From a80857822b0c2ed608c93504bd3687b78f20c619 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 1 Dec 2014 15:06:38 -0800 Subject: samples: bpf: trivial eBPF program in C 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 Signed-off-by: David S. Miller --- samples/bpf/sockex1_user.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 samples/bpf/sockex1_user.c (limited to 'samples/bpf/sockex1_user.c') diff --git a/samples/bpf/sockex1_user.c b/samples/bpf/sockex1_user.c new file mode 100644 index 000000000000..34a443ff3831 --- /dev/null +++ b/samples/bpf/sockex1_user.c @@ -0,0 +1,49 @@ +#include +#include +#include +#include "libbpf.h" +#include "bpf_load.h" +#include +#include + +int main(int ac, char **argv) +{ + char filename[256]; + FILE *f; + int i, sock; + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + + if (load_bpf_file(filename)) { + printf("%s", bpf_log_buf); + return 1; + } + + sock = open_raw_sock("lo"); + + assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, prog_fd, + sizeof(prog_fd[0])) == 0); + + f = popen("ping -c5 localhost", "r"); + (void) f; + + for (i = 0; i < 5; i++) { + long long tcp_cnt, udp_cnt, icmp_cnt; + int key; + + key = IPPROTO_TCP; + assert(bpf_lookup_elem(map_fd[0], &key, &tcp_cnt) == 0); + + key = IPPROTO_UDP; + assert(bpf_lookup_elem(map_fd[0], &key, &udp_cnt) == 0); + + key = IPPROTO_ICMP; + assert(bpf_lookup_elem(map_fd[0], &key, &icmp_cnt) == 0); + + printf("TCP %lld UDP %lld ICMP %lld packets\n", + tcp_cnt, udp_cnt, icmp_cnt); + sleep(1); + } + + return 0; +} -- cgit v1.2.1