bsd/netinet6/esp_output.c

   1 /*      $FreeBSD: src/sys/netinet6/esp_output.c,v 1.1.2.2 2001/07/03 11:01:50 ume Exp $ */
   2 /*      $KAME: esp_output.c,v 1.43 2001/03/01 07:10:45 itojun Exp $     */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 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 #define _IP_VHL
  34
  35 /*
  36  * RFC1827/2406 Encapsulated Security Payload.
  37  */
  38
  39 #include <sys/param.h>
  40 #include <sys/systm.h>
  41 #include <sys/malloc.h>
  42 #include <sys/mbuf.h>
  43 #include <sys/domain.h>
  44 #include <sys/protosw.h>
  45 #include <sys/socket.h>
  46 #include <sys/socketvar.h>
  47 #include <sys/errno.h>
  48 #include <sys/time.h>
  49 #include <sys/kernel.h>
  50 #include <sys/syslog.h>
  51
  52 #include <net/if.h>
  53 #include <net/route.h>
  54
  55 #include <netinet/in.h>
  56 #include <netinet/in_systm.h>
  57 #include <netinet/ip.h>
  58 #include <netinet/in_var.h>
  59
  60 #if INET6
  61 #include <netinet/ip6.h>
  62 #include <netinet6/ip6_var.h>
  63 #include <netinet/icmp6.h>
  64 #endif
  65
  66 #include <netinet6/ipsec.h>
  67 #if INET6
  68 #include <netinet6/ipsec6.h>
  69 #endif
  70 #include <netinet6/ah.h>
  71 #if INET6
  72 #include <netinet6/ah6.h>
  73 #endif
  74 #include <netinet6/esp.h>
  75 #if INET6
  76 #include <netinet6/esp6.h>
  77 #endif
  78 #include <netkey/key.h>
  79 #include <netkey/keydb.h>
  80
  81 #include <net/net_osdep.h>
  82
  83 static int esp_output __P((struct mbuf *, u_char *, struct mbuf *,
  84         struct ipsecrequest *, int));
  85
  86 /*
  87  * compute ESP header size.
  88  */
  89 size_t
  90 esp_hdrsiz(isr)
  91         struct ipsecrequest *isr;
  92 {
  93         struct secasvar *sav;
  94         const struct esp_algorithm *algo;
  95         const struct ah_algorithm *aalgo;
  96         size_t ivlen;
  97         size_t authlen;
  98         size_t hdrsiz;
  99
 100         /* sanity check */
 101         if (isr == NULL)
 102                 panic("esp_hdrsiz: NULL was passed.\n");
 103
 104         sav = isr->sav;
 105
 106         if (isr->saidx.proto != IPPROTO_ESP)
 107                 panic("unsupported mode passed to esp_hdrsiz");
 108
 109         if (sav == NULL)
 110                 goto estimate;
 111         if (sav->state != SADB_SASTATE_MATURE
 112          && sav->state != SADB_SASTATE_DYING)
 113                 goto estimate;
 114
 115         /* we need transport mode ESP. */
 116         algo = esp_algorithm_lookup(sav->alg_enc);
 117         if (!algo)
 118                 goto estimate;
 119         ivlen = sav->ivlen;
 120         if (ivlen < 0)
 121                 goto estimate;
 122
 123         /*
 124          * XXX
 125          * right now we don't calcurate the padding size.  simply
 126          * treat the padding size as constant, for simplicity.
 127          *
 128          * XXX variable size padding support
 129          */
 130         if (sav->flags & SADB_X_EXT_OLD) {
 131                 /* RFC 1827 */
 132                 hdrsiz = sizeof(struct esp) + ivlen + 9;
 133         } else {
 134                 /* RFC 2406 */
 135                 aalgo = ah_algorithm_lookup(sav->alg_auth);
 136                 if (aalgo && sav->replay && sav->key_auth)
 137                         authlen = (aalgo->sumsiz)(sav);
 138                 else
 139                         authlen = 0;
 140                 hdrsiz = sizeof(struct newesp) + ivlen + 9 + authlen;
 141         }
 142
 143         return hdrsiz;
 144
 145    estimate:
 146         /*
 147          * ASSUMING:
 148          *      sizeof(struct newesp) > sizeof(struct esp).
