Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Things to sort out: |
| 3 | * |
| 4 | * o tbusy handling |
| 5 | * o allow users to set the parameters |
| 6 | * o sync/async switching ? |
| 7 | * |
| 8 | * Note: This does _not_ implement CCITT X.25 asynchronous framing |
| 9 | * recommendations. Its primarily for testing purposes. If you wanted |
| 10 | * to do CCITT then in theory all you need is to nick the HDLC async |
| 11 | * checksum routines from ppp.c |
| 12 | * Changes: |
| 13 | * |
| 14 | * 2000-10-29 Henner Eisen lapb_data_indication() return status. |
| 15 | */ |
| 16 | |
| 17 | #include <linux/module.h> |
| 18 | |
| 19 | #include <asm/system.h> |
| 20 | #include <asm/uaccess.h> |
| 21 | #include <linux/bitops.h> |
| 22 | #include <linux/string.h> |
| 23 | #include <linux/mm.h> |
| 24 | #include <linux/interrupt.h> |
| 25 | #include <linux/in.h> |
| 26 | #include <linux/tty.h> |
| 27 | #include <linux/errno.h> |
| 28 | #include <linux/netdevice.h> |
| 29 | #include <linux/etherdevice.h> |
| 30 | #include <linux/skbuff.h> |
| 31 | #include <linux/if_arp.h> |
| 32 | #include <linux/x25.h> |
| 33 | #include <linux/lapb.h> |
| 34 | #include <linux/init.h> |
| 35 | #include "x25_asy.h" |
| 36 | |
| 37 | #include <net/x25device.h> |
| 38 | |
| 39 | static struct net_device **x25_asy_devs; |
| 40 | static int x25_asy_maxdev = SL_NRUNIT; |
| 41 | |
| 42 | module_param(x25_asy_maxdev, int, 0); |
| 43 | MODULE_LICENSE("GPL"); |
| 44 | |
| 45 | static int x25_asy_esc(unsigned char *p, unsigned char *d, int len); |
| 46 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char c); |
| 47 | static void x25_asy_setup(struct net_device *dev); |
| 48 | |
| 49 | /* Find a free X.25 channel, and link in this `tty' line. */ |
| 50 | static struct x25_asy *x25_asy_alloc(void) |
| 51 | { |
| 52 | struct net_device *dev = NULL; |
| 53 | struct x25_asy *sl; |
| 54 | int i; |
| 55 | |
| 56 | if (x25_asy_devs == NULL) |
| 57 | return NULL; /* Master array missing ! */ |
| 58 | |
| 59 | for (i = 0; i < x25_asy_maxdev; i++) { |
| 60 | dev = x25_asy_devs[i]; |
| 61 | |
| 62 | /* Not allocated ? */ |
| 63 | if (dev == NULL) |
| 64 | break; |
| 65 | |
| 66 | sl = dev->priv; |
| 67 | /* Not in use ? */ |
| 68 | if (!test_and_set_bit(SLF_INUSE, &sl->flags)) |
| 69 | return sl; |
| 70 | } |
| 71 | |
| 72 | |
| 73 | /* Sorry, too many, all slots in use */ |
| 74 | if (i >= x25_asy_maxdev) |
| 75 | return NULL; |
| 76 | |
| 77 | /* If no channels are available, allocate one */ |
| 78 | if (!dev) { |
| 79 | char name[IFNAMSIZ]; |
| 80 | sprintf(name, "x25asy%d", i); |
| 81 | |
| 82 | dev = alloc_netdev(sizeof(struct x25_asy), |
| 83 | name, x25_asy_setup); |
| 84 | if (!dev) |
| 85 | return NULL; |
| 86 | |
| 87 | /* Initialize channel control data */ |
| 88 | sl = dev->priv; |
| 89 | dev->base_addr = i; |
| 90 | |
| 91 | /* register device so that it can be ifconfig'ed */ |
| 92 | if (register_netdev(dev) == 0) { |
| 93 | /* (Re-)Set the INUSE bit. Very Important! */ |
| 94 | set_bit(SLF_INUSE, &sl->flags); |
| 95 | x25_asy_devs[i] = dev; |
| 96 | return sl; |
| 97 | } else { |
| 98 | printk("x25_asy_alloc() - register_netdev() failure.\n"); |
| 99 | free_netdev(dev); |
| 100 | } |
| 101 | } |
| 102 | return NULL; |
| 103 | } |
| 104 | |
| 105 | |
| 106 | /* Free an X.25 channel. */ |
| 107 | static void x25_asy_free(struct x25_asy *sl) |
| 108 | { |
| 109 | /* Free all X.25 frame buffers. */ |
