1 /* 2 * LAPB release 002 3 * 4 * This code REQUIRES 2.1.15 or higher/ NET3.038 5 * 6 * This module: 7 * This module is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 * 12 * History 13 * LAPB 001 Jonathan Naylor Started Coding 14 * LAPB 002 Jonathan Naylor New timer architecture. 15 * 2000-10-29 Henner Eisen lapb_data_indication() return status. 16 */ 17 18 #include <linux/module.h> 19 #include <linux/errno.h> 20 #include <linux/types.h> 21 #include <linux/socket.h> 22 #include <linux/in.h> 23 #include <linux/kernel.h> 24 #include <linux/jiffies.h> 25 #include <linux/timer.h> 26 #include <linux/string.h> 27 #include <linux/sockios.h> 28 #include <linux/net.h> 29 #include <linux/inet.h> 30 #include <linux/if_arp.h> 31 #include <linux/skbuff.h> 32 #include <net/sock.h> 33 #include <asm/uaccess.h> 34 #include <asm/system.h> 35 #include <linux/fcntl.h> 36 #include <linux/mm.h> 37 #include <linux/interrupt.h> 38 #include <linux/stat.h> 39 #include <linux/init.h> 40 #include <net/lapb.h> 41 42 static struct list_head lapb_list = LIST_HEAD_INIT(lapb_list); 43 static DEFINE_RWLOCK(lapb_list_lock); 44 45 /* 46 * Free an allocated lapb control block. 47 */ 48 static void lapb_free_cb(struct lapb_cb *lapb) 49 { 50 kfree(lapb); 51 } 52 53 static __inline__ void lapb_hold(struct lapb_cb *lapb) 54 { 55 atomic_inc(&lapb->refcnt); 56 } 57 58 static __inline__ void lapb_put(struct lapb_cb *lapb) 59 { 60 if (atomic_dec_and_test(&lapb->refcnt)) 61 lapb_free_cb(lapb); 62 } 63 64 /* 65 * Socket removal during an interrupt is now safe. 66 */ 67 static void __lapb_remove_cb(struct lapb_cb *lapb) 68 { 69 if (lapb->node.next) { 70 list_del(&lapb->node); 71 lapb_put(lapb); 72 } 73 } 74 75 /* 76 * Add a socket to the bound sockets list. 77 */ 78 static void __lapb_insert_cb(struct lapb_cb *lapb) 79 { 80 list_add(&lapb->node, &lapb_list); 81 lapb_hold(lapb); 82 } 83 84 static struct lapb_cb *__lapb_devtostruct(struct net_device *dev) 85 { 86 struct list_head *entry; 87 struct lapb_cb *lapb, *use = NULL; 88 89 list_for_each(entry, &lapb_list) { 90 lapb = list_entry(entry, struct lapb_cb, node); 91 if (lapb->dev == dev) { 92 use = lapb; 93 break; 94 } 95 } 96 97 if (use) 98 lapb_hold(use); 99 100 return use; 101 } 102 103 static struct lapb_cb *lapb_devtostruct(struct net_device *dev) 104 { 105 struct lapb_cb *rc; 106 107 read_lock_bh(&lapb_list_lock); 108 rc = __lapb_devtostruct(dev); 109 read_unlock_bh(&lapb_list_lock); 110 111 return rc; 112 } 113 /* 114 * Create an empty LAPB control block. 115 */ 116 static struct lapb_cb *lapb_create_cb(void) 117 { 118 struct lapb_cb *lapb = kzalloc(sizeof(*lapb), GFP_ATOMIC); 119 120 121 if (!lapb) 122 goto out; 123 124 skb_queue_head_init(&lapb->write_queue); 125 skb_queue_head_init(&lapb->ack_queue); 126 127 init_timer(&lapb->t1timer); 128 init_timer(&lapb->t2timer); 129 130 lapb->t1 = LAPB_DEFAULT_T1; 131 lapb->t2 = LAPB_DEFAULT_T2; 132 lapb->n2 = LAPB_DEFAULT_N2; 133 lapb->mode = LAPB_DEFAULT_MODE; 134 lapb->window = LAPB_DEFAULT_WINDOW; 135 lapb->state = LAPB_STATE_0; 136 atomic_set(&lapb->refcnt, 1); 137 out: 138 return lapb; 139 } 140 141 int lapb_register(struct net_device *dev, struct lapb_register_struct *callbacks) 142 { 143 struct lapb_cb *lapb; 144 int rc = LAPB_BADTOKEN; 145 146 write_lock_bh(&lapb_list_lock); 147 148 lapb = __lapb_devtostruct(dev); 149 if (lapb) { 150 lapb_put(lapb); 151 goto out; 152 } 153 154 lapb = lapb_create_cb(); 155 rc = LAPB_NOMEM; 156 if (!lapb) 157 goto out; 158 159 lapb->dev = dev; 160 lapb->callbacks = *callbacks; 161 162 __lapb_insert_cb(lapb); 163 164 lapb_start_t1timer(lapb); 165 166 rc = LAPB_OK; 167 out: 168 write_unlock_bh(&lapb_list_lock); 169 return rc; 170 } 171 172 int lapb_unregister(struct net_device *dev) 173 { 174 struct lapb_cb *lapb; 175 int rc = LAPB_BADTOKEN; 176 177 write_lock_bh(&lapb_list_lock); 178 lapb = __lapb_devtostruct(dev); 179 if (!lapb) 180 goto out; 181 182 lapb_stop_t1timer(lapb); 183 lapb_stop_t2timer(lapb); 184 185 lapb_clear_queues(lapb); 186 187 __lapb_remove_cb(lapb); 188 189 lapb_put(lapb); 190 rc = LAPB_OK; 191 out: 192 write_unlock_bh(&lapb_list_lock); 193 return rc; 194 } 195 196 int lapb_getparms(struct net_device *dev, struct lapb_parms_struct *parms) 197 { 198 int rc = LAPB_BADTOKEN; 199 struct lapb_cb *lapb = lapb_devtostruct(dev); 200 201 if (!lapb) 202 goto out; 203 204 parms->t1 = lapb->t1 / HZ; 205 parms->t2 = lapb->t2 / HZ; 206 parms->n2 = lapb->n2; 207 parms->n2count = lapb->n2count; 208 parms->state = lapb->state; 209 parms->window = lapb->window; 210 parms->mode = lapb->mode; 211 212 if (!timer_pending(&lapb->t1timer)) 213 parms->t1timer = 0; 214 else 215 parms->t1timer = (lapb->t1timer.expires - jiffies) / HZ; 216 217 if (!timer_pending(&lapb->t2timer)) 218 parms->t2timer = 0; 219 else 220 parms->t2timer = (lapb->t2timer.expires - jiffies) / HZ; 221 222 lapb_put(lapb); 223 rc = LAPB_OK; 224 out: 225 return rc; 226 } 227 228 int lapb_setparms(struct net_device *dev, struct lapb_parms_struct *parms) 229 { 230 int rc = LAPB_BADTOKEN; 231 struct lapb_cb *lapb = lapb_devtostruct(dev); 232 233 if (!lapb) 234 goto out; 235 236 rc = LAPB_INVALUE; 237 if (parms->t1 < 1 || parms->t2 < 1 || parms->n2 < 1) 238 goto out_put; 239 240 if (lapb->state == LAPB_STATE_0) { 241 if (((parms->mode & LAPB_EXTENDED) && 242 (parms->window < 1 || parms->window > 127)) || 243 (parms->window < 1 || parms->window > 7)) 244 goto out_put; 245 246 lapb->mode = parms->mode; 247 lapb->window = parms->window; 248 } 249 250 lapb->t1 = parms->t1 * HZ; 251 lapb->t2 = parms->t2 * HZ; 252 lapb->n2 = parms->n2; 253 254 rc = LAPB_OK; 255 out_put: 256 lapb_put(lapb); 257 out: 258 return rc; 259 } 260 261 int lapb_connect_request(struct net_device *dev) 262 { 263 struct lapb_cb *lapb = lapb_devtostruct(dev); 264 int rc = LAPB_BADTOKEN; 265 266 if (!lapb) 267 goto out; 268 269 rc = LAPB_OK; 270 if (lapb->state == LAPB_STATE_1) 271 goto out_put; 272 273 rc = LAPB_CONNECTED; 274 if (lapb->state == LAPB_STATE_3 || lapb->state == LAPB_STATE_4) 275 goto out_put; 276 277 lapb_establish_data_link(lapb); 278 279 #if LAPB_DEBUG > 0 280 printk(KERN_DEBUG "lapb: (%p) S0 -> S1\n", lapb->dev); 281 #endif 282 lapb->state = LAPB_STATE_1; 283 284 rc = LAPB_OK; 285 out_put: 286 lapb_put(lapb); 287 out: 288 return rc; 289 } 290 291 int lapb_disconnect_request(struct net_device *dev) 292 { 293 struct lapb_cb *lapb = lapb_devtostruct(dev); 294 int rc = LAPB_BADTOKEN; 295 296 if (!lapb) 297 goto out; 298 299 switch (lapb->state) { 300 case LAPB_STATE_0: 301 rc = LAPB_NOTCONNECTED; 302 goto out_put; 303 304 case LAPB_STATE_1: 305 #if LAPB_DEBUG > 1 306 printk(KERN_DEBUG "lapb: (%p) S1 TX DISC(1)\n", lapb->dev); 307 #endif 308 #if LAPB_DEBUG > 0 309 printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->dev); 310 #endif 311 