Commit | Line | Data |
---|---|---|
0744dd00 ED |
1 | #include <linux/skbuff.h> |
2 | #include <linux/ip.h> | |
3 | #include <linux/ipv6.h> | |
4 | #include <linux/if_vlan.h> | |
5 | #include <net/ip.h> | |
6 | #include <linux/if_tunnel.h> | |
7 | #include <linux/if_pppox.h> | |
8 | #include <linux/ppp_defs.h> | |
9 | #include <net/flow_keys.h> | |
10 | ||
4d77d2b5 ED |
11 | /* copy saddr & daddr, possibly using 64bit load/store |
12 | * Equivalent to : flow->src = iph->saddr; | |
13 | * flow->dst = iph->daddr; | |
14 | */ | |
15 | static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph) | |
16 | { | |
17 | BUILD_BUG_ON(offsetof(typeof(*flow), dst) != | |
18 | offsetof(typeof(*flow), src) + sizeof(flow->src)); | |
19 | memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst)); | |
20 | } | |
0744dd00 ED |
21 | |
22 | bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow) | |
23 | { | |
24 | int poff, nhoff = skb_network_offset(skb); | |
25 | u8 ip_proto; | |
26 | __be16 proto = skb->protocol; | |
27 | ||
28 | memset(flow, 0, sizeof(*flow)); | |
29 | ||
30 | again: | |
31 | switch (proto) { | |
32 | case __constant_htons(ETH_P_IP): { | |
33 | const struct iphdr *iph; | |
34 | struct iphdr _iph; | |
35 | ip: | |
36 | iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); | |
37 | if (!iph) | |
38 | return false; | |
39 | ||
40 | if (ip_is_fragment(iph)) | |
41 | ip_proto = 0; | |
42 | else | |
43 | ip_proto = iph->protocol; | |
4d77d2b5 | 44 | iph_to_flow_copy_addrs(flow, iph); |
0744dd00 ED |
45 | nhoff += iph->ihl * 4; |
46 | break; | |
47 | } | |
48 | case __constant_htons(ETH_P_IPV6): { | |
49 | const struct ipv6hdr *iph; | |
50 | struct ipv6hdr _iph; | |
51 | ipv6: | |
52 | iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); | |
53 | if (!iph) | |
54 | return false; | |
55 | ||
56 | ip_proto = iph->nexthdr; | |
57 | flow->src = iph->saddr.s6_addr32[3]; | |
58 | flow->dst = iph->daddr.s6_addr32[3]; | |
59 | nhoff += sizeof(struct ipv6hdr); | |
60 | break; | |
61 | } | |
62 | case __constant_htons(ETH_P_8021Q): { | |
63 | const struct vlan_hdr *vlan; | |
64 | struct vlan_hdr _vlan; | |
65 | ||
66 | vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan); | |
67 | if (!vlan) | |
68 | return false; | |
69 | ||
70 | proto = vlan->h_vlan_encapsulated_proto; | |
71 | nhoff += sizeof(*vlan); | |
72 | goto again; | |
73 | } | |
74 | case __constant_htons(ETH_P_PPP_SES): { | |
75 | struct { | |
76 | struct pppoe_hdr hdr; | |
77 | __be16 proto; | |
78 | } *hdr, _hdr; | |
79 | hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr); | |
80 | if (!hdr) | |
81 | return false; | |
82 | proto = hdr->proto; | |
83 | nhoff += PPPOE_SES_HLEN; | |
84 | switch (proto) { | |
85 | case __constant_htons(PPP_IP): | |
86 | goto ip; | |
87 | case __constant_htons(PPP_IPV6): | |
88 | goto ipv6; | |
89 | default: | |
90 | return false; | |
91 | } | |
92 | } | |
93 | default: | |
94 | return false; | |
95 | } | |
96 | ||
97 | switch (ip_proto) { | |
98 | case IPPROTO_GRE: { | |
99 | struct gre_hdr { | |
100 | __be16 flags; | |
101 | __be16 proto; | |
102 | } *hdr, _hdr; | |
103 | ||
104 | hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr); | |
105 | if (!hdr) | |
106 | return false; | |
107 | /* | |
108 | * Only look inside GRE if version zero and no | |
109 | * routing | |
110 | */ | |
111 | if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) { | |
112 | proto = hdr->proto; | |
113 | nhoff += 4; | |
114 | if (hdr->flags & GRE_CSUM) | |
115 | nhoff += 4; | |
116 | if (hdr->flags & GRE_KEY) | |
117 | nhoff += 4; | |
118 | if (hdr->flags & GRE_SEQ) | |
119 | nhoff += 4; | |
120 | goto again; | |
121 | } | |
122 | break; | |
123 | } | |
124 | case IPPROTO_IPIP: | |
125 | goto again; | |
126 | default: | |
127 | break; | |
128 | } | |
129 | ||
130 | flow->ip_proto = ip_proto; | |
131 | poff = proto_ports_offset(ip_proto); | |
132 | if (poff >= 0) { | |
133 | __be32 *ports, _ports; | |
134 | ||
135 | nhoff += poff; | |
136 | ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports); | |
137 | if (ports) | |
138 | flow->ports = *ports; | |
139 | } | |
140 | ||
141 | return true; | |
142 | } | |
143 | EXPORT_SYMBOL(skb_flow_dissect); |