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 *
40 * $FreeBSD: src/sys/netgraph/ng_rfc1490.c,v 1.24 2005/01/07 01:45:39 imp Exp $
41 * $Whistle: ng_rfc1490.c,v 1.22 1999/11/01 09:24:52 julian Exp $
42 */
43
44 /*
45 * This node does RFC 1490 multiplexing.
46 *
47 * NOTE: RFC 1490 is updated by RFC 2427.
48 */
49
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/errno.h>
53 #include <sys/kernel.h>
54 #include <sys/malloc.h>
55 #include <sys/mbuf.h>
56 #include <sys/socket.h>
57
58 #include <net/if.h>
59 #include <netinet/in.h>
60 #include <netinet/if_ether.h>
61
62 #include <netgraph7/ng_message.h>
63 #include <netgraph7/netgraph.h>
64 #include <netgraph7/ng_parse.h>
65 #include "ng_rfc1490.h"
66
67 /*
68 * DEFINITIONS
69 */
70
71 /* Q.922 stuff -- see RFC 1490 */
72 #define HDLC_UI 0x03
73
74 #define NLPID_IP 0xCC
75 #define NLPID_PPP 0xCF
76 #define NLPID_SNAP 0x80
77 #define NLPID_Q933 0x08
78 #define NLPID_CLNP 0x81
79 #define NLPID_ESIS 0x82
80 #define NLPID_ISIS 0x83
81
82 #define ERROUT(x) do { error = (x); goto done; } while (0)
83
84 /* Encapsulation methods we understand */
85 enum {
86 NG_RFC1490_ENCAP_IETF_IP = 1, /* see RFC2427, chapter 7, table 1 */
87 NG_RFC1490_ENCAP_IETF_SNAP, /* see RFC2427, chapter 7, table 2 */
88 NG_RFC1490_ENCAP_CISCO, /* Cisco's proprietary encapsulation */
89 };
90
91 struct ng_rfc1490_encap_t {
92 u_int8_t method;
93 const char *name;
94 };
95
96 static const struct ng_rfc1490_encap_t ng_rfc1490_encaps[] = {
97 { NG_RFC1490_ENCAP_IETF_IP, "ietf-ip" },
98 { NG_RFC1490_ENCAP_IETF_SNAP, "ietf-snap" },
99 { NG_RFC1490_ENCAP_CISCO, "cisco" },
100 { 0, NULL},
101 };
102
103 /* Node private data */
104 struct ng_rfc1490_private {
105 hook_p downlink;
106 hook_p ppp;
107 hook_p inet;
108 hook_p ethernet;
109 const struct ng_rfc1490_encap_t *enc;
110 };
111 typedef struct ng_rfc1490_private *priv_p;
112
113 /* Netgraph node methods */
114 static ng_constructor_t ng_rfc1490_constructor;
115 static ng_rcvmsg_t ng_rfc1490_rcvmsg;
116 static ng_shutdown_t ng_rfc1490_shutdown;
117 static ng_newhook_t ng_rfc1490_newhook;
118 static ng_rcvdata_t ng_rfc1490_rcvdata;
119 static ng_disconnect_t ng_rfc1490_disconnect;
120
121 /* List of commands and how to convert arguments to/from ASCII */
122 static const struct ng_cmdlist ng_rfc1490_cmds[] = {
123 {
124 NGM_RFC1490_COOKIE,
125 NGM_RFC1490_SET_ENCAP,
126 "setencap",
127 &ng_parse_string_type,
128 NULL
129 },
130 {
131 NGM_RFC1490_COOKIE,
132 NGM_RFC1490_GET_ENCAP,
133 "getencap",
134 NULL,
135 &ng_parse_string_type
136 },
137 { 0 }
138 };
139
140 /* Node type descriptor */
141 static struct ng_type typestruct = {
142 .version = NG_ABI_VERSION,
143 .name = NG_RFC1490_NODE_TYPE,
144 .constructor = ng_rfc1490_constructor,
145 .rcvmsg = ng_rfc1490_rcvmsg,
146 .shutdown = ng_rfc1490_shutdown,
147 .newhook = ng_rfc1490_newhook,
148 .rcvdata = ng_rfc1490_rcvdata,
149 .disconnect = ng_rfc1490_disconnect,
150 .cmdlist = ng_rfc1490_cmds,
151 };
152 NETGRAPH_INIT(rfc1490, &typestruct);
153
