b56a7b516d2479a228598bb3a3651f333f9ac89c
[sfrench/cifs-2.6.git] / drivers / net / wan / syncppp.c
1 /*
2  *      NET3:   A (fairly minimal) implementation of synchronous PPP for Linux
3  *              as well as a CISCO HDLC implementation. See the copyright 
4  *              message below for the original source.
5  *
6  *      This program is free software; you can redistribute it and/or
7  *      modify it under the terms of the GNU General Public License
8  *      as published by the Free Software Foundation; either version
9  *      2 of the license, or (at your option) any later version.
10  *
11  *      Note however. This code is also used in a different form by FreeBSD.
12  *      Therefore when making any non OS specific change please consider
13  *      contributing it back to the original author under the terms
14  *      below in addition.
15  *              -- Alan
16  *
17  *      Port for Linux-2.1 by Jan "Yenya" Kasprzak <kas@fi.muni.cz>
18  */
19
20 /*
21  * Synchronous PPP/Cisco link level subroutines.
22  * Keepalive protocol implemented in both Cisco and PPP modes.
23  *
24  * Copyright (C) 1994 Cronyx Ltd.
25  * Author: Serge Vakulenko, <vak@zebub.msk.su>
26  *
27  * This software is distributed with NO WARRANTIES, not even the implied
28  * warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
29  *
30  * Authors grant any other persons or organisations permission to use
31  * or modify this software as long as this message is kept with the software,
32  * all derivative works or modified versions.
33  *
34  * Version 1.9, Wed Oct  4 18:58:15 MSK 1995
35  *
36  * $Id: syncppp.c,v 1.18 2000/04/11 05:25:31 asj Exp $
37  */
38 #undef DEBUG
39
40 #include <linux/config.h>
41 #include <linux/module.h>
42 #include <linux/kernel.h>
43 #include <linux/errno.h>
44 #include <linux/init.h>
45 #include <linux/if_arp.h>
46 #include <linux/skbuff.h>
47 #include <linux/route.h>
48 #include <linux/netdevice.h>
49 #include <linux/inetdevice.h>
50 #include <linux/random.h>
51 #include <linux/pkt_sched.h>
52 #include <linux/spinlock.h>
53 #include <linux/rcupdate.h>
54
55 #include <net/syncppp.h>
56
57 #include <asm/byteorder.h>
58 #include <asm/uaccess.h>
59
60 #define MAXALIVECNT     6               /* max. alive packets */
61
62 #define PPP_ALLSTATIONS 0xff            /* All-Stations broadcast address */
63 #define PPP_UI          0x03            /* Unnumbered Information */
64 #define PPP_IP          0x0021          /* Internet Protocol */
65 #define PPP_ISO         0x0023          /* ISO OSI Protocol */
66 #define PPP_XNS         0x0025          /* Xerox NS Protocol */
67 #define PPP_IPX         0x002b          /* Novell IPX Protocol */
68 #define PPP_LCP         0xc021          /* Link Control Protocol */
69 #define PPP_IPCP        0x8021          /* Internet Protocol Control Protocol */
70
71 #define LCP_CONF_REQ    1               /* PPP LCP configure request */
72 #define LCP_CONF_ACK    2               /* PPP LCP configure acknowledge */
73 #define LCP_CONF_NAK    3               /* PPP LCP configure negative ack */
74 #define LCP_CONF_REJ    4               /* PPP LCP configure reject */
75 #define LCP_TERM_REQ    5               /* PPP LCP terminate request */
76 #define LCP_TERM_ACK    6               /* PPP LCP terminate acknowledge */
77 #define LCP_CODE_REJ    7               /* PPP LCP code reject */
78 #define LCP_PROTO_REJ   8               /* PPP LCP protocol reject */
79 #define LCP_ECHO_REQ    9               /* PPP LCP echo request */
80 #define LCP_ECHO_REPLY  10              /* PPP LCP echo reply */
81 #define LCP_DISC_REQ    11              /* PPP LCP discard request */
82
83 #define LCP_OPT_MRU             1       /* maximum receive unit */
84 #define LCP_OPT_ASYNC_MAP       2       /* async control character map */
85 #define LCP_OPT_AUTH_PROTO      3       /* authentication protocol */
86 #define LCP_OPT_QUAL_PROTO      4       /* quality protocol */
87 #define LCP_OPT_MAGIC           5       /* magic number */
88 #define LCP_OPT_RESERVED        6       /* reserved */
89 #define LCP_OPT_PROTO_COMP      7       /* protocol field compression */
90 #define LCP_OPT_ADDR_COMP       8       /* address/control field compression */
91
92 #define IPCP_CONF_REQ   LCP_CONF_REQ    /* PPP IPCP configure request */
93 #define IPCP_CONF_ACK   LCP_CONF_ACK    /* PPP IPCP configure acknowledge */
94 #define IPCP_CONF_NAK   LCP_CONF_NAK    /* PPP IPCP configure negative ack */
95 #define IPCP_CONF_REJ   LCP_CONF_REJ    /* PPP IPCP configure reject */
96 #define IPCP_TERM_REQ   LCP_TERM_REQ    /* PPP IPCP terminate request */
97 #define IPCP_TERM_ACK   LCP_TERM_ACK    /* PPP IPCP terminate acknowledge */
98 #define IPCP_CODE_REJ   LCP_CODE_REJ    /* PPP IPCP code reject */
99
100 #define CISCO_MULTICAST         0x8f    /* Cisco multicast address */
101 #define CISCO_UNICAST           0x0f    /* Cisco unicast address */
102 #define CISCO_KEEPALIVE         0x8035  /* Cisco keepalive protocol */
103 #define CISCO_ADDR_REQ          0       /* Cisco address request */
104 #define CISCO_ADDR_REPLY        1       /* Cisco address reply */
105 #define CISCO_KEEPALIVE_REQ     2       /* Cisco keepalive request */
106
107 struct ppp_header {
108         u8 address;
109         u8 control;
110         u16 protocol;
111 };
112 #define PPP_HEADER_LEN          sizeof (struct ppp_header)
113
114 struct lcp_header {
115         u8 type;
116         u8 ident;
117         u16 len;
118 };
119 #define LCP_HEADER_LEN          sizeof (struct lcp_header)
120
121 struct cisco_packet {
122         u32 type;
123         u32 par1;
124         u32 par2;
125         u16 rel;
126         u16 time0;
127         u16 time1;
128 };
129 #define CISCO_PACKET_LEN 18
130 #define CISCO_BIG_PACKET_LEN 20
131
132 static struct sppp *spppq;
133 static struct timer_list sppp_keepalive_timer;
134 static DEFINE_SPINLOCK(spppq_lock);
135
136 /* global xmit queue for sending packets while spinlock is held */
137 static struct sk_buff_head tx_queue;
138
139 static void sppp_keepalive (unsigned long dummy);
140 static void sppp_cp_send (struct sppp *sp, u16 proto, u8 type,
141         u8 ident, u16 len, void *data);
142 static void sppp_cisco_send (struct sppp *sp, int type, long par1, long par2);
143 static void sppp_lcp_input (struct sppp *sp, struct sk_buff *m);
144 static void sppp_cisco_input (struct sppp *sp, struct sk_buff *m);
145 static void sppp_ipcp_input (struct sppp *sp, struct sk_buff *m);
146 static void sppp_lcp_open (struct sppp *sp);
147 static void sppp_ipcp_open (struct sppp *sp);
148 static int sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h,
149         int len, u32 *magic);
150 static void sppp_cp_timeout (unsigned long arg);
151 static char *sppp_lcp_type_name (u8 type);
152 static char *sppp_ipcp_type_name (u8 type);
153 static void sppp_print_bytes (u8 *p, u16 len);
154
155 static int debug;
156
157 /* Flush global outgoing packet queue to dev_queue_xmit().
