Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[linux-2.6] / drivers / net / wan / hdlc_cisco.c
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 #include <linux/slab.h>
24
25 #undef DEBUG_HARD_HEADER
26
27 #define CISCO_MULTICAST         0x8F    /* Cisco multicast address */
28 #define CISCO_UNICAST           0x0F    /* Cisco unicast address */
29 #define CISCO_KEEPALIVE         0x8035  /* Cisco keepalive protocol */
30 #define CISCO_SYS_INFO          0x2000  /* Cisco interface/system info */
31 #define CISCO_ADDR_REQ          0       /* Cisco address request */
32 #define CISCO_ADDR_REPLY        1       /* Cisco address reply */
33 #define CISCO_KEEPALIVE_REQ     2       /* Cisco keepalive request */
34
35
36 struct hdlc_header {
37         u8 address;
38         u8 control;
39         __be16 protocol;
40 }__attribute__ ((packed));
41
42
43 struct cisco_packet {
44         __be32 type;            /* code */
45         __be32 par1;
46         __be32 par2;
47         __be16 rel;             /* reliability */
48         __be32 time;
49 }__attribute__ ((packed));
50 #define CISCO_PACKET_LEN        18
51 #define CISCO_BIG_PACKET_LEN    20
52
53
54 struct cisco_state {
55         cisco_proto settings;
56
57         struct timer_list timer;
58         spinlock_t lock;
59         unsigned long last_poll;
60         int up;
61         int request_sent;
62         u32 txseq; /* TX sequence number */
63         u32 rxseq; /* RX sequence number */
64 };
65
66
67 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr);
68
69
70 static inline struct cisco_state* state(hdlc_device *hdlc)
71 {
72         return (struct cisco_state *)hdlc->state;
73 }
74
75
76 static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,
77                              u16 type, const void *daddr, const void *saddr,
78                              unsigned int len)
79 {
80         struct hdlc_header *data;
81 #ifdef DEBUG_HARD_HEADER
82         printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);
83 #endif
84
85         skb_push(skb, sizeof(struct hdlc_header));
86         data = (struct hdlc_header*)skb->data;
87         if (type == CISCO_KEEPALIVE)
88                 data->address = CISCO_MULTICAST;
89         else
90                 data->address = CISCO_UNICAST;
91         data->control = 0;
92         data->protocol = htons(type);
93
94         return sizeof(struct hdlc_header);
95 }
96
97
98
99 static void cisco_keepalive_send(struct net_device *dev, u32 type,
100                                  __be32 par1, __be32 par2)
101 {
102         struct sk_buff *skb;
103         struct cisco_packet *data;
104
105         skb = dev_alloc_skb(sizeof(struct hdlc_header) +
106                             sizeof(struct cisco_packet));
107         if (!skb) {
108                 printk(KERN_WARNING
109                        "%s: Memory squeeze on cisco_keepalive_send()\n",
110                        dev->name);
111                 return;
112         }
113         skb_reserve(skb, 4);
114         cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
115         data = (struct cisco_packet*)(skb->data + 4);
116
117         data->type = htonl(type);
118         data->par1 = par1;
119         data->par2 = par2;
120         data->rel = __constant_htons(0xFFFF);
121         /* we will need do_div here if 1000 % HZ != 0 */
122         data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));
123
124         skb_put(skb, sizeof(struct cisco_packet));
125         skb->priority = TC_PRIO_CONTROL;
126         skb->dev = dev;
127         skb_reset_network_header(skb);
128
129         dev_queue_xmit(skb);
130 }
131
132
133
134 static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev)
135 {
136         struct hdlc_header *data = (struct hdlc_header*)skb->data;
137
138         if (skb->len < sizeof(struct hdlc_header))
139                 return __constant_htons(ETH_P_HDLC);
140
141         if (data->address != CISCO_MULTICAST &&
142             data->address != CISCO_UNICAST)
143                 return __constant_htons(ETH_P_HDLC);
144
145         switch(data->protocol) {
146         case __constant_htons(ETH_P_IP):
147         case __constant_htons(ETH_P_IPX):
148         case __constant_htons(ETH_P_IPV6):
149                 skb_pull(skb, sizeof(struct hdlc_header));
