sys/netinet6/ipcomp_input.c

   1 /*      $FreeBSD: src/sys/netinet6/ipcomp_input.c,v 1.1.2.3 2002/04/28 05:40:27 suz Exp $       */
   2 /*      $DragonFly: src/sys/netinet6/ipcomp_input.c,v 1.8 2006/10/24 06:18:42 hsu Exp $ */
   3 /*      $KAME: ipcomp_input.c,v 1.25 2001/03/01 09:12:09 itojun Exp $   */
   4
   5 /*
   6  * Copyright (C) 1999 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  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
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * RFC2393 IP payload compression protocol (IPComp).
  36  */
  37
  38 #include "opt_inet.h"
  39 #include "opt_inet6.h"
  40
  41 #include <sys/param.h>
  42 #include <sys/systm.h>
  43 #include <sys/mbuf.h>
  44 #include <sys/domain.h>
  45 #include <sys/protosw.h>
  46 #include <sys/socket.h>
  47 #include <sys/errno.h>
  48 #include <sys/time.h>
  49 #include <sys/syslog.h>
  50
  51 #include <net/if.h>
  52 #include <net/route.h>
  53 #include <net/netisr.h>
  54 #include <net/zlib.h>
  55 #include <machine/cpu.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
  64 #ifdef INET6
  65 #include <netinet/ip6.h>
  66 #include <netinet6/ip6_var.h>
  67 #endif
  68 #include <netinet6/ipcomp.h>
  69 #ifdef INET6
  70 #include <netinet6/ipcomp6.h>
  71 #endif
  72
  73 #include <netinet6/ipsec.h>
  74 #ifdef INET6
  75 #include <netinet6/ipsec6.h>
  76 #endif
  77 #include <netproto/key/key.h>
  78 #include <netproto/key/keydb.h>
  79
  80 #include <machine/stdarg.h>
  81
  82 #include <net/net_osdep.h>
  83
  84 #define IPLEN_FLIPPED
  85
  86 #ifdef INET
  87 extern struct protosw inetsw[];
  88
  89 void
  90 ipcomp4_input(struct mbuf *m, ...)
  91 {
  92         int off, proto;
  93         struct mbuf *md;
  94         struct ip *ip;
  95         struct ipcomp *ipcomp;
  96         const struct ipcomp_algorithm *algo;
  97         u_int16_t cpi;  /* host order */
  98         u_int16_t nxt;
  99         size_t hlen;
 100         int error;
 101         size_t newlen, olen;
 102         struct secasvar *sav = NULL;
 103         __va_list ap;
 104
 105         __va_start(ap, m);
 106         off = __va_arg(ap, int);
 107         proto = __va_arg(ap, int);
 108         __va_end(ap);
 109
 110         if (m->m_pkthdr.len < off + sizeof(struct ipcomp)) {
 111                 ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
 112                     "(packet too short)\n"));
 113                 ipsecstat.in_inval++;
 114                 goto fail;
 115         }
 116
 117         md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
 118         if (!m) {
 119                 m = NULL;       /* already freed */
 120                 ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
 121                     "(pulldown failure)\n"));
 122                 ipsecstat.in_inval++;
 123                 goto fail;
 124         }
 125         ipcomp = mtod(md, struct ipcomp *);
 126         ip = mtod(m, struct ip *);
 127         nxt = ipcomp->comp_nxt;
 128 #ifdef _IP_VHL
 129         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 130 #else
 131         hlen = ip->ip_hl << 2;
 132 #endif
 133
 134         cpi = ntohs(ipcomp->comp_cpi);
 135
 136         if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
 137                 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src,
 138                         (caddr_t)&ip->ip_dst, IPPROTO_IPCOMP, htonl(cpi));
 139                 if (sav != NULL
 140                  && (sav->state == SADB_SASTATE_MATURE
 141                   || sav->state == SADB_SASTATE_DYING)) {
 142                         cpi = sav->alg_enc;     /* XXX */
 143                         /* other parameters to look at? */
 144                 }
 145         }
 146         algo = ipcomp_algorithm_lookup(cpi);
 147         if (!algo) {
 148                 ipseclog((LOG_WARNING, "IPv4 IPComp input: unknown cpi %u\n",
 149                         cpi));
 150                 ipsecstat.in_nosa++;
 151                 goto fail;
 152         }
 153
 154         /* chop ipcomp header */
 155         ipcomp = NULL;
 156         md->m_data += sizeof(struct ipcomp);
 157         md->m_len -= sizeof(struct ipcomp);
 158         m->m_pkthdr.len -= sizeof(struct ipcomp);
 159 #ifdef IPLEN_FLIPPED
 160         ip->ip_len -= sizeof(struct ipcomp);
 161 #else
 162         ip->ip_len = htons(ntohs(ip->ip_len) - sizeof(struct ipcomp));
 163 #endif
 164
 165         olen = m->m_pkthdr.len;
 166         newlen = m->m_pkthdr.len - off;
 167         error = (*algo->decompress)(m, m->m_next, &newlen);
 168         if (error != 0) {
 169                 if (error == EINVAL)
 170                         ipsecstat.in_inval++;
 171                 else if (error == ENOBUFS)
 172                         ipsecstat.in_nomem++;
 173                 m = NULL;
 174                 goto fail;
 175         }
 176         ipsecstat.in_comphist[cpi]++;
 177
 178         /*
 179          * returning decompressed packet onto icmp is meaningless.
