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/ppp-ioctl.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 __rcu **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 __be16 protocol;
87 __be16 payload_len;
88 __be16 call_id;
89 __be32 seq;
90 __be32 ack;
91 } __packed;
92
lookup_chan(u16 call_id,__be32 s_addr)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
lookup_chan_dst(u16 call_id,__be32 d_addr)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 i = 1;
120 for_each_set_bit_from(i, callid_bitmap, MAX_CALLID) {
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
add_chan(struct pppox_sock * sock,struct pptp_addr * sa)134 static int add_chan(struct pppox_sock *sock,
135 struct pptp_addr *sa)
136 {
137 static int call_id;
138
139 spin_lock(&chan_lock);
140 if (!sa->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 sa->call_id = call_id;
148 } else if (test_bit(sa->call_id, callid_bitmap)) {
149 goto out_err;
150 }
151
152 sock->proto.pptp.src_addr = *sa;
153 set_bit(sa->call_id, callid_bitmap);
154 rcu_assign_pointer(callid_sock[sa->call_id], sock);
155 spin_unlock(&chan_lock);
156
157 return 0;
158
159 out_err:
160 spin_unlock(&chan_lock);
161 return -1;
162 }
163
del_chan(struct pppox_sock * sock)164 static void del_chan(struct pppox_sock *sock)
165 {
166 spin_lock(&chan_lock);
167 clear_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap);
168 RCU_INIT_POINTER(callid_sock[sock->proto.pptp.src_addr.call_id], NULL);
169 spin_unlock(&chan_lock);
170 synchronize_rcu();
171 }
172
pptp_xmit(struct ppp_channel * chan,struct sk_buff * skb)173 static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
174 {
175 struct sock *sk = (struct sock *) chan->private;
176 struct pppox_sock *po = pppox_sk(sk);
177 struct pptp_opt *opt = &po->proto.pptp;
178 struct pptp_gre_header *hdr;
179 unsigned int header_len = sizeof(*hdr);
180 struct flowi4 fl4;
181 int islcp;
182 int len;
183 unsigned char *data;
184 __u32 seq_recv;
185
186
187 struct rtable *rt;
188 struct net_device *tdev;
189 struct iphdr *iph;
190 int max_headroom;
191
192 if (sk_pppox(po)->sk_state & PPPOX_DEAD)
193 goto tx_error;
194
195 rt = ip_route_output_ports(sock_net(sk), &fl4, NULL,
196 opt->dst_addr.sin_addr.s_addr,
197 opt->src_addr.sin_addr.s_addr,
198 0, 0, IPPROTO_GRE,
199 RT_TOS(0), 0);
200 if (IS_ERR(rt))
201 goto tx_error;
202
203 tdev = rt->dst.dev;
204
205 max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(*iph) + sizeof(*hdr) + 2;
206
207 if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
208 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
209 if (!new_skb) {
210 ip_rt_put(rt);
211 goto tx_error;
212 }
213 if (skb->sk)
214 skb_set_owner_w(new_skb, skb->sk);
215 consume_skb(skb);
216 skb = new_skb;
217 }
218
219 data = skb->data;
220 islcp = ((data[0] << 8) + data[1]) == PPP_LCP && 1 <= data[2] && data[2] <= 7;
221
222 /* compress protocol field */
223 if ((opt->ppp_flags & SC_COMP_PROT) && data[0] == 0 && !islcp)
224 skb_pull(skb, 1);
225
226 /* Put in the address/control bytes if necessary */
227 if ((opt->ppp_flags & SC_COMP_AC) == 0 || islcp) {
228 data = skb_push(skb, 2);
229 data[0] = PPP_ALLSTATIONS;
230 data[1] = PPP_UI;
231 }
232
233 len = skb->len;
234
235 seq_recv = opt->seq_recv;
236
237 if (opt->ack_sent == seq_recv)
