/drivers/net/wan/hdlc_cisco.c
C | 413 lines | 316 code | 84 blank | 13 comment | 40 complexity | 180c2945d465a9bdc7f4fd3b3d1d9f74 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
1/*
2 * Generic HDLC support routines for Linux
3 * Cisco HDLC support
4 *
5 * Copyright (C) 2000 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of version 2 of the GNU General Public License
9 * as published by the Free Software Foundation.
10 */
11
12#include <linux/errno.h>
13#include <linux/hdlc.h>
14#include <linux/if_arp.h>
15#include <linux/inetdevice.h>
16#include <linux/init.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/pkt_sched.h>
20#include <linux/poll.h>
21#include <linux/rtnetlink.h>
22#include <linux/skbuff.h>
23
24#undef DEBUG_HARD_HEADER
25
26#define CISCO_MULTICAST 0x8F /* Cisco multicast address */
27#define CISCO_UNICAST 0x0F /* Cisco unicast address */
28#define CISCO_KEEPALIVE 0x8035 /* Cisco keepalive protocol */
29#define CISCO_SYS_INFO 0x2000 /* Cisco interface/system info */
30#define CISCO_ADDR_REQ 0 /* Cisco address request */
31#define CISCO_ADDR_REPLY 1 /* Cisco address reply */
32#define CISCO_KEEPALIVE_REQ 2 /* Cisco keepalive request */
33
34
35struct hdlc_header {
36 u8 address;
37 u8 control;
38 __be16 protocol;
39}__packed;
40
41
42struct cisco_packet {
43 __be32 type; /* code */
44 __be32 par1;
45 __be32 par2;
46 __be16 rel; /* reliability */
47 __be32 time;
48}__packed;
49#define CISCO_PACKET_LEN 18
50#define CISCO_BIG_PACKET_LEN 20
51
52
53struct cisco_state {
54 cisco_proto settings;
55
56 struct timer_list timer;
57 spinlock_t lock;
58 unsigned long last_poll;
59 int up;
60 u32 txseq; /* TX sequence number, 0 = none */
61 u32 rxseq; /* RX sequence number */
62};
63
64
65static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr);
66
67
68static inline struct cisco_state* state(hdlc_device *hdlc)
69{
70 return (struct cisco_state *)hdlc->state;
71}
72
73
74static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,
75 u16 type, const void *daddr, const void *saddr,
76 unsigned int len)
77{
78 struct hdlc_header *data;
79#ifdef DEBUG_HARD_HEADER
80 printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);
81#endif
82
83 skb_push(skb, sizeof(struct hdlc_header));
84 data = (struct hdlc_header*)skb->data;
85 if (type == CISCO_KEEPALIVE)
86 data->address = CISCO_MULTICAST;
87 else
88 data->address = CISCO_UNICAST;
89 data->control = 0;
90 data->protocol = htons(type);
91
92 return sizeof(struct hdlc_header);
93}
94
95
96
97static void cisco_keepalive_send(struct net_device *dev, u32 type,
98 __be32 par1, __be32 par2)
99{
100 struct sk_buff *skb;
101 struct cisco_packet *data;
102
103 skb = dev_alloc_skb(sizeof(struct hdlc_header) +
104 sizeof(struct cisco_packet));
105 if (!skb) {
106 printk(KERN_WARNING
107 "%s: Memory squeeze on cisco_keepalive_send()\n",
108 dev->name);
109 return;
110 }
111 skb_reserve(skb, 4);
112 cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
113 data = (struct cisco_packet*)(skb->data + 4);
114
115 data->type = htonl(type);
116 data->par1 = par1;
117 data->par2 = par2;
118 data->rel = cpu_to_be16(0xFFFF);
119 /* we will need do_div here if 1000 % HZ != 0 */
120 data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));
121
122 skb_put(skb, sizeof(struct cisco_packet));
123 skb->priority = TC_PRIO_CONTROL;
124 skb->dev = dev;
125 skb_reset_network_header(skb);
126
127 dev_queue_xmit(skb);
128}
129
130
131
132static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev)
133{
134 struct hdlc_header *data = (struct hdlc_header*)skb->data;
135
