Merge branch 'linux-next' of git://git.infradead.org/ubi-2.6
[linux-2.6] / drivers / net / wan / hdlc_ppp.c
1 /*
2  * Generic HDLC support routines for Linux
3  * Point-to-point protocol support
4  *
5  * Copyright (C) 1999 - 2008 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/skbuff.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
24
25 #define DEBUG_CP                0 /* also bytes# to dump */
26 #define DEBUG_STATE             0
27 #define DEBUG_HARD_HEADER       0
28
29 #define HDLC_ADDR_ALLSTATIONS   0xFF
30 #define HDLC_CTRL_UI            0x03
31
32 #define PID_LCP                 0xC021
33 #define PID_IP                  0x0021
34 #define PID_IPCP                0x8021
35 #define PID_IPV6                0x0057
36 #define PID_IPV6CP              0x8057
37
38 enum {IDX_LCP = 0, IDX_IPCP, IDX_IPV6CP, IDX_COUNT};
39 enum {CP_CONF_REQ = 1, CP_CONF_ACK, CP_CONF_NAK, CP_CONF_REJ, CP_TERM_REQ,
40       CP_TERM_ACK, CP_CODE_REJ, LCP_PROTO_REJ, LCP_ECHO_REQ, LCP_ECHO_REPLY,
41       LCP_DISC_REQ, CP_CODES};
42 #if DEBUG_CP
43 static const char *const code_names[CP_CODES] = {
44         "0", "ConfReq", "ConfAck", "ConfNak", "ConfRej", "TermReq",
45         "TermAck", "CodeRej", "ProtoRej", "EchoReq", "EchoReply", "Discard"
46 };
47 static char debug_buffer[64 + 3 * DEBUG_CP];
48 #endif
49
50 enum {LCP_OPTION_MRU = 1, LCP_OPTION_ACCM, LCP_OPTION_MAGIC = 5};
51
52 struct hdlc_header {
53         u8 address;
54         u8 control;
55         __be16 protocol;
56 };
57
58 struct cp_header {
59         u8 code;
60         u8 id;
61         __be16 len;
62 };
63
64
65 struct proto {
66         struct net_device *dev;
67         struct timer_list timer;
68         unsigned long timeout;
69         u16 pid;                /* protocol ID */
70         u8 state;
71         u8 cr_id;               /* ID of last Configuration-Request */
72         u8 restart_counter;
73 };
74
75 struct ppp {
76         struct proto protos[IDX_COUNT];
77         spinlock_t lock;
78         unsigned long last_pong;
79         unsigned int req_timeout, cr_retries, term_retries;
80         unsigned int keepalive_interval, keepalive_timeout;
81         u8 seq;                 /* local sequence number for requests */
82         u8 echo_id;             /* ID of last Echo-Request (LCP) */
83 };
84
85 enum {CLOSED = 0, STOPPED, STOPPING, REQ_SENT, ACK_RECV, ACK_SENT, OPENED,
86       STATES, STATE_MASK = 0xF};
87 enum {START = 0, STOP, TO_GOOD, TO_BAD, RCR_GOOD, RCR_BAD, RCA, RCN, RTR, RTA,
88       RUC, RXJ_GOOD, RXJ_BAD, EVENTS};
89 enum {INV = 0x10, IRC = 0x20, ZRC = 0x40, SCR = 0x80, SCA = 0x100,
90       SCN = 0x200, STR = 0x400, STA = 0x800, SCJ = 0x1000};
91
92 #if DEBUG_STATE
93 static const char *const state_names[STATES] = {
94         "Closed", "Stopped", "Stopping", "ReqSent", "AckRecv", "AckSent",
95         "Opened"
96 };
97 static const char *const event_names[EVENTS] = {
98         "Start", "Stop", "TO+", "TO-", "RCR+", "RCR-", "RCA", "RCN",
99         "RTR", "RTA", "RUC", "RXJ+", "RXJ-"
100 };
101 #endif
102
103 static struct sk_buff_head tx_queue; /* used when holding the spin lock */
104
105 static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr);
106
107 static inline struct ppp* get_ppp(struct net_device *dev)
108 {
109         return (struct ppp *)dev_to_hdlc(dev)->state;
110 }
111
112 static inline struct proto* get_proto(struct net_device *dev, u16 pid)
113 {
114         struct ppp *ppp = get_ppp(dev);
115
116         switch (pid) {
117         case PID_LCP:
118                 return &ppp->protos[IDX_LCP];
119         case PID_IPCP:
120                 return &ppp->protos[IDX_IPCP];
121         case PID_IPV6CP:
122                 return &ppp->protos[IDX_IPV6CP];
123         default:
124                 return NULL;
125         }
126 }
127
128 static inline const char* proto_name(u16 pid)
129 {
