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 <libkern/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 #include <netinet/kpi_ipfilter_var.h>
  63
  64 #if INET6
  65 #include <netinet/ip6.h>
  66 #include <netinet6/ip6_var.h>
  67 #endif
  68 #include <netinet6/ipcomp.h>
  69 #if INET6
  70 #include <netinet6/ipcomp6.h>
  71 #endif
  72
  73 #include <netinet6/ipsec.h>
  74 #if INET6
  75 #include <netinet6/ipsec6.h>
  76 #endif
  77 #include <netkey/key.h>
  78 #include <netkey/keydb.h>
  79
  80 #include <net/net_osdep.h>
  81 #include <mach/sdt.h>
  82
  83 #define IPLEN_FLIPPED
  84
  85 void
  86 ipcomp4_input(struct mbuf *m, int off)
  87 {
  88         struct mbuf *md;
  89         struct ip *ip;
  90         struct ipcomp *ipcomp;
  91         const struct ipcomp_algorithm *algo;
  92         u_int16_t cpi;  /* host order */
  93         u_int16_t nxt;
  94         size_t hlen;
  95         int error;
  96         size_t newlen, olen;
  97         struct secasvar *sav = NULL;
  98
  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         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                 IPSEC_STAT_INCREMENT(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         error = (*algo->decompress)(m, m->m_next, &newlen);
 158         if (error != 0) {
 159                 if (error == EINVAL) {
 160                         IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
 161                 } else if (error == ENOBUFS)
 162                         IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
 163                 m = NULL;
 164                 goto fail;
 165         }
 166         IPSEC_STAT_INCREMENT(ipsecstat.in_comphist[cpi]);
 167
 168         /*
 169          * returning decompressed packet onto icmp is meaningless.
 170          * mark it decrypted to prevent icmp from attaching original packet.
 171          */
 172         m->m_flags |= M_DECRYPTED;
 173
 174         m->m_pkthdr.len = off + newlen;
 175         ip = mtod(m, struct ip *);
 176     {
 177         size_t len;
 178 #ifdef IPLEN_FLIPPED
 179         len = ip->ip_len;
 180 #else
 181         len = ntohs(ip->ip_len);
 182 #endif
 183         /*
 184          * be careful about underflow.  also, do not assign exact value
 185          * as ip_len is manipulated differently on *BSDs.
 186          */
 187         len += m->m_pkthdr.len;
 188         len -= olen;
 189         if (len & ~0xffff) {
 190                 /* packet too big after decompress */
 191                 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
 192                 goto fail;
 193         }
 194 #ifdef IPLEN_FLIPPED
 195         ip->ip_len = len & 0xffff;
 196 #else
 197         ip->ip_len = htons(len & 0xffff);
 198 #endif
 199         ip->ip_p = nxt;
 200     }
 201
 202         if (sav) {
 203                 key_sa_recordxfer(sav, m);
 204                 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
 205                         IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
 206                         goto fail;
 207                 }
 208                 key_freesav(sav, KEY_SADB_UNLOCKED);
 209                 sav = NULL;
 210         }
 211
 212         if (nxt != IPPROTO_DONE) {
 213                 if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
 214                     ipsec4_in_reject(m, NULL)) {
 215                         IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
 216                         goto fail;
 217                 }
 218
 219                 DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
 220                         struct ip *, ip, struct ifnet *, m->m_pkthdr.rcvif,
 221                         struct ip *, ip, struct ip6_hdr *, NULL);
 222
 223                 ip_proto_dispatch_in(m, off, nxt, 0);
 224         } else
 225                 m_freem(m);
 226         m = NULL;
 227
 228         IPSEC_STAT_INCREMENT(ipsecstat.in_success);
 229         return;
 230
 231 fail:
 232         if (sav)
 233                 key_freesav(sav, KEY_SADB_UNLOCKED);
 234
 235         if (m)
 236                 m_freem(m);
