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9bccf70c
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1/* $FreeBSD: src/sys/netinet6/ipcomp_output.c,v 1.1.2.2 2001/07/03 11:01:54 ume Exp $ */
2/* $KAME: ipcomp_output.c,v 1.23 2001/01/23 08:59:37 itojun Exp $ */
1c79356b
A
3
4/*
5 * Copyright (C) 1999 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33/*
34 * RFC2393 IP payload compression protocol (IPComp).
35 */
36
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37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/malloc.h>
41#include <sys/mbuf.h>
42#include <sys/domain.h>
43#include <sys/protosw.h>
44#include <sys/socket.h>
45#include <sys/errno.h>
46#include <sys/time.h>
47#include <sys/kernel.h>
48#include <sys/syslog.h>
49
50#include <net/if.h>
51#include <net/route.h>
2d21ac55 52#include <libkern/zlib.h>
1c79356b 53#include <kern/cpu_number.h>
91447636 54#include <kern/locks.h>
1c79356b
A
55
56#include <netinet/in.h>
57#include <netinet/in_systm.h>
58#include <netinet/in_var.h>
59#include <netinet/ip.h>
60#include <netinet/ip_var.h>
61#include <netinet/ip_ecn.h>
62
63#if INET6
64#include <netinet/ip6.h>
65#include <netinet6/ip6_var.h>
66#endif
67#include <netinet6/ipcomp.h>
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68#if INET6
69#include <netinet6/ipcomp6.h>
70#endif
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71
72#include <netinet6/ipsec.h>
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73#if INET6
74#include <netinet6/ipsec6.h>
75#endif
1c79356b
A
76#include <netkey/key.h>
77#include <netkey/keydb.h>
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A
78
79#include <net/net_osdep.h>
80
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A
81
82static int ipcomp_output(struct mbuf *, u_char *, struct mbuf *,
2d21ac55 83 int, struct secasvar *sav);
1c79356b
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84
85/*
86 * Modify the packet so that the payload is compressed.
87 * The mbuf (m) must start with IPv4 or IPv6 header.
9bccf70c 88 * On failure, free the given mbuf and return non-zero.
1c79356b
A
89 *
90 * on invocation:
91 * m nexthdrp md
92 * v v v
93 * IP ......... payload
94 * during the encryption:
95 * m nexthdrp mprev md
96 * v v v v
97 * IP ............... ipcomp payload
98 * <-----><----->
99 * complen plen
100 * <-> hlen
101 * <-----------------> compoff
102 */
103static int
2d21ac55 104ipcomp_output(m, nexthdrp, md, af, sav)
1c79356b
A
105 struct mbuf *m;
106 u_char *nexthdrp;
107 struct mbuf *md;
1c79356b 108 int af;
2d21ac55 109 struct secasvar *sav;
1c79356b
A
110{
111 struct mbuf *n;
112 struct mbuf *md0;
9bccf70c 113 struct mbuf *mcopy;
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114 struct mbuf *mprev;
115 struct ipcomp *ipcomp;
9bccf70c 116 const struct ipcomp_algorithm *algo;
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117 u_int16_t cpi; /* host order */
118 size_t plen0, plen; /*payload length to be compressed*/
119 size_t compoff;
120 int afnumber;
121 int error = 0;
9bccf70c 122 struct ipsecstat *stat;
1c79356b
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123
124 switch (af) {
125#if INET
126 case AF_INET:
127 afnumber = 4;
9bccf70c 128 stat = &ipsecstat;
1c79356b
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129 break;
130#endif
131#if INET6
132 case AF_INET6:
133 afnumber = 6;
9bccf70c 134 stat = &ipsec6stat;
1c79356b
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135 break;
136#endif
137 default:
138 ipseclog((LOG_ERR, "ipcomp_output: unsupported af %d\n", af));
139 return 0; /* no change at all */
140 }
141
142 /* grab parameters */
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A
143 algo = ipcomp_algorithm_lookup(sav->alg_enc);
144 if ((ntohl(sav->spi) & ~0xffff) != 0 || !algo) {
2d21ac55 145 IPSEC_STAT_INCREMENT(stat->out_inval);
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146 m_freem(m);
147 return EINVAL;
148 }
149 if ((sav->flags & SADB_X_EXT_RAWCPI) == 0)
150 cpi = sav->alg_enc;
151 else
152 cpi = ntohl(sav->spi) & 0xffff;
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153
154 /* compute original payload length */
155 plen = 0;
156 for (n = md; n; n = n->m_next)
157 plen += n->m_len;
158
159 /* if the payload is short enough, we don't need to compress */
160 if (plen < algo->minplen)
161 return 0;
162
163 /*
9bccf70c
A
164 * retain the original packet for two purposes:
165 * (1) we need to backout our changes when compression is not necessary.
166 * (2) byte lifetime computation should use the original packet.
167 * see RFC2401 page 23.
168 * compromise two m_copym(). we will be going through every byte of
169 * the payload during compression process anyways.
1c79356b 170 */
9bccf70c
A
171 mcopy = m_copym(m, 0, M_COPYALL, M_NOWAIT);
172 if (mcopy == NULL) {
173 error = ENOBUFS;
174 return 0;
175 }
1c79356b
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176 md0 = m_copym(md, 0, M_COPYALL, M_NOWAIT);
177 if (md0 == NULL) {
9bccf70c 178 m_freem(mcopy);
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179 error = ENOBUFS;
180 return 0;
181 }
182 plen0 = plen;
183
184 /* make the packet over-writable */
185 for (mprev = m; mprev && mprev->m_next != md; mprev = mprev->m_next)
186 ;
187 if (mprev == NULL || mprev->m_next != md) {
188 ipseclog((LOG_DEBUG, "ipcomp%d_output: md is not in chain\n",
189 afnumber));
2d21ac55 190 IPSEC_STAT_INCREMENT(stat->out_inval);
1c79356b
A
191 m_freem(m);
192 m_freem(md0);
9bccf70c 193 m_freem(mcopy);
1c79356b
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194 return EINVAL;
195 }
196 mprev->m_next = NULL;
197 if ((md = ipsec_copypkt(md)) == NULL) {
198 m_freem(m);
199 m_freem(md0);
9bccf70c 200 m_freem(mcopy);
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201 error = ENOBUFS;
202 goto fail;
203 }
204 mprev->m_next = md;
205
206 /* compress data part */
207 if ((*algo->compress)(m, md, &plen) || mprev->m_next == NULL) {
208 ipseclog((LOG_ERR, "packet compression failure\n"));
209 m = NULL;
210 m_freem(md0);
9bccf70c 211 m_freem(mcopy);
2d21ac55 212 IPSEC_STAT_INCREMENT(stat->out_inval);
1c79356b
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213 error = EINVAL;
214 goto fail;
215 }
2d21ac55 216 IPSEC_STAT_INCREMENT(stat->out_comphist[sav->alg_enc]);
1c79356b
A
217 md = mprev->m_next;
218
219 /*
220 * if the packet became bigger, meaningless to use IPComp.
221 * we've only wasted our cpu time.
222 */
223 if (plen0 < plen) {
224 m_freem(md);
9bccf70c 225 m_freem(mcopy);
1c79356b
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226 mprev->m_next = md0;
227 return 0;
228 }
229
9bccf70c
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230 /*
231 * no need to backout change beyond here.
232 */
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233 m_freem(md0);
234 md0 = NULL;
9bccf70c 235
1c79356b
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236 m->m_pkthdr.len -= plen0;
237 m->m_pkthdr.len += plen;
238
239 {
240 /*
241 * insert IPComp header.
242 */
243#if INET
244 struct ip *ip = NULL;
245#endif
246#if INET6
247 struct ip6_hdr *ip6 = NULL;
248#endif
249 size_t hlen = 0; /*ip header len*/
250 size_t complen = sizeof(struct ipcomp);
251
252 switch (af) {
253#if INET
254 case AF_INET:
255 ip = mtod(m, struct ip *);
256#ifdef _IP_VHL
257 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
258#else
259 hlen = ip->ip_hl << 2;
260#endif
261 break;
262#endif
263#if INET6
264 case AF_INET6:
265 ip6 = mtod(m, struct ip6_hdr *);
266 hlen = sizeof(*ip6);
267 break;
268#endif
269 }
270
271 compoff = m->m_pkthdr.len - plen;
272
273 /*
274 * grow the mbuf to accomodate ipcomp header.
