61e24b7a45a306da29fe20916a3e8ca40e45c1d6
[linux-3.10.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/module.h>
41 #include <linux/kernel.h>
42 #include <linux/errno.h>
43 #include <linux/init.h>
44 #include <linux/if_arp.h>
45 #include <linux/skbuff.h>
46 #include <linux/route.h>
47 #include <linux/netdevice.h>
48 #include <linux/inetdevice.h>
49 #include <linux/random.h>
50 #include <linux/pkt_sched.h>
51 #include <linux/spinlock.h>
52 #include <linux/rcupdate.h>
53
54 #include <net/net_namespace.h>
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         __be16 protocol;
111 };
112 #define PPP_HEADER_LEN          sizeof (struct ppp_header)
113
114 struct lcp_header {
115         u8 type;
116         u8 ident;
117         __be16 len;
118 };
119 #define LCP_HEADER_LEN          sizeof (struct lcp_header)
120
121 struct cisco_packet {
122         __be32 type;
123         __be32 par1;
124         __be32 par2;
125         __be16 rel;
126         __be16 time0;
127         __be16 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, u32 par1, u32 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_reset_mac_header(skb);
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,
363                             struct net_device *dev, __u16 type,
364                             const void *daddr, const void *saddr,
365                             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 const struct header_ops sppp_header_ops = {
398         .create = sppp_hard_header,
399 };
400
401 /*
402  * Send keepalive packets, every 10 seconds.
403  */
404
405 static void sppp_keepalive (unsigned long dummy)
406 {
407         struct sppp *sp;
408         unsigned long flags;
409
410         spin_lock_irqsave(&spppq_lock, flags);
411
412         for (sp=spppq; sp; sp=sp->pp_next) 
413         {
414                 struct net_device *dev = sp->pp_if;
415
416                 /* Keepalive mode disabled or channel down? */
417                 if (! (sp->pp_flags & PP_KEEPALIVE) ||
418                     ! (dev->flags & IFF_UP))
419                         continue;
420
421                 spin_lock(&sp->lock);
422
423                 /* No keepalive in PPP mode if LCP not opened yet. */
424                 if (! (sp->pp_flags & PP_CISCO) &&
425                     sp->lcp.state != LCP_STATE_OPENED) {
426                         spin_unlock(&sp->lock);
427                         continue;
428                 }
429
430                 if (sp->pp_alivecnt == MAXALIVECNT) {
431                         /* No keepalive packets got.  Stop the interface. */
432                         printk (KERN_WARNING "%s: protocol down\n", dev->name);
433                         if_down (dev);
434                         if (! (sp->pp_flags & PP_CISCO)) {
435                                 /* Shut down the PPP link. */
436                                 sp->lcp.magic = jiffies;
437                                 sp->lcp.state = LCP_STATE_CLOSED;
438                                 sp->ipcp.state = IPCP_STATE_CLOSED;
439                                 sppp_clear_timeout (sp);
440                                 /* Initiate negotiation. */
441                                 sppp_lcp_open (sp);
442                         }
443                 }
444                 if (sp->pp_alivecnt <= MAXALIVECNT)
445                         ++sp->pp_alivecnt;
446                 if (sp->pp_flags & PP_CISCO)
447                         sppp_cisco_send (sp, CISCO_KEEPALIVE_REQ, ++sp->pp_seq,
448                                 sp->pp_rseq);
449                 else if (sp->lcp.state == LCP_STATE_OPENED) {
450                         __be32 nmagic = htonl (sp->lcp.magic);
451                         sp->lcp.echoid = ++sp->pp_seq;
452                         sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REQ,
453                                 sp->lcp.echoid, 4, &nmagic);
454                 }
455
456                 spin_unlock(&sp->lock);
457         }
458         spin_unlock_irqrestore(&spppq_lock, flags);
459         sppp_flush_xmit();
460         sppp_keepalive_timer.expires=jiffies+10*HZ;
461         add_timer(&sppp_keepalive_timer);
462 }
463
464 /*
465  * Handle incoming PPP Link Control Protocol packets.
