[PATCH bpf-next 1/2] bpf: Add support for {set|get} socket options from setsockopt BPF
From: Prankur gupta <hidden>
Date: 2021-08-17 22:42:30
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Add logic to call bpf_setsockopt and bpf_getsockopt from setsockopt BPF programs. Example use case, 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_getsockopti, so it is made available to BPF_CGROUP_SETSOCKOPT only. Signed-off-by: Prankur gupta <redacted> Acked-by: Song Liu <redacted> --- kernel/bpf/cgroup.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 9f35928bab0a..8e9d99e2ade4 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c@@ -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:
--
2.30.2