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 /*      $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 <netproto/key/key.h>
  77 #include <netproto/key/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 int
  89 ipcomp4_input(struct mbuf **mp, int *offp, int proto)
  90 {
  91         int off;
  92         struct mbuf *md;
  93         struct mbuf *m;
  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         int error;
 100         size_t newlen, olen;
 101         struct secasvar *sav = NULL;
 102
 103         off = *offp;
 104         m = *mp;
 105         *mp = NULL;
 106
 107         if (m->m_pkthdr.len < off + sizeof(struct ipcomp)) {
 108                 ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
 109                     "(packet too short)\n"));
 110                 ipsecstat.in_inval++;
 111                 goto fail;
 112         }
 113
 114         md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
 115         if (!md) {
 116                 m = NULL;       /* already freed */
 117                 ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
 118                     "(pulldown failure)\n"));
 119                 ipsecstat.in_inval++;
 120                 goto fail;
 121         }
 122         ipcomp = mtod(md, struct ipcomp *);
 123         ip = mtod(m, struct ip *);
 124         nxt = ipcomp->comp_nxt;
 125
 126         cpi = ntohs(ipcomp->comp_cpi);
 127
 128         if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
 129                 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src,
 130                         (caddr_t)&ip->ip_dst, IPPROTO_IPCOMP, htonl(cpi));
 131                 if (sav != NULL
 132                  && (sav->state == SADB_SASTATE_MATURE
 133                   || sav->state == SADB_SASTATE_DYING)) {
 134                         cpi = sav->alg_enc;     /* XXX */
 135                         /* other parameters to look at? */
 136                 }
 137         }
 138         algo = ipcomp_algorithm_lookup(cpi);
 139         if (!algo) {
 140                 ipseclog((LOG_WARNING, "IPv4 IPComp input: unknown cpi %u\n",
 141                         cpi));
 142                 ipsecstat.in_nosa++;
 143                 goto fail;
 144         }
 145
 146         /* chop ipcomp header */
 147         ipcomp = NULL;
 148         md->m_data += sizeof(struct ipcomp);
 149         md->m_len -= sizeof(struct ipcomp);
 150         m->m_pkthdr.len -= sizeof(struct ipcomp);
 151 #ifdef IPLEN_FLIPPED
 152         ip->ip_len -= sizeof(struct ipcomp);
 153 #else
 154         ip->ip_len = htons(ntohs(ip->ip_len) - sizeof(struct ipcomp));
 155 #endif
 156
 157         olen = m->m_pkthdr.len;
 158         newlen = m->m_pkthdr.len - off;
 159         error = (*algo->decompress)(m, m->m_next, &newlen);
 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 ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) &&
 216                     ipsec4_in_reject(m, NULL)) {
 217                         ipsecstat.in_polvio++;
 218                         goto fail;
 219                 }
 220                 *mp = m;
 221                 *offp = off;
 222                 (*inetsw[ip_protox[nxt]].pr_input)(mp, offp, nxt);
 223         } else {
 224                 m_freem(m);
 225         }
 226         m = NULL;
 227
 228         ipsecstat.in_success++;
 229         return(IPPROTO_DONE);
 230
 231 fail:
 232         if (sav)
 233                 key_freesav(sav);
 234         if (m)
 235                 m_freem(m);
 236         return(IPPROTO_DONE);
 237 }
 238 #endif /* INET */
 239
 240 #ifdef INET6
 241 int
 242 ipcomp6_input(struct mbuf **mp, int *offp, int proto)
 243 {
 244         struct mbuf *m, *md;
 245         int off;
 246         struct ip6_hdr *ip6;
 247         struct ipcomp *ipcomp;
 248         const struct ipcomp_algorithm *algo;
 249         u_int16_t cpi;  /* host order */
 250         u_int16_t nxt;
 251         int error;
 252         size_t newlen;
 253         struct secasvar *sav = NULL;
 254         char *prvnxtp;
 255
 256         m = *mp;
 257         off = *offp;
 258
 259         md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
 260         if (!md) {
 261                 m = NULL;       /* already freed */
 262                 ipseclog((LOG_DEBUG, "IPv6 IPComp input: assumption failed "
 263                     "(pulldown failure)\n"));
 264                 ipsec6stat.in_inval++;
 265                 goto fail;
 266         }
 267         ipcomp = mtod(md, struct ipcomp *);
 268         ip6 = mtod(m, struct ip6_hdr *);
 269         nxt = ipcomp->comp_nxt;
 270
 271         cpi = ntohs(ipcomp->comp_cpi);
 272
 273         if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
 274                 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src,
 275                     (caddr_t)&ip6->ip6_dst, IPPROTO_IPCOMP, htonl(cpi));
 276                 if (sav != NULL
 277                  && (sav->state == SADB_SASTATE_MATURE
 278                   || sav->state == SADB_SASTATE_DYING)) {
 279                         cpi = sav->alg_enc;     /* XXX */
 280                         /* other parameters to look at? */
 281                 }
 282         }
 283         algo = ipcomp_algorithm_lookup(cpi);
 284         if (!algo) {
 285                 ipseclog((LOG_WARNING, "IPv6 IPComp input: unknown cpi %u; "
 286                         "dropping the packet for simplicity\n", cpi));
 287                 ipsec6stat.in_nosa++;
 288                 goto fail;
 289         }
 290
 291         /* chop ipcomp header */
 292         ipcomp = NULL;
 293         md->m_data += sizeof(struct ipcomp);
 294         md->m_len -= sizeof(struct ipcomp);
 295         m->m_pkthdr.len -= sizeof(struct ipcomp);
 296
 297         newlen = m->m_pkthdr.len - off;
 298         error = (*algo->decompress)(m, md, &newlen);
 299         if (error != 0) {
 300                 if (error == EINVAL)
 301                         ipsec6stat.in_inval++;
 302                 else if (error == ENOBUFS)
 303                         ipsec6stat.in_nomem++;
 304                 m = NULL;
 305                 goto fail;
 306         }
 307         ipsec6stat.in_comphist[cpi]++;
 308         m->m_pkthdr.len = off + newlen;
 309
 310         /*
 311          * returning decompressed packet onto icmp is meaningless.
 312          * mark it decrypted to prevent icmp from attaching original packet.
 313          */
 314         m->m_flags |= M_DECRYPTED;
 315
 316         /* update next header field */
 317         prvnxtp = ip6_get_prevhdr(m, off);
 318         *prvnxtp = nxt;
 319
 320         /*
 321          * no need to adjust payload length, as all the IPv6 protocols
 322          * look at m->m_pkthdr.len
 323          */
 324
 325         if (sav) {
 326                 key_sa_recordxfer(sav, m);
 327                 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
 328                         ipsec6stat.in_nomem++;
 329                         goto fail;
 330                 }
 331                 key_freesav(sav);
 332                 sav = NULL;
 333         }
 334         *offp = off;
 335         *mp = m;
 336         ipsec6stat.in_success++;
 337         return nxt;
 338
 339 fail:
 340         if (m)
 341                 m_freem(m);
 342         if (sav)
 343                 key_freesav(sav);
 344         return IPPROTO_DONE;
 345 }
 346 #endif /* INET6 */