svn commit: r199906 - head/sys/opencrypto

[Bjoern A. Zeeb]

Author: bz
Date: Sun Nov 29 17:53:57 2009
New Revision: 199906
URL: http://svn.freebsd.org/changeset/base/199906

Log:
  In case the compression result is the same size as the orignal version,
  the compression was useless as well.  Make sure to not update the data
  and return, else we would waste resources when decompressing.
  
  This also avoids the copyback() changing data other consumers like
  xform_ipcomp.c would have ignored because of no win and sent out without
  noting that compression was used, resulting in invalid packets at the
  receiver.
  
  MFC after:	5 days

Modified:
  head/sys/opencrypto/cryptosoft.c

Modified: head/sys/opencrypto/cryptosoft.c
==============================================================================
--- head/sys/opencrypto/cryptosoft.c	Sun Nov 29 17:47:49 2009	(r199905)
+++ head/sys/opencrypto/cryptosoft.c	Sun Nov 29 17:53:57 2009	(r199906)
@@ -552,7 +552,7 @@ swcr_compdec(struct cryptodesc *crd, str
 	sw->sw_size = result;
 	/* Check the compressed size when doing compression */
 	if (crd->crd_flags & CRD_F_COMP) {
-		if (result > crd->crd_len) {
+		if (result >= crd->crd_len) {
 			/* Compression was useless, we lost time */
 			free(out, M_CRYPTO_DATA);
 			return 0;