FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_vjc.c
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: releng/5.3/sys/netgraph/ng_vjc.c 136588 2004-10-16 08:43:07Z cvs2svn $
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 */
77 struct 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 };
85 typedef struct ng_vjc_private *priv_p;
86
87 #define ERROUT(x) do { error = (x); goto done; } while (0)
88
89 /* Netgraph node methods */
90 static ng_constructor_t ng_vjc_constructor;
91 static ng_rcvmsg_t ng_vjc_rcvmsg;
92 static ng_shutdown_t ng_vjc_shutdown;
93 static ng_newhook_t ng_vjc_newhook;
94 static ng_rcvdata_t ng_vjc_rcvdata;
95 static ng_disconnect_t ng_vjc_disconnect;
96
97 /* Helper stuff */
98 static struct mbuf *ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP);
99
100 /* Parse type for struct ngm_vjc_config */
101 static const struct ng_parse_struct_field ng_vjc_config_type_fields[]
102 = NG_VJC_CONFIG_TYPE_INFO;
103 static const struct ng_parse_type ng_vjc_config_type = {
104 &ng_parse_struct_type,
105 &ng_vjc_config_type_fields
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. */
120 static const struct ng_parse_fixedarray_info ng_vjc_cs_hdr_type_info = {
121 &ng_parse_hint8_type,
122 MAX_HDR
123 };
124 static 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 */
130 static const struct ng_parse_struct_field ng_vjc_cstate_type_fields[] = {
131 { "cs_next", NG_VJC_TSTATE_PTR_TYPE },
132 { "cs_hlen", &ng_parse_uint16_type },
133 { "cs_id", &ng_parse_uint8_type },
134 { "cs_filler", &ng_parse_uint8_type },
135 { "cs_hdr", &ng_vjc_cs_hdr_type },
136 { NULL }
137 };
138 static const struct ng_parse_type ng_vjc_cstate_type = {
139 &ng_parse_struct_type,
140 &ng_vjc_cstate_type_fields
141 };
142
143 /* Parse type for an array of MAX_STATES struct cstate's, ie, tstate & rstate */
144 static const struct ng_parse_fixedarray_info ng_vjc_cstatearray_type_info = {
145 &ng_vjc_cstate_type,
146 MAX_STATES
147 };
148 static const struct ng_parse_type ng_vjc_cstatearray_type = {
149 &ng_parse_fixedarray_type,
150 &ng_vjc_cstatearray_type_info
151 };
152
153 /* Parse type for struct slcompress. Keep this in sync with the
154 definition of struct slcompress defined in <net/slcompress.h> */
155 static const struct ng_parse_struct_field ng_vjc_slcompress_type_fields[] = {
156 { "last_cs", NG_VJC_TSTATE_PTR_TYPE },
157 { "last_recv", &ng_parse_uint8_type },
158 { "last_xmit", &ng_parse_uint8_type },
159 { "flags", &ng_parse_hint16_type },
160 #ifndef SL_NO_STATS
161 { "sls_packets", &ng_parse_uint32_type },
162 { "sls_compressed", &ng_parse_uint32_type },
163 { "sls_searches", &ng_parse_uint32_type },
164 { "sls_misses", &ng_parse_uint32_type },
165 { "sls_uncompressedin", &ng_parse_uint32_type },
166 { "sls_compressedin", &ng_parse_uint32_type },
167 { "sls_errorin", &ng_parse_uint32_type },
168 { "sls_tossed", &ng_parse_uint32_type },
169 #endif
170 { "tstate", &ng_vjc_cstatearray_type },
171 { "rstate", &ng_vjc_cstatearray_type },
172 { NULL }
173 };
174 static const struct ng_parse_type ng_vjc_slcompress_type = {
175 &ng_parse_struct_type,
176 &ng_vjc_slcompress_type_fields
177 };
178
179 /* List of commands and how to convert arguments to/from ASCII */
180 static const struct ng_cmdlist ng_vjc_cmds[] = {
181 {
182 NGM_VJC_COOKIE,
183 NGM_VJC_SET_CONFIG,
184 "setconfig",
185 &ng_vjc_config_type,
186 NULL
187 },
188 {
189 NGM_VJC_COOKIE,
190 NGM_VJC_GET_CONFIG,
191 "getconfig",
192 NULL,
193 &ng_vjc_config_type,
