drivers/net/pptp.c

   1 /*
   2  *  Point-to-Point Tunneling Protocol for Linux
   3  *
   4  *      Authors: Dmitry Kozlov <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/errno.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/net.h>
  20 #include <linux/skbuff.h>
  21 #include <linux/vmalloc.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/rcupdate.h>
  34 #include <linux/spinlock.h>
  35
  36 #include <net/sock.h>
  37 #include <net/protocol.h>
  38 #include <net/ip.h>
  39 #include <net/icmp.h>
  40 #include <net/route.h>
  41 #include <net/gre.h>
  42
  43 #include <linux/uaccess.h>
  44
  45 #define PPTP_DRIVER_VERSION "0.8.5"
  46
  47 #define MAX_CALLID 65535
  48
  49 static DECLARE_BITMAP(callid_bitmap, MAX_CALLID + 1);
  50 static struct pppox_sock **callid_sock;
  51
  52 static DEFINE_SPINLOCK(chan_lock);
  53
  54 static struct proto pptp_sk_proto __read_mostly;
  55 static const struct ppp_channel_ops pptp_chan_ops;
  56 static const struct proto_ops pptp_ops;
  57
  58 #define PPP_LCP_ECHOREQ 0x09
  59 #define PPP_LCP_ECHOREP 0x0A
  60 #define SC_RCV_BITS     (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
  61
  62 #define MISSING_WINDOW 20
  63 #define WRAPPED(curseq, lastseq)\
  64         ((((curseq) & 0xffffff00) == 0) &&\
  65         (((lastseq) & 0xffffff00) == 0xffffff00))
  66
  67 #define PPTP_GRE_PROTO  0x880B
  68 #define PPTP_GRE_VER    0x1
  69
  70 #define PPTP_GRE_FLAG_C 0x80
  71 #define PPTP_GRE_FLAG_R 0x40
  72 #define PPTP_GRE_FLAG_K 0x20
  73 #define PPTP_GRE_FLAG_S 0x10
  74 #define PPTP_GRE_FLAG_A 0x80
  75
  76 #define PPTP_GRE_IS_C(f) ((f)&PPTP_GRE_FLAG_C)
  77 #define PPTP_GRE_IS_R(f) ((f)&PPTP_GRE_FLAG_R)
  78 #define PPTP_GRE_IS_K(f) ((f)&PPTP_GRE_FLAG_K)
  79 #define PPTP_GRE_IS_S(f) ((f)&PPTP_GRE_FLAG_S)
  80 #define PPTP_GRE_IS_A(f) ((f)&PPTP_GRE_FLAG_A)
  81
  82 #define PPTP_HEADER_OVERHEAD (2+sizeof(struct pptp_gre_header))
  83 struct pptp_gre_header {
  84         u8  flags;
  85         u8  ver;
  86         u16 protocol;
  87         u16 payload_len;
  88         u16 call_id;
  89         u32 seq;
  90         u32 ack;
  91 } __packed;
  92
  93 static struct pppox_sock *lookup_chan(u16 call_id, __be32 s_addr)
  94 {
  95         struct pppox_sock *sock;
  96         struct pptp_opt *opt;
  97
  98         rcu_read_lock();
  99         sock = rcu_dereference(callid_sock[call_id]);
 100         if (sock) {
 101                 opt = &sock->proto.pptp;
 102                 if (opt->dst_addr.sin_addr.s_addr != s_addr)
 103                         sock = NULL;
 104                 else
 105                         sock_hold(sk_pppox(sock));
 106         }
 107         rcu_read_unlock();
 108
 109         return sock;
 110 }
 111
 112 static int lookup_chan_dst(u16 call_id, __be32 d_addr)
 113 {
 114         struct pppox_sock *sock;
 115         struct pptp_opt *opt;
 116         int i;
 117
 118         rcu_read_lock();
 119         for (i = find_next_bit(callid_bitmap, MAX_CALLID, 1); i < MAX_CALLID;
 120              i = find_next_bit(callid_bitmap, MAX_CALLID, i + 1)) {
 121                 sock = rcu_dereference(callid_sock[i]);
 122                 if (!sock)
 123                         continue;
 124                 opt = &sock->proto.pptp;
 125                 if (opt->dst_addr.call_id == call_id &&
 126                           opt->dst_addr.sin_addr.s_addr == d_addr)
 127                         break;
 128         }
 129         rcu_read_unlock();
 130
 131         return i < MAX_CALLID;
 132 }
 133
 134 static int add_chan(struct pppox_sock *sock)
 135 {
 136         static int call_id;
 137
 138         spin_lock(&chan_lock);
 139         if (!sock->proto.pptp.src_addr.call_id) {
 140                 call_id = find_next_zero_bit(callid_bitmap, MAX_CALLID, call_id + 1);
 141                 if (call_id == MAX_CALLID) {
 142                         call_id = find_next_zero_bit(callid_bitmap, MAX_CALLID, 1);
 143                         if (call_id == MAX_CALLID)
