2 * Copyright (c) 2009, 2010 Nicira Networks.
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.
25 #include "dynamic-string.h"
29 #include "poll-loop.h"
31 #include "reconnect.h"
35 #define THIS_MODULE VLM_jsonrpc
39 struct stream *stream;
45 struct json_parser *parser;
46 struct jsonrpc_msg *received;
49 struct ovs_queue output;
53 /* Rate limit for error messages. */
54 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 5);
56 static void jsonrpc_received(struct jsonrpc *);
57 static void jsonrpc_cleanup(struct jsonrpc *);
60 jsonrpc_open(struct stream *stream)
64 assert(stream != NULL);
66 rpc = xzalloc(sizeof *rpc);
67 rpc->name = xstrdup(stream_get_name(stream));
69 byteq_init(&rpc->input);
70 queue_init(&rpc->output);
76 jsonrpc_close(struct jsonrpc *rpc)
86 jsonrpc_run(struct jsonrpc *rpc)
92 stream_run(rpc->stream);
93 while (!queue_is_empty(&rpc->output)) {
94 struct ofpbuf *buf = rpc->output.head;
97 retval = stream_send(rpc->stream, buf->data, buf->size);
99 rpc->backlog -= retval;
100 ofpbuf_pull(buf, retval);
102 ofpbuf_delete(queue_pop_head(&rpc->output));
105 if (retval != -EAGAIN) {
106 VLOG_WARN_RL(&rl, "%s: send error: %s",
107 rpc->name, strerror(-retval));
108 jsonrpc_error(rpc, -retval);
116 jsonrpc_wait(struct jsonrpc *rpc)
119 stream_run_wait(rpc->stream);
120 if (!queue_is_empty(&rpc->output)) {
121 stream_send_wait(rpc->stream);
127 jsonrpc_get_status(const struct jsonrpc *rpc)
133 jsonrpc_get_backlog(const struct jsonrpc *rpc)
135 return rpc->status ? 0 : rpc->backlog;
139 jsonrpc_get_name(const struct jsonrpc *rpc)
145 jsonrpc_log_msg(const struct jsonrpc *rpc, const char *title,
146 const struct jsonrpc_msg *msg)
148 if (VLOG_IS_DBG_ENABLED()) {
149 struct ds s = DS_EMPTY_INITIALIZER;
151 ds_put_format(&s, ", method=\"%s\"", msg->method);
154 ds_put_cstr(&s, ", params=");
155 ds_put_and_free_cstr(&s, json_to_string(msg->params, 0));
158 ds_put_cstr(&s, ", result=");
159 ds_put_and_free_cstr(&s, json_to_string(msg->result, 0));
162 ds_put_cstr(&s, ", error=");
163 ds_put_and_free_cstr(&s, json_to_string(msg->error, 0));
166 ds_put_cstr(&s, ", id=");
167 ds_put_and_free_cstr(&s, json_to_string(msg->id, 0));
169 VLOG_DBG("%s: %s %s%s", rpc->name, title,
170 jsonrpc_msg_type_to_string(msg->type), ds_cstr(&s));
176 jsonrpc_send(struct jsonrpc *rpc, struct jsonrpc_msg *msg)
184 jsonrpc_msg_destroy(msg);
188 jsonrpc_log_msg(rpc, "send", msg);
190 json = jsonrpc_msg_to_json(msg);
191 s = json_to_string(json, 0);
195 buf = xmalloc(sizeof *buf);
196 ofpbuf_use(buf, s, length);
198 queue_push_tail(&rpc->output, buf);
199 rpc->backlog += length;
201 if (rpc->output.n == 1) {
208 jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp)
215 while (!rpc->received) {
216 if (byteq_is_empty(&rpc->input)) {
220 chunk = byteq_headroom(&rpc->input);
221 retval = stream_recv(rpc->stream, byteq_head(&rpc->input), chunk);
223 if (retval == -EAGAIN) {
226 VLOG_WARN_RL(&rl, "%s: receive error: %s",
227 rpc->name, strerror(-retval));
228 jsonrpc_error(rpc, -retval);
231 } else if (retval == 0) {
232 VLOG_INFO_RL(&rl, "%s: connection closed", rpc->name);
233 jsonrpc_error(rpc, EOF);
236 byteq_advance_head(&rpc->input, retval);
241 rpc->parser = json_parser_create(0);
243 n = byteq_tailroom(&rpc->input);
244 used = json_parser_feed(rpc->parser,
245 (char *) byteq_tail(&rpc->input), n);
246 byteq_advance_tail(&rpc->input, used);
247 if (json_parser_is_done(rpc->parser)) {
248 jsonrpc_received(rpc);
