2 * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
24 #include "dynamic-string.h"
25 #include "fatal-signal.h"
29 #include "ovs-thread.h"
30 #include "poll-loop.h"
31 #include "reconnect.h"
34 #include "openvswitch/vlog.h"
36 VLOG_DEFINE_THIS_MODULE(jsonrpc);
39 struct stream *stream;
45 uint8_t input_buffer[512];
46 struct json_parser *parser;
49 struct ovs_list output; /* Contains "struct ofpbuf"s. */
50 size_t output_count; /* Number of elements in "output". */
54 /* Rate limit for error messages. */
55 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 5);
57 static struct jsonrpc_msg *jsonrpc_parse_received_message(struct jsonrpc *);
58 static void jsonrpc_cleanup(struct jsonrpc *);
59 static void jsonrpc_error(struct jsonrpc *, int error);
61 /* This is just the same as stream_open() except that it uses the default
62 * JSONRPC port if none is specified. */
64 jsonrpc_stream_open(const char *name, struct stream **streamp, uint8_t dscp)
66 return stream_open_with_default_port(name, OVSDB_PORT, streamp, dscp);
69 /* This is just the same as pstream_open() except that it uses the default
70 * JSONRPC port if none is specified. */
72 jsonrpc_pstream_open(const char *name, struct pstream **pstreamp, uint8_t dscp)
74 return pstream_open_with_default_port(name, OVSDB_PORT, pstreamp, dscp);
77 /* Returns a new JSON-RPC stream that uses 'stream' for input and output. The
78 * new jsonrpc object takes ownership of 'stream'. */
80 jsonrpc_open(struct stream *stream)
84 ovs_assert(stream != NULL);
86 rpc = xzalloc(sizeof *rpc);
87 rpc->name = xstrdup(stream_get_name(stream));
89 byteq_init(&rpc->input, rpc->input_buffer, sizeof rpc->input_buffer);
90 list_init(&rpc->output);
95 /* Destroys 'rpc', closing the stream on which it is based, and frees its
98 jsonrpc_close(struct jsonrpc *rpc)
101 jsonrpc_cleanup(rpc);
107 /* Performs periodic maintenance on 'rpc', such as flushing output buffers. */
109 jsonrpc_run(struct jsonrpc *rpc)
115 stream_run(rpc->stream);
116 while (!list_is_empty(&rpc->output)) {
117 struct ofpbuf *buf = ofpbuf_from_list(rpc->output.next);
120 retval = stream_send(rpc->stream, buf->data, buf->size);
122 rpc->backlog -= retval;
123 ofpbuf_pull(buf, retval);
125 list_remove(&buf->list_node);
130 if (retval != -EAGAIN) {
131 VLOG_WARN_RL(&rl, "%s: send error: %s",
132 rpc->name, ovs_strerror(-retval));
133 jsonrpc_error(rpc, -retval);
140 /* Arranges for the poll loop to wake up when 'rpc' needs to perform
141 * maintenance activities. */
143 jsonrpc_wait(struct jsonrpc *rpc)
146 stream_run_wait(rpc->stream);
147 if (!list_is_empty(&rpc->output)) {
148 stream_send_wait(rpc->stream);
154 * Returns the current status of 'rpc'. The possible return values are:
157 * - EOF: end of file (remote end closed connection; not necessarily an error).
