Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy...
[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/module.h>
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/poll.h>
16 #include <linux/errno.h>
17 #include <linux/if_arp.h>
18 #include <linux/init.h>
19 #include <linux/skbuff.h>
20 #include <linux/pkt_sched.h>
21 #include <linux/inetdevice.h>
22 #include <linux/lapb.h>
23 #include <linux/rtnetlink.h>
24 #include <linux/hdlc.h>
25
26 #undef DEBUG_HARD_HEADER
27
28 #define CISCO_MULTICAST         0x8F    /* Cisco multicast address */
29 #define CISCO_UNICAST           0x0F    /* Cisco unicast address */
30 #define CISCO_KEEPALIVE         0x8035  /* Cisco keepalive protocol */
31 #define CISCO_SYS_INFO          0x2000  /* Cisco interface/system info */
32 #define CISCO_ADDR_REQ          0       /* Cisco address request */
33 #define CISCO_ADDR_REPLY        1       /* Cisco address reply */
34 #define CISCO_KEEPALIVE_REQ     2       /* Cisco keepalive request */
35
36
37 struct hdlc_header {
38         u8 address;
39         u8 control;
40         __be16 protocol;
41 }__attribute__ ((packed));
42
43
44 struct cisco_packet {
45         __be32 type;            /* code */
46         __be32 par1;
47         __be32 par2;
48         __be16 rel;             /* reliability */
49         __be32 time;
50 }__attribute__ ((packed));
51 #define CISCO_PACKET_LEN        18
52 #define CISCO_BIG_PACKET_LEN    20
53
54
55 struct cisco_state {
56         cisco_proto settings;
57
58         struct timer_list timer;
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 hdlc_header *data = (struct hdlc_header*)skb->data;
162         struct cisco_packet *cisco_data;
163         struct in_device *in_dev;
164         __be32 addr, mask;
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                         in_dev = dev->ip_ptr;
195                         addr = 0;
196                         mask = __constant_htonl(~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                         dev_kfree_skb_any(skb);
215                         return NET_RX_SUCCESS;
216
217                 case CISCO_ADDR_REPLY:
218                         printk(KERN_INFO "%s: Unexpected Cisco IP address "
219                                "reply\n", dev->name);
220                         goto rx_error;
221
222                 case CISCO_KEEPALIVE_REQ:
223                         state(hdlc)->rxseq = ntohl(cisco_data->par1);
224                         if (state(hdlc)->request_sent &&
225                             ntohl(cisco_data->par2) == state(hdlc)->txseq) {
226                                 state(hdlc)->last_poll = jiffies;
227                                 if (!state(hdlc)->up) {
228                                         u32 sec, min, hrs, days;
229                                         sec = ntohl(cisco_data->time) / 1000;
230                                         min = sec / 60; sec -= min * 60;
231                                         hrs = min / 60; min -= hrs * 60;
232                                         days = hrs / 24; hrs -= days * 24;
233                                         printk(KERN_INFO "%s: Link up (peer "
234                                                "uptime %ud%uh%um%us)\n",
235                                                dev->name, days, hrs,
236                                                min, sec);
237                                         netif_dormant_off(dev);
238                                         state(hdlc)->up = 1;
239                                 }
240                         }
241
242                         dev_kfree_skb_any(skb);
243                         return NET_RX_SUCCESS;
244                 } /* switch(keepalive type) */
245         } /* switch(protocol) */
246
247         printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name,
248                ntohs(data->protocol));
249         dev_kfree_skb_any(skb);
250         return NET_RX_DROP;
251
252  rx_error:
253         dev_to_hdlc(dev)->stats.rx_errors++; /* Mark error */
254         dev_kfree_skb_any(skb);
255         return NET_RX_DROP;
256 }
257
258
259
260 static void cisco_timer(unsigned long arg)
261 {
262         struct net_device *dev = (struct net_device *)arg;
263         hdlc_device *hdlc = dev_to_hdlc(dev);
264
265         if (state(hdlc)->up &&
266             time_after(jiffies, state(hdlc)->last_poll +
267                        state(hdlc)->settings.timeout * HZ)) {
