net: Allow userns root to control the network bridge code.

Allow an unpriviled user who has created a user namespace, and then
created a network namespace to effectively use the new network
namespace, by reducing capable(CAP_NET_ADMIN) and
capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.

Allow setting bridge paramters via sysfs.

Allow all of the bridge ioctls:
BRCTL_ADD_IF
BRCTL_DEL_IF
BRCTL_SET_BRDIGE_FORWARD_DELAY
BRCTL_SET_BRIDGE_HELLO_TIME
BRCTL_SET_BRIDGE_MAX_AGE
BRCTL_SET_BRIDGE_AGING_TIME
BRCTL_SET_BRIDGE_STP_STATE
BRCTL_SET_BRIDGE_PRIORITY
BRCTL_SET_PORT_PRIORITY
BRCTL_SET_PATH_COST
BRCTL_ADD_BRIDGE
BRCTL_DEL_BRDIGE

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

1 files changed, 13 insertions, 12 deletions

diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c
index 7222fe1d5460..cd8c3a44ab7d 100644
--- a/net/bridge/br_ioctl.c
+++ b/net/bridge/br_ioctl.c
@@ -85,13 +85,14 @@ static int get_fdb_entries(struct net_bridge *br, void __user *userbuf,
 /* called with RTNL */
 static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
 {
+        struct net *net = dev_net(br->dev);
         struct net_device *dev;
         int ret;
 
-        if (!capable(CAP_NET_ADMIN))
+        if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
                 return -EPERM;
 
-        dev = __dev_get_by_index(dev_net(br->dev), ifindex);
+        dev = __dev_get_by_index(net, ifindex);
         if (dev == NULL)
                 return -EINVAL;
 
@@ -178,25 +179,25 @@ static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
         }
 
         case BRCTL_SET_BRIDGE_FORWARD_DELAY:
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 return br_set_forward_delay(br, args[1]);
 
         case BRCTL_SET_BRIDGE_HELLO_TIME:
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 return br_set_hello_time(br, args[1]);
 
         case BRCTL_SET_BRIDGE_MAX_AGE:
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 return br_set_max_age(br, args[1]);
 
         case BRCTL_SET_AGEING_TIME:
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 br->ageing_time = clock_t_to_jiffies(args[1]);
@@ -236,14 +237,14 @@ static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
         }
 
         case BRCTL_SET_BRIDGE_STP_STATE:
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 br_stp_set_enabled(br, args[1]);
                 return 0;
 
         case BRCTL_SET_BRIDGE_PRIORITY:
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 spin_lock_bh(&br->lock);
@@ -256,7 +257,7 @@ static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
                 struct net_bridge_port *p;
                 int ret;
 
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 spin_lock_bh(&br->lock);
@@ -273,7 +274,7 @@ static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
                 struct net_bridge_port *p;
                 int ret;
 
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 spin_lock_bh(&br->lock);
@@ -330,7 +331,7 @@ static int old_deviceless(struct net *net, void __user *uarg)
         {
                 char buf[IFNAMSIZ];
 
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
@@ -360,7 +361,7 @@ int br_ioctl_deviceless_stub(struct net *net, unsigned int cmd, void __user *uar
         {
                 char buf[IFNAMSIZ];
 
-                if (!capable(CAP_NET_ADMIN))
+                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
                         return -EPERM;
 
                 if (copy_from_user(buf, uarg, IFNAMSIZ))