[IRDA]: ali-ircc: using device model power management
[linux-2.6] / 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 static 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 /*
359  *      Handle transmit packets.
360  */
361  
362 static int sppp_hard_header(struct sk_buff *skb, struct net_device *dev, __u16 type,
363                 void *daddr, void *saddr, unsigned int len)
364 {
365         struct sppp *sp = (struct sppp *)sppp_of(dev);
366         struct ppp_header *h;
367         skb_push(skb,sizeof(struct ppp_header));
368         h=(struct ppp_header *)skb->data;
369         if(sp->pp_flags&PP_CISCO)
370         {
371                 h->address = CISCO_UNICAST;
372                 h->control = 0;
373         }
374         else
375         {
376                 h->address = PPP_ALLSTATIONS;
377                 h->control = PPP_UI;
378         }
379         if(sp->pp_flags & PP_CISCO)
380         {
381                 h->protocol = htons(type);
382         }
383         else switch(type)
384         {
385                 case ETH_P_IP:
386                         h->protocol = htons(PPP_IP);
387                         break;
388                 case ETH_P_IPX:
389                         h->protocol = htons(PPP_IPX);
390                         break;
391         }
392         return sizeof(struct ppp_header);
393 }
394
395 static int sppp_rebuild_header(struct sk_buff *skb)
396 {
397         return 0;
398 }
399
400 /*
401  * Send keepalive packets, every 10 seconds.
402  */
403
404 static void sppp_keepalive (unsigned long dummy)
405 {
406         struct sppp *sp;
407         unsigned long flags;
408
409         spin_lock_irqsave(&spppq_lock, flags);
410
411         for (sp=spppq; sp; sp=sp->pp_next) 
412         {
413                 struct net_device *dev = sp->pp_if;
414
415                 /* Keepalive mode disabled or channel down? */
416                 if (! (sp->pp_flags & PP_KEEPALIVE) ||
417                     ! (dev->flags & IFF_UP))
418                         continue;
419
420                 spin_lock(&sp->lock);
421
422                 /* No keepalive in PPP mode if LCP not opened yet. */
423                 if (! (sp->pp_flags & PP_CISCO) &&
424                     sp->lcp.state != LCP_STATE_OPENED) {
425                         spin_unlock(&sp->lock);
426                         continue;
427                 }
428
429                 if (sp->pp_alivecnt == MAXALIVECNT) {
430                         /* No keepalive packets got.  Stop the interface. */
431                         printk (KERN_WARNING "%s: protocol down\n", dev->name);
432                         if_down (dev);
433                         if (! (sp->pp_flags & PP_CISCO)) {
434                                 /* Shut down the PPP link. */
435                                 sp->lcp.magic = jiffies;
436                                 sp->lcp.state = LCP_STATE_CLOSED;
437                                 sp->ipcp.state = IPCP_STATE_CLOSED;
438                                 sppp_clear_timeout (sp);
439                                 /* Initiate negotiation. */
440                                 sppp_lcp_open (sp);
441                         }
442                 }
443                 if (sp->pp_alivecnt <= MAXALIVECNT)
444                         ++sp->pp_alivecnt;
445                 if (sp->pp_flags & PP_CISCO)
446                         sppp_cisco_send (sp, CISCO_KEEPALIVE_REQ, ++sp->pp_seq,
447                                 sp->pp_rseq);
448                 else if (sp->lcp.state == LCP_STATE_OPENED) {
449                         long nmagic = htonl (sp->lcp.magic);
450                         sp->lcp.echoid = ++sp->pp_seq;
451                         sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REQ,
452                                 sp->lcp.echoid, 4, &nmagic);
453                 }
454
455                 spin_unlock(&sp->lock);
456         }
457         spin_unlock_irqrestore(&spppq_lock, flags);
458         sppp_flush_xmit();
459         sppp_keepalive_timer.expires=jiffies+10*HZ;
460         add_timer(&sppp_keepalive_timer);
461 }
462
463 /*
464  * Handle incoming PPP Link Control Protocol packets.
465  */
466  
467 static void sppp_lcp_input (struct sppp *sp, struct sk_buff *skb)
468 {
469         struct lcp_header *h;
470         struct net_device *dev = sp->pp_if;
471         int len = skb->len;
472         u8 *p, opt[6];
473         u32 rmagic;
474
475         if (!pskb_may_pull(skb, sizeof(struct lcp_header))) {
476                 if (sp->pp_flags & PP_DEBUG)
477                         printk (KERN_WARNING "%s: invalid lcp packet length: %d bytes\n",
478                                 dev->name, len);
479                 return;
480         }
481         h = (struct lcp_header *)skb->data;
482         skb_pull(skb,sizeof(struct lcp_header *));
483         
484         if (sp->pp_flags & PP_DEBUG) 
485         {
486                 char state = '?';
487                 switch (sp->lcp.state) {
488                 case LCP_STATE_CLOSED:   state = 'C'; break;
489                 case LCP_STATE_ACK_RCVD: state = 'R'; break;
490                 case LCP_STATE_ACK_SENT: state = 'S'; break;
491                 case LCP_STATE_OPENED:   state = 'O'; break;
492                 }
493                 printk (KERN_WARNING "%s: lcp input(%c): %d bytes <%s id=%xh len=%xh",
494                         dev->name, state, len,
495                         sppp_lcp_type_name (h->type), h->ident, ntohs (h->len));
496                 if (len > 4)
497                         sppp_print_bytes ((u8*) (h+1), len-4);
498                 printk (">\n");
499         }
500         if (len > ntohs (h->len))
501                 len = ntohs (h->len);
502         switch (h->type) {
503         default:
504                 /* Unknown packet type -- send Code-Reject packet. */
505                 sppp_cp_send (sp, PPP_LCP, LCP_CODE_REJ, ++sp->pp_seq,
506                         skb->len, h);
507                 break;
508         case LCP_CONF_REQ:
509                 if (len < 4) {
510                         if (sp->pp_flags & PP_DEBUG)
511                                 printk (KERN_DEBUG"%s: invalid lcp configure request packet length: %d bytes\n",
512                                         dev->name, len);
513                         break;
514                 }
515                 if (len>4 && !sppp_lcp_conf_parse_options (sp, h, len, &rmagic))
516                         goto badreq;
517                 if (rmagic == sp->lcp.magic) {
518                         /* Local and remote magics equal -- loopback? */
519                         if (sp->pp_loopcnt >= MAXALIVECNT*5) {
520                                 printk (KERN_WARNING "%s: loopback\n",
521                                         dev->name);
522                                 sp->pp_loopcnt = 0;
523                                 if (dev->flags & IFF_UP) {
524                                         if_down (dev);
525                                 }
526                         } else if (sp->pp_flags & PP_DEBUG)
527                                 printk (KERN_DEBUG "%s: conf req: magic glitch\n",
528                                         dev->name);
529                         ++sp->pp_loopcnt;
530
531                         /* MUST send Conf-Nack packet. */
532                         rmagic = ~sp->lcp.magic;
533                         opt[0] = LCP_OPT_MAGIC;
534                         opt[1] = sizeof (opt);
535                         opt[2] = rmagic >> 24;
536                         opt[3] = rmagic >> 16;
537                         opt[4] = rmagic >> 8;
538                         opt[5] = rmagic;
539                         sppp_cp_send (sp, PPP_LCP, LCP_CONF_NAK,
540                                 h->ident, sizeof (opt), &opt);
541 badreq:
542                         switch (sp->lcp.state) {
543                         case LCP_STATE_OPENED:
544                                 /* Initiate renegotiation. */
545                                 sppp_lcp_open (sp);
546                                 /* fall through... */
547                         case LCP_STATE_ACK_SENT:
548                                 /* Go to closed state. */
549                                 sp->lcp.state = LCP_STATE_CLOSED;
550                                 sp->ipcp.state = IPCP_STATE_CLOSED;
551                         }
552                         break;
553                 }
554                 /* Send Configure-Ack packet. */
555                 sp->pp_loopcnt = 0;
556                 if (sp->lcp.state != LCP_STATE_OPENED) {
557                         sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK,
558                                         h->ident, len-4, h+1);
559                 }
560                 /* Change the state. */
561                 switch (sp->lcp.state) {
562                 case LCP_STATE_CLOSED:
563                         sp->lcp.state = LCP_STATE_ACK_SENT;
564                         break;
565                 case LCP_STATE_ACK_RCVD:
566                         sp->lcp.state = LCP_STATE_OPENED;
567                         sppp_ipcp_open (sp);
568                         break;
569                 case LCP_STATE_OPENED:
570                         /* Remote magic changed -- close session. */
571                         sp->lcp.state = LCP_STATE_CLOSED;
572                         sp->ipcp.state = IPCP_STATE_CLOSED;
573                         /* Initiate renegotiation. */
574                         sppp_lcp_open (sp);
575                         /* Send ACK after our REQ in attempt to break loop */
576                         sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK,
577                                         h->ident, len-4, h+1);
578                         sp->lcp.state = LCP_STATE_ACK_SENT;
579                         break;
580                 }
581                 break;
582         case LCP_CONF_ACK:
583                 if (h->ident != sp->lcp.confid)
584                         break;
585                 sppp_clear_timeout (sp);
586                 if ((sp->pp_link_state != SPPP_LINK_UP) &&
587                     (dev->flags & IFF_UP)) {
588                         /* Coming out of loopback mode. */
589                         sp->pp_link_state=SPPP_LINK_UP;
590                         printk (KERN_INFO "%s: protocol up\n", dev->name);
591                 }
592                 switch (sp->lcp.state) {
593                 case LCP_STATE_CLOSED:
594                         sp->lcp.state = LCP_STATE_ACK_RCVD;
595                         sppp_set_timeout (sp, 5);
596                         break;
597                 case LCP_STATE_ACK_SENT:
598                         sp->lcp.state = LCP_STATE_OPENED;
599                         sppp_ipcp_open (sp);
600                         break;
601                 }
602                 break;
603         case LCP_CONF_NAK:
604                 if (h->ident != sp->lcp.confid)
605                         break;
606                 p = (u8*) (h+1);
607                 if (len>=10 && p[0] == LCP_OPT_MAGIC && p[1] >= 4) {
608                         rmagic = (u32)p[2] << 24 |
609                                 (u32)p[3] << 16 | p[4] << 8 | p[5];
610                         if (rmagic == ~sp->lcp.magic) {
611                                 int newmagic;
612                                 if (sp->pp_flags & PP_DEBUG)
613                                         printk (KERN_DEBUG "%s: conf nak: magic glitch\n",
614                                                 dev->name);
615                                 get_random_bytes(&newmagic, sizeof(newmagic));
616                                 sp->lcp.magic += newmagic;
617                         } else
618                                 sp->lcp.magic = rmagic;
619                         }
620                 if (sp->lcp.state != LCP_STATE_ACK_SENT) {
621                         /* Go to closed state. */
622                         sp->lcp.state = LCP_STATE_CLOSED;
623                         sp->ipcp.state = IPCP_STATE_CLOSED;
624                 }
625                 /* The link will be renegotiated after timeout,
626                  * to avoid endless req-nack loop. */
627                 sppp_clear_timeout (sp);
628                 sppp_set_timeout (sp, 2);
629                 break;
630         case LCP_CONF_REJ:
631                 if (h->ident != sp->lcp.confid)
632                         break;
633                 sppp_clear_timeout (sp);
634                 /* Initiate renegotiation. */
635                 sppp_lcp_open (sp);
636                 if (sp->lcp.state != LCP_STATE_ACK_SENT) {
637                         /* Go to closed state. */
638                         sp->lcp.state = LCP_STATE_CLOSED;
639                         sp->ipcp.state = IPCP_STATE_CLOSED;
640                 }
641                 break;
642         case LCP_TERM_REQ:
643                 sppp_clear_timeout (sp);
644                 /* Send Terminate-Ack packet. */
645                 sppp_cp_send (sp, PPP_LCP, LCP_TERM_ACK, h->ident, 0, NULL);
646                 /* Go to closed state. */