159 * When this functions nonzero, 'rpc' is effectively out of commission. 'rpc'
160 * will not receive any more messages and any further messages that one
161 * attempts to send with 'rpc' will be discarded. The caller can keep 'rpc'
162 * around as long as it wants, but it's not going to provide any more useful
166 jsonrpc_get_status(const struct jsonrpc *rpc)
171 /* Returns the number of bytes buffered by 'rpc' to be written to the
172 * underlying stream. Always returns 0 if 'rpc' has encountered an error or if
173 * the remote end closed the connection. */
175 jsonrpc_get_backlog(const struct jsonrpc *rpc)
177 return rpc->status ? 0 : rpc->backlog;
180 /* Returns the number of bytes that have been received on 'rpc''s underlying
181 * stream. (The value wraps around if it exceeds UINT_MAX.) */
183 jsonrpc_get_received_bytes(const struct jsonrpc *rpc)
185 return rpc->input.head;
188 /* Returns 'rpc''s name, that is, the name returned by stream_get_name() for
189 * the stream underlying 'rpc' when 'rpc' was created. */
191 jsonrpc_get_name(const struct jsonrpc *rpc)
197 jsonrpc_log_msg(const struct jsonrpc *rpc, const char *title,
198 const struct jsonrpc_msg *msg)
200 if (VLOG_IS_DBG_ENABLED()) {
201 struct ds s = DS_EMPTY_INITIALIZER;
203 ds_put_format(&s, ", method=\"%s\"", msg->method);
206 ds_put_cstr(&s, ", params=");
207 json_to_ds(msg->params, 0, &s);
210 ds_put_cstr(&s, ", result=");
211 json_to_ds(msg->result, 0, &s);
214 ds_put_cstr(&s, ", error=");
215 json_to_ds(msg->error, 0, &s);
218 ds_put_cstr(&s, ", id=");
219 json_to_ds(msg->id, 0, &s);
221 VLOG_DBG("%s: %s %s%s", rpc->name, title,
222 jsonrpc_msg_type_to_string(msg->type), ds_cstr(&s));
227 /* Schedules 'msg' to be sent on 'rpc' and returns 'rpc''s status (as with
228 * jsonrpc_get_status()).
230 * If 'msg' cannot be sent immediately, it is appended to a buffer. The caller
231 * is responsible for ensuring that the amount of buffered data is somehow
232 * limited. (jsonrpc_get_backlog() returns the amount of data currently
233 * buffered in 'rpc'.)
235 * Always takes ownership of 'msg', regardless of success. */
237 jsonrpc_send(struct jsonrpc *rpc, struct jsonrpc_msg *msg)
241 struct ds ds = DS_EMPTY_INITIALIZER;
245 jsonrpc_msg_destroy(msg);
249 jsonrpc_log_msg(rpc, "send", msg);
251 json = jsonrpc_msg_to_json(msg);
252 json_to_ds(json, 0, &ds);
256 buf = xmalloc(sizeof *buf);
257 ofpbuf_use_ds(buf, &ds);
258 list_push_back(&rpc->output, &buf->list_node);
260 rpc->backlog += length;
262 if (rpc->output_count >= 50) {
263 VLOG_INFO_RL(&rl, "excessive sending backlog, jsonrpc: %s, num of"
264 " msgs: %"PRIuSIZE", backlog: %"PRIuSIZE".", rpc->name,
265 rpc->output_count, rpc->backlog);
268 if (rpc->backlog == length) {
274 /* Attempts to receive a message from 'rpc'.
276 * If successful, stores the received message in '*msgp' and returns 0. The
277 * caller takes ownership of '*msgp' and must eventually destroy it with
278 * jsonrpc_msg_destroy().
280 * Otherwise, stores NULL in '*msgp' and returns one of the following:
282 * - EAGAIN: No message has been received.
284 * - EOF: The remote end closed the connection gracefully.
286 * - Otherwise an errno value that represents a JSON-RPC protocol violation
287 * or another error fatal to the connection. 'rpc' will not send or
288 * receive any more messages.
291 jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp)
300 for (i = 0; i < 50; i++) {
303 /* Fill our input buffer if it's empty. */
304 if (byteq_is_empty(&rpc->input)) {
308 chunk = byteq_headroom(&rpc->input);
309 retval = stream_recv(rpc->stream, byteq_head(&rpc->input), chunk);
311 if (retval == -EAGAIN) {
314 VLOG_WARN_RL(&rl, "%s: receive error: %s",
315 rpc->name, ovs_strerror(-retval));
316 jsonrpc_error(rpc, -retval);
319 } else if (retval == 0) {
320 jsonrpc_error(rpc, EOF);
323 byteq_advance_head(&rpc->input, retval);
326 /* We have some input. Feed it into the JSON parser. */
328 rpc->parser = json_parser_create(0);
330 n = byteq_tailroom(&rpc->input);
331 used = json_parser_feed(rpc->parser,
332 (char *) byteq_tail(&rpc->input), n);
333 byteq_advance_tail(&rpc->input, used);
335 /* If we have complete JSON, attempt to parse it as JSON-RPC. */
336 if (json_parser_is_done(rpc->parser)) {
337 *msgp = jsonrpc_parse_received_message(rpc);
343 const struct byteq *q = &rpc->input;
344 if (q->head <= q->size) {
345 stream_report_content(q->buffer, q->head, STREAM_JSONRPC,
346 THIS_MODULE, rpc->name);
356 /* Causes the poll loop to wake up when jsonrpc_recv() may return a value other
359 jsonrpc_recv_wait(struct jsonrpc *rpc)
361 if (rpc->status || !byteq_is_empty(&rpc->input)) {
362 poll_immediate_wake_at(rpc->name);
364 stream_recv_wait(rpc->stream);
368 /* Sends 'msg' on 'rpc' and waits for it to be successfully queued to the
369 * underlying stream. Returns 0 if 'msg' was sent successfully, otherwise a
370 * status value (see jsonrpc_get_status()).
