commit 778d80be52699596bf70e0eb0761cf5e1e46088d
author YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Sat Jun 28 14:17:11 2008 +0900
committer YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Thu Jul 03 17:51:55 2008 +0900
tree 607d0bd6fe7c7d6f59d88b9287fc534f6693998d
parent 5ce83afaac956238c3c25f60a899c511e9d8cbf4

ipv6: Add disable_ipv6 sysctl to disable IPv6 operaion on specific interface.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Documentation/networking/ip-sysctl.txt

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 71c7bea..dae980e 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1025,6 +1025,10 @@
 	autoconfigured addresses.
 	Default: 16
 
+disable_ipv6 - BOOLEAN
+	Disable IPv6 operation.
+	Default: FALSE (enable IPv6 operation)
+
 icmp/*:
 ratelimit - INTEGER
 	Limit the maximal rates for sending ICMPv6 packets.

include/linux/ipv6.h

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index cde056e..d9d7f9b 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -163,6 +163,7 @@
 #ifdef CONFIG_IPV6_MROUTE
 	__s32		mc_forwarding;
 #endif
+	__s32		disable_ipv6;
 	void		*sysctl;
 };
 
@@ -194,6 +195,7 @@
 	DEVCONF_OPTIMISTIC_DAD,
 	DEVCONF_ACCEPT_SOURCE_ROUTE,
 	DEVCONF_MC_FORWARDING,
+	DEVCONF_DISABLE_IPV6,
 	DEVCONF_MAX
 };
 

net/ipv6/addrconf.c

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8b6875f..8c5cff5 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -183,6 +183,7 @@
 #endif
 	.proxy_ndp		= 0,
 	.accept_source_route	= 0,	/* we do not accept RH0 by default. */
+	.disable_ipv6		= 0,
 };
 
 static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -215,6 +216,7 @@
 #endif
 	.proxy_ndp		= 0,
 	.accept_source_route	= 0,	/* we do not accept RH0 by default. */
+	.disable_ipv6		= 0,
 };
 
 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
@@ -3657,6 +3659,7 @@
 #ifdef CONFIG_IPV6_MROUTE
 	array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding;
 #endif
+	array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6;
 }
 
 static inline size_t inet6_if_nlmsg_size(void)
@@ -4216,6 +4219,14 @@
 		},
 #endif
 		{
+			.ctl_name	=	CTL_UNNUMBERED,
+			.procname	=	"disable_ipv6",
+			.data		=	&ipv6_devconf.disable_ipv6,
+			.maxlen		=	sizeof(int),
+			.mode		=	0644,
+			.proc_handler	=	&proc_dointvec,
+		},
+		{
 			.ctl_name	=	0,	/* sentinel */
 		}
 	},

net/ipv6/ip6_input.c

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 34e5a96..ea81c61 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -71,7 +71,8 @@
 
 	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INRECEIVES);
 
-	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
+	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
+	    !idev || unlikely(idev->cnf.disable_ipv6)) {
 		IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
 		rcu_read_unlock();
 		goto out;

net/ipv6/ip6_output.c

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 871bdec..0981c1e 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -173,6 +173,13 @@
 
 int ip6_output(struct sk_buff *skb)
 {
+	struct inet6_dev *idev = ip6_dst_idev(skb->dst);
+	if (unlikely(idev->cnf.disable_ipv6)) {
+		IP6_INC_STATS(idev, IPSTATS_MIB_OUTDISCARDS);
+		kfree_skb(skb);
+		return 0;
+	}
+
 	if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
 				dst_allfrag(skb->dst))
 		return ip6_fragment(skb, ip6_output2);