 144                                 goto out_err;
 145                 }
 146                 sock->proto.pptp.src_addr.call_id = call_id;
 147         } else if (test_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap))
 148                 goto out_err;
 149
 150         set_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap);
 151         rcu_assign_pointer(callid_sock[sock->proto.pptp.src_addr.call_id], sock);
 152         spin_unlock(&chan_lock);
 153
 154         return 0;
 155
 156 out_err:
 157         spin_unlock(&chan_lock);
 158         return -1;
 159 }
 160
 161 static void del_chan(struct pppox_sock *sock)
 162 {
 163         spin_lock(&chan_lock);
 164         clear_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap);
 165         rcu_assign_pointer(callid_sock[sock->proto.pptp.src_addr.call_id], NULL);
 166         spin_unlock(&chan_lock);
 167         synchronize_rcu();
 168 }
 169
 170 static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 171 {
 172         struct sock *sk = (struct sock *) chan->private;
 173         struct pppox_sock *po = pppox_sk(sk);
 174         struct pptp_opt *opt = &po->proto.pptp;
 175         struct pptp_gre_header *hdr;
 176         unsigned int header_len = sizeof(*hdr);
 177         struct flowi4 fl4;
 178         int islcp;
 179         int len;
 180         unsigned char *data;
 181         __u32 seq_recv;
 182
 183
 184         struct rtable *rt;
 185         struct net_device *tdev;
 186         struct iphdr  *iph;
 187         int    max_headroom;
 188
 189         if (sk_pppox(po)->sk_state & PPPOX_DEAD)
 190                 goto tx_error;
 191
 192         rt = ip_route_output_ports(&init_net, &fl4, NULL,
 193                                    opt->dst_addr.sin_addr.s_addr,
 194                                    opt->src_addr.sin_addr.s_addr,
 195                                    0, 0, IPPROTO_GRE,
 196                                    RT_TOS(0), 0);
 197         if (IS_ERR(rt))
 198                 goto tx_error;
 199
 200         tdev = rt->dst.dev;
 201
 202         max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(*iph) + sizeof(*hdr) + 2;
 203
 204         if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
 205                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 206                 if (!new_skb) {
 207                         ip_rt_put(rt);
 208                         goto tx_error;
 209                 }
 210                 if (skb->sk)
 211                         skb_set_owner_w(new_skb, skb->sk);
 212                 kfree_skb(skb);
 213                 skb = new_skb;
 214         }
 215
 216         data = skb->data;
 217         islcp = ((data[0] << 8) + data[1]) == PPP_LCP && 1 <= data[2] && data[2] <= 7;
 218
 219         /* compress protocol field */
 220         if ((opt->ppp_flags & SC_COMP_PROT) && data[0] == 0 && !islcp)
 221                 skb_pull(skb, 1);
 222
 223         /* Put in the address/control bytes if necessary */
 224         if ((opt->ppp_flags & SC_COMP_AC) == 0 || islcp) {
 225                 data = skb_push(skb, 2);
 226                 data[0] = PPP_ALLSTATIONS;
 227                 data[1] = PPP_UI;
 228         }
 229
 230         len = skb->len;
 231
 232         seq_recv = opt->seq_recv;
 233
 234         if (opt->ack_sent == seq_recv)
 235                 header_len -= sizeof(hdr->ack);
 236
 237         /* Push down and install GRE header */
 238         skb_push(skb, header_len);
 239         hdr = (struct pptp_gre_header *)(skb->data);
 240
 241         hdr->flags       = PPTP_GRE_FLAG_K;
 242         hdr->ver         = PPTP_GRE_VER;
 243         hdr->protocol    = htons(PPTP_GRE_PROTO);
 244         hdr->call_id     = htons(opt->dst_addr.call_id);
 245
 246         hdr->flags      |= PPTP_GRE_FLAG_S;
 247         hdr->seq         = htonl(++opt->seq_sent);
 248         if (opt->ack_sent != seq_recv)  {
 249                 /* send ack with this message */
 250                 hdr->ver |= PPTP_GRE_FLAG_A;
