTR(c
- 1));
1395 assert(v
->server
->n_connections
> 0);
1396 v
->server
->n_connections
--;
1398 /* If this is a connection associated to a server, then let's disconnect the server and the
1399 * connection from each other. This drops the dangling reference that connect_callback() set up. But
1400 * before we release the references, let's call the disconnection callback if it is defined. */
1402 saved_server
= TAKE_PTR(v
->server
);
1404 if (saved_server
->disconnect_callback
)
1405 saved_server
->disconnect_callback(saved_server
, v
, saved_server
->userdata
);
1407 varlink_server_unref(saved_server
);
1411 int varlink_close(Varlink
*v
) {
1412 assert_return(v
, -EINVAL
);
1414 if (v
->state
== VARLINK_DISCONNECTED
)
1417 varlink_set_state(v
, VARLINK_DISCONNECTED
);
1419 /* Let's take a reference first, since varlink_detach_server() might drop the final (dangling) ref
1420 * which would destroy us before we can call varlink_clear() */
1422 varlink_detach_server(v
);
1429 Varlink
* varlink_close_unref(Varlink
*v
) {
1433 (void) varlink_close(v
);
1434 return varlink_unref(v
);
1437 Varlink
* varlink_flush_close_unref(Varlink
*v
) {
1441 (void) varlink_flush(v
);
1442 return varlink_close_unref(v
);
1445 static int varlink_format_json(Varlink
*v
, JsonVariant
*m
) {
1446 _cleanup_(erase_and_freep
) char *text
= NULL
;
1452 r
= json_variant_format(m
, 0, &text
);
1455 assert(text
[r
] == '\0');
1457 if (v
->output_buffer_size
+ r
+ 1 > VARLINK_BUFFER_MAX
)
1460 varlink_log(v
, "Sending message: %s", text
);
1462 if (v
->output_buffer_size
== 0) {
1464 free_and_replace(v
->output_buffer
, text
);
1466 v
->output_buffer_size
= r
+ 1;
1467 v
->output_buffer_index
= 0;
1469 } else if (v
->output_buffer_index
== 0) {
1471 if (!GREEDY_REALLOC(v
->output_buffer
, v
->output_buffer_size
+ r
+ 1))
1474 memcpy(v
->output_buffer
+ v
->output_buffer_size
, text
, r
+ 1);
1475 v
->output_buffer_size
+= r
+ 1;
1478 const size_t new_size
= v
->output_buffer_size
+ r
+ 1;
1480 n
= new(char, new_size
);
1484 memcpy(mempcpy(n
, v
->output_buffer
+ v
->output_buffer_index
, v
->output_buffer_size
), text
, r
+ 1);
1486 free_and_replace(v
->output_buffer
, n
);
1487 v
->output_buffer_size
= new_size
;
1488 v
->output_buffer_index
= 0;
1491 if (json_variant_is_sensitive(m
))
1492 v
->output_buffer_sensitive
= true; /* Propagate sensitive flag */
1494 text
= mfree(text
); /* No point in the erase_and_free() destructor declared above */
1499 static int varlink_enqueue_json(Varlink
*v
, JsonVariant
*m
) {
1500 VarlinkJsonQueueItem
*q
;
1505 /* If there are no file descriptors to be queued and no queue entries yet we can shortcut things and
1506 * append this entry directly to the output buffer */
1507 if (v
->n_pushed_fds
== 0 && !v
->output_queue
)
1508 return varlink_format_json(v
, m
);
1510 /* Otherwise add a queue entry for this */
1511 q
= varlink_json_queue_item_new(m
, v
->pushed_fds
, v
->n_pushed_fds
);
1515 v
->n_pushed_fds
= 0; /* fds now belong to the queue entry */
1517 LIST_INSERT_AFTER(queue
, v
->output_queue
, v
->output_queue_tail
, q
);
1518 v
->output_queue_tail
= q
;
1522 static int varlink_format_queue(Varlink
*v
) {
1527 /* Takes entries out of the output queue and formats them into the output buffer. But only if this
1528 * would not corrupt our fd message boundaries */
1530 while (v
->output_queue
) {
1531 _cleanup_free_
int *array
= NULL
;
1532 VarlinkJsonQueueItem
*q
= v
->output_queue
;
1534 if (v
->n_output_fds
> 0) /* unwritten fds? if we'd add more we'd corrupt the fd message boundaries, hence wait */
1538 array
= newdup(int, q
->fds
, q
->n_fds
);
1543 r
= varlink_format_json(v
, q
->data
);
1547 /* Take possession of the queue element's fds */
1548 free(v
->output_fds
);
1549 v
->output_fds
= TAKE_PTR(array
);
1550 v
->n_output_fds
= q
->n_fds
;
1553 LIST_REMOVE(queue
, v
->output_queue
, q
);
1554 if (!v
->output_queue
)
1555 v
->output_queue_tail
= NULL
;
1557 varlink_json_queue_item_free(q
);
1563 int varlink_send(Varlink
*v
, const char *method
, JsonVariant
*parameters
) {
1564 _cleanup_(json_variant_unrefp
) JsonVariant
*m
= NULL
;
1567 assert_return(v
, -EINVAL
);
1568 assert_return(method
, -EINVAL
);
1570 if (v
->state
== VARLINK_DISCONNECTED
)
1571 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1573 /* We allow enqueuing multiple method calls at once! */
1574 if (!IN_SET(v
->state
, VARLINK_IDLE_CLIENT
, VARLINK_AWAITING_REPLY
))
1575 return varlink_log_errno(v
, SYNTHETIC_ERRNO(EBUSY
), "Connection busy.");
1577 r
= varlink_sanitize_parameters(¶meters
);
1579 return varlink_log_errno(v
, r
, "Failed to sanitize parameters: %m");
1581 r
= json_build(&m
, JSON_BUILD_OBJECT(
1582 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method
)),
1583 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters
)),
1584 JSON_BUILD_PAIR("oneway", JSON_BUILD_BOOLEAN(true))));
1586 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1588 r
= varlink_enqueue_json(v
