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
50static const void *agr_m_extract(struct mbuf *, int, int, void *);
51
52static const void *
53agr_m_extract(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
71uint32_t
72agrether_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