Joe Stringer 6acc9b432e bpf: Add helper to retrieve socket in BPF ... This patch adds new BPF helper functions, bpf_sk_lookup_tcp() and bpf_sk_lookup_udp() which allows BPF programs to find out if there is a socket listening on this host, and returns a socket pointer which the BPF program can then access to determine, for instance, whether to forward or drop traffic. bpf_sk_lookup_xxx() may take a reference on the socket, so when a BPF program makes use of this function, it must subsequently pass the returned pointer into the newly added sk_release() to return the reference. By way of example, the following pseudocode would filter inbound connections at XDP if there is no corresponding service listening for the traffic: struct bpf_sock_tuple tuple; struct bpf_sock_ops *sk; populate_tuple(ctx, &tuple); // Extract the 5tuple from the packet sk = bpf_sk_lookup_tcp(ctx, &tuple, sizeof tuple, netns, 0); if (!sk) { // Couldn't find a socket listening for this traffic. Drop. return TC_ACT_SHOT; } bpf_sk_release(sk, 0); return TC_ACT_OK; Signed-off-by: Joe Stringer <joe@wand.net.nz> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>		2018-10-03 02:53:47 +02:00
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asm	tools/headers: Synchronize kernel ABI headers	2017-11-04 09:27:46 +01:00
asm-generic	mn10300: Remove the architecture	2018-03-09 23:19:56 +01:00
linux	tools/lib/lockdep: Add dummy task_struct state member	2018-09-10 13:48:24 +02:00
tools	tools: bpf: fix license for a compat header file	2018-09-19 23:49:58 +02:00
trace/events	tools/lib/lockdep: Remove private kernel headers	2017-06-05 09:28:14 +02:00
uapi	bpf: Add helper to retrieve socket in BPF	2018-10-03 02:53:47 +02:00