320039d329c7d17a5473d17d12e77e244a94a79b
[muen/linux.git] / 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
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
35 struct hdlc_header {
36         u8 address;
37         u8 control;
38         __be16 protocol;
39 }__packed;
40
41
42 struct 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
53 struct cisco_state {
54         cisco_proto settings;
55
56         struct timer_list timer;
57         struct net_device *dev;
58         spinlock_t lock;
59         unsigned long last_poll;
60         int up;
61         u32 txseq; /* TX sequence number, 0 = none */
62         u32 rxseq; /* RX sequence number */
63 };
64
65
66 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr);
67
68
69 static inline struct cisco_state* state(hdlc_device *hdlc)
70 {
71         return (struct cisco_state *)hdlc->state;
72 }
73
74
75 static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,
76                              u16 type, const void *daddr, const void *saddr,
77                              unsigned int len)
78 {
79         struct hdlc_header *data;
80 #ifdef DEBUG_HARD_HEADER
81         printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);
82 #endif
83
84         skb_push(skb, sizeof(struct hdlc_header));
85         data = (struct hdlc_header*)skb->data;
86         if (type == CISCO_KEEPALIVE)
87                 data->address = CISCO_MULTICAST;
88         else
89                 data->address = CISCO_UNICAST;
90         data->control = 0;
91         data->protocol = htons(type);
92
93         return sizeof(struct hdlc_header);
94 }
95
96
97
98 static void cisco_keepalive_send(struct net_device *dev, u32 type,
99                                  __be32 par1, __be32 par2)
100 {
101         struct sk_buff *skb;
102         struct cisco_packet *data;
103
104         skb = dev_alloc_skb(sizeof(struct hdlc_header) +
105                             sizeof(struct cisco_packet));
106         if (!skb) {
107                 netdev_warn(dev, "Memory squeeze on cisco_keepalive_send()\n");
108                 return;
109         }
110         skb_reserve(skb, 4);
111         cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
112         data = (struct cisco_packet*)(skb->data + 4);
113
114         data->type = htonl(type);
115         data->par1 = par1;
116         data->par2 = par2;
117         data->rel = cpu_to_be16(0xFFFF);
118         /* we will need do_div here if 1000 % HZ != 0 */
119         data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));
120
121         skb_put(skb, sizeof(struct cisco_packet));
122         skb->priority = TC_PRIO_CONTROL;
123         skb->dev = dev;
124         skb_reset_network_header(skb);
125
126         dev_queue_xmit(skb);
127 }
128
129
130
131 static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev)
132 {
133         struct hdlc_header *data = (struct hdlc_header*)skb->data;
134
135         if (skb->len < sizeof(struct hdlc_header))
136                 return cpu_to_be16(ETH_P_HDLC);
137
138         if (data->address != CISCO_MULTICAST &&
139             data->address != CISCO_UNICAST)
140                 return cpu_to_be16(ETH_P_HDLC);
141
142         switch (data->protocol) {
143         case cpu_to_be16(ETH_P_IP):
144         case cpu_to_be16(ETH_P_IPX):
145         case cpu_to_be16(ETH_P_IPV6):
146                 skb_pull(skb, sizeof(struct hdlc_header));
147                 return data->protocol;
148         default:
149                 return cpu_to_be16(ETH_P_HDLC);
150         }
151 }
152
153
154 static int cisco_rx(struct sk_buff *skb)
155 {
156         struct net_device *dev = skb->dev;
157         hdlc_device *hdlc = dev_to_hdlc(dev);
158         struct cisco_state *st = state(hdlc);
159         struct hdlc_header *data = (struct hdlc_header*)skb->data;
160         struct cisco_packet *cisco_data;
161         struct in_device *in_dev;
162         __be32 addr, mask;
163         u32 ack;
164
165         if (skb->len < sizeof(struct hdlc_header))
166                 goto rx_error;
167
168         if (data->address != CISCO_MULTICAST &&
169             data->address != CISCO_UNICAST)
170                 goto rx_error;
171
172         switch (ntohs(data->protocol)) {
173         case CISCO_SYS_INFO:
174                 /* Packet is not needed, drop it. */
175                 dev_kfree_skb_any(skb);
176                 return NET_RX_SUCCESS;
177
178         case CISCO_KEEPALIVE:
179                 if ((skb->len != sizeof(struct hdlc_header) +
180                      CISCO_PACKET_LEN) &&
181                     (skb->len != sizeof(struct hdlc_header) +
182                      CISCO_BIG_PACKET_LEN)) {
183                         netdev_info(dev, "Invalid length of Cisco control packet (%d bytes)\n",
184                                     skb->len);
185                         goto rx_error;
186                 }
187
188                 cisco_data = (struct cisco_packet*)(skb->data + sizeof
189                                                     (struct hdlc_header));
190
191                 switch (ntohl (cisco_data->type)) {
192                 case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
193                         rcu_read_lock();
194                         in_dev = __in_dev_get_rcu(dev);
195                         addr = 0;
196                         mask = ~cpu_to_be32(0); /* is the mask correct? */
197
198                         if (in_dev != NULL) {
199                                 struct in_ifaddr **ifap = &in_dev->ifa_list;
200
201                                 while (*ifap != NULL) {
202                                         if (strcmp(dev->name,
203                                                    (*ifap)->ifa_label) == 0) {
204                                                 addr = (*ifap)->ifa_local;
205                                                 mask = (*ifap)->ifa_mask;
206                                                 break;
207                                         }
208                                         ifap = &(*ifap)->ifa_next;
209                                 }
210
211                                 cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
212                                                      addr, mask);
213                         }
214                         rcu_read_unlock();
215                         dev_kfree_skb_any(skb);
