lib/vconn-provider.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2012, 2013 Nicira, Inc.
   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 "openvswitch/vconn.h"
  24 #include "util.h"
  25 #include "openflow/openflow-common.h"
  26 \f
  27 /* Active virtual connection to an OpenFlow device. */
  28
  29 void vconn_init(struct vconn *, const struct vconn_class *, int connect_status,
  30                 const char *name, uint32_t allowed_versions);
  31 void vconn_free_data(struct vconn *vconn);
  32 static inline void vconn_assert_class(const struct vconn *vconn,
  33                                       const struct vconn_class *vclass)
  34 {
  35     ovs_assert(vconn->vclass == vclass);
  36 }
  37
  38 struct vconn_class {
  39     /* Prefix for connection names, e.g. "nl", "tcp". */
  40     const char *name;
  41
  42     /* Attempts to connect to an OpenFlow device.  'name' is the full
  43      * connection name provided by the user, e.g. "tcp:1.2.3.4".  This name is
  44      * useful for error messages but must not be modified.
  45      *
  46      * 'allowed_versions' is the OpenFlow versions that may be
  47      * negotiated for a connection.
  48      *
  49      * 'suffix' is a copy of 'name' following the colon and may be modified.
  50      * 'dscp' is the DSCP value that the new connection should use in the IP
  51      * packets it sends.
  52      *
  53      * Returns 0 if successful, otherwise a positive errno value.  If
  54      * successful, stores a pointer to the new connection in '*vconnp'.
  55      *
  56      * The open function must not block waiting for a connection to complete.
  57      * If the connection cannot be completed immediately, it should return
  58      * EAGAIN (not EINPROGRESS, as returned by the connect system call) and
  59      * continue the connection in the background. */
  60     int (*open)(const char *name, uint32_t allowed_versions,
  61                 char *suffix, struct vconn **vconnp, uint8_t dscp);
  62
  63     /* Closes 'vconn' and frees associated memory. */
  64     void (*close)(struct vconn *vconn);
  65
  66     /* Tries to complete the connection on 'vconn'.  If 'vconn''s connection is
  67      * complete, returns 0 if the connection was successful or a positive errno
  68      * value if it failed.  If the connection is still in progress, returns
  69      * EAGAIN.
  70      *
  71      * The connect function must not block waiting for the connection to
  72      * complete; instead, it should return EAGAIN immediately. */
  73     int (*connect)(struct vconn *vconn);
  74
  75     /* Tries to receive an OpenFlow message from 'vconn'.  If successful,
  76      * stores the received message into '*msgp' and returns 0.  The caller is
  77      * responsible for destroying the message with ofpbuf_delete().  On
  78      * failure, returns a positive errno value and stores a null pointer into
  79      * '*msgp'.
  80      *
  81      * If the connection has been closed in the normal fashion, returns EOF.
  82      *
  83      * The recv function must not block waiting for a packet to arrive.  If no
  84      * packets have been received, it should return EAGAIN. */
  85     int (*recv)(struct vconn *vconn, struct ofpbuf **msgp);
  86
  87     /* Tries to queue 'msg' for transmission on 'vconn'.  If successful,
  88      * returns 0, in which case ownership of 'msg' is transferred to the vconn.
  89      * Success does not guarantee that 'msg' has been or ever will be delivered
  90      * to the peer, only that it has been queued for transmission.
  91      *
  92      * Returns a positive errno value on failure, in which case the caller
  93      * retains ownership of 'msg'.
  94      *
  95      * The send function must not block.  If 'msg' cannot be immediately
  96      * accepted for transmission, it should return EAGAIN. */
  97     int (*send)(struct vconn *vconn, struct ofpbuf *msg);
  98
  99     /* Allows 'vconn' to perform maintenance activities, such as flushing
 100      * output buffers.
 101      *
 102      * May be null if 'vconn' doesn't have anything to do here. */
 103     void (*run)(struct vconn *vconn);
 104
 105     /* Arranges for the poll loop to wake up when 'vconn' needs to perform
 106      * maintenance activities.
 107      *
 108      * May be null if 'vconn' doesn't have anything to do here. */
 109     void (*run_wait)(struct vconn *vconn);
 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 void pvconn_init(struct pvconn *pvconn, const struct pvconn_class *pvclass,
 119                  const char *name, uint32_t allowed_versions);
 120 static inline void pvconn_assert_class(const struct pvconn *pvconn,
 121                                        const struct pvconn_class *pvclass)
 122 {
 123     ovs_assert(pvconn->pvclass == pvclass);
 124 }
 125
 126 struct pvconn_class {
 127     /* Prefix for connection names, e.g. "ptcp", "pssl". */
 128     const char *name;
 129
 130     /* Attempts to start listening for OpenFlow connections.  'name' is the
 131      * full connection name provided by the user, e.g. "ptcp:1234".  This name
 132      * is useful for error messages but must not be modified.
 133      *
 134      * 'allowed_versions' is the OpenFlow protocol versions that may
 135      * be negotiated for a session.
 136      *
 137      * 'suffix' is a copy of 'name' following the colon and may be modified.
 138      * 'dscp' is the DSCP value that the new connection should use in the IP
 139      * packets it sends.
 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, uint32_t allowed_versions,
 149                   char *suffix, struct pvconn **pvconnp, uint8_t dscp);
 150
 151     /* Closes 'pvconn' and frees associated memory. */
 152     void (*close)(struct pvconn *pvconn);
 153
 154     /* Tries to accept a new connection on 'pvconn'.  If successful, stores the
 155      * new connection in '*new_vconnp' and returns 0.  Otherwise, returns a
 156      * positive errno value.
 157      *
 158      * The accept function must not block waiting for a connection.  If no
 159      * connection is ready to be accepted, it should return EAGAIN. */
 160     int (*accept)(struct pvconn *pvconn, struct vconn **new_vconnp);
 161
 162     /* Arranges for the poll loop to wake up when a connection is ready to be
 163      * accepted on 'pvconn'. */
 164     void (*wait)(struct pvconn *pvconn);
 165 };
 166
 167 /* Active and passive vconn classes. */
 168 extern const struct vconn_class tcp_vconn_class;
 169 extern const struct pvconn_class ptcp_pvconn_class;
 170 extern const struct vconn_class unix_vconn_class;
 171 extern const struct pvconn_class punix_pvconn_class;
 172 #ifdef HAVE_OPENSSL
 173 extern const struct vconn_class ssl_vconn_class;
 174 extern const struct pvconn_class pssl_pvconn_class;
 175 #endif
 176
 177 #endif /* vconn-provider.h */