if_vlan.c revision 41514 
1/*
2 * Copyright 1998 Massachusetts Institute of Technology
3 *
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose and without fee is hereby
6 * granted, provided that both the above copyright notice and this
7 * permission notice appear in all copies, that both the above
8 * copyright notice and this permission notice appear in all
9 * supporting documentation, and that the name of M.I.T. not be used
10 * in advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission.  M.I.T. makes
12 * no representations about the suitability of this software for any
13 * purpose.  It is provided "as is" without express or implied
14 * warranty.
15 *
16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	$Id: if_vlan.c,v 1.3 1998/08/23 03:07:10 wollman Exp $
30 */
31
32/*
33 * if_vlan.c - pseudo-device driver for IEEE 802.1Q virtual LANs.
34 * Might be extended some day to also handle IEEE 802.1p priority
35 * tagging.  This is sort of sneaky in the implementation, since
36 * we need to pretend to be enough of an Ethernet implementation
37 * to make arp work.  The way we do this is by telling everyone
38 * that we are an Ethernet, and then catch the packets that
39 * ether_output() left on our output queue queue when it calls
40 * if_start(), rewrite them for use by the real outgoing interface,
41 * and ask it to send them.
42 */
43
44#include "vlan.h"
45#if NVLAN > 0
46#include "opt_inet.h"
47#include "bpfilter.h"
48
49#include <sys/param.h>
50#include <sys/kernel.h>
51#include <sys/mbuf.h>
52#include <sys/socket.h>
53#include <sys/sockio.h>
54#include <sys/sysctl.h>
55#include <sys/systm.h>
56
57#if NBPFILTER > 0
58#include <net/bpf.h>
59#endif
60#include <net/ethernet.h>
61#include <net/if.h>
62#include <net/if_arp.h>
63#include <net/if_dl.h>
64#include <net/if_types.h>
65#include <net/if_vlan_var.h>
66
67#ifdef INET
68#include <netinet/in.h>
69#include <netinet/if_ether.h>
70#endif
71
72SYSCTL_NODE(_net_link, IFT_8021_VLAN, vlan, CTLFLAG_RW, 0, "IEEE 802.1Q VLAN");
73SYSCTL_NODE(_net_link_vlan, PF_LINK, link, CTLFLAG_RW, 0, "for consistency");
74
75u_int	vlan_proto = ETHERTYPE_VLAN;
76SYSCTL_INT(_net_link_vlan_link, VLANCTL_PROTO, proto, CTLFLAG_RW, &vlan_proto,
77	   0, "Ethernet protocol used for VLAN encapsulation");
78
79static	struct ifvlan ifv_softc[NVLAN];
80
81static	void vlan_start(struct ifnet *ifp);
82static	void vlan_ifinit(void *foo);
83static	int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr);
84
85static void
86vlaninit(void *dummy)
87{
88	int i;
89
90	for (i = 0; i < NVLAN; i++) {
91		struct ifnet *ifp = &ifv_softc[i].ifv_if;
92
93		ifp->if_softc = &ifv_softc[i];
94		ifp->if_name = "vlan";
95		ifp->if_unit = i;
96		/* NB: flags are not set here */
97		ifp->if_linkmib = &ifv_softc[i].ifv_mib;
98		ifp->if_linkmiblen = sizeof ifv_softc[i].ifv_mib;
99		/* NB: mtu is not set here */
100
101		ifp->if_init = vlan_ifinit;
102		ifp->if_start = vlan_start;
103		ifp->if_ioctl = vlan_ioctl;
104		ifp->if_output = ether_output;
105		if_attach(ifp);
106		ether_ifattach(ifp);
107#if NBPFILTER > 0
108		bpfattach(ifp, DLT_EN10MB, sizeof(struct ether_header));
109#endif
110		/* Now undo some of the damage... */
111		ifp->if_data.ifi_type = IFT_8021_VLAN;
112		ifp->if_data.ifi_hdrlen = EVL_ENCAPLEN;
113		ifp->if_resolvemulti = 0;
114	}
115}
116PSEUDO_SET(vlaninit, if_vlan);
117
118static void
119vlan_ifinit(void *foo)
120{
121	;
122}
123
124static void
125vlan_start(struct ifnet *ifp)
126{
127	struct ifvlan *ifv;
128	struct ifnet *p;
129	struct ether_vlan_header *evl;
130	struct mbuf *m;
131
132	ifv = ifp->if_softc;
133	p = ifv->ifv_p;
134
135	ifp->if_flags |= IFF_OACTIVE;
136	for (;;) {
137		IF_DEQUEUE(&ifp->if_snd, m);
138		if (m == 0)
139			break;
140#if NBPFILTER > 0
141		if (ifp->if_bpf)
142			bpf_mtap(ifp, m);
143#endif /* NBPFILTER > 0 */
144
145		M_PREPEND(m, EVL_ENCAPLEN, M_DONTWAIT);
146		if (m == 0)
147			continue;
148		/* M_PREPEND takes care of m_len, m_pkthdr.len for us */
149
150		/*
151		 * Transform the Ethernet header into an Ethernet header
152		 * with 802.1Q encapsulation.