647                 sp->lcp.state = LCP_STATE_CLOSED;
648                 sp->ipcp.state = IPCP_STATE_CLOSED;
649                 /* Initiate renegotiation. */
650                 sppp_lcp_open (sp);
651                 break;
652         case LCP_TERM_ACK:
653         case LCP_CODE_REJ:
654         case LCP_PROTO_REJ:
655                 /* Ignore for now. */
656                 break;
657         case LCP_DISC_REQ:
658                 /* Discard the packet. */
659                 break;
660         case LCP_ECHO_REQ:
661                 if (sp->lcp.state != LCP_STATE_OPENED)
662                         break;
663                 if (len < 8) {
664                         if (sp->pp_flags & PP_DEBUG)
665                                 printk (KERN_WARNING "%s: invalid lcp echo request packet length: %d bytes\n",
666                                         dev->name, len);
667                         break;
668                 }
669                 if (ntohl (*(long*)(h+1)) == sp->lcp.magic) {
670                         /* Line loopback mode detected. */
671                         printk (KERN_WARNING "%s: loopback\n", dev->name);
672                         if_down (dev);
673
674                         /* Shut down the PPP link. */
675                         sp->lcp.state = LCP_STATE_CLOSED;
676                         sp->ipcp.state = IPCP_STATE_CLOSED;
677                         sppp_clear_timeout (sp);
678                         /* Initiate negotiation. */
679                         sppp_lcp_open (sp);
680                         break;
681                 }
682                 *(long*)(h+1) = htonl (sp->lcp.magic);
683                 sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REPLY, h->ident, len-4, h+1);
684                 break;
685         case LCP_ECHO_REPLY:
686                 if (h->ident != sp->lcp.echoid)
687                         break;
688                 if (len < 8) {
689                         if (sp->pp_flags & PP_DEBUG)
690                                 printk (KERN_WARNING "%s: invalid lcp echo reply packet length: %d bytes\n",
691                                         dev->name, len);
692                         break;
693                 }
694                 if (ntohl (*(long*)(h+1)) != sp->lcp.magic)
695                 sp->pp_alivecnt = 0;
696                 break;
697         }
698 }
699
700 /*
701  * Handle incoming Cisco keepalive protocol packets.
702  */
703
704 static void sppp_cisco_input (struct sppp *sp, struct sk_buff *skb)
705 {
706         struct cisco_packet *h;
707         struct net_device *dev = sp->pp_if;
708
709         if (!pskb_may_pull(skb, sizeof(struct cisco_packet))
710             || (skb->len != CISCO_PACKET_LEN
711                 && skb->len != CISCO_BIG_PACKET_LEN)) {
712                 if (sp->pp_flags & PP_DEBUG)
713                         printk (KERN_WARNING "%s: invalid cisco packet length: %d bytes\n",
714                                 dev->name,  skb->len);
715                 return;
716         }
717         h = (struct cisco_packet *)skb->data;
718         skb_pull(skb, sizeof(struct cisco_packet*));
719         if (sp->pp_flags & PP_DEBUG)
720                 printk (KERN_WARNING "%s: cisco input: %d bytes <%xh %xh %xh %xh %xh-%xh>\n",
721                         dev->name,  skb->len,
722                         ntohl (h->type), h->par1, h->par2, h->rel,
723                         h->time0, h->time1);
724         switch (ntohl (h->type)) {
725         default:
726                 if (sp->pp_flags & PP_DEBUG)
727                         printk (KERN_WARNING "%s: unknown cisco packet type: 0x%x\n",
728                                 dev->name,  ntohl (h->type));
729                 break;
730         case CISCO_ADDR_REPLY:
731                 /* Reply on address request, ignore */
732                 break;
733         case CISCO_KEEPALIVE_REQ:
734                 sp->pp_alivecnt = 0;
735                 sp->pp_rseq = ntohl (h->par1);
736                 if (sp->pp_seq == sp->pp_rseq) {
737                         /* Local and remote sequence numbers are equal.
738                          * Probably, the line is in loopback mode. */
739                         int newseq;
740                         if (sp->pp_loopcnt >= MAXALIVECNT) {
741                                 printk (KERN_WARNING "%s: loopback\n",
742                                         dev->name);
743                                 sp->pp_loopcnt = 0;
744                                 if (dev->flags & IFF_UP) {
745                                         if_down (dev);
746                                 }
747                         }
748                         ++sp->pp_loopcnt;
749
750                         /* Generate new local sequence number */
751                         get_random_bytes(&newseq, sizeof(newseq));
752                         sp->pp_seq ^= newseq;
753                         break;
754                 }
755                 sp->pp_loopcnt = 0;
756                 if (sp->pp_link_state==SPPP_LINK_DOWN &&
757                     (dev->flags & IFF_UP)) {
758                         sp->pp_link_state=SPPP_LINK_UP;
759                         printk (KERN_INFO "%s: protocol up\n", dev->name);
760                 }
761                 break;
762         case CISCO_ADDR_REQ:
763                 /* Stolen from net/ipv4/devinet.c -- SIOCGIFADDR ioctl */
764                 {
765                 struct in_device *in_dev;
766                 struct in_ifaddr *ifa;
767                 u32 addr = 0, mask = ~0; /* FIXME: is the mask correct? */
768 #ifdef CONFIG_INET
769                 rcu_read_lock();
770                 if ((in_dev = __in_dev_get_rcu(dev)) != NULL)
771                 {
772                         for (ifa=in_dev->ifa_list; ifa != NULL;
773                                 ifa=ifa->ifa_next) {
774                                 if (strcmp(dev->name, ifa->ifa_label) == 0) 
775                                 {
776                                         addr = ifa->ifa_local;
777                                         mask = ifa->ifa_mask;
778                                         break;
779                                 }
780                         }
781                 }
782                 rcu_read_unlock();
783 #endif          
784                 /* I hope both addr and mask are in the net order */
785                 sppp_cisco_send (sp, CISCO_ADDR_REPLY, addr, mask);
786                 break;
787                 }
788         }
789 }
790
791
792 /*
793  * Send PPP LCP packet.
