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/mcache.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/kernel.h>
  49 #include <sys/syslog.h>
  50
  51 #include <net/if.h>
  52 #include <net/route.h>
  53 #include <libkern/zlib.h>
  54 #include <kern/cpu_number.h>
  55 #include <kern/locks.h>
  56
  57 #include <netinet/in.h>
  58 #include <netinet/in_systm.h>
  59 #include <netinet/in_var.h>
  60 #include <netinet/ip.h>
  61 #include <netinet/ip_var.h>
  62 #include <netinet/ip_ecn.h>
  63 #include <netinet/kpi_ipfilter_var.h>
  64
  65 #if INET6
  66 #include <netinet/ip6.h>
  67 #include <netinet6/ip6_var.h>
  68 #endif
  69 #include <netinet6/ipcomp.h>
  70 #if INET6
  71 #include <netinet6/ipcomp6.h>
  72 #endif
  73
  74 #include <netinet6/ipsec.h>
  75 #if INET6
  76 #include <netinet6/ipsec6.h>
  77 #endif
  78 #include <netkey/key.h>
  79 #include <netkey/keydb.h>
  80
  81 #include <net/net_osdep.h>
  82 #include <mach/sdt.h>
  83
  84 #define IPLEN_FLIPPED
  85
  86 void
  87 ipcomp4_input(struct mbuf *m, int off)
  88 {
  89         struct mbuf *md;
  90         struct ip *ip;
  91         struct ipcomp *ipcomp;
  92         const struct ipcomp_algorithm *algo;
  93         u_int16_t cpi;  /* host order */
  94         u_int16_t nxt;
  95         size_t hlen;
  96         int error;
  97         size_t newlen, olen;
  98         struct secasvar *sav = NULL;
  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
 117         /* Expect 32-bit aligned data pointer on strict-align platforms */
 118         MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
 119
 120         ip = mtod(m, struct ip *);
 121         nxt = ipcomp->comp_nxt;
 122 #ifdef _IP_VHL
 123         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 124 #else
 125         hlen = ip->ip_hl << 2;
 126 #endif
 127
 128         cpi = ntohs(ipcomp->comp_cpi);
 129
 130         if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
 131                 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src,
 132                     (caddr_t)&ip->ip_dst, IPPROTO_IPCOMP, htonl(cpi));
 133                 if (sav != NULL
 134                     && (sav->state == SADB_SASTATE_MATURE
 135                     || sav->state == SADB_SASTATE_DYING)) {
 136                         cpi = sav->alg_enc;     /*XXX*/
 137                         /* other parameters to look at? */
 138                 }
 139         }
 140         algo = ipcomp_algorithm_lookup(cpi);
 141         if (!algo) {
 142                 ipseclog((LOG_WARNING, "IPv4 IPComp input: unknown cpi %u\n",
 143                     cpi));
 144                 IPSEC_STAT_INCREMENT(ipsecstat.in_nosa);
 145                 goto fail;
 146         }
 147
 148         /* chop ipcomp header */
 149         ipcomp = NULL;
 150         md->m_data += sizeof(struct ipcomp);
 151         md->m_len -= sizeof(struct ipcomp);
 152         m->m_pkthdr.len -= sizeof(struct ipcomp);
 153 #ifdef IPLEN_FLIPPED
 154         ip->ip_len -= sizeof(struct ipcomp);
 155 #else
 156         ip->ip_len = htons(ntohs(ip->ip_len) - sizeof(struct ipcomp));
 157 #endif
 158
 159         olen = m->m_pkthdr.len;
 160         newlen = m->m_pkthdr.len - off;
 161         error = (*algo->decompress)(m, m->m_next, &newlen);
 162         if (error != 0) {
 163                 if (error == EINVAL) {
 164                         IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
 165                 } else if (error == ENOBUFS) {
 166                         IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
 167                 }
 168                 m = NULL;
 169                 goto fail;
 170         }
 171         IPSEC_STAT_INCREMENT(ipsecstat.in_comphist[cpi]);
 172
 173         /*
 174          * returning decompressed packet onto icmp is meaningless.
 175          * mark it decrypted to prevent icmp from attaching original packet.
 176          */
 177         m->m_flags |= M_DECRYPTED;
 178
 179         m->m_pkthdr.len = off + newlen;
 180         ip = mtod(m, struct ip *);
 181         {
 182                 size_t len;
 183 #ifdef IPLEN_FLIPPED
 184                 len = ip->ip_len;
 185 #else
 186                 len = ntohs(ip->ip_len);
 187 #endif
 188                 /*
 189                  * be careful about underflow.  also, do not assign exact value
 190                  * as ip_len is manipulated differently on *BSDs.
