1/*
2 * ng_rfc1490.c
3 */
4
5/*-
6 * Copyright (c) 1996-1999 Whistle Communications, Inc.
7 * All rights reserved.
8 *
9 * Subject to the following obligations and disclaimer of warranty, use and
10 * redistribution of this software, in source or object code forms, with or
11 * without modifications are expressly permitted by Whistle Communications;
12 * provided, however, that:
13 * 1. Any and all reproductions of the source or object code must include the
14 *    copyright notice above and the following disclaimer of warranties; and
15 * 2. No rights are granted, in any manner or form, to use Whistle
16 *    Communications, Inc. trademarks, including the mark "WHISTLE
17 *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18 *    such appears in the above copyright notice or in the software.
19 *
20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36 * OF SUCH DAMAGE.
37 *
38 * Author: Julian Elischer <julian@freebsd.org>
39 * $Whistle: ng_rfc1490.c,v 1.22 1999/11/01 09:24:52 julian Exp $
40 */
41
42/*
43 * This node does RFC 1490 multiplexing.
44 *
45 * NOTE: RFC 1490 is updated by RFC 2427.
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/malloc.h>
53#include <sys/mbuf.h>
54#include <sys/errno.h>
55#include <sys/socket.h>
56
57#include <net/if.h>
58#include <netinet/in.h>
59#include <netinet/if_ether.h>
60
61#include <netgraph/ng_message.h>
62#include <netgraph/netgraph.h>
63#include <netgraph/ng_parse.h>
64#include <netgraph/ng_rfc1490.h>
65
66/*
67 * DEFINITIONS
68 */
69
70/* Q.922 stuff -- see RFC 1490 */
71#define HDLC_UI		0x03
72
73#define NLPID_IP	0xCC
74#define NLPID_PPP	0xCF
75#define NLPID_SNAP	0x80
76#define NLPID_Q933	0x08
77#define NLPID_CLNP	0x81
78#define NLPID_ESIS	0x82
79#define NLPID_ISIS	0x83
80
81#define ERROUT(x)	do { error = (x); goto done; } while (0)
82
83/* Encapsulation methods we understand */
84enum {
85	NG_RFC1490_ENCAP_IETF_IP = 1,	/* see RFC2427, chapter 7, table 1 */
86	NG_RFC1490_ENCAP_IETF_SNAP,	/* see RFC2427, chapter 7, table 2 */
87	NG_RFC1490_ENCAP_CISCO,		/* Cisco's proprietary encapsulation */
88};
89
90struct ng_rfc1490_encap_t {
91	u_int8_t	method;
92	const char	*name;
93};
94
95static const struct ng_rfc1490_encap_t ng_rfc1490_encaps[] = {
96	{ NG_RFC1490_ENCAP_IETF_IP,	"ietf-ip" },
97	{ NG_RFC1490_ENCAP_IETF_SNAP,	"ietf-snap" },
98	{ NG_RFC1490_ENCAP_CISCO,	"cisco" },
99	{ 0, NULL},
100};
101
102/* Node private data */
103struct ng_rfc1490_private {
104	hook_p  downlink;
105	hook_p  ppp;
106	hook_p  inet;
107	hook_p  ethernet;
108	const struct ng_rfc1490_encap_t *enc;
109};
110typedef struct ng_rfc1490_private *priv_p;
111
112/* Netgraph node methods */
113static ng_constructor_t	ng_rfc1490_constructor;
114static ng_rcvmsg_t	ng_rfc1490_rcvmsg;
115static ng_shutdown_t	ng_rfc1490_shutdown;
116static ng_newhook_t	ng_rfc1490_newhook;
117static ng_rcvdata_t	ng_rfc1490_rcvdata;
118static ng_disconnect_t	ng_rfc1490_disconnect;
119
120/* List of commands and how to convert arguments to/from ASCII */
121static const struct ng_cmdlist ng_rfc1490_cmds[] = {
122	{
123	  NGM_RFC1490_COOKIE,
124	  NGM_RFC1490_SET_ENCAP,
125	  "setencap",
126	  &ng_parse_string_type,
127	  NULL
128	},
129	{
130	  NGM_RFC1490_COOKIE,
131	  NGM_RFC1490_GET_ENCAP,
132	  "getencap",
133	  NULL,
134	  &ng_parse_string_type
135	},
136	{ 0 }
137};
138
139/* Node type descriptor */