194 },
195 {
196 NGM_VJC_COOKIE,
197 NGM_VJC_GET_STATE,
198 "getstate",
199 NULL,
200 &ng_vjc_slcompress_type,
201 },
202 {
203 NGM_VJC_COOKIE,
204 NGM_VJC_CLR_STATS,
205 "clrstats",
206 NULL,
207 NULL,
208 },
209 {
210 NGM_VJC_COOKIE,
211 NGM_VJC_RECV_ERROR,
212 "recverror",
213 NULL,
214 NULL,
215 },
216 { 0 }
217 };
218
219 /* Node type descriptor */
220 static struct ng_type ng_vjc_typestruct = {
221 .version = NG_ABI_VERSION,
222 .name = NG_VJC_NODE_TYPE,
223 .constructor = ng_vjc_constructor,
224 .rcvmsg = ng_vjc_rcvmsg,
225 .shutdown = ng_vjc_shutdown,
226 .newhook = ng_vjc_newhook,
227 .rcvdata = ng_vjc_rcvdata,
228 .disconnect = ng_vjc_disconnect,
229 .cmdlist = ng_vjc_cmds,
230 };
231 NETGRAPH_INIT(vjc, &ng_vjc_typestruct);
232
233 /************************************************************************
234 NETGRAPH NODE METHODS
235 ************************************************************************/
236
237 /*
238 * Create a new node
239 */
240 static int
241 ng_vjc_constructor(node_p node)
242 {
243 priv_p priv;
244
245 /* Allocate private structure */
246 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
247 if (priv == NULL)
248 return (ENOMEM);
249
250 NG_NODE_SET_PRIVATE(node, priv);
251
252 /* Done */
253 return (0);
254 }
255
256 /*
257 * Add a new hook
258 */
259 static int
260 ng_vjc_newhook(node_p node, hook_p hook, const char *name)
261 {
262 const priv_p priv = NG_NODE_PRIVATE(node);
263 hook_p *hookp;
264
265 /* Get hook */
266 if (strcmp(name, NG_VJC_HOOK_IP) == 0)
267 hookp = &priv->ip;
268 else if (strcmp(name, NG_VJC_HOOK_VJCOMP) == 0)
269 hookp = &priv->vjcomp;
270 else if (strcmp(name, NG_VJC_HOOK_VJUNCOMP) == 0)
271 hookp = &priv->vjuncomp;
272 else if (strcmp(name, NG_VJC_HOOK_VJIP) == 0)
273 hookp = &priv->vjip;
274 else
275 return (EINVAL);
276
277 /* See if already connected */
278 if (*hookp)
279 return (EISCONN);
280
281 /* OK */
282 *hookp = hook;
283 return (0);
284 }
285
286 /*
287 * Receive a control message
288 */
289 static int
290 ng_vjc_rcvmsg(node_p node, item_p item, hook_p lasthook)
291 {
292 const priv_p priv = NG_NODE_PRIVATE(node);
293 struct ng_mesg *resp = NULL;
294 int error = 0;
295 struct ng_mesg *msg;
296
297 NGI_GET_MSG(item, msg);
298 /* Check type cookie */
299 switch (msg->header.typecookie) {
300 case NGM_VJC_COOKIE:
301 switch (msg->header.cmd) {
302 case NGM_VJC_SET_CONFIG:
303 {
304 struct ngm_vjc_config *const c =
305 (struct ngm_vjc_config *) msg->data;
306
307 if (msg->header.arglen != sizeof(*c))
308 ERROUT(EINVAL);
309 if ((priv->conf.enableComp || priv->conf.enableDecomp)
310 && (c->enableComp || c->enableDecomp))
311 ERROUT(EALREADY);
312 if (c->enableComp) {
313 if (c->maxChannel > NG_VJC_MAX_CHANNELS - 1
314 || c->maxChannel < NG_VJC_MIN_CHANNELS - 1)
315 ERROUT(EINVAL);
316 } else
317 c->maxChannel = NG_VJC_MAX_CHANNELS - 1;
318 if (c->enableComp != 0 || c->enableDecomp != 0) {
319 bzero(&priv->slc, sizeof(priv->slc));
320 sl_compress_init(&priv->slc, c->maxChannel);
321 }
322 priv->conf = *c;
323 break;
324 }
325 case NGM_VJC_GET_CONFIG:
326 {
327 struct ngm_vjc_config *conf;
328
329 NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
330 if (resp == NULL)
331 ERROUT(ENOMEM);
332 conf = (struct ngm_vjc_config *)resp->data;
333 *conf = priv->conf;
334 break;
335 }
336 case NGM_VJC_GET_STATE:
337 {
338 const struct slcompress *const sl0 = &priv->slc;
339 struct slcompress *sl;
340 u_int16_t index;
341 int i;
342
343 /* Get response structure */
