xref: /freebsd/sys/netgraph/ng_gif_demux.c (revision 5908d366fb365362004d549066a6225f0c46d3e6)
1 /*
2  * ng_gif_demux.c
3  *
4  * Copyright 2001 The Aerospace Corporation.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions, and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of The Aerospace Corporation may not be used to endorse or
16  *    promote products derived from this software.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AEROSPACE CORPORATION ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AEROSPACE CORPORATION BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *
31  * Copyright (c) 1996-1999 Whistle Communications, Inc.
32  * All rights reserved.
33  *
34  * Subject to the following obligations and disclaimer of warranty, use and
35  * redistribution of this software, in source or object code forms, with or
36  * without modifications are expressly permitted by Whistle Communications;
37  * provided, however, that:
38  * 1. Any and all reproductions of the source or object code must include the
39  *    copyright notice above and the following disclaimer of warranties; and
40  * 2. No rights are granted, in any manner or form, to use Whistle
41  *    Communications, Inc. trademarks, including the mark "WHISTLE
42  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
43  *    such appears in the above copyright notice or in the software.
44  *
45  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
46  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
47  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
48  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
49  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
50  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
51  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
52  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
53  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
54  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
55  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
56  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
57  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
60  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
61  * OF SUCH DAMAGE.
62  *
63  * $FreeBSD$
64  */
65 
66 /*
67  * ng_gif_demux(4) netgraph node type
68  *
69  * Packets received on the "gif" hook have their type header removed
70  * and are passed to the appropriate hook protocol hook.  Packets
71  * recieved on a protocol hook have a type header added back and are
72  * passed out the gif hook. The currently supported protocol hooks are:
73  */
74 
75 #include <sys/param.h>
76 #include <sys/systm.h>
77 #include <sys/kernel.h>
78 #include <sys/malloc.h>
79 #include <sys/ctype.h>
80 #include <sys/mbuf.h>
81 #include <sys/errno.h>
82 #include <sys/socket.h>
83 
84 #include <netgraph/ng_message.h>
85 #include <netgraph/netgraph.h>
86 #include <netgraph/ng_parse.h>
87 #include <netgraph/ng_gif_demux.h>
88 
89 #ifdef NG_SEPARATE_MALLOC
90 MALLOC_DEFINE(M_NETGRAPH_GIF_DEMUX, "netgraph_gif_demux",
91     "netgraph gif demux node");
92 #else
93 #define M_NETGRAPH_GIF_DEMUX M_NETGRAPH
94 #endif
95 
96 /* This struct describes one address family */
97 struct iffam {
98 	sa_family_t	family;		/* Address family */
99 	const char	*hookname;	/* Name for hook */
100 };
101 typedef const struct iffam *iffam_p;
102 
103 /* List of address families supported by our interface */
104 const static struct iffam gFamilies[] = {
105 	{ AF_INET,	NG_GIF_DEMUX_HOOK_INET	},
106 	{ AF_INET6,	NG_GIF_DEMUX_HOOK_INET6	},
107 	{ AF_APPLETALK,	NG_GIF_DEMUX_HOOK_ATALK	},
108 	{ AF_IPX,	NG_GIF_DEMUX_HOOK_IPX	},
109 	{ AF_ATM,	NG_GIF_DEMUX_HOOK_ATM	},
110 	{ AF_NATM,	NG_GIF_DEMUX_HOOK_NATM	},
111 };
112 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
113 
114 /* Per-node private data */
115 struct ng_gif_demux_private {
116 	node_p	node;			/* Our netgraph node */
117 	hook_p	gif;			/* The gif hook */
118 	hook_p	hooks[NUM_FAMILIES];	/* The protocol hooks */
119 };
120 typedef struct ng_gif_demux_private *priv_p;
121 
122 /* Netgraph node methods */
123 static ng_constructor_t	ng_gif_demux_constructor;
124 static ng_rcvmsg_t	ng_gif_demux_rcvmsg;
125 static ng_shutdown_t	ng_gif_demux_shutdown;
126 static ng_newhook_t	ng_gif_demux_newhook;
127 static ng_rcvdata_t	ng_gif_demux_rcvdata;
128 static ng_disconnect_t	ng_gif_demux_disconnect;
129 
130 /* Helper stuff */
131 static iffam_p	get_iffam_from_af(sa_family_t family);
132 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
133 static iffam_p	get_iffam_from_name(const char *name);
134 static hook_p	*get_hook_from_iffam(priv_p priv, iffam_p iffam);
135 
136 /******************************************************************
137 		    NETGRAPH PARSE TYPES
138 ******************************************************************/
139 
140 /* List of commands and how to convert arguments to/from ASCII */
141 static const struct ng_cmdlist ng_gif_demux_cmdlist[] = {
142 	{ 0 }
143 };
144 
145 /* Node type descriptor */
146 static struct ng_type ng_gif_demux_typestruct = {
147 	.version =	NG_ABI_VERSION,
148 	.name =		NG_GIF_DEMUX_NODE_TYPE,
149 	.constructor =	ng_gif_demux_constructor,
150 	.rcvmsg =	ng_gif_demux_rcvmsg,
151 	.shutdown =	ng_gif_demux_shutdown,
152 	.newhook =	ng_gif_demux_newhook,
153 	.rcvdata =	ng_gif_demux_rcvdata,
154 	.disconnect =	ng_gif_demux_disconnect,
155 	.cmdlist =	ng_gif_demux_cmdlist,
156 };
157 NETGRAPH_INIT(gif_demux, &ng_gif_demux_typestruct);
158 
159 /************************************************************************
160 		    HELPER STUFF
161  ************************************************************************/
162 
163 /*
164  * Get the family descriptor from the family ID
165  */
166 static __inline iffam_p
167 get_iffam_from_af(sa_family_t family)
168 {
169 	iffam_p iffam;
170 	int k;
171 
172 	for (k = 0; k < NUM_FAMILIES; k++) {
173 		iffam = &gFamilies[k];
174 		if (iffam->family == family)
175 			return (iffam);
176 	}
177 	return (NULL);
178 }
179 
180 /*
181  * Get the family descriptor from the hook
182  */
183 static __inline iffam_p
184 get_iffam_from_hook(priv_p priv, hook_p hook)
185 {
186 	int k;
187 
188 	for (k = 0; k < NUM_FAMILIES; k++)
189 		if (priv->hooks[k] == hook)
190 			return (&gFamilies[k]);
191 	return (NULL);
192 }
193 
194 /*
195  * Get the hook from the iffam descriptor
196  */
197 
198 static __inline hook_p *
199 get_hook_from_iffam(priv_p priv, iffam_p iffam)
200 {
201 	return (&priv->hooks[iffam - gFamilies]);
202 }
203 
204 /*
205  * Get the iffam descriptor from the name
206  */
207 static __inline iffam_p
208 get_iffam_from_name(const char *name)
209 {
210 	iffam_p iffam;
211 	int k;
212 
213 	for (k = 0; k < NUM_FAMILIES; k++) {
214 		iffam = &gFamilies[k];
215 		if (!strcmp(iffam->hookname, name))
216 			return (iffam);
217 	}
218 	return (NULL);
219 }
220 
221 /******************************************************************
222 		    NETGRAPH NODE METHODS
223 ******************************************************************/
224 
225 /*
226  * Node constructor
227  */
228 static int
229 ng_gif_demux_constructor(node_p node)
230 {
231 	priv_p priv;
232 
233 	/* Allocate and initialize private info */
234 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_GIF_DEMUX,
235 	    M_NOWAIT | M_ZERO);
236 	if (priv == NULL)
237 		return (ENOMEM);
