hdlc_ppp.c revision eb2a2fd91f7c8a53b15063d6f08cf22b9a56cbfb 
1/*
2 * Generic HDLC support routines for Linux
3 * Point-to-point protocol support
4 *
5 * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of version 2 of the GNU General Public License
9 * as published by the Free Software Foundation.
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/slab.h>
15#include <linux/poll.h>
16#include <linux/errno.h>
17#include <linux/if_arp.h>
18#include <linux/init.h>
19#include <linux/skbuff.h>
20#include <linux/pkt_sched.h>
21#include <linux/inetdevice.h>
22#include <linux/lapb.h>
23#include <linux/rtnetlink.h>
24#include <linux/hdlc.h>
25#include <net/syncppp.h>
26
27struct ppp_state {
28	struct ppp_device pppdev;
29	struct ppp_device *syncppp_ptr;
30	int (*old_change_mtu)(struct net_device *dev, int new_mtu);
31};
32
33static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr);
34
35
36static inline struct ppp_state* state(hdlc_device *hdlc)
37{
38	return(struct ppp_state *)(hdlc->state);
39}
40
41
42static int ppp_open(struct net_device *dev)
43{
44	hdlc_device *hdlc = dev_to_hdlc(dev);
45	void *old_ioctl;
46	int result;
47
48	dev->priv = &state(hdlc)->syncppp_ptr;
49	state(hdlc)->syncppp_ptr = &state(hdlc)->pppdev;
50	state(hdlc)->pppdev.dev = dev;
51
52	old_ioctl = dev->do_ioctl;
53	state(hdlc)->old_change_mtu = dev->change_mtu;
54	sppp_attach(&state(hdlc)->pppdev);
55	/* sppp_attach nukes them. We don't need syncppp's ioctl */
56	dev->do_ioctl = old_ioctl;
57	state(hdlc)->pppdev.sppp.pp_flags &= ~PP_CISCO;
58	dev->type = ARPHRD_PPP;
59	result = sppp_open(dev);
60	if (result) {
61		sppp_detach(dev);
62		return result;
63	}
64
65	return 0;
66}
67
68
69
70static void ppp_close(struct net_device *dev)
71{
72	hdlc_device *hdlc = dev_to_hdlc(dev);
73
74	sppp_close(dev);
75	sppp_detach(dev);
76	dev->rebuild_header = NULL;
77	dev->change_mtu = state(hdlc)->old_change_mtu;
78	dev->mtu = HDLC_MAX_MTU;
79	dev->hard_header_len = 16;
80}
81
82
83
84static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)
85{
86	return __constant_htons(ETH_P_WAN_PPP);
87}
88
89
90
91static struct hdlc_proto proto = {
92	.open		= ppp_open,
93	.close		= ppp_close,
94	.type_trans	= ppp_type_trans,
95	.ioctl		= ppp_ioctl,
96	.module		= THIS_MODULE,
97};
98
99
100static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr)
101{
102	hdlc_device *hdlc = dev_to_hdlc(dev);
103	int result;
104
105	switch (ifr->ifr_settings.type) {
106	case IF_GET_PROTO:
107		if (dev_to_hdlc(dev)->proto != &proto)
108			return -EINVAL;
109		ifr->ifr_settings.type = IF_PROTO_PPP;
110		return 0; /* return protocol only, no settable parameters */
111
112	case IF_PROTO_PPP:
113		if(!capable(CAP_NET_ADMIN))
114			return -EPERM;
115
116		if(dev->flags & IFF_UP)
117			return -EBUSY;
118
119		/* no settable parameters */
120
121		result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
122		if (result)
123			return result;
124
125		result = attach_hdlc_protocol(dev, &proto, NULL,
126					      sizeof(struct ppp_state));
127		if (result)
128			return result;
129		dev->hard_start_xmit = hdlc->xmit;
130		dev->hard_header = NULL;
131		dev->type = ARPHRD_PPP;
132		dev->addr_len = 0;
133		netif_dormant_off(dev);
134		return 0;
135	}
136
137	return -EINVAL;
138}
139
140
141static int __init mod_init(void)
142{
143	register_hdlc_protocol(&proto);
144	return 0;
145}
146
147
148
149static void __exit mod_exit(void)
150{
151	unregister_hdlc_protocol(&proto);
152}
153
154
155module_init(mod_init);
156module_exit(mod_exit);
157
158MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
159MODULE_DESCRIPTION("PPP protocol support for generic HDLC");
160MODULE_LICENSE("GPL v2");
161