256 *msgp = rpc->received;
257 rpc->received = NULL;
262 jsonrpc_recv_wait(struct jsonrpc *rpc)
264 if (rpc->status || rpc->received || !byteq_is_empty(&rpc->input)) {
265 poll_immediate_wake();
267 stream_recv_wait(rpc->stream);
272 jsonrpc_send_block(struct jsonrpc *rpc, struct jsonrpc_msg *msg)
276 error = jsonrpc_send(rpc, msg);
283 if (queue_is_empty(&rpc->output) || rpc->status) {
292 jsonrpc_recv_block(struct jsonrpc *rpc, struct jsonrpc_msg **msgp)
295 int error = jsonrpc_recv(rpc, msgp);
296 if (error != EAGAIN) {
302 jsonrpc_recv_wait(rpc);
308 jsonrpc_transact_block(struct jsonrpc *rpc, struct jsonrpc_msg *request,
309 struct jsonrpc_msg **replyp)
311 struct jsonrpc_msg *reply = NULL;
315 id = json_clone(request->id);
316 error = jsonrpc_send_block(rpc, request);
319 error = jsonrpc_recv_block(rpc, &reply);
321 || (reply->type == JSONRPC_REPLY
322 && json_equal(id, reply->id))) {
325 jsonrpc_msg_destroy(reply);
328 *replyp = error ? NULL : reply;
334 jsonrpc_received(struct jsonrpc *rpc)
336 struct jsonrpc_msg *msg;
340 json = json_parser_finish(rpc->parser);
342 if (json->type == JSON_STRING) {
343 VLOG_WARN_RL(&rl, "%s: error parsing stream: %s",
344 rpc->name, json_string(json));
345 jsonrpc_error(rpc, EPROTO);
350 error = jsonrpc_msg_from_json(json, &msg);
352 VLOG_WARN_RL(&rl, "%s: received bad JSON-RPC message: %s",
355 jsonrpc_error(rpc, EPROTO);
359 jsonrpc_log_msg(rpc, "received", msg);
364 jsonrpc_error(struct jsonrpc *rpc, int error)
369 jsonrpc_cleanup(rpc);
374 jsonrpc_cleanup(struct jsonrpc *rpc)
376 stream_close(rpc->stream);
379 json_parser_abort(rpc->parser);
382 jsonrpc_msg_destroy(rpc->received);
383 rpc->received = NULL;
385 queue_clear(&rpc->output);
389 static struct jsonrpc_msg *
390 jsonrpc_create(enum jsonrpc_msg_type type, const char *method,
391 struct json *params, struct json *result, struct json *error,
394 struct jsonrpc_msg *msg = xmalloc(sizeof *msg);
396 msg->method = method ? xstrdup(method) : NULL;
397 msg->params = params;
398 msg->result = result;
405 jsonrpc_create_id(void)
407 static unsigned int id;
408 return json_integer_create(id++);
412 jsonrpc_create_request(const char *method, struct json *params,
415 struct json *id = jsonrpc_create_id();
417 *idp = json_clone(id);
419 return jsonrpc_create(JSONRPC_REQUEST, method, params, NULL, NULL, id);
423 jsonrpc_create_notify(const char *method, struct json *params)
425 return jsonrpc_create(JSONRPC_NOTIFY, method, params, NULL, NULL, NULL);
429 jsonrpc_create_reply(struct json *result, const struct json *id)
431 return jsonrpc_create(JSONRPC_REPLY, NULL, NULL, result, NULL,
436 jsonrpc_create_error(struct json *error, const struct json *id)
438 return jsonrpc_create(JSONRPC_REPLY, NULL, NULL, NULL, error,
443 jsonrpc_msg_type_to_string(enum jsonrpc_msg_type type)
446 case JSONRPC_REQUEST:
450 return "notification";
462 jsonrpc_msg_is_valid(const struct jsonrpc_msg *m)
464 const char *type_name;
465 unsigned int pattern;
467 if (m->params && m->params->type != JSON_ARRAY) {
468 return xstrdup("\"params\" must be JSON array");
472 case JSONRPC_REQUEST:
489 return xasprintf("invalid JSON-RPC message type %d", m->type);
492 type_name = jsonrpc_msg_type_to_string(m->type);
493 if ((m->method != NULL) != ((pattern & 0x10000) != 0)) {
494 return xasprintf("%s must%s have \"method\"",
495 type_name, (pattern & 0x10000) ? "" : " not");
498 if ((m->params != NULL) != ((pattern & 0x1000) != 0)) {