238 header_len -= sizeof(hdr->ack);
239
240 /* Push down and install GRE header */
241 skb_push(skb, header_len);
242 hdr = (struct pptp_gre_header *)(skb->data);
243
244 hdr->flags = PPTP_GRE_FLAG_K;
245 hdr->ver = PPTP_GRE_VER;
246 hdr->protocol = htons(PPTP_GRE_PROTO);
247 hdr->call_id = htons(opt->dst_addr.call_id);
248
249 hdr->flags |= PPTP_GRE_FLAG_S;
250 hdr->seq = htonl(++opt->seq_sent);
251 if (opt->ack_sent != seq_recv) {
252 /* send ack with this message */
253 hdr->ver |= PPTP_GRE_FLAG_A;
254 hdr->ack = htonl(seq_recv);
255 opt->ack_sent = seq_recv;
256 }
257 hdr->payload_len = htons(len);
258
259 /* Push down and install the IP header. */
260
261 skb_reset_transport_header(skb);
262 skb_push(skb, sizeof(*iph));
263 skb_reset_network_header(skb);
264 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
265 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED);
266
267 iph = ip_hdr(skb);
268 iph->version = 4;
269 iph->ihl = sizeof(struct iphdr) >> 2;
270 if (ip_dont_fragment(sk, &rt->dst))
271 iph->frag_off = htons(IP_DF);
272 else
273 iph->frag_off = 0;
274 iph->protocol = IPPROTO_GRE;
275 iph->tos = 0;
276 iph->daddr = fl4.daddr;
277 iph->saddr = fl4.saddr;
278 iph->ttl = ip4_dst_hoplimit(&rt->dst);
279 iph->tot_len = htons(skb->len);
280
281 skb_dst_drop(skb);
282 skb_dst_set(skb, &rt->dst);
283
284 nf_reset(skb);
285
286 skb->ip_summed = CHECKSUM_NONE;
287 ip_select_ident(sock_net(sk), skb, NULL);
288 ip_send_check(iph);
289
290 ip_local_out(skb);
291 return 1;
292
293 tx_error:
294 kfree_skb(skb);
295 return 1;
296 }
297
pptp_rcv_core(struct sock * sk,struct sk_buff * skb)298 static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb)
299 {
300 struct pppox_sock *po = pppox_sk(sk);
301 struct pptp_opt *opt = &po->proto.pptp;
302 int headersize, payload_len, seq;
303 __u8 *payload;
304 struct pptp_gre_header *header;
305
306 if (!(sk->sk_state & PPPOX_CONNECTED)) {
307 if (sock_queue_rcv_skb(sk, skb))
308 goto drop;
309 return NET_RX_SUCCESS;
310 }
311
312 header = (struct pptp_gre_header *)(skb->data);
313 headersize = sizeof(*header);
314
315 /* test if acknowledgement present */
316 if (PPTP_GRE_IS_A(header->ver)) {
317 __u32 ack;
318
319 if (!pskb_may_pull(skb, headersize))
320 goto drop;
321 header = (struct pptp_gre_header *)(skb->data);
322
323 /* ack in different place if S = 0 */
324 ack = PPTP_GRE_IS_S(header->flags) ? header->ack : header->seq;
325
326 ack = ntohl(ack);
327
328 if (ack > opt->ack_recv)
329 opt->ack_recv = ack;
330 /* also handle sequence number wrap-around */
331 if (WRAPPED(ack, opt->ack_recv))
332 opt->ack_recv = ack;
333 } else {
334 headersize -= sizeof(header->ack);
335 }
336 /* test if payload present */
337 if (!PPTP_GRE_IS_S(header->flags))
338 goto drop;
339
340 payload_len = ntohs(header->payload_len);
341 seq = ntohl(header->seq);
342
343 /* check for incomplete packet (length smaller than expected) */
344 if (!pskb_may_pull(skb, headersize + payload_len))
345 goto drop;
346
347 payload = skb->data + headersize;
348 /* check for expected sequence number */
349 if (seq < opt->seq_recv + 1 || WRAPPED(opt->seq_recv, seq)) {
350 if ((payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) &&
351 (PPP_PROTOCOL(payload) == PPP_LCP) &&
352 ((payload[4] == PPP_LCP_ECHOREQ) || (payload[4] == PPP_LCP_ECHOREP)))
