path: root/sys/net/if_vlan.c

/*	$OpenBSD: if_vlan.c,v 1.2 2000/04/26 22:57:27 chris Exp $ */
/*
 * Copyright 1998 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby
 * granted, provided that both the above copyright notice and this
 * permission notice appear in all copies, that both the above
 * copyright notice and this permission notice appear in all
 * supporting documentation, and that the name of M.I.T. not be used
 * in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.  M.I.T. makes
 * no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 * 
 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: src/sys/net/if_vlan.c,v 1.16 2000/03/26 15:21:40 charnier Exp $
 */

/*
 * if_vlan.c - pseudo-device driver for IEEE 802.1Q virtual LANs.
 * Might be extended some day to also handle IEEE 802.1p priority
 * tagging.  This is sort of sneaky in the implementation, since
 * we need to pretend to be enough of an Ethernet implementation
 * to make arp work.  The way we do this is by telling everyone
 * that we are an Ethernet, and then catch the packets that
 * ether_output() left on our output queue when it calls
 * if_start(), rewrite them for use by the real outgoing interface,
 * and ask it to send them.
 *
 *
 * XXX It's incorrect to assume that we must always kludge up
 * headers on the physical device's behalf: some devices support
 * VLAN tag insersion and extraction in firmware. For these cases,
 * one can change the behavior of the vlan interface by setting
 * the LINK0 flag on it (that is setting the vlan interface's LINK0
 * flag, _not_ the parent's LINK0 flag; we try to leave the parent
 * alone). If the interface as the LINK0 flag set, then it will
 * not modify the ethernet header on output because the parent
 * can do that for itself. On input, the parent can call vlan_input_tag()
 * directly in order to supply us with an incoming mbuf and the vlan
 * tag value that goes with it.
 */

#include "vlan.h"
#if NVLAN > 0

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/proc.h>

#include "bpfilter.h"
#if NBPFILTER > 0
#include <net/bpf.h>
#endif

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>

#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif

#include <net/if_vlan_var.h>

struct	ifaddr	**ifnet_addrs;

u_int	vlan_proto = ETHERTYPE_8021Q;

struct ifvlan ifv_softc[NVLAN];

extern int ifqmaxlen;

void	vlan_start (struct ifnet *ifp);
int	vlan_ioctl (struct ifnet *ifp, u_long cmd, caddr_t addr);
int	vlan_setmulti (struct ifnet *ifp);
int	vlan_unconfig (struct ifnet *ifp);
int	vlan_config (struct ifvlan *ifv, struct ifnet *p);
void	vlanattach (void *dummy);

/*
 * Program our multicast filter. What we're actually doing is
 * programming the multicast filter of the parent. This has the
 * side effect of causing the parent interface to receive multicast
 * traffic that it doesn't really want, which ends up being discarded
 * later by the upper protocol layers. Unfortunately, there's no way
 * to avoid this: there really is only one physical interface.
 */

int vlan_setmulti(struct ifnet *ifp)
{
	struct ifreq		*ifr_p;
	struct ether_multi	*enm;
	struct ether_multistep	step;
	struct ifvlan		*sc;
	struct vlan_mc_entry	*mc = NULL;
	int			error;

	/* Find the parent. */
	sc = ifp->if_softc;
	ifr_p = (struct ifreq *)&sc->ifv_p->if_data;

	/* First, remove any existing filter entries. */
	while(sc->vlan_mc_listhead.slh_first != NULL) {
		mc = sc->vlan_mc_listhead.slh_first;
		error = ether_delmulti(ifr_p, &sc->ifv_ac);
		if (error)
			return(error);
		SLIST_REMOVE_HEAD(&sc->vlan_mc_listhead, mc_entries);
		free(mc, M_DEVBUF);
	}

	/* Now program new ones. */
	ETHER_FIRST_MULTI(step, &sc->ifv_ac, enm);
	while (enm != NULL) {
		mc = malloc(sizeof(struct vlan_mc_entry), M_DEVBUF, M_NOWAIT);
		bcopy(enm->enm_addrlo,
		      (void *) &mc->mc_addr, ETHER_ADDR_LEN);
		SLIST_INSERT_HEAD(&sc->vlan_mc_listhead, mc, mc_entries);
		error = ether_addmulti(ifr_p, &sc->ifv_ac);
		if (error)
			return(error);
		ETHER_NEXT_MULTI(step, enm);
	}

	return(0);
}

void
vlanattach(void *dummy)
{
	struct ifnet *ifp;
	int i;

	bzero(ifv_softc, sizeof(ifv_softc));

