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 "vconn.h"
  24 #include "util.h"
  25 #include "openflow/openflow-common.h"
  26 \f
  27 /* Active virtual connection to an OpenFlow device. */
  28
  29 /* Active virtual connection to an OpenFlow device.
  30  *
  31  * This structure should be treated as opaque by vconn implementations. */
  32 struct vconn {
  33     const struct vconn_class *class;
  34     int state;
  35     int error;
  36
  37     /* OpenFlow versions. */
  38     uint32_t allowed_versions;  /* Bitmap of versions we will accept. */
  39     uint32_t peer_versions;     /* Peer's bitmap of versions it will accept. */
  40     enum ofp_version version;   /* Negotiated version (or 0). */
  41     bool recv_any_version;      /* True to receive a message of any version. */
  42
  43     char *name;
  44 };
  45
  46 void vconn_init(struct vconn *, const struct vconn_class *, int connect_status,
  47                 const char *name, uint32_t allowed_versions);
  48 void vconn_free_data(struct vconn *vconn);
  49 static inline void vconn_assert_class(const struct vconn *vconn,
  50                                       const struct vconn_class *class)
  51 {
  52     ovs_assert(vconn->class == class);
  53 }
  54
  55 struct vconn_class {
  56     /* Prefix for connection names, e.g. "nl", "tcp". */
  57     const char *name;
  58
  59     /* Attempts to connect to an OpenFlow device.  'name' is the full
  60      * connection name provided by the user, e.g. "tcp:1.2.3.4".  This name is
  61      * useful for error messages but must not be modified.
  62      *
  63      * 'allowed_versions' is the OpenFlow versions that may be
  64      * negotiated for a connection.
  65      *
  66      * 'suffix' is a copy of 'name' following the colon and may be modified.
  67      * 'dscp' is the DSCP value that the new connection should use in the IP
  68      * packets it sends.
  69      *
  70      * Returns 0 if successful, otherwise a positive errno value.  If
  71      * successful, stores a pointer to the new connection in '*vconnp'.
  72      *
  73      * The open function must not block waiting for a connection to complete.
  74      * If the connection cannot be completed immediately, it should return
  75      * EAGAIN (not EINPROGRESS, as returned by the connect system call) and
  76      * continue the connection in the background. */
  77     int (*open)(const char *name, uint32_t allowed_versions,
  78                 char *suffix, struct vconn **vconnp, uint8_t dscp);
  79
  80     /* Closes 'vconn' and frees associated memory. */
  81     void (*close)(struct vconn *vconn);
  82
  83     /* Tries to complete the connection on 'vconn'.  If 'vconn''s connection is
  84      * complete, returns 0 if the connection was successful or a positive errno
  85      * value if it failed.  If the connection is still in progress, returns
  86      * EAGAIN.
  87      *
  88      * The connect function must not block waiting for the connection to
  89      * complete; instead, it should return EAGAIN immediately. */
  90     int (*connect)(struct vconn *vconn);
  91
  92     /* Tries to receive an OpenFlow message from 'vconn'.  If successful,
  93      * stores the received message into '*msgp' and returns 0.  The caller is
  94      * responsible for destroying the message with ofpbuf_delete().  On
  95      * failure, returns a positive errno value and stores a null pointer into
  96      * '*msgp'.
  97      *
  98      * If the connection has been closed in the normal fashion, returns EOF.
  99      *
 100      * The recv function must not block waiting for a packet to arrive.  If no
 101      * packets have been received, it should return EAGAIN. */
 102     int (*recv)(struct vconn *vconn, struct ofpbuf **msgp);
 103
 104     /* Tries to queue 'msg' for transmission on 'vconn'.  If successful,
 105      * returns 0, in which case ownership of 'msg' is transferred to the vconn.
 106      * Success does not guarantee that 'msg' has been or ever will be delivered
 107      * to the peer, only that it has been queued for transmission.
 108      *
 109      * Returns a positive errno value on failure, in which case the caller
 110      * retains ownership of 'msg'.
