X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fjsonrpc.c;h=4ebff104a96180136b4c31b214b5eb2b7c8ec04e;hb=f30ed558723fa94d6da72d1ef3cf0ce3910f6552;hp=13ec4257d573477e1f8aca1c10da7e7537f6de66;hpb=41630cfbc3230ee48d6b4031ec6cffba2cbb3d10;p=sliver-openvswitch.git

diff --git a/lib/jsonrpc.c b/lib/jsonrpc.c
index 13ec4257d..4ebff104a 100644
--- a/lib/jsonrpc.c
+++ b/lib/jsonrpc.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2010 Nicira Networks.
+ * Copyright (c) 2009, 2010, 2011, 2012 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,13 +28,12 @@
 #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);
 
 struct jsonrpc {
     struct stream *stream;
@@ -47,7 +46,7 @@ struct jsonrpc {
     struct jsonrpc_msg *received;
 
     /* Output. */
-    struct ovs_queue output;
+    struct list output;         /* Contains "struct ofpbuf"s. */
     size_t backlog;
 };
 
@@ -56,25 +55,29 @@ 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)
+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)
 {
@@ -86,11 +89,13 @@ jsonrpc_open(struct stream *stream)
     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)
 {
@@ -101,6 +106,7 @@ jsonrpc_close(struct jsonrpc *rpc)
     }
 }
 
+/* Performs periodic maintenance on 'rpc', such as flushing output buffers. */
 void
 jsonrpc_run(struct jsonrpc *rpc)
 {
@@ -109,8 +115,8 @@ 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);
@@ -118,7 +124,8 @@ jsonrpc_run(struct jsonrpc *rpc)
             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) {
@@ -131,29 +138,48 @@ jsonrpc_run(struct jsonrpc *rpc)
     }
 }
 
+/* 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 '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)
 {
@@ -191,7 +217,15 @@ jsonrpc_log_msg(const struct jsonrpc *rpc, const char *title,
     }
 }
 
-/* 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)
 {
@@ -215,25 +249,47 @@ 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;
 
@@ -249,7 +305,6 @@ jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp)
                     return rpc->status;
                 }
             } else if (retval == 0) {
-                VLOG_INFO_RL(&rl, "%s: connection closed", rpc->name);
                 jsonrpc_error(rpc, EOF);
                 return EOF;
             }
@@ -279,22 +334,26 @@ jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp)
         }
     }
 
-    *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)
 {
@@ -309,7 +368,7 @@ 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);
@@ -317,6 +376,8 @@ jsonrpc_send_block(struct jsonrpc *rpc, struct jsonrpc_msg *msg)
     }
 }
 
+/* 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)
 {
@@ -334,7 +395,15 @@ 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)
@@ -348,9 +417,11 @@ jsonrpc_transact_block(struct jsonrpc *rpc, struct jsonrpc_msg *request,
     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);
@@ -391,7 +462,7 @@ jsonrpc_received(struct jsonrpc *rpc)
     rpc->received = msg;
 }
 
-void
+static void
 jsonrpc_error(struct jsonrpc *rpc, int error)
 {
     assert(error);
@@ -413,7 +484,7 @@ jsonrpc_cleanup(struct jsonrpc *rpc)
     jsonrpc_msg_destroy(rpc->received);
     rpc->received = NULL;
 
-    queue_clear(&rpc->output);
+    ofpbuf_list_delete(&rpc->output);
     rpc->backlog = 0;
 }
 
@@ -667,6 +738,7 @@ struct jsonrpc_session {
     struct stream *stream;
     struct pstream *pstream;
     unsigned int seqno;
+    uint8_t dscp;
 };
 
 /* Creates and returns a jsonrpc_session to 'name', which should be a string
@@ -692,16 +764,24 @@ jsonrpc_session_open(const char *name)
     s->stream = NULL;
     s->pstream = NULL;
     s->seqno = 0;
+    s->dscp = 0;
 
     if (!pstream_verify_name(name)) {
         reconnect_set_passive(s->reconnect, true, time_msec());
     }
 
+    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)
 {
@@ -709,6 +789,7 @@ jsonrpc_session_open_unreliably(struct jsonrpc *jsonrpc)
 
     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());
@@ -755,12 +836,13 @@ jsonrpc_session_connect(struct jsonrpc_session *s)
 
     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 {
-        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());
         }
@@ -867,6 +949,8 @@ 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)
 {
@@ -900,8 +984,8 @@ jsonrpc_session_recv(struct jsonrpc_session *s)
                 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;
@@ -938,8 +1022,41 @@ 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;
+}
+
+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)
+{
+    s->dscp = dscp;
+}