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Diffstat (limited to 'drivers/isdn/i4l/isdn_x25iface.c')
-rw-r--r--drivers/isdn/i4l/isdn_x25iface.c328
1 files changed, 328 insertions, 0 deletions
diff --git a/drivers/isdn/i4l/isdn_x25iface.c b/drivers/isdn/i4l/isdn_x25iface.c
new file mode 100644
index 000000000000..4ab7600cf9c1
--- /dev/null
+++ b/drivers/isdn/i4l/isdn_x25iface.c
@@ -0,0 +1,328 @@
1/* $Id: isdn_x25iface.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
2 *
3 * Linux ISDN subsystem, X.25 related functions
4 *
5 * This software may be used and distributed according to the terms
6 * of the GNU General Public License, incorporated herein by reference.
7 *
8 * stuff needed to support the Linux X.25 PLP code on top of devices that
9 * can provide a lab_b service using the concap_proto mechanism.
10 * This module supports a network interface wich provides lapb_sematics
11 * -- as defined in Documentation/networking/x25-iface.txt -- to
12 * the upper layer and assumes that the lower layer provides a reliable
13 * data link service by means of the concap_device_ops callbacks.
14 *
15 * Only protocol specific stuff goes here. Device specific stuff
16 * goes to another -- device related -- concap_proto support source file.
17 *
18 */
19
20/* #include <linux/isdn.h> */
21#include <linux/netdevice.h>
22#include <linux/concap.h>
23#include <linux/wanrouter.h>
24#include <net/x25device.h>
25#include "isdn_x25iface.h"
26
27/* for debugging messages not to cause an oops when device pointer is NULL*/
28#define MY_DEVNAME(dev) ( (dev) ? (dev)->name : "DEVICE UNSPECIFIED" )
29
30
31typedef struct isdn_x25iface_proto_data {
32 int magic;
33 enum wan_states state;
34 /* Private stuff, not to be accessed via proto_data. We provide the
35 other storage for the concap_proto instance here as well,
36 enabling us to allocate both with just one kmalloc(): */
37 struct concap_proto priv;
38} ix25_pdata_t;
39
40
41
42/* is now in header file (extern): struct concap_proto * isdn_x25iface_proto_new(void); */
43void isdn_x25iface_proto_del( struct concap_proto * );
44int isdn_x25iface_proto_close( struct concap_proto * );
45int isdn_x25iface_proto_restart( struct concap_proto *,
46 struct net_device *,
47 struct concap_device_ops *);
48int isdn_x25iface_xmit( struct concap_proto *, struct sk_buff * );
49int isdn_x25iface_receive( struct concap_proto *, struct sk_buff * );
50int isdn_x25iface_connect_ind( struct concap_proto * );
51int isdn_x25iface_disconn_ind( struct concap_proto * );
52
53
54static struct concap_proto_ops ix25_pops = {
55 &isdn_x25iface_proto_new,
56 &isdn_x25iface_proto_del,
57 &isdn_x25iface_proto_restart,
58 &isdn_x25iface_proto_close,
59 &isdn_x25iface_xmit,
60 &isdn_x25iface_receive,
61 &isdn_x25iface_connect_ind,
62 &isdn_x25iface_disconn_ind
63};
64
65/* error message helper function */
66static void illegal_state_warn( unsigned state, unsigned char firstbyte)
67{
68 printk( KERN_WARNING "isdn_x25iface: firstbyte %x illegal in"
69 "current state %d\n",firstbyte, state );
70}
71
72/* check protocol data field for consistency */
73static int pdata_is_bad( ix25_pdata_t * pda ){
74
75 if( pda && pda -> magic == ISDN_X25IFACE_MAGIC ) return 0;
76 printk( KERN_WARNING
77 "isdn_x25iface_xxx: illegal pointer to proto data\n" );
78 return 1;
79}
80
81/* create a new x25 interface protocol instance
82 */
83struct concap_proto * isdn_x25iface_proto_new(void)
84{
85 ix25_pdata_t * tmp = kmalloc(sizeof(ix25_pdata_t),GFP_KERNEL);
86 IX25DEBUG("isdn_x25iface_proto_new\n");
87 if( tmp ){
88 tmp -> magic = ISDN_X25IFACE_MAGIC;
89 tmp -> state = WAN_UNCONFIGURED;
90 /* private data space used to hold the concap_proto data.