, m
);
1590 return varlink_log_errno(v
, r
, "Failed to enqueue json message: %m");
1592 /* No state change here, this is one-way only after all */
1593 v
->timestamp
= now(CLOCK_MONOTONIC
);
1597 int varlink_sendb(Varlink
*v
, const char *method
, ...) {
1598 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters
= NULL
;
1602 assert_return(v
, -EINVAL
);
1604 va_start(ap
, method
);
1605 r
= json_buildv(¶meters
, ap
);
1609 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1611 return varlink_send(v
, method
, parameters
);
1614 int varlink_invoke(Varlink
*v
, const char *method
, JsonVariant
*parameters
) {
1615 _cleanup_(json_variant_unrefp
) JsonVariant
*m
= NULL
;
1618 assert_return(v
, -EINVAL
);
1619 assert_return(method
, -EINVAL
);
1621 if (v
->state
== VARLINK_DISCONNECTED
)
1622 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1624 /* We allow enqueuing multiple method calls at once! */
1625 if (!IN_SET(v
->state
, VARLINK_IDLE_CLIENT
, VARLINK_AWAITING_REPLY
))
1626 return varlink_log_errno(v
, SYNTHETIC_ERRNO(EBUSY
), "Connection busy.");
1628 r
= varlink_sanitize_parameters(¶meters
);
1630 return varlink_log_errno(v
, r
, "Failed to sanitize parameters: %m");
1632 r
= json_build(&m
, JSON_BUILD_OBJECT(
1633 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method
)),
1634 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters
))));
1636 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1638 r
= varlink_enqueue_json(v
, m
);
1640 return varlink_log_errno(v
, r
, "Failed to enqueue json message: %m");
1642 varlink_set_state(v
, VARLINK_AWAITING_REPLY
);
1644 v
->timestamp
= now(CLOCK_MONOTONIC
);
1649 int varlink_invokeb(Varlink
*v
, const char *method
, ...) {
1650 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters
= NULL
;
1654 assert_return(v
, -EINVAL
);
1656 va_start(ap
, method
);
1657 r
= json_buildv(¶meters
, ap
);
1661 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1663 return varlink_invoke(v
, method
, parameters
);
1666 int varlink_observe(Varlink
*v
, const char *method
, JsonVariant
*parameters
) {
1667 _cleanup_(json_variant_unrefp
) JsonVariant
*m
= NULL
;
1670 assert_return(v
, -EINVAL
);
1671 assert_return(method
, -EINVAL
);
1673 if (v
->state
== VARLINK_DISCONNECTED
)
1674 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1676 /* Note that we don't allow enqueuing multiple method calls when we are in more/continues mode! We
1677 * thus insist on an idle client here. */
1678 if (v
->state
!= VARLINK_IDLE_CLIENT
)
1679 return varlink_log_errno(v
, SYNTHETIC_ERRNO(EBUSY
), "Connection busy.");
1681 r
= varlink_sanitize_parameters(¶meters
);
1683 return varlink_log_errno(v
, r
, "Failed to sanitize parameters: %m");
1685 r
= json_build(&m
, JSON_BUILD_OBJECT(
1686 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method
)),
1687 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters
)),
1688 JSON_BUILD_PAIR("more", JSON_BUILD_BOOLEAN(true))));
1690 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1692 r
= varlink_enqueue_json(v
, m
);
1694 return varlink_log_errno(v
, r
, "Failed to enqueue json message: %m");
1696 varlink_set_state(v
, VARLINK_AWAITING_REPLY_MORE
);
1698 v
->timestamp
= now(CLOCK_MONOTONIC
);
1703 int varlink_observeb(Varlink
*v
, const char *method
, ...) {
1704 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters
= NULL
;
1708 assert_return(v
, -EINVAL
);
1710 va_start(ap
, method
);
1711 r
= json_buildv(¶meters
, ap
);
1715 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1717 return varlink_observe(v
, method
, parameters
);
1723 JsonVariant
*parameters
,
1724 JsonVariant
**ret_parameters
,
1725 const char **ret_error_id
,
1726 VarlinkReplyFlags
*ret_flags
) {
1728 _cleanup_(json_variant_unrefp
) JsonVariant
*m
= NULL
;
1731 assert_return(v
, -EINVAL
);
1732 assert_return(method
, -EINVAL
);
1734 if (v
->state
== VARLINK_DISCONNECTED
)
1735 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1736 if (v
->state
!= VARLINK_IDLE_CLIENT
)
1737 return varlink_log_errno(v
, SYNTHETIC_ERRNO(EBUSY
), "Connection busy.");
1739 assert(v
->n_pending
== 0); /* n_pending can't be > 0 if we are in VARLINK_IDLE_CLIENT state */
1741 /* If there was still a reply pinned from a previous call, now it's the time to get rid of it, so
1742 * that we can assign a new reply shortly. */
1743 varlink_clear_current(v
);
1745 r
= varlink_sanitize_parameters(¶meters
);
1747 return varlink_log_errno(v
, r
, "Failed to sanitize parameters: %m");
1749 r
= json_build(&m
, JSON_BUILD_OBJECT(
1750 JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method
)),
1751 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters
))));
1753 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1755 r
= varlink_enqueue_json(v
, m
);
1757 return varlink_log_errno(v
, r
, "Failed to enqueue json message: %m");
1759 varlink_set_state(v
, VARLINK_CALLING
);
1761 v
->timestamp
= now(CLOCK_MONOTONIC
);
1763 while (v
->state
== VARLINK_CALLING
) {
1765 r
= varlink_process(v
);
1771 r
= varlink_wait(v
, USEC_INFINITY
);
1778 case VARLINK_CALLED
:
1781 varlink_set_state(v
, VARLINK_IDLE_CLIENT
);
1782 assert(v
->n_pending
== 1);
1786 *ret_parameters
= json_variant_by_key(v
->current
, "parameters");
1788 *ret_error_id
= json_variant_string(json_variant_by_key(v
->current
, "error"));
1794 case VARLINK_PENDING_DISCONNECT
:
1795 case VARLINK_DISCONNECTED
:
1796 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ECONNRESET
), "Connection was closed.");
1798 case VARLINK_PENDING_TIMEOUT
:
1799 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ETIME
), "Connection timed out.");
1802 assert_not_reached();
1809 JsonVariant
**ret_parameters
,
1810 const char **ret_error_id
,
1811 VarlinkReplyFlags
*ret_flags
, ...) {
1813 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters
= NULL
;
1817 assert_return(v
, -EINVAL
);
1819 va_start(ap
, ret_flags
);
1820 r
= json_buildv(¶meters
, ap
);
1824 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1826 return varlink_call(v
, method
, parameters
, ret_parameters
, ret_error_id
, ret_flags
);
1829 int varlink_reply(Varlink
*v
, JsonVariant
*parameters
) {
1830 _cleanup_(json_variant_unrefp
) JsonVariant
*m
= NULL
;
1833 assert_return(v
, -EINVAL
);
1835 if (v
->state
== VARLINK_DISCONNECTED
)
1837 if (!IN_SET(v
->state
,
1838 VARLINK_PROCESSING_METHOD
, VARLINK_PROCESSING_METHOD_MORE
,
1839 VARLINK_PENDING_METHOD
, VARLINK_PENDING_METHOD_MORE
))
1842 r
= varlink_sanitize_parameters(¶meters
);
1844 return varlink_log_errno(v
, r
, "Failed to sanitize parameters: %m");
1846 r
= json_build(&m
, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters
))));
1848 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1850 r
= varlink_enqueue_json(v
, m
);
1852 return varlink_log_errno(v
, r
, "Failed to enqueue json message: %m");
1854 if (IN_SET(v
->state
, VARLINK_PENDING_METHOD
, VARLINK_PENDING_METHOD_MORE
)) {
1855 /* We just replied to a method call that was let hanging for a while (i.e. we were outside of
1856 * the varlink_dispatch_method() stack frame), which means with this reply we are ready to
1857 * process further messages. */
1858 varlink_clear_current(v
);
1859 varlink_set_state(v
, VARLINK_IDLE_SERVER
);
1861 /* We replied to a method call from within the varlink_dispatch_method() stack frame), which
1862 * means we should it handle the rest of the state engine. */
1863 varlink_set_state(v
, VARLINK_PROCESSED_METHOD
);
1868 int varlink_replyb(Varlink
*v
, ...) {
1869 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters
= NULL
;
1873 assert_return(v
, -EINVAL
);
1876 r
= json_buildv(¶meters
, ap
);
1882 return varlink_reply(v
, parameters
);
1885 int varlink_error(Varlink
*v
, const char *error_id
, JsonVariant
*parameters
) {
1886 _cleanup_(json_variant_unrefp
) JsonVariant
*m
= NULL
;
1889 assert_return(v
, -EINVAL
);
1890 assert_return(error_id
, -EINVAL
);
1892 if (v
->state
== VARLINK_DISCONNECTED
)
1893 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
1894 if (!IN_SET(v
->state
,
1895 VARLINK_PROCESSING_METHOD
, VARLINK_PROCESSING_METHOD_MORE
,
1896 VARLINK_PENDING_METHOD
, VARLINK_PENDING_METHOD_MORE
))
1897 return varlink_log_errno(v
, SYNTHETIC_ERRNO(EBUSY
), "Connection busy.");
1899 /* Reset the list of pushed file descriptors before sending an error reply. We do this here to
1900 * simplify code that puts together a complex reply message with fds, and half-way something
1901 * fails. In that case the pushed fds need to be flushed out again. Under the assumption that it
1902 * never makes sense to send fds along with errors we simply flush them out here beforehand, so that
1903 * the callers don't need to do this explicitly. */
1904 varlink_reset_fds(v
);
1906 r
= varlink_sanitize_parameters(¶meters
);
1908 return varlink_log_errno(v
, r
, "Failed to sanitize parameters: %m");
1910 r
= json_build(&m
, JSON_BUILD_OBJECT(
1911 JSON_BUILD_PAIR("error", JSON_BUILD_STRING(error_id
)),
1912 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters
))));
1914 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1916 r
= varlink_enqueue_json(v
, m
);
1918 return varlink_log_errno(v
, r
, "Failed to enqueue json message: %m");
1920 if (IN_SET(v
->state
, VARLINK_PENDING_METHOD
, VARLINK_PENDING_METHOD_MORE
)) {
1921 varlink_clear_current(v
);
1922 varlink_set_state(v
, VARLINK_IDLE_SERVER
);
1924 varlink_set_state(v
, VARLINK_PROCESSED_METHOD
);
1929 int varlink_errorb(Varlink
*v
, const char *error_id
, ...) {
1930 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters
= NULL
;
1934 assert_return(v
, -EINVAL
);
1935 assert_return(error_id
, -EINVAL
);
1937 va_start(ap
, error_id
);
1938 r
= json_buildv(¶meters
, ap
);
1942 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
1944 return varlink_error(v
, error_id
, parameters
);
1947 int varlink_error_invalid_parameter(Varlink
*v
, JsonVariant
*parameters
