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