e867638067a65cff846fd13dfa4644c248847a97
[muen/linux.git] / drivers / net / wan / hdlc_x25.c
1 /*
2  * Generic HDLC support routines for Linux
3  * X.25 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/errno.h>
13 #include <linux/gfp.h>
14 #include <linux/hdlc.h>
15 #include <linux/if_arp.h>
16 #include <linux/inetdevice.h>
17 #include <linux/init.h>
18 #include <linux/kernel.h>
19 #include <linux/lapb.h>
20 #include <linux/module.h>
21 #include <linux/pkt_sched.h>
22 #include <linux/poll.h>
23 #include <linux/rtnetlink.h>
24 #include <linux/skbuff.h>
25 #include <net/x25device.h>
26
27 static int x25_ioctl(struct net_device *dev, struct ifreq *ifr);
28
29 /* These functions are callbacks called by LAPB layer */
30
31 static void x25_connect_disconnect(struct net_device *dev, int reason, int code)
32 {
33         struct sk_buff *skb;
34         unsigned char *ptr;
35
36         if ((skb = dev_alloc_skb(1)) == NULL) {
37                 netdev_err(dev, "out of memory\n");
38                 return;
39         }
40
41         ptr = skb_put(skb, 1);
42         *ptr = code;
43
44         skb->protocol = x25_type_trans(skb, dev);
45         netif_rx(skb);
46 }
47
48
49
50 static void x25_connected(struct net_device *dev, int reason)
51 {
52         x25_connect_disconnect(dev, reason, X25_IFACE_CONNECT);
53 }
54
55
56
57 static void x25_disconnected(struct net_device *dev, int reason)
58 {
59         x25_connect_disconnect(dev, reason, X25_IFACE_DISCONNECT);
60 }
61
62
63
64 static int x25_data_indication(struct net_device *dev, struct sk_buff *skb)
65 {
66         unsigned char *ptr;
67
68         skb_push(skb, 1);
69
70         if (skb_cow(skb, 1))
71                 return NET_RX_DROP;
72
73         ptr  = skb->data;
74         *ptr = X25_IFACE_DATA;
75
76         skb->protocol = x25_type_trans(skb, dev);
77         return netif_rx(skb);
78 }
79
80
81
82 static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb)
83 {
84         hdlc_device *hdlc = dev_to_hdlc(dev);
85         hdlc->xmit(skb, dev); /* Ignore return value :-( */
86 }
87
88
89
90 static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev)
91 {
92         int result;
93
94
95         /* X.25 to LAPB */
96         switch (skb->data[0]) {
97         case X25_IFACE_DATA:    /* Data to be transmitted */
98                 skb_pull(skb, 1);
99                 if ((result = lapb_data_request(dev, skb)) != LAPB_OK)
100                         dev_kfree_skb(skb);
101                 return NETDEV_TX_OK;
102
103         case X25_IFACE_CONNECT:
104                 if ((result = lapb_connect_request(dev))!= LAPB_OK) {
105                         if (result == LAPB_CONNECTED)
106                                 /* Send connect confirm. msg to level 3 */
107                                 x25_connected(dev, 0);
108                         else
109                                 netdev_err(dev, "LAPB connect request failed, error code = %i\n",
110                                            result);
111                 }
112                 break;
113
114         case X25_IFACE_DISCONNECT:
115                 if ((result = lapb_disconnect_request(dev)) != LAPB_OK) {
116                         if (result == LAPB_NOTCONNECTED)
117                                 /* Send disconnect confirm. msg to level 3 */
118                                 x25_disconnected(dev, 0);
119                         else
120                                 netdev_err(dev, "LAPB disconnect request failed, error code = %i\n",
121                                            result);
122                 }
123                 break;
124
125         default:                /* to be defined */
126                 break;
127         }
128
129         dev_kfree_skb(skb);
130         return NETDEV_TX_OK;
131 }
132
133
134
135 static int x25_open(struct net_device *dev)
136 {
137         int result;
138         static const struct lapb_register_struct cb = {
139                 .connect_confirmation = x25_connected,
140                 .connect_indication = x25_connected,
141                 .disconnect_confirmation = x25_disconnected,
142                 .disconnect_indication = x25_disconnected,
143                 .data_indication = x25_data_indication,
144                 .data_transmit = x25_data_transmit,
145         };
146
147         result = lapb_register(dev, &cb);
148         if (result != LAPB_OK)
149                 return result;
150         return 0;
151 }
152
153
154
155 static void x25_close(struct net_device *dev)
156 {
157         lapb_unregister(dev);
158 }
159
160
161
162 static int x25_rx(struct sk_buff *skb)
163 {
164         struct net_device *dev = skb->dev;
165
166         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
167                 dev->stats.rx_dropped++;
168                 return NET_RX_DROP;
169         }
170
171         if (lapb_data_received(dev, skb) == LAPB_OK)
172                 return NET_RX_SUCCESS;
173
174         dev->stats.rx_errors++;
175         dev_kfree_skb_any(skb);
176         return NET_RX_DROP;
177 }
178
179
180 static struct hdlc_proto proto = {
181         .open           = x25_open,
182         .close          = x25_close,
183         .ioctl          = x25_ioctl,
184         .netif_rx       = x25_rx,
185         .xmit           = x25_xmit,
186         .module         = THIS_MODULE,
187 };
188
189
190 static int x25_ioctl(struct net_device *dev, struct ifreq *ifr)
191 {
192         hdlc_device *hdlc = dev_to_hdlc(dev);
193         int result;
194
195         switch (ifr->ifr_settings.type) {
196         case IF_GET_PROTO:
197                 if (dev_to_hdlc(dev)->proto != &proto)
198                         return -EINVAL;
199                 ifr->ifr_settings.type = IF_PROTO_X25;
200                 return 0; /* return protocol only, no settable parameters */
201
202         case IF_PROTO_X25:
203                 if (!capable(CAP_NET_ADMIN))
204                         return -EPERM;
205
206                 if (dev->flags & IFF_UP)
207                         return -EBUSY;
208
209                 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
210                 if (result)
211                         return result;
212
213                 if ((result = attach_hdlc_protocol(dev, &proto, 0)))
214                         return result;
215                 dev->type = ARPHRD_X25;
216                 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
217                 netif_dormant_off(dev);
218                 return 0;
219         }
220
221         return -EINVAL;
222 }
223
224
225 static int __init mod_init(void)
226 {
227         register_hdlc_protocol(&proto);
228         return 0;
229 }
230
231
232
233 static void __exit mod_exit(void)
234 {
235         unregister_hdlc_protocol(&proto);
236 }
237
238
239 module_init(mod_init);
240 module_exit(mod_exit);
241
242 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
243 MODULE_DESCRIPTION("X.25 protocol support for generic HDLC");
244 MODULE_LICENSE("GPL v2");