[IPV6]: ADDRCONF: Add accept_ra_pinfo sysctl.

This controls whether we accept Prefix Information in RAs.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 23 insertions, 3 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 8001faa76ea2..404afacb468d 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -723,6 +723,12 @@ accept_ra_defrtr - BOOLEAN
         Functional default: enabled if accept_ra is enabled.
                             disabled if accept_ra is disabled.
 
+accept_ra_pinfo - BOOLEAN
+        Learn Prefix Inforamtion in Router Advertisement.
+
+        Functional default: enabled if accept_ra is enabled.
+                            disabled if accept_ra is disabled.
+
 accept_redirects - BOOLEAN
         Accept Redirects.
 
@@ -733,8 +739,8 @@ autoconf - BOOLEAN
         Autoconfigure addresses using Prefix Information in Router 
         Advertisements.
 
-        Functional default: enabled if accept_ra is enabled.
-                            disabled if accept_ra is disabled.
+        Functional default: enabled if accept_ra_pinfo is enabled.
+                            disabled if accept_ra_pinfo is disabled.
 
 dad_transmits - INTEGER
         The amount of Duplicate Address Detection probes to send.
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index c5131a02869a..2c3b799480c5 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -146,6 +146,7 @@ struct ipv6_devconf {
 #endif
         __s32           max_addresses;
         __s32           accept_ra_defrtr;
+        __s32           accept_ra_pinfo;
         void            *sysctl;
 };
 
@@ -169,6 +170,7 @@ enum {
         DEVCONF_MAX_ADDRESSES,
         DEVCONF_FORCE_MLD_VERSION,
         DEVCONF_ACCEPT_RA_DEFRTR,
+        DEVCONF_ACCEPT_RA_PINFO,
         DEVCONF_MAX
 };
 
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 0f494137d037..09378ea505bd 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -532,6 +532,7 @@ enum {
         NET_IPV6_MAX_ADDRESSES=16,
         NET_IPV6_FORCE_MLD_VERSION=17,
         NET_IPV6_ACCEPT_RA_DEFRTR=18,
+        NET_IPV6_ACCEPT_RA_PINFO=19,
         __NET_IPV6_MAX
 };
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index fbcdcc6ba93b..631b51d0ccbc 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -166,6 +166,7 @@ struct ipv6_devconf ipv6_devconf = {
 #endif
         .max_addresses          = IPV6_MAX_ADDRESSES,
         .accept_ra_defrtr       = 1,
+        .accept_ra_pinfo        = 1,
 };
 
 static struct ipv6_devconf ipv6_devconf_dflt = {
@@ -188,6 +189,7 @@ static struct ipv6_devconf ipv6_devconf_dflt = {
 #endif
         .max_addresses          = IPV6_MAX_ADDRESSES,
         .accept_ra_defrtr       = 1,
+        .accept_ra_pinfo        = 1,
 };
 
 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
@@ -3119,6 +3121,7 @@ static void inline ipv6_store_devconf(struct ipv6_devconf *cnf,
 #endif
         array[DEVCONF_MAX_ADDRESSES] = cnf->max_addresses;
         array[DEVCONF_ACCEPT_RA_DEFRTR] = cnf->accept_ra_defrtr;
+        array[DEVCONF_ACCEPT_RA_PINFO] = cnf->accept_ra_pinfo;
 }
 
 static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev, 
@@ -3580,6 +3583,14 @@ static struct addrconf_sysctl_table
                         .proc_handler   =       &proc_dointvec,
                 },
                 {
+                        .ctl_name       =       NET_IPV6_ACCEPT_RA_PINFO,
+                        .procname       =       "accept_ra_pinfo",
+                        .data           =       &ipv6_devconf.accept_ra_pinfo,
+                        .maxlen         =       sizeof(int),
+                        .mode           =       0644,
+                        .proc_handler   =       &proc_dointvec,
+                },
+                {
                         .ctl_name       =       0,      /* sentinel */
                 }
         },
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index e17116796059..3b56be85234e 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1191,7 +1191,7 @@ skip_defrtr:
                              NEIGH_UPDATE_F_ISROUTER);
         }
 
-        if (ndopts.nd_opts_pi) {
+        if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
                 struct nd_opt_hdr *p;
                 for (p = ndopts.nd_opts_pi;
                      p;