release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/net/pptp.c

   1 /*
   2  *  Point-to-Point Tunneling Protocol for Linux
   3  *
   4  *      Authors: Kozlov D. (xeb@mail.ru)
   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  */
  12
  13 #include <linux/string.h>
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/slab.h>
  17 #include <linux/vmalloc.h>
  18 #include <linux/errno.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/net.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/init.h>
  23 #include <linux/ppp_channel.h>
  24 #include <linux/ppp_defs.h>
  25 #include <linux/if_pppox.h>
  26 #include <linux/if_ppp.h>
  27 #include <linux/notifier.h>
  28 #include <linux/file.h>
  29 #include <linux/in.h>
  30 #include <linux/ip.h>
  31 #include <linux/netfilter.h>
  32 #include <linux/netfilter_ipv4.h>
  33 #include <linux/version.h>
  34
  35 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
  36 #include <asm/bitops.h>
  37 #endif
  38
  39 #include <net/sock.h>
  40 #include <net/protocol.h>
  41 #include <net/ip.h>
  42 #include <net/icmp.h>
  43 #include <net/route.h>
  44
  45 #include <asm/uaccess.h>
  46
  47 //#define DEBUG
  48 //#define CONFIG_NET_IPGRE_DEMUX
  49 #define HAVE_FIND_NEXT_BIT
  50 #define HAVE_SKB_CLONE_WRITABLE
  51
  52 #if defined(CONFIG_NET_IPGRE_DEMUX) || defined(CONFIG_NET_IPGRE_DEMUX_MODULE)
  53 #include <net/gre.h>
  54 #endif
  55
  56 #define PPTP_DRIVER_VERSION "0.8.5"
  57
  58 #ifdef DEBUG
  59 static int log_level=0;
  60 static int log_packets=10;
  61 #endif
  62
  63 #define MAX_CALLID 65535
  64 #define PPP_LCP_ECHOREQ 0x09
  65 #define PPP_LCP_ECHOREP 0x0A
  66
  67 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,4,20)
  68 #define BITS_TO_LONGS(bits) \
  69         (((bits)+BITS_PER_LONG-1)/BITS_PER_LONG)
  70 #define DECLARE_BITMAP(name,bits) \
  71         unsigned long name[BITS_TO_LONGS(bits)]
  72 #define CLEAR_BITMAP(name,bits) \
  73         memset(name, 0, BITS_TO_LONGS(bits)*sizeof(unsigned long))
  74 #endif
  75
  76 static DECLARE_BITMAP(callid_bitmap, MAX_CALLID + 1);
  77 static struct pppox_sock **callid_sock;
  78
  79 #define SC_RCV_BITS     (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
  80
  81 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
  82 #define INIT_TIMER(_timer,_routine,_data) \
  83 do { \
  84         (_timer)->function=_routine; \
  85         (_timer)->data=_data; \
  86         init_timer(_timer); \
  87 } while (0);
  88
  89 static inline void *kzalloc(size_t size,int gfp)
  90 {
  91         void *p=kmalloc(size,gfp);
  92         memset(p,0,size);
  93         return p;
  94 }
  95
  96 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,4,20)
  97 static inline void nf_reset(struct sk_buff *skb)
  98 {
  99 #ifdef CONFIG_NETFILTER
 100         nf_conntrack_put(skb->nfct);
 101         skb->nfct=NULL;
 102 #ifdef CONFIG_NETFILTER_DEBUG
 103         skb->nf_debug=0;
 104 #endif
 105 #endif
 106 }
 107 #define __user
 108 #endif
 109 #endif
 110
 111 #ifndef HAVE_FIND_NEXT_BIT
 112 /**
 113  * __ffs - find first bit in word.
 114  * @word: The word to search
 115  *
 116  * Undefined if no bit exists, so code should check against 0 first.
 117  */
 118 static inline unsigned long __ffs(unsigned long word)
 119 {
 120         int num = 0;
 121
 122 #if BITS_PER_LONG == 64
 123         if ((word & 0xffffffff) == 0) {
 124                 num += 32;
 125                 word >>= 32;
 126         }
 127 #endif
 128         if ((word & 0xffff) == 0) {
 129                 num += 16;
 130                 word >>= 16;
 131         }
 132         if ((word & 0xff) == 0) {
 133                 num += 8;
 134                 word >>= 8;
 135         }
 136         if ((word & 0xf) == 0) {
 137                 num += 4;
 138                 word >>= 4;
 139         }
 140         if ((word & 0x3) == 0) {
 141                 num += 2;
 142                 word >>= 2;
 143         }
 144         if ((word & 0x1) == 0)
 145                 num += 1;
 146         return num;
 147 }
 148
 149 #define BITOP_WORD(nr)          ((nr) / BITS_PER_LONG)
 150 /*
 151  * Find the next set bit in a memory region.
 152  */
 153 static unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
 154                             unsigned long offset)
 155 {
 156         const unsigned long *p = addr + BITOP_WORD(offset);
 157         unsigned long result = offset & ~(BITS_PER_LONG-1);
 158         unsigned long tmp;
 159
 160         if (offset >= size)
 161                 return size;
 162         size -= result;
 163         offset %= BITS_PER_LONG;
 164         if (offset) {
 165                 tmp = *(p++);
 166                 tmp &= (~0UL << offset);
 167                 if (size < BITS_PER_LONG)
 168                         goto found_first;
 169                 if (tmp)
 170                         goto found_middle;
 171                 size -= BITS_PER_LONG;
 172                 result += BITS_PER_LONG;
 173         }
 174         while (size & ~(BITS_PER_LONG-1)) {
 175                 if ((tmp = *(p++)))
 176                         goto found_middle;
 177                 result += BITS_PER_LONG;
 178                 size -= BITS_PER_LONG;
 179         }
 180         if (!size)
 181                 return result;
 182         tmp = *p;
 183
 184 found_first:
 185         tmp &= (~0UL >> (BITS_PER_LONG - size));
 186         if (tmp == 0UL)         /* Are any bits set? */
 187                 return result + size;   /* Nope. */
 188 found_middle:
 189         return result + __ffs(tmp);
 190 }
 191 #endif
 192
 193
 194 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 195 static rwlock_t chan_lock=RW_LOCK_UNLOCKED;
 196 #define SK_STATE(sk) (sk)->state
 197 #else
 198 static DEFINE_SPINLOCK(chan_lock);
 199 #define SK_STATE(sk) (sk)->sk_state
 200 #endif
 201
 202 static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
 203 static int pptp_ppp_ioctl(struct ppp_channel *chan, unsigned int cmd,
 204                            unsigned long arg);
 205 static int pptp_rcv_core(struct sock *sk,struct sk_buff *skb);
 206
 207 static struct ppp_channel_ops pptp_chan_ops= {
 208         .start_xmit = pptp_xmit,
 209         .ioctl=pptp_ppp_ioctl,
 210 };
 211
 212
 213 #define MISSING_WINDOW 20
 214 #define WRAPPED( curseq, lastseq) \
 215     ((((curseq) & 0xffffff00) == 0) && \
 216      (((lastseq) & 0xffffff00 ) == 0xffffff00))
 217
 218 /* gre header structure: -------------------------------------------- */
 219
 220 #define PPTP_GRE_PROTO  0x880B
 221 #define PPTP_GRE_VER    0x1
 222
 223 #define PPTP_GRE_FLAG_C 0x80
 224 #define PPTP_GRE_FLAG_R 0x40
 225 #define PPTP_GRE_FLAG_K 0x20
 226 #define PPTP_GRE_FLAG_S 0x10
 227 #define PPTP_GRE_FLAG_A 0x80
 228
 229 #define PPTP_GRE_IS_C(f) ((f)&PPTP_GRE_FLAG_C)
 230 #define PPTP_GRE_IS_R(f) ((f)&PPTP_GRE_FLAG_R)
 231 #define PPTP_GRE_IS_K(f) ((f)&PPTP_GRE_FLAG_K)
 232 #define PPTP_GRE_IS_S(f) ((f)&PPTP_GRE_FLAG_S)
 233 #define PPTP_GRE_IS_A(f) ((f)&PPTP_GRE_FLAG_A)
 234
 235 struct pptp_gre_header {
 236   u8 flags;             /* bitfield */
 237   u8 ver;                       /* should be PPTP_GRE_VER (enhanced GRE) */
 238   u16 protocol;         /* should be PPTP_GRE_PROTO (ppp-encaps) */
 239   u16 payload_len;      /* size of ppp payload, not inc. gre header */
 240   u16 call_id;          /* peer's call_id for this session */
 241   u32 seq;              /* sequence number.  Present if S==1 */
 242   u32 ack;              /* seq number of highest packet recieved by */
 243                                 /*  sender in this session */
 244 } __attribute__ ((__packed__));
 245 #define PPTP_HEADER_OVERHEAD (2+sizeof(struct pptp_gre_header))
 246
 247 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 248 static struct pppox_sock * lookup_chan(u16 call_id, u32 s_addr)
 249 #else
 250 static struct pppox_sock * lookup_chan(u16 call_id, __be32 s_addr)
 251 #endif
 252 {
 253         struct pppox_sock *sock;
 254         struct pptp_opt *opt;
 255
 256 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 257         rcu_read_lock();
 258         sock = rcu_dereference(callid_sock[call_id]);
 259 #else
 260         read_lock(&chan_lock);
 261         sock = callid_sock[call_id];
 262 #endif
 263         if (sock) {
 264                 opt=&sock->proto.pptp;
 265                 if (opt->dst_addr.sin_addr.s_addr!=s_addr) sock=NULL;
 266                 else sock_hold(sk_pppox(sock));
 267         }
 268 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 269         rcu_read_unlock();
 270 #else
 271         read_unlock(&chan_lock);
 272 #endif
 273
 274         return sock;
 275 }
 276
 277 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 278 static int lookup_chan_dst(u16 call_id, u32 d_addr)
 279 #else
 280 static int lookup_chan_dst(u16 call_id, __be32 d_addr)
 281 #endif
 282 {
 283         struct pppox_sock *sock;
 284         struct pptp_opt *opt;
 285         int i;
 286
 287 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 288         rcu_read_lock();
 289 #else
 290         read_lock(&chan_lock);
 291 #endif
 292         for(i = find_next_bit(callid_bitmap,MAX_CALLID,1); i < MAX_CALLID;
 293                         i = find_next_bit(callid_bitmap, MAX_CALLID, i + 1)){
 294 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 295             sock = rcu_dereference(callid_sock[i]);
 296 #else
 297             sock = callid_sock[i];
 298 #endif
 299             if (!sock)
 300                 continue;
 301             opt = &sock->proto.pptp;
 302             if (opt->dst_addr.call_id == call_id && opt->dst_addr.sin_addr.s_addr == d_addr) break;
 303         }
 304 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 305         rcu_read_unlock();
 306 #else
 307         read_unlock(&chan_lock);
 308 #endif
 309
 310         return i<MAX_CALLID;
 311 }
 312
 313 static int add_chan(struct pppox_sock *sock)
 314 {
 315         static int call_id=0;
 316         int res=-1;
 317
 318 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 319         spin_lock(&chan_lock);
 320 #else
 321         write_lock_bh(&chan_lock);
 322 #endif
 323
 324         if (!sock->proto.pptp.src_addr.call_id)
 325         {
 326             call_id=find_next_zero_bit(callid_bitmap,MAX_CALLID,call_id+1);
 327             if (call_id==MAX_CALLID)
 328                                 call_id=find_next_zero_bit(callid_bitmap,MAX_CALLID,1);
 329             sock->proto.pptp.src_addr.call_id=call_id;
 330         }
 331         else if (test_bit(sock->proto.pptp.src_addr.call_id,callid_bitmap))
 332                 goto exit;
