net/atm/ioctl.c

   1 /* ATM ioctl handling */
   2
   3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
   4 /* 2003 John Levon  <levon@movementarian.org> */
   5
   6
   7 #include <linux/module.h>
   8 #include <linux/kmod.h>
   9 #include <linux/net.h>          /* struct socket, struct proto_ops */
  10 #include <linux/atm.h>          /* ATM stuff */
  11 #include <linux/atmdev.h>
  12 #include <linux/atmclip.h>      /* CLIP_*ENCAP */
  13 #include <linux/atmarp.h>       /* manifest constants */
  14 #include <linux/capability.h>
  15 #include <linux/sonet.h>        /* for ioctls */
  16 #include <linux/atmsvc.h>
  17 #include <linux/atmmpc.h>
  18 #include <net/atmclip.h>
  19 #include <linux/atmlec.h>
  20 #include <linux/mutex.h>
  21 #include <asm/ioctls.h>
  22
  23 #include "resources.h"
  24 #include "signaling.h"          /* for WAITING and sigd_attach */
  25 #include "common.h"
  26
  27
  28 static DEFINE_MUTEX(ioctl_mutex);
  29 static LIST_HEAD(ioctl_list);
  30
  31
  32 void register_atm_ioctl(struct atm_ioctl *ioctl)
  33 {
  34         mutex_lock(&ioctl_mutex);
  35         list_add_tail(&ioctl->list, &ioctl_list);
  36         mutex_unlock(&ioctl_mutex);
  37 }
  38
  39 void deregister_atm_ioctl(struct atm_ioctl *ioctl)
  40 {
  41         mutex_lock(&ioctl_mutex);
  42         list_del(&ioctl->list);
  43         mutex_unlock(&ioctl_mutex);
  44 }
  45
  46 EXPORT_SYMBOL(register_atm_ioctl);
  47 EXPORT_SYMBOL(deregister_atm_ioctl);
  48
  49 int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
  50 {
  51         struct sock *sk = sock->sk;
  52         struct atm_vcc *vcc;
  53         int error;
  54         struct list_head * pos;
  55         void __user *argp = (void __user *)arg;
  56
  57         vcc = ATM_SD(sock);
  58         switch (cmd) {
  59                 case SIOCOUTQ:
  60                         if (sock->state != SS_CONNECTED ||
  61                             !test_bit(ATM_VF_READY, &vcc->flags)) {
  62                                 error =  -EINVAL;
  63                                 goto done;
  64                         }
  65                         error = put_user(sk->sk_sndbuf -
  66                                          atomic_read(&sk->sk_wmem_alloc),
  67                                          (int __user *) argp) ? -EFAULT : 0;
  68                         goto done;
  69                 case SIOCINQ:
  70                         {
  71                                 struct sk_buff *skb;
  72
  73                                 if (sock->state != SS_CONNECTED) {
  74                                         error = -EINVAL;
  75                                         goto done;
  76                                 }
  77                                 skb = skb_peek(&sk->sk_receive_queue);
  78                                 error = put_user(skb ? skb->len : 0,
  79                                                  (int __user *)argp) ? -EFAULT : 0;
  80                                 goto done;
  81                         }
  82                 case SIOCGSTAMP: /* borrowed from IP */
  83                         error = sock_get_timestamp(sk, argp);
  84                         goto done;
  85                 case ATM_SETSC:
  86                         printk(KERN_WARNING "ATM_SETSC is obsolete\n");
  87                         error = 0;
  88                         goto done;
  89                 case ATMSIGD_CTRL:
  90                         if (!capable(CAP_NET_ADMIN)) {
  91                                 error = -EPERM;
  92                                 goto done;
  93                         }
  94                         /*
  95                          * The user/kernel protocol for exchanging signalling
  96                          * info uses kernel pointers as opaque references,
  97                          * so the holder of the file descriptor can scribble
  98                          * on the kernel... so we should make sure that we
  99                          * have the same privledges that /proc/kcore needs
 100                          */
 101                         if (!capable(CAP_SYS_RAWIO)) {
 102                                 error = -EPERM;
 103                                 goto done;
 104                         }
 105                         error = sigd_attach(vcc);
 106                         if (!error)
 107                                 sock->state = SS_CONNECTED;
 108                         goto done;
 109                 case ATM_SETBACKEND:
 110                 case ATM_NEWBACKENDIF:
 111                         {
 112                                 atm_backend_t backend;
 113                                 error = get_user(backend, (atm_backend_t __user *) argp);
 114                                 if (error)
 115                                         goto done;
 116                                 switch (backend) {
 117                                         case ATM_BACKEND_PPP:
 118                                                 request_module("pppoatm");
 119                                                 break;
 120                                         case ATM_BACKEND_BR2684:
 121                                                 request_module("br2684");
 122                                                 break;
 123                                 }
 124                         }
 125                         break;
 126                 case ATMMPC_CTRL:
 127                 case ATMMPC_DATA:
 128                         request_module("mpoa");
 129                         break;
 130                 case ATMARPD_CTRL:
 131                         request_module("clip");
 132                         break;
 133                 case ATMLEC_CTRL:
 134                         request_module("lec");
 135                         break;
 136         }
 137
 138         error = -ENOIOCTLCMD;
 139
 140         mutex_lock(&ioctl_mutex);
 141         list_for_each(pos, &ioctl_list) {
 142                 struct atm_ioctl * ic = list_entry(pos, struct atm_ioctl, list);
 143                 if (try_module_get(ic->owner)) {
 144                         error = ic->ioctl(sock, cmd, arg);
 145                         module_put(ic->owner);
 146                         if (error != -ENOIOCTLCMD)
 147                                 break;
 148                 }
 149         }
 150         mutex_unlock(&ioctl_mutex);
 151
 152         if (error != -ENOIOCTLCMD)
 153                 goto done;
 154
 155         error = atm_dev_ioctl(cmd, argp);
 156
 157 done:
 158         return error;
 159 }