summaryrefslogtreecommitdiffstats
path: root/sys/netgraph/ng_vjc.c
blob: 8667b2b0d7345ab3c19c78469e36200d9de71885 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469

/*
 * ng_vjc.c
 *
 * Copyright (c) 1996-1999 Whistle Communications, Inc.
 * All rights reserved.
 * 
 * Subject to the following obligations and disclaimer of warranty, use and
 * redistribution of this software, in source or object code forms, with or
 * without modifications are expressly permitted by Whistle Communications;
 * provided, however, that:
 * 1. Any and all reproductions of the source or object code must include the
 *    copyright notice above and the following disclaimer of warranties; and
 * 2. No rights are granted, in any manner or form, to use Whistle
 *    Communications, Inc. trademarks, including the mark "WHISTLE
 *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
 *    such appears in the above copyright notice or in the software.
 * 
 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * Author: Archie Cobbs <archie@whistle.com>
 *
 * $FreeBSD$
 * $Whistle: ng_vjc.c,v 1.17 1999/11/01 09:24:52 julian Exp $
 */

/*
 * This node performs Van Jacobson IP header (de)compression.
 * You must have included net/slcompress.c in your kernel compilation.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/errno.h>

#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_vjc.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>

#include <net/slcompress.h>

/* Check agreement with slcompress.c */
#if MAX_STATES != NG_VJC_MAX_CHANNELS
#error NG_VJC_MAX_CHANNELS must be the same as MAX_STATES
#endif

/* Maximum length of a compressed TCP VJ header */
#define MAX_VJHEADER		19

/* Node private data */
struct ng_vjc_private {
	struct	ngm_vjc_config conf;
	struct	slcompress slc;
	hook_p	ip;
	hook_p	vjcomp;
	hook_p	vjuncomp;
	hook_p	vjip;
};
typedef struct ng_vjc_private *priv_p;

#define ERROUT(x)	do { error = (x); goto done; } while (0)

/* Netgraph node methods */
static ng_constructor_t	ng_vjc_constructor;
static ng_rcvmsg_t	ng_vjc_rcvmsg;
static ng_shutdown_t	ng_vjc_rmnode;
static ng_newhook_t	ng_vjc_newhook;
static ng_rcvdata_t	ng_vjc_rcvdata;
static ng_disconnect_t	ng_vjc_disconnect;

/* Helper stuff */
static struct mbuf *ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP);

/* Node type descriptor */
static struct ng_type typestruct = {
	NG_VERSION,
	NG_VJC_NODE_TYPE,
	NULL,
	ng_vjc_constructor,
	ng_vjc_rcvmsg,
	ng_vjc_rmnode,
	ng_vjc_newhook,
	NULL,
	NULL,
	ng_vjc_rcvdata,
	ng_vjc_rcvdata,
	ng_vjc_disconnect,
	NULL
};
NETGRAPH_INIT(vjc, &typestruct);

/************************************************************************
			NETGRAPH NODE METHODS
 ************************************************************************/

/*
 * Create a new node
 */
static int
ng_vjc_constructor(node_p *nodep)
{
	priv_p priv;
	int error;

	/* Allocate private structure */
	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
	if (priv == NULL)
		return (ENOMEM);
	bzero(priv, sizeof(*priv));

	/* Call generic node constructor */
	if ((error = ng_make_node_common(&typestruct, nodep))) {
		FREE(priv, M_NETGRAPH);
		return (error);
	}
	(*nodep)->private = priv;

	/* Done */
	return (0);
}

/*
 * Add a new hook
 */
static int
ng_vjc_newhook(node_p node, hook_p hook, const char *name)
{
	const priv_p priv = (priv_p) node->private;
	hook_p *hookp;

	/* Get hook */
	if (strcmp(name, NG_VJC_HOOK_IP) == 0)
		hookp = &priv->ip;
	else if (strcmp(name, NG_VJC_HOOK_VJCOMP) == 0)
		hookp = &priv->vjcomp;
	else if (strcmp(name, NG_VJC_HOOK_VJUNCOMP) == 0)
		hookp = &priv->vjuncomp;
	else if (strcmp(name, NG_VJC_HOOK_VJIP) == 0)
		hookp = &priv->vjip;
	else
		return (EINVAL);

	/* See if already connected */
	if (*hookp)
		return (EISCONN);

	/* OK */
	*hookp = hook;
	return (0);
}

/*
 * Receive a control message
 */
static int
ng_vjc_rcvmsg(node_p node, struct ng_mesg *msg,
	      const char *raddr, struct ng_mesg **rptr, hook_p lasthook)
{
	const priv_p priv = (priv_p) node->private;
	struct ng_mesg *resp = NULL;
	int error = 0;

