sys/netinet6/ipcomp_input.c

   1 /*      $FreeBSD$       */
   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 #include "opt_inet.h"
  38 #include "opt_inet6.h"
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/mbuf.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/syslog.h>
  49
  50 #include <net/if.h>
  51 #include <net/route.h>
  52 #include <net/netisr.h>
  53 #include <net/zlib.h>
  54 #include <machine/cpu.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 #ifdef INET6
  64 #include <netinet/ip6.h>
  65 #include <netinet6/ip6_var.h>
  66 #endif
  67 #include <netinet6/ipcomp.h>
  68 #ifdef INET6
  69 #include <netinet6/ipcomp6.h>
  70 #endif
  71
  72 #include <netinet6/ipsec.h>
  73 #ifdef INET6
  74 #include <netinet6/ipsec6.h>
  75 #endif
  76 #include <netkey/key.h>
  77 #include <netkey/keydb.h>
  78
  79 #include <machine/stdarg.h>
  80
  81 #include <net/net_osdep.h>
  82
  83 #define IPLEN_FLIPPED
  84
  85 #ifdef INET
  86 extern struct protosw inetsw[];
  87
  88 void
  89 ipcomp4_input(m, off)
  90         struct mbuf *m;
  91         int off;
  92 {
  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         int proto;
 104
 105         if (m->m_pkthdr.len < off + sizeof(struct ipcomp)) {
 106                 ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
 107                     "(packet too short)\n"));
 108                 ipsecstat.in_inval++;
 109                 goto fail;
 110         }
 111
 112         md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
 113         if (!m) {
 114                 m = NULL;       /*already freed*/
 115                 ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
 116                     "(pulldown failure)\n"));
 117                 ipsecstat.in_inval++;
 118                 goto fail;
 119         }
 120         ipcomp = mtod(md, struct ipcomp *);
 121         ip = mtod(m, struct ip *);
 122         proto = ip->ip_p;
 123         nxt = ipcomp->comp_nxt;
 124 #ifdef _IP_VHL
 125         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 126 #else
 127         hlen = ip->ip_hl << 2;
 128 #endif
 129
 130         cpi = ntohs(ipcomp->comp_cpi);
 131
 132         if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
 133                 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src,
 134                         (caddr_t)&ip->ip_dst, IPPROTO_IPCOMP, htonl(cpi));
 135                 if (sav != NULL
 136                  && (sav->state == SADB_SASTATE_MATURE
 137                   || sav->state == SADB_SASTATE_DYING)) {
 138                         cpi = sav->alg_enc;     /*XXX*/
 139                         /* other parameters to look at? */
 140                 }
 141         }
 142         algo = ipcomp_algorithm_lookup(cpi);
 143         if (!algo) {
 144                 ipseclog((LOG_WARNING, "IPv4 IPComp input: unknown cpi %u\n",
 145                         cpi));
 146                 ipsecstat.in_nosa++;
 147                 goto fail;
 148         }
 149
 150         /* chop ipcomp header */
 151         ipcomp = NULL;
 152         md->m_data += sizeof(struct ipcomp);
 153         md->m_len -= sizeof(struct ipcomp);
 154         m->m_pkthdr.len -= sizeof(struct ipcomp);
 155 #ifdef IPLEN_FLIPPED
 156         ip->ip_len -= sizeof(struct ipcomp);
 157 #else
 158         ip->ip_len = htons(ntohs(ip->ip_len) - sizeof(struct ipcomp));
 159 #endif
 160
 161         olen = m->m_pkthdr.len;
 162         newlen = m->m_pkthdr.len - off;
 163         error = (*algo->decompress)(m, m->m_next, &newlen);
 164         if (error != 0) {
 165                 if (error == EINVAL)
 166                         ipsecstat.in_inval++;
 167                 else if (error == ENOBUFS)
 168                         ipsecstat.in_nomem++;
 169                 m = NULL;
 170                 goto fail;
 171         }
 172         ipsecstat.in_comphist[cpi]++;
 173
 174         /*
 175          * returning decompressed packet onto icmp is meaningless.
 176          * mark it decrypted to prevent icmp from attaching original packet.
 177          */
 178         m->m_flags |= M_DECRYPTED;
 179
 180         m->m_pkthdr.len = off + newlen;
 181         ip = mtod(m, struct ip *);
 182     {
 183         size_t len;
 184 #ifdef IPLEN_FLIPPED
 185         len = ip->ip_len;
 186 #else
 187         len = ntohs(ip->ip_len);
 188 #endif
 189         /*
 190          * be careful about underflow.  also, do not assign exact value
 191          * as ip_len is manipulated differently on *BSDs.
