lkml.org 
[lkml]   [2018]   [Aug]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH v2] 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>
---
Changes in v2:
- Added support for sysctl interface (and not just /proc filesystem)

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 | 16 +++++++++++++---
5 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index ce8fbf5..5042a13 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1863,6 +1863,11 @@ 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
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 762ac99..f0e396a 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -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;
diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
index 6b58371..d71013f 100644
--- a/include/uapi/linux/sysctl.h
+++ b/include/uapi/linux/sysctl.h
@@ -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> */
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 9ed0eae..d0033b3 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -833,6 +833,7 @@ 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;
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index ef2505a..1d869f1 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -800,6 +800,7 @@ 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;
@@ -849,7 +850,8 @@ 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:
@@ -1110,6 +1112,13 @@ 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,
+ },
{ },
};

@@ -1121,9 +1130,10 @@ 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
--
2.7.4
\
 
 \ /
  Last update: 2018-08-10 17:48    [W:0.035 / U:40.212 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site