 333
 334 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 335         rcu_assign_pointer(callid_sock[sock->proto.pptp.src_addr.call_id],sock);
 336 #else
 337         callid_sock[sock->proto.pptp.src_addr.call_id] = sock;
 338 #endif
 339         set_bit(sock->proto.pptp.src_addr.call_id,callid_bitmap);
 340         res=0;
 341
 342 exit:
 343         #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 344         spin_unlock(&chan_lock);
 345         #else
 346         write_unlock_bh(&chan_lock);
 347         #endif
 348
 349         return res;
 350 }
 351
 352 static void del_chan(struct pppox_sock *sock)
 353 {
 354 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 355         spin_lock(&chan_lock);
 356 #else
 357         write_lock_bh(&chan_lock);
 358 #endif
 359         clear_bit(sock->proto.pptp.src_addr.call_id,callid_bitmap);
 360 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 361         rcu_assign_pointer(callid_sock[sock->proto.pptp.src_addr.call_id],NULL);
 362         spin_unlock(&chan_lock);
 363         synchronize_rcu();
 364 #else
 365         callid_sock[sock->proto.pptp.src_addr.call_id] = NULL;
 366         write_unlock_bh(&chan_lock);
 367 #endif
 368 }
 369
 370 static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 371 {
 372         struct sock *sk = (struct sock *) chan->private;
 373         struct pppox_sock *po = pppox_sk(sk);
 374         struct pptp_opt *opt=&po->proto.pptp;
 375         struct pptp_gre_header *hdr;
 376         unsigned int header_len=sizeof(*hdr);
 377         int err=0;
 378         int islcp;
 379         int len;
 380         unsigned char *data;
 381         u32 seq_recv;
 382
 383
 384         struct rtable *rt;                      /* Route to the other host */
 385         struct net_device *tdev;                        /* Device to other host */
 386         struct iphdr  *iph;                     /* Our new IP header */
 387         int    max_headroom;                    /* The extra header space needed */
 388
 389         if (SK_STATE(sk_pppox(po)) & PPPOX_DEAD)
 390             goto tx_error;
 391
 392 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 393         {
 394                 struct rt_key key = {
 395                         .dst=opt->dst_addr.sin_addr.s_addr,
 396                         .src=opt->src_addr.sin_addr.s_addr,
 397                         .tos=RT_TOS(0),
 398                 };
 399                 if ((err=ip_route_output_key(&rt, &key))) {
 400                         goto tx_error;
 401                 }
 402         }
 403 #else
 404         {
 405                 struct flowi fl = { .oif = 0,
 406                                     .nl_u = { .ip4_u =
 407                                               { .daddr = opt->dst_addr.sin_addr.s_addr,
 408                                                 .saddr = opt->src_addr.sin_addr.s_addr,
 409                                                 .tos = RT_TOS(0) } },
 410                                     .proto = IPPROTO_GRE };
 411 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 412                 if ((err=ip_route_output_key(&rt, &fl))) {
 413 #else
 414                 if ((err=ip_route_output_key(&init_net,&rt, &fl))) {
 415 #endif
 416                         goto tx_error;
 417                 }
 418         }
 419 #endif
 420         tdev = rt->dst.dev;
 421
 422 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 423         max_headroom = ((tdev->hard_header_len+15)&~15) + sizeof(*iph)+sizeof(*hdr)+2;
 424 #else
 425         max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(*iph)+sizeof(*hdr)+2;
 426 #endif
 427
 428 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23) && !defined(HAVE_SKB_CLONE_WRITABLE)
 429         if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
 430 #else
 431         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 432                   (skb_cloned(skb) && !skb_clone_writable(skb,0))) {
 433 #endif
 434                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 435                 if (!new_skb) {
 436                         ip_rt_put(rt);
 437                         goto tx_error;
 438                 }
 439                 if (skb->sk)
 440                 skb_set_owner_w(new_skb, skb->sk);
 441                 kfree_skb(skb);
 442                 skb = new_skb;
 443         }
 444
 445         data=skb->data;
 446         islcp=((data[0] << 8) + data[1])== PPP_LCP && 1 <= data[2] && data[2] <= 7;
 447
 448         /* compress protocol field */
 449         if ((opt->ppp_flags & SC_COMP_PROT) && data[0]==0 && !islcp)
 450                 skb_pull(skb,1);
 451
 452         /*
 453                 * Put in the address/control bytes if necessary
 454                 */
 455         if ((opt->ppp_flags & SC_COMP_AC) == 0 || islcp) {
 456                 data=skb_push(skb,2);
 457                 data[0]=PPP_ALLSTATIONS;
 458                 data[1]=PPP_UI;
 459         }
 460
 461         len=skb->len;
 462
 463         seq_recv = opt->seq_recv;
 464
 465         if (opt->ack_sent == seq_recv) header_len-=sizeof(hdr->ack);
 466
 467         // Push down and install GRE header
 468         skb_push(skb,header_len);
 469         hdr=(struct pptp_gre_header *)(skb->data);
 470
 471         hdr->flags       = PPTP_GRE_FLAG_K;
 472         hdr->ver         = PPTP_GRE_VER;
 473         hdr->protocol    = htons(PPTP_GRE_PROTO);
 474         hdr->call_id     = htons(opt->dst_addr.call_id);
 475
 476         hdr->flags |= PPTP_GRE_FLAG_S;
 477         hdr->seq    = htonl(++opt->seq_sent);
 478 #ifdef DEBUG
 479         if (log_level>=3 && opt->seq_sent<=log_packets)
 480                 printk(KERN_INFO"PPTP[%i]: send packet: seq=%i",opt->src_addr.call_id,opt->seq_sent);
 481 #endif
 482         if (opt->ack_sent != seq_recv)  {
 483         /* send ack with this message */
 484                 hdr->ver |= PPTP_GRE_FLAG_A;
 485                 hdr->ack  = htonl(seq_recv);
 486                 opt->ack_sent = seq_recv;
 487 #ifdef DEBUG
 488                 if (log_level>=3 && opt->seq_sent<=log_packets)
 489                         printk(" ack=%i",seq_recv);
 490 #endif
 491         }
 492         hdr->payload_len = htons(len);
 493 #ifdef DEBUG
 494         if (log_level>=3 && opt->seq_sent<=log_packets)
 495                 printk("\n");
 496 #endif
 497
 498         /*
 499          *      Push down and install the IP header.
