svn commit: r337736 - in head/sys: netinet netinet6

[Andrey V. Elsukov]

Author: ae
Date: Tue Aug 14 07:54:14 2018
New Revision: 337736
URL: https://svnweb.freebsd.org/changeset/base/337736

Log:
  Restore ability to send ICMP and ICMPv6 redirects.
  
  It was lost when tryforward appeared. Now ip[6]_tryforward will be enabled
  only when sending redirects for corresponding IP version is disabled via
  sysctl. Otherwise will be used default forwarding function.
  
  PR:		221137
  Submitted by:	mckay@
  MFC after:	2 weeks

Modified:
  head/sys/netinet/ip_input.c
  head/sys/netinet6/ip6_input.c

Modified: head/sys/netinet/ip_input.c
==============================================================================
--- head/sys/netinet/ip_input.c	Tue Aug 14 05:18:43 2018	(r337735)
+++ head/sys/netinet/ip_input.c	Tue Aug 14 07:54:14 2018	(r337736)
@@ -557,13 +557,15 @@ tooshort:
 
 	/*
 	 * Try to forward the packet, but if we fail continue.
+	 * ip_tryforward() does not generate redirects, so fall
+	 * through to normal processing if redirects are required.
 	 * ip_tryforward() does inbound and outbound packet firewall
 	 * processing. If firewall has decided that destination becomes
 	 * our local address, it sets M_FASTFWD_OURS flag. In this
 	 * case skip another inbound firewall processing and update
 	 * ip pointer.
 	 */
-	if (V_ipforwarding != 0
+	if (V_ipforwarding != 0 && V_ipsendredirects == 0
 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 	    && (!IPSEC_ENABLED(ipv4) ||
 	    IPSEC_CAPS(ipv4, m, IPSEC_CAP_OPERABLE) == 0)

Modified: head/sys/netinet6/ip6_input.c
==============================================================================
--- head/sys/netinet6/ip6_input.c	Tue Aug 14 05:18:43 2018	(r337735)
+++ head/sys/netinet6/ip6_input.c	Tue Aug 14 07:54:14 2018	(r337736)
@@ -720,13 +720,15 @@ ip6_input(struct mbuf *m)
 #endif
 	/*
 	 * Try to forward the packet, but if we fail continue.
+	 * ip6_tryforward() does not generate redirects, so fall
+	 * through to normal processing if redirects are required.
 	 * ip6_tryforward() does inbound and outbound packet firewall
 	 * processing. If firewall has decided that destination becomes
 	 * our local address, it sets M_FASTFWD_OURS flag. In this
 	 * case skip another inbound firewall processing and update
 	 * ip6 pointer.
 	 */
-	if (V_ip6_forwarding != 0
+	if (V_ip6_forwarding != 0 && V_ip6_sendredirects == 0
 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 	    && (!IPSEC_ENABLED(ipv6) ||
 	    IPSEC_CAPS(ipv6, m, IPSEC_CAP_OPERABLE) == 0)