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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> | |
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 | ||
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; | |
39 | ||
40 | ||
41 | ||
42 | /* is now in header file (extern): struct concap_proto * isdn_x25iface_proto_new(void); */ | |
3e206b0a AB |
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 * ); | |
1da177e4 LT |
52 | |
53 | ||
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 | |
63 | }; | |
64 | ||
65 | /* error message helper function */ | |
66 | static 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 */ | |
73 | static 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 | */ | |
83 | struct 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 | */ | |
3e206b0a | 105 | static int isdn_x25iface_proto_close(struct concap_proto *cprot){ |
1da177e4 LT |
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 | */ | |
3e206b0a | 132 | static void isdn_x25iface_proto_del(struct concap_proto *cprot){ |
1da177e4 LT |
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 | */ | |
3e206b0a AB |
161 | static int isdn_x25iface_proto_restart(struct concap_proto *cprot, |
162 | struct net_device *ndev, | |
163 | struct concap_device_ops *dops) | |
1da177e4 LT |
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 | */ | |
3e206b0a | 190 | static int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb) |
1da177e4 LT |
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 | */ | |
3e206b0a | 209 | static int isdn_x25iface_connect_ind(struct concap_proto *cprot) |
1da177e4 | 210 | { |
d81931d9 | 211 | struct sk_buff * skb; |
1da177e4 LT |
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; | |
d81931d9 ES |
223 | |
224 | skb = dev_alloc_skb(1); | |
1da177e4 LT |
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; | |
235 | } | |
236 | } | |
237 | ||
238 | /* a disconnect is indicated by lower layer | |
239 | */ | |
3e206b0a | 240 | static int isdn_x25iface_disconn_ind(struct concap_proto *cprot) |
1da177e4 LT |
241 | { |
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; | |
250 | } | |
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; | |
263 | } | |
264 | } | |
265 | ||
266 | /* process a frame handed over to us from linux network layer. First byte | |
267 | semantics as defined in Documentation/networking/x25-iface.txt | |
268 | */ | |
3e206b0a | 269 | static int isdn_x25iface_xmit(struct concap_proto *cprot, struct sk_buff *skb) |
1da177e4 LT |
270 | { |
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; | |
284 | } | |
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); | |
295 | } | |
296 | } else { | |
297 | illegal_state_warn( *state, firstbyte ); | |
298 | } | |
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 ); | |
318 | } | |
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); | |
327 | } | |
328 | dev_kfree_skb(skb); | |
329 | return 0; | |
330 | } |