lib/vconn-provider.h

   1 /*
   2  * Copyright (c) 2008, 2009 Nicira Networks.
   3  *
   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:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  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.
  15  */
  16
  17 #ifndef VCONN_PROVIDER_H
  18 #define VCONN_PROVIDER_H 1
  19
  20 /* Provider interface to vconns, which provide a virtual connection to an
  21  * OpenFlow device. */
  22
  23 #include <assert.h>
  24 #include "vconn.h"
  25 \f
  26 /* Active virtual connection to an OpenFlow device. */
  27
  28 /* Active virtual connection to an OpenFlow device.
  29  *
  30  * This structure should be treated as opaque by vconn implementations. */
  31 struct vconn {
  32     struct vconn_class *class;
  33     int state;
  34     int error;
  35     int min_version;
  36     int version;
  37     uint32_t remote_ip;
  38     uint16_t remote_port;
  39     uint32_t local_ip;
  40     uint16_t local_port;
  41     char *name;
  42 };
  43
  44 void vconn_init(struct vconn *, struct vconn_class *, int connect_status,
  45                 const char *name);
  46 void vconn_set_remote_ip(struct vconn *, uint32_t remote_ip);
  47 void vconn_set_remote_port(struct vconn *, uint16_t remote_port);
  48 void vconn_set_local_ip(struct vconn *, uint32_t local_ip);
  49 void vconn_set_local_port(struct vconn *, uint16_t local_port);
  50 static inline void vconn_assert_class(const struct vconn *vconn,
  51                                       const struct vconn_class *class)
  52 {
  53     assert(vconn->class == class);
  54 }
  55
  56 struct vconn_class {
  57     /* Prefix for connection names, e.g. "nl", "tcp". */
  58     const char *name;
  59
  60     /* Attempts to connect to an OpenFlow device.  'name' is the full
  61      * connection name provided by the user, e.g. "tcp:1.2.3.4".  This name is
  62      * useful for error messages but must not be modified.
  63      *
  64      * 'suffix' is a copy of 'name' following the colon and may be modified.
  65      *
  66      * Returns 0 if successful, otherwise a positive errno value.  If
  67      * successful, stores a pointer to the new connection in '*vconnp'.
  68      *
  69      * The open function must not block waiting for a connection to complete.
  70      * If the connection cannot be completed immediately, it should return
  71      * EAGAIN (not EINPROGRESS, as returned by the connect system call) and
  72      * continue the connection in the background. */
  73     int (*open)(const char *name, char *suffix, struct vconn **vconnp);
  74
  75     /* Closes 'vconn' and frees associated memory. */
  76     void (*close)(struct vconn *vconn);
  77
  78     /* Tries to complete the connection on 'vconn'.  If 'vconn''s connection is
  79      * complete, returns 0 if the connection was successful or a positive errno
  80      * value if it failed.  If the connection is still in progress, returns
  81      * EAGAIN.
  82      *
  83      * The connect function must not block waiting for the connection to
  84      * complete; instead, it should return EAGAIN immediately. */
  85     int (*connect)(struct vconn *vconn);
  86
  87     /* Tries to receive an OpenFlow message from 'vconn'.  If successful,
  88      * stores the received message into '*msgp' and returns 0.  The caller is
  89      * responsible for destroying the message with ofpbuf_delete().  On
  90      * failure, returns a positive errno value and stores a null pointer into
  91      * '*msgp'.
  92      *
  93      * If the connection has been closed in the normal fashion, returns EOF.
  94      *
  95      * The recv function must not block waiting for a packet to arrive.  If no
  96      * packets have been received, it should return EAGAIN. */
  97     int (*recv)(struct vconn *vconn, struct ofpbuf **msgp);
  98
  99     /* Tries to queue 'msg' for transmission on 'vconn'.  If successful,
 100      * returns 0, in which case ownership of 'msg' is transferred to the vconn.
 101      * Success does not guarantee that 'msg' has been or ever will be delivered
 102      * to the peer, only that it has been queued for transmission.
 103      *
 104      * Returns a positive errno value on failure, in which case the caller
 105      * retains ownership of 'msg'.
 106      *
 107      * The send function must not block.  If 'msg' cannot be immediately
 108      * accepted for transmission, it should return EAGAIN. */
 109     int (*send)(struct vconn *vconn, struct ofpbuf *msg);
 110
 111     /* Arranges for the poll loop to wake up when 'vconn' is ready to take an
 112      * action of the given 'type'. */
 113     void (*wait)(struct vconn *vconn, enum vconn_wait_type type);
 114 };
 115 \f
 116 /* Passive virtual connection to an OpenFlow device.
 117  *
 118  * This structure should be treated as opaque by vconn implementations. */
 119 struct pvconn {
 120     struct pvconn_class *class;
 121     char *name;
 122 };
 123
 124 void pvconn_init(struct pvconn *, struct pvconn_class *, const char *name);
 125 static inline void pvconn_assert_class(const struct pvconn *pvconn,
 126                                        const struct pvconn_class *class)
 127 {
 128     assert(pvconn->class == class);
 129 }
 130
 131 struct pvconn_class {
 132     /* Prefix for connection names, e.g. "ptcp", "pssl". */
 133     const char *name;
 134
 135     /* Attempts to start listening for OpenFlow connections.  'name' is the
 136      * full connection name provided by the user, e.g. "ptcp:1234".  This name
 137      * is useful for error messages but must not be modified.
 138      *
 139      * 'suffix' is a copy of 'name' following the colon and may be modified.
 140      *
 141      * Returns 0 if successful, otherwise a positive errno value.  If
 142      * successful, stores a pointer to the new connection in '*pvconnp'.
 143      *
 144      * The listen function must not block.  If the connection cannot be
 145      * completed immediately, it should return EAGAIN (not EINPROGRESS, as
 146      * returned by the connect system call) and continue the connection in the
 147      * background. */
 148     int (*listen)(const char *name, char *suffix, struct pvconn **pvconnp);
 149
 150     /* Closes 'pvconn' and frees associated memory. */
 151     void (*close)(struct pvconn *pvconn);
 152
 153     /* Tries to accept a new connection on 'pvconn'.  If successful, stores the
 154      * new connection in '*new_vconnp' and returns 0.  Otherwise, returns a
 155      * positive errno value.
 156      *
 157      * The accept function must not block waiting for a connection.  If no
 158      * connection is ready to be accepted, it should return EAGAIN. */
 159     int (*accept)(struct pvconn *pvconn, struct vconn **new_vconnp);
 160
 161     /* Arranges for the poll loop to wake up when a connection is ready to be
 162      * accepted on 'pvconn'. */
 163     void (*wait)(struct pvconn *pvconn);
 164 };
 165
 166 /* Active and passive vconn classes. */
 167 extern struct vconn_class tcp_vconn_class;
 168 extern struct pvconn_class ptcp_pvconn_class;
 169 extern struct vconn_class unix_vconn_class;
 170 extern struct pvconn_class punix_pvconn_class;
 171 #ifdef HAVE_OPENSSL
 172 extern struct vconn_class ssl_vconn_class;
 173 extern struct pvconn_class pssl_pvconn_class;
 174 #endif
 175
 176 #endif /* vconn-provider.h */