Jesper Juhl | 6a5d362 | 2005-05-03 14:33:27 -0700 | [diff] [blame] | 110 | kfree(sl->rbuff); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | sl->rbuff = NULL; |
Jesper Juhl | 6a5d362 | 2005-05-03 14:33:27 -0700 | [diff] [blame] | 112 | kfree(sl->xbuff); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | sl->xbuff = NULL; |
| 114 | |
| 115 | if (!test_and_clear_bit(SLF_INUSE, &sl->flags)) { |
| 116 | printk("%s: x25_asy_free for already free unit.\n", sl->dev->name); |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | static int x25_asy_change_mtu(struct net_device *dev, int newmtu) |
| 121 | { |
| 122 | struct x25_asy *sl = dev->priv; |
| 123 | unsigned char *xbuff, *rbuff; |
| 124 | int len = 2* newmtu; |
| 125 | |
Robert P. J. Day | 5cbded5 | 2006-12-13 00:35:56 -0800 | [diff] [blame] | 126 | xbuff = kmalloc(len + 4, GFP_ATOMIC); |
| 127 | rbuff = kmalloc(len + 4, GFP_ATOMIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
| 129 | if (xbuff == NULL || rbuff == NULL) |
| 130 | { |
| 131 | printk("%s: unable to grow X.25 buffers, MTU change cancelled.\n", |
| 132 | dev->name); |
Jesper Juhl | 6a5d362 | 2005-05-03 14:33:27 -0700 | [diff] [blame] | 133 | kfree(xbuff); |
| 134 | kfree(rbuff); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | return -ENOMEM; |
| 136 | } |
| 137 | |
| 138 | spin_lock_bh(&sl->lock); |
| 139 | xbuff = xchg(&sl->xbuff, xbuff); |
| 140 | if (sl->xleft) { |
| 141 | if (sl->xleft <= len) { |
| 142 | memcpy(sl->xbuff, sl->xhead, sl->xleft); |
| 143 | } else { |
| 144 | sl->xleft = 0; |
| 145 | sl->stats.tx_dropped++; |
| 146 | } |
| 147 | } |
| 148 | sl->xhead = sl->xbuff; |
| 149 | |
| 150 | rbuff = xchg(&sl->rbuff, rbuff); |
| 151 | if (sl->rcount) { |
| 152 | if (sl->rcount <= len) { |
| 153 | memcpy(sl->rbuff, rbuff, sl->rcount); |
| 154 | } else { |
| 155 | sl->rcount = 0; |
| 156 | sl->stats.rx_over_errors++; |
| 157 | set_bit(SLF_ERROR, &sl->flags); |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | dev->mtu = newmtu; |
| 162 | sl->buffsize = len; |
| 163 | |
| 164 | spin_unlock_bh(&sl->lock); |
| 165 | |
Jesper Juhl | 6a5d362 | 2005-05-03 14:33:27 -0700 | [diff] [blame] | 166 | kfree(xbuff); |
| 167 | kfree(rbuff); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | return 0; |
| 169 | } |
| 170 | |
| 171 | |
| 172 | /* Set the "sending" flag. This must be atomic, hence the ASM. */ |
| 173 | |
| 174 | static inline void x25_asy_lock(struct x25_asy *sl) |
| 175 | { |
| 176 | netif_stop_queue(sl->dev); |
| 177 | } |
| 178 | |
| 179 | |
| 180 | /* Clear the "sending" flag. This must be atomic, hence the ASM. */ |
| 181 | |
| 182 | static inline void x25_asy_unlock(struct x25_asy *sl) |
| 183 | { |
| 184 | netif_wake_queue(sl->dev); |
| 185 | } |
| 186 | |
| 187 | /* Send one completely decapsulated IP datagram to the IP layer. */ |
| 188 | |
| 189 | static void x25_asy_bump(struct x25_asy *sl) |
| 190 | { |
| 191 | struct sk_buff *skb; |
| 192 | int count; |
| 193 | int err; |
| 194 | |
| 195 | count = sl->rcount; |
| 196 | sl->stats.rx_bytes+=count; |
| 197 | |
| 198 | skb = dev_alloc_skb(count+1); |
| 199 | if (skb == NULL) |
| 200 | { |
| 201 | printk("%s: memory squeeze, dropping packet.\n", sl->dev->name); |
| 202 | sl->stats.rx_dropped++; |
| 203 | return; |
| 204 | } |
| 205 | skb_push(skb,1); /* LAPB internal control */ |
| 206 | memcpy(skb_put(skb,count), sl->rbuff, count); |