	for (i = 0; i < NVLAN; i++) {
		ifp = &ifv_softc[i].ifv_if;
		ifp->if_softc = &ifv_softc[i];
		sprintf(ifp->if_xname, "vlan%d", i);
		/* NB: flags are not set here */
		/* NB: mtu is not set here */

		ifp->if_start = vlan_start;
		ifp->if_ioctl = vlan_ioctl;
		ifp->if_output = ether_output;
		ifp->if_snd.ifq_maxlen = ifqmaxlen;
		if_attach(ifp);
		ether_ifattach(ifp);
#if NBPFILTER > 0
		bpfattach(&ifp->if_bpf, ifp, DLT_EN10MB, sizeof(struct ether_header));
#endif
		/* Now undo some of the damage... */
		ifp->if_data.ifi_type = IFT_8021_VLAN;
		ifp->if_data.ifi_hdrlen = EVL_ENCAPLEN;
	}
}

void
vlan_start(struct ifnet *ifp)
{
	struct ifvlan *ifv;
	struct ifnet *p;
	struct ether_vlan_header *evl;
	struct mbuf *m;

	ifv = ifp->if_softc;
	p = ifv->ifv_p;

	ifp->if_flags |= IFF_OACTIVE;
	for (;;) {
		IF_DEQUEUE(&ifp->if_snd, m);
		if (m == 0)
			break;
#if NBPFILTER > 0
		if (ifp->if_bpf)
			bpf_mtap(ifp->if_bpf, m);
#endif

		/*
		 * If the LINK0 flag is set, it means the underlying interface
		 * can do VLAN tag insertion itself and doesn't require us to
	 	 * create a special header for it. In this case, we just pass
		 * the packet along. However, we need some way to tell the
		 * interface where the packet came from so that it knows how
		 * to find the VLAN tag to use, so we set the rcvif in the
		 * mbuf header to our ifnet.
		 *
		 * Note: we also set the M_PROTO1 flag in the mbuf to let
		 * the parent driver know that the rcvif pointer is really
		 * valid. We need to do this because sometimes mbufs will
		 * be allocated by other parts of the system that contain
		 * garbage in the rcvif pointer. Using the M_PROTO1 flag
		 * lets the driver perform a proper sanity check and avoid
		 * following potentially bogus rcvif pointers off into
		 * never-never land.
		 */
		if (ifp->if_flags & IFF_LINK0) {
			m->m_pkthdr.rcvif = ifp;
			m->m_flags |= M_PROTO1;
		} else {
			M_PREPEND(m, EVL_ENCAPLEN, M_DONTWAIT);
			if (m == NULL) {
				printf("%s: M_PREPEND failed", ifv->ifv_p->if_xname);
				ifp->if_ierrors++;
				continue;
			}
			/* M_PREPEND takes care of m_len, m_pkthdr.len for us */

			m = m_pullup(m, ETHER_HDR_LEN + EVL_ENCAPLEN);
			if (m == NULL) {
				printf("%s: m_pullup failed", ifv->ifv_p->if_xname);
				ifp->if_ierrors++;
				continue;
			}

			/*
			 * Transform the Ethernet header into an Ethernet header
			 * with 802.1Q encapsulation.
			 */
			bcopy(mtod(m, char *) + EVL_ENCAPLEN, mtod(m, char *),
			      sizeof(struct ether_header));
			evl = mtod(m, struct ether_vlan_header *);
			evl->evl_proto = evl->evl_encap_proto;
			evl->evl_encap_proto = htons(vlan_proto);
			evl->evl_tag = htons(ifv->ifv_tag);
#ifdef DEBUG
			printf("vlan_start: %*D\n", sizeof *evl,
			    (char *)evl, ":");
#endif
		}

		/*
		 * Send it, precisely as ether_output() would have.
		 * We are already running at splimp.
		 */
		if (IF_QFULL(&p->if_snd)) {
			IF_DROP(&p->if_snd);
				/* XXX stats */
			ifp->if_oerrors++;
			m_freem(m);
			continue;
		}
		IF_ENQUEUE(&p->if_snd, m);
		if ((p->if_flags & IFF_OACTIVE) == 0) {
			p->if_start(p);
			ifp->if_opackets++;
		}
	}
	ifp->if_flags &= ~IFF_OACTIVE;

	return;
}

int
vlan_input_tag(struct ether_header *eh, struct mbuf *m, u_int16_t t)
{
	int i;
	struct ifvlan *ifv;

	for (i = 0; i < NVLAN; i++) {
		ifv = &ifv_softc[i];
		if (ifv->ifv_tag == t)
			break;
	}

	if (i >= NVLAN || (ifv->ifv_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
	    (IFF_UP|IFF_RUNNING)) {
		m_free(m);
		return -1;	/* so the parent can take note */
	}

