xref: /freebsd/usr.sbin/ppp/layer.h (revision f0a75d274af375d15b97b830966b99a02b7db911)
1 /*-
2  * Copyright (c) 1999 Brian Somers <brian@Awfulhak.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #define	LAYER_ASYNC	2
30 #define	LAYER_SYNC	3
31 #define	LAYER_HDLC	4
32 #define	LAYER_ACF	5
33 #define	LAYER_PROTO	6
34 #define	LAYER_LQR	7
35 #define	LAYER_CCP	8
36 #define	LAYER_VJ	9
37 #define	LAYER_NAT	10
38 
39 #define	LAYER_MAX	10	/* How many layers we can handle on a link */
40 
41 struct mbuf;
42 struct link;
43 struct bundle;
44 
45 struct layer {
46   int type;
47   const char *name;
48   struct mbuf *(*push)(struct bundle *, struct link *, struct mbuf *,
49                        int pri, u_short *proto);
50   struct mbuf *(*pull)(struct bundle *, struct link *, struct mbuf *,
51                        u_short *);
52 };
53