158  *
159  * dev_queue_xmit() must be called with interrupts enabled
160  * which means it can't be called with spinlocks held.
161  * If a packet needs to be sent while a spinlock is held,
162  * then put the packet into tx_queue, and call sppp_flush_xmit()
163  * after spinlock is released.
164  */
165 static void sppp_flush_xmit(void)
166 {
167         struct sk_buff *skb;
168         while ((skb = skb_dequeue(&tx_queue)) != NULL)
169                 dev_queue_xmit(skb);
170 }
171
172 /*
173  *      Interface down stub
174  */     
175
176 static void if_down(struct net_device *dev)
177 {
178         struct sppp *sp = (struct sppp *)sppp_of(dev);
179
180         sp->pp_link_state=SPPP_LINK_DOWN;
181 }
182
183 /*
184  * Timeout routine activations.
185  */
186
187 static void sppp_set_timeout(struct sppp *p,int s) 
188 {
189         if (! (p->pp_flags & PP_TIMO)) 
190         {
191                 init_timer(&p->pp_timer);
192                 p->pp_timer.function=sppp_cp_timeout;
193                 p->pp_timer.expires=jiffies+s*HZ;
194                 p->pp_timer.data=(unsigned long)p;
195                 p->pp_flags |= PP_TIMO;
196                 add_timer(&p->pp_timer);
197         }
198 }
199
200 static void sppp_clear_timeout(struct sppp *p)
201 {
202         if (p->pp_flags & PP_TIMO) 
203         {
204                 del_timer(&p->pp_timer);
205                 p->pp_flags &= ~PP_TIMO; 
206         }
207 }
208
209 /**
210  *      sppp_input -    receive and process a WAN PPP frame
211  *      @skb:   The buffer to process
212  *      @dev:   The device it arrived on
213  *
214  *      This can be called directly by cards that do not have
215  *      timing constraints but is normally called from the network layer
216  *      after interrupt servicing to process frames queued via netif_rx().
217  *
218  *      We process the options in the card. If the frame is destined for
219  *      the protocol stacks then it requeues the frame for the upper level
220  *      protocol. If it is a control from it is processed and discarded
221  *      here.
222  */
223  
224 void sppp_input (struct net_device *dev, struct sk_buff *skb)
225 {
226         struct ppp_header *h;
227         struct sppp *sp = (struct sppp *)sppp_of(dev);
228         unsigned long flags;
229
230         skb->dev=dev;
231         skb->mac.raw=skb->data;
232
233         if (dev->flags & IFF_RUNNING)
234         {
235                 /* Count received bytes, add FCS and one flag */
236                 sp->ibytes+= skb->len + 3;
237                 sp->ipkts++;
238         }
239
240         if (!pskb_may_pull(skb, PPP_HEADER_LEN)) {
241                 /* Too small packet, drop it. */
242                 if (sp->pp_flags & PP_DEBUG)
243                         printk (KERN_DEBUG "%s: input packet is too small, %d bytes\n",
244                                 dev->name, skb->len);
245                 kfree_skb(skb);
246                 return;
247         }
248
249         /* Get PPP header. */
250         h = (struct ppp_header *)skb->data;
251         skb_pull(skb,sizeof(struct ppp_header));
252
253         spin_lock_irqsave(&sp->lock, flags);
254         
255         switch (h->address) {
256         default:        /* Invalid PPP packet. */
257                 goto invalid;
258         case PPP_ALLSTATIONS:
259                 if (h->control != PPP_UI)
260                         goto invalid;
261                 if (sp->pp_flags & PP_CISCO) {
262                         if (sp->pp_flags & PP_DEBUG)
263                                 printk (KERN_WARNING "%s: PPP packet in Cisco mode <0x%x 0x%x 0x%x>\n",
264                                         dev->name,
265                                         h->address, h->control, ntohs (h->protocol));
266                         goto drop;
267                 }
268                 switch (ntohs (h->protocol)) {
269                 default:
270                         if (sp->lcp.state == LCP_STATE_OPENED)
271                                 sppp_cp_send (sp, PPP_LCP, LCP_PROTO_REJ,
272                                         ++sp->pp_seq, skb->len + 2,
273                                         &h->protocol);
274                         if (sp->pp_flags & PP_DEBUG)
275                                 printk (KERN_WARNING "%s: invalid input protocol <0x%x 0x%x 0x%x>\n",
276                                         dev->name,
277                                         h->address, h->control, ntohs (h->protocol));
278                         goto drop;
279                 case PPP_LCP:
280                         sppp_lcp_input (sp, skb);
281                         goto drop;
282                 case PPP_IPCP:
283                         if (sp->lcp.state == LCP_STATE_OPENED)
284                                 sppp_ipcp_input (sp, skb);
285                         else
286                                 printk(KERN_DEBUG "IPCP when still waiting LCP finish.\n");
287                         goto drop;
288                 case PPP_IP:
289                         if (sp->ipcp.state == IPCP_STATE_OPENED) {
290                                 if(sp->pp_flags&PP_DEBUG)
291                                         printk(KERN_DEBUG "Yow an IP frame.\n");
292                                 skb->protocol=htons(ETH_P_IP);
293                                 netif_rx(skb);
294                                 dev->last_rx = jiffies;
295                                 goto done;
296                         }
297                         break;
298 #ifdef IPX
299                 case PPP_IPX:
300                         /* IPX IPXCP not implemented yet */
301                         if (sp->lcp.state == LCP_STATE_OPENED) {
302                                 skb->protocol=htons(ETH_P_IPX);
303                                 netif_rx(skb);
304                                 dev->last_rx = jiffies;
305                                 goto done;
306                         }
307                         break;
308 #endif
309                 }
310                 break;
311         case CISCO_MULTICAST:
312         case CISCO_UNICAST:
313                 /* Don't check the control field here (RFC 1547). */
314                 if (! (sp->pp_flags & PP_CISCO)) {
315                         if (sp->pp_flags & PP_DEBUG)
316                                 printk (KERN_WARNING "%s: Cisco packet in PPP mode <0x%x 0x%x 0x%x>\n",
317                                         dev->name,
318                                         h->address, h->control, ntohs (h->protocol));
319                         goto drop;
320                 }
321                 switch (ntohs (h->protocol)) {
322                 default:
323                         goto invalid;
324                 case CISCO_KEEPALIVE:
325                         sppp_cisco_input (sp, skb);
326                         goto drop;
327 #ifdef CONFIG_INET
328                 case ETH_P_IP:
329                         skb->protocol=htons(ETH_P_IP);
330                         netif_rx(skb);
331                         dev->last_rx = jiffies;
332                         goto done;
333 #endif
334 #ifdef CONFIG_IPX
335                 case ETH_P_IPX:
336                         skb->protocol=htons(ETH_P_IPX);
337                         netif_rx(skb);
338                         dev->last_rx = jiffies;
339                         goto done;
340 #endif
341                 }
342                 break;
343         }
344         goto drop;
345
346 invalid:
347         if (sp->pp_flags & PP_DEBUG)
348                 printk (KERN_WARNING "%s: invalid input packet <0x%x 0x%x 0x%x>\n",
349                         dev->name, h->address, h->control, ntohs (h->protocol));
350 drop:
351         kfree_skb(skb);
352 done:
353         spin_unlock_irqrestore(&sp->lock, flags);
354         sppp_flush_xmit();
355         return;
356 }
357
358 EXPORT_SYMBOL(sppp_input);
359
360 /*
361  *      Handle transmit packets.