136 if (skb->len < sizeof(struct hdlc_header))
137 return cpu_to_be16(ETH_P_HDLC);
138
139 if (data->address != CISCO_MULTICAST &&
140 data->address != CISCO_UNICAST)
141 return cpu_to_be16(ETH_P_HDLC);
142
143 switch (data->protocol) {
144 case cpu_to_be16(ETH_P_IP):
145 case cpu_to_be16(ETH_P_IPX):
146 case cpu_to_be16(ETH_P_IPV6):
147 skb_pull(skb, sizeof(struct hdlc_header));
148 return data->protocol;
149 default:
150 return cpu_to_be16(ETH_P_HDLC);
151 }
152}
153
154
155static int cisco_rx(struct sk_buff *skb)
156{
157 struct net_device *dev = skb->dev;
158 hdlc_device *hdlc = dev_to_hdlc(dev);
159 struct cisco_state *st = state(hdlc);
160 struct hdlc_header *data = (struct hdlc_header*)skb->data;
161 struct cisco_packet *cisco_data;
162 struct in_device *in_dev;
163 __be32 addr, mask;
164 u32 ack;
165
166 if (skb->len < sizeof(struct hdlc_header))
167 goto rx_error;
168
169 if (data->address != CISCO_MULTICAST &&
170 data->address != CISCO_UNICAST)
171 goto rx_error;
172
173 switch (ntohs(data->protocol)) {
174 case CISCO_SYS_INFO:
175 /* Packet is not needed, drop it. */
176 dev_kfree_skb_any(skb);
177 return NET_RX_SUCCESS;
178
179 case CISCO_KEEPALIVE:
180 if ((skb->len != sizeof(struct hdlc_header) +
181 CISCO_PACKET_LEN) &&
182 (skb->len != sizeof(struct hdlc_header) +
183 CISCO_BIG_PACKET_LEN)) {
184 printk(KERN_INFO "%s: Invalid length of Cisco control"
185 " packet (%d bytes)\n", dev->name, skb->len);
186 goto rx_error;
187 }
188
189 cisco_data = (struct cisco_packet*)(skb->data + sizeof
190 (struct hdlc_header));
191
192 switch (ntohl (cisco_data->type)) {
193 case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
194 rcu_read_lock();
195 in_dev = __in_dev_get_rcu(dev);
196 addr = 0;
197 mask = ~cpu_to_be32(0); /* is the mask correct? */
198
199 if (in_dev != NULL) {
200 struct in_ifaddr **ifap = &in_dev->ifa_list;
201
202 while (*ifap != NULL) {
203 if (strcmp(dev->name,
204 (*ifap)->ifa_label) == 0) {
205 addr = (*ifap)->ifa_local;
206 mask = (*ifap)->ifa_mask;
207 break;
208 }
209 ifap = &(*ifap)->ifa_next;
210 }
211
212 cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
213 addr, mask);
214 }
215 rcu_read_unlock();
216 dev_kfree_skb_any(skb);
217 return NET_RX_SUCCESS;
218
219 case CISCO_ADDR_REPLY:
220 printk(KERN_INFO "%s: Unexpected Cisco IP address "
221 "reply\n", dev->name);
222 goto rx_error;
223
224 case CISCO_KEEPALIVE_REQ:
225 spin_lock(&st->lock);
226 st->rxseq = ntohl(cisco_data->par1);
227 ack = ntohl(cisco_data->par2);
228 if (ack && (ack == st->txseq ||
229 /* our current REQ may be in transit */
230 ack == st->txseq - 1)) {
231 st->last_poll = jiffies;
232 if (!st->up) {
233 u32 sec, min, hrs, days;
234 sec = ntohl(cisco_data->time) / 1000;
235 min = sec / 60; sec -= min * 60;
236 hrs = min / 60; min -= hrs * 60;
237 days = hrs / 24; hrs -= days * 24;
238 printk(KERN_INFO "%s: Link up (peer "
239 "uptime %ud%uh%um%us)\n",
240 dev->name, days, hrs, min, sec);
241 netif_dormant_off(dev);
242 st->up = 1;
243 }
244 }
245 spin_unlock(&st->lock);
246
247 dev_kfree_skb_any(skb);
248 return NET_RX_SUCCESS;
249 } /* switch (keepalive type) */
250 } /* switch (protocol) */
251
252 printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name,
253 ntohs(data->protocol));
254 dev_kfree_skb_any(skb);
255 return NET_RX_DROP;
256
257rx_error:
258 dev->stats.rx_errors++; /* Mark error */
259 dev_kfree_skb_any(skb);
260 return NET_RX_DROP;
261}
262
263
264
265static void cisco_timer(unsigned long arg)
266{
267 struct net_device *dev = (struct net_device *)arg;
268 hdlc_device *hdlc = dev_to_hdlc(dev);
