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00959ade DK |
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> | |
00959ade DK |
33 | #include <linux/rcupdate.h> |
34 | #include <linux/spinlock.h> | |
35 | ||
36 | #include <net/sock.h> | |
37 | #include <net/protocol.h> | |
38 | #include <net/ip.h> | |
39 | #include <net/icmp.h> | |
40 | #include <net/route.h> | |
41 | #include <net/gre.h> | |
42 | ||
43 | #include <linux/uaccess.h> | |
44 | ||
45 | #define PPTP_DRIVER_VERSION "0.8.5" | |
46 | ||
47 | #define MAX_CALLID 65535 | |
48 | ||
49 | static DECLARE_BITMAP(callid_bitmap, MAX_CALLID + 1); | |
50 | static struct pppox_sock **callid_sock; | |
51 | ||
52 | static DEFINE_SPINLOCK(chan_lock); | |
53 | ||
54 | static struct proto pptp_sk_proto __read_mostly; | |
756e64a0 | 55 | static const struct ppp_channel_ops pptp_chan_ops; |
00959ade DK |
56 | static const struct proto_ops pptp_ops; |
57 | ||
58 | #define PPP_LCP_ECHOREQ 0x09 | |
59 | #define PPP_LCP_ECHOREP 0x0A | |
60 | #define SC_RCV_BITS (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP) | |
61 | ||
62 | #define MISSING_WINDOW 20 | |
63 | #define WRAPPED(curseq, lastseq)\ | |
64 | ((((curseq) & 0xffffff00) == 0) &&\ | |
65 | (((lastseq) & 0xffffff00) == 0xffffff00)) | |
66 | ||
67 | #define PPTP_GRE_PROTO 0x880B | |
68 | #define PPTP_GRE_VER 0x1 | |
69 | ||
70 | #define PPTP_GRE_FLAG_C 0x80 | |
71 | #define PPTP_GRE_FLAG_R 0x40 | |
72 | #define PPTP_GRE_FLAG_K 0x20 | |
73 | #define PPTP_GRE_FLAG_S 0x10 | |
74 | #define PPTP_GRE_FLAG_A 0x80 | |
75 | ||
76 | #define PPTP_GRE_IS_C(f) ((f)&PPTP_GRE_FLAG_C) | |
77 | #define PPTP_GRE_IS_R(f) ((f)&PPTP_GRE_FLAG_R) | |
78 | #define PPTP_GRE_IS_K(f) ((f)&PPTP_GRE_FLAG_K) | |
79 | #define PPTP_GRE_IS_S(f) ((f)&PPTP_GRE_FLAG_S) | |
80 | #define PPTP_GRE_IS_A(f) ((f)&PPTP_GRE_FLAG_A) | |
81 | ||
82 | #define PPTP_HEADER_OVERHEAD (2+sizeof(struct pptp_gre_header)) | |
83 | struct pptp_gre_header { | |
84 | u8 flags; | |
85 | u8 ver; | |
86 | u16 protocol; | |
87 | u16 payload_len; | |
88 | u16 call_id; | |
89 | u32 seq; | |
90 | u32 ack; | |
91 | } __packed; | |
92 | ||
93 | static struct pppox_sock *lookup_chan(u16 call_id, __be32 s_addr) | |
94 | { | |
95 | struct pppox_sock *sock; | |
96 | struct pptp_opt *opt; | |
97 | ||
98 | rcu_read_lock(); | |
99 | sock = rcu_dereference(callid_sock[call_id]); | |
100 | if (sock) { | |
101 | opt = &sock->proto.pptp; | |
102 | if (opt->dst_addr.sin_addr.s_addr != s_addr) | |
103 | sock = NULL; | |
104 | else | |
105 | sock_hold(sk_pppox(sock)); | |
106 | } | |
107 | rcu_read_unlock(); | |
108 | ||
109 | return sock; | |
110 | } | |
111 | ||
112 | static int lookup_chan_dst(u16 call_id, __be32 d_addr) | |
113 | { | |
114 | struct pppox_sock *sock; | |
115 | struct pptp_opt *opt; | |
116 | int i; | |
117 | ||
118 | rcu_read_lock(); | |
119 | for (i = find_next_bit(callid_bitmap, MAX_CALLID, 1); i < MAX_CALLID; | |
120 | i = find_next_bit(callid_bitmap, MAX_CALLID, i + 1)) { | |
121 | sock = rcu_dereference(callid_sock[i]); | |
122 | if (!sock) | |
123 | continue; | |
124 | opt = &sock->proto.pptp; | |
125 | if (opt->dst_addr.call_id == call_id && | |
126 | opt->dst_addr.sin_addr.s_addr == d_addr) | |
127 | break; | |
128 | } | |
129 | rcu_read_unlock(); | |
130 | ||
131 | return i < MAX_CALLID; | |
132 | } | |
133 | ||
134 | static int add_chan(struct pppox_sock *sock) | |
135 | { | |
136 | static int call_id; | |
137 | ||
138 | spin_lock(&chan_lock); | |
139 | if (!sock->proto.pptp.src_addr.call_id) { | |
140 | call_id = find_next_zero_bit(callid_bitmap, MAX_CALLID, call_id + 1); | |
141 | if (call_id == MAX_CALLID) { | |
142 | call_id = find_next_zero_bit(callid_bitmap, MAX_CALLID, 1); | |
143 | if (call_id == MAX_CALLID) | |
144 | goto out_err; | |
145 | } | |
146 | sock->proto.pptp.src_addr.call_id = call_id; | |
147 | } else if (test_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap)) | |
148 | goto out_err; | |
149 | ||
150 | set_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap); | |
151 | rcu_assign_pointer(callid_sock[sock->proto.pptp.src_addr.call_id], sock); | |
152 | spin_unlock(&chan_lock); | |
153 | ||
154 | return 0; | |
155 | ||
156 | out_err: | |
157 | spin_unlock(&chan_lock); | |
158 | return -1; | |
159 | } | |
160 | ||
161 | static void del_chan(struct pppox_sock *sock) | |
162 | { | |
163 | spin_lock(&chan_lock); | |
164 | clear_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap); | |
165 | rcu_assign_pointer(callid_sock[sock->proto.pptp.src_addr.call_id], NULL); | |
166 | spin_unlock(&chan_lock); | |
167 | synchronize_rcu(); | |
168 | } | |
169 | ||
170 | static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb) | |
171 | { | |
172 | struct sock *sk = (struct sock *) chan->private; | |
173 | struct pppox_sock *po = pppox_sk(sk); | |
174 | struct pptp_opt *opt = &po->proto.pptp; | |
175 | struct pptp_gre_header *hdr; | |
176 | unsigned int header_len = sizeof(*hdr); | |
31e4543d | 177 | struct flowi4 fl4; |
00959ade DK |
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 | ||
31e4543d | 192 | rt = ip_route_output_ports(&init_net, &fl4, NULL, |
78fbfd8a DM |
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 | ||
00959ade DK |
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; | |
28c90da0 DM |
273 | iph->daddr = fl4.daddr; |
274 | iph->saddr = fl4.saddr; | |
323e126f | 275 | iph->ttl = ip4_dst_hoplimit(&rt->dst); |
00959ade DK |
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); | |
8bae8bd6 | 288 | return 1; |
00959ade DK |
289 | |
290 | tx_error: | |
8bae8bd6 | 291 | kfree_skb(skb); |
00959ade DK |
292 | return 1; |
293 | } | |
294 | ||
295 | static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb) | |
296 | { | |
297 | struct pppox_sock *po = pppox_sk(sk); | |
298 | struct pptp_opt *opt = &po->proto.pptp; | |
299 | int headersize, payload_len, seq; | |
300 | __u8 *payload; | |
301 | struct pptp_gre_header *header; | |
302 | ||
303 | if (!(sk->sk_state & PPPOX_CONNECTED)) { | |
304 | if (sock_queue_rcv_skb(sk, skb)) | |
305 | goto drop; | |
306 | return NET_RX_SUCCESS; | |
307 | } | |
308 | ||
309 | header = (struct pptp_gre_header *)(skb->data); | |
4ea2739e | 310 | headersize = sizeof(*header); |
00959ade DK |
311 | |
312 | /* test if acknowledgement present */ | |
313 | if (PPTP_GRE_IS_A(header->ver)) { | |
4ea2739e ED |
314 | __u32 ack; |
315 | ||