362  */
363  
364 static int sppp_hard_header(struct sk_buff *skb, struct net_device *dev, __u16 type,
365                 void *daddr, void *saddr, unsigned int len)
366 {
367         struct sppp *sp = (struct sppp *)sppp_of(dev);
368         struct ppp_header *h;
369         skb_push(skb,sizeof(struct ppp_header));
370         h=(struct ppp_header *)skb->data;
371         if(sp->pp_flags&PP_CISCO)
372         {
373                 h->address = CISCO_UNICAST;
374                 h->control = 0;
375         }
376         else
377         {
378                 h->address = PPP_ALLSTATIONS;
379                 h->control = PPP_UI;
380         }
381         if(sp->pp_flags & PP_CISCO)
382         {
383                 h->protocol = htons(type);
384         }
385         else switch(type)
386         {
387                 case ETH_P_IP:
388                         h->protocol = htons(PPP_IP);
389                         break;
390                 case ETH_P_IPX:
391                         h->protocol = htons(PPP_IPX);
392                         break;
393         }
394         return sizeof(struct ppp_header);
395 }
396
397 static int sppp_rebuild_header(struct sk_buff *skb)
398 {
399         return 0;
400 }
401
402 /*
403  * Send keepalive packets, every 10 seconds.
404  */
405
406 static void sppp_keepalive (unsigned long dummy)
407 {
408         struct sppp *sp;
409         unsigned long flags;
410
411         spin_lock_irqsave(&spppq_lock, flags);
412
413         for (sp=spppq; sp; sp=sp->pp_next) 
414         {
415                 struct net_device *dev = sp->pp_if;
416
417                 /* Keepalive mode disabled or channel down? */
418                 if (! (sp->pp_flags & PP_KEEPALIVE) ||
419                     ! (dev->flags & IFF_UP))
420                         continue;
421
422                 spin_lock(&sp->lock);
423
424                 /* No keepalive in PPP mode if LCP not opened yet. */
425                 if (! (sp->pp_flags & PP_CISCO) &&
426                     sp->lcp.state != LCP_STATE_OPENED) {
427                         spin_unlock(&sp->lock);
428                         continue;
429                 }
430
431                 if (sp->pp_alivecnt == MAXALIVECNT) {
432                         /* No keepalive packets got.  Stop the interface. */
433                         printk (KERN_WARNING "%s: protocol down\n", dev->name);
434                         if_down (dev);
435                         if (! (sp->pp_flags & PP_CISCO)) {
436                                 /* Shut down the PPP link. */
437                                 sp->lcp.magic = jiffies;
438                                 sp->lcp.state = LCP_STATE_CLOSED;
439                                 sp->ipcp.state = IPCP_STATE_CLOSED;
440                                 sppp_clear_timeout (sp);
441                                 /* Initiate negotiation. */
442                                 sppp_lcp_open (sp);
443                         }
444                 }
445                 if (sp->pp_alivecnt <= MAXALIVECNT)
446                         ++sp->pp_alivecnt;
447                 if (sp->pp_flags & PP_CISCO)
448                         sppp_cisco_send (sp, CISCO_KEEPALIVE_REQ, ++sp->pp_seq,
449                                 sp->pp_rseq);
450                 else if (sp->lcp.state == LCP_STATE_OPENED) {
451                         long nmagic = htonl (sp->lcp.magic);
452                         sp->lcp.echoid = ++sp->pp_seq;
453                         sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REQ,
454                                 sp->lcp.echoid, 4, &nmagic);
455                 }
456
457                 spin_unlock(&sp->lock);
458         }
459         spin_unlock_irqrestore(&spppq_lock, flags);
460         sppp_flush_xmit();
461         sppp_keepalive_timer.expires=jiffies+10*HZ;
462         add_timer(&sppp_keepalive_timer);
463 }
464
465 /*
466  * Handle incoming PPP Link Control Protocol packets.
467  */
468  
469 static void sppp_lcp_input (struct sppp *sp, struct sk_buff *skb)
470 {
471         struct lcp_header *h;
472         struct net_device *dev = sp->pp_if;
473         int len = skb->len;
474         u8 *p, opt[6];
475         u32 rmagic;
476
477         if (!pskb_may_pull(skb, sizeof(struct lcp_header))) {
478                 if (sp->pp_flags & PP_DEBUG)
479                         printk (KERN_WARNING "%s: invalid lcp packet length: %d bytes\n",
480                                 dev->name, len);
481                 return;
482         }
483         h = (struct lcp_header *)skb->data;
484         skb_pull(skb,sizeof(struct lcp_header *));
485         
486         if (sp->pp_flags & PP_DEBUG) 
487         {
488                 char state = '?';
489                 switch (sp->lcp.state) {
490                 case LCP_STATE_CLOSED:   state = 'C'; break;
491                 case LCP_STATE_ACK_RCVD: state = 'R'; break;
492                 case LCP_STATE_ACK_SENT: state = 'S'; break;
493                 case LCP_STATE_OPENED:   state = 'O'; break;
494                 }
495                 printk (KERN_WARNING "%s: lcp input(%c): %d bytes <%s id=%xh len=%xh",
496                         dev->name, state, len,
497                         sppp_lcp_type_name (h->type), h->ident, ntohs (h->len));
498                 if (len > 4)
499                         sppp_print_bytes ((u8*) (h+1), len-4);
500                 printk (">\n");
501         }
502         if (len > ntohs (h->len))
503                 len = ntohs (h->len);
504         switch (h->type) {
505         default:
506                 /* Unknown packet type -- send Code-Reject packet. */
507                 sppp_cp_send (sp, PPP_LCP, LCP_CODE_REJ, ++sp->pp_seq,
508                         skb->len, h);
509                 break;
510         case LCP_CONF_REQ:
511                 if (len < 4) {
512                         if (sp->pp_flags & PP_DEBUG)
513                                 printk (KERN_DEBUG"%s: invalid lcp configure request packet length: %d bytes\n",
514                                         dev->name, len);
515                         break;
516                 }
517                 if (len>4 && !sppp_lcp_conf_parse_options (sp, h, len, &rmagic))
518                         goto badreq;
519                 if (rmagic == sp->lcp.magic) {
520                         /* Local and remote magics equal -- loopback? */
521                         if (sp->pp_loopcnt >= MAXALIVECNT*5) {
522                                 printk (KERN_WARNING "%s: loopback\n",
523                                         dev->name);
524                                 sp->pp_loopcnt = 0;
525                                 if (dev->flags & IFF_UP) {
526                                         if_down (dev);
527                                 }
528                         } else if (sp->pp_flags & PP_DEBUG)
529                                 printk (KERN_DEBUG "%s: conf req: magic glitch\n",
530                                         dev->name);
531                         ++sp->pp_loopcnt;
532
533                         /* MUST send Conf-Nack packet. */
534                         rmagic = ~sp->lcp.magic;
535                         opt[0] = LCP_OPT_MAGIC;
536                         opt[1] = sizeof (opt);
537                         opt[2] = rmagic >> 24;
538                         opt[3] = rmagic >> 16;
539                         opt[4] = rmagic >> 8;
540                         opt[5] = rmagic;
541                         sppp_cp_send (sp, PPP_LCP, LCP_CONF_NAK,
542                                 h->ident, sizeof (opt), &opt);
543 badreq:
544                         switch (sp->lcp.state) {
545                         case LCP_STATE_OPENED:
546                                 /* Initiate renegotiation. */
547                                 sppp_lcp_open (sp);
548                                 /* fall through... */
549                         case LCP_STATE_ACK_SENT:
550                                 /* Go to closed state. */
551                                 sp->lcp.state = LCP_STATE_CLOSED;
552                                 sp->ipcp.state = IPCP_STATE_CLOSED;
553                         }
554                         break;
555                 }
556                 /* Send Configure-Ack packet. */
557                 sp->pp_loopcnt = 0;
558                 if (sp->lcp.state != LCP_STATE_OPENED) {
559                         sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK,
560                                         h->ident, len-4, h+1);
561                 }
562                 /* Change the state. */
563                 switch (sp->lcp.state) {
564                 case LCP_STATE_CLOSED:
565                         sp->lcp.state = LCP_STATE_ACK_SENT;
566                         break;
567                 case LCP_STATE_ACK_RCVD:
568                         sp->lcp.state = LCP_STATE_OPENED;
569                         sppp_ipcp_open (sp);
570                         break;
571                 case LCP_STATE_OPENED:
572                         /* Remote magic changed -- close session. */
573                         sp->lcp.state = LCP_STATE_CLOSED;
574                         sp->ipcp.state = IPCP_STATE_CLOSED;
575                         /* Initiate renegotiation. */
576                         sppp_lcp_open (sp);
577                         /* Send ACK after our REQ in attempt to break loop */
578                         sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK,
579                                         h->ident, len-4, h+1);
580                         sp->lcp.state = LCP_STATE_ACK_SENT;
581                         break;
582                 }
583                 break;
584         case LCP_CONF_ACK:
585                 if (h->ident != sp->lcp.confid)
586                         break;
587                 sppp_clear_timeout (sp);
588                 if ((sp->pp_link_state != SPPP_LINK_UP) &&
589                     (dev->flags & IFF_UP)) {
590                         /* Coming out of loopback mode. */
591                         sp->pp_link_state=SPPP_LINK_UP;
592                         printk (KERN_INFO "%s: protocol up\n", dev->name);
593                 }
594                 switch (sp->lcp.state) {
595                 case LCP_STATE_CLOSED:
596                         sp->lcp.state = LCP_STATE_ACK_RCVD;
597                         sppp_set_timeout (sp, 5);
598                         break;
599                 case LCP_STATE_ACK_SENT:
600                         sp->lcp.state = LCP_STATE_OPENED;
601                         sppp_ipcp_open (sp);
602                         break;
603                 }
604                 break;
605         case LCP_CONF_NAK:
606                 if (h->ident != sp->lcp.confid)
607                         break;
608                 p = (u8*) (h+1);
609                 if (len>=10 && p[0] == LCP_OPT_MAGIC && p[1] >= 4) {
610                         rmagic = (u32)p[2] << 24 |
611                                 (u32)p[3] << 16 | p[4] << 8 | p[5];
612                         if (rmagic == ~sp->lcp.magic) {
613                                 int newmagic;
614                                 if (sp->pp_flags & PP_DEBUG)
615                                         printk (KERN_DEBUG "%s: conf nak: magic glitch\n",
616                                                 dev->name);
617                                 get_random_bytes(&newmagic, sizeof(newmagic));
618                                 sp->lcp.magic += newmagic;
619                         } else
620                                 sp->lcp.magic = rmagic;
621                         }
622                 if (sp->lcp.state != LCP_STATE_ACK_SENT) {
623                         /* Go to closed state. */
624                         sp->lcp.state = LCP_STATE_CLOSED;
625                         sp->ipcp.state = IPCP_STATE_CLOSED;
626                 }
627                 /* The link will be renegotiated after timeout,
628                  * to avoid endless req-nack loop. */
629                 sppp_clear_timeout (sp);
630                 sppp_set_timeout (sp, 2);
631                 break;
632         case LCP_CONF_REJ:
633                 if (h->ident != sp->lcp.confid)
634                         break;
635                 sppp_clear_timeout (sp);
636                 /* Initiate renegotiation. */
637                 sppp_lcp_open (sp);
638                 if (sp->lcp.state != LCP_STATE_ACK_SENT) {
639                         /* Go to closed state. */
640                         sp->lcp.state = LCP_STATE_CLOSED;
641                         sp->ipcp.state = IPCP_STATE_CLOSED;
642                 }
643                 break;
644         case LCP_TERM_REQ:
645                 sppp_clear_timeout (sp);
646                 /* Send Terminate-Ack packet. */
647                 sppp_cp_send (sp, PPP_LCP, LCP_TERM_ACK, h->ident, 0, NULL);
648                 /* Go to closed state. */
649                 sp->lcp.state = LCP_STATE_CLOSED;
650                 sp->ipcp.state = IPCP_STATE_CLOSED;
651                 /* Initiate renegotiation. */
652                 sppp_lcp_open (sp);
653                 break;
654         case LCP_TERM_ACK:
655         case LCP_CODE_REJ:
656         case LCP_PROTO_REJ:
657                 /* Ignore for now. */
658                 break;
659         case LCP_DISC_REQ:
660                 /* Discard the packet. */
661                 break;
662         case LCP_ECHO_REQ:
663                 if (sp->lcp.state != LCP_STATE_OPENED)
664                         break;
665                 if (len < 8) {
666                         if (sp->pp_flags & PP_DEBUG)
667                                 printk (KERN_WARNING "%s: invalid lcp echo request packet length: %d bytes\n",
668                                         dev->name, len);
669                         break;
670                 }
671                 if (ntohl (*(long*)(h+1)) == sp->lcp.magic) {
672                         /* Line loopback mode detected. */
673                         printk (KERN_WARNING "%s: loopback\n", dev->name);
674                         if_down (dev);
675
676                         /* Shut down the PPP link. */
677                         sp->lcp.state = LCP_STATE_CLOSED;
678                         sp->ipcp.state = IPCP_STATE_CLOSED;
679                         sppp_clear_timeout (sp);
680                         /* Initiate negotiation. */
681                         sppp_lcp_open (sp);
682                         break;
683                 }
684                 *(long*)(h+1) = htonl (sp->lcp.magic);
685                 sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REPLY, h->ident, len-4, h+1);
686                 break;
687         case LCP_ECHO_REPLY:
688                 if (h->ident != sp->lcp.echoid)
689                         break;
690                 if (len < 8) {
691                         if (sp->pp_flags & PP_DEBUG)
692                                 printk (KERN_WARNING "%s: invalid lcp echo reply packet length: %d bytes\n",
693                                         dev->name, len);
694                         break;
695                 }
696                 if (ntohl (*(long*)(h+1)) != sp->lcp.magic)
697                 sp->pp_alivecnt = 0;
698                 break;
699         }
700 }
701
702 /*
703  * Handle incoming Cisco keepalive protocol packets.
704  */
705
706 static void sppp_cisco_input (struct sppp *sp, struct sk_buff *skb)
707 {
708         struct cisco_packet *h;
709         struct net_device *dev = sp->pp_if;
710
711         if (!pskb_may_pull(skb, sizeof(struct cisco_packet))
712             || (skb->len != CISCO_PACKET_LEN
713                 && skb->len != CISCO_BIG_PACKET_LEN)) {
714                 if (sp->pp_flags & PP_DEBUG)
715                         printk (KERN_WARNING "%s: invalid cisco packet length: %d bytes\n",
716                                 dev->name,  skb->len);
717                 return;
718         }
719         h = (struct cisco_packet *)skb->data;
720         skb_pull(skb, sizeof(struct cisco_packet*));
721         if (sp->pp_flags & PP_DEBUG)
722                 printk (KERN_WARNING "%s: cisco input: %d bytes <%xh %xh %xh %xh %xh-%xh>\n",
723                         dev->name,  skb->len,
724                         ntohl (h->type), h->par1, h->par2, h->rel,
725                         h->time0, h->time1);
726         switch (ntohl (h->type)) {
727         default:
728                 if (sp->pp_flags & PP_DEBUG)
729                         printk (KERN_WARNING "%s: unknown cisco packet type: 0x%x\n",
730                                 dev->name,  ntohl (h->type));
731                 break;
732         case CISCO_ADDR_REPLY:
733                 /* Reply on address request, ignore */
734                 break;
735         case CISCO_KEEPALIVE_REQ:
736                 sp->pp_alivecnt = 0;
737                 sp->pp_rseq = ntohl (h->par1);
738                 if (sp->pp_seq == sp->pp_rseq) {
739                         /* Local and remote sequence numbers are equal.
740                          * Probably, the line is in loopback mode. */
741                         int newseq;
742                         if (sp->pp_loopcnt >= MAXALIVECNT) {
743                                 printk (KERN_WARNING "%s: loopback\n",
744                                         dev->name);
745                                 sp->pp_loopcnt = 0;
746                                 if (dev->flags & IFF_UP) {
747                                         if_down (dev);
748                                 }
749                         }
750                         ++sp->pp_loopcnt;
751
752                         /* Generate new local sequence number */
753                         get_random_bytes(&newseq, sizeof(newseq));
754                         sp->pp_seq ^= newseq;
755                         break;
756                 }
757                 sp->pp_loopcnt = 0;
758                 if (sp->pp_link_state==SPPP_LINK_DOWN &&
759                     (dev->flags & IFF_UP)) {
760                         sp->pp_link_state=SPPP_LINK_UP;
761                         printk (KERN_INFO "%s: protocol up\n", dev->name);
762                 }
763                 break;
764         case CISCO_ADDR_REQ:
765                 /* Stolen from net/ipv4/devinet.c -- SIOCGIFADDR ioctl */
766                 {
767                 struct in_device *in_dev;
768                 struct in_ifaddr *ifa;
769                 u32 addr = 0, mask = ~0; /* FIXME: is the mask correct? */
770 #ifdef CONFIG_INET
771                 rcu_read_lock();
772                 if ((in_dev = __in_dev_get(dev)) != NULL)
773                 {
774                         for (ifa=in_dev->ifa_list; ifa != NULL;
775                                 ifa=ifa->ifa_next) {
776                                 if (strcmp(dev->name, ifa->ifa_label) == 0) 
777                                 {
778                                         addr = ifa->ifa_local;
779                                         mask = ifa->ifa_mask;
780                                         break;
781                                 }
782                         }
783                 }
784                 rcu_read_unlock();
785 #endif          
786                 /* I hope both addr and mask are in the net order */
787                 sppp_cisco_send (sp, CISCO_ADDR_REPLY, addr, mask);
788                 break;
789                 }
790         }
791 }
792
793
794 /*
795  * Send PPP LCP packet.
796  */
797
798 static void sppp_cp_send (struct sppp *sp, u16 proto, u8 type,
799         u8 ident, u16 len, void *data)
800 {
801         struct ppp_header *h;
802         struct lcp_header *lh;
803         struct sk_buff *skb;
804         struct net_device *dev = sp->pp_if;
805
806         skb=alloc_skb(dev->hard_header_len+PPP_HEADER_LEN+LCP_HEADER_LEN+len,
807                 GFP_ATOMIC);
808         if (skb==NULL)
809                 return;
810
811         skb_reserve(skb,dev->hard_header_len);
812         
813         h = (struct ppp_header *)skb_put(skb, sizeof(struct ppp_header));
814         h->address = PPP_ALLSTATIONS;        /* broadcast address */
815         h->control = PPP_UI;                 /* Unnumbered Info */
816         h->protocol = htons (proto);         /* Link Control Protocol */
817
818         lh = (struct lcp_header *)skb_put(skb, sizeof(struct lcp_header));
819         lh->type = type;
820         lh->ident = ident;
821         lh->len = htons (LCP_HEADER_LEN + len);
822
823         if (len)
824                 memcpy(skb_put(skb,len),data, len);
825
826         if (sp->pp_flags & PP_DEBUG) {
827                 printk (KERN_WARNING "%s: %s output <%s id=%xh len=%xh",
828                         dev->name, 
829                         proto==PPP_LCP ? "lcp" : "ipcp",
830                         proto==PPP_LCP ? sppp_lcp_type_name (lh->type) :
831                         sppp_ipcp_type_name (lh->type), lh->ident,
832                         ntohs (lh->len));
833                 if (len)
834                         sppp_print_bytes ((u8*) (lh+1), len);
835                 printk (">\n");
836         }
837         sp->obytes += skb->len;
838         /* Control is high priority so it doesn't get queued behind data */
839         skb->priority=TC_PRIO_CONTROL;
840         skb->dev = dev;
841         skb_queue_tail(&tx_queue, skb);
842 }
843
844 /*
845  * Send Cisco keepalive packet.
846  */
847
848 static void sppp_cisco_send (struct sppp *sp, int type, long par1, long par2)
849 {
850         struct ppp_header *h;
851         struct cisco_packet *ch;
852         struct sk_buff *skb;
853         struct net_device *dev = sp->pp_if;
854         u32 t = jiffies * 1000/HZ;
855
856         skb=alloc_skb(dev->hard_header_len+PPP_HEADER_LEN+CISCO_PACKET_LEN,
857                 GFP_ATOMIC);
858
859         if(skb==NULL)
860                 return;
861                 
862         skb_reserve(skb, dev->hard_header_len);
863         h = (struct ppp_header *)skb_put (skb, sizeof(struct ppp_header));
864         h->address = CISCO_MULTICAST;
865         h->control = 0;
866         h->protocol = htons (CISCO_KEEPALIVE);
867
868         ch = (struct cisco_packet*)skb_put(skb, CISCO_PACKET_LEN);
869         ch->type = htonl (type);
870         ch->par1 = htonl (par1);
871         ch->par2 = htonl (par2);
872         ch->rel = -1;
873         ch->time0 = htons ((u16) (t >> 16));
874         ch->time1 = htons ((u16) t);
875
876         if (sp->pp_flags & PP_DEBUG)
877                 printk (KERN_WARNING "%s: cisco output: <%xh %xh %xh %xh %xh-%xh>\n",
878                         dev->name,  ntohl (ch->type), ch->par1,
879                         ch->par2, ch->rel, ch->time0, ch->time1);
880         sp->obytes += skb->len;
881         skb->priority=TC_PRIO_CONTROL;
882         skb->dev = dev;
883         skb_queue_tail(&tx_queue, skb);
884 }
885
886 /**
887  *      sppp_close - close down a synchronous PPP or Cisco HDLC link
888  *      @dev: The network device to drop the link of
889  *
890  *      This drops the logical interface to the channel. It is not
891  *      done politely as we assume we will also be dropping DTR. Any
892  *      timeouts are killed.
893  */
894
895 int sppp_close (struct net_device *dev)
896 {
897         struct sppp *sp = (struct sppp *)sppp_of(dev);
898         unsigned long flags;
899
900         spin_lock_irqsave(&sp->lock, flags);
901         sp->pp_link_state = SPPP_LINK_DOWN;
902         sp->lcp.state = LCP_STATE_CLOSED;
903         sp->ipcp.state = IPCP_STATE_CLOSED;
904         sppp_clear_timeout (sp);
905         spin_unlock_irqrestore(&sp->lock, flags);
906
907         return 0;
908 }
909
910 EXPORT_SYMBOL(sppp_close);
911
912 /**
913  *      sppp_open - open a synchronous PPP or Cisco HDLC link
914  *      @dev:   Network device to activate
915  *      
916  *      Close down any existing synchronous session and commence
917  *      from scratch. In the PPP case this means negotiating LCP/IPCP
918  *      and friends, while for Cisco HDLC we simply need to start sending
919  *      keepalives
920  */
921
922 int sppp_open (struct net_device *dev)
923 {
924         struct sppp *sp = (struct sppp *)sppp_of(dev);
925         unsigned long flags;
926
927         sppp_close(dev);
928
929         spin_lock_irqsave(&sp->lock, flags);
930         if (!(sp->pp_flags & PP_CISCO)) {
931                 sppp_lcp_open (sp);
932         }
933         sp->pp_link_state = SPPP_LINK_DOWN;
934         spin_unlock_irqrestore(&sp->lock, flags);
935         sppp_flush_xmit();
936
937         return 0;
938 }
939
940 EXPORT_SYMBOL(sppp_open);
941
942 /**
943  *      sppp_reopen - notify of physical link loss
944  *      @dev: Device that lost the link
945  *
946  *      This function informs the synchronous protocol code that
947  *      the underlying link died (for example a carrier drop on X.21)
948  *
949  *      We increment the magic numbers to ensure that if the other end
950  *      failed to notice we will correctly start a new session. It happens
951  *      do to the nature of telco circuits is that you can lose carrier on
952  *      one endonly.
953  *
954  *      Having done this we go back to negotiating. This function may
955  *      be called from an interrupt context.
956  */
957  
958 int sppp_reopen (struct net_device *dev)
959 {
960         struct sppp *sp = (struct sppp *)sppp_of(dev);
961         unsigned long flags;
962
963         sppp_close(dev);
964
965         spin_lock_irqsave(&sp->lock, flags);
966         if (!(sp->pp_flags & PP_CISCO))
967         {
968                 sp->lcp.magic = jiffies;
969                 ++sp->pp_seq;
970                 sp->lcp.state = LCP_STATE_CLOSED;
971                 sp->ipcp.state = IPCP_STATE_CLOSED;
972                 /* Give it a moment for the line to settle then go */
973                 sppp_set_timeout (sp, 1);
974         } 
975         sp->pp_link_state=SPPP_LINK_DOWN;
976         spin_unlock_irqrestore(&sp->lock, flags);
977
978         return 0;
979 }
980
981 EXPORT_SYMBOL(sppp_reopen);
982
983 /**
984  *      sppp_change_mtu - Change the link MTU
985  *      @dev:   Device to change MTU on
986  *      @new_mtu: New MTU
987  *
988  *      Change the MTU on the link. This can only be called with
989  *      the link down. It returns an error if the link is up or
990  *      the mtu is out of range.
991  */
992  
993 int sppp_change_mtu(struct net_device *dev, int new_mtu)
994 {
995         if(new_mtu<128||new_mtu>PPP_MTU||(dev->flags&IFF_UP))
996                 return -EINVAL;
997         dev->mtu=new_mtu;
998         return 0;
999 }
1000
1001 EXPORT_SYMBOL(sppp_change_mtu);
1002
1003 /**
1004  *      sppp_do_ioctl - Ioctl handler for ppp/hdlc
1005  *      @dev: Device subject to ioctl
1006  *      @ifr: Interface request block from the user
1007  *      @cmd: Command that is being issued
1008  *      
1009  *      This function handles the ioctls that may be issued by the user
1010  *      to control the settings of a PPP/HDLC link. It does both busy
1011  *      and security checks. This function is intended to be wrapped by
1012  *      callers who wish to add additional ioctl calls of their own.
1013  */
1014  
1015 int sppp_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1016 {
1017         struct sppp *sp = (struct sppp *)sppp_of(dev);
1018
1019         if(dev->flags&IFF_UP)
1020                 return -EBUSY;
1021                 
1022         if(!capable(CAP_NET_ADMIN))
1023                 return -EPERM;
1024         
1025         switch(cmd)
1026         {
1027                 case SPPPIOCCISCO:
1028                         sp->pp_flags|=PP_CISCO;
1029                         dev->type = ARPHRD_HDLC;
1030                         break;
1031                 case SPPPIOCPPP:
1032                         sp->pp_flags&=~PP_CISCO;
1033                         dev->type = ARPHRD_PPP;
1034                         break;
1035                 case SPPPIOCDEBUG:
1036                         sp->pp_flags&=~PP_DEBUG;
1037                         if(ifr->ifr_flags)
1038                                 sp->pp_flags|=PP_DEBUG;
1039                         break;
1040                 case SPPPIOCGFLAGS:
1041                         if(copy_to_user(ifr->ifr_data, &sp->pp_flags, sizeof(sp->pp_flags)))
1042                                 return -EFAULT;
1043                         break;
1044                 case SPPPIOCSFLAGS:
1045                         if(copy_from_user(&sp->pp_flags, ifr->ifr_data, sizeof(sp->pp_flags)))
1046                                 return -EFAULT;
1047                         break;
1048                 default:
1049                         return -EINVAL;
1050         }
1051         return 0;
1052 }
1053
1054 EXPORT_SYMBOL(sppp_do_ioctl);
1055
1056 /**
1057  *      sppp_attach - attach synchronous PPP/HDLC to a device
1058  *      @pd:    PPP device to initialise
1059  *
1060  *      This initialises the PPP/HDLC support on an interface. At the
1061  *      time of calling the dev element must point to the network device
1062  *      that this interface is attached to. The interface should not yet
1063  *      be registered. 
1064  */
1065  
1066 void sppp_attach(struct ppp_device *pd)
1067 {
1068         struct net_device *dev = pd->dev;
1069         struct sppp *sp = &pd->sppp;
1070         unsigned long flags;
1071
1072         /* Make sure embedding is safe for sppp_of */
1073         BUG_ON(sppp_of(dev) != sp);
1074
1075         spin_lock_irqsave(&spppq_lock, flags);
1076         /* Initialize keepalive handler. */
1077         if (! spppq)
1078         {
1079                 init_timer(&sppp_keepalive_timer);
1080                 sppp_keepalive_timer.expires=jiffies+10*HZ;
1081                 sppp_keepalive_timer.function=sppp_keepalive;
1082                 add_timer(&sppp_keepalive_timer);
1083         }
1084         /* Insert new entry into the keepalive list. */
1085         sp->pp_next = spppq;
1086         spppq = sp;
1087         spin_unlock_irqrestore(&spppq_lock, flags);
1088
1089         sp->pp_loopcnt = 0;
1090         sp->pp_alivecnt = 0;
1091         sp->pp_seq = 0;
1092         sp->pp_rseq = 0;
1093         sp->pp_flags = PP_KEEPALIVE|PP_CISCO|debug;/*PP_DEBUG;*/
1094         sp->lcp.magic = 0;
1095         sp->lcp.state = LCP_STATE_CLOSED;
1096         sp->ipcp.state = IPCP_STATE_CLOSED;
1097         sp->pp_if = dev;
1098         spin_lock_init(&sp->lock);
1099         
1100         /* 
1101          *      Device specific setup. All but interrupt handler and
1102          *      hard_start_xmit.
1103          */
1104          
1105         dev->hard_header = sppp_hard_header;
1106         dev->rebuild_header = sppp_rebuild_header;
1107         dev->tx_queue_len = 10;
1108         dev->type = ARPHRD_HDLC;
1109         dev->addr_len = 0;
1110         dev->hard_header_len = sizeof(struct ppp_header);
1111         dev->mtu = PPP_MTU;
1112         /*
1113          *      These 4 are callers but MUST also call sppp_ functions
1114          */
1115         dev->do_ioctl = sppp_do_ioctl;
1116 #if 0
1117         dev->get_stats = NULL;          /* Let the driver override these */
1118         dev->open = sppp_open;
1119         dev->stop = sppp_close;
1120 #endif  
1121         dev->change_mtu = sppp_change_mtu;
1122         dev->hard_header_cache = NULL;
1123         dev->header_cache_update = NULL;
1124         dev->flags = IFF_MULTICAST|IFF_POINTOPOINT|IFF_NOARP;
1125 }
1126
1127 EXPORT_SYMBOL(sppp_attach);
1128
1129 /**
1130  *      sppp_detach - release PPP resources from a device
1131  *      @dev:   Network device to release
1132  *
1133  *      Stop and free up any PPP/HDLC resources used by this
1134  *      interface. This must be called before the device is
1135  *      freed.
1136  */
1137  
1138 void sppp_detach (struct net_device *dev)
1139 {
1140         struct sppp **q, *p, *sp = (struct sppp *)sppp_of(dev);
1141         unsigned long flags;
1142
1143         spin_lock_irqsave(&spppq_lock, flags);
1144         /* Remove the entry from the keepalive list. */
1145         for (q = &spppq; (p = *q); q = &p->pp_next)
1146                 if (p == sp) {
1147                         *q = p->pp_next;
1148                         break;
1149                 }
1150
1151         /* Stop keepalive handler. */
1152         if (! spppq)
1153                 del_timer(&sppp_keepalive_timer);
1154         sppp_clear_timeout (sp);
1155         spin_unlock_irqrestore(&spppq_lock, flags);
1156 }
1157
1158 EXPORT_SYMBOL(sppp_detach);
1159
1160 /*
1161  * Analyze the LCP Configure-Request options list
1162  * for the presence of unknown options.
1163  * If the request contains unknown options, build and
1164  * send Configure-reject packet, containing only unknown options.
1165  */
1166 static int
1167 sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h,
1168         int len, u32 *magic)
1169 {
1170         u8 *buf, *r, *p;
1171         int rlen;
1172
1173         len -= 4;
1174         buf = r = kmalloc (len, GFP_ATOMIC);
1175         if (! buf)
1176                 return (0);
1177
1178         p = (void*) (h+1);
1179         for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
1180                 switch (*p) {
1181                 case LCP_OPT_MAGIC:
1182                         /* Magic number -- extract. */
1183                         if (len >= 6 && p[1] == 6) {
1184                                 *magic = (u32)p[2] << 24 |
1185                                         (u32)p[3] << 16 | p[4] << 8 | p[5];
1186                                 continue;
1187                         }
1188                         break;
1189                 case LCP_OPT_ASYNC_MAP:
1190                         /* Async control character map -- check to be zero. */
1191                         if (len >= 6 && p[1] == 6 && ! p[2] && ! p[3] &&
1192                             ! p[4] && ! p[5])
1193                                 continue;
1194                         break;
1195                 case LCP_OPT_MRU:
1196                         /* Maximum receive unit -- always OK. */
1197                         continue;
1198                 default:
1199                         /* Others not supported. */
1200                         break;
1201                 }
1202                 /* Add the option to rejected list. */
1203                 memcpy(r, p, p[1]);
1204                 r += p[1];
1205                 rlen += p[1];
1206         }
1207         if (rlen)
1208                 sppp_cp_send (sp, PPP_LCP, LCP_CONF_REJ, h->ident, rlen, buf);
1209         kfree(buf);
1210         return (rlen == 0);
1211 }
1212
1213 static void sppp_ipcp_input (struct sppp *sp, struct sk_buff *skb)
1214 {
1215         struct lcp_header *h;
1216         struct net_device *dev = sp->pp_if;
1217         int len = skb->len;
1218
1219         if (!pskb_may_pull(skb, sizeof(struct lcp_header))) {
1220                 if (sp->pp_flags & PP_DEBUG)
1221                         printk (KERN_WARNING "%s: invalid ipcp packet length: %d bytes\n",
1222                                 dev->name,  len);
1223                 return;
1224         }
1225         h = (struct lcp_header *)skb->data;
1226         skb_pull(skb,sizeof(struct lcp_header));
1227         if (sp->pp_flags & PP_DEBUG) {
1228                 printk (KERN_WARNING "%s: ipcp input: %d bytes <%s id=%xh len=%xh",
1229                         dev->name,  len,
1230                         sppp_ipcp_type_name (h->type), h->ident, ntohs (h->len));
1231                 if (len > 4)
1232                         sppp_print_bytes ((u8*) (h+1), len-4);
1233                 printk (">\n");
1234         }
1235         if (len > ntohs (h->len))
1236                 len = ntohs (h->len);
1237         switch (h->type) {
1238         default:
1239                 /* Unknown packet type -- send Code-Reject packet. */
1240                 sppp_cp_send (sp, PPP_IPCP, IPCP_CODE_REJ, ++sp->pp_seq, len, h);
1241                 break;
1242         case IPCP_CONF_REQ:
1243                 if (len < 4) {
1244                         if (sp->pp_flags & PP_DEBUG)
1245                                 printk (KERN_WARNING "%s: invalid ipcp configure request packet length: %d bytes\n",
1246                                         dev->name, len);
1247                         return;
1248                 }
1249                 if (len > 4) {
1250                         sppp_cp_send (sp, PPP_IPCP, LCP_CONF_REJ, h->ident,
1251                                 len-4, h+1);
1252
1253                         switch (sp->ipcp.state) {
1254                         case IPCP_STATE_OPENED:
1255                                 /* Initiate renegotiation. */
1256                                 sppp_ipcp_open (sp);
1257                                 /* fall through... */
1258                         case IPCP_STATE_ACK_SENT:
1259                                 /* Go to closed state. */
1260                                 sp->ipcp.state = IPCP_STATE_CLOSED;
1261                         }
1262                 } else {
1263                         /* Send Configure-Ack packet. */
1264                         sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_ACK, h->ident,
1265                                 0, NULL);
1266                         /* Change the state. */
1267                         if (sp->ipcp.state == IPCP_STATE_ACK_RCVD)
1268                                 sp->ipcp.state = IPCP_STATE_OPENED;
1269                         else
1270                                 sp->ipcp.state = IPCP_STATE_ACK_SENT;
1271                 }
1272                 break;
1273         case IPCP_CONF_ACK:
1274                 if (h->ident != sp->ipcp.confid)
1275                         break;
1276                 sppp_clear_timeout (sp);
1277                 switch (sp->ipcp.state) {
1278                 case IPCP_STATE_CLOSED:
1279                         sp->ipcp.state = IPCP_STATE_ACK_RCVD;
1280                         sppp_set_timeout (sp, 5);
1281                         break;
1282                 case IPCP_STATE_ACK_SENT:
1283                         sp->ipcp.state = IPCP_STATE_OPENED;
1284                         break;
1285                 }
1286                 break;
1287         case IPCP_CONF_NAK:
1288         case IPCP_CONF_REJ:
1289                 if (h->ident != sp->ipcp.confid)
1290                         break;
1291                 sppp_clear_timeout (sp);
1292                         /* Initiate renegotiation. */
1293                 sppp_ipcp_open (sp);
1294                 if (sp->ipcp.state != IPCP_STATE_ACK_SENT)
1295                         /* Go to closed state. */
1296                         sp->ipcp.state = IPCP_STATE_CLOSED;
1297                 break;
1298         case IPCP_TERM_REQ:
1299                 /* Send Terminate-Ack packet. */
1300                 sppp_cp_send (sp, PPP_IPCP, IPCP_TERM_ACK, h->ident, 0, NULL);
1301                 /* Go to closed state. */
1302                 sp->ipcp.state = IPCP_STATE_CLOSED;
1303                 /* Initiate renegotiation. */
1304                 sppp_ipcp_open (sp);
1305                 break;
1306         case IPCP_TERM_ACK:
1307                 /* Ignore for now. */
1308         case IPCP_CODE_REJ:
1309                 /* Ignore for now. */
1310                 break;
1311         }
1312 }
1313
1314 static void sppp_lcp_open (struct sppp *sp)
1315 {
1316         char opt[6];
1317
1318         if (! sp->lcp.magic)
1319                 sp->lcp.magic = jiffies;
1320         opt[0] = LCP_OPT_MAGIC;
1321         opt[1] = sizeof (opt);
1322         opt[2] = sp->lcp.magic >> 24;
1323         opt[3] = sp->lcp.magic >> 16;
1324         opt[4] = sp->lcp.magic >> 8;
1325         opt[5] = sp->lcp.magic;
1326         sp->lcp.confid = ++sp->pp_seq;
1327         sppp_cp_send (sp, PPP_LCP, LCP_CONF_REQ, sp->lcp.confid,
1328                 sizeof (opt), &opt);
1329         sppp_set_timeout (sp, 2);
1330 }
1331
1332 static void sppp_ipcp_open (struct sppp *sp)
1333 {
1334         sp->ipcp.confid = ++sp->pp_seq;
1335         sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_REQ, sp->ipcp.confid, 0, NULL);
1336         sppp_set_timeout (sp, 2);
1337 }
1338
1339 /*
1340  * Process PPP control protocol timeouts.
1341  */
1342  
1343 static void sppp_cp_timeout (unsigned long arg)
1344 {
1345         struct sppp *sp = (struct sppp*) arg;
1346         unsigned long flags;
1347
1348         spin_lock_irqsave(&sp->lock, flags);
1349
1350         sp->pp_flags &= ~PP_TIMO;
1351         if (! (sp->pp_if->flags & IFF_UP) || (sp->pp_flags & PP_CISCO)) {
1352                 spin_unlock_irqrestore(&sp->lock, flags);
1353                 return;
1354         }
1355         switch (sp->lcp.state) {
1356         case LCP_STATE_CLOSED:
1357                 /* No ACK for Configure-Request, retry. */
1358                 sppp_lcp_open (sp);
1359                 break;
1360         case LCP_STATE_ACK_RCVD:
1361                 /* ACK got, but no Configure-Request for peer, retry. */
1362                 sppp_lcp_open (sp);
1363                 sp->lcp.state = LCP_STATE_CLOSED;
1364                 break;
1365         case LCP_STATE_ACK_SENT:
1366                 /* ACK sent but no ACK for Configure-Request, retry. */
1367                 sppp_lcp_open (sp);
1368                 break;
1369         case LCP_STATE_OPENED:
1370                 /* LCP is already OK, try IPCP. */
1371                 switch (sp->ipcp.state) {
1372                 case IPCP_STATE_CLOSED:
1373                         /* No ACK for Configure-Request, retry. */
1374                         sppp_ipcp_open (sp);
1375                         break;
1376                 case IPCP_STATE_ACK_RCVD:
1377                         /* ACK got, but no Configure-Request for peer, retry. */
1378                         sppp_ipcp_open (sp);
1379                         sp->ipcp.state = IPCP_STATE_CLOSED;
1380                         break;
1381                 case IPCP_STATE_ACK_SENT:
1382                         /* ACK sent but no ACK for Configure-Request, retry. */
1383                         sppp_ipcp_open (sp);
1384                         break;
1385                 case IPCP_STATE_OPENED:
1386                         /* IPCP is OK. */
1387                         break;
1388                 }
1389                 break;
1390         }
1391         spin_unlock_irqrestore(&sp->lock, flags);
1392         sppp_flush_xmit();
1393 }
1394
1395 static char *sppp_lcp_type_name (u8 type)
1396 {
1397         static char buf [8];
1398         switch (type) {
1399         case LCP_CONF_REQ:   return ("conf-req");
1400         case LCP_CONF_ACK:   return ("conf-ack");
1401         case LCP_CONF_NAK:   return ("conf-nack");
1402         case LCP_CONF_REJ:   return ("conf-rej");
1403         case LCP_TERM_REQ:   return ("term-req");
1404         case LCP_TERM_ACK:   return ("term-ack");
1405         case LCP_CODE_REJ:   return ("code-rej");
1406         case LCP_PROTO_REJ:  return ("proto-rej");
1407         case LCP_ECHO_REQ:   return ("echo-req");
1408         case LCP_ECHO_REPLY: return ("echo-reply");
1409         case LCP_DISC_REQ:   return ("discard-req");
1410         }
1411         sprintf (buf, "%xh", type);
1412         return (buf);
1413 }
1414
1415 static char *sppp_ipcp_type_name (u8 type)
1416 {
1417         static char buf [8];
1418         switch (type) {
1419         case IPCP_CONF_REQ:   return ("conf-req");
1420         case IPCP_CONF_ACK:   return ("conf-ack");
1421         case IPCP_CONF_NAK:   return ("conf-nack");
1422         case IPCP_CONF_REJ:   return ("conf-rej");
1423         case IPCP_TERM_REQ:   return ("term-req");
1424         case IPCP_TERM_ACK:   return ("term-ack");
1425         case IPCP_CODE_REJ:   return ("code-rej");
1426         }
1427         sprintf (buf, "%xh", type);
1428         return (buf);
1429 }
1430
1431 static void sppp_print_bytes (u_char *p, u16 len)
1432 {
1433         printk (" %x", *p++);
1434         while (--len > 0)
1435                 printk ("-%x", *p++);
1436 }
1437
1438 /**
1439  *      sppp_rcv -      receive and process a WAN PPP frame
1440  *      @skb:   The buffer to process
1441  *      @dev:   The device it arrived on
1442  *      @p: Unused
1443  *      @orig_dev: Unused
1444  *
1445  *      Protocol glue. This drives the deferred processing mode the poorer
1446  *      cards use. This can be called directly by cards that do not have
1447  *      timing constraints but is normally called from the network layer
1448  *      after interrupt servicing to process frames queued via netif_rx.
1449  */
1450
1451 static int sppp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *p, struct net_device *orig_dev)
1452 {
1453         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
1454                 return NET_RX_DROP;
1455         sppp_input(dev,skb);
1456         return 0;
1457 }
1458
1459 struct packet_type sppp_packet_type = {
1460         .type   = __constant_htons(ETH_P_WAN_PPP),
1461         .func   = sppp_rcv,
1462 };
1463
1464 static char banner[] __initdata = 
1465         KERN_INFO "Cronyx Ltd, Synchronous PPP and CISCO HDLC (c) 1994\n"
1466         KERN_INFO "Linux port (c) 1998 Building Number Three Ltd & "
1467                   "Jan \"Yenya\" Kasprzak.\n";
1468
1469 static int __init sync_ppp_init(void)
1470 {
1471         if(debug)
1472                 debug=PP_DEBUG;
1473         printk(banner);
1474         skb_queue_head_init(&tx_queue);
1475         dev_add_pack(&sppp_packet_type);
1476         return 0;
1477 }
1478
1479
1480 static void __exit sync_ppp_cleanup(void)
1481 {
1482         dev_remove_pack(&sppp_packet_type);
1483 }
1484
1485 module_init(sync_ppp_init);
1486 module_exit(sync_ppp_cleanup);
1487 module_param(debug, int, 0);
1488 MODULE_LICENSE("GPL");
1489