) {
1950 assert_return(v
, -EINVAL
);
1951 assert_return(parameters
, -EINVAL
);
1953 /* We expect to be called in one of two ways: the 'parameters' argument is a string variant in which
1954 * case it is the parameter key name that is invalid. Or the 'parameters' argument is an object
1955 * variant in which case we'll pull out the first key. The latter mode is useful in functions that
1956 * don't expect any arguments. */
1958 /* varlink_error(...) expects a json object as the third parameter. Passing a string variant causes
1959 * parameter sanitization to fail, and it returns -EINVAL. */
1961 if (json_variant_is_string(parameters
)) {
1962 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters_obj
= NULL
;
1964 r
= json_build(¶meters_obj
,
1966 JSON_BUILD_PAIR("parameter", JSON_BUILD_VARIANT(parameters
))));
1970 return varlink_error(v
, VARLINK_ERROR_INVALID_PARAMETER
, parameters_obj
);
1973 if (json_variant_is_object(parameters
) &&
1974 json_variant_elements(parameters
) > 0) {
1975 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters_obj
= NULL
;
1977 r
= json_build(¶meters_obj
,
1979 JSON_BUILD_PAIR("parameter", JSON_BUILD_VARIANT(json_variant_by_index(parameters
, 0)))));
1983 return varlink_error(v
, VARLINK_ERROR_INVALID_PARAMETER
, parameters_obj
);
1989 int varlink_error_errno(Varlink
*v
, int error
) {
1990 return varlink_errorb(
1992 VARLINK_ERROR_SYSTEM
,
1993 JSON_BUILD_OBJECT(JSON_BUILD_PAIR("errno", JSON_BUILD_INTEGER(abs(error
)))));
1996 int varlink_notify(Varlink
*v
, JsonVariant
*parameters
) {
1997 _cleanup_(json_variant_unrefp
) JsonVariant
*m
= NULL
;
2000 assert_return(v
, -EINVAL
);
2002 if (v
->state
== VARLINK_DISCONNECTED
)
2003 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENOTCONN
), "Not connected.");
2004 if (!IN_SET(v
->state
, VARLINK_PROCESSING_METHOD_MORE
, VARLINK_PENDING_METHOD_MORE
))
2005 return varlink_log_errno(v
, SYNTHETIC_ERRNO(EBUSY
), "Connection busy.");
2007 r
= varlink_sanitize_parameters(¶meters
);
2009 return varlink_log_errno(v
, r
, "Failed to sanitize parameters: %m");
2011 r
= json_build(&m
, JSON_BUILD_OBJECT(
2012 JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters
)),
2013 JSON_BUILD_PAIR("continues", JSON_BUILD_BOOLEAN(true))));
2015 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
2017 r
= varlink_enqueue_json(v
, m
);
2019 return varlink_log_errno(v
, r
, "Failed to enqueue json message: %m");
2021 /* No state change, as more is coming */
2025 int varlink_notifyb(Varlink
*v
, ...) {
2026 _cleanup_(json_variant_unrefp
) JsonVariant
*parameters
= NULL
;
2030 assert_return(v
, -EINVAL
);
2033 r
= json_buildv(¶meters
, ap
);
2037 return varlink_log_errno(v
, r
, "Failed to build json message: %m");
2039 return varlink_notify(v
, parameters
);
2042 int varlink_bind_reply(Varlink
*v
, VarlinkReply callback
) {
2043 assert_return(v
, -EINVAL
);
2045 if (callback
&& v
->reply_callback
&& callback
!= v
->reply_callback
)
2046 return varlink_log_errno(v
, SYNTHETIC_ERRNO(EBUSY
), "A different callback was already set.");
2048 v
->reply_callback
= callback
;
2053 void* varlink_set_userdata(Varlink
*v
, void *userdata
) {
2056 assert_return(v
, NULL
);
2059 v
->userdata
= userdata
;
2064 void* varlink_get_userdata(Varlink
*v
) {
2065 assert_return(v
, NULL
);
2070 static int varlink_acquire_ucred(Varlink
*v
) {
2075 if (v
->ucred_acquired
)
2078 r
= getpeercred(v
->fd
, &v
->ucred
);
2082 v
->ucred_acquired
= true;
2086 int varlink_get_peer_uid(Varlink
*v
, uid_t
*ret
) {
2089 assert_return(v
, -EINVAL
);
2090 assert_return(ret
, -EINVAL
);
2092 r
= varlink_acquire_ucred(v
);
2094 return varlink_log_errno(v
, r
, "Failed to acquire credentials: %m");
2096 if (!uid_is_valid(v
->ucred
.uid
))
2097 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENODATA
), "Peer uid is invalid.");
2099 *ret
= v
->ucred
.uid
;
2103 int varlink_get_peer_pid(Varlink
*v
, pid_t
*ret
) {
2106 assert_return(v
, -EINVAL
);
2107 assert_return(ret
, -EINVAL
);
2109 r
= varlink_acquire_ucred(v
);
2111 return varlink_log_errno(v
, r
, "Failed to acquire credentials: %m");
2113 if (!pid_is_valid(v
->ucred
.pid
))
2114 return varlink_log_errno(v
, SYNTHETIC_ERRNO(ENODATA
), "Peer uid is invalid.");
2116 *ret
= v
->ucred
.pid
;
2120 int varlink_set_relative_timeout(Varlink
*v
, usec_t timeout
) {
2121 assert_return(v
, -EINVAL
);
2122 assert_return(timeout
> 0, -EINVAL
);
2124 v
->timeout
= timeout
;
2128 VarlinkServer
*varlink_get_server(Varlink
*v
) {
2129 assert_return(v
, NULL
);
2134 int varlink_set_description(Varlink
*v
, const char *description
) {
2135 assert_return(v
, -EINVAL
);
2137 return free_and_strdup(&v
->description
, description
);
2140 static int io_callback(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
2141 Varlink
*v
= ASSERT_PTR(userdata
);
2145 handle_revents(v
, revents
);
2146 (void) varlink_process(v
);
2151 static int time_callback(sd_event_source
*s
, uint64_t usec
, void *userdata
