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>
This commit is contained in:
Virgile Jarry 2018-08-10 17:48:15 +02:00 committed by David S. Miller
parent 8f78004442
commit e6f86b0f7a
5 changed files with 22 additions and 4 deletions

View File

@ -1882,6 +1882,11 @@ ratelimit - INTEGER
otherwise the minimal space between responses in milliseconds.
Default: 1000
echo_ignore_all - BOOLEAN
If set non-zero, then the kernel will ignore all ICMP ECHO
requests sent to it over the IPv6 protocol.
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

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@ -32,6 +32,7 @@ struct netns_sysctl_ipv6 {
int flowlabel_consistency;
int auto_flowlabels;
int icmpv6_time;
int icmpv6_echo_ignore_all;
int anycast_src_echo_reply;
int ip_nonlocal_bind;
int fwmark_reflect;

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@ -575,7 +575,8 @@ enum {
/* /proc/sys/net/ipv6/icmp */
enum {
NET_IPV6_ICMP_RATELIMIT=1
NET_IPV6_ICMP_RATELIMIT = 1,
NET_IPV6_ICMP_ECHO_IGNORE_ALL = 2
};
/* /proc/sys/net/<protocol>/neigh/<dev> */

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@ -832,6 +832,7 @@ 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.flowlabel_consistency = 1;
net->ipv6.sysctl.auto_flowlabels = IP6_DEFAULT_AUTO_FLOW_LABELS;
net->ipv6.sysctl.idgen_retries = 3;

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@ -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