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1da177e4 LT |
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. | |
c30fe7f7 | 10 | * This module supports a network interface which provides lapb_sematics |
1da177e4 LT |
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> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
1da177e4 LT |
24 | #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 | ||
32 | typedef 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); */ | |
3e206b0a AB |
44 | static void isdn_x25iface_proto_del( struct concap_proto * ); |
45 | static int isdn_x25iface_proto_close( struct concap_proto * ); | |
46 | static int isdn_x25iface_proto_restart( struct concap_proto *, | |
47 | struct net_device *, | |
48 | struct concap_device_ops *); | |
49 | static int isdn_x25iface_xmit( struct concap_proto *, struct sk_buff * ); | |
50 | static int isdn_x25iface_receive( struct concap_proto *, struct sk_buff * ); | |
51 | static int isdn_x25iface_connect_ind( struct concap_proto * ); | |
52 | static int isdn_x25iface_disconn_ind( struct concap_proto * ); | |
1da177e4 LT |
53 | |
54 | ||
55 | static 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 */ | |
67 | static 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 */ | |
74 | static 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 | */ | |
84 | struct 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 | */ | |
3e206b0a | 106 | static int isdn_x25iface_proto_close(struct concap_proto *cprot){ |
1da177e4 LT |
107 | |
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 | */ | |
3e206b0a | 133 | static void isdn_x25iface_proto_del(struct concap_proto *cprot){ |
1da177e4 LT |
134 | |
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 | */ | |
3e206b0a AB |
162 | static int isdn_x25iface_proto_restart(struct concap_proto *cprot, |
163 | struct net_device *ndev, | |
164 | struct concap_device_ops *dops) | |
1da177e4 LT |
165 | { |
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 | */ | |
3e206b0a | 191 | static int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb) |
1da177e4 LT |
192 | { |
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)){ | |
197 | skb -> data[0]=0x00; | |
198 | 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 | */ | |
3e206b0a | 210 | static int isdn_x25iface_connect_ind(struct concap_proto *cprot) |
1da177e4 | 211 | { |
d81931d9 | 212 | struct sk_buff * skb; |
1da177e4 LT |
213 | 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; | |
d81931d9 ES |
224 | |
225 | skb = dev_alloc_skb(1); | |
1da177e4 LT |
226 | if( skb ){ |
227 | *( skb_put(skb, 1) ) = 0x01; | |
228 | 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 | */ | |
3e206b0a | 241 | static int isdn_x25iface_disconn_ind(struct concap_proto *cprot) |
1da177e4 LT |
242 | { |
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 ){ | |
256 | *( skb_put(skb, 1) ) = 0x02; | |
257 | 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 | */ | |
3e206b0a | 270 | static int isdn_x25iface_xmit(struct concap_proto *cprot, struct sk_buff *skb) |
1da177e4 LT |
271 | { |
272 | unsigned char firstbyte = skb->data[0]; | |
273 | enum wan_states *state = &((ix25_pdata_t*)cprot->proto_data)->state; | |
274 | int ret = 0; | |
275 | IX25DEBUG( "isdn_x25iface_xmit: %s first=%x state=%d \n", MY_DEVNAME(cprot -> net_dev), firstbyte, *state ); | |
276 | switch ( firstbyte ){ | |
277 | case 0x00: /* dl_data request */ | |
278 | if( *state == WAN_CONNECTED ){ | |
279 | skb_pull(skb, 1); | |
280 | cprot -> net_dev -> trans_start = jiffies; | |
281 | ret = ( cprot -> dops -> data_req(cprot, skb) ); | |
282 | /* prepare for future retransmissions */ | |
283 | if( ret ) skb_push(skb,1); | |
284 | return ret; | |
285 | } | |
286 | illegal_state_warn( *state, firstbyte ); | |
287 | break; | |
288 | case 0x01: /* dl_connect request */ | |
289 | if( *state == WAN_DISCONNECTED ){ | |
290 | *state = WAN_CONNECTING; | |
291 | ret = cprot -> dops -> connect_req(cprot); | |
292 | if(ret){ | |
293 | /* reset state and notify upper layer about | |
294 | * immidiatly failed attempts */ | |
295 | isdn_x25iface_disconn_ind(cprot); | |
296 | } | |
297 | } else { | |
298 | illegal_state_warn( *state, firstbyte ); | |
299 | } | |
300 | break; | |
301 | case 0x02: /* dl_disconnect request */ | |
302 | switch ( *state ){ | |
303 | case WAN_DISCONNECTED: | |
304 | /* Should not happen. However, give upper layer a | |
305 | chance to recover from inconstistency but don't | |
306 | trust the lower layer sending the disconn_confirm | |
307 | when already disconnected */ | |
308 | printk(KERN_WARNING "isdn_x25iface_xmit: disconnect " | |
309 | " requested while disconnected\n" ); | |
310 | isdn_x25iface_disconn_ind(cprot); | |
311 | break; /* prevent infinite loops */ | |
312 | case WAN_CONNECTING: | |
313 | case WAN_CONNECTED: | |
314 | *state = WAN_DISCONNECTED; | |
315 | cprot -> dops -> disconn_req(cprot); | |
316 | break; | |
317 | default: | |
318 | illegal_state_warn( *state, firstbyte ); | |
319 | } | |
320 | break; | |
321 | case 0x03: /* changing lapb parameters requested */ | |
322 | printk(KERN_WARNING "isdn_x25iface_xmit: setting of lapb" | |
323 | " options not yet supported\n"); | |
324 | break; | |
325 | default: | |
326 | printk(KERN_WARNING "isdn_x25iface_xmit: frame with illegal" | |
327 | " first byte %x ignored:\n", firstbyte); | |
328 | } | |
329 | dev_kfree_skb(skb); | |
330 | return 0; | |
331 | } |