91 Only to be accessed via the returned pointer */
92 spin_lock_init(&tmp->priv.lock);
93 tmp -> priv.dops = NULL;
94 tmp -> priv.net_dev = NULL;
95 tmp -> priv.pops = &ix25_pops;
96 tmp -> priv.flags = 0;
97 tmp -> priv.proto_data = tmp;
98 return( &(tmp -> priv) );
99 }
100 return NULL;
101};
102
103/* close the x25iface encapsulation protocol
104 */
105int isdn_x25iface_proto_close(struct concap_proto *cprot){
106
107 ix25_pdata_t *tmp;
108 int ret = 0;
109 ulong flags;
110
111 if( ! cprot ){
112 printk( KERN_ERR "isdn_x25iface_proto_close: "
113 "invalid concap_proto pointer\n" );
114 return -1;
115 }
116 IX25DEBUG( "isdn_x25iface_proto_close %s \n", MY_DEVNAME(cprot -> net_dev) );
117 spin_lock_irqsave(&cprot->lock, flags);
118 cprot -> dops = NULL;
119 cprot -> net_dev = NULL;
120 tmp = cprot -> proto_data;
121 if( pdata_is_bad( tmp ) ){
122 ret = -1;
123 } else {
124 tmp -> state = WAN_UNCONFIGURED;
125 }
126 spin_unlock_irqrestore(&cprot->lock, flags);
127 return ret;
128}
129
130/* Delete the x25iface encapsulation protocol instance
131 */
132void isdn_x25iface_proto_del(struct concap_proto *cprot){
133
134 ix25_pdata_t * tmp;
135
136 IX25DEBUG( "isdn_x25iface_proto_del \n" );
137 if( ! cprot ){
138 printk( KERN_ERR "isdn_x25iface_proto_del: "
139 "concap_proto pointer is NULL\n" );
140 return;
141 }
142 tmp = cprot -> proto_data;
143 if( tmp == NULL ){
144 printk( KERN_ERR "isdn_x25iface_proto_del: inconsistent "
145 "proto_data pointer (maybe already deleted?)\n");
146 return;
147 }
148 /* close if the protocol is still open */
149 if( cprot -> dops ) isdn_x25iface_proto_close(cprot);
150 /* freeing the storage should be sufficient now. But some additional
151 settings might help to catch wild pointer bugs */
152 tmp -> magic = 0;
153 cprot -> proto_data = NULL;
154
155 kfree( tmp );
156 return;
157}
158
159/* (re-)initialize the data structures for x25iface encapsulation
160 */
161int isdn_x25iface_proto_restart(struct concap_proto *cprot,
162 struct net_device *ndev,
163 struct concap_device_ops *dops)
164{
165 ix25_pdata_t * pda = cprot -> proto_data ;
166 ulong flags;
167
168 IX25DEBUG( "isdn_x25iface_proto_restart %s \n", MY_DEVNAME(ndev) );
169
170 if ( pdata_is_bad( pda ) ) return -1;
171
172 if( !( dops && dops -> data_req && dops -> connect_req
173 && dops -> disconn_req ) ){
174 printk( KERN_WARNING "isdn_x25iface_restart: required dops"
175 " missing\n" );
176 isdn_x25iface_proto_close(cprot);
177 return -1;
178 }
179 spin_lock_irqsave(&cprot->lock, flags);
180 cprot -> net_dev = ndev;
181 cprot -> pops = &ix25_pops;
182 cprot -> dops = dops;
183 pda -> state = WAN_DISCONNECTED;
184 spin_unlock_irqrestore(&cprot->lock, flags);
185 return 0;
186}
187
188/* deliver a dl_data frame received from i4l HL driver to the network layer
189 */
190int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb)
191{
192 IX25DEBUG( "isdn_x25iface_receive %s \n", MY_DEVNAME(cprot->net_dev) );
193 if ( ( (ix25_pdata_t*) (cprot->proto_data) )
194 -> state == WAN_CONNECTED ){
195 if( skb_push(skb, 1)){
196 skb -> data[0]=0x00;
197 skb->protocol = x25_type_trans(skb, cprot->net_dev);
198 netif_rx(skb);
199 return 0;
200 }
201 }
202 printk(KERN_WARNING "isdn_x25iface_receive %s: not connected, skb dropped\n", MY_DEVNAME(cprot->net_dev) );
203 dev_kfree_skb(skb);
204 return -1;
205}
206
207/* a connection set up is indicated by lower layer
208 */
209int isdn_x25iface_connect_ind(struct concap_proto *cprot)
210{
211 struct sk_buff * skb = dev_alloc_skb(1);
212 enum wan_states *state_p
213 = &( ( (ix25_pdata_t*) (cprot->proto_data) ) -> state);
214 IX25DEBUG( "isdn_x25iface_connect_ind %s \n"
