1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * DLCI Implementation of Frame Relay protocol for Linux, according to
4 * RFC 1490. This generic device provides en/decapsulation for an
5 * underlying hardware driver. Routes & IPs are assigned to these
6 * interfaces. Requires 'dlcicfg' program to create usable
7 * interfaces, the initial one, 'dlci' is for IOCTL use only.
9 * Version: @(#)dlci.c 0.35 4 Jan 1997
11 * Author: Mike McLagan <mike.mclagan@linux.org>
15 * 0.15 Mike Mclagan Packet freeing, bug in kmalloc call
17 * 0.20 Mike McLagan More conservative on which packets
18 * are returned for retry and which are
19 * are dropped. If DLCI_RET_DROP is
20 * returned from the FRAD, the packet is
21 * sent back to Linux for re-transmission
22 * 0.25 Mike McLagan Converted to use SIOC IOCTL calls
23 * 0.30 Jim Freeman Fixed to allow IPX traffic
24 * 0.35 Michael Elizabeth Fixed incorrect memcpy_fromfs
27 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29 #include <linux/module.h>
30 #include <linux/kernel.h>
31 #include <linux/types.h>
32 #include <linux/fcntl.h>
33 #include <linux/interrupt.h>
34 #include <linux/ptrace.h>
35 #include <linux/ioport.h>
37 #include <linux/init.h>
38 #include <linux/slab.h>
39 #include <linux/string.h>
40 #include <linux/errno.h>
41 #include <linux/netdevice.h>
42 #include <linux/skbuff.h>
43 #include <linux/if_arp.h>
44 #include <linux/if_frad.h>
45 #include <linux/bitops.h>
51 #include <linux/uaccess.h>
53 static const char version[] = "DLCI driver v0.35, 4 Jan 1997, mike.mclagan@linux.org";
55 static LIST_HEAD(dlci_devs);
57 static void dlci_setup(struct net_device *);
60 * these encapsulate the RFC 1490 requirements as well as
61 * deal with packet transmission and reception, working with
62 * the upper network layers
65 static int dlci_header(struct sk_buff *skb, struct net_device *dev,
66 unsigned short type, const void *daddr,
67 const void *saddr, unsigned len)
73 hdr.control = FRAD_I_UI;
77 hdr.IP_NLPID = FRAD_P_IP;
78 hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
81 /* feel free to add other types, if necessary */
84 hdr.pad = FRAD_P_PADDING;
85 hdr.NLPID = FRAD_P_SNAP;
86 memset(hdr.OUI, 0, sizeof(hdr.OUI));
87 hdr.PID = htons(type);
92 dest = skb_push(skb, hlen);
96 memcpy(dest, &hdr, hlen);
101 static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
106 if (!pskb_may_pull(skb, sizeof(*hdr))) {
107 netdev_notice(dev, "invalid data no header\n");
108 dev->stats.rx_errors++;
113 hdr = (struct frhdr *) skb->data;
118 if (hdr->control != FRAD_I_UI)
120 netdev_notice(dev, "Invalid header flag 0x%02X\n",
122 dev->stats.rx_errors++;
125 switch (hdr->IP_NLPID)
128 if (hdr->NLPID != FRAD_P_SNAP)
130 netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
132 dev->stats.rx_errors++;
136 if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
138 netdev_notice(dev, "Unsupported organizationally unique identifier 0x%02X-%02X-%02X\n",
142 dev->stats.rx_errors++;
146 /* at this point, it's an EtherType frame */
147 header = sizeof(struct frhdr);
148 /* Already in network order ! */
149 skb->protocol = hdr->PID;
154 header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
155 skb->protocol = htons(ETH_P_IP);
162 netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
164 dev->stats.rx_errors++;
168 netdev_notice(dev, "Invalid pad byte 0x%02X\n",
170 dev->stats.rx_errors++;
176 /* we've set up the protocol, so discard the header */
177 skb_reset_mac_header(skb);
178 skb_pull(skb, header);
179 dev->stats.rx_bytes += skb->len;
181 dev->stats.rx_packets++;
187 static netdev_tx_t dlci_transmit(struct sk_buff *skb, struct net_device *dev)
189 struct dlci_local *dlp = netdev_priv(dev);
192 struct netdev_queue *txq = skb_get_tx_queue(dev, skb);
193 netdev_start_xmit(skb, dlp->slave, txq, false);
198 static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
200 struct dlci_conf config;
201 struct dlci_local *dlp;
202 struct frad_local *flp;
205 dlp = netdev_priv(dev);
207 flp = netdev_priv(dlp->slave);
211 if (copy_from_user(&config, conf, sizeof(struct dlci_conf)))
213 if (config.flags & ~DLCI_VALID_FLAGS)
215 memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
219 err = (*flp->dlci_conf)(dlp->slave, dev, get);
225 if (copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
232 static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