499 return xasprintf("%s must%s have \"params\"",
500 type_name, (pattern & 0x1000) ? "" : " not");
503 if ((m->result != NULL) != ((pattern & 0x100) != 0)) {
504 return xasprintf("%s must%s have \"result\"",
505 type_name, (pattern & 0x100) ? "" : " not");
508 if ((m->error != NULL) != ((pattern & 0x10) != 0)) {
509 return xasprintf("%s must%s have \"error\"",
510 type_name, (pattern & 0x10) ? "" : " not");
513 if ((m->id != NULL) != ((pattern & 0x1) != 0)) {
514 return xasprintf("%s must%s have \"id\"",
515 type_name, (pattern & 0x1) ? "" : " not");
522 jsonrpc_msg_destroy(struct jsonrpc_msg *m)
526 json_destroy(m->params);
527 json_destroy(m->result);
528 json_destroy(m->error);
535 null_from_json_null(struct json *json)
537 if (json && json->type == JSON_NULL) {
545 jsonrpc_msg_from_json(struct json *json, struct jsonrpc_msg **msgp)
547 struct json *method = NULL;
548 struct jsonrpc_msg *msg = NULL;
549 struct shash *object;
552 if (json->type != JSON_OBJECT) {
553 error = xstrdup("message is not a JSON object");
556 object = json_object(json);
558 method = shash_find_and_delete(object, "method");
559 if (method && method->type != JSON_STRING) {
560 error = xstrdup("method is not a JSON string");
564 msg = xzalloc(sizeof *msg);
565 msg->method = method ? xstrdup(method->u.string) : NULL;
566 msg->params = null_from_json_null(shash_find_and_delete(object, "params"));
567 msg->result = null_from_json_null(shash_find_and_delete(object, "result"));
568 msg->error = null_from_json_null(shash_find_and_delete(object, "error"));
569 msg->id = null_from_json_null(shash_find_and_delete(object, "id"));
570 msg->type = (msg->result ? JSONRPC_REPLY
571 : msg->error ? JSONRPC_ERROR
572 : msg->id ? JSONRPC_REQUEST
574 if (!shash_is_empty(object)) {
575 error = xasprintf("message has unexpected member \"%s\"",
576 shash_first(object)->name);
579 error = jsonrpc_msg_is_valid(msg);
585 json_destroy(method);
588 jsonrpc_msg_destroy(msg);
596 jsonrpc_msg_to_json(struct jsonrpc_msg *m)
598 struct json *json = json_object_create();
601 json_object_put(json, "method", json_string_create_nocopy(m->method));
605 json_object_put(json, "params", m->params);
609 json_object_put(json, "result", m->result);
610 } else if (m->type == JSONRPC_ERROR) {
611 json_object_put(json, "result", json_null_create());
615 json_object_put(json, "error", m->error);
616 } else if (m->type == JSONRPC_REPLY) {
617 json_object_put(json, "error", json_null_create());
621 json_object_put(json, "id", m->id);
622 } else if (m->type == JSONRPC_NOTIFY) {
623 json_object_put(json, "id", json_null_create());
631 /* A JSON-RPC session with reconnection. */
633 struct jsonrpc_session {
634 struct reconnect *reconnect;
636 struct stream *stream;
640 /* Creates and returns a jsonrpc_session that connects and reconnects, with
641 * back-off, to 'name', which should be a string acceptable to
643 struct jsonrpc_session *
644 jsonrpc_session_open(const char *name)
646 struct jsonrpc_session *s;
648 s = xmalloc(sizeof *s);
649 s->reconnect = reconnect_create(time_msec());
650 reconnect_set_name(s->reconnect, name);
651 reconnect_enable(s->reconnect, time_msec());
659 /* Creates and returns a jsonrpc_session that is initially connected to
660 * 'jsonrpc'. If the connection is dropped, it will not be reconnected. */
661 struct jsonrpc_session *
662 jsonrpc_session_open_unreliably(struct jsonrpc *jsonrpc)
664 struct jsonrpc_session *s;
666 s = xmalloc(sizeof *s);
667 s->reconnect = reconnect_create(time_msec());