316 | if (!pskb_may_pull(skb, headersize)) | |
317 | goto drop; | |
318 | header = (struct pptp_gre_header *)(skb->data); | |
319 | ||
320 | /* ack in different place if S = 0 */ | |
321 | ack = PPTP_GRE_IS_S(header->flags) ? header->ack : header->seq; | |
00959ade DK |
322 | |
323 | ack = ntohl(ack); | |
324 | ||
325 | if (ack > opt->ack_recv) | |
326 | opt->ack_recv = ack; | |
327 | /* also handle sequence number wrap-around */ | |
328 | if (WRAPPED(ack, opt->ack_recv)) | |
329 | opt->ack_recv = ack; | |
4ea2739e ED |
330 | } else { |
331 | headersize -= sizeof(header->ack); | |
00959ade | 332 | } |
00959ade DK |
333 | /* test if payload present */ |
334 | if (!PPTP_GRE_IS_S(header->flags)) | |
335 | goto drop; | |
336 | ||
00959ade DK |
337 | payload_len = ntohs(header->payload_len); |
338 | seq = ntohl(header->seq); | |
339 | ||
00959ade | 340 | /* check for incomplete packet (length smaller than expected) */ |
4ea2739e | 341 | if (!pskb_may_pull(skb, headersize + payload_len)) |
00959ade DK |
342 | goto drop; |
343 | ||
344 | payload = skb->data + headersize; | |
345 | /* check for expected sequence number */ | |
346 | if (seq < opt->seq_recv + 1 || WRAPPED(opt->seq_recv, seq)) { | |
347 | if ((payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) && | |
348 | (PPP_PROTOCOL(payload) == PPP_LCP) && | |
349 | ((payload[4] == PPP_LCP_ECHOREQ) || (payload[4] == PPP_LCP_ECHOREP))) | |
350 | goto allow_packet; | |
351 | } else { | |
352 | opt->seq_recv = seq; | |
353 | allow_packet: | |
354 | skb_pull(skb, headersize); | |
355 | ||
356 | if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI) { | |
357 | /* chop off address/control */ | |
358 | if (skb->len < 3) | |
359 | goto drop; | |
360 | skb_pull(skb, 2); | |
361 | } | |
362 | ||
363 | if ((*skb->data) & 1) { | |
364 | /* protocol is compressed */ | |
365 | skb_push(skb, 1)[0] = 0; | |
366 | } | |
367 | ||
368 | skb->ip_summed = CHECKSUM_NONE; | |
369 | skb_set_network_header(skb, skb->head-skb->data); | |
370 | ppp_input(&po->chan, skb); | |
371 | ||
372 | return NET_RX_SUCCESS; | |
373 | } | |
374 | drop: | |
375 | kfree_skb(skb); | |
376 | return NET_RX_DROP; | |
377 | } | |
378 | ||
379 | static int pptp_rcv(struct sk_buff *skb) | |
380 | { | |
381 | struct pppox_sock *po; | |
382 | struct pptp_gre_header *header; | |
383 | struct iphdr *iph; | |
384 | ||
385 | if (skb->pkt_type != PACKET_HOST) | |
386 | goto drop; | |
387 | ||
388 | if (!pskb_may_pull(skb, 12)) | |
389 | goto drop; | |
390 | ||
391 | iph = ip_hdr(skb); | |
392 | ||
393 | header = (struct pptp_gre_header *)skb->data; | |
394 | ||
395 | if (ntohs(header->protocol) != PPTP_GRE_PROTO || /* PPTP-GRE protocol for PPTP */ | |
396 | PPTP_GRE_IS_C(header->flags) || /* flag C should be clear */ | |
397 | PPTP_GRE_IS_R(header->flags) || /* flag R should be clear */ | |
398 | !PPTP_GRE_IS_K(header->flags) || /* flag K should be set */ | |
399 | (header->flags&0xF) != 0) /* routing and recursion ctrl = 0 */ | |
400 | /* if invalid, discard this packet */ | |
401 | goto drop; | |
402 | ||
403 | po = lookup_chan(htons(header->call_id), iph->saddr); | |
404 | if (po) { | |
405 | skb_dst_drop(skb); | |
406 | nf_reset(skb); | |
