| /* Copyright (c) 2015 PLUMgrid, http://plumgrid.com |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of version 2 of the GNU General Public |
| * License as published by the Free Software Foundation. |
| */ |
| #include <uapi/linux/bpf.h> |
| #include "bpf_helpers.h" |
| #include <uapi/linux/in.h> |
| #include <uapi/linux/if.h> |
| #include <uapi/linux/if_ether.h> |
| #include <uapi/linux/ip.h> |
| #include <uapi/linux/ipv6.h> |
| #include <uapi/linux/if_tunnel.h> |
| #include <uapi/linux/mpls.h> |
| #define IP_MF 0x2000 |
| #define IP_OFFSET 0x1FFF |
| |
| #define PROG(F) SEC("socket/"__stringify(F)) int bpf_func_##F |
| |
| struct bpf_map_def SEC("maps") jmp_table = { |
| .type = BPF_MAP_TYPE_PROG_ARRAY, |
| .key_size = sizeof(u32), |
| .value_size = sizeof(u32), |
| .max_entries = 8, |
| }; |
| |
| #define PARSE_VLAN 1 |
| #define PARSE_MPLS 2 |
| #define PARSE_IP 3 |
| #define PARSE_IPV6 4 |
| |
| /* protocol dispatch routine. |
| * It tail-calls next BPF program depending on eth proto |
| * Note, we could have used: |
| * bpf_tail_call(skb, &jmp_table, proto); |
| * but it would need large prog_array |
| */ |
| static inline void parse_eth_proto(struct __sk_buff *skb, u32 proto) |
| { |
| switch (proto) { |
| case ETH_P_8021Q: |
| case ETH_P_8021AD: |
| bpf_tail_call(skb, &jmp_table, PARSE_VLAN); |
| break; |
| case ETH_P_MPLS_UC: |
| case ETH_P_MPLS_MC: |
| bpf_tail_call(skb, &jmp_table, PARSE_MPLS); |
| break; |
| case ETH_P_IP: |
| bpf_tail_call(skb, &jmp_table, PARSE_IP); |
| break; |
| case ETH_P_IPV6: |
| bpf_tail_call(skb, &jmp_table, PARSE_IPV6); |
| break; |
| } |
| } |
| |
| struct vlan_hdr { |
| __be16 h_vlan_TCI; |
| __be16 h_vlan_encapsulated_proto; |
| }; |
| |
| struct flow_key_record { |
| __be32 src; |
| __be32 dst; |
| union { |
| __be32 ports; |
| __be16 port16[2]; |
| }; |
| __u32 ip_proto; |
| }; |
| |
| static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff) |
| { |
| return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off)) |
| & (IP_MF | IP_OFFSET); |
| } |
| |
| static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off) |
| { |
| __u64 w0 = load_word(ctx, off); |
| __u64 w1 = load_word(ctx, off + 4); |
| __u64 w2 = load_word(ctx, off + 8); |
| __u64 w3 = load_word(ctx, off + 12); |
| |
| return (__u32)(w0 ^ w1 ^ w2 ^ w3); |
| } |
| |
| struct globals { |
| struct flow_key_record flow; |
| }; |
| |
| struct bpf_map_def SEC("maps") percpu_map = { |
| .type = BPF_MAP_TYPE_ARRAY, |
| .key_size = sizeof(__u32), |
| .value_size = sizeof(struct globals), |
| .max_entries = 32, |
| }; |
| |
| /* user poor man's per_cpu until native support is ready */ |
| static struct globals *this_cpu_globals(void) |
| { |
| u32 key = bpf_get_smp_processor_id(); |
| |
| return bpf_map_lookup_elem(&percpu_map, &key); |
| } |
| |
| /* some simple stats for user space consumption */ |
| struct pair { |
| __u64 packets; |
| __u64 bytes; |
| }; |
| |
| struct bpf_map_def SEC("maps") hash_map = { |
| .type = BPF_MAP_TYPE_HASH, |
| .key_size = sizeof(struct flow_key_record), |
| .value_size = sizeof(struct pair), |
| .max_entries = 1024, |
| }; |
| |
| static void update_stats(struct __sk_buff *skb, struct globals *g) |
| { |
| struct flow_key_record key = g->flow; |
| struct pair *value; |
| |
| value = bpf_map_lookup_elem(&hash_map, &key); |
| if (value) { |
| __sync_fetch_and_add(&value->packets, 1); |
| __sync_fetch_and_add(&value->bytes, skb->len); |
| } else { |
| struct pair val = {1, skb->len}; |
| |
| bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY); |
| } |
| } |
| |
| static __always_inline void parse_ip_proto(struct __sk_buff *skb, |
| struct globals *g, __u32 ip_proto) |
| { |
| __u32 nhoff = skb->cb[0]; |
| int poff; |
| |
| switch (ip_proto) { |
| case IPPROTO_GRE: { |
| struct gre_hdr { |
| __be16 flags; |
| __be16 proto; |
| }; |
| |
| __u32 gre_flags = load_half(skb, |
| nhoff + offsetof(struct gre_hdr, flags)); |
| __u32 gre_proto = load_half(skb, |
| nhoff + offsetof(struct gre_hdr, proto)); |
| |
| if (gre_flags & (GRE_VERSION|GRE_ROUTING)) |
| break; |
| |
| nhoff += 4; |
| if (gre_flags & GRE_CSUM) |
| nhoff += 4; |
| if (gre_flags & GRE_KEY) |
| nhoff += 4; |
| if (gre_flags & GRE_SEQ) |
| nhoff += 4; |
| |
| skb->cb[0] = nhoff; |
| parse_eth_proto(skb, gre_proto); |
| break; |
| } |
| case IPPROTO_IPIP: |
| parse_eth_proto(skb, ETH_P_IP); |
| break; |
| case IPPROTO_IPV6: |
| parse_eth_proto(skb, ETH_P_IPV6); |
| break; |
| case IPPROTO_TCP: |
| case IPPROTO_UDP: |
| g->flow.ports = load_word(skb, nhoff); |
| case IPPROTO_ICMP: |
| g->flow.ip_proto = ip_proto; |
| update_stats(skb, g); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| PROG(PARSE_IP)(struct __sk_buff *skb) |
| { |
| struct globals *g = this_cpu_globals(); |
| __u32 nhoff, verlen, ip_proto; |
| |
| if (!g) |
| return 0; |
| |
| nhoff = skb->cb[0]; |
| |
| if (unlikely(ip_is_fragment(skb, nhoff))) |
| return 0; |
| |
| ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol)); |
| |
| if (ip_proto != IPPROTO_GRE) { |
| g->flow.src = load_word(skb, nhoff + offsetof(struct iphdr, saddr)); |
| g->flow.dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr)); |
| } |
| |
| verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/); |
| nhoff += (verlen & 0xF) << 2; |
| |
| skb->cb[0] = nhoff; |
| parse_ip_proto(skb, g, ip_proto); |
| return 0; |
| } |
| |
| PROG(PARSE_IPV6)(struct __sk_buff *skb) |
| { |
| struct globals *g = this_cpu_globals(); |
| __u32 nhoff, ip_proto; |
| |
| if (!g) |
| return 0; |
| |
| nhoff = skb->cb[0]; |
| |
| ip_proto = load_byte(skb, |
| nhoff + offsetof(struct ipv6hdr, nexthdr)); |
| g->flow.src = ipv6_addr_hash(skb, |
| nhoff + offsetof(struct ipv6hdr, saddr)); |
| g->flow.dst = ipv6_addr_hash(skb, |
| nhoff + offsetof(struct ipv6hdr, daddr)); |
| nhoff += sizeof(struct ipv6hdr); |
| |
| skb->cb[0] = nhoff; |
| parse_ip_proto(skb, g, ip_proto); |
| return 0; |
| } |
| |
| PROG(PARSE_VLAN)(struct __sk_buff *skb) |
| { |
| __u32 nhoff, proto; |
| |
| nhoff = skb->cb[0]; |
| |
| proto = load_half(skb, nhoff + offsetof(struct vlan_hdr, |
| h_vlan_encapsulated_proto)); |
| nhoff += sizeof(struct vlan_hdr); |
| skb->cb[0] = nhoff; |
| |
| parse_eth_proto(skb, proto); |
| |
| return 0; |
| } |
| |
| PROG(PARSE_MPLS)(struct __sk_buff *skb) |
| { |
| __u32 nhoff, label; |
| |
| nhoff = skb->cb[0]; |
| |
| label = load_word(skb, nhoff); |
| nhoff += sizeof(struct mpls_label); |
| skb->cb[0] = nhoff; |
| |
| if (label & MPLS_LS_S_MASK) { |
| __u8 verlen = load_byte(skb, nhoff); |
| if ((verlen & 0xF0) == 4) |
| parse_eth_proto(skb, ETH_P_IP); |
| else |
| parse_eth_proto(skb, ETH_P_IPV6); |
| } else { |
| parse_eth_proto(skb, ETH_P_MPLS_UC); |
| } |
| |
| return 0; |
| } |
| |
| SEC("socket/0") |
| int main_prog(struct __sk_buff *skb) |
| { |
| __u32 nhoff = ETH_HLEN; |
| __u32 proto = load_half(skb, 12); |
| |
| skb->cb[0] = nhoff; |
| parse_eth_proto(skb, proto); |
| return 0; |
| } |
| |
| char _license[] SEC("license") = "GPL"; |