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