Commit | Line | Data |
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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*/ | |
475be4d8 | 29 | #define MY_DEVNAME(dev) ((dev) ? (dev)->name : "DEVICE UNSPECIFIED") |
1da177e4 LT |
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, | |
475be4d8 | 37 | enabling us to allocate both with just one kmalloc(): */ |
1da177e4 LT |
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); */ | |
475be4d8 JP |
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 */ | |
475be4d8 | 67 | static void illegal_state_warn(unsigned state, unsigned char firstbyte) |
1da177e4 | 68 | { |
475be4d8 JP |
69 | printk(KERN_WARNING "isdn_x25iface: firstbyte %x illegal in" |
70 | "current state %d\n", firstbyte, state); | |
1da177e4 LT |
71 | } |
72 | ||
73 | /* check protocol data field for consistency */ | |
475be4d8 | 74 | static int pdata_is_bad(ix25_pdata_t *pda) { |
1da177e4 | 75 | |
475be4d8 JP |
76 | if (pda && pda->magic == ISDN_X25IFACE_MAGIC) return 0; |
77 | printk(KERN_WARNING | |
78 | "isdn_x25iface_xxx: illegal pointer to proto data\n"); | |
1da177e4 LT |
79 | return 1; |
80 | } | |
81 | ||
82 | /* create a new x25 interface protocol instance | |
83 | */ | |
475be4d8 | 84 | struct concap_proto *isdn_x25iface_proto_new(void) |
1da177e4 | 85 | { |
475be4d8 | 86 | ix25_pdata_t *tmp = kmalloc(sizeof(ix25_pdata_t), GFP_KERNEL); |
1da177e4 | 87 | IX25DEBUG("isdn_x25iface_proto_new\n"); |
475be4d8 JP |
88 | if (tmp) { |
89 | tmp->magic = ISDN_X25IFACE_MAGIC; | |
90 | tmp->state = WAN_UNCONFIGURED; | |
1da177e4 LT |
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); | |
475be4d8 JP |
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)); | |
1da177e4 LT |
100 | } |
101 | return NULL; | |
102 | }; | |
103 | ||
475be4d8 | 104 | /* close the x25iface encapsulation protocol |
1da177e4 | 105 | */ |
475be4d8 | 106 | static int isdn_x25iface_proto_close(struct concap_proto *cprot) { |
1da177e4 LT |
107 | |
108 | ix25_pdata_t *tmp; | |
475be4d8 | 109 | int ret = 0; |
1da177e4 LT |
110 | ulong flags; |
111 | ||
475be4d8 JP |
112 | if (!cprot) { |
113 | printk(KERN_ERR "isdn_x25iface_proto_close: " | |
114 | "invalid concap_proto pointer\n"); | |
1da177e4 LT |
115 | return -1; |
116 | } | |
475be4d8 | 117 | IX25DEBUG("isdn_x25iface_proto_close %s \n", MY_DEVNAME(cprot->net_dev)); |
1da177e4 | 118 | spin_lock_irqsave(&cprot->lock, flags); |
475be4d8 JP |
119 | cprot->dops = NULL; |
120 | cprot->net_dev = NULL; | |
121 | tmp = cprot->proto_data; | |
122 | if (pdata_is_bad(tmp)) { | |
1da177e4 LT |
123 | ret = -1; |
124 | } else { | |
475be4d8 | 125 | tmp->state = WAN_UNCONFIGURED; |
1da177e4 LT |
126 | } |
127 | spin_unlock_irqrestore(&cprot->lock, flags); | |
128 | return ret; | |
129 | } | |
130 | ||
131 | /* Delete the x25iface encapsulation protocol instance | |
132 | */ | |
475be4d8 JP |
133 | static void isdn_x25iface_proto_del(struct concap_proto *cprot) { |
134 | ||
135 | ix25_pdata_t *tmp; | |
1da177e4 | 136 | |
475be4d8 JP |
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"); | |
1da177e4 LT |
141 | return; |
142 | } | |
475be4d8 JP |
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"); | |
1da177e4 LT |
147 | return; |
148 | } | |
149 | /* close if the protocol is still open */ | |
475be4d8 | 150 | if (cprot->dops) isdn_x25iface_proto_close(cprot); |
1da177e4 LT |
151 | /* freeing the storage should be sufficient now. But some additional |
152 | settings might help to catch wild pointer bugs */ | |
475be4d8 JP |
153 | tmp->magic = 0; |
154 | cprot->proto_data = NULL; | |
1da177e4 | 155 | |
475be4d8 | 156 | kfree(tmp); |
1da177e4 LT |
157 | return; |
158 | } | |
159 | ||
160 | /* (re-)initialize the data structures for x25iface encapsulation | |
161 | */ | |
3e206b0a | 162 | static int isdn_x25iface_proto_restart(struct concap_proto *cprot, |
475be4d8 JP |
163 | struct net_device *ndev, |
164 | struct concap_device_ops *dops) | |
1da177e4 | 165 | { |
475be4d8 | 166 | ix25_pdata_t *pda = cprot->proto_data; |
1da177e4 LT |
167 | ulong flags; |
168 | ||
475be4d8 | 169 | IX25DEBUG("isdn_x25iface_proto_restart %s \n", MY_DEVNAME(ndev)); |
1da177e4 | 170 | |
475be4d8 | 171 | if (pdata_is_bad(pda)) return -1; |
1da177e4 | 172 | |
475be4d8 JP |
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"); | |
1da177e4 LT |
177 | isdn_x25iface_proto_close(cprot); |
178 | return -1; | |
179 | } | |
180 | spin_lock_irqsave(&cprot->lock, flags); | |
475be4d8 JP |
181 | cprot->net_dev = ndev; |
182 | cprot->pops = &ix25_pops; | |
183 | cprot->dops = dops; | |
184 | pda->state = WAN_DISCONNECTED; | |
1da177e4 LT |
185 | spin_unlock_irqrestore(&cprot->lock, flags); |
186 | return 0; | |
187 | } | |
188 | ||
475be4d8 | 189 | /* deliver a dl_data frame received from i4l HL driver to the network layer |
1da177e4 | 190 | */ |
3e206b0a | 191 | static int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb) |
1da177e4 | 192 | { |
475be4d8 JP |
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)) { | |
4150bbf3 | 197 | skb->data[0] = X25_IFACE_DATA; |
1da177e4 LT |
198 | skb->protocol = x25_type_trans(skb, cprot->net_dev); |
199 | netif_rx(skb); | |
200 | return 0; | |
201 | } | |
202 | } | |
475be4d8 | 203 | printk(KERN_WARNING "isdn_x25iface_receive %s: not connected, skb dropped\n", MY_DEVNAME(cprot->net_dev)); |
1da177e4 LT |
204 | dev_kfree_skb(skb); |
205 | return -1; | |
206 | } | |
207 | ||
475be4d8 | 208 | /* a connection set up is indicated by lower layer |
1da177e4 | 209 | */ |
3e206b0a | 210 | static int isdn_x25iface_connect_ind(struct concap_proto *cprot) |
1da177e4 | 211 | { |
475be4d8 JP |
212 | struct sk_buff *skb; |
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 | |
1da177e4 | 219 | "isdn_x25iface_connect_ind while unconfigured %s\n" |
475be4d8 | 220 | , MY_DEVNAME(cprot->net_dev)); |
1da177e4 LT |
221 | return -1; |
222 | } | |
223 | *state_p = WAN_CONNECTED; | |
d81931d9 ES |
224 | |
225 | skb = dev_alloc_skb(1); | |
475be4d8 | 226 | if (skb) { |
4150bbf3 | 227 | *(skb_put(skb, 1)) = X25_IFACE_CONNECT; |
