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

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

5 files changed, 26 insertions, 1 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 71c7bea97160..dae980e8f1b9 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1025,6 +1025,10 @@ max_addresses - INTEGER
         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.
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index cde056e08181..d9d7f9b69eb4 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -163,6 +163,7 @@ struct ipv6_devconf {
 #ifdef CONFIG_IPV6_MROUTE
         __s32           mc_forwarding;
 #endif
+        __s32           disable_ipv6;
         void            *sysctl;
 };
 
@@ -194,6 +195,7 @@ enum {
         DEVCONF_OPTIMISTIC_DAD,
         DEVCONF_ACCEPT_SOURCE_ROUTE,
         DEVCONF_MC_FORWARDING,
+        DEVCONF_DISABLE_IPV6,
         DEVCONF_MAX
 };
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8b6875f02039..8c5cff50bbed 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -183,6 +183,7 @@ struct ipv6_devconf ipv6_devconf __read_mostly = {
 #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 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
 #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 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
 #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 @@ static struct addrconf_sysctl_table
                 },
 #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 */
                 }
         },
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 34e5a96623ae..ea81c614dde2 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -71,7 +71,8 @@ int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt
 
         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;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 871bdec09edb..0981c1ef3057 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -173,6 +173,13 @@ static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
 
 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);