[PATCH net-next V6 3/6] net: add sysctl for enabling RFC 8335 PROBE messages
From: Andreas Roeseler <hidden>
Date: 2021-03-30 01:46:26
Subsystem:
documentation, networking [general], the rest · Maintainers:
Jonathan Corbet, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- Changes: v1 -> v2: - Combine patches related to sysctl v2 -> v3: Suggested by Willem de Bruijn [off-list ref] - 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