/*
- * Copyright (c) 2009, 2010 Nicira Networks.
+ * 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.
#include "jsonrpc.h"
-#include <assert.h>
#include <errno.h>
#include "byteq.h"
#include "list.h"
#include "ofpbuf.h"
#include "poll-loop.h"
-#include "queue.h"
#include "reconnect.h"
#include "stream.h"
#include "timeval.h"
-
-#define THIS_MODULE VLM_jsonrpc
#include "vlog.h"
+
+VLOG_DEFINE_THIS_MODULE(jsonrpc);
\f
struct jsonrpc {
struct stream *stream;
struct jsonrpc_msg *received;
/* Output. */
- struct ovs_queue output;
+ struct list output; /* Contains "struct ofpbuf"s. */
size_t backlog;
};
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)
+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);
+ 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)
+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);
+ 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;
- assert(stream != NULL);
+ ovs_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);
+ 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)
{
}
}
+/* Performs periodic maintenance on 'rpc', such as flushing output buffers. */
void
jsonrpc_run(struct jsonrpc *rpc)
{
}
stream_run(rpc->stream);
- while (!queue_is_empty(&rpc->output)) {
- struct ofpbuf *buf = rpc->output.head;
+ 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);
rpc->backlog -= retval;
ofpbuf_pull(buf, retval);
if (!buf->size) {
- ofpbuf_delete(queue_pop_head(&rpc->output));
+ list_remove(&buf->list_node);
+ ofpbuf_delete(buf);
}
} else {
if (retval != -EAGAIN) {
}
}
+/* 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 (!queue_is_empty(&rpc->output)) {
+ 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)
{
}
}
-/* Always takes ownership of 'msg', regardless of success. */
+/* 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)
{
buf = xmalloc(sizeof *buf);
ofpbuf_use(buf, s, length);
buf->size = length;
- queue_push_tail(&rpc->output, buf);
+ list_push_back(&rpc->output, &buf->list_node);
rpc->backlog += length;
- if (rpc->output.n == 1) {
+ 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;
}
- while (!rpc->received) {
- if (byteq_is_empty(&rpc->input)) {
+ 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;
return rpc->status;
}
} else if (retval == 0) {
- VLOG_INFO_RL(&rl, "%s: connection closed", rpc->name);
jsonrpc_error(rpc, EOF);
return EOF;
}
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;
+ 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();
+ (poll_immediate_wake)(rpc->name);
} else {
stream_recv_wait(rpc->stream);
}
}
-/* Always takes ownership of 'msg', regardless of success. */
+/* 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)
{
for (;;) {
jsonrpc_run(rpc);
- if (queue_is_empty(&rpc->output) || rpc->status) {
+ if (list_is_empty(&rpc->output) || rpc->status) {
return rpc->status;
}
jsonrpc_wait(rpc);
}
}
+/* 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)
{
}
}
-/* Always takes ownership of 'request', regardless of success. */
+/* 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)
if (!error) {
for (;;) {
error = jsonrpc_recv_block(rpc, &reply);
- if (error
- || (reply->type == JSONRPC_REPLY
- && json_equal(id, reply->id))) {
+ if (error) {
+ break;
+ }
+ if ((reply->type == JSONRPC_REPLY || reply->type == JSONRPC_ERROR)
+ && json_equal(id, reply->id)) {
break;
}
jsonrpc_msg_destroy(reply);
rpc->received = msg;
}
-void
+static void
jsonrpc_error(struct jsonrpc *rpc, int error)
{
- assert(error);
+ ovs_assert(error);
if (!rpc->status) {
rpc->status = error;
jsonrpc_cleanup(rpc);
jsonrpc_msg_destroy(rpc->received);
rpc->received = NULL;
- queue_clear(&rpc->output);
+ ofpbuf_list_delete(&rpc->output);
rpc->backlog = 0;
}
\f
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 and reconnects, with back-off, to 'name'.
+ * 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)
+jsonrpc_session_open(const char *name, bool retry)
{
struct jsonrpc_session *s;
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. */
+ * '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)
+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;
jsonrpc_session_disconnect(s);
if (!reconnect_is_passive(s->reconnect)) {
- error = jsonrpc_stream_open(name, &s->stream);
+ 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);
+ error = s->pstream ? 0 : jsonrpc_pstream_open(name, &s->pstream,
+ s->dscp);
if (!error) {
reconnect_listening(s->reconnect, time_msec());
}
}
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(), 0);
+ reconnect_disconnected(s->reconnect, time_msec(), error);
jsonrpc_session_disconnect(s);
+ s->last_error = error;
}
} else if (s->stream) {
int error;
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)
{
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) {
- 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")) {
+ && 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;
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), 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);
+ }
+}