154 /************************************************************************
155 NETGRAPH NODE STUFF
156 ************************************************************************/
157
158 /*
159 * Node constructor
160 */
161 static int
ng_rfc1490_constructor(node_p node)162 ng_rfc1490_constructor(node_p node)
163 {
164 priv_p priv;
165
166 /* Allocate private structure */
167 priv = kmalloc(sizeof(*priv), M_NETGRAPH,
168 M_WAITOK | M_NULLOK | M_ZERO);
169 if (priv == NULL)
170 return (ENOMEM);
171
172 /* Initialize to default encapsulation method - ietf-ip */
173 priv->enc = ng_rfc1490_encaps;
174
175 NG_NODE_SET_PRIVATE(node, priv);
176
177 /* Done */
178 return (0);
179 }
180
181 /*
182 * Give our ok for a hook to be added
183 */
184 static int
ng_rfc1490_newhook(node_p node,hook_p hook,const char * name)185 ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
186 {
187 const priv_p priv = NG_NODE_PRIVATE(node);
188
189 if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
190 if (priv->downlink)
191 return (EISCONN);
192 priv->downlink = hook;
193 } else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
194 if (priv->ppp)
195 return (EISCONN);
196 priv->ppp = hook;
197 } else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
198 if (priv->inet)
199 return (EISCONN);
200 priv->inet = hook;
201 } else if (!strcmp(name, NG_RFC1490_HOOK_ETHERNET)) {
202 if (priv->ethernet)
203 return (EISCONN);
204 priv->ethernet = hook;
205 } else
206 return (EINVAL);
207 return (0);
208 }
209
210 /*
211 * Receive a control message.
212 */
213 static int
ng_rfc1490_rcvmsg(node_p node,item_p item,hook_p lasthook)214 ng_rfc1490_rcvmsg(node_p node, item_p item, hook_p lasthook)
215 {
216 const priv_p priv = NG_NODE_PRIVATE(node);
217 struct ng_mesg *msg;
218 struct ng_mesg *resp = NULL;
219 int error = 0;
220
221 NGI_GET_MSG(item, msg);
222
223 if (msg->header.typecookie == NGM_RFC1490_COOKIE) {
224 switch (msg->header.cmd) {
225 case NGM_RFC1490_SET_ENCAP:
226 {
227 const struct ng_rfc1490_encap_t *enc;
228 char *s;
229 size_t len;
230
231 if (msg->header.arglen == 0)
232 ERROUT(EINVAL);
233
234 s = (char *)msg->data;
235 len = msg->header.arglen - 1;
236
237 /* Search for matching encapsulation method */
238 for (enc = ng_rfc1490_encaps; enc->method != 0; enc++ )
239 if ((strlen(enc->name) == len) &&
240 !strncmp(enc->name, s, len))
241 break; /* found */
242
243 if (enc->method != 0)
244 priv->enc = enc;
245 else
246 error = EINVAL;
247 break;
248 }
249 case NGM_RFC1490_GET_ENCAP:
250
251 NG_MKRESPONSE(resp, msg, strlen(priv->enc->name) + 1, M_WAITOK | M_NULLOK);
252 if (resp == NULL)
253 ERROUT(ENOMEM);
254
255 strlcpy((char *)resp->data, priv->enc->name,
256 strlen(priv->enc->name) + 1);
257 break;
258
259 default:
260 error = EINVAL;
261 break;
262 }
263 } else
264 error = EINVAL;
265
266 done:
267 NG_RESPOND_MSG(error, node, item, resp);
268 NG_FREE_MSG(msg);
269 return (error);
270 }
271
272 /*
273 * Receive data on a hook and encapsulate according to RFC 1490.
274 * Only those nodes marked (*) are supported by this routine so far.
