1 /*
2 * DLCI Implementation of Frame Relay protocol for Linux, according to
3 * RFC 1490. This generic device provides en/decapsulation for an
4 * underlying hardware driver. Routes & IPs are assigned to these
5 * interfaces. Requires 'dlcicfg' program to create usable
6 * interfaces, the initial one, 'dlci' is for IOCTL use only.
7 *
8 * Version: @(#)dlci.c 0.35 4 Jan 1997
9 *
10 * Author: Mike McLagan <mike.mclagan@linux.org>
11 *
12 * Changes:
13 *
14 * 0.15 Mike Mclagan Packet freeing, bug in kmalloc call
15 * DLCI_RET handling
16 * 0.20 Mike McLagan More conservative on which packets
17 * are returned for retry and whic are
18 * are dropped. If DLCI_RET_DROP is
19 * returned from the FRAD, the packet is
20 * sent back to Linux for re-transmission
21 * 0.25 Mike McLagan Converted to use SIOC IOCTL calls
22 * 0.30 Jim Freeman Fixed to allow IPX traffic
23 * 0.35 Michael Elizabeth Fixed incorrect memcpy_fromfs
24 *
25 * This program is free software; you can redistribute it and/or
26 * modify it under the terms of the GNU General Public License
27 * as published by the Free Software Foundation; either version
28 * 2 of the License, or (at your option) any later version.
29 */
30
31 #include <linux/config.h> /* for CONFIG_DLCI_COUNT */
32 #include <linux/module.h>
33
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/types.h>
37 #include <linux/fcntl.h>
38 #include <linux/interrupt.h>
39 #include <linux/ptrace.h>
40 #include <linux/ioport.h>
41 #include <linux/in.h>
42 #include <linux/slab.h>
43 #include <linux/string.h>
44 #include <linux/init.h>
45 #include <asm/system.h>
46 #include <asm/bitops.h>
47 #include <asm/io.h>
48 #include <asm/dma.h>
49 #include <asm/uaccess.h>
50
51 #include <linux/errno.h>
52
53 #include <linux/netdevice.h>
54 #include <linux/skbuff.h>
55 #include <linux/if_arp.h>
56 #include <linux/if_frad.h>
57
58 #include <net/sock.h>
59
60 static const char devname[] = "dlci";
61 static const char version[] = "DLCI driver v0.35, 4 Jan 1997, mike.mclagan@linux.org";
62
63 static struct net_device *open_dev[CONFIG_DLCI_COUNT];
64
65 static char *basename[16];
66
67 int dlci_init(struct net_device *dev);
68
69 /* allow FRAD's to register their name as a valid FRAD */
register_frad(const char * name)70 int register_frad(const char *name)
71 {
72 int i;
73
74 if (!name)
75 return(-EINVAL);
76
77 for (i=0;i<sizeof(basename) / sizeof(char *);i++)
78 {
79 if (!basename[i])
80 break;
81
82 /* take care of multiple registrations */
83 if (strcmp(basename[i], name) == 0)
84 return(0);
85 }
86
87 if (i == sizeof(basename) / sizeof(char *))
88 return(-EMLINK);
89
90 basename[i] = kmalloc(strlen(name) + 1, GFP_KERNEL);
91 if (!basename[i])
92 return(-ENOMEM);
93
94 strcpy(basename[i], name);
95
96 return(0);
97 }
98
unregister_frad(const char * name)99 int unregister_frad(const char *name)
100 {
101 int i;
102
103 if (!name)
104 return(-EINVAL);
105
106 for (i=0;i<sizeof(basename) / sizeof(char *);i++)
107 if (basename[i] && (strcmp(basename[i], name) == 0))
108 break;
109
110 if (i == sizeof(basename) / sizeof(char *))
111 return(-EINVAL);
112
113 kfree(basename[i]);
114 basename[i] = NULL;
115
116 return(0);
117 }
118
119 /*
120 * these encapsulate the RFC 1490 requirements as well as
121 * deal with packet transmission and reception, working with
122 * the upper network layers
123 */
124
dlci_header(struct sk_buff * skb,struct net_device * dev,unsigned short type,void * daddr,void * saddr,unsigned len)125 static int dlci_header(struct sk_buff *skb, struct net_device *dev,
126 unsigned short type, void *daddr, void *saddr,
127 unsigned len)
128 {
129 struct frhdr hdr;
130 struct dlci_local *dlp;
131 unsigned int hlen;
132 char *dest;
133
134 dlp = dev->priv;
135
136 hdr.control = FRAD_I_UI;
137 switch(type)
138 {
139 case ETH_P_IP:
140 hdr.IP_NLPID = FRAD_P_IP;
141 hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
142 break;
143
144 /* feel free to add other types, if necessary */
145
146 default:
147 hdr.pad = FRAD_P_PADDING;
148 hdr.NLPID = FRAD_P_SNAP;
149 memset(hdr.OUI, 0, sizeof(hdr.OUI));
150 hdr.PID = htons(type);
151 hlen = sizeof(hdr);
152 break;
153 }
154
155 dest = skb_push(skb, hlen);
156 if (!dest)
157 return(0);
158
159 memcpy(dest, &hdr, hlen);
160
161 return(hlen);
162 }
163
dlci_receive(struct sk_buff * skb,struct net_device * dev)164 static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
165 {
166 struct dlci_local *dlp;
167 struct frhdr *hdr;
168 int process, header;
169
170 dlp = dev->priv;
171 hdr = (struct frhdr *) skb->data;
172 process = 0;
173 header = 0;
174 skb->dev = dev;
175
176 if (hdr->control != FRAD_I_UI)
177 {
178 printk(KERN_NOTICE "%s: Invalid header flag 0x%02X.\n", dev->name, hdr->control);
179 dlp->stats.rx_errors++;
180 }
181 else
182 switch(hdr->IP_NLPID)
183 {
184 case FRAD_P_PADDING:
185 if (hdr->NLPID != FRAD_P_SNAP)
186 {
187 printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->NLPID);
188 dlp->stats.rx_errors++;
189 break;
190 }
191
192 if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
193 {
194 printk(KERN_NOTICE "%s: Unsupported organizationally unique identifier 0x%02X-%02X-%02X.\n", dev->name, hdr->OUI[0], hdr->OUI[1], hdr->OUI[2]);
195 dlp->stats.rx_errors++;
196 break;
197 }
198
199 /* at this point, it's an EtherType frame */
200 header = sizeof(struct frhdr);
201 /* Already in network order ! */
202 skb->protocol = hdr->PID;
203 process = 1;
204 break;
205
206 case FRAD_P_IP:
207 header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
208 skb->protocol = htons(ETH_P_IP);
209 process = 1;
210 break;
211
212 case FRAD_P_SNAP:
213 case FRAD_P_Q933:
214 case FRAD_P_CLNP:
215 printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->pad);
216 dlp->stats.rx_errors++;
217 break;
218
219 default:
220 printk(KERN_NOTICE "%s: Invalid pad byte 0x%02X.\n", dev->name, hdr->pad);
221 dlp->stats.rx_errors++;
222 break;
223 }
224
225 if (process)
226 {
227 /* we've set up the protocol, so discard the header */
228 skb->mac.raw = skb->data;
229 skb_pull(skb, header);
230 dlp->stats.rx_bytes += skb->len;
231 netif_rx(skb);
232 dlp->stats.rx_packets++;
233 dev->last_rx = jiffies;
234 }
235 else
236 dev_kfree_skb(skb);
237 }
238
dlci_transmit(struct sk_buff * skb,struct net_device * dev)239 static int dlci_transmit(struct sk_buff *skb, struct net_device *dev)
240 {
241 struct dlci_local *dlp;
242 int ret;
243
244 ret = 0;
245
246 if (!skb || !dev)
247 return(0);
248
249 dlp = dev->priv;
250
251 netif_stop_queue(dev);
252
253 ret = dlp->slave->hard_start_xmit(skb, dlp->slave);
254 switch (ret)
255 {
256 case DLCI_RET_OK:
257 dlp->stats.tx_packets++;
258 ret = 0;
259 break;
260 case DLCI_RET_ERR:
261 dlp->stats.tx_errors++;
262 ret = 0;
263 break;
264 case DLCI_RET_DROP:
265 dlp->stats.tx_dropped++;
266 ret = 1;
267 break;
268 }
269 /* Alan Cox recommends always returning 0, and always freeing the packet */
270 /* experience suggest a slightly more conservative approach */
271
272 if (!ret)
273 {
274 dev_kfree_skb(skb);
275 netif_wake_queue(dev);
276 }
277 return(ret);
278 }
279
dlci_config(struct net_device * dev,struct dlci_conf * conf,int get)280 int dlci_config(struct net_device *dev, struct dlci_conf *conf, int get)
281 {
282 struct dlci_conf config;
283 struct dlci_local *dlp;
284 struct frad_local *flp;
285 int err;
286
287 dlp = dev->priv;
288
289 flp = dlp->slave->priv;
290
291 if (!get)
292 {
293 if(copy_from_user(&config, conf, sizeof(struct dlci_conf)))
294 return -EFAULT;
295 if (config.flags & ~DLCI_VALID_FLAGS)
296 return(-EINVAL);
297 memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
298 dlp->configured = 1;
299 }
300
301 err = (*flp->dlci_conf)(dlp->slave, dev, get);
302 if (err)
303 return(err);
304
305 if (get)
306 {
307 if(copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
308 return -EFAULT;
309 }
310
311 return(0);
312 }
313
dlci_dev_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)314 int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
315 {
316 struct dlci_local *dlp;
317
318 if (!capable(CAP_NET_ADMIN))
319 return(-EPERM);
320
321 dlp = dev->priv;
322
323 switch(cmd)
324 {
325 case DLCI_GET_SLAVE:
326 if (!*(short *)(dev->dev_addr))
327 return(-EINVAL);
328
329 strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
330 break;
331
332 case DLCI_GET_CONF:
333 case DLCI_SET_CONF:
334 if (!*(short *)(dev->dev_addr))
335 return(-EINVAL);
336
337 return(dlci_config(dev, (struct dlci_conf *) ifr->ifr_data, cmd == DLCI_GET_CONF));
338 break;
339
340 default:
341 return(-EOPNOTSUPP);
342 }
343 return(0);
344 }
345
dlci_change_mtu(struct net_device * dev,int new_mtu)346 static int dlci_change_mtu(struct net_device *dev, int new_mtu)
347 {
348 struct dlci_local *dlp;
349
350 dlp = dev->priv;
351
352 return((*dlp->slave->change_mtu)(dlp->slave, new_mtu));
353 }
354
dlci_open(struct net_device * dev)355 static int dlci_open(struct net_device *dev)
356 {
357 struct dlci_local *dlp;
358 struct frad_local *flp;
359 int err;
360
361 dlp = dev->priv;
362
363 if (!*(short *)(dev->dev_addr))
364 return(-EINVAL);
365
366 if (!netif_running(dlp->slave))
367 return(-ENOTCONN);
368
369 flp = dlp->slave->priv;
370 err = (*flp->activate)(dlp->slave, dev);
371 if (err)
372 return(err);
373
374 netif_start_queue(dev);
375
376 return 0;
377 }
378
dlci_close(struct net_device * dev)379 static int dlci_close(struct net_device *dev)
380 {
381 struct dlci_local *dlp;
382 struct frad_local *flp;
383 int err;
384
385 netif_stop_queue(dev);
386
387 dlp = dev->priv;
388
389 flp = dlp->slave->priv;
390 err = (*flp->deactivate)(dlp->slave, dev);
391
392 return 0;
393 }
394
dlci_get_stats(struct net_device * dev)395 static struct net_device_stats *dlci_get_stats(struct net_device *dev)
396 {
397 struct dlci_local *dlp;
398
399 dlp = dev->priv;
400
401 return(&dlp->stats);
402 }
403
dlci_add(struct dlci_add * dlci)404 int dlci_add(struct dlci_add *dlci)
405 {
406 struct net_device *master, *slave;
407 struct dlci_local *dlp;
408 struct frad_local *flp;
409 int err, i;
410 char buf[10];
411
412 /* validate slave device */
413 slave = __dev_get_by_name(dlci->devname);
414 if (!slave)
415 return(-ENODEV);
416
417 if (slave->type != ARPHRD_FRAD)
418 return(-EINVAL);
419
420 /* check for registration */
421 for (i=0;i<sizeof(basename) / sizeof(char *); i++)
422 if ((basename[i]) &&
423 (strncmp(dlci->devname, basename[i], strlen(basename[i])) == 0) &&
424 (strlen(dlci->devname) > strlen(basename[i])))
425 break;
426
427 if (i == sizeof(basename) / sizeof(char *))
428 return(-EINVAL);
429
430 /* check for too many open devices : should this be dynamic ? */
431 for(i=0;i<CONFIG_DLCI_COUNT;i++)
432 if (!open_dev[i])
433 break;
434
435 if (i == CONFIG_DLCI_COUNT)
436 return(-ENOSPC); /* #### Alan: Comments on this?? */
437
438 /* create device name */
439 sprintf(buf, "%s%02i", devname, i);
440
441 master = kmalloc(sizeof(*master), GFP_KERNEL);
442 if (!master)
443 return(-ENOMEM);
444
445 memset(master, 0, sizeof(*master));
446
447 strcpy(master->name, buf);
448 master->init = dlci_init;
449 master->flags = 0;
450
451 err = register_netdev(master);
452 if (err < 0)
453 {
454 kfree(master);
455 return(err);
456 }
457
458 *(short *)(master->dev_addr) = dlci->dlci;
459
460 dlp = (struct dlci_local *) master->priv;
461 dlp->slave = slave;
462
463 flp = slave->priv;
464 err = flp ? (*flp->assoc)(slave, master) : -EINVAL;
465 if (err < 0)
466 {
467 unregister_netdev(master);
468 kfree(master->priv);
469 kfree(master);
470 return(err);
471 }
472
473 strcpy(dlci->devname, buf);
474 open_dev[i] = master;
475 MOD_INC_USE_COUNT;
476 return(0);
477 }
478
dlci_del(struct dlci_add * dlci)479 int dlci_del(struct dlci_add *dlci)
480 {
481 struct dlci_local *dlp;
482 struct frad_local *flp;
483 struct net_device *master, *slave;
484 int i, err;
485
486 /* validate slave device */
487 master = __dev_get_by_name(dlci->devname);
488 if (!master)
489 return(-ENODEV);
490
491 if (netif_running(master))
492 return(-EBUSY);
493
494 dlp = master->priv;
495 slave = dlp->slave;
496 flp = slave->priv;
497
498 err = (*flp->deassoc)(slave, master);
499 if (err)
500 return(err);
501
502 unregister_netdev(master);
503
504 for(i=0;i<CONFIG_DLCI_COUNT;i++)
505 if (master == open_dev[i])
506 break;
507
508 if (i<CONFIG_DLCI_COUNT)
509 open_dev[i] = NULL;
510
511 kfree(master->priv);
512 kfree(master);
513
514 MOD_DEC_USE_COUNT;
515
516 return(0);
517 }
518
dlci_ioctl(unsigned int cmd,void * arg)519 int dlci_ioctl(unsigned int cmd, void *arg)
520 {
521 struct dlci_add add;
522 int err;
523
524 if (!capable(CAP_NET_ADMIN))
525 return(-EPERM);
526
527 if(copy_from_user(&add, arg, sizeof(struct dlci_add)))
528 return -EFAULT;
529
530 switch (cmd)
531 {
532 case SIOCADDDLCI:
533 err = dlci_add(&add);
534
535 if (!err)
536 if(copy_to_user(arg, &add, sizeof(struct dlci_add)))
537 return -EFAULT;
538 break;
539
540 case SIOCDELDLCI:
541 err = dlci_del(&add);
542 break;
543
544 default:
545 err = -EINVAL;
546 }
547
548 return(err);
549 }
550
dlci_init(struct net_device * dev)551 int dlci_init(struct net_device *dev)
552 {
553 struct dlci_local *dlp;
554
555 dev->priv = kmalloc(sizeof(struct dlci_local), GFP_KERNEL);
556 if (!dev->priv)
557 return(-ENOMEM);
558
559 memset(dev->priv, 0, sizeof(struct dlci_local));
560 dlp = dev->priv;
561
562 dev->flags = 0;
563 dev->open = dlci_open;
564 dev->stop = dlci_close;
565 dev->do_ioctl = dlci_dev_ioctl;
566 dev->hard_start_xmit = dlci_transmit;
567 dev->hard_header = dlci_header;
568 dev->get_stats = dlci_get_stats;
569 dev->change_mtu = dlci_change_mtu;
570
571 dlp->receive = dlci_receive;
572
573 dev->type = ARPHRD_DLCI;
574 dev->hard_header_len = sizeof(struct frhdr);
575 dev->addr_len = sizeof(short);
576 memset(dev->dev_addr, 0, sizeof(dev->dev_addr));
577
578 return(0);
579 }
580
dlci_setup(void)581 int __init dlci_setup(void)
582 {
583 int i;
584
585 printk("%s.\n", version);
586
587 for(i=0;i<CONFIG_DLCI_COUNT;i++)
588 open_dev[i] = NULL;
589
590 for(i=0;i<sizeof(basename) / sizeof(char *);i++)
591 basename[i] = NULL;
592
593 return(0);
594 }
595
596 #ifdef MODULE
597
598 extern int (*dlci_ioctl_hook)(unsigned int, void *);
599
init_module(void)600 int init_module(void)
601 {
602 dlci_ioctl_hook = dlci_ioctl;
603
604 return(dlci_setup());
605 }
606
cleanup_module(void)607 void cleanup_module(void)
608 {
609 dlci_ioctl_hook = NULL;
610 }
611 #endif /* MODULE */
612
613 MODULE_AUTHOR("Mike McLagan");
614 MODULE_DESCRIPTION("Frame Relay DLCI layer");
615 MODULE_LICENSE("GPL");
616