xref: /linux/drivers/net/wan/hdlc_ppp.c (revision 6e8331ac6973435b1e7604c30f2ad394035b46e1)
1 /*
2  * Generic HDLC support routines for Linux
3  * Point-to-point protocol support
4  *
5  * Copyright (C) 1999 - 2003 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 
26 
27 static int ppp_open(struct net_device *dev)
28 {
29 	hdlc_device *hdlc = dev_to_hdlc(dev);
30 	void *old_ioctl;
31 	int result;
32 
33 	dev->priv = &hdlc->state.ppp.syncppp_ptr;
34 	hdlc->state.ppp.syncppp_ptr = &hdlc->state.ppp.pppdev;
35 	hdlc->state.ppp.pppdev.dev = dev;
36 
37 	old_ioctl = dev->do_ioctl;
38 	hdlc->state.ppp.old_change_mtu = dev->change_mtu;
39 	sppp_attach(&hdlc->state.ppp.pppdev);
40 	/* sppp_attach nukes them. We don't need syncppp's ioctl */
41 	dev->do_ioctl = old_ioctl;
42 	hdlc->state.ppp.pppdev.sppp.pp_flags &= ~PP_CISCO;
43 	dev->type = ARPHRD_PPP;
44 	result = sppp_open(dev);
45 	if (result) {
46 		sppp_detach(dev);
47 		return result;
48 	}
49 
50 	return 0;
51 }
52 
53 
54 
55 static void ppp_close(struct net_device *dev)
56 {
57 	hdlc_device *hdlc = dev_to_hdlc(dev);
58 
59 	sppp_close(dev);
60 	sppp_detach(dev);
61 	dev->rebuild_header = NULL;
62 	dev->change_mtu = hdlc->state.ppp.old_change_mtu;
63 	dev->mtu = HDLC_MAX_MTU;
64 	dev->hard_header_len = 16;
65 }
66 
67 
68 
69 static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)
70 {
71 	return __constant_htons(ETH_P_WAN_PPP);
72 }
73 
74 
75 
76 int hdlc_ppp_ioctl(struct net_device *dev, struct ifreq *ifr)
77 {
78 	hdlc_device *hdlc = dev_to_hdlc(dev);
79 	int result;
80 
81 	switch (ifr->ifr_settings.type) {
82 	case IF_GET_PROTO:
83 		ifr->ifr_settings.type = IF_PROTO_PPP;
84 		return 0; /* return protocol only, no settable parameters */
85 
86 	case IF_PROTO_PPP:
87 		if(!capable(CAP_NET_ADMIN))
88 			return -EPERM;
89 
90 		if(dev->flags & IFF_UP)
91 			return -EBUSY;
92 
93 		/* no settable parameters */
94 
95 		result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
96 		if (result)
97 			return result;
98 
99 		hdlc_proto_detach(hdlc);
100 		memset(&hdlc->proto, 0, sizeof(hdlc->proto));
101 
102 		hdlc->proto.open = ppp_open;
103 		hdlc->proto.close = ppp_close;
104 		hdlc->proto.type_trans = ppp_type_trans;
105 		hdlc->proto.id = IF_PROTO_PPP;
106 		dev->hard_start_xmit = hdlc->xmit;
107 		dev->hard_header = NULL;
108 		dev->type = ARPHRD_PPP;
109 		dev->addr_len = 0;
110 		netif_dormant_off(dev);
111 		return 0;
112 	}
113 
114 	return -EINVAL;
115 }
116