linux-2.4.22-tun-new-style.patch

   1
   2   "new style" netdevice allocation patch for TUN driver (2.4.18 kernel)
   3
   4 From: Jacek Konieczny (jajcus@pld.org.pl)
   5 Date: Thu Aug 01 2002 - 08:35:06 EST
   6
   7 I had a lot of problem with tun devices created with both openvpn and
   8 vtund. When I wanted to shut down my system when the devices were in
   9 use (eg. TCP connection established on tun0 interface), even if the
  10 tunneling daemon was killed, it stopped while trying to deconfigure
  11 network. And "unregister_netdevice: waiting for tun0 to become free"
  12 message was displayed again and again. I tried to resolve this problem
  13 using Google, but I have only found out, that this is behaviour of 2.4
  14 kernels, and that it is proper. After further investigation, in kernel
  15 sources, I found out, that there are "old style" and "new style" network
  16 devices, and that only the "old style" devices have this problem.
  17 I had similar problem with VLAN devices some time ago, so I checked VLAN
  18 driver sources too. As I suspected, it was "new style" device now.
  19 The patch below is my try to make tun device "new style" too. It seems
  20 to work for me, but I am not sure if it is 100% proper. This is patch
  21 against 2.4.18 sources.
  22
  23 Sorry, for spamming all those addresses, but I am not sure which one is
  24 correct. Driver on URL given in MAINTAINERS file seems to be a bit
  25 outdated.
  26
  27 Greets,
  28         Jacek
  29
  30 diff -ur linux-2.4.22-up/drivers/net/tun.c linux-2.4.22-tun/drivers/net/tun.c
  31 --- linux-2.4.22-up/drivers/net/tun.c   Sat Aug  3 02:39:44 2002
  32 +++ linux-2.4.22-tun/drivers/net/tun.c  Sun Sep 21 00:08:08 2003
  33 @@ -20,6 +20,14 @@
  34   *    Modifications for 2.3.99-pre5 kernel.
  35   */
  36
  37 +/*
  38 + * 01.08.2002
  39 + * Jacek Konieczny <jajcus@pld.org.pl>
  40 + * Modifications for "new style" device allocation
  41 + * (fixes "wating for tunX to become free" problem)
  42 + */
  43 +
  44 +
  45  #define TUN_VER "1.5"
  46
  47  #include <linux/config.h>
  48 @@ -159,6 +167,17 @@
  49         return 0;
  50  }
  51
  52 +void tun_net_destruct(struct net_device *dev)
  53 +{
  54 +       if (dev) {
  55 +               if (dev->priv) {
  56 +                       kfree(dev->priv);
  57 +                       dev->priv=NULL;
  58 +                       MOD_DEC_USE_COUNT;
  59 +               }
  60 +       }
  61 +}
  62 +
  63  /* Character device part */
  64
  65  /* Poll */
  66 @@ -202,14 +221,14 @@
  67         skb_reserve(skb, 2);
  68         memcpy_fromiovec(skb_put(skb, len), iv, len);
  69
  70 -       skb->dev = &tun->dev;
  71 +       skb->dev = tun->dev;
  72         switch (tun->flags & TUN_TYPE_MASK) {
  73         case TUN_TUN_DEV:
  74                 skb->mac.raw = skb->data;
  75                 skb->protocol = pi.proto;
  76                 break;
  77         case TUN_TAP_DEV:
  78 -               skb->protocol = eth_type_trans(skb, &tun->dev);
  79 +               skb->protocol = eth_type_trans(skb, tun->dev);
  80                 break;
  81         };
  82
  83 @@ -326,7 +345,7 @@
  84                         schedule();
  85                         continue;
  86                 }
  87 -               netif_start_queue(&tun->dev);
  88 +               netif_start_queue(tun->dev);
  89
  90                 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
  91
  92 @@ -378,8 +397,6 @@
  93                 init_waitqueue_head(&tun->read_wait);
  94
  95                 tun->owner = -1;
  96 -               tun->dev.init = tun_net_init;
  97 -               tun->dev.priv = tun;
  98
  99                 err = -EINVAL;
 100
 101 @@ -398,18 +415,24 @@
 102                 if (*ifr->ifr_name)
 103                         name = ifr->ifr_name;
 104
 105 -               if ((err = dev_alloc_name(&tun->dev, name)) < 0)
 106 +               dev = dev_alloc(name, &err);
 107 +               if (!dev)
 108                         goto failed;
 109 -               if ((err = register_netdevice(&tun->dev)))
 110 +
 111 +               tun->dev=dev;
 112 +               dev->init = tun_net_init;
 113 +               dev->priv = tun;
 114 +               dev->destructor = tun_net_destruct;
 115 +               dev->features |= NETIF_F_DYNALLOC;
 116 +               tun->name = dev->name;
 117 +
 118 +               err=register_netdevice(dev);
 119 +               if (err<0)
 120                         goto failed;
 121 -
 122 -               MOD_INC_USE_COUNT;
 123
 124 -               tun->name = tun->dev.name;
 125 +               MOD_INC_USE_COUNT;
 126         }
 127
 128 -       DBG(KERN_INFO "%s: tun_set_iff\n", tun->name);
 129 -
 130         if (ifr->ifr_flags & IFF_NO_PI)
 131                 tun->flags |= TUN_NO_PI;
 132
 133 @@ -423,6 +446,7 @@
 134         return 0;
 135
 136  failed:
 137 +       kfree(dev);
 138         kfree(tun);
 139         return err;
 140  }
 141 @@ -553,10 +577,8 @@
 142         skb_queue_purge(&tun->readq);
 143
 144         if (!(tun->flags & TUN_PERSIST)) {
 145 -               dev_close(&tun->dev);
 146 -               unregister_netdevice(&tun->dev);
 147 -               kfree(tun);
 148 -               MOD_DEC_USE_COUNT;
 149 +               dev_close(tun->dev);
 150 +               unregister_netdevice(tun->dev);
 151         }
 152
 153         rtnl_unlock();
 154 diff -ur linux-2.4.22-up/include/linux/if_tun.h linux-2.4.22-tun/include/linux/if_tun.h
 155 --- linux-2.4.22-up/include/linux/if_tun.h      Tue Jun 12 04:15:27 2001
 156 +++ linux-2.4.22-tun/include/linux/if_tun.h     Sun Sep 21 00:08:08 2003
 157 @@ -40,7 +40,7 @@
 158         wait_queue_head_t       read_wait;
 159         struct sk_buff_head     readq;
 160
 161 -       struct net_device       dev;
 162 +       struct net_device       *dev;
 163         struct net_device_stats stats;
 164
 165         struct fasync_struct    *fasync;