1 /* SPDX-License-Identifier: BSD-3-Clause */
2 /*
3  * Copyright (c) 1982, 1986, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *	@(#)ip.h	8.1 (Berkeley) 6/10/93
31  * ip.h,v 1.3 1994/08/21 05:27:30 paul Exp
32  */
33 
34 #ifndef IP_H
35 #define IP_H
36 
37 #include <glib.h>
38 
39 #if G_BYTE_ORDER == G_BIG_ENDIAN
40 #undef NTOHL
41 #undef NTOHS
42 #undef HTONL
43 #undef HTONS
44 #define NTOHL(d)
45 #define NTOHS(d)
46 #define HTONL(d)
47 #define HTONS(d)
48 #else
49 #ifndef NTOHL
50 #define NTOHL(d) ((d) = ntohl((d)))
51 #endif
52 #ifndef NTOHS
53 #define NTOHS(d) ((d) = ntohs((uint16_t)(d)))
54 #endif
55 #ifndef HTONL
56 #define HTONL(d) ((d) = htonl((d)))
57 #endif
58 #ifndef HTONS
59 #define HTONS(d) ((d) = htons((uint16_t)(d)))
60 #endif
61 #endif
62 
63 typedef uint32_t n_long; /* long as received from the net */
64 
65 /*
66  * Definitions for internet protocol version 4.
67  * Per RFC 791, September 1981.
68  */
69 #define IPVERSION 4
70 
71 /*
72  * Structure of an internet header, naked of options.
73  */
74 struct ip {
75 #if G_BYTE_ORDER == G_BIG_ENDIAN
76     uint8_t ip_v : 4, /* version */
77         ip_hl : 4; /* header length */
78 #else
79     uint8_t ip_hl : 4, /* header length */
80         ip_v : 4; /* version */
81 #endif
82     uint8_t ip_tos; /* type of service */
83     uint16_t ip_len; /* total length */
84     uint16_t ip_id; /* identification */
85     uint16_t ip_off; /* fragment offset field */
86 #define IP_DF 0x4000 /* don't fragment flag */
87 #define IP_MF 0x2000 /* more fragments flag */
88 #define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
89     uint8_t ip_ttl; /* time to live */
90     uint8_t ip_p; /* protocol */
91     uint16_t ip_sum; /* checksum */
92     struct in_addr ip_src, ip_dst; /* source and dest address */
93 } SLIRP_PACKED;
94 
95 #define IP_MAXPACKET 65535 /* maximum packet size */
96 
97 /*
98  * Definitions for IP type of service (ip_tos)
99  */
100 #define IPTOS_LOWDELAY 0x10
101 #define IPTOS_THROUGHPUT 0x08
102 #define IPTOS_RELIABILITY 0x04
103 
104 /*
105  * Definitions for options.
106  */
107 #define IPOPT_COPIED(o) ((o)&0x80)
108 #define IPOPT_CLASS(o) ((o)&0x60)
109 #define IPOPT_NUMBER(o) ((o)&0x1f)
110 
111 #define IPOPT_CONTROL 0x00
112 #define IPOPT_RESERVED1 0x20
113 #define IPOPT_DEBMEAS 0x40
114 #define IPOPT_RESERVED2 0x60
115 
116 #define IPOPT_EOL 0 /* end of option list */
117 #define IPOPT_NOP 1 /* no operation */
118 
119 #define IPOPT_RR 7 /* record packet route */
120 #define IPOPT_TS 68 /* timestamp */
121 #define IPOPT_SECURITY 130 /* provide s,c,h,tcc */
122 #define IPOPT_LSRR 131 /* loose source route */
123 #define IPOPT_SATID 136 /* satnet id */
124 #define IPOPT_SSRR 137 /* strict source route */
125 
126 /*
127  * Offsets to fields in options other than EOL and NOP.
128  */
129 #define IPOPT_OPTVAL 0 /* option ID */
130 #define IPOPT_OLEN 1 /* option length */
131 #define IPOPT_OFFSET 2 /* offset within option */
132 #define IPOPT_MINOFF 4 /* min value of above */
133 
134 /*
135  * Time stamp option structure.
