ng_vjc.c revision 70784
1 2/* 3 * ng_vjc.c 4 * 5 * Copyright (c) 1996-1999 Whistle Communications, Inc. 6 * All rights reserved. 7 * 8 * Subject to the following obligations and disclaimer of warranty, use and 9 * redistribution of this software, in source or object code forms, with or 10 * without modifications are expressly permitted by Whistle Communications; 11 * provided, however, that: 12 * 1. Any and all reproductions of the source or object code must include the 13 * copyright notice above and the following disclaimer of warranties; and 14 * 2. No rights are granted, in any manner or form, to use Whistle 15 * Communications, Inc. trademarks, including the mark "WHISTLE 16 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 17 * such appears in the above copyright notice or in the software. 18 * 19 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 22 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 24 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 25 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 26 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 27 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 28 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 29 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 30 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 31 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 35 * OF SUCH DAMAGE. 36 * 37 * Author: Archie Cobbs <archie@freebsd.org> 38 * 39 * $FreeBSD: head/sys/netgraph/ng_vjc.c 70784 2001-01-08 05:34:06Z julian $ 40 * $Whistle: ng_vjc.c,v 1.17 1999/11/01 09:24:52 julian Exp $ 41 */ 42 43/* 44 * This node performs Van Jacobson IP header (de)compression. 45 * You must have included net/slcompress.c in your kernel compilation. 46 */ 47 48#include <sys/param.h> 49#include <sys/systm.h> 50#include <sys/errno.h> 51#include <sys/kernel.h> 52#include <sys/mbuf.h> 53#include <sys/malloc.h> 54#include <sys/errno.h> 55 56#include <netgraph/ng_message.h> 57#include <netgraph/netgraph.h> 58#include <netgraph/ng_parse.h> 59#include <netgraph/ng_vjc.h> 60 61#include <netinet/in.h> 62#include <netinet/in_systm.h> 63#include <netinet/ip.h> 64#include <netinet/tcp.h> 65 66#include <net/slcompress.h> 67 68/* Check agreement with slcompress.c */ 69#if MAX_STATES != NG_VJC_MAX_CHANNELS 70#error NG_VJC_MAX_CHANNELS must be the same as MAX_STATES 71#endif 72 73/* Maximum length of a compressed TCP VJ header */ 74#define MAX_VJHEADER 19 75 76/* Node private data */ 77struct ng_vjc_private { 78 struct ngm_vjc_config conf; 79 struct slcompress slc; 80 hook_p ip; 81 hook_p vjcomp; 82 hook_p vjuncomp; 83 hook_p vjip; 84}; 85typedef struct ng_vjc_private *priv_p; 86 87#define ERROUT(x) do { error = (x); goto done; } while (0) 88 89/* Netgraph node methods */ 90static ng_constructor_t ng_vjc_constructor; 91static ng_rcvmsg_t ng_vjc_rcvmsg; 92static ng_shutdown_t ng_vjc_shutdown; 93static ng_newhook_t ng_vjc_newhook; 94static ng_rcvdata_t ng_vjc_rcvdata; 95static ng_disconnect_t ng_vjc_disconnect; 96 97/* Helper stuff */ 98static struct mbuf *ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP); 99 100/* Parse type for struct ngm_vjc_config */ 101static const struct ng_parse_struct_info ng_vjc_config_type_info 102 = NG_VJC_CONFIG_TYPE_INFO; 103static const struct ng_parse_type ng_vjc_config_type = { 104 &ng_parse_struct_type, 105 &ng_vjc_config_type_info 106}; 107 108/* Parse type for the 'last_cs' and 'cs_next' fields in struct slcompress, 109 which are pointers converted to integer indices, so parse them that way. */ 110#if _MACHINE_ARCH == i386 111#define NG_VJC_TSTATE_PTR_TYPE &ng_parse_uint32_type 112#elif _MACHINE_ARCH == alpha 113#define NG_VJC_TSTATE_PTR_TYPE &ng_parse_uint64_type 114#else 115#error Unspported _MACHINE_ARCH 116#endif 117 118/* Parse type for the 'cs_hdr' field in a struct cstate. Ideally we would 119 like to use a 'struct ip' type instead of a simple array of bytes. */ 120static const struct ng_parse_fixedarray_info ng_vjc_cs_hdr_type_info = { 121 &ng_parse_hint8_type, 122 MAX_HDR 123}; 124static const struct ng_parse_type ng_vjc_cs_hdr_type = { 125 &ng_parse_fixedarray_type, 126 &ng_vjc_cs_hdr_type_info 127}; 128 129/* Parse type for a struct cstate */ 130static const struct ng_parse_struct_info ng_vjc_cstate_type_info = { 131 { 132 { "cs_next", NG_VJC_TSTATE_PTR_TYPE }, 133 { "cs_hlen", &ng_parse_uint16_type }, 134 { "cs_id", &ng_parse_uint8_type }, 135 { "cs_filler", &ng_parse_uint8_type }, 136 { "cs_hdr", &ng_vjc_cs_hdr_type }, 137 { NULL }, 138 } 139}; 140static const struct ng_parse_type ng_vjc_cstate_type = { 141 &ng_parse_struct_type, 142 &ng_vjc_cstate_type_info 143}; 144 145/* Parse type for an array of MAX_STATES struct cstate's, ie, tstate & rstate */ 146static const struct ng_parse_fixedarray_info ng_vjc_cstatearray_type_info = { 147 &ng_vjc_cstate_type, 148 MAX_STATES 149}; 150static 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> */ 157static const struct ng_parse_struct_info ng_vjc_slcompress_type_info = { 158 { 159 { "last_cs", NG_VJC_TSTATE_PTR_TYPE }, 160 { "last_recv", &ng_parse_uint8_type }, 161 { "last_xmit", &ng_parse_uint8_type }, 162 { "flags", &ng_parse_hint16_type }, 163#ifndef SL_NO_STATS 164 { "sls_packets", &ng_parse_uint32_type }, 165 { "sls_compressed", &ng_parse_uint32_type }, 166 { "sls_searches", &ng_parse_uint32_type }, 167 { "sls_misses", &ng_parse_uint32_type }, 168 { "sls_uncompressedin", &ng_parse_uint32_type }, 169 { "sls_compressedin", &ng_parse_uint32_type }, 170 { "sls_errorin", &ng_parse_uint32_type }, 171 { "sls_tossed", &ng_parse_uint32_type }, 172#endif 173 { "tstate", &ng_vjc_cstatearray_type }, 174 { "rstate", &ng_vjc_cstatearray_type }, 175 { NULL }, 176 } 177}; 178static const struct ng_parse_type ng_vjc_slcompress_type = { 179 &ng_parse_struct_type, 180 &ng_vjc_slcompress_type_info 181}; 182 183/* List of commands and how to convert arguments to/from ASCII */ 184static const struct ng_cmdlist ng_vjc_cmds[] = { 185 { 186 NGM_VJC_COOKIE, 187 NGM_VJC_SET_CONFIG, 188 "setconfig", 189 &ng_vjc_config_type, 190 NULL 191 }, 192 { 193 NGM_VJC_COOKIE, 194 NGM_VJC_GET_CONFIG, 195 "getconfig", 196 NULL, 197 &ng_vjc_config_type, 198 }, 199 { 200 NGM_VJC_COOKIE, 201 NGM_VJC_GET_STATE, 202 "getstate", 203 NULL, 204 &ng_vjc_slcompress_type, 205 }, 206 { 207 NGM_VJC_COOKIE, 208 NGM_VJC_CLR_STATS, 209 "clrstats", 210 NULL, 211 NULL, 212 }, 213 { 214 NGM_VJC_COOKIE, 215 NGM_VJC_RECV_ERROR, 216 "recverror", 217 NULL, 218 NULL, 219 }, 220 { 0 } 221}; 222 223/* Node type descriptor */ 224static struct ng_type ng_vjc_typestruct = { 225 