LXR linux/drivers/net/ppp/pppox.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/** -*- linux-c -*- ***********************************************************
   3 * Linux PPP over X/Ethernet (PPPoX/PPPoE) Sockets
   4 *
   5 * PPPoX --- Generic PPP encapsulation socket family
   6 * PPPoE --- PPP over Ethernet (RFC 2516)
   7 *
   8 * Version:     0.5.2
   9 *
  10 * Author:      Michal Ostrowski <mostrows@speakeasy.net>
  11 *
  12 * 051000 :     Initialization cleanup
  13 *
  14 * License:
  15 */
  16
  17#include <linux/string.h>
  18#include <linux/module.h>
  19#include <linux/kernel.h>
  20#include <linux/compat.h>
  21#include <linux/errno.h>
  22#include <linux/netdevice.h>
  23#include <linux/net.h>
  24#include <linux/init.h>
  25#include <linux/if_pppox.h>
  26#include <linux/ppp_defs.h>
  27#include <linux/ppp-ioctl.h>
  28#include <linux/ppp_channel.h>
  29#include <linux/kmod.h>
  30
  31#include <net/sock.h>
  32
  33#include <linux/uaccess.h>
  34
  35static const struct pppox_proto *pppox_protos[PX_MAX_PROTO + 1];
  36
  37int register_pppox_proto(int proto_num, const struct pppox_proto *pp)
  38{
  39        if (proto_num < 0 || proto_num > PX_MAX_PROTO)
  40                return -EINVAL;
  41        if (pppox_protos[proto_num])
  42                return -EALREADY;
  43        pppox_protos[proto_num] = pp;
  44        return 0;
  45}
  46
  47void unregister_pppox_proto(int proto_num)
  48{
  49        if (proto_num >= 0 && proto_num <= PX_MAX_PROTO)
  50                pppox_protos[proto_num] = NULL;
  51}
  52
  53void pppox_unbind_sock(struct sock *sk)
  54{
  55        /* Clear connection to ppp device, if attached. */
  56
  57        if (sk->sk_state & (PPPOX_BOUND | PPPOX_CONNECTED)) {
  58                ppp_unregister_channel(&pppox_sk(sk)->chan);
  59                sk->sk_state = PPPOX_DEAD;
  60        }
  61}
  62
  63EXPORT_SYMBOL(register_pppox_proto);
  64EXPORT_SYMBOL(unregister_pppox_proto);
  65EXPORT_SYMBOL(pppox_unbind_sock);
  66
  67int pppox_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
  68{
  69        struct sock *sk = sock->sk;
  70        struct pppox_sock *po = pppox_sk(sk);
  71        int rc;
  72
  73        lock_sock(sk);
  74
  75        switch (cmd) {
  76        case PPPIOCGCHAN: {
  77                int index;
  78                rc = -ENOTCONN;
  79                if (!(sk->sk_state & PPPOX_CONNECTED))
  80                        break;
  81
  82                rc = -EINVAL;
  83                index = ppp_channel_index(&po->chan);
  84                if (put_user(index , (int __user *) arg))
  85                        break;
  86
  87                rc = 0;
  88                sk->sk_state |= PPPOX_BOUND;
  89                break;
  90        }
  91        default:
  92                rc = pppox_protos[sk->sk_protocol]->ioctl ?
  93                        pppox_protos[sk->sk_protocol]->ioctl(sock, cmd, arg) : -ENOTTY;
  94        }
  95
  96        release_sock(sk);
  97        return rc;
  98}
  99
 100EXPORT_SYMBOL(pppox_ioctl);
 101
 102#ifdef CONFIG_COMPAT
 103int pppox_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 104{
 105        if (cmd == PPPOEIOCSFWD32)
 106                cmd = PPPOEIOCSFWD;
 107
 108        return pppox_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
 109}
 110
 111EXPORT_SYMBOL(pppox_compat_ioctl);
 112#endif
 113
 114static int pppox_create(struct net *net, struct socket *sock, int protocol,
 115                        int kern)
 116{
 117        int rc = -EPROTOTYPE;
 118
 119        if (protocol < 0 || protocol > PX_MAX_PROTO)
 120                goto out;
 121
 122        rc = -EPROTONOSUPPORT;
 123        if (!pppox_protos[protocol])
 124                request_module("net-pf-%d-proto-%d", PF_PPPOX, protocol);
 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, kern);
 130
 131        module_put(pppox_protos[protocol]->owner);
 132out:
 133        return rc;
 134}
 135
 136static const struct net_proto_family pppox_proto_family = {
 137        .family = PF_PPPOX,
 138        .create = pppox_create,
 139        .owner  = THIS_MODULE,
 140};
 141
 142static int __init pppox_init(void)
 143{
 144        return sock_register(&pppox_proto_family);
 145}
 146
 147static void __exit pppox_exit(void)
 148{
 149        sock_unregister(PF_PPPOX);
 150}
 151
 152module_init(pppox_init);
 153module_exit(pppox_exit);
 154
 155MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
 156MODULE_DESCRIPTION("PPP over Ethernet driver (generic socket layer)");
 157MODULE_LICENSE("GPL");
 158MODULE_ALIAS_NETPROTO(PF_PPPOX);
 159