xref: /dragonfly/sys/netgraph7/ng_vlan.c (revision 91dc43dd)
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: src/sys/netgraph/ng_vlan.c,v 1.5 2007/06/11 15:29:02 imp Exp $
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 "ng_message.h"
45 #include "ng_parse.h"
46 #include "ng_vlan.h"
47 #include "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 	priv = kmalloc(sizeof(*priv), M_NETGRAPH,
165 		       M_WAITOK | M_NULLOK | M_ZERO);
166 	if (priv == NULL)
167 		return (ENOMEM);
168 	for (i = 0; i < HASHSIZE; i++)
169 		LIST_INIT(&priv->hashtable[i]);
170 	NG_NODE_SET_PRIVATE(node, priv);
171 	return (0);
172 }
173 
174 static int
175 ng_vlan_newhook(node_p node, hook_p hook, const char *name)
176 {
177 	const priv_p priv = NG_NODE_PRIVATE(node);
178 
179 	if (strcmp(name, NG_VLAN_HOOK_DOWNSTREAM) == 0)
180 		priv->downstream_hook = hook;
181 	else if (strcmp(name, NG_VLAN_HOOK_NOMATCH) == 0)
182 		priv->nomatch_hook = hook;
183 	else {
184 		/*
185 		 * Any other hook name is valid and can
186 		 * later be associated with a filter rule.
187 		 */
188 	}
189 	NG_HOOK_SET_PRIVATE(hook, NULL);
190 	return (0);
191 }
192 
193 static int
194 ng_vlan_rcvmsg(node_p node, item_p item, hook_p lasthook)
195 {
196 	const priv_p priv = NG_NODE_PRIVATE(node);
197 	int error = 0;
198 	struct ng_mesg *msg, *resp = NULL;
199 	struct ng_vlan_filter *vf;
200 	struct filter *f;
201 	hook_p hook;
202 	struct ng_vlan_table *t;
203 	int i;
204 
205 	NGI_GET_MSG(item, msg);
206 	/* Deal with message according to cookie and command. */
207 	switch (msg->header.typecookie) {
208 	case NGM_VLAN_COOKIE:
209 		switch (msg->header.cmd) {
210 		case NGM_VLAN_ADD_FILTER:
211 			/* Check that message is long enough. */
212 			if (msg->header.arglen != sizeof(*vf)) {
213 				error = EINVAL;
214 				break;
215 			}
216 			vf = (struct ng_vlan_filter *)msg->data;
217 			/* Sanity check the VLAN ID value. */
218 			if (vf->vlan & ~EVL_VLID_MASK) {
219 				error = EINVAL;
220 				break;
221 			}
222 			/* Check that a referenced hook exists. */
223 			hook = ng_findhook(node, vf->hook);
224 			if (hook == NULL) {
225 				error = ENOENT;
226 				break;
227 			}
228 			/* And is not one of the special hooks. */
229 			if (hook == priv->downstream_hook ||
230 			    hook == priv->nomatch_hook) {
231 				error = EINVAL;
232 				break;
233 			}
234 			/* And is not already in service. */
235 			if (NG_HOOK_PRIVATE(hook) != NULL) {
236 				error = EEXIST;
237 				break;
238 			}
239 			/* Check we don't already trap this VLAN. */
240 			if (ng_vlan_findentry(priv, vf->vlan)) {
241 				error = EEXIST;
242 				break;
243 			}
244 			/* Create filter. */
245 			f = kmalloc(sizeof(*f), M_NETGRAPH,
246 				    M_WAITOK | M_NULLOK | M_ZERO);
247 			if (f == NULL) {
248 				error = ENOMEM;
249 				break;
250 			}
251 			/* Link filter and hook together. */
252 			f->hook = hook;
253 			f->vlan = vf->vlan;
254 			NG_HOOK_SET_PRIVATE(hook, f);
255 			/* Register filter in a hash table. */
256 			LIST_INSERT_HEAD(
257 			    &priv->hashtable[HASH(f->vlan)], f, next);
258 			priv->nent++;
259 			break;
260 		case NGM_VLAN_DEL_FILTER:
261 			/* Check that message is long enough. */
262 			if (msg->header.arglen != NG_HOOKSIZ) {
263 				error = EINVAL;
264 				break;
265 			}
266 			/* Check that hook exists and is active. */
267 			hook = ng_findhook(node, (char *)msg->data);
268 			if (hook == NULL ||
269 			    (f = NG_HOOK_PRIVATE(hook)) == NULL) {
270 				error = ENOENT;
271 				break;
272 			}
273 			/* Purge a rule that refers to this hook. */
274 			NG_HOOK_SET_PRIVATE(hook, NULL);
275 			LIST_REMOVE(f, next);
276 			priv->nent--;
277 			kfree(f, M_NETGRAPH);
278 			break;
279 		case NGM_VLAN_GET_TABLE:
280 			NG_MKRESPONSE(resp, msg, sizeof(*t) +
281 			    priv->nent * sizeof(*t->filter), M_WAITOK | M_NULLOK);
282 			if (resp == NULL) {
283 				error = ENOMEM;
284 				break;
285 			}
286 			t = (struct ng_vlan_table *)resp->data;
287 			t->n = priv->nent;
288 			vf = &t->filter[0];
289 			for (i = 0; i < HASHSIZE; i++) {
290 				LIST_FOREACH(f, &priv->hashtable[i], next) {
291 					vf->vlan = f->vlan;
292 					strncpy(vf->hook, NG_HOOK_NAME(f->hook),
293 					    NG_HOOKSIZ);
294 					vf++;
295 				}
296 			}
297 			break;
298 		default:		/* Unknown command. */
299 			error = EINVAL;
300 			break;
301 		}
302 		break;
303 	case NGM_FLOW_COOKIE:
304 	    {
305 		struct ng_mesg *copy;
306 		struct filterhead *chain;
307 		struct filter *f;
308 
309 		/*
310 		 * Flow control messages should come only
311 		 * from downstream.
312 		 */
313 
314 		if (lasthook == NULL)
315 			break;
316 		if (lasthook != priv->downstream_hook)
317 			break;
318 
319 		/* Broadcast the event to all uplinks. */
320 		for (i = 0, chain = priv->hashtable; i < HASHSIZE;
321 		    i++, chain++) {
322 			LIST_FOREACH(f, chain, next) {
323 				NG_COPYMESSAGE(copy, msg, M_WAITOK | M_NULLOK);
324 				if (copy == NULL)
325 					continue;
326 				NG_SEND_MSG_HOOK(error, node, copy, f->hook, 0);
327 			}
328 		}
329 
330 		break;
331 	    }
332 	default:			/* Unknown type cookie. */
333 		error = EINVAL;
334 		break;
335 	}
336 	NG_RESPOND_MSG(error, node, item, resp);
337 	NG_FREE_MSG(msg);
338 	return (error);
339 }
340 
341 static int
342 ng_vlan_rcvdata(hook_p hook, item_p item)
343 {
344 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
345 	struct ether_header *eh;
346 	struct ether_vlan_header *evl = NULL;
347 	int error;
348 	u_int16_t vlan;
349 	struct mbuf *m;
350 	struct filter *f;
351 
352 	/* Make sure we have an entire header. */
353 	NGI_GET_M(item, m);
354 	if (m->m_len < sizeof(*eh) &&
355 	    (m = m_pullup(m, sizeof(*eh))) == NULL) {
356 		NG_FREE_ITEM(item);
357 		return (EINVAL);
358 	}
359 	eh = mtod(m, struct ether_header *);
360 	if (hook == priv->downstream_hook) {
361 		/*
362 		 * If from downstream, select between a match hook
363 		 * or the nomatch hook.
364 		 */
365 		if (m->m_flags & M_VLANTAG ||
366 		    eh->ether_type == htons(ETHERTYPE_VLAN)) {
367 			if (m->m_flags & M_VLANTAG) {
368 				/*
369 				 * Packet is tagged, m contains a normal
370 				 * Ethernet frame; tag is stored out-of-band.
371 				 */
372 				vlan = EVL_VLANOFTAG(m->m_pkthdr.ether_vtag);
373 			} else {
374 				if (m->m_len < sizeof(*evl) &&
375 				    (m = m_pullup(m, sizeof(*evl))) == NULL) {
376 					NG_FREE_ITEM(item);
377 					return (EINVAL);
378 				}
379 				evl = mtod(m, struct ether_vlan_header *);
380 				vlan = EVL_VLANOFTAG(ntohs(evl->evl_tag));
381 			}
382 			if ((f = ng_vlan_findentry(priv, vlan)) != NULL) {
383 				if (m->m_flags & M_VLANTAG) {
384 					m->m_pkthdr.ether_vtag = 0;
385 					m->m_flags &= ~M_VLANTAG;
386 				} else {
387 					evl->evl_encap_proto = evl->evl_proto;
388 					bcopy(mtod(m, caddr_t),
389 					    mtod(m, caddr_t) +
390 					    ETHER_VLAN_ENCAP_LEN,
391 					    ETHER_HDR_LEN);
392 					m_adj(m, ETHER_VLAN_ENCAP_LEN);
393 				}
394 			}
395 		} else
396 			f = NULL;
397 		if (f != NULL)
398 			NG_FWD_NEW_DATA(error, item, f->hook, m);
399 		else
400 			NG_FWD_NEW_DATA(error, item, priv->nomatch_hook, m);
401 	} else {
402 		/*
403 		 * It is heading towards the downstream.
404 		 * If from nomatch, pass it unmodified.
405 		 * Otherwise, do the VLAN encapsulation.
406 		 */
407 		if (hook != priv->nomatch_hook) {
408 			if ((f = NG_HOOK_PRIVATE(hook)) == NULL) {
409 				NG_FREE_ITEM(item);
410 				NG_FREE_M(m);
411 				return (EOPNOTSUPP);
412 			}
413 			M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_NOWAIT);
414 			/* M_PREPEND takes care of m_len and m_pkthdr.len. */
415 			if (m == NULL || (m->m_len < sizeof(*evl) &&
416 			    (m = m_pullup(m, sizeof(*evl))) == NULL)) {
417 				NG_FREE_ITEM(item);
418 				return (ENOMEM);
419 			}
420 			/*
421 			 * Transform the Ethernet header into an Ethernet header
422 			 * with 802.1Q encapsulation.
423 			 */
424 			bcopy(mtod(m, char *) + ETHER_VLAN_ENCAP_LEN,
425 			    mtod(m, char *), ETHER_HDR_LEN);
426 			evl = mtod(m, struct ether_vlan_header *);
427 			evl->evl_proto = evl->evl_encap_proto;
428 			evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
429 			evl->evl_tag = htons(f->vlan);
430 		}
431 		NG_FWD_NEW_DATA(error, item, priv->downstream_hook, m);
432 	}
433 	return (error);
434 }
435 
436 static int
437 ng_vlan_shutdown(node_p node)
438 {
439 	const priv_p priv = NG_NODE_PRIVATE(node);
440 
441 	NG_NODE_SET_PRIVATE(node, NULL);
442 	NG_NODE_UNREF(node);
443 	kfree(priv, M_NETGRAPH);
444 	return (0);
445 }
446 
447 static int
448 ng_vlan_disconnect(hook_p hook)
449 {
450 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
451 	struct filter *f;
452 
453 	if (hook == priv->downstream_hook)
454 		priv->downstream_hook = NULL;
455 	else if (hook == priv->nomatch_hook)
456 		priv->nomatch_hook = NULL;
457 	else {
458 		/* Purge a rule that refers to this hook. */
459 		if ((f = NG_HOOK_PRIVATE(hook)) != NULL) {
460 			LIST_REMOVE(f, next);
461 			priv->nent--;
462 			kfree(f, M_NETGRAPH);
463 		}
464 	}
465 	NG_HOOK_SET_PRIVATE(hook, NULL);
466 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
467 	    (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
468 		ng_rmnode_self(NG_HOOK_NODE(hook));
469 	return (0);
470 }
471