1 2 /* 3 * ng_vjc.c 4 */ 5 6 /*- 7 * Copyright (c) 1996-1999 Whistle Communications, Inc. 8 * All rights reserved. 9 * 10 * Subject to the following obligations and disclaimer of warranty, use and 11 * redistribution of this software, in source or object code forms, with or 12 * without modifications are expressly permitted by Whistle Communications; 13 * provided, however, that: 14 * 1. Any and all reproductions of the source or object code must include the 15 * copyright notice above and the following disclaimer of warranties; and 16 * 2. No rights are granted, in any manner or form, to use Whistle 17 * Communications, Inc. trademarks, including the mark "WHISTLE 18 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 19 * such appears in the above copyright notice or in the software. 20 * 21 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 22 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 23 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 24 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 26 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 27 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 28 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 29 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 30 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 31 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 32 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 33 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 36 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 37 * OF SUCH DAMAGE. 38 * 39 * Author: Archie Cobbs <archie@freebsd.org> 40 * 41 * $FreeBSD$ 42 * $Whistle: ng_vjc.c,v 1.17 1999/11/01 09:24:52 julian Exp $ 43 */ 44 45 /* 46 * This node performs Van Jacobson IP header (de)compression. 47 * You must have included net/slcompress.c in your kernel compilation. 48 */ 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/errno.h> 53 #include <sys/kernel.h> 54 #include <sys/mbuf.h> 55 #include <sys/malloc.h> 56 #include <sys/errno.h> 57 58 #include <netgraph/ng_message.h> 59 #include <netgraph/netgraph.h> 60 #include <netgraph/ng_parse.h> 61 #include <netgraph/ng_vjc.h> 62 63 #include <netinet/in.h> 64 #include <netinet/in_systm.h> 65 #include <netinet/ip.h> 66 #include <netinet/tcp.h> 67 68 #include <net/slcompress.h> 69 70 /* Check agreement with slcompress.c */ 71 #if MAX_STATES != NG_VJC_MAX_CHANNELS 72 #error NG_VJC_MAX_CHANNELS must be the same as MAX_STATES 73 #endif 74 75 /* Maximum length of a compressed TCP VJ header */ 76 #define MAX_VJHEADER 19 77 78 /* Node private data */ 79 struct ng_vjc_private { 80 struct ngm_vjc_config conf; 81 struct slcompress slc; 82 hook_p ip; 83 hook_p vjcomp; 84 hook_p vjuncomp; 85 hook_p vjip; 86 }; 87 typedef struct ng_vjc_private *priv_p; 88 89 #define ERROUT(x) do { error = (x); goto done; } while (0) 90 91 /* Netgraph node methods */ 92 static ng_constructor_t ng_vjc_constructor; 93 static ng_rcvmsg_t ng_vjc_rcvmsg; 94 static ng_shutdown_t ng_vjc_shutdown; 95 static ng_newhook_t ng_vjc_newhook; 96 static ng_rcvdata_t ng_vjc_rcvdata; 97 static ng_disconnect_t ng_vjc_disconnect; 98 99 /* Helper stuff */ 100 static struct mbuf *ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP); 101 102 /* Parse type for struct ngm_vjc_config */ 103 static const struct ng_parse_struct_field ng_vjc_config_type_fields[] 104 = NG_VJC_CONFIG_TYPE_INFO; 