Commit | Line | Data |
---|---|---|
0744dd00 | 1 | #include <linux/skbuff.h> |
c452ed70 | 2 | #include <linux/export.h> |
0744dd00 ED |
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 | ||
4d77d2b5 ED |
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 | } | |
0744dd00 ED |
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; | |
4d77d2b5 | 45 | iph_to_flow_copy_addrs(flow, iph); |
0744dd00 ED |
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(skb_flow_dissect); |