 191                  */
 192                 len += m->m_pkthdr.len;
 193                 len -= olen;
 194                 if (len & ~0xffff) {
 195                         /* packet too big after decompress */
 196                         IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
 197                         goto fail;
 198                 }
 199 #ifdef IPLEN_FLIPPED
 200                 ip->ip_len = len & 0xffff;
 201 #else
 202                 ip->ip_len = htons(len & 0xffff);
 203 #endif
 204                 ip->ip_p = nxt;
 205         }
 206
 207         if (sav) {
 208                 key_sa_recordxfer(sav, m);
 209                 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
 210                         IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
 211                         goto fail;
 212                 }
 213                 key_freesav(sav, KEY_SADB_UNLOCKED);
 214                 sav = NULL;
 215         }
 216
 217         if (nxt != IPPROTO_DONE) {
 218                 if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
 219                     ipsec4_in_reject(m, NULL)) {
 220                         IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
 221                         goto fail;
 222                 }
 223
 224                 DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
 225                     struct ip *, ip, struct ifnet *, m->m_pkthdr.rcvif,
 226                     struct ip *, ip, struct ip6_hdr *, NULL);
 227
 228                 ip_proto_dispatch_in(m, off, nxt, 0);
 229         } else {
 230                 m_freem(m);
 231         }
 232         m = NULL;
 233
 234         IPSEC_STAT_INCREMENT(ipsecstat.in_success);
 235         return;
 236
 237 fail:
 238         if (sav) {
 239                 key_freesav(sav, KEY_SADB_UNLOCKED);
 240         }
 241
 242         if (m) {
 243                 m_freem(m);
 244         }
 245         return;
 246 }
 247
 248 #if INET6
 249 int
 250 ipcomp6_input(struct mbuf **mp, int *offp, int proto)
 251 {
 252 #pragma unused(proto)
 253         struct mbuf *m, *md;
 254         int off;
 255         struct ip6_hdr *ip6;
 256         struct ipcomp *ipcomp;
 257         const struct ipcomp_algorithm *algo;
 258         u_int16_t cpi;  /* host order */
 259         u_int16_t nxt;
 260         int error;
 261         size_t newlen;
 262         struct secasvar *sav = NULL;
 263         char *prvnxtp;
 264
 265         m = *mp;
 266         off = *offp;
 267
 268         md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
 269         if (!md) {
 270                 m = NULL;       /*already freed*/
 271                 ipseclog((LOG_DEBUG, "IPv6 IPComp input: assumption failed "
 272                     "(pulldown failure)\n"));
 273                 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
 274                 goto fail;
 275         }
 276         ipcomp = mtod(md, struct ipcomp *);
 277
 278         /* Expect 32-bit aligned data pointer on strict-align platforms */
 279         MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
 280
 281         ip6 = mtod(m, struct ip6_hdr *);
 282         nxt = ipcomp->comp_nxt;
 283
 284         cpi = ntohs(ipcomp->comp_cpi);
 285
 286         if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
 287                 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src,
 288                     (caddr_t)&ip6->ip6_dst, IPPROTO_IPCOMP, htonl(cpi));
 289                 if (sav != NULL
 290                     && (sav->state == SADB_SASTATE_MATURE
 291                     || sav->state == SADB_SASTATE_DYING)) {
 292                         cpi = sav->alg_enc;     /*XXX*/
 293                         /* other parameters to look at? */
 294                 }
 295         }
 296         algo = ipcomp_algorithm_lookup(cpi);
 297         if (!algo) {
 298                 ipseclog((LOG_WARNING, "IPv6 IPComp input: unknown cpi %u; "
 299                     "dropping the packet for simplicity\n", cpi));
 300                 IPSEC_STAT_INCREMENT(ipsec6stat.in_nosa);
 301                 goto fail;
 302         }
 303
 304         /* chop ipcomp header */
 305         ipcomp = NULL;
 306         md->m_data += sizeof(struct ipcomp);
 307         md->m_len -= sizeof(struct ipcomp);
 308         m->m_pkthdr.len -= sizeof(struct ipcomp);
 309
 310         newlen = m->m_pkthdr.len - off;
 311         error = (*algo->decompress)(m, md, &newlen);
 312         if (error != 0) {
 313                 if (error == EINVAL) {
 314                         IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
 315                 } else if (error == ENOBUFS) {
 316                         IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
 317                 }
 318                 m = NULL;
 319                 goto fail;
 320         }
 321         IPSEC_STAT_INCREMENT(ipsec6stat.in_comphist[cpi]);
 322         m->m_pkthdr.len = off + newlen;
 323
 324         /*
 325          * returning decompressed packet onto icmp is meaningless.
 326          * mark it decrypted to prevent icmp from attaching original packet.
 327          */
 328         m->m_flags |= M_DECRYPTED;
 329
 330         /* update next header field */
 331         prvnxtp = ip6_get_prevhdr(m, off);
 332         *prvnxtp = nxt;
 333
 334         /*
 335          * no need to adjust payload length, as all the IPv6 protocols
 336          * look at m->m_pkthdr.len
 337          */
 338
 339         if (sav) {
 340                 key_sa_recordxfer(sav, m);
 341                 if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
 342                         IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
 343                         goto fail;
 344                 }
 345                 key_freesav(sav, KEY_SADB_UNLOCKED);
 346                 sav = NULL;
 347         }
 348         *offp = off;
 349         *mp = m;
 350         IPSEC_STAT_INCREMENT(ipsec6stat.in_success);
 351         return nxt;
 352
 353 fail:
 354         if (m) {
 355                 m_freem(m);
 356         }
 357         if (sav) {
 358                 key_freesav(sav, KEY_SADB_UNLOCKED);
 359         }
 360         return IPPROTO_DONE;
 361 }
 362 #endif /* INET6 */