 149          *      esp_max_ivlen() = max ivlen for CBC mode
 150          *      9 = (maximum padding length without random padding length)
 151          *         + (Pad Length field) + (Next Header field).
 152          *      16 = maximum ICV we support.
 153          */
 154         return sizeof(struct newesp) + esp_max_ivlen() + 9 + 16;
 155 }
 156
 157 /*
 158  * Modify the packet so that the payload is encrypted.
 159  * The mbuf (m) must start with IPv4 or IPv6 header.
 160  * On failure, free the given mbuf and return NULL.
 161  *
 162  * on invocation:
 163  *      m   nexthdrp md
 164  *      v   v        v
 165  *      IP ......... payload
 166  * during the encryption:
 167  *      m   nexthdrp mprev md
 168  *      v   v        v     v
 169  *      IP ............... esp iv payload pad padlen nxthdr
 170  *                         <--><-><------><--------------->
 171  *                         esplen plen    extendsiz
 172  *                             ivlen
 173  *                         <-----> esphlen
 174  *      <-> hlen
 175  *      <-----------------> espoff
 176  */
 177 static int
 178 esp_output(m, nexthdrp, md, isr, af)
 179         struct mbuf *m;
 180         u_char *nexthdrp;
 181         struct mbuf *md;
 182         struct ipsecrequest *isr;
 183         int af;
 184 {
 185         struct mbuf *n;
 186         struct mbuf *mprev;
 187         struct esp *esp;
 188         struct esptail *esptail;
 189         struct secasvar *sav = isr->sav;
 190         const struct esp_algorithm *algo;
 191         u_int32_t spi;
 192         u_int8_t nxt = 0;
 193         size_t plen;    /*payload length to be encrypted*/
 194         size_t espoff;
 195         int ivlen;
 196         int afnumber;
 197         size_t extendsiz;
 198         int error = 0;
 199         struct ipsecstat *stat;
 200
 201         switch (af) {
 202 #if INET
 203         case AF_INET:
 204                 afnumber = 4;
 205                 stat = &ipsecstat;
 206                 break;
 207 #endif
 208 #if INET6
 209         case AF_INET6:
 210                 afnumber = 6;
 211                 stat = &ipsec6stat;
 212                 break;
 213 #endif
 214         default:
 215                 ipseclog((LOG_ERR, "esp_output: unsupported af %d\n", af));
 216                 return 0;       /* no change at all */
 217         }
 218
 219         /* some sanity check */
 220         if ((sav->flags & SADB_X_EXT_OLD) == 0 && !sav->replay) {
 221                 switch (af) {
 222 #if INET
 223                 case AF_INET:
 224                     {
 225                         struct ip *ip;
 226
 227                         ip = mtod(m, struct ip *);
 228                         ipseclog((LOG_DEBUG, "esp4_output: internal error: "
 229                                 "sav->replay is null: %x->%x, SPI=%u\n",
 230                                 (u_int32_t)ntohl(ip->ip_src.s_addr),
 231                                 (u_int32_t)ntohl(ip->ip_dst.s_addr),
 232                                 (u_int32_t)ntohl(sav->spi)));
 233                         ipsecstat.out_inval++;
 234                         break;
 235                     }
 236 #endif /*INET*/
 237 #if INET6
 238                 case AF_INET6:
 239                         ipseclog((LOG_DEBUG, "esp6_output: internal error: "
 240                                 "sav->replay is null: SPI=%u\n",
 241                                 (u_int32_t)ntohl(sav->spi)));
 242                         ipsec6stat.out_inval++;
 243                         break;
 244 #endif /*INET6*/
 245                 default:
 246                         panic("esp_output: should not reach here");
 247                 }
 248                 m_freem(m);
 249                 return EINVAL;
 250         }
 251
 252         algo = esp_algorithm_lookup(sav->alg_enc);
 253         if (!algo) {
 254                 ipseclog((LOG_ERR, "esp_output: unsupported algorithm: "
 255                     "SPI=%u\n", (u_int32_t)ntohl(sav->spi)));
 256                 m_freem(m);
 257                 return EINVAL;
 258         }
 259         spi = sav->spi;
 260         ivlen = sav->ivlen;
 261         /* should be okey */
 262         if (ivlen < 0) {
 263                 panic("invalid ivlen");
 264         }
 265
 266     {
 267         /*
 268          * insert ESP header.
