net: socket: simplify dev_ifconf handling

The dev_ifconf() calling conventions make compat handling
more complicated than necessary, simplify this by moving
the in_compat_syscall() check into the function.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 6630a9f0b0f0e0b60068afaf075d63b2eb8e6d45..da2c273c7e0ab0370269473aa61703b2928baf71 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4008,7 +4008,7 @@ void netdev_rx_handler_unregister(struct net_device *dev);
 bool dev_valid_name(const char *name);
 int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
                bool *need_copyout);
-int dev_ifconf(struct net *net, struct ifconf *, int);
+int dev_ifconf(struct net *net, struct ifconf __user *ifc);
 int dev_ethtool(struct net *net, struct ifreq *);
 unsigned int dev_get_flags(const struct net_device *);
 int __dev_change_flags(struct net_device *dev, unsigned int flags,

diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index c22c3dc15ce9a2cae0caca76d370349eb5538c81..950e2fe5d56afdb9bcc7934f293a444141fd301a 100644 (file)
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -31,48 +31,51 @@ static int dev_ifname(struct net *net, struct ifreq *ifr)
  *     size eventually, and there is nothing I can do about it.
  *     Thus we will need a 'compatibility mode'.
  */
-
-int dev_ifconf(struct net *net, struct ifconf *ifc, int size)
+int dev_ifconf(struct net *net, struct ifconf __user *uifc)
 {
        struct net_device *dev;
-       char __user *pos;
-       int len;
-       int total;
-       int i;
+       void __user *pos;
+       size_t size;
+       int len, total = 0, done;
 
-       /*
-        *      Fetch the caller's info block.
-        */
+       /* both the ifconf and the ifreq structures are slightly different */
+       if (in_compat_syscall()) {
+               struct compat_ifconf ifc32;
+
+               if (copy_from_user(&ifc32, uifc, sizeof(struct compat_ifconf)))
+                       return -EFAULT;
 
-       pos = ifc->ifc_buf;
-       len = ifc->ifc_len;
+               pos = compat_ptr(ifc32.ifcbuf);
+               len = ifc32.ifc_len;
+               size = sizeof(struct compat_ifreq);
+       } else {
+               struct ifconf ifc;
 
-       /*
-        *      Loop over the interfaces, and write an info block for each.
-        */
+               if (copy_from_user(&ifc, uifc, sizeof(struct ifconf)))
+                       return -EFAULT;
 
-       total = 0;
+               pos = ifc.ifc_buf;
+               len = ifc.ifc_len;
+               size = sizeof(struct ifreq);
+       }
+
+       /* Loop over the interfaces, and write an info block for each. */
+       rtnl_lock();
        for_each_netdev(net, dev) {
-               int done;
                if (!pos)
                        done = inet_gifconf(dev, NULL, 0, size);
                else
                        done = inet_gifconf(dev, pos + total,
                                            len - total, size);
-               if (done < 0)
+               if (done < 0) {
+                       rtnl_unlock();
                        return -EFAULT;
+               }
                total += done;
        }
+       rtnl_unlock();
 
-       /*
-        *      All done.  Write the updated control block back to the caller.
-        */
-       ifc->ifc_len = total;
-
-       /*
-        *      Both BSD and Solaris return 0 here, so we do too.
-        */
-       return 0;
+       return put_user(total, &uifc->ifc_len);
 }
 
 static int dev_getifmap(struct net_device *dev, struct ifreq *ifr)

diff --git a/net/socket.c b/net/socket.c
index 62005a12ec70ba5b7a86328943c212043bb929e4..ecdb7913a3bdca584d964819e97fb21a3fe2e2d9 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -1088,6 +1088,8 @@ EXPORT_SYMBOL(vlan_ioctl_set);
 static long sock_do_ioctl(struct net *net, struct socket *sock,
                          unsigned int cmd, unsigned long arg)
 {
+       struct ifreq ifr;
+       bool need_copyout;
        int err;
        void __user *argp = (void __user *)arg;
 
@@ -1100,25 +1102,13 @@ static long sock_do_ioctl(struct net *net, struct socket *sock,
        if (err != -ENOIOCTLCMD)
                return err;
 
-       if (cmd == SIOCGIFCONF) {
-               struct ifconf ifc;
-               if (copy_from_user(&ifc, argp, sizeof(struct ifconf)))
-                       return -EFAULT;
-               rtnl_lock();
-               err = dev_ifconf(net, &ifc, sizeof(struct ifreq));
-               rtnl_unlock();
-               if (!err && copy_to_user(argp, &ifc, sizeof(struct ifconf)))
-                       err = -EFAULT;
-       } else {
-               struct ifreq ifr;
-               bool need_copyout;
-               if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
+       if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
+               return -EFAULT;
+       err = dev_ioctl(net, cmd, &ifr, &need_copyout);
+       if (!err && need_copyout)
+               if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
                        return -EFAULT;
-               err = dev_ioctl(net, cmd, &ifr, &need_copyout);
-               if (!err && need_copyout)
-                       if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
-                               return -EFAULT;
-       }
+
        return err;
 }
 
@@ -1217,6 +1207,11 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
                                                   cmd == SIOCGSTAMP_NEW,
                                                   false);
                        break;
+
+               case SIOCGIFCONF:
+                       err = dev_ifconf(net, argp);
+                       break;
+
                default:
                        err = sock_do_ioctl(net, sock, cmd, arg);
                        break;
@@ -3127,31 +3122,6 @@ void socket_seq_show(struct seq_file *seq)
 #endif                         /* CONFIG_PROC_FS */
 
 #ifdef CONFIG_COMPAT
-static int compat_dev_ifconf(struct net *net, struct compat_ifconf __user *uifc32)
-{
-       struct compat_ifconf ifc32;
-       struct ifconf ifc;
-       int err;
-
-       if (copy_from_user(&ifc32, uifc32, sizeof(struct compat_ifconf)))
-               return -EFAULT;
-
-       ifc.ifc_len = ifc32.ifc_len;
-       ifc.ifc_req = compat_ptr(ifc32.ifcbuf);
-
-       rtnl_lock();
-       err = dev_ifconf(net, &ifc, sizeof(struct compat_ifreq));
-       rtnl_unlock();
-       if (err)
-               return err;
-
-       ifc32.ifc_len = ifc.ifc_len;
-       if (copy_to_user(uifc32, &ifc32, sizeof(struct compat_ifconf)))
-               return -EFAULT;
-
-       return 0;
-}
-
 static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32)
 {
        compat_uptr_t uptr32;
@@ -3270,8 +3240,6 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
        case SIOCSIFBR:
        case SIOCGIFBR:
                return old_bridge_ioctl(argp);
-       case SIOCGIFCONF:
-               return compat_dev_ifconf(net, argp);
        case SIOCWANDEV:
                return compat_siocwandev(net, argp);
        case SIOCGSTAMP_OLD:
@@ -3299,6 +3267,7 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
        case SIOCGSKNS:
        case SIOCGSTAMP_NEW:
        case SIOCGSTAMPNS_NEW:
+       case SIOCGIFCONF:
                return sock_ioctl(file, cmd, arg);
 
        case SIOCGIFFLAGS: