compat-2.6.h: include generated config.h
[~tnikolova/compat/.git] / compat / flow_dissector.c
1 #include <linux/skbuff.h>
2 #include <linux/export.h>
3 #include <linux/ip.h>
4 #include <linux/ipv6.h>
5 #include <linux/if_vlan.h>
6 #include <net/ip.h>
7 #include <linux/if_tunnel.h>
8 #include <linux/if_pppox.h>
9 #include <linux/ppp_defs.h>
10 #include <net/flow_keys.h>
11
12 /* copy saddr & daddr, possibly using 64bit load/store
13  * Equivalent to :      flow->src = iph->saddr;
14  *                      flow->dst = iph->daddr;
15  */
16 static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph)
17 {
18         BUILD_BUG_ON(offsetof(typeof(*flow), dst) !=
19                      offsetof(typeof(*flow), src) + sizeof(flow->src));
20         memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
21 }
22
23 bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow)
24 {
25         int poff, nhoff = skb_network_offset(skb);
26         u8 ip_proto;
27         __be16 proto = skb->protocol;
28
29         memset(flow, 0, sizeof(*flow));
30
31 again:
32         switch (proto) {
33         case __constant_htons(ETH_P_IP): {
34                 const struct iphdr *iph;
35                 struct iphdr _iph;
36 ip:
37                 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
38                 if (!iph)
39                         return false;
40
41                 if (ip_is_fragment(iph))
42                         ip_proto = 0;
43                 else
44                         ip_proto = iph->protocol;
45                 iph_to_flow_copy_addrs(flow, iph);
46                 nhoff += iph->ihl * 4;
47                 break;
48         }
49         case __constant_htons(ETH_P_IPV6): {
50                 const struct ipv6hdr *iph;
51                 struct ipv6hdr _iph;
52 ipv6:
53                 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
54                 if (!iph)
55                         return false;
56
57                 ip_proto = iph->nexthdr;
58                 flow->src = iph->saddr.s6_addr32[3];
59                 flow->dst = iph->daddr.s6_addr32[3];
60                 nhoff += sizeof(struct ipv6hdr);
61                 break;
62         }
63         case __constant_htons(ETH_P_8021Q): {
64                 const struct vlan_hdr *vlan;
65                 struct vlan_hdr _vlan;
66
67                 vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan);
68                 if (!vlan)
69                         return false;
70
71                 proto = vlan->h_vlan_encapsulated_proto;
72                 nhoff += sizeof(*vlan);
73                 goto again;
74         }
75         case __constant_htons(ETH_P_PPP_SES): {
76                 struct {
77                         struct pppoe_hdr hdr;
78                         __be16 proto;
79                 } *hdr, _hdr;
80                 hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
81                 if (!hdr)
82                         return false;
83                 proto = hdr->proto;
84                 nhoff += PPPOE_SES_HLEN;
85                 switch (proto) {
86                 case __constant_htons(PPP_IP):
87                         goto ip;
88                 case __constant_htons(PPP_IPV6):
89                         goto ipv6;
90                 default:
91                         return false;
92                 }
93         }
94         default:
95                 return false;
96         }
97
98         switch (ip_proto) {
99         case IPPROTO_GRE: {
100                 struct gre_hdr {
101                         __be16 flags;
102                         __be16 proto;
103                 } *hdr, _hdr;
104
105                 hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
106                 if (!hdr)
107                         return false;
108                 /*
109                  * Only look inside GRE if version zero and no
110                  * routing
111                  */
112                 if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) {
113                         proto = hdr->proto;
114                         nhoff += 4;
115                         if (hdr->flags & GRE_CSUM)
116                                 nhoff += 4;
117                         if (hdr->flags & GRE_KEY)
118                                 nhoff += 4;
119                         if (hdr->flags & GRE_SEQ)
120                                 nhoff += 4;
121                         goto again;
122                 }
123                 break;
124         }
125         case IPPROTO_IPIP:
126                 goto again;
127         default:
128                 break;
129         }
130
131         flow->ip_proto = ip_proto;
132         poff = proto_ports_offset(ip_proto);
133         if (poff >= 0) {
134                 __be32 *ports, _ports;
135
136                 nhoff += poff;
137                 ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports);
138                 if (ports)
139                         flow->ports = *ports;
140         }
141
142         return true;
143 }
144 EXPORT_SYMBOL_GPL(skb_flow_dissect);