netdev - Re: unintended ipv4 broadcast policy change

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]

Date:	Wed, 22 Jun 2011 17:42:13 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	herbert@...dor.hengli.com.au
Cc:	netdev@...r.kernel.org
Subject: Re: unintended ipv4 broadcast policy change

From: David Miller <davem@...emloft.net>
Date: Wed, 22 Jun 2011 16:39:35 -0700 (PDT)

> Contrary to previous discussions I see no code in the ISC dhcp
> client that needs to get at the MAC address.  It merely wants
> it there so that it's packet parsing engine can skip over it
> to get at the ipv4/UDP bits.

I take this back, it does want the "from" MAC address.  When
using plain BSD sockets, it zeros out the address since as we
know the MAC info is not available with normal UDP sockets.

But the ISC DHCP code never actually uses this information at all,
it only stores it away in the "struct packet" structure, never to
be used again.

That's probably because the info it needs is present in the "chaddr"
field of the DHCP packet.  And only the server side actually needs
this.
--
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