466  */
467  
468 static void sppp_lcp_input (struct sppp *sp, struct sk_buff *skb)
469 {
470         struct lcp_header *h;
471         struct net_device *dev = sp->pp_if;
472         int len = skb->len;
473         u8 *p, opt[6];
474         u32 rmagic = 0;
475
476         if (!pskb_may_pull(skb, sizeof(struct lcp_header))) {
477                 if (sp->pp_flags & PP_DEBUG)
478                         printk (KERN_WARNING "%s: invalid lcp packet length: %d bytes\n",
479                                 dev->name, len);
480                 return;
481         }
482         h = (struct lcp_header *)skb->data;
483         skb_pull(skb,sizeof(struct lcp_header *));
484         
485         if (sp->pp_flags & PP_DEBUG) 
486         {
487                 char state = '?';
488                 switch (sp->lcp.state) {
489                 case LCP_STATE_CLOSED:   state = 'C'; break;
490                 case LCP_STATE_ACK_RCVD: state = 'R'; break;
491                 case LCP_STATE_ACK_SENT: state = 'S'; break;
492                 case LCP_STATE_OPENED:   state = 'O'; break;
493                 }
494                 printk (KERN_WARNING "%s: lcp input(%c): %d bytes <%s id=%xh len=%xh",
495                         dev->name, state, len,
496                         sppp_lcp_type_name (h->type), h->ident, ntohs (h->len));
497                 if (len > 4)
498                         sppp_print_bytes ((u8*) (h+1), len-4);
499                 printk (">\n");
500         }
501         if (len > ntohs (h->len))
502                 len = ntohs (h->len);
503         switch (h->type) {
504         default:
505                 /* Unknown packet type -- send Code-Reject packet. */
506                 sppp_cp_send (sp, PPP_LCP, LCP_CODE_REJ, ++sp->pp_seq,
507                         skb->len, h);
508                 break;
509         case LCP_CONF_REQ:
510                 if (len < 4) {
511                         if (sp->pp_flags & PP_DEBUG)
512                                 printk (KERN_DEBUG"%s: invalid lcp configure request packet length: %d bytes\n",
513                                         dev->name, len);
514                         break;
515                 }
516                 if (len>4 && !sppp_lcp_conf_parse_options (sp, h, len, &rmagic))
517                         goto badreq;
518                 if (rmagic == sp->lcp.magic) {
519                         /* Local and remote magics equal -- loopback? */
520                         if (sp->pp_loopcnt >= MAXALIVECNT*5) {
521                                 printk (KERN_WARNING "%s: loopback\n",
522                                         dev->name);
523                                 sp->pp_loopcnt = 0;
524                                 if (dev->flags & IFF_UP) {
525                                         if_down (dev);
526                                 }
527                         } else if (sp->pp_flags & PP_DEBUG)
528                                 printk (KERN_DEBUG "%s: conf req: magic glitch\n",
529                                         dev->name);
530                         ++sp->pp_loopcnt;
531
532                         /* MUST send Conf-Nack packet. */
533                         rmagic = ~sp->lcp.magic;
534                         opt[0] = LCP_OPT_MAGIC;
535                         opt[1] = sizeof (opt);
536                         opt[2] = rmagic >> 24;
537                         opt[3] = rmagic >> 16;
538                         opt[4] = rmagic >> 8;
539                         opt[5] = rmagic;
540                         sppp_cp_send (sp, PPP_LCP, LCP_CONF_NAK,
541                                 h->ident, sizeof (opt), &opt);
542 badreq:
543                         switch (sp->lcp.state) {
544                         case LCP_STATE_OPENED:
545                                 /* Initiate renegotiation. */
546                                 sppp_lcp_open (sp);
547                                 /* fall through... */
548                         case LCP_STATE_ACK_SENT:
549                                 /* Go to closed state. */
550                                 sp->lcp.state = LCP_STATE_CLOSED;
551                                 sp->ipcp.state = IPCP_STATE_CLOSED;
552                         }
553                         break;
554                 }
555                 /* Send Configure-Ack packet. */
556                 sp->pp_loopcnt = 0;
557                 if (sp->lcp.state != LCP_STATE_OPENED) {
558                         sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK,
559                                         h->ident, len-4, h+1);
560                 }
561                 /* Change the state. */
562                 switch (sp->lcp.state) {
563                 case LCP_STATE_CLOSED:
564                         sp->lcp.state = LCP_STATE_ACK_SENT;
565                         break;
566                 case LCP_STATE_ACK_RCVD:
567                         sp->lcp.state = LCP_STATE_OPENED;
568                         sppp_ipcp_open (sp);
569                         break;
570                 case LCP_STATE_OPENED:
571                         /* Remote magic changed -- close session. */
572                         sp->lcp.state = LCP_STATE_CLOSED;
573                         sp->ipcp.state = IPCP_STATE_CLOSED;
574                         /* Initiate renegotiation. */
575                         sppp_lcp_open (sp);
576                         /* Send ACK after our REQ in attempt to break loop */
577                         sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK,
578                                         h->ident, len-4, h+1);
579                         sp->lcp.state = LCP_STATE_ACK_SENT;
580                         break;
581                 }
582                 break;
583         case LCP_CONF_ACK:
584                 if (h->ident != sp->lcp.confid)
585                         break;
586                 sppp_clear_timeout (sp);
587                 if ((sp->pp_link_state != SPPP_LINK_UP) &&
588                     (dev->flags & IFF_UP)) {
589                         /* Coming out of loopback mode. */
590                         sp->pp_link_state=SPPP_LINK_UP;
591                         printk (KERN_INFO "%s: protocol up\n", dev->name);
592                 }
593                 switch (sp->lcp.state) {
594                 case LCP_STATE_CLOSED:
595                         sp->lcp.state = LCP_STATE_ACK_RCVD;
596                         sppp_set_timeout (sp, 5);
597                         break;
598                 case LCP_STATE_ACK_SENT:
599                         sp->lcp.state = LCP_STATE_OPENED;
600                         sppp_ipcp_open (sp);
601                         break;
602                 }
603                 break;
604         case LCP_CONF_NAK:
605                 if (h->ident != sp->lcp.confid)
606                         break;
607                 p = (u8*) (h+1);
608                 if (len>=10 && p[0] == LCP_OPT_MAGIC && p[1] >= 4) {
609                         rmagic = (u32)p[2] << 24 |
610                                 (u32)p[3] << 16 | p[4] << 8 | p[5];
611                         if (rmagic == ~sp->lcp.magic) {
612                                 int newmagic;
613                                 if (sp->pp_flags & PP_DEBUG)
614                                         printk (KERN_DEBUG "%s: conf nak: magic glitch\n",
615                                                 dev->name);
616                                 get_random_bytes(&newmagic, sizeof(newmagic));
617                                 sp->lcp.magic += newmagic;
618                         } else
619                                 sp->lcp.magic = rmagic;
620                         }
621                 if (sp->lcp.state != LCP_STATE_ACK_SENT) {
622                         /* Go to closed state. */
623                         sp->lcp.state = LCP_STATE_CLOSED;
624                         sp->ipcp.state = IPCP_STATE_CLOSED;
625                 }
626                 /* The link will be renegotiated after timeout,
627                  * to avoid endless req-nack loop. */
628                 sppp_clear_timeout (sp);
629                 sppp_set_timeout (sp, 2);
630                 break;
631         case LCP_CONF_REJ:
632                 if (h->ident != sp->lcp.confid)
633                         break;
634                 sppp_clear_timeout (sp);
635                 /* Initiate renegotiation. */
636                 sppp_lcp_open (sp);
637                 if (sp->lcp.state != LCP_STATE_ACK_SENT) {
638                         /* Go to closed state. */
639                         sp->lcp.state = LCP_STATE_CLOSED;
640                         sp->ipcp.state = IPCP_STATE_CLOSED;
641                 }
642                 break;
