svn commit: r349654 - in stable: 11/sys/contrib/ipfilter/netinet 12/sys/contrib/ipfilter/netinet

[Cy Schubert]

Author: cy
Date: Wed Jul  3 17:04:44 2019
New Revision: 349654
URL: https://svnweb.freebsd.org/changeset/base/349654

Log:
  MFC r349399-349400,349567-349568:
  
  Prompted by r349366, ipfilter is also does not conform to RFC 3128
  by dropping TCP fragments with offset = 1.
  
  In addition to dropping these fragments, add a DTrace probe to allow
  for more detailed monitoring and diagnosis if required.

Modified:
  stable/12/sys/contrib/ipfilter/netinet/fil.c
Directory Properties:
  stable/12/   (props changed)

Changes in other areas also in this revision:
Modified:
  stable/11/sys/contrib/ipfilter/netinet/fil.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/12/sys/contrib/ipfilter/netinet/fil.c
==============================================================================
--- stable/12/sys/contrib/ipfilter/netinet/fil.c	Wed Jul  3 16:53:59 2019	(r349653)
+++ stable/12/sys/contrib/ipfilter/netinet/fil.c	Wed Jul  3 17:04:44 2019	(r349654)
@@ -1728,6 +1728,10 @@ ipf_pr_ipv4hdr(fin)
 
 		fi->fi_flx |= FI_FRAG;
 		off &= IP_OFFMASK;
+		if (off == 1 && p == IPPROTO_TCP) {
+			fin->fin_flx |= FI_SHORT;	/* RFC 3128 */
+			DT1(ipf_fi_tcp_frag_off_1, fr_info_t *, fin);
+		}
 		if (off != 0) {
 			fin->fin_flx |= FI_FRAGBODY;
 			off <<= 3;