 237         return;
 238 }
 239
 240 #if INET6
 241 int
 242 ipcomp6_input(struct mbuf **mp, int *offp, int proto)
 243 {
 244 #pragma unused(proto)
 245         struct mbuf *m, *md;
 246         int off;
 247         struct ip6_hdr *ip6;
 248         struct ipcomp *ipcomp;
 249         const struct ipcomp_algorithm *algo;
 250         u_int16_t cpi;  /* host order */
 251         u_int16_t nxt;
 252         int error;
 253         size_t newlen;
 254         struct secasvar *sav = NULL;
 255         char *prvnxtp;
 256
 257         m = *mp;
 258         off = *offp;
 259
 260         md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
 261         if (!md) {
 262                 m = NULL;       /*already freed*/
 263                 ipseclog((LOG_DEBUG, "IPv6 IPComp input: assumption failed "
 264                     "(pulldown failure)\n"));
 265                 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
 266                 goto fail;
 267         }
 268         ipcomp = mtod(md, struct ipcomp *);
 269         ip6 = mtod(m, struct ip6_hdr *);
 270         nxt = ipcomp->comp_nxt;
 271
 272         cpi = ntohs(ipcomp->comp_cpi);
 273
 274         if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
 275                 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src,
 276                         (caddr_t)&ip6->ip6_dst, IPPROTO_IPCOMP, htonl(cpi));
 277                 if (sav != NULL
 278                  && (sav->state == SADB_SASTATE_MATURE
 279                   || sav->state == SADB_SASTATE_DYING)) {
 280                         cpi = sav->alg_enc;     /*XXX*/
 281                         /* other parameters to look at? */
 282                 }
 283         }
 284         algo = ipcomp_algorithm_lookup(cpi);
 285         if (!algo) {
 286                 ipseclog((LOG_WARNING, "IPv6 IPComp input: unknown cpi %u; "
 287                         "dropping the packet for simplicity\n", cpi));
 288                 IPSEC_STAT_INCREMENT(ipsec6stat.in_nosa);
 289                 goto fail;
 290         }
 291
 292         /* chop ipcomp header */
 293         ipcomp = NULL;
 294         md->m_data += sizeof(struct ipcomp);
 295         md->m_len -= sizeof(struct ipcomp);
 296         m->m_pkthdr.len -= sizeof(struct ipcomp);
 297
 298         newlen = m->m_pkthdr.len - off;
 299         error = (*algo->decompress)(m, md, &newlen);
 300         if (error != 0) {
 301                 if (error == EINVAL) {
 302                         IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
 303                 } else if (error == ENOBUFS)
 304                         IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
 305                 m = NULL;
 306                 goto fail;
 307         }
 308         IPSEC_STAT_INCREMENT(ipsec6stat.in_comphist[cpi]);
 309         m->m_pkthdr.len = off + newlen;
 310
 311         /*
 312          * returning decompressed packet onto icmp is meaningless.
 313          * mark it decrypted to prevent icmp from attaching original packet.
 314          */
 315         m->m_flags |= M_DECRYPTED;
 316
 317         /* update next header field */
 318         prvnxtp = ip6_get_prevhdr(m, off);
 319         *prvnxtp = nxt;
 320
 321         /*
 322          * no need to adjust payload length, as all the IPv6 protocols
 323          * look at m->m_pkthdr.len
 324          */
 325
 326         if (sav) {
 327                 key_sa_recordxfer(sav, m);
 328                 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
 329                         IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
 330                         goto fail;
 331                 }
 332                 key_freesav(sav, KEY_SADB_UNLOCKED);
 333                 sav = NULL;
 334         }
 335         *offp = off;
 336         *mp = m;
 337         IPSEC_STAT_INCREMENT(ipsec6stat.in_success);
 338         return nxt;
 339
 340 fail:
 341         if (m)
 342                 m_freem(m);
 343         if (sav)
 344                 key_freesav(sav, KEY_SADB_UNLOCKED);
 345         return IPPROTO_DONE;
 346 }
 347 #endif /* INET6 */