 251                 hdr->ack  = htonl(seq_recv);
 252                 opt->ack_sent = seq_recv;
 253         }
 254         hdr->payload_len = htons(len);
 255
 256         /*      Push down and install the IP header. */
 257
 258         skb_reset_transport_header(skb);
 259         skb_push(skb, sizeof(*iph));
 260         skb_reset_network_header(skb);
 261         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 262         IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED);
 263
 264         iph =   ip_hdr(skb);
 265         iph->version =  4;
 266         iph->ihl =      sizeof(struct iphdr) >> 2;
 267         if (ip_dont_fragment(sk, &rt->dst))
 268                 iph->frag_off   =       htons(IP_DF);
 269         else
 270                 iph->frag_off   =       0;
 271         iph->protocol = IPPROTO_GRE;
 272         iph->tos      = 0;
 273         iph->daddr    = fl4.daddr;
 274         iph->saddr    = fl4.saddr;
 275         iph->ttl      = ip4_dst_hoplimit(&rt->dst);
 276         iph->tot_len  = htons(skb->len);
 277
 278         skb_dst_drop(skb);
 279         skb_dst_set(skb, &rt->dst);
 280
 281         nf_reset(skb);
 282
 283         skb->ip_summed = CHECKSUM_NONE;
 284         ip_select_ident(iph, &rt->dst, NULL);
 285         ip_send_check(iph);
 286
 287         ip_local_out(skb);
 288         return 1;
 289
 290 tx_error:
 291         kfree_skb(skb);
 292         return 1;
 293 }
 294
 295 static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)
 296 {
 297         struct pppox_sock *po = pppox_sk(sk);
 298         struct pptp_opt *opt = &po->proto.pptp;
 299         int headersize, payload_len, seq;
 300         __u8 *payload;
 301         struct pptp_gre_header *header;
 302
 303         if (!(sk->sk_state & PPPOX_CONNECTED)) {
 304                 if (sock_queue_rcv_skb(sk, skb))
 305                         goto drop;
 306                 return NET_RX_SUCCESS;
 307         }
 308
 309         header = (struct pptp_gre_header *)(skb->data);
 310         headersize  = sizeof(*header);
 311
 312         /* test if acknowledgement present */
 313         if (PPTP_GRE_IS_A(header->ver)) {
 314                 __u32 ack;
 315
 316                 if (!pskb_may_pull(skb, headersize))
 317                         goto drop;
 318                 header = (struct pptp_gre_header *)(skb->data);
 319
 320                 /* ack in different place if S = 0 */
 321                 ack = PPTP_GRE_IS_S(header->flags) ? header->ack : header->seq;
 322
 323                 ack = ntohl(ack);
 324
 325                 if (ack > opt->ack_recv)
 326                         opt->ack_recv = ack;
 327                 /* also handle sequence number wrap-around  */
 328                 if (WRAPPED(ack, opt->ack_recv))
 329                         opt->ack_recv = ack;
 330         } else {
 331                 headersize -= sizeof(header->ack);
 332         }
 333         /* test if payload present */
 334         if (!PPTP_GRE_IS_S(header->flags))
 335                 goto drop;
 336
 337         payload_len = ntohs(header->payload_len);
 338         seq         = ntohl(header->seq);
 339
 340         /* check for incomplete packet (length smaller than expected) */
 341         if (!pskb_may_pull(skb, headersize + payload_len))
 342                 goto drop;
 343
 344         payload = skb->data + headersize;
 345         /* check for expected sequence number */
 346         if (seq < opt->seq_recv + 1 || WRAPPED(opt->seq_recv, seq)) {
 347                 if ((payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) &&
 348                                 (PPP_PROTOCOL(payload) == PPP_LCP) &&
 349                                 ((payload[4] == PPP_LCP_ECHOREQ) || (payload[4] == PPP_LCP_ECHOREP)))
 350                         goto allow_packet;
 351         } else {
 352                 opt->seq_recv = seq;
 353 allow_packet:
 354                 skb_pull(skb, headersize);
 355
 356                 if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI) {