353 goto allow_packet;
354 } else {
355 opt->seq_recv = seq;
356 allow_packet:
357 skb_pull(skb, headersize);
358
359 if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI) {
360 /* chop off address/control */
361 if (skb->len < 3)
362 goto drop;
363 skb_pull(skb, 2);
364 }
365
366 if ((*skb->data) & 1) {
367 /* protocol is compressed */
368 skb_push(skb, 1)[0] = 0;
369 }
370
371 skb->ip_summed = CHECKSUM_NONE;
372 skb_set_network_header(skb, skb->head-skb->data);
373 ppp_input(&po->chan, skb);
374
375 return NET_RX_SUCCESS;
376 }
377 drop:
378 kfree_skb(skb);
379 return NET_RX_DROP;
380 }
381
pptp_rcv(struct sk_buff * skb)382 static int pptp_rcv(struct sk_buff *skb)
383 {
384 struct pppox_sock *po;
385 struct pptp_gre_header *header;
386 struct iphdr *iph;
387
388 if (skb->pkt_type != PACKET_HOST)
389 goto drop;
390
391 if (!pskb_may_pull(skb, 12))
392 goto drop;
393
394 iph = ip_hdr(skb);
395
396 header = (struct pptp_gre_header *)skb->data;
397
398 if (ntohs(header->protocol) != PPTP_GRE_PROTO || /* PPTP-GRE protocol for PPTP */
399 PPTP_GRE_IS_C(header->flags) || /* flag C should be clear */
400 PPTP_GRE_IS_R(header->flags) || /* flag R should be clear */
401 !PPTP_GRE_IS_K(header->flags) || /* flag K should be set */
402 (header->flags&0xF) != 0) /* routing and recursion ctrl = 0 */
403 /* if invalid, discard this packet */
404 goto drop;
405
406 po = lookup_chan(htons(header->call_id), iph->saddr);
407 if (po) {
408 skb_dst_drop(skb);
409 nf_reset(skb);
410 return sk_receive_skb(sk_pppox(po), skb, 0);
411 }
412 drop:
413 kfree_skb(skb);
414 return NET_RX_DROP;
415 }
416
pptp_bind(struct socket * sock,struct sockaddr * uservaddr,int sockaddr_len)417 static int pptp_bind(struct socket *sock, struct sockaddr *uservaddr,
418 int sockaddr_len)
419 {
420 struct sock *sk = sock->sk;
421 struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
422 struct pppox_sock *po = pppox_sk(sk);
423 int error = 0;
424
425 if (sockaddr_len < sizeof(struct sockaddr_pppox))
426 return -EINVAL;
427
428 lock_sock(sk);
429
430 if (sk->sk_state & PPPOX_DEAD) {
431 error = -EALREADY;
432 goto out;
433 }
434
435 if (sk->sk_state & PPPOX_BOUND) {
436 error = -EBUSY;
437 goto out;
438 }
439
440 if (add_chan(po, &sp->sa_addr.pptp))
441 error = -EBUSY;
442 else
443 sk->sk_state |= PPPOX_BOUND;
444
445 out:
446 release_sock(sk);
447 return error;
448 }
449
pptp_connect(struct socket * sock,struct sockaddr * uservaddr,int sockaddr_len,int flags)450 static int pptp_connect(struct socket *sock, struct sockaddr *uservaddr,
451 int sockaddr_len, int flags)
452 {
453 struct sock *sk = sock->sk;
454 struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
455 struct pppox_sock *po = pppox_sk(sk);
456 struct pptp_opt *opt = &po->proto.pptp;
457 struct rtable *rt;
458 struct flowi4 fl4;
459 int error = 0;
460
461 if (sockaddr_len < sizeof(struct sockaddr_pppox))
462 return -EINVAL;
463
464 if (sp->sa_protocol != PX_PROTO_PPTP)
465 return -EINVAL;
466
467 if (lookup_chan_dst(sp->sa_addr.pptp.call_id, sp->sa_addr.pptp.sin_addr.s_addr))
468 return -EALREADY;
469
470 lock_sock(sk);
471 /* Check for already bound sockets */
472 if (sk->sk_state & PPPOX_CONNECTED) {
473 error = -EBUSY;
474 goto end;
475 }
476
477 /* Check for already disconnected sockets, on attempts to disconnect */