) {
2152 Varlink
*v
= ASSERT_PTR(userdata
);
2156 (void) varlink_process(v
);
2160 static int defer_callback(sd_event_source
*s
, void *userdata
) {
2161 Varlink
*v
= ASSERT_PTR(userdata
);
2165 (void) varlink_process(v
);
2169 static int prepare_callback(sd_event_source
*s
, void *userdata
) {
2170 Varlink
*v
= ASSERT_PTR(userdata
);
2177 e
= varlink_get_events(v
);
2181 r
= sd_event_source_set_io_events(v
->io_event_source
, e
);
2183 return varlink_log_errno(v
, r
, "Failed to set source events: %m");
2185 r
= varlink_get_timeout(v
, &until
);
2188 have_timeout
= r
> 0;
2191 r
= sd_event_source_set_time(v
->time_event_source
, until
);
2193 return varlink_log_errno(v
, r
, "Failed to set source time: %m");
2196 r
= sd_event_source_set_enabled(v
->time_event_source
, have_timeout
? SD_EVENT_ON
: SD_EVENT_OFF
);
2198 return varlink_log_errno(v
, r
, "Failed to enable event source: %m");
2203 static int quit_callback(sd_event_source
*event
, void *userdata
) {
2204 Varlink
*v
= ASSERT_PTR(userdata
);
2214 int varlink_attach_event(Varlink
*v
, sd_event
*e
, int64_t priority
) {
2217 assert_return(v
, -EINVAL
);
2218 assert_return(!v
->event
, -EBUSY
);
2221 v
->event
= sd_event_ref(e
);
2223 r
= sd_event_default(&v
->event
);
2225 return varlink_log_errno(v
, r
, "Failed to create event source: %m");
2228 r
= sd_event_add_time(v
->event
, &v
->time_event_source
, CLOCK_MONOTONIC
, 0, 0, time_callback
, v
);
2232 r
= sd_event_source_set_priority(v
->time_event_source
, priority
);
2236 (void) sd_event_source_set_description(v
->time_event_source
, "varlink-time");
2238 r
= sd_event_add_exit(v
->event
, &v
->quit_event_source
, quit_callback
, v
);
2242 r
= sd_event_source_set_priority(v
->quit_event_source
, priority
);
2246 (void) sd_event_source_set_description(v
->quit_event_source
, "varlink-quit");
2248 r
= sd_event_add_io(v
->event
, &v
->io_event_source
, v
->fd
, 0, io_callback
, v
);
2252 r
= sd_event_source_set_prepare(v
->io_event_source
, prepare_callback
);
2256 r
= sd_event_source_set_priority(v
->io_event_source
, priority
);
2260 (void) sd_event_source_set_description(v
->io_event_source
, "varlink-io");
2262 r
= sd_event_add_defer(v
->event
, &v
->defer_event_source
, defer_callback
, v
);
2266 r
= sd_event_source_set_priority(v
->defer_event_source
, priority
);
2270 (void) sd_event_source_set_description(v
->defer_event_source
, "varlink-defer");
2275 varlink_log_errno(v
, r
, "Failed to setup event source: %m");
2276 varlink_detach_event(v
);
2280 void varlink_detach_event(Varlink
*v
) {
2284 varlink_detach_event_sources(v
);
2286 v
->event
= sd_event_unref(v
->event
);
2289 sd_event
*varlink_get_event(Varlink
*v
) {
2290 assert_return(v
, NULL
);
2295 int varlink_push_fd(Varlink
*v
, int fd
) {
2298 assert_return(v
, -EINVAL
);
2299 assert_return(fd
>= 0, -EBADF
);
2301 /* Takes an fd to send along with the *next* varlink message sent via this varlink connection. This
2302 * takes ownership of the specified fd. Use varlink_dup_fd() below to duplicate the fd first. */
2304 if (!v
->allow_fd_passing_output
)
2307 if (v
->n_pushed_fds
>= INT_MAX
)
2310 if (!GREEDY_REALLOC(v
->pushed_fds
, v
->n_pushed_fds
+ 1))
2313 i
= (int) v
->n_pushed_fds
;
2314 v
->pushed_fds
[v
->n_pushed_fds
++] = fd
;
2318 int varlink_dup_fd(Varlink
*v
, int fd
) {
2319 _cleanup_close_
int dp
= -1;
2322 assert_return(v
, -EINVAL
);
2323 assert_return(fd
>= 0, -EBADF
);
2325 /* Like varlink_push_fd() but duplicates the specified fd instead of taking possession of it */
2327 dp
= fcntl(fd
, F_DUPFD_CLOEXEC
, 3);
2331 r
= varlink_push_fd(v
, dp
);
2339 int varlink_reset_fds(Varlink
*v
) {
2340 assert_return(v
, -EINVAL
);
2342 /* Closes all currently pending fds to send. This may be used whenever the caller is in the process
2343 * of putting together a message with fds, and then eventually something fails and they need to
2344 * rollback the fds. Note that this is implicitly called whenever an error reply is sent, see above. */
2346 close_many(v
->output_fds
, v
->n_output_fds
);
2347 v
->n_output_fds
= 0;
2351 int varlink_peek_fd(Varlink
*v
, size_t i
) {
2352 assert_return(v
, -EINVAL
);
2354 /* Returns one of the file descriptors that were received along with the current message. This does
2355 * not duplicate the fd nor invalidate it, it hence remains in our possession. */
2357 if (!v
->allow_fd_passing_input
)
2360 if (i
>= v
->n_input_fds
)
2363 return v
->input_fds
[i
];
2366 int varlink_take_fd(Varlink
*v
, size_t i
) {
2367 assert_return(v
, -EINVAL
);
2369 /* Similar to varlink_peek_fd() but the file descriptor's ownership is passed to the caller, and
2370 * we'll invalidate the reference to it under our possession. If called twice in a row will return
2373 if (!v
->allow_fd_passing_input
)
2376 if (i
>= v
->n_input_fds
)
2379 return TAKE_FD(v
->input_fds
[i
]);
2382 static int verify_unix_socket(Varlink
*v
) {
2388 if (fstat(v
->fd
, &st
) < 0)
2390 if (!S_ISSOCK(st