NG_ABI_VERSION, 226 NG_VJC_NODE_TYPE, 227 NULL, 228 ng_vjc_constructor, 229 ng_vjc_rcvmsg, 230 ng_vjc_shutdown, 231 ng_vjc_newhook, 232 NULL, 233 NULL, 234 ng_vjc_rcvdata, 235 ng_vjc_disconnect, 236 ng_vjc_cmds 237}; 238NETGRAPH_INIT(vjc, &ng_vjc_typestruct); 239 240/************************************************************************ 241 NETGRAPH NODE METHODS 242 ************************************************************************/ 243 244/* 245 * Create a new node 246 */ 247static int 248ng_vjc_constructor(node_p node) 249{ 250 priv_p priv; 251 252 /* Allocate private structure */ 253 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 254 if (priv == NULL) 255 return (ENOMEM); 256 257 NG_NODE_SET_PRIVATE(node, priv); 258 259 /* Done */ 260 return (0); 261} 262 263/* 264 * Add a new hook 265 */ 266static int 267ng_vjc_newhook(node_p node, hook_p hook, const char *name) 268{ 269 const priv_p priv = NG_NODE_PRIVATE(node); 270 hook_p *hookp; 271 272 /* Get hook */ 273 if (strcmp(name, NG_VJC_HOOK_IP) == 0) 274 hookp = &priv->ip; 275 else if (strcmp(name, NG_VJC_HOOK_VJCOMP) == 0) 276 hookp = &priv->vjcomp; 277 else if (strcmp(name, NG_VJC_HOOK_VJUNCOMP) == 0) 278 hookp = &priv->vjuncomp; 279 else if (strcmp(name, NG_VJC_HOOK_VJIP) == 0) 280 hookp = &priv->vjip; 281 else 282 return (EINVAL); 283 284 /* See if already connected */ 285 if (*hookp) 286 return (EISCONN); 287 288 /* OK */ 289 *hookp = hook; 290 return (0); 291} 292 293/* 294 * Receive a control message 295 */ 296static int 297ng_vjc_rcvmsg(node_p node, item_p item, hook_p lasthook) 298{ 299 const priv_p priv = NG_NODE_PRIVATE(node); 300 struct ng_mesg *resp = NULL; 301 int error = 0; 302 struct ng_mesg *msg; 303 304 NGI_GET_MSG(item, msg); 305 /* Check type cookie */ 306 switch (msg->header.typecookie) { 307 case NGM_VJC_COOKIE: 308 switch (msg->header.cmd) { 309 case NGM_VJC_SET_CONFIG: 310 { 311 struct ngm_vjc_config *const c = 312 (struct ngm_vjc_config *) msg->data; 313 314 if (msg->header.arglen != sizeof(*c)) 315 ERROUT(EINVAL); 316 if ((priv->conf.enableComp || priv->conf.enableDecomp) 317 && (c->enableComp || c->enableDecomp)) 318 ERROUT(EALREADY); 319 if (c->enableComp) { 320 if (c->maxChannel > NG_VJC_MAX_CHANNELS - 1 321 || c->maxChannel < NG_VJC_MIN_CHANNELS - 1) 322 ERROUT(EINVAL); 323 } else 324 c->maxChannel = NG_VJC_MAX_CHANNELS - 1; 325 if (c->enableComp != 0 || c->enableDecomp != 0) { 326 bzero(&priv->slc, sizeof(priv->slc)); 327 sl_compress_init(&priv->slc, c->maxChannel); 328 } 329 priv->conf = *c; 330 break; 331 } 332 case NGM_VJC_GET_CONFIG: 333 { 334 struct ngm_vjc_config *conf; 335 336 NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT); 337 if (resp == NULL) 338 ERROUT(ENOMEM); 339 conf = (struct ngm_vjc_config *)resp->data; 340 *conf = priv->conf; 341 break; 342 } 343 case NGM_VJC_GET_STATE: 344 { 345 const struct slcompress *const sl0 = &priv->slc; 346 struct slcompress *sl; 347 u_int16_t index; 348 int i; 349 350 /* Get response structure */ 351 NG_MKRESPONSE(resp, msg, sizeof(*sl), M_NOWAIT); 352 if (resp == NULL) 353 ERROUT(ENOMEM); 354 sl = (struct slcompress *)resp->data; 355 *sl = *sl0; 356 357 /* Replace pointers with integer indicies */ 358 if (sl->last_cs != NULL) { 359 index = sl0->last_cs - sl0->tstate; 360 bzero(&sl->last_cs, sizeof(sl->last_cs)); 