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