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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* $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.
Uwe Zeisbergerc30fe7f2006-03-24 18:23:14 +010010 * This module supports a network interface which provides lapb_sematics
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * -- 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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/wanrouter.h>
25#include <net/x25device.h>
26#include "isdn_x25iface.h"
27
28/* for debugging messages not to cause an oops when device pointer is NULL*/
29#define MY_DEVNAME(dev) ( (dev) ? (dev)->name : "DEVICE UNSPECIFIED" )
30
31
32typedef struct isdn_x25iface_proto_data {
33 int magic;
34 enum wan_states state;
35 /* Private stuff, not to be accessed via proto_data. We provide the
36 other storage for the concap_proto instance here as well,
37 enabling us to allocate both with just one kmalloc(): */
38 struct concap_proto priv;
39} ix25_pdata_t;
40
41
42
43/* is now in header file (extern): struct concap_proto * isdn_x25iface_proto_new(void); */
Adrian Bunk3e206b02005-06-25 14:58:35 -070044static void isdn_x25iface_proto_del( struct concap_proto * );
45static int isdn_x25iface_proto_close( struct concap_proto * );
46static int isdn_x25iface_proto_restart( struct concap_proto *,
47 struct net_device *,
48 struct concap_device_ops *);
49static int isdn_x25iface_xmit( struct concap_proto *, struct sk_buff * );
50static int isdn_x25iface_receive( struct concap_proto *, struct sk_buff * );
51static int isdn_x25iface_connect_ind( struct concap_proto * );
52static int isdn_x25iface_disconn_ind( struct concap_proto * );
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54
55static struct concap_proto_ops ix25_pops = {
56 &isdn_x25iface_proto_new,
57 &isdn_x25iface_proto_del,
58 &isdn_x25iface_proto_restart,
59 &isdn_x25iface_proto_close,
60 &isdn_x25iface_xmit,
61 &isdn_x25iface_receive,
62 &isdn_x25iface_connect_ind,
63 &isdn_x25iface_disconn_ind
64};
65
66/* error message helper function */
67static void illegal_state_warn( unsigned state, unsigned char firstbyte)
68{
69 printk( KERN_WARNING "isdn_x25iface: firstbyte %x illegal in"
70 "current state %d\n",firstbyte, state );
71}
72
73/* check protocol data field for consistency */
74static int pdata_is_bad( ix25_pdata_t * pda ){
75
76 if( pda && pda -> magic == ISDN_X25IFACE_MAGIC ) return 0;
77 printk( KERN_WARNING
78 "isdn_x25iface_xxx: illegal pointer to proto data\n" );
79 return 1;
80}
81
82/* create a new x25 interface protocol instance
83 */
84struct concap_proto * isdn_x25iface_proto_new(void)
85{
86 ix25_pdata_t * tmp = kmalloc(sizeof(ix25_pdata_t),GFP_KERNEL);
87 IX25DEBUG("isdn_x25iface_proto_new\n");
88 if( tmp ){
89 tmp -> magic = ISDN_X25IFACE_MAGIC;
90 tmp -> state = WAN_UNCONFIGURED;
91 /* private data space used to hold the concap_proto data.
92 Only to be accessed via the returned pointer */
93 spin_lock_init(&tmp->priv.lock);
94 tmp -> priv.dops = NULL;
95 tmp -> priv.net_dev = NULL;
96 tmp -> priv.pops = &ix25_pops;
97 tmp -> priv.flags = 0;
98 tmp -> priv.proto_data = tmp;
99 return( &(tmp -> priv) );
100 }
101 return NULL;
102};
103
104/* close the x25iface encapsulation protocol
105 */
Adrian Bunk3e206b02005-06-25 14:58:35 -0700106static int isdn_x25iface_proto_close(struct concap_proto *cprot){
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
108 ix25_pdata_t *tmp;
109 int ret = 0;
110 ulong flags;
111
112 if( ! cprot ){
113 printk( KERN_ERR "isdn_x25iface_proto_close: "
114 "invalid concap_proto pointer\n" );
115 return -1;
116 }
117 IX25DEBUG( "isdn_x25iface_proto_close %s \n", MY_DEVNAME(cprot -> net_dev) );
118 spin_lock_irqsave(&cprot->lock, flags);
119 cprot -> dops = NULL;
120 cprot -> net_dev = NULL;
121 tmp = cprot -> proto_data;
122 if( pdata_is_bad( tmp ) ){
123 ret = -1;
124 } else {
125 tmp -> state = WAN_UNCONFIGURED;
126 }
127 spin_unlock_irqrestore(&cprot->lock, flags);
128 return ret;
129}
130
131/* Delete the x25iface encapsulation protocol instance
132 */
Adrian Bunk3e206b02005-06-25 14:58:35 -0700133static void isdn_x25iface_proto_del(struct concap_proto *cprot){
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
135 ix25_pdata_t * tmp;
136
137 IX25DEBUG( "isdn_x25iface_proto_del \n" );
138 if( ! cprot ){
139 printk( KERN_ERR "isdn_x25iface_proto_del: "
140 "concap_proto pointer is NULL\n" );
141 return;
142 }
143 tmp = cprot -> proto_data;
144 if( tmp == NULL ){
145 printk( KERN_ERR "isdn_x25iface_proto_del: inconsistent "
146 "proto_data pointer (maybe already deleted?)\n");
147 return;
148 }
149 /* close if the protocol is still open */
150 if( cprot -> dops ) isdn_x25iface_proto_close(cprot);
151 /* freeing the storage should be sufficient now. But some additional
152 settings might help to catch wild pointer bugs */
153 tmp -> magic = 0;
154 cprot -> proto_data = NULL;
155
156 kfree( tmp );
157 return;
158}
159
160/* (re-)initialize the data structures for x25iface encapsulation
161 */
Adrian Bunk3e206b02005-06-25 14:58:35 -0700162static int isdn_x25iface_proto_restart(struct concap_proto *cprot,
163 struct net_device *ndev,
164 struct concap_device_ops *dops)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165{
166 ix25_pdata_t * pda = cprot -> proto_data ;
167 ulong flags;
168
169 IX25DEBUG( "isdn_x25iface_proto_restart %s \n", MY_DEVNAME(ndev) );
170
171 if ( pdata_is_bad( pda ) ) return -1;
172
173 if( !( dops && dops -> data_req && dops -> connect_req
174 && dops -> disconn_req ) ){
175 printk( KERN_WARNING "isdn_x25iface_restart: required dops"
176 " missing\n" );
177 isdn_x25iface_proto_close(cprot);
178 return -1;
179 }
180 spin_lock_irqsave(&cprot->lock, flags);
181 cprot -> net_dev = ndev;
182 cprot -> pops = &ix25_pops;
183 cprot -> dops = dops;
184 pda -> state = WAN_DISCONNECTED;
185 spin_unlock_irqrestore(&cprot->lock, flags);
186 return 0;
187}
188
189/* deliver a dl_data frame received from i4l HL driver to the network layer
190 */
Adrian Bunk3e206b02005-06-25 14:58:35 -0700191static int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192{
193 IX25DEBUG( "isdn_x25iface_receive %s \n", MY_DEVNAME(cprot->net_dev) );
194 if ( ( (ix25_pdata_t*) (cprot->proto_data) )
195 -> state == WAN_CONNECTED ){
196 if( skb_push(skb, 1)){
andrew hendry4150bbf2010-04-19 13:29:06 +0000197 skb->data[0] = X25_IFACE_DATA;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 skb->protocol = x25_type_trans(skb, cprot->net_dev);
199 netif_rx(skb);
200 return 0;
201 }
202 }
203 printk(KERN_WARNING "isdn_x25iface_receive %s: not connected, skb dropped\n", MY_DEVNAME(cprot->net_dev) );
204 dev_kfree_skb(skb);
205 return -1;
206}
207
208/* a connection set up is indicated by lower layer
209 */
Adrian Bunk3e206b02005-06-25 14:58:35 -0700210static int isdn_x25iface_connect_ind(struct concap_proto *cprot)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211{
Eric Sesterhennd81931d2006-06-29 02:24:34 -0700212 struct sk_buff * skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 enum wan_states *state_p
214 = &( ( (ix25_pdata_t*) (cprot->proto_data) ) -> state);
215 IX25DEBUG( "isdn_x25iface_connect_ind %s \n"
216 , MY_DEVNAME(cprot->net_dev) );
217 if( *state_p == WAN_UNCONFIGURED ){
218 printk(KERN_WARNING
219 "isdn_x25iface_connect_ind while unconfigured %s\n"
220 , MY_DEVNAME(cprot->net_dev) );
221 return -1;
222 }
223 *state_p = WAN_CONNECTED;
Eric Sesterhennd81931d2006-06-29 02:24:34 -0700224
225 skb = dev_alloc_skb(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 if( skb ){
andrew hendry4150bbf2010-04-19 13:29:06 +0000227 *(skb_put(skb, 1)) = X25_IFACE_CONNECT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 skb->protocol = x25_type_trans(skb, cprot->net_dev);
229 netif_rx(skb);
230 return 0;
231 } else {