344 NG_MKRESPONSE(resp, msg, sizeof(*sl), M_NOWAIT);
345 if (resp == NULL)
346 ERROUT(ENOMEM);
347 sl = (struct slcompress *)resp->data;
348 *sl = *sl0;
349
350 /* Replace pointers with integer indicies */
351 if (sl->last_cs != NULL) {
352 index = sl0->last_cs - sl0->tstate;
353 bzero(&sl->last_cs, sizeof(sl->last_cs));
354 *((u_int16_t *)&sl->last_cs) = index;
355 }
356 for (i = 0; i < MAX_STATES; i++) {
357 struct cstate *const cs = &sl->tstate[i];
358
359 index = sl0->tstate[i].cs_next - sl0->tstate;
360 bzero(&cs->cs_next, sizeof(cs->cs_next));
361 *((u_int16_t *)&cs->cs_next) = index;
362 }
363 break;
364 }
365 case NGM_VJC_CLR_STATS:
366 priv->slc.sls_packets = 0;
367 priv->slc.sls_compressed = 0;
368 priv->slc.sls_searches = 0;
369 priv->slc.sls_misses = 0;
370 priv->slc.sls_uncompressedin = 0;
371 priv->slc.sls_compressedin = 0;
372 priv->slc.sls_errorin = 0;
373 priv->slc.sls_tossed = 0;
374 break;
375 case NGM_VJC_RECV_ERROR:
376 sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &priv->slc);
377 break;
378 default:
379 error = EINVAL;
380 break;
381 }
382 break;
383 default:
384 error = EINVAL;
385 break;
386 }
387 done:
388 NG_RESPOND_MSG(error, node, item, resp);
389 NG_FREE_MSG(msg);
390 return (error);
391 }
392
393 /*
394 * Receive data
395 */
396 static int
397 ng_vjc_rcvdata(hook_p hook, item_p item)
398 {
399 const node_p node = NG_HOOK_NODE(hook);
400 const priv_p priv = NG_NODE_PRIVATE(node);
401 int error = 0;
402 struct mbuf *m;
403
404 NGI_GET_M(item, m);
405 if (hook == priv->ip) { /* outgoing packet */
406 u_int type = TYPE_IP;
407
408 /* Compress packet if enabled and proto is TCP */
409 if (priv->conf.enableComp) {
410 struct ip *ip;
411
412 if ((m = ng_vjc_pulluphdrs(m, 0)) == NULL) {
413 NG_FREE_ITEM(item);
414 return (ENOBUFS);
415 }
416 ip = mtod(m, struct ip *);
417 if (ip->ip_p == IPPROTO_TCP) {
418 const int origLen = m->m_len;
419
420 type = sl_compress_tcp(m, ip,
421 &priv->slc, priv->conf.compressCID);
422 m->m_pkthdr.len += m->m_len - origLen;
423 }
424 }
425
426 /* Dispatch to the appropriate outgoing hook */
427 switch (type) {
428 case TYPE_IP:
429 hook = priv->vjip;
430 break;
431 case TYPE_UNCOMPRESSED_TCP:
432 hook = priv->vjuncomp;
433 break;
434 case TYPE_COMPRESSED_TCP:
435 hook = priv->vjcomp;
436 break;
437 default:
438 panic("%s: type=%d", __func__, type);
439 }
440 } else if (hook == priv->vjcomp) { /* incoming compressed packet */
441 int vjlen, need2pullup;
442 struct mbuf *hm;
443 u_char *hdr;
444 u_int hlen;
445
446 /* Are we decompressing? */
447 if (!priv->conf.enableDecomp) {
448 NG_FREE_M(m);
449 NG_FREE_ITEM(item);
450 return (ENXIO);
451 }
452
453 /* Pull up the necessary amount from the mbuf */
454 need2pullup = MAX_VJHEADER;
455 if (need2pullup > m->m_pkthdr.len)
456 need2pullup = m->m_pkthdr.len;
457 if (m->m_len < need2pullup
458 && (m = m_pullup(m, need2pullup)) == NULL) {
459 priv->slc.sls_errorin++;
460 NG_FREE_ITEM(item);
461 return (ENOBUFS);
462 }
463
464 /* Uncompress packet to reconstruct TCP/IP header */
465 vjlen = sl_uncompress_tcp_core(mtod(m, u_char *),
466 m->m_len, m->m_pkthdr.len, TYPE_COMPRESSED_TCP,
467 &priv->slc, &hdr, &hlen);
468 if (vjlen <= 0) {
469 NG_FREE_M(m);
470 NG_FREE_ITEM(item);
471 return (EINVAL);
472 }
473 m_adj(m, vjlen);
474
475 /* Copy the reconstructed TCP/IP headers into a new mbuf */
476 MGETHDR(hm, M_DONTWAIT, MT_DATA);
477 if (hm == NULL) {
478 priv->slc.sls_errorin++;
479 NG_FREE_M(m);
480 NG_FREE_ITEM(item);
