xref: /freebsd/sys/netgraph/ng_gif_demux.c (revision 729362425c09cf6b362366aabc6fb547eee8035a)
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 	NG_ABI_VERSION,
148 	NG_GIF_DEMUX_NODE_TYPE,
149 	NULL,
150 	ng_gif_demux_constructor,
151 	ng_gif_demux_rcvmsg,
152 	ng_gif_demux_shutdown,
153 	ng_gif_demux_newhook,
154 	NULL,
155 	NULL,
156 	ng_gif_demux_rcvdata,
157 	ng_gif_demux_disconnect,
158 	ng_gif_demux_cmdlist,
159 };
160 NETGRAPH_INIT(gif_demux, &ng_gif_demux_typestruct);
161 
162 /************************************************************************
163 		    HELPER STUFF
164  ************************************************************************/
165 
166 /*
167  * Get the family descriptor from the family ID
168  */
169 static __inline__ iffam_p
170 get_iffam_from_af(sa_family_t family)
171 {
172 	iffam_p iffam;
173 	int k;
174 
175 	for (k = 0; k < NUM_FAMILIES; k++) {
176 		iffam = &gFamilies[k];
177 		if (iffam->family == family)
178 			return (iffam);
179 	}
180 	return (NULL);
181 }
182 
183 /*
184  * Get the family descriptor from the hook
185  */
186 static __inline__ iffam_p
187 get_iffam_from_hook(priv_p priv, hook_p hook)
188 {
189 	int k;
190 
191 	for (k = 0; k < NUM_FAMILIES; k++)
192 		if (priv->hooks[k] == hook)
193 			return (&gFamilies[k]);
194 	return (NULL);
195 }
196 
197 /*
198  * Get the hook from the iffam descriptor
199  */
200 
201 static __inline__ hook_p *
202 get_hook_from_iffam(priv_p priv, iffam_p iffam)
203 {
204 	return (&priv->hooks[iffam - gFamilies]);
205 }
206 
207 /*
208  * Get the iffam descriptor from the name
209  */
210 static __inline__ iffam_p
211 get_iffam_from_name(const char *name)
212 {
213 	iffam_p iffam;
214 	int k;
215 
216 	for (k = 0; k < NUM_FAMILIES; k++) {
217 		iffam = &gFamilies[k];
218 		if (!strcmp(iffam->hookname, name))
219 			return (iffam);
220 	}
221 	return (NULL);
222 }
223 
224 /******************************************************************
225 		    NETGRAPH NODE METHODS
226 ******************************************************************/
227 
228 /*
229  * Node constructor
230  */
231 static int
232 ng_gif_demux_constructor(node_p node)
233 {
234 	priv_p priv;
235 
236 	/* Allocate and initialize private info */
237 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_GIF_DEMUX,
238 	    M_NOWAIT | M_ZERO);
239 	if (priv == NULL)
240 		return (ENOMEM);
241 	priv->node = node;
242 
243 	NG_NODE_SET_PRIVATE(node, priv);
244 
245 	/* Done */
246 	return (0);
247 }
248 
249 /*
250  * Method for attaching a new hook
251  */
252 static	int
253 ng_gif_demux_newhook(node_p node, hook_p hook, const char *name)
254 {
255 	const priv_p priv = NG_NODE_PRIVATE(node);
256 	iffam_p iffam;
257 	hook_p *hookptr;
258 
259 	if (strcmp(NG_GIF_DEMUX_HOOK_GIF, name) == 0)
260 		hookptr = &priv->gif;
261 	else {
262 		iffam = get_iffam_from_name(name);
263 		if (iffam == NULL)
264 			return (EPFNOSUPPORT);
265 		hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
266 	}
