Commit 562dc56a authored by Yixin Shen's avatar Yixin Shen Committed by Martin KaFai Lau
Browse files

bpf: allow a TCP CC to write app_limited 



A CC that implements tcp_congestion_ops.cong_control() should be able to
write app_limited. A built-in CC or one from a kernel module is already
able to write to this member of struct tcp_sock.
For a BPF program, write access has not been allowed, yet.

Signed-off-by: default avatarYixin Shen <bobankhshen@gmail.com>
Link: https://lore.kernel.org/r/20230329073558.8136-2-bobankhshen@gmail.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent d8d8b008

net/ipv4/bpf_tcp_ca.c

+3 −0
Original line number Diff line number Diff line
@@ -113,6 +113,9 @@ static int bpf_tcp_ca_btf_struct_access(struct bpf_verifier_log *log, 
	case offsetof(struct tcp_sock, ecn_flags):

		end = offsetofend(struct tcp_sock, ecn_flags);

		break;

	case offsetof(struct tcp_sock, app_limited):

		end = offsetofend(struct tcp_sock, app_limited);

		break;

	default:

		bpf_log(log, "no write support to tcp_sock at off %d\n", off);

		return -EACCES;