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