netdev - [PATCH bpf-next v2 2/3] bpf: support TCP_RTO_MAX_MS for bpf

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250217034245.11063-3-kerneljasonxing@gmail.com>
Date: Mon, 17 Feb 2025 11:42:44 +0800
From: Jason Xing <kerneljasonxing@...il.com>
To: davem@...emloft.net,
	edumazet@...gle.com,
	kuba@...nel.org,
	pabeni@...hat.com,
	dsahern@...nel.org,
	kuniyu@...zon.com,
	ast@...nel.org,
	daniel@...earbox.net,
	andrii@...nel.org,
	martin.lau@...ux.dev,
	eddyz87@...il.com,
	song@...nel.org,
	yonghong.song@...ux.dev,
	john.fastabend@...il.com,
	kpsingh@...nel.org,
	sdf@...ichev.me,
	haoluo@...gle.com,
	jolsa@...nel.org,
	shuah@...nel.org,
	ykolal@...com
Cc: bpf@...r.kernel.org,
	netdev@...r.kernel.org,
	Jason Xing <kerneljasonxing@...il.com>
Subject: [PATCH bpf-next v2 2/3] bpf: support TCP_RTO_MAX_MS for bpf_setsockopt

Some applications don't want to wait for too long because the
time of retransmission increases exponentially and can reach more
than 10 seconds, for example. Eric implements the core logic
on supporting rto max feature in the stack previously. Based on that,
we can support it for BPF use.

This patch reuses the same logic of TCP_RTO_MAX_MS in do_tcp_setsockopt()
and do_tcp_getsockopt(). BPF program can call bpf_{set/get}sockopt()
to set/get the maximum value of RTO.

It would be good if a BPF program sets max value of RTO before
transmission as we can see in the later patch (selftests).

Signed-off-by: Jason Xing <kerneljasonxing@...il.com>
---
 net/core/filter.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 2ec162dd83c4..ffec7b4357f9 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5382,6 +5382,7 @@ static int sol_tcp_sockopt(struct sock *sk, int optname,
 	case TCP_USER_TIMEOUT:
 	case TCP_NOTSENT_LOWAT:
 	case TCP_SAVE_SYN:
+	case TCP_RTO_MAX_MS:
 		if (*optlen != sizeof(int))
 			return -EINVAL;
 		break;
-- 
2.43.5