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 68876 2000-11-18 15:17:43Z dwmalone $
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_rmnode;
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_VERSION,
226 NG_VJC_NODE_TYPE,
227 NULL,
228 ng_vjc_constructor,
229 ng_vjc_rcvmsg,
230 ng_vjc_rmnode,
231 ng_vjc_newhook,
232 NULL,
233 NULL,
234 ng_vjc_rcvdata,
235 ng_vjc_rcvdata,
236 ng_vjc_disconnect,
237 ng_vjc_cmds
238};
239NETGRAPH_INIT(vjc, &ng_vjc_typestruct);
240
241/************************************************************************
242 NETGRAPH NODE METHODS
243 ************************************************************************/
244
245/*
246 * Create a new node
247 */
248static int
249ng_vjc_constructor(node_p *nodep)
250{
251 priv_p priv;
252 int error;
253
254 /* Allocate private structure */
255 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
256 if (priv == NULL)
257 return (ENOMEM);
258
259 /* Call generic node constructor */
260 if ((error = ng_make_node_common(&ng_vjc_typestruct, nodep))) {
261 FREE(priv, M_NETGRAPH);
262 return (error);
263 }
264 (*nodep)->private = priv;
265
266 /* Done */
267 return (0);
268}
269
270/*
271 * Add a new hook
272 */
273static int
274ng_vjc_newhook(node_p node, hook_p hook, const char *name)
275{
276 const priv_p priv = (priv_p) node->private;
277 hook_p *hookp;
278
279 /* Get hook */
280 if (strcmp(name, NG_VJC_HOOK_IP) == 0)
281 hookp = &priv->ip;
282 else if (strcmp(name, NG_VJC_HOOK_VJCOMP) == 0)
283 hookp = &priv->vjcomp;
284 else if (strcmp(name, NG_VJC_HOOK_VJUNCOMP) == 0)
285 hookp = &priv->vjuncomp;
286 else if (strcmp(name, NG_VJC_HOOK_VJIP) == 0)
287 hookp = &priv->vjip;
288 else
289 return (EINVAL);
290
291 /* See if already connected */
292 if (*hookp)
293 return (EISCONN);
294
295 /* OK */
296 *hookp = hook;
297 return (0);
298}
299
300/*
301 * Receive a control message
302 */
303static int
304ng_vjc_rcvmsg(node_p node, struct ng_mesg *msg,
305 const char *raddr, struct ng_mesg **rptr, hook_p lasthook)
306{
307 const priv_p priv = (priv_p) node->private;
308 struct ng_mesg *resp = NULL;
309 int error = 0;
310
311 /* Check type cookie */
312 switch (msg->header.typecookie) {
313 case NGM_VJC_COOKIE:
314 switch (msg->header.cmd) {
315 case NGM_VJC_SET_CONFIG:
316 {
317 struct ngm_vjc_config *const c =
318 (struct ngm_vjc_config *) msg->data;
319
320 if (msg->header.arglen != sizeof(*c))
321 ERROUT(EINVAL);
322 if ((priv->conf.enableComp || priv->conf.enableDecomp)
323 && (c->enableComp || c->enableDecomp))
324 ERROUT(EALREADY);
325 if (c->enableComp) {
326 if (c->maxChannel > NG_VJC_MAX_CHANNELS - 1
327 || c->maxChannel < NG_VJC_MIN_CHANNELS - 1)
328 ERROUT(EINVAL);
329 } else
330 c->maxChannel = NG_VJC_MAX_CHANNELS - 1;
331 if (c->enableComp != 0 || c->enableDecomp != 0) {
332 bzero(&priv->slc, sizeof(priv->slc));
333 sl_compress_init(&priv->slc, c->maxChannel);
334 }
335 priv->conf = *c;
336 break;
337 }
338 case NGM_VJC_GET_CONFIG:
339 {
340 struct ngm_vjc_config *conf;
341
342 NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
343 if (resp == NULL)
344 ERROUT(ENOMEM);
345 conf = (struct ngm_vjc_config *)resp->data;
346 *conf = priv->conf;
347 break;
348 }
349 case NGM_VJC_GET_STATE:
350 {
351 const struct slcompress *const sl0 = &priv->slc;
352 struct slcompress *sl;
353 u_int16_t index;
354 int i;
355
356 /* Get response structure */