372 * Always takes ownership of 'msg', regardless of success. */
374 jsonrpc_send_block(struct jsonrpc *rpc, struct jsonrpc_msg *msg)
380 error = jsonrpc_send(rpc, msg);
387 if (list_is_empty(&rpc->output) || rpc->status) {
395 /* Waits for a message to be received on 'rpc'. Same semantics as
396 * jsonrpc_recv() except that EAGAIN will never be returned. */
398 jsonrpc_recv_block(struct jsonrpc *rpc, struct jsonrpc_msg **msgp)
401 int error = jsonrpc_recv(rpc, msgp);
402 if (error != EAGAIN) {
409 jsonrpc_recv_wait(rpc);
414 /* Sends 'request' to 'rpc' then waits for a reply. The return value is 0 if
415 * successful, in which case '*replyp' is set to the reply, which the caller
416 * must eventually free with jsonrpc_msg_destroy(). Otherwise returns a status
417 * value (see jsonrpc_get_status()).
419 * Discards any message received on 'rpc' that is not a reply to 'request'
420 * (based on message id).
422 * Always takes ownership of 'request', regardless of success. */
424 jsonrpc_transact_block(struct jsonrpc *rpc, struct jsonrpc_msg *request,
425 struct jsonrpc_msg **replyp)
427 struct jsonrpc_msg *reply = NULL;
431 id = json_clone(request->id);
432 error = jsonrpc_send_block(rpc, request);
435 error = jsonrpc_recv_block(rpc, &reply);
439 if ((reply->type == JSONRPC_REPLY || reply->type == JSONRPC_ERROR)
440 && json_equal(id, reply->id)) {
443 jsonrpc_msg_destroy(reply);
446 *replyp = error ? NULL : reply;
451 /* Attempts to parse the content of 'rpc->parser' (which is complete JSON) as a
452 * JSON-RPC message. If successful, returns the JSON-RPC message. On failure,
453 * signals an error on 'rpc' with jsonrpc_error() and returns NULL. */
454 static struct jsonrpc_msg *
455 jsonrpc_parse_received_message(struct jsonrpc *rpc)
457 struct jsonrpc_msg *msg;
461 json = json_parser_finish(rpc->parser);
463 if (json->type == JSON_STRING) {
464 VLOG_WARN_RL(&rl, "%s: error parsing stream: %s",
465 rpc->name, json_string(json));
466 jsonrpc_error(rpc, EPROTO);
471 error = jsonrpc_msg_from_json(json, &msg);
473 VLOG_WARN_RL(&rl, "%s: received bad JSON-RPC message: %s",
476 jsonrpc_error(rpc, EPROTO);
480 jsonrpc_log_msg(rpc, "received", msg);
485 jsonrpc_error(struct jsonrpc *rpc, int error)
490 jsonrpc_cleanup(rpc);
495 jsonrpc_cleanup(struct jsonrpc *rpc)
497 stream_close(rpc->stream);
500 json_parser_abort(rpc->parser);
503 ofpbuf_list_delete(&rpc->output);
505 rpc->output_count = 0;
508 static struct jsonrpc_msg *
509 jsonrpc_create(enum jsonrpc_msg_type type, const char *method,
510 struct json *params, struct json *result, struct json *error,
513 struct jsonrpc_msg *msg = xmalloc(sizeof *msg);
515 msg->method = method ? xstrdup(method) : NULL;
516 msg->params = params;
517 msg->result = result;
524 jsonrpc_create_id(void)
526 static atomic_count next_id = ATOMIC_COUNT_INIT(0);
529 id = atomic_count_inc(&next_id);
530 return json_integer_create(id);
534 jsonrpc_create_request(const char *method, struct json *params,
537 struct json *id = jsonrpc_create_id();
539 *idp = json_clone(id);
541 return jsonrpc_create(JSONRPC_REQUEST, method, params, NULL, NULL, id);
545 jsonrpc_create_notify(const char *method, struct json *params)
547 return jsonrpc_create(JSONRPC_NOTIFY, method, params, NULL, NULL, NULL);
551 jsonrpc_create_reply(struct json *result, const struct json *id)
553 return jsonrpc_create(JSONRPC_REPLY, NULL, NULL, result, NULL,
558 jsonrpc_create_error(struct json *error, const struct json *id)
560 return jsonrpc_create(JSONRPC_REPLY, NULL, NULL, NULL, error,
565 jsonrpc_msg_type_to_string(enum jsonrpc_msg_type type)
568 case JSONRPC_REQUEST:
572 return "notification";
584 jsonrpc_msg_is_valid(const struct jsonrpc_msg *m)
586 const char *type_name;
587 unsigned int pattern;
589 if (m->params && m->params->type != JSON_ARRAY) {
590 return xstrdup("\"params\" must be JSON array");
594 case JSONRPC_REQUEST:
611 return xasprintf("invalid JSON-RPC message type %d", m->type);
614 type_name = jsonrpc_msg_type_to_string(m->type);
615 if ((m->method != NULL) != ((pattern & 0x10000) != 0)) {
616 return xasprintf("%s must%s have \"method\"",
617 type_name, (pattern & 0x10000) ? "" : " not");
620 if ((m->params != NULL) != ((pattern & 0x1000) != 0)) {
621 return xasprintf("%s must%s have \"params\"",
622 type_name, (pattern & 0x1000) ? "" : " not");
625 if ((m->result != NULL) != ((pattern & 0x100) != 0)) {
626 return xasprintf("%s must%s have \"result\"",
627 type_name, (pattern & 0x100) ? "" : " not");
630 if ((m->error != NULL) != ((pattern & 0x10) != 0)) {
631 return xasprintf("%s must%s have \"error\"",
632 type_name, (pattern & 0x10) ? "" : " not");
635 if ((m->id != NULL) != ((pattern & 0x1) != 0)) {
636 return xasprintf("%s must%s have \"id\"",
637 type_name, (pattern & 0x1) ? "" : " not");
644 jsonrpc_msg_destroy(struct jsonrpc_msg *m)
648 json_destroy(m->params);
649 json_destroy(m->result);
650 json_destroy(m->error);
657 null_from_json_null(struct json *json)
659 if (json && json->type == JSON_NULL) {
667 jsonrpc_msg_from_json(struct json *json, struct jsonrpc_msg **msgp)
669 struct json *method = NULL;
670 struct jsonrpc_msg *msg = NULL;
671 struct shash *object;
674 if (json->type != JSON_OBJECT) {
675 error = xstrdup("message is not a JSON object");
678 object = json_object(json);
680 method = shash_find_and_delete(object, "method");
681 if (method && method->type != JSON_STRING) {
682 error = xstrdup("method is not a JSON string");
686 msg = xzalloc(sizeof *msg);
687 msg->method = method ? xstrdup(method->u.string) : NULL;
688 msg->params = null_from_json_null(shash_find_and_delete(object, "params"));
689 msg->result = null_from_json_null(shash_find_and_delete(object, "result"));
690 msg->error = null_from_json_null(shash_find_and_delete(object, "error"));
691 msg->id = null_from_json_null(shash_find_and_delete(object, "id"));
692 msg->type = (msg->result ? JSONRPC_REPLY
693 : msg->error ? JSONRPC_ERROR
694 : msg->id ? JSONRPC_REQUEST
696 if (!shash_is_empty(object)) {
697 error = xasprintf("message has unexpected member \"%s\"",
698 shash_first(object)->name);
701 error = jsonrpc_msg_is_valid(msg);
707 json_destroy(method);
710 jsonrpc_msg_destroy(msg);
718 jsonrpc_msg_to_json(struct jsonrpc_msg *m)
720 struct json *json = json_object_create();
723 json_object_put(json, "method", json_string_create_nocopy(m->method));
727 json_object_put(json, "params", m->params);
731 json_object_put(json, "result", m->result);
732 } else if (m->type == JSONRPC_ERROR) {
733 json_object_put(json, "result", json_null_create());
737 json_object_put(json, "error", m->error);
738 } else if (m->type == JSONRPC_REPLY) {
739 json_object_put(json, "error", json_null_create());
743 json_object_put(json, "id", m->id);
744 } else if (m->type == JSONRPC_NOTIFY) {
745 json_object_put(json, "id", json_null_create());
753 /* A JSON-RPC session with reconnection. */
755 struct jsonrpc_session {
756 struct reconnect *reconnect;
758 struct stream *stream;
759 struct pstream *pstream;
765 /* Creates and returns a jsonrpc_session to 'name', which should be a string
766 * acceptable to stream_open() or pstream_open().
