2 * Copyright (c) 2009, 2010, 2012, 2013 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef STREAM_PROVIDER_H
18 #define STREAM_PROVIDER_H 1
20 #include <sys/types.h>
23 /* Active stream connection. */
25 /* Active stream connection.
27 * This structure should be treated as opaque by implementation. */
29 const struct stream_class *class;
35 void stream_init(struct stream *, const struct stream_class *,
36 int connect_status, const char *name);
37 static inline void stream_assert_class(const struct stream *stream,
38 const struct stream_class *class)
40 ovs_assert(stream->class == class);
44 /* Prefix for connection names, e.g. "tcp", "ssl", "unix". */
47 /* True if this stream needs periodic probes to verify connectivity. For
48 * streams which need probes, it can take a long time to notice the
49 * connection was dropped. */
52 /* Attempts to connect to a peer. 'name' is the full connection name
53 * provided by the user, e.g. "tcp:1.2.3.4". This name is useful for error
54 * messages but must not be modified.
56 * 'suffix' is a copy of 'name' following the colon and may be modified.
57 * 'dscp' is the DSCP value that the new connection should use in the IP
60 * Returns 0 if successful, otherwise a positive errno value. If
61 * successful, stores a pointer to the new connection in '*streamp'.
63 * The open function must not block waiting for a connection to complete.
64 * If the connection cannot be completed immediately, it should return
65 * EAGAIN (not EINPROGRESS, as returned by the connect system call) and
66 * continue the connection in the background. */
67 int (*open)(const char *name, char *suffix, struct stream **streamp,
70 /* Closes 'stream' and frees associated memory. */
71 void (*close)(struct stream *stream);
73 /* Tries to complete the connection on 'stream'. If 'stream''s connection
74 * is complete, returns 0 if the connection was successful or a positive
75 * errno value if it failed. If the connection is still in progress,
78 * The connect function must not block waiting for the connection to
79 * complete; instead, it should return EAGAIN immediately. */
80 int (*connect)(struct stream *stream);
82 /* Tries to receive up to 'n' bytes from 'stream' into 'buffer', and
85 * - If successful, the number of bytes received (between 1 and 'n').
87 * - On error, a negative errno value.
89 * - 0, if the connection has been closed in the normal fashion.
91 * The recv function will not be passed a zero 'n'.
93 * The recv function must not block waiting for data to arrive. If no data
94 * have been received, it should return -EAGAIN immediately. */
95 ssize_t (*recv)(struct stream *stream, void *buffer, size_t n);
97 /* Tries to send up to 'n' bytes of 'buffer' on 'stream', and returns:
99 * - If successful, the number of bytes sent (between 1 and 'n').
101 * - On error, a negative errno value.
105 * The send function will not be passed a zero 'n'.
107 * The send function must not block. If no bytes can be immediately
108 * accepted for transmission, it should return -EAGAIN immediately. */
109 ssize_t (*send)(struct stream *stream, const void *buffer, size_t n);
111 /* Allows 'stream' to perform maintenance activities, such as flushing
114 * May be null if 'stream' doesn't have anything to do here. */
115 void (*run)(struct stream *stream);
117 /* Arranges for the poll loop to wake up when 'stream' needs to perform
118 * maintenance activities.
120 * May be null if 'stream' doesn't have anything to do here. */
121 void (*run_wait)(struct stream *stream);
123 /* Arranges for the poll loop to wake up when 'stream' is ready to take an
124 * action of the given 'type'. */
125 void (*wait)(struct stream *stream, enum stream_wait_type type);
128 /* Passive listener for incoming stream connections.
130 * This structure should be treated as opaque by stream implementations. */
132 const struct pstream_class *class;
137 void pstream_init(struct pstream *, const struct pstream_class *, const char *name);
138 void pstream_set_bound_port(struct pstream *, ovs_be16 bound_port);
139 static inline void pstream_assert_class(const struct pstream *pstream,
140 const struct pstream_class *class)
142 ovs_assert(pstream->class == class);
145 struct pstream_class {
146 /* Prefix for connection names, e.g. "ptcp", "pssl", "punix". */
149 /* True if this pstream needs periodic probes to verify connectivity. For
150 * pstreams which need probes, it can take a long time to notice the
151 * connection was dropped. */
154 /* Attempts to start listening for stream connections. 'name' is the full
155 * connection name provided by the user, e.g. "ptcp:1234". This name is
156 * useful for error messages but must not be modified.
158 * 'suffix' is a copy of 'name' following the colon and may be modified.
159 * 'dscp' is the DSCP value that the new connection should use in the IP
162 * Returns 0 if successful, otherwise a positive errno value. If
163 * successful, stores a pointer to the new connection in '*pstreamp'.
165 * The listen function must not block. If the connection cannot be
166 * completed immediately, it should return EAGAIN (not EINPROGRESS, as
167 * returned by the connect system call) and continue the connection in the
169 int (*listen)(const char *name, char *suffix, struct pstream **pstreamp,
172 /* Closes 'pstream' and frees associated memory. */
173 void (*close)(struct pstream *pstream);
175 /* Tries to accept a new connection on 'pstream'. If successful, stores
176 * the new connection in '*new_streamp' and returns 0. Otherwise, returns
177 * a positive errno value.
179 * The accept function must not block waiting for a connection. If no
180 * connection is ready to be accepted, it should return EAGAIN. */
181 int (*accept)(struct pstream *pstream, struct stream **new_streamp);
183 /* Arranges for the poll loop to wake up when a connection is ready to be
184 * accepted on 'pstream'. */
185 void (*wait)(struct pstream *pstream);
187 /* Set DSCP value of the listening socket. */
188 int (*set_dscp)(struct pstream *pstream, uint8_t dscp);
191 /* Active and passive stream classes. */
192 extern const struct stream_class tcp_stream_class;
193 extern const struct pstream_class ptcp_pstream_class;
195 extern const struct stream_class unix_stream_class;
196 extern const struct pstream_class punix_pstream_class;
198 extern const struct stream_class windows_stream_class;
199 extern const struct pstream_class pwindows_pstream_class;
202 extern const struct stream_class ssl_stream_class;
203 extern const struct pstream_class pssl_pstream_class;
206 #endif /* stream-provider.h */