ipv6 sit: Avoid extra need for compat layer in PRL management.

We've introduced extra need of compat layer for ip_tunnel_prl{}
for PRL (Potential Router List) management.  Though compat_ioctl
is still missing in ipv4/ipv6, let's make the interface more
straight-forward and eliminate extra need for nasty compat layer
anyway since the interface is new for 2.6.26.

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

2 files changed, 25 insertions, 21 deletions

diff --git a/include/linux/if_tunnel.h b/include/linux/if_tunnel.h
index f1fbe9c930d7..d4efe4014705 100644
--- a/include/linux/if_tunnel.h
+++ b/include/linux/if_tunnel.h
@@ -41,7 +41,7 @@ struct ip_tunnel_prl {
         __u16                   __reserved;
         __u32                   datalen;
         __u32                   __reserved2;
-        void __user             *data;
+        /* data follows */
 };
 
 /* PRL flags */
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 3de6ffdaedf2..32e871a6c25a 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -222,15 +222,18 @@ __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 
 }
 
-static int ipip6_tunnel_get_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
+static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
+                                struct ip_tunnel_prl __user *a)
 {
-        struct ip_tunnel_prl *kp;
+        struct ip_tunnel_prl kprl, *kp;
         struct ip_tunnel_prl_entry *prl;
         unsigned int cmax, c = 0, ca, len;
         int ret = 0;
 
-        cmax = a->datalen / sizeof(*a);
-        if (cmax > 1 && a->addr != htonl(INADDR_ANY))
+        if (copy_from_user(&kprl, a, sizeof(kprl)))
+                return -EFAULT;
+        cmax = kprl.datalen / sizeof(kprl);
+        if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
                 cmax = 1;
 
         /* For simple GET or for root users,
@@ -261,26 +264,25 @@ static int ipip6_tunnel_get_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
         for (prl = t->prl; prl; prl = prl->next) {
                 if (c > cmax)
                         break;
-                if (a->addr != htonl(INADDR_ANY) && prl->addr != a->addr)
+                if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
                         continue;
                 kp[c].addr = prl->addr;
                 kp[c].flags = prl->flags;
                 c++;
-                if (a->addr != htonl(INADDR_ANY))
+                if (kprl.addr != htonl(INADDR_ANY))
                         break;
         }
 out:
         read_unlock(&ipip6_lock);
 
         len = sizeof(*kp) * c;
-        ret = len ? copy_to_user(a->data, kp, len) : 0;
+        ret = 0;
+        if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
+                ret = -EFAULT;
 
         kfree(kp);
-        if (ret)
-                return -EFAULT;
 
-        a->datalen = len;
-        return 0;
+        return ret;
 }
 
 static int
@@ -873,11 +875,20 @@ ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
                 break;
 
         case SIOCGETPRL:
+                err = -EINVAL;
+                if (dev == sitn->fb_tunnel_dev)
+                        goto done;
+                err = -ENOENT;
+                if (!(t = netdev_priv(dev)))
+                        goto done;
+                err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
+                break;
+
         case SIOCADDPRL:
         case SIOCDELPRL:
         case SIOCCHGPRL:
                 err = -EPERM;
-                if (cmd != SIOCGETPRL && !capable(CAP_NET_ADMIN))
+                if (!capable(CAP_NET_ADMIN))
                         goto done;
                 err = -EINVAL;
                 if (dev == sitn->fb_tunnel_dev)
@@ -890,12 +901,6 @@ ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
                         goto done;
 
                 switch (cmd) {
-                case SIOCGETPRL:
-                        err = ipip6_tunnel_get_prl(t, &prl);
-                        if (!err && copy_to_user(ifr->ifr_ifru.ifru_data,
-                                                 &prl, sizeof(prl)))
-                                err = -EFAULT;
-                        break;
                 case SIOCDELPRL:
                         err = ipip6_tunnel_del_prl(t, &prl);
                         break;
@@ -904,8 +909,7 @@ ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
                         err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
                         break;
                 }
-                if (cmd != SIOCGETPRL)
-                        netdev_state_change(dev);
+                netdev_state_change(dev);
                 break;
 
         default: