fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / drivers / isdn / i4l / isdn_x25iface.c
blob8b3efc243161a201fd8029d5d43900371c48b2b5
1 /* $Id: isdn_x25iface.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
3 * Linux ISDN subsystem, X.25 related functions
5 * This software may be used and distributed according to the terms
6 * of the GNU General Public License, incorporated herein by reference.
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 which 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.
15 * Only protocol specific stuff goes here. Device specific stuff
16 * goes to another -- device related -- concap_proto support source file.
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"
27 /* for debugging messages not to cause an oops when device pointer is NULL*/
28 #define MY_DEVNAME(dev) ( (dev) ? (dev)->name : "DEVICE UNSPECIFIED" )
31 typedef 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;
42 /* is now in header file (extern): struct concap_proto * isdn_x25iface_proto_new(void); */
43 static void isdn_x25iface_proto_del( struct concap_proto * );
44 static int isdn_x25iface_proto_close( struct concap_proto * );
45 static int isdn_x25iface_proto_restart( struct concap_proto *,
46 struct net_device *,
47 struct concap_device_ops *);
48 static int isdn_x25iface_xmit( struct concap_proto *, struct sk_buff * );
49 static int isdn_x25iface_receive( struct concap_proto *, struct sk_buff * );
50 static int isdn_x25iface_connect_ind( struct concap_proto * );
51 static int isdn_x25iface_disconn_ind( struct concap_proto * );
54 static 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
65 /* error message helper function */
66 static void illegal_state_warn( unsigned state, unsigned char firstbyte)
68 printk( KERN_WARNING "isdn_x25iface: firstbyte %x illegal in"
69 "current state %d\n",firstbyte, state );
72 /* check protocol data field for consistency */
73 static int pdata_is_bad( ix25_pdata_t * pda ){
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;
81 /* create a new x25 interface protocol instance
83 struct concap_proto * isdn_x25iface_proto_new(void)
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) );
100 return NULL;
103 /* close the x25iface encapsulation protocol
105 static int isdn_x25iface_proto_close(struct concap_proto *cprot){
107 ix25_pdata_t *tmp;
108 int ret = 0;
109 ulong flags;
111 if( ! cprot ){
112 printk( KERN_ERR "isdn_x25iface_proto_close: "
113 "invalid concap_proto pointer\n" );
114 return -1;
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;
126 spin_unlock_irqrestore(&cprot->lock, flags);
127 return ret;
130 /* Delete the x25iface encapsulation protocol instance
132 static void isdn_x25iface_proto_del(struct concap_proto *cprot){
134 ix25_pdata_t * tmp;
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;
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;
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;
155 kfree( tmp );
156 return;
159 /* (re-)initialize the data structures for x25iface encapsulation
161 static int isdn_x25iface_proto_restart(struct concap_proto *cprot,
162 struct net_device *ndev,
163 struct concap_device_ops *dops)
165 ix25_pdata_t * pda = cprot -> proto_data ;
166 ulong flags;
168 IX25DEBUG( "isdn_x25iface_proto_restart %s \n", MY_DEVNAME(ndev) );
170 if ( pdata_is_bad( pda ) ) return -1;
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;
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;
188 /* deliver a dl_data frame received from i4l HL driver to the network layer
190 static int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb)
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;
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;
207 /* a connection set up is indicated by lower layer
209 static int isdn_x25iface_connect_ind(struct concap_proto *cprot)
211 struct sk_buff * skb;
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;
222 *state_p = WAN_CONNECTED;
224 skb = dev_alloc_skb(1);
225 if( skb ){
226 *( skb_put(skb, 1) ) = 0x01;
227 skb->protocol = x25_type_trans(skb, cprot->net_dev);
228 netif_rx(skb);
229 return 0;
230 } else {
231 printk(KERN_WARNING "isdn_x25iface_connect_ind: "
232 " out of memory -- disconnecting\n");
233 cprot -> dops -> disconn_req(cprot);
234 return -1;
238 /* a disconnect is indicated by lower layer
240 static int isdn_x25iface_disconn_ind(struct concap_proto *cprot)
242 struct sk_buff *skb;
243 enum wan_states *state_p
244 = &( ( (ix25_pdata_t*) (cprot->proto_data) ) -> state);
245 IX25DEBUG( "isdn_x25iface_disconn_ind %s \n", MY_DEVNAME(cprot -> net_dev) );
246 if( *state_p == WAN_UNCONFIGURED ){
247 printk(KERN_WARNING
248 "isdn_x25iface_disconn_ind while unconfigured\n");
249 return -1;
251 if(! cprot -> net_dev) return -1;
252 *state_p = WAN_DISCONNECTED;
253 skb = dev_alloc_skb(1);
254 if( skb ){
255 *( skb_put(skb, 1) ) = 0x02;
256 skb->protocol = x25_type_trans(skb, cprot->net_dev);
257 netif_rx(skb);
258 return 0;
259 } else {
260 printk(KERN_WARNING "isdn_x25iface_disconn_ind:"
261 " out of memory\n");
262 return -1;
266 /* process a frame handed over to us from linux network layer. First byte
267 semantics as defined in Documentation/networking/x25-iface.txt
269 static int isdn_x25iface_xmit(struct concap_proto *cprot, struct sk_buff *skb)
271 unsigned char firstbyte = skb->data[0];
272 enum wan_states *state = &((ix25_pdata_t*)cprot->proto_data)->state;
273 int ret = 0;
274 IX25DEBUG( "isdn_x25iface_xmit: %s first=%x state=%d \n", MY_DEVNAME(cprot -> net_dev), firstbyte, *state );
275 switch ( firstbyte ){
276 case 0x00: /* dl_data request */
277 if( *state == WAN_CONNECTED ){
278 skb_pull(skb, 1);
279 cprot -> net_dev -> trans_start = jiffies;
280 ret = ( cprot -> dops -> data_req(cprot, skb) );
281 /* prepare for future retransmissions */
282 if( ret ) skb_push(skb,1);
283 return ret;
285 illegal_state_warn( *state, firstbyte );
286 break;
287 case 0x01: /* dl_connect request */
288 if( *state == WAN_DISCONNECTED ){
289 *state = WAN_CONNECTING;
290 ret = cprot -> dops -> connect_req(cprot);
291 if(ret){
292 /* reset state and notify upper layer about
293 * immidiatly failed attempts */
294 isdn_x25iface_disconn_ind(cprot);
296 } else {
297 illegal_state_warn( *state, firstbyte );
299 break;
300 case 0x02: /* dl_disconnect request */
301 switch ( *state ){
302 case WAN_DISCONNECTED:
303 /* Should not happen. However, give upper layer a
304 chance to recover from inconstistency but don't
305 trust the lower layer sending the disconn_confirm
306 when already disconnected */
307 printk(KERN_WARNING "isdn_x25iface_xmit: disconnect "
308 " requested while disconnected\n" );
309 isdn_x25iface_disconn_ind(cprot);
310 break; /* prevent infinite loops */
311 case WAN_CONNECTING:
312 case WAN_CONNECTED:
313 *state = WAN_DISCONNECTED;
314 cprot -> dops -> disconn_req(cprot);
315 break;
316 default:
317 illegal_state_warn( *state, firstbyte );
319 break;
320 case 0x03: /* changing lapb parameters requested */
321 printk(KERN_WARNING "isdn_x25iface_xmit: setting of lapb"
322 " options not yet supported\n");
323 break;
324 default:
325 printk(KERN_WARNING "isdn_x25iface_xmit: frame with illegal"
326 " first byte %x ignored:\n", firstbyte);
328 dev_kfree_skb(skb);
329 return 0;