xform_ipcomp.c revision 199905
1/* $FreeBSD: head/sys/netipsec/xform_ipcomp.c 199905 2009-11-29 17:47:49Z bz $ */ 2/* $OpenBSD: ip_ipcomp.c,v 1.1 2001/07/05 12:08:52 jjbg Exp $ */ 3 4/*- 5 * Copyright (c) 2001 Jean-Jacques Bernard-Gundol (jj@wabbitt.org) 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 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. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31/* IP payload compression protocol (IPComp), see RFC 2393 */ 32#include "opt_inet.h" 33#include "opt_inet6.h" 34 35#include <sys/param.h> 36#include <sys/systm.h> 37#include <sys/mbuf.h> 38#include <sys/lock.h> 39#include <sys/mutex.h> 40#include <sys/socket.h> 41#include <sys/kernel.h> 42#include <sys/protosw.h> 43#include <sys/sysctl.h> 44 45#include <netinet/in.h> 46#include <netinet/in_systm.h> 47#include <netinet/ip.h> 48#include <netinet/ip_var.h> 49 50#include <net/route.h> 51#include <net/vnet.h> 52 53#include <netipsec/ipsec.h> 54#include <netipsec/xform.h> 55 56#ifdef INET6 57#include <netinet/ip6.h> 58#include <netipsec/ipsec6.h> 59#endif 60 61#include <netipsec/ipcomp.h> 62#include <netipsec/ipcomp_var.h> 63 64#include <netipsec/key.h> 65#include <netipsec/key_debug.h> 66 67#include <opencrypto/cryptodev.h> 68#include <opencrypto/deflate.h> 69#include <opencrypto/xform.h> 70 71VNET_DEFINE(int, ipcomp_enable) = 0; 72VNET_DEFINE(struct ipcompstat, ipcompstat); 73 74SYSCTL_DECL(_net_inet_ipcomp); 75SYSCTL_VNET_INT(_net_inet_ipcomp, OID_AUTO, 76 ipcomp_enable, CTLFLAG_RW, &VNET_NAME(ipcomp_enable), 0, ""); 77SYSCTL_VNET_STRUCT(_net_inet_ipcomp, IPSECCTL_STATS, 78 stats, CTLFLAG_RD, &VNET_NAME(ipcompstat), ipcompstat, ""); 79 80static int ipcomp_input_cb(struct cryptop *crp); 81static int ipcomp_output_cb(struct cryptop *crp); 82 83struct comp_algo * 84ipcomp_algorithm_lookup(int alg) 85{ 86 if (alg >= IPCOMP_ALG_MAX) 87 return NULL; 88 switch (alg) { 89 case SADB_X_CALG_DEFLATE: 90 return &comp_algo_deflate; 91 } 92 return NULL; 93} 94 95/* 96 * ipcomp_init() is called when an CPI is being set up. 97 */ 98static int 99ipcomp_init(struct secasvar *sav, struct xformsw *xsp) 100{ 101 struct comp_algo *tcomp; 102 struct cryptoini cric; 103 104 /* NB: algorithm really comes in alg_enc and not alg_comp! */ 105 tcomp = ipcomp_algorithm_lookup(sav->alg_enc); 106 if (tcomp == NULL) { 107 DPRINTF(("%s: unsupported compression algorithm %d\n", __func__, 108 sav->alg_comp)); 109 return EINVAL; 110 } 111 sav->alg_comp = sav->alg_enc; /* set for doing histogram */ 112 sav->tdb_xform = xsp; 113 sav->tdb_compalgxform = tcomp; 114 115 /* Initialize crypto session */ 116 bzero(&cric, sizeof (cric)); 117 cric.cri_alg = sav->tdb_compalgxform->type; 118 119 return crypto_newsession(&sav->tdb_cryptoid, &cric, V_crypto_support); 120} 121 122/* 123 * ipcomp_zeroize() used when IPCA is deleted 124 */ 125static int 126ipcomp_zeroize(struct secasvar *sav) 127{ 128 int err; 129 130 err = crypto_freesession(sav->tdb_cryptoid); 131 sav->tdb_cryptoid = 0; 132 return err; 133} 134 135/* 136 * ipcomp_input() gets called to uncompress an input packet 137 */ 138static int 139ipcomp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 140{ 141 struct tdb_crypto *tc; 142 struct cryptodesc *crdc; 143 struct cryptop *crp; 144 int hlen = IPCOMP_HLENGTH; 145 146 /* Get crypto descriptors */ 147 crp = crypto_getreq(1); 148 if (crp == NULL) { 149 m_freem(m); 150 DPRINTF(("%s: no crypto descriptors\n", __func__)); 151 V_ipcompstat.ipcomps_crypto++; 152 return ENOBUFS; 153 } 154 /* Get IPsec-specific opaque pointer */ 155 tc = (struct tdb_crypto *) malloc(sizeof (*tc), M_XDATA, M_NOWAIT|M_ZERO); 156 if (tc == NULL) { 157 m_freem(m); 158 crypto_freereq(crp); 159 DPRINTF(("%s: cannot allocate tdb_crypto\n", __func__)); 160 V_ipcompstat.ipcomps_crypto++; 161 return ENOBUFS; 162 } 163 crdc = crp->crp_desc; 164 165 crdc->crd_skip = skip + hlen; 166 crdc->crd_len = m->m_pkthdr.len - (skip + hlen); 167 crdc->crd_inject = skip; 168 169 tc->tc_ptr = 0; 170 171 /* Decompression operation */ 172 crdc->crd_alg = sav->tdb_compalgxform->type; 173 174 /* Crypto operation descriptor */ 175 crp->crp_ilen = m->m_pkthdr.len - (skip + hlen); 176 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 177 crp->crp_buf = (caddr_t) m; 178 crp->crp_callback = ipcomp_input_cb; 179 crp->crp_sid = sav->tdb_cryptoid; 180 crp->crp_opaque = (caddr_t) tc; 181 182 /* These are passed as-is to the callback */ 183 tc->tc_spi = sav->spi; 184 tc->tc_dst = sav->sah->saidx.dst; 185 tc->tc_proto = sav->sah->saidx.proto; 186 tc->tc_protoff = protoff; 187 tc->tc_skip = skip; 188 189 return crypto_dispatch(crp); 190} 191 192#ifdef INET6 193#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ 194 if (saidx->dst.sa.sa_family == AF_INET6) { \ 195 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ 196 } else { \ 197 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ 198 } \ 199} while (0) 200#else 201#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ 202 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) 203#endif 204 205/* 206 * IPComp input callback from the crypto driver. 207 */ 208static int 209ipcomp_input_cb(struct cryptop *crp) 210{ 211 struct cryptodesc *crd; 212 struct tdb_crypto *tc; 213 int skip, protoff; 214 struct mtag *mtag; 215 struct mbuf *m; 216 struct secasvar *sav; 217 struct secasindex *saidx; 218 int hlen = IPCOMP_HLENGTH, error, clen; 219 u_int8_t nproto; 220 caddr_t addr; 221 222 crd = crp->crp_desc; 223 224 tc = (struct tdb_crypto *) crp->crp_opaque; 225 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!")); 226 skip = tc->tc_skip; 227 protoff = tc->tc_protoff; 228 mtag = (struct mtag *) tc->tc_ptr; 229 m = (struct mbuf *) crp->crp_buf; 230 231 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 232 if (sav == NULL) { 233 V_ipcompstat.ipcomps_notdb++; 234 DPRINTF(("%s: SA expired while in crypto\n", __func__)); 235 error = ENOBUFS; /*XXX*/ 236 goto bad; 237 } 238 239 saidx = &sav->sah->saidx; 240 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || 241 saidx->dst.sa.sa_family == AF_INET6, 242 ("unexpected protocol family %u", saidx->dst.sa.sa_family)); 243 244 /* Check for crypto errors */ 245 if (crp->crp_etype) { 246 /* Reset the session ID */ 247 if (sav->tdb_cryptoid != 0) 248 sav->tdb_cryptoid = crp->crp_sid; 249 250 if (crp->crp_etype == EAGAIN) { 251 KEY_FREESAV(&sav); 252 return crypto_dispatch(crp); 253 } 254 V_ipcompstat.ipcomps_noxform++; 255 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 256 