361 *((u_int16_t *)&sl->last_cs) = index; 362 } 363 for (i = 0; i < MAX_STATES; i++) { 364 struct cstate *const cs = &sl->tstate[i]; 365 366 index = sl0->tstate[i].cs_next - sl0->tstate; 367 bzero(&cs->cs_next, sizeof(cs->cs_next)); 368 *((u_int16_t *)&cs->cs_next) = index; 369 } 370 break; 371 } 372 case NGM_VJC_CLR_STATS: 373 priv->slc.sls_packets = 0; 374 priv->slc.sls_compressed = 0; 375 priv->slc.sls_searches = 0; 376 priv->slc.sls_misses = 0; 377 priv->slc.sls_uncompressedin = 0; 378 priv->slc.sls_compressedin = 0; 379 priv->slc.sls_errorin = 0; 380 priv->slc.sls_tossed = 0; 381 break; 382 case NGM_VJC_RECV_ERROR: 383 sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &priv->slc); 384 break; 385 default: 386 error = EINVAL; 387 break; 388 } 389 break; 390 default: 391 error = EINVAL; 392 break; 393 } 394done: 395 NG_RESPOND_MSG(error, node, item, resp); 396 NG_FREE_MSG(msg); 397 return (error); 398} 399 400/* 401 * Receive data 402 */ 403static int 404ng_vjc_rcvdata(hook_p hook, item_p item) 405{ 406 const node_p node = NG_HOOK_NODE(hook); 407 const priv_p priv = NG_NODE_PRIVATE(node); 408 int error = 0; 409 struct mbuf *m; 410 411 NGI_GET_M(item, m); 412 if (hook == priv->ip) { /* outgoing packet */ 413 u_int type = TYPE_IP; 414 415 /* Compress packet if enabled and proto is TCP */ 416 if (priv->conf.enableComp) { 417 struct ip *ip; 418 419 if ((m = ng_vjc_pulluphdrs(m, 0)) == NULL) { 420 NG_FREE_ITEM(item); 421 return (ENOBUFS); 422 } 423 ip = mtod(m, struct ip *); 424 if (ip->ip_p == IPPROTO_TCP) { 425 const int origLen = m->m_len; 426 427 type = sl_compress_tcp(m, ip, 428 &priv->slc, priv->conf.compressCID); 429 m->m_pkthdr.len += m->m_len - origLen; 430 } 431 } 432 433 /* Dispatch to the appropriate outgoing hook */ 434 switch (type) { 435 case TYPE_IP: 436 hook = priv->vjip; 437 break; 438 case TYPE_UNCOMPRESSED_TCP: 439 hook = priv->vjuncomp; 440 break; 441 case TYPE_COMPRESSED_TCP: 442 hook = priv->vjcomp; 443 break; 444 default: 445 panic("%s: type=%d", __FUNCTION__, type); 446 } 447 } else if (hook == priv->vjcomp) { /* incoming compressed packet */ 448 int vjlen, need2pullup; 449 struct mbuf *hm; 450 u_char *hdr; 451 u_int hlen; 452 453 /* Are we decompressing? */ 454 if (!priv->conf.enableDecomp) { 455 NG_FREE_M(m); 456 NG_FREE_ITEM(item); 457 return (ENXIO); 458 } 459 460 /* Pull up the necessary amount from the mbuf */ 461 need2pullup = MAX_VJHEADER; 462 if (need2pullup > m->m_pkthdr.len) 463 need2pullup = m->m_pkthdr.len; 464 if (m->m_len < need2pullup 465 && (m = m_pullup(m, need2pullup)) == NULL) { 466 priv->slc.sls_errorin++; 467 NG_FREE_ITEM(item); 468 return (ENOBUFS); 469 } 470 471 /* Uncompress packet to reconstruct TCP/IP header */ 472 vjlen = sl_uncompress_tcp_core(mtod(m, u_char *), 473 m->m_len, m->m_pkthdr.len, TYPE_COMPRESSED_TCP, 474 &priv->slc, &hdr, &hlen); 475 if (vjlen <= 0) { 476 NG_FREE_M(m); 477 NG_FREE_ITEM(item); 478 return (EINVAL); 479 } 480 m_adj(m, vjlen); 481 482 /* Copy the reconstructed TCP/IP headers into a new mbuf */ 483 MGETHDR(hm, M_DONTWAIT, MT_DATA); 484 if (hm == NULL) { 485 priv->slc.sls_errorin++; 486 NG_FREE_M(m); 487 NG_FREE_ITEM(item); 488 return (ENOBUFS); 489 } 490 hm->m_len = 0; 491 hm->m_pkthdr.rcvif = NULL; 492 if (hlen > MHLEN) { /* unlikely, but