267 	if (*hookptr != NULL)
268 		return (EISCONN);
269 	*hookptr = hook;
270 	return (0);
271 }
272 
273 /*
274  * Receive a control message
275  */
276 static int
277 ng_gif_demux_rcvmsg(node_p node, item_p item, hook_p lasthook)
278 {
279 	struct ng_mesg *resp = NULL;
280 	int error = 0;
281 	struct ng_mesg *msg;
282 
283 	NGI_GET_MSG(item, msg);
284 	switch (msg->header.typecookie) {
285 	case NGM_GIF_DEMUX_COOKIE:
286 		switch (msg->header.cmd) {
287 		/* XXX: Add commands here. */
288 		default:
289 			error = EINVAL;
290 			break;
291 		}
292 		break;
293 	default:
294 		error = EINVAL;
295 		break;
296 	}
297 
298 	/* Done */
299 	NG_RESPOND_MSG(error, node, item, resp);
300 	NG_FREE_MSG(msg);
301 	return (error);
302 }
303 
304 /*
305  * Receive data on a hook
306  */
307 static int
308 ng_gif_demux_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 	iffam_p iffam;
313 	hook_p outhook;
314 	int error = 0;
315 	struct mbuf *m;
316 
317 	/* Pull the mbuf out of the item for processing. */
318 	NGI_GET_M(item, m);
319 
320 	if (hook == priv->gif) {
321 		/*
322 		 * Pull off the address family header and find the
323 		 * output hook.
324 		 */
325 		if (m->m_pkthdr.len < sizeof(sa_family_t)) {
326 			NG_FREE_M(m);
327 			NG_FREE_ITEM(item);
328 			return (EINVAL);
329 		}
330 		if (m->m_len < sizeof(sa_family_t)
331 		    && (m = m_pullup(m, sizeof(sa_family_t))) == NULL) {
332 			NG_FREE_ITEM(item);
333 			return (ENOBUFS);
334 		}
335 		iffam = get_iffam_from_af(*mtod(m, sa_family_t *));
336 		if (iffam == NULL) {
337 			NG_FREE_M(m);
338 			NG_FREE_ITEM(item);
339 			return (EINVAL);
340 		}
341 		outhook = *get_hook_from_iffam(priv, iffam);
342 		m_adj(m, sizeof(sa_family_t));
343 	} else {
344 		/*
345 		 * Add address family header and set the output hook.
346 		 */
347 		iffam = get_iffam_from_hook(priv, hook);
348 		M_PREPEND(m, sizeof (iffam->family), M_DONTWAIT);
349 		if (m == NULL) {
350 			NG_FREE_M(m);
351 			NG_FREE_ITEM(item);
352 			return (ENOBUFS);
353 		}
354 		bcopy(&iffam->family, mtod(m, sa_family_t *),
355 		    sizeof(iffam->family));
356 		outhook = priv->gif;
357 	}
358 
359 	/* Stuff the mbuf back in. */
360 	NGI_M(item) = m;
361 
362 	/* Deliver packet */
363 	NG_FWD_ITEM_HOOK(error, item, outhook);
364 	return (error);
365 }
366 
367 /*
368  * Shutdown node
369  */
370 static int
371 ng_gif_demux_shutdown(node_p node)
372 {
373 	const priv_p priv = NG_NODE_PRIVATE(node);
374 
375 	FREE(priv, M_NETGRAPH_GIF_DEMUX);
376 	NG_NODE_SET_PRIVATE(node, NULL);
377 	NG_NODE_UNREF(node);
378 	return (0);
379 }
380 
381 /*
382  * Hook disconnection.
383  */
384 static int
385 ng_gif_demux_disconnect(hook_p hook)
386 {
387 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
388 	iffam_p iffam;
389 
390 	if (hook == priv->gif)
391 		priv->gif = NULL;
392 	else {
393 		iffam = get_iffam_from_hook(priv, hook);
394 		if (iffam == NULL)
395 			panic(__func__);
396 		*get_hook_from_iffam(priv, iffam) = NULL;
397 	}
398 
399 	return (0);
400 }
401