 500          */
 501
 502 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,31)
 503         skb_reset_transport_header(skb);
 504         skb_push(skb, sizeof(*iph));
 505         skb_reset_network_header(skb);
 506 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
 507         skb->transport_header = skb->network_header;
 508         skb_push(skb, sizeof(*iph));
 509         skb_reset_network_header(skb);
 510 #else
 511         skb->h.raw = skb->nh.raw;
 512         skb->nh.raw = skb_push(skb, sizeof(*iph));
 513 #endif
 514         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 515 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 516         IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
 517                               IPSKB_REROUTED);
 518 #endif
 519
 520 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
 521         iph                     =       ip_hdr(skb);
 522 #else
 523         iph                     =       skb->nh.iph;
 524 #endif
 525         iph->version            =       4;
 526         iph->ihl                =       sizeof(struct iphdr) >> 2;
 527         if (ip_dont_fragment(sk, &rt->dst))
 528                 iph->frag_off   =       htons(IP_DF);
 529         else
 530                 iph->frag_off   =       0;
 531         iph->protocol           =       IPPROTO_GRE;
 532         iph->tos                =       0;
 533         iph->daddr              =       rt->rt_dst;
 534         iph->saddr              =       rt->rt_src;
 535 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 536         iph->ttl = sk->protinfo.af_inet.ttl;
 537 #else
 538         iph->ttl = dst_metric(&rt->dst, RTAX_HOPLIMIT);
 539 #endif
 540         iph->tot_len = htons(skb->len);
 541
 542 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,31)
 543         skb_dst_drop(skb);
 544         skb_dst_set(skb,&rt->dst);
 545 #else
 546         dst_release(skb->dst);
 547         skb->dst = &rt->dst;
 548 #endif
 549
 550         nf_reset(skb);
 551
 552         skb->ip_summed = CHECKSUM_NONE;
 553         ip_select_ident(iph, &rt->dst, NULL);
 554         ip_send_check(iph);
 555
 556 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 557         err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->dst.dev, ip_send);
 558 #elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 559         err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->dst.dev, dst_output);
 560 #else
 561         err = ip_local_out(skb);
 562 #endif
 563
 564 tx_error:
 565         return 1;
 566 }
 567
 568 static int pptp_rcv_core(struct sock *sk,struct sk_buff *skb)
 569 {
 570         struct pppox_sock *po = pppox_sk(sk);
 571         struct pptp_opt *opt=&po->proto.pptp;
 572         int headersize,payload_len,seq;
 573         u8 *payload;
 574         struct pptp_gre_header *header;
 575
 576         if (!(SK_STATE(sk) & PPPOX_CONNECTED)) {
 577                 if (sock_queue_rcv_skb(sk, skb))
 578                         goto drop;
 579                 return NET_RX_SUCCESS;
 580         }
 581
 582         header = (struct pptp_gre_header *)(skb->data);
 583
 584         /* test if acknowledgement present */
 585         if (PPTP_GRE_IS_A(header->ver)){
 586                         u32 ack = (PPTP_GRE_IS_S(header->flags))?
 587                                         header->ack:header->seq; /* ack in different place if S = 0 */
 588
 589                         ack = ntohl( ack);
 590
 591                         if (ack > opt->ack_recv) opt->ack_recv = ack;
 592                         /* also handle sequence number wrap-around  */
 593                         if (WRAPPED(ack,opt->ack_recv)) opt->ack_recv = ack;
 594         }
 595
 596         /* test if payload present */
 597         if (!PPTP_GRE_IS_S(header->flags)){
 598                 goto drop;
 599         }
 600
 601         headersize  = sizeof(*header);
 602         payload_len = ntohs(header->payload_len);
 603         seq         = ntohl(header->seq);
 604
 605         /* no ack present? */
 606         if (!PPTP_GRE_IS_A(header->ver)) headersize -= sizeof(header->ack);
 607         /* check for incomplete packet (length smaller than expected) */
 608         if (skb->len - headersize < payload_len){
 609 #ifdef DEBUG
 610                 if (log_level>=1)
 611                         printk(KERN_INFO"PPTP: discarding truncated packet (expected %d, got %d bytes)\n",
 612                                                 payload_len, skb->len - headersize);
 613 #endif
 614                 goto drop;
 615         }
 616
 617         payload=skb->data+headersize;
 618         /* check for expected sequence number */
 619         if ( seq < opt->seq_recv + 1 || WRAPPED(opt->seq_recv, seq) ){
 620                 if ( (payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) &&
 621                      (PPP_PROTOCOL(payload) == PPP_LCP) &&
 622                      ((payload[4] == PPP_LCP_ECHOREQ) || (payload[4] == PPP_LCP_ECHOREP)) ){
 623 #ifdef DEBUG
 624                         if ( log_level >= 1)
 625                                 printk(KERN_INFO"PPTP[%i]: allowing old LCP Echo packet %d (expecting %d)\n", opt->src_addr.call_id,
 626                                                         seq, opt->seq_recv + 1);
 627 #endif
 628                         goto allow_packet;
 629                 }
 630 #ifdef DEBUG
 631                 if ( log_level >= 1)
 632                         printk(KERN_INFO"PPTP[%i]: discarding duplicate or old packet %d (expecting %d)\n",opt->src_addr.call_id,
 633                                                         seq, opt->seq_recv + 1);
 634 #endif
 635         }else{
 636                 opt->seq_recv = seq;
 637 allow_packet:
 638 #ifdef DEBUG
 639                 if ( log_level >= 3 && opt->seq_sent<=log_packets)
 640                         printk(KERN_INFO"PPTP[%i]: accepting packet %d size=%i (%02x %02x %02x %02x %02x %02x)\n",opt->src_addr.call_id, seq,payload_len,
 641                                 *(payload +0),
 642                                 *(payload +1),
 643                                 *(payload +2),
 644                                 *(payload +3),
 645                                 *(payload +4),
 646                                 *(payload +5));
 647 #endif
 648
 649                 skb_pull(skb,headersize);
 650
 651                 if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI){
 652                         /* chop off address/control */
 653                         if (skb->len < 3)
 654                                 goto drop;
 655                         skb_pull(skb,2);
 656                 }
 657
 658                 if ((*skb->data) & 1){
 659                         /* protocol is compressed */
 660                         skb_push(skb, 1)[0] = 0;
 661                 }
 662
 663                 skb->ip_summed=CHECKSUM_NONE;
 664 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,21)
 665                 skb_set_network_header(skb,skb->head-skb->data);
 666 #endif
 667                 ppp_input(&po->chan,skb);
 668
 669                 return NET_RX_SUCCESS;
 670         }
 671 drop:
 672         kfree_skb(skb);
 673         return NET_RX_DROP;
 674 }
 675
 676 static int pptp_rcv(struct sk_buff *skb)
 677 {
 678         struct pppox_sock *po;
 679         struct pptp_gre_header *header;
 680         struct iphdr *iph;
 681 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,0)
 682         int ret;
 683         struct sock *sk;
 684 #endif
 685
 686         if (skb->pkt_type != PACKET_HOST)
 687                 goto drop;
 688
 689 #if !defined(CONFIG_NET_IPGRE_DEMUX) && !defined(CONFIG_NET_IPGRE_DEMUX_MODULE)
 690         if (!pskb_may_pull(skb, 12))
 691                 goto drop;
 692 #endif
 693
 694 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
 695         iph = ip_hdr(skb);
 696 #else
 697         iph = skb->nh.iph;
 698 #endif
 699
 700         header = (struct pptp_gre_header *)skb->data;
 701
 702         if (    /* version should be 1 */
 703                                         ((header->ver & 0x7F) != PPTP_GRE_VER) ||
 704                                         /* PPTP-GRE protocol for PPTP */
 705                                         (ntohs(header->protocol) != PPTP_GRE_PROTO)||
 706                                         /* flag C should be clear   */
 707                                         PPTP_GRE_IS_C(header->flags) ||
 708                                         /* flag R should be clear   */
 709                                         PPTP_GRE_IS_R(header->flags) ||
 710                                         /* flag K should be set     */
 711                                         (!PPTP_GRE_IS_K(header->flags)) ||
 712                                         /* routing and recursion ctrl = 0  */
 713                                         ((header->flags&0xF) != 0)){
 714                 /* if invalid, discard this packet */
 715 #ifdef DEBUG
 716                 if (log_level>=1)
 717                         printk(KERN_INFO"PPTP: Discarding GRE: %X %X %X %X %X %X\n",
 718                                                         header->ver&0x7F, ntohs(header->protocol),
 719                                                         PPTP_GRE_IS_C(header->flags),
 720                                                         PPTP_GRE_IS_R(header->flags),
 721                                                         PPTP_GRE_IS_K(header->flags),
 722                                                         header->flags & 0xF);
 723 #endif
 724                 goto drop;
 725         }
 726
 727
 728         if ((po=lookup_chan(htons(header->call_id),iph->saddr))) {
 729 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,31)
 730                 skb_dst_drop(skb);
 731 #else
 732                 dst_release(skb->dst);
 733                 skb->dst = NULL;
 734 #endif
 735                 nf_reset(skb);
 736 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,0)
 737                 sk=sk_pppox(po);
 738                 bh_lock_sock(sk);
 739                 /* Socket state is unknown, must put skb into backlog. */
 740                 if (sk->lock.users != 0) {
 741                     sk_add_backlog(sk, skb);
 742                     ret = NET_RX_SUCCESS;
 743                 } else {
 744                     ret = pptp_rcv_core(sk, skb);
 745                 }
 746                 bh_unlock_sock(sk);
 747                 sock_put(sk);
 748                 return ret;
 749
 750 #else /* LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,0) */
 751
 752 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,19)
 753                 return sk_receive_skb(sk_pppox(po), skb);
 754 #else
 755                 return sk_receive_skb(sk_pppox(po), skb, 0);
 756 #endif
 757
 758 #endif /* LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,0) */
 759         }else {
 760 #ifdef DEBUG
 761                 if (log_level>=1)
 762                         printk(KERN_INFO"PPTP: Discarding packet from unknown call_id %i\n",htons(header->call_id));
 763 #endif
 764         }
 765
 766 drop:
 767         kfree_skb(skb);
 768         return NET_RX_DROP;