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); 312 lapb->state = LAPB_STATE_0; 313 lapb_start_t1timer(lapb); 314 rc = LAPB_NOTCONNECTED; 315 goto out_put; 316 317 case LAPB_STATE_2: 318 rc = LAPB_OK; 319 goto out_put; 320 } 321 322 lapb_clear_queues(lapb); 323 lapb->n2count = 0; 324 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); 325 lapb_start_t1timer(lapb); 326 lapb_stop_t2timer(lapb); 327 lapb->state = LAPB_STATE_2; 328 329 #if LAPB_DEBUG > 1 330 printk(KERN_DEBUG "lapb: (%p) S3 DISC(1)\n", lapb->dev); 331 #endif 332 #if LAPB_DEBUG > 0 333 printk(KERN_DEBUG "lapb: (%p) S3 -> S2\n", lapb->dev); 334 #endif 335 336 rc = LAPB_OK; 337 out_put: 338 lapb_put(lapb); 339 out: 340 return rc; 341 } 342 343 int lapb_data_request(struct net_device *dev, struct sk_buff *skb) 344 { 345 struct lapb_cb *lapb = lapb_devtostruct(dev); 346 int rc = LAPB_BADTOKEN; 347 348 if (!lapb) 349 goto out; 350 351 rc = LAPB_NOTCONNECTED; 352 if (lapb->state != LAPB_STATE_3 && lapb->state != LAPB_STATE_4) 353 goto out_put; 354 355 skb_queue_tail(&lapb->write_queue, skb); 356 lapb_kick(lapb); 357 rc = LAPB_OK; 358 out_put: 359 lapb_put(lapb); 360 out: 361 return rc; 362 } 363 364 int lapb_data_received(struct net_device *dev, struct sk_buff *skb) 365 { 366 struct lapb_cb *lapb = lapb_devtostruct(dev); 367 int rc = LAPB_BADTOKEN; 368 369 if (lapb) { 370 lapb_data_input(lapb, skb); 371 lapb_put(lapb); 372 rc = LAPB_OK; 373 } 374 375 return rc; 376 } 377 378 void lapb_connect_confirmation(struct lapb_cb *lapb, int reason) 379 { 380 if (lapb->callbacks.connect_confirmation) 381 lapb->callbacks.connect_confirmation(lapb->dev, reason); 382 } 383 384 void lapb_connect_indication(struct lapb_cb *lapb, int reason) 385 { 386 if (lapb->callbacks.connect_indication) 387 lapb->callbacks.connect_indication(lapb->dev, reason); 388 } 389 390 void lapb_disconnect_confirmation(struct lapb_cb *lapb, int reason) 391 { 392 if (lapb->callbacks.disconnect_confirmation) 393 lapb->callbacks.disconnect_confirmation(lapb->dev, reason); 394 } 395 396 void lapb_disconnect_indication(struct lapb_cb *lapb, int reason) 397 { 398 if (lapb->callbacks.disconnect_indication) 399 lapb->callbacks.disconnect_indication(lapb->dev, reason); 400 } 401 402 int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *skb) 403 { 404 if (lapb->callbacks.data_indication) 405 return lapb->callbacks.data_indication(lapb->dev, skb); 406 407 kfree_skb(skb); 408 return NET_RX_CN_HIGH; /* For now; must be != NET_RX_DROP */ 409 } 410 411 int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb) 412 { 413 int used = 0; 414 415 if (lapb->callbacks.data_transmit) { 416 lapb->callbacks.data_transmit(lapb->dev, skb); 417 used = 1; 418 } 419 420 return used; 421 } 422 423 EXPORT_SYMBOL(lapb_register); 424 EXPORT_SYMBOL(lapb_unregister); 425 EXPORT_SYMBOL(lapb_getparms); 426 EXPORT_SYMBOL(lapb_setparms); 427 EXPORT_SYMBOL(lapb_connect_request); 428 EXPORT_SYMBOL(lapb_disconnect_request); 429 EXPORT_SYMBOL(lapb_data_request); 430 EXPORT_SYMBOL(lapb_data_received); 431 432 static int __init lapb_init(void) 433 { 434 return 0; 435 } 436 437 static void __exit lapb_exit(void) 438 { 439 WARN_ON(!list_empty(&lapb_list)); 440 } 441 442 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>"); 443 MODULE_DESCRIPTION("The X.25 Link Access Procedure B link layer protocol"); 444 MODULE_LICENSE("GPL"); 445 446 module_init(lapb_init); 447 module_exit(lapb_exit); 448