root/drivers/net/ppp/pptp.c

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DEFINITIONS

This source file includes following definitions.
  1. lookup_chan
  2. lookup_chan_dst
  3. add_chan
  4. del_chan
  5. pptp_xmit
  6. pptp_rcv_core
  7. pptp_rcv
  8. pptp_bind
  9. pptp_connect
  10. pptp_getname
  11. pptp_release
  12. pptp_sock_destruct
  13. pptp_create
  14. pptp_ppp_ioctl
  15. pptp_init_module
  16. pptp_exit_module

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Point-to-Point Tunneling Protocol for Linux
   4  *
   5  *      Authors: Dmitry Kozlov <xeb@mail.ru>
   6  */
   7 
   8 #include <linux/string.h>
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/slab.h>
  12 #include <linux/errno.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/net.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/init.h>
  18 #include <linux/ppp_channel.h>
  19 #include <linux/ppp_defs.h>
  20 #include <linux/if_pppox.h>
  21 #include <linux/ppp-ioctl.h>
  22 #include <linux/notifier.h>
  23 #include <linux/file.h>
  24 #include <linux/in.h>
  25 #include <linux/ip.h>
  26 #include <linux/rcupdate.h>
  27 #include <linux/spinlock.h>
  28 
  29 #include <net/sock.h>
  30 #include <net/protocol.h>
  31 #include <net/ip.h>
  32 #include <net/icmp.h>
  33 #include <net/route.h>
  34 #include <net/gre.h>
  35 #include <net/pptp.h>
  36 
  37 #include <linux/uaccess.h>
  38 
  39 #define PPTP_DRIVER_VERSION "0.8.5"
  40 
  41 #define MAX_CALLID 65535
  42 
  43 static DECLARE_BITMAP(callid_bitmap, MAX_CALLID + 1);
  44 static struct pppox_sock __rcu **callid_sock;
  45 
  46 static DEFINE_SPINLOCK(chan_lock);
  47 
  48 static struct proto pptp_sk_proto __read_mostly;
  49 static const struct ppp_channel_ops pptp_chan_ops;
  50 static const struct proto_ops pptp_ops;
  51 
  52 static struct pppox_sock *lookup_chan(u16 call_id, __be32 s_addr)
  53 {
  54         struct pppox_sock *sock;
  55         struct pptp_opt *opt;
  56 
  57         rcu_read_lock();
  58         sock = rcu_dereference(callid_sock[call_id]);
  59         if (sock) {
  60                 opt = &sock->proto.pptp;
  61                 if (opt->dst_addr.sin_addr.s_addr != s_addr)
  62                         sock = NULL;
  63                 else
  64                         sock_hold(sk_pppox(sock));
  65         }
  66         rcu_read_unlock();
  67 
  68         return sock;
  69 }
  70 
  71 static int lookup_chan_dst(u16 call_id, __be32 d_addr)
  72 {
  73         struct pppox_sock *sock;
  74         struct pptp_opt *opt;
  75         int i;
  76 
  77         rcu_read_lock();
  78         i = 1;
  79         for_each_set_bit_from(i, callid_bitmap, MAX_CALLID) {
  80                 sock = rcu_dereference(callid_sock[i]);
  81                 if (!sock)
  82                         continue;
  83                 opt = &sock->proto.pptp;
  84                 if (opt->dst_addr.call_id == call_id &&
  85                           opt->dst_addr.sin_addr.s_addr == d_addr)
  86                         break;
  87         }
  88         rcu_read_unlock();
  89 
  90         return i < MAX_CALLID;
  91 }
  92 
  93 static int add_chan(struct pppox_sock *sock,
  94                     struct pptp_addr *sa)
  95 {
  96         static int call_id;
  97 
  98         spin_lock(&chan_lock);
  99         if (!sa->call_id)       {
 100                 call_id = find_next_zero_bit(callid_bitmap, MAX_CALLID, call_id + 1);
 101                 if (call_id == MAX_CALLID) {
 102                         call_id = find_next_zero_bit(callid_bitmap, MAX_CALLID, 1);
 103                         if (call_id == MAX_CALLID)
 104                                 goto out_err;
 105                 }
 106                 sa->call_id = call_id;
 107         } else if (test_bit(sa->call_id, callid_bitmap)) {
 108                 goto out_err;
 109         }
 110 
 111         sock->proto.pptp.src_addr = *sa;
 112         set_bit(sa->call_id, callid_bitmap);
 113         rcu_assign_pointer(callid_sock[sa->call_id], sock);
 114         spin_unlock(&chan_lock);
 115 
 116         return 0;
 117 
 118 out_err:
 119         spin_unlock(&chan_lock);
 120         return -1;
 121 }
 122 
 123 static void del_chan(struct pppox_sock *sock)
 124 {
 125         spin_lock(&chan_lock);
 126         clear_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap);
 127         RCU_INIT_POINTER(callid_sock[sock->proto.pptp.src_addr.call_id], NULL);
 128         spin_unlock(&chan_lock);
 129 }
 130 
 131 static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 132 {
 133         struct sock *sk = (struct sock *) chan->private;
 134         struct pppox_sock *po = pppox_sk(sk);
 135         struct net *net = sock_net(sk);
 136         struct pptp_opt *opt = &po->proto.pptp;
 137         struct pptp_gre_header *hdr;
 138         unsigned int header_len = sizeof(*hdr);
 139         struct flowi4 fl4;
 140         int islcp;
 141         int len;
 142         unsigned char *data;
 143         __u32 seq_recv;
 144 
 145 
 146         struct rtable *rt;
 147         struct net_device *tdev;
 148         struct iphdr  *iph;
 149         int    max_headroom;
 150 
 151         if (sk_pppox(po)->sk_state & PPPOX_DEAD)
 152                 goto tx_error;
 153 
 154         rt = ip_route_output_ports(net, &fl4, NULL,
 155                                    opt->dst_addr.sin_addr.s_addr,
 156                                    opt->src_addr.sin_addr.s_addr,
 157                                    0, 0, IPPROTO_GRE,
 158                                    RT_TOS(0), 0);
 159         if (IS_ERR(rt))
 160                 goto tx_error;
 161 
 162         tdev = rt->dst.dev;
 163 
 164         max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(*iph) + sizeof(*hdr) + 2;
 165 
 166         if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
 167                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 168                 if (!new_skb) {
 169                         ip_rt_put(rt);
 170                         goto tx_error;
 171                 }
 172                 if (skb->sk)
 173                         skb_set_owner_w(new_skb, skb->sk);
 174                 consume_skb(skb);
 175                 skb = new_skb;
 176         }
 177 
 178         data = skb->data;
 179         islcp = ((data[0] << 8) + data[1]) == PPP_LCP && 1 <= data[2] && data[2] <= 7;
 180 
 181         /* compress protocol field */
 182         if ((opt->ppp_flags & SC_COMP_PROT) && data[0] == 0 && !islcp)
 183                 skb_pull(skb, 1);
 184 
 185         /* Put in the address/control bytes if necessary */
 186         if ((opt->ppp_flags & SC_COMP_AC) == 0 || islcp) {
 187                 data = skb_push(skb, 2);
 188                 data[0] = PPP_ALLSTATIONS;
 189                 data[1] = PPP_UI;
 190         }
 191 
 192         len = skb->len;
 193 
 194         seq_recv = opt->seq_recv;
 195 
 196         if (opt->ack_sent == seq_recv)
 197                 header_len -= sizeof(hdr->ack);
 198 
 199         /* Push down and install GRE header */
 200         skb_push(skb, header_len);
 201         hdr = (struct pptp_gre_header *)(skb->data);
 202 
 203         hdr->gre_hd.flags = GRE_KEY | GRE_VERSION_1 | GRE_SEQ;
 204         hdr->gre_hd.protocol = GRE_PROTO_PPP;
 205         hdr->call_id = htons(opt->dst_addr.call_id);
 206 
 207         hdr->seq = htonl(++opt->seq_sent);
 208         if (opt->ack_sent != seq_recv)  {
 209                 /* send ack with this message */
 210                 hdr->gre_hd.flags |= GRE_ACK;
 211                 hdr->ack  = htonl(seq_recv);
 212                 opt->ack_sent = seq_recv;
 213         }
 214         hdr->payload_len = htons(len);
 215 
 216         /*      Push down and install the IP header. */
 217 
 218         skb_reset_transport_header(skb);
 219         skb_push(skb, sizeof(*iph));
 220         skb_reset_network_header(skb);
 221         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 222         IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED);
