Section 8 of RFC 8335 specifies potential security concerns of
responding to PROBE requests, and states that nodes that support PROBE
functionality MUST be able to enable/disable responses and that
responses MUST be disabled by default
Signed-off-by: Andreas Roeseler <andreas.a.roese...@gmail.com>
---
Changes:
v1 -> v2:
- Combine patches related to sysctl
v2 -> v3:
Suggested by Willem de Bruijn <willemdebruijn.ker...@gmail.com>
- Use proc_dointvec_minmax with zero and one
v5 -> v6:
- Add documentation to ip-sysctl.rst
---
Documentation/networking/ip-sysctl.rst | 6 ++++++
include/net/netns/ipv4.h | 1 +
net/ipv4/sysctl_net_ipv4.c | 9 +++++++++
3 files changed, 16 insertions(+)
diff --git a/Documentation/networking/ip-sysctl.rst
b/Documentation/networking/ip-sysctl.rst
index c7952ac5bd2f..4130bce40765 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1143,6 +1143,12 @@ icmp_echo_ignore_all - BOOLEAN
Default: 0
+icmp_echo_enable_probe - BOOLEAN
+ If set to one, then the kernel will respond to RFC 8335 PROBE
+ requests sent to it.
+
+ Default: 0
+
icmp_echo_ignore_broadcasts - BOOLEAN
If set non-zero, then the kernel will ignore all ICMP ECHO and
TIMESTAMP requests sent to it via broadcast/multicast.
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index d377266d133f..9c8dd424d79b 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -84,6 +84,7 @@ struct netns_ipv4 {
#endif
u8 sysctl_icmp_echo_ignore_all;
+ u8 sysctl_icmp_echo_enable_probe;
u8 sysctl_icmp_echo_ignore_broadcasts;
u8 sysctl_icmp_ignore_bogus_error_responses;
u8 sysctl_icmp_errors_use_inbound_ifaddr;
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 442ff4be1bde..b1a340e8738f 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -599,6 +599,15 @@ static struct ctl_table ipv4_net_table[] = {
.mode = 0644,
.proc_handler = proc_dou8vec_minmax,
},
+ {
+ .procname = "icmp_echo_enable_probe",
+ .data = &init_net.ipv4.sysctl_icmp_echo_enable_probe,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE
+ },
{
.procname = "icmp_echo_ignore_broadcasts",
.data =
&init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
--
2.17.1