407 | return sk_receive_skb(sk_pppox(po), skb, 0); | |
408 | } | |
409 | drop: | |
410 | kfree_skb(skb); | |
411 | return NET_RX_DROP; | |
412 | } | |
413 | ||
414 | static int pptp_bind(struct socket *sock, struct sockaddr *uservaddr, | |
415 | int sockaddr_len) | |
416 | { | |
417 | struct sock *sk = sock->sk; | |
418 | struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr; | |
419 | struct pppox_sock *po = pppox_sk(sk); | |
420 | struct pptp_opt *opt = &po->proto.pptp; | |
421 | int error = 0; | |
422 | ||
423 | lock_sock(sk); | |
424 | ||
425 | opt->src_addr = sp->sa_addr.pptp; | |
426 | if (add_chan(po)) { | |
427 | release_sock(sk); | |
428 | error = -EBUSY; | |
429 | } | |
430 | ||
431 | release_sock(sk); | |
432 | return error; | |
433 | } | |
434 | ||
435 | static int pptp_connect(struct socket *sock, struct sockaddr *uservaddr, | |
436 | int sockaddr_len, int flags) | |
437 | { | |
438 | struct sock *sk = sock->sk; | |
439 | struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr; | |
440 | struct pppox_sock *po = pppox_sk(sk); | |
441 | struct pptp_opt *opt = &po->proto.pptp; | |
442 | struct rtable *rt; | |
31e4543d | 443 | struct flowi4 fl4; |
00959ade DK |
444 | int error = 0; |
445 | ||
446 | if (sp->sa_protocol != PX_PROTO_PPTP) | |
447 | return -EINVAL; | |
448 | ||
449 | if (lookup_chan_dst(sp->sa_addr.pptp.call_id, sp->sa_addr.pptp.sin_addr.s_addr)) | |
450 | return -EALREADY; | |
451 | ||
452 | lock_sock(sk); | |
453 | /* Check for already bound sockets */ | |
454 | if (sk->sk_state & PPPOX_CONNECTED) { | |
455 | error = -EBUSY; | |
456 | goto end; | |
457 | } | |
458 | ||
459 | /* Check for already disconnected sockets, on attempts to disconnect */ | |
460 | if (sk->sk_state & PPPOX_DEAD) { | |
461 | error = -EALREADY; | |
462 | goto end; | |
463 | } | |
464 | ||
465 | if (!opt->src_addr.sin_addr.s_addr || !sp->sa_addr.pptp.sin_addr.s_addr) { | |
466 | error = -EINVAL; | |
467 | goto end; | |
468 | } | |
469 | ||
470 | po->chan.private = sk; | |
471 | po->chan.ops = &pptp_chan_ops; | |
472 | ||
31e4543d | 473 | rt = ip_route_output_ports(&init_net, &fl4, sk, |
78fbfd8a DM |
474 | opt->dst_addr.sin_addr.s_addr, |
475 | opt->src_addr.sin_addr.s_addr, | |
476 | 0, 0, | |
477 | IPPROTO_GRE, RT_CONN_FLAGS(sk), 0); | |
478 | if (IS_ERR(rt)) { | |
479 | error = -EHOSTUNREACH; | |
480 | goto end; | |
00959ade | 481 | } |
78fbfd8a DM |
482 | sk_setup_caps(sk, &rt->dst); |
483 | ||
00959ade DK |
484 | po->chan.mtu = dst_mtu(&rt->dst); |
485 | if (!po->chan.mtu) | |
486 | po->chan.mtu = PPP_MTU; | |
487 | ip_rt_put(rt); | |
488 | po->chan.mtu -= PPTP_HEADER_OVERHEAD; | |
489 | ||
490 | po->chan.hdrlen = 2 + sizeof(struct pptp_gre_header); | |
491 | error = ppp_register_channel(&po->chan); | |
492 | if (error) { | |
493 | pr_err("PPTP: failed to register PPP channel (%d)\n", error); | |
494 | goto end; | |
495 | } | |
496 | ||
497 | opt->dst_addr = sp->sa_addr.pptp; | |
498 | sk->sk_state = PPPOX_CONNECTED; | |
499 | ||
500 | end: | |
501 | release_sock(sk); | |
502 | return error; | |
503 | } | |
504 | ||
505 | static int pptp_getname(struct socket *sock, struct sockaddr *uaddr, | |
506 | int *usockaddr_len, int peer) | |
507 | { | |
508 | int len = sizeof(struct sockaddr_pppox); | |
509 | struct sockaddr_pppox sp; | |
510 | ||
511 | sp.sa_family = AF_PPPOX; | |
512 | sp.sa_protocol = PX_PROTO_PPTP; | |
513 | sp.sa_addr.pptp = pppox_sk(sock->sk)->proto.pptp.src_addr; | |
514 | ||
515 | memcpy(uaddr, &sp, len); | |
516 | ||
517 | *usockaddr_len = len; | |
518 | ||
519 | return 0; | |
520 | } | |
521 | ||
522 | static int pptp_release(struct socket *sock) | |
523 | { | |
524 | struct sock *sk = sock->sk; | |
525 | struct pppox_sock *po; | |
526 | struct pptp_opt *opt; | |
527 | int error = 0; | |
528 | ||
529 | if (!sk) | |
530 | return 0; | |
531 | ||
532 | lock_sock(sk); | |
533 | ||
534 | if (sock_flag(sk, SOCK_DEAD)) { | |
535 | release_sock(sk); | |
536 | return -EBADF; | |
537 | } | |
538 | ||
539 | po = pppox_sk(sk); | |
540 | opt = &po->proto.pptp; | |
541 | del_chan(po); | |
542 | ||
543 | pppox_unbind_sock(sk); | |
544 | sk->sk_state = PPPOX_DEAD; | |
545 | ||
546 | sock_orphan(sk); | |
547 | sock->sk = NULL; | |
548 | ||
549 | release_sock(sk); | |
550 | sock_put(sk); | |
551 | ||
552 | return error; | |
553 | } | |
554 | ||
555 | static void pptp_sock_destruct(struct sock *sk) | |
556 | { | |
557 | if (!(sk->sk_state & PPPOX_DEAD)) { | |
558 | del_chan(pppox_sk(sk)); | |
559 | pppox_unbind_sock(sk); | |
560 | } | |
561 | skb_queue_purge(&sk->sk_receive_queue); | |
562 | } | |
563 | ||
564 | static int pptp_create(struct net *net, struct socket *sock) | |
565 | { | |
566 | int error = -ENOMEM; | |
567 | struct sock *sk; | |
568 | struct pppox_sock *po; | |
569 | struct pptp_opt *opt; | |
570 | ||
571 | sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pptp_sk_proto); | |
572 | if (!sk) | |
573 | goto out; | |
574 | ||
575 | sock_init_data(sock, sk); | |
576 | ||
577 | sock->state = SS_UNCONNECTED; | |
578 | sock->ops = &pptp_ops; | |
579 | ||
580 | sk->sk_backlog_rcv = pptp_rcv_core; | |
581 | sk->sk_state = PPPOX_NONE; | |
582 | sk->sk_type = SOCK_STREAM; | |
583 | sk->sk_family = PF_PPPOX; | |
584 | sk->sk_protocol = PX_PROTO_PPTP; | |
585 | sk->sk_destruct = pptp_sock_destruct; | |
586 | ||
587 | po = pppox_sk(sk); | |
588 | opt = &po->proto.pptp; | |
589 | ||
590 | opt->seq_sent = 0; opt->seq_recv = 0; | |
591 | opt->ack_recv = 0; opt->ack_sent = 0; | |
592 | ||
593 | error = 0; | |
594 | out: | |
595 | return error; | |
596 | } | |
597 | ||
598 | static int pptp_ppp_ioctl(struct ppp_channel *chan, unsigned int cmd, | |
599 | unsigned long arg) | |
600 | { | |
601 | struct sock *sk = (struct sock *) chan->private; | |
602 | struct pppox_sock *po = pppox_sk(sk); | |
603 | struct pptp_opt *opt = &po->proto.pptp; | |
604 | void __user *argp = (void __user *)arg; | |
605 | int __user *p = argp; | |
606 | int err, val; | |
607 | ||
608 | err = -EFAULT; | |
609 | switch (cmd) { | |
610 | case PPPIOCGFLAGS: | |
611 | val = opt->ppp_flags; | |
612 | if (put_user(val, p)) | |
613 | break; | |
614 | err = 0; | |
615 | break; | |
616 | case PPPIOCSFLAGS: | |
617 | if (get_user(val, p)) | |
618 | break; | |
619 | opt->ppp_flags = val & ~SC_RCV_BITS; | |
620 | err = 0; | |
621 | break; | |
622 | default: | |
623 | err = -ENOTTY; | |
624 | } | |
625 | ||
626 | return err; | |
627 | } | |
628 | ||
756e64a0 | 629 | static const struct ppp_channel_ops pptp_chan_ops = { |
00959ade DK |
630 | .start_xmit = pptp_xmit, |
631 | .ioctl = pptp_ppp_ioctl, | |
632 | }; | |
633 | ||
634 | static struct proto pptp_sk_proto __read_mostly = { | |
635 | .name = "PPTP", | |
636 | .owner = THIS_MODULE, | |
637 | .obj_size = sizeof(struct pppox_sock), | |
638 | }; | |
639 | ||
640 | static const struct proto_ops pptp_ops = { | |
641 | .family = AF_PPPOX, | |
642 | .owner = THIS_MODULE, | |
643 | .release = pptp_release, | |
644 | .bind = pptp_bind, | |
645 | .connect = pptp_connect, | |
646 | .socketpair = sock_no_socketpair, | |
647 | .accept = sock_no_accept, | |
648 | .getname = pptp_getname, | |
649 | .poll = sock_no_poll, | |
650 | .listen = sock_no_listen, | |
651 | .shutdown = sock_no_shutdown, | |
652 | .setsockopt = sock_no_setsockopt, | |
653 | .getsockopt = sock_no_getsockopt, | |
654 | .sendmsg = sock_no_sendmsg, | |
655 | .recvmsg = sock_no_recvmsg, | |
656 | .mmap = sock_no_mmap, | |
657 | .ioctl = pppox_ioctl, | |
658 | }; | |
659 | ||
756e64a0 | 660 | static const struct pppox_proto pppox_pptp_proto = { |
00959ade DK |
661 | .create = pptp_create, |
662 | .owner = THIS_MODULE, | |
663 | }; | |
664 | ||
756e64a0 | 665 | static const struct gre_protocol gre_pptp_protocol = { |
00959ade DK |
666 | .handler = pptp_rcv, |
667 | }; | |
668 | ||
669 | static int __init pptp_init_module(void) | |
670 | { | |
671 | int err = 0; | |
672 | pr_info("PPTP driver version " PPTP_DRIVER_VERSION "\n"); | |
673 | ||
89bf67f1 | 674 | callid_sock = vzalloc((MAX_CALLID + 1) * sizeof(void *)); |
00959ade DK |
675 | if (!callid_sock) { |
676 | pr_err("PPTP: cann't allocate memory\n"); | |
677 | return -ENOMEM; | |
678 | } | |
679 | ||
680 | err = gre_add_protocol(&gre_pptp_protocol, GREPROTO_PPTP); | |
681 | if (err) { | |
682 | pr_err("PPTP: can't add gre protocol\n"); | |
683 | goto out_mem_free; | |
684 | } | |
685 | ||
686 | err = proto_register(&pptp_sk_proto, 0); | |
687 | if (err) { | |
688 | pr_err("PPTP: can't register sk_proto\n"); | |
689 | goto out_gre_del_protocol; | |
690 | } | |
691 | ||
692 | err = register_pppox_proto(PX_PROTO_PPTP, &pppox_pptp_proto); | |
693 | if (err) { | |
694 | pr_err("PPTP: can't register pppox_proto\n"); | |
695 | goto out_unregister_sk_proto; | |
696 | } | |
697 | ||
698 | return 0; | |
699 | ||
700 | out_unregister_sk_proto: | |
701 | proto_unregister(&pptp_sk_proto); | |
702 | out_gre_del_protocol: | |
703 | gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP); | |
704 | out_mem_free: | |
705 | vfree(callid_sock); | |
706 | ||
707 | return err; | |
708 | } | |
709 | ||
710 | static void __exit pptp_exit_module(void) | |
711 | { | |
712 | unregister_pppox_proto(PX_PROTO_PPTP); | |
713 | proto_unregister(&pptp_sk_proto); | |
714 | gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP); | |
715 | vfree(callid_sock); | |
716 | } | |
717 | ||
718 | module_init(pptp_init_module); | |
719 | module_exit(pptp_exit_module); | |
720 | ||
721 | MODULE_DESCRIPTION("Point-to-Point Tunneling Protocol"); | |
722 | MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)"); | |
723 | MODULE_LICENSE("GPL"); |