232 printk(KERN_WARNING "isdn_x25iface_connect_ind: "
233 " out of memory -- disconnecting\n");
234 cprot -> dops -> disconn_req(cprot);
235 return -1;
236 }
237}
238
239/* a disconnect is indicated by lower layer
240 */
Adrian Bunk3e206b02005-06-25 14:58:35 -0700241static int isdn_x25iface_disconn_ind(struct concap_proto *cprot)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242{
243 struct sk_buff *skb;
244 enum wan_states *state_p
245 = &( ( (ix25_pdata_t*) (cprot->proto_data) ) -> state);
246 IX25DEBUG( "isdn_x25iface_disconn_ind %s \n", MY_DEVNAME(cprot -> net_dev) );
247 if( *state_p == WAN_UNCONFIGURED ){
248 printk(KERN_WARNING
249 "isdn_x25iface_disconn_ind while unconfigured\n");
250 return -1;
251 }
252 if(! cprot -> net_dev) return -1;
253 *state_p = WAN_DISCONNECTED;
254 skb = dev_alloc_skb(1);
255 if( skb ){
andrew hendry4150bbf2010-04-19 13:29:06 +0000256 *(skb_put(skb, 1)) = X25_IFACE_DISCONNECT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 skb->protocol = x25_type_trans(skb, cprot->net_dev);
258 netif_rx(skb);
259 return 0;
260 } else {
261 printk(KERN_WARNING "isdn_x25iface_disconn_ind:"
262 " out of memory\n");
263 return -1;
264 }
265}
266
267/* process a frame handed over to us from linux network layer. First byte
268 semantics as defined in Documentation/networking/x25-iface.txt
269 */
Adrian Bunk3e206b02005-06-25 14:58:35 -0700270static int isdn_x25iface_xmit(struct concap_proto *cprot, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271{
272 unsigned char firstbyte = skb->data[0];
273 enum wan_states *state = &((ix25_pdata_t*)cprot->proto_data)->state;
274 int ret = 0;
andrew hendry4150bbf2010-04-19 13:29:06 +0000275 IX25DEBUG("isdn_x25iface_xmit: %s first=%x state=%d\n",
276 MY_DEVNAME(cprot->net_dev), firstbyte, *state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 switch ( firstbyte ){
andrew hendry4150bbf2010-04-19 13:29:06 +0000278 case X25_IFACE_DATA:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 if( *state == WAN_CONNECTED ){
280 skb_pull(skb, 1);
281 cprot -> net_dev -> trans_start = jiffies;
282 ret = ( cprot -> dops -> data_req(cprot, skb) );
283 /* prepare for future retransmissions */
284 if( ret ) skb_push(skb,1);
285 return ret;
286 }
287 illegal_state_warn( *state, firstbyte );
288 break;
andrew hendry4150bbf2010-04-19 13:29:06 +0000289 case X25_IFACE_CONNECT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 if( *state == WAN_DISCONNECTED ){
291 *state = WAN_CONNECTING;
292 ret = cprot -> dops -> connect_req(cprot);
293 if(ret){
294 /* reset state and notify upper layer about
295 * immidiatly failed attempts */
296 isdn_x25iface_disconn_ind(cprot);
297 }
298 } else {
299 illegal_state_warn( *state, firstbyte );
300 }
301 break;
andrew hendry4150bbf2010-04-19 13:29:06 +0000302 case X25_IFACE_DISCONNECT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 switch ( *state ){
304 case WAN_DISCONNECTED:
305 /* Should not happen. However, give upper layer a
306 chance to recover from inconstistency but don't
307 trust the lower layer sending the disconn_confirm
308 when already disconnected */
309 printk(KERN_WARNING "isdn_x25iface_xmit: disconnect "
310 " requested while disconnected\n" );
311 isdn_x25iface_disconn_ind(cprot);
312 break; /* prevent infinite loops */
313 case WAN_CONNECTING:
314 case WAN_CONNECTED:
315 *state = WAN_DISCONNECTED;
316 cprot -> dops -> disconn_req(cprot);
317 break;
318 default:
319 illegal_state_warn( *state, firstbyte );
320 }
321 break;
andrew hendry4150bbf2010-04-19 13:29:06 +0000322 case X25_IFACE_PARAMS:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 printk(KERN_WARNING "isdn_x25iface_xmit: setting of lapb"
324 " options not yet supported\n");
325 break;
326 default:
327 printk(KERN_WARNING "isdn_x25iface_xmit: frame with illegal"
328 " first byte %x ignored:\n", firstbyte);
329 }
330 dev_kfree_skb(skb);
331 return 0;
332}