From 4ad1c464fee6b16b7d2fc6b2836b9929a9876587 Mon Sep 17 00:00:00 2001 From: Andre Oppermann Date: Mon, 22 Jun 2009 21:46:40 +0000 Subject: [PATCH] In sbappendstream_locked() demote all incoming packet mbufs (and chains) to pure data mbufs using m_demote(). This removes the packet header and all m_tag information as they are not meaningful anymore on a stream socket where mbufs are linked through m->m_next. Strictly speaking a packet header can be only ever valid on the first mbuf in an m_next chain. sbcompress() was doing this already when the mbuf chain layout lent itself to it (e.g. header splitting or merge-append), just not consistently. This frees resources at socket buffer append time instead of at sbdrop_internal() time after data has been read from the socket. For MAC the per packet information has done its duty and during socket buffer appending the policy of the socket itself takes over. With the append the packet boundaries disappear naturally and with it any context that was based on it. None of the residual information from mbuf headers in the socket buffer on stream sockets was looked at. --- sys/kern/uipc_sockbuf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sys/kern/uipc_sockbuf.c b/sys/kern/uipc_sockbuf.c index 2d86d740996c..2060a2e2176a 100644 --- a/sys/kern/uipc_sockbuf.c +++ b/sys/kern/uipc_sockbuf.c @@ -528,6 +528,9 @@ sbappendstream_locked(struct sockbuf *sb, struct mbuf *m) SBLASTMBUFCHK(sb); + /* Remove all packet headers and mbuf tags to get a pure data chain. */ + m_demote(m, 1); + sbcompress(sb, m, sb->sb_mbtail); sb->sb_lastrecord = sb->sb_mb;