[NET]: Make /proc/net per network namespace
[linux-2.6.git] / drivers / net / pppoe.c
1 /** -*- linux-c -*- ***********************************************************
2  * Linux PPP over Ethernet (PPPoX/PPPoE) Sockets
3  *
4  * PPPoX --- Generic PPP encapsulation socket family
5  * PPPoE --- PPP over Ethernet (RFC 2516)
6  *
7  *
8  * Version:     0.7.0
9  *
10  * 070228 :     Fix to allow multiple sessions with same remote MAC and same
11  *              session id by including the local device ifindex in the
12  *              tuple identifying a session. This also ensures packets can't
13  *              be injected into a session from interfaces other than the one
14  *              specified by userspace. Florian Zumbiehl <florz@florz.de>
15  *              (Oh, BTW, this one is YYMMDD, in case you were wondering ...)
16  * 220102 :     Fix module use count on failure in pppoe_create, pppox_sk -acme
17  * 030700 :     Fixed connect logic to allow for disconnect.
18  * 270700 :     Fixed potential SMP problems; we must protect against
19  *              simultaneous invocation of ppp_input
20  *              and ppp_unregister_channel.
21  * 040800 :     Respect reference count mechanisms on net-devices.
22  * 200800 :     fix kfree(skb) in pppoe_rcv (acme)
23  *              Module reference count is decremented in the right spot now,
24  *              guards against sock_put not actually freeing the sk
25  *              in pppoe_release.
26  * 051000 :     Initialization cleanup.
27  * 111100 :     Fix recvmsg.
28  * 050101 :     Fix PADT procesing.
29  * 140501 :     Use pppoe_rcv_core to handle all backlog. (Alexey)
30  * 170701 :     Do not lock_sock with rwlock held. (DaveM)
31  *              Ignore discovery frames if user has socket
32  *              locked. (DaveM)
33  *              Ignore return value of dev_queue_xmit in __pppoe_xmit
34  *              or else we may kfree an SKB twice. (DaveM)
35  * 190701 :     When doing copies of skb's in __pppoe_xmit, always delete
36  *              the original skb that was passed in on success, never on
37  *              failure.  Delete the copy of the skb on failure to avoid
38  *              a memory leak.
39  * 081001 :     Misc. cleanup (licence string, non-blocking, prevent
40  *              reference of device on close).
41  * 121301 :     New ppp channels interface; cannot unregister a channel
42  *              from interrupts.  Thus, we mark the socket as a ZOMBIE
43  *              and do the unregistration later.
44  * 081002 :     seq_file support for proc stuff -acme
45  * 111602 :     Merge all 2.4 fixes into 2.5/2.6 tree.  Label 2.5/2.6
46  *              as version 0.7.  Spacing cleanup.
47  * Author:      Michal Ostrowski <mostrows@speakeasy.net>
48  * Contributors:
49  *              Arnaldo Carvalho de Melo <acme@conectiva.com.br>
50  *              David S. Miller (davem@redhat.com)
51  *
52  * License:
53  *              This program is free software; you can redistribute it and/or
54  *              modify it under the terms of the GNU General Public License
55  *              as published by the Free Software Foundation; either version
56  *              2 of the License, or (at your option) any later version.
