| 1 | /* $NetBSD: if_agrether_hash.c,v 1.3 2007/05/05 18:23:23 yamt Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c)2005 YAMAMOTO Takashi, |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 17 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 20 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 21 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 22 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 23 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 24 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 25 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 26 | * SUCH DAMAGE. |
| 27 | */ |
| 28 | |
| 29 | #include <sys/cdefs.h> |
| 30 | __KERNEL_RCSID(0, "$NetBSD: if_agrether_hash.c,v 1.3 2007/05/05 18:23:23 yamt Exp $" ); |
| 31 | |
| 32 | #include <sys/param.h> |
| 33 | #include <sys/mbuf.h> |
| 34 | #include <sys/hash.h> |
| 35 | |
| 36 | #include <net/if.h> |
| 37 | #include <net/if_dl.h> |
| 38 | #include <net/if_ether.h> |
| 39 | #include <net/if_vlanvar.h> |
| 40 | |
| 41 | #include <net/agr/if_agrethervar.h> |
| 42 | |
| 43 | #include <netinet/in.h> |
| 44 | #include <netinet/in_systm.h> |
| 45 | #include <netinet/ip.h> |
| 46 | #include <netinet/ip6.h> |
| 47 | |
| 48 | #define HASH(p, l, h) hash32_buf((p), (l), (h)) |
| 49 | |
| 50 | static const void *agr_m_extract(struct mbuf *, int, int, void *); |
| 51 | |
| 52 | static const void * |
| 53 | (struct mbuf *m, int off, int len, void *buf) |
| 54 | { |
| 55 | const void *result; |
| 56 | |
| 57 | KASSERT((m->m_flags & M_PKTHDR) != 0); |
| 58 | |
| 59 | if (m->m_pkthdr.len < off + len) { |
| 60 | result = NULL; |
| 61 | } else if (m->m_len >= off + len) { |
| 62 | result = mtod(m, char *) + off; |
| 63 | } else { |
| 64 | m_copydata(m, off, len, buf); |
| 65 | result = buf; |
| 66 | } |
| 67 | |
| 68 | return result; |
| 69 | } |
| 70 | |
| 71 | uint32_t |
| 72 | agrether_hashmbuf(struct agr_softc *sc, struct mbuf *m) |
| 73 | { |
| 74 | struct ether_header eh_store; |
| 75 | const struct ether_header *eh; |
| 76 | uint32_t hash = HASH32_BUF_INIT; |
| 77 | int off = 0; |
| 78 | uint16_t tci; |
| 79 | uint16_t etype; |
| 80 | struct m_tag *mtag; |
| 81 | |
| 82 | eh = agr_m_extract(m, off, sizeof(*eh), &eh_store); |
| 83 | if (eh == NULL) { |
| 84 | return hash; |
| 85 | } |
| 86 | |
| 87 | hash = HASH(&eh->ether_dhost, sizeof(eh->ether_dhost), hash); |
| 88 | hash = HASH(&eh->ether_shost, sizeof(eh->ether_shost), hash); |
| 89 | etype = eh->ether_type; |
| 90 | |
| 91 | if (etype == htobe16(ETHERTYPE_VLAN)) { |
| 92 | struct ether_vlan_header vlanhdr_store; |
| 93 | const struct ether_vlan_header *vlanhdr; |
| 94 | |
| 95 | vlanhdr = agr_m_extract(m, off, sizeof(*vlanhdr), |
| 96 | &vlanhdr_store); |
| 97 | if (vlanhdr == NULL) { |
| 98 | return hash; |
| 99 | } |
| 100 | |
| 101 | tci = vlanhdr->evl_tag; |
| 102 | etype = vlanhdr->evl_proto; |
| 103 | off += sizeof(*vlanhdr) - sizeof(*eh); |
| 104 | } else if ((mtag = m_tag_find(m, PACKET_TAG_VLAN, NULL)) != NULL) { |
| 105 | tci = htole16((*(u_int *)(mtag + 1)) & 0xffff); |
| 106 | } else { |
| 107 | tci = 0; |
| 108 | } |
| 109 | hash = HASH(&tci, sizeof(tci), hash); |
| 110 | |
| 111 | off += sizeof(*eh); |
| 112 | if (etype == htobe16(ETHERTYPE_IP)) { |
| 113 | struct ip ip_store; |
| 114 | const struct ip *ip; |
| 115 | |
| 116 | ip = agr_m_extract(m, off, sizeof(*ip), &ip_store); |
| 117 | if (ip == NULL) { |
| 118 | return hash; |
| 119 | } |
| 120 | |
| 121 | hash = HASH(&ip->ip_src, sizeof(ip->ip_src), hash); |
| 122 | hash = HASH(&ip->ip_dst, sizeof(ip->ip_dst), hash); |
| 123 | hash = HASH(&ip->ip_p, sizeof(ip->ip_p), hash); |
| 124 | |
| 125 | /* use port numbers for tcp and udp? */ |
| 126 | |
| 127 | } else if (etype == htobe16(ETHERTYPE_IPV6)) { |
| 128 | struct ip6_hdr ip6_store; |
| 129 | const struct ip6_hdr *ip6; |
| 130 | uint32_t flowlabel; |
| 131 | |
| 132 | ip6 = agr_m_extract(m, off, sizeof(*ip6), &ip6_store); |
| 133 | if (ip6 == NULL) { |
| 134 | return hash; |
| 135 | } |
| 136 | |
| 137 | hash = HASH(&ip6->ip6_src, sizeof(ip6->ip6_src), hash); |
| 138 | hash = HASH(&ip6->ip6_dst, sizeof(ip6->ip6_dst), hash); |
| 139 | /* hash = HASH(&ip6->ip6_nxt, sizeof(ip6->ip6_nxt), hash); */ |
| 140 | |
| 141 | flowlabel = ip6->ip6_flow & IPV6_FLOWLABEL_MASK; |
| 142 | hash = HASH(&flowlabel, sizeof(flowlabel), hash); |
| 143 | |
| 144 | /* use port numbers for tcp and udp? */ |
| 145 | } |
| 146 | |
| 147 | return hash; |
| 148 | } |
| 149 | |