238 	priv->node = node;
239 
240 	NG_NODE_SET_PRIVATE(node, priv);
241 
242 	/* Done */
243 	return (0);
244 }
245 
246 /*
247  * Method for attaching a new hook
248  */
249 static	int
250 ng_gif_demux_newhook(node_p node, hook_p hook, const char *name)
251 {
252 	const priv_p priv = NG_NODE_PRIVATE(node);
253 	iffam_p iffam;
254 	hook_p *hookptr;
255 
256 	if (strcmp(NG_GIF_DEMUX_HOOK_GIF, name) == 0)
257 		hookptr = &priv->gif;
258 	else {
259 		iffam = get_iffam_from_name(name);
260 		if (iffam == NULL)
261 			return (EPFNOSUPPORT);
262 		hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
263 	}
264 	if (*hookptr != NULL)
265 		return (EISCONN);
266 	*hookptr = hook;
267 	return (0);
268 }
269 
270 /*
271  * Receive a control message
272  */
273 static int
274 ng_gif_demux_rcvmsg(node_p node, item_p item, hook_p lasthook)
275 {
276 	struct ng_mesg *resp = NULL;
277 	int error = 0;
278 	struct ng_mesg *msg;
279 
280 	NGI_GET_MSG(item, msg);
281 	switch (msg->header.typecookie) {
282 	case NGM_GIF_DEMUX_COOKIE:
283 		switch (msg->header.cmd) {
284 		/* XXX: Add commands here. */
285 		default:
286 			error = EINVAL;
287 			break;
288 		}
289 		break;
290 	default:
291 		error = EINVAL;
292 		break;
293 	}
294 
295 	/* Done */
296 	NG_RESPOND_MSG(error, node, item, resp);
297 	NG_FREE_MSG(msg);
298 	return (error);
299 }
300 
301 /*
302  * Receive data on a hook
303  */
304 static int
305 ng_gif_demux_rcvdata(hook_p hook, item_p item)
306 {
307 	const node_p node = NG_HOOK_NODE(hook);
308 	const priv_p priv = NG_NODE_PRIVATE(node);
309 	iffam_p iffam;
310 	hook_p outhook;
311 	int error = 0;
312 	struct mbuf *m;
313 
314 	/* Pull the mbuf out of the item for processing. */
315 	NGI_GET_M(item, m);
316 
317 	if (hook == priv->gif) {
318 		/*
319 		 * Pull off the address family header and find the
320 		 * output hook.
321 		 */
322 		if (m->m_pkthdr.len < sizeof(sa_family_t)) {
323 			NG_FREE_M(m);
324 			NG_FREE_ITEM(item);
325 			return (EINVAL);
326 		}
327 		if (m->m_len < sizeof(sa_family_t)
328 		    && (m = m_pullup(m, sizeof(sa_family_t))) == NULL) {
329 			NG_FREE_ITEM(item);
330 			return (ENOBUFS);
331 		}
332 		iffam = get_iffam_from_af(*mtod(m, sa_family_t *));
333 		if (iffam == NULL) {
334 			NG_FREE_M(m);
335 			NG_FREE_ITEM(item);
336 			return (EINVAL);
337 		}
338 		outhook = *get_hook_from_iffam(priv, iffam);
339 		m_adj(m, sizeof(sa_family_t));
340 	} else {
341 		/*
342 		 * Add address family header and set the output hook.
343 		 */
344 		iffam = get_iffam_from_hook(priv, hook);
345 		M_PREPEND(m, sizeof (iffam->family), M_DONTWAIT);
346 		if (m == NULL) {
347 			NG_FREE_M(m);
348 			NG_FREE_ITEM(item);
349 			return (ENOBUFS);
350 		}
351 		bcopy(&iffam->family, mtod(m, sa_family_t *),
352 		    sizeof(iffam->family));
353 		outhook = priv->gif;
354 	}
355 
356 	/* Stuff the mbuf back in. */
357 	NGI_M(item) = m;
358 
359 	/* Deliver packet */
360 	NG_FWD_ITEM_HOOK(error, item, outhook);
361 	return (error);
362 }
363 
364 /*
365  * Shutdown node
366  */
367 static int
368 ng_gif_demux_shutdown(node_p node)
369 {
370 	const priv_p priv = NG_NODE_PRIVATE(node);
371 
372 	FREE(priv, M_NETGRAPH_GIF_DEMUX);
373 	NG_NODE_SET_PRIVATE(node, NULL);
374 	NG_NODE_UNREF(node);
375 	return (0);
376 }
377 
378 /*
379  * Hook disconnection.
380  */
381 static int
382 ng_gif_demux_disconnect(hook_p hook)
383 {
384 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
385 	iffam_p iffam;
386 
387 	if (hook == priv->gif)
388 		priv->gif = NULL;
389 	else {
390 		iffam = get_iffam_from_hook(priv, hook);
391 		if (iffam == NULL)
392 			panic(__func__);
393 		*get_hook_from_iffam(priv, iffam) = NULL;
394 	}
395 
396 	return (0);
397 }
398