57  *
58  */
59
60 #include <linux/string.h>
61 #include <linux/module.h>
62 #include <linux/kernel.h>
63 #include <linux/slab.h>
64 #include <linux/errno.h>
65 #include <linux/netdevice.h>
66 #include <linux/net.h>
67 #include <linux/inetdevice.h>
68 #include <linux/etherdevice.h>
69 #include <linux/skbuff.h>
70 #include <linux/init.h>
71 #include <linux/if_ether.h>
72 #include <linux/if_pppox.h>
73 #include <linux/ppp_channel.h>
74 #include <linux/ppp_defs.h>
75 #include <linux/if_ppp.h>
76 #include <linux/notifier.h>
77 #include <linux/file.h>
78 #include <linux/proc_fs.h>
79 #include <linux/seq_file.h>
80
81 #include <net/net_namespace.h>
82 #include <net/sock.h>
83
84 #include <asm/uaccess.h>
85
86 #define PPPOE_HASH_BITS 4
87 #define PPPOE_HASH_SIZE (1<<PPPOE_HASH_BITS)
88
89 static struct ppp_channel_ops pppoe_chan_ops;
90
91 static int pppoe_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
92 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb);
93 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
94
95 static const struct proto_ops pppoe_ops;
96 static DEFINE_RWLOCK(pppoe_hash_lock);
97
98 static struct ppp_channel_ops pppoe_chan_ops;
99
100 static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
101 {
102         return (a->sid == b->sid &&
103                 (memcmp(a->remote, b->remote, ETH_ALEN) == 0));
104 }
105
106 static inline int cmp_addr(struct pppoe_addr *a, unsigned long sid, char *addr)
107 {
108         return (a->sid == sid &&
109                 (memcmp(a->remote,addr,ETH_ALEN) == 0));
110 }
111
112 #if 8%PPPOE_HASH_BITS
113 #error 8 must be a multiple of PPPOE_HASH_BITS
114 #endif
115
116 static int hash_item(unsigned int sid, unsigned char *addr)
117 {
118         unsigned char hash = 0;
119         unsigned int i;
120
121         for (i = 0 ; i < ETH_ALEN ; i++) {
122                 hash ^= addr[i];
123         }
124         for (i = 0 ; i < sizeof(sid_t)*8 ; i += 8 ){
125                 hash ^= sid>>i;
126         }
127         for (i = 8 ; (i>>=1) >= PPPOE_HASH_BITS ; ) {
128                 hash ^= hash>>i;
129         }
130
131         return hash & ( PPPOE_HASH_SIZE - 1 );
132 }
133
134 /* zeroed because its in .bss */
135 static struct pppox_sock *item_hash_table[PPPOE_HASH_SIZE];
136
137 /**********************************************************************
138  *
139  *  Set/get/delete/rehash items  (internal versions)
140  *
141  **********************************************************************/
142 static struct pppox_sock *__get_item(unsigned long sid, unsigned char *addr, int ifindex)
143 {
144         int hash = hash_item(sid, addr);
145         struct pppox_sock *ret;
146
147         ret = item_hash_table[hash];
148
149         while (ret && !(cmp_addr(&ret->pppoe_pa, sid, addr) && ret->pppoe_ifindex == ifindex))
150                 ret = ret->next;
151
152         return ret;
153 }
154
155 static int __set_item(struct pppox_sock *po)
156 {
157         int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
158         struct pppox_sock *ret;
159
160         ret = item_hash_table[hash];
161         while (ret) {
162                 if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) && ret->pppoe_ifindex == po->pppoe_ifindex)
163                         return -EALREADY;
164
165                 ret = ret->next;
166         }
167
168         po->next = item_hash_table[hash];
169         item_hash_table[hash] = po;
170
171         return 0;
172 }
173
174 static struct pppox_sock *__delete_item(unsigned long sid, char *addr, int ifindex)
175 {
176         int hash = hash_item(sid, addr);
177         struct pppox_sock *ret, **src;
178
179         ret = item_hash_table[hash];
180         src = &item_hash_table[hash];
181
182         while (ret) {
183                 if (cmp_addr(&ret->pppoe_pa, sid, addr) && ret->pppoe_ifindex == ifindex) {
184                         *src = ret->next;
185                         break;
186                 }
187
188                 src = &ret->next;
189                 ret = ret->next;
190         }
191
192         return ret;
193 }
194
195 /**********************************************************************
196  *
197  *  Set/get/delete/rehash items
198  *
199  **********************************************************************/
200 static inline struct pppox_sock *get_item(unsigned long sid,
201                                          unsigned char *addr, int ifindex)
202 {
203         struct pppox_sock *po;
204