error = crp->crp_etype; 257 goto bad; 258 } 259 /* Shouldn't happen... */ 260 if (m == NULL) { 261 V_ipcompstat.ipcomps_crypto++; 262 DPRINTF(("%s: null mbuf returned from crypto\n", __func__)); 263 error = EINVAL; 264 goto bad; 265 } 266 V_ipcompstat.ipcomps_hist[sav->alg_comp]++; 267 268 clen = crp->crp_olen; /* Length of data after processing */ 269 270 /* Release the crypto descriptors */ 271 free(tc, M_XDATA), tc = NULL; 272 crypto_freereq(crp), crp = NULL; 273 274 /* In case it's not done already, adjust the size of the mbuf chain */ 275 m->m_pkthdr.len = clen + hlen + skip; 276 277 if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) { 278 V_ipcompstat.ipcomps_hdrops++; /*XXX*/ 279 DPRINTF(("%s: m_pullup failed\n", __func__)); 280 error = EINVAL; /*XXX*/ 281 goto bad; 282 } 283 284 /* Keep the next protocol field */ 285 addr = (caddr_t) mtod(m, struct ip *) + skip; 286 nproto = ((struct ipcomp *) addr)->comp_nxt; 287 288 /* Remove the IPCOMP header */ 289 error = m_striphdr(m, skip, hlen); 290 if (error) { 291 V_ipcompstat.ipcomps_hdrops++; 292 DPRINTF(("%s: bad mbuf chain, IPCA %s/%08lx\n", __func__, 293 ipsec_address(&sav->sah->saidx.dst), 294 (u_long) ntohl(sav->spi))); 295 goto bad; 296 } 297 298 /* Restore the Next Protocol field */ 299 m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto); 300 301 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, NULL); 302 303 KEY_FREESAV(&sav); 304 return error; 305bad: 306 if (sav) 307 KEY_FREESAV(&sav); 308 if (m) 309 m_freem(m); 310 if (tc != NULL) 311 free(tc, M_XDATA); 312 if (crp) 313 crypto_freereq(crp); 314 return error; 315} 316 317/* 318 * IPComp output routine, called by ipsec[46]_process_packet() 319 */ 320static int 321ipcomp_output( 322 struct mbuf *m, 323 struct ipsecrequest *isr, 324 struct mbuf **mp, 325 int skip, 326 int protoff 327) 328{ 329 struct secasvar *sav; 330 struct comp_algo *ipcompx; 331 int error, ralen, maxpacketsize; 332 struct cryptodesc *crdc; 333 struct cryptop *crp; 334 struct tdb_crypto *tc; 335 336 sav = isr->sav; 337 IPSEC_ASSERT(sav != NULL, ("null SA")); 338 ipcompx = sav->tdb_compalgxform; 339 IPSEC_ASSERT(ipcompx != NULL, ("null compression xform")); 340 341 /* 342 * Do not touch the packet in case our payload to compress 343 * is lower than the minimal threshold of the compression 344 * alogrithm. We will just send out the data uncompressed. 345 * See RFC 3173, 2.2. Non-Expansion Policy. 346 */ 347 if (m->m_pkthdr.len <= ipcompx->minlen) { 348 /* XXX-BZ V_ipcompstat.threshold++; */ 349 return ipsec_process_done(m, isr); 350 } 351 352 ralen = m->m_pkthdr.len - skip; /* Raw payload length before comp. */ 353 V_ipcompstat.ipcomps_output++; 354 355 /* Check for maximum packet size violations. */ 356 switch (sav->sah->saidx.dst.sa.sa_family) { 357#ifdef INET 358 case AF_INET: 359 maxpacketsize = IP_MAXPACKET; 360 break; 361#endif /* INET */ 362#ifdef INET6 363 case AF_INET6: 364 maxpacketsize = IPV6_MAXPACKET; 365 break; 366#endif /* INET6 */ 367 default: 368 V_ipcompstat.ipcomps_nopf++; 369 DPRINTF(("%s: unknown/unsupported protocol family %d, " 370 "IPCA %s/%08lx\n", __func__, 371 sav->sah->saidx.dst.sa.sa_family, 372 ipsec_address(&sav->sah->saidx.dst), 373 (u_long) ntohl(sav->spi))); 374 error = EPFNOSUPPORT; 375 goto bad; 376 } 377 if (ralen + skip + IPCOMP_HLENGTH > maxpacketsize) { 378 V_ipcompstat.ipcomps_toobig++; 379 DPRINTF(("%s: packet in IPCA %s/%08lx got too big " 380 "(len %u, max len %u)\n", __func__, 381 ipsec_address(&sav->sah->saidx.dst), 382 (u_long) ntohl(sav->spi), 383 ralen + skip + IPCOMP_HLENGTH, maxpacketsize)); 384 error = EMSGSIZE; 385 goto bad; 386 } 387 388 /* Update the counters */ 389 V_ipcompstat.ipcomps_obytes += m->m_pkthdr.len - skip; 390 391 m = m_unshare(m, M_NOWAIT); 392 if (m == NULL) { 393 V_ipcompstat.ipcomps_hdrops++; 394 DPRINTF(("%s: cannot clone mbuf chain, IPCA %s/%08lx\n", 395 __func__, ipsec_address(&sav->sah->saidx.dst), 396 (u_long) ntohl(sav->spi))); 397 error = ENOBUFS; 398 goto bad; 399 } 400 401 /* Ok now, we can pass to the crypto processing. */ 402 403 /* Get crypto descriptors */ 404 crp = crypto_getreq(1); 405 if (crp == NULL) { 406 V_ipcompstat.ipcomps_crypto++; 407 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__)); 408 error = ENOBUFS; 409 goto bad; 410 } 411 crdc = crp->crp_desc; 412 413 /* Compression descriptor */ 414 crdc->crd_skip = skip; 415 crdc->crd_len = ralen; 416 crdc->crd_flags = CRD_F_COMP; 417 crdc->crd_inject = skip; 418 419 /* Compression operation */ 420 crdc->crd_alg = ipcompx->type; 421 422 /* IPsec-specific opaque crypto info */ 423 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 424 M_XDATA, M_NOWAIT|M_ZERO); 425 if (tc == NULL) { 426 V_ipcompstat.ipcomps_crypto++; 427 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 428 crypto_freereq(crp); 429 error = ENOBUFS; 430 goto bad; 431 } 432 433 tc->tc_isr = isr; 434 tc->tc_spi = sav->spi; 435 tc->tc_dst = sav->sah->saidx.dst; 436 tc->tc_proto = sav->sah->saidx.proto; 437 tc->tc_protoff = protoff; 438 tc->tc_skip = skip; 439 440 /* Crypto operation descriptor */ 441 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */ 442 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 443 crp->crp_buf = (caddr_t) m; 444 crp->crp_callback = ipcomp_output_cb; 445 crp->crp_opaque = (caddr_t) tc; 446 crp->crp_sid = sav->tdb_cryptoid; 447 448 return crypto_dispatch(crp); 449bad: 450 if (m) 451 m_freem(m); 452 return (error); 453} 454 455/* 456 * IPComp output callback from the crypto driver. 457 */ 458static int 459ipcomp_output_cb(struct cryptop *crp) 460{ 461 struct tdb_crypto *tc; 462 struct ipsecrequest *isr; 463 struct secasvar *sav; 464 struct mbuf *m; 465 int error, skip; 466 467 tc = (struct tdb_crypto *) crp->crp_opaque; 468 IPSEC_ASSERT(tc != NULL, ("null opaque data area!")); 469 m = (struct mbuf *) crp->crp_buf; 470 skip = tc->tc_skip; 471 472 isr = tc->tc_isr; 473 IPSECREQUEST_LOCK(isr); 474 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 475 if (sav == NULL) { 476 V_ipcompstat.ipcomps_notdb++; 477 DPRINTF(("%s: SA expired while in crypto\n", __func__)); 478 error = ENOBUFS; /*XXX*/ 479 goto bad; 480 } 481 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n")); 482 483 /* Check for crypto errors */ 484 if (crp->crp_etype) { 485 /* Reset the session ID */ 486 if (sav->tdb_cryptoid != 0) 487 sav->tdb_cryptoid = crp->crp_sid; 488 489 if (crp->crp_etype == EAGAIN) { 490 KEY_FREESAV(&sav); 491 IPSECREQUEST_UNLOCK(isr); 492 return