| 207 | skb->protocol = x25_type_trans(skb, sl->dev); |
| 208 | if((err=lapb_data_received(skb->dev, skb))!=LAPB_OK) |
| 209 | { |
| 210 | kfree_skb(skb); |
| 211 | printk(KERN_DEBUG "x25_asy: data received err - %d\n",err); |
| 212 | } |
| 213 | else |
| 214 | { |
| 215 | netif_rx(skb); |
| 216 | sl->dev->last_rx = jiffies; |
| 217 | sl->stats.rx_packets++; |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | /* Encapsulate one IP datagram and stuff into a TTY queue. */ |
| 222 | static void x25_asy_encaps(struct x25_asy *sl, unsigned char *icp, int len) |
| 223 | { |
| 224 | unsigned char *p; |
| 225 | int actual, count, mtu = sl->dev->mtu; |
| 226 | |
| 227 | if (len > mtu) |
| 228 | { /* Sigh, shouldn't occur BUT ... */ |
| 229 | len = mtu; |
| 230 | printk ("%s: truncating oversized transmit packet!\n", sl->dev->name); |
| 231 | sl->stats.tx_dropped++; |
| 232 | x25_asy_unlock(sl); |
| 233 | return; |
| 234 | } |
| 235 | |
| 236 | p = icp; |
| 237 | count = x25_asy_esc(p, (unsigned char *) sl->xbuff, len); |
| 238 | |
| 239 | /* Order of next two lines is *very* important. |
| 240 | * When we are sending a little amount of data, |
| 241 | * the transfer may be completed inside driver.write() |
| 242 | * routine, because it's running with interrupts enabled. |
| 243 | * In this case we *never* got WRITE_WAKEUP event, |
| 244 | * if we did not request it before write operation. |
| 245 | * 14 Oct 1994 Dmitry Gorodchanin. |
| 246 | */ |
| 247 | sl->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP); |
| 248 | actual = sl->tty->driver->write(sl->tty, sl->xbuff, count); |
| 249 | sl->xleft = count - actual; |
| 250 | sl->xhead = sl->xbuff + actual; |
| 251 | /* VSV */ |
| 252 | clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */ |
| 253 | } |
| 254 | |
| 255 | /* |
| 256 | * Called by the driver when there's room for more data. If we have |
| 257 | * more packets to send, we send them here. |
| 258 | */ |
| 259 | static void x25_asy_write_wakeup(struct tty_struct *tty) |
| 260 | { |
| 261 | int actual; |
| 262 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; |
| 263 | |
| 264 | /* First make sure we're connected. */ |
| 265 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) |
| 266 | return; |
| 267 | |
| 268 | if (sl->xleft <= 0) |
| 269 | { |
| 270 | /* Now serial buffer is almost free & we can start |
| 271 | * transmission of another packet */ |
| 272 | sl->stats.tx_packets++; |
| 273 | tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); |
| 274 | x25_asy_unlock(sl); |
| 275 | return; |
| 276 | } |
| 277 | |
| 278 | actual = tty->driver->write(tty, sl->xhead, sl->xleft); |
| 279 | sl->xleft -= actual; |
| 280 | sl->xhead += actual; |
| 281 | } |
| 282 | |
| 283 | static void x25_asy_timeout(struct net_device *dev) |
| 284 | { |
| 285 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); |
| 286 | |
| 287 | spin_lock(&sl->lock); |
| 288 | if (netif_queue_stopped(dev)) { |
| 289 | /* May be we must check transmitter timeout here ? |
| 290 | * 14 Oct 1994 Dmitry Gorodchanin. |
| 291 | */ |
| 292 | printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name, |
| 293 | (sl->tty->driver->chars_in_buffer(sl->tty) || sl->xleft) ? |
| 294 | "bad line quality" : "driver error"); |
| 295 | sl->xleft = 0; |
| 296 | sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); |
| 297 | x25_asy_unlock(sl); |
| 298 | } |
| 299 | spin_unlock(&sl->lock); |