205         read_lock_bh(&pppoe_hash_lock);
206         po = __get_item(sid, addr, ifindex);
207         if (po)
208                 sock_hold(sk_pppox(po));
209         read_unlock_bh(&pppoe_hash_lock);
210
211         return po;
212 }
213
214 static inline struct pppox_sock *get_item_by_addr(struct sockaddr_pppox *sp)
215 {
216         struct net_device *dev;
217         int ifindex;
218
219         dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
220         if(!dev)
221                 return NULL;
222         ifindex = dev->ifindex;
223         dev_put(dev);
224         return get_item(sp->sa_addr.pppoe.sid, sp->sa_addr.pppoe.remote, ifindex);
225 }
226
227 static inline struct pppox_sock *delete_item(unsigned long sid, char *addr, int ifindex)
228 {
229         struct pppox_sock *ret;
230
231         write_lock_bh(&pppoe_hash_lock);
232         ret = __delete_item(sid, addr, ifindex);
233         write_unlock_bh(&pppoe_hash_lock);
234
235         return ret;
236 }
237
238
239
240 /***************************************************************************
241  *
242  *  Handler for device events.
243  *  Certain device events require that sockets be unconnected.
244  *
245  **************************************************************************/
246
247 static void pppoe_flush_dev(struct net_device *dev)
248 {
249         int hash;
250         BUG_ON(dev == NULL);
251
252         write_lock_bh(&pppoe_hash_lock);
253         for (hash = 0; hash < PPPOE_HASH_SIZE; hash++) {
254                 struct pppox_sock *po = item_hash_table[hash];
255
256                 while (po != NULL) {
257                         struct sock *sk = sk_pppox(po);
258                         if (po->pppoe_dev != dev) {
259                                 po = po->next;
260                                 continue;
261                         }
262                         po->pppoe_dev = NULL;
263                         dev_put(dev);
264
265
266                         /* We always grab the socket lock, followed by the
267                          * pppoe_hash_lock, in that order.  Since we should
268                          * hold the sock lock while doing any unbinding,
269                          * we need to release the lock we're holding.
270                          * Hold a reference to the sock so it doesn't disappear
271                          * as we're jumping between locks.
272                          */
273
274                         sock_hold(sk);
275
276                         write_unlock_bh(&pppoe_hash_lock);
277                         lock_sock(sk);
278
279                         if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
280                                 pppox_unbind_sock(sk);
281                                 sk->sk_state = PPPOX_ZOMBIE;
282                                 sk->sk_state_change(sk);
283                         }
284
285                         release_sock(sk);
286                         sock_put(sk);
287
288                         /* Restart scan at the beginning of this hash chain.
289                          * While the lock was dropped the chain contents may
290                          * have changed.
291                          */
292                         write_lock_bh(&pppoe_hash_lock);
293                         po = item_hash_table[hash];
294                 }
295         }
296         write_unlock_bh(&pppoe_hash_lock);
297 }
298
299 static int pppoe_device_event(struct notifier_block *this,
300                               unsigned long event, void *ptr)
301 {
302         struct net_device *dev = (struct net_device *) ptr;
303
304         /* Only look at sockets that are using this specific device. */
305         switch (event) {
306         case NETDEV_CHANGEMTU:
307                 /* A change in mtu is a bad thing, requiring
308                  * LCP re-negotiation.
309                  */
310
311         case NETDEV_GOING_DOWN:
312         case NETDEV_DOWN:
313                 /* Find every socket on this device and kill it. */
314                 pppoe_flush_dev(dev);
315                 break;
316
317         default:
318                 break;
319         };
320
321         return NOTIFY_DONE;
322 }
323
324
325 static struct notifier_block pppoe_notifier = {
326         .notifier_call = pppoe_device_event,
327 };
328
329
330 /************************************************************************
331  *
332  * Do the real work of receiving a PPPoE Session frame.
