drivers/net/pppox.c

   1 /** -*- linux-c -*- ***********************************************************
   2  * Linux PPP over X/Ethernet (PPPoX/PPPoE) Sockets
   3  *
   4  * PPPoX --- Generic PPP encapsulation socket family
   5  * PPPoE --- PPP over Ethernet (RFC 2516)
   6  *
   7  *
   8  * Version:     0.5.2
   9  *
  10  * Author:      Michal Ostrowski <mostrows@speakeasy.net>
  11  *
  12  * 051000 :     Initialization cleanup
  13  *
  14  * License:
  15  *              This program is free software; you can redistribute it and/or
  16  *              modify it under the terms of the GNU General Public License
  17  *              as published by the Free Software Foundation; either version
  18  *              2 of the License, or (at your option) any later version.
  19  *
  20  */
  21
  22 #include <linux/string.h>
  23 #include <linux/module.h>
  24 #include <linux/kernel.h>
  25 #include <linux/slab.h>
  26 #include <linux/errno.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/net.h>
  29 #include <linux/init.h>
  30 #include <linux/if_pppox.h>
  31 #include <linux/ppp_defs.h>
  32 #include <linux/if_ppp.h>
  33 #include <linux/ppp_channel.h>
  34
  35 #include <net/sock.h>
  36
  37 #include <asm/uaccess.h>
  38
  39 static struct pppox_proto *pppox_protos[PX_MAX_PROTO + 1];
  40
  41 int register_pppox_proto(int proto_num, struct pppox_proto *pp)
  42 {
  43         if (proto_num < 0 || proto_num > PX_MAX_PROTO)
  44                 return -EINVAL;
  45         if (pppox_protos[proto_num])
  46                 return -EALREADY;
  47         pppox_protos[proto_num] = pp;
  48         return 0;
  49 }
  50
  51 void unregister_pppox_proto(int proto_num)
  52 {
  53         if (proto_num >= 0 && proto_num <= PX_MAX_PROTO)
  54                 pppox_protos[proto_num] = NULL;
  55 }
  56
  57 void pppox_unbind_sock(struct sock *sk)
  58 {
  59         /* Clear connection to ppp device, if attached. */
  60
  61         if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE)) {
  62                 ppp_unregister_channel(&pppox_sk(sk)->chan);
  63                 sk->sk_state = PPPOX_DEAD;
  64         }
  65 }
  66
  67 EXPORT_SYMBOL(register_pppox_proto);
  68 EXPORT_SYMBOL(unregister_pppox_proto);
  69 EXPORT_SYMBOL(pppox_unbind_sock);
  70
  71 static int pppox_ioctl(struct socket* sock, unsigned int cmd,
  72                        unsigned long arg)
  73 {
  74         struct sock *sk = sock->sk;
  75         struct pppox_sock *po = pppox_sk(sk);
  76         int rc = 0;
  77
  78         lock_sock(sk);
  79
  80         switch (cmd) {
  81         case PPPIOCGCHAN: {
  82                 int index;
  83                 rc = -ENOTCONN;
  84                 if (!(sk->sk_state & PPPOX_CONNECTED))
  85                         break;
  86
  87                 rc = -EINVAL;
  88                 index = ppp_channel_index(&po->chan);
  89                 if (put_user(index , (int __user *) arg))
  90                         break;
  91
  92                 rc = 0;
  93                 sk->sk_state |= PPPOX_BOUND;
  94                 break;
  95         }
  96         default:
  97                 if (pppox_protos[sk->sk_protocol]->ioctl)
  98                         rc = pppox_protos[sk->sk_protocol]->ioctl(sock, cmd,
  99                                                                   arg);
 100
 101                 break;
 102         };
 103
 104         release_sock(sk);
 105         return rc;
 106 }
 107
 108
 109 static int pppox_create(struct socket *sock, int protocol)
 110 {
 111         int rc = -EPROTOTYPE;
 112
 113         if (protocol < 0 || protocol > PX_MAX_PROTO)
 114                 goto out;
 115
 116         rc = -EPROTONOSUPPORT;
 117         if (!pppox_protos[protocol] ||
 118             !try_module_get(pppox_protos[protocol]->owner))
 119                 goto out;
 120
 121         rc = pppox_protos[protocol]->create(sock);
 122         if (!rc) {
 123                 /* We get to set the ioctl handler. */
 124                 /* For everything else, pppox is just a shell. */
 125                 sock->ops->ioctl = pppox_ioctl;
 126         }
 127         module_put(pppox_protos[protocol]->owner);
 128 out:
 129         return rc;
 130 }
 131
 132 static struct net_proto_family pppox_proto_family = {
 133         .family = PF_PPPOX,
 134         .create = pppox_create,
 135         .owner  = THIS_MODULE,
 136 };
 137
 138 static int __init pppox_init(void)
 139 {
 140         return sock_register(&pppox_proto_family);
 141 }
 142
 143 static void __exit pppox_exit(void)
 144 {
 145         sock_unregister(PF_PPPOX);
 146 }
 147
 148 module_init(pppox_init);
 149 module_exit(pppox_exit);
 150
 151 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
 152 MODULE_DESCRIPTION("PPP over Ethernet driver (generic socket layer)");
 153 MODULE_LICENSE("GPL");