643         case LCP_TERM_REQ:
644                 sppp_clear_timeout (sp);
645                 /* Send Terminate-Ack packet. */
646                 sppp_cp_send (sp, PPP_LCP, LCP_TERM_ACK, h->ident, 0, NULL);
647                 /* Go to closed state. */
648                 sp->lcp.state = LCP_STATE_CLOSED;
649                 sp->ipcp.state = IPCP_STATE_CLOSED;
650                 /* Initiate renegotiation. */
651                 sppp_lcp_open (sp);
652                 break;
653         case LCP_TERM_ACK:
654         case LCP_CODE_REJ:
655         case LCP_PROTO_REJ:
656                 /* Ignore for now. */
657                 break;
658         case LCP_DISC_REQ:
659                 /* Discard the packet. */
660                 break;
661         case LCP_ECHO_REQ:
662                 if (sp->lcp.state != LCP_STATE_OPENED)
663                         break;
664                 if (len < 8) {
665                         if (sp->pp_flags & PP_DEBUG)
666                                 printk (KERN_WARNING "%s: invalid lcp echo request packet length: %d bytes\n",
667                                         dev->name, len);
668                         break;
669                 }
670                 if (ntohl (*(__be32*)(h+1)) == sp->lcp.magic) {
671                         /* Line loopback mode detected. */
672                         printk (KERN_WARNING "%s: loopback\n", dev->name);
673                         if_down (dev);
674
675                         /* Shut down the PPP link. */
676                         sp->lcp.state = LCP_STATE_CLOSED;
677                         sp->ipcp.state = IPCP_STATE_CLOSED;
678                         sppp_clear_timeout (sp);
679                         /* Initiate negotiation. */
680                         sppp_lcp_open (sp);
681                         break;
682                 }
683                 *(__be32 *)(h+1) = htonl (sp->lcp.magic);
684                 sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REPLY, h->ident, len-4, h+1);
685                 break;
686         case LCP_ECHO_REPLY:
687                 if (h->ident != sp->lcp.echoid)
688                         break;
689                 if (len < 8) {
690                         if (sp->pp_flags & PP_DEBUG)
691                                 printk (KERN_WARNING "%s: invalid lcp echo reply packet length: %d bytes\n",
692                                         dev->name, len);
693                         break;
694                 }
695                 if (ntohl(*(__be32 *)(h+1)) != sp->lcp.magic)
696                 sp->pp_alivecnt = 0;
697                 break;
698         }
699 }
700
701 /*
702  * Handle incoming Cisco keepalive protocol packets.
703  */
704
705 static void sppp_cisco_input (struct sppp *sp, struct sk_buff *skb)
706 {
707         struct cisco_packet *h;
708         struct net_device *dev = sp->pp_if;
709
710         if (!pskb_may_pull(skb, sizeof(struct cisco_packet))
711             || (skb->len != CISCO_PACKET_LEN
712                 && skb->len != CISCO_BIG_PACKET_LEN)) {
713                 if (sp->pp_flags & PP_DEBUG)
714                         printk (KERN_WARNING "%s: invalid cisco packet length: %d bytes\n",
715                                 dev->name,  skb->len);
716                 return;
717         }
718         h = (struct cisco_packet *)skb->data;
719         skb_pull(skb, sizeof(struct cisco_packet*));
720         if (sp->pp_flags & PP_DEBUG)
721                 printk (KERN_WARNING "%s: cisco input: %d bytes <%xh %xh %xh %xh %xh-%xh>\n",
722                         dev->name,  skb->len,
723                         ntohl (h->type), h->par1, h->par2, h->rel,
724                         h->time0, h->time1);
725         switch (ntohl (h->type)) {
726         default:
727                 if (sp->pp_flags & PP_DEBUG)
728                         printk (KERN_WARNING "%s: unknown cisco packet type: 0x%x\n",
729                                 dev->name,  ntohl (h->type));
730                 break;
731         case CISCO_ADDR_REPLY:
732                 /* Reply on address request, ignore */
733                 break;
734         case CISCO_KEEPALIVE_REQ:
735                 sp->pp_alivecnt = 0;
736                 sp->pp_rseq = ntohl (h->par1);
737                 if (sp->pp_seq == sp->pp_rseq) {
738                         /* Local and remote sequence numbers are equal.
739                          * Probably, the line is in loopback mode. */
740                         int newseq;
741                         if (sp->pp_loopcnt >= MAXALIVECNT) {
742                                 printk (KERN_WARNING "%s: loopback\n",
743                                         dev->name);
744                                 sp->pp_loopcnt = 0;
745                                 if (dev->flags & IFF_UP) {
746                                         if_down (dev);
747                                 }
748                         }
749                         ++sp->pp_loopcnt;
750
751                         /* Generate new local sequence number */
752                         get_random_bytes(&newseq, sizeof(newseq));
753                         sp->pp_seq ^= newseq;
754                         break;
755                 }
756                 sp->pp_loopcnt = 0;
757                 if (sp->pp_link_state==SPPP_LINK_DOWN &&
758                     (dev->flags & IFF_UP)) {
759                         sp->pp_link_state=SPPP_LINK_UP;
760                         printk (KERN_INFO "%s: protocol up\n", dev->name);
761                 }
762                 break;
763         case CISCO_ADDR_REQ:
764                 /* Stolen from net/ipv4/devinet.c -- SIOCGIFADDR ioctl */
765                 {
766                 struct in_device *in_dev;
767                 struct in_ifaddr *ifa;
768                 __be32 addr = 0, mask = htonl(~0U); /* FIXME: is the mask correct? */
769 #ifdef CONFIG_INET
770                 rcu_read_lock();
771                 if ((in_dev = __in_dev_get_rcu(dev)) != NULL)
772                 {
773                         for (ifa=in_dev->ifa_list; ifa != NULL;
774                                 ifa=ifa->ifa_next) {
775                                 if (strcmp(dev->name, ifa->ifa_label) == 0) 
776                                 {
777                                         addr = ifa->ifa_local;
778                                         mask = ifa->ifa_mask;
779                                         break;
780                                 }
781                         }
782                 }
783                 rcu_read_unlock();
784 #endif          
785                 sppp_cisco_send (sp, CISCO_ADDR_REPLY, ntohl(addr), ntohl(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, u32 par1, u32 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 = htons(0xffff);
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->header_ops = &sppp_header_ops;
1102
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->flags = IFF_MULTICAST|IFF_POINTOPOINT|IFF_NOARP;
1119 }
1120
1121 EXPORT_SYMBOL(sppp_attach);
1122
1123 /**
1124  *      sppp_detach - release PPP resources from a device
1125  *      @dev:   Network device to release
1126  *
1127  *      Stop and free up any PPP/HDLC resources used by this
1128  *      interface. This must be called before the device is
1129  *      freed.
1130  */
1131  
1132 void sppp_detach (struct net_device *dev)
1133 {
1134         struct sppp **q, *p, *sp = (struct sppp *)sppp_of(dev);
1135         unsigned long flags;
1136
1137         spin_lock_irqsave(&spppq_lock, flags);
1138         /* Remove the entry from the keepalive list. */
1139         for (q = &spppq; (p = *q); q = &p->pp_next)
1140                 if (p == sp) {
1141                         *q = p->pp_next;
1142                         break;
1143                 }
1144
1145         /* Stop keepalive handler. */
1146         if (! spppq)
1147                 del_timer(&sppp_keepalive_timer);
1148         sppp_clear_timeout (sp);
1149         spin_unlock_irqrestore(&spppq_lock, flags);
1150 }
1151
1152 EXPORT_SYMBOL(sppp_detach);
1153
1154 /*
1155  * Analyze the LCP Configure-Request options list
1156  * for the presence of unknown options.
1157  * If the request contains unknown options, build and
1158  * send Configure-reject packet, containing only unknown options.