140static struct ng_type typestruct = {
141	.version =	NG_ABI_VERSION,
142	.name =		NG_RFC1490_NODE_TYPE,
143	.constructor =	ng_rfc1490_constructor,
144	.rcvmsg =	ng_rfc1490_rcvmsg,
145	.shutdown =	ng_rfc1490_shutdown,
146	.newhook =	ng_rfc1490_newhook,
147	.rcvdata =	ng_rfc1490_rcvdata,
148	.disconnect =	ng_rfc1490_disconnect,
149	.cmdlist =	ng_rfc1490_cmds,
150};
151NETGRAPH_INIT(rfc1490, &typestruct);
152
153/************************************************************************
154			NETGRAPH NODE STUFF
155 ************************************************************************/
156
157/*
158 * Node constructor
159 */
160static int
161ng_rfc1490_constructor(node_p node)
162{
163	priv_p priv;
164
165	/* Allocate private structure */
166	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
167
168	/* Initialize to default encapsulation method - ietf-ip */
169	priv->enc = ng_rfc1490_encaps;
170
171	NG_NODE_SET_PRIVATE(node, priv);
172
173	/* Done */
174	return (0);
175}
176
177/*
178 * Give our ok for a hook to be added
179 */
180static int
181ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
182{
183	const priv_p priv = NG_NODE_PRIVATE(node);
184
185	if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
186		if (priv->downlink)
187			return (EISCONN);
188		priv->downlink = hook;
189	} else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
190		if (priv->ppp)
191			return (EISCONN);
192		priv->ppp = hook;
193	} else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
194		if (priv->inet)
195			return (EISCONN);
196		priv->inet = hook;
197	} else if (!strcmp(name, NG_RFC1490_HOOK_ETHERNET)) {
198		if (priv->ethernet)
199			return (EISCONN);
200		priv->ethernet = hook;
201	} else
202		return (EINVAL);
203	return (0);
204}
205
206/*
207 * Receive a control message.
208 */
209static int
210ng_rfc1490_rcvmsg(node_p node, item_p item, hook_p lasthook)
211{
212	const priv_p priv = NG_NODE_PRIVATE(node);
213	struct ng_mesg *msg;
214	struct ng_mesg *resp = NULL;
215	int error = 0;
216
217	NGI_GET_MSG(item, msg);
218
219	if (msg->header.typecookie == NGM_RFC1490_COOKIE) {
220		switch (msg->header.cmd) {
221		case NGM_RFC1490_SET_ENCAP:
222		{
223			const struct ng_rfc1490_encap_t *enc;
224			char *s;
225			size_t len;
226
227			if (msg->header.arglen == 0)
228				ERROUT(EINVAL);
229
230			s = (char *)msg->data;
231			len = msg->header.arglen - 1;
232
233			/* Search for matching encapsulation method */
234			for (enc = ng_rfc1490_encaps; enc->method != 0; enc++ )
235				if ((strlen(enc->name) == len) &&
236				    !strncmp(enc->name, s, len))
237					break;	/* found */
238
239			if (enc->method != 0)
240				priv->enc = enc;
241			else
242				error = EINVAL;
243			break;
244		}
245		case NGM_RFC1490_GET_ENCAP:
246
247			NG_MKRESPONSE(resp, msg, strlen(priv->enc->name) + 1, M_NOWAIT);
248			if (resp == NULL)
249				ERROUT(ENOMEM);
250
251			strlcpy((char *)resp->data, priv->enc->name,
252			    strlen(priv->enc->name) + 1);
253			break;
254
255		default:
256			error = EINVAL;
257			break;
258		}
259	} else
260		error = EINVAL;
261
262done:
263	NG_RESPOND_MSG(error, node, item, resp);
264	NG_FREE_MSG(msg);
265	return (error);
266}
267
268/*
269 * Receive data on a hook and encapsulate according to RFC 1490.
270 * Only those nodes marked (*) are supported by this routine so far.