	/* Check type cookie */
	switch (msg->header.typecookie) {
	case NGM_VJC_COOKIE:
		switch (msg->header.cmd) {
		case NGM_VJC_SET_CONFIG:
		    {
			struct ngm_vjc_config *const c =
				(struct ngm_vjc_config *) msg->data;

			if (msg->header.arglen != sizeof(*c))
				ERROUT(EINVAL);
			if ((priv->conf.enableComp || priv->conf.enableDecomp)
			    && (c->enableComp || c->enableDecomp))
				ERROUT(EALREADY);
			if (c->enableComp) {
				if (c->maxChannel > NG_VJC_MAX_CHANNELS - 1
				    || c->maxChannel < NG_VJC_MIN_CHANNELS - 1)
					ERROUT(EINVAL);
			} else
				c->maxChannel = NG_VJC_MAX_CHANNELS - 1;
			if (c->enableComp != 0 || c->enableDecomp != 0) {
				bzero(&priv->slc, sizeof(priv->slc));
				sl_compress_init(&priv->slc, c->maxChannel);
			}
			priv->conf = *c;
			break;
		    }
		case NGM_VJC_GET_STATE:
			NG_MKRESPONSE(resp, msg, sizeof(priv->slc), M_NOWAIT);
			if (resp == NULL)
				ERROUT(ENOMEM);
			*((struct slcompress *) resp->data) = priv->slc;
			break;
		case NGM_VJC_CLR_STATS:
			priv->slc.sls_packets = 0;
			priv->slc.sls_compressed = 0;
			priv->slc.sls_searches = 0;
			priv->slc.sls_misses = 0;
			priv->slc.sls_uncompressedin = 0;
			priv->slc.sls_compressedin = 0;
			priv->slc.sls_errorin = 0;
			priv->slc.sls_tossed = 0;
			break;
		case NGM_VJC_RECV_ERROR:
			sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &priv->slc);
			break;
		default:
			error = EINVAL;
			break;
		}
		break;
	default:
		error = EINVAL;
		break;
	}
	if (rptr)
		*rptr = resp;
	else if (resp)
		FREE(resp, M_NETGRAPH);

done:
	FREE(msg, M_NETGRAPH);
	return (error);
}

/*
 * Receive data
 */
static int
ng_vjc_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
		struct mbuf **ret_m, meta_p *ret_meta)
{
	const node_p node = hook->node;
	const priv_p priv = (priv_p) node->private;
	int error = 0;

	if (hook == priv->ip) {			/* outgoing packet */
		u_int type = TYPE_IP;

		/* Compress packet if enabled and proto is TCP */
		if (priv->conf.enableComp) {
			struct ip *ip;

			if ((m = ng_vjc_pulluphdrs(m, 0)) == NULL) {
				NG_FREE_META(meta);
				return (ENOBUFS);
			}
			ip = mtod(m, struct ip *);
			if (ip->ip_p == IPPROTO_TCP) {
				const int origLen = m->m_len;

				type = sl_compress_tcp(m, ip,
				    &priv->slc, priv->conf.compressCID);
				m->m_pkthdr.len += m->m_len - origLen;
			}
		}

		/* Dispatch to the appropriate outgoing hook */
		switch (type) {
		case TYPE_IP:
			hook = priv->vjip;
			break;
		case TYPE_UNCOMPRESSED_TCP:
			hook = priv->vjuncomp;
			break;
		case TYPE_COMPRESSED_TCP:
			hook = priv->vjcomp;
			break;
		default:
			panic("%s: type=%d", __FUNCTION__, type);
		}
	} else if (hook == priv->vjcomp) {	/* incoming compressed packet */
		int vjlen, need2pullup;
		struct mbuf *hm;
		u_char *hdr;
		u_int hlen;

		/* Are we decompressing? */
		if (!priv->conf.enableDecomp) {
			NG_FREE_DATA(m, meta);
			return (ENXIO);
		}

		/* Pull up the necessary amount from the mbuf */
		need2pullup = MAX_VJHEADER;
		if (need2pullup > m->m_pkthdr.len)
			need2pullup = m->m_pkthdr.len;
		if (m->m_len < need2pullup
		    && (m = m_pullup(m, need2pullup)) == NULL) {
			priv->slc.sls_errorin++;
			NG_FREE_META(meta);
			return (ENOBUFS);
		}

		/* Uncompress packet to reconstruct TCP/IP header */
		vjlen = sl_uncompress_tcp_core(mtod(m, u_char *),
		    m->m_len, m->m_pkthdr.len, TYPE_COMPRESSED_TCP,
		    &priv->slc, &hdr, &hlen);
		if (vjlen <= 0) {
			NG_FREE_DATA(m, meta);
			return (EINVAL);
		}
		m_adj(m, vjlen);

