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 <linux/slab.h> 33 #include <net/sock.h> 34 #include <asm/uaccess.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 LIST_HEAD(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, 142 const struct lapb_register_struct *callbacks) 143 { 144 struct lapb_cb *lapb; 145 int rc = LAPB_BADTOKEN; 146 147 write_lock_bh(&lapb_list_lock); 148 149 lapb = __lapb_devtostruct(dev); 150 if (lapb) { 151 lapb_put(lapb); 152 goto out; 153 } 154 155 lapb = lapb_create_cb(); 156 rc = LAPB_NOMEM; 157 if (!lapb) 158 goto out; 159 160 lapb->dev = dev; 161 lapb->callbacks = callbacks; 162 163 __lapb_insert_cb(lapb); 164 165 lapb_start_t1timer(lapb); 166 167 rc = LAPB_OK; 168 out: 169 write_unlock_bh(&lapb_list_lock); 170 return rc; 171 } 172 173 int lapb_unregister(struct net_device *dev) 174 { 175 struct lapb_cb *lapb; 176 int rc = LAPB_BADTOKEN; 177 178 write_lock_bh(&lapb_list_lock); 179 lapb = __lapb_devtostruct(dev); 180 if (!lapb) 181 goto out; 182 183 lapb_stop_t1timer(lapb); 184 lapb_stop_t2timer(lapb); 185 186 lapb_clear_queues(lapb); 187 188 __lapb_remove_cb(lapb); 189 190 lapb_put(lapb); 191 rc = LAPB_OK; 192 out: 193 write_unlock_bh(&lapb_list_lock); 194 return rc; 195 } 196 197 int lapb_getparms(struct net_device *dev, struct lapb_parms_struct *parms) 198 { 199 int rc = LAPB_BADTOKEN; 200 struct lapb_cb *lapb = lapb_devtostruct(dev); 201 202 if (!lapb) 203 goto out; 204 205 parms->t1 = lapb->t1 / HZ; 206 parms->t2 = lapb->t2 / HZ; 207 parms->n2 = lapb->n2; 208 parms->n2count = lapb->n2count; 209 parms->state = lapb->state; 210 parms->window = lapb->window; 211 parms->mode = lapb->mode; 212 213 if (!timer_pending(&lapb->t1timer)) 214 parms->t1timer = 0; 215 else 216 parms->t1timer = (lapb->t1timer.expires - jiffies) / HZ; 217 218 if (!timer_pending(&lapb->t2timer)) 219 parms->t2timer = 0; 220 else 221 parms->t2timer = (lapb->t2timer.expires - jiffies) / HZ; 222 223 lapb_put(lapb); 224 rc = LAPB_OK; 225 out: 226 return rc; 227 } 228 229 int lapb_setparms(struct net_device *dev, struct lapb_parms_struct *parms) 230 { 231 int rc = LAPB_BADTOKEN; 232 struct lapb_cb *lapb = lapb_devtostruct(dev); 233 234 if (!lapb) 235 goto out; 236 237 rc = LAPB_INVALUE; 238 if (parms->t1 < 1 || parms->t2 < 1 || parms->n2 < 1) 239 goto out_put; 240 241 if (lapb->state == LAPB_STATE_0) { 242 if (parms->mode & LAPB_EXTENDED) { 243 if (parms->window < 1 || parms->window > 127) 244 goto out_put; 245 } else { 246 if (parms->window < 1 || parms->window > 7) 247 goto out_put; 248 } 249 lapb->mode = parms->mode; 250 lapb->window = parms->window; 251 } 252 253 lapb->t1 = parms->t1 * HZ; 254 lapb->t2 = parms->t2 * HZ; 255 lapb->n2 = parms->n2; 256 257 rc = LAPB_OK; 258 out_put: 259 lapb_put(lapb); 260 out: 261 return rc; 262 } 263 264 int lapb_connect_request(struct net_device *dev) 265 { 266 struct lapb_cb *lapb = lapb_devtostruct(dev); 267 int rc = LAPB_BADTOKEN; 268 269 if (!lapb) 270 goto out; 271 272 rc = LAPB_OK; 273 if (lapb->state == LAPB_STATE_1) 274 goto out_put; 275 276 rc = LAPB_CONNECTED; 277 if (lapb->state == LAPB_STATE_3 || lapb->state == LAPB_STATE_4) 278 goto out_put; 279 280 lapb_establish_data_link(lapb); 281 282 #if LAPB_DEBUG > 0 283 printk(KERN_DEBUG "lapb: (%p) S0 -> S1\n", lapb->dev); 284 #endif 285 lapb->state = LAPB_STATE_1; 286 287 rc = LAPB_OK; 288 out_put: 289 lapb_put(lapb); 290 out: 291 return rc; 292 } 293 294 int lapb_disconnect_request(struct net_device *dev) 295 { 296 struct lapb_cb *lapb = lapb_devtostruct(dev); 297 int rc = LAPB_BADTOKEN; 298 299 if (!lapb) 300 goto out; 301 302 switch (lapb->state) { 303 case LAPB_STATE_0: 304 rc = LAPB_NOTCONNECTED; 305 goto out_put; 