668 reconnect_set_name(s->reconnect, jsonrpc_get_name(jsonrpc));
669 reconnect_set_max_tries(s->reconnect, 0);
670 reconnect_connected(s->reconnect, time_msec());
679 jsonrpc_session_close(struct jsonrpc_session *s)
682 jsonrpc_close(s->rpc);
683 reconnect_destroy(s->reconnect);
689 jsonrpc_session_disconnect(struct jsonrpc_session *s)
692 jsonrpc_error(s->rpc, EOF);
693 jsonrpc_close(s->rpc);
696 } else if (s->stream) {
697 stream_close(s->stream);
704 jsonrpc_session_connect(struct jsonrpc_session *s)
708 jsonrpc_session_disconnect(s);
709 error = stream_open(reconnect_get_name(s->reconnect), &s->stream);
711 reconnect_connect_failed(s->reconnect, time_msec(), error);
713 reconnect_connecting(s->reconnect, time_msec());
719 jsonrpc_session_run(struct jsonrpc_session *s)
725 error = jsonrpc_get_status(s->rpc);
727 reconnect_disconnected(s->reconnect, time_msec(), 0);
728 jsonrpc_session_disconnect(s);
730 } else if (s->stream) {
733 stream_run(s->stream);
734 error = stream_connect(s->stream);
736 reconnect_connected(s->reconnect, time_msec());
737 s->rpc = jsonrpc_open(s->stream);
739 } else if (error != EAGAIN) {
740 reconnect_connect_failed(s->reconnect, time_msec(), error);
741 stream_close(s->stream);
746 switch (reconnect_run(s->reconnect, time_msec())) {
747 case RECONNECT_CONNECT:
748 jsonrpc_session_connect(s);
751 case RECONNECT_DISCONNECT:
752 reconnect_disconnected(s->reconnect, time_msec(), 0);
753 jsonrpc_session_disconnect(s);
756 case RECONNECT_PROBE:
759 struct jsonrpc_msg *request;
761 params = json_array_create_empty();
762 request = jsonrpc_create_request("echo", params, NULL);
763 json_destroy(request->id);
764 request->id = json_string_create("echo");
765 jsonrpc_send(s->rpc, request);
772 jsonrpc_session_wait(struct jsonrpc_session *s)
775 jsonrpc_wait(s->rpc);
776 } else if (s->stream) {
777 stream_run_wait(s->stream);
778 stream_connect_wait(s->stream);
780 reconnect_wait(s->reconnect, time_msec());
784 jsonrpc_session_get_backlog(const struct jsonrpc_session *s)
786 return s->rpc ? jsonrpc_get_backlog(s->rpc) : 0;
790 jsonrpc_session_get_name(const struct jsonrpc_session *s)
792 return reconnect_get_name(s->reconnect);
796 jsonrpc_session_send(struct jsonrpc_session *s, struct jsonrpc_msg *msg)
798 return s->rpc ? jsonrpc_send(s->rpc, msg) : ENOTCONN;
802 jsonrpc_session_recv(struct jsonrpc_session *s)
805 struct jsonrpc_msg *msg;
806 jsonrpc_recv(s->rpc, &msg);
808 reconnect_received(s->reconnect, time_msec());
809 if (msg->type == JSONRPC_REQUEST && !strcmp(msg->method, "echo")) {
810 /* Echo request. Send reply. */
811 struct jsonrpc_msg *reply;
813 reply = jsonrpc_create_reply(json_clone(msg->params), msg->id);
814 jsonrpc_session_send(s, reply);
815 } else if (msg->type == JSONRPC_REPLY
816 && msg->id && msg->id->type == JSON_STRING
817 && !strcmp(msg->id->u.string, "echo")) {
818 /* It's a reply to our echo request. Suppress it. */
822 jsonrpc_msg_destroy(msg);
829 jsonrpc_session_recv_wait(struct jsonrpc_session *s)
832 jsonrpc_recv_wait(s->rpc);
837 jsonrpc_session_is_alive(const struct jsonrpc_session *s)
839 return s->rpc || s->stream || reconnect_get_max_tries(s->reconnect);
843 jsonrpc_session_is_connected(const struct jsonrpc_session *s)
845 return s->rpc != NULL;
849 jsonrpc_session_get_seqno(const struct jsonrpc_session *s)
855 jsonrpc_session_force_reconnect(struct jsonrpc_session *s)
857 reconnect_force_reconnect(s->reconnect, time_msec());