234 struct dlci_local *dlp;
236 if (!capable(CAP_NET_ADMIN))
239 dlp = netdev_priv(dev);
244 if (!*(short *)(dev->dev_addr))
247 strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
252 if (!*(short *)(dev->dev_addr))
255 return dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF);
263 static int dlci_change_mtu(struct net_device *dev, int new_mtu)
265 struct dlci_local *dlp = netdev_priv(dev);
267 return dev_set_mtu(dlp->slave, new_mtu);
270 static int dlci_open(struct net_device *dev)
272 struct dlci_local *dlp;
273 struct frad_local *flp;
276 dlp = netdev_priv(dev);
278 if (!*(short *)(dev->dev_addr))
281 if (!netif_running(dlp->slave))
284 flp = netdev_priv(dlp->slave);
285 err = (*flp->activate)(dlp->slave, dev);
289 netif_start_queue(dev);
294 static int dlci_close(struct net_device *dev)
296 struct dlci_local *dlp;
297 struct frad_local *flp;
299 netif_stop_queue(dev);
301 dlp = netdev_priv(dev);
303 flp = netdev_priv(dlp->slave);
304 (*flp->deactivate)(dlp->slave, dev);
309 static int dlci_add(struct dlci_add *dlci)
311 struct net_device *master, *slave;
312 struct dlci_local *dlp;
313 struct frad_local *flp;
317 /* validate slave device */
318 slave = dev_get_by_name(&init_net, dlci->devname);
322 if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
325 /* create device name */
326 master = alloc_netdev(sizeof(struct dlci_local), "dlci%d",
327 NET_NAME_UNKNOWN, dlci_setup);
333 /* make sure same slave not already registered */
335 list_for_each_entry(dlp, &dlci_devs, list) {
336 if (dlp->slave == slave) {
342 *(short *)(master->dev_addr) = dlci->dlci;
344 dlp = netdev_priv(master);
346 dlp->master = master;
348 flp = netdev_priv(slave);
349 err = (*flp->assoc)(slave, master);
353 err = register_netdevice(master);
357 strcpy(dlci->devname, master->name);
359 list_add(&dlp->list, &dlci_devs);
372 static int dlci_del(struct dlci_add *dlci)
374 struct dlci_local *dlp;
375 struct frad_local *flp;
376 struct net_device *master, *slave;
382 /* validate slave device */
383 master = __dev_get_by_name(&init_net, dlci->devname);
389 list_for_each_entry(dlp, &dlci_devs, list) {
390 if (dlp->master == master) {
400 if (netif_running(master)) {
405 dlp = netdev_priv(master);
407 flp = netdev_priv(slave);
409 err = (*flp->deassoc)(slave, master);
411 list_del(&dlp->list);
413 unregister_netdevice(master);
422 static int dlci_ioctl(unsigned int cmd, void __user *arg)
427 if (!capable(CAP_NET_ADMIN))
430 if (copy_from_user(&add, arg, sizeof(struct dlci_add)))
436 err = dlci_add(&add);
439 if (copy_to_user(arg, &add, sizeof(struct dlci_add)))
444 err = dlci_del(&add);
454 static const struct header_ops dlci_header_ops = {
455 .create = dlci_header,
458 static const struct net_device_ops dlci_netdev_ops = {
459 .ndo_open = dlci_open,
460 .ndo_stop = dlci_close,
461 .ndo_do_ioctl = dlci_dev_ioctl,
462 .ndo_start_xmit = dlci_transmit,
463 .ndo_change_mtu = dlci_change_mtu,
466 static void dlci_setup(struct net_device *dev)
468 struct dlci_local *dlp = netdev_priv(dev);
471 dev->header_ops = &dlci_header_ops;
472 dev->netdev_ops = &dlci_netdev_ops;
473 dev->needs_free_netdev = true;
475 dlp->receive = dlci_receive;
477 dev->type = ARPHRD_DLCI;
478 dev->hard_header_len = sizeof(struct frhdr);
479 dev->addr_len = sizeof(short);
483 /* if slave is unregistering, then cleanup master */
484 static int dlci_dev_event(struct notifier_block *unused,
485 unsigned long event, void *ptr)
487 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
489 if (dev_net(dev) != &init_net)
492 if (event == NETDEV_UNREGISTER) {
493 struct dlci_local *dlp;
495 list_for_each_entry(dlp, &dlci_devs, list) {
496 if (dlp->slave == dev) {
497 list_del(&dlp->list);
498 unregister_netdevice(dlp->master);
507 static struct notifier_block dlci_notifier = {
508 .notifier_call = dlci_dev_event,
511 static int __init init_dlci(void)
513 dlci_ioctl_set(dlci_ioctl);
514 register_netdevice_notifier(&dlci_notifier);
516 printk("%s.\n", version);
521 static void __exit dlci_exit(void)
523 struct dlci_local *dlp, *nxt;
525 dlci_ioctl_set(NULL);
526 unregister_netdevice_notifier(&dlci_notifier);
529 list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
530 unregister_netdevice(dlp->master);
536 module_init(init_dlci);
537 module_exit(dlci_exit);
539 MODULE_AUTHOR("Mike McLagan");
540 MODULE_DESCRIPTION("Frame Relay DLCI layer");
541 MODULE_LICENSE("GPL");