105 static const struct ng_parse_type ng_vjc_config_type = { 106 &ng_parse_struct_type, 107 &ng_vjc_config_type_fields 108 }; 109 110 /* Parse type for the 'last_cs' and 'cs_next' fields in struct slcompress, 111 which are pointers converted to integer indices, so parse them that way. */ 112 #if _MACHINE_ARCH == i386 113 #define NG_VJC_TSTATE_PTR_TYPE &ng_parse_uint32_type 114 #elif _MACHINE_ARCH == alpha 115 #define NG_VJC_TSTATE_PTR_TYPE &ng_parse_uint64_type 116 #else 117 #error Unspported _MACHINE_ARCH 118 #endif 119 120 /* Parse type for the 'cs_hdr' field in a struct cstate. Ideally we would 121 like to use a 'struct ip' type instead of a simple array of bytes. */ 122 static const struct ng_parse_fixedarray_info ng_vjc_cs_hdr_type_info = { 123 &ng_parse_hint8_type, 124 MAX_HDR 125 }; 126 static const struct ng_parse_type ng_vjc_cs_hdr_type = { 127 &ng_parse_fixedarray_type, 128 &ng_vjc_cs_hdr_type_info 129 }; 130 131 /* Parse type for a struct cstate */ 132 static const struct ng_parse_struct_field ng_vjc_cstate_type_fields[] = { 133 { "cs_next", NG_VJC_TSTATE_PTR_TYPE }, 134 { "cs_hlen", &ng_parse_uint16_type }, 135 { "cs_id", &ng_parse_uint8_type }, 136 { "cs_filler", &ng_parse_uint8_type }, 137 { "cs_hdr", &ng_vjc_cs_hdr_type }, 138 { NULL } 139 }; 140 static const struct ng_parse_type ng_vjc_cstate_type = { 141 &ng_parse_struct_type, 142 &ng_vjc_cstate_type_fields 143 }; 144 145 /* Parse type for an array of MAX_STATES struct cstate's, ie, tstate & rstate */ 146 static const struct ng_parse_fixedarray_info ng_vjc_cstatearray_type_info = { 147 &ng_vjc_cstate_type, 148 MAX_STATES 149 }; 150 static const struct ng_parse_type ng_vjc_cstatearray_type = { 151 &ng_parse_fixedarray_type, 152 &ng_vjc_cstatearray_type_info 153 }; 154 155 /* Parse type for struct slcompress. Keep this in sync with the 156 definition of struct slcompress defined in <net/slcompress.h> */ 157 static const struct ng_parse_struct_field ng_vjc_slcompress_type_fields[] = { 158 { "last_cs", NG_VJC_TSTATE_PTR_TYPE }, 159 { "last_recv", &ng_parse_uint8_type }, 160 { "last_xmit", &ng_parse_uint8_type }, 161 { "flags", &ng_parse_hint16_type }, 162 #ifndef SL_NO_STATS 163 { "sls_packets", &ng_parse_uint32_type }, 164 { "sls_compressed", &ng_parse_uint32_type }, 165 { "sls_searches", &ng_parse_uint32_type }, 166 { "sls_misses", &ng_parse_uint32_type }, 167 { "sls_uncompressedin", &ng_parse_uint32_type }, 168 { "sls_compressedin", &ng_parse_uint32_type }, 169 { "sls_errorin", &ng_parse_uint32_type }, 170 { "sls_tossed", &ng_parse_uint32_type }, 171 #endif 172 { "tstate", &ng_vjc_cstatearray_type }, 173 { "rstate", &ng_vjc_cstatearray_type }, 174 { NULL } 175 }; 176 static const struct ng_parse_type ng_vjc_slcompress_type = { 177 &ng_parse_struct_type, 178 &ng_vjc_slcompress_type_fields 179 }; 180 181 /* List of commands and how to convert arguments to/from ASCII */ 182 static const struct ng_cmdlist ng_vjc_cmds[] = { 183 { 184 NGM_VJC_COOKIE, 185 NGM_VJC_SET_CONFIG, 186 "setconfig", 187 &ng_vjc_config_type, 188 NULL 189 }, 190 { 191 NGM_VJC_COOKIE, 192 NGM_VJC_GET_CONFIG, 193 "getconfig", 194 NULL, 195 &ng_vjc_config_type, 196 }, 197 { 198 NGM_VJC_COOKIE, 199 NGM_VJC_GET_STATE, 200 "getstate", 201 NULL, 202 &ng_vjc_slcompress_type, 203 }, 204 { 205 NGM_VJC_COOKIE, 206 NGM_VJC_CLR_STATS, 207 "clrstats", 208 NULL, 209 NULL, 210 }, 211 { 212 NGM_VJC_COOKIE, 