275 * before: IP ... payload
276 * after: IP ... ipcomp payload
277 */
278 if (M_LEADINGSPACE(md) < complen) {
279 MGET(n, M_DONTWAIT, MT_DATA);
280 if (!n) {
281 m_freem(m);
282 error = ENOBUFS;
283 goto fail;
284 }
285 n->m_len = complen;
286 mprev->m_next = n;
287 n->m_next = md;
288 m->m_pkthdr.len += complen;
289 ipcomp = mtod(n, struct ipcomp *);
290 } else {
291 md->m_len += complen;
292 md->m_data -= complen;
293 m->m_pkthdr.len += complen;
294 ipcomp = mtod(md, struct ipcomp *);
295 }
296
297 bzero(ipcomp, sizeof(*ipcomp));
298 ipcomp->comp_nxt = *nexthdrp;
299 *nexthdrp = IPPROTO_IPCOMP;
300 ipcomp->comp_cpi = htons(cpi);
301 switch (af) {
302#if INET
303 case AF_INET:
304 if (compoff + complen + plen < IP_MAXPACKET)
305 ip->ip_len = htons(compoff + complen + plen);
306 else {
307 ipseclog((LOG_ERR,
308 "IPv4 ESP output: size exceeds limit\n"));
2d21ac55 309 IPSEC_STAT_INCREMENT(ipsecstat.out_inval);
1c79356b
A
310 m_freem(m);
311 error = EMSGSIZE;
312 goto fail;
313 }
314 break;
315#endif
316#if INET6
317 case AF_INET6:
318 /* total packet length will be computed in ip6_output() */
319 break;
320#endif
321 }
322 }
323
324 if (!m) {
325 ipseclog((LOG_DEBUG,
326 "NULL mbuf after compression in ipcomp%d_output",
327 afnumber));
2d21ac55 328 IPSEC_STAT_INCREMENT(stat->out_inval);
1c79356b 329 }
2d21ac55 330 IPSEC_STAT_INCREMENT(stat->out_success);
9bccf70c
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331
332 /* compute byte lifetime against original packet */
333 key_sa_recordxfer(sav, mcopy);
334 m_freem(mcopy);
335
1c79356b
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336 return 0;
337
338fail:
339#if 1
340 return error;
341#else
342 panic("something bad in ipcomp_output");
343#endif
344}
345
346#if INET
347int
2d21ac55 348ipcomp4_output(m, sav)
1c79356b 349 struct mbuf *m;
2d21ac55 350 struct secasvar *sav;
1c79356b
A
351{
352 struct ip *ip;
353 if (m->m_len < sizeof(struct ip)) {
354 ipseclog((LOG_DEBUG, "ipcomp4_output: first mbuf too short\n"));
2d21ac55 355 IPSEC_STAT_INCREMENT(ipsecstat.out_inval);
1c79356b 356 m_freem(m);
9bccf70c 357 return 0;
1c79356b
A
358 }
359 ip = mtod(m, struct ip *);
360 /* XXX assumes that m->m_next points to payload */
2d21ac55 361 return ipcomp_output(m, &ip->ip_p, m->m_next, AF_INET, sav);
1c79356b
A
362}
363#endif /*INET*/
364
2d21ac55 365#if INET6
1c79356b 366int
2d21ac55 367ipcomp6_output(m, nexthdrp, md, sav)
1c79356b
A
368 struct mbuf *m;
369 u_char *nexthdrp;
370 struct mbuf *md;
2d21ac55 371 struct secasvar *sav;
1c79356b
A
372{
373 if (m->m_len < sizeof(struct ip6_hdr)) {
374 ipseclog((LOG_DEBUG, "ipcomp6_output: first mbuf too short\n"));
2d21ac55 375 IPSEC_STAT_INCREMENT(ipsec6stat.out_inval);
1c79356b 376 m_freem(m);
9bccf70c 377 return 0;
1c79356b 378 }
2d21ac55 379 return ipcomp_output(m, nexthdrp, md, AF_INET6, sav);
1c79356b
A
380}
381#endif /*INET6*/