153		 */
154		bcopy(mtod(m, char *) + EVL_ENCAPLEN, mtod(m, char *),
155		      sizeof(struct ether_header));
156		evl = mtod(m, struct ether_vlan_header *);
157		evl->evl_proto = evl->evl_encap_proto;
158		evl->evl_encap_proto = htons(vlan_proto);
159		evl->evl_tag = htons(ifv->ifv_tag);
160		printf("vlan_start: %*D\n", sizeof *evl, (char *)evl, ":");
161
162		/*
163		 * Send it, precisely as ether_output() would have.
164		 * We are already running at splimp.
165		 */
166		if (IF_QFULL(&p->if_snd)) {
167			IF_DROP(&p->if_snd);
168				/* XXX stats */
169		}
170		IF_ENQUEUE(&p->if_snd, m);
171		if ((p->if_flags & IFF_OACTIVE) == 0)
172			p->if_start(p);
173	}
174	ifp->if_flags &= ~IFF_OACTIVE;
175}
176
177int
178vlan_input(struct ether_header *eh, struct mbuf *m)
179{
180	int i;
181	struct ifvlan *ifv;
182
183	for (i = 0; i < NVLAN; i++) {
184		ifv = &ifv_softc[i];
185		if (m->m_pkthdr.rcvif == ifv->ifv_p
186		    && (EVL_VLANOFTAG(ntohs(*mtod(m, u_int16_t *)))
187			== ifv->ifv_tag))
188			break;
189	}
190
191	if (i >= NVLAN || (ifv->ifv_if.if_flags & IFF_UP) == 0) {
192		m_freem(m);
193		return -1;	/* so ether_input can take note */
194	}
195
196	/*
197	 * Having found a valid vlan interface corresponding to
198	 * the given source interface and vlan tag, remove the
199	 * encapsulation, and run the real packet through
200	 * ether_input() a second time (it had better be
201	 * reentrant!).
202	 */
203	m->m_pkthdr.rcvif = &ifv->ifv_if;
204	eh->ether_type = mtod(m, u_int16_t *)[1];
205	m->m_data += EVL_ENCAPLEN;
206	m->m_len -= EVL_ENCAPLEN;
207	m->m_pkthdr.len -= EVL_ENCAPLEN;
208
209#if NBPFILTER > 0
210	if (ifv->ifv_if.if_bpf) {
211		/*
212		 * Do the usual BPF fakery.  Note that we don't support
213		 * promiscuous mode here, since it would require the
214		 * drivers to know about VLANs and we're not ready for
215		 * that yet.
216		 */
217		struct mbuf m0;
218		m0.m_next = m;
219		m0.m_len = sizeof(struct ether_header);
220		m0.m_data = (char *)eh;
221		bpf_mtap(&ifv->ifv_if, &m0);
222	}
223#endif
224	ether_input(&ifv->ifv_if, eh, m);
225	return 0;
226}
227
228static int
229vlan_config(struct ifvlan *ifv, struct ifnet *p)
230{
231	struct ifaddr *ifa1, *ifa2;
232	struct sockaddr_dl *sdl1, *sdl2;
233
234	if (p->if_data.ifi_type != IFT_ETHER)
235		return EPROTONOSUPPORT;
236	if (ifv->ifv_p)
237		return EBUSY;
238	ifv->ifv_p = p;
239	if (p->if_data.ifi_hdrlen == sizeof(struct ether_vlan_header))
240		ifv->ifv_if.if_mtu = p->if_mtu;
241	else
242		ifv->ifv_if.if_mtu = p->if_data.ifi_mtu - EVL_ENCAPLEN;
243
244	/*
245	 * NB: we don't support multicast at this point.
