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30 * @(#)ip.h 8.2 (Berkeley) 6/1/94
34 #ifndef _NETINET_IP_H_
35 #define _NETINET_IP_H_
37 #include <sys/cdefs.h>
40 * Definitions for internet protocol version 4.
42 * Per RFC 791, September 1981.
47 * Structure of an internet header, naked of options.
50 #if BYTE_ORDER == LITTLE_ENDIAN
51 u_int ip_hl:4, /* header length */
54 #if BYTE_ORDER == BIG_ENDIAN
55 u_int ip_v:4, /* version */
56 ip_hl:4; /* header length */
58 u_char ip_tos; /* type of service */
59 u_short ip_len; /* total length */
60 u_short ip_id; /* identification */
61 u_short ip_off; /* fragment offset field */
62 #define IP_RF 0x8000 /* reserved fragment flag */
63 #define IP_DF 0x4000 /* dont fragment flag */
64 #define IP_MF 0x2000 /* more fragments flag */
65 #define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
66 u_char ip_ttl; /* time to live */
67 u_char ip_p; /* protocol */
68 u_short ip_sum; /* checksum */
69 struct in_addr ip_src,ip_dst; /* source and dest address */
70 } __packed __aligned(4);
73 CTASSERT(sizeof (struct ip) == 20);
76 #define IP_MAXPACKET 65535 /* maximum packet size */
79 * Definitions for IP type of service (ip_tos).
81 #define IPTOS_LOWDELAY 0x10
82 #define IPTOS_THROUGHPUT 0x08
83 #define IPTOS_RELIABILITY 0x04
84 #define IPTOS_MINCOST 0x02
87 * Definitions for IP precedence (also in ip_tos) (hopefully unused).
89 #define IPTOS_PREC_NETCONTROL 0xe0
90 #define IPTOS_PREC_INTERNETCONTROL 0xc0
91 #define IPTOS_PREC_CRITIC_ECP 0xa0
92 #define IPTOS_PREC_FLASHOVERRIDE 0x80
93 #define IPTOS_PREC_FLASH 0x60
94 #define IPTOS_PREC_IMMEDIATE 0x40
95 #define IPTOS_PREC_PRIORITY 0x20
96 #define IPTOS_PREC_ROUTINE 0x00
99 * ECN (Explicit Congestion Notification) codepoints in RFC3168 mapped to the
100 * lower 2 bits of the TOS field.
102 #define IPTOS_ECN_NOTECT 0x00 /* not-ECT */
103 #define IPTOS_ECN_ECT1 0x01 /* ECN-capable transport (1) */
104 #define IPTOS_ECN_ECT0 0x02 /* ECN-capable transport (0) */
105 #define IPTOS_ECN_CE 0x03 /* congestion experienced */
106 #define IPTOS_ECN_MASK 0x03 /* ECN field mask */
109 * Definitions for options.
111 #define IPOPT_COPIED(o) ((o)&0x80)
112 #define IPOPT_CLASS(o) ((o)&0x60)
113 #define IPOPT_NUMBER(o) ((o)&0x1f)
115 #define IPOPT_CONTROL 0x00
116 #define IPOPT_RESERVED1 0x20
117 #define IPOPT_DEBMEAS 0x40
118 #define IPOPT_RESERVED2 0x60
120 #define IPOPT_EOL 0 /* end of option list */
121 #define IPOPT_NOP 1 /* no operation */
123 #define IPOPT_RR 7 /* record packet route */
124 #define IPOPT_TS 68 /* timestamp */
125 #define IPOPT_SECURITY 130 /* provide s,c,h,tcc */
126 #define IPOPT_LSRR 131 /* loose source route */
127 #define IPOPT_ESO 133 /* extended security */
128 #define IPOPT_CIPSO 134 /* commerical security */
129 #define IPOPT_SATID 136 /* satnet id */
130 #define IPOPT_SSRR 137 /* strict source route */
131 #define IPOPT_RA 148 /* router alert */
134 * Offsets to fields in options other than EOL and NOP.
136 #define IPOPT_OPTVAL 0 /* option ID */
137 #define IPOPT_OLEN 1 /* option length */
138 #define IPOPT_OFFSET 2 /* offset within option */
139 #define IPOPT_MINOFF 4 /* min value of above */
142 * Time stamp option structure.
144 struct ip_timestamp {
145 u_char ipt_code; /* IPOPT_TS */
146 u_char ipt_len; /* size of structure (variable) */
147 u_char ipt_ptr; /* index of current entry */
148 #if BYTE_ORDER == LITTLE_ENDIAN
149 u_int ipt_flg:4, /* flags, see below */
150 ipt_oflw:4; /* overflow counter */
152 #if BYTE_ORDER == BIG_ENDIAN
153 u_int ipt_oflw:4, /* overflow counter */
154 ipt_flg:4; /* flags, see below */
156 union ipt_timestamp {
159 struct in_addr ipt_addr;
165 /* Flag bits for ipt_flg. */
166 #define IPOPT_TS_TSONLY 0 /* timestamps only */
167 #define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */
168 #define IPOPT_TS_PRESPEC 3 /* specified modules only */
170 /* Bits for security (not byte swapped). */
171 #define IPOPT_SECUR_UNCLASS 0x0000
172 #define IPOPT_SECUR_CONFID 0xf135
173 #define IPOPT_SECUR_EFTO 0x789a
174 #define IPOPT_SECUR_MMMM 0xbc4d
175 #define IPOPT_SECUR_RESTR 0xaf13
176 #define IPOPT_SECUR_SECRET 0xd788
177 #define IPOPT_SECUR_TOPSECRET 0x6bc5
180 * Internet implementation parameters.
182 #define MAXTTL 255 /* maximum time to live (seconds) */
183 #define IPDEFTTL 64 /* default ttl, from RFC 1340 */
184 #define IPFRAGTTL 60 /* time to live for frags, slowhz */
185 #define IPTTLDEC 1 /* subtracted when forwarding */
186 #define IP_MSS 576 /* default maximum segment size */
189 * This is the real IPv4 pseudo header, used for computing the TCP and UDP
190 * checksums. For the Internet checksum, struct ipovly can be used instead.
191 * For stronger checksums, the real thing must be used.
194 struct in_addr ippseudo_src; /* source internet address */
195 struct in_addr ippseudo_dst; /* destination internet address */
196 u_char ippseudo_pad; /* pad, must be zero */
197 u_char ippseudo_p; /* protocol */
198 u_short ippseudo_len; /* protocol length */