ipv6: Add icmp_echo_ignore_all support for ICMPv6
Preventing the kernel from responding to ICMP Echo Requests messages
can be useful in several ways. The sysctl parameter
'icmp_echo_ignore_all' can be used to prevent the kernel from
responding to IPv4 ICMP echo requests. For IPv6 pings, such
a sysctl kernel parameter did not exist.
Add the ability to prevent the kernel from responding to IPv6
ICMP echo requests through the use of the following sysctl
parameter : /proc/sys/net/ipv6/icmp/echo_ignore_all.
Update the documentation to reflect this change.
Signed-off-by: Virgile Jarry <virgile@acceis.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 7f6b1f8..c9c53ad 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -794,6 +794,7 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
static int icmpv6_rcv(struct sk_buff *skb)
{
+ struct net *net = dev_net(skb->dev);
struct net_device *dev = skb->dev;
struct inet6_dev *idev = __in6_dev_get(dev);
const struct in6_addr *saddr, *daddr;
@@ -843,7 +844,8 @@ static int icmpv6_rcv(struct sk_buff *skb)
switch (type) {
case ICMPV6_ECHO_REQUEST:
- icmpv6_echo_reply(skb);
+ if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
+ icmpv6_echo_reply(skb);
break;
case ICMPV6_ECHO_REPLY:
@@ -1104,6 +1106,13 @@ static struct ctl_table ipv6_icmp_table_template[] = {
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
},
+ {
+ .procname = "echo_ignore_all",
+ .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
{ },
};
@@ -1115,9 +1124,10 @@ struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
sizeof(ipv6_icmp_table_template),
GFP_KERNEL);
- if (table)
+ if (table) {
table[0].data = &net->ipv6.sysctl.icmpv6_time;
-
+ table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
+ }
return table;
}
#endif