275 *
276 * Q.922 control
277 * |
278 * |
279 * ---------------------------------------------------------------------
280 * | 0x03 | |
281 * UI I Frame Cisco
282 * | | Encapsulation
283 * --------------------------------- -------------- |
284 * | 0x08 | 0x81 |0xCC |0xCF | 0x00 |..01.... |..10.... --------------
285 * | | | | | 0x80 | | |0x800 |
286 * Q.933 CLNP IP(*) PPP(*) SNAP ISO 8208 ISO 8208 | |
287 * | (rfc1973) | Modulo 8 Modulo 128 IP(*) Others
288 * | |
289 * -------------------- OUI
290 * | | |
291 * L2 ID L3 ID -------------------------
292 * | User |00-80-C2 |00-00-00
293 * | specified | |
294 * | 0x70 PID Ethertype
295 * | | |
296 * ------------------- -----------------... ----------
297 * |0x51 |0x4E | |0x4C |0x7 |0xB | |0x806 |
298 * | | | | | | | | |
299 * 7776 Q.922 Others 802.2 802.3(*) 802.6 Others IP(*) Others
300 *
301 *
302 */
303
304 #define MAX_ENCAPS_HDR 8
305 #define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
306
307 static int
ng_rfc1490_rcvdata(hook_p hook,item_p item)308 ng_rfc1490_rcvdata(hook_p hook, item_p item)
309 {
310 const node_p node = NG_HOOK_NODE(hook);
311 const priv_p priv = NG_NODE_PRIVATE(node);
312 int error = 0;
313 struct mbuf *m;
314
315 NGI_GET_M(item, m);
316 if (hook == priv->downlink) {
317 const u_char *start;
318 const u_char *ptr;
319
320 if (m->m_len < MAX_ENCAPS_HDR
321 && !(m = m_pullup(m, MAX_ENCAPS_HDR)))
322 ERROUT(ENOBUFS);
323 ptr = start = mtod(m, const u_char *);
324
325 if (priv->enc->method == NG_RFC1490_ENCAP_CISCO)
326 goto switch_on_etype;
327
328 /* Must be UI frame */
329 if (*ptr++ != HDLC_UI)
330 ERROUT(0);
331
332 /* Eat optional zero pad byte */
333 if (*ptr == 0x00)
334 ptr++;
335
336 /* Multiplex on NLPID */
337 switch (*ptr++) {
338 case NLPID_SNAP:
339 if (OUICMP(ptr, 0, 0, 0)) { /* It's an ethertype */
340 u_int16_t etype;
341
342 ptr += 3;
343 switch_on_etype: etype = ntohs(*((const u_int16_t *)ptr));
344 ptr += 2;
345 m_adj(m, ptr - start);
346 switch (etype) {
347 case ETHERTYPE_IP:
348 NG_FWD_NEW_DATA(error, item,
349 priv->inet, m);
350 break;
351 case ETHERTYPE_ARP:
352 case ETHERTYPE_REVARP:
353 default:
354 ERROUT(0);
355 }
356 } else if (OUICMP(ptr, 0x00, 0x80, 0xc2)) {
357 /* 802.1 bridging */
358 ptr += 3;
359 if (*ptr++ != 0x00)
360 ERROUT(0); /* unknown PID octet 0 */
361 if (*ptr++ != 0x07)
362 ERROUT(0); /* not FCS-less 802.3 */
363 m_adj(m, ptr - start);
364 NG_FWD_NEW_DATA(error, item, priv->ethernet, m);
365 } else /* Other weird stuff... */
366 ERROUT(0);
367 break;
368 case NLPID_IP:
369 m_adj(m, ptr - start);
370 NG_FWD_NEW_DATA(error, item, priv->inet, m);
371 break;
372 case NLPID_PPP:
373 m_adj(m, ptr - start);
374 NG_FWD_NEW_DATA(error, item, priv->ppp, m);
375 break;
376 case NLPID_Q933:
377 case NLPID_CLNP:
378 case NLPID_ESIS:
379 case NLPID_ISIS:
380 ERROUT(0);
381 default: /* Try PPP (see RFC 1973) */
382 ptr--; /* NLPID becomes PPP proto */
383 if ((*ptr & 0x01) == 0x01)
384 ERROUT(0);
385 m_adj(m, ptr - start);
386 NG_FWD_NEW_DATA(error, item, priv->ppp, m);
387 break;
388 }
389 } else if (hook == priv->ppp) {
390 M_PREPEND(m, 2, M_NOWAIT); /* Prepend PPP NLPID */
391 if (!m)
392 ERROUT(ENOBUFS);
393 mtod(m, u_char *)[0] = HDLC_UI;
394 mtod(m, u_char *)[1] = NLPID_PPP;
395 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
396 } else if (hook == priv->inet) {
397 switch (priv->enc->method) {
398 case NG_RFC1490_ENCAP_IETF_IP:
399 M_PREPEND(m, 2, M_NOWAIT); /* Prepend IP NLPID */
400 if (!m)
401 ERROUT(ENOBUFS);
402 mtod(m, u_char *)[0] = HDLC_UI;
403 mtod(m, u_char *)[1] = NLPID_IP;
404 break;
405 case NG_RFC1490_ENCAP_IETF_SNAP:
406 /*
407 * According to RFC2427 frame should begin with
408 * HDLC_UI PAD NLIPID OUI PID
409 * 03 00 80 00 00 00 08 00
410 */
411 M_PREPEND(m, 8, M_NOWAIT);
412 if (!m)
413 ERROUT(ENOBUFS);
414 mtod(m, u_char *)[0] = HDLC_UI;
415 mtod(m, u_char *)[1] = 0x00; /* PAD */
416 mtod(m, u_char *)[2] = NLPID_SNAP;
417 bzero((char *)(mtod(m, u_char *) + 3), 3); /* OUI 0-0-0 */
418 *((u_int16_t *)mtod(m, u_int16_t *) + 6/sizeof(u_int16_t))
419 = htons(ETHERTYPE_IP); /* PID */
420 break;
421 case NG_RFC1490_ENCAP_CISCO:
422 M_PREPEND(m, 2, M_NOWAIT); /* Prepend IP ethertype */
423 if (!m)
424 ERROUT(ENOBUFS);
425 *((u_int16_t *)mtod(m, u_int16_t *)) = htons(ETHERTYPE_IP);
426 break;
427 }
428 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
429 } else if (hook == priv->ethernet) {
430 M_PREPEND(m, 8, M_NOWAIT); /* Prepend NLPID, OUI, PID */
431 if (!m)
432 ERROUT(ENOBUFS);
433 mtod(m, u_char *)[0] = HDLC_UI;
434 mtod(m, u_char *)[1] = 0x00; /* pad */
435 mtod(m, u_char *)[2] = NLPID_SNAP;
436 mtod(m, u_char *)[3] = 0x00; /* OUI */
437 mtod(m, u_char *)[4] = 0x80;
438 mtod(m, u_char *)[5] = 0xc2;
439 mtod(m, u_char *)[6] = 0x00; /* PID */
440 mtod(m, u_char *)[7] = 0x07;
441 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
442 } else
443 panic(__func__);
444
445 done:
446 if (item)
447 NG_FREE_ITEM(item);
448 NG_FREE_M(m);
449 return (error);
450 }
451
452 /*
453 * Nuke node
454 */
455 static int
ng_rfc1490_shutdown(node_p node)456 ng_rfc1490_shutdown(node_p node)
457 {
458 const priv_p priv = NG_NODE_PRIVATE(node);
459
460 /* Take down netgraph node */
461 bzero(priv, sizeof(*priv));
462 kfree(priv, M_NETGRAPH);
463 NG_NODE_SET_PRIVATE(node, NULL);
464 NG_NODE_UNREF(node); /* let the node escape */
465 return (0);
466 }
467
468 /*
469 * Hook disconnection
470 */
471 static int
ng_rfc1490_disconnect(hook_p hook)472 ng_rfc1490_disconnect(hook_p hook)
473 {
474 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
475
476 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
477 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
478 ng_rmnode_self(NG_HOOK_NODE(hook));
479 else if (hook == priv->downlink)
480 priv->downlink = NULL;
481 else if (hook == priv->inet)
482 priv->inet = NULL;
483 else if (hook == priv->ppp)
484 priv->ppp = NULL;
485 else if (hook == priv->ethernet)
486 priv->ethernet = NULL;
487 else
488 panic(__func__);
489 return (0);
490 }
491
492