1159  */
1160 static int
1161 sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h,
1162         int len, u32 *magic)
1163 {
1164         u8 *buf, *r, *p;
1165         int rlen;
1166
1167         len -= 4;
1168         buf = r = kmalloc (len, GFP_ATOMIC);
1169         if (! buf)
1170                 return (0);
1171
1172         p = (void*) (h+1);
1173         for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
1174                 switch (*p) {
1175                 case LCP_OPT_MAGIC:
1176                         /* Magic number -- extract. */
1177                         if (len >= 6 && p[1] == 6) {
1178                                 *magic = (u32)p[2] << 24 |
1179                                         (u32)p[3] << 16 | p[4] << 8 | p[5];
1180                                 continue;
1181                         }
1182                         break;
1183                 case LCP_OPT_ASYNC_MAP:
1184                         /* Async control character map -- check to be zero. */
1185                         if (len >= 6 && p[1] == 6 && ! p[2] && ! p[3] &&
1186                             ! p[4] && ! p[5])
1187                                 continue;
1188                         break;
1189                 case LCP_OPT_MRU:
1190                         /* Maximum receive unit -- always OK. */
1191                         continue;
1192                 default:
1193                         /* Others not supported. */
1194                         break;
1195                 }
1196                 /* Add the option to rejected list. */
1197                 memcpy(r, p, p[1]);
1198                 r += p[1];
1199                 rlen += p[1];
1200         }
1201         if (rlen)
1202                 sppp_cp_send (sp, PPP_LCP, LCP_CONF_REJ, h->ident, rlen, buf);
1203         kfree(buf);
1204         return (rlen == 0);
1205 }
1206
1207 static void sppp_ipcp_input (struct sppp *sp, struct sk_buff *skb)
1208 {
1209         struct lcp_header *h;
1210         struct net_device *dev = sp->pp_if;
1211         int len = skb->len;
1212
1213         if (!pskb_may_pull(skb, sizeof(struct lcp_header))) {
1214                 if (sp->pp_flags & PP_DEBUG)
1215                         printk (KERN_WARNING "%s: invalid ipcp packet length: %d bytes\n",
1216                                 dev->name,  len);
1217                 return;
1218         }
1219         h = (struct lcp_header *)skb->data;
1220         skb_pull(skb,sizeof(struct lcp_header));
1221         if (sp->pp_flags & PP_DEBUG) {
1222                 printk (KERN_WARNING "%s: ipcp input: %d bytes <%s id=%xh len=%xh",
1223                         dev->name,  len,
1224                         sppp_ipcp_type_name (h->type), h->ident, ntohs (h->len));
1225                 if (len > 4)
1226                         sppp_print_bytes ((u8*) (h+1), len-4);
1227                 printk (">\n");
1228         }
1229         if (len > ntohs (h->len))
1230                 len = ntohs (h->len);
1231         switch (h->type) {
1232         default:
1233                 /* Unknown packet type -- send Code-Reject packet. */
1234                 sppp_cp_send (sp, PPP_IPCP, IPCP_CODE_REJ, ++sp->pp_seq, len, h);
1235                 break;
1236         case IPCP_CONF_REQ:
1237                 if (len < 4) {
1238                         if (sp->pp_flags & PP_DEBUG)
1239                                 printk (KERN_WARNING "%s: invalid ipcp configure request packet length: %d bytes\n",
1240                                         dev->name, len);
1241                         return;
1242                 }
1243                 if (len > 4) {
1244                         sppp_cp_send (sp, PPP_IPCP, LCP_CONF_REJ, h->ident,
1245                                 len-4, h+1);
1246
1247                         switch (sp->ipcp.state) {
1248                         case IPCP_STATE_OPENED:
1249                                 /* Initiate renegotiation. */
1250                                 sppp_ipcp_open (sp);
1251                                 /* fall through... */
1252                         case IPCP_STATE_ACK_SENT:
1253                                 /* Go to closed state. */
1254                                 sp->ipcp.state = IPCP_STATE_CLOSED;
1255                         }
1256                 } else {
1257                         /* Send Configure-Ack packet. */
