From 03f4723ed7a52bd31da26eefe2cdde563ea0f468 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 1 Dec 2014 15:06:36 -0800 Subject: samples: bpf: example of stateful socket filtering this socket filter example does: - creates arraymap in kernel with key 4 bytes and value 8 bytes - loads eBPF program which assumes that packet is IPv4 and loads one byte of IP->proto from the packet and uses it as a key in a map r0 = skb->data[ETH_HLEN + offsetof(struct iphdr, protocol)]; *(u32*)(fp - 4) = r0; value = bpf_map_lookup_elem(map_fd, fp - 4); if (value) (*(u64*)value) += 1; - attaches this program to raw socket - every second user space reads map[IPPROTO_TCP], map[IPPROTO_UDP], map[IPPROTO_ICMP] to see how many packets of given protocol were seen on loopback interface Usage: $sudo samples/bpf/sock_example TCP 0 UDP 0 ICMP 0 packets TCP 187600 UDP 0 ICMP 4 packets TCP 376504 UDP 0 ICMP 8 packets TCP 563116 UDP 0 ICMP 12 packets TCP 753144 UDP 0 ICMP 16 packets Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller --- samples/bpf/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'samples/bpf/Makefile') diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 0718d9ce4619..f46d3492d032 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -3,9 +3,11 @@ obj- := dummy.o # List of programs to build hostprogs-y := test_verifier test_maps +hostprogs-y += sock_example test_verifier-objs := test_verifier.o libbpf.o test_maps-objs := test_maps.o libbpf.o +sock_example-objs := sock_example.o libbpf.o # Tell kbuild to always build the programs always := $(hostprogs-y) -- cgit v1.2.3