xref: /freebsd/usr.sbin/ppp/layer.h (revision 60d717baf2144cf344ec9b47d715ce837b5d46d4)
1  /*-
2   * SPDX-License-Identifier: BSD-2-Clause
3   *
4   * Copyright (c) 1999 Brian Somers <brian@Awfulhak.org>
5   * All rights reserved.
6   *
7   * Redistribution and use in source and binary forms, with or without
8   * modification, are permitted provided that the following conditions
9   * are met:
10   * 1. Redistributions of source code must retain the above copyright
11   *    notice, this list of conditions and the following disclaimer.
12   * 2. Redistributions in binary form must reproduce the above copyright
13   *    notice, this list of conditions and the following disclaimer in the
14   *    documentation and/or other materials provided with the distribution.
15   *
16   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26   * SUCH DAMAGE.
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