 223 
 224         iph =   ip_hdr(skb);
 225         iph->version =  4;
 226         iph->ihl =      sizeof(struct iphdr) >> 2;
 227         if (ip_dont_fragment(sk, &rt->dst))
 228                 iph->frag_off   =       htons(IP_DF);
 229         else
 230                 iph->frag_off   =       0;
 231         iph->protocol = IPPROTO_GRE;
 232         iph->tos      = 0;
 233         iph->daddr    = fl4.daddr;
 234         iph->saddr    = fl4.saddr;
 235         iph->ttl      = ip4_dst_hoplimit(&rt->dst);
 236         iph->tot_len  = htons(skb->len);
 237 
 238         skb_dst_drop(skb);
 239         skb_dst_set(skb, &rt->dst);
 240 
 241         nf_reset_ct(skb);
 242 
 243         skb->ip_summed = CHECKSUM_NONE;
 244         ip_select_ident(net, skb, NULL);
 245         ip_send_check(iph);
 246 
 247         ip_local_out(net, skb->sk, skb);
 248         return 1;
 249 
 250 tx_error:
 251         kfree_skb(skb);
 252         return 1;
 253 }
 254 
 255 static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)
 256 {
 257         struct pppox_sock *po = pppox_sk(sk);
 258         struct pptp_opt *opt = &po->proto.pptp;
 259         int headersize, payload_len, seq;
 260         __u8 *payload;
 261         struct pptp_gre_header *header;
 262 
 263         if (!(sk->sk_state & PPPOX_CONNECTED)) {
 264                 if (sock_queue_rcv_skb(sk, skb))
 265                         goto drop;
 266                 return NET_RX_SUCCESS;
 267         }
 268 
 269         header = (struct pptp_gre_header *)(skb->data);
 270         headersize  = sizeof(*header);
 271 
 272         /* test if acknowledgement present */
 273         if (GRE_IS_ACK(header->gre_hd.flags)) {
 274                 __u32 ack;
 275 
 276                 if (!pskb_may_pull(skb, headersize))
 277                         goto drop;
 278                 header = (struct pptp_gre_header *)(skb->data);
 279 
 280                 /* ack in different place if S = 0 */
 281                 ack = GRE_IS_SEQ(header->gre_hd.flags) ? header->ack : header->seq;
 282 
 283                 ack = ntohl(ack);
 284 
 285                 if (ack > opt->ack_recv)
 286                         opt->ack_recv = ack;
 287                 /* also handle sequence number wrap-around  */
 288                 if (WRAPPED(ack, opt->ack_recv))
 289                         opt->ack_recv = ack;
 290         } else {
 291                 headersize -= sizeof(header->ack);
 292         }
 293         /* test if payload present */
 294         if (!GRE_IS_SEQ(header->gre_hd.flags))
 295                 goto drop;
 296 
 297         payload_len = ntohs(header->payload_len);
 298         seq         = ntohl(header->seq);
 299 
 300         /* check for incomplete packet (length smaller than expected) */
 301         if (!pskb_may_pull(skb, headersize + payload_len))
 302                 goto drop;
 303 
 304         payload = skb->data + headersize;
 305         /* check for expected sequence number */
 306         if (seq < opt->seq_recv + 1 || WRAPPED(opt->seq_recv, seq)) {
 307                 if ((payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) &&
 308                                 (PPP_PROTOCOL(payload) == PPP_LCP) &&
 309                                 ((payload[4] == PPP_LCP_ECHOREQ) || (payload[4] == PPP_LCP_ECHOREP)))
 310                         goto allow_packet;
 311         } else {
 312                 opt->seq_recv = seq;
 313 allow_packet:
 314                 skb_pull(skb, headersize);
 315 
 316                 if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI) {
 317                         /* chop off address/control */
 318                         if (skb->len < 3)
 319                                 goto drop;
 320                         skb_pull(skb, 2);
 321                 }
 322 
 323                 skb->ip_summed = CHECKSUM_NONE;
 324                 skb_set_network_header(skb, skb->head-skb->data);
 325                 ppp_input(&po->chan, skb);
 326 
 327                 return NET_RX_SUCCESS;
 328         }
 329 drop:
 330         kfree_skb(skb);
 331         return NET_RX_DROP;
 332 }
 333 
 334 static int pptp_rcv(struct sk_buff *skb)
 335 {
 336         struct pppox_sock *po;
 337         struct pptp_gre_header *header;
 338         struct iphdr *iph;
 339 
 340         if (skb->pkt_type != PACKET_HOST)
 341                 goto drop;
 342 
 343         if (!pskb_may_pull(skb, 12))
 344                 goto drop;
 345 
 346         iph = ip_hdr(skb);
 347 
 348         header = (struct pptp_gre_header *)skb->data;
 349 
 350         if (header->gre_hd.protocol != GRE_PROTO_PPP || /* PPTP-GRE protocol for PPTP */
 351                 GRE_IS_CSUM(header->gre_hd.flags) ||    /* flag CSUM should be clear */
 352                 GRE_IS_ROUTING(header->gre_hd.flags) || /* flag ROUTING should be clear */
 353                 !GRE_IS_KEY(header->gre_hd.flags) ||    /* flag KEY should be set */
 354                 (header->gre_hd.flags & GRE_FLAGS))     /* flag Recursion Ctrl should be clear */
 355                 /* if invalid, discard this packet */
 356                 goto drop;
 357 
 358         po = lookup_chan(htons(header->call_id), iph->saddr);
 359         if (po) {
 360                 skb_dst_drop(skb);
 361                 nf_reset_ct(skb);
 362                 return sk_receive_skb(sk_pppox(po), skb, 0);
 363         }
 364 drop:
 365         kfree_skb(skb);
 366         return NET_RX_DROP;
 367 }
 368 
 369 static int pptp_bind(struct socket *sock, struct sockaddr *uservaddr,
 370         int sockaddr_len)
 371 {
 372         struct sock *sk = sock->sk;
 373         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
 374         struct pppox_sock *po = pppox_sk(sk);
 375         int error = 0;
 376 
 377         if (sockaddr_len < sizeof(struct sockaddr_pppox))
 378                 return -EINVAL;
 379 
 380         lock_sock(sk);
 381 
 382         if (sk->sk_state & PPPOX_DEAD) {
 383                 error = -EALREADY;
 384                 goto out;
 385         }
 386 
 387         if (sk->sk_state & PPPOX_BOUND) {
 388                 error = -EBUSY;
 389                 goto out;
 390         }
 391 
 392         if (add_chan(po, &sp->sa_addr.pptp))
 393                 error = -EBUSY;
 394         else
 395                 sk->sk_state |= PPPOX_BOUND;
 396 
 397 out:
 398         release_sock(sk);
 399         return error;
 400 }
 401 
 402 static int pptp_connect(struct socket *sock, struct sockaddr *uservaddr,
 403         int sockaddr_len, int flags)
 404 {
 405         struct sock *sk = sock->sk;
 406         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
 407         struct pppox_sock *po = pppox_sk(sk);
 408         struct pptp_opt *opt = &po->proto.pptp;
 409         struct rtable *rt;
 410         struct flowi4 fl4;
 411         int error = 0;
 412 
 413         if (sockaddr_len < sizeof(struct sockaddr_pppox))
 414                 return -EINVAL;
 415 
 416         if (sp->sa_protocol != PX_PROTO_PPTP)
 417                 return -EINVAL;
 418 
 419         if (lookup_chan_dst(sp->sa_addr.pptp.call_id, sp->sa_addr.pptp.sin_addr.s_addr))
 420                 return -EALREADY;
 421 
 422         lock_sock(sk);
 423         /* Check for already bound sockets */
 424         if (sk->sk_state & PPPOX_CONNECTED) {
 425                 error = -EBUSY;
 426                 goto end;
 427         }
 428 
 429         /* Check for already disconnected sockets, on attempts to disconnect */
 430         if (sk->sk_state & PPPOX_DEAD) {
 431                 error = -EALREADY;
 432                 goto end;
 433         }
 434 
 435         if (!opt->src_addr.sin_addr.s_addr || !sp->sa_addr.pptp.sin_addr.s_addr) {
 436                 error = -EINVAL;
 437                 goto end;
 438         }
 439 
 440         po->chan.private = sk;
 441         po->chan.ops = &pptp_chan_ops;
 442 
 443         rt = ip_route_output_ports(sock_net(sk), &fl4, sk,