		/* Copy the reconstructed TCP/IP headers into a new mbuf */
		MGETHDR(hm, M_DONTWAIT, MT_DATA);
		if (hm == NULL) {
			priv->slc.sls_errorin++;
			NG_FREE_DATA(m, meta);
			return (ENOBUFS);
		}
		hm->m_len = 0;
		hm->m_pkthdr.rcvif = NULL;
		if (hlen > MHLEN) {		/* unlikely, but can happen */
			MCLGET(hm, M_DONTWAIT);
			if ((hm->m_flags & M_EXT) == 0) {
				m_freem(hm);
				priv->slc.sls_errorin++;
				NG_FREE_DATA(m, meta);
				return (ENOBUFS);
			}
		}
		bcopy(hdr, mtod(hm, u_char *), hlen);
		hm->m_len = hlen;

		/* Glue TCP/IP headers and rest of packet together */
		hm->m_next = m;
		hm->m_pkthdr.len = hlen + m->m_pkthdr.len;
		m = hm;
		hook = priv->ip;
	} else if (hook == priv->vjuncomp) {	/* incoming uncompressed pkt */
		u_char *hdr;
		u_int hlen;

		/* Are we decompressing? */
		if (!priv->conf.enableDecomp) {
			NG_FREE_DATA(m, meta);
			return (ENXIO);
		}

		/* Pull up IP+TCP headers */
		if ((m = ng_vjc_pulluphdrs(m, 1)) == NULL) {
			NG_FREE_META(meta);
			return (ENOBUFS);
		}

		/* Run packet through uncompressor */
		if (sl_uncompress_tcp_core(mtod(m, u_char *),
		    m->m_len, m->m_pkthdr.len, TYPE_UNCOMPRESSED_TCP,
		    &priv->slc, &hdr, &hlen) < 0) {
			NG_FREE_DATA(m, meta);
			return (EINVAL);
		}
		hook = priv->ip;
	} else if (hook == priv->vjip)	/* incoming regular packet (bypass) */
		hook = priv->ip;
	else
		panic("%s: unknown hook", __FUNCTION__);

	/* Send result back out */
	NG_SEND_DATA(error, hook, m, meta);
	return (error);
}

/*
 * Shutdown node
 */
static int
ng_vjc_rmnode(node_p node)
{
	const priv_p priv = (priv_p) node->private;

	node->flags |= NG_INVALID;
	ng_cutlinks(node);
	ng_unname(node);
	bzero(priv, sizeof(*priv));
	FREE(priv, M_NETGRAPH);
	node->private = NULL;
	ng_unref(node);
	return (0);
}

/*
 * Hook disconnection
 */
static int
ng_vjc_disconnect(hook_p hook)
{
	const node_p node = hook->node;
	const priv_p priv = node->private;

	/* Zero out hook pointer */
	if (hook == priv->ip)
		priv->ip = NULL;
	else if (hook == priv->vjcomp)
		priv->vjcomp = NULL;
	else if (hook == priv->vjuncomp)
		priv->vjuncomp = NULL;
	else if (hook == priv->vjip)
		priv->vjip = NULL;
	else
		panic("%s: unknown hook", __FUNCTION__);

	/* Go away if no hooks left */
	if (node->numhooks == 0)
		ng_rmnode(node);
	return (0);
}

/************************************************************************
			HELPER STUFF
 ************************************************************************/

/*
 * Pull up the full IP and TCP headers of a packet. If packet is not
 * a TCP packet, just pull up the IP header.
 */
static struct mbuf *
ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP)
{
	struct ip *ip;
	struct tcphdr *tcp;
	int ihlen, thlen;

	if (m->m_len < sizeof(*ip) && (m = m_pullup(m, sizeof(*ip))) == NULL)
		return (NULL);
	ip = mtod(m, struct ip *);
	if (!knownTCP && ip->ip_p != IPPROTO_TCP)
		return (m);
	ihlen = ip->ip_hl << 2;
	if (m->m_len < ihlen + sizeof(*tcp)) {
		if ((m = m_pullup(m, ihlen + sizeof(*tcp))) == NULL)
			return (NULL);
		ip = mtod(m, struct ip *);
	}
	tcp = (struct tcphdr *)((u_char *)ip + ihlen);
	thlen = tcp->th_off << 2;
	if (m->m_len < ihlen + thlen)
		m = m_pullup(m, ihlen + thlen);
	return (m);
}

OpenPOWER on IntegriCloud