1 /* Copyright (C) 2007 Board of Trustees, Leland Stanford Jr. University.
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to
5 * deal in the Software without restriction, including without limitation the
6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
32 /* Client interface. */
34 /* Virtual connection to an OpenFlow device. */
36 struct vconn_class *class;
39 /* What kind of operation do we want to perform? */
41 WANT_ACCEPT = 1 << 0, /* Want to accept a new connection. */
42 WANT_RECV = 1 << 1, /* Want to receive a message. */
43 WANT_SEND = 1 << 2 /* Want to send a message. */
46 int vconn_open(const char *name, struct vconn **);
47 void vconn_close(struct vconn *);
48 bool vconn_is_passive(const struct vconn *);
49 bool vconn_prepoll(struct vconn *, int want, struct pollfd *);
50 void vconn_postpoll(struct vconn *, short int *revents);
51 int vconn_accept(struct vconn *, struct vconn **);
52 int vconn_recv(struct vconn *, struct buffer **);
53 int vconn_send(struct vconn *, struct buffer *);
54 int vconn_send_wait(struct vconn *, struct buffer *);
56 struct buffer *make_add_simple_flow(const struct flow *,
57 uint32_t buffer_id, uint16_t out_port);
58 struct buffer *make_buffered_packet_out(uint32_t buffer_id,
59 uint16_t in_port, uint16_t out_port);
60 struct buffer *make_unbuffered_packet_out(const struct buffer *packet,
61 uint16_t in_port, uint16_t out_port);
63 /* Provider interface. */
66 /* Prefix for connection names, e.g. "nl", "tcp". */
69 /* Attempts to connect to an OpenFlow device. 'name' is the full
70 * connection name provided by the user, e.g. "nl:0", "tcp:1.2.3.4". This
71 * name is useful for error messages but must not be modified.
73 * 'suffix' is a copy of 'name' following the colon and may be modified.
75 * Returns 0 if successful, otherwise a positive errno value. If
76 * successful, stores a pointer to the new connection in '*vconnp'. */
77 int (*open)(const char *name, char *suffix, struct vconn **vconnp);
79 /* Closes 'vconn' and frees associated memory. */
80 void (*close)(struct vconn *vconn);
82 /* Called by the main loop before calling poll(), this function must
83 * initialize 'pfd->fd' and 'pfd->events' appropriately so that poll() will
84 * wake up when the connection becomes available for the operations
85 * specified in 'want'. The prepoll function may also set bits in 'pfd' to
86 * allow for internal processing.
88 * Should return false normally. May return true to indicate that no
89 * blocking should happen in poll() because the connection is available for
90 * some operation specified in 'want' but that status cannot be detected
91 * via poll() and thus poll() could block forever otherwise. */
92 bool (*prepoll)(struct vconn *, int want, struct pollfd *pfd);
94 /* Called by the main loop after calling poll(), this function may perform
95 * any internal processing needed by the connection. It is provided with
96 * the vconn file descriptor's status in '*revents', as reported by poll().
98 * The postpoll function should adjust '*revents' to reflect the status of
99 * the connection from the caller's point of view: that is, upon return
100 * '*revents & POLLIN' should indicate that a packet is (potentially) ready
101 * to be read (for an active vconn) or a new connection is ready to be
102 * accepted (for a passive vconn) and '*revents & POLLOUT' should indicate
103 * that a packet is (potentially) ready to be written.
105 * This function may be a null pointer in a vconn class that has no use for
106 * it, that is, if the vconn does not need to do any internal processing
107 * and poll's revents out properly reflects the vconn's status. */
108 void (*postpoll)(struct vconn *, short int *revents);
110 /* Tries to accept a new connection on 'vconn', which must be a passive
111 * vconn. If successful, stores the new connection in '*new_vconnp' and
112 * returns 0. Otherwise, returns a positive errno value.
114 * The accept function must not block waiting for a connection. If no
115 * connection is ready to be accepted, it should return EAGAIN.
117 * Nonnull iff this is a passive vconn (one that accepts connection and
118 * does not transfer data). */
119 int (*accept)(struct vconn *vconn, struct vconn **new_vconnp);
121 /* Tries to receive an OpenFlow message from 'vconn', which must be an
122 * active vconn. If successful, stores the received message into '*msgp'
123 * and returns 0. The caller is responsible for destroying the message
124 * with buffer_delete(). On failure, returns a positive errno value and
125 * stores a null pointer into '*msgp'.
127 * If the connection has been closed in the normal fashion, returns EOF.
129 * The recv function must not block waiting for a packet to arrive. If no
130 * packets have been received, it should return EAGAIN.
132 * Nonnull iff this is an active vconn (one that transfers data and does
133 * not accept connections). */
134 int (*recv)(struct vconn *vconn, struct buffer **msgp);
136 /* Tries to queue 'msg' for transmission on 'vconn', which must be an
137 * active vconn. If successful, returns 0, in which case ownership of
138 * 'msg' is transferred to the vconn. Success does not guarantee that
139 * 'msg' has been or ever will be delivered to the peer, only that it has
140 * been queued for transmission.
142 * Returns a positive errno value on failure, in which case the caller
143 * retains ownership of 'msg'.
145 * The send function must not block. If 'msg' cannot be immediately
146 * accepted for transmission, it should return EAGAIN.
148 * Nonnull iff this is an active vconn (one that transfers data and does
149 * not accept connections). */
150 int (*send)(struct vconn *vconn, struct buffer *msg);
153 extern struct vconn_class tcp_vconn_class;
154 extern struct vconn_class ptcp_vconn_class;
156 extern struct vconn_class ssl_vconn_class;
157 extern struct vconn_class pssl_vconn_class;
160 extern struct vconn_class netlink_vconn_class;