 769 }
 770
 771 static int pptp_bind(struct socket *sock,struct sockaddr *uservaddr,int sockaddr_len)
 772 {
 773         struct sock *sk = sock->sk;
 774         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
 775         struct pppox_sock *po = pppox_sk(sk);
 776         struct pptp_opt *opt=&po->proto.pptp;
 777         int error=0;
 778
 779 #ifdef DEBUG
 780         if (log_level>=1)
 781                 printk(KERN_INFO"PPTP: bind: addr=%X call_id=%i\n",sp->sa_addr.pptp.sin_addr.s_addr,
 782                                                 sp->sa_addr.pptp.call_id);
 783 #endif
 784         lock_sock(sk);
 785
 786         opt->src_addr=sp->sa_addr.pptp;
 787         if (add_chan(po))
 788                 error=-EBUSY;
 789 #ifdef DEBUG
 790         if (log_level>=1)
 791                 printk(KERN_INFO"PPTP: using call_id %i\n",opt->src_addr.call_id);
 792 #endif
 793
 794         release_sock(sk);
 795         return error;
 796 }
 797
 798 static int pptp_connect(struct socket *sock, struct sockaddr *uservaddr,
 799                   int sockaddr_len, int flags)
 800 {
 801         struct sock *sk = sock->sk;
 802         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
 803         struct pppox_sock *po = pppox_sk(sk);
 804         struct pptp_opt *opt = &po->proto.pptp;
 805         struct rtable *rt;                      /* Route to the other host */
 806         int error=0;
 807
 808         if (sp->sa_protocol != PX_PROTO_PPTP)
 809                 return -EINVAL;
 810
 811 #ifdef DEBUG
 812         if (log_level>=1)
 813                 printk(KERN_INFO"PPTP[%i]: connect: addr=%X call_id=%i\n",opt->src_addr.call_id,
 814                                                 sp->sa_addr.pptp.sin_addr.s_addr,sp->sa_addr.pptp.call_id);
 815 #endif
 816
 817         if (lookup_chan_dst(sp->sa_addr.pptp.call_id,sp->sa_addr.pptp.sin_addr.s_addr))
 818                 return -EALREADY;
 819
 820         lock_sock(sk);
 821         /* Check for already bound sockets */
 822         if (SK_STATE(sk) & PPPOX_CONNECTED){
 823                 error = -EBUSY;
 824                 goto end;
 825         }
 826
 827         /* Check for already disconnected sockets, on attempts to disconnect */
 828         if (SK_STATE(sk) & PPPOX_DEAD){
 829                 error = -EALREADY;
 830                 goto end;
 831         }
 832
 833         if (!opt->src_addr.sin_addr.s_addr || !sp->sa_addr.pptp.sin_addr.s_addr){
 834                 error = -EINVAL;
 835                 goto end;
 836         }
 837
 838         po->chan.private=sk;
 839         po->chan.ops=&pptp_chan_ops;
 840
 841 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 842         {
 843                 struct rt_key key = {
 844                         .dst=opt->dst_addr.sin_addr.s_addr,
 845                         .src=opt->src_addr.sin_addr.s_addr,
 846                         .tos=RT_TOS(0),
 847                 };
 848 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 849                 if (ip_route_output_key(&rt, &key)) {
 850 #else
 851                 if (ip_route_output_key(&init_net, &rt, &key)) {
 852 #endif
 853                         error = -EHOSTUNREACH;
 854                         goto end;
 855                 }
 856         }
 857 #else
 858         {
 859                 struct flowi fl = {
 860                                     .nl_u = { .ip4_u =
 861                                               { .daddr = opt->dst_addr.sin_addr.s_addr,
 862                                                 .saddr = opt->src_addr.sin_addr.s_addr,
 863                                                 .tos = RT_CONN_FLAGS(sk) } },
 864                                     .proto = IPPROTO_GRE };
 865 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
 866                 security_sk_classify_flow(sk, &fl);
 867 #endif
 868 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 869                 if (ip_route_output_key(&rt, &fl)){
 870 #else
 871                 if (ip_route_output_key(&init_net, &rt, &fl)){
 872 #endif
 873                         error = -EHOSTUNREACH;
 874                         goto end;
 875                 }
 876                 sk_setup_caps(sk, &rt->dst);
 877         }
 878 #endif
 879 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 880         po->chan.mtu=PPP_MTU;
 881 #else
 882         po->chan.mtu=dst_mtu(&rt->dst);
 883         if (!po->chan.mtu) po->chan.mtu=PPP_MTU;
 884 #endif
 885         ip_rt_put(rt);
 886         po->chan.mtu-=PPTP_HEADER_OVERHEAD;
 887
 888         po->chan.hdrlen=2+sizeof(struct pptp_gre_header);
 889         po->chan.hdrlen += LL_MAX_HEADER + sizeof(struct iphdr);
 890         error = ppp_register_channel(&po->chan);
 891         if (error){
 892                 printk(KERN_ERR "PPTP: failed to register PPP channel (%d)\n",error);
 893                 goto end;
 894         }
 895
 896         opt->dst_addr=sp->sa_addr.pptp;
 897         SK_STATE(sk) = PPPOX_CONNECTED;
 898
 899  end:
 900         release_sock(sk);
 901         return error;
 902 }
 903
 904 static int pptp_getname(struct socket *sock, struct sockaddr *uaddr,
 905                   int *usockaddr_len, int peer)
 906 {
 907         int len = sizeof(struct sockaddr_pppox);
 908         struct sockaddr_pppox sp;
 909
 910         sp.sa_family    = AF_PPPOX;
 911         sp.sa_protocol  = PX_PROTO_PPTP;
 912         sp.sa_addr.pptp=pppox_sk(sock->sk)->proto.pptp.src_addr;
 913
 914         memcpy(uaddr, &sp, len);
 915
 916         *usockaddr_len = len;
 917
 918         return 0;
 919 }
 920
 921 static int pptp_release(struct socket *sock)
