From fbe3310840c65f3cf97dd90d23e177d061c376f2 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 1 Dec 2014 15:06:39 -0800 Subject: samples: bpf: large eBPF program in C sockex2_kern.c is purposefully large eBPF program in C. llvm compiles ~200 lines of C code into ~300 eBPF instructions. It's similar to __skb_flow_dissect() to demonstrate that complex packet parsing can be done by eBPF. Then it uses (struct flow_keys)->dst IP address (or hash of ipv6 dst) to keep stats of number of packets per IP. User space loads eBPF program, attaches it to loopback interface and prints dest_ip->#packets stats every second. Usage: $sudo samples/bpf/sockex2 ip 127.0.0.1 count 19 ip 127.0.0.1 count 178115 ip 127.0.0.1 count 369437 ip 127.0.0.1 count 559841 ip 127.0.0.1 count 750539 Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller --- samples/bpf/sockex2_user.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 samples/bpf/sockex2_user.c (limited to 'samples/bpf/sockex2_user.c') diff --git a/samples/bpf/sockex2_user.c b/samples/bpf/sockex2_user.c new file mode 100644 index 000000000000..d2d5f5a790d3 --- /dev/null +++ b/samples/bpf/sockex2_user.c @@ -0,0 +1,44 @@ +#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++) { + int key = 0, next_key; + long long value; + + while (bpf_get_next_key(map_fd[0], &key, &next_key) == 0) { + bpf_lookup_elem(map_fd[0], &next_key, &value); + printf("ip %s count %lld\n", + inet_ntoa((struct in_addr){htonl(next_key)}), + value); + key = next_key; + } + sleep(1); + } + return 0; +} -- cgit v1.2.3-59-g8ed1b