projects / linux.git / blame
| 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> | |
| ddbe5032 | 7 | #include <net/ipv6.h> |
| 0744dd00 ED |
8 | #include <linux/if_tunnel.h> |
| 9 | #include <linux/if_pppox.h> | |
| 10 | #include <linux/ppp_defs.h> | |
| 11 | #include <net/flow_keys.h> | |
| 12 | ||
| 4d77d2b5 ED |
13 | /* copy saddr & daddr, possibly using 64bit load/store |
| 14 | * Equivalent to : flow->src = iph->saddr; | |
| 15 | * flow->dst = iph->daddr; | |
| 16 | */ | |
| 17 | static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph) | |
| 18 | { | |
| 19 | BUILD_BUG_ON(offsetof(typeof(*flow), dst) != | |
| 20 | offsetof(typeof(*flow), src) + sizeof(flow->src)); | |
| 21 | memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst)); | |
| 22 | } | |
| 0744dd00 ED |
23 | |
| 24 | bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow) | |
| 25 | { | |
| 26 | int poff, nhoff = skb_network_offset(skb); | |
| 27 | u8 ip_proto; | |
| 28 | __be16 proto = skb->protocol; | |
| 29 | ||
| 30 | memset(flow, 0, sizeof(*flow)); | |
| 31 | ||
| 32 | again: | |
| 33 | switch (proto) { | |
| 34 | case __constant_htons(ETH_P_IP): { | |
| 35 | const struct iphdr *iph; | |
| 36 | struct iphdr _iph; | |
| 37 | ip: | |
| 38 | iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); | |
| 39 | if (!iph) | |
| 40 | return false; | |
| 41 | ||
| 42 | if (ip_is_fragment(iph)) | |
| 43 | ip_proto = 0; | |
| 44 | else | |
| 45 | ip_proto = iph->protocol; | |
| 4d77d2b5 | 46 | iph_to_flow_copy_addrs(flow, iph); |
| 0744dd00 ED |
47 | nhoff += iph->ihl * 4; |
| 48 | break; | |
| 49 | } | |
| 50 | case __constant_htons(ETH_P_IPV6): { | |
| 51 | const struct ipv6hdr *iph; | |
| 52 | struct ipv6hdr _iph; | |
| 53 | ipv6: | |
| 54 | iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); | |
| 55 | if (!iph) | |
| 56 | return false; | |
| 57 | ||
| 58 | ip_proto = iph->nexthdr; | |
| ddbe5032 ED |
59 | flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr); |
| 60 | flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr); | |
| 0744dd00 ED |
61 | nhoff += sizeof(struct ipv6hdr); |
| 62 | break; | |
| 63 | } | |
| 64 | case __constant_htons(ETH_P_8021Q): { | |
| 65 | const struct vlan_hdr *vlan; | |
| 66 | struct vlan_hdr _vlan; | |
| 67 | ||
| 68 | vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan); | |
| 69 | if (!vlan) | |
| 70 | return false; | |
| 71 | ||
| 72 | proto = vlan->h_vlan_encapsulated_proto; | |
| 73 | nhoff += sizeof(*vlan); | |
| 74 | goto again; | |
| 75 | } | |
| 76 | case __constant_htons(ETH_P_PPP_SES): { | |
| 77 | struct { | |
| 78 | struct pppoe_hdr hdr; | |
| 79 | __be16 proto; | |
| 80 | } *hdr, _hdr; | |
| 81 | hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr); | |
| 82 | if (!hdr) | |
| 83 | return false; | |
| 84 | proto = hdr->proto; | |
| 85 | nhoff += PPPOE_SES_HLEN; | |
| 86 | switch (proto) { | |
| 87 | case __constant_htons(PPP_IP): | |
| 88 | goto ip; | |
| 89 | case __constant_htons(PPP_IPV6): | |
| 90 | goto ipv6; | |
| 91 | default: | |
| 92 | return false; | |
| 93 | } | |
| 94 | } | |
| 95 | default: | |
| 96 | return false; | |
| 97 | } | |
| 98 | ||
| 99 | switch (ip_proto) { | |
| 100 | case IPPROTO_GRE: { | |
| 101 | struct gre_hdr { | |
| 102 | __be16 flags; | |
| 103 | __be16 proto; | |
| 104 | } *hdr, _hdr; | |
| 105 | ||
| 106 | hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr); | |
| 107 | if (!hdr) | |
| 108 | return false; | |
| 109 | /* | |
| 110 | * Only look inside GRE if version zero and no | |
| 111 | * routing | |
| 112 | */ | |
| 113 | if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) { | |
| 114 | proto = hdr->proto; | |
| 115 | nhoff += 4; | |
| 116 | if (hdr->flags & GRE_CSUM) | |
| 117 | nhoff += 4; | |
| 118 | if (hdr->flags & GRE_KEY) | |
| 119 | nhoff += 4; | |
| 120 | if (hdr->flags & GRE_SEQ) | |
| 121 | nhoff += 4; | |
| 122 | goto again; | |
| 123 | } | |
| 124 | break; | |
| 125 | } | |
| 126 | case IPPROTO_IPIP: | |
| 127 | goto again; | |
| 128 | default: | |
| 129 | break; | |
| 130 | } | |
| 131 | ||
| 132 | flow->ip_proto = ip_proto; | |
| 133 | poff = proto_ports_offset(ip_proto); | |
| 134 | if (poff >= 0) { | |
| 135 | __be32 *ports, _ports; | |
| 136 | ||
| 137 | nhoff += poff; | |
| 138 | ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports); | |
| 139 | if (ports) | |
| 140 | flow->ports = *ports; | |
| 141 | } | |
| 142 | ||
| 143 | return true; | |
| 144 | } | |
| 145 | EXPORT_SYMBOL(skb_flow_dissect); |