130         switch (pid) {
131         case PID_LCP:
132                 return "LCP";
133         case PID_IPCP:
134                 return "IPCP";
135         case PID_IPV6CP:
136                 return "IPV6CP";
137         default:
138                 return NULL;
139         }
140 }
141
142 static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)
143 {
144         struct hdlc_header *data = (struct hdlc_header*)skb->data;
145
146         if (skb->len < sizeof(struct hdlc_header))
147                 return htons(ETH_P_HDLC);
148         if (data->address != HDLC_ADDR_ALLSTATIONS ||
149             data->control != HDLC_CTRL_UI)
150                 return htons(ETH_P_HDLC);
151
152         switch (data->protocol) {
153         case cpu_to_be16(PID_IP):
154                 skb_pull(skb, sizeof(struct hdlc_header));
155                 return htons(ETH_P_IP);
156
157         case cpu_to_be16(PID_IPV6):
158                 skb_pull(skb, sizeof(struct hdlc_header));
159                 return htons(ETH_P_IPV6);
160
161         default:
162                 return htons(ETH_P_HDLC);
163         }
164 }
165
166
167 static int ppp_hard_header(struct sk_buff *skb, struct net_device *dev,
168                            u16 type, const void *daddr, const void *saddr,
169                            unsigned int len)
170 {
171         struct hdlc_header *data;
172 #if DEBUG_HARD_HEADER
173         printk(KERN_DEBUG "%s: ppp_hard_header() called\n", dev->name);
174 #endif
175
176         skb_push(skb, sizeof(struct hdlc_header));
177         data = (struct hdlc_header*)skb->data;
178
179         data->address = HDLC_ADDR_ALLSTATIONS;
180         data->control = HDLC_CTRL_UI;
181         switch (type) {
182         case ETH_P_IP:
183                 data->protocol = htons(PID_IP);
184                 break;
185         case ETH_P_IPV6:
186                 data->protocol = htons(PID_IPV6);
187                 break;
188         case PID_LCP:
189         case PID_IPCP:
190         case PID_IPV6CP:
191                 data->protocol = htons(type);
192                 break;
193         default:                /* unknown protocol */
194                 data->protocol = 0;
195         }
196         return sizeof(struct hdlc_header);
197 }
198
199
200 static void ppp_tx_flush(void)
201 {
202         struct sk_buff *skb;
203         while ((skb = skb_dequeue(&tx_queue)) != NULL)
204                 dev_queue_xmit(skb);
205 }
206
207 static void ppp_tx_cp(struct net_device *dev, u16 pid, u8 code,
208                       u8 id, unsigned int len, const void *data)
209 {
210         struct sk_buff *skb;
211         struct cp_header *cp;
212         unsigned int magic_len = 0;
213         static u32 magic;
214
215 #if DEBUG_CP
216         int i;
217         char *ptr;
218 #endif
219
220         if (pid == PID_LCP && (code == LCP_ECHO_REQ || code == LCP_ECHO_REPLY))
221                 magic_len = sizeof(magic);
222
223         skb = dev_alloc_skb(sizeof(struct hdlc_header) +
224                             sizeof(struct cp_header) + magic_len + len);
225         if (!skb) {
226                 printk(KERN_WARNING "%s: out of memory in ppp_tx_cp()\n",
227                        dev->name);
228                 return;
229         }
230         skb_reserve(skb, sizeof(struct hdlc_header));
231
232         cp = (struct cp_header *)skb_put(skb, sizeof(struct cp_header));
233         cp->code = code;
234         cp->id = id;
235         cp->len = htons(sizeof(struct cp_header) + magic_len + len);
236
237         if (magic_len)
238                 memcpy(skb_put(skb, magic_len), &magic, magic_len);
239         if (len)
240                 memcpy(skb_put(skb, len), data, len);
241
242 #if DEBUG_CP
243         BUG_ON(code >= CP_CODES);
244         ptr = debug_buffer;
245         *ptr = '\x0';
246         for (i = 0; i < min_t(unsigned int, magic_len + len, DEBUG_CP); i++) {
247                 sprintf(ptr, " %02X", skb->data[sizeof(struct cp_header) + i]);
248                 ptr += strlen(ptr);
249         }
250         printk(KERN_DEBUG "%s: TX %s [%s id 0x%X]%s\n", dev->name,
251                proto_name(pid), code_names[code], id, debug_buffer);
252 #endif
253
254         ppp_hard_header(skb, dev, pid, NULL, NULL, 0);
255
256         skb->priority = TC_PRIO_CONTROL;
257         skb->dev = dev;
258         skb_reset_network_header(skb);
259         skb_queue_tail(&tx_queue, skb);
260 }
261
262
263 /* State transition table (compare STD-51)
264    Events                                   Actions
265    TO+  = Timeout with counter > 0          irc = Initialize-Restart-Count
266    TO-  = Timeout with counter expired      zrc = Zero-Restart-Count
267
268    RCR+ = Receive-Configure-Request (Good)  scr = Send-Configure-Request
269    RCR- = Receive-Configure-Request (Bad)
270    RCA  = Receive-Configure-Ack             sca = Send-Configure-Ack
271    RCN  = Receive-Configure-Nak/Rej         scn = Send-Configure-Nak/Rej
272
273    RTR  = Receive-Terminate-Request         str = Send-Terminate-Request
274    RTA  = Receive-Terminate-Ack             sta = Send-Terminate-Ack
275
276    RUC  = Receive-Unknown-Code              scj = Send-Code-Reject
277    RXJ+ = Receive-Code-Reject (permitted)
278        or Receive-Protocol-Reject
279    RXJ- = Receive-Code-Reject (catastrophic)
280        or Receive-Protocol-Reject
281 */
282 static int cp_table[EVENTS][STATES] = {
283         /* CLOSED     STOPPED STOPPING REQ_SENT ACK_RECV ACK_SENT OPENED
284              0           1         2       3       4      5          6    */
285         {IRC|SCR|3,     INV     , INV ,   INV   , INV ,  INV    ,   INV   }, /* START */
286         {   INV   ,      0      ,  0  ,    0    ,  0  ,   0     ,    0    }, /* STOP */
287         {   INV   ,     INV     ,STR|2,  SCR|3  ,SCR|3,  SCR|5  ,   INV   }, /* TO+ */
288         {   INV   ,     INV     ,  1  ,    1    ,  1  ,    1    ,   INV   }, /* TO- */
289         {  STA|0  ,IRC|SCR|SCA|5,  2  ,  SCA|5  ,SCA|6,  SCA|5  ,SCR|SCA|5}, /* RCR+ */
290         {  STA|0  ,IRC|SCR|SCN|3,  2  ,  SCN|3  ,SCN|4,  SCN|3  ,SCR|SCN|3}, /* RCR- */
291         {  STA|0  ,    STA|1    ,  2  ,  IRC|4  ,SCR|3,    6    , SCR|3   }, /* RCA */
292         {  STA|0  ,    STA|1    ,  2  ,IRC|SCR|3,SCR|3,IRC|SCR|5, SCR|3   }, /* RCN */
293         {  STA|0  ,    STA|1    ,STA|2,  STA|3  ,STA|3,  STA|3  ,ZRC|STA|2}, /* RTR */
294         {    0    ,      1      ,  1  ,    3    ,  3  ,    5    ,  SCR|3  }, /* RTA */
295         {  SCJ|0  ,    SCJ|1    ,SCJ|2,  SCJ|3  ,SCJ|4,  SCJ|5  ,  SCJ|6  }, /* RUC */
296         {    0    ,      1      ,  2  ,    3    ,  3  ,    5    ,    6    }, /* RXJ+ */
297         {    0    ,      1      ,  1  ,    1    ,  1  ,    1    ,IRC|STR|2}, /* RXJ- */
298 };
299
300
301 /* SCA: RCR+ must supply id, len and data
302    SCN: RCR- must supply code, id, len and data
303    STA: RTR must supply id
304    SCJ: RUC must supply CP packet len and data */
305 static void ppp_cp_event(struct net_device *dev, u16 pid, u16 event, u8 code,
306                          u8 id, unsigned int len, const void *data)
307 {
308         int old_state, action;
309         struct ppp *ppp = get_ppp(dev);
310         struct proto *proto = get_proto(dev, pid);
311
312         old_state = proto->state;
313         BUG_ON(old_state >= STATES);
314         BUG_ON(event >= EVENTS);
315
316 #if DEBUG_STATE
317         printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) %s ...\n", dev->name,
318                proto_name(pid), event_names[event], state_names[proto->state]);
319 #endif
320
321         action = cp_table[event][old_state];
322
323         proto->state = action & STATE_MASK;
324         if (action & (SCR | STR)) /* set Configure-Req/Terminate-Req timer */
325                 mod_timer(&proto->timer, proto->timeout =
326                           jiffies + ppp->req_timeout * HZ);
327         if (action & ZRC)
328                 proto->restart_counter = 0;
329         if (action & IRC)
330                 proto->restart_counter = (proto->state == STOPPING) ?
331                         ppp->term_retries : ppp->cr_retries;
332
333         if (action & SCR)       /* send Configure-Request */
334                 ppp_tx_cp(dev, pid, CP_CONF_REQ, proto->cr_id = ++ppp->seq,
335                           0, NULL);
336         if (action & SCA)       /* send Configure-Ack */
337                 ppp_tx_cp(dev, pid, CP_CONF_ACK, id, len, data);
338         if (action & SCN)       /* send Configure-Nak/Reject */
339                 ppp_tx_cp(dev, pid, code, id, len, data);
340         if (action & STR)       /* send Terminate-Request */
341                 ppp_tx_cp(dev, pid, CP_TERM_REQ, ++ppp->seq, 0, NULL);
342         if (action & STA)       /* send Terminate-Ack */
343                 ppp_tx_cp(dev, pid, CP_TERM_ACK, id, 0, NULL);
344         if (action & SCJ)       /* send Code-Reject */
345                 ppp_tx_cp(dev, pid, CP_CODE_REJ, ++ppp->seq, len, data);
346
347         if (old_state != OPENED && proto->state == OPENED) {
348                 printk(KERN_INFO "%s: %s up\n", dev->name, proto_name(pid));
349                 if (pid == PID_LCP) {
350                         netif_dormant_off(dev);
351                         ppp_cp_event(dev, PID_IPCP, START, 0, 0, 0, NULL);
352                         ppp_cp_event(dev, PID_IPV6CP, START, 0, 0, 0, NULL);
353                         ppp->last_pong = jiffies;
354                         mod_timer(&proto->timer, proto->timeout =
355                                   jiffies + ppp->keepalive_interval * HZ);
356                 }
357         }
358         if (old_state == OPENED && proto->state != OPENED) {
359                 printk(KERN_INFO "%s: %s down\n", dev->name, proto_name(pid));
360                 if (pid == PID_LCP) {
361                         netif_dormant_on(dev);
362                         ppp_cp_event(dev, PID_IPCP, STOP, 0, 0, 0, NULL);
363                         ppp_cp_event(dev, PID_IPV6CP, STOP, 0, 0, 0, NULL);
364                 }
365         }
366         if (old_state != CLOSED && proto->state == CLOSED)
367                 del_timer(&proto->timer);
368
369 #if DEBUG_STATE
370         printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) ... %s\n", dev->name,
371                proto_name(pid), event_names[event], state_names[proto->state]);
372 #endif
373 }
374
375
376 static void ppp_cp_parse_cr(struct net_device *dev, u16 pid, u8 id,
377                             unsigned int req_len, const u8 *data)
378 {
379         static u8 const valid_accm[6] = { LCP_OPTION_ACCM, 6, 0, 0, 0, 0 };
380         const u8 *opt;
381         u8 *out;
382         unsigned int len = req_len, nak_len = 0, rej_len = 0;
383
384         if (!(out = kmalloc(len, GFP_ATOMIC))) {
385                 dev->stats.rx_dropped++;
386                 return; /* out of memory, ignore CR packet */
387         }
388
389         for (opt = data; len; len -= opt[1], opt += opt[1]) {
390                 if (len < 2 || len < opt[1]) {
391                         dev->stats.rx_errors++;
392                         return; /* bad packet, drop silently */
393                 }
394
395                 if (pid == PID_LCP)
396                         switch (opt[0]) {
397                         case LCP_OPTION_MRU:
398                                 continue; /* MRU always OK and > 1500 bytes? */
399
400                         case LCP_OPTION_ACCM: /* async control character map */
401                                 if (!memcmp(opt, valid_accm,
402                                             sizeof(valid_accm)))
403                                         continue;
404                                 if (!rej_len) { /* NAK it */
405                                         memcpy(out + nak_len, valid_accm,
406                                                sizeof(valid_accm));
407                                         nak_len += sizeof(valid_accm);
408                                         continue;
409                                 }
410                                 break;
411                         case LCP_OPTION_MAGIC:
412                                 if (opt[1] != 6 || (!opt[2] && !opt[3] &&
413                                                     !opt[4] && !opt[5]))
414                                         break; /* reject invalid magic number */
415                                 continue;
416                         }
417                 /* reject this option */
418                 memcpy(out + rej_len, opt, opt[1]);
419                 rej_len += opt[1];
420         }
421
422         if (rej_len)
423                 ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_REJ, id, rej_len, out);
424         else if (nak_len)
425                 ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_NAK, id, nak_len, out);
426         else
427                 ppp_cp_event(dev, pid, RCR_GOOD, CP_CONF_ACK, id, req_len, data);
428
429         kfree(out);
430 }
431
432 static int ppp_rx(struct sk_buff *skb)
433 {
434         struct hdlc_header *hdr = (struct hdlc_header*)skb->data;
435         struct net_device *dev = skb->dev;
436         struct ppp *ppp = get_ppp(dev);
437         struct proto *proto;
438         struct cp_header *cp;
439         unsigned long flags;
440         unsigned int len;
441         u16 pid;
442 #if DEBUG_CP
443         int i;
444         char *ptr;
445 #endif
446
447         spin_lock_irqsave(&ppp->lock, flags);
448         /* Check HDLC header */
449         if (skb->len < sizeof(struct hdlc_header))
450                 goto rx_error;
451         cp = (struct cp_header*)skb_pull(skb, sizeof(struct hdlc_header));
452         if (hdr->address != HDLC_ADDR_ALLSTATIONS ||
453             hdr->control != HDLC_CTRL_UI)
454                 goto rx_error;
455
456         pid = ntohs(hdr->protocol);
457         proto = get_proto(dev, pid);
458         if (!proto) {
459                 if (ppp->protos[IDX_LCP].state == OPENED)
460                         ppp_tx_cp(dev, PID_LCP, LCP_PROTO_REJ,
461                                   ++ppp->seq, skb->len + 2, &hdr->protocol);
462                 goto rx_error;
463         }
464
465         len = ntohs(cp->len);
466         if (len < sizeof(struct cp_header) /* no complete CP header? */ ||
467             skb->len < len /* truncated packet? */)
468                 goto rx_error;
469         skb_pull(skb, sizeof(struct cp_header));
470         len -= sizeof(struct cp_header);
471
472         /* HDLC and CP headers stripped from skb */
473 #if DEBUG_CP
474         if (cp->code < CP_CODES)
475                 sprintf(debug_buffer, "[%s id 0x%X]", code_names[cp->code],
476                         cp->id);
477         else
478                 sprintf(debug_buffer, "[code %u id 0x%X]", cp->code, cp->id);
479         ptr = debug_buffer + strlen(debug_buffer);
480         for (i = 0; i < min_t(unsigned int, len, DEBUG_CP); i++) {
481                 sprintf(ptr, " %02X", skb->data[i]);
482                 ptr += strlen(ptr);
483         }
484         printk(KERN_DEBUG "%s: RX %s %s\n", dev->name, proto_name(pid),
485                debug_buffer);
486 #endif
487
488         /* LCP only */
489         if (pid == PID_LCP)
490                 switch (cp->code) {
491                 case LCP_PROTO_REJ:
492                         pid = ntohs(*(__be16*)skb->data);
493                         if (pid == PID_LCP || pid == PID_IPCP ||
494                             pid == PID_IPV6CP)
495                                 ppp_cp_event(dev, pid, RXJ_BAD, 0, 0,
496                                              0, NULL);
497                         goto out;
498
499                 case LCP_ECHO_REQ: /* send Echo-Reply */
500                         if (len >= 4 && proto->state == OPENED)
501                                 ppp_tx_cp(dev, PID_LCP, LCP_ECHO_REPLY,
502                                           cp->id, len - 4, skb->data + 4);
503                         goto out;
504
505                 case LCP_ECHO_REPLY:
506                         if (cp->id == ppp->echo_id)
507                                 ppp->last_pong = jiffies;
508                         goto out;
509
510                 case LCP_DISC_REQ: /* discard */
511                         goto out;
512                 }
513
514         /* LCP, IPCP and IPV6CP */
515         switch (cp->code) {
516         case CP_CONF_REQ:
517                 ppp_cp_parse_cr(dev, pid, cp->id, len, skb->data);
518                 goto out;
519
520         case CP_CONF_ACK:
521                 if (cp->id == proto->cr_id)
522                         ppp_cp_event(dev, pid, RCA, 0, 0, 0, NULL);
523                 goto out;
524
525         case CP_CONF_REJ:
526         case CP_CONF_NAK:
527                 if (cp->id == proto->cr_id)
528                         ppp_cp_event(dev, pid, RCN, 0, 0, 0, NULL);
529                 goto out;
530
531         case CP_TERM_REQ:
532                 ppp_cp_event(dev, pid, RTR, 0, cp->id, 0, NULL);
533                 goto out;
534
535         case CP_TERM_ACK:
536                 ppp_cp_event(dev, pid, RTA, 0, 0, 0, NULL);
537                 goto out;
538
539         case CP_CODE_REJ:
540                 ppp_cp_event(dev, pid, RXJ_BAD, 0, 0, 0, NULL);
541                 goto out;
542
543         default:
544                 len += sizeof(struct cp_header);
545                 if (len > dev->mtu)
546                         len = dev->mtu;
547                 ppp_cp_event(dev, pid, RUC, 0, 0, len, cp);
548                 goto out;
549         }
550         goto out;
551
552 rx_error:
553         dev->stats.rx_errors++;
554 out:
555         spin_unlock_irqrestore(&ppp->lock, flags);
556         dev_kfree_skb_any(skb);
557         ppp_tx_flush();
558         return NET_RX_DROP;
559 }
560
561 static void ppp_timer(unsigned long arg)
562 {
563         struct proto *proto = (struct proto *)arg;
564         struct ppp *ppp = get_ppp(proto->dev);
565         unsigned long flags;
566
567         spin_lock_irqsave(&ppp->lock, flags);
568         switch (proto->state) {
569         case STOPPING:
570         case REQ_SENT:
571         case ACK_RECV:
572         case ACK_SENT:
573                 if (proto->restart_counter) {
574                         ppp_cp_event(proto->dev, proto->pid, TO_GOOD, 0, 0,
575                                      0, NULL);
576                         proto->restart_counter--;
577                 } else
578                         ppp_cp_event(proto->dev, proto->pid, TO_BAD, 0, 0,
579                                      0, NULL);
580                 break;
581
582         case OPENED:
583                 if (proto->pid != PID_LCP)
584                         break;
585                 if (time_after(jiffies, ppp->last_pong +
586                                ppp->keepalive_timeout * HZ)) {
587                         printk(KERN_INFO "%s: Link down\n", proto->dev->name);
588                         ppp_cp_event(proto->dev, PID_LCP, STOP, 0, 0, 0, NULL);
589                         ppp_cp_event(proto->dev, PID_LCP, START, 0, 0, 0, NULL);
590                 } else {        /* send keep-alive packet */
591                         ppp->echo_id = ++ppp->seq;
592                         ppp_tx_cp(proto->dev, PID_LCP, LCP_ECHO_REQ,
593                                   ppp->echo_id, 0, NULL);
594                         proto->timer.expires = jiffies +
595                                 ppp->keepalive_interval * HZ;
596                         add_timer(&proto->timer);
597                 }
598                 break;
599         }
600         spin_unlock_irqrestore(&ppp->lock, flags);
601         ppp_tx_flush();
602 }
603
604
605 static void ppp_start(struct net_device *dev)
606 {
607         struct ppp *ppp = get_ppp(dev);
608         int i;
609
610         for (i = 0; i < IDX_COUNT; i++) {
611                 struct proto *proto = &ppp->protos[i];
612                 proto->dev = dev;
613                 init_timer(&proto->timer);
614                 proto->timer.function = ppp_timer;
615                 proto->timer.data = (unsigned long)proto;
616                 proto->state = CLOSED;
617         }
618         ppp->protos[IDX_LCP].pid = PID_LCP;
619         ppp->protos[IDX_IPCP].pid = PID_IPCP;
620         ppp->protos[IDX_IPV6CP].pid = PID_IPV6CP;
621
622         ppp_cp_event(dev, PID_LCP, START, 0, 0, 0, NULL);
623 }
624
625 static void ppp_stop(struct net_device *dev)
626 {
627         ppp_cp_event(dev, PID_LCP, STOP, 0, 0, 0, NULL);
628 }
629
630 static struct hdlc_proto proto = {
631         .start          = ppp_start,
632         .stop           = ppp_stop,
633         .type_trans     = ppp_type_trans,
634         .ioctl          = ppp_ioctl,
635         .netif_rx       = ppp_rx,
636         .module         = THIS_MODULE,
637 };
638
639 static const struct header_ops ppp_header_ops = {
640         .create = ppp_hard_header,
641 };
642
643 static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr)
644 {
645         hdlc_device *hdlc = dev_to_hdlc(dev);
646         struct ppp *ppp;
647         int result;
648
649         switch (ifr->ifr_settings.type) {
650         case IF_GET_PROTO:
651                 if (dev_to_hdlc(dev)->proto != &proto)
652                         return -EINVAL;
653                 ifr->ifr_settings.type = IF_PROTO_PPP;
654                 return 0; /* return protocol only, no settable parameters */
655
656         case IF_PROTO_PPP:
657                 if (!capable(CAP_NET_ADMIN))
658                         return -EPERM;
659
660                 if (dev->flags & IFF_UP)
661                         return -EBUSY;
662
663                 /* no settable parameters */
664
665                 result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
666                 if (result)
667                         return result;
668
669                 result = attach_hdlc_protocol(dev, &proto, sizeof(struct ppp));
670                 if (result)
671                         return result;
672
673                 ppp = get_ppp(dev);
674                 spin_lock_init(&ppp->lock);
675                 ppp->req_timeout = 2;
676                 ppp->cr_retries = 10;
677                 ppp->term_retries = 2;
678                 ppp->keepalive_interval = 10;
679                 ppp->keepalive_timeout = 60;
680
681                 dev->hard_header_len = sizeof(struct hdlc_header);
682                 dev->header_ops = &ppp_header_ops;
683                 dev->type = ARPHRD_PPP;
684                 netif_dormant_on(dev);
685                 return 0;
686         }
687
688         return -EINVAL;
689 }
690
691
692 static int __init mod_init(void)
693 {
694         skb_queue_head_init(&tx_queue);
695         register_hdlc_protocol(&proto);
696         return 0;
697 }
698
699 static void __exit mod_exit(void)
700 {
701         unregister_hdlc_protocol(&proto);
702 }
703
704
705 module_init(mod_init);
706 module_exit(mod_exit);
707
708 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
709 MODULE_DESCRIPTION("PPP protocol support for generic HDLC");
710 MODULE_LICENSE("GPL v2");