291 lines
6.1 KiB
C
291 lines
6.1 KiB
C
/* 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_keys {
|
|
__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_keys 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_keys),
|
|
.value_size = sizeof(struct pair),
|
|
.max_entries = 1024,
|
|
};
|
|
|
|
static void update_stats(struct __sk_buff *skb, struct globals *g)
|
|
{
|
|
struct flow_keys 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";
|