271 *
272 *                            Q.922 control
273 *                                 |
274 *                                 |
275 *            ---------------------------------------------------------------------
276 *            | 0x03                                     |                        |
277 *           UI                                       I Frame                   Cisco
278 *            |                                          |                  Encapsulation
279 *      ---------------------------------         --------------                  |
280 *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....   --------------
281 *      |       |       |       |       | 0x80    |            |           |0x800       |
282 *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208       |            |
283 *      |                    (rfc1973)  |       Modulo 8    Modulo 128     IP(*)     Others
284 *      |                               |
285 *      --------------------           OUI
286 *      |                  |            |
287 *     L2 ID              L3 ID      -------------------------
288 *      |               User         |00-80-C2               |00-00-00
289 *      |               specified    |                       |
290 *      |               0x70        PID                     Ethertype
291 *      |                            |                       |
292 *      -------------------        -----------------...     ----------
293 *      |0x51 |0x4E |     |0x4C    |0x7      |0xB  |        |0x806   |
294 *      |     |     |     |        |         |     |        |        |
295 *     7776  Q.922 Others 802.2   802.3(*)  802.6 Others    IP(*)   Others
296 *
297 *
298 */
299
300#define MAX_ENCAPS_HDR	8
301#define OUICMP(P,A,B,C)	((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
302
303static int
304ng_rfc1490_rcvdata(hook_p hook, item_p item)
305{
306	const node_p node = NG_HOOK_NODE(hook);
307	const priv_p priv = NG_NODE_PRIVATE(node);
308	int error = 0;
309	struct mbuf *m;
310
311	NGI_GET_M(item, m);
312	if (hook == priv->downlink) {
313		const u_char *start;
314		const u_char *ptr;
315
316		if (m->m_len < MAX_ENCAPS_HDR
317		    && !(m = m_pullup(m, MAX_ENCAPS_HDR)))
318			ERROUT(ENOBUFS);
319		ptr = start = mtod(m, const u_char *);
320
321		if (priv->enc->method == NG_RFC1490_ENCAP_CISCO)
322			goto switch_on_etype;
323
324		/* Must be UI frame */
325		if (*ptr++ != HDLC_UI)
326			ERROUT(0);
327
328		/* Eat optional zero pad byte */
329		if (*ptr == 0x00)
330			ptr++;
331
332		/* Multiplex on NLPID */
333		switch (*ptr++) {
334		case NLPID_SNAP:
335			if (OUICMP(ptr, 0, 0, 0)) {	/* It's an ethertype */
336				u_int16_t etype;
337
338				ptr += 3;
339switch_on_etype:		etype = ntohs(*((const u_int16_t *)ptr));
340				ptr += 2;
341				m_adj(m, ptr - start);
342				switch (etype) {
343				case ETHERTYPE_IP:
344					NG_FWD_NEW_DATA(error, item,
345					    priv->inet, m);
346					break;
347				case ETHERTYPE_ARP:
348				case ETHERTYPE_REVARP:
349				default:
350					ERROUT(0);
351				}
352			} else if (OUICMP(ptr, 0x00, 0x80, 0xc2)) {
353				/* 802.1 bridging */
354				ptr += 3;
355				if (*ptr++ != 0x00)
356					ERROUT(0);	/* unknown PID octet 0 */
357				if (*ptr++ != 0x07)
358					ERROUT(0);	/* not FCS-less 802.3 */
359				m_adj(m, ptr - start);
360				NG_FWD_NEW_DATA(error, item, priv->ethernet, m);
361			} else	/* Other weird stuff... */
362				ERROUT(0);
363			break;
364		case NLPID_IP:
365			m_adj(m, ptr - start);