crypto_dispatch(crp); 493 } 494 V_ipcompstat.ipcomps_noxform++; 495 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 496 error = crp->crp_etype; 497 goto bad; 498 } 499 /* Shouldn't happen... */ 500 if (m == NULL) { 501 V_ipcompstat.ipcomps_crypto++; 502 DPRINTF(("%s: bogus return buffer from crypto\n", __func__)); 503 error = EINVAL; 504 goto bad; 505 } 506 V_ipcompstat.ipcomps_hist[sav->alg_comp]++; 507 508 if (crp->crp_ilen - skip > crp->crp_olen) { 509 struct mbuf *mo; 510 struct ipcomp *ipcomp; 511 int roff; 512 uint8_t prot; 513 514 /* Compression helped, inject IPCOMP header. */ 515 mo = m_makespace(m, skip, IPCOMP_HLENGTH, &roff); 516 if (mo == NULL) { 517 V_ipcompstat.ipcomps_wrap++; 518 DPRINTF(("%s: IPCOMP header inject failed for IPCA %s/%08lx\n", 519 __func__, ipsec_address(&sav->sah->saidx.dst), 520 (u_long) ntohl(sav->spi))); 521 error = ENOBUFS; 522 goto bad; 523 } 524 ipcomp = (struct ipcomp *)(mtod(mo, caddr_t) + roff); 525 526 /* Initialize the IPCOMP header */ 527 /* XXX alignment always correct? */ 528 switch (sav->sah->saidx.dst.sa.sa_family) { 529#ifdef INET 530 case AF_INET: 531 ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p; 532 break; 533#endif /* INET */ 534#ifdef INET6 535 case AF_INET6: 536 ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt; 537 break; 538#endif 539 } 540 ipcomp->comp_flags = 0; 541 ipcomp->comp_cpi = htons((u_int16_t) ntohl(sav->spi)); 542 543 /* Fix Next Protocol in IPv4/IPv6 header */ 544 prot = IPPROTO_IPCOMP; 545 m_copyback(m, tc->tc_protoff, sizeof(u_int8_t), 546 (u_char *)&prot); 547 548 /* Adjust the length in the IP header */ 549 switch (sav->sah->saidx.dst.sa.sa_family) { 550#ifdef INET 551 case AF_INET: 552 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len); 553 break; 554#endif /* INET */ 555#ifdef INET6 556 case AF_INET6: 557 mtod(m, struct ip6_hdr *)->ip6_plen = 558 htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr); 559 break; 560#endif /* INET6 */ 561 default: 562 V_ipcompstat.ipcomps_nopf++; 563 DPRINTF(("%s: unknown/unsupported protocol " 564 "family %d, IPCA %s/%08lx\n", __func__, 565 sav->sah->saidx.dst.sa.sa_family, 566 ipsec_address(&sav->sah->saidx.dst), 567 (u_long) ntohl(sav->spi))); 568 error = EPFNOSUPPORT; 569 goto bad; 570 } 571 } else { 572 /* compression was useless, we have lost time */ 573 /* XXX add statistic */ 574 /* XXX remember state to not compress the next couple 575 * of packets, RFC 3173, 2.2. Non-Expansion Policy */ 576 } 577 578 /* Release the crypto descriptor */ 579 free(tc, M_XDATA); 580 crypto_freereq(crp); 581 582 /* NB: m is reclaimed by ipsec_process_done. */ 583 error = ipsec_process_done(m, isr); 584 KEY_FREESAV(&sav); 585 IPSECREQUEST_UNLOCK(isr); 586 return error; 587bad: 588 if (sav) 589 KEY_FREESAV(&sav); 590 IPSECREQUEST_UNLOCK(isr); 591 if (m) 592 m_freem(m); 593 free(tc, M_XDATA); 594 crypto_freereq(crp); 595 return error; 596} 597 598static struct xformsw ipcomp_xformsw = { 599 XF_IPCOMP, XFT_COMP, "IPcomp", 600 ipcomp_init, ipcomp_zeroize, ipcomp_input, 601 ipcomp_output 602}; 603 604static void 605ipcomp_attach(void) 606{ 607 608 xform_register(&ipcomp_xformsw); 609} 610 611SYSINIT(ipcomp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipcomp_attach, NULL); 612