netns: ip6mr: allocate mroute6_socket per-namespace.

Preliminary work to make IPv6 multicast forwarding netns-aware.

Make IPv6 multicast forwarding mroute6_socket per-namespace,
moves it into struct netns_ipv6.

At the moment, mroute6_socket is only referenced in init_net.

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 21 insertions, 15 deletions

diff --git a/include/linux/mroute6.h b/include/linux/mroute6.h
index 6f4c180179e2..2cd9901ee5c7 100644
--- a/include/linux/mroute6.h
+++ b/include/linux/mroute6.h
@@ -117,6 +117,7 @@ struct sioc_mif_req6
 
 #include <linux/pim.h>
 #include <linux/skbuff.h>       /* for struct sk_buff_head */
+#include <net/net_namespace.h>
 
 #ifdef CONFIG_IPV6_MROUTE
 static inline int ip6_mroute_opt(int opt)
@@ -232,10 +233,13 @@ struct rtmsg;
 extern int ip6mr_get_route(struct sk_buff *skb, struct rtmsg *rtm, int nowait);
 
 #ifdef CONFIG_IPV6_MROUTE
-extern struct sock *mroute6_socket;
+static inline struct sock *mroute6_socket(struct net *net)
+{
+        return net->ipv6.mroute6_sk;
+}
 extern int ip6mr_sk_done(struct sock *sk);
 #else
-#define mroute6_socket NULL
+static inline struct sock *mroute6_socket(struct net *net) { return NULL; }
 static inline int ip6mr_sk_done(struct sock *sk) { return 0; }
 #endif
 #endif
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 2932721180c0..8a0a67d073b3 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -55,5 +55,8 @@ struct netns_ipv6 {
         struct sock             *ndisc_sk;
         struct sock             *tcp_sk;
         struct sock             *igmp_sk;
+#ifdef CONFIG_IPV6_MROUTE
+        struct sock             *mroute6_sk;
+#endif
 };
 #endif
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 7d92fd97cfb9..4b15938bef4d 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -137,7 +137,8 @@ static int ip6_output2(struct sk_buff *skb)
                 struct inet6_dev *idev = ip6_dst_idev(skb->dst);
 
                 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
-                    ((mroute6_socket && !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
+                    ((mroute6_socket(dev_net(dev)) &&
+                     !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
                      ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
                                          &ipv6_hdr(skb)->saddr))) {
                         struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index d1008e6891e7..02163dbf84c3 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -49,9 +49,6 @@
 #include <net/addrconf.h>
 #include <linux/netfilter_ipv6.h>
 
-struct sock *mroute6_socket;
-
-
 /* Big lock, protecting vif table, mrt cache and mroute socket state.
    Note that the changes are semaphored via rtnl_lock.
  */
@@ -820,7 +817,7 @@ static int ip6mr_cache_report(struct sk_buff *pkt, mifi_t mifi, int assert)
         skb_pull(skb, sizeof(struct ipv6hdr));
         }
 
-        if (mroute6_socket == NULL) {
+        if (init_net.ipv6.mroute6_sk == NULL) {
                 kfree_skb(skb);
                 return -EINVAL;
         }
@@ -828,7 +825,8 @@ static int ip6mr_cache_report(struct sk_buff *pkt, mifi_t mifi, int assert)
         /*
          *      Deliver to user space multicast routing algorithms
          */
-        if ((ret = sock_queue_rcv_skb(mroute6_socket, skb)) < 0) {
+        ret = sock_queue_rcv_skb(init_net.ipv6.mroute6_sk, skb);
+        if (ret < 0) {
                 if (net_ratelimit())
                         printk(KERN_WARNING "mroute6: pending queue full, dropping entries.\n");
                 kfree_skb(skb);
@@ -1145,8 +1143,8 @@ static int ip6mr_sk_init(struct sock *sk)
 
         rtnl_lock();
         write_lock_bh(&mrt_lock);
-        if (likely(mroute6_socket == NULL))
-                mroute6_socket = sk;
+        if (likely(init_net.ipv6.mroute6_sk == NULL))
+                init_net.ipv6.mroute6_sk = sk;
         else
                 err = -EADDRINUSE;
         write_unlock_bh(&mrt_lock);
@@ -1161,9 +1159,9 @@ int ip6mr_sk_done(struct sock *sk)
         int err = 0;
 
         rtnl_lock();
-        if (sk == mroute6_socket) {
+        if (sk == init_net.ipv6.mroute6_sk) {
                 write_lock_bh(&mrt_lock);
-                mroute6_socket = NULL;
+                init_net.ipv6.mroute6_sk = NULL;
                 write_unlock_bh(&mrt_lock);
 
                 mroute_clean_tables(sk);
@@ -1189,7 +1187,7 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, int
         mifi_t mifi;
 
         if (optname != MRT6_INIT) {
-                if (sk != mroute6_socket && !capable(CAP_NET_ADMIN))
+                if (sk != init_net.ipv6.mroute6_sk && !capable(CAP_NET_ADMIN))
                         return -EACCES;
         }
 
@@ -1214,7 +1212,7 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, int
                 if (vif.mif6c_mifi >= MAXMIFS)
                         return -ENFILE;
                 rtnl_lock();
-                ret = mif6_add(&vif, sk == mroute6_socket);
+                ret = mif6_add(&vif, sk == init_net.ipv6.mroute6_sk);
                 rtnl_unlock();
                 return ret;
 
@@ -1242,7 +1240,7 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, int
                 if (optname == MRT6_DEL_MFC)
                         ret = ip6mr_mfc_delete(&mfc);
                 else
-                        ret = ip6mr_mfc_add(&mfc, sk == mroute6_socket);
+                        ret = ip6mr_mfc_add(&mfc, sk == init_net.ipv6.mroute6_sk);
                 rtnl_unlock();
                 return ret;