| 300 | } |
| 301 | |
| 302 | /* Encapsulate an IP datagram and kick it into a TTY queue. */ |
| 303 | |
| 304 | static int x25_asy_xmit(struct sk_buff *skb, struct net_device *dev) |
| 305 | { |
| 306 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); |
| 307 | int err; |
| 308 | |
| 309 | if (!netif_running(sl->dev)) { |
| 310 | printk("%s: xmit call when iface is down\n", dev->name); |
| 311 | kfree_skb(skb); |
| 312 | return 0; |
| 313 | } |
| 314 | |
| 315 | switch(skb->data[0]) |
| 316 | { |
| 317 | case 0x00:break; |
| 318 | case 0x01: /* Connection request .. do nothing */ |
| 319 | if((err=lapb_connect_request(dev))!=LAPB_OK) |
| 320 | printk(KERN_ERR "x25_asy: lapb_connect_request error - %d\n", err); |
| 321 | kfree_skb(skb); |
| 322 | return 0; |
| 323 | case 0x02: /* Disconnect request .. do nothing - hang up ?? */ |
| 324 | if((err=lapb_disconnect_request(dev))!=LAPB_OK) |
| 325 | printk(KERN_ERR "x25_asy: lapb_disconnect_request error - %d\n", err); |
| 326 | default: |
| 327 | kfree_skb(skb); |
| 328 | return 0; |
| 329 | } |
| 330 | skb_pull(skb,1); /* Remove control byte */ |
| 331 | /* |
| 332 | * If we are busy already- too bad. We ought to be able |
| 333 | * to queue things at this point, to allow for a little |
| 334 | * frame buffer. Oh well... |
| 335 | * ----------------------------------------------------- |
| 336 | * I hate queues in X.25 driver. May be it's efficient, |
| 337 | * but for me latency is more important. ;) |
| 338 | * So, no queues ! |
| 339 | * 14 Oct 1994 Dmitry Gorodchanin. |
| 340 | */ |
| 341 | |
| 342 | if((err=lapb_data_request(dev,skb))!=LAPB_OK) |
| 343 | { |
| 344 | printk(KERN_ERR "lapbeth: lapb_data_request error - %d\n", err); |
| 345 | kfree_skb(skb); |
| 346 | return 0; |
| 347 | } |
| 348 | return 0; |
| 349 | } |
| 350 | |
| 351 | |
| 352 | /* |
| 353 | * LAPB interface boilerplate |
| 354 | */ |
| 355 | |
| 356 | /* |
| 357 | * Called when I frame data arrives. We did the work above - throw it |
| 358 | * at the net layer. |
| 359 | */ |
| 360 | |
| 361 | static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb) |
| 362 | { |
| 363 | skb->dev->last_rx = jiffies; |
| 364 | return netif_rx(skb); |
| 365 | } |
| 366 | |
| 367 | /* |
| 368 | * Data has emerged from the LAPB protocol machine. We don't handle |
| 369 | * busy cases too well. Its tricky to see how to do this nicely - |
| 370 | * perhaps lapb should allow us to bounce this ? |
| 371 | */ |
| 372 | |
| 373 | static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb) |
| 374 | { |
| 375 | struct x25_asy *sl=dev->priv; |
| 376 | |
| 377 | spin_lock(&sl->lock); |
| 378 | if (netif_queue_stopped(sl->dev) || sl->tty == NULL) |
| 379 | { |
| 380 | spin_unlock(&sl->lock); |
| 381 | printk(KERN_ERR "x25_asy: tbusy drop\n"); |
| 382 | kfree_skb(skb); |
| 383 | return; |
| 384 | } |
| 385 | /* We were not busy, so we are now... :-) */ |
| 386 | if (skb != NULL) |
| 387 | { |
| 388 | x25_asy_lock(sl); |
| 389 | sl->stats.tx_bytes+=skb->len; |
| 390 | x25_asy_encaps(sl, skb->data, skb->len); |
| 391 | dev_kfree_skb(skb); |
| 392 | } |
| 393 | spin_unlock(&sl->lock); |
| 394 | } |
| 395 | |
| 396 | /* |
| 397 | * LAPB connection establish/down information. |
| 398 | */ |
| 399 | |
| 400 | static void x25_asy_connected(struct net_device *dev, int reason) |
| 401 | { |
| 402 | struct x25_asy *sl = dev->priv; |
| 403 | struct sk_buff *skb; |