366			NG_FWD_NEW_DATA(error, item, priv->inet, m);
367			break;
368		case NLPID_PPP:
369			m_adj(m, ptr - start);
370			NG_FWD_NEW_DATA(error, item, priv->ppp, m);
371			break;
372		case NLPID_Q933:
373		case NLPID_CLNP:
374		case NLPID_ESIS:
375		case NLPID_ISIS:
376			ERROUT(0);
377		default:	/* Try PPP (see RFC 1973) */
378			ptr--;	/* NLPID becomes PPP proto */
379			if ((*ptr & 0x01) == 0x01)
380				ERROUT(0);
381			m_adj(m, ptr - start);
382			NG_FWD_NEW_DATA(error, item, priv->ppp, m);
383			break;
384		}
385	} else if (hook == priv->ppp) {
386		M_PREPEND(m, 2, M_NOWAIT);	/* Prepend PPP NLPID */
387		if (!m)
388			ERROUT(ENOBUFS);
389		mtod(m, u_char *)[0] = HDLC_UI;
390		mtod(m, u_char *)[1] = NLPID_PPP;
391		NG_FWD_NEW_DATA(error, item, priv->downlink, m);
392	} else if (hook == priv->inet) {
393		switch (priv->enc->method) {
394		case NG_RFC1490_ENCAP_IETF_IP:
395			M_PREPEND(m, 2, M_NOWAIT);	/* Prepend IP NLPID */
396			if (!m)
397				ERROUT(ENOBUFS);
398			mtod(m, u_char *)[0] = HDLC_UI;
399			mtod(m, u_char *)[1] = NLPID_IP;
400			break;
401		case NG_RFC1490_ENCAP_IETF_SNAP:
402			/*
403			 *  According to RFC2427 frame should begin with
404			 *  HDLC_UI  PAD  NLIPID  OUI      PID
405			 *  03      00   80      00 00 00  08 00
406			 */
407			M_PREPEND(m, 8, M_NOWAIT);
408			if (!m)
409				ERROUT(ENOBUFS);
410			mtod(m, u_char *)[0] = HDLC_UI;
411			mtod(m, u_char *)[1] = 0x00;			/* PAD */
412			mtod(m, u_char *)[2] = NLPID_SNAP;
413			bzero((char *)(mtod(m, u_char *) + 3), 3);	/* OUI 0-0-0 */
414			*((u_int16_t *)mtod(m, u_int16_t *) + 6/sizeof(u_int16_t))
415			    = htons(ETHERTYPE_IP);  /* PID */
416			break;
417		case NG_RFC1490_ENCAP_CISCO:
418			M_PREPEND(m, 2, M_NOWAIT);	/* Prepend IP ethertype */
419			if (!m)
420				ERROUT(ENOBUFS);
421			*((u_int16_t *)mtod(m, u_int16_t *)) = htons(ETHERTYPE_IP);
422			break;
423		}
424		NG_FWD_NEW_DATA(error, item, priv->downlink, m);
425	} else if (hook == priv->ethernet) {
426		M_PREPEND(m, 8, M_NOWAIT);	/* Prepend NLPID, OUI, PID */
427		if (!m)
428			ERROUT(ENOBUFS);
429		mtod(m, u_char *)[0] = HDLC_UI;
430		mtod(m, u_char *)[1] = 0x00;		/* pad */
431		mtod(m, u_char *)[2] = NLPID_SNAP;
432		mtod(m, u_char *)[3] = 0x00;		/* OUI */
433		mtod(m, u_char *)[4] = 0x80;
434		mtod(m, u_char *)[5] = 0xc2;
435		mtod(m, u_char *)[6] = 0x00;		/* PID */
436		mtod(m, u_char *)[7] = 0x07;
437		NG_FWD_NEW_DATA(error, item, priv->downlink, m);
438	} else
439		panic("%s", __func__);
440
441done:
442	if (item)
443		NG_FREE_ITEM(item);
444	NG_FREE_M(m);
445	return (error);
446}
447
448/*
449 * Nuke node
450 */
451static int
452ng_rfc1490_shutdown(node_p node)
453{
454	const priv_p priv = NG_NODE_PRIVATE(node);
455
456	/* Take down netgraph node */
457	bzero(priv, sizeof(*priv));
458	free(priv, M_NETGRAPH);
459	NG_NODE_SET_PRIVATE(node, NULL);
460	NG_NODE_UNREF(node);		/* let the node escape */
461	return (0);
462}
463
464/*
465 * Hook disconnection
466 */
467static int
468ng_rfc1490_disconnect(hook_p hook)
469{
470	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
471
472	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
473	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
474		ng_rmnode_self(NG_HOOK_NODE(hook));
475	else if (hook == priv->downlink)
476		priv->downlink = NULL;
477	else if (hook == priv->inet)
478		priv->inet = NULL;
479	else if (hook == priv->ppp)
480		priv->ppp = NULL;
481	else if (hook == priv->ethernet)
482		priv->ethernet = NULL;
483	else
484		panic("%s", __func__);
485	return (0);
486}
487