	/*
	 * Having found a valid vlan interface corresponding to
	 * the given source interface and vlan tag, run the
	 * the real packet through ethert_input().
	 */
	m->m_pkthdr.rcvif = &ifv->ifv_if;

#if NBPFILTER > 0
	if (ifv->ifv_if.if_bpf) {
		/*
		 * Do the usual BPF fakery.  Note that we don't support
		 * promiscuous mode here, since it would require the
		 * drivers to know about VLANs and we're not ready for
		 * that yet.
		 */
		struct mbuf m0;
		m0.m_next = m;
		m0.m_len = sizeof(struct ether_header);
		m0.m_data = (char *)eh;
		bpf_mtap(ifv->ifv_if.if_bpf, &m0);
	}
#endif
	ifv->ifv_if.if_ipackets++;
	ether_input(&ifv->ifv_if, eh, m);
	return 0;
}

int
vlan_input(eh, m)
	struct ether_header *eh;
	struct mbuf *m;
{
	int i;
	struct ifvlan *ifv;

	for (i = 0; i < NVLAN; i++) {
		ifv = &ifv_softc[i];
		if (m->m_pkthdr.rcvif == ifv->ifv_p
		    && (EVL_VLANOFTAG(ntohs(*mtod(m, u_int16_t *)))
			== ifv->ifv_tag))
			break;
	}

	if (i >= NVLAN || (ifv->ifv_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
	    (IFF_UP|IFF_RUNNING)) {
		m_freem(m);
		return -1;	/* so ether_input can take note */
	}

	/*
	 * Having found a valid vlan interface corresponding to
	 * the given source interface and vlan tag, remove the
	 * encapsulation, and run the real packet through
	 * ether_input() a second time (it had better be
	 * reentrant!).
	 */
	m->m_pkthdr.rcvif = &ifv->ifv_if;
	eh->ether_type = mtod(m, u_int16_t *)[1];
	m->m_data += EVL_ENCAPLEN;
	m->m_len -= EVL_ENCAPLEN;
	m->m_pkthdr.len -= EVL_ENCAPLEN;

#if NBPFILTER > 0
	if (ifv->ifv_if.if_bpf) {
		/*
		 * Do the usual BPF fakery.  Note that we don't support
		 * promiscuous mode here, since it would require the
		 * drivers to know about VLANs and we're not ready for
		 * that yet.
		 */
		struct mbuf m0;
		m0.m_next = m;
		m0.m_len = sizeof(struct ether_header);
		m0.m_data = (char *)eh;
		bpf_mtap(ifv->ifv_if.if_bpf, &m0);
	}
#endif
	ifv->ifv_if.if_ipackets++;
	ether_input(&ifv->ifv_if, eh, m);

	return 0;
}

int
vlan_config(struct ifvlan *ifv, struct ifnet *p)
{
	struct ifaddr *ifa1, *ifa2;
	struct sockaddr_dl *sdl1, *sdl2;

	if (p->if_data.ifi_type != IFT_ETHER)
		return EPROTONOSUPPORT;
	if (ifv->ifv_p)
		return EBUSY;
	ifv->ifv_p = p;
	ifv->ifv_if.if_mtu = p->if_data.ifi_mtu;

	/*
	 * Preserve the state of the LINK0 flag for ourselves.
	 */
	ifv->ifv_if.if_flags = (p->if_flags & ~(IFF_LINK0));

	/*
	 * Set up our ``Ethernet address'' to reflect the underlying
	 * physical interface's.
	 */
	ifa1 = ifnet_addrs[ifv->ifv_if.if_index];
	ifa2 = ifnet_addrs[p->if_index];
	sdl1 = (struct sockaddr_dl *)ifa1->ifa_addr;
	sdl2 = (struct sockaddr_dl *)ifa2->ifa_addr;
	sdl1->sdl_type = IFT_ETHER;
	sdl1->sdl_alen = ETHER_ADDR_LEN;
	bcopy(LLADDR(sdl2), LLADDR(sdl1), ETHER_ADDR_LEN);
	bcopy(LLADDR(sdl2), ifv->ifv_ac.ac_enaddr, ETHER_ADDR_LEN);
	return 0;
}

int
vlan_unconfig(struct ifnet *ifp)
{
	struct ifaddr *ifa;
	struct sockaddr_dl *sdl;
	struct ifvlan *ifv;
	struct ifnet *p;
	struct ifreq *ifr, *ifr_p;
	struct vlan_mc_entry *mc;
	int error;

	ifv = ifp->if_softc;
	p = ifv->ifv_p;
	ifr = (struct ifreq *)&ifp->if_data;
	ifr_p = (struct ifreq *)&ifv->ifv_p->if_data;