768 * If 'name' is an active connection method, e.g. "tcp:127.1.2.3", the new
769 * jsonrpc_session connects to 'name'. If 'retry' is true, then the new
770 * session connects and reconnects to 'name', with backoff. If 'retry' is
771 * false, the new session will only try to connect once and after a connection
772 * failure or a disconnection jsonrpc_session_is_alive() will return false for
775 * If 'name' is a passive connection method, e.g. "ptcp:", the new
776 * jsonrpc_session listens for connections to 'name'. It maintains at most one
777 * connection at any given time. Any new connection causes the previous one
778 * (if any) to be dropped. */
779 struct jsonrpc_session *
780 jsonrpc_session_open(const char *name, bool retry)
782 struct jsonrpc_session *s;
784 s = xmalloc(sizeof *s);
785 s->reconnect = reconnect_create(time_msec());
786 reconnect_set_name(s->reconnect, name);
787 reconnect_enable(s->reconnect, time_msec());
795 if (!pstream_verify_name(name)) {
796 reconnect_set_passive(s->reconnect, true, time_msec());
798 reconnect_set_max_tries(s->reconnect, 1);
799 reconnect_set_backoff(s->reconnect, INT_MAX, INT_MAX);
802 if (!stream_or_pstream_needs_probes(name)) {
803 reconnect_set_probe_interval(s->reconnect, 0);
809 /* Creates and returns a jsonrpc_session that is initially connected to
810 * 'jsonrpc'. If the connection is dropped, it will not be reconnected.
812 * On the assumption that such connections are likely to be short-lived
813 * (e.g. from ovs-vsctl), informational logging for them is suppressed. */
814 struct jsonrpc_session *
815 jsonrpc_session_open_unreliably(struct jsonrpc *jsonrpc, uint8_t dscp)
817 struct jsonrpc_session *s;
819 s = xmalloc(sizeof *s);
820 s->reconnect = reconnect_create(time_msec());
821 reconnect_set_quiet(s->reconnect, true);
822 reconnect_set_name(s->reconnect, jsonrpc_get_name(jsonrpc));
823 reconnect_set_max_tries(s->reconnect, 0);
824 reconnect_connected(s->reconnect, time_msec());
835 jsonrpc_session_close(struct jsonrpc_session *s)
838 jsonrpc_close(s->rpc);
839 reconnect_destroy(s->reconnect);
840 stream_close(s->stream);
841 pstream_close(s->pstream);
847 jsonrpc_session_disconnect(struct jsonrpc_session *s)
850 jsonrpc_error(s->rpc, EOF);
851 jsonrpc_close(s->rpc);
854 } else if (s->stream) {
855 stream_close(s->stream);
862 jsonrpc_session_connect(struct jsonrpc_session *s)
864 const char *name = reconnect_get_name(s->reconnect);
867 jsonrpc_session_disconnect(s);
868 if (!reconnect_is_passive(s->reconnect)) {
869 error = jsonrpc_stream_open(name, &s->stream, s->dscp);
871 reconnect_connecting(s->reconnect, time_msec());
873 s->last_error = error;
876 error = s->pstream ? 0 : jsonrpc_pstream_open(name, &s->pstream,
879 reconnect_listening(s->reconnect, time_msec());
884 reconnect_connect_failed(s->reconnect, time_msec(), error);
890 jsonrpc_session_run(struct jsonrpc_session *s)
893 struct stream *stream;
896 error = pstream_accept(s->pstream, &stream);
898 if (s->rpc || s->stream) {
900 "%s: new connection replacing active connection",
901 reconnect_get_name(s->reconnect));
902 jsonrpc_session_disconnect(s);
904 reconnect_connected(s->reconnect, time_msec());
905 s->rpc = jsonrpc_open(stream);
906 } else if (error != EAGAIN) {
907 reconnect_listen_error(s->reconnect, time_msec(), error);
908 pstream_close(s->pstream);
917 backlog = jsonrpc_get_backlog(s->rpc);
919 if (jsonrpc_get_backlog(s->rpc) < backlog) {
920 /* Data previously caught in a queue was successfully sent (or
921 * there's an error, which we'll catch below.)
923 * We don't count data that is successfully sent immediately as
924 * activity, because there's a lot of queuing downstream from us,
925 * which means that we can push a lot of data into a connection
926 * that has stalled and won't ever recover.
928 reconnect_activity(s->reconnect, time_msec());
931 error = jsonrpc_get_status(s->rpc);
933 reconnect_disconnected(s->reconnect, time_msec(), error);
934 jsonrpc_session_disconnect(s);
935 s->last_error = error;
937 } else if (s->stream) {
940 stream_run(s->stream);
941 error = stream_connect(s->stream);
943 reconnect_connected(s->reconnect, time_msec());
944 s->rpc = jsonrpc_open(s->stream);
946 } else if (error != EAGAIN) {
947 reconnect_connect_failed(s->reconnect, time_msec(), error);
948 stream_close(s->stream);
950 s->last_error = error;
954 switch (reconnect_run(s->reconnect, time_msec())) {
955 case RECONNECT_CONNECT:
956 jsonrpc_session_connect(s);
959 case RECONNECT_DISCONNECT:
960 reconnect_disconnected(s->reconnect, time_msec(), 0);
961 jsonrpc_session_disconnect(s);
964 case RECONNECT_PROBE:
967 struct jsonrpc_msg *request;
969 params = json_array_create_empty();
970 request = jsonrpc_create_request("echo", params, NULL);
971 json_destroy(request->id);
972 request->id = json_string_create("echo");
973 jsonrpc_send(s->rpc, request);
980 jsonrpc_session_wait(struct jsonrpc_session *s)
983 jsonrpc_wait(s->rpc);
984 } else if (s->stream) {
985 stream_run_wait(s->stream);
986 stream_connect_wait(s->stream);
989 pstream_wait(s->pstream);
991 reconnect_wait(s->reconnect, time_msec());
995 jsonrpc_session_get_backlog(const struct jsonrpc_session *s)
997 return s->rpc ? jsonrpc_get_backlog(s->rpc) : 0;
1000 /* Always returns a pointer to a valid C string, assuming 's' was initialized
1003 jsonrpc_session_get_name(const struct jsonrpc_session *s)
1005 return reconnect_get_name(s->reconnect);
1008 /* Always takes ownership of 'msg', regardless of success. */
1010 jsonrpc_session_send(struct jsonrpc_session *s, struct jsonrpc_msg *msg)
1013 return jsonrpc_send(s->rpc, msg);
1015 jsonrpc_msg_destroy(msg);
1020 struct jsonrpc_msg *
1021 jsonrpc_session_recv(struct jsonrpc_session *s)
1024 unsigned int received_bytes;
1025 struct jsonrpc_msg *msg;
1027 received_bytes = jsonrpc_get_received_bytes(s->rpc);
1028 jsonrpc_recv(s->rpc, &msg);
1029 if (received_bytes != jsonrpc_get_received_bytes(s->rpc)) {
1030 /* Data was successfully received.
1032 * Previously we only counted receiving a full message as activity,
1033 * but with large messages or a slow connection that policy could
1034 * time out the session mid-message. */
1035 reconnect_activity(s->reconnect, time_msec());
1039 if (msg->type == JSONRPC_REQUEST && !strcmp(msg->method, "echo")) {
1040 /* Echo request. Send reply. */
1041 struct jsonrpc_msg *reply;
1043 reply = jsonrpc_create_reply(json_clone(msg->params), msg->id);
1044 jsonrpc_session_send(s, reply);
1045 } else if (msg->type == JSONRPC_REPLY
1046 && msg->id && msg->id->type == JSON_STRING
1047 && !strcmp(msg->id->u.string, "echo")) {
1048 /* It's a reply to our echo request. Suppress it. */
1052 jsonrpc_msg_destroy(msg);
1059 jsonrpc_session_recv_wait(struct jsonrpc_session *s)
1062 jsonrpc_recv_wait(s->rpc);
1066 /* Returns true if 's' is currently connected or trying to connect. */
1068 jsonrpc_session_is_alive(const struct jsonrpc_session *s)
1070 return s->rpc || s->stream || reconnect_get_max_tries(s->reconnect);
1073 /* Returns true if 's' is currently connected. */
1075 jsonrpc_session_is_connected(const struct jsonrpc_session *s)
1077 return s->rpc != NULL;
1080 /* Returns a sequence number for 's'. The sequence number increments every
1081 * time 's' connects or disconnects. Thus, a caller can use the change (or
1082 * lack of change) in the sequence number to figure out whether the underlying
1083 * connection is the same as before. */
1085 jsonrpc_session_get_seqno(const struct jsonrpc_session *s)
1090 /* Returns the current status of 's'. If 's' is NULL or is disconnected, this
1091 * is 0, otherwise it is the status of the connection, as reported by
1092 * jsonrpc_get_status(). */
1094 jsonrpc_session_get_status(const struct jsonrpc_session *s)
1096 return s && s->rpc ? jsonrpc_get_status(s->rpc) : 0;
1099 /* Returns the last error reported on a connection by 's'. The return value is
1100 * 0 only if no connection made by 's' has ever encountered an error. See
1101 * jsonrpc_get_status() for return value interpretation. */
1103 jsonrpc_session_get_last_error(const struct jsonrpc_session *s)
1105 return s->last_error;
1108 /* Populates 'stats' with statistics from 's'. */
1110 jsonrpc_session_get_reconnect_stats(const struct jsonrpc_session *s,
1111 struct reconnect_stats *stats)
1113 reconnect_get_stats(s->reconnect, time_msec(), stats);
1116 /* Enables 's' to reconnect to the peer if the connection drops. */
1118 jsonrpc_session_enable_reconnect(struct jsonrpc_session *s)
1120 reconnect_set_max_tries(s->reconnect, UINT_MAX);
1121 reconnect_set_backoff(s->reconnect, RECONNECT_DEFAULT_MIN_BACKOFF,
1122 RECONNECT_DEFAULT_MAX_BACKOFF);
1125 /* Forces 's' to drop its connection (if any) and reconnect. */
1127 jsonrpc_session_force_reconnect(struct jsonrpc_session *s)
1129 reconnect_force_reconnect(s->reconnect, time_msec());
1132 /* Sets 'max_backoff' as the maximum time, in milliseconds, to wait after a
1133 * connection attempt fails before attempting to connect again. */
1135 jsonrpc_session_set_max_backoff(struct jsonrpc_session *s, int max_backoff)
1137 reconnect_set_backoff(s->reconnect, 0, max_backoff);
1140 /* Sets the "probe interval" for 's' to 'probe_interval', in milliseconds. If
1141 * this is zero, it disables the connection keepalive feature. Otherwise, if
1142 * 's' is idle for 'probe_interval' milliseconds then 's' will send an echo
1143 * request and, if no reply is received within an additional 'probe_interval'
1144 * milliseconds, close the connection (then reconnect, if that feature is
1147 jsonrpc_session_set_probe_interval(struct jsonrpc_session *s,
1150 reconnect_set_probe_interval(s->reconnect, probe_interval);
1153 /* Sets the DSCP value used for 's''s connection to 'dscp'. If this is
1154 * different from the DSCP value currently in use then the connection is closed
1155 * and reconnected. */
1157 jsonrpc_session_set_dscp(struct jsonrpc_session *s, uint8_t dscp)
1159 if (s->dscp != dscp) {
1160 pstream_close(s->pstream);
1164 jsonrpc_session_force_reconnect(s);