 192          */
 193         len += m->m_pkthdr.len;
 194         len -= olen;
 195         if (len & ~0xffff) {
 196                 /* packet too big after decompress */
 197                 ipsecstat.in_inval++;
 198                 goto fail;
 199         }
 200 #ifdef IPLEN_FLIPPED
 201         ip->ip_len = len & 0xffff;
 202 #else
 203         ip->ip_len = htons(len & 0xffff);
 204 #endif
 205         ip->ip_p = nxt;
 206     }
 207
 208         if (sav) {
 209                 key_sa_recordxfer(sav, m);
 210                 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
 211                         ipsecstat.in_nomem++;
 212                         goto fail;
 213                 }
 214                 key_freesav(sav);
 215                 sav = NULL;
 216         }
 217
 218         if (nxt != IPPROTO_DONE) {
 219                 if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
 220                     ipsec4_in_reject(m, NULL)) {
 221                         ipsecstat.in_polvio++;
 222                         goto fail;
 223                 }
 224                 (*inetsw[ip_protox[nxt]].pr_input)(m, off);
 225         } else
 226                 m_freem(m);
 227         m = NULL;
 228
 229         ipsecstat.in_success++;
 230         return;
 231
 232 fail:
 233         if (sav)
 234                 key_freesav(sav);
 235         if (m)
 236                 m_freem(m);
 237         return;
 238 }
 239 #endif /* INET */
 240
 241 #ifdef INET6
 242 int
 243 ipcomp6_input(mp, offp, proto)
 244         struct mbuf **mp;
 245         int *offp, proto;
 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         md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
 263         if (!m) {
 264                 m = NULL;       /*already freed*/
 265                 ipseclog((LOG_DEBUG, "IPv6 IPComp input: assumption failed "
 266                     "(pulldown failure)\n"));
 267                 ipsec6stat.in_inval++;
 268                 goto fail;
 269         }
 270         ipcomp = mtod(md, struct ipcomp *);
 271         ip6 = mtod(m, struct ip6_hdr *);
 272         nxt = ipcomp->comp_nxt;
 273
 274         cpi = ntohs(ipcomp->comp_cpi);
 275
 276         if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
 277                 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src,
 278                         (caddr_t)&ip6->ip6_dst, IPPROTO_IPCOMP, htonl(cpi));
 279                 if (sav != NULL
 280                  && (sav->state == SADB_SASTATE_MATURE
 281                   || sav->state == SADB_SASTATE_DYING)) {
 282                         cpi = sav->alg_enc;     /*XXX*/
 283                         /* other parameters to look at? */
 284                 }
 285         }
 286         algo = ipcomp_algorithm_lookup(cpi);
 287         if (!algo) {
 288                 ipseclog((LOG_WARNING, "IPv6 IPComp input: unknown cpi %u; "
 289                         "dropping the packet for simplicity\n", cpi));
 290                 ipsec6stat.in_nosa++;
 291                 goto fail;
 292         }
 293
 294         /* chop ipcomp header */
 295         ipcomp = NULL;
 296         md->m_data += sizeof(struct ipcomp);
 297         md->m_len -= sizeof(struct ipcomp);
 298         m->m_pkthdr.len -= sizeof(struct ipcomp);
 299
 300         newlen = m->m_pkthdr.len - off;
 301         error = (*algo->decompress)(m, md, &newlen);
 302         if (error != 0) {
 303                 if (error == EINVAL)
 304                         ipsec6stat.in_inval++;
 305                 else if (error == ENOBUFS)
 306                         ipsec6stat.in_nomem++;
 307                 m = NULL;
 308                 goto fail;
 309         }
 310         ipsec6stat.in_comphist[cpi]++;
 311         m->m_pkthdr.len = off + newlen;
 312
 313         /*
 314          * returning decompressed packet onto icmp is meaningless.
 315          * mark it decrypted to prevent icmp from attaching original packet.
 316          */
 317         m->m_flags |= M_DECRYPTED;
 318
 319         /* update next header field */
 320         prvnxtp = ip6_get_prevhdr(m, off);
 321         *prvnxtp = nxt;
 322
 323         /*
 324          * no need to adjust payload length, as all the IPv6 protocols
 325          * look at m->m_pkthdr.len
 326          */
 327
 328         if (sav) {
 329                 key_sa_recordxfer(sav, m);
 330                 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
 331                         ipsec6stat.in_nomem++;
 332                         goto fail;
 333                 }
 334                 key_freesav(sav);
 335                 sav = NULL;
 336         }
 337         *offp = off;
 338         *mp = m;
 339         ipsec6stat.in_success++;
 340         return nxt;
 341
 342 fail:
 343         if (m)
 344                 m_freem(m);
 345         if (sav)
 346                 key_freesav(sav);
 347         return IPPROTO_DONE;
 348 }
 349 #endif /* INET6 */