1da177e4 LT |
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"); | |
475be4d8 | 234 | cprot->dops->disconn_req(cprot); |
1da177e4 LT |
235 | return -1; |
236 | } | |
237 | } | |
475be4d8 JP |
238 | |
239 | /* a disconnect is indicated by lower layer | |
1da177e4 | 240 | */ |
3e206b0a | 241 | static int isdn_x25iface_disconn_ind(struct concap_proto *cprot) |
1da177e4 LT |
242 | { |
243 | struct sk_buff *skb; | |
475be4d8 JP |
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 | |
1da177e4 LT |
249 | "isdn_x25iface_disconn_ind while unconfigured\n"); |
250 | return -1; | |
251 | } | |
475be4d8 | 252 | if (!cprot->net_dev) return -1; |
1da177e4 LT |
253 | *state_p = WAN_DISCONNECTED; |
254 | skb = dev_alloc_skb(1); | |
475be4d8 | 255 | if (skb) { |
4150bbf3 | 256 | *(skb_put(skb, 1)) = X25_IFACE_DISCONNECT; |
1da177e4 LT |
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 | |
475be4d8 | 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]; | |
475be4d8 | 273 | enum wan_states *state = &((ix25_pdata_t *)cprot->proto_data)->state; |
1da177e4 | 274 | int ret = 0; |
4150bbf3 | 275 | IX25DEBUG("isdn_x25iface_xmit: %s first=%x state=%d\n", |
475be4d8 JP |
276 | MY_DEVNAME(cprot->net_dev), firstbyte, *state); |
277 | switch (firstbyte) { | |
4150bbf3 | 278 | case X25_IFACE_DATA: |
475be4d8 | 279 | if (*state == WAN_CONNECTED) { |
1da177e4 | 280 | skb_pull(skb, 1); |
475be4d8 JP |
281 | cprot->net_dev->trans_start = jiffies; |
282 | ret = (cprot->dops->data_req(cprot, skb)); | |
1da177e4 | 283 | /* prepare for future retransmissions */ |
475be4d8 | 284 | if (ret) skb_push(skb, 1); |
1da177e4 LT |
285 | return ret; |
286 | } | |
475be4d8 | 287 | illegal_state_warn(*state, firstbyte); |
1da177e4 | 288 | break; |
4150bbf3 | 289 | case X25_IFACE_CONNECT: |
475be4d8 | 290 | if (*state == WAN_DISCONNECTED) { |
1da177e4 | 291 | *state = WAN_CONNECTING; |
475be4d8 JP |
292 | ret = cprot->dops->connect_req(cprot); |
293 | if (ret) { | |
1da177e4 LT |
294 | /* reset state and notify upper layer about |
295 | * immidiatly failed attempts */ | |
296 | isdn_x25iface_disconn_ind(cprot); | |
297 | } | |
298 | } else { | |
475be4d8 | 299 | illegal_state_warn(*state, firstbyte); |
1da177e4 LT |
300 | } |
301 | break; | |
4150bbf3 | 302 | case X25_IFACE_DISCONNECT: |
475be4d8 JP |
303 | switch (*state) { |
304 | case WAN_DISCONNECTED: | |
1da177e4 LT |
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 " | |
475be4d8 | 310 | " requested while disconnected\n"); |
1da177e4 LT |
311 | isdn_x25iface_disconn_ind(cprot); |
312 | break; /* prevent infinite loops */ | |
313 | case WAN_CONNECTING: | |
314 | case WAN_CONNECTED: | |
315 | *state = WAN_DISCONNECTED; | |
475be4d8 | 316 | cprot->dops->disconn_req(cprot); |
1da177e4 LT |
317 | break; |
318 | default: | |
475be4d8 | 319 | illegal_state_warn(*state, firstbyte); |
1da177e4 LT |
320 | } |
321 | break; | |
4150bbf3 | 322 | case X25_IFACE_PARAMS: |
1da177e4 LT |
323 | 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 | } |