/* * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include #include "jsonrpc.h" #include #include "byteq.h" #include "openvswitch/dynamic-string.h" #include "fatal-signal.h" #include "openvswitch/json.h" #include "openvswitch/list.h" #include "openvswitch/ofpbuf.h" #include "ovs-thread.h" #include "openvswitch/poll-loop.h" #include "reconnect.h" #include "stream.h" #include "timeval.h" #include "openvswitch/vlog.h" VLOG_DEFINE_THIS_MODULE(jsonrpc); struct jsonrpc { struct stream *stream; char *name; int status; /* Input. */ struct byteq input; uint8_t input_buffer[512]; struct json_parser *parser; /* Output. */ struct ovs_list output; /* Contains "struct ofpbuf"s. */ size_t output_count; /* Number of elements in "output". */ size_t backlog; }; /* Rate limit for error messages. */ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 5); static struct jsonrpc_msg *jsonrpc_parse_received_message(struct jsonrpc *); static void jsonrpc_cleanup(struct jsonrpc *); static void jsonrpc_error(struct jsonrpc *, int error); /* This is just the same as stream_open() except that it uses the default * JSONRPC port if none is specified. */ int jsonrpc_stream_open(const char *name, struct stream **streamp, uint8_t dscp) { return stream_open_with_default_port(name, OVSDB_PORT, streamp, dscp); } /* This is just the same as pstream_open() except that it uses the default * JSONRPC port if none is specified. */ int jsonrpc_pstream_open(const char *name, struct pstream **pstreamp, uint8_t dscp) { return pstream_open_with_default_port(name, OVSDB_PORT, pstreamp, dscp); } /* Returns a new JSON-RPC stream that uses 'stream' for input and output. The * new jsonrpc object takes ownership of 'stream'. */ struct jsonrpc * jsonrpc_open(struct stream *stream) { struct jsonrpc *rpc; ovs_assert(stream != NULL); rpc = xzalloc(sizeof *rpc); rpc->name = xstrdup(stream_get_name(stream)); rpc->stream = stream; byteq_init(&rpc->input, rpc->input_buffer, sizeof rpc->input_buffer); ovs_list_init(&rpc->output); return rpc; } /* Destroys 'rpc', closing the stream on which it is based, and frees its * memory. */ void jsonrpc_close(struct jsonrpc *rpc) { if (rpc) { jsonrpc_cleanup(rpc); free(rpc->name); free(rpc); } } /* Performs periodic maintenance on 'rpc', such as flushing output buffers. */ void jsonrpc_run(struct jsonrpc *rpc) { if (rpc->status) { return; } stream_run(rpc->stream); while (!ovs_list_is_empty(&rpc->output)) { struct ofpbuf *buf = ofpbuf_from_list(rpc->output.next); int retval; retval = stream_send(rpc->stream, buf->data, buf->size); if (retval >= 0) { rpc->backlog -= retval; ofpbuf_pull(buf, retval); if (!buf->size) { ovs_list_remove(&buf->list_node); rpc->output_count--; ofpbuf_delete(buf); } } else { if (retval != -EAGAIN) { VLOG_WARN_RL(&rl, "%s: send error: %s", rpc->name, ovs_strerror(-retval)); jsonrpc_error(rpc, -retval); } break; } } } /* Arranges for the poll loop to wake up when 'rpc' needs to perform * maintenance activities. */ void jsonrpc_wait(struct jsonrpc *rpc) { if (!rpc->status) { stream_run_wait(rpc->stream); if (!ovs_list_is_empty(&rpc->output)) { stream_send_wait(rpc->stream); } } } /* * Returns the current status of 'rpc'. The possible return values are: * - 0: no error yet * - >0: errno value * - EOF: end of file (remote end closed connection; not necessarily an error). * * When this function returns nonzero, 'rpc' is effectively out of * commission. 'rpc' will not receive any more messages and any further * messages that one attempts to send with 'rpc' will be discarded. The * caller can keep 'rpc' around as long as it wants, but it's not going * to provide any more useful services. */ int jsonrpc_get_status(const struct jsonrpc *rpc) { return rpc->status; } /* Returns the number of bytes buffered by 'rpc' to be written to the * underlying stream. Always returns 0 if 'rpc' has encountered an error or if * the remote end closed the connection. */ size_t jsonrpc_get_backlog(const struct jsonrpc *rpc) { return rpc->status ? 0 : rpc->backlog; } /* Returns the number of bytes that have been received on 'rpc''s underlying * stream. (The value wraps around if it exceeds UINT_MAX.) */ unsigned int jsonrpc_get_received_bytes(const struct jsonrpc *rpc) { return rpc->input.head; } /* Returns 'rpc''s name, that is, the name returned by stream_get_name() for * the stream underlying 'rpc' when 'rpc' was created. */ const char * jsonrpc_get_name(const struct jsonrpc *rpc) { return rpc->name; } static void jsonrpc_log_msg(const struct jsonrpc *rpc, const char *title, const struct jsonrpc_msg *msg) { if (VLOG_IS_DBG_ENABLED()) { struct ds s = DS_EMPTY_INITIALIZER; if (msg->method) { ds_put_format(&s, ", method=\"%s\"", msg->method); } if (msg->params) { ds_put_cstr(&s, ", params="); json_to_ds(msg->params, 0, &s); } if (msg->result) { ds_put_cstr(&s, ", result="); json_to_ds(msg->result, 0, &s); } if (msg->error) { ds_put_cstr(&s, ", error="); json_to_ds(msg->error, 0, &s); } if (msg->id) { ds_put_cstr(&s, ", id="); json_to_ds(msg->id, 0, &s); } VLOG_DBG("%s: %s %s%s", rpc->name, title, jsonrpc_msg_type_to_string(msg->type), ds_cstr(&s)); ds_destroy(&s); } } /* Schedules 'msg' to be sent on 'rpc' and returns 'rpc''s status (as with * jsonrpc_get_status()). * * If 'msg' cannot be sent immediately, it is appended to a buffer. The caller * is responsible for ensuring that the amount of buffered data is somehow * limited. (jsonrpc_get_backlog() returns the amount of data currently * buffered in 'rpc'.) * * Always takes ownership of 'msg', regardless of success. */ int jsonrpc_send(struct jsonrpc *rpc, struct jsonrpc_msg *msg) { struct ofpbuf *buf; struct json *json; struct ds ds = DS_EMPTY_INITIALIZER; size_t length; if (rpc->status) { jsonrpc_msg_destroy(msg); return rpc->status; } jsonrpc_log_msg(rpc, "send", msg); json = jsonrpc_msg_to_json(msg); json_to_ds(json, 0, &ds); length = ds.length; json_destroy(json); buf = xmalloc(sizeof *buf); ofpbuf_use_ds(buf, &ds); ovs_list_push_back(&rpc->output, &buf->list_node); rpc->output_count++; rpc->backlog += length; if (rpc->output_count >= 50) { VLOG_INFO_RL(&rl, "excessive sending backlog, jsonrpc: %s, num of" " msgs: %"PRIuSIZE", backlog: %"PRIuSIZE".", rpc->name, rpc->output_count, rpc->backlog); } if (rpc->backlog == length) { jsonrpc_run(rpc); } return rpc->status; } /* Attempts to receive a message from 'rpc'. * * If successful, stores the received message in '*msgp' and returns 0. The * caller takes ownership of '*msgp' and must eventually destroy it with * jsonrpc_msg_destroy(). * * Otherwise, stores NULL in '*msgp' and returns one of the following: * * - EAGAIN: No message has been received. * * - EOF: The remote end closed the connection gracefully. * * - Otherwise an errno value that represents a JSON-RPC protocol violation * or another error fatal to the connection. 