xref: /linux/drivers/net/ppp/pppox.c (revision ac94be498f84f7327533b62faca4c3da64434904)
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