1
2 /*
3 * ng_rfc1490.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: Julian Elischer <julian@freebsd.org>
38 *
39 * $FreeBSD$
40 * $Whistle: ng_rfc1490.c,v 1.22 1999/11/01 09:24:52 julian Exp $
41 */
42
43 /*
44 * This node does RFC 1490 multiplexing.
45 *
46 * NOTE: RFC 1490 is updated by RFC 2427.
47 */
48
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/errno.h>
52 #include <sys/kernel.h>
53 #include <sys/malloc.h>
54 #include <sys/mbuf.h>
55 #include <sys/errno.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 <netgraph/ng_message.h>
63 #include <netgraph/netgraph.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 /* Node private data */
82 struct ng_rfc1490_private {
83 hook_p downlink;
84 hook_p ppp;
85 hook_p inet;
86 };
87 typedef struct ng_rfc1490_private *priv_p;
88
89 /* Netgraph node methods */
90 static ng_constructor_t ng_rfc1490_constructor;
91 static ng_rcvmsg_t ng_rfc1490_rcvmsg;
92 static ng_shutdown_t ng_rfc1490_rmnode;
93 static ng_newhook_t ng_rfc1490_newhook;
94 static ng_rcvdata_t ng_rfc1490_rcvdata;
95 static ng_disconnect_t ng_rfc1490_disconnect;
96
97 /* Node type descriptor */
98 static struct ng_type typestruct = {
99 NG_VERSION,
100 NG_RFC1490_NODE_TYPE,
101 NULL,
102 ng_rfc1490_constructor,
103 ng_rfc1490_rcvmsg,
104 ng_rfc1490_rmnode,
105 ng_rfc1490_newhook,
106 NULL,
107 NULL,
108 ng_rfc1490_rcvdata,
109 ng_rfc1490_rcvdata,
110 ng_rfc1490_disconnect,
111 NULL
112 };
113 NETGRAPH_INIT(rfc1490, &typestruct);
114
115 /************************************************************************
116 NETGRAPH NODE STUFF
117 ************************************************************************/
118
119 /*
120 * Node constructor
121 */
122 static int
123 ng_rfc1490_constructor(node_p *nodep)
124 {
125 priv_p priv;
126 int error;
127
128 /* Allocate private structure */
129 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT);
130 if (priv == NULL)
131 return (ENOMEM);
132 bzero(priv, sizeof(*priv));
133
134 /* Call generic node constructor */
135 if ((error = ng_make_node_common(&typestruct, nodep))) {
136 FREE(priv, M_NETGRAPH);
137 return (error);
138 }
139 (*nodep)->private = priv;
140
141 /* Done */
142 return (0);
143 }
144
145 /*
146 * Give our ok for a hook to be added
147 */
148 static int
149 ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
150 {
151 const priv_p priv = node->private;
152
153 if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
154 if (priv->downlink)
155 return (EISCONN);
156 priv->downlink = hook;
157 } else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
158 if (priv->ppp)
159 return (EISCONN);
160 priv->ppp = hook;
161 } else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
162 if (priv->inet)
163 return (EISCONN);
164 priv->inet = hook;
165 } else
166 return (EINVAL);
167 return (0);
168 }
169
170 /*
171 * Receive a control message. We don't support any special ones.
172 */
173 static int
174 ng_rfc1490_rcvmsg(node_p node, struct ng_mesg *msg,
175 const char *raddr, struct ng_mesg **rp)
176 {
177 FREE(msg, M_NETGRAPH);
178 return (EINVAL);
179 }
180
181 /*
182 * Receive data on a hook and encapsulate according to RFC 1490.
183 * Only those nodes marked (*) are supported by this routine so far.
184 *
185 * Q.922 control
186 * |
187 * |
188 * --------------------------------------------
189 * | 0x03 |
190 * UI I Frame
191 * | |
192 * --------------------------------- --------------
193 * | 0x08 | 0x81 |0xCC |0xCF | 0x00 |..01.... |..10....
