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