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_net(dev) != &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