netdev - Re: [PATCH 0/4] [UDP]: memory accounting and limitation (take 10)

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

Message-Id: <20071215.213426.257974943.davem@davemloft.net>
Date:	Sat, 15 Dec 2007 21:34:26 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	haoki@...hat.com
Cc:	herbert@...dor.apana.org.au, netdev@...r.kernel.org,
	tyasui@...hat.com, mhiramat@...hat.com,
	satoshi.oshima.fk@...achi.com, billfink@...dspring.com,
	andi@...stfloor.org, johnpol@....mipt.ru,
	shemminger@...ux-foundation.org, yoshfuji@...ux-ipv6.org,
	yumiko.sugita.yf@...achi.com
Subject: Re: [PATCH 0/4] [UDP]: memory accounting and limitation (take 10)

From: Hideo AOKI <haoki@...hat.com>
Date: Sat, 15 Dec 2007 00:07:44 -0500

> Changelog take 9 -> take 10:
>  * supported using sk_forward_alloc
>  * introduced several memory accounting functions with spin lock
>  * changed detagram receive functions to be able to customize
>    destructor
>  * fixed accounting bugs in previous takes

This is not what Herbert and I meant with our suggestion.

We meant to convert all of UDP and datagram handling to lock
sockets precisely like TCP does, by calling lock_sock()
on entry to functions like udp_recvmsg() and release_sock()
on exit from those functions.

Then in the packet input processing, a sequence, just like
TCP, such as:

	bh_lock_sock_nested(sk);
	if (!sock_owned_by_user(sk)) {
		udp_do_rcv(sk, skb);
	} else
		sk_add_backlog(sk, skb);

Then a suitably defined ->backlog_rcv is hooked up for these
protocols as well.

Again, use TCP as a guide.

There is much more work involved to implement this properly,
and make the accounting code sharable with TCP, than the
simplistic and minimal spin lock code you added here.

Please do this correctly, thank you.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html