IPv4 has icmp_echo_ignore_broadcast to prevent responding to broadcast pings.
IPv6 needs a similar mechanism.
Signed-off-by: Stephen Suryaputra <ssuryae...@gmail.com>
---
Documentation/networking/ip-sysctl.txt | 5 +++++
include/net/netns/ipv6.h | 1 +
include/uapi/linux/sysctl.h | 3 ++-
net/ipv6/af_inet6.c | 1 +
net/ipv6/icmp.c | 12 ++++++++++++
5 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/Documentation/networking/ip-sysctl.txt
b/Documentation/networking/ip-sysctl.txt
index acdfb5d2bcaa..55ea7def46be 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1918,6 +1918,11 @@ echo_ignore_all - BOOLEAN
requests sent to it over the IPv6 protocol.
Default: 0
+echo_ignore_multicast - BOOLEAN
+ If set non-zero, then the kernel will ignore all ICMP ECHO
+ requests sent to it over the IPv6 protocol via multicast.
+ Default: 0
+
xfrm6_gc_thresh - INTEGER
The threshold at which we will start garbage collecting for IPv6
destination cache entries. At twice this value the system will
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index b028a1dc150d..e29aff15acc9 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -33,6 +33,7 @@ struct netns_sysctl_ipv6 {
int auto_flowlabels;
int icmpv6_time;
int icmpv6_echo_ignore_all;
+ int icmpv6_echo_ignore_multicast;
int anycast_src_echo_reply;
int ip_nonlocal_bind;
int fwmark_reflect;
diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
index 87aa2a6d9125..bd83ddedc014 100644
--- a/include/uapi/linux/sysctl.h
+++ b/include/uapi/linux/sysctl.h
@@ -577,7 +577,8 @@ enum {
/* /proc/sys/net/ipv6/icmp */
enum {
NET_IPV6_ICMP_RATELIMIT = 1,
- NET_IPV6_ICMP_ECHO_IGNORE_ALL = 2
+ NET_IPV6_ICMP_ECHO_IGNORE_ALL = 2,
+ NET_IPV6_ICMP_ECHO_IGNORE_MULTICAST = 3
};
/* /proc/sys/net/<protocol>/neigh/<dev> */
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 2f45d2a3e3a3..fdc117de849c 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -847,6 +847,7 @@ static int __net_init inet6_net_init(struct net *net)
net->ipv6.sysctl.bindv6only = 0;
net->ipv6.sysctl.icmpv6_time = 1*HZ;
net->ipv6.sysctl.icmpv6_echo_ignore_all = 0;
+ net->ipv6.sysctl.icmpv6_echo_ignore_multicast = 0;
net->ipv6.sysctl.flowlabel_consistency = 1;
net->ipv6.sysctl.auto_flowlabels = IP6_DEFAULT_AUTO_FLOW_LABELS;
net->ipv6.sysctl.idgen_retries = 3;
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 802faa2fcc0e..0907bcede5e5 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -684,6 +684,10 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
struct ipcm6_cookie ipc6;
u32 mark = IP6_REPLY_MARK(net, skb->mark);
+ if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
+ net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
+ return;
+
saddr = &ipv6_hdr(skb)->daddr;
if (!ipv6_unicast_destination(skb) &&
@@ -1115,6 +1119,13 @@ static struct ctl_table ipv6_icmp_table_template[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
+ {
+ .procname = "echo_ignore_multicast",
+ .data =
&init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
{ },
};
@@ -1129,6 +1140,7 @@ struct ctl_table * __net_init
ipv6_icmp_sysctl_init(struct net *net)
if (table) {
table[0].data = &net->ipv6.sysctl.icmpv6_time;
table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
+ table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
}
return table;
}
--
2.17.1
