xref: /freebsd/sys/netgraph/ng_gif_demux.c (revision fe267a559009cbf34f9341666fe4d88a92c02d5e)
1 /*
2  * ng_gif_demux.c
3  */
4 
5 /*-
6  * SPDX-License-Identifier: BSD-3-Clause AND BSD-2-Clause
7  *
8  * Copyright 2001 The Aerospace Corporation.  All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  *
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions, and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The name of The Aerospace Corporation may not be used to endorse or
20  *    promote products derived from this software.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AEROSPACE CORPORATION ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AEROSPACE CORPORATION BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *
35  * Copyright (c) 1996-1999 Whistle Communications, Inc.
36  * All rights reserved.
37  *
38  * Subject to the following obligations and disclaimer of warranty, use and
39  * redistribution of this software, in source or object code forms, with or
40  * without modifications are expressly permitted by Whistle Communications;
41  * provided, however, that:
42  * 1. Any and all reproductions of the source or object code must include the
43  *    copyright notice above and the following disclaimer of warranties; and
44  * 2. No rights are granted, in any manner or form, to use Whistle
45  *    Communications, Inc. trademarks, including the mark "WHISTLE
46  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
47  *    such appears in the above copyright notice or in the software.
48  *
49  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
50  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
51  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
52  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
53  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
54  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
55  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
56  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
57  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
58  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
59  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
60  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
61  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
62  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
63  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
64  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
65  * OF SUCH DAMAGE.
66  *
67  * $FreeBSD$
68  */
69 
70 /*
71  * ng_gif_demux(4) netgraph node type
72  *
73  * Packets received on the "gif" hook have their type header removed
74  * and are passed to the appropriate hook protocol hook.  Packets
75  * received on a protocol hook have a type header added back and are
76  * passed out the gif hook. The currently supported protocol hooks are:
77  */
78 
79 #include <sys/param.h>
80 #include <sys/systm.h>
81 #include <sys/kernel.h>
82 #include <sys/malloc.h>
83 #include <sys/ctype.h>
84 #include <sys/mbuf.h>
85 #include <sys/errno.h>
86 #include <sys/socket.h>
87 
88 #include <netgraph/ng_message.h>
89 #include <netgraph/netgraph.h>
90 #include <netgraph/ng_parse.h>
91 #include <netgraph/ng_gif_demux.h>
92 
93 #ifdef NG_SEPARATE_MALLOC
94 static MALLOC_DEFINE(M_NETGRAPH_GIF_DEMUX, "netgraph_gif_demux",
95     "netgraph gif demux node");
96 #else
97 #define M_NETGRAPH_GIF_DEMUX M_NETGRAPH
98 #endif
99 
100 /* This struct describes one address family */
101 struct iffam {
102 	sa_family_t	family;		/* Address family */
103 	const char	*hookname;	/* Name for hook */
104 };
105 typedef const struct iffam *iffam_p;
106 
107 /* List of address families supported by our interface */
108 const static struct iffam gFamilies[] = {
109 	{ AF_INET,	NG_GIF_DEMUX_HOOK_INET	},
110 	{ AF_INET6,	NG_GIF_DEMUX_HOOK_INET6	},
111 	{ AF_APPLETALK,	NG_GIF_DEMUX_HOOK_ATALK	},
112 	{ AF_IPX,	NG_GIF_DEMUX_HOOK_IPX	},
113 	{ AF_ATM,	NG_GIF_DEMUX_HOOK_ATM	},
114 	{ AF_NATM,	NG_GIF_DEMUX_HOOK_NATM	},
115 };
116 #define	NUM_FAMILIES		nitems(gFamilies)
117 
118 /* Per-node private data */
119 struct ng_gif_demux_private {
120 	node_p	node;			/* Our netgraph node */
121 	hook_p	gif;			/* The gif hook */
122 	hook_p	hooks[NUM_FAMILIES];	/* The protocol hooks */
123 };
124 typedef struct ng_gif_demux_private *priv_p;
125 
126 /* Netgraph node methods */
127 static ng_constructor_t	ng_gif_demux_constructor;
128 static ng_rcvmsg_t	ng_gif_demux_rcvmsg;
129 static ng_shutdown_t	ng_gif_demux_shutdown;
130 static ng_newhook_t	ng_gif_demux_newhook;
131 static ng_rcvdata_t	ng_gif_demux_rcvdata;
132 static ng_disconnect_t	ng_gif_demux_disconnect;
133 
134 /* Helper stuff */
135 static iffam_p	get_iffam_from_af(sa_family_t family);
136 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
137 static iffam_p	get_iffam_from_name(const char *name);
138 static hook_p	*get_hook_from_iffam(priv_p priv, iffam_p iffam);
139 
140 /******************************************************************
141 		    NETGRAPH PARSE TYPES
142 ******************************************************************/
143 
144 /* List of commands and how to convert arguments to/from ASCII */
145 static const struct ng_cmdlist ng_gif_demux_cmdlist[] = {
146 	{ 0 }
147 };
148 
149 /* Node type descriptor */
150 static struct ng_type ng_gif_demux_typestruct = {
151 	.version =	NG_ABI_VERSION,
152 	.name =		NG_GIF_DEMUX_NODE_TYPE,
153 	.constructor =	ng_gif_demux_constructor,
154 	.rcvmsg =	ng_gif_demux_rcvmsg,
155 	.shutdown =	ng_gif_demux_shutdown,
156 	.newhook =	ng_gif_demux_newhook,
157 	.rcvdata =	ng_gif_demux_rcvdata,
158 	.disconnect =	ng_gif_demux_disconnect,
159 	.cmdlist =	ng_gif_demux_cmdlist,
160 };
161 NETGRAPH_INIT(gif_demux, &ng_gif_demux_typestruct);
162 
163 /************************************************************************
164 		    HELPER STUFF
165  ************************************************************************/
166 
167 /*
168  * Get the family descriptor from the family ID
169  */
170 static __inline iffam_p
171 get_iffam_from_af(sa_family_t family)
172 {
173 	iffam_p iffam;
174 	int k;
175 
176 	for (k = 0; k < NUM_FAMILIES; k++) {
177 		iffam = &gFamilies[k];
178 		if (iffam->family == family)
179 			return (iffam);
180 	}
181 	return (NULL);
182 }
183 
184 /*
185  * Get the family descriptor from the hook
186  */
187 static __inline iffam_p
188 get_iffam_from_hook(priv_p priv, hook_p hook)
189 {
190 	int k;
191 
192 	for (k = 0; k < NUM_FAMILIES; k++)
193 		if (priv->hooks[k] == hook)
194 			return (&gFamilies[k]);
195 	return (NULL);
196 }
197 
198 /*
199  * Get the hook from the iffam descriptor
200  */
201 
202 static __inline hook_p *
203 get_hook_from_iffam(priv_p priv, iffam_p iffam)
204 {
205 	return (&priv->hooks[iffam - gFamilies]);
206 }
207 
208 /*
209  * Get the iffam descriptor from the name
210  */
211 static __inline iffam_p
212 get_iffam_from_name(const char *name)
213 {
214 	iffam_p iffam;
215 	int k;
216 
217 	for (k = 0; k < NUM_FAMILIES; k++) {
218 		iffam = &gFamilies[k];
219 		if (!strcmp(iffam->hookname, name))
220 			return (iffam);
221 	}
222 	return (NULL);
223 }
224 
225 /******************************************************************
226 		    NETGRAPH NODE METHODS
227 ******************************************************************/
228 
229 /*
230  * Node constructor
231  */
232 static int
233 ng_gif_demux_constructor(node_p node)
234 {
235 	priv_p priv;
236 
237 	/* Allocate and initialize private info */
