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