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 */ 31 32 #include <sys/param.h> 33 #include <sys/mbuf.h> 34 #include <sys/serialize.h> 35 36 #include <net/bpf.h> 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/netmsg.h> 42 43 #include <net/vlan/if_vlan_var.h> 44 #include <net/vlan/if_vlan_ether.h> 45 46 void 47 vlan_start_dispatch(netmsg_t msg) 48 { 49 struct netmsg_packet *nmp = &msg->packet; 50 struct mbuf *m; 51 struct ifnet *ifp; 52 struct altq_pktattr pktattr; 53 54 m = nmp->nm_packet; 55 ifp = msg->lmsg.u.ms_resultp; 56 57 M_ASSERTPKTHDR(m); 58 KASSERT(m->m_flags & M_VLANTAG, ("mbuf has not been vlan tagged!")); 59 60 /* 61 * If ALTQ is enabled on the parent interface, do 62 * classification; the queueing discipline might 63 * not require classification, but might require 64 * the address family/header pointer in the pktattr. 65 */ 66 if (ifq_is_enabled(&ifp->if_snd)) 67 altq_etherclassify(&ifp->if_snd, m, &pktattr); 68 69 /* 70 * If underlying interface can do VLAN tag insertion itself, 71 * just pass the packet along. 72 */ 73 if ((ifp->if_capenable & IFCAP_VLAN_HWTAGGING) == 0) { 74 uint16_t vlantag = m->m_pkthdr.ether_vlantag; 75 struct ether_vlan_header *evl; 76 77 M_PREPEND(m, EVL_ENCAPLEN, MB_DONTWAIT); 78 if (m == NULL) { 79 if_printf(ifp, "vlan%u M_PREPEND failed", vlantag); 80 return; 81 } 82 /* M_PREPEND takes care of m_len, m_pkthdr.len for us */ 83 84 m = m_pullup(m, ETHER_HDR_LEN + EVL_ENCAPLEN); 85 if (m == NULL) { 86 if_printf(ifp, "vlan%u m_pullup failed", vlantag); 87 return; 88 } 89 m->m_pkthdr.csum_lhlen = sizeof(struct ether_vlan_header); 90 91 /* 92 * Transform the Ethernet header into an Ethernet header 93 * with 802.1Q encapsulation. 94 */ 95 bcopy(mtod(m, char *) + EVL_ENCAPLEN, mtod(m, char *), 96 sizeof(struct ether_header)); 97 evl = mtod(m, struct ether_vlan_header *); 98 evl->evl_proto = evl->evl_encap_proto; 99 evl->evl_encap_proto = htons(ETHERTYPE_VLAN); 100 evl->evl_tag = htons(vlantag); 101 #ifdef DEBUG 102 kprintf("vlan_start: %*D\n", (int)sizeof *evl, 103 (unsigned char *)evl, ":"); 104 #endif 105 /* Hardware does not need to setup vlan tagging */ 106 m->m_flags &= ~M_VLANTAG; 107 } 108 ifq_dispatch(ifp, m, &pktattr); 109 } 110 111 void 112 vlan_ether_ptap(struct bpf_if *bp, struct mbuf *m, uint16_t vlantag) 113 { 114 const struct ether_header *eh; 115 struct ether_vlan_header evh; 116 117 KASSERT(m->m_len >= ETHER_HDR_LEN, 118 ("ether header is not contiguous!")); 119 120 eh = mtod(m, const struct ether_header *); 121 m_adj(m, ETHER_HDR_LEN); 122 123 bcopy(eh, &evh, 2 * ETHER_ADDR_LEN); 124 evh.evl_encap_proto = htons(ETHERTYPE_VLAN); 125 evh.evl_tag = htons(vlantag); 126 evh.evl_proto = eh->ether_type; 127 bpf_ptap(bp, m, &evh, ETHER_HDR_LEN + EVL_ENCAPLEN); 128 129 /* XXX assumes data was left intact */ 130 M_PREPEND(m, ETHER_HDR_LEN, MB_WAIT); 131 } 132 133 void 134 vlan_ether_decap(struct mbuf **m0) 135 { 136 struct mbuf *m = *m0; 137 struct ether_vlan_header *evh; 138 139 KKASSERT((m->m_flags & M_VLANTAG) == 0); 140 141 if (m->m_len < sizeof(*evh)) { 142 /* Error in the caller */ 143 m_freem(m); 144 *m0 = NULL; 145 return; 146 } 147 evh = mtod(m, struct ether_vlan_header *); 148 149 m->m_pkthdr.ether_vlantag = ntohs(evh->evl_tag); 150 m->m_flags |= M_VLANTAG; 151 152 bcopy((uint8_t *)evh, (uint8_t *)evh + EVL_ENCAPLEN, 153 2 * ETHER_ADDR_LEN); 154 m_adj(m, EVL_ENCAPLEN); 155 *m0 = m; 156 } 157