794  */
795
796 static void sppp_cp_send (struct sppp *sp, u16 proto, u8 type,
797         u8 ident, u16 len, void *data)
798 {
799         struct ppp_header *h;
800         struct lcp_header *lh;
801         struct sk_buff *skb;
802         struct net_device *dev = sp->pp_if;
803
804         skb=alloc_skb(dev->hard_header_len+PPP_HEADER_LEN+LCP_HEADER_LEN+len,
805                 GFP_ATOMIC);
806         if (skb==NULL)
807                 return;
808
809         skb_reserve(skb,dev->hard_header_len);
810         
811         h = (struct ppp_header *)skb_put(skb, sizeof(struct ppp_header));
812         h->address = PPP_ALLSTATIONS;        /* broadcast address */
813         h->control = PPP_UI;                 /* Unnumbered Info */
814         h->protocol = htons (proto);         /* Link Control Protocol */
815
816         lh = (struct lcp_header *)skb_put(skb, sizeof(struct lcp_header));
817         lh->type = type;
818         lh->ident = ident;
819         lh->len = htons (LCP_HEADER_LEN + len);
820
821         if (len)
822                 memcpy(skb_put(skb,len),data, len);
823
824         if (sp->pp_flags & PP_DEBUG) {
825                 printk (KERN_WARNING "%s: %s output <%s id=%xh len=%xh",
826                         dev->name, 
827                         proto==PPP_LCP ? "lcp" : "ipcp",
828                         proto==PPP_LCP ? sppp_lcp_type_name (lh->type) :
829                         sppp_ipcp_type_name (lh->type), lh->ident,
830                         ntohs (lh->len));
831                 if (len)
832                         sppp_print_bytes ((u8*) (lh+1), len);
833                 printk (">\n");
834         }
835         sp->obytes += skb->len;
836         /* Control is high priority so it doesn't get queued behind data */
837         skb->priority=TC_PRIO_CONTROL;
838         skb->dev = dev;
839         skb_queue_tail(&tx_queue, skb);
840 }
841
842 /*
843  * Send Cisco keepalive packet.
844  */
845
846 static void sppp_cisco_send (struct sppp *sp, int type, long par1, long par2)
847 {
848         struct ppp_header *h;
849         struct cisco_packet *ch;
850         struct sk_buff *skb;
851         struct net_device *dev = sp->pp_if;
852         u32 t = jiffies * 1000/HZ;
853
854         skb=alloc_skb(dev->hard_header_len+PPP_HEADER_LEN+CISCO_PACKET_LEN,
855                 GFP_ATOMIC);
856
857         if(skb==NULL)
858                 return;
859                 
860         skb_reserve(skb, dev->hard_header_len);
861         h = (struct ppp_header *)skb_put (skb, sizeof(struct ppp_header));
862         h->address = CISCO_MULTICAST;
863         h->control = 0;
864         h->protocol = htons (CISCO_KEEPALIVE);
865
866         ch = (struct cisco_packet*)skb_put(skb, CISCO_PACKET_LEN);
867         ch->type = htonl (type);
868         ch->par1 = htonl (par1);
869         ch->par2 = htonl (par2);
870         ch->rel = -1;
871         ch->time0 = htons ((u16) (t >> 16));
872         ch->time1 = htons ((u16) t);
873
874         if (sp->pp_flags & PP_DEBUG)
875                 printk (KERN_WARNING "%s: cisco output: <%xh %xh %xh %xh %xh-%xh>\n",
876                         dev->name,  ntohl (ch->type), ch->par1,
877                         ch->par2, ch->rel, ch->time0, ch->time1);
878         sp->obytes += skb->len;
879         skb->priority=TC_PRIO_CONTROL;
880         skb->dev = dev;
881         skb_queue_tail(&tx_queue, skb);
882 }
883
884 /**
885  *      sppp_close - close down a synchronous PPP or Cisco HDLC link
886  *      @dev: The network device to drop the link of
887  *
888  *      This drops the logical interface to the channel. It is not
889  *      done politely as we assume we will also be dropping DTR. Any
890  *      timeouts are killed.
