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/errno.h>
26 #include <linux/netdevice.h>
27 #include <linux/net.h>
28 #include <linux/init.h>
29 #include <linux/if_pppox.h>
30 #include <linux/ppp_defs.h>
31 #include <linux/if_ppp.h>
32 #include <linux/ppp_channel.h>
33 #include <linux/kmod.h>
34 
35 #include <net/sock.h>
36 
37 #include <asm/uaccess.h>
38 
39 static const struct pppox_proto *pppox_protos[PX_MAX_PROTO + 1];
40 
register_pppox_proto(int proto_num,const struct pppox_proto * pp)41 int register_pppox_proto(int proto_num, const 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 
unregister_pppox_proto(int proto_num)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 
pppox_unbind_sock(struct sock * sk)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_CONNECTED | 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 
pppox_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)71 int pppox_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
72 {
73 	struct sock *sk = sock->sk;
74 	struct pppox_sock *po = pppox_sk(sk);
75 	int rc;
76 
77 	lock_sock(sk);
78 
79 	switch (cmd) {
80 	case PPPIOCGCHAN: {
81 		int index;
82 		rc = -ENOTCONN;
83 		if (!(sk->sk_state & PPPOX_CONNECTED))
84 			break;
85 
86 		rc = -EINVAL;
87 		index = ppp_channel_index(&po->chan);
88 		if (put_user(index , (int __user *) arg))
89 			break;
90 
91 		rc = 0;
92 		sk->sk_state |= PPPOX_BOUND;
93 		break;
94 	}
95 	default:
96 		rc = pppox_protos[sk->sk_protocol]->ioctl ?
97 			pppox_protos[sk->sk_protocol]->ioctl(sock, cmd, arg) : -ENOTTY;
98 	}
99 
100 	release_sock(sk);
101 	return rc;
102 }
103 
104 EXPORT_SYMBOL(pppox_ioctl);
105 
pppox_create(struct net * net,struct socket * sock,int protocol,int kern)106 static int pppox_create(struct net *net, struct socket *sock, int protocol,
107 			int kern)
108 {
109 	int rc = -EPROTOTYPE;
110 
111 	if (protocol < 0 || protocol > PX_MAX_PROTO)
112 		goto out;
113 
114 	rc = -EPROTONOSUPPORT;
115 	if (!pppox_protos[protocol])
116 		request_module("pppox-proto-%d", protocol);
117 	if (!pppox_protos[protocol] ||
118 	    !try_module_get(pppox_protos[protocol]->owner))
119 		goto out;
120 
121 	rc = pppox_protos[protocol]->create(net, sock);
122 
123 	module_put(pppox_protos[protocol]->owner);
124 out:
125 	return rc;
126 }
127 
128 static const struct net_proto_family pppox_proto_family = {
129 	.family	= PF_PPPOX,
130 	.create	= pppox_create,
131 	.owner	= THIS_MODULE,
132 };
133 
pppox_init(void)134 static int __init pppox_init(void)
135 {
136 	return sock_register(&pppox_proto_family);
137 }
138 
pppox_exit(void)139 static void __exit pppox_exit(void)
140 {
141 	sock_unregister(PF_PPPOX);
142 }
143 
144 module_init(pppox_init);
145 module_exit(pppox_exit);
146 
147 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
148 MODULE_DESCRIPTION("PPP over Ethernet driver (generic socket layer)");
149 MODULE_LICENSE("GPL");
150