| 404 | unsigned char *ptr; |
| 405 | |
| 406 | if ((skb = dev_alloc_skb(1)) == NULL) { |
| 407 | printk(KERN_ERR "lapbeth: out of memory\n"); |
| 408 | return; |
| 409 | } |
| 410 | |
| 411 | ptr = skb_put(skb, 1); |
| 412 | *ptr = 0x01; |
| 413 | |
| 414 | skb->protocol = x25_type_trans(skb, sl->dev); |
| 415 | netif_rx(skb); |
| 416 | sl->dev->last_rx = jiffies; |
| 417 | } |
| 418 | |
| 419 | static void x25_asy_disconnected(struct net_device *dev, int reason) |
| 420 | { |
| 421 | struct x25_asy *sl = dev->priv; |
| 422 | struct sk_buff *skb; |
| 423 | unsigned char *ptr; |
| 424 | |
| 425 | if ((skb = dev_alloc_skb(1)) == NULL) { |
| 426 | printk(KERN_ERR "x25_asy: out of memory\n"); |
| 427 | return; |
| 428 | } |
| 429 | |
| 430 | ptr = skb_put(skb, 1); |
| 431 | *ptr = 0x02; |
| 432 | |
| 433 | skb->protocol = x25_type_trans(skb, sl->dev); |
| 434 | netif_rx(skb); |
| 435 | sl->dev->last_rx = jiffies; |
| 436 | } |
| 437 | |
| 438 | static struct lapb_register_struct x25_asy_callbacks = { |
| 439 | .connect_confirmation = x25_asy_connected, |
| 440 | .connect_indication = x25_asy_connected, |
| 441 | .disconnect_confirmation = x25_asy_disconnected, |
| 442 | .disconnect_indication = x25_asy_disconnected, |
| 443 | .data_indication = x25_asy_data_indication, |
| 444 | .data_transmit = x25_asy_data_transmit, |
| 445 | |
| 446 | }; |
| 447 | |
| 448 | |
| 449 | /* Open the low-level part of the X.25 channel. Easy! */ |
| 450 | static int x25_asy_open(struct net_device *dev) |
| 451 | { |
| 452 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); |
| 453 | unsigned long len; |
| 454 | int err; |
| 455 | |
| 456 | if (sl->tty == NULL) |
| 457 | return -ENODEV; |
| 458 | |
| 459 | /* |
| 460 | * Allocate the X.25 frame buffers: |
| 461 | * |
| 462 | * rbuff Receive buffer. |
| 463 | * xbuff Transmit buffer. |
| 464 | */ |
| 465 | |
| 466 | len = dev->mtu * 2; |
| 467 | |
Robert P. J. Day | 5cbded5 | 2006-12-13 00:35:56 -0800 | [diff] [blame] | 468 | sl->rbuff = kmalloc(len + 4, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | if (sl->rbuff == NULL) { |
| 470 | goto norbuff; |
| 471 | } |
Robert P. J. Day | 5cbded5 | 2006-12-13 00:35:56 -0800 | [diff] [blame] | 472 | sl->xbuff = kmalloc(len + 4, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | if (sl->xbuff == NULL) { |
| 474 | goto noxbuff; |
| 475 | } |
| 476 | |
| 477 | sl->buffsize = len; |
| 478 | sl->rcount = 0; |
| 479 | sl->xleft = 0; |
| 480 | sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */ |
| 481 | |
| 482 | netif_start_queue(dev); |
| 483 | |
| 484 | /* |
| 485 | * Now attach LAPB |
| 486 | */ |
| 487 | if((err=lapb_register(dev, &x25_asy_callbacks))==LAPB_OK) |
| 488 | return 0; |
| 489 | |
| 490 | /* Cleanup */ |
| 491 | kfree(sl->xbuff); |
| 492 | noxbuff: |
| 493 | kfree(sl->rbuff); |
| 494 | norbuff: |
| 495 | return -ENOMEM; |
| 496 | } |
| 497 | |
| 498 | |
| 499 | /* Close the low-level part of the X.25 channel. Easy! */ |
| 500 | static int x25_asy_close(struct net_device *dev) |
| 501 | { |
| 502 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); |
| 503 | int err; |
| 504 | |
| 505 | spin_lock(&sl->lock); |
| 506 | if (sl->tty) |
| 507 | sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); |
| 508 | |
| 509 | netif_stop_queue(dev); |
| 510 | sl->rcount = 0; |
| 511 | sl->xleft = 0; |
| 512 | if((err=lapb_unregister(dev))!=LAPB_OK) |
| 513 | printk(KERN_ERR "x25_asy_close: lapb_unregister error -%d\n",err); |
