sys/net/vlan/if_vlan_ether.c

   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  * $FreeBSD: src/sys/net/if_vlan.c,v 1.15.2.13 2003/02/14 22:25:58 fenner Exp $
  30  * $DragonFly: src/sys/net/vlan/if_vlan_ether.c,v 1.1 2008/03/10 10:47:57 sephe Exp $
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/mbuf.h>
  35 #include <sys/serialize.h>
  36
  37 #include <net/ethernet.h>
  38 #include <net/if.h>
  39 #include <net/if_arp.h>
  40 #include <net/ifq_var.h>
  41 #include <net/vlan/if_vlan_var.h>
  42 #include <net/netmsg.h>
  43
  44 void    vlan_start_dispatch(struct netmsg *);
  45
  46 void
  47 vlan_start_dispatch(struct netmsg *nmsg)
  48 {
  49         struct netmsg_packet *nmp = (struct netmsg_packet *)nmsg;
  50         struct mbuf *m;
  51         struct ifnet *ifp;
  52         struct altq_pktattr pktattr;
  53
  54         m = nmp->nm_packet;
  55         ifp = nmsg->nm_lmsg.u.ms_resultp;
  56
  57         M_ASSERTPKTHDR(m);
  58         KASSERT(m->m_flags & M_VLANTAG, ("mbuf has not been vlan tagged!\n"));
  59
  60         lwkt_serialize_enter(ifp->if_serializer);
  61
  62         /*
  63          * Make sure that the interface is still UP and RUNNING,
  64          * since interface state may have been changed when the
  65          * mbuf is pending on the msgport.
  66          */
  67         if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) !=
  68             (IFF_UP | IFF_RUNNING)) {
  69                 m_freem(m);
  70                 goto back;
  71         }
  72
  73         /*
  74          * If ALTQ is enabled on the parent interface, do
  75          * classification; the queueing discipline might
  76          * not require classification, but might require
  77          * the address family/header pointer in the pktattr.
  78          */
  79         if (ifq_is_enabled(&ifp->if_snd))
  80                 altq_etherclassify(&ifp->if_snd, m, &pktattr);
  81
  82         /*
  83          * If underlying interface can do VLAN tag insertion itself,
  84          * just pass the packet along.
  85          */
  86         if ((ifp->if_capenable & IFCAP_VLAN_HWTAGGING) == 0) {
  87                 uint16_t vlantag = m->m_pkthdr.ether_vlantag;
  88                 struct ether_vlan_header *evl;
  89
  90                 M_PREPEND(m, EVL_ENCAPLEN, MB_DONTWAIT);
  91                 if (m == NULL) {
  92                         if_printf(ifp, "vlan%u M_PREPEND failed", vlantag);
  93                         goto back;
  94                 }
  95                 /* M_PREPEND takes care of m_len, m_pkthdr.len for us */
  96
  97                 m = m_pullup(m, ETHER_HDR_LEN + EVL_ENCAPLEN);
  98                 if (m == NULL) {
  99                         if_printf(ifp, "vlan%u m_pullup failed", vlantag);
 100                         goto back;
 101                 }
 102
 103                 /*
 104                  * Transform the Ethernet header into an Ethernet header
 105                  * with 802.1Q encapsulation.
 106                  */
 107                 bcopy(mtod(m, char *) + EVL_ENCAPLEN, mtod(m, char *),
 108                       sizeof(struct ether_header));
 109                 evl = mtod(m, struct ether_vlan_header *);
 110                 evl->evl_proto = evl->evl_encap_proto;
 111                 evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
 112                 evl->evl_tag = htons(vlantag);
 113 #ifdef DEBUG
 114                 kprintf("vlan_start: %*D\n", sizeof *evl,
 115                         (unsigned char *)evl, ":");
 116 #endif
 117                 /* Hardware does not need to setup vlan tagging */
 118                 m->m_flags &= ~M_VLANTAG;
 119         }
 120         ifq_handoff(ifp, m, &pktattr);
 121 back:
 122         lwkt_serialize_exit(ifp->if_serializer);
 123 }