194 * | | | | | 0x80 | |
195 * Q.933 CLNP IP(*) PPP(*) SNAP ISO 8208 ISO 8208
196 * | (rfc1973) | Modulo 8 Modulo 128
197 * | |
198 * -------------------- OUI
199 * | | |
200 * L2 ID L3 ID -------------------------
201 * | User |00-80-C2 |00-00-00
202 * | specified | |
203 * | 0x70 PID Ethertype
204 * | | |
205 * ------------------- --------------... ----------
206 * |0x51 |0x4E | |0x4C |0x1 |0xB | |0x806 |
207 * | | | | | | | | |
208 * 7776 Q.922 Others 802.2 802.3 802.6 Others ARP(*) Others
209 *
210 *
211 */
212
213 #define MAX_ENCAPS_HDR 8
214 #define ERROUT(x) do { error = (x); goto done; } while (0)
215 #define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
216
217 static int
218 ng_rfc1490_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
219 {
220 const node_p node = hook->node;
221 const priv_p priv = node->private;
222 int error = 0;
223
224 if (hook == priv->downlink) {
225 const u_char *start;
226 const u_char *ptr;
227
228 if (!m || (m->m_len < MAX_ENCAPS_HDR
229 && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
230 ERROUT(ENOBUFS);
231 ptr = start = mtod(m, const u_char *);
232
233 /* Must be UI frame */
234 if (*ptr++ != HDLC_UI)
235 ERROUT(0);
236
237 /* Eat optional zero pad byte */
238 if (*ptr == 0x00)
239 ptr++;
240
241 /* Multiplex on NLPID */
242 switch (*ptr++) {
243 case NLPID_SNAP:
244 if (OUICMP(ptr, 0, 0, 0)) { /* It's an ethertype */
245 u_int16_t etype;
246
247 ptr += 3;
248 etype = ntohs(*((const u_int16_t *)ptr));
249 ptr += 2;
250 m_adj(m, ptr - start);
251 switch (etype) {
252 case ETHERTYPE_IP:
253 NG_SEND_DATA(error,
254 priv->inet, m, meta);
255 break;
256 case ETHERTYPE_ARP:
257 case ETHERTYPE_REVARP:
258 default:
259 ERROUT(0);
260 }
261 } else if (OUICMP(ptr, 0x00, 0x80, 0xc2)) /* 802.1 bridging */
262 ERROUT(0);
263 else /* Other weird stuff... */
264 ERROUT(0);
265 break;
266 case NLPID_IP:
267 m_adj(m, ptr - start);
268 NG_SEND_DATA(error, priv->inet, m, meta);
269 break;
270 case NLPID_PPP:
271 m_adj(m, ptr - start);
272 NG_SEND_DATA(error, priv->ppp, m, meta);
273 break;
274 case NLPID_Q933:
275 case NLPID_CLNP:
276 case NLPID_ESIS:
277 case NLPID_ISIS:
278 ERROUT(0);
279 default: /* Try PPP (see RFC 1973) */
280 ptr--; /* NLPID becomes PPP proto */
281 if ((*ptr & 0x01) == 0x01)
282 ERROUT(0);
283 m_adj(m, ptr - start);
284 NG_SEND_DATA(error, priv->ppp, m, meta);
285 break;
286 }
287 } else if (hook == priv->ppp) {
288 M_PREPEND(m, 2, M_DONTWAIT); /* Prepend PPP NLPID */
289 if (!m)
290 ERROUT(ENOBUFS);
291 mtod(m, u_char *)[0] = HDLC_UI;
292 mtod(m, u_char *)[1] = NLPID_PPP;
293 NG_SEND_DATA(error, priv->downlink, m, meta);
294 } else if (hook == priv->inet) {
295 M_PREPEND(m, 2, M_DONTWAIT); /* Prepend IP NLPID */
296 if (!m)
297 ERROUT(ENOBUFS);
298 mtod(m, u_char *)[0] = HDLC_UI;
299 mtod(m, u_char *)[1] = NLPID_IP;
300 NG_SEND_DATA(error, priv->downlink, m, meta);
301 } else
302 panic(__FUNCTION__);
303
304 done:
305 NG_FREE_DATA(m, meta);
306 return (error);
307 }
308
309 /*
310 * Nuke node
311 */
312 static int
313 ng_rfc1490_rmnode(node_p node)
314 {
315 const priv_p priv = node->private;
316
317 /* Take down netgraph node */
318 node->flags |= NG_INVALID;
319 ng_cutlinks(node);
320 ng_unname(node);
321 bzero(priv, sizeof(*priv));
322 node->private = NULL;
323 FREE(priv, M_NETGRAPH);
324 ng_unref(node); /* let the node escape */
325 return (0);
326 }
327
328 /*
329 * Hook disconnection
330 */
331 static int
332 ng_rfc1490_disconnect(hook_p hook)
333 {
334 const priv_p priv = hook->node->private;
335
336 if (hook->node->numhooks == 0)
337 ng_rmnode(hook->node);
338 else if (hook == priv->downlink)
339 priv->downlink = NULL;
340 else if (hook == priv->inet)
341 priv->inet = NULL;
342 else if (hook == priv->ppp)
343 priv->ppp = NULL;
344 else
345 panic(__FUNCTION__);
346 return (0);
347 }
348
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