150                 return data->protocol;
151         default:
152                 return __constant_htons(ETH_P_HDLC);
153         }
154 }
155
156
157 static int cisco_rx(struct sk_buff *skb)
158 {
159         struct net_device *dev = skb->dev;
160         hdlc_device *hdlc = dev_to_hdlc(dev);
161         struct cisco_state *st = state(hdlc);
162         struct hdlc_header *data = (struct hdlc_header*)skb->data;
163         struct cisco_packet *cisco_data;
164         struct in_device *in_dev;
165         __be32 addr, mask;
166
167         if (skb->len < sizeof(struct hdlc_header))
168                 goto rx_error;
169
170         if (data->address != CISCO_MULTICAST &&
171             data->address != CISCO_UNICAST)
172                 goto rx_error;
173
174         switch (ntohs(data->protocol)) {
175         case CISCO_SYS_INFO:
176                 /* Packet is not needed, drop it. */
177                 dev_kfree_skb_any(skb);
178                 return NET_RX_SUCCESS;
179
180         case CISCO_KEEPALIVE:
181                 if ((skb->len != sizeof(struct hdlc_header) +
182                      CISCO_PACKET_LEN) &&
183                     (skb->len != sizeof(struct hdlc_header) +
184                      CISCO_BIG_PACKET_LEN)) {
185                         printk(KERN_INFO "%s: Invalid length of Cisco control"
186                                " packet (%d bytes)\n", dev->name, skb->len);
187                         goto rx_error;
188                 }
189
190                 cisco_data = (struct cisco_packet*)(skb->data + sizeof
191                                                     (struct hdlc_header));
192
193                 switch(ntohl (cisco_data->type)) {
194                 case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
195                         in_dev = dev->ip_ptr;
196                         addr = 0;
197                         mask = __constant_htonl(~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                         dev_kfree_skb_any(skb);
216                         return NET_RX_SUCCESS;
217
218                 case CISCO_ADDR_REPLY:
219                         printk(KERN_INFO "%s: Unexpected Cisco IP address "
220                                "reply\n", dev->name);
221                         goto rx_error;
222
223                 case CISCO_KEEPALIVE_REQ:
224                         spin_lock(&st->lock);
225                         st->rxseq = ntohl(cisco_data->par1);
226                         if (st->request_sent &&
227                             ntohl(cisco_data->par2) == st->txseq) {
228                                 st->last_poll = jiffies;
229                                 if (!st->up) {
230                                         u32 sec, min, hrs, days;
231                                         sec = ntohl(cisco_data->time) / 1000;
232                                         min = sec / 60; sec -= min * 60;
233                                         hrs = min / 60; min -= hrs * 60;
234                                         days = hrs / 24; hrs -= days * 24;
235                                         printk(KERN_INFO "%s: Link up (peer "
236                                                "uptime %ud%uh%um%us)\n",
237                                                dev->name, days, hrs, min, sec);
238                                         netif_dormant_off(dev);
239                                         st->up = 1;
240                                 }
241                         }
242                         spin_unlock(&st->lock);
243
244                         dev_kfree_skb_any(skb);
245                         return NET_RX_SUCCESS;
246                 } /* switch(keepalive type) */
247         } /* switch(protocol) */
248
249         printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name,
250                ntohs(data->protocol));
251         dev_kfree_skb_any(skb);
252         return NET_RX_DROP;
253
254 rx_error:
255         dev->stats.rx_errors++; /* Mark error */
256         dev_kfree_skb_any(skb);
257         return NET_RX_DROP;
258 }
259
260
261
262 static void cisco_timer(unsigned long arg)
263 {
264         struct net_device *dev = (struct net_device *)arg;
265         hdlc_device *hdlc = dev_to_hdlc(dev);
