bsd/netinet6/ipcomp_input.c

   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
  86 void
  87 ipcomp4_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
 235 fail:
 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
 245 int
 246 ipcomp6_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
 348 fail:
 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 */