lib/vconn-provider.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2012, 2013, 2015 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 /* This structure should be treated as opaque by vconn implementations. */
  30 struct vconn {
  31     const struct vconn_class *vclass;
  32     int state;
  33     int error;
  34
  35     /* OpenFlow versions. */
  36     uint32_t allowed_versions;  /* Bitmap of versions we will accept. */
  37     uint32_t peer_versions;     /* Peer's bitmap of versions it will accept. */
  38     enum ofp_version version;   /* Negotiated version (or 0). */
  39     bool recv_any_version;      /* True to receive a message of any version. */
  40
  41     char *name;
  42 };
  43
  44 void vconn_init(struct vconn *, const struct vconn_class *, int connect_status,
  45                 const char *name, uint32_t allowed_versions);
  46 void vconn_free_data(struct vconn *vconn);
  47 static inline void vconn_assert_class(const struct vconn *vconn,
  48                                       const struct vconn_class *vclass)
  49 {
  50     ovs_assert(vconn->vclass == vclass);
  51 }
  52
  53 struct vconn_class {
  54     /* Prefix for connection names, e.g. "nl", "tcp". */
  55     const char *name;
  56
  57     /* Attempts to connect to an OpenFlow device.  'name' is the full
  58      * connection name provided by the user, e.g. "tcp:1.2.3.4".  This name is
  59      * useful for error messages but must not be modified.
  60      *
  61      * 'allowed_versions' is the OpenFlow versions that may be
  62      * negotiated for a connection.
  63      *
  64      * 'suffix' is a copy of 'name' following the colon and may be modified.
  65      * 'dscp' is the DSCP value that the new connection should use in the IP
  66      * packets it sends.
  67      *
  68      * Returns 0 if successful, otherwise a positive errno value.  If
  69      * successful, stores a pointer to the new connection in '*vconnp'.
  70      *
  71      * The open function must not block waiting for a connection to complete.
  72      * If the connection cannot be completed immediately, it should return
  73      * EAGAIN (not EINPROGRESS, as returned by the connect system call) and
  74      * continue the connection in the background. */
  75     int (*open)(const char *name, uint32_t allowed_versions,
  76                 char *suffix, struct vconn **vconnp, uint8_t dscp);
  77
  78     /* Closes 'vconn' and frees associated memory. */
  79     void (*close)(struct vconn *vconn);
  80
  81     /* Tries to complete the connection on 'vconn'.  If 'vconn''s connection is
  82      * complete, returns 0 if the connection was successful or a positive errno
  83      * value if it failed.  If the connection is still in progress, returns
  84      * EAGAIN.
  85      *
  86      * The connect function must not block waiting for the connection to
  87      * complete; instead, it should return EAGAIN immediately. */
  88     int (*connect)(struct vconn *vconn);
  89
  90     /* Tries to receive an OpenFlow message from 'vconn'.  If successful,
  91      * stores the received message into '*msgp' and returns 0.  The caller is
  92      * responsible for destroying the message with ofpbuf_delete().  On
  93      * failure, returns a positive errno value and stores a null pointer into
  94      * '*msgp'.
  95      *
  96      * If the connection has been closed in the normal fashion, returns EOF.
  97      *
  98      * The recv function must not block waiting for a packet to arrive.  If no
  99      * packets have been received, it should return EAGAIN. */
 100     int (*recv)(struct vconn *vconn, struct ofpbuf **msgp);
 101
 102     /* Tries to queue 'msg' for transmission on 'vconn'.  If successful,
 103      * returns 0, in which case ownership of 'msg' is transferred to the vconn.
 104      * Success does not guarantee that 'msg' has been or ever will be delivered
 105      * to the peer, only that it has been queued for transmission.
 106      *
 107      * Returns a positive errno value on failure, in which case the caller
 108      * retains ownership of 'msg'.
 109      *
 110      * The send function must not block.  If 'msg' cannot be immediately
 111      * accepted for transmission, it should return EAGAIN. */
 112     int (*send)(struct vconn *vconn, struct ofpbuf *msg);
 113
 114     /* Allows 'vconn' to perform maintenance activities, such as flushing
 115      * output buffers.
 116      *
 117      * May be null if 'vconn' doesn't have anything to do here. */
 118     void (*run)(struct vconn *vconn);
 119
 120     /* Arranges for the poll loop to wake up when 'vconn' needs to perform
 121      * maintenance activities.
 122      *
 123      * May be null if 'vconn' doesn't have anything to do here. */
 124     void (*run_wait)(struct vconn *vconn);
 125
 126     /* Arranges for the poll loop to wake up when 'vconn' is ready to take an
 127      * action of the given 'type'. */
 128     void (*wait)(struct vconn *vconn, enum vconn_wait_type type);
 129 };
 130 \f
 131 /* Passive virtual connection to an OpenFlow device. */
 132
 133 /* This structure should be treated as opaque by vconn implementations. */
 134 struct pvconn {
 135     const struct pvconn_class *pvclass;
 136     char *name;
 137     uint32_t allowed_versions;
 138 };
 139 void pvconn_init(struct pvconn *pvconn, const struct pvconn_class *pvclass,
 140                  const char *name, uint32_t allowed_versions);
 141 static inline void pvconn_assert_class(const struct pvconn *pvconn,
 142                                        const struct pvconn_class *pvclass)
 143 {
 144     ovs_assert(pvconn->pvclass == pvclass);
 145 }
 146
 147 struct pvconn_class {
 148     /* Prefix for connection names, e.g. "ptcp", "pssl". */
 149     const char *name;
 150
 151     /* Attempts to start listening for OpenFlow connections.  'name' is the
 152      * full connection name provided by the user, e.g. "ptcp:1234".  This name
 153      * is useful for error messages but must not be modified.
 154      *
 155      * 'allowed_versions' is the OpenFlow protocol versions that may
 156      * be negotiated for a session.
 157      *
 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
 160      * packets it sends.
 161      *
 162      * Returns 0 if successful, otherwise a positive errno value.  If
 163      * successful, stores a pointer to the new connection in '*pvconnp'.
 164      *
 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
 168      * background. */
 169     int (*listen)(const char *name, uint32_t allowed_versions,
 170                   char *suffix, struct pvconn **pvconnp, uint8_t dscp);
 171
 172     /* Closes 'pvconn' and frees associated memory. */
 173     void (*close)(struct pvconn *pvconn);
 174
 175     /* Tries to accept a new connection on 'pvconn'.  If successful, stores the
 176      * new connection in '*new_vconnp' and returns 0.  Otherwise, returns a
 177      * positive errno value.
 178      *
 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 pvconn *pvconn, struct vconn **new_vconnp);
 182
 183     /* Arranges for the poll loop to wake up when a connection is ready to be
 184      * accepted on 'pvconn'. */
 185     void (*wait)(struct pvconn *pvconn);
 186 };
 187
 188 /* Active and passive vconn classes. */
 189 extern const struct vconn_class tcp_vconn_class;
 190 extern const struct pvconn_class ptcp_pvconn_class;
 191 extern const struct vconn_class unix_vconn_class;
 192 extern const struct pvconn_class punix_pvconn_class;
 193 #ifdef HAVE_OPENSSL
 194 extern const struct vconn_class ssl_vconn_class;
 195 extern const struct pvconn_class pssl_pvconn_class;
 196 #endif
 197
 198 #endif /* vconn-provider.h */