 357                         /* chop off address/control */
 358                         if (skb->len < 3)
 359                                 goto drop;
 360                         skb_pull(skb, 2);
 361                 }
 362
 363                 if ((*skb->data) & 1) {
 364                         /* protocol is compressed */
 365                         skb_push(skb, 1)[0] = 0;
 366                 }
 367
 368                 skb->ip_summed = CHECKSUM_NONE;
 369                 skb_set_network_header(skb, skb->head-skb->data);
 370                 ppp_input(&po->chan, skb);
 371
 372                 return NET_RX_SUCCESS;
 373         }
 374 drop:
 375         kfree_skb(skb);
 376         return NET_RX_DROP;
 377 }
 378
 379 static int pptp_rcv(struct sk_buff *skb)
 380 {
 381         struct pppox_sock *po;
 382         struct pptp_gre_header *header;
 383         struct iphdr *iph;
 384
 385         if (skb->pkt_type != PACKET_HOST)
 386                 goto drop;
 387
 388         if (!pskb_may_pull(skb, 12))
 389                 goto drop;
 390
 391         iph = ip_hdr(skb);
 392
 393         header = (struct pptp_gre_header *)skb->data;
 394
 395         if (ntohs(header->protocol) != PPTP_GRE_PROTO || /* PPTP-GRE protocol for PPTP */
 396                 PPTP_GRE_IS_C(header->flags) ||                /* flag C should be clear */
 397                 PPTP_GRE_IS_R(header->flags) ||                /* flag R should be clear */
 398                 !PPTP_GRE_IS_K(header->flags) ||               /* flag K should be set */
 399                 (header->flags&0xF) != 0)                      /* routing and recursion ctrl = 0 */
 400                 /* if invalid, discard this packet */
 401                 goto drop;
 402
 403         po = lookup_chan(htons(header->call_id), iph->saddr);
 404         if (po) {
 405                 skb_dst_drop(skb);
 406                 nf_reset(skb);
 407                 return sk_receive_skb(sk_pppox(po), skb, 0);
 408         }
 409 drop:
 410         kfree_skb(skb);
 411         return NET_RX_DROP;
 412 }
 413
 414 static int pptp_bind(struct socket *sock, struct sockaddr *uservaddr,
 415         int sockaddr_len)
 416 {
 417         struct sock *sk = sock->sk;
 418         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
 419         struct pppox_sock *po = pppox_sk(sk);
 420         struct pptp_opt *opt = &po->proto.pptp;
 421         int error = 0;
 422
 423         lock_sock(sk);
 424
 425         opt->src_addr = sp->sa_addr.pptp;
 426         if (add_chan(po)) {
 427                 release_sock(sk);
 428                 error = -EBUSY;
 429         }
 430
 431         release_sock(sk);
 432         return error;
 433 }
 434
 435 static int pptp_connect(struct socket *sock, struct sockaddr *uservaddr,
 436         int sockaddr_len, int flags)
 437 {
 438         struct sock *sk = sock->sk;
 439         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
 440         struct pppox_sock *po = pppox_sk(sk);
 441         struct pptp_opt *opt = &po->proto.pptp;
 442         struct rtable *rt;
 443         struct flowi4 fl4;
 444         int error = 0;
 445
 446         if (sp->sa_protocol != PX_PROTO_PPTP)
 447                 return -EINVAL;
 448
 449         if (lookup_chan_dst(sp->sa_addr.pptp.call_id, sp->sa_addr.pptp.sin_addr.s_addr))
 450                 return -EALREADY;
 451
 452         lock_sock(sk);
 453         /* Check for already bound sockets */
 454         if (sk->sk_state & PPPOX_CONNECTED) {
 455                 error = -EBUSY;
 456                 goto end;
 457         }
 458
 459         /* Check for already disconnected sockets, on attempts to disconnect */
 460         if (sk->sk_state & PPPOX_DEAD) {
 461                 error = -EALREADY;
 462                 goto end;
 463         }
 464
 465         if (!opt->src_addr.sin_addr.s_addr || !sp->sa_addr.pptp.sin_addr.s_addr) {
 466                 error = -EINVAL;
 467                 goto end;
 468         }
 469
 470         po->chan.private = sk;
 471         po->chan.ops = &pptp_chan_ops;
 472
 473         rt = ip_route_output_ports(&init_net, &fl4, sk,
 474                                    opt->dst_addr.sin_addr.s_addr,
 475                                    opt->src_addr.sin_addr.s_addr,
 476                                    0, 0,
 477                                    IPPROTO_GRE, RT_CONN_FLAGS(sk), 0);
 478         if (IS_ERR(rt)) {
 479                 error = -EHOSTUNREACH;
 480                 goto end;
 481         }
 482         sk_setup_caps(sk, &rt->dst);
 483
 484         po->chan.mtu = dst_mtu(&rt->dst);
 485         if (!po->chan.mtu)
 486                 po->chan.mtu = PPP_MTU;
 487         ip_rt_put(rt);
 488         po->chan.mtu -= PPTP_HEADER_OVERHEAD;
 489
 490         po->chan.hdrlen = 2 + sizeof(struct pptp_gre_header);
 491         error = ppp_register_channel(&po->chan);
 492         if (error) {
 493                 pr_err("PPTP: failed to register PPP channel (%d)\n", error);
 494                 goto end;
 495         }
 496
 497         opt->dst_addr = sp->sa_addr.pptp;
 498         sk->sk_state = PPPOX_CONNECTED;
 499
 500  end:
 501         release_sock(sk);
 502         return error;
 503 }
 504
 505 static int pptp_getname(struct socket *sock, struct sockaddr *uaddr,
 506         int *usockaddr_len, int peer)
 507 {
 508         int len = sizeof(struct sockaddr_pppox);
 509         struct sockaddr_pppox sp;
 510
 511         sp.sa_family      = AF_PPPOX;
 512         sp.sa_protocol  = PX_PROTO_PPTP;
 513         sp.sa_addr.pptp = pppox_sk(sock->sk)->proto.pptp.src_addr;
 514
 515         memcpy(uaddr, &sp, len);
 516
 517         *usockaddr_len = len;
 518
 519         return 0;
 520 }
 521
 522 static int pptp_release(struct socket *sock)
 523 {
 524         struct sock *sk = sock->sk;
 525         struct pppox_sock *po;
 526         struct pptp_opt *opt;
 527         int error = 0;
 528
 529         if (!sk)
 530                 return 0;
 531
 532         lock_sock(sk);
 533
 534         if (sock_flag(sk, SOCK_DEAD)) {
 535                 release_sock(sk);
 536                 return -EBADF;
 537         }
 538
 539         po = pppox_sk(sk);
 540         opt = &po->proto.pptp;
 541         del_chan(po);
 542
 543         pppox_unbind_sock(sk);
 544         sk->sk_state = PPPOX_DEAD;
 545
 546         sock_orphan(sk);
 547         sock->sk = NULL;
 548
 549         release_sock(sk);
 550         sock_put(sk);
 551
 552         return error;
 553 }
 554
 555 static void pptp_sock_destruct(struct sock *sk)
 556 {
 557         if (!(sk->sk_state & PPPOX_DEAD)) {
 558                 del_chan(pppox_sk(sk));
 559                 pppox_unbind_sock(sk);
 560         }
 561         skb_queue_purge(&sk->sk_receive_queue);
 562 }
 563
 564 static int pptp_create(struct net *net, struct socket *sock)
 565 {
 566         int error = -ENOMEM;
 567         struct sock *sk;
 568         struct pppox_sock *po;
 569         struct pptp_opt *opt;
 570
 571         sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pptp_sk_proto);
 572         if (!sk)
 573                 goto out;
 574
 575         sock_init_data(sock, sk);
 576
 577         sock->state = SS_UNCONNECTED;
 578         sock->ops   = &pptp_ops;
 579
 580         sk->sk_backlog_rcv = pptp_rcv_core;
 581         sk->sk_state       = PPPOX_NONE;
 582         sk->sk_type        = SOCK_STREAM;
 583         sk->sk_family      = PF_PPPOX;
 584         sk->sk_protocol    = PX_PROTO_PPTP;
 585         sk->sk_destruct    = pptp_sock_destruct;
 586
 587         po = pppox_sk(sk);
 588         opt = &po->proto.pptp;
 589
 590         opt->seq_sent = 0; opt->seq_recv = 0;
 591         opt->ack_recv = 0; opt->ack_sent = 0;
 592
 593         error = 0;
 594 out:
 595         return error;
 596 }
 597
 598 static int pptp_ppp_ioctl(struct ppp_channel *chan, unsigned int cmd,
 599         unsigned long arg)
 600 {
 601         struct sock *sk = (struct sock *) chan->private;
