[IPV6]: ROUTE: Add accept_ra_rtr_pref sysctl.

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

5 files changed, 32 insertions, 1 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 404afacb468d..87bbd774c2b2 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -729,6 +729,12 @@ accept_ra_pinfo - BOOLEAN
         Functional default: enabled if accept_ra is enabled.
                             disabled if accept_ra is disabled.
 
+accept_ra_rtr_pref - BOOLEAN
+        Accept Router Preference in RA.
+
+        Functional default: enabled if accept_ra is enabled.
+                            disabled if accept_ra is disabled.
+
 accept_redirects - BOOLEAN
         Accept Redirects.
 
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 2c3b799480c5..108b75dccd9f 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -147,6 +147,9 @@ struct ipv6_devconf {
         __s32           max_addresses;
         __s32           accept_ra_defrtr;
         __s32           accept_ra_pinfo;
+#ifdef CONFIG_IPV6_ROUTER_PREF
+        __s32           accept_ra_rtr_pref;
+#endif
         void            *sysctl;
 };
 
@@ -171,6 +174,7 @@ enum {
         DEVCONF_FORCE_MLD_VERSION,
         DEVCONF_ACCEPT_RA_DEFRTR,
         DEVCONF_ACCEPT_RA_PINFO,
+        DEVCONF_ACCEPT_RA_RTR_PREF,
         DEVCONF_MAX
 };
 
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 09378ea505bd..236f537b38d2 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -533,6 +533,7 @@ enum {
         NET_IPV6_FORCE_MLD_VERSION=17,
         NET_IPV6_ACCEPT_RA_DEFRTR=18,
         NET_IPV6_ACCEPT_RA_PINFO=19,
+        NET_IPV6_ACCEPT_RA_RTR_PREF=20,
         __NET_IPV6_MAX
 };
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 631b51d0ccbc..51edba5fea26 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -167,6 +167,9 @@ struct ipv6_devconf ipv6_devconf = {
         .max_addresses          = IPV6_MAX_ADDRESSES,
         .accept_ra_defrtr       = 1,
         .accept_ra_pinfo        = 1,
+#ifdef CONFIG_IPV6_ROUTER_PREF
+        .accept_ra_rtr_pref     = 1,
+#endif
 };
 
 static struct ipv6_devconf ipv6_devconf_dflt = {
@@ -190,6 +193,9 @@ static struct ipv6_devconf ipv6_devconf_dflt = {
         .max_addresses          = IPV6_MAX_ADDRESSES,
         .accept_ra_defrtr       = 1,
         .accept_ra_pinfo        = 1,
+#ifdef CONFIG_IPV6_ROUTER_PREF
+        .accept_ra_rtr_pref     = 1,
+#endif
 };
 
 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
@@ -3122,6 +3128,9 @@ static void inline ipv6_store_devconf(struct ipv6_devconf *cnf,
         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;
+#ifdef CONFIG_IPV6_ROUTER_PREF
+        array[DEVCONF_ACCEPT_RA_RTR_PREF] = cnf->accept_ra_rtr_pref;
+#endif
 }
 
 static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev, 
@@ -3590,6 +3599,16 @@ static struct addrconf_sysctl_table
                         .mode           =       0644,
                         .proc_handler   =       &proc_dointvec,
                 },
+#ifdef CONFIG_IPV6_ROUTER_PREF
+                {
+                        .ctl_name       =       NET_IPV6_ACCEPT_RA_RTR_PREF,
+                        .procname       =       "accept_ra_rtr_pref",
+                        .data           =       &ipv6_devconf.accept_ra_rtr_pref,
+                        .maxlen         =       sizeof(int),
+                        .mode           =       0644,
+                        .proc_handler   =       &proc_dointvec,
+                },
+#endif
                 {
                         .ctl_name       =       0,      /* sentinel */
                 }
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 966ab6b3022e..f4462ee33024 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1090,7 +1090,8 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 #ifdef CONFIG_IPV6_ROUTER_PREF
         pref = ra_msg->icmph.icmp6_router_pref;
         /* 10b is handled as if it were 00b (medium) */
-        if (pref == ICMPV6_ROUTER_PREF_INVALID)
+        if (pref == ICMPV6_ROUTER_PREF_INVALID ||
+            in6_dev->cnf.accept_ra_rtr_pref)
                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
 #endif