From 0b03a5ca8b14321366eec4a903922d2b46d585ff Mon Sep 17 00:00:00 2001 From: Stephen Suryaputra Date: Wed, 20 Mar 2019 10:29:27 -0400 Subject: ipv6: Add icmp_echo_ignore_anycast for ICMPv6 In addition to icmp_echo_ignore_multicast, there is a need to also prevent responding to pings to anycast addresses for security. Signed-off-by: Stephen Suryaputra Signed-off-by: David S. Miller --- net/ipv6/icmp.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'net/ipv6/icmp.c') diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 0907bcede5e5..cc14b9998941 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -683,6 +683,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb) struct dst_entry *dst; struct ipcm6_cookie ipc6; u32 mark = IP6_REPLY_MARK(net, skb->mark); + bool acast; if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) && net->ipv6.sysctl.icmpv6_echo_ignore_multicast) @@ -690,9 +691,12 @@ static void icmpv6_echo_reply(struct sk_buff *skb) saddr = &ipv6_hdr(skb)->daddr; + acast = ipv6_anycast_destination(skb_dst(skb), saddr); + if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast) + return; + if (!ipv6_unicast_destination(skb) && - !(net->ipv6.sysctl.anycast_src_echo_reply && - ipv6_anycast_destination(skb_dst(skb), saddr))) + !(net->ipv6.sysctl.anycast_src_echo_reply && acast)) saddr = NULL; memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); @@ -1126,6 +1130,13 @@ static struct ctl_table ipv6_icmp_table_template[] = { .mode = 0644, .proc_handler = proc_dointvec, }, + { + .procname = "echo_ignore_anycast", + .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, { }, }; @@ -1141,6 +1152,7 @@ struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) 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; + table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast; } return table; } -- cgit v1.2.3-59-g8ed1b