136  */
137 struct ip_timestamp {
138     uint8_t ipt_code; /* IPOPT_TS */
139     uint8_t ipt_len; /* size of structure (variable) */
140     uint8_t ipt_ptr; /* index of current entry */
141 #if G_BYTE_ORDER == G_BIG_ENDIAN
142     uint8_t ipt_oflw : 4, /* overflow counter */
143         ipt_flg : 4; /* flags, see below */
144 #else
145     uint8_t ipt_flg : 4, /* flags, see below */
146         ipt_oflw : 4; /* overflow counter */
147 #endif
148     union ipt_timestamp {
149         n_long ipt_time[1];
150         struct ipt_ta {
151             struct in_addr ipt_addr;
152             n_long ipt_time;
153         } ipt_ta[1];
154     } ipt_timestamp;
155 } SLIRP_PACKED;
156 
157 /* flag bits for ipt_flg */
158 #define IPOPT_TS_TSONLY 0 /* timestamps only */
159 #define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */
160 #define IPOPT_TS_PRESPEC 3 /* specified modules only */
161 
162 /* bits for security (not byte swapped) */
163 #define IPOPT_SECUR_UNCLASS 0x0000
164 #define IPOPT_SECUR_CONFID 0xf135
165 #define IPOPT_SECUR_EFTO 0x789a
166 #define IPOPT_SECUR_MMMM 0xbc4d
167 #define IPOPT_SECUR_RESTR 0xaf13
168 #define IPOPT_SECUR_SECRET 0xd788
169 #define IPOPT_SECUR_TOPSECRET 0x6bc5
170 
171 /*
172  * Internet implementation parameters.
173  */
174 #define MAXTTL 255 /* maximum time to live (seconds) */
175 #define IPDEFTTL 64 /* default ttl, from RFC 1340 */
176 #define IPFRAGTTL 60 /* time to live for frags, slowhz */
177 #define IPTTLDEC 1 /* subtracted when forwarding */
178 
179 #define IP_MSS 576 /* default maximum segment size */
180 
181 #if GLIB_SIZEOF_VOID_P == 4
182 struct mbuf_ptr {
183     struct mbuf *mptr;
184     uint32_t dummy;
185 } SLIRP_PACKED;
186 #else
187 struct mbuf_ptr {
188     struct mbuf *mptr;
189 } SLIRP_PACKED;
190 #endif
191 struct qlink {
192     void *next, *prev;
193 };
194 
195 /*
196  * Overlay for ip header used by other protocols (tcp, udp).
197  */
198 struct ipovly {
199     struct mbuf_ptr ih_mbuf; /* backpointer to mbuf */
200     uint8_t ih_x1; /* (unused) */
201     uint8_t ih_pr; /* protocol */
202     uint16_t ih_len; /* protocol length */
203     struct in_addr ih_src; /* source internet address */
204     struct in_addr ih_dst; /* destination internet address */
205 } SLIRP_PACKED;
206 
207 /*
208  * Ip reassembly queue structure.  Each fragment
209  * being reassembled is attached to one of these structures.
210  * They are timed out after ipq_ttl drops to 0, and may also
211  * be reclaimed if memory becomes tight.
212  * size 28 bytes
213  */
214 struct ipq {
215     struct qlink frag_link; /* to ip headers of fragments */
216     struct qlink ip_link; /* to other reass headers */
217     uint8_t ipq_ttl; /* time for reass q to live */
218     uint8_t ipq_p; /* protocol of this fragment */
219     uint16_t ipq_id; /* sequence id for reassembly */
220     struct in_addr ipq_src, ipq_dst;
221 };
222 
223 /*
224  * Ip header, when holding a fragment.
225  *
226  * Note: ipf_link must be at same offset as frag_link above
227  */
228 struct ipasfrag {
229     struct qlink ipf_link;
230     struct ip ipf_ip;
231 };
232 
233 G_STATIC_ASSERT(offsetof(struct ipq, frag_link) ==
234                 offsetof(struct ipasfrag, ipf_link));
235 
236 #define ipf_off ipf_ip.ip_off
237 #define ipf_tos ipf_ip.ip_tos
238 #define ipf_len ipf_ip.ip_len
239 #define ipf_next ipf_link.next
240 #define ipf_prev ipf_link.prev
241 
242 #endif
243