269 struct cisco_state *st = state(hdlc);
270
271 spin_lock(&st->lock);
272 if (st->up &&
273 time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) {
274 st->up = 0;
275 printk(KERN_INFO "%s: Link down\n", dev->name);
276 netif_dormant_on(dev);
277 }
278
279 cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq),
280 htonl(st->rxseq));
281 spin_unlock(&st->lock);
282
283 st->timer.expires = jiffies + st->settings.interval * HZ;
284 st->timer.function = cisco_timer;
285 st->timer.data = arg;
286 add_timer(&st->timer);
287}
288
289
290
291static void cisco_start(struct net_device *dev)
292{
293 hdlc_device *hdlc = dev_to_hdlc(dev);
294 struct cisco_state *st = state(hdlc);
295 unsigned long flags;
296
297 spin_lock_irqsave(&st->lock, flags);
298 st->up = st->txseq = st->rxseq = 0;
299 spin_unlock_irqrestore(&st->lock, flags);
300
301 init_timer(&st->timer);
302 st->timer.expires = jiffies + HZ; /* First poll after 1 s */
303 st->timer.function = cisco_timer;
304 st->timer.data = (unsigned long)dev;
305 add_timer(&st->timer);
306}
307
308
309
310static void cisco_stop(struct net_device *dev)
311{
312 hdlc_device *hdlc = dev_to_hdlc(dev);
313 struct cisco_state *st = state(hdlc);
314 unsigned long flags;
315
316 del_timer_sync(&st->timer);
317
318 spin_lock_irqsave(&st->lock, flags);
319 netif_dormant_on(dev);
320 st->up = st->txseq = 0;
321 spin_unlock_irqrestore(&st->lock, flags);
322}
323
324
325static struct hdlc_proto proto = {
326 .start = cisco_start,
327 .stop = cisco_stop,
328 .type_trans = cisco_type_trans,
329 .ioctl = cisco_ioctl,
330 .netif_rx = cisco_rx,
331 .module = THIS_MODULE,
332};
333
334static const struct header_ops cisco_header_ops = {
335 .create = cisco_hard_header,
336};
337
338static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
339{
340 cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
341 const size_t size = sizeof(cisco_proto);
342 cisco_proto new_settings;
343 hdlc_device *hdlc = dev_to_hdlc(dev);
344 int result;
345
346 switch (ifr->ifr_settings.type) {
347 case IF_GET_PROTO:
348 if (dev_to_hdlc(dev)->proto != &proto)
349 return -EINVAL;
350 ifr->ifr_settings.type = IF_PROTO_CISCO;
351 if (ifr->ifr_settings.size < size) {
352 ifr->ifr_settings.size = size; /* data size wanted */
353 return -ENOBUFS;
354 }
355 if (copy_to_user(cisco_s, &state(hdlc)->settings, size))
356 return -EFAULT;
357 return 0;
358
359 case IF_PROTO_CISCO:
360 if (!capable(CAP_NET_ADMIN))
361 return -EPERM;
362
363 if (dev->flags & IFF_UP)
364 return -EBUSY;
365
366 if (copy_from_user(&new_settings, cisco_s, size))
367 return -EFAULT;
368
369 if (new_settings.interval < 1 ||
370 new_settings.timeout < 2)
371 return -EINVAL;
372
373 result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
374 if (result)
375 return result;
376
377 result = attach_hdlc_protocol(dev, &proto,
378 sizeof(struct cisco_state));
379 if (result)
380 return result;
381
382 memcpy(&state(hdlc)->settings, &new_settings, size);
383 spin_lock_init(&state(hdlc)->lock);
384 dev->header_ops = &cisco_header_ops;
385 dev->type = ARPHRD_CISCO;
386 netif_dormant_on(dev);
387 return 0;
388 }
389
390 return -EINVAL;
391}
392
393
394static int __init mod_init(void)
395{
396 register_hdlc_protocol(&proto);
397 return 0;
398}
399
400
401
402static void __exit mod_exit(void)
403{
404 unregister_hdlc_protocol(&proto);
405}
406
407
408module_init(mod_init);
409module_exit(mod_exit);
410
411MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
412MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC");
413MODULE_LICENSE("GPL v2");