Eric Dumazet | 0744dd0 | 2011-11-28 05:22:18 +0000 | [diff] [blame] | 1 | #include <linux/skbuff.h> |
Jesper Dangaard Brouer | c452ed7 | 2012-01-24 16:03:33 -0500 | [diff] [blame] | 2 | #include <linux/export.h> |
Eric Dumazet | 0744dd0 | 2011-11-28 05:22:18 +0000 | [diff] [blame] | 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 | |
Eric Dumazet | 4d77d2b | 2011-11-28 20:30:35 +0000 | [diff] [blame] | 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 | } |
Eric Dumazet | 0744dd0 | 2011-11-28 05:22:18 +0000 | [diff] [blame] | 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; |
Eric Dumazet | 4d77d2b | 2011-11-28 20:30:35 +0000 | [diff] [blame] | 45 | iph_to_flow_copy_addrs(flow, iph); |
Eric Dumazet | 0744dd0 | 2011-11-28 05:22:18 +0000 | [diff] [blame] | 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); |