xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

samples: bpf: trivial eBPF program in C

Browse Source 
this example does the same task as previous socket example
in assembler, but this one does it in C.

eBPF program in kernel does:
    /* assume that packet is IPv4, load one byte of IP->proto */
    int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
    long *value;

    value = bpf_map_lookup_elem(&my_map, &index);
    if (value)
        __sync_fetch_and_add(value, 1);

Corresponding user space reads map[tcp], map[udp], map[icmp]
and prints protocol stats every second

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexei Starovoitov
2014-12-01 15:06:38 -08:00
committed by David S. Miller
parent 249b812d80
commit a80857822b
4 changed files with 89 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
samples/bpf/libbpf.h
View File

@@ -15,7 +15,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
const struct bpf_insn *insns, int insn_len,
const char *license);
#define LOG_BUF_SIZE 8192
#define LOG_BUF_SIZE 65536
extern char bpf_log_buf[LOG_BUF_SIZE];
/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */