[NET]: Make the loopback device per network namespace.

This patch makes loopback_dev per network namespace.  Adding
code to create a different loopback device for each network
namespace and adding the code to free a loopback device
when a network namespace exits.

This patch modifies all users the loopback_dev so they
access it as init_net.loopback_dev, keeping all of the
code compiling and working.  A later pass will be needed to
update the users to use something other than the initial network
namespace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 10 insertions, 10 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index ca2878dc6188..2a9b363e820c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1402,8 +1402,8 @@ static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 {
         struct rtable *rt = (struct rtable *) dst;
         struct in_device *idev = rt->idev;
-        if (dev != loopback_dev && idev && idev->dev == dev) {
-                struct in_device *loopback_idev = in_dev_get(loopback_dev);
+        if (dev != init_net.loopback_dev && idev && idev->dev == dev) {
+                struct in_device *loopback_idev = in_dev_get(init_net.loopback_dev);
                 if (loopback_idev) {
                         rt->idev = loopback_idev;
                         in_dev_put(idev);
@@ -1555,7 +1555,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 #endif
         rth->rt_iif     =
         rth->fl.iif     = dev->ifindex;
-        rth->u.dst.dev  = loopback_dev;
+        rth->u.dst.dev  = init_net.loopback_dev;
         dev_hold(rth->u.dst.dev);
         rth->idev       = in_dev_get(rth->u.dst.dev);
         rth->fl.oif     = 0;
@@ -1812,7 +1812,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
         if (res.type == RTN_LOCAL) {
                 int result;
                 result = fib_validate_source(saddr, daddr, tos,
-                                             loopback_dev->ifindex,
+                                             init_net.loopback_dev->ifindex,
                                              dev, &spec_dst, &itag);
                 if (result < 0)
                         goto martian_source;
@@ -1879,7 +1879,7 @@ local_input:
 #endif
         rth->rt_iif     =
         rth->fl.iif     = dev->ifindex;
-        rth->u.dst.dev  = loopback_dev;
+        rth->u.dst.dev  = init_net.loopback_dev;
         dev_hold(rth->u.dst.dev);
         rth->idev       = in_dev_get(rth->u.dst.dev);
         rth->rt_gateway = daddr;
@@ -2149,7 +2149,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
                                                   RT_SCOPE_UNIVERSE),
                                       } },
                             .mark = oldflp->mark,
-                            .iif = loopback_dev->ifindex,
+                            .iif = init_net.loopback_dev->ifindex,
                             .oif = oldflp->oif };
         struct fib_result res;
         unsigned flags = 0;
@@ -2243,9 +2243,9 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
                         fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
                 if (dev_out)
                         dev_put(dev_out);
-                dev_out = loopback_dev;
+                dev_out = init_net.loopback_dev;
                 dev_hold(dev_out);
-                fl.oif = loopback_dev->ifindex;
+                fl.oif = init_net.loopback_dev->ifindex;
                 res.type = RTN_LOCAL;
                 flags |= RTCF_LOCAL;
                 goto make_route;
@@ -2290,7 +2290,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
                         fl.fl4_src = fl.fl4_dst;
                 if (dev_out)
                         dev_put(dev_out);
-                dev_out = loopback_dev;
+                dev_out = init_net.loopback_dev;
                 dev_hold(dev_out);
                 fl.oif = dev_out->ifindex;
                 if (res.fi)
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 29ab3de8c47f..329825ca68fe 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -306,7 +306,7 @@ static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 
         xdst = (struct xfrm_dst *)dst;
         if (xdst->u.rt.idev->dev == dev) {
-                struct in_device *loopback_idev = in_dev_get(loopback_dev);
+                struct in_device *loopback_idev = in_dev_get(init_net.loopback_dev);
                 BUG_ON(!loopback_idev);
 
                 do {