333  *
334  ***********************************************************************/
335 static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb)
336 {
337         struct pppox_sock *po = pppox_sk(sk);
338         struct pppox_sock *relay_po;
339
340         if (sk->sk_state & PPPOX_BOUND) {
341                 struct pppoe_hdr *ph = pppoe_hdr(skb);
342                 int len = ntohs(ph->length);
343                 skb_pull_rcsum(skb, sizeof(struct pppoe_hdr));
344                 if (pskb_trim_rcsum(skb, len))
345                         goto abort_kfree;
346
347                 ppp_input(&po->chan, skb);
348         } else if (sk->sk_state & PPPOX_RELAY) {
349                 relay_po = get_item_by_addr(&po->pppoe_relay);
350
351                 if (relay_po == NULL)
352                         goto abort_kfree;
353
354                 if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0)
355                         goto abort_put;
356
357                 skb_pull(skb, sizeof(struct pppoe_hdr));
358                 if (!__pppoe_xmit(sk_pppox(relay_po), skb))
359                         goto abort_put;
360         } else {
361                 if (sock_queue_rcv_skb(sk, skb))
362                         goto abort_kfree;
363         }
364
365         return NET_RX_SUCCESS;
366
367 abort_put:
368         sock_put(sk_pppox(relay_po));
369
370 abort_kfree:
371         kfree_skb(skb);
372         return NET_RX_DROP;
373 }
374
375 /************************************************************************
376  *
377  * Receive wrapper called in BH context.
378  *
379  ***********************************************************************/
380 static int pppoe_rcv(struct sk_buff *skb,
381                      struct net_device *dev,
382                      struct packet_type *pt,
383                      struct net_device *orig_dev)
384
385 {
386         struct pppoe_hdr *ph;
387         struct pppox_sock *po;
388
389         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
390                 goto out;
391
392         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
393                 goto drop;
394
395         ph = pppoe_hdr(skb);
396
397         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
398         if (po != NULL)
399                 return sk_receive_skb(sk_pppox(po), skb, 0);
400 drop:
401         kfree_skb(skb);
402 out:
403         return NET_RX_DROP;
404 }
405
406 /************************************************************************
407  *
408  * Receive a PPPoE Discovery frame.
409  * This is solely for detection of PADT frames
410  *
411  ***********************************************************************/
412 static int pppoe_disc_rcv(struct sk_buff *skb,
413                           struct net_device *dev,
414                           struct packet_type *pt,
415                           struct net_device *orig_dev)
416
417 {
418         struct pppoe_hdr *ph;
419         struct pppox_sock *po;
420
421         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
422                 goto abort;
423
424         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
425                 goto out;
426
427         ph = pppoe_hdr(skb);
428         if (ph->code != PADT_CODE)
429                 goto abort;
430
431         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
432         if (po) {
433                 struct sock *sk = sk_pppox(po);
434
435                 bh_lock_sock(sk);
436
437                 /* If the user has locked the socket, just ignore
438                  * the packet.  With the way two rcv protocols hook into
439                  * one socket family type, we cannot (easily) distinguish
440                  * what kind of SKB it is during backlog rcv.
441                  */
442                 if (sock_owned_by_user(sk) == 0) {
443                         /* We're no longer connect at the PPPOE layer,
444                          * and must wait for ppp channel to disconnect us.
445                          */
446                         sk->sk_state = PPPOX_ZOMBIE;
447                 }
448
449                 bh_unlock_sock(sk);
450                 sock_put(sk);
451         }
452
453 abort:
454         kfree_skb(skb);
455 out:
456         return NET_RX_SUCCESS; /* Lies... :-) */
457 }
458
459 static struct packet_type pppoes_ptype = {
460         .type   = __constant_htons(ETH_P_PPP_SES),
461         .func   = pppoe_rcv,
462 };
463
464 static struct packet_type pppoed_ptype = {
465         .type   = __constant_htons(ETH_P_PPP_DISC),
466         .func   = pppoe_disc_rcv,
467 };
468
469 static struct proto pppoe_sk_proto = {
470         .name     = "PPPOE",
471         .owner    = THIS_MODULE,
472         .obj_size = sizeof(struct pppox_sock),
473 };
474
475 /***********************************************************************
476  *
477  * Initialize a new struct sock.
478  *
479  **********************************************************************/
480 static int pppoe_create(struct socket *sock)
481 {
482         int error = -ENOMEM;
483         struct sock *sk;
484
485         sk = sk_alloc(PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, 1);
486         if (!sk)
487                 goto out;
488
489         sock_init_data(sock, sk);
490
491         sock->state = SS_UNCONNECTED;
492         sock->ops   = &pppoe_ops;
493
494         sk->sk_backlog_rcv = pppoe_rcv_core;
495         sk->sk_state       = PPPOX_NONE;
496         sk->sk_type        = SOCK_STREAM;
497         sk->sk_family      = PF_PPPOX;
498         sk->sk_protocol    = PX_PROTO_OE;
499
500         error = 0;
501 out:    return error;
502 }
503
504 static int pppoe_release(struct socket *sock)
505 {
506         struct sock *sk = sock->sk;
507         struct pppox_sock *po;
508
509         if (!sk)
510                 return 0;
511
512         lock_sock(sk);
513         if (sock_flag(sk, SOCK_DEAD)){
514                 release_sock(sk);
515                 return -EBADF;
516         }
517
518         pppox_unbind_sock(sk);
519
520         /* Signal the death of the socket. */
521         sk->sk_state = PPPOX_DEAD;
522
523
524         /* Write lock on hash lock protects the entire "po" struct from
525          * concurrent updates via pppoe_flush_dev. The "po" struct should
526          * be considered part of the hash table contents, thus protected
527          * by the hash table lock */
528         write_lock_bh(&pppoe_hash_lock);
529
530         po = pppox_sk(sk);
531         if (po->pppoe_pa.sid) {
532                 __delete_item(po->pppoe_pa.sid,
533                               po->pppoe_pa.remote, po->pppoe_ifindex);
534         }
535
536         if (po->pppoe_dev) {
537                 dev_put(po->pppoe_dev);
538                 po->pppoe_dev = NULL;
539         }
540
541         write_unlock_bh(&pppoe_hash_lock);
542
543         sock_orphan(sk);
544         sock->sk = NULL;
545
546         skb_queue_purge(&sk->sk_receive_queue);
547         release_sock(sk);
548         sock_put(sk);
549
550         return 0;
551 }
552
553
554 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
555                   int sockaddr_len, int flags)
556 {
557         struct sock *sk = sock->sk;
558         struct net_device *dev;
559         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
560         struct pppox_sock *po = pppox_sk(sk);
561         int error;
562
563         lock_sock(sk);
564
565         error = -EINVAL;
566         if (sp->sa_protocol != PX_PROTO_OE)
567                 goto end;
568
569         /* Check for already bound sockets */
570         error = -EBUSY;
571         if ((sk->sk_state & PPPOX_CONNECTED) && sp->sa_addr.pppoe.sid)
572                 goto end;
573
574         /* Check for already disconnected sockets, on attempts to disconnect */
575         error = -EALREADY;
576         if ((sk->sk_state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
577                 goto end;
578
579         error = 0;
580         if (po->pppoe_pa.sid) {
581                 pppox_unbind_sock(sk);
582
583                 /* Delete the old binding */
584                 delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote,po->pppoe_ifindex);
585
586                 if(po->pppoe_dev)
587                         dev_put(po->pppoe_dev);
588
589                 memset(sk_pppox(po) + 1, 0,
590                        sizeof(struct pppox_sock) - sizeof(struct sock));
591
592                 sk->sk_state = PPPOX_NONE;
593         }
594
595         /* Don't re-bind if sid==0 */
596         if (sp->sa_addr.pppoe.sid != 0) {
597                 dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
598
599                 error = -ENODEV;
600                 if (!dev)
601                         goto end;
602
603                 po->pppoe_dev = dev;
604                 po->pppoe_ifindex = dev->ifindex;
605
606                 write_lock_bh(&pppoe_hash_lock);
607                 if (!(dev->flags & IFF_UP)){
608                         write_unlock_bh(&pppoe_hash_lock);
609                         goto err_put;
610                 }
611
612                 memcpy(&po->pppoe_pa,
613                        &sp->sa_addr.pppoe,
614                        sizeof(struct pppoe_addr));
615
616                 error = __set_item(po);
617                 write_unlock_bh(&pppoe_hash_lock);
618                 if (error < 0)
619                         goto err_put;
620
621                 po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
622                                    dev->hard_header_len);
623
624                 po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr);
625                 po->chan.private = sk;
626                 po->chan.ops = &pppoe_chan_ops;
627
628                 error = ppp_register_channel(&po->chan);
629                 if (error)
630                         goto err_put;
631
632                 sk->sk_state = PPPOX_CONNECTED;
633         }
634
635         po->num = sp->sa_addr.pppoe.sid;
636
637  end:
638         release_sock(sk);
639         return error;
640 err_put:
641         if (po->pppoe_dev) {
642                 dev_put(po->pppoe_dev);
643                 po->pppoe_dev = NULL;
644         }
645         goto end;
646 }
647
648
649 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
650                   int *usockaddr_len, int peer)
651 {
652         int len = sizeof(struct sockaddr_pppox);
653         struct sockaddr_pppox sp;
654
655         sp.sa_family    = AF_PPPOX;
656         sp.sa_protocol  = PX_PROTO_OE;
657         memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
658                sizeof(struct pppoe_addr));
659
660         memcpy(uaddr, &sp, len);
661
662         *usockaddr_len = len;
663
664         return 0;
665 }
666
667
668 static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
669                 unsigned long arg)
670 {
671         struct sock *sk = sock->sk;
672         struct pppox_sock *po = pppox_sk(sk);
673         int val;
674         int err;
675
676         switch (cmd) {
677         case PPPIOCGMRU:
678                 err = -ENXIO;
679
680                 if (!(sk->sk_state & PPPOX_CONNECTED))
681                         break;
682
683                 err = -EFAULT;
684                 if (put_user(po->pppoe_dev->mtu -
685                              sizeof(struct pppoe_hdr) -
686                              PPP_HDRLEN,
687                              (int __user *) arg))
688                         break;
689                 err = 0;
690                 break;
691
692         case PPPIOCSMRU:
693                 err = -ENXIO;
694                 if (!(sk->sk_state & PPPOX_CONNECTED))
695                         break;
696
697                 err = -EFAULT;
698                 if (get_user(val,(int __user *) arg))
699                         break;
700
701                 if (val < (po->pppoe_dev->mtu
702                            - sizeof(struct pppoe_hdr)
703                            - PPP_HDRLEN))
704                         err = 0;
705                 else
706                         err = -EINVAL;
707                 break;
708
709         case PPPIOCSFLAGS:
710                 err = -EFAULT;
711                 if (get_user(val, (int __user *) arg))
712                         break;
713                 err = 0;
714                 break;
715
716         case PPPOEIOCSFWD:
717         {
718                 struct pppox_sock *relay_po;
719
720                 err = -EBUSY;
721                 if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD))
722                         break;
723
724                 err = -ENOTCONN;
725                 if (!(sk->sk_state & PPPOX_CONNECTED))
726                         break;
727
728                 /* PPPoE address from the user specifies an outbound
729                    PPPoE address which frames are forwarded to */
730                 err = -EFAULT;
731                 if (copy_from_user(&po->pppoe_relay,
732                                    (void __user *)arg,
733                                    sizeof(struct sockaddr_pppox)))
734                         break;
735
736                 err = -EINVAL;