can happen */ 493 MCLGET(hm, M_DONTWAIT); 494 if ((hm->m_flags & M_EXT) == 0) { 495 m_freem(hm); 496 priv->slc.sls_errorin++; 497 NG_FREE_M(m); 498 NG_FREE_ITEM(item); 499 return (ENOBUFS); 500 } 501 } 502 bcopy(hdr, mtod(hm, u_char *), hlen); 503 hm->m_len = hlen; 504 505 /* Glue TCP/IP headers and rest of packet together */ 506 hm->m_next = m; 507 hm->m_pkthdr.len = hlen + m->m_pkthdr.len; 508 m = hm; 509 hook = priv->ip; 510 } else if (hook == priv->vjuncomp) { /* incoming uncompressed pkt */ 511 u_char *hdr; 512 u_int hlen; 513 514 /* Are we decompressing? */ 515 if (!priv->conf.enableDecomp) { 516 NG_FREE_M(m); 517 NG_FREE_ITEM(item); 518 return (ENXIO); 519 } 520 521 /* Pull up IP+TCP headers */ 522 if ((m = ng_vjc_pulluphdrs(m, 1)) == NULL) { 523 NG_FREE_ITEM(item); 524 return (ENOBUFS); 525 } 526 527 /* Run packet through uncompressor */ 528 if (sl_uncompress_tcp_core(mtod(m, u_char *), 529 m->m_len, m->m_pkthdr.len, TYPE_UNCOMPRESSED_TCP, 530 &priv->slc, &hdr, &hlen) < 0) { 531 NG_FREE_M(m); 532 NG_FREE_ITEM(item); 533 return (EINVAL); 534 } 535 hook = priv->ip; 536 } else if (hook == priv->vjip) /* incoming regular packet (bypass) */ 537 hook = priv->ip; 538 else 539 panic("%s: unknown hook", __FUNCTION__); 540 541 /* Send result back out */ 542 NG_FWD_NEW_DATA(error, item, hook, m); 543 return (error); 544} 545 546/* 547 * Shutdown node 548 */ 549static int 550ng_vjc_shutdown(node_p node) 551{ 552 const priv_p priv = NG_NODE_PRIVATE(node); 553 554 bzero(priv, sizeof(*priv)); 555 FREE(priv, M_NETGRAPH); 556 NG_NODE_SET_PRIVATE(node, NULL); 557 NG_NODE_UNREF(node); 558 return (0); 559} 560 561/* 562 * Hook disconnection 563 */ 564static int 565ng_vjc_disconnect(hook_p hook) 566{ 567 const node_p node = NG_HOOK_NODE(hook); 568 const priv_p priv = NG_NODE_PRIVATE(node); 569 570 /* Zero out hook pointer */ 571 if (hook == priv->ip) 572 priv->ip = NULL; 573 else if (hook == priv->vjcomp) 574 priv->vjcomp = NULL; 575 else if (hook == priv->vjuncomp) 576 priv->vjuncomp = NULL; 577 else if (hook == priv->vjip) 578 priv->vjip = NULL; 579 else 580 panic("%s: unknown hook", __FUNCTION__); 581 582 /* Go away if no hooks left */ 583 if ((NG_NODE_NUMHOOKS(node) == 0) 584 && (NG_NODE_IS_VALID(node))) 585 ng_rmnode_self(node); 586 return (0); 587} 588 589/************************************************************************ 590 HELPER STUFF 591 ************************************************************************/ 592 593/* 594 * Pull up the full IP and TCP headers of a packet. If packet is not 595 * a TCP packet, just pull up the IP header. 596 */ 597static struct mbuf * 598ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP) 599{ 600 struct ip *ip; 601 struct tcphdr *tcp; 602 int ihlen, thlen; 603 604 if (m->m_len < sizeof(*ip) && (m = m_pullup(m, sizeof(*ip))) == NULL) 605 return (NULL); 606 ip = mtod(m, struct ip *); 607 if (!knownTCP && ip->ip_p != IPPROTO_TCP) 608 return (m); 609 ihlen = ip->ip_hl << 2; 610 if (m->m_len < ihlen + sizeof(*tcp)) { 611 if ((m = m_pullup(m, ihlen + sizeof(*tcp))) == NULL) 612 return (NULL); 613 ip = mtod(m, struct ip *); 614 } 615 tcp = (struct tcphdr *)((u_char *)ip + ihlen); 616 thlen = tcp->th_off << 2; 617 if (m->m_len < ihlen + thlen) 618 m = m_pullup(m, ihlen + thlen); 619 return (m); 620} 621 622