1/* $FreeBSD: src/sys/netinet6/ipcomp_input.c,v 1.1.2.2 2001/07/03 11:01:54 ume Exp $ */
2/* $KAME: ipcomp_input.c,v 1.25 2001/03/01 09:12:09 itojun Exp $ */
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
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/malloc.h>
41#include <sys/mbuf.h>
42#include <sys/mcache.h>
43#include <sys/domain.h>
44#include <sys/protosw.h>
45#include <sys/socket.h>
46#include <sys/errno.h>
47#include <sys/time.h>
48#include <sys/kernel.h>
49#include <sys/syslog.h>
50
51#include <net/if.h>
52#include <net/route.h>
53#include <libkern/zlib.h>
54#include <kern/cpu_number.h>
55#include <kern/locks.h>
56
57#include <netinet/in.h>
58#include <netinet/in_systm.h>
59#include <netinet/in_var.h>
60#include <netinet/ip.h>
61#include <netinet/ip_var.h>
62#include <netinet/ip_ecn.h>
63#include <netinet/kpi_ipfilter_var.h>
64
65#if INET6
66#include <netinet/ip6.h>
67#include <netinet6/ip6_var.h>
68#endif
69#include <netinet6/ipcomp.h>
70#if INET6
71#include <netinet6/ipcomp6.h>
72#endif
73
74#include <netinet6/ipsec.h>
75#if INET6
76#include <netinet6/ipsec6.h>
77#endif
78#include <netkey/key.h>
79#include <netkey/keydb.h>
80
81#include <net/net_osdep.h>
82#include <mach/sdt.h>
83
84#define IPLEN_FLIPPED
85
86void
87ipcomp4_input(struct mbuf *m, int off)
88{
89 struct mbuf *md;
90 struct ip *ip;
91 struct ipcomp *ipcomp;
92 const struct ipcomp_algorithm *algo;
93 u_int16_t cpi; /* host order */
94 u_int16_t nxt;
95 size_t hlen;
96 int error;
97 size_t newlen, olen;
98 struct secasvar *sav = NULL;
99
100 if (m->m_pkthdr.len < off + sizeof(struct ipcomp)) {
101 ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
102 "(packet too short)\n"));
103 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
104 goto fail;
105 }
106
107 md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
108 if (!md) {
109 m = NULL; /*already freed*/
110 ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
111 "(pulldown failure)\n"));
112 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
113 goto fail;
114 }
115 ipcomp = mtod(md, struct ipcomp *);
116
117 /* Expect 32-bit aligned data pointer on strict-align platforms */
118 MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
119
120 ip = mtod(m, struct ip *);
121 nxt = ipcomp->comp_nxt;
122#ifdef _IP_VHL
123 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
124#else
125 hlen = ip->ip_hl << 2;
126#endif
127
128 cpi = ntohs(ipcomp->comp_cpi);
129
130 if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
131 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src,
132 (caddr_t)&ip->ip_dst, IPPROTO_IPCOMP, htonl(cpi));
133 if (sav != NULL
134 && (sav->state == SADB_SASTATE_MATURE
135 || sav->state == SADB_SASTATE_DYING)) {
136 cpi = sav->alg_enc; /*XXX*/
137 /* other parameters to look at? */
138 }
139 }
140 algo = ipcomp_algorithm_lookup(cpi);
141 if (!algo) {
142 ipseclog((LOG_WARNING, "IPv4 IPComp input: unknown cpi %u\n",
143 cpi));
144 IPSEC_STAT_INCREMENT(ipsecstat.in_nosa);
145 goto fail;
146 }
147
148 /* chop ipcomp header */
149 ipcomp = NULL;
150 md->m_data += sizeof(struct ipcomp);
151 md->m_len -= sizeof(struct ipcomp);
152 m->m_pkthdr.len -= sizeof(struct ipcomp);
153#ifdef IPLEN_FLIPPED
154 ip->ip_len -= sizeof(struct ipcomp);
155#else
156 ip->ip_len = htons(ntohs(ip->ip_len) - sizeof(struct ipcomp));
157#endif
158
159 olen = m->m_pkthdr.len;
160 newlen = m->m_pkthdr.len - off;
161 error = (*algo->decompress)(m, m->m_next, &newlen);
162 if (error != 0) {
163 if (error == EINVAL) {
164 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
165 } else if (error == ENOBUFS)
166 IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
167 m = NULL;
168 goto fail;
169 }
170 IPSEC_STAT_INCREMENT(ipsecstat.in_comphist[cpi]);
171
172 /*
173 * returning decompressed packet onto icmp is meaningless.
174 * mark it decrypted to prevent icmp from attaching original packet.
175 */
176 m->m_flags |= M_DECRYPTED;
177
178 m->m_pkthdr.len = off + newlen;
179 ip = mtod(m, struct ip *);
180 {
181 size_t len;
182#ifdef IPLEN_FLIPPED
183 len = ip->ip_len;
184#else
185 len = ntohs(ip->ip_len);
186#endif
187 /*
188 * be careful about underflow. also, do not assign exact value
189 * as ip_len is manipulated differently on *BSDs.
