Commit 2c531639 authored by Prankur Gupta's avatar Prankur Gupta Committed by Daniel Borkmann
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bpf: Add support for {set|get} socket options from setsockopt BPF 



Add logic to call bpf_setsockopt() and bpf_getsockopt() from setsockopt BPF
programs. An example use case is when the user sets the IPV6_TCLASS socket
option, we would also like to change the tcp-cc for that socket.

We don't have any use case for calling bpf_setsockopt() from supposedly read-
only sys_getsockopt(), so it is made available to BPF_CGROUP_SETSOCKOPT only
at this point.

Signed-off-by: default avatarPrankur Gupta <prankgup@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210817224221.3257826-2-prankgup@fb.com
parent 44779a4b

kernel/bpf/cgroup.c

+8 −0
Original line number Diff line number Diff line
@@ -1873,6 +1873,14 @@ cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_sk_storage_get_proto;

	case BPF_FUNC_sk_storage_delete:

		return &bpf_sk_storage_delete_proto;

	case BPF_FUNC_setsockopt:

		if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT)

			return &bpf_sk_setsockopt_proto;

		return NULL;

	case BPF_FUNC_getsockopt:

		if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT)

			return &bpf_sk_getsockopt_proto;

		return NULL;

#endif

#ifdef CONFIG_INET

	case BPF_FUNC_tcp_sock: