/* * Copyright (c) 2009, 2010 Nicira Networks. * * 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 #include "byteq.h" #include "dynamic-string.h" #include "fatal-signal.h" #include "json.h" #include "list.h" #include "ofpbuf.h" #include "poll-loop.h" #include "queue.h" #include "reconnect.h" #include "stream.h" #include "timeval.h" #include "vlog.h" VLOG_DEFINE_THIS_MODULE(jsonrpc) struct jsonrpc { struct stream *stream; char *name; int status; /* Input. */ struct byteq input; struct json_parser *parser; struct jsonrpc_msg *received; /* Output. */ struct ovs_queue output; size_t backlog; }; /* Rate limit for error messages. */ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 5); static void jsonrpc_received(struct jsonrpc *); static void jsonrpc_cleanup(struct jsonrpc *); /* This is just the same as stream_open() except that it uses the default * JSONRPC ports if none is specified. */ int jsonrpc_stream_open(const char *name, struct stream **streamp) { return stream_open_with_default_ports(name, JSONRPC_TCP_PORT, JSONRPC_SSL_PORT, streamp); } /* This is just the same as pstream_open() except that it uses the default * JSONRPC ports if none is specified. */ int jsonrpc_pstream_open(const char *name, struct pstream **pstreamp) { return pstream_open_with_default_ports(name, JSONRPC_TCP_PORT, JSONRPC_SSL_PORT, pstreamp); } struct jsonrpc * jsonrpc_open(struct stream *stream) { struct jsonrpc *rpc; assert(stream != NULL); rpc = xzalloc(sizeof *rpc); rpc->name = xstrdup(stream_get_name(stream)); rpc->stream = stream; byteq_init(&rpc->input); queue_init(&rpc->output); return rpc; } void jsonrpc_close(struct jsonrpc *rpc) { if (rpc) { jsonrpc_cleanup(rpc); free(rpc->name); free(rpc); } } void jsonrpc_run(struct jsonrpc *rpc) { if (rpc->status) { return; } stream_run(rpc->stream); while (!queue_is_empty(&rpc->output)) { struct ofpbuf *buf = rpc->output.head; int retval; retval = stream_send(rpc->stream, buf->data, buf->size); if (retval >= 0) { rpc->backlog -= retval; ofpbuf_pull(buf, retval); if (!buf->size) { ofpbuf_delete(queue_pop_head(&rpc->output)); } } else { if (retval != -EAGAIN) { VLOG_WARN_RL(&rl, "%s: send error: %s", rpc->name, strerror(-retval)); jsonrpc_error(rpc, -retval); } break; } } } void jsonrpc_wait(struct jsonrpc *rpc) { if (!rpc->status) { stream_run_wait(rpc->stream); if (!queue_is_empty(&rpc->output)) { stream_send_wait(rpc->stream); } } } int jsonrpc_get_status(const struct jsonrpc *rpc) { return rpc->status; } size_t jsonrpc_get_backlog(const struct jsonrpc *rpc) { return rpc->status ? 0 : rpc->backlog; } 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); } } /* Always takes ownership of 'msg', regardless of success. */ int jsonrpc_send(struct jsonrpc *rpc, struct jsonrpc_msg *msg) { struct ofpbuf *buf; struct json *json; size_t length; char *s; if (rpc->status) { jsonrpc_msg_destroy(msg); return rpc->status; } jsonrpc_log_msg(rpc, "send", msg); json = jsonrpc_msg_to_json(msg); s = json_to_string(json, 0); length = strlen(s); json_destroy(json); buf = xmalloc(sizeof *buf); ofpbuf_use(buf, s, length); buf->size = length; queue_push_tail(&rpc->output, buf); rpc->backlog += length; if (rpc->output.n == 1) { jsonrpc_run(rpc); } return rpc->status; } int jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp) { *msgp = NULL; if (rpc->status) { return rpc->status; } while (!rpc->received) { 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, 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); } else { size_t n, used; 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 (json_parser_is_done(rpc->parser)) { jsonrpc_received(rpc); if (rpc->status) { const struct byteq *q = &rpc->input; if (q->head <= BYTEQ_SIZE) { stream_report_content(q->buffer, q->head, STREAM_JSONRPC, THIS_MODULE, rpc->name); } return rpc->status; } } } } *msgp = rpc->received; rpc->received = NULL; return 0; } void jsonrpc_recv_wait(struct jsonrpc *rpc) { if (rpc->status || rpc->received || !byteq_is_empty(&rpc->input)) { poll_immediate_wake(); } else { stream_recv_wait(rpc->stream); } } /* 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 (queue_is_empty(&rpc->output) || rpc->status) { return rpc->status; } jsonrpc_wait(rpc); poll_block(); } } 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(); } } /* 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 || (reply->type == JSONRPC_REPLY && json_equal(id, reply->id))) { break; } jsonrpc_msg_destroy(reply); } } *replyp = error ? NULL : reply; json_destroy(id); return error; } static void jsonrpc_received(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; } 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; } jsonrpc_log_msg(rpc, "received", msg); rpc->received = msg; } void jsonrpc_error(struct jsonrpc *rpc, int error) { 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; jsonrpc_msg_destroy(rpc->received); rpc->received = NULL; queue_clear(&rpc->output); rpc->backlog = 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 = method ? xstrdup(method) : NULL; msg->params = params; msg->result = result; msg->error = error; msg->id = id; return msg; } static struct json * jsonrpc_create_id(void) { static unsigned int 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; unsigned int seqno; }; /* 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 and reconnects, with back-off, to 'name'. * * 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) { 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; if (!pstream_verify_name(name)) { reconnect_set_passive(s->reconnect, true, time_msec()); } 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) { 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->rpc = jsonrpc; s->stream = NULL; s->pstream = NULL; s->seqno = 0; 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); if (!error) { reconnect_connecting(s->reconnect, time_msec()); } } else { error = s->pstream ? 0 : jsonrpc_pstream_open(name, &s->pstream); if (!error) { reconnect_listening(s->reconnect, time_msec()); } } if (error) { reconnect_connect_failed(s->reconnect, time_msec(), error); } s->seqno++; } 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); } else if (error != EAGAIN) { reconnect_listen_error(s->reconnect, time_msec(), error); pstream_close(s->pstream); s->pstream = NULL; } } if (s->rpc) { int error; jsonrpc_run(s->rpc); error = jsonrpc_get_status(s->rpc); if (error) { reconnect_disconnected(s->reconnect, time_msec(), error); jsonrpc_session_disconnect(s); } } 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; } else if (error != EAGAIN) { reconnect_connect_failed(s->reconnect, time_msec(), error); stream_close(s->stream); s->stream = NULL; } } 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; } const char * jsonrpc_session_get_name(const struct jsonrpc_session *s) { return reconnect_get_name(s->reconnect); } /* 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) { struct jsonrpc_msg *msg; jsonrpc_recv(s->rpc, &msg); if (msg) { reconnect_received(s->reconnect, time_msec()); 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); } } bool jsonrpc_session_is_alive(const struct jsonrpc_session *s) { return s->rpc || s->stream || reconnect_get_max_tries(s->reconnect); } bool jsonrpc_session_is_connected(const struct jsonrpc_session *s) { return s->rpc != NULL; } unsigned int jsonrpc_session_get_seqno(const struct jsonrpc_session *s) { return s->seqno; } void jsonrpc_session_force_reconnect(struct jsonrpc_session *s) { reconnect_force_reconnect(s->reconnect, time_msec()); }