'rpc' will not send or * receive any more messages. */ int jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp) { int i; *msgp = NULL; if (rpc->status) { return rpc->status; } for (i = 0; i < 50; i++) { size_t n, used; /* Fill our input buffer if it's empty. */ if (byteq_is_empty(&rpc->input)) { size_t chunk; int retval; chunk = byteq_headroom(&rpc->input); retval = stream_recv(rpc->stream, byteq_head(&rpc->input), chunk); if (retval < 0) { if (retval == -EAGAIN) { return EAGAIN; } else { VLOG_WARN_RL(&rl, "%s: receive error: %s", rpc->name, ovs_strerror(-retval)); jsonrpc_error(rpc, -retval); return rpc->status; } } else if (retval == 0) { jsonrpc_error(rpc, EOF); return EOF; } byteq_advance_head(&rpc->input, retval); } /* We have some input. Feed it into the JSON parser. */ if (!rpc->parser) { rpc->parser = json_parser_create(0); } n = byteq_tailroom(&rpc->input); used = json_parser_feed(rpc->parser, (char *) byteq_tail(&rpc->input), n); byteq_advance_tail(&rpc->input, used); /* If we have complete JSON, attempt to parse it as JSON-RPC. */ if (json_parser_is_done(rpc->parser)) { *msgp = jsonrpc_parse_received_message(rpc); if (*msgp) { return 0; } if (rpc->status) { const struct byteq *q = &rpc->input; if (q->head <= q->size) { stream_report_content(q->buffer, q->head, STREAM_JSONRPC, &this_module, rpc->name); } return rpc->status; } } } return EAGAIN; } /* Causes the poll loop to wake up when jsonrpc_recv() may return a value other * than EAGAIN. */ void jsonrpc_recv_wait(struct jsonrpc *rpc) { if (rpc->status || !byteq_is_empty(&rpc->input)) { poll_immediate_wake_at(rpc->name); } else { stream_recv_wait(rpc->stream); } } /* Sends 'msg' on 'rpc' and waits for it to be successfully queued to the * underlying stream. Returns 0 if 'msg' was sent successfully, otherwise a * status value (see jsonrpc_get_status()). * * Always takes ownership of 'msg', regardless of success. */ int jsonrpc_send_block(struct jsonrpc *rpc, struct jsonrpc_msg *msg) { int error; fatal_signal_run(); error = jsonrpc_send(rpc, msg); if (error) { return error; } for (;;) { jsonrpc_run(rpc); if (ovs_list_is_empty(&rpc->output) || rpc->status) { return rpc->status; } jsonrpc_wait(rpc); poll_block(); } } /* Waits for a message to be received on 'rpc'. Same semantics as * jsonrpc_recv() except that EAGAIN will never be returned. */ int jsonrpc_recv_block(struct jsonrpc *rpc, struct jsonrpc_msg **msgp) { for (;;) { int error = jsonrpc_recv(rpc, msgp); if (error != EAGAIN) { fatal_signal_run(); return error; } jsonrpc_run(rpc); jsonrpc_wait(rpc); jsonrpc_recv_wait(rpc); poll_block(); } } /* Sends 'request' to 'rpc' then waits for a reply. The return value is 0 if * successful, in which case '*replyp' is set to the reply, which the caller * must eventually free with jsonrpc_msg_destroy(). Otherwise returns a status * value (see jsonrpc_get_status()). * * Discards any message received on 'rpc' that is not a reply to 'request' * (based on message id). * * Always takes ownership of 'request', regardless of success. */ int jsonrpc_transact_block(struct jsonrpc *rpc, struct jsonrpc_msg *request, struct jsonrpc_msg **replyp) { struct jsonrpc_msg *reply = NULL; struct json *id; int error; id = json_clone(request->id); error = jsonrpc_send_block(rpc, request); if (!error) { for (;;) { error = jsonrpc_recv_block(rpc, &reply); if (error) { break; } if ((reply->type == JSONRPC_REPLY || reply->type == JSONRPC_ERROR) && json_equal(id, reply->id)) { break; } jsonrpc_msg_destroy(reply); } } *replyp = error ? NULL : reply; json_destroy(id); return error; } /* Attempts to parse the content of 'rpc->parser' (which is complete JSON) as a * JSON-RPC message. If successful, returns the JSON-RPC message. On failure, * signals an error on 'rpc' with jsonrpc_error() and returns NULL. */ static struct jsonrpc_msg * jsonrpc_parse_received_message(struct jsonrpc *rpc) { struct jsonrpc_msg *msg; struct json *json; char *error; json = json_parser_finish(rpc->parser); rpc->parser = NULL; if (json->type == JSON_STRING) { VLOG_WARN_RL(&rl, "%s: error parsing stream: %s", rpc->name, json_string(json)); jsonrpc_error(rpc, EPROTO); json_destroy(json); return NULL; } error = jsonrpc_msg_from_json(json, &msg); if (error) { VLOG_WARN_RL(&rl, "%s: received bad JSON-RPC message: %s", rpc->name, error); free(error); jsonrpc_error(rpc, EPROTO); return NULL; } jsonrpc_log_msg(rpc, "received", msg); return msg; } static void jsonrpc_error(struct jsonrpc *rpc, int error) { ovs_assert(error); if (!rpc->status) { rpc->status = error; jsonrpc_cleanup(rpc); } } static void jsonrpc_cleanup(struct jsonrpc *rpc) { stream_close(rpc->stream); rpc->stream = NULL; json_parser_abort(rpc->parser); rpc->parser = NULL; ofpbuf_list_delete(&rpc->output); rpc->backlog = 0; rpc->output_count = 0; } static struct jsonrpc_msg * jsonrpc_create(enum jsonrpc_msg_type type, const char *method, struct json *params, struct json *result, struct json *error, struct json *id) { struct jsonrpc_msg *msg = xmalloc(sizeof *msg); msg->type = type; msg->method = nullable_xstrdup(method); msg->params = params; msg->result = result; msg->error = error; msg->id = id; return msg; } static struct json * jsonrpc_create_id(void) { static atomic_count next_id = ATOMIC_COUNT_INIT(0); unsigned int id; id = atomic_count_inc(&next_id); return json_integer_create(id); } struct jsonrpc_msg * jsonrpc_create_request(const char *method, struct json *params, struct json **idp) { struct json *id = jsonrpc_create_id(); if (idp) { *idp = json_clone(id); } return jsonrpc_create(JSONRPC_REQUEST, method, params, NULL, NULL, id); } struct jsonrpc_msg * jsonrpc_create_notify(const char *method, struct json *params) { return jsonrpc_create(JSONRPC_NOTIFY, method, params, NULL, NULL, NULL); } struct jsonrpc_msg * jsonrpc_create_reply(struct json *result, const struct json *id) { return jsonrpc_create(JSONRPC_REPLY, NULL, NULL, result, NULL, json_clone(id)); } struct jsonrpc_msg * jsonrpc_create_error(struct json *error, const struct json *id) { return jsonrpc_create(JSONRPC_REPLY, NULL, NULL, NULL, error, json_clone(id)); } const char * jsonrpc_msg_type_to_string(enum jsonrpc_msg_type type) { switch (type) { case JSONRPC_REQUEST: return "request"; case JSONRPC_NOTIFY: return "notification"; case JSONRPC_REPLY: return "reply"; case JSONRPC_ERROR: return "error"; } return "(null)"; } char * jsonrpc_msg_is_valid(const struct jsonrpc_msg *m) { const char *type_name; unsigned int pattern; if (m->params && m->params->type != JSON_ARRAY) { return xstrdup("\"params\" must be JSON array"); } switch (m->type) { case JSONRPC_REQUEST: pattern = 0x11001; break; case JSONRPC_NOTIFY: pattern = 0x11000; break; case JSONRPC_REPLY: pattern = 0x00101; break; case JSONRPC_ERROR: pattern = 0x00011; break; default: return xasprintf("invalid JSON-RPC message type %d", m->type); } type_name = jsonrpc_msg_type_to_string(m->type); if ((m->method != NULL) != ((pattern & 0x10000) != 0)) { return xasprintf("%s must%s have \"method\"", type_name, (pattern & 