1258                         sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_ACK, h->ident,
1259                                 0, NULL);
1260                         /* Change the state. */
1261                         if (sp->ipcp.state == IPCP_STATE_ACK_RCVD)
1262                                 sp->ipcp.state = IPCP_STATE_OPENED;
1263                         else
1264                                 sp->ipcp.state = IPCP_STATE_ACK_SENT;
1265                 }
1266                 break;
1267         case IPCP_CONF_ACK:
1268                 if (h->ident != sp->ipcp.confid)
1269                         break;
1270                 sppp_clear_timeout (sp);
1271                 switch (sp->ipcp.state) {
1272                 case IPCP_STATE_CLOSED:
1273                         sp->ipcp.state = IPCP_STATE_ACK_RCVD;
1274                         sppp_set_timeout (sp, 5);
1275                         break;
1276                 case IPCP_STATE_ACK_SENT:
1277                         sp->ipcp.state = IPCP_STATE_OPENED;
1278                         break;
1279                 }
1280                 break;
1281         case IPCP_CONF_NAK:
1282         case IPCP_CONF_REJ:
1283                 if (h->ident != sp->ipcp.confid)
1284                         break;
1285                 sppp_clear_timeout (sp);
1286                         /* Initiate renegotiation. */
1287                 sppp_ipcp_open (sp);
1288                 if (sp->ipcp.state != IPCP_STATE_ACK_SENT)
1289                         /* Go to closed state. */
1290                         sp->ipcp.state = IPCP_STATE_CLOSED;
1291                 break;
1292         case IPCP_TERM_REQ:
1293                 /* Send Terminate-Ack packet. */
1294                 sppp_cp_send (sp, PPP_IPCP, IPCP_TERM_ACK, h->ident, 0, NULL);
1295                 /* Go to closed state. */
1296                 sp->ipcp.state = IPCP_STATE_CLOSED;
1297                 /* Initiate renegotiation. */
1298                 sppp_ipcp_open (sp);
1299                 break;
1300         case IPCP_TERM_ACK:
1301                 /* Ignore for now. */
1302         case IPCP_CODE_REJ:
1303                 /* Ignore for now. */
1304                 break;
1305         }
1306 }
1307
1308 static void sppp_lcp_open (struct sppp *sp)
1309 {
1310         char opt[6];
1311
1312         if (! sp->lcp.magic)
1313                 sp->lcp.magic = jiffies;
1314         opt[0] = LCP_OPT_MAGIC;
1315         opt[1] = sizeof (opt);
1316         opt[2] = sp->lcp.magic >> 24;
1317         opt[3] = sp->lcp.magic >> 16;
1318         opt[4] = sp->lcp.magic >> 8;
1319         opt[5] = sp->lcp.magic;
1320         sp->lcp.confid = ++sp->pp_seq;
1321         sppp_cp_send (sp, PPP_LCP, LCP_CONF_REQ, sp->lcp.confid,
1322                 sizeof (opt), &opt);
1323         sppp_set_timeout (sp, 2);
1324 }
1325
1326 static void sppp_ipcp_open (struct sppp *sp)
1327 {
1328         sp->ipcp.confid = ++sp->pp_seq;
1329         sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_REQ, sp->ipcp.confid, 0, NULL);
1330         sppp_set_timeout (sp, 2);
1331 }
1332
1333 /*
1334  * Process PPP control protocol timeouts.
1335  */
1336  
1337 static void sppp_cp_timeout (unsigned long arg)
1338 {
1339         struct sppp *sp = (struct sppp*) arg;
1340         unsigned long flags;
1341
1342         spin_lock_irqsave(&sp->lock, flags);
1343
1344         sp->pp_flags &= ~PP_TIMO;
1345         if (! (sp->pp_if->flags & IFF_UP) || (sp->pp_flags & PP_CISCO)) {
1346                 spin_unlock_irqrestore(&sp->lock, flags);
1347                 return;
1348         }
1349         switch (sp->lcp.state) {
1350         case LCP_STATE_CLOSED:
1351                 /* No ACK for Configure-Request, retry. */
1352                 sppp_lcp_open (sp);
1353                 break;
1354         case LCP_STATE_ACK_RCVD:
1355                 /* ACK got, but no Configure-Request for peer, retry. */
1356                 sppp_lcp_open (sp);
1357                 sp->lcp.state = LCP_STATE_CLOSED;
1358                 break;
1359         case LCP_STATE_ACK_SENT:
1360                 /* ACK sent but no ACK for Configure-Request, retry. */
1361                 sppp_lcp_open (sp);
1362                 break;
1363         case LCP_STATE_OPENED:
1364                 /* LCP is already OK, try IPCP. */
1365                 switch (sp->ipcp.state) {
1366                 case IPCP_STATE_CLOSED:
1367                         /* No ACK for Configure-Request, retry. */
1368                         sppp_ipcp_open (sp);
1369                         break;
1370                 case IPCP_STATE_ACK_RCVD:
1371                         /* ACK got, but no Configure-Request for peer, retry. */
1372                         sppp_ipcp_open (sp);
1373                         sp->ipcp.state = IPCP_STATE_CLOSED;
1374                         break;
1375                 case IPCP_STATE_ACK_SENT:
1376                         /* ACK sent but no ACK for Configure-Request, retry. */
1377                         sppp_ipcp_open (sp);
1378                         break;
1379                 case IPCP_STATE_OPENED:
1380                         /* IPCP is OK. */
1381                         break;
1382                 }
1383                 break;
1384         }
1385         spin_unlock_irqrestore(&sp->lock, flags);
1386         sppp_flush_xmit();
1387 }
1388
1389 static char *sppp_lcp_type_name (u8 type)
1390 {
1391         static char buf [8];
1392         switch (type) {
1393         case LCP_CONF_REQ:   return ("conf-req");
1394         case LCP_CONF_ACK:   return ("conf-ack");
1395         case LCP_CONF_NAK:   return ("conf-nack");
1396         case LCP_CONF_REJ:   return ("conf-rej");
1397         case LCP_TERM_REQ:   return ("term-req");
1398         case LCP_TERM_ACK:   return ("term-ack");
1399         case LCP_CODE_REJ:   return ("code-rej");
1400         case LCP_PROTO_REJ:  return ("proto-rej");
1401         case LCP_ECHO_REQ:   return ("echo-req");
1402         case LCP_ECHO_REPLY: return ("echo-reply");
1403         case LCP_DISC_REQ:   return ("discard-req");
1404         }
1405         sprintf (buf, "%xh", type);
1406         return (buf);
1407 }
1408
1409 static char *sppp_ipcp_type_name (u8 type)
1410 {
1411         static char buf [8];
1412         switch (type) {
1413         case IPCP_CONF_REQ:   return ("conf-req");
1414         case IPCP_CONF_ACK:   return ("conf-ack");
1415         case IPCP_CONF_NAK:   return ("conf-nack");
1416         case IPCP_CONF_REJ:   return ("conf-rej");
1417         case IPCP_TERM_REQ:   return ("term-req");
1418         case IPCP_TERM_ACK:   return ("term-ack");
1419         case IPCP_CODE_REJ:   return ("code-rej");
1420         }
1421         sprintf (buf, "%xh", type);
1422         return (buf);
1423 }
1424
1425 static void sppp_print_bytes (u_char *p, u16 len)
1426 {
1427         printk (" %x", *p++);
1428         while (--len > 0)
1429                 printk ("-%x", *p++);
1430 }
1431
1432 /**
1433  *      sppp_rcv -      receive and process a WAN PPP frame
1434  *      @skb:   The buffer to process
1435  *      @dev:   The device it arrived on
1436  *      @p: Unused
1437  *      @orig_dev: Unused
1438  *
1439  *      Protocol glue. This drives the deferred processing mode the poorer
1440  *      cards use. This can be called directly by cards that do not have
1441  *      timing constraints but is normally called from the network layer
1442  *      after interrupt servicing to process frames queued via netif_rx.
1443  */
1444
1445 static int sppp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *p, struct net_device *orig_dev)
1446 {
1447         if (dev->nd_net != &init_net) {
1448                 kfree_skb(skb);
1449                 return 0;
1450         }
1451
1452         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
1453                 return NET_RX_DROP;
1454         sppp_input(dev,skb);
1455         return 0;
1456 }
1457
1458 static struct packet_type sppp_packet_type = {
1459         .type   = __constant_htons(ETH_P_WAN_PPP),
1460         .func   = sppp_rcv,
1461 };
1462
1463 static char banner[] __initdata = 
1464         KERN_INFO "Cronyx Ltd, Synchronous PPP and CISCO HDLC (c) 1994\n"
1465         KERN_INFO "Linux port (c) 1998 Building Number Three Ltd & "
1466                   "Jan \"Yenya\" Kasprzak.\n";
1467
1468 static int __init sync_ppp_init(void)
1469 {
1470         if(debug)
1471                 debug=PP_DEBUG;
1472         printk(banner);
1473         skb_queue_head_init(&tx_queue);
1474         dev_add_pack(&sppp_packet_type);
1475         return 0;
1476 }
1477
1478
1479 static void __exit sync_ppp_cleanup(void)
1480 {
1481         dev_remove_pack(&sppp_packet_type);
1482 }
1483
1484 module_init(sync_ppp_init);
1485 module_exit(sync_ppp_cleanup);
1486 module_param(debug, int, 0);
1487 MODULE_LICENSE("GPL");
1488