	/*
 	 * Since the interface is being unconfigured, we need to
	 * empty the list of multicast groups that we may have joined
	 * while we were alive and remove them from the parent's list
	 * as well.
	 */
	while(ifv->vlan_mc_listhead.slh_first != NULL) {

		mc = ifv->vlan_mc_listhead.slh_first;
		error = ether_delmulti(ifr_p, &ifv->ifv_ac);
		error = ether_delmulti(ifr, &ifv->ifv_ac);
		if (error)
			return(error);
		SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries);
		free(mc, M_DEVBUF);
	}

	/* Disconnect from parent. */
	ifv->ifv_p = NULL;
	ifv->ifv_if.if_mtu = ETHERMTU;

	/* Clear our MAC address. */
	ifa = ifnet_addrs[ifv->ifv_if.if_index];
	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
	sdl->sdl_type = IFT_ETHER;
	sdl->sdl_alen = ETHER_ADDR_LEN;
	bzero(LLADDR(sdl), ETHER_ADDR_LEN);
	bzero(ifv->ifv_ac.ac_enaddr, ETHER_ADDR_LEN);

	return 0;
}

int
vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
	struct proc *p = curproc;	/* XXX */
	struct ifaddr *ifa;
	struct ifnet *pr;
	struct ifreq *ifr;
	struct ifvlan *ifv;
	struct vlanreq vlr;
	int error = 0;

	ifr = (struct ifreq *)data;
	ifa = (struct ifaddr *)data;
	ifv = ifp->if_softc;

	switch (cmd) {
	case SIOCSIFADDR:
		ifp->if_flags |= IFF_UP;

		switch (ifa->ifa_addr->sa_family) {
#ifdef INET
		case AF_INET:
			arp_ifinit(&ifv->ifv_ac, ifa);
			break;
#endif
		default:
			break;
		}
		break;

	case SIOCGIFADDR:
		{
			struct sockaddr *sa;

			sa = (struct sockaddr *) &ifr->ifr_data;
			bcopy(((struct arpcom *)ifp->if_softc)->ac_enaddr,
			      (caddr_t) sa->sa_data, ETHER_ADDR_LEN);
		}
		break;

	case SIOCSIFMTU:
		/*
		 * XXX Set the interface MTU.
		 * This is bogus. The underlying interface might support
	 	 * jumbo frames.  It would be nice to replace ETHERMTU
		 * with the parent interface's MTU in the following statement.
		 */
		if (ifr->ifr_mtu > ETHERMTU) {
			error = EINVAL;
		} else {
			ifp->if_mtu = ifr->ifr_mtu;
		}
		break;

	case SIOCSETVLAN:
		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
			break;
		if ((error = copyin(ifr->ifr_data, &vlr, sizeof vlr)))
			break;
		if (vlr.vlr_parent[0] == '\0') {
			vlan_unconfig(ifp);
			if_down(ifp);
			ifp->if_flags &= ~(IFF_UP|IFF_RUNNING);
			break;
		}
		pr = ifunit(vlr.vlr_parent);
		if (pr == 0) {
			error = ENOENT;
			break;
		}
		error = vlan_config(ifv, pr);
		if (error)
			break;
		ifv->ifv_tag = vlr.vlr_tag;
		ifp->if_flags |= IFF_RUNNING;
		break;
		
	case SIOCGETVLAN:
		bzero(&vlr, sizeof vlr);
		if (ifv->ifv_p) {
			snprintf(vlr.vlr_parent, sizeof(vlr.vlr_parent),
			    "%s", ifv->ifv_p->if_xname);
			vlr.vlr_tag = ifv->ifv_tag;
		}
		error = copyout(&vlr, ifr->ifr_data, sizeof vlr);
		break;
		
	case SIOCSIFFLAGS:
		/*
		 * We don't support promiscuous mode
		 * right now because it would require help from the
		 * underlying drivers, which hasn't been implemented.
		 */
		if (ifr->ifr_flags & (IFF_PROMISC)) {
			ifp->if_flags &= ~(IFF_PROMISC);
			error = EINVAL;
		}
		break;
	case SIOCADDMULTI:
	case SIOCDELMULTI:
		error = vlan_setmulti(ifp);
		break;
	default:
		error = EINVAL;
	}
	return error;
}

#endif /* NVLAN > 0 */