 922 {
 923         struct sock *sk = sock->sk;
 924         struct pppox_sock *po;
 925         struct pptp_opt *opt;
 926         int error = 0;
 927
 928         if (!sk)
 929             return 0;
 930
 931         lock_sock(sk);
 932
 933 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 934         if (sk->dead)
 935 #else
 936         if (sock_flag(sk, SOCK_DEAD))
 937 #endif
 938         {
 939             release_sock(sk);
 940             return -EBADF;
 941         }
 942
 943         po = pppox_sk(sk);
 944         opt=&po->proto.pptp;
 945         del_chan(po);
 946
 947         pppox_unbind_sock(sk);
 948         SK_STATE(sk) = PPPOX_DEAD;
 949
 950 #ifdef DEBUG
 951         if (log_level>=1)
 952                 printk(KERN_INFO"PPTP[%i]: release\n",opt->src_addr.call_id);
 953 #endif
 954
 955         sock_orphan(sk);
 956         sock->sk = NULL;
 957
 958         release_sock(sk);
 959         sock_put(sk);
 960
 961         return error;
 962 }
 963
 964
 965 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 966 static struct proto pptp_sk_proto = {
 967         .name     = "PPTP",
 968         .owner    = THIS_MODULE,
 969         .obj_size = sizeof(struct pppox_sock),
 970 };
 971 #endif
 972
 973 static struct proto_ops pptp_ops = {
 974     .family             = AF_PPPOX,
 975 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
 976     .owner              = THIS_MODULE,
 977 #endif
 978     .release            = pptp_release,
 979     .bind               =  pptp_bind,
 980     .connect            = pptp_connect,
 981     .socketpair         = sock_no_socketpair,
 982     .accept             = sock_no_accept,
 983     .getname            = pptp_getname,
 984     .poll               = sock_no_poll,
 985     .listen             = sock_no_listen,
 986     .shutdown           = sock_no_shutdown,
 987     .setsockopt         = sock_no_setsockopt,
 988     .getsockopt         = sock_no_getsockopt,
 989     .sendmsg            = sock_no_sendmsg,
 990     .recvmsg            = sock_no_recvmsg,
 991     .mmap               = sock_no_mmap,
 992 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 993     .ioctl              = pppox_ioctl,
 994 #endif
 995 };
 996
 997
 998 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
 999 static void pptp_sock_destruct(struct sock *sk)
1000 {
1001         skb_queue_purge(&sk->receive_queue);
1002         if (!(SK_STATE(sk) & PPPOX_DEAD)) {
1003                 del_chan(pppox_sk(sk));
1004                 pppox_unbind_sock(sk);
1005         }
1006         if (sk->protinfo.destruct_hook)
1007                 kfree(sk->protinfo.destruct_hook);
1008
1009         MOD_DEC_USE_COUNT;
1010 }
1011
1012 static int pptp_create(struct socket *sock)
1013 {
1014         int error = -ENOMEM;
1015         struct sock *sk;
1016         struct pppox_sock *po;
1017         struct pptp_opt *opt;
1018
1019         MOD_INC_USE_COUNT;
1020
1021         sk = sk_alloc(PF_PPPOX, GFP_KERNEL, 1);
1022         if (!sk)
1023                 goto out;
1024
1025         sock_init_data(sock, sk);
1026
1027         sock->state = SS_UNCONNECTED;
1028         sock->ops   = &pptp_ops;
1029
1030         //sk->sk_backlog_rcv = pppoe_rcv_core;
1031         sk->state          = PPPOX_NONE;
1032         sk->type           = SOCK_STREAM;
1033         sk->family         = PF_PPPOX;
1034         sk->protocol       = PX_PROTO_PPTP;
1035
1036         sk->protinfo.pppox=kzalloc(sizeof(struct pppox_sock),GFP_KERNEL);
1037         sk->destruct=pptp_sock_destruct;
1038         sk->protinfo.destruct_hook=sk->protinfo.pppox;
1039
1040         po = pppox_sk(sk);
1041         po->sk=sk;
1042         opt=&po->proto.pptp;
1043
1044         opt->seq_sent=0; opt->seq_recv=0;
1045         opt->ack_recv=0; opt->ack_sent=0;
1046
1047         error = 0;
1048 out:
1049         return error;
1050 }
1051 #else
1052 static void pptp_sock_destruct(struct sock *sk)
1053 {
1054     if (!(SK_STATE(sk) & PPPOX_DEAD)){
1055             del_chan(pppox_sk(sk));
1056             pppox_unbind_sock(sk);
1057     }
1058     skb_queue_purge(&sk->sk_receive_queue);
1059 }
1060 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
1061 static int pptp_create(struct socket *sock)
1062 #else
1063 static int pptp_create(struct net *net, struct socket *sock)
1064 #endif
1065 {
1066         int error = -ENOMEM;
1067         struct sock *sk;
1068         struct pppox_sock *po;
1069         struct pptp_opt *opt;
1070
1071 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
1072         sk = sk_alloc(PF_PPPOX, GFP_KERNEL, &pptp_sk_proto, 1);
1073 #else
1074         sk = sk_alloc(net,PF_PPPOX, GFP_KERNEL, &pptp_sk_proto);
1075 #endif
1076         if (!sk)
1077                 goto out;
1078
1079         sock_init_data(sock, sk);
1080
1081         sock->state = SS_UNCONNECTED;
1082         sock->ops   = &pptp_ops;
1083
1084         sk->sk_backlog_rcv = pptp_rcv_core;
1085         sk->sk_state       = PPPOX_NONE;
1086         sk->sk_type        = SOCK_STREAM;
1087         sk->sk_family      = PF_PPPOX;
1088         sk->sk_protocol    = PX_PROTO_PPTP;
1089         sk->sk_destruct    = pptp_sock_destruct;
1090
1091         po = pppox_sk(sk);
1092 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
1093         po->sk=sk;
1094 #endif
1095         opt=&po->proto.pptp;
1096
1097         opt->seq_sent = 0; opt->seq_recv = 0xffffffff;
1098         opt->ack_recv = 0; opt->ack_sent = 0xffffffff;
1099
1100         error = 0;
1101 out:
1102         return error;
1103 }
1104 #endif
1105
1106
1107 static int pptp_ppp_ioctl(struct ppp_channel *chan, unsigned int cmd,
