netdev - [PATCH iproute2] man: ip-link.8: add a note for gso_ipv4_max

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 for Android: free password hash cracker in your pocket

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

Date: Mon, 19 Feb 2024 14:16:04 -0500
From: Xin Long <lucien.xin@...il.com>
To: network dev <netdev@...r.kernel.org>,
	David Ahern <dsahern@...il.com>,
	stephen@...workplumber.org
Cc: Paolo Abeni <pabeni@...hat.com>,
	Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH iproute2] man: ip-link.8: add a note for gso_ipv4_max_size

As Paolo noticed, a skb->len check against gso_max_size was added in:

  https://lore.kernel.org/netdev/20231219125331.4127498-1-edumazet@google.com/

gso_max_size needs to be set to a value greater than or equal to
gso_ipv4_max_size to make BIG TCP IPv4 work properly.

To not break the current setup, this patch just adds a note into its
man doc for this.

Reported-by: Xiumei Mu <xmu@...hat.com>
Signed-off-by: Xin Long <lucien.xin@...il.com>
---
 man/man8/ip-link.8.in | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index c8c65657..444e7bca 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -441,6 +441,11 @@ TCP for IPv6 on this device when the size is greater than 65536.
 specifies the recommended maximum size of a IPv4 Generic Segment Offload
 packet the new device should accept. This is especially used to enable
 BIG TCP for IPv4 on this device by setting to a size greater than 65536.
+Note that
+.B gso_max_size
+needs to be set to a size greater than or equal to
+.B gso_ipv4_max_size
+to really enable BIG TCP for IPv4.
 
 .TP
 .BI gso_max_segs " SEGMENTS "
-- 
2.39.1