0x10000) ? "" : " not"); } if ((m->params != NULL) != ((pattern & 0x1000) != 0)) { return xasprintf("%s must%s have \"params\"", type_name, (pattern & 0x1000) ? "" : " not"); } if ((m->result != NULL) != ((pattern & 0x100) != 0)) { return xasprintf("%s must%s have \"result\"", type_name, (pattern & 0x100) ? "" : " not"); } if ((m->error != NULL) != ((pattern & 0x10) != 0)) { return xasprintf("%s must%s have \"error\"", type_name, (pattern & 0x10) ? "" : " not"); } if ((m->id != NULL) != ((pattern & 0x1) != 0)) { return xasprintf("%s must%s have \"id\"", type_name, (pattern & 0x1) ? "" : " not"); } return NULL; } void jsonrpc_msg_destroy(struct jsonrpc_msg *m) { if (m) { free(m->method); json_destroy(m->params); json_destroy(m->result); json_destroy(m->error); json_destroy(m->id); free(m); } } static struct json * null_from_json_null(struct json *json) { if (json && json->type == JSON_NULL) { json_destroy(json); return NULL; } return json; } char * jsonrpc_msg_from_json(struct json *json, struct jsonrpc_msg **msgp) { struct json *method = NULL; struct jsonrpc_msg *msg = NULL; struct shash *object; char *error; if (json->type != JSON_OBJECT) { error = xstrdup("message is not a JSON object"); goto exit; } object = json_object(json); method = shash_find_and_delete(object, "method"); if (method && method->type != JSON_STRING) { error = xstrdup("method is not a JSON string"); goto exit; } msg = xzalloc(sizeof *msg); msg->method = method ? xstrdup(method->u.string) : NULL; msg->params = null_from_json_null(shash_find_and_delete(object, "params")); msg->result = null_from_json_null(shash_find_and_delete(object, "result")); msg->error = null_from_json_null(shash_find_and_delete(object, "error")); msg->id = null_from_json_null(shash_find_and_delete(object, "id")); msg->type = (msg->result ? JSONRPC_REPLY : msg->error ? JSONRPC_ERROR : msg->id ? JSONRPC_REQUEST : JSONRPC_NOTIFY); if (!shash_is_empty(object)) { error = xasprintf("message has unexpected member \"%s\"", shash_first(object)->name); goto exit; } error = jsonrpc_msg_is_valid(msg); if (error) { goto exit; } exit: json_destroy(method); json_destroy(json); if (error) { jsonrpc_msg_destroy(msg); msg = NULL; } *msgp = msg; return error; } struct json * jsonrpc_msg_to_json(struct jsonrpc_msg *m) { struct json *json = json_object_create(); if (m->method) { json_object_put(json, "method", json_string_create_nocopy(m->method)); } if (m->params) { json_object_put(json, "params", m->params); } if (m->result) { json_object_put(json, "result", m->result); } else if (m->type == JSONRPC_ERROR) { json_object_put(json, "result", json_null_create()); } if (m->error) { json_object_put(json, "error", m->error); } else if (m->type == JSONRPC_REPLY) { json_object_put(json, "error", json_null_create()); } if (m->id) { json_object_put(json, "id", m->id); } else if (m->type == JSONRPC_NOTIFY) { json_object_put(json, "id", json_null_create()); } free(m); return json; } /* A JSON-RPC session with reconnection. */ struct jsonrpc_session { struct reconnect *reconnect; struct jsonrpc *rpc; struct stream *stream; struct pstream *pstream; int last_error; unsigned int seqno; uint8_t dscp; }; /* Creates and returns a jsonrpc_session to 'name', which should be a string * acceptable to stream_open() or pstream_open(). * * If 'name' is an active connection method, e.g. "tcp:127.1.2.3", the new * jsonrpc_session connects to 'name'. If 'retry' is true, then the new * session connects and reconnects to 