216                         return NET_RX_SUCCESS;
217
218                 case CISCO_ADDR_REPLY:
219                         netdev_info(dev, "Unexpected Cisco IP address reply\n");
220                         goto rx_error;
221
222                 case CISCO_KEEPALIVE_REQ:
223                         spin_lock(&st->lock);
224                         st->rxseq = ntohl(cisco_data->par1);
225                         ack = ntohl(cisco_data->par2);
226                         if (ack && (ack == st->txseq ||
227                                     /* our current REQ may be in transit */
228                                     ack == st->txseq - 1)) {
229                                 st->last_poll = jiffies;
230                                 if (!st->up) {
231                                         u32 sec, min, hrs, days;
232                                         sec = ntohl(cisco_data->time) / 1000;
233                                         min = sec / 60; sec -= min * 60;
234                                         hrs = min / 60; min -= hrs * 60;
235                                         days = hrs / 24; hrs -= days * 24;
236                                         netdev_info(dev, "Link up (peer uptime %ud%uh%um%us)\n",
237                                                     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         netdev_info(dev, "Unsupported protocol %x\n", ntohs(data->protocol));
250         dev_kfree_skb_any(skb);
251         return NET_RX_DROP;
252
253 rx_error:
254         dev->stats.rx_errors++; /* Mark error */
255         dev_kfree_skb_any(skb);
256         return NET_RX_DROP;
257 }
258
259
260
261 static void cisco_timer(struct timer_list *t)
262 {
263         struct cisco_state *st = from_timer(st, t, timer);
264         struct net_device *dev = st->dev;
265
266         spin_lock(&st->lock);
267         if (st->up &&
268             time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) {
269                 st->up = 0;
270                 netdev_info(dev, "Link down\n");
271                 netif_dormant_on(dev);
272         }
273
274         cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq),
275                              htonl(st->rxseq));
276         spin_unlock(&st->lock);
277
278         st->timer.expires = jiffies + st->settings.interval * HZ;
279         add_timer(&st->timer);
280 }
281
282
283
284 static void cisco_start(struct net_device *dev)
285 {
286         hdlc_device *hdlc = dev_to_hdlc(dev);
287         struct cisco_state *st = state(hdlc);
288         unsigned long flags;
289
290         spin_lock_irqsave(&st->lock, flags);
291         st->up = st->txseq = st->rxseq = 0;
292         spin_unlock_irqrestore(&st->lock, flags);
293
294         st->dev = dev;
295         timer_setup(&st->timer, cisco_timer, 0);
296         st->timer.expires = jiffies + HZ; /* First poll after 1 s */
297         add_timer(&st->timer);
298 }
299
300
301
302 static void cisco_stop(struct net_device *dev)
303 {
304         hdlc_device *hdlc = dev_to_hdlc(dev);
305         struct cisco_state *st = state(hdlc);
306         unsigned long flags;
307
308         del_timer_sync(&st->timer);
309
310         spin_lock_irqsave(&st->lock, flags);
311         netif_dormant_on(dev);
312         st->up = st->txseq = 0;
313         spin_unlock_irqrestore(&st->lock, flags);
314 }
315
316
317 static struct hdlc_proto proto = {
318         .start          = cisco_start,
319         .stop           = cisco_stop,
320         .type_trans     = cisco_type_trans,
321         .ioctl          = cisco_ioctl,
322         .netif_rx       = cisco_rx,
323         .module         = THIS_MODULE,
324 };
325
326 static const struct header_ops cisco_header_ops = {
327         .create = cisco_hard_header,
328 };
329
330 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
331 {
332         cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
333         const size_t size = sizeof(cisco_proto);
334         cisco_proto new_settings;
335         hdlc_device *hdlc = dev_to_hdlc(dev);
336         int result;
337
338         switch (ifr->ifr_settings.type) {
339         case IF_GET_PROTO:
340                 if (dev_to_hdlc(dev)->proto != &proto)
341                         return -EINVAL;
342                 ifr->ifr_settings.type = IF_PROTO_CISCO;
343                 if (ifr->ifr_settings.size < size) {
344                         ifr->ifr_settings.size = size; /* data size wanted */
345                         return -ENOBUFS;
346                 }
347                 if (copy_to_user(cisco_s, &state(hdlc)->settings, size))
348                         return -EFAULT;
349                 return 0;
350
351         case IF_PROTO_CISCO:
352                 if (!capable(CAP_NET_ADMIN))
353                         return -EPERM;
354
355                 if (dev->flags & IFF_UP)
356                         return -EBUSY;
357
358                 if (copy_from_user(&new_settings, cisco_s, size))
359                         return -EFAULT;
360
361                 if (new_settings.interval < 1 ||
362                     new_settings.timeout < 2)
363                         return -EINVAL;
364
365                 result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
366                 if (result)
367                         return result;
368
369                 result = attach_hdlc_protocol(dev, &proto,
370                                               sizeof(struct cisco_state));
371                 if (result)
372                         return result;
373
374                 memcpy(&state(hdlc)->settings, &new_settings, size);
375                 spin_lock_init(&state(hdlc)->lock);
376                 dev->header_ops = &cisco_header_ops;
377                 dev->type = ARPHRD_CISCO;
378                 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
379                 netif_dormant_on(dev);
380                 return 0;
381         }
382
383         return -EINVAL;
384 }
385
386
387 static int __init mod_init(void)
388 {
389         register_hdlc_protocol(&proto);
390         return 0;
391 }
392
393
394
395 static void __exit mod_exit(void)
396 {
397         unregister_hdlc_protocol(&proto);
398 }
399
400
401 module_init(mod_init);
402 module_exit(mod_exit);
403
404 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
405 MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC");
406 MODULE_LICENSE("GPL v2");