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 which 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
33 #include <linux/module.h>
34 #include <linux/kernel.h>
35 #include <linux/types.h>
36 #include <linux/fcntl.h>
37 #include <linux/interrupt.h>
38 #include <linux/ptrace.h>
39 #include <linux/ioport.h>
40 #include <linux/in.h>
41 #include <linux/init.h>
42 #include <linux/slab.h>
43 #include <linux/string.h>
44 #include <linux/errno.h>
45 #include <linux/netdevice.h>
46 #include <linux/skbuff.h>
47 #include <linux/if_arp.h>
48 #include <linux/if_frad.h>
49 #include <linux/bitops.h>
50
51 #include <net/sock.h>
52
53 #include <asm/io.h>
54 #include <asm/dma.h>
55 #include <linux/uaccess.h>
56
57 static const char version[] = "DLCI driver v0.35, 4 Jan 1997, mike.mclagan@linux.org";
58
59 static LIST_HEAD(dlci_devs);
60
61 static void dlci_setup(struct net_device *);
62
63 /*
64 * these encapsulate the RFC 1490 requirements as well as
65 * deal with packet transmission and reception, working with
66 * the upper network layers
67 */
68
dlci_header(struct sk_buff * skb,struct net_device * dev,unsigned short type,const void * daddr,const void * saddr,unsigned len)69 static int dlci_header(struct sk_buff *skb, struct net_device *dev,
70 unsigned short type, const void *daddr,
71 const void *saddr, unsigned len)
72 {
73 struct frhdr hdr;
74 unsigned int hlen;
75 char *dest;
76
77 hdr.control = FRAD_I_UI;
78 switch (type)
79 {
80 case ETH_P_IP:
81 hdr.IP_NLPID = FRAD_P_IP;
82 hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
83 break;
84
85 /* feel free to add other types, if necessary */
86
87 default:
88 hdr.pad = FRAD_P_PADDING;
89 hdr.NLPID = FRAD_P_SNAP;
90 memset(hdr.OUI, 0, sizeof(hdr.OUI));
91 hdr.PID = htons(type);
92 hlen = sizeof(hdr);
93 break;
94 }
95
96 dest = skb_push(skb, hlen);
97 if (!dest)
98 return 0;
99
100 memcpy(dest, &hdr, hlen);
101
102 return hlen;
103 }
104
dlci_receive(struct sk_buff * skb,struct net_device * dev)105 static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
106 {
107 struct frhdr *hdr;
108 int process, header;
109
110 if (!pskb_may_pull(skb, sizeof(*hdr))) {
111 netdev_notice(dev, "invalid data no header\n");
112 dev->stats.rx_errors++;
113 kfree_skb(skb);
114 return;
115 }
116
117 hdr = (struct frhdr *) skb->data;
118 process = 0;
119 header = 0;
120 skb->dev = dev;
121
122 if (hdr->control != FRAD_I_UI)
123 {
124 netdev_notice(dev, "Invalid header flag 0x%02X\n",
125 hdr->control);
126 dev->stats.rx_errors++;
127 }
128 else
129 switch (hdr->IP_NLPID)
130 {
131 case FRAD_P_PADDING:
132 if (hdr->NLPID != FRAD_P_SNAP)
133 {
134 netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
135 hdr->NLPID);
136 dev->stats.rx_errors++;
137 break;
138 }
139
140 if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
141 {
142 netdev_notice(dev, "Unsupported organizationally unique identifier 0x%02X-%02X-%02X\n",
143 hdr->OUI[0],
144 hdr->OUI[1],
145 hdr->OUI[2]);
146 dev->stats.rx_errors++;
147 break;
148 }
149
150 /* at this point, it's an EtherType frame */
151 header = sizeof(struct frhdr);
152 /* Already in network order ! */
153 skb->protocol = hdr->PID;
154 process = 1;
155 break;
156
157 case FRAD_P_IP:
158 header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
159 skb->protocol = htons(ETH_P_IP);
160 process = 1;
161 break;
162
163 case FRAD_P_SNAP:
164 case FRAD_P_Q933:
165 case FRAD_P_CLNP:
166 netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
167 hdr->pad);
168 dev->stats.rx_errors++;
169 break;
170
171 default:
172 netdev_notice(dev, "Invalid pad byte 0x%02X\n",
173 hdr->pad);
174 dev->stats.rx_errors++;
175 break;
176 }
177
178 if (process)
179 {
180 /* we've set up the protocol, so discard the header */
181 skb_reset_mac_header(skb);
182 skb_pull(skb, header);
183 dev->stats.rx_bytes += skb->len;
184 netif_rx(skb);
185 dev->stats.rx_packets++;
186 }
187 else
188 dev_kfree_skb(skb);
189 }
190
dlci_transmit(struct sk_buff * skb,struct net_device * dev)191 static netdev_tx_t dlci_transmit(struct sk_buff *skb, struct net_device *dev)
192 {
193 struct dlci_local *dlp = netdev_priv(dev);
194
195 if (skb) {
196 struct netdev_queue *txq = skb_get_tx_queue(dev, skb);
197 netdev_start_xmit(skb, dlp->slave, txq, false);
198 }
199 return NETDEV_TX_OK;
200 }
201
dlci_config(struct net_device * dev,struct dlci_conf __user * conf,int get)202 static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
203 {
204 struct dlci_conf config;
205 struct dlci_local *dlp;
206 struct frad_local *flp;
207 int err;
208
209 dlp = netdev_priv(dev);
210
211 flp = netdev_priv(dlp->slave);
212
213 if (!get)
214 {
215 if (copy_from_user(&config, conf, sizeof(struct dlci_conf)))
216 return -EFAULT;
217 if (config.flags & ~DLCI_VALID_FLAGS)
218 return -EINVAL;
219 memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
220 dlp->configured = 1;
221 }
222
223 err = (*flp->dlci_conf)(dlp->slave, dev, get);
224 if (err)
225 return err;
226
227 if (get)
228 {
229 if (copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
230 return -EFAULT;
231 }
232
233 return 0;
234 }
235
dlci_dev_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)236 static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
237 {
238 struct dlci_local *dlp;
239
240 if (!capable(CAP_NET_ADMIN))
241 return -EPERM;
242
243 dlp = netdev_priv(dev);
244
245 switch (cmd)
246 {
247 case DLCI_GET_SLAVE:
248 if (!*(short *)(dev->dev_addr))
249 return -EINVAL;
250
251 strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
252 break;
253
254 case DLCI_GET_CONF:
255 case DLCI_SET_CONF:
256 if (!*(short *)(dev->dev_addr))
257 return -EINVAL;
258
259 return dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF);
260
261 default:
262 return -EOPNOTSUPP;
263 }
264 return 0;
265 }
266
dlci_change_mtu(struct net_device * dev,int new_mtu)267 static int dlci_change_mtu(struct net_device *dev, int new_mtu)
268 {
269 struct dlci_local *dlp = netdev_priv(dev);
270
271 return dev_set_mtu(dlp->slave, new_mtu);
272 }
273
dlci_open(struct net_device * dev)274 static int dlci_open(struct net_device *dev)
275 {
276 struct dlci_local *dlp;
277 struct frad_local *flp;
278 int err;
279
280 dlp = netdev_priv(dev);
281
282 if (!*(short *)(dev->dev_addr))
283 return -EINVAL;
284
285 if (!netif_running(dlp->slave))
286 return -ENOTCONN;
287
288 flp = netdev_priv(dlp->slave);
289 err = (*flp->activate)(dlp->slave, dev);
290 if (err)
291 return err;
292
293 netif_start_queue(dev);
294
295 return 0;
296 }
297
dlci_close(struct net_device * dev)298 static int dlci_close(struct net_device *dev)
299 {
300 struct dlci_local *dlp;
301 struct frad_local *flp;
302 int err;
303
304 netif_stop_queue(dev);
305
306 dlp = netdev_priv(dev);
307
308 flp = netdev_priv(dlp->slave);
309 err = (*flp->deactivate)(dlp->slave, dev);
310
311 return 0;
312 }
313
dlci_add(struct dlci_add * dlci)314 static int dlci_add(struct dlci_add *dlci)
315 {
316 struct net_device *master, *slave;
317 struct dlci_local *dlp;
318 struct frad_local *flp;
319 int err = -EINVAL;
320
321
322 /* validate slave device */
323 slave = dev_get_by_name(&init_net, dlci->devname);
324 if (!slave)
325 return -ENODEV;
326
327 if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
328 goto err1;
329
330 /* create device name */
331 master = alloc_netdev(sizeof(struct dlci_local), "dlci%d",
332 NET_NAME_UNKNOWN, dlci_setup);
333 if (!master) {
334 err = -ENOMEM;
335 goto err1;
336 }
337
338 /* make sure same slave not already registered */
339 rtnl_lock();
340 list_for_each_entry(dlp, &dlci_devs, list) {
341 if (dlp->slave == slave) {
342 err = -EBUSY;
343 goto err2;
344 }
345 }
346
347 *(short *)(master->dev_addr) = dlci->dlci;
348
349 dlp = netdev_priv(master);
350 dlp->slave = slave;
351 dlp->master = master;
352
353 flp = netdev_priv(slave);
354 err = (*flp->assoc)(slave, master);
355 if (err < 0)
356 goto err2;
357
358 err = register_netdevice(master);
359 if (err < 0)
360 goto err2;
361
362 strcpy(dlci->devname, master->name);
363
