svn commit: r201502 - stable/6/sys/netipsec

[Bjoern A. Zeeb]

Author: bz
Date: Mon Jan  4 14:56:16 2010
New Revision: 201502
URL: http://svn.freebsd.org/changeset/base/201502

Log:
  MFC r199896:
  
    Directly send data uncompressed if the packet payload size is lower than
    the compression algorithm threshold.

Modified:
  stable/6/sys/netipsec/xform_ipcomp.c
Directory Properties:
  stable/6/sys/   (props changed)
  stable/6/sys/contrib/pf/   (props changed)
  stable/6/sys/dev/cxgb/   (props changed)

Modified: stable/6/sys/netipsec/xform_ipcomp.c
==============================================================================
--- stable/6/sys/netipsec/xform_ipcomp.c	Mon Jan  4 14:52:45 2010	(r201501)
+++ stable/6/sys/netipsec/xform_ipcomp.c	Mon Jan  4 14:56:16 2010	(r201502)
@@ -350,6 +350,17 @@ ipcomp_output(
 	ipcompx = sav->tdb_compalgxform;
 	IPSEC_ASSERT(ipcompx != NULL, ("null compression xform"));
 
+	/*
+	 * Do not touch the packet in case our payload to compress
+	 * is lower than the minimal threshold of the compression
+	 * alogrithm.  We will just send out the data uncompressed.
+	 * See RFC 3173, 2.2. Non-Expansion Policy.
+	 */
+	if (m->m_pkthdr.len <= ipcompx->minlen) {
+		/* XXX-BZ V_ipcompstat.threshold++; */
+		return ipsec_process_done(m, isr);
+	}
+
 	ralen = m->m_pkthdr.len - skip;	/* Raw payload length before comp. */
 	hlen = IPCOMP_HLENGTH;