'name', with backoff. If 'retry' is * false, the new session will only try to connect once and after a connection * failure or a disconnection jsonrpc_session_is_alive() will return false for * the new session. * * If 'name' is a passive connection method, e.g. "ptcp:", the new * jsonrpc_session listens for connections to 'name'. It maintains at most one * connection at any given time. Any new connection causes the previous one * (if any) to be dropped. */ struct jsonrpc_session * jsonrpc_session_open(const char *name, bool retry) { struct jsonrpc_session *s; s = xmalloc(sizeof *s); s->reconnect = reconnect_create(time_msec()); reconnect_set_name(s->reconnect, name); reconnect_enable(s->reconnect, time_msec()); s->rpc = NULL; s->stream = NULL; s->pstream = NULL; s->seqno = 0; s->dscp = 0; s->last_error = 0; if (!pstream_verify_name(name)) { reconnect_set_passive(s->reconnect, true, time_msec()); } else if (!retry) { reconnect_set_max_tries(s->reconnect, 1); reconnect_set_backoff(s->reconnect, INT_MAX, INT_MAX); } if (!stream_or_pstream_needs_probes(name)) { reconnect_set_probe_interval(s->reconnect, 0); } return s; } /* Creates and returns a jsonrpc_session that is initially connected to * 'jsonrpc'. If the connection is dropped, it will not be reconnected. * * On the assumption that such connections are likely to be short-lived * (e.g. from ovs-vsctl), informational logging for them is suppressed. */ struct jsonrpc_session * jsonrpc_session_open_unreliably(struct jsonrpc *jsonrpc, uint8_t dscp) { struct jsonrpc_session *s; s = xmalloc(sizeof *s); s->reconnect = reconnect_create(time_msec()); reconnect_set_quiet(s->reconnect, true); reconnect_set_name(s->reconnect, jsonrpc_get_name(jsonrpc)); reconnect_set_max_tries(s->reconnect, 0); reconnect_connected(s->reconnect, time_msec()); s->dscp = dscp; s->rpc = jsonrpc; s->stream = NULL; s->pstream = NULL; s->seqno = 1; return s; } void jsonrpc_session_close(struct jsonrpc_session *s) { if (s) { jsonrpc_close(s->rpc); reconnect_destroy(s->reconnect); stream_close(s->stream); pstream_close(s->pstream); free(s); } } static void jsonrpc_session_disconnect(struct jsonrpc_session *s) { if (s->rpc) { jsonrpc_error(s->rpc, EOF); jsonrpc_close(s->rpc); s->rpc = NULL; s->seqno++; } else if (s->stream) { stream_close(s->stream); s->stream = NULL; s->seqno++; } } static void jsonrpc_session_connect(struct jsonrpc_session *s) { const char *name = reconnect_get_name(s->reconnect); int error; jsonrpc_session_disconnect(s); if (!reconnect_is_passive(s->reconnect)) { error = jsonrpc_stream_open(name, &s->stream, s->dscp); if (!error) { reconnect_connecting(s->reconnect, time_msec()); } else { s->last_error = error; } } else { error = s->pstream ? 0 : jsonrpc_pstream_open(name, &s->pstream, s->dscp); if (!error) { reconnect_listening(s->reconnect, time_msec()); } } if (error) { reconnect_connect_failed(s->reconnect, time_msec(), error); } } void jsonrpc_session_run(struct jsonrpc_session *s) { if (s->pstream) { struct stream *stream; int error; error = pstream_accept(s->pstream, &stream); if (!error) { if (s->rpc || s->stream) { VLOG_INFO_RL(&rl, "%s: new connection replacing active connection", reconnect_get_name(s->reconnect)); jsonrpc_session_disconnect(s); } reconnect_connected(s->reconnect, time_msec()); s->rpc = jsonrpc_open(stream); s->seqno++; } else if (error != EAGAIN) { reconnect_listen_error(s->reconnect, time_msec(), error); pstream_close(s->pstream); s->pstream = NULL; } } if (s->rpc) { size_t backlog; int error; backlog = jsonrpc_get_backlog(s->rpc); jsonrpc_run(s->rpc); if (jsonrpc_get_backlog(s->rpc) < backlog) { /* Data previously caught in a queue was successfully sent (or * there's an error, which we'll catch below.) * * We don't count data that is successfully sent immediately as * activity, because there's a lot of queuing downstream from us, * which means that we can push a lot of data into a connection * that has stalled and won't ever recover. */ reconnect_activity(s->reconnect, time_msec()); } error = jsonrpc_get_status(s->rpc); if (error) { reconnect_disconnected(s->reconnect, time_msec(), error); jsonrpc_session_disconnect(s); s->last_error = error; } } else if (s->stream) { int error; stream_run(s->stream); error = stream_connect(s->stream); if (!error) { reconnect_connected(s->reconnect, time_msec()); s->rpc = jsonrpc_open(s->stream); s->stream = NULL; s->seqno++; } else if (error != EAGAIN) { reconnect_connect_failed(s->reconnect, time_msec(), error); stream_close(s->stream); s->stream = NULL; s->last_error = error; } } switch (reconnect_run(s->reconnect, time_msec())) { case RECONNECT_CONNECT: jsonrpc_session_connect(s); break; case RECONNECT_DISCONNECT: reconnect_disconnected(s->reconnect, time_msec(), 0); jsonrpc_session_disconnect(s); break; case RECONNECT_PROBE: if (s->rpc) { struct json *params; struct jsonrpc_msg *request; params = json_array_create_empty(); request = jsonrpc_create_request("echo", params, NULL); json_destroy(request->id); request->id = json_string_create("echo"); jsonrpc_send(s->rpc, request); } break; } } void jsonrpc_session_wait(struct jsonrpc_session *s) { if (s->rpc) { jsonrpc_wait(s->rpc); } else if (s->stream) { stream_run_wait(s->stream); stream_connect_wait(s->stream); } if (s->pstream) { pstream_wait(s->pstream); } reconnect_wait(s->reconnect, time_msec()); } size_t jsonrpc_session_get_backlog(const struct jsonrpc_session *s) { return s->rpc ? jsonrpc_get_backlog(s->rpc) : 0; } /* Always returns a pointer to a valid C string, assuming 's' was initialized * correctly. */ const char * jsonrpc_session_get_name(const struct jsonrpc_session *s) { return reconnect_get_name(s->reconnect); } const char * jsonrpc_session_get_id(const struct jsonrpc_session *s) { if (s->rpc && s->rpc->stream) { return stream_get_peer_id(s->rpc->stream); } else { return NULL; } } /* Always takes ownership of 'msg', regardless of success. */ int jsonrpc_session_send(struct jsonrpc_session *s, struct jsonrpc_msg *msg) { if (s->rpc) { return jsonrpc_send(s->rpc, msg); } else { jsonrpc_msg_destroy(msg); return ENOTCONN; } } struct jsonrpc_msg * jsonrpc_session_recv(struct jsonrpc_session *s) { if (s->rpc) { unsigned int received_bytes; struct jsonrpc_msg *msg; received_bytes = jsonrpc_get_received_bytes(s->rpc); jsonrpc_recv(s->rpc, &msg); if (received_bytes != jsonrpc_get_received_bytes(s->rpc)) { /* Data was successfully received. * * Previously we only counted receiving a full message as activity, * but with large messages or a slow connection that policy could * time out the session mid-message. */ reconnect_activity(s->reconnect, time_msec()); } if (msg) { if (msg->type == JSONRPC_REQUEST && !strcmp(msg->method, "echo")) { /* Echo request. Send reply. */ struct jsonrpc_msg *reply; reply = jsonrpc_create_reply(json_clone(msg->params), msg->id); jsonrpc_session_send(s, reply); } else if (msg->type == JSONRPC_REPLY && msg->id && msg->id->type == JSON_STRING && !strcmp(msg->id->u.string, "echo")) { /* It's a reply to our echo request. Suppress it. */ } else { return msg; } jsonrpc_msg_destroy(msg); } } return NULL; } void jsonrpc_session_recv_wait(struct jsonrpc_session *s) { if (s->rpc) { jsonrpc_recv_wait(s->rpc); } } /* Returns true if 's' is currently connected or trying to connect. */ bool jsonrpc_session_is_alive(const struct jsonrpc_session *s) { return s->rpc || s->stream || reconnect_get_max_tries(s->reconnect); } /* Returns true if 's' is currently connected. */ bool jsonrpc_session_is_connected(const struct jsonrpc_session *s) { return s->rpc != NULL; } /* Returns a sequence number for 's'. The sequence number increments every * time 's' connects or disconnects. Thus, a caller can use the change (or * lack of change) in the sequence number to figure out whether the underlying * connection is the same as before. */ unsigned int jsonrpc_session_get_seqno(const struct jsonrpc_session *s) { return s->seqno; } /* Returns the current status of 's'. If 's' is NULL or is disconnected, this * is 0, otherwise it is the status of the connection, as reported by * jsonrpc_get_status(). */ int jsonrpc_session_get_status(const struct jsonrpc_session *s) { return s && s->rpc ? jsonrpc_get_status(s->rpc) : 0; } /* Returns the last error reported on a connection by 's'. The return value is * 0 only if no connection made by 's' has ever encountered an error. See * jsonrpc_get_status() for return value interpretation. */ int jsonrpc_session_get_last_error(const struct jsonrpc_session *s) { return s->last_error; } /* Populates 'stats' with statistics from 's'. */ void jsonrpc_session_get_reconnect_stats(const struct jsonrpc_session *s, struct reconnect_stats *stats) { reconnect_get_stats(s->reconnect, time_msec(), stats); } /* Enables 's' to reconnect to the peer if the connection drops. */ void jsonrpc_session_enable_reconnect(struct jsonrpc_session *s) { reconnect_set_max_tries(s->reconnect, UINT_MAX); reconnect_set_backoff(s->reconnect, RECONNECT_DEFAULT_MIN_BACKOFF, RECONNECT_DEFAULT_MAX_BACKOFF); } /* Forces 's' to drop its connection (if any) and reconnect. */ void jsonrpc_session_force_reconnect(struct jsonrpc_session *s) { reconnect_force_reconnect(s->reconnect, time_msec()); } /* Sets 'max_backoff' as the maximum time, in milliseconds, to wait after a * connection attempt fails before attempting to connect again. */ void jsonrpc_session_set_max_backoff(struct jsonrpc_session *s, int max_backoff) { reconnect_set_backoff(s->reconnect, 0, max_backoff); } /* Sets the "probe interval" for 's' to 'probe_interval', in milliseconds. If * this is zero, it disables the connection keepalive feature. Otherwise, if * 's' is idle for 'probe_interval' milliseconds then 's' will send an echo * request and, if no reply is received within an additional 'probe_interval' * milliseconds, close the connection (then reconnect, if that feature is * enabled). */ void jsonrpc_session_set_probe_interval(struct jsonrpc_session *s, int probe_interval) { reconnect_set_probe_interval(s->reconnect, probe_interval); } /* Sets the DSCP value used for 's''s connection to 'dscp'. If this is * different from the DSCP value currently in use then the connection is closed * and reconnected. */ void jsonrpc_session_set_dscp(struct jsonrpc_session *s, uint8_t dscp) { if (s->dscp != dscp) { pstream_close(s->pstream); s->pstream = NULL; s->dscp = dscp; jsonrpc_session_force_reconnect(s); } }