238 	priv = malloc(sizeof(*priv), M_NETGRAPH_GIF_DEMUX, M_WAITOK | M_ZERO);
239 	priv->node = node;
240 
241 	NG_NODE_SET_PRIVATE(node, priv);
242 
243 	/* Done */
244 	return (0);
245 }
246 
247 /*
248  * Method for attaching a new hook
249  */
250 static	int
251 ng_gif_demux_newhook(node_p node, hook_p hook, const char *name)
252 {
253 	const priv_p priv = NG_NODE_PRIVATE(node);
254 	iffam_p iffam;
255 	hook_p *hookptr;
256 
257 	if (strcmp(NG_GIF_DEMUX_HOOK_GIF, name) == 0)
258 		hookptr = &priv->gif;
259 	else {
260 		iffam = get_iffam_from_name(name);
261 		if (iffam == NULL)
262 			return (EPFNOSUPPORT);
263 		hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
264 	}
265 	if (*hookptr != NULL)
266 		return (EISCONN);
267 	*hookptr = hook;
268 	return (0);
269 }
270 
271 /*
272  * Receive a control message
273  */
274 static int
275 ng_gif_demux_rcvmsg(node_p node, item_p item, hook_p lasthook)
276 {
277 	struct ng_mesg *resp = NULL;
278 	int error = 0;
279 	struct ng_mesg *msg;
280 
281 	NGI_GET_MSG(item, msg);
282 	switch (msg->header.typecookie) {
283 	case NGM_GIF_DEMUX_COOKIE:
284 		switch (msg->header.cmd) {
285 		/* XXX: Add commands here. */
286 		default:
287 			error = EINVAL;
288 			break;
289 		}
290 		break;
291 	default:
292 		error = EINVAL;
293 		break;
294 	}
295 
296 	/* Done */
297 	NG_RESPOND_MSG(error, node, item, resp);
298 	NG_FREE_MSG(msg);
299 	return (error);
300 }
301 
302 /*
303  * Receive data on a hook
304  */
305 static int
306 ng_gif_demux_rcvdata(hook_p hook, item_p item)
307 {
308 	const node_p node = NG_HOOK_NODE(hook);
309 	const priv_p priv = NG_NODE_PRIVATE(node);
310 	iffam_p iffam;
311 	hook_p outhook;
312 	int error = 0;
313 	struct mbuf *m;
314 
315 	/* Pull the mbuf out of the item for processing. */
316 	NGI_GET_M(item, m);
317 
318 	if (hook == priv->gif) {
319 		/*
320 		 * Pull off the address family header and find the
321 		 * output hook.
322 		 */
323 		if (m->m_pkthdr.len < sizeof(sa_family_t)) {
324 			NG_FREE_M(m);
325 			NG_FREE_ITEM(item);
326 			return (EINVAL);
327 		}
328 		if (m->m_len < sizeof(sa_family_t)
329 		    && (m = m_pullup(m, sizeof(sa_family_t))) == NULL) {
330 			NG_FREE_ITEM(item);
331 			return (ENOBUFS);
332 		}
333 		iffam = get_iffam_from_af(*mtod(m, sa_family_t *));
334 		if (iffam == NULL) {
335 			NG_FREE_M(m);
336 			NG_FREE_ITEM(item);
337 			return (EINVAL);
338 		}
339 		outhook = *get_hook_from_iffam(priv, iffam);
340 		m_adj(m, sizeof(sa_family_t));
341 	} else {
342 		/*
343 		 * Add address family header and set the output hook.
344 		 */
345 		iffam = get_iffam_from_hook(priv, hook);
346 		M_PREPEND(m, sizeof (iffam->family), M_NOWAIT);
347 		if (m == NULL) {
348 			NG_FREE_M(m);
349 			NG_FREE_ITEM(item);
350 			return (ENOBUFS);
351 		}
352 		bcopy(&iffam->family, mtod(m, sa_family_t *),
353 		    sizeof(iffam->family));
354 		outhook = priv->gif;
355 	}
356 
357 	/* Stuff the mbuf back in. */
358 	NGI_M(item) = m;
359 
360 	/* Deliver packet */
361 	NG_FWD_ITEM_HOOK(error, item, outhook);
362 	return (error);
363 }
364 
365 /*
366  * Shutdown node
367  */
368 static int
369 ng_gif_demux_shutdown(node_p node)
370 {
371 	const priv_p priv = NG_NODE_PRIVATE(node);
372 
373 	free(priv, M_NETGRAPH_GIF_DEMUX);
374 	NG_NODE_SET_PRIVATE(node, NULL);
375 	NG_NODE_UNREF(node);
376 	return (0);
377 }
378 
379 /*
380  * Hook disconnection.
381  */
382 static int
383 ng_gif_demux_disconnect(hook_p hook)
384 {
385 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
386 	iffam_p iffam;
387 
388 	if (hook == priv->gif)
389 		priv->gif = NULL;
390 	else {
391 		iffam = get_iffam_from_hook(priv, hook);
392 		if (iffam == NULL)
393 			panic("%s", __func__);
394 		*get_hook_from_iffam(priv, iffam) = NULL;
395 	}
396 
397 	return (0);
398 }
399