357 NG_MKRESPONSE(resp, msg, sizeof(*sl), M_NOWAIT);
358 if (resp == NULL)
359 ERROUT(ENOMEM);
360 sl = (struct slcompress *)resp->data;
361 *sl = *sl0;
362
363 /* Replace pointers with integer indicies */
364 if (sl->last_cs != NULL) {
365 index = sl0->last_cs - sl0->tstate;
366 bzero(&sl->last_cs, sizeof(sl->last_cs));
367 *((u_int16_t *)&sl->last_cs) = index;
368 }
369 for (i = 0; i < MAX_STATES; i++) {
370 struct cstate *const cs = &sl->tstate[i];
371
372 index = sl0->tstate[i].cs_next - sl0->tstate;
373 bzero(&cs->cs_next, sizeof(cs->cs_next));
374 *((u_int16_t *)&cs->cs_next) = index;
375 }
376 break;
377 }
378 case NGM_VJC_CLR_STATS:
379 priv->slc.sls_packets = 0;
380 priv->slc.sls_compressed = 0;
381 priv->slc.sls_searches = 0;
382 priv->slc.sls_misses = 0;
383 priv->slc.sls_uncompressedin = 0;
384 priv->slc.sls_compressedin = 0;
385 priv->slc.sls_errorin = 0;
386 priv->slc.sls_tossed = 0;
387 break;
388 case NGM_VJC_RECV_ERROR:
389 sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &priv->slc);
390 break;
391 default:
392 error = EINVAL;
393 break;
394 }
395 break;
396 default:
397 error = EINVAL;
398 break;
399 }
400 if (rptr)
401 *rptr = resp;
402 else if (resp)
403 FREE(resp, M_NETGRAPH);
404
405done:
406 FREE(msg, M_NETGRAPH);
407 return (error);
408}
409
410/*
411 * Receive data
412 */
413static int
414ng_vjc_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
415 struct mbuf **ret_m, meta_p *ret_meta)
416{
417 const node_p node = hook->node;
418 const priv_p priv = (priv_p) node->private;
419 int error = 0;
420
421 if (hook == priv->ip) { /* outgoing packet */
422 u_int type = TYPE_IP;
423
424 /* Compress packet if enabled and proto is TCP */
425 if (priv->conf.enableComp) {
426 struct ip *ip;
427
428 if ((m = ng_vjc_pulluphdrs(m, 0)) == NULL) {
429 NG_FREE_META(meta);
430 return (ENOBUFS);
431 }
432 ip = mtod(m, struct ip *);
433 if (ip->ip_p == IPPROTO_TCP) {
434 const int origLen = m->m_len;
435
436 type = sl_compress_tcp(m, ip,
437 &priv->slc, priv->conf.compressCID);
438 m->m_pkthdr.len += m->m_len - origLen;
439 }
440 }
441
442 /* Dispatch to the appropriate outgoing hook */
443 switch (type) {
444 case TYPE_IP:
445 hook = priv->vjip;
446 break;
447 case TYPE_UNCOMPRESSED_TCP:
448 hook = priv->vjuncomp;
449 break;
450 case TYPE_COMPRESSED_TCP:
451 hook = priv->vjcomp;
452 break;
453 default:
454 panic("%s: type=%d", __FUNCTION__, type);
455 }
456 } else if (hook == priv->vjcomp) { /* incoming compressed packet */
457 int vjlen, need2pullup;
458 struct mbuf *hm;
459 u_char *hdr;
460 u_int hlen;
461
462 /* Are we decompressing? */
463 if (!priv->conf.enableDecomp) {
464 NG_FREE_DATA(m, meta);
465 return (ENXIO);
466 }
467
468 /* Pull up the necessary amount from the mbuf */
469 need2pullup = MAX_VJHEADER;
470 if (need2pullup > m->m_pkthdr.len)
471 need2pullup = m->m_pkthdr.len;
472 if (m->m_len < need2pullup
473 && (m = m_pullup(m, need2pullup)) == NULL) {
474 priv->slc.sls_errorin++;
475 NG_FREE_META(meta);
476 return (ENOBUFS);
477 }
478
479 /* Uncompress packet to reconstruct TCP/IP header */
480 vjlen = sl_uncompress_tcp_core(mtod(m, u_char *),
481 m->m_len, m->m_pkthdr.len, TYPE_COMPRESSED_TCP,
482 &priv->slc, &hdr, &hlen);
483 if (vjlen <= 0) {
484 NG_FREE_DATA(m, meta);
485 return (EINVAL);
486 }
487 m_adj(m, vjlen);
488
489 /* Copy the reconstructed TCP/IP headers into a new mbuf */
490 MGETHDR(hm, M_DONTWAIT, MT_DATA);
491 if (hm == NULL) {