1108                            unsigned long arg)
1109 {
1110         struct sock *sk = (struct sock *) chan->private;
1111         struct pppox_sock *po = pppox_sk(sk);
1112         struct pptp_opt *opt=&po->proto.pptp;
1113         void __user *argp = (void __user *)arg;
1114         int __user *p = argp;
1115         int err, val;
1116
1117         err = -EFAULT;
1118         switch (cmd) {
1119         case PPPIOCGFLAGS:
1120                 val = opt->ppp_flags;
1121                 if (put_user(val, p))
1122                         break;
1123                 err = 0;
1124                 break;
1125         case PPPIOCSFLAGS:
1126                 if (get_user(val, p))
1127                         break;
1128                 opt->ppp_flags = val & ~SC_RCV_BITS;
1129                 err = 0;
1130                 break;
1131         default:
1132                 err = -ENOTTY;
1133         }
1134
1135         return err;
1136 }
1137
1138
1139 static struct pppox_proto pppox_pptp_proto = {
1140     .create     = pptp_create,
1141 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,15)
1142     .owner      = THIS_MODULE,
1143 #endif
1144 };
1145
1146 #if defined(CONFIG_NET_IPGRE_DEMUX) || defined(CONFIG_NET_IPGRE_DEMUX_MODULE)
1147 static struct gre_protocol gre_pptp_protocol = {
1148         .handler        = pptp_rcv,
1149 };
1150 #elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
1151 static struct inet_protocol net_pptp_protocol = {
1152         .handler        = pptp_rcv,
1153         .protocol = IPPROTO_GRE,
1154         .name     = "PPTP",
1155 };
1156 #else
1157 static struct net_protocol net_pptp_protocol = {
1158         .handler        = pptp_rcv,
1159 };
1160 #endif
1161
1162 static int __init pptp_init_module(void)
1163 {
1164         int err=0;
1165         printk(KERN_INFO "PPTP driver version " PPTP_DRIVER_VERSION "\n");
1166 printk("=== PPTP init ===\n");
1167 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
1168         callid_sock = __vmalloc((MAX_CALLID + 1) * sizeof(void *),
1169                                 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
1170 #else
1171         callid_sock = __vmalloc((MAX_CALLID + 1) * sizeof(void *),
1172                                 GFP_KERNEL, PAGE_KERNEL);
1173         memset(callid_sock, 0, (MAX_CALLID + 1) * sizeof(void *));
1174 #endif
1175         if (!callid_sock) {
1176                 printk(KERN_ERR "PPTP: cann't allocate memory\n");
1177                 return -ENOMEM;
1178         }
1179
1180 #if defined(CONFIG_NET_IPGRE_DEMUX) || defined(CONFIG_NET_IPGRE_DEMUX_MODULE)
1181         if (gre_add_protocol(&gre_pptp_protocol, GREPROTO_PPTP) < 0) {
1182                 printk(KERN_INFO "PPTP: can't add protocol\n");
1183                 goto out_free_mem;
1184         }
1185 #elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
1186         inet_add_protocol(&net_pptp_protocol);
1187 #else
1188         if (inet_add_protocol(&net_pptp_protocol, IPPROTO_GRE) < 0) {
1189                 printk(KERN_INFO "PPTP: can't add protocol\n");
1190                 goto out_free_mem;
1191         }
1192 #endif
1193
1194 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
1195         err = proto_register(&pptp_sk_proto, 0);
1196         if (err){
1197                 printk(KERN_INFO "PPTP: can't register sk_proto\n");
1198                 goto out_inet_del_protocol;
1199         }
1200 #endif
1201
1202         err = register_pppox_proto(PX_PROTO_PPTP, &pppox_pptp_proto);
1203         if (err){
1204                 printk(KERN_INFO "PPTP: can't register pppox_proto\n");
1205                 goto out_unregister_sk_proto;
1206         }
1207
1208         return 0;
1209 out_unregister_sk_proto:
1210 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
1211         proto_unregister(&pptp_sk_proto);
1212 #endif
1213
1214 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
1215 out_inet_del_protocol:
1216 #endif
1217
1218 #if defined(CONFIG_NET_IPGRE_DEMUX) || defined(CONFIG_NET_IPGRE_DEMUX_MODULE)
1219         gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
1220 #elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
1221         inet_del_protocol(&net_pptp_protocol);
1222 #else
1223         inet_del_protocol(&net_pptp_protocol, IPPROTO_GRE);
1224 #endif
1225 out_free_mem:
1226         vfree(callid_sock);
1227
1228         return err;
1229 }
1230
1231 static void __exit pptp_exit_module(void)
1232 {
1233         unregister_pppox_proto(PX_PROTO_PPTP);
1234 #if defined(CONFIG_NET_IPGRE_DEMUX) || defined(CONFIG_NET_IPGRE_DEMUX_MODULE)
1235 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0)
1236         proto_unregister(&pptp_sk_proto);
1237 #endif
1238         gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
1239 #elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
1240         inet_del_protocol(&net_pptp_protocol);
1241 #else
1242         proto_unregister(&pptp_sk_proto);
1243         inet_del_protocol(&net_pptp_protocol, IPPROTO_GRE);
1244 #endif
1245         vfree(callid_sock);
1246 }
1247
1248 module_init(pptp_init_module);
1249 module_exit(pptp_exit_module);
1250
1251 MODULE_DESCRIPTION("Point-to-Point Tunneling Protocol for Linux");
1252 MODULE_AUTHOR("Kozlov D. (xeb@mail.ru)");
1253 MODULE_LICENSE("GPL");
1254
1255 #ifdef DEBUG
1256 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
1257 MODULE_PARM(log_level,"i");
1258 MODULE_PARM(log_packets,"i");
1259 #else
1260 module_param(log_level,int,0);
1261 module_param(log_packets,int,0);
1262 #endif
1263 MODULE_PARM_DESC(log_level,"Logging level (default=0)");
1264 #endif