Re: [PATCH bpf-next v4 1/2] bpf: allow rewriting to ports under ip_unprivileged_port_start
From: Martin KaFai Lau <hidden>
Date: 2021-01-27 12:45:45
Also in:
bpf
On Tue, Jan 26, 2021 at 11:35:43AM -0800, Stanislav Fomichev wrote:
At the moment, BPF_CGROUP_INET{4,6}_BIND hooks can rewrite user_port
to the privileged ones (< ip_unprivileged_port_start), but it will
be rejected later on in the __inet_bind or __inet6_bind.
Let's add another return value to indicate that CAP_NET_BIND_SERVICE
check should be ignored. Use the same idea as we currently use
in cgroup/egress where bit #1 indicates CN. Instead, for
cgroup/bind{4,6}, bit #1 indicates that CAP_NET_BIND_SERVICE should
be bypassed.
v4:
- Add missing IPv6 support (Martin KaFai Lau)
v3:
- Update description (Martin KaFai Lau)
- Fix capability restore in selftest (Martin KaFai Lau)
v2:
- Switch to explicit return code (Martin KaFai Lau)Reviewed-by: Martin KaFai Lau <redacted>