 269          * XXX inserts ESP header right after IPv4 header.  should
 270          * chase the header chain.
 271          * XXX sequential number
 272          */
 273 #if INET
 274         struct ip *ip = NULL;
 275 #endif
 276 #if INET6
 277         struct ip6_hdr *ip6 = NULL;
 278 #endif
 279         size_t esplen;  /*sizeof(struct esp/newesp)*/
 280         size_t esphlen; /*sizeof(struct esp/newesp) + ivlen*/
 281         size_t hlen = 0;        /*ip header len*/
 282
 283         if (sav->flags & SADB_X_EXT_OLD) {
 284                 /* RFC 1827 */
 285                 esplen = sizeof(struct esp);
 286         } else {
 287                 /* RFC 2406 */
 288                 if (sav->flags & SADB_X_EXT_DERIV)
 289                         esplen = sizeof(struct esp);
 290                 else
 291                         esplen = sizeof(struct newesp);
 292         }
 293         esphlen = esplen + ivlen;
 294
 295         for (mprev = m; mprev && mprev->m_next != md; mprev = mprev->m_next)
 296                 ;
 297         if (mprev == NULL || mprev->m_next != md) {
 298                 ipseclog((LOG_DEBUG, "esp%d_output: md is not in chain\n",
 299                     afnumber));
 300                 m_freem(m);
 301                 return EINVAL;
 302         }
 303
 304         plen = 0;
 305         for (n = md; n; n = n->m_next)
 306                 plen += n->m_len;
 307
 308         switch (af) {
 309 #if INET
 310         case AF_INET:
 311                 ip = mtod(m, struct ip *);
 312 #ifdef _IP_VHL
 313                 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 314 #else
 315                 hlen = ip->ip_hl << 2;
 316 #endif
 317                 break;
 318 #endif
 319 #if INET6
 320         case AF_INET6:
 321                 ip6 = mtod(m, struct ip6_hdr *);
 322                 hlen = sizeof(*ip6);
 323                 break;
 324 #endif
 325         }
 326
 327         /* make the packet over-writable */
 328         mprev->m_next = NULL;
 329         if ((md = ipsec_copypkt(md)) == NULL) {
 330                 m_freem(m);
 331                 error = ENOBUFS;
 332                 goto fail;
 333         }
 334         mprev->m_next = md;
 335
 336         espoff = m->m_pkthdr.len - plen;
 337
 338         /*
 339          * grow the mbuf to accomodate ESP header.
 340          * before: IP ... payload
 341          * after:  IP ... ESP IV payload
 342          */
 343         if (M_LEADINGSPACE(md) < esphlen || (md->m_flags & M_EXT) != 0) {
 344                 MGET(n, M_DONTWAIT, MT_DATA);
 345                 if (!n) {
 346                         m_freem(m);
 347                         error = ENOBUFS;
 348                         goto fail;
 349                 }
 350                 n->m_len = esphlen;
 351                 mprev->m_next = n;
 352                 n->m_next = md;
 353                 m->m_pkthdr.len += esphlen;
 354                 esp = mtod(n, struct esp *);
 355         } else {
 356                 md->m_len += esphlen;
 357                 md->m_data -= esphlen;
 358                 m->m_pkthdr.len += esphlen;
 359                 esp = mtod(md, struct esp *);
 360         }
 361
 362         nxt = *nexthdrp;
 363         *nexthdrp = IPPROTO_ESP;
 364         switch (af) {
 365 #if INET
 366         case AF_INET:
 367                 if (esphlen < (IP_MAXPACKET - ntohs(ip->ip_len)))
 368                         ip->ip_len = htons(ntohs(ip->ip_len) + esphlen);
 369                 else {
 370                         ipseclog((LOG_ERR,
 371                             "IPv4 ESP output: size exceeds limit\n"));
 372                         ipsecstat.out_inval++;
 373                         m_freem(m);
 374                         error = EMSGSIZE;
 375                         goto fail;
 376                 }
 377                 break;
 378 #endif
 379 #if INET6
 380         case AF_INET6:
 381                 /* total packet length will be computed in ip6_output() */
 382                 break;
 383 #endif
 384         }
 385     }
 386
 387         /* initialize esp header. */
 388         esp->esp_spi = spi;
 389         if ((sav->flags & SADB_X_EXT_OLD) == 0) {
 390                 struct newesp *nesp;
 391                 nesp = (struct newesp *)esp;
 392                 if (sav->replay->count == ~0) {
 393                         if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
 394                                 /* XXX Is it noisy ? */
 395                                 ipseclog((LOG_WARNING,
 396                                     "replay counter overflowed. %s\n",
 397                                     ipsec_logsastr(sav)));
 398                                 stat->out_inval++;
 399                                 m_freem(m);
 400                                 return EINVAL;
 401                         }
 402                 }
 403                 sav->replay->count++;
 404                 /*
 405                  * XXX sequence number must not be cycled, if the SA is
 406                  * installed by IKE daemon.
 407                  */
 408                 nesp->esp_seq = htonl(sav->replay->count);
 409         }
 410
 411     {
 412         /*
 413          * find the last mbuf. make some room for ESP trailer.
 414          */
 415 #if INET
 416         struct ip *ip = NULL;
 417 #endif
 418         size_t padbound;
 419         u_char *extend;
 420         int i;
 421         int randpadmax;
 422
 423         if (algo->padbound)
 424                 padbound = algo->padbound;
 425         else
 426                 padbound = 4;
 427         /* ESP packet, including nxthdr field, must be length of 4n */
 428         if (padbound < 4)
 429                 padbound = 4;
 430
 431         extendsiz = padbound - (plen % padbound);
 432         if (extendsiz == 1)
 433                 extendsiz = padbound + 1;
 434
 435         /* random padding */
 436         switch (af) {
 437 #if INET
 438         case AF_INET:
 439                 randpadmax = ip4_esp_randpad;
 440                 break;
 441 #endif
 442 #if INET6
 443         case AF_INET6:
 444                 randpadmax = ip6_esp_randpad;
 445                 break;
 446 #endif
 447         default:
 448                 randpadmax = -1;
 449                 break;
 450         }
 451         if (randpadmax < 0 || plen + extendsiz >= randpadmax)
 452                 ;
 453         else {
 454                 int n;
 455
 456                 /* round */
 457                 randpadmax = (randpadmax / padbound) * padbound;
 458                 n = (randpadmax - plen + extendsiz) / padbound;
 459
 460                 if (n > 0)
 461                         n = (random() % n) * padbound;
 462                 else
 463                         n = 0;
 464
 465                 /*
 466                  * make sure we do not pad too much.
 467                  * MLEN limitation comes from the trailer attachment
 468                  * code below.
 469                  * 256 limitation comes from sequential padding.
 470                  * also, the 1-octet length field in ESP trailer imposes
 471                  * limitation (but is less strict than sequential padding
 472                  * as length field do not count the last 2 octets).
 473                  */
 474                 if (extendsiz + n <= MLEN && extendsiz + n < 256)
 475                         extendsiz += n;
 476         }
 477
 478 #if DIAGNOSTIC
 479         if (extendsiz > MLEN || extendsiz >= 256)
 480                 panic("extendsiz too big in esp_output");
 481 #endif
 482
 483         n = m;
 484         while (n->m_next)
 485                 n = n->m_next;
 486
 487         /*
 488          * if M_EXT, the external mbuf data may be shared among
 489          * two consequtive TCP packets, and it may be unsafe to use the
 490          * trailing space.