 444                                    opt->dst_addr.sin_addr.s_addr,
 445                                    opt->src_addr.sin_addr.s_addr,
 446                                    0, 0,
 447                                    IPPROTO_GRE, RT_CONN_FLAGS(sk), 0);
 448         if (IS_ERR(rt)) {
 449                 error = -EHOSTUNREACH;
 450                 goto end;
 451         }
 452         sk_setup_caps(sk, &rt->dst);
 453 
 454         po->chan.mtu = dst_mtu(&rt->dst);
 455         if (!po->chan.mtu)
 456                 po->chan.mtu = PPP_MRU;
 457         po->chan.mtu -= PPTP_HEADER_OVERHEAD;
 458 
 459         po->chan.hdrlen = 2 + sizeof(struct pptp_gre_header);
 460         error = ppp_register_channel(&po->chan);
 461         if (error) {
 462                 pr_err("PPTP: failed to register PPP channel (%d)\n", error);
 463                 goto end;
 464         }
 465 
 466         opt->dst_addr = sp->sa_addr.pptp;
 467         sk->sk_state |= PPPOX_CONNECTED;
 468 
 469  end:
 470         release_sock(sk);
 471         return error;
 472 }
 473 
 474 static int pptp_getname(struct socket *sock, struct sockaddr *uaddr,
 475         int peer)
 476 {
 477         int len = sizeof(struct sockaddr_pppox);
 478         struct sockaddr_pppox sp;
 479 
 480         memset(&sp.sa_addr, 0, sizeof(sp.sa_addr));
 481 
 482         sp.sa_family    = AF_PPPOX;
 483         sp.sa_protocol  = PX_PROTO_PPTP;
 484         sp.sa_addr.pptp = pppox_sk(sock->sk)->proto.pptp.src_addr;
 485 
 486         memcpy(uaddr, &sp, len);
 487 
 488         return len;
 489 }
 490 
 491 static int pptp_release(struct socket *sock)
 492 {
 493         struct sock *sk = sock->sk;
 494         struct pppox_sock *po;
 495         int error = 0;
 496 
 497         if (!sk)
 498                 return 0;
 499 
 500         lock_sock(sk);
 501 
 502         if (sock_flag(sk, SOCK_DEAD)) {
 503                 release_sock(sk);
 504                 return -EBADF;
 505         }
 506 
 507         po = pppox_sk(sk);
 508         del_chan(po);
 509         synchronize_rcu();
 510 
 511         pppox_unbind_sock(sk);
 512         sk->sk_state = PPPOX_DEAD;
 513 
 514         sock_orphan(sk);
 515         sock->sk = NULL;
 516 
 517         release_sock(sk);
 518         sock_put(sk);
 519 
 520         return error;
 521 }
 522 
 523 static void pptp_sock_destruct(struct sock *sk)
 524 {
 525         if (!(sk->sk_state & PPPOX_DEAD)) {
 526                 del_chan(pppox_sk(sk));
 527                 pppox_unbind_sock(sk);
 528         }
 529         skb_queue_purge(&sk->sk_receive_queue);
 530         dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
 531 }
 532 
 533 static int pptp_create(struct net *net, struct socket *sock, int kern)
 534 {
 535         int error = -ENOMEM;
 536         struct sock *sk;
 537         struct pppox_sock *po;
 538         struct pptp_opt *opt;
 539 
 540         sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pptp_sk_proto, kern);
 541         if (!sk)
 542                 goto out;
 543 
 544         sock_init_data(sock, sk);
 545 
 546         sock->state = SS_UNCONNECTED;
 547         sock->ops   = &pptp_ops;
 548 
 549         sk->sk_backlog_rcv = pptp_rcv_core;
 550         sk->sk_state       = PPPOX_NONE;
 551         sk->sk_type        = SOCK_STREAM;
 552         sk->sk_family      = PF_PPPOX;
 553         sk->sk_protocol    = PX_PROTO_PPTP;
 554         sk->sk_destruct    = pptp_sock_destruct;
 555 
 556         po = pppox_sk(sk);
 557         opt = &po->proto.pptp;
 558 
 559         opt->seq_sent = 0; opt->seq_recv = 0xffffffff;
 560         opt->ack_recv = 0; opt->ack_sent = 0xffffffff;
 561 
 562         error = 0;
 563 out:
 564         return error;
 565 }
 566 
 567 static int pptp_ppp_ioctl(struct ppp_channel *chan, unsigned int cmd,
 568         unsigned long arg)
 569 {
 570         struct sock *sk = (struct sock *) chan->private;
 571         struct pppox_sock *po = pppox_sk(sk);
 572         struct pptp_opt *opt = &po->proto.pptp;
 573         void __user *argp = (void __user *)arg;