 111      *
 112      * The send function must not block.  If 'msg' cannot be immediately
 113      * accepted for transmission, it should return EAGAIN. */
 114     int (*send)(struct vconn *vconn, struct ofpbuf *msg);
 115
 116     /* Allows 'vconn' to perform maintenance activities, such as flushing
 117      * output buffers.
 118      *
 119      * May be null if 'vconn' doesn't have anything to do here. */
 120     void (*run)(struct vconn *vconn);
 121
 122     /* Arranges for the poll loop to wake up when 'vconn' needs to perform
 123      * maintenance activities.
 124      *
 125      * May be null if 'vconn' doesn't have anything to do here. */
 126     void (*run_wait)(struct vconn *vconn);
 127
 128     /* Arranges for the poll loop to wake up when 'vconn' is ready to take an
 129      * action of the given 'type'. */
 130     void (*wait)(struct vconn *vconn, enum vconn_wait_type type);
 131 };
 132 \f
 133 /* Passive virtual connection to an OpenFlow device.
 134  *
 135  * This structure should be treated as opaque by vconn implementations. */
 136 struct pvconn {
 137     const struct pvconn_class *class;
 138     char *name;
 139     uint32_t allowed_versions;
 140 };
 141
 142 void pvconn_init(struct pvconn *pvconn, const struct pvconn_class *class,
 143                  const char *name, uint32_t allowed_versions);
 144 static inline void pvconn_assert_class(const struct pvconn *pvconn,
 145                                        const struct pvconn_class *class)
 146 {
 147     ovs_assert(pvconn->class == class);
 148 }
 149
 150 struct pvconn_class {
 151     /* Prefix for connection names, e.g. "ptcp", "pssl". */
 152     const char *name;
 153
 154     /* Attempts to start listening for OpenFlow connections.  'name' is the
 155      * full connection name provided by the user, e.g. "ptcp:1234".  This name
 156      * is useful for error messages but must not be modified.
 157      *
 158      * 'allowed_versions' is the OpenFlow protocol versions that may
 159      * be negotiated for a session.
 160      *
 161      * 'suffix' is a copy of 'name' following the colon and may be modified.
 162      * 'dscp' is the DSCP value that the new connection should use in the IP
 163      * packets it sends.
 164      *
 165      * Returns 0 if successful, otherwise a positive errno value.  If
 166      * successful, stores a pointer to the new connection in '*pvconnp'.
 167      *
 168      * The listen function must not block.  If the connection cannot be
 169      * completed immediately, it should return EAGAIN (not EINPROGRESS, as
 170      * returned by the connect system call) and continue the connection in the
 171      * background. */
 172     int (*listen)(const char *name, uint32_t allowed_versions,
 173                   char *suffix, struct pvconn **pvconnp, uint8_t dscp);
 174
 175     /* Closes 'pvconn' and frees associated memory. */
 176     void (*close)(struct pvconn *pvconn);
 177
 178     /* Tries to accept a new connection on 'pvconn'.  If successful, stores the
 179      * new connection in '*new_vconnp' and returns 0.  Otherwise, returns a
 180      * positive errno value.
 181      *
 182      * The accept function must not block waiting for a connection.  If no
 183      * connection is ready to be accepted, it should return EAGAIN. */
 184     int (*accept)(struct pvconn *pvconn, struct vconn **new_vconnp);
 185
 186     /* Arranges for the poll loop to wake up when a connection is ready to be
 187      * accepted on 'pvconn'. */
 188     void (*wait)(struct pvconn *pvconn);
 189 };
 190
 191 /* Active and passive vconn classes. */
 192 extern const struct vconn_class tcp_vconn_class;
 193 extern const struct pvconn_class ptcp_pvconn_class;
 194 extern const struct vconn_class unix_vconn_class;
 195 extern const struct pvconn_class punix_pvconn_class;
 196 #ifdef HAVE_OPENSSL
 197 extern const struct vconn_class ssl_vconn_class;
 198 extern const struct pvconn_class pssl_pvconn_class;
 199 #endif
 200
 201 #endif /* vconn-provider.h */