213 NGM_VJC_RECV_ERROR, 214 "recverror", 215 NULL, 216 NULL, 217 }, 218 { 0 } 219 }; 220 221 /* Node type descriptor */ 222 static struct ng_type ng_vjc_typestruct = { 223 .version = NG_ABI_VERSION, 224 .name = NG_VJC_NODE_TYPE, 225 .constructor = ng_vjc_constructor, 226 .rcvmsg = ng_vjc_rcvmsg, 227 .shutdown = ng_vjc_shutdown, 228 .newhook = ng_vjc_newhook, 229 .rcvdata = ng_vjc_rcvdata, 230 .disconnect = ng_vjc_disconnect, 231 .cmdlist = ng_vjc_cmds, 232 }; 233 NETGRAPH_INIT(vjc, &ng_vjc_typestruct); 234 235 /************************************************************************ 236 NETGRAPH NODE METHODS 237 ************************************************************************/ 238 239 /* 240 * Create a new node 241 */ 242 static int 243 ng_vjc_constructor(node_p node) 244 { 245 priv_p priv; 246 247 /* Allocate private structure */ 248 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 249 if (priv == NULL) 250 return (ENOMEM); 251 252 NG_NODE_SET_PRIVATE(node, priv); 253 254 /* Done */ 255 return (0); 256 } 257 258 /* 259 * Add a new hook 260 */ 261 static int 262 ng_vjc_newhook(node_p node, hook_p hook, const char *name) 263 { 264 const priv_p priv = NG_NODE_PRIVATE(node); 265 hook_p *hookp; 266 267 /* Get hook */ 268 if (strcmp(name, NG_VJC_HOOK_IP) == 0) 269 hookp = &priv->ip; 270 else if (strcmp(name, NG_VJC_HOOK_VJCOMP) == 0) 271 hookp = &priv->vjcomp; 272 else if (strcmp(name, NG_VJC_HOOK_VJUNCOMP) == 0) 273 hookp = &priv->vjuncomp; 274 else if (strcmp(name, NG_VJC_HOOK_VJIP) == 0) 275 hookp = &priv->vjip; 276 else 277 return (EINVAL); 278 279 /* See if already connected */ 280 if (*hookp) 281 return (EISCONN); 282 283 /* OK */ 284 *hookp = hook; 285 return (0); 286 } 287 288 /* 289 * Receive a control message 290 */ 291 static int 292 ng_vjc_rcvmsg(node_p node, item_p item, hook_p lasthook) 293 { 294 const priv_p priv = NG_NODE_PRIVATE(node); 295 struct ng_mesg *resp = NULL; 296 int error = 0; 297 struct ng_mesg *msg; 298 299 NGI_GET_MSG(item, msg); 300 /* Check type cookie */ 301 switch (msg->header.typecookie) { 302 case NGM_VJC_COOKIE: 303 switch (msg->header.cmd) { 304 case NGM_VJC_SET_CONFIG: 305 { 306 struct ngm_vjc_config *const c = 307 (struct ngm_vjc_config *) msg->data; 308 309 if (msg->header.arglen != sizeof(*c)) 310 ERROUT(EINVAL); 311 if ((priv->conf.enableComp || priv->conf.enableDecomp) 312 && (c->enableComp || c->enableDecomp)) 313 ERROUT(EALREADY); 314 if (c->enableComp) { 315 if (c->maxChannel > NG_VJC_MAX_CHANNELS - 1 316 || c->maxChannel < NG_VJC_MIN_CHANNELS - 1) 317 ERROUT(EINVAL); 318 } else 319 c->maxChannel = NG_VJC_MAX_CHANNELS - 1; 320 if (c->enableComp != 0 || c->enableDecomp != 0) { 321 bzero(&priv->slc, sizeof(priv->slc)); 322 sl_compress_init(&priv->slc, c->maxChannel); 323 } 324 priv->conf = *c; 325 break; 326 } 327 case NGM_VJC_GET_CONFIG: 328 { 329 struct ngm_vjc_config *conf; 330 331 NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT); 332 if (resp == NULL) 333 ERROUT(ENOMEM); 334 conf = (struct ngm_vjc_config *)resp->data; 335 *conf = priv->conf; 336 break; 337 } 338 case NGM_VJC_GET_STATE: 339 { 340 const struct slcompress *const sl0 = &priv->slc; 341 struct slcompress *sl; 342 u_int16_t index; 343 int i; 344 345 /* Get response structure */ 346 NG_MKRESPONSE(resp, msg, sizeof(*sl), M_NOWAIT); 347 if (resp == NULL) 348 ERROUT(ENOMEM); 349 sl = (struct slcompress *)resp->data; 350 *sl = *sl0; 351 352 /* Replace pointers with integer indicies */ 353 if (sl->last_cs != NULL) { 354 index = sl0->last_cs - sl0->tstate; 355 bzero(&sl->last_cs, sizeof(sl->last_cs)); 356 *((u_int16_t *)&sl->last_cs) = index; 357 } 358 for (i = 0; i < MAX_STATES; i++) { 359 struct cstate *const cs = &sl->tstate[i]; 360 361 index = sl0->tstate[i].cs_next - sl0->tstate; 362 bzero(&cs->cs_next, sizeof(cs->cs_next)); 363 *((u_int16_t *)&cs->cs_next) = index; 364 } 365 break; 366 } 367 case NGM_VJC_CLR_STATS: 368 priv->slc.sls_packets = 0; 369 priv->slc.sls_compressed = 0; 370 priv->slc.sls_searches = 0; 371 priv->slc.sls_misses = 0; 372 priv->slc.sls_uncompressedin = 0; 373 priv->slc.sls_compressedin = 0; 374 priv->slc.sls_errorin = 0; 375 priv->slc.sls_tossed = 0; 376 break; 377 case NGM_VJC_RECV_ERROR: 378 sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &priv->slc); 379 break; 380 default: 381 error = EINVAL; 382 break; 383 } 384 break; 385 default: 386 error = EINVAL; 387 break; 388 } 389 done: 390 NG_RESPOND_MSG(error, node, item, resp); 391 NG_FREE_MSG(msg); 392 return (error); 393 } 394 395 /* 396 * Receive data 397 */ 398 static int 399 ng_vjc_rcvdata(hook_p hook, item_p item) 400 { 401 const node_p node = NG_HOOK_NODE(hook); 402 const priv_p priv = NG_NODE_PRIVATE(node); 403 int error = 0; 404 struct mbuf *m; 405 406 NGI_GET_M(item, m); 407 if (hook == priv->ip) { /* outgoing packet */ 408 u_int type = TYPE_IP; 409 410 /* Compress packet if enabled and proto is TCP */ 411 if (priv->conf.enableComp) { 412 struct ip *ip; 413 414 if ((m = ng_vjc_pulluphdrs(m, 0)) == NULL) { 415 NG_FREE_ITEM(item); 416 return (ENOBUFS); 417 } 418 ip = mtod(m, struct ip *); 419 if (ip->ip_p == IPPROTO_TCP) { 420 const int origLen = m->m_len; 421 422 type = sl_compress_tcp(m, ip, 423 &priv->slc, priv->conf.compressCID); 424 m->m_pkthdr.len += m->m_len - origLen; 425 } 426 } 427 428 /* Dispatch to the appropriate outgoing hook */ 429 switch (type) { 430 case TYPE_IP: 431 hook = priv->vjip; 432 break; 433 case TYPE_UNCOMPRESSED_TCP: 434 hook = priv->vjuncomp; 435 break; 436 case TYPE_COMPRESSED_TCP: 437 hook = priv->vjcomp; 438 break; 439 default: 440 panic("%s: type=%d", __func__, type); 441 } 442 } else if (hook == priv->vjcomp) { /* incoming compressed packet */ 443 int vjlen, need2pullup; 444 struct mbuf *hm; 445 u_char *hdr; 446 u_int hlen; 447 448 /* Are we decompressing? */ 449 if (!priv->conf.enableDecomp) { 450 NG_FREE_M(m); 451 NG_FREE_ITEM(item); 452 return (ENXIO); 453 } 454 455 /* Pull up the necessary amount from the mbuf */ 456 need2pullup = MAX_VJHEADER; 457 if (need2pullup > m->m_pkthdr.len) 458 need2pullup = m->m_pkthdr.len; 459 if (m->m_len < need2pullup 460 && (m = m_pullup(m, need2pullup)) == NULL) { 461 priv->slc.sls_errorin++; 462 NG_FREE_ITEM(item); 463 return (ENOBUFS); 464 } 465 466 /* Uncompress packet to reconstruct TCP/IP header */ 467 vjlen = sl_uncompress_tcp_core(mtod(m, u_char *), 468 m->m_len, m->m_pkthdr.len, TYPE_COMPRESSED_TCP, 469 &priv->slc, &hdr, &hlen); 470 if (vjlen <= 0) { 471 NG_FREE_M(m); 472 NG_FREE_ITEM(item); 473 return (EINVAL); 474 } 475 m_adj(m, vjlen); 476 477 /* Copy the reconstructed TCP/IP headers into a new mbuf */ 478 MGETHDR(hm, M_DONTWAIT, MT_DATA); 479 if (hm == NULL) { 480 priv->slc.sls_errorin++; 481 NG_FREE_M(m); 482 NG_FREE_ITEM(item); 483 return (ENOBUFS); 484 } 485 hm->m_len = 0; 486 hm->m_pkthdr.rcvif = NULL; 487 if (hlen > MHLEN) { /* unlikely, but can happen */ 488 MCLGET(hm, M_DONTWAIT); 489 if ((hm->m_flags & M_EXT) == 0) { 490 m_freem(hm); 491 priv->slc.sls_errorin++; 492 NG_FREE_M(m); 493 NG_FREE_ITEM(item); 494 return (ENOBUFS); 495 } 496 } 497 bcopy(hdr, mtod(hm, u_char *), hlen); 498 hm->m_len = hlen; 499 500 /* Glue TCP/IP headers and rest of packet together */ 501 hm->m_next = m; 502 hm->m_pkthdr.len = hlen + m->m_pkthdr.len; 503 m = hm; 504 hook = priv->ip; 505 } else if (hook == priv->vjuncomp) { /* incoming uncompressed pkt */ 506 u_char *hdr; 507 u_int hlen; 508 509 /* Are we decompressing? */ 510 if (!priv->conf.enableDecomp) { 511 NG_FREE_M(m); 512 NG_FREE_ITEM(item); 513 return (ENXIO); 514 } 515 516 /* Pull up IP+TCP headers */ 517 if ((m = ng_vjc_pulluphdrs(m, 1)) == NULL) { 518 NG_FREE_ITEM(item); 519 return (ENOBUFS); 520 } 521 522 /* Run packet through uncompressor */ 523 if (sl_uncompress_tcp_core(mtod(m, u_char *), 524 m->m_len, m->m_pkthdr.len, TYPE_UNCOMPRESSED_TCP, 525 &priv->slc, &hdr, &hlen) < 0) { 526 NG_FREE_M(m); 527 NG_FREE_ITEM(item); 528 return (EINVAL); 529 } 530 hook = priv->ip; 531 } else if (hook == priv->vjip) /* incoming regular packet (bypass) */ 532 hook = priv->ip; 533 else 534 panic("%s: unknown hook", __func__); 535 536 /* Send result back out */ 537 NG_FWD_NEW_DATA(error, item, hook, m); 538 return (error); 539 } 540 541 /* 542 * Shutdown node 543 */ 544 static int 545 ng_vjc_shutdown(node_p node) 546 { 547 const priv_p priv = NG_NODE_PRIVATE(node); 548 549 bzero(priv, sizeof(*priv)); 550 FREE(priv, M_NETGRAPH); 551 NG_NODE_SET_PRIVATE(node, NULL); 552 NG_NODE_UNREF(node); 553 return (0); 554 } 555 556 /* 557 * Hook disconnection 558 */ 559 static int 560 ng_vjc_disconnect(hook_p hook) 561 { 562 const node_p node = NG_HOOK_NODE(hook); 563 const priv_p priv = NG_NODE_PRIVATE(node); 564 565 /* Zero out hook pointer */ 566 if (hook == priv->ip) 567 priv->ip = NULL; 568 else if (hook == priv->vjcomp) 569 priv->vjcomp = NULL; 570 else if (hook == priv->vjuncomp) 571 priv->vjuncomp = NULL; 572 else if (hook == priv->vjip) 573 priv->vjip = NULL; 574 else 575 panic("%s: unknown hook", __func__); 576 577 /* Go away if no hooks left */ 578 if ((NG_NODE_NUMHOOKS(node) == 0) 579 && (NG_NODE_IS_VALID(node))) 580 ng_rmnode_self(node); 581 return (0); 582 } 583 584 /************************************************************************ 585 HELPER STUFF 586 ************************************************************************/ 587 588 /* 589 * Pull up the full IP and TCP headers of a packet. If packet is not 590 * a TCP packet, just pull up the IP header. 591 */ 592 static struct mbuf * 593 ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP) 594 { 595 struct ip *ip; 596 struct tcphdr *tcp; 597 int ihlen, thlen; 598 599 if (m->m_len < sizeof(*ip) && (m = m_pullup(m, sizeof(*ip))) == NULL) 600 return (NULL); 601 ip = mtod(m, struct ip *); 602 if (!knownTCP && ip->ip_p != IPPROTO_TCP) 603 return (m); 604 ihlen = ip->ip_hl << 2; 605 if (m->m_len < ihlen + sizeof(*tcp)) { 606 if ((m = m_pullup(m, ihlen + sizeof(*tcp))) == NULL) 607 return (NULL); 608 ip = mtod(m, struct ip *); 609 } 610 tcp = (struct tcphdr *)((u_char *)ip + ihlen); 611 thlen = tcp->th_off << 2; 612 if (m->m_len < ihlen + thlen) 613 m = m_pullup(m, ihlen + thlen); 614 return (m); 615 } 616 617