 602         struct pppox_sock *po = pppox_sk(sk);
 603         struct pptp_opt *opt = &po->proto.pptp;
 604         void __user *argp = (void __user *)arg;
 605         int __user *p = argp;
 606         int err, val;
 607
 608         err = -EFAULT;
 609         switch (cmd) {
 610         case PPPIOCGFLAGS:
 611                 val = opt->ppp_flags;
 612                 if (put_user(val, p))
 613                         break;
 614                 err = 0;
 615                 break;
 616         case PPPIOCSFLAGS:
 617                 if (get_user(val, p))
 618                         break;
 619                 opt->ppp_flags = val & ~SC_RCV_BITS;
 620                 err = 0;
 621                 break;
 622         default:
 623                 err = -ENOTTY;
 624         }
 625
 626         return err;
 627 }
 628
 629 static const struct ppp_channel_ops pptp_chan_ops = {
 630         .start_xmit = pptp_xmit,
 631         .ioctl      = pptp_ppp_ioctl,
 632 };
 633
 634 static struct proto pptp_sk_proto __read_mostly = {
 635         .name     = "PPTP",
 636         .owner    = THIS_MODULE,
 637         .obj_size = sizeof(struct pppox_sock),
 638 };
 639
 640 static const struct proto_ops pptp_ops = {
 641         .family     = AF_PPPOX,
 642         .owner      = THIS_MODULE,
 643         .release    = pptp_release,
 644         .bind       = pptp_bind,
 645         .connect    = pptp_connect,
 646         .socketpair = sock_no_socketpair,
 647         .accept     = sock_no_accept,
 648         .getname    = pptp_getname,
 649         .poll       = sock_no_poll,
 650         .listen     = sock_no_listen,
 651         .shutdown   = sock_no_shutdown,
 652         .setsockopt = sock_no_setsockopt,
 653         .getsockopt = sock_no_getsockopt,
 654         .sendmsg    = sock_no_sendmsg,
 655         .recvmsg    = sock_no_recvmsg,
 656         .mmap       = sock_no_mmap,
 657         .ioctl      = pppox_ioctl,
 658 };
 659
 660 static const struct pppox_proto pppox_pptp_proto = {
 661         .create = pptp_create,
 662         .owner  = THIS_MODULE,
 663 };
 664
 665 static const struct gre_protocol gre_pptp_protocol = {
 666         .handler = pptp_rcv,
 667 };
 668
 669 static int __init pptp_init_module(void)
 670 {
 671         int err = 0;
 672         pr_info("PPTP driver version " PPTP_DRIVER_VERSION "\n");
 673
 674         callid_sock = vzalloc((MAX_CALLID + 1) * sizeof(void *));
 675         if (!callid_sock) {
 676                 pr_err("PPTP: cann't allocate memory\n");
 677                 return -ENOMEM;
 678         }
 679
 680         err = gre_add_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
 681         if (err) {
 682                 pr_err("PPTP: can't add gre protocol\n");
 683                 goto out_mem_free;
 684         }
 685
 686         err = proto_register(&pptp_sk_proto, 0);
 687         if (err) {
 688                 pr_err("PPTP: can't register sk_proto\n");
 689                 goto out_gre_del_protocol;
 690         }
 691
 692         err = register_pppox_proto(PX_PROTO_PPTP, &pppox_pptp_proto);
 693         if (err) {
 694                 pr_err("PPTP: can't register pppox_proto\n");
 695                 goto out_unregister_sk_proto;
 696         }
 697
 698         return 0;
 699
 700 out_unregister_sk_proto:
 701         proto_unregister(&pptp_sk_proto);
 702 out_gre_del_protocol:
 703         gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
 704 out_mem_free:
 705         vfree(callid_sock);
 706
 707         return err;
 708 }
 709
 710 static void __exit pptp_exit_module(void)
 711 {
 712         unregister_pppox_proto(PX_PROTO_PPTP);
 713         proto_unregister(&pptp_sk_proto);
 714         gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
 715         vfree(callid_sock);
 716 }
 717
 718 module_init(pptp_init_module);
 719 module_exit(pptp_exit_module);
 720
 721 MODULE_DESCRIPTION("Point-to-Point Tunneling Protocol");
 722 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
 723 MODULE_LICENSE("GPL");