737                 if (po->pppoe_relay.sa_family != AF_PPPOX ||
738                     po->pppoe_relay.sa_protocol!= PX_PROTO_OE)
739                         break;
740
741                 /* Check that the socket referenced by the address
742                    actually exists. */
743                 relay_po = get_item_by_addr(&po->pppoe_relay);
744
745                 if (!relay_po)
746                         break;
747
748                 sock_put(sk_pppox(relay_po));
749                 sk->sk_state |= PPPOX_RELAY;
750                 err = 0;
751                 break;
752         }
753
754         case PPPOEIOCDFWD:
755                 err = -EALREADY;
756                 if (!(sk->sk_state & PPPOX_RELAY))
757                         break;
758
759                 sk->sk_state &= ~PPPOX_RELAY;
760                 err = 0;
761                 break;
762
763         default:
764                 err = -ENOTTY;
765         }
766
767         return err;
768 }
769
770
771 static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
772                   struct msghdr *m, size_t total_len)
773 {
774         struct sk_buff *skb;
775         struct sock *sk = sock->sk;
776         struct pppox_sock *po = pppox_sk(sk);
777         int error;
778         struct pppoe_hdr hdr;
779         struct pppoe_hdr *ph;
780         struct net_device *dev;
781         char *start;
782
783         lock_sock(sk);
784         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
785                 error = -ENOTCONN;
786                 goto end;
787         }
788
789         hdr.ver = 1;
790         hdr.type = 1;
791         hdr.code = 0;
792         hdr.sid = po->num;
793
794         dev = po->pppoe_dev;
795
796         error = -EMSGSIZE;
797         if (total_len > (dev->mtu + dev->hard_header_len))
798                 goto end;
799
800
801         skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32,
802                            0, GFP_KERNEL);
803         if (!skb) {
804                 error = -ENOMEM;
805                 goto end;
806         }
807
808         /* Reserve space for headers. */
809         skb_reserve(skb, dev->hard_header_len);
810         skb_reset_network_header(skb);
811
812         skb->dev = dev;
813
814         skb->priority = sk->sk_priority;
815         skb->protocol = __constant_htons(ETH_P_PPP_SES);
816
817         ph = (struct pppoe_hdr *) skb_put(skb, total_len + sizeof(struct pppoe_hdr));
818         start = (char *) &ph->tag[0];
819
820         error = memcpy_fromiovec(start, m->msg_iov, total_len);
821
822         if (error < 0) {
823                 kfree_skb(skb);
824                 goto end;
825         }
826
827         error = total_len;
828         dev->hard_header(skb, dev, ETH_P_PPP_SES,
829                          po->pppoe_pa.remote, NULL, total_len);
830
831         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
832
833         ph->length = htons(total_len);
834
835         dev_queue_xmit(skb);
836
837 end:
838         release_sock(sk);
839         return error;
840 }
841
842
843 /************************************************************************
844  *
845  * xmit function for internal use.
846  *
847  ***********************************************************************/
848 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
849 {
850         struct pppox_sock *po = pppox_sk(sk);
851         struct net_device *dev = po->pppoe_dev;
852         struct pppoe_hdr *ph;
853         int data_len = skb->len;
854
855         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
856                 goto abort;
857
858         if (!dev)
859                 goto abort;
860
861         /* Copy the data if there is no space for the header or if it's
862          * read-only.
863          */
864         if (skb_cow_head(skb, sizeof(*ph) + dev->hard_header_len))
865                 goto abort;
866
867         __skb_push(skb, sizeof(*ph));
868         skb_reset_network_header(skb);
869
870         ph = pppoe_hdr(skb);
871         ph->ver = 1;
872         ph->type = 1;
873         ph->code = 0;
874         ph->sid = po->num;