netdev - [PATCH net-next v4 0/2] tcp: add a new TW

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-next>] [day] [month] [year] [list]

Message-ID: <20250409112614.16153-1-jiayuan.chen@linux.dev>
Date: Wed,  9 Apr 2025 19:26:03 +0800
From: Jiayuan Chen <jiayuan.chen@...ux.dev>
To: kuba@...nel.org,
	edumazet@...gle.com
Cc: mrpre@....com,
	Jiayuan Chen <jiayuan.chen@...ux.dev>,
	"David S. Miller" <davem@...emloft.net>,
	Paolo Abeni <pabeni@...hat.com>,
	Simon Horman <horms@...nel.org>,
	Jonathan Corbet <corbet@....net>,
	Neal Cardwell <ncardwell@...gle.com>,
	Kuniyuki Iwashima <kuniyu@...zon.com>,
	David Ahern <dsahern@...nel.org>,
	Steffen Klassert <steffen.klassert@...unet.com>,
	Sabrina Dubroca <sd@...asysnail.net>,
	Antony Antony <antony.antony@...unet.com>,
	Christian Hopps <chopps@...n.net>,
	netdev@...r.kernel.org,
	linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH net-next v4 0/2] tcp: add a new TW_PAWS drop reason

Devices in the networking path, such as firewalls, NATs, or routers, which
can perform SNAT or DNAT, use addresses from their own limited address
pools to masquerade the source address during forwarding, causing PAWS
verification to fail more easily under TW status.

Currently, packet loss statistics for PAWS can only be viewed through MIB,
which is a global metric and cannot be precisely obtained through tracing
to get the specific 4-tuple of the dropped packet. In the past, we had to
use kprobe ret to retrieve relevant skb information from
tcp_timewait_state_process().

We add a drop_reason pointer and a new counter.

---
v3 -> v4:
1. Update commit message and make it more concise.
2. Integrated Reviewed-by tag from v3.
https://lore.kernel.org/netdev/20250407140001.13886-1-jiayuan.chen@linux.dev/T/#t

v2 -> v3: Use new SNMP counter and drop reason suggested by Eric.
https://lore.kernel.org/netdev/5cdc1bdd9caee92a6ae932638a862fd5c67630e8@linux.dev/T/#t

I didn't provide a packetdrill script.
I struggled for a long time to get packetdrill to fix the client port, but
ultimately failed to do so...

Instead, I wrote my own program to trigger PAWS, which can be found at
https://github.com/mrpre/nettrigger/tree/main
'''
//assume nginx running on 172.31.75.114:9999, current host is 172.31.75.115
iptables -t filter -I OUTPUT -p tcp --sport 12345 --tcp-flags RST RST -j DROP
./nettrigger -i eth0 -s 172.31.75.115:12345 -d 172.31.75.114:9999 -action paws
'''

Jiayuan Chen (2):
  tcp: add TCP_RFC7323_TW_PAWS drop reason
  tcp: add LINUX_MIB_PAWS_TW_REJECTED counter

 Documentation/networking/net_cachelines/snmp.rst | 2 ++
 include/net/dropreason-core.h                    | 7 +++++++
 include/net/tcp.h                                | 3 ++-
 include/uapi/linux/snmp.h                        | 1 +
 net/ipv4/proc.c                                  | 1 +
 net/ipv4/tcp_ipv4.c                              | 3 ++-
 net/ipv4/tcp_minisocks.c                         | 9 ++++++---
 net/ipv6/tcp_ipv6.c                              | 3 ++-
 8 files changed, 23 insertions(+), 6 deletions(-)

-- 
2.47.1