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author | Alexei Starovoitov <ast@plumgrid.com> | 2014-12-01 15:06:39 -0800 |
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committer | David S. Miller <davem@davemloft.net> | 2014-12-05 21:47:34 -0800 |
commit | fbe3310840c65f3cf97dd90d23e177d061c376f2 (patch) | |
tree | ee28163a6c53e0131fd2d3d626d02b0610eaed2b /samples/bpf/sockex2_user.c | |
parent | a80857822b0c2ed608c93504bd3687b78f20c619 (diff) | |
download | linux-fbe3310840c65f3cf97dd90d23e177d061c376f2.tar.gz linux-fbe3310840c65f3cf97dd90d23e177d061c376f2.tar.bz2 linux-fbe3310840c65f3cf97dd90d23e177d061c376f2.zip |
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 <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples/bpf/sockex2_user.c')
-rw-r--r-- | samples/bpf/sockex2_user.c | 44 |
1 files changed, 44 insertions, 0 deletions
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 <stdio.h> +#include <assert.h> +#include <linux/bpf.h> +#include "libbpf.h" +#include "bpf_load.h" +#include <unistd.h> +#include <arpa/inet.h> + +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; +} |