891  */
892
893 int sppp_close (struct net_device *dev)
894 {
895         struct sppp *sp = (struct sppp *)sppp_of(dev);
896         unsigned long flags;
897
898         spin_lock_irqsave(&sp->lock, flags);
899         sp->pp_link_state = SPPP_LINK_DOWN;
900         sp->lcp.state = LCP_STATE_CLOSED;
901         sp->ipcp.state = IPCP_STATE_CLOSED;
902         sppp_clear_timeout (sp);
903         spin_unlock_irqrestore(&sp->lock, flags);
904
905         return 0;
906 }
907
908 EXPORT_SYMBOL(sppp_close);
909
910 /**
911  *      sppp_open - open a synchronous PPP or Cisco HDLC link
912  *      @dev:   Network device to activate
913  *      
914  *      Close down any existing synchronous session and commence
915  *      from scratch. In the PPP case this means negotiating LCP/IPCP
916  *      and friends, while for Cisco HDLC we simply need to start sending
917  *      keepalives
918  */
919
920 int sppp_open (struct net_device *dev)
921 {
922         struct sppp *sp = (struct sppp *)sppp_of(dev);
923         unsigned long flags;
924
925         sppp_close(dev);
926
927         spin_lock_irqsave(&sp->lock, flags);
928         if (!(sp->pp_flags & PP_CISCO)) {
929                 sppp_lcp_open (sp);
930         }
931         sp->pp_link_state = SPPP_LINK_DOWN;
932         spin_unlock_irqrestore(&sp->lock, flags);
933         sppp_flush_xmit();
934
935         return 0;
936 }
937
938 EXPORT_SYMBOL(sppp_open);
939
940 /**
941  *      sppp_reopen - notify of physical link loss
942  *      @dev: Device that lost the link
943  *
944  *      This function informs the synchronous protocol code that
945  *      the underlying link died (for example a carrier drop on X.21)
946  *
947  *      We increment the magic numbers to ensure that if the other end
948  *      failed to notice we will correctly start a new session. It happens
949  *      do to the nature of telco circuits is that you can lose carrier on
950  *      one endonly.
951  *
952  *      Having done this we go back to negotiating. This function may
953  *      be called from an interrupt context.
954  */
955  
956 int sppp_reopen (struct net_device *dev)
957 {
958         struct sppp *sp = (struct sppp *)sppp_of(dev);
959         unsigned long flags;
960
961         sppp_close(dev);
962
963         spin_lock_irqsave(&sp->lock, flags);
964         if (!(sp->pp_flags & PP_CISCO))
965         {
966                 sp->lcp.magic = jiffies;
967                 ++sp->pp_seq;
968                 sp->lcp.state = LCP_STATE_CLOSED;
969                 sp->ipcp.state = IPCP_STATE_CLOSED;
970                 /* Give it a moment for the line to settle then go */
971                 sppp_set_timeout (sp, 1);
972         } 
973         sp->pp_link_state=SPPP_LINK_DOWN;
974         spin_unlock_irqrestore(&sp->lock, flags);
975
976         return 0;
977 }
978
979 EXPORT_SYMBOL(sppp_reopen);
980
981 /**
982  *      sppp_change_mtu - Change the link MTU
983  *      @dev:   Device to change MTU on
984  *      @new_mtu: New MTU
985  *
986  *      Change the MTU on the link. This can only be called with
987  *      the link down. It returns an error if the link is up or
988  *      the mtu is out of range.
989  */
990  
991 static int sppp_change_mtu(struct net_device *dev, int new_mtu)
992 {
993         if(new_mtu<128||new_mtu>PPP_MTU||(dev->flags&IFF_UP))
994                 return -EINVAL;
995         dev->mtu=new_mtu;
996         return 0;
997 }
998
999 /**
1000  *      sppp_do_ioctl - Ioctl handler for ppp/hdlc
1001  *      @dev: Device subject to ioctl
1002  *      @ifr: Interface request block from the user
1003  *      @cmd: Command that is being issued
1004  *      
1005  *      This function handles the ioctls that may be issued by the user
1006  *      to control the settings of a PPP/HDLC link. It does both busy
1007  *      and security checks. This function is intended to be wrapped by
1008  *      callers who wish to add additional ioctl calls of their own.
1009  */
1010  
1011 int sppp_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1012 {
1013         struct sppp *sp = (struct sppp *)sppp_of(dev);
1014
1015         if(dev->flags&IFF_UP)
1016                 return -EBUSY;
1017                 
1018         if(!capable(CAP_NET_ADMIN))
1019                 return -EPERM;
1020         
1021         switch(cmd)
1022         {
1023                 case SPPPIOCCISCO:
1024                         sp->pp_flags|=PP_CISCO;
1025                         dev->type = ARPHRD_HDLC;
1026                         break;
1027                 case SPPPIOCPPP:
1028                         sp->pp_flags&=~PP_CISCO;
1029                         dev->type = ARPHRD_PPP;
1030                         break;
1031                 case SPPPIOCDEBUG:
1032                         sp->pp_flags&=~PP_DEBUG;
1033                         if(ifr->ifr_flags)
1034                                 sp->pp_flags|=PP_DEBUG;
1035                         break;
1036                 case SPPPIOCGFLAGS:
1037                         if(copy_to_user(ifr->ifr_data, &sp->pp_flags, sizeof(sp->pp_flags)))
1038                                 return -EFAULT;
1039                         break;
1040                 case SPPPIOCSFLAGS:
1041                         if(copy_from_user(&sp->pp_flags, ifr->ifr_data, sizeof(sp->pp_flags)))
1042                                 return -EFAULT;
1043                         break;
1044                 default:
1045                         return -EINVAL;
1046         }
1047         return 0;
1048 }
1049
1050 EXPORT_SYMBOL(sppp_do_ioctl);
1051
1052 /**
1053  *      sppp_attach - attach synchronous PPP/HDLC to a device
1054  *      @pd:    PPP device to initialise
1055  *
1056  *      This initialises the PPP/HDLC support on an interface. At the
1057  *      time of calling the dev element must point to the network device
1058  *      that this interface is attached to. The interface should not yet
1059  *      be registered. 
