Subject: Re: netinet/udp_usrreq.c: extraneous mbuf copying in udp4_realinput()?
To: None <email@example.com>
From: None <firstname.lastname@example.org>
Date: 06/11/2002 06:17:12
>I was looking through the code in netinet/udp_usrreq.c and noticed that
>the mbuf chain was copied both for unicast and broadcast/multicast
>packets in udp4_realinput() (the copy operation is invoked from
>udp4_sendup()). It seems to me that in the unicast case there is no
>apparent reason for this. Prior to rev. 1.53 the copying did only
>happen for the broadcast/multicast case.
>Does anyone know why the extra copying was introduced for the unicast
due to the extra complexity in supporting RFC2553 IPv4 mapped address
(IPv4 traffic to AF_INET6 socket) i simplified the codepath, hence
the extra mbuf copy. usually m_copym() will not require real
duplication of packet, as they tend to be M_EXT cluster mbuf.