215 , MY_DEVNAME(cprot->net_dev) );
216 if( *state_p == WAN_UNCONFIGURED ){
217 printk(KERN_WARNING
218 "isdn_x25iface_connect_ind while unconfigured %s\n"
219 , MY_DEVNAME(cprot->net_dev) );
220 return -1;
221 }
222 *state_p = WAN_CONNECTED;
223 if( skb ){
224 *( skb_put(skb, 1) ) = 0x01;
225 skb->protocol = x25_type_trans(skb, cprot->net_dev);
226 netif_rx(skb);
227 return 0;
228 } else {
229 printk(KERN_WARNING "isdn_x25iface_connect_ind: "
230 " out of memory -- disconnecting\n");
231 cprot -> dops -> disconn_req(cprot);
232 return -1;
233 }
234}
235
236/* a disconnect is indicated by lower layer
237 */
238int isdn_x25iface_disconn_ind(struct concap_proto *cprot)
239{
240 struct sk_buff *skb;
241 enum wan_states *state_p
242 = &( ( (ix25_pdata_t*) (cprot->proto_data) ) -> state);
243 IX25DEBUG( "isdn_x25iface_disconn_ind %s \n", MY_DEVNAME(cprot -> net_dev) );
244 if( *state_p == WAN_UNCONFIGURED ){
245 printk(KERN_WARNING
246 "isdn_x25iface_disconn_ind while unconfigured\n");
247 return -1;
248 }
249 if(! cprot -> net_dev) return -1;
250 *state_p = WAN_DISCONNECTED;
251 skb = dev_alloc_skb(1);
252 if( skb ){
253 *( skb_put(skb, 1) ) = 0x02;
254 skb->protocol = x25_type_trans(skb, cprot->net_dev);
255 netif_rx(skb);
256 return 0;
257 } else {
258 printk(KERN_WARNING "isdn_x25iface_disconn_ind:"
259 " out of memory\n");
260 return -1;
261 }
262}
263
264/* process a frame handed over to us from linux network layer. First byte
265 semantics as defined in Documentation/networking/x25-iface.txt
266 */
267int isdn_x25iface_xmit(struct concap_proto *cprot, struct sk_buff *skb)
268{
269 unsigned char firstbyte = skb->data[0];
270 enum wan_states *state = &((ix25_pdata_t*)cprot->proto_data)->state;
271 int ret = 0;
272 IX25DEBUG( "isdn_x25iface_xmit: %s first=%x state=%d \n", MY_DEVNAME(cprot -> net_dev), firstbyte, *state );
273 switch ( firstbyte ){
274 case 0x00: /* dl_data request */
275 if( *state == WAN_CONNECTED ){
276 skb_pull(skb, 1);
277 cprot -> net_dev -> trans_start = jiffies;
278 ret = ( cprot -> dops -> data_req(cprot, skb) );
279 /* prepare for future retransmissions */
280 if( ret ) skb_push(skb,1);
281 return ret;
282 }
283 illegal_state_warn( *state, firstbyte );
284 break;
285 case 0x01: /* dl_connect request */
286 if( *state == WAN_DISCONNECTED ){
287 *state = WAN_CONNECTING;
288 ret = cprot -> dops -> connect_req(cprot);
289 if(ret){
290 /* reset state and notify upper layer about
291 * immidiatly failed attempts */
292 isdn_x25iface_disconn_ind(cprot);
293 }
294 } else {
295 illegal_state_warn( *state, firstbyte );
296 }
297 break;
298 case 0x02: /* dl_disconnect request */
299 switch ( *state ){
300 case WAN_DISCONNECTED:
301 /* Should not happen. However, give upper layer a
302 chance to recover from inconstistency but don't
303 trust the lower layer sending the disconn_confirm
304 when already disconnected */
305 printk(KERN_WARNING "isdn_x25iface_xmit: disconnect "
306 " requested while disconnected\n" );
307 isdn_x25iface_disconn_ind(cprot);
308 break; /* prevent infinite loops */
309 case WAN_CONNECTING:
310 case WAN_CONNECTED:
311 *state = WAN_DISCONNECTED;
312 cprot -> dops -> disconn_req(cprot);
313 break;
314 default:
315 illegal_state_warn( *state, firstbyte );
316 }
317 break;
318 case 0x03: /* changing lapb parameters requested */
319 printk(KERN_WARNING "isdn_x25iface_xmit: setting of lapb"
320 " options not yet supported\n");
321 break;
322 default:
323 printk(KERN_WARNING "isdn_x25iface_xmit: frame with illegal"
324 " first byte %x ignored:\n", firstbyte);
325 }
326 dev_kfree_skb(skb);
327 return 0;
328}
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-07 12:09:34 -0500