xref: /openbmc/linux/drivers/net/wan/hdlc_ppp.c (revision 22246614)
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 
27 struct 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 
33 static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr);
34 
35 
36 static inline struct ppp_state* state(hdlc_device *hdlc)
37 {
38 	return(struct ppp_state *)(hdlc->state);
39 }
40 
41 
42 static int ppp_open(struct net_device *dev)
43 {
44 	hdlc_device *hdlc = dev_to_hdlc(dev);
45 	int (*old_ioctl)(struct net_device *, struct ifreq *, int);
46 	int result;
47 
48 	dev->ml_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 
70 static 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 
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 
84 static __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 
91 static 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 
100 static 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,
126 					      sizeof(struct ppp_state));
127 		if (result)
128 			return result;
129 		dev->hard_start_xmit = hdlc->xmit;
130 		dev->type = ARPHRD_PPP;
131 		netif_dormant_off(dev);
132 		return 0;
133 	}
134 
135 	return -EINVAL;
136 }
137 
138 
139 static int __init mod_init(void)
140 {
141 	register_hdlc_protocol(&proto);
142 	return 0;
143 }
144 
145 
146 
147 static void __exit mod_exit(void)
148 {
149 	unregister_hdlc_protocol(&proto);
150 }
151 
152 
153 module_init(mod_init);
154 module_exit(mod_exit);
155 
156 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
157 MODULE_DESCRIPTION("PPP protocol support for generic HDLC");
158 MODULE_LICENSE("GPL v2");
159