1 /* $NetBSD: if_agrether_hash.c,v 1.4 2017/09/26 07:42:06 knakahara 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 1.4 2017/09/26 07:42:06 knakahara 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 *
agr_m_extract(struct mbuf * m,int off,int len,void * buf)53 agr_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
71 uint32_t
agrether_hashmbuf(struct agr_softc * sc,struct mbuf * m)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
81 eh = agr_m_extract(m, off, sizeof(*eh), &eh_store);
82 if (eh == NULL) {
83 return hash;
84 }
85
86 hash = HASH(&eh->ether_dhost, sizeof(eh->ether_dhost), hash);
87 hash = HASH(&eh->ether_shost, sizeof(eh->ether_shost), hash);
88 etype = eh->ether_type;
89
90 if (etype == htobe16(ETHERTYPE_VLAN)) {
91 struct ether_vlan_header vlanhdr_store;
92 const struct ether_vlan_header *vlanhdr;
93
94 vlanhdr = agr_m_extract(m, off, sizeof(*vlanhdr),
95 &vlanhdr_store);
96 if (vlanhdr == NULL) {
97 return hash;
98 }
99
100 tci = vlanhdr->evl_tag;
101 etype = vlanhdr->evl_proto;
102 off += sizeof(*vlanhdr) - sizeof(*eh);
103 } else if (vlan_has_tag(m)) {
104 tci = htole16(vlan_get_tag(m));
105 } else {
106 tci = 0;
107 }
108 hash = HASH(&tci, sizeof(tci), hash);
109
110 off += sizeof(*eh);
111 if (etype == htobe16(ETHERTYPE_IP)) {
112 struct ip ip_store;
113 const struct ip *ip;
114
115 ip = agr_m_extract(m, off, sizeof(*ip), &ip_store);
116 if (ip == NULL) {
117 return hash;
118 }
119
120 hash = HASH(&ip->ip_src, sizeof(ip->ip_src), hash);
121 hash = HASH(&ip->ip_dst, sizeof(ip->ip_dst), hash);
122 hash = HASH(&ip->ip_p, sizeof(ip->ip_p), hash);
123
124 /* use port numbers for tcp and udp? */
125
126 } else if (etype == htobe16(ETHERTYPE_IPV6)) {
127 struct ip6_hdr ip6_store;
128 const struct ip6_hdr *ip6;
129 uint32_t flowlabel;
130
131 ip6 = agr_m_extract(m, off, sizeof(*ip6), &ip6_store);
132 if (ip6 == NULL) {
133 return hash;
134 }
135
136 hash = HASH(&ip6->ip6_src, sizeof(ip6->ip6_src), hash);
137 hash = HASH(&ip6->ip6_dst, sizeof(ip6->ip6_dst), hash);
138 /* hash = HASH(&ip6->ip6_nxt, sizeof(ip6->ip6_nxt), hash); */
139
140 flowlabel = ip6->ip6_flow & IPV6_FLOWLABEL_MASK;
141 hash = HASH(&flowlabel, sizeof(flowlabel), hash);
142
143 /* use port numbers for tcp and udp? */
144 }
145
146 return hash;
147 }
148