[IPV6] NDISC: Add proxy_ndp sysctl.

We do not always need proxy NDP functionality even we
enable forwarding.

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

6 files changed, 27 insertions, 2 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 307cd4ec8edd..935e298f674a 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -765,6 +765,9 @@ conf/all/forwarding - BOOLEAN
 
         This referred to as global forwarding.
 
+proxy_ndp - BOOLEAN
+        Do proxy ndp.
+
 conf/interface/*:
         Change special settings per interface.
 
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 1d6d3ccc9413..caca57df0d7d 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -176,6 +176,7 @@ struct ipv6_devconf {
         __s32           accept_ra_rt_info_max_plen;
 #endif
 #endif
+        __s32           proxy_ndp;
         void            *sysctl;
 };
 
@@ -203,6 +204,7 @@ enum {
         DEVCONF_ACCEPT_RA_RTR_PREF,
         DEVCONF_RTR_PROBE_INTERVAL,
         DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
+        DEVCONF_PROXY_NDP,
         DEVCONF_MAX
 };
 
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index af61d9235409..736ed917a4f8 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -556,6 +556,7 @@ enum {
         NET_IPV6_ACCEPT_RA_RTR_PREF=20,
         NET_IPV6_RTR_PROBE_INTERVAL=21,
         NET_IPV6_ACCEPT_RA_RT_INFO_MAX_PLEN=22,
+        NET_IPV6_PROXY_NDP=23,
         __NET_IPV6_MAX
 };
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 1e5a296d0a82..825a291d5aa5 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -175,6 +175,7 @@ struct ipv6_devconf ipv6_devconf __read_mostly = {
         .accept_ra_rt_info_max_plen = 0,
 #endif
 #endif
+        .proxy_ndp              = 0,
 };
 
 static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -205,6 +206,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
         .accept_ra_rt_info_max_plen = 0,
 #endif
 #endif
+        .proxy_ndp              = 0,
 };
 
 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
@@ -3337,6 +3339,7 @@ static void inline ipv6_store_devconf(struct ipv6_devconf *cnf,
         array[DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN] = cnf->accept_ra_rt_info_max_plen;
 #endif
 #endif
+        array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp;
 }
 
 /* Maximum length of ifinfomsg attributes */
@@ -3860,6 +3863,14 @@ static struct addrconf_sysctl_table
 #endif
 #endif
                 {
+                        .ctl_name       =       NET_IPV6_PROXY_NDP,
+                        .procname       =       "proxy_ndp",
+                        .data           =       &ipv6_devconf.proxy_ndp,
+                        .maxlen         =       sizeof(int),
+                        .mode           =       0644,
+                        .proc_handler   =       &proc_dointvec,
+                },
+                {
                         .ctl_name       =       0,      /* sentinel */
                 }
         },
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index b2be749d2217..66716911962e 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -412,7 +412,9 @@ int ip6_forward(struct sk_buff *skb)
                 return -ETIMEDOUT;
         }
 
-        if (pneigh_lookup(&nd_tbl, &hdr->daddr, skb->dev, 0)) {
+        /* XXX: idev->cnf.proxy_ndp? */
+        if (ipv6_devconf.proxy_ndp &&
+            pneigh_lookup(&nd_tbl, &hdr->daddr, skb->dev, 0)) {
                 int proxied = ip6_forward_proxy_check(skb);
                 if (proxied > 0)
                         return ip6_input(skb);
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index ddf038636f01..76517a5f6576 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -824,6 +824,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
 
                 if (ipv6_chk_acast_addr(dev, &msg->target) ||
                     (idev->cnf.forwarding && 
+                     (ipv6_devconf.proxy_ndp || idev->cnf.proxy_ndp) &&
                      (pneigh = pneigh_lookup(&nd_tbl,
                                              &msg->target, dev, 0)) != NULL)) {
                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
@@ -966,8 +967,13 @@ static void ndisc_recv_na(struct sk_buff *skb)
                  * has already sent a NA to us.
                  */
                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
-                    pneigh_lookup(&nd_tbl, &msg->target, dev, 0))
+                    ipv6_devconf.forwarding && ipv6_devconf.proxy_ndp &&
+                    pneigh_lookup(&nd_tbl, &msg->target, dev, 0)) {
+                        /* XXX: idev->cnf.prixy_ndp */
+                        WARN_ON(skb->dst != NULL &&
+                                ((struct rt6_info *)skb->dst)->rt6i_idev);
                         goto out;
+                }
 
                 neigh_update(neigh, lladdr,
                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,