xref: /freebsd/sys/netgraph/ng_vlan.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
1 /*-
2  * Copyright (c) 2003 IPNET Internet Communication Company
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * Author: Ruslan Ermilov <ru@FreeBSD.org>
27  *
28  * $FreeBSD$
29  */
30 
31 #include <sys/param.h>
32 #include <sys/errno.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <sys/mbuf.h>
36 #include <sys/queue.h>
37 #include <sys/socket.h>
38 #include <sys/systm.h>
39 
40 #include <net/ethernet.h>
41 #include <net/if.h>
42 #include <net/if_vlan_var.h>
43 
44 #include <netgraph/ng_message.h>
45 #include <netgraph/ng_parse.h>
46 #include <netgraph/ng_vlan.h>
47 #include <netgraph/netgraph.h>
48 
49 static ng_constructor_t	ng_vlan_constructor;
50 static ng_rcvmsg_t	ng_vlan_rcvmsg;
51 static ng_shutdown_t	ng_vlan_shutdown;
52 static ng_newhook_t	ng_vlan_newhook;
53 static ng_rcvdata_t	ng_vlan_rcvdata;
54 static ng_disconnect_t	ng_vlan_disconnect;
55 
56 /* Parse type for struct ng_vlan_filter. */
57 static const struct ng_parse_struct_field ng_vlan_filter_fields[] =
58 	NG_VLAN_FILTER_FIELDS;
59 static const struct ng_parse_type ng_vlan_filter_type = {
60 	&ng_parse_struct_type,
61 	&ng_vlan_filter_fields
62 };
63 
64 static int
65 ng_vlan_getTableLength(const struct ng_parse_type *type,
66     const u_char *start, const u_char *buf)
67 {
68 	const struct ng_vlan_table *const table =
69 	    (const struct ng_vlan_table *)(buf - sizeof(u_int32_t));
70 
71 	return table->n;
72 }
73 
74 /* Parse type for struct ng_vlan_table. */
75 static const struct ng_parse_array_info ng_vlan_table_array_info = {
76 	&ng_vlan_filter_type,
77 	ng_vlan_getTableLength
78 };
79 static const struct ng_parse_type ng_vlan_table_array_type = {
80 	&ng_parse_array_type,
81 	&ng_vlan_table_array_info
82 };
83 static const struct ng_parse_struct_field ng_vlan_table_fields[] =
84 	NG_VLAN_TABLE_FIELDS;
85 static const struct ng_parse_type ng_vlan_table_type = {
86 	&ng_parse_struct_type,
87 	&ng_vlan_table_fields
88 };
89 
90 /* List of commands and how to convert arguments to/from ASCII. */
91 static const struct ng_cmdlist ng_vlan_cmdlist[] = {
92 	{
93 	  NGM_VLAN_COOKIE,
94 	  NGM_VLAN_ADD_FILTER,
95 	  "addfilter",
96 	  &ng_vlan_filter_type,
97 	  NULL
98 	},
99 	{
100 	  NGM_VLAN_COOKIE,
101 	  NGM_VLAN_DEL_FILTER,
102 	  "delfilter",
103 	  &ng_parse_hookbuf_type,
104 	  NULL
105 	},
106 	{
107 	  NGM_VLAN_COOKIE,
108 	  NGM_VLAN_GET_TABLE,
109 	  "gettable",
110 	  NULL,
111 	  &ng_vlan_table_type
112 	},
113 	{ 0 }
114 };
115 
116 static struct ng_type ng_vlan_typestruct = {
117 	.version =	NG_ABI_VERSION,
118 	.name =		NG_VLAN_NODE_TYPE,
119 	.constructor =	ng_vlan_constructor,
120 	.rcvmsg =	ng_vlan_rcvmsg,
121 	.shutdown =	ng_vlan_shutdown,
122 	.newhook =	ng_vlan_newhook,
123 	.rcvdata =	ng_vlan_rcvdata,
124 	.disconnect =	ng_vlan_disconnect,
125 	.cmdlist =	ng_vlan_cmdlist,
126 };
127 NETGRAPH_INIT(vlan, &ng_vlan_typestruct);
128 
129 struct filter {
130 	LIST_ENTRY(filter) next;
131 	u_int16_t	vlan;
132 	hook_p		hook;
133 };
134 
135 #define	HASHSIZE	16
136 #define	HASH(id)	((((id) >> 8) ^ ((id) >> 4) ^ (id)) & 0x0f)
137 LIST_HEAD(filterhead, filter);
138 
139 typedef struct {
140 	hook_p		downstream_hook;
141 	hook_p		nomatch_hook;
142 	struct filterhead hashtable[HASHSIZE];
143 	u_int32_t	nent;
144 } *priv_p;
145 
146 static struct filter *
147 ng_vlan_findentry(priv_p priv, u_int16_t vlan)
148 {
149 	struct filterhead *chain = &priv->hashtable[HASH(vlan)];
150 	struct filter *f;
151 
152 	LIST_FOREACH(f, chain, next)
153 		if (f->vlan == vlan)
154 			return (f);
155 	return (NULL);
156 }
157 
158 static int
159 ng_vlan_constructor(node_p node)
160 {
161 	priv_p priv;
162 	int i;
163 
164 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
165 	if (priv == NULL)
166 		return (ENOMEM);
167 	for (i = 0; i < HASHSIZE; i++)
168 		LIST_INIT(&priv->hashtable[i]);
169 	NG_NODE_SET_PRIVATE(node, priv);
170 	return (0);
171 }
172 
173 static int
174 ng_vlan_newhook(node_p node, hook_p hook, const char *name)
175 {
176 	const priv_p priv = NG_NODE_PRIVATE(node);
177 
178 	if (strcmp(name, NG_VLAN_HOOK_DOWNSTREAM) == 0)
179 		priv->downstream_hook = hook;
180 	else if (strcmp(name, NG_VLAN_HOOK_NOMATCH) == 0)
181 		priv->nomatch_hook = hook;
182 	else {
183 		/*
184 		 * Any other hook name is valid and can
185 		 * later be associated with a filter rule.
186 		 */
187 	}
188 	NG_HOOK_SET_PRIVATE(hook, NULL);
189 	return (0);
190 }
191 
192 static int
193 ng_vlan_rcvmsg(node_p node, item_p item, hook_p lasthook)
194 {
195 	const priv_p priv = NG_NODE_PRIVATE(node);
196 	int error = 0;
197 	struct ng_mesg *msg, *resp = NULL;
198 	struct ng_vlan_filter *vf;
199 	struct filter *f;
200 	hook_p hook;
201 	struct ng_vlan_table *t;
202 	int i;
203 
204 	NGI_GET_MSG(item, msg);
205 	/* Deal with message according to cookie and command. */
206 	switch (msg->header.typecookie) {
207 	case NGM_VLAN_COOKIE:
208 		switch (msg->header.cmd) {
209 		case NGM_VLAN_ADD_FILTER:
210 			/* Check that message is long enough. */
211 			if (msg->header.arglen != sizeof(*vf)) {
212 				error = EINVAL;
213 				break;
214 			}
215 			vf = (struct ng_vlan_filter *)msg->data;
216 			/* Sanity check the VLAN ID value. */
217 			if (vf->vlan & ~EVL_VLID_MASK) {
218 				error = EINVAL;
219 				break;
220 			}
221 			/* Check that a referenced hook exists. */
222 			hook = ng_findhook(node, vf->hook);
223 			if (hook == NULL) {
224 				error = ENOENT;
225 				break;
226 			}
227 			/* And is not one of the special hooks. */
228 			if (hook == priv->downstream_hook ||
229 			    hook == priv->nomatch_hook) {
230 				error = EINVAL;
231 				break;
232 			}
233 			/* And is not already in service. */
234 			if (NG_HOOK_PRIVATE(hook) != NULL) {
235 				error = EEXIST;
236 				break;
237 			}
238 			/* Check we don't already trap this VLAN. */
239 			if (ng_vlan_findentry(priv, vf->vlan)) {
240 				error = EEXIST;
241 				break;
242 			}
243 			/* Create filter. */
244 			MALLOC(f, struct filter *, sizeof(*f),
245 			    M_NETGRAPH, M_NOWAIT | M_ZERO);
246 			if (f == NULL) {
247 				error = ENOMEM;
248 				break;
249 			}
250 			/* Link filter and hook together. */
251 			f->hook = hook;
252 			f->vlan = vf->vlan;
253 			NG_HOOK_SET_PRIVATE(hook, f);
254 			/* Register filter in a hash table. */
255 			LIST_INSERT_HEAD(
256 			    &priv->hashtable[HASH(f->vlan)], f, next);
257 			priv->nent++;
258 			break;
259 		case NGM_VLAN_DEL_FILTER:
260 			/* Check that message is long enough. */
261 			if (msg->header.arglen != NG_HOOKSIZ) {
262 				error = EINVAL;
263 				break;
264 			}
265 			/* Check that hook exists and is active. */
266 			hook = ng_findhook(node, (char *)msg->data);
267 			if (hook == NULL ||
268 			    (f = NG_HOOK_PRIVATE(hook)) == NULL) {
269 				error = ENOENT;
270 				break;
271 			}
272 			/* Purge a rule that refers to this hook. */
273 			NG_HOOK_SET_PRIVATE(hook, NULL);
274 			LIST_REMOVE(f, next);
275 			priv->nent--;
276 			FREE(f, M_NETGRAPH);
277 			break;
278 		case NGM_VLAN_GET_TABLE:
279 			NG_MKRESPONSE(resp, msg, sizeof(*t) +
280 			    priv->nent * sizeof(*t->filter), M_NOWAIT);
281 			if (resp == NULL) {
282 				error = ENOMEM;
283 				break;
284 			}
285 			t = (struct ng_vlan_table *)resp->data;
286 			t->n = priv->nent;
287 			vf = &t->filter[0];
288 			for (i = 0; i < HASHSIZE; i++) {
289 				LIST_FOREACH(f, &priv->hashtable[i], next) {
290 					vf->vlan = f->vlan;
291 					strncpy(vf->hook, NG_HOOK_NAME(f->hook),
292 					    NG_HOOKSIZ);
293 					vf++;
294 				}
295 			}
296 			break;
297 		default:		/* Unknown command. */
298 			error = EINVAL;
299 			break;
300 		}
301 		break;
302 	case NGM_FLOW_COOKIE:
303 	    {
304 		struct ng_mesg *copy;
305 		struct filterhead *chain;
306 		struct filter *f;
307 
308 		/*
309 		 * Flow control messages should come only
310 		 * from downstream.
311 		 */
312 
313 		if (lasthook == NULL)
314 			break;
315 		if (lasthook != priv->downstream_hook)
316 			break;
317 
318 		/* Broadcast the event to all uplinks. */
319 		for (i = 0, chain = priv->hashtable; i < HASHSIZE;
320 		    i++, chain++)
321 		LIST_FOREACH(f, chain, next) {
322 			NG_COPYMESSAGE(copy, msg, M_NOWAIT);
323 			if (copy == NULL)
324 				continue;
325 			NG_SEND_MSG_HOOK(error, node, copy, f->hook, 0);
326 		}
327 
328 		break;
329 	    }
330 	default:			/* Unknown type cookie. */
331 		error = EINVAL;
332 		break;
333 	}
334 	NG_RESPOND_MSG(error, node, item, resp);
335 	NG_FREE_MSG(msg);
336 	return (error);
337 }
338 
339 static int
340 ng_vlan_rcvdata(hook_p hook, item_p item)
341 {
342 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
343 	struct ether_header *eh;
344 	struct ether_vlan_header *evl;
345 	int error;
346 	u_int16_t vlan;
347 	struct mbuf *m;
348 	struct filter *f;
349 
350 	/* Make sure we have an entire header. */
351 	NGI_GET_M(item, m);
352 	if (m->m_len < sizeof(*eh) &&
353 	    (m = m_pullup(m, sizeof(*eh))) == NULL) {
354 		NG_FREE_ITEM(item);
355 		return (EINVAL);
356 	}
357 	eh = mtod(m, struct ether_header *);
358 	if (hook == priv->downstream_hook) {
359 		/*
360 		 * If from downstream, select between a match hook
361 		 * or the nomatch hook.
362 		 */
363 		if (m->m_flags & M_VLANTAG ||
364 		    eh->ether_type == htons(ETHERTYPE_VLAN)) {
365 			if (m->m_flags & M_VLANTAG) {
366 				/*
367 				 * Packet is tagged, m contains a normal
368 				 * Ethernet frame; tag is stored out-of-band.
369 				 */
370 				vlan = EVL_VLANOFTAG(m->m_pkthdr.ether_vtag);
371 				(void)&evl;	/* XXX silence GCC */
372 			} else {
373 				if (m->m_len < sizeof(*evl) &&
374 				    (m = m_pullup(m, sizeof(*evl))) == NULL) {
375 					NG_FREE_ITEM(item);
376 					return (EINVAL);
377 				}
378 				evl = mtod(m, struct ether_vlan_header *);
379 				vlan = EVL_VLANOFTAG(ntohs(evl->evl_tag));
380 			}
381 			if ((f = ng_vlan_findentry(priv, vlan)) != NULL) {
382 				if (m->m_flags & M_VLANTAG) {
383 					m->m_pkthdr.ether_vtag = 0;
384 					m->m_flags &= ~M_VLANTAG;
385 				} else {
386 					evl->evl_encap_proto = evl->evl_proto;
387 					bcopy(mtod(m, caddr_t),
388 					    mtod(m, caddr_t) +
389 					    ETHER_VLAN_ENCAP_LEN,
390 					    ETHER_HDR_LEN);
391 					m_adj(m, ETHER_VLAN_ENCAP_LEN);
392 				}
393 			}
394 		} else
395 			f = NULL;
396 		if (f != NULL)
397 			NG_FWD_NEW_DATA(error, item, f->hook, m);
398 		else
399 			NG_FWD_NEW_DATA(error, item, priv->nomatch_hook, m);
400 	} else {
401 		/*
402 		 * It is heading towards the downstream.
403 		 * If from nomatch, pass it unmodified.
404 		 * Otherwise, do the VLAN encapsulation.
405 		 */
406 		if (hook != priv->nomatch_hook) {
407 			if ((f = NG_HOOK_PRIVATE(hook)) == NULL) {
408 				NG_FREE_ITEM(item);
409 				NG_FREE_M(m);
410 				return (EOPNOTSUPP);
411 			}
412 			M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_DONTWAIT);
413 			/* M_PREPEND takes care of m_len and m_pkthdr.len. */
414 			if (m == NULL || (m->m_len < sizeof(*evl) &&
415 			    (m = m_pullup(m, sizeof(*evl))) == NULL)) {
416 				NG_FREE_ITEM(item);
417 				return (ENOMEM);
418 			}
419 			/*
420 			 * Transform the Ethernet header into an Ethernet header
421 			 * with 802.1Q encapsulation.
422 			 */
423 			bcopy(mtod(m, char *) + ETHER_VLAN_ENCAP_LEN,
424 			    mtod(m, char *), ETHER_HDR_LEN);
425 			evl = mtod(m, struct ether_vlan_header *);
426 			evl->evl_proto = evl->evl_encap_proto;
427 			evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
428 			evl->evl_tag = htons(f->vlan);
429 		}
430 		NG_FWD_NEW_DATA(error, item, priv->downstream_hook, m);
431 	}
432 	return (error);
433 }
434 
435 static int
436 ng_vlan_shutdown(node_p node)
437 {
438 	const priv_p priv = NG_NODE_PRIVATE(node);
439 
440 	NG_NODE_SET_PRIVATE(node, NULL);
441 	NG_NODE_UNREF(node);
442 	FREE(priv, M_NETGRAPH);
443 	return (0);
444 }
445 
446 static int
447 ng_vlan_disconnect(hook_p hook)
448 {
449 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
450 	struct filter *f;
451 
452 	if (hook == priv->downstream_hook)
453 		priv->downstream_hook = NULL;
454 	else if (hook == priv->nomatch_hook)
455 		priv->nomatch_hook = NULL;
456 	else {
457 		/* Purge a rule that refers to this hook. */
458 		if ((f = NG_HOOK_PRIVATE(hook)) != NULL) {
459 			LIST_REMOVE(f, next);
460 			priv->nent--;
461 			FREE(f, M_NETGRAPH);
462 		}
463 	}
464 	NG_HOOK_SET_PRIVATE(hook, NULL);
465 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
466 	    (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
467 		ng_rmnode_self(NG_HOOK_NODE(hook));
468 	return (0);
469 }
470