 180          * mark it decrypted to prevent icmp from attaching original packet.
 181          */
 182         m->m_flags |= M_DECRYPTED;
 183
 184         m->m_pkthdr.len = off + newlen;
 185         ip = mtod(m, struct ip *);
 186     {
 187         size_t len;
 188 #ifdef IPLEN_FLIPPED
 189         len = ip->ip_len;
 190 #else
 191         len = ntohs(ip->ip_len);
 192 #endif
 193         /*
 194          * be careful about underflow.  also, do not assign exact value
 195          * as ip_len is manipulated differently on *BSDs.
 196          */
 197         len += m->m_pkthdr.len;
 198         len -= olen;
 199         if (len & ~0xffff) {
 200                 /* packet too big after decompress */
 201                 ipsecstat.in_inval++;
 202                 goto fail;
 203         }
 204 #ifdef IPLEN_FLIPPED
 205         ip->ip_len = len & 0xffff;
 206 #else
 207         ip->ip_len = htons(len & 0xffff);
 208 #endif
 209         ip->ip_p = nxt;
 210     }
 211
 212         if (sav) {
 213                 key_sa_recordxfer(sav, m);
 214                 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
 215                         ipsecstat.in_nomem++;
 216                         goto fail;
 217                 }
 218                 key_freesav(sav);
 219                 sav = NULL;
 220         }
 221
 222         if (nxt != IPPROTO_DONE) {
 223                 if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) &&
 224                     ipsec4_in_reject(m, NULL)) {
 225                         ipsecstat.in_polvio++;
 226                         goto fail;
 227                 }
 228                 (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
 229         } else
 230                 m_freem(m);
 231         m = NULL;
 232
 233         ipsecstat.in_success++;
 234         return;
 235
 236 fail:
 237         if (sav)
 238                 key_freesav(sav);
 239         if (m)
 240                 m_freem(m);
 241         return;
 242 }
 243 #endif /* INET */
 244
 245 #ifdef INET6
 246 int
 247 ipcomp6_input(struct mbuf **mp, int *offp, int proto)
 248 {
 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 (!m) {
 266                 m = NULL;       /* already freed */
 267                 ipseclog((LOG_DEBUG, "IPv6 IPComp input: assumption failed "
 268                     "(pulldown failure)\n"));
 269                 ipsec6stat.in_inval++;
 270                 goto fail;
 271         }
 272         ipcomp = mtod(md, struct ipcomp *);
 273         ip6 = mtod(m, struct ip6_hdr *);
 274         nxt = ipcomp->comp_nxt;
 275
 276         cpi = ntohs(ipcomp->comp_cpi);
 277
 278         if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
 279                 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src,
 280                         (caddr_t)&ip6->ip6_dst, IPPROTO_IPCOMP, htonl(cpi));
 281                 if (sav != NULL
 282                  && (sav->state == SADB_SASTATE_MATURE
 283                   || sav->state == SADB_SASTATE_DYING)) {
 284                         cpi = sav->alg_enc;     /* XXX */
 285                         /* other parameters to look at? */
 286                 }
 287         }
 288         algo = ipcomp_algorithm_lookup(cpi);
 289         if (!algo) {
 290                 ipseclog((LOG_WARNING, "IPv6 IPComp input: unknown cpi %u; "
 291                         "dropping the packet for simplicity\n", cpi));
 292                 ipsec6stat.in_nosa++;
 293                 goto fail;
 294         }
 295
 296         /* chop ipcomp header */
 297         ipcomp = NULL;
 298         md->m_data += sizeof(struct ipcomp);
 299         md->m_len -= sizeof(struct ipcomp);
 300         m->m_pkthdr.len -= sizeof(struct ipcomp);
 301
 302         newlen = m->m_pkthdr.len - off;
 303         error = (*algo->decompress)(m, md, &newlen);
 304         if (error != 0) {
 305                 if (error == EINVAL)
 306                         ipsec6stat.in_inval++;
 307                 else if (error == ENOBUFS)
 308                         ipsec6stat.in_nomem++;
 309                 m = NULL;
 310                 goto fail;
 311         }
 312         ipsec6stat.in_comphist[cpi]++;
 313         m->m_pkthdr.len = off + newlen;
 314
 315         /*
 316          * returning decompressed packet onto icmp is meaningless.
 317          * mark it decrypted to prevent icmp from attaching original packet.
 318          */
 319         m->m_flags |= M_DECRYPTED;
 320
 321         /* update next header field */
 322         prvnxtp = ip6_get_prevhdr(m, off);
 323         *prvnxtp = nxt;
 324
 325         /*
 326          * no need to adjust payload length, as all the IPv6 protocols
 327          * look at m->m_pkthdr.len
 328          */
 329
 330         if (sav) {
 331                 key_sa_recordxfer(sav, m);
 332                 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
 333                         ipsec6stat.in_nomem++;
 334                         goto fail;
 335                 }
 336                 key_freesav(sav);
 337                 sav = NULL;
 338         }
 339         *offp = off;
 340         *mp = m;
 341         ipsec6stat.in_success++;
 342         return nxt;
 343
 344 fail:
 345         if (m)
 346                 m_freem(m);
 347         if (sav)
 348                 key_freesav(sav);
 349         return IPPROTO_DONE;
 350 }
 351 #endif /* INET6 */