1060  */
1061  
1062 void sppp_attach(struct ppp_device *pd)
1063 {
1064         struct net_device *dev = pd->dev;
1065         struct sppp *sp = &pd->sppp;
1066         unsigned long flags;
1067
1068         /* Make sure embedding is safe for sppp_of */
1069         BUG_ON(sppp_of(dev) != sp);
1070
1071         spin_lock_irqsave(&spppq_lock, flags);
1072         /* Initialize keepalive handler. */
1073         if (! spppq)
1074         {
1075                 init_timer(&sppp_keepalive_timer);
1076                 sppp_keepalive_timer.expires=jiffies+10*HZ;
1077                 sppp_keepalive_timer.function=sppp_keepalive;
1078                 add_timer(&sppp_keepalive_timer);
1079         }
1080         /* Insert new entry into the keepalive list. */
1081         sp->pp_next = spppq;
1082         spppq = sp;
1083         spin_unlock_irqrestore(&spppq_lock, flags);
1084
1085         sp->pp_loopcnt = 0;
1086         sp->pp_alivecnt = 0;
1087         sp->pp_seq = 0;
1088         sp->pp_rseq = 0;
1089         sp->pp_flags = PP_KEEPALIVE|PP_CISCO|debug;/*PP_DEBUG;*/
1090         sp->lcp.magic = 0;
1091         sp->lcp.state = LCP_STATE_CLOSED;
1092         sp->ipcp.state = IPCP_STATE_CLOSED;
1093         sp->pp_if = dev;
1094         spin_lock_init(&sp->lock);
1095         
1096         /* 
1097          *      Device specific setup. All but interrupt handler and
1098          *      hard_start_xmit.
1099          */
1100          
1101         dev->hard_header = sppp_hard_header;
1102         dev->rebuild_header = sppp_rebuild_header;
1103         dev->tx_queue_len = 10;
1104         dev->type = ARPHRD_HDLC;
1105         dev->addr_len = 0;
1106         dev->hard_header_len = sizeof(struct ppp_header);
1107         dev->mtu = PPP_MTU;
1108         /*
1109          *      These 4 are callers but MUST also call sppp_ functions
1110          */
1111         dev->do_ioctl = sppp_do_ioctl;
1112 #if 0
1113         dev->get_stats = NULL;          /* Let the driver override these */
1114         dev->open = sppp_open;
1115         dev->stop = sppp_close;
1116 #endif  
1117         dev->change_mtu = sppp_change_mtu;
1118         dev->hard_header_cache = NULL;
1119         dev->header_cache_update = NULL;
1120         dev->flags = IFF_MULTICAST|IFF_POINTOPOINT|IFF_NOARP;
1121 }
1122
1123 EXPORT_SYMBOL(sppp_attach);
1124
1125 /**
1126  *      sppp_detach - release PPP resources from a device
1127  *      @dev:   Network device to release
1128  *
1129  *      Stop and free up any PPP/HDLC resources used by this
1130  *      interface. This must be called before the device is
1131  *      freed.
1132  */
1133  
1134 void sppp_detach (struct net_device *dev)
1135 {
1136         struct sppp **q, *p, *sp = (struct sppp *)sppp_of(dev);
1137         unsigned long flags;
1138
1139         spin_lock_irqsave(&spppq_lock, flags);
1140         /* Remove the entry from the keepalive list. */
1141         for (q = &spppq; (p = *q); q = &p->pp_next)
1142                 if (p == sp) {
1143                         *q = p->pp_next;
1144                         break;
1145                 }
1146
1147         /* Stop keepalive handler. */
1148         if (! spppq)
1149                 del_timer(&sppp_keepalive_timer);
1150         sppp_clear_timeout (sp);
1151         spin_unlock_irqrestore(&spppq_lock, flags);
1152 }
1153
1154 EXPORT_SYMBOL(sppp_detach);
1155
1156 /*
1157  * Analyze the LCP Configure-Request options list
1158  * for the presence of unknown options.
1159  * If the request contains unknown options, build and
1160  * send Configure-reject packet, containing only unknown options.
1161  */
1162 static int
1163 sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h,
1164         int len, u32 *magic)
1165 {
1166         u8 *buf, *r, *p;
1167         int rlen;
1168
1169         len -= 4;
1170         buf = r = kmalloc (len, GFP_ATOMIC);
1171         if (! buf)
1172                 return (0);
1173
1174         p = (void*) (h+1);
1175         for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
1176                 switch (*p) {
1177                 case LCP_OPT_MAGIC:
1178                         /* Magic number -- extract. */
1179                         if (len >= 6 && p[1] == 6) {
1180                                 *magic = (u32)p[2] << 24 |
1181                                         (u32)p[3] << 16 | p[4] << 8 | p[5];
1182                                 continue;
1183                         }
1184                         break;
1185                 case LCP_OPT_ASYNC_MAP:
1186                         /* Async control character map -- check to be zero. */
1187                         if (len >= 6 && p[1] == 6 && ! p[2] && ! p[3] &&
1188                             ! p[4] && ! p[5])
1189                                 continue;
1190                         break;
1191                 case LCP_OPT_MRU:
1192                         /* Maximum receive unit -- always OK. */
1193                         continue;
1194                 default:
1195                         /* Others not supported. */
1196                         break;
1197                 }
1198                 /* Add the option to rejected list. */
1199                 memcpy(r, p, p[1]);
1200                 r += p[1];
1201                 rlen += p[1];
1202         }
1203         if (rlen)
1204                 sppp_cp_send (sp, PPP_LCP, LCP_CONF_REJ, h->ident, rlen, buf);
1205         kfree(buf);
1206         return (rlen == 0);
1207 }
1208
1209 static void sppp_ipcp_input (struct sppp *sp, struct sk_buff *skb)
1210 {
1211         struct lcp_header *h;
1212         struct net_device *dev = sp->pp_if;
1213         int len = skb->len;
1214
1215         if (!pskb_may_pull(skb, sizeof(struct lcp_header))) {
1216                 if (sp->pp_flags & PP_DEBUG)
1217                         printk (KERN_WARNING "%s: invalid ipcp packet length: %d bytes\n",
1218                                 dev->name,  len);
1219                 return;
1220         }
1221         h = (struct lcp_header *)skb->data;
1222         skb_pull(skb,sizeof(struct lcp_header));
1223         if (sp->pp_flags & PP_DEBUG) {
1224                 printk (KERN_WARNING "%s: ipcp input: %d bytes <%s id=%xh len=%xh",
1225                         dev->name,  len,
1226                         sppp_ipcp_type_name (h->type), h->ident, ntohs (h->len));
1227                 if (len > 4)
1228                         sppp_print_bytes ((u8*) (h+1), len-4);
1229                 printk (">\n");
1230         }
1231         if (len > ntohs (h->len))
1232                 len = ntohs (h->len);
1233         switch (h->type) {
1234         default:
1235                 /* Unknown packet type -- send Code-Reject packet. */
1236                 sppp_cp_send (sp, PPP_IPCP, IPCP_CODE_REJ, ++sp->pp_seq, len, h);
1237                 break;
1238         case IPCP_CONF_REQ:
1239                 if (len < 4) {
1240                         if (sp->pp_flags & PP_DEBUG)
1241                                 printk (KERN_WARNING "%s: invalid ipcp configure request packet length: %d bytes\n",
1242                                         dev->name, len);
1243                         return;
1244                 }
1245                 if (len > 4) {
1246                         sppp_cp_send (sp, PPP_IPCP, LCP_CONF_REJ, h->ident,
1247                                 len-4, h+1);
1248
1249                         switch (sp->ipcp.state) {
1250                         case IPCP_STATE_OPENED:
1251                                 /* Initiate renegotiation. */
1252                                 sppp_ipcp_open (sp);
1253                                 /* fall through... */
1254                         case IPCP_STATE_ACK_SENT:
1255                                 /* Go to closed state. */
1256                                 sp->ipcp.state = IPCP_STATE_CLOSED;
1257                         }
1258                 } else {
1259                         /* Send Configure-Ack packet. */
1260                         sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_ACK, h->ident,
1261                                 0, NULL);
1262                         /* Change the state. */
1263                         if (sp->ipcp.state == IPCP_STATE_ACK_RCVD)
1264                                 sp->ipcp.state = IPCP_STATE_OPENED;
1265                         else
1266                                 sp->ipcp.state = IPCP_STATE_ACK_SENT;
1267                 }
1268                 break;
1269         case IPCP_CONF_ACK:
1270                 if (h->ident != sp->ipcp.confid)
1271                         break;
1272                 sppp_clear_timeout (sp);
1273                 switch (sp->ipcp.state) {
1274                 case IPCP_STATE_CLOSED:
1275                         sp->ipcp.state = IPCP_STATE_ACK_RCVD;
1276                         sppp_set_timeout (sp, 5);
1277                         break;
1278                 case IPCP_STATE_ACK_SENT:
1279                         sp->ipcp.state = IPCP_STATE_OPENED;
1280                         break;
1281                 }
1282                 break;
1283         case IPCP_CONF_NAK:
1284         case IPCP_CONF_REJ:
1285                 if (h->ident != sp->ipcp.confid)
1286                         break;
1287                 sppp_clear_timeout (sp);
1288                         /* Initiate renegotiation. */
1289                 sppp_ipcp_open (sp);
1290                 if (sp->ipcp.state != IPCP_STATE_ACK_SENT)
1291                         /* Go to closed state. */
1292                         sp->ipcp.state = IPCP_STATE_CLOSED;
1293                 break;
1294         case IPCP_TERM_REQ:
1295                 /* Send Terminate-Ack packet. */
1296                 sppp_cp_send (sp, PPP_IPCP, IPCP_TERM_ACK, h->ident, 0, NULL);
1297                 /* Go to closed state. */
1298                 sp->ipcp.state = IPCP_STATE_CLOSED;
1299                 /* Initiate renegotiation. */
1300                 sppp_ipcp_open (sp);
1301                 break;
1302         case IPCP_TERM_ACK:
1303                 /* Ignore for now. */
1304         case IPCP_CODE_REJ:
1305                 /* Ignore for now. */
1306                 break;
1307         }
1308 }
1309
1310 static void sppp_lcp_open (struct sppp *sp)
1311 {
1312         char opt[6];
1313
1314         if (! sp->lcp.magic)
1315                 sp->lcp.magic = jiffies;
1316         opt[0] = LCP_OPT_MAGIC;
1317         opt[1] = sizeof (opt);
1318         opt[2] = sp->lcp.magic >> 24;
1319         opt[3] = sp->lcp.magic >> 16;
1320         opt[4] = sp->lcp.magic >> 8;
1321         opt[5] = sp->lcp.magic;
1322         sp->lcp.confid = ++sp->pp_seq;
1323         sppp_cp_send (sp, PPP_LCP, LCP_CONF_REQ, sp->lcp.confid,
1324                 sizeof (opt), &opt);
1325         sppp_set_timeout (sp, 2);
1326 }
1327
1328 static void sppp_ipcp_open (struct sppp *sp)
1329 {
1330         sp->ipcp.confid = ++sp->pp_seq;
1331         sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_REQ, sp->ipcp.confid, 0, NULL);
1332         sppp_set_timeout (sp, 2);
1333 }
1334
1335 /*
1336  * Process PPP control protocol timeouts.
