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 #include <linux/kmod.h>
  35
  36 #include <net/sock.h>
  37
  38 #include <asm/uaccess.h>
  39
  40 static struct pppox_proto *pppox_protos[PX_MAX_PROTO + 1];
  41
  42 int register_pppox_proto(int proto_num, struct pppox_proto *pp)
  43 {
  44         if (proto_num < 0 || proto_num > PX_MAX_PROTO)
  45                 return -EINVAL;
  46         if (pppox_protos[proto_num])
  47                 return -EALREADY;
  48         pppox_protos[proto_num] = pp;
  49         return 0;
  50 }
  51
  52 void unregister_pppox_proto(int proto_num)
  53 {
  54         if (proto_num >= 0 && proto_num <= PX_MAX_PROTO)
  55                 pppox_protos[proto_num] = NULL;
  56 }
  57
  58 void pppox_unbind_sock(struct sock *sk)
  59 {
  60         /* Clear connection to ppp device, if attached. */
  61
  62         if (sk->sk_state & (PPPOX_BOUND | PPPOX_CONNECTED | PPPOX_ZOMBIE)) {
  63                 ppp_unregister_channel(&pppox_sk(sk)->chan);
  64                 sk->sk_state = PPPOX_DEAD;
  65         }
  66 }
  67
  68 EXPORT_SYMBOL(register_pppox_proto);
  69 EXPORT_SYMBOL(unregister_pppox_proto);
  70 EXPORT_SYMBOL(pppox_unbind_sock);
  71
  72 int pppox_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
  73 {
  74         struct sock *sk = sock->sk;
  75         struct pppox_sock *po = pppox_sk(sk);
  76         int rc;
  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                 rc = pppox_protos[sk->sk_protocol]->ioctl ?
  98                         pppox_protos[sk->sk_protocol]->ioctl(sock, cmd, arg) : -ENOTTY;
  99         }
 100
 101         release_sock(sk);
 102         return rc;
 103 }
 104
 105 EXPORT_SYMBOL(pppox_ioctl);
 106
 107 static int pppox_create(struct net *net, struct socket *sock, int protocol)
 108 {
 109         int rc = -EPROTOTYPE;
 110
 111         if (net != &init_net)
 112                 return -EAFNOSUPPORT;
 113
 114         if (protocol < 0 || protocol > PX_MAX_PROTO)
 115                 goto out;
 116
 117         rc = -EPROTONOSUPPORT;
 118 #ifdef CONFIG_KMOD
 119         if (!pppox_protos[protocol]) {
 120                 char buffer[32];
 121                 sprintf(buffer, "pppox-proto-%d", protocol);
 122                 request_module(buffer);
 123         }
 124 #endif
 125         if (!pppox_protos[protocol] ||
 126             !try_module_get(pppox_protos[protocol]->owner))
 127                 goto out;
 128
 129         rc = pppox_protos[protocol]->create(net, sock);
 130
 131         module_put(pppox_protos[protocol]->owner);
 132 out:
 133         return rc;
 134 }
 135
 136 static struct net_proto_family pppox_proto_family = {
 137         .family = PF_PPPOX,
 138         .create = pppox_create,
 139         .owner  = THIS_MODULE,
 140 };
 141
 142 static int __init pppox_init(void)
 143 {
 144         return sock_register(&pppox_proto_family);
 145 }
 146
 147 static void __exit pppox_exit(void)
 148 {
 149         sock_unregister(PF_PPPOX);
 150 }
 151
 152 module_init(pppox_init);
 153 module_exit(pppox_exit);
 154
 155 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
 156 MODULE_DESCRIPTION("PPP over Ethernet driver (generic socket layer)");
 157 MODULE_LICENSE("GPL");