1 /* $FreeBSD: src/sys/netinet6/ipcomp_output.c,v 1.1.2.4 2003/04/29 08:33:50 suz Exp $ */
2 /* $DragonFly: src/sys/netinet6/ipcomp_output.c,v 1.7 2004/06/02 14:43:01 eirikn Exp $ */
3 /* $KAME: ipcomp_output.c,v 1.25 2002/06/09 14:44:00 itojun Exp $ */
6 * Copyright (C) 1999 WIDE Project.
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10 * modification, are permitted provided that the following conditions
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14 * 2. Redistributions in binary form must reproduce the above copyright
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18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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35 * RFC2393 IP payload compression protocol (IPComp).
39 #include "opt_inet6.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/malloc.h>
45 #include <sys/domain.h>
46 #include <sys/protosw.h>
47 #include <sys/socket.h>
48 #include <sys/errno.h>
50 #include <sys/syslog.h>
53 #include <net/route.h>
54 #include <net/netisr.h>
56 #include <machine/cpu.h>
58 #include <netinet/in.h>
59 #include <netinet/in_systm.h>
60 #include <netinet/in_var.h>
61 #include <netinet/ip.h>
62 #include <netinet/ip_var.h>
63 #include <netinet/ip_ecn.h>
66 #include <netinet/ip6.h>
67 #include <netinet6/ip6_var.h>
69 #include <netinet6/ipcomp.h>
71 #include <netinet6/ipcomp6.h>
74 #include <netinet6/ipsec.h>
76 #include <netinet6/ipsec6.h>
78 #include <netproto/key/key.h>
79 #include <netproto/key/keydb.h>
81 #include <machine/stdarg.h>
83 #include <net/net_osdep.h>
85 static int ipcomp_output (struct mbuf *, u_char *, struct mbuf *,
86 struct ipsecrequest *, int);
89 * Modify the packet so that the payload is compressed.
90 * The mbuf (m) must start with IPv4 or IPv6 header.
91 * On failure, free the given mbuf and return non-zero.
96 * IP ......... payload
97 * during the encryption:
100 * IP ............... ipcomp payload
104 * <-----------------> compoff
107 ipcomp_output(struct mbuf *m, u_char *nexthdrp, struct mbuf *md,
108 struct ipsecrequest *isr, int af)
114 struct ipcomp *ipcomp;
115 struct secasvar *sav = isr->sav;
116 const struct ipcomp_algorithm *algo;
117 u_int16_t cpi; /* host order */
118 size_t plen0, plen; /* payload length to be compressed */
122 struct ipsecstat *stat;
138 ipseclog((LOG_ERR, "ipcomp_output: unsupported af %d\n", af));
139 return 0; /* no change at all */
142 /* grab parameters */
143 algo = ipcomp_algorithm_lookup(sav->alg_enc);
144 if ((ntohl(sav->spi) & ~0xffff) != 0 || !algo) {
149 if ((sav->flags & SADB_X_EXT_RAWCPI) == 0)
152 cpi = ntohl(sav->spi) & 0xffff;
154 /* compute original payload length */
156 for (n = md; n; n = n->m_next)
159 /* if the payload is short enough, we don't need to compress */
160 if (plen < algo->minplen)
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.
171 mcopy = m_copym(m, 0, M_COPYALL, MB_DONTWAIT);
176 md0 = m_copym(md, 0, M_COPYALL, MB_DONTWAIT);
184 /* make the packet over-writable */
185 for (mprev = m; mprev && mprev->m_next != md; mprev = mprev->m_next)
187 if (mprev == NULL || mprev->m_next != md) {
188 ipseclog((LOG_DEBUG, "ipcomp%d_output: md is not in chain\n",
196 mprev->m_next = NULL;
197 if ((md = ipsec_copypkt(md)) == NULL) {
206 /* compress data part */
207 if ((*algo->compress)(m, md, &plen) || mprev->m_next == NULL) {
208 ipseclog((LOG_ERR, "packet compression failure\n"));
216 stat->out_comphist[sav->alg_enc]++;
220 * if the packet became bigger, meaningless to use IPComp.
221 * we've only wasted our cpu time.
231 * no need to backout change beyond here.
236 m->m_pkthdr.len -= plen0;
237 m->m_pkthdr.len += plen;
241 * insert IPComp header.
244 struct ip *ip = NULL;
247 struct ip6_hdr *ip6 = NULL;
249 size_t hlen = 0; /* ip header len */
250 size_t complen = sizeof(struct ipcomp);
255 ip = mtod(m, struct ip *);
257 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
259 hlen = ip->ip_hl << 2;
265 ip6 = mtod(m, struct ip6_hdr *);
271 compoff = m->m_pkthdr.len - plen;
274 * grow the mbuf to accomodate ipcomp header.
275 * before: IP ... payload
276 * after: IP ... ipcomp payload
278 if (M_LEADINGSPACE(md) < complen) {
279 MGET(n, MB_DONTWAIT, MT_DATA);
288 m->m_pkthdr.len += complen;
289 ipcomp = mtod(n, struct ipcomp *);
291 md->m_len += complen;
292 md->m_data -= complen;
293 m->m_pkthdr.len += complen;
294 ipcomp = mtod(md, struct ipcomp *);
297 bzero(ipcomp, sizeof(*ipcomp));
298 ipcomp->comp_nxt = *nexthdrp;
299 *nexthdrp = IPPROTO_IPCOMP;
300 ipcomp->comp_cpi = htons(cpi);
304 if (compoff + complen + plen < IP_MAXPACKET)
305 ip->ip_len = htons(compoff + complen + plen);
308 "IPv4 ESP output: size exceeds limit\n"));
309 ipsecstat.out_inval++;
318 /* total packet length will be computed in ip6_output() */
326 "NULL mbuf after compression in ipcomp%d_output",
332 /* compute byte lifetime against original packet */
333 key_sa_recordxfer(sav, mcopy);
342 panic("something bad in ipcomp_output");
348 ipcomp4_output(struct mbuf *m, struct ipsecrequest *isr)
351 if (m->m_len < sizeof(struct ip)) {
352 ipseclog((LOG_DEBUG, "ipcomp4_output: first mbuf too short\n"));
353 ipsecstat.out_inval++;
357 ip = mtod(m, struct ip *);
358 /* XXX assumes that m->m_next points to payload */
359 return ipcomp_output(m, &ip->ip_p, m->m_next, isr, AF_INET);
365 ipcomp6_output(struct mbuf *m, u_char *nexthdrp, struct mbuf *md,
366 struct ipsecrequest *isr)
368 if (m->m_len < sizeof(struct ip6_hdr)) {
369 ipseclog((LOG_DEBUG, "ipcomp6_output: first mbuf too short\n"));
370 ipsec6stat.out_inval++;
374 return ipcomp_output(m, nexthdrp, md, isr, AF_INET6);