ipv4: ip_ptr cleanups
[linux-2.6.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         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
65 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr);
66
67
68 static inline struct cisco_state* state(hdlc_device *hdlc)
69 {
70         return (struct cisco_state *)hdlc->state;
71 }
72
73
74 static 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
97 static 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
132 static __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
155 static 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
257 rx_error:
258         dev->stats.rx_errors++; /* Mark error */
259         dev_kfree_skb_any(skb);
260         return NET_RX_DROP;
261 }
262
263
264
265 static 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
291 static 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
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 = st->txseq = 0;
321         spin_unlock_irqrestore(&st->lock, flags);
322 }
323
324
325 static 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
334 static const struct header_ops cisco_header_ops = {
335         .create = cisco_hard_header,
336 };
337
338 static 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
394 static int __init mod_init(void)
395 {
396         register_hdlc_protocol(&proto);
397         return 0;
398 }
399
400
401
402 static void __exit mod_exit(void)
403 {
404         unregister_hdlc_protocol(&proto);
405 }
406
407
408 module_init(mod_init);
409 module_exit(mod_exit);
410
411 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
412 MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC");
413 MODULE_LICENSE("GPL v2");