1337  */
1338  
1339 static void sppp_cp_timeout (unsigned long arg)
1340 {
1341         struct sppp *sp = (struct sppp*) arg;
1342         unsigned long flags;
1343
1344         spin_lock_irqsave(&sp->lock, flags);
1345
1346         sp->pp_flags &= ~PP_TIMO;
1347         if (! (sp->pp_if->flags & IFF_UP) || (sp->pp_flags & PP_CISCO)) {
1348                 spin_unlock_irqrestore(&sp->lock, flags);
1349                 return;
1350         }
1351         switch (sp->lcp.state) {
1352         case LCP_STATE_CLOSED:
1353                 /* No ACK for Configure-Request, retry. */
1354                 sppp_lcp_open (sp);
1355                 break;
1356         case LCP_STATE_ACK_RCVD:
1357                 /* ACK got, but no Configure-Request for peer, retry. */
1358                 sppp_lcp_open (sp);
1359                 sp->lcp.state = LCP_STATE_CLOSED;
1360                 break;
1361         case LCP_STATE_ACK_SENT:
1362                 /* ACK sent but no ACK for Configure-Request, retry. */
1363                 sppp_lcp_open (sp);
1364                 break;
1365         case LCP_STATE_OPENED:
1366                 /* LCP is already OK, try IPCP. */
1367                 switch (sp->ipcp.state) {
1368                 case IPCP_STATE_CLOSED:
1369                         /* No ACK for Configure-Request, retry. */
1370                         sppp_ipcp_open (sp);
1371                         break;
1372                 case IPCP_STATE_ACK_RCVD:
1373                         /* ACK got, but no Configure-Request for peer, retry. */
1374                         sppp_ipcp_open (sp);
1375                         sp->ipcp.state = IPCP_STATE_CLOSED;
1376                         break;
1377                 case IPCP_STATE_ACK_SENT:
1378                         /* ACK sent but no ACK for Configure-Request, retry. */
1379                         sppp_ipcp_open (sp);
1380                         break;
1381                 case IPCP_STATE_OPENED:
1382                         /* IPCP is OK. */
1383                         break;
1384                 }
1385                 break;
1386         }
1387         spin_unlock_irqrestore(&sp->lock, flags);
1388         sppp_flush_xmit();
1389 }
1390
1391 static char *sppp_lcp_type_name (u8 type)
1392 {
1393         static char buf [8];
1394         switch (type) {
1395         case LCP_CONF_REQ:   return ("conf-req");
1396         case LCP_CONF_ACK:   return ("conf-ack");
1397         case LCP_CONF_NAK:   return ("conf-nack");
1398         case LCP_CONF_REJ:   return ("conf-rej");
1399         case LCP_TERM_REQ:   return ("term-req");
1400         case LCP_TERM_ACK:   return ("term-ack");
1401         case LCP_CODE_REJ:   return ("code-rej");
1402         case LCP_PROTO_REJ:  return ("proto-rej");
1403         case LCP_ECHO_REQ:   return ("echo-req");
1404         case LCP_ECHO_REPLY: return ("echo-reply");
1405         case LCP_DISC_REQ:   return ("discard-req");
1406         }
1407         sprintf (buf, "%xh", type);
1408         return (buf);
1409 }
1410
1411 static char *sppp_ipcp_type_name (u8 type)
1412 {
1413         static char buf [8];
1414         switch (type) {
1415         case IPCP_CONF_REQ:   return ("conf-req");
1416         case IPCP_CONF_ACK:   return ("conf-ack");
1417         case IPCP_CONF_NAK:   return ("conf-nack");
1418         case IPCP_CONF_REJ:   return ("conf-rej");
1419         case IPCP_TERM_REQ:   return ("term-req");
1420         case IPCP_TERM_ACK:   return ("term-ack");
1421         case IPCP_CODE_REJ:   return ("code-rej");
1422         }
1423         sprintf (buf, "%xh", type);
1424         return (buf);
1425 }
1426
1427 static void sppp_print_bytes (u_char *p, u16 len)
1428 {
1429         printk (" %x", *p++);
1430         while (--len > 0)
1431                 printk ("-%x", *p++);
1432 }
1433
1434 /**
1435  *      sppp_rcv -      receive and process a WAN PPP frame
1436  *      @skb:   The buffer to process
1437  *      @dev:   The device it arrived on
1438  *      @p: Unused
1439  *      @orig_dev: Unused
1440  *
1441  *      Protocol glue. This drives the deferred processing mode the poorer
1442  *      cards use. This can be called directly by cards that do not have
1443  *      timing constraints but is normally called from the network layer
1444  *      after interrupt servicing to process frames queued via netif_rx.
1445  */
1446
1447 static int sppp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *p, struct net_device *orig_dev)
1448 {
1449         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
1450                 return NET_RX_DROP;
1451         sppp_input(dev,skb);
1452         return 0;
1453 }
1454
1455 static struct packet_type sppp_packet_type = {
1456         .type   = __constant_htons(ETH_P_WAN_PPP),
1457         .func   = sppp_rcv,
1458 };
1459
1460 static char banner[] __initdata = 
1461         KERN_INFO "Cronyx Ltd, Synchronous PPP and CISCO HDLC (c) 1994\n"
1462         KERN_INFO "Linux port (c) 1998 Building Number Three Ltd & "
1463                   "Jan \"Yenya\" Kasprzak.\n";
1464
1465 static int __init sync_ppp_init(void)
1466 {
1467         if(debug)
1468                 debug=PP_DEBUG;
1469         printk(banner);
1470         skb_queue_head_init(&tx_queue);
1471         dev_add_pack(&sppp_packet_type);
1472         return 0;
1473 }
1474
1475
1476 static void __exit sync_ppp_cleanup(void)
1477 {
1478         dev_remove_pack(&sppp_packet_type);
1479 }
1480
1481 module_init(sync_ppp_init);
1482 module_exit(sync_ppp_cleanup);
1483 module_param(debug, int, 0);
1484 MODULE_LICENSE("GPL");
1485