From e6f86b0f7ae473969a3301b74bf98af9e42ecd0e Mon Sep 17 00:00:00 2001 From: Virgile Jarry Date: Fri, 10 Aug 2018 17:48:15 +0200 Subject: 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 Signed-off-by: David S. Miller --- net/ipv6/icmp.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'net/ipv6/icmp.c') diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 7f6b1f81c200..c9c53ade55c3 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -794,6 +794,7 @@ out: 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 -- cgit v1.2.3-59-g8ed1b