| #include <linux/skbuff.h> |
| #include <linux/export.h> |
| #include <linux/ip.h> |
| #include <linux/ipv6.h> |
| #include <linux/if_vlan.h> |
| #include <net/ip.h> |
| #include <net/ipv6.h> |
| #include <linux/igmp.h> |
| #include <linux/icmp.h> |
| #include <linux/sctp.h> |
| #include <linux/dccp.h> |
| #include <linux/if_tunnel.h> |
| #include <linux/if_pppox.h> |
| #include <linux/ppp_defs.h> |
| #include <net/flow_keys.h> |
| |
| /* copy saddr & daddr, possibly using 64bit load/store |
| * Equivalent to : flow->src = iph->saddr; |
| * flow->dst = iph->daddr; |
| */ |
| static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph) |
| { |
| BUILD_BUG_ON(offsetof(typeof(*flow), dst) != |
| offsetof(typeof(*flow), src) + sizeof(flow->src)); |
| memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst)); |
| } |
| |
| /** |
| * skb_flow_get_ports - extract the upper layer ports and return them |
| * @skb: buffer to extract the ports from |
| * @thoff: transport header offset |
| * @ip_proto: protocol for which to get port offset |
| * |
| * The function will try to retrieve the ports at offset thoff + poff where poff |
| * is the protocol port offset returned from proto_ports_offset |
| */ |
| __be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto) |
| { |
| int poff = proto_ports_offset(ip_proto); |
| |
| if (poff >= 0) { |
| __be32 *ports, _ports; |
| |
| ports = skb_header_pointer(skb, thoff + poff, |
| sizeof(_ports), &_ports); |
| if (ports) |
| return *ports; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(skb_flow_get_ports); |
| |
| bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow) |
| { |
| int nhoff = skb_network_offset(skb); |
| u8 ip_proto; |
| __be16 proto = skb->protocol; |
| |
| memset(flow, 0, sizeof(*flow)); |
| |
| again: |
| switch (proto) { |
| case __constant_htons(ETH_P_IP): { |
| const struct iphdr *iph; |
| struct iphdr _iph; |
| ip: |
| iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); |
| if (!iph || iph->ihl < 5) |
| return false; |
| nhoff += iph->ihl * 4; |
| |
| ip_proto = iph->protocol; |
| if (ip_is_fragment(iph)) |
| ip_proto = 0; |
| |
| iph_to_flow_copy_addrs(flow, iph); |
| break; |
| } |
| case __constant_htons(ETH_P_IPV6): { |
| const struct ipv6hdr *iph; |
| struct ipv6hdr _iph; |
| ipv6: |
| iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); |
| if (!iph) |
| return false; |
| |
| ip_proto = iph->nexthdr; |
| flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr); |
| flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr); |
| nhoff += sizeof(struct ipv6hdr); |
| break; |
| } |
| case __constant_htons(ETH_P_8021AD): |
| case __constant_htons(ETH_P_8021Q): { |
| const struct vlan_hdr *vlan; |
| struct vlan_hdr _vlan; |
| |
| vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan); |
| if (!vlan) |
| return false; |
| |
| proto = vlan->h_vlan_encapsulated_proto; |
| nhoff += sizeof(*vlan); |
| goto again; |
| } |
| case __constant_htons(ETH_P_PPP_SES): { |
| struct { |
| struct pppoe_hdr hdr; |
| __be16 proto; |
| } *hdr, _hdr; |
| hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr); |
| if (!hdr) |
| return false; |
| proto = hdr->proto; |
| nhoff += PPPOE_SES_HLEN; |
| switch (proto) { |
| case __constant_htons(PPP_IP): |
| goto ip; |
| case __constant_htons(PPP_IPV6): |
| goto ipv6; |
| default: |
| return false; |
| } |
| } |
| default: |
| return false; |
| } |
| |
| switch (ip_proto) { |
| case IPPROTO_GRE: { |
| struct gre_hdr { |
| __be16 flags; |
| __be16 proto; |
| } *hdr, _hdr; |
| |
| hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr); |
| if (!hdr) |
| return false; |
| /* |
| * Only look inside GRE if version zero and no |
| * routing |
| */ |
| if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) { |
| proto = hdr->proto; |
| nhoff += 4; |
| if (hdr->flags & GRE_CSUM) |
| nhoff += 4; |
| if (hdr->flags & GRE_KEY) |
| nhoff += 4; |
| if (hdr->flags & GRE_SEQ) |
| nhoff += 4; |
| if (proto == htons(ETH_P_TEB)) { |
| const struct ethhdr *eth; |
| struct ethhdr _eth; |
| |
| eth = skb_header_pointer(skb, nhoff, |
| sizeof(_eth), &_eth); |
| if (!eth) |
| return false; |
| proto = eth->h_proto; |
| nhoff += sizeof(*eth); |
| } |
| goto again; |
| } |
| break; |
| } |
| case IPPROTO_IPIP: |
| proto = htons(ETH_P_IP); |
| goto ip; |
| case IPPROTO_IPV6: |
| proto = htons(ETH_P_IPV6); |
| goto ipv6; |
| default: |
| break; |
| } |
| |
| flow->ip_proto = ip_proto; |
| flow->ports = skb_flow_get_ports(skb, nhoff, ip_proto); |
| #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,9,0) |
| flow->thoff = (u16) nhoff; |
| #endif |
| |
| return true; |
| } |
| EXPORT_SYMBOL(skb_flow_dissect); |