xref: /openbsd/sys/net/if_gre.h (revision 097a140d)
1 /*      $OpenBSD: if_gre.h,v 1.16 2021/03/10 10:21:48 jsg Exp $ */
2 /*	$NetBSD: if_gre.h,v 1.5 1999/11/19 20:41:19 thorpej Exp $ */
3 
4 /*
5  * Copyright (c) 1998 The NetBSD Foundation, Inc.
6  * All rights reserved
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Heiko W.Rupp <hwr@pilhuhn.de>
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #ifndef _NET_IF_GRE_H
34 #define _NET_IF_GRE_H
35 
36 struct gre_h {
37 	u_int16_t flags;	/* GRE flags */
38 	u_int16_t ptype;	/* protocol type of payload typically
39                                Ether protocol type*/
40 /*
41  *  from here on: fields are optional, presence indicated by flags
42  *
43 	u_int_16 checksum	 checksum (one-complements of GRE header
44                              and payload
45                              Present if (ck_pres | rt_pres == 1).
46                              Valid if (ck_pres == 1).
47 	u_int_16 offset			 offset from start of routing filed to
48                              first octet of active SRE (see below).
49                              Present if (ck_pres | rt_pres == 1).
50                              Valid if (rt_pres == 1).
51 	u_int_32 key         inserted by encapsulator e.g. for
52                              authentication
53                              Present if (key_pres ==1 ).
54 	u_int_32 seq_num     Sequence number to allow for packet order
55                              Present if (seq_pres ==1 ).
56 
57     struct gre_sre[] routing Routing fields (see below)
58                              Present if (rt_pres == 1)
59 */
60 } __packed;
61 
62 struct greip {
63 	struct ip gi_i;
64 	struct gre_h  gi_g;
65 } __packed;
66 
67 #define gi_pr           gi_i.ip_p
68 #define gi_len          gi_i.ip_len
69 #define gi_src          gi_i.ip_src
70 #define gi_dst          gi_i.ip_dst
71 #define gi_ptype	gi_g.ptype
72 #define gi_flags	gi_g.flags
73 
74 #define GRE_CP          0x8000  /* Checksum Present */
75 #define GRE_RP          0x4000  /* Routing Present */
76 #define GRE_KP          0x2000  /* Key Present */
77 #define GRE_SP          0x1000  /* Sequence Present */
78 #define GRE_SS		0x0800	/* Strict Source Route */
79 
80 /* gre_sre defines a Source route Entry. These are needed if packets
81  *  should be routed over more than one tunnel hop by hop
82  */
83 
84 struct gre_sre {
85 	u_int16_t sre_family;	/* address family */
86 	u_char  sre_offset;	/* offset to first octet of active entry */
87 	u_char  sre_length;	/* number of octets in the SRE.
88                                sre_lengthl==0 -> last entry. */
89 	u_char  *sre_rtinfo;	/* the routing information */
90 };
91 
92 struct greioctl {
93 	int unit;
94 	struct    in_addr addr;
95 };
96 
97 /* for mobile encaps */
98 
99 struct mobile_h {
100 	u_int16_t proto;		/* protocol and S-bit */
101 	u_int16_t hcrc;			/* header checksum */
102 	u_int32_t odst;			/* original destination address */
103 	u_int32_t osrc;			/* original source addr, if S-bit set */
104 } __packed;
105 
106 struct mobip_h {
107 	struct ip       mi;
108 	struct mobile_h mh;
109 } __packed;
110 
111 
112 #define MOB_H_SIZ_S		(sizeof(struct mobile_h) - sizeof(u_int32_t))
113 #define MOB_H_SIZ_L		(sizeof(struct mobile_h))
114 #define MOB_H_SBIT	0x0080
115 
116 #ifdef _KERNEL
117 int	gre_sysctl(int *, u_int, void *, size_t *, void *, size_t);
118 int	gre_input(struct mbuf **, int *, int, int);
119 int	gre_input6(struct mbuf **, int *, int, int);
120 #endif
121 #endif /* _NET_IF_GRE_H_ */
122