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ovs/lib/jsonrpc.c
Ben Pfaff 10a89ef04d Replace all uses of strerror() by ovs_strerror(), for thread safety. 
Signed-off-by: Ben Pfaff <blp@nicira.com>
2013-06-28 16:09:38 -07:00

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/*
* Copyright (c) 2009, 2010, 2011, 2012, 2013 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 <config.h>
#include "jsonrpc.h"
#include <errno.h>
#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 "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 list output; /* Contains "struct ofpbuf"s. */
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 *);
static void jsonrpc_error(struct jsonrpc *, int error);
/* 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, uint8_t dscp)
{
return stream_open_with_default_ports(name, JSONRPC_TCP_PORT,
JSONRPC_SSL_PORT, streamp,
dscp);
}
/* 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, uint8_t dscp)
{
return pstream_open_with_default_ports(name, JSONRPC_TCP_PORT,
JSONRPC_SSL_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);
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 (!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) {
list_remove(&buf->list_node);
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 (!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 functions 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;
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;
list_push_back(&rpc->output, &buf->list_node);
rpc->backlog += length;
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++) {
if (rpc->received) {
*msgp = rpc->received;
rpc->received = NULL;
return 0;
} else 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);
} 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;
}
}
}
}
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 || rpc->received || !byteq_is_empty(&rpc->input)) {
(poll_immediate_wake)(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 (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;
}
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;
}
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;
jsonrpc_msg_destroy(rpc->received);
rpc->received = NULL;
ofpbuf_list_delete(&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;
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 = 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, 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);
}
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) {
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;
} 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;
}
/* 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);
}
/* 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);
}
}
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;
}
int
jsonrpc_session_get_status(const struct jsonrpc_session *s)
{
return s && s->rpc ? jsonrpc_get_status(s->rpc) : 0;
}
int
jsonrpc_session_get_last_error(const struct jsonrpc_session *s)
{
return s->last_error;
}
void
jsonrpc_session_get_reconnect_stats(const struct jsonrpc_session *s,
struct reconnect_stats *stats)
{
reconnect_get_stats(s->reconnect, time_msec(), stats);
}
void
jsonrpc_session_force_reconnect(struct jsonrpc_session *s)
{
reconnect_force_reconnect(s->reconnect, time_msec());
}
void
jsonrpc_session_set_max_backoff(struct jsonrpc_session *s, int max_backoff)
{
reconnect_set_backoff(s->reconnect, 0, max_backoff);
}
void
jsonrpc_session_set_probe_interval(struct jsonrpc_session *s,
int probe_interval)
{
reconnect_set_probe_interval(s->reconnect, probe_interval);
}
void
jsonrpc_session_set_dscp(struct jsonrpc_session *s,
uint8_t dscp)
{
if (s->dscp != dscp) {
if (s->pstream) {
int error;
error = pstream_set_dscp(s->pstream, dscp);
if (error) {
VLOG_ERR("%s: failed set_dscp %s",
reconnect_get_name(s->reconnect),
ovs_strerror(error));
}
/*
* XXX race window between setting dscp to listening socket
* and accepting socket. accepted socket may have old dscp value.
* Ignore this race window for now.
*/
}
s->dscp = dscp;
jsonrpc_session_force_reconnect(s);
}
}
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