481 return (ENOBUFS);
482 }
483 hm->m_len = 0;
484 hm->m_pkthdr.rcvif = NULL;
485 if (hlen > MHLEN) { /* unlikely, but can happen */
486 MCLGET(hm, M_DONTWAIT);
487 if ((hm->m_flags & M_EXT) == 0) {
488 m_freem(hm);
489 priv->slc.sls_errorin++;
490 NG_FREE_M(m);
491 NG_FREE_ITEM(item);
492 return (ENOBUFS);
493 }
494 }
495 bcopy(hdr, mtod(hm, u_char *), hlen);
496 hm->m_len = hlen;
497
498 /* Glue TCP/IP headers and rest of packet together */
499 hm->m_next = m;
500 hm->m_pkthdr.len = hlen + m->m_pkthdr.len;
501 m = hm;
502 hook = priv->ip;
503 } else if (hook == priv->vjuncomp) { /* incoming uncompressed pkt */
504 u_char *hdr;
505 u_int hlen;
506
507 /* Are we decompressing? */
508 if (!priv->conf.enableDecomp) {
509 NG_FREE_M(m);
510 NG_FREE_ITEM(item);
511 return (ENXIO);
512 }
513
514 /* Pull up IP+TCP headers */
515 if ((m = ng_vjc_pulluphdrs(m, 1)) == NULL) {
516 NG_FREE_ITEM(item);
517 return (ENOBUFS);
518 }
519
520 /* Run packet through uncompressor */
521 if (sl_uncompress_tcp_core(mtod(m, u_char *),
522 m->m_len, m->m_pkthdr.len, TYPE_UNCOMPRESSED_TCP,
523 &priv->slc, &hdr, &hlen) < 0) {
524 NG_FREE_M(m);
525 NG_FREE_ITEM(item);
526 return (EINVAL);
527 }
528 hook = priv->ip;
529 } else if (hook == priv->vjip) /* incoming regular packet (bypass) */
530 hook = priv->ip;
531 else
532 panic("%s: unknown hook", __func__);
533
534 /* Send result back out */
535 NG_FWD_NEW_DATA(error, item, hook, m);
536 return (error);
537 }
538
539 /*
540 * Shutdown node
541 */
542 static int
543 ng_vjc_shutdown(node_p node)
544 {
545 const priv_p priv = NG_NODE_PRIVATE(node);
546
547 bzero(priv, sizeof(*priv));
548 FREE(priv, M_NETGRAPH);
549 NG_NODE_SET_PRIVATE(node, NULL);
550 NG_NODE_UNREF(node);
551 return (0);
552 }
553
554 /*
555 * Hook disconnection
556 */
557 static int
558 ng_vjc_disconnect(hook_p hook)
559 {
560 const node_p node = NG_HOOK_NODE(hook);
561 const priv_p priv = NG_NODE_PRIVATE(node);
562
563 /* Zero out hook pointer */
564 if (hook == priv->ip)
565 priv->ip = NULL;
566 else if (hook == priv->vjcomp)
567 priv->vjcomp = NULL;
568 else if (hook == priv->vjuncomp)
569 priv->vjuncomp = NULL;
570 else if (hook == priv->vjip)
571 priv->vjip = NULL;
572 else
573 panic("%s: unknown hook", __func__);
574
575 /* Go away if no hooks left */
576 if ((NG_NODE_NUMHOOKS(node) == 0)
577 && (NG_NODE_IS_VALID(node)))
578 ng_rmnode_self(node);
579 return (0);
580 }
581
582 /************************************************************************
583 HELPER STUFF
584 ************************************************************************/
585
586 /*
587 * Pull up the full IP and TCP headers of a packet. If packet is not
588 * a TCP packet, just pull up the IP header.
589 */
590 static struct mbuf *
591 ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP)
592 {
593 struct ip *ip;
594 struct tcphdr *tcp;
595 int ihlen, thlen;
596
597 if (m->m_len < sizeof(*ip) && (m = m_pullup(m, sizeof(*ip))) == NULL)
598 return (NULL);
599 ip = mtod(m, struct ip *);
600 if (!knownTCP && ip->ip_p != IPPROTO_TCP)
601 return (m);
602 ihlen = ip->ip_hl << 2;
603 if (m->m_len < ihlen + sizeof(*tcp)) {
604 if ((m = m_pullup(m, ihlen + sizeof(*tcp))) == NULL)
605 return (NULL);
606 ip = mtod(m, struct ip *);
607 }
608 tcp = (struct tcphdr *)((u_char *)ip + ihlen);
609 thlen = tcp->th_off << 2;
610 if (m->m_len < ihlen + thlen)
611 m = m_pullup(m, ihlen + thlen);
612 return (m);
613 }
614
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