306 307 case LAPB_STATE_1: 308 #if LAPB_DEBUG > 1 309 printk(KERN_DEBUG "lapb: (%p) S1 TX DISC(1)\n", lapb->dev); 310 #endif 311 #if LAPB_DEBUG > 0 312 printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->dev); 313 #endif 314 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); 315 lapb->state = LAPB_STATE_0; 316 lapb_start_t1timer(lapb); 317 rc = LAPB_NOTCONNECTED; 318 goto out_put; 319 320 case LAPB_STATE_2: 321 rc = LAPB_OK; 322 goto out_put; 323 } 324 325 lapb_clear_queues(lapb); 326 lapb->n2count = 0; 327 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); 328 lapb_start_t1timer(lapb); 329 lapb_stop_t2timer(lapb); 330 lapb->state = LAPB_STATE_2; 331 332 #if LAPB_DEBUG > 1 333 printk(KERN_DEBUG "lapb: (%p) S3 DISC(1)\n", lapb->dev); 334 #endif 335 #if LAPB_DEBUG > 0 336 printk(KERN_DEBUG "lapb: (%p) S3 -> S2\n", lapb->dev); 337 #endif 338 339 rc = LAPB_OK; 340 out_put: 341 lapb_put(lapb); 342 out: 343 return rc; 344 } 345 346 int lapb_data_request(struct net_device *dev, struct sk_buff *skb) 347 { 348 struct lapb_cb *lapb = lapb_devtostruct(dev); 349 int rc = LAPB_BADTOKEN; 350 351 if (!lapb) 352 goto out; 353 354 rc = LAPB_NOTCONNECTED; 355 if (lapb->state != LAPB_STATE_3 && lapb->state != LAPB_STATE_4) 356 goto out_put; 357 358 skb_queue_tail(&lapb->write_queue, skb); 359 lapb_kick(lapb); 360 rc = LAPB_OK; 361 out_put: 362 lapb_put(lapb); 363 out: 364 return rc; 365 } 366 367 int lapb_data_received(struct net_device *dev, struct sk_buff *skb) 368 { 369 struct lapb_cb *lapb = lapb_devtostruct(dev); 370 int rc = LAPB_BADTOKEN; 371 372 if (lapb) { 373 lapb_data_input(lapb, skb); 374 lapb_put(lapb); 375 rc = LAPB_OK; 376 } 377 378 return rc; 379 } 380 381 void lapb_connect_confirmation(struct lapb_cb *lapb, int reason) 382 { 383 if (lapb->callbacks->connect_confirmation) 384 lapb->callbacks->connect_confirmation(lapb->dev, reason); 385 } 386 387 void lapb_connect_indication(struct lapb_cb *lapb, int reason) 388 { 389 if (lapb->callbacks->connect_indication) 390 lapb->callbacks->connect_indication(lapb->dev, reason); 391 } 392 393 void lapb_disconnect_confirmation(struct lapb_cb *lapb, int reason) 394 { 395 if (lapb->callbacks->disconnect_confirmation) 396 lapb->callbacks->disconnect_confirmation(lapb->dev, reason); 397 } 398 399 void lapb_disconnect_indication(struct lapb_cb *lapb, int reason) 400 { 401 if (lapb->callbacks->disconnect_indication) 402 lapb->callbacks->disconnect_indication(lapb->dev, reason); 403 } 404 405 int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *skb) 406 { 407 if (lapb->callbacks->data_indication) 408 return lapb->callbacks->data_indication(lapb->dev, skb); 409 410 kfree_skb(skb); 411 return NET_RX_SUCCESS; /* For now; must be != NET_RX_DROP */ 412 } 413 414 int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb) 415 { 416 int used = 0; 417 418 if (lapb->callbacks->data_transmit) { 419 lapb->callbacks->data_transmit(lapb->dev, skb); 420 used = 1; 421 } 422 423 return used; 424 } 425 426 EXPORT_SYMBOL(lapb_register); 427 EXPORT_SYMBOL(lapb_unregister); 428 EXPORT_SYMBOL(lapb_getparms); 429 EXPORT_SYMBOL(lapb_setparms); 430 EXPORT_SYMBOL(lapb_connect_request); 431 EXPORT_SYMBOL(lapb_disconnect_request); 432 EXPORT_SYMBOL(lapb_data_request); 433 EXPORT_SYMBOL(lapb_data_received); 434 435 static int __init lapb_init(void) 436 { 437 return 0; 438 } 439 440 static void __exit lapb_exit(void) 441 { 442 WARN_ON(!list_empty(&lapb_list)); 443 } 444 445 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>"); 446 MODULE_DESCRIPTION("The X.25 Link Access Procedure B link layer protocol"); 447 MODULE_LICENSE("GPL"); 448 449 module_init(lapb_init); 450 module_exit(lapb_exit); 451