[IPV6] NDISC: Don't rely on node-type hint from L2 unless required.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

3 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index e10e55c9b081..e517701c25ba 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -313,7 +313,9 @@ struct sk_buff {
         __u16                   tc_verd;        /* traffic control verdict */
 #endif
 #endif
+#ifdef CONFIG_IPV6_NDISC_NODETYPE
         __u8                    ndisc_nodetype:2;
+#endif
         /* 14 bit hole */
 
 #ifdef CONFIG_NET_DMA
diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 47263e45bacb..7d2e7f0941ac 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -168,6 +168,7 @@ config IPV6_SIT
         tristate "IPv6: IPv6-in-IPv4 tunnel (SIT driver)"
         depends on IPV6
         select INET_TUNNEL
+        select IPV6_NDISC_NODETYPE
         default y
         ---help---
           Tunneling means encapsulating data of one protocol type within
@@ -178,6 +179,9 @@ config IPV6_SIT
 
           Saying M here will produce a module called sit.ko. If unsure, say Y.
 
+config IPV6_NDISC_NODETYPE
+        bool
+
 config IPV6_TUNNEL
         tristate "IPv6: IP-in-IPv6 tunnel (RFC2473)"
         select INET6_TUNNEL
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 16273e11e53d..c400b874097a 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1092,11 +1092,13 @@ static void ndisc_router_discovery(struct sk_buff *skb)
                 return;
         }
 
+#ifdef CONFIG_IPV6_NDISC_NODETYPE
         if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
                 ND_PRINTK2(KERN_WARNING
                            "ICMPv6 RA: from host or unauthorized router\n");
                 return;
         }
+#endif
 
         /*
          *      set the RA_RECV flag in the interface
@@ -1121,9 +1123,11 @@ static void ndisc_router_discovery(struct sk_buff *skb)
                 return;
         }
 
+#ifdef CONFIG_IPV6_NDISC_NODETYPE
         /* skip link-specific parameters from interior routers */
         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
                 goto skip_linkparms;
+#endif
 
         if (in6_dev->if_flags & IF_RS_SENT) {
                 /*
@@ -1239,7 +1243,9 @@ skip_defrtr:
                 }
         }
 
+#ifdef CONFIG_IPV6_NDISC_NODETYPE
 skip_linkparms:
+#endif
 
         /*
          *      Process options.
@@ -1286,9 +1292,11 @@ skip_linkparms:
         }
 #endif
 
+#ifdef CONFIG_IPV6_NDISC_NODETYPE
         /* skip link-specific ndopts from interior routers */
         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
                 goto out;
+#endif
 
         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
                 struct nd_opt_hdr *p;
@@ -1353,6 +1361,7 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
         int optlen;
         u8 *lladdr = NULL;
 
+#ifdef CONFIG_IPV6_NDISC_NODETYPE
         switch (skb->ndisc_nodetype) {
         case NDISC_NODETYPE_HOST:
         case NDISC_NODETYPE_NODEFAULT:
@@ -1360,6 +1369,7 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
                            "ICMPv6 Redirect: from host or unauthorized router\n");
                 return;
         }
+#endif
 
         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
                 ND_PRINTK2(KERN_WARNING