266         struct cisco_state *st = state(hdlc);
267
268         spin_lock(&st->lock);
269         if (st->up &&
270             time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) {
271                 st->up = 0;
272                 printk(KERN_INFO "%s: Link down\n", dev->name);
273                 netif_dormant_on(dev);
274         }
275
276         cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq),
277                              htonl(st->rxseq));
278         st->request_sent = 1;
279         spin_unlock(&st->lock);
280
281         st->timer.expires = jiffies + st->settings.interval * HZ;
282         st->timer.function = cisco_timer;
283         st->timer.data = arg;
284         add_timer(&st->timer);
285 }
286
287
288
289 static void cisco_start(struct net_device *dev)
290 {
291         hdlc_device *hdlc = dev_to_hdlc(dev);
292         struct cisco_state *st = state(hdlc);
293         unsigned long flags;
294
295         spin_lock_irqsave(&st->lock, flags);
296         st->up = 0;
297         st->request_sent = 0;
298         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
310 static 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 = 0;
321         st->request_sent = 0;
322         spin_unlock_irqrestore(&st->lock, flags);
323 }
324
325
326 static struct hdlc_proto proto = {
327         .start          = cisco_start,
328         .stop           = cisco_stop,
329         .type_trans     = cisco_type_trans,
330         .ioctl          = cisco_ioctl,
331         .netif_rx       = cisco_rx,
332         .module         = THIS_MODULE,
333 };
334
335 static const struct header_ops cisco_header_ops = {
336         .create = cisco_hard_header,
337 };
338
339 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
340 {
341         cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
342         const size_t size = sizeof(cisco_proto);
343         cisco_proto new_settings;
344         hdlc_device *hdlc = dev_to_hdlc(dev);
345         int result;
346
347         switch (ifr->ifr_settings.type) {
348         case IF_GET_PROTO:
349                 if (dev_to_hdlc(dev)->proto != &proto)
350                         return -EINVAL;
351                 ifr->ifr_settings.type = IF_PROTO_CISCO;
352                 if (ifr->ifr_settings.size < size) {
353                         ifr->ifr_settings.size = size; /* data size wanted */
354                         return -ENOBUFS;
355                 }
356                 if (copy_to_user(cisco_s, &state(hdlc)->settings, size))
357                         return -EFAULT;
358                 return 0;
359
360         case IF_PROTO_CISCO:
361                 if (!capable(CAP_NET_ADMIN))
362                         return -EPERM;
363
364                 if (dev->flags & IFF_UP)
365                         return -EBUSY;
366
367                 if (copy_from_user(&new_settings, cisco_s, size))
368                         return -EFAULT;
369
370                 if (new_settings.interval < 1 ||
371                     new_settings.timeout < 2)
372                         return -EINVAL;
373
374                 result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
375                 if (result)
376                         return result;
377
378                 result = attach_hdlc_protocol(dev, &proto,
379                                               sizeof(struct cisco_state));
380                 if (result)
381                         return result;
382
383                 memcpy(&state(hdlc)->settings, &new_settings, size);
384                 spin_lock_init(&state(hdlc)->lock);
385                 dev->hard_start_xmit = hdlc->xmit;
386                 dev->header_ops = &cisco_header_ops;
387                 dev->type = ARPHRD_CISCO;
388                 netif_dormant_on(dev);
389                 return 0;
390         }
391
392         return -EINVAL;
393 }
394
395
396 static int __init mod_init(void)
397 {
398         register_hdlc_protocol(&proto);
399         return 0;
400 }
401
402
403
404 static void __exit mod_exit(void)
405 {
406         unregister_hdlc_protocol(&proto);
407 }
408
409
410 module_init(mod_init);
411 module_exit(mod_exit);
412
413 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
414 MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC");
415 MODULE_LICENSE("GPL v2");