lib/vconn-provider.h

   1 /*
   2  * Copyright (c) 2008, 2009 Nicira Networks.
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  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 ip;
  38     char *name;
  39     bool reconnectable;
  40 };
  41
  42 void vconn_init(struct vconn *, struct vconn_class *, int connect_status,
  43                 uint32_t ip, const char *name, bool reconnectable);
  44 static inline void vconn_assert_class(const struct vconn *vconn,
  45                                       const struct vconn_class *class)
  46 {
  47     assert(vconn->class == class);
  48 }
  49
  50 struct vconn_class {
  51     /* Prefix for connection names, e.g. "nl", "tcp". */
  52     const char *name;
  53
  54     /* Attempts to connect to an OpenFlow device.  'name' is the full
  55      * connection name provided by the user, e.g. "tcp:1.2.3.4".  This name is
  56      * useful for error messages but must not be modified.
  57      *
  58      * 'suffix' is a copy of 'name' following the colon and may be modified.
  59      *
  60      * Returns 0 if successful, otherwise a positive errno value.  If
  61      * successful, stores a pointer to the new connection in '*vconnp'.
  62      *
  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 vconn **vconnp);
  68
  69     /* Closes 'vconn' and frees associated memory. */
  70     void (*close)(struct vconn *vconn);
  71
  72     /* Tries to complete the connection on 'vconn'.  If 'vconn''s connection is
  73      * complete, returns 0 if the connection was successful or a positive errno
  74      * value if it failed.  If the connection is still in progress, returns
  75      * EAGAIN.
  76      *
  77      * The connect function must not block waiting for the connection to
  78      * complete; instead, it should return EAGAIN immediately. */
  79     int (*connect)(struct vconn *vconn);
  80
  81     /* Tries to receive an OpenFlow message from 'vconn'.  If successful,
  82      * stores the received message into '*msgp' and returns 0.  The caller is
  83      * responsible for destroying the message with ofpbuf_delete().  On
  84      * failure, returns a positive errno value and stores a null pointer into
  85      * '*msgp'.
  86      *
  87      * If the connection has been closed in the normal fashion, returns EOF.
  88      *
  89      * The recv function must not block waiting for a packet to arrive.  If no
  90      * packets have been received, it should return EAGAIN. */
  91     int (*recv)(struct vconn *vconn, struct ofpbuf **msgp);
  92
  93     /* Tries to queue 'msg' for transmission on 'vconn'.  If successful,
  94      * returns 0, in which case ownership of 'msg' is transferred to the vconn.
  95      * Success does not guarantee that 'msg' has been or ever will be delivered
  96      * to the peer, only that it has been queued for transmission.
  97      *
  98      * Returns a positive errno value on failure, in which case the caller
  99      * retains ownership of 'msg'.
 100      *
 101      * The send function must not block.  If 'msg' cannot be immediately
 102      * accepted for transmission, it should return EAGAIN. */
 103     int (*send)(struct vconn *vconn, struct ofpbuf *msg);
 104
 105     /* Arranges for the poll loop to wake up when 'vconn' is ready to take an
 106      * action of the given 'type'. */
 107     void (*wait)(struct vconn *vconn, enum vconn_wait_type type);
 108 };
 109 \f
 110 /* Passive virtual connection to an OpenFlow device.
 111  *
 112  * This structure should be treated as opaque by vconn implementations. */
 113 struct pvconn {
 114     struct pvconn_class *class;
 115     char *name;
 116 };
 117
 118 void pvconn_init(struct pvconn *, struct pvconn_class *, const char *name);
 119 static inline void pvconn_assert_class(const struct pvconn *pvconn,
 120                                        const struct pvconn_class *class)
 121 {
 122     assert(pvconn->class == class);
 123 }
 124
 125 struct pvconn_class {
 126     /* Prefix for connection names, e.g. "ptcp", "pssl". */
 127     const char *name;
 128
 129     /* Attempts to start listening for OpenFlow connections.  'name' is the
 130      * full connection name provided by the user, e.g. "ptcp:1234".  This name
 131      * is useful for error messages but must not be modified.
 132      *
 133      * 'suffix' is a copy of 'name' following the colon and may be modified.
 134      *
 135      * Returns 0 if successful, otherwise a positive errno value.  If
 136      * successful, stores a pointer to the new connection in '*pvconnp'.
 137      *
 138      * The listen function must not block.  If the connection cannot be
 139      * completed immediately, it should return EAGAIN (not EINPROGRESS, as
 140      * returned by the connect system call) and continue the connection in the
 141      * background. */
 142     int (*listen)(const char *name, char *suffix, struct pvconn **pvconnp);
 143
 144     /* Closes 'pvconn' and frees associated memory. */
 145     void (*close)(struct pvconn *pvconn);
 146
 147     /* Tries to accept a new connection on 'pvconn'.  If successful, stores the
 148      * new connection in '*new_vconnp' and returns 0.  Otherwise, returns a
 149      * positive errno value.
 150      *
 151      * The accept function must not block waiting for a connection.  If no
 152      * connection is ready to be accepted, it should return EAGAIN. */
 153     int (*accept)(struct pvconn *pvconn, struct vconn **new_vconnp);
 154
 155     /* Arranges for the poll loop to wake up when a connection is ready to be
 156      * accepted on 'pvconn'. */
 157     void (*wait)(struct pvconn *pvconn);
 158 };
 159
 160 /* Active and passive vconn classes. */
 161 extern struct vconn_class tcp_vconn_class;
 162 extern struct pvconn_class ptcp_pvconn_class;
 163 extern struct vconn_class unix_vconn_class;
 164 extern struct pvconn_class punix_pvconn_class;
 165 #ifdef HAVE_OPENSSL
 166 extern struct vconn_class ssl_vconn_class;
 167 extern struct pvconn_class pssl_pvconn_class;
 168 #endif
 169
 170 #endif /* vconn-provider.h */