1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		Definitions for the IP protocol.
7  *
8  * Version:	@(#)ip.h	1.0.2	04/28/93
9  *
10  * Authors:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11  *
12  *		This program is free software; you can redistribute it and/or
13  *		modify it under the terms of the GNU General Public License
14  *		as published by the Free Software Foundation; either version
15  *		2 of the License, or (at your option) any later version.
16  */
17 #ifndef _LINUX_IP_H
18 #define _LINUX_IP_H
19 #include <linux/types.h>
20 #include <asm/byteorder.h>
21 
22 #define IPTOS_TOS_MASK		0x1E
23 #define IPTOS_TOS(tos)		((tos)&IPTOS_TOS_MASK)
24 #define	IPTOS_LOWDELAY		0x10
25 #define	IPTOS_THROUGHPUT	0x08
26 #define	IPTOS_RELIABILITY	0x04
27 #define	IPTOS_MINCOST		0x02
28 
29 #define IPTOS_PREC_MASK		0xE0
30 #define IPTOS_PREC(tos)		((tos)&IPTOS_PREC_MASK)
31 #define IPTOS_PREC_NETCONTROL           0xe0
32 #define IPTOS_PREC_INTERNETCONTROL      0xc0
33 #define IPTOS_PREC_CRITIC_ECP           0xa0
34 #define IPTOS_PREC_FLASHOVERRIDE        0x80
35 #define IPTOS_PREC_FLASH                0x60
36 #define IPTOS_PREC_IMMEDIATE            0x40
37 #define IPTOS_PREC_PRIORITY             0x20
38 #define IPTOS_PREC_ROUTINE              0x00
39 
40 
41 /* IP options */
42 #define IPOPT_COPY		0x80
43 #define IPOPT_CLASS_MASK	0x60
44 #define IPOPT_NUMBER_MASK	0x1f
45 
46 #define	IPOPT_COPIED(o)		((o)&IPOPT_COPY)
47 #define	IPOPT_CLASS(o)		((o)&IPOPT_CLASS_MASK)
48 #define	IPOPT_NUMBER(o)		((o)&IPOPT_NUMBER_MASK)
49 
50 #define	IPOPT_CONTROL		0x00
51 #define	IPOPT_RESERVED1		0x20
52 #define	IPOPT_MEASUREMENT	0x40
53 #define	IPOPT_RESERVED2		0x60
54 
55 #define IPOPT_END	(0 |IPOPT_CONTROL)
56 #define IPOPT_NOOP	(1 |IPOPT_CONTROL)
57 #define IPOPT_SEC	(2 |IPOPT_CONTROL|IPOPT_COPY)
58 #define IPOPT_LSRR	(3 |IPOPT_CONTROL|IPOPT_COPY)
59 #define IPOPT_TIMESTAMP	(4 |IPOPT_MEASUREMENT)
60 #define IPOPT_CIPSO	(6 |IPOPT_CONTROL|IPOPT_COPY)
61 #define IPOPT_RR	(7 |IPOPT_CONTROL)
62 #define IPOPT_SID	(8 |IPOPT_CONTROL|IPOPT_COPY)
63 #define IPOPT_SSRR	(9 |IPOPT_CONTROL|IPOPT_COPY)
64 #define IPOPT_RA	(20|IPOPT_CONTROL|IPOPT_COPY)
65 
66 #define IPVERSION	4
67 #define MAXTTL		255
68 #define IPDEFTTL	64
69 
70 #define IPOPT_OPTVAL 0
71 #define IPOPT_OLEN   1
72 #define IPOPT_OFFSET 2
73 #define IPOPT_MINOFF 4
74 #define MAX_IPOPTLEN 40
75 #define IPOPT_NOP IPOPT_NOOP
76 #define IPOPT_EOL IPOPT_END
77 #define IPOPT_TS  IPOPT_TIMESTAMP
78 
79 #define	IPOPT_TS_TSONLY		0		/* timestamps only */
80 #define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
81 #define	IPOPT_TS_PRESPEC	3		/* specified modules only */
82 
83 #define IPV4_BEET_PHMAXLEN 8
84 
85 struct iphdr {
86 #if defined(__LITTLE_ENDIAN_BITFIELD)
87 	__u8	ihl:4,
88 		version:4;
89 #elif defined (__BIG_ENDIAN_BITFIELD)
90 	__u8	version:4,
91   		ihl:4;
92 #else
93 #error	"Please fix <asm/byteorder.h>"
94 #endif
95 	__u8	tos;
96 	__be16	tot_len;
97 	__be16	id;
98 	__be16	frag_off;
99 	__u8	ttl;
100 	__u8	protocol;
101 	__sum16	check;
102 	__be32	saddr;
103 	__be32	daddr;
104 	/*The options start here. */
105 };
106 
107 #ifdef __KERNEL__
108 #include <linux/skbuff.h>
109 
ip_hdr(const struct sk_buff * skb)110 static inline struct iphdr *ip_hdr(const struct sk_buff *skb)
111 {
112 	return (struct iphdr *)skb_network_header(skb);
113 }
114 
ipip_hdr(const struct sk_buff * skb)115 static inline struct iphdr *ipip_hdr(const struct sk_buff *skb)
116 {
117 	return (struct iphdr *)skb_transport_header(skb);
118 }
119 #endif
120 
121 struct ip_auth_hdr {
122 	__u8  nexthdr;
123 	__u8  hdrlen;		/* This one is measured in 32 bit units! */
124 	__be16 reserved;
125 	__be32 spi;
126 	__be32 seq_no;		/* Sequence number */
127 	__u8  auth_data[0];	/* Variable len but >=4. Mind the 64 bit alignment! */
128 };
129 
130 struct ip_esp_hdr {
131 	__be32 spi;
132 	__be32 seq_no;		/* Sequence number */
133 	__u8  enc_data[0];	/* Variable len but >=8. Mind the 64 bit alignment! */
134 };
135 
136 struct ip_comp_hdr {
137 	__u8 nexthdr;
138 	__u8 flags;
139 	__be16 cpi;
140 };
141 
142 struct ip_beet_phdr {
143 	__u8 nexthdr;
144 	__u8 hdrlen;
145 	__u8 padlen;
146 	__u8 reserved;
147 };
148 
149 #endif	/* _LINUX_IP_H */
150