190 */
191 len += m->m_pkthdr.len;
192 len -= olen;
193 if (len & ~0xffff) {
194 /* packet too big after decompress */
195 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
196 goto fail;
197 }
198#ifdef IPLEN_FLIPPED
199 ip->ip_len = len & 0xffff;
200#else
201 ip->ip_len = htons(len & 0xffff);
202#endif
203 ip->ip_p = nxt;
204 }
205
206 if (sav) {
207 key_sa_recordxfer(sav, m);
208 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
209 IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
210 goto fail;
211 }
212 key_freesav(sav, KEY_SADB_UNLOCKED);
213 sav = NULL;
214 }
215
216 if (nxt != IPPROTO_DONE) {
217 if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
218 ipsec4_in_reject(m, NULL)) {
219 IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
220 goto fail;
221 }
222
223 DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
224 struct ip *, ip, struct ifnet *, m->m_pkthdr.rcvif,
225 struct ip *, ip, struct ip6_hdr *, NULL);
226
227 ip_proto_dispatch_in(m, off, nxt, 0);
228 } else
229 m_freem(m);
230 m = NULL;
231
232 IPSEC_STAT_INCREMENT(ipsecstat.in_success);
233 return;
234
235fail:
236 if (sav)
237 key_freesav(sav, KEY_SADB_UNLOCKED);
238
239 if (m)
240 m_freem(m);
241 return;
242}
243
244#if INET6
245int
246ipcomp6_input(struct mbuf **mp, int *offp, int proto)
247{
248#pragma unused(proto)
249 struct mbuf *m, *md;
250 int off;
251 struct ip6_hdr *ip6;
252 struct ipcomp *ipcomp;
253 const struct ipcomp_algorithm *algo;
254 u_int16_t cpi; /* host order */
255 u_int16_t nxt;
256 int error;
257 size_t newlen;
258 struct secasvar *sav = NULL;
259 char *prvnxtp;
260
261 m = *mp;
262 off = *offp;
263
264 md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
265 if (!md) {
266 m = NULL; /*already freed*/
267 ipseclog((LOG_DEBUG, "IPv6 IPComp input: assumption failed "
268 "(pulldown failure)\n"));
269 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
270 goto fail;
271 }
272 ipcomp = mtod(md, struct ipcomp *);
273
274 /* Expect 32-bit aligned data pointer on strict-align platforms */
275 MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
276
277 ip6 = mtod(m, struct ip6_hdr *);
278 nxt = ipcomp->comp_nxt;
279
280 cpi = ntohs(ipcomp->comp_cpi);
281
282 if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
283 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src,
284 (caddr_t)&ip6->ip6_dst, IPPROTO_IPCOMP, htonl(cpi));
285 if (sav != NULL
286 && (sav->state == SADB_SASTATE_MATURE
287 || sav->state == SADB_SASTATE_DYING)) {
288 cpi = sav->alg_enc; /*XXX*/
289 /* other parameters to look at? */
290 }
291 }
292 algo = ipcomp_algorithm_lookup(cpi);
293 if (!algo) {
294 ipseclog((LOG_WARNING, "IPv6 IPComp input: unknown cpi %u; "
295 "dropping the packet for simplicity\n", cpi));
296 IPSEC_STAT_INCREMENT(ipsec6stat.in_nosa);
297 goto fail;
298 }
299
300 /* chop ipcomp header */
301 ipcomp = NULL;
302 md->m_data += sizeof(struct ipcomp);
303 md->m_len -= sizeof(struct ipcomp);
304 m->m_pkthdr.len -= sizeof(struct ipcomp);
305
306 newlen = m->m_pkthdr.len - off;
307 error = (*algo->decompress)(m, md, &newlen);
308 if (error != 0) {
309 if (error == EINVAL) {
310 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
311 } else if (error == ENOBUFS)
312 IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
313 m = NULL;
314 goto fail;
315 }
316 IPSEC_STAT_INCREMENT(ipsec6stat.in_comphist[cpi]);
317 m->m_pkthdr.len = off + newlen;
318
319 /*
320 * returning decompressed packet onto icmp is meaningless.
321 * mark it decrypted to prevent icmp from attaching original packet.
322 */
323 m->m_flags |= M_DECRYPTED;
324
325 /* update next header field */
326 prvnxtp = ip6_get_prevhdr(m, off);
327 *prvnxtp = nxt;
328
329 /*
330 * no need to adjust payload length, as all the IPv6 protocols
331 * look at m->m_pkthdr.len
332 */
333
334 if (sav) {
335 key_sa_recordxfer(sav, m);
336 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
337 IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
338 goto fail;
339 }
340 key_freesav(sav, KEY_SADB_UNLOCKED);
341 sav = NULL;
342 }
343 *offp = off;
344 *mp = m;
345 IPSEC_STAT_INCREMENT(ipsec6stat.in_success);
346 return nxt;
347
348fail:
349 if (m)
350 m_freem(m);
351 if (sav)
352 key_freesav(sav, KEY_SADB_UNLOCKED);
353 return IPPROTO_DONE;
354}
355#endif /* INET6 */
356