.st_mode
)) {
2395 v
->af
= socket_get_family(v
->fd
);
2400 return v
->af
== AF_UNIX
? 0 : -ENOMEDIUM
;
2403 int varlink_set_allow_fd_passing_input(Varlink
*v
, bool b
) {
2406 assert_return(v
, -EINVAL
);
2408 if (v
->allow_fd_passing_input
== b
)
2412 v
->allow_fd_passing_input
= false;
2416 r
= verify_unix_socket(v
);
2420 v
->allow_fd_passing_input
= true;
2424 int varlink_set_allow_fd_passing_output(Varlink
*v
, bool b
) {
2427 assert_return(v
, -EINVAL
);
2429 if (v
->allow_fd_passing_output
== b
)
2433 v
->allow_fd_passing_output
= false;
2437 r
= verify_unix_socket(v
);
2441 v
->allow_fd_passing_output
= true;
2445 int varlink_server_new(VarlinkServer
**ret
, VarlinkServerFlags flags
) {
2448 assert_return(ret
, -EINVAL
);
2449 assert_return((flags
& ~_VARLINK_SERVER_FLAGS_ALL
) == 0, -EINVAL
);
2451 s
= new(VarlinkServer
, 1);
2453 return log_oom_debug();
2455 *s
= (VarlinkServer
) {
2458 .connections_max
= varlink_server_connections_max(NULL
),
2459 .connections_per_uid_max
= varlink_server_connections_per_uid_max(NULL
),
2466 static VarlinkServer
* varlink_server_destroy(VarlinkServer
*s
) {
2472 varlink_server_shutdown(s
);
2474 while ((m
= hashmap_steal_first_key(s
->methods
)))
2477 hashmap_free(s
->methods
);
2478 hashmap_free(s
->by_uid
);
2480 sd_event_unref(s
->event
);
2482 free(s
->description
);
2487 DEFINE_TRIVIAL_REF_UNREF_FUNC(VarlinkServer
, varlink_server
, varlink_server_destroy
);
2489 static int validate_connection(VarlinkServer
*server
, const struct ucred
*ucred
) {
2495 if (FLAGS_SET(server
->flags
, VARLINK_SERVER_ROOT_ONLY
))
2496 allowed
= ucred
->uid
== 0;
2498 if (FLAGS_SET(server
->flags
, VARLINK_SERVER_MYSELF_ONLY
))
2499 allowed
= allowed
> 0 || ucred
->uid
== getuid();
2501 if (allowed
== 0) { /* Allow access when it is explicitly allowed or when neither
2502 * VARLINK_SERVER_ROOT_ONLY nor VARLINK_SERVER_MYSELF_ONLY are specified. */
2503 varlink_server_log(server
, "Unprivileged client attempted connection, refusing.");
2507 if (server
->n_connections
>= server
->connections_max
) {
2508 varlink_server_log(server
, "Connection limit of %u reached, refusing.", server
->connections_max
);
2512 if (FLAGS_SET(server
->flags
, VARLINK_SERVER_ACCOUNT_UID
)) {
2515 if (!uid_is_valid(ucred
->uid
)) {
2516 varlink_server_log(server
, "Client with invalid UID attempted connection, refusing.");
2520 c
= PTR_TO_UINT(hashmap_get(server
->by_uid
, UID_TO_PTR(ucred
->uid
)));
2521 if (c
>= server
->connections_per_uid_max
) {
2522 varlink_server_log(server
, "Per-UID connection limit of %u reached, refusing.",
2523 server
->connections_per_uid_max
);
2531 static int count_connection(VarlinkServer
*server
, const struct ucred
*ucred
) {
2538 server
->n_connections
++;
2540 if (FLAGS_SET(server
->flags
, VARLINK_SERVER_ACCOUNT_UID
)) {
2541 r
= hashmap_ensure_allocated(&server
->by_uid
, NULL
);
2543 return log_debug_errno(r
, "Failed to allocate UID hash table: %m");
2545 c
= PTR_TO_UINT(hashmap_get(server
->by_uid
, UID_TO_PTR(ucred
->uid
)));
2547 varlink_server_log(server
, "Connections of user " UID_FMT
": %u (of %u max)",
2548 ucred
->uid
, c
, server
->connections_per_uid_max
);
2550 r
= hashmap_replace(server
->by_uid
, UID_TO_PTR(ucred
->uid
), UINT_TO_PTR(c
+ 1));
2552 return log_debug_errno(r
, "Failed to increment counter in UID hash table: %m");
2558 int varlink_server_add_connection(VarlinkServer
*server
, int fd
, Varlink
**ret
) {
2559 _cleanup_(varlink_unrefp
) Varlink
*v
= NULL
;
2560 struct ucred ucred
= UCRED_INVALID
;
2561 bool ucred_acquired
;
2564 assert_return(server
, -EINVAL
);
2565 assert_return(fd
>= 0, -EBADF
);
2567 if ((server
->flags
& (VARLINK_SERVER_ROOT_ONLY
|VARLINK_SERVER_ACCOUNT_UID
)) != 0) {
2568 r
= getpeercred(fd
, &ucred
);
2570 return varlink_server_log_errno(server
, r
, "Failed to acquire peer credentials of incoming socket, refusing: %m");
2572 ucred_acquired
= true;
2574 r
= validate_connection(server
, &ucred
);
2580 ucred_acquired
= false;
2582 r
= varlink_new(&v
);
2584 return varlink_server_log_errno(server
, r
, "Failed to allocate connection object: %m");
2586 r
= count_connection(server
, &ucred
);
2591 if (server
->flags
& VARLINK_SERVER_INHERIT_USERDATA
)
2592 v
->userdata
= server
->userdata
;
2594 if (ucred_acquired
) {
2596 v
->ucred_acquired
= true;
2599 _cleanup_free_
char *desc
= NULL
;
2600 if (asprintf(&desc
, "%s-%i", server
->description
?: "varlink", v
->fd
) >= 0)
2601 v
->description
= TAKE_PTR(desc
);
2603 /* Link up the server and the connection, and take reference in both directions. Note that the
2604 * reference on the connection is left dangling. It will be dropped when the connection is closed,
2605 * which happens in varlink_close(), including in the event loop quit callback. */
2606 v
->server
= varlink_server_ref(server
);
2609 varlink_set_state(v
, VARLINK_IDLE_SERVER
);
2611 if (server
->event
) {
2612 r
= varlink_attach_event(v
, server
->event
, server
->event_priority
);
2614 varlink_log_errno(v
, r
, "Failed to attach new connection: %m");
2615 v
->fd
= -EBADF
; /* take the fd out of the connection again */
2627 static VarlinkServerSocket
*varlink_server_socket_free(VarlinkServerSocket
*ss
) {
2635 DEFINE_TRIVIAL_CLEANUP_FUNC(VarlinkServerSocket
*, varlink_server_socket_free
);
2637 static int connect_callback(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
) {
2638 VarlinkServerSocket
*ss
= ASSERT_PTR(userdata
);
2639 _cleanup_close_
int cfd
= -EBADF
;
2645 varlink_server_log(ss
->server
, "New incoming connection.");
2647 cfd
= accept4(fd
, NULL
, NULL
, SOCK_NONBLOCK
|SOCK_CLOEXEC
);
2649 if (ERRNO_IS_ACCEPT_AGAIN(errno
))
2652 return varlink_server_log_errno(ss
->server
, errno
, "Failed to accept incoming socket: %m");
2655 r
= varlink_server_add_connection(ss
->server
, cfd
, &v
);
2661 if (ss
->server
->connect_callback
) {
2662 r
= ss
->server
->connect_callback(ss
->server
, v
, ss
->server
->userdata
);
2664 varlink_log_errno(v
, r
, "Connection callback returned error, disconnecting client: %m");
2673 static int varlink_server_create_listen_fd_socket(VarlinkServer
*s
, int fd
, VarlinkServerSocket
**ret_ss
) {
2674 _cleanup_(varlink_server_socket_freep
) VarlinkServerSocket
*ss
= NULL
;
2681 r
= fd_nonblock(fd
, true);
2685 ss
= new(VarlinkServerSocket
, 1);
2687 return log_oom_debug();
2689 *ss
= (VarlinkServerSocket
) {
2695 r
= sd_event_add_io(s
->event
, &ss
->event_source
, fd
, EPOLLIN
, connect_callback
, ss
);
2699 r
= sd_event_source_set_priority(ss
->event_source
, s
->event_priority
);
2704 *ret_ss
= TAKE_PTR(ss
);
2708 int varlink_server_listen_fd(VarlinkServer
*s
, int fd
) {
2709 _cleanup_(varlink_server_socket_freep
) VarlinkServerSocket
*ss
= NULL
;
2712 assert_return(s
, -EINVAL
);
2713 assert_return(fd
>= 0, -EBADF
);
2715 r
= varlink_server_create_listen_fd_socket(s
, fd
, &ss
);
2719 LIST_PREPEND(sockets
, s
->sockets
, TAKE_PTR(ss
));
2723 int varlink_server_listen_address(VarlinkServer
*s
, const char *address
, mode_t m
) {
2724 _cleanup_(varlink_server_socket_freep
) VarlinkServerSocket
*ss
= NULL
;
2725 union sockaddr_union sockaddr
;
2726 socklen_t sockaddr_len
;
2727 _cleanup_close_
int fd
= -EBADF
;
2730 assert_return(s
, -EINVAL
);
2731 assert_return(address
, -EINVAL
);
2732 assert_return((m
& ~0777) == 0, -EINVAL
);
2734 r
= sockaddr_un_set_path(&sockaddr
.un
, address
);
2739 fd
= socket(AF_UNIX
, SOCK_STREAM
|SOCK_CLOEXEC
|SOCK_NONBLOCK
, 0);
2743 fd
= fd_move_above_stdio(fd
);
2745 (void) sockaddr_un_unlink(&sockaddr
.un
);
2747 WITH_UMASK(~m
& 0777) {
2748 r
= mac_selinux_bind(fd
, &sockaddr
.sa
, sockaddr_len
);
2753 if (listen(fd
, SOMAXCONN
) < 0)
2756 r
= varlink_server_create_listen_fd_socket(s
, fd
, &ss
);
2760 r
= free_and_strdup(&ss
->address
, address
);
2764 LIST_PREPEND(sockets
, s
->sockets
, TAKE_PTR(ss
));
2769 void* varlink_server_set_userdata(VarlinkServer
*s
, void *userdata
) {
2772 assert_return(s
, NULL
);
2775 s
->userdata
= userdata
;
2780 void* varlink_server_get_userdata(VarlinkServer
*s
) {
2781 assert_return(s
, NULL
);
2786 static VarlinkServerSocket
* varlink_server_socket_destroy(VarlinkServerSocket
*ss
) {
2791 LIST_REMOVE(sockets
, ss
->server
->sockets
, ss
);
2793 sd_event_source_disable_unref(ss
->event_source
);
2801 int varlink_server_shutdown(VarlinkServer
*s
) {
2802 assert_return(s
, -EINVAL
);
2805 varlink_server_socket_destroy(s
->sockets
);
2810 static int varlink_server_add_socket_event_source(VarlinkServer
*s
, VarlinkServerSocket
*ss
, int64_t priority
) {
2811 _cleanup_(sd_event_source_unrefp
) sd_event_source
*es
= NULL
;
2818 assert(ss
->fd
>= 0);
2819 assert(!ss
->event_source
);
2821 r
= sd_event_add_io(s
->event
, &es
, ss
->fd
, EPOLLIN
, connect_callback
, ss
);
2825 r
= sd_event_source_set_priority(es
, priority
);
2829 ss
->event_source
= TAKE_PTR(es
);
2833 int varlink_server_attach_event(VarlinkServer
*s
, sd_event
*e
, int64_t priority
) {
2836 assert_return(s
, -EINVAL
);
2837 assert_return(!s
->event
, -EBUSY
);
2840 s
->event
= sd_event_ref(e
);
2842 r
= sd_event_default(&s
->event
);
2847 LIST_FOREACH(sockets
, ss
, s
->sockets
) {
2848 r
= varlink_server_add_socket_event_source(s
, ss
, priority
);
2853 s
->event_priority
= priority
;
2857 varlink_server_detach_event(s
);
2861 int varlink_server_detach_event(VarlinkServer
*s
) {
2862 assert_return(s
, -EINVAL
);
2864 LIST_FOREACH(sockets
, ss
, s
->sockets
)
2865 ss
->event_source
= sd_event_source_disable_unref(ss
->event_source
);
2867 sd_event_unref(s
->event
);
2871 sd_event
*varlink_server_get_event(VarlinkServer
*s
) {
2872 assert_return(s
, NULL
);
2877 int varlink_server_bind_method(VarlinkServer
*s
, const char *method
, VarlinkMethod callback
) {
2878 _cleanup_free_
char *m
= NULL
;
2881 assert_return(s
, -EINVAL
);
2882 assert_return(method
, -EINVAL
);
2883 assert_return(callback
, -EINVAL
);
2885 if (startswith(method
, "org.varlink.service."))