268                 state(hdlc)->up = 0;
269                 printk(KERN_INFO "%s: Link down\n", dev->name);
270                 netif_dormant_on(dev);
271         }
272
273         cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ,
274                              htonl(++state(hdlc)->txseq),
275                              htonl(state(hdlc)->rxseq));
276         state(hdlc)->request_sent = 1;
277         state(hdlc)->timer.expires = jiffies +
278                 state(hdlc)->settings.interval * HZ;
279         state(hdlc)->timer.function = cisco_timer;
280         state(hdlc)->timer.data = arg;
281         add_timer(&state(hdlc)->timer);
282 }
283
284
285
286 static void cisco_start(struct net_device *dev)
287 {
288         hdlc_device *hdlc = dev_to_hdlc(dev);
289         state(hdlc)->up = 0;
290         state(hdlc)->request_sent = 0;
291         state(hdlc)->txseq = state(hdlc)->rxseq = 0;
292
293         init_timer(&state(hdlc)->timer);
294         state(hdlc)->timer.expires = jiffies + HZ; /*First poll after 1s*/
295         state(hdlc)->timer.function = cisco_timer;
296         state(hdlc)->timer.data = (unsigned long)dev;
297         add_timer(&state(hdlc)->timer);
298 }
299
300
301
302 static void cisco_stop(struct net_device *dev)
303 {
304         hdlc_device *hdlc = dev_to_hdlc(dev);
305         del_timer_sync(&state(hdlc)->timer);
306         netif_dormant_on(dev);
307         state(hdlc)->up = 0;
308         state(hdlc)->request_sent = 0;
309 }
310
311
312 static struct hdlc_proto proto = {
313         .start          = cisco_start,
314         .stop           = cisco_stop,
315         .type_trans     = cisco_type_trans,
316         .ioctl          = cisco_ioctl,
317         .netif_rx       = cisco_rx,
318         .module         = THIS_MODULE,
319 };
320
321 static const struct header_ops cisco_header_ops = {
322         .create = cisco_hard_header,
323 };
324  
325 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
326 {
327         cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
328         const size_t size = sizeof(cisco_proto);
329         cisco_proto new_settings;
330         hdlc_device *hdlc = dev_to_hdlc(dev);
331         int result;
332
333         switch (ifr->ifr_settings.type) {
334         case IF_GET_PROTO:
335                 if (dev_to_hdlc(dev)->proto != &proto)
336                         return -EINVAL;
337                 ifr->ifr_settings.type = IF_PROTO_CISCO;
338                 if (ifr->ifr_settings.size < size) {
339                         ifr->ifr_settings.size = size; /* data size wanted */
340                         return -ENOBUFS;
341                 }
342                 if (copy_to_user(cisco_s, &state(hdlc)->settings, size))
343                         return -EFAULT;
344                 return 0;
345
346         case IF_PROTO_CISCO:
347                 if(!capable(CAP_NET_ADMIN))
348                         return -EPERM;
349
350                 if(dev->flags & IFF_UP)
351                         return -EBUSY;
352
353                 if (copy_from_user(&new_settings, cisco_s, size))
354                         return -EFAULT;
355
356                 if (new_settings.interval < 1 ||
357                     new_settings.timeout < 2)
358                         return -EINVAL;
359
360                 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
361                 if (result)
362                         return result;
363
364                 result = attach_hdlc_protocol(dev, &proto,
365                                               sizeof(struct cisco_state));
366                 if (result)
367                         return result;
368
369                 memcpy(&state(hdlc)->settings, &new_settings, size);
370                 dev->hard_start_xmit = hdlc->xmit;
371                 dev->header_ops = &cisco_header_ops;
372                 dev->type = ARPHRD_CISCO;
373                 netif_dormant_on(dev);
374                 return 0;
375         }
376
377         return -EINVAL;
378 }
379
380
381 static int __init mod_init(void)
382 {
383         register_hdlc_protocol(&proto);
384         return 0;
385 }
386
387
388
389 static void __exit mod_exit(void)
390 {
391         unregister_hdlc_protocol(&proto);
392 }
393
394
395 module_init(mod_init);
396 module_exit(mod_exit);
397
398 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
399 MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC");
400 MODULE_LICENSE("GPL v2");