364 list_add(&dlp->list, &dlci_devs);
365 rtnl_unlock();
366
367 return 0;
368
369 err2:
370 rtnl_unlock();
371 free_netdev(master);
372 err1:
373 dev_put(slave);
374 return err;
375 }
376
dlci_del(struct dlci_add * dlci)377 static int dlci_del(struct dlci_add *dlci)
378 {
379 struct dlci_local *dlp;
380 struct frad_local *flp;
381 struct net_device *master, *slave;
382 int err;
383 bool found = false;
384
385 rtnl_lock();
386
387 /* validate slave device */
388 master = __dev_get_by_name(&init_net, dlci->devname);
389 if (!master) {
390 err = -ENODEV;
391 goto out;
392 }
393
394 list_for_each_entry(dlp, &dlci_devs, list) {
395 if (dlp->master == master) {
396 found = true;
397 break;
398 }
399 }
400 if (!found) {
401 err = -ENODEV;
402 goto out;
403 }
404
405 if (netif_running(master)) {
406 err = -EBUSY;
407 goto out;
408 }
409
410 dlp = netdev_priv(master);
411 slave = dlp->slave;
412 flp = netdev_priv(slave);
413
414 err = (*flp->deassoc)(slave, master);
415 if (!err) {
416 list_del(&dlp->list);
417
418 unregister_netdevice(master);
419
420 dev_put(slave);
421 }
422 out:
423 rtnl_unlock();
424 return err;
425 }
426
dlci_ioctl(unsigned int cmd,void __user * arg)427 static int dlci_ioctl(unsigned int cmd, void __user *arg)
428 {
429 struct dlci_add add;
430 int err;
431
432 if (!capable(CAP_NET_ADMIN))
433 return -EPERM;
434
435 if (copy_from_user(&add, arg, sizeof(struct dlci_add)))
436 return -EFAULT;
437
438 switch (cmd)
439 {
440 case SIOCADDDLCI:
441 err = dlci_add(&add);
442
443 if (!err)
444 if (copy_to_user(arg, &add, sizeof(struct dlci_add)))
445 return -EFAULT;
446 break;
447
448 case SIOCDELDLCI:
449 err = dlci_del(&add);
450 break;
451
452 default:
453 err = -EINVAL;
454 }
455
456 return err;
457 }
458
459 static const struct header_ops dlci_header_ops = {
460 .create = dlci_header,
461 };
462
463 static const struct net_device_ops dlci_netdev_ops = {
464 .ndo_open = dlci_open,
465 .ndo_stop = dlci_close,
466 .ndo_do_ioctl = dlci_dev_ioctl,
467 .ndo_start_xmit = dlci_transmit,
468 .ndo_change_mtu = dlci_change_mtu,
469 };
470
dlci_setup(struct net_device * dev)471 static void dlci_setup(struct net_device *dev)
472 {
473 struct dlci_local *dlp = netdev_priv(dev);
474
475 dev->flags = 0;
476 dev->header_ops = &dlci_header_ops;
477 dev->netdev_ops = &dlci_netdev_ops;
478 dev->needs_free_netdev = true;
479
480 dlp->receive = dlci_receive;
481
482 dev->type = ARPHRD_DLCI;
483 dev->hard_header_len = sizeof(struct frhdr);
484 dev->addr_len = sizeof(short);
485
486 }
487
488 /* if slave is unregistering, then cleanup master */
dlci_dev_event(struct notifier_block * unused,unsigned long event,void * ptr)489 static int dlci_dev_event(struct notifier_block *unused,
490 unsigned long event, void *ptr)
491 {
492 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
493
494 if (dev_net(dev) != &init_net)
495 return NOTIFY_DONE;
496
497 if (event == NETDEV_UNREGISTER) {
498 struct dlci_local *dlp;
499
500 list_for_each_entry(dlp, &dlci_devs, list) {
501 if (dlp->slave == dev) {
502 list_del(&dlp->list);
503 unregister_netdevice(dlp->master);
504 dev_put(dlp->slave);
505 break;
506 }
507 }
508 }
509 return NOTIFY_DONE;
510 }
511
512 static struct notifier_block dlci_notifier = {
513 .notifier_call = dlci_dev_event,
514 };
515
init_dlci(void)516 static int __init init_dlci(void)
517 {
518 dlci_ioctl_set(dlci_ioctl);
519 register_netdevice_notifier(&dlci_notifier);
520
521 printk("%s.\n", version);
522
523 return 0;
524 }
525
dlci_exit(void)526 static void __exit dlci_exit(void)
527 {
528 struct dlci_local *dlp, *nxt;
529
530 dlci_ioctl_set(NULL);
531 unregister_netdevice_notifier(&dlci_notifier);
532
533 rtnl_lock();
534 list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
535 unregister_netdevice(dlp->master);
536 dev_put(dlp->slave);
537 }
538 rtnl_unlock();
539 }
540
541 module_init(init_dlci);
542 module_exit(dlci_exit);
543
544 MODULE_AUTHOR("Mike McLagan");
545 MODULE_DESCRIPTION("Frame Relay DLCI layer");
546 MODULE_LICENSE("GPL");
547