492 priv->slc.sls_errorin++;
493 NG_FREE_DATA(m, meta);
494 return (ENOBUFS);
495 }
496 hm->m_len = 0;
497 hm->m_pkthdr.rcvif = NULL;
498 if (hlen > MHLEN) { /* unlikely, but can happen */
499 MCLGET(hm, M_DONTWAIT);
500 if ((hm->m_flags & M_EXT) == 0) {
501 m_freem(hm);
502 priv->slc.sls_errorin++;
503 NG_FREE_DATA(m, meta);
504 return (ENOBUFS);
505 }
506 }
507 bcopy(hdr, mtod(hm, u_char *), hlen);
508 hm->m_len = hlen;
509
510 /* Glue TCP/IP headers and rest of packet together */
511 hm->m_next = m;
512 hm->m_pkthdr.len = hlen + m->m_pkthdr.len;
513 m = hm;
514 hook = priv->ip;
515 } else if (hook == priv->vjuncomp) { /* incoming uncompressed pkt */
516 u_char *hdr;
517 u_int hlen;
518
519 /* Are we decompressing? */
520 if (!priv->conf.enableDecomp) {
521 NG_FREE_DATA(m, meta);
522 return (ENXIO);
523 }
524
525 /* Pull up IP+TCP headers */
526 if ((m = ng_vjc_pulluphdrs(m, 1)) == NULL) {
527 NG_FREE_META(meta);
528 return (ENOBUFS);
529 }
530
531 /* Run packet through uncompressor */
532 if (sl_uncompress_tcp_core(mtod(m, u_char *),
533 m->m_len, m->m_pkthdr.len, TYPE_UNCOMPRESSED_TCP,
534 &priv->slc, &hdr, &hlen) < 0) {
535 NG_FREE_DATA(m, meta);
536 return (EINVAL);
537 }
538 hook = priv->ip;
539 } else if (hook == priv->vjip) /* incoming regular packet (bypass) */
540 hook = priv->ip;
541 else
542 panic("%s: unknown hook", __FUNCTION__);
543
544 /* Send result back out */
545 NG_SEND_DATA(error, hook, m, meta);
546 return (error);
547}
548
549/*
550 * Shutdown node
551 */
552static int
553ng_vjc_rmnode(node_p node)
554{
555 const priv_p priv = (priv_p) node->private;
556
557 node->flags |= NG_INVALID;
558 ng_cutlinks(node);
559 ng_unname(node);
560 bzero(priv, sizeof(*priv));
561 FREE(priv, M_NETGRAPH);
562 node->private = NULL;
563 ng_unref(node);
564 return (0);
565}
566
567/*
568 * Hook disconnection
569 */
570static int
571ng_vjc_disconnect(hook_p hook)
572{
573 const node_p node = hook->node;
574 const priv_p priv = node->private;
575
576 /* Zero out hook pointer */
577 if (hook == priv->ip)
578 priv->ip = NULL;
579 else if (hook == priv->vjcomp)
580 priv->vjcomp = NULL;
581 else if (hook == priv->vjuncomp)
582 priv->vjuncomp = NULL;
583 else if (hook == priv->vjip)
584 priv->vjip = NULL;
585 else
586 panic("%s: unknown hook", __FUNCTION__);
587
588 /* Go away if no hooks left */
589 if (node->numhooks == 0)
590 ng_rmnode(node);
591 return (0);
592}
593
594/************************************************************************
595 HELPER STUFF
596 ************************************************************************/
597
598/*
599 * Pull up the full IP and TCP headers of a packet. If packet is not
600 * a TCP packet, just pull up the IP header.
601 */
602static struct mbuf *
603ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP)
604{
605 struct ip *ip;
606 struct tcphdr *tcp;
607 int ihlen, thlen;
608
609 if (m->m_len < sizeof(*ip) && (m = m_pullup(m, sizeof(*ip))) == NULL)
610 return (NULL);
611 ip = mtod(m, struct ip *);
612 if (!knownTCP && ip->ip_p != IPPROTO_TCP)
613 return (m);
614 ihlen = ip->ip_hl << 2;
615 if (m->m_len < ihlen + sizeof(*tcp)) {
616 if ((m = m_pullup(m, ihlen + sizeof(*tcp))) == NULL)
617 return (NULL);
618 ip = mtod(m, struct ip *);
619 }
620 tcp = (struct tcphdr *)((u_char *)ip + ihlen);
621 thlen = tcp->th_off << 2;
622 if (m->m_len < ihlen + thlen)
623 m = m_pullup(m, ihlen + thlen);
624 return (m);
625}
626