 574         int __user *p = argp;
 575         int err, val;
 576 
 577         err = -EFAULT;
 578         switch (cmd) {
 579         case PPPIOCGFLAGS:
 580                 val = opt->ppp_flags;
 581                 if (put_user(val, p))
 582                         break;
 583                 err = 0;
 584                 break;
 585         case PPPIOCSFLAGS:
 586                 if (get_user(val, p))
 587                         break;
 588                 opt->ppp_flags = val & ~SC_RCV_BITS;
 589                 err = 0;
 590                 break;
 591         default:
 592                 err = -ENOTTY;
 593         }
 594 
 595         return err;
 596 }
 597 
 598 static const struct ppp_channel_ops pptp_chan_ops = {
 599         .start_xmit = pptp_xmit,
 600         .ioctl      = pptp_ppp_ioctl,
 601 };
 602 
 603 static struct proto pptp_sk_proto __read_mostly = {
 604         .name     = "PPTP",
 605         .owner    = THIS_MODULE,
 606         .obj_size = sizeof(struct pppox_sock),
 607 };
 608 
 609 static const struct proto_ops pptp_ops = {
 610         .family     = AF_PPPOX,
 611         .owner      = THIS_MODULE,
 612         .release    = pptp_release,
 613         .bind       = pptp_bind,
 614         .connect    = pptp_connect,
 615         .socketpair = sock_no_socketpair,
 616         .accept     = sock_no_accept,
 617         .getname    = pptp_getname,
 618         .listen     = sock_no_listen,
 619         .shutdown   = sock_no_shutdown,
 620         .setsockopt = sock_no_setsockopt,
 621         .getsockopt = sock_no_getsockopt,
 622         .sendmsg    = sock_no_sendmsg,
 623         .recvmsg    = sock_no_recvmsg,
 624         .mmap       = sock_no_mmap,
 625         .ioctl      = pppox_ioctl,
 626 #ifdef CONFIG_COMPAT
 627         .compat_ioctl = pppox_compat_ioctl,
 628 #endif
 629 };
 630 
 631 static const struct pppox_proto pppox_pptp_proto = {
 632         .create = pptp_create,
 633         .owner  = THIS_MODULE,
 634 };
 635 
 636 static const struct gre_protocol gre_pptp_protocol = {
 637         .handler = pptp_rcv,
 638 };
 639 
 640 static int __init pptp_init_module(void)
 641 {
 642         int err = 0;
 643         pr_info("PPTP driver version " PPTP_DRIVER_VERSION "\n");
 644 
 645         callid_sock = vzalloc(array_size(sizeof(void *), (MAX_CALLID + 1)));
 646         if (!callid_sock)
 647                 return -ENOMEM;
 648 
 649         err = gre_add_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
 650         if (err) {
 651                 pr_err("PPTP: can't add gre protocol\n");
 652                 goto out_mem_free;
 653         }
 654 
 655         err = proto_register(&pptp_sk_proto, 0);
 656         if (err) {
 657                 pr_err("PPTP: can't register sk_proto\n");
 658                 goto out_gre_del_protocol;
 659         }
 660 
 661         err = register_pppox_proto(PX_PROTO_PPTP, &pppox_pptp_proto);
 662         if (err) {
 663                 pr_err("PPTP: can't register pppox_proto\n");
 664                 goto out_unregister_sk_proto;
 665         }
 666 
 667         return 0;
 668 
 669 out_unregister_sk_proto:
 670         proto_unregister(&pptp_sk_proto);
 671 out_gre_del_protocol:
 672         gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
 673 out_mem_free:
 674         vfree(callid_sock);
 675 
 676         return err;
 677 }
 678 
 679 static void __exit pptp_exit_module(void)
 680 {
 681         unregister_pppox_proto(PX_PROTO_PPTP);
 682         proto_unregister(&pptp_sk_proto);
 683         gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
 684         vfree(callid_sock);
 685 }
 686 
 687 module_init(pptp_init_module);
 688 module_exit(pptp_exit_module);
 689 
 690 MODULE_DESCRIPTION("Point-to-Point Tunneling Protocol");
 691 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
 692 MODULE_LICENSE("GPL");
 693 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_PPTP);

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