2886 return log_debug_errno(SYNTHETIC_ERRNO(EEXIST
), "Cannot bind server to '%s'.", method
);
2890 return log_oom_debug();
2892 r
= hashmap_ensure_put(&s
->methods
, &string_hash_ops
, m
, callback
);
2894 return log_oom_debug();
2896 return log_debug_errno(r
, "Failed to register callback: %m");
2903 int varlink_server_bind_method_many_internal(VarlinkServer
*s
, ...) {
2907 assert_return(s
, -EINVAL
);
2911 VarlinkMethod callback
;
2914 method
= va_arg(ap
, const char *);
2918 callback
= va_arg(ap
, VarlinkMethod
);
2920 r
= varlink_server_bind_method(s
, method
, callback
);
2929 int varlink_server_bind_connect(VarlinkServer
*s
, VarlinkConnect callback
) {
2930 assert_return(s
, -EINVAL
);
2932 if (callback
&& s
->connect_callback
&& callback
!= s
->connect_callback
)
2933 return log_debug_errno(SYNTHETIC_ERRNO(EBUSY
), "A different callback was already set.");
2935 s
->connect_callback
= callback
;
2939 int varlink_server_bind_disconnect(VarlinkServer
*s
, VarlinkDisconnect callback
) {
2940 assert_return(s
, -EINVAL
);
2942 if (callback
&& s
->disconnect_callback
&& callback
!= s
->disconnect_callback
)
2943 return log_debug_errno(SYNTHETIC_ERRNO(EBUSY
), "A different callback was already set.");
2945 s
->disconnect_callback
= callback
;
2949 unsigned varlink_server_connections_max(VarlinkServer
*s
) {
2952 /* If a server is specified, return the setting for that server, otherwise the default value */
2954 return s
->connections_max
;
2956 dts
= getdtablesize();
2959 /* Make sure we never use up more than ¾th of RLIMIT_NOFILE for IPC */
2960 if (VARLINK_DEFAULT_CONNECTIONS_MAX
> (unsigned) dts
/ 4 * 3)
2963 return VARLINK_DEFAULT_CONNECTIONS_MAX
;
2966 unsigned varlink_server_connections_per_uid_max(VarlinkServer
*s
) {
2970 return s
->connections_per_uid_max
;
2972 /* Make sure to never use up more than ¾th of available connections for a single user */
2973 m
= varlink_server_connections_max(NULL
);
2974 if (VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX
> m
)
2977 return VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX
;
2980 int varlink_server_set_connections_per_uid_max(VarlinkServer
*s
, unsigned m
) {
2981 assert_return(s
, -EINVAL
);
2982 assert_return(m
> 0, -EINVAL
);
2984 s
->connections_per_uid_max
= m
;
2988 int varlink_server_set_connections_max(VarlinkServer
*s
, unsigned m
) {
2989 assert_return(s
, -EINVAL
);
2990 assert_return(m
> 0, -EINVAL
);
2992 s
->connections_max
= m
;
2996 unsigned varlink_server_current_connections(VarlinkServer
*s
) {
2997 assert_return(s
, UINT_MAX
);
2999 return s
->n_connections
;
3002 int varlink_server_set_description(VarlinkServer
*s
, const char *description
) {
3003 assert_return(s
, -EINVAL
);
3005 return free_and_strdup(&s
->description
, description
);
3008 int varlink_server_serialize(VarlinkServer
*s
, FILE *f
, FDSet
*fds
) {
3015 LIST_FOREACH(sockets
, ss
, s
->sockets
) {
3018 assert(ss
->address
);
3019 assert(ss
->fd
>= 0);
3021 fprintf(f
, "varlink-server-socket-address=%s", ss
->address
);
3023 /* If we fail to serialize the fd, it will be considered an error during deserialization */
3024 copy
= fdset_put_dup(fds
, ss
->fd
);
3028 fprintf(f
, " varlink-server-socket-fd=%i", copy
);
3036 int varlink_server_deserialize_one(VarlinkServer
*s
, const char *value
, FDSet
*fds
) {
3037 _cleanup_(varlink_server_socket_freep
) VarlinkServerSocket
*ss
= NULL
;
3038 _cleanup_free_
char *address
= NULL
;
3039 const char *v
= ASSERT_PTR(value
);
3047 n
= strcspn(v
, " ");
3048 address
= strndup(v
, n
);
3050 return log_oom_debug();
3053 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL
),
3054 "Failed to deserialize VarlinkServerSocket: %s: %m", value
);
3055 v
= startswith(v
+ n
+ 1, "varlink-server-socket-fd=");
3057 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL
),
3058 "Failed to deserialize VarlinkServerSocket fd %s: %m", value
);
3060 n
= strcspn(v
, " ");
3061 buf
= strndupa_safe(v
, n
);
3065 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL
),
3066 "VarlinkServerSocket varlink-server-socket-fd= has an invalid value: %s", buf
);
3068 return log_debug_errno(fd
, "Unable to parse VarlinkServerSocket varlink-server-socket-fd=%s: %m", buf
);
3069 if (!fdset_contains(fds
, fd
))
3070 return log_debug_errno(SYNTHETIC_ERRNO(EBADF
),
3071 "VarlinkServerSocket varlink-server-socket-fd= has unknown fd %d: %m", fd
);
3073 ss
= new(VarlinkServerSocket
, 1);
3075 return log_oom_debug();
3077 *ss
= (VarlinkServerSocket
) {
3079 .address
= TAKE_PTR(address
),
3080 .fd
= fdset_remove(fds
, fd
),
3083 r
= varlink_server_add_socket_event_source(s
, ss
, SD_EVENT_PRIORITY_NORMAL
);
3085 return log_debug_errno(r
, "Failed to add VarlinkServerSocket event source to the event loop: %m");
3087 LIST_PREPEND(sockets
, s
->sockets
, TAKE_PTR(ss
));