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  
35  static const struct pppox_proto *pppox_protos[PX_MAX_PROTO + 1];
36  
register_pppox_proto(int proto_num,const struct pppox_proto * pp)37  int 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  
unregister_pppox_proto(int proto_num)47  void 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  
pppox_unbind_sock(struct sock * sk)53  void 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  
63  EXPORT_SYMBOL(register_pppox_proto);
64  EXPORT_SYMBOL(unregister_pppox_proto);
65  EXPORT_SYMBOL(pppox_unbind_sock);
66  
pppox_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)67  int 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  
100  EXPORT_SYMBOL(pppox_ioctl);
101  
102  #ifdef CONFIG_COMPAT
pppox_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)103  int 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  
111  EXPORT_SYMBOL(pppox_compat_ioctl);
112  #endif
113  
pppox_create(struct net * net,struct socket * sock,int protocol,int kern)114  static 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);
132  out:
133  	return rc;
134  }
135  
136  static const struct net_proto_family pppox_proto_family = {
137  	.family	= PF_PPPOX,
138  	.create	= pppox_create,
139  	.owner	= THIS_MODULE,
140  };
141  
pppox_init(void)142  static int __init pppox_init(void)
143  {
144  	return sock_register(&pppox_proto_family);
145  }
146  
pppox_exit(void)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");
158  MODULE_ALIAS_NETPROTO(PF_PPPOX);
159