/*
 * 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 1.15.2.13 2003/02/14 22:25:58 fenner Exp $
 */

#include <sys/param.h>
#include <sys/malloc.h> /* for M_NOWAIT */
#include <sys/mbuf.h>
#include <sys/serialize.h>

#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/ifq_var.h>
#include <net/netmsg.h>

#include <net/vlan/if_vlan_var.h>
#include <net/vlan/if_vlan_ether.h>

void
vlan_start_dispatch(netmsg_t msg)
{
        struct netmsg_packet *nmp = &msg->packet;
        struct mbuf *m;
        struct ifnet *ifp;
        struct altq_pktattr pktattr;
#ifdef DEBUG
        char hexstr[HEX_NCPYLEN(sizeof(struct ether_vlan_header))];
#endif
        m = nmp->nm_packet;
        ifp = msg->lmsg.u.ms_resultp;

        M_ASSERTPKTHDR(m);
        KASSERT(m->m_flags & M_VLANTAG, ("mbuf has not been vlan tagged!"));

        /*
         * If ALTQ is enabled on the parent interface, do
         * classification; the queueing discipline might
         * not require classification, but might require
         * the address family/header pointer in the pktattr.
         */
        if (ifq_is_enabled(&ifp->if_snd))
                altq_etherclassify(&ifp->if_snd, m, &pktattr);

        /*
         * If underlying interface can do VLAN tag insertion itself,
         * just pass the packet along.
         */
        if ((ifp->if_capenable & IFCAP_VLAN_HWTAGGING) == 0) {
                uint16_t vlantag = m->m_pkthdr.ether_vlantag;
                struct ether_vlan_header *evl;

                M_PREPEND(m, EVL_ENCAPLEN, M_NOWAIT);
                if (m == NULL) {
                        if_printf(ifp, "vlan%u M_PREPEND failed", vlantag);
                        return;
                }
                /* M_PREPEND takes care of m_len, m_pkthdr.len for us */

                m = m_pullup(m, ETHER_HDR_LEN + EVL_ENCAPLEN);
                if (m == NULL) {
                        if_printf(ifp, "vlan%u m_pullup failed", vlantag);
                        return;
                }
                m->m_pkthdr.csum_lhlen = sizeof(struct ether_vlan_header);

                /*
                 * 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(ETHERTYPE_VLAN);
                evl->evl_tag = htons(vlantag);
#ifdef DEBUG
                kprintf("vlan_start: %s\n", hexncpy((u_char *)evl, sizeof(*evl),
                        hexstr, HEX_NCPYLEN(sizeof(*evl)), ":"));
#endif
                /* Hardware does not need to setup vlan tagging */
                m->m_flags &= ~M_VLANTAG;
        }
        ifq_dispatch(ifp, m, &pktattr);
}

void
vlan_ether_ptap(struct bpf_if *bp, struct mbuf *m, uint16_t vlantag)
{
        const struct ether_header *eh;
        struct ether_vlan_header evh;

        KASSERT(m->m_len >= ETHER_HDR_LEN,
                ("ether header is not contiguous!"));

        eh = mtod(m, const struct ether_header *);
        m_adj(m, ETHER_HDR_LEN);

        bcopy(eh, &evh, 2 * ETHER_ADDR_LEN);
        evh.evl_encap_proto = htons(ETHERTYPE_VLAN);
        evh.evl_tag = htons(vlantag);
        evh.evl_proto = eh->ether_type;
        bpf_ptap(bp, m, &evh, ETHER_HDR_LEN + EVL_ENCAPLEN);

        /* XXX assumes data was left intact */
        M_PREPEND(m, ETHER_HDR_LEN, M_WAITOK);
}

void
vlan_ether_decap(struct mbuf **m0)
{
        struct mbuf *m = *m0;
        struct ether_vlan_header *evh;

        KKASSERT((m->m_flags & M_VLANTAG) == 0);

        if (m->m_len < sizeof(*evh)) {
                /* Error in the caller */
                m_freem(m);
                *m0 = NULL;
                return;
        }
        evh = mtod(m, struct ether_vlan_header *);

        m->m_pkthdr.ether_vlantag = ntohs(evh->evl_tag);
        m->m_flags |= M_VLANTAG;

        bcopy((uint8_t *)evh, (uint8_t *)evh + EVL_ENCAPLEN,
              2 * ETHER_ADDR_LEN);
        m_adj(m, EVL_ENCAPLEN);
        *m0 = m;
}