246	 */
247	ifv->ifv_if.if_flags = (p->if_flags & ~IFF_MULTICAST); /* XXX */
248
249	/*
250	 * Set up our ``Ethernet address'' to reflect the underlying
251	 * physical interface's.
252	 */
253	ifa1 = ifnet_addrs[ifv->ifv_if.if_index - 1];
254	ifa2 = ifnet_addrs[p->if_index - 1];
255	sdl1 = (struct sockaddr_dl *)ifa1->ifa_addr;
256	sdl2 = (struct sockaddr_dl *)ifa2->ifa_addr;
257	sdl1->sdl_type = IFT_ETHER;
258	sdl1->sdl_alen = ETHER_ADDR_LEN;
259	bcopy(LLADDR(sdl2), LLADDR(sdl1), ETHER_ADDR_LEN);
260	bcopy(LLADDR(sdl2), ifv->ifv_ac.ac_enaddr, ETHER_ADDR_LEN);
261	return 0;
262}
263
264static int
265vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
266{
267	struct ifaddr *ifa;
268	struct ifnet *p;
269	struct ifreq *ifr;
270	struct ifvlan *ifv;
271	struct vlanreq vlr;
272	int error = 0;
273
274	ifr = (struct ifreq *)data;
275	ifa = (struct ifaddr *)data;
276	ifv = ifp->if_softc;
277
278	switch (cmd) {
279	case SIOCSIFADDR:
280		ifp->if_flags |= IFF_UP;
281
282		switch (ifa->ifa_addr->sa_family) {
283#ifdef INET
284		case AF_INET:
285			arp_ifinit(&ifv->ifv_ac, ifa);
286			break;
287#endif
288		default:
289			break;
290		}
291		break;
292
293	case SIOCGIFADDR:
294		{
295			struct sockaddr *sa;
296
297			sa = (struct sockaddr *) &ifr->ifr_data;
298			bcopy(((struct arpcom *)ifp->if_softc)->ac_enaddr,
299			      (caddr_t) sa->sa_data, ETHER_ADDR_LEN);
300		}
301		break;
302
303	case SIOCSIFMTU:
304		/*
305		 * Set the interface MTU.
306		 */
307		if (ifr->ifr_mtu > ETHERMTU) {
308			error = EINVAL;
309		} else {
310			ifp->if_mtu = ifr->ifr_mtu;
311		}
312		break;
313
314	case SIOCSETVLAN:
315		error = copyin(ifr->ifr_data, &vlr, sizeof vlr);
316		if (error)
317			break;
318		if (vlr.vlr_parent[0] == '\0') {
319			ifv->ifv_p = 0;
320			if_down(ifp);
321			break;
322		}
323		p = ifunit(vlr.vlr_parent);
324		if (p == 0) {
325			error = ENOENT;
326			break;
327		}
328		error = vlan_config(ifv, p);
329		if (error)
330			break;
331		ifv->ifv_tag = vlr.vlr_tag;
332		break;
333
334	case SIOCGETVLAN:
335		bzero(&vlr, sizeof vlr);
336		if (ifv->ifv_p) {
337			snprintf(vlr.vlr_parent, sizeof(vlr.vlr_parent),
338			    "%s%d", ifv->ifv_p->if_name, ifv->ifv_p->if_unit);
339			vlr.vlr_tag = ifv->ifv_tag;
340		}
341		error = copyout(&vlr, ifr->ifr_data, sizeof vlr);
342		break;
343
344	case SIOCSIFFLAGS:
345		/*
346		 * We don't support all-multicast or promiscuous modes
347		 * right now because it would require help from the
348		 * underlying drivers, which hasn't been implemented.
349		 */
350		if (ifr->ifr_flags & (IFF_PROMISC|IFF_ALLMULTI)) {
351			ifp->if_flags &= ~(IFF_PROMISC|IFF_ALLMULTI);
352			error = EINVAL;
353		}
354		break;
355
356		/* NB: this will reject multicast state changes */
357	default:
358		error = EINVAL;
359	}
360	return error;
361}
362
363#endif /* NVLAN > 0 */
364