 491          */
 492         if (!(n->m_flags & M_EXT) && extendsiz < M_TRAILINGSPACE(n)) {
 493                 extend = mtod(n, u_char *) + n->m_len;
 494                 n->m_len += extendsiz;
 495                 m->m_pkthdr.len += extendsiz;
 496         } else {
 497                 struct mbuf *nn;
 498
 499                 MGET(nn, M_DONTWAIT, MT_DATA);
 500                 if (!nn) {
 501                         ipseclog((LOG_DEBUG, "esp%d_output: can't alloc mbuf",
 502                             afnumber));
 503                         m_freem(m);
 504                         error = ENOBUFS;
 505                         goto fail;
 506                 }
 507                 extend = mtod(nn, u_char *);
 508                 nn->m_len = extendsiz;
 509                 nn->m_next = NULL;
 510                 n->m_next = nn;
 511                 n = nn;
 512                 m->m_pkthdr.len += extendsiz;
 513         }
 514         switch (sav->flags & SADB_X_EXT_PMASK) {
 515         case SADB_X_EXT_PRAND:
 516                 key_randomfill(extend, extendsiz);
 517                 break;
 518         case SADB_X_EXT_PZERO:
 519                 bzero(extend, extendsiz);
 520                 break;
 521         case SADB_X_EXT_PSEQ:
 522                 for (i = 0; i < extendsiz; i++)
 523                         extend[i] = (i + 1) & 0xff;
 524                 break;
 525         }
 526
 527         /* initialize esp trailer. */
 528         esptail = (struct esptail *)
 529                 (mtod(n, u_int8_t *) + n->m_len - sizeof(struct esptail));
 530         esptail->esp_nxt = nxt;
 531         esptail->esp_padlen = extendsiz - 2;
 532
 533         /* modify IP header (for ESP header part only) */
 534         switch (af) {
 535 #if INET
 536         case AF_INET:
 537                 ip = mtod(m, struct ip *);
 538                 if (extendsiz < (IP_MAXPACKET - ntohs(ip->ip_len)))
 539                         ip->ip_len = htons(ntohs(ip->ip_len) + extendsiz);
 540                 else {
 541                         ipseclog((LOG_ERR,
 542                             "IPv4 ESP output: size exceeds limit\n"));
 543                         ipsecstat.out_inval++;
 544                         m_freem(m);
 545                         error = EMSGSIZE;
 546                         goto fail;
 547                 }
 548                 break;
 549 #endif
 550 #if INET6
 551         case AF_INET6:
 552                 /* total packet length will be computed in ip6_output() */
 553                 break;
 554 #endif
 555         }
 556     }
 557
 558         /*
 559          * pre-compute and cache intermediate key
 560          */
 561         error = esp_schedule(algo, sav);
 562         if (error) {
 563                 m_freem(m);
 564                 stat->out_inval++;
 565                 goto fail;
 566         }
 567
 568         /*
 569          * encrypt the packet, based on security association
 570          * and the algorithm specified.
 571          */
 572         if (!algo->encrypt)
 573                 panic("internal error: no encrypt function");
 574         if ((*algo->encrypt)(m, espoff, plen + extendsiz, sav, algo, ivlen)) {
 575                 /* m is already freed */
 576                 ipseclog((LOG_ERR, "packet encryption failure\n"));
 577                 stat->out_inval++;
 578                 error = EINVAL;
 579                 goto fail;
 580         }
 581
 582         /*
 583          * calculate ICV if required.
 584          */
 585         if (!sav->replay)
 586                 goto noantireplay;
 587         if (!sav->key_auth)
 588                 goto noantireplay;
 589         if (sav->key_auth == SADB_AALG_NONE)
 590                 goto noantireplay;
 591
 592     {
 593         const struct ah_algorithm *aalgo;
 594         u_char authbuf[AH_MAXSUMSIZE];
 595         struct mbuf *n;
 596         u_char *p;
 597         size_t siz;
 598 #if INET
 599         struct ip *ip;
 600 #endif
 601
 602         aalgo = ah_algorithm_lookup(sav->alg_auth);
 603         if (!aalgo)
 604                 goto noantireplay;
 605         siz = ((aalgo->sumsiz)(sav) + 3) & ~(4 - 1);
 606         if (AH_MAXSUMSIZE < siz)
 607                 panic("assertion failed for AH_MAXSUMSIZE");
 608
 609         if (esp_auth(m, espoff, m->m_pkthdr.len - espoff, sav, authbuf)) {
 610                 ipseclog((LOG_ERR, "ESP checksum generation failure\n"));
 611                 m_freem(m);
 612                 error = EINVAL;
 613                 stat->out_inval++;
 614                 goto fail;
 615         }
 616
 617         n = m;
 618         while (n->m_next)
 619                 n = n->m_next;
 620
 621         if (!(n->m_flags & M_EXT) && siz < M_TRAILINGSPACE(n)) {        /*XXX*/
 622                 n->m_len += siz;
 623                 m->m_pkthdr.len += siz;
 624                 p = mtod(n, u_char *) + n->m_len - siz;
 625         } else {
 626                 struct mbuf *nn;
 627
 628                 MGET(nn, M_DONTWAIT, MT_DATA);
 629                 if (!nn) {
 630                         ipseclog((LOG_DEBUG, "can't alloc mbuf in esp%d_output",
 631                             afnumber));
 632                         m_freem(m);
 633                         error = ENOBUFS;
 634                         goto fail;
 635                 }
 636                 nn->m_len = siz;
 637                 nn->m_next = NULL;
 638                 n->m_next = nn;
 639                 n = nn;
 640                 m->m_pkthdr.len += siz;
 641                 p = mtod(nn, u_char *);
 642         }
 643         bcopy(authbuf, p, siz);
 644
 645         /* modify IP header (for ESP header part only) */
 646         switch (af) {
 647 #if INET
 648         case AF_INET:
 649                 ip = mtod(m, struct ip *);
 650                 if (siz < (IP_MAXPACKET - ntohs(ip->ip_len)))
 651                         ip->ip_len = htons(ntohs(ip->ip_len) + siz);
 652                 else {
 653                         ipseclog((LOG_ERR,
 654                             "IPv4 ESP output: size exceeds limit\n"));
 655                         ipsecstat.out_inval++;
 656                         m_freem(m);
 657                         error = EMSGSIZE;
 658                         goto fail;
 659                 }
 660                 break;
 661 #endif
 662 #if INET6
 663         case AF_INET6:
 664                 /* total packet length will be computed in ip6_output() */
 665                 break;
 666 #endif
 667         }
 668     }
 669
 670 noantireplay:
 671         if (!m) {
 672                 ipseclog((LOG_ERR,
 673                     "NULL mbuf after encryption in esp%d_output", afnumber));
 674         } else
 675                 stat->out_success++;
 676         stat->out_esphist[sav->alg_enc]++;
 677         key_sa_recordxfer(sav, m);
 678         return 0;
 679
 680 fail:
 681 #if 1
 682         return error;
 683 #else
 684         panic("something bad in esp_output");
 685 #endif
 686 }
 687
 688 #if INET
 689 int
 690 esp4_output(m, isr)
 691         struct mbuf *m;
 692         struct ipsecrequest *isr;
 693 {
 694         struct ip *ip;
 695         if (m->m_len < sizeof(struct ip)) {
 696                 ipseclog((LOG_DEBUG, "esp4_output: first mbuf too short\n"));
 697                 m_freem(m);
 698                 return 0;
 699         }
 700         ip = mtod(m, struct ip *);
 701         /* XXX assumes that m->m_next points to payload */
 702         return esp_output(m, &ip->ip_p, m->m_next, isr, AF_INET);
 703 }
 704 #endif /*INET*/
 705
 706 #if INET6
 707 int
 708 esp6_output(m, nexthdrp, md, isr)
 709         struct mbuf *m;
 710         u_char *nexthdrp;
 711         struct mbuf *md;
 712         struct ipsecrequest *isr;
 713 {
 714         if (m->m_len < sizeof(struct ip6_hdr)) {
 715                 ipseclog((LOG_DEBUG, "esp6_output: first mbuf too short\n"));
 716                 m_freem(m);
 717                 return 0;
 718         }
 719         return esp_output(m, nexthdrp, md, isr, AF_INET6);
 720 }
 721 #endif /*INET6*/