478 if (sk->sk_state & PPPOX_DEAD) {
479 error = -EALREADY;
480 goto end;
481 }
482
483 if (!opt->src_addr.sin_addr.s_addr || !sp->sa_addr.pptp.sin_addr.s_addr) {
484 error = -EINVAL;
485 goto end;
486 }
487
488 po->chan.private = sk;
489 po->chan.ops = &pptp_chan_ops;
490
491 rt = ip_route_output_ports(sock_net(sk), &fl4, sk,
492 opt->dst_addr.sin_addr.s_addr,
493 opt->src_addr.sin_addr.s_addr,
494 0, 0,
495 IPPROTO_GRE, RT_CONN_FLAGS(sk), 0);
496 if (IS_ERR(rt)) {
497 error = -EHOSTUNREACH;
498 goto end;
499 }
500 sk_setup_caps(sk, &rt->dst);
501
502 po->chan.mtu = dst_mtu(&rt->dst);
503 if (!po->chan.mtu)
504 po->chan.mtu = PPP_MRU;
505 ip_rt_put(rt);
506 po->chan.mtu -= PPTP_HEADER_OVERHEAD;
507
508 po->chan.hdrlen = 2 + sizeof(struct pptp_gre_header);
509 error = ppp_register_channel(&po->chan);
510 if (error) {
511 pr_err("PPTP: failed to register PPP channel (%d)\n", error);
512 goto end;
513 }
514
515 opt->dst_addr = sp->sa_addr.pptp;
516 sk->sk_state |= PPPOX_CONNECTED;
517
518 end:
519 release_sock(sk);
520 return error;
521 }
522
pptp_getname(struct socket * sock,struct sockaddr * uaddr,int * usockaddr_len,int peer)523 static int pptp_getname(struct socket *sock, struct sockaddr *uaddr,
524 int *usockaddr_len, int peer)
525 {
526 int len = sizeof(struct sockaddr_pppox);
527 struct sockaddr_pppox sp;
528
529 memset(&sp.sa_addr, 0, sizeof(sp.sa_addr));
530
531 sp.sa_family = AF_PPPOX;
532 sp.sa_protocol = PX_PROTO_PPTP;
533 sp.sa_addr.pptp = pppox_sk(sock->sk)->proto.pptp.src_addr;
534
535 memcpy(uaddr, &sp, len);
536
537 *usockaddr_len = len;
538
539 return 0;
540 }
541
pptp_release(struct socket * sock)542 static int pptp_release(struct socket *sock)
543 {
544 struct sock *sk = sock->sk;
545 struct pppox_sock *po;
546 struct pptp_opt *opt;
547 int error = 0;
548
549 if (!sk)
550 return 0;
551
552 lock_sock(sk);
553
554 if (sock_flag(sk, SOCK_DEAD)) {
555 release_sock(sk);
556 return -EBADF;
557 }
558
559 po = pppox_sk(sk);
560 opt = &po->proto.pptp;
561 del_chan(po);
562
563 pppox_unbind_sock(sk);
564 sk->sk_state = PPPOX_DEAD;
565
566 sock_orphan(sk);
567 sock->sk = NULL;
568
569 release_sock(sk);
570 sock_put(sk);
571
572 return error;
573 }
574
pptp_sock_destruct(struct sock * sk)575 static void pptp_sock_destruct(struct sock *sk)
576 {
577 if (!(sk->sk_state & PPPOX_DEAD)) {
578 del_chan(pppox_sk(sk));
579 pppox_unbind_sock(sk);
580 }
581 skb_queue_purge(&sk->sk_receive_queue);
582 }
583
pptp_create(struct net * net,struct socket * sock)584 static int pptp_create(struct net *net, struct socket *sock)
585 {
586 int error = -ENOMEM;
587 struct sock *sk;
588 struct pppox_sock *po;
589 struct pptp_opt *opt;
590
591 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pptp_sk_proto);
592 if (!sk)
593 goto out;
594
595 sock_init_data(sock, sk);
596
597 sock->state = SS_UNCONNECTED;
598 sock->ops = &pptp_ops;
599
600 sk->sk_backlog_rcv = pptp_rcv_core;
601 sk->sk_state = PPPOX_NONE;
602 sk->sk_type = SOCK_STREAM;
603 sk->sk_family = PF_PPPOX;
604 sk->sk_protocol = PX_PROTO_PPTP;
605 sk->sk_destruct = pptp_sock_destruct;
606
607 po = pppox_sk(sk);
608 opt = &po->proto.pptp;
609
610 opt->seq_sent = 0; opt->seq_recv = 0xffffffff;
611 opt->ack_recv = 0; opt->ack_sent = 0xffffffff;
612
613 error = 0;
614 out:
615 return error;
616 }
617
pptp_ppp_ioctl(struct ppp_channel * chan,unsigned int cmd,unsigned long arg)618 static int pptp_ppp_ioctl(struct ppp_channel *chan, unsigned int cmd,
619 unsigned long arg)
620 {
621 struct sock *sk = (struct sock *) chan->private;
622 struct pppox_sock *po = pppox_sk(sk);
623 struct pptp_opt *opt = &po->proto.pptp;
624 void __user *argp = (void __user *)arg;
625 int __user *p = argp;
626 int err, val;
627
628 err = -EFAULT;
629 switch (cmd) {
630 case PPPIOCGFLAGS:
631 val = opt->ppp_flags;
632 if (put_user(val, p))
633 break;
634 err = 0;
635 break;
636 case PPPIOCSFLAGS:
637 if (get_user(val, p))
638 break;
639 opt->ppp_flags = val & ~SC_RCV_BITS;
640 err = 0;
641 break;
642 default:
643 err = -ENOTTY;
644 }
645
646 return err;
647 }
648
649 static const struct ppp_channel_ops pptp_chan_ops = {
650 .start_xmit = pptp_xmit,
651 .ioctl = pptp_ppp_ioctl,
652 };
653
654 static struct proto pptp_sk_proto __read_mostly = {
655 .name = "PPTP",
656 .owner = THIS_MODULE,
657 .obj_size = sizeof(struct pppox_sock),
658 };
659
660 static const struct proto_ops pptp_ops = {
661 .family = AF_PPPOX,
662 .owner = THIS_MODULE,
663 .release = pptp_release,
664 .bind = pptp_bind,
665 .connect = pptp_connect,
666 .socketpair = sock_no_socketpair,
667 .accept = sock_no_accept,
668 .getname = pptp_getname,
669 .poll = sock_no_poll,
670 .listen = sock_no_listen,
671 .shutdown = sock_no_shutdown,
672 .setsockopt = sock_no_setsockopt,
673 .getsockopt = sock_no_getsockopt,
674 .sendmsg = sock_no_sendmsg,
675 .recvmsg = sock_no_recvmsg,
676 .mmap = sock_no_mmap,
677 .ioctl = pppox_ioctl,
678 };
679
680 static const struct pppox_proto pppox_pptp_proto = {
681 .create = pptp_create,
682 .owner = THIS_MODULE,
683 };
684
685 static const struct gre_protocol gre_pptp_protocol = {
686 .handler = pptp_rcv,
687 };
688
pptp_init_module(void)689 static int __init pptp_init_module(void)
690 {
691 int err = 0;
692 pr_info("PPTP driver version " PPTP_DRIVER_VERSION "\n");
693
694 callid_sock = vzalloc((MAX_CALLID + 1) * sizeof(void *));
695 if (!callid_sock)
696 return -ENOMEM;
697
698 err = gre_add_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
699 if (err) {
700 pr_err("PPTP: can't add gre protocol\n");
701 goto out_mem_free;
702 }
703
704 err = proto_register(&pptp_sk_proto, 0);
705 if (err) {
706 pr_err("PPTP: can't register sk_proto\n");
707 goto out_gre_del_protocol;
708 }
709
710 err = register_pppox_proto(PX_PROTO_PPTP, &pppox_pptp_proto);
711 if (err) {
712 pr_err("PPTP: can't register pppox_proto\n");
713 goto out_unregister_sk_proto;
714 }
715
716 return 0;
717
718 out_unregister_sk_proto:
719 proto_unregister(&pptp_sk_proto);
720 out_gre_del_protocol:
721 gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
722 out_mem_free:
723 vfree(callid_sock);
724
725 return err;
726 }
727
pptp_exit_module(void)728 static void __exit pptp_exit_module(void)
729 {
730 unregister_pppox_proto(PX_PROTO_PPTP);
731 proto_unregister(&pptp_sk_proto);
732 gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP);
733 vfree(callid_sock);
734 }
735
736 module_init(pptp_init_module);
737 module_exit(pptp_exit_module);
738
739 MODULE_DESCRIPTION("Point-to-Point Tunneling Protocol");
740 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
741 MODULE_LICENSE("GPL");
742