| 514 | spin_unlock(&sl->lock); |
| 515 | return 0; |
| 516 | } |
| 517 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | /* |
| 519 | * Handle the 'receiver data ready' interrupt. |
| 520 | * This function is called by the 'tty_io' module in the kernel when |
| 521 | * a block of X.25 data has been received, which can now be decapsulated |
| 522 | * and sent on to some IP layer for further processing. |
| 523 | */ |
| 524 | |
| 525 | static void x25_asy_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) |
| 526 | { |
| 527 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; |
| 528 | |
| 529 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) |
| 530 | return; |
| 531 | |
| 532 | |
| 533 | /* Read the characters out of the buffer */ |
| 534 | while (count--) { |
| 535 | if (fp && *fp++) { |
| 536 | if (!test_and_set_bit(SLF_ERROR, &sl->flags)) { |
| 537 | sl->stats.rx_errors++; |
| 538 | } |
| 539 | cp++; |
| 540 | continue; |
| 541 | } |
| 542 | x25_asy_unesc(sl, *cp++); |
| 543 | } |
| 544 | } |
| 545 | |
| 546 | /* |
| 547 | * Open the high-level part of the X.25 channel. |
| 548 | * This function is called by the TTY module when the |
| 549 | * X.25 line discipline is called for. Because we are |
| 550 | * sure the tty line exists, we only have to link it to |
| 551 | * a free X.25 channel... |
| 552 | */ |
| 553 | |
| 554 | static int x25_asy_open_tty(struct tty_struct *tty) |
| 555 | { |
| 556 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; |
Alan Cox | 11b0cc3 | 2008-02-08 15:00:48 -0800 | [diff] [blame^] | 557 | struct tty_ldisc *ld; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | int err; |
| 559 | |
| 560 | /* First make sure we're not already connected. */ |
| 561 | if (sl && sl->magic == X25_ASY_MAGIC) { |
| 562 | return -EEXIST; |
| 563 | } |
| 564 | |
| 565 | /* OK. Find a free X.25 channel to use. */ |
| 566 | if ((sl = x25_asy_alloc()) == NULL) { |
| 567 | return -ENFILE; |
| 568 | } |
| 569 | |
| 570 | sl->tty = tty; |
| 571 | tty->disc_data = sl; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 572 | tty->receive_room = 65536; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | if (tty->driver->flush_buffer) { |
| 574 | tty->driver->flush_buffer(tty); |
| 575 | } |
Alan Cox | 11b0cc3 | 2008-02-08 15:00:48 -0800 | [diff] [blame^] | 576 | tty_ldisc_flush(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | |
| 578 | /* Restore default settings */ |
| 579 | sl->dev->type = ARPHRD_X25; |
| 580 | |
| 581 | /* Perform the low-level X.25 async init */ |
| 582 | if ((err = x25_asy_open(sl->dev))) |
| 583 | return err; |
| 584 | |
| 585 | /* Done. We have linked the TTY line to a channel. */ |
| 586 | return sl->dev->base_addr; |
| 587 | } |
| 588 | |
| 589 | |
| 590 | /* |
| 591 | * Close down an X.25 channel. |
| 592 | * This means flushing out any pending queues, and then restoring the |
| 593 | * TTY line discipline to what it was before it got hooked to X.25 |
| 594 | * (which usually is TTY again). |
| 595 | */ |
| 596 | static void x25_asy_close_tty(struct tty_struct *tty) |
| 597 | { |
| 598 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; |
| 599 | |
| 600 | /* First make sure we're connected. */ |
| 601 | if (!sl || sl->magic != X25_ASY_MAGIC) |
| 602 | return; |
| 603 | |
| 604 | if (sl->dev->flags & IFF_UP) |
| 605 | { |
| 606 | (void) dev_close(sl->dev); |
| 607 | } |
| 608 | |
| 609 | tty->disc_data = NULL; |
| 610 | sl->tty = NULL; |
| 611 | x25_asy_free(sl); |
| 612 | } |
| 613 | |
| 614 | |
| 615 | static struct net_device_stats *x25_asy_get_stats(struct net_device *dev) |
| 616 | { |
| 617 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); |
| 618 | |
| 619 | return &sl->stats; |
| 620 | } |
| 621 | |
| 622 | |
| 623 | /************************************************************************ |
| 624 | * STANDARD X.25 ENCAPSULATION * |
| 625 | ************************************************************************/ |
| 626 | |
| 627 | int x25_asy_esc(unsigned char *s, unsigned char *d, int len) |
| 628 | { |
| 629 | unsigned char *ptr = d; |
| 630 | unsigned char c; |
| 631 | |
| 632 | /* |
| 633 | * Send an initial END character to flush out any |
| 634 | * data that may have accumulated in the receiver |
| 635 | * due to line noise. |
| 636 | */ |
| 637 | |
| 638 | *ptr++ = X25_END; /* Send 10111110 bit seq */ |
| 639 | |
| 640 | /* |
| 641 | * For each byte in the packet, send the appropriate |
| 642 | * character sequence, according to the X.25 protocol. |
| 643 | */ |
| 644 | |
| 645 | while (len-- > 0) |
| 646 | { |
| 647 | switch(c = *s++) |
| 648 | { |
| 649 | case X25_END: |
| 650 | *ptr++ = X25_ESC; |
| 651 | *ptr++ = X25_ESCAPE(X25_END); |
| 652 | break; |
| 653 | case X25_ESC: |
| 654 | *ptr++ = X25_ESC; |
| 655 | *ptr++ = X25_ESCAPE(X25_ESC); |
| 656 | break; |
| 657 | default: |
| 658 | *ptr++ = c; |
| 659 | break; |
| 660 | } |
| 661 | } |
| 662 | *ptr++ = X25_END; |
| 663 | return (ptr - d); |
| 664 | } |
| 665 | |
| 666 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char s) |
| 667 | { |
| 668 | |
| 669 | switch(s) |
| 670 | { |
| 671 | case X25_END: |
| 672 | if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && (sl->rcount > 2)) |
| 673 | { |
| 674 | x25_asy_bump(sl); |
| 675 | } |
| 676 | clear_bit(SLF_ESCAPE, &sl->flags); |
| 677 | sl->rcount = 0; |
| 678 | return; |
| 679 | |
| 680 | case X25_ESC: |
| 681 | set_bit(SLF_ESCAPE, &sl->flags); |
| 682 | return; |
| 683 | |
| 684 | case X25_ESCAPE(X25_ESC): |
| 685 | case X25_ESCAPE(X25_END): |
| 686 | if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) |
| 687 | s = X25_UNESCAPE(s); |
| 688 | break; |
| 689 | } |
| 690 | if (!test_bit(SLF_ERROR, &sl->flags)) |
| 691 | { |
| 692 | if (sl->rcount < sl->buffsize) |
| 693 | { |
| 694 | sl->rbuff[sl->rcount++] = s; |
| 695 | return; |
| 696 | } |
| 697 | sl->stats.rx_over_errors++; |
| 698 | set_bit(SLF_ERROR, &sl->flags); |
| 699 | } |
| 700 | } |
| 701 | |
| 702 | |
| 703 | /* Perform I/O control on an active X.25 channel. */ |
| 704 | static int x25_asy_ioctl(struct tty_struct *tty, struct file *file, |
| 705 | unsigned int cmd, unsigned long arg) |
| 706 | { |
| 707 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; |
| 708 | |
| 709 | /* First make sure we're connected. */ |
| 710 | if (!sl || sl->magic != X25_ASY_MAGIC) |
| 711 | return -EINVAL; |
| 712 | |
| 713 | switch(cmd) { |
| 714 | case SIOCGIFNAME: |
| 715 | if (copy_to_user((void __user *)arg, sl->dev->name, |
| 716 | strlen(sl->dev->name) + 1)) |
| 717 | return -EFAULT; |
| 718 | return 0; |
| 719 | case SIOCSIFHWADDR: |
| 720 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | default: |
Alan Cox | d012753 | 2007-11-07 01:27:34 -0800 | [diff] [blame] | 722 | return tty_mode_ioctl(tty, file, cmd, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | } |
| 724 | } |
| 725 | |
| 726 | static int x25_asy_open_dev(struct net_device *dev) |
| 727 | { |
| 728 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); |
| 729 | if(sl->tty==NULL) |
| 730 | return -ENODEV; |
| 731 | return 0; |
| 732 | } |
| 733 | |
| 734 | /* Initialise the X.25 driver. Called by the device init code */ |
| 735 | static void x25_asy_setup(struct net_device *dev) |
| 736 | { |
| 737 | struct x25_asy *sl = dev->priv; |
| 738 | |
| 739 | sl->magic = X25_ASY_MAGIC; |
| 740 | sl->dev = dev; |
| 741 | spin_lock_init(&sl->lock); |
| 742 | set_bit(SLF_INUSE, &sl->flags); |
| 743 | |
| 744 | /* |
| 745 | * Finish setting up the DEVICE info. |
| 746 | */ |
| 747 | |
| 748 | dev->mtu = SL_MTU; |
| 749 | dev->hard_start_xmit = x25_asy_xmit; |
| 750 | dev->tx_timeout = x25_asy_timeout; |
| 751 | dev->watchdog_timeo = HZ*20; |
| 752 | dev->open = x25_asy_open_dev; |
| 753 | dev->stop = x25_asy_close; |
| 754 | dev->get_stats = x25_asy_get_stats; |
| 755 | dev->change_mtu = x25_asy_change_mtu; |
| 756 | dev->hard_header_len = 0; |
| 757 | dev->addr_len = 0; |
| 758 | dev->type = ARPHRD_X25; |
| 759 | dev->tx_queue_len = 10; |
| 760 | |
| 761 | /* New-style flags. */ |
| 762 | dev->flags = IFF_NOARP; |
| 763 | } |
| 764 | |
| 765 | static struct tty_ldisc x25_ldisc = { |
| 766 | .owner = THIS_MODULE, |
| 767 | .magic = TTY_LDISC_MAGIC, |
| 768 | .name = "X.25", |
| 769 | .open = x25_asy_open_tty, |
| 770 | .close = x25_asy_close_tty, |
| 771 | .ioctl = x25_asy_ioctl, |
| 772 | .receive_buf = x25_asy_receive_buf, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | .write_wakeup = x25_asy_write_wakeup, |
| 774 | }; |
| 775 | |
| 776 | static int __init init_x25_asy(void) |
| 777 | { |
| 778 | if (x25_asy_maxdev < 4) |
| 779 | x25_asy_maxdev = 4; /* Sanity */ |
| 780 | |
| 781 | printk(KERN_INFO "X.25 async: version 0.00 ALPHA " |
| 782 | "(dynamic channels, max=%d).\n", x25_asy_maxdev ); |
| 783 | |
Yoann Padioleau | dd00cc4 | 2007-07-19 01:49:03 -0700 | [diff] [blame] | 784 | x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device*), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 785 | if (!x25_asy_devs) { |
| 786 | printk(KERN_WARNING "X25 async: Can't allocate x25_asy_ctrls[] " |
| 787 | "array! Uaargh! (-> No X.25 available)\n"); |
| 788 | return -ENOMEM; |
| 789 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 790 | |
| 791 | return tty_register_ldisc(N_X25, &x25_ldisc); |
| 792 | } |
| 793 | |
| 794 | |
| 795 | static void __exit exit_x25_asy(void) |
| 796 | { |
| 797 | struct net_device *dev; |
| 798 | int i; |
| 799 | |
| 800 | for (i = 0; i < x25_asy_maxdev; i++) { |
| 801 | dev = x25_asy_devs[i]; |
| 802 | if (dev) { |
| 803 | struct x25_asy *sl = dev->priv; |
| 804 | |
| 805 | spin_lock_bh(&sl->lock); |
| 806 | if (sl->tty) |
| 807 | tty_hangup(sl->tty); |
| 808 | |
| 809 | spin_unlock_bh(&sl->lock); |
| 810 | /* |
| 811 | * VSV = if dev->start==0, then device |
| 812 | * unregistered while close proc. |
| 813 | */ |
| 814 | unregister_netdev(dev); |
| 815 | free_netdev(dev); |
| 816 | } |
| 817 | } |
| 818 | |
| 819 | kfree(x25_asy_devs); |
Alexey Dobriyan | 64ccd71 | 2005-06-23 00:10:33 -0700 | [diff] [blame] | 820 | tty_unregister_ldisc(N_X25); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 821 | } |
| 822 | |
| 823 | module_init(init_x25_asy); |
| 824 | module_exit(exit_x25_asy); |