IPv6: Add 'autoconf' and 'disable_ipv6' module parameters

Add 'autoconf' and 'disable_ipv6' parameters to the IPv6 module.

The first controls if IPv6 addresses are autoconfigured from
prefixes received in Router Advertisements.  The IPv6 loopback
(::1) and link-local addresses are still configured.

The second controls if IPv6 addresses are desired at all.  No
IPv6 addresses will be added to any interfaces.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 44 insertions, 0 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 3ffd233c369c..8be76235fe67 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1057,6 +1057,13 @@ disable_ipv6 - BOOLEAN
         address.
         Default: FALSE (enable IPv6 operation)
 
+        When this value is changed from 1 to 0 (IPv6 is being enabled),
+        it will dynamically create a link-local address on the given
+        interface and start Duplicate Address Detection, if necessary.
+
+        When this value is changed from 0 to 1 (IPv6 is being disabled),
+        it will dynamically delete all address on the given interface.
+
 accept_dad - INTEGER
         Whether to accept DAD (Duplicate Address Detection).
         0: Disable DAD
diff --git a/Documentation/networking/ipv6.txt b/Documentation/networking/ipv6.txt
index 268e5c103dd8..9fd7e21296c8 100644
--- a/Documentation/networking/ipv6.txt
+++ b/Documentation/networking/ipv6.txt
@@ -33,3 +33,40 @@ disable
 
                 A reboot is required to enable IPv6.
 
+autoconf
+
+        Specifies whether to enable IPv6 address autoconfiguration
+        on all interfaces.  This might be used when one does not wish
+        for addresses to be automatically generated from prefixes
+        received in Router Advertisements.
+
+        The possible values and their effects are:
+
+        0
+                IPv6 address autoconfiguration is disabled on all interfaces.
+
+                Only the IPv6 loopback address (::1) and link-local addresses
+                will be added to interfaces.
+
+        1
+                IPv6 address autoconfiguration is enabled on all interfaces.
+
+                This is the default value.
+
+disable_ipv6
+
+        Specifies whether to disable IPv6 on all interfaces.
+        This might be used when no IPv6 addresses are desired.
+
+        The possible values and their effects are:
+
+        0
+                IPv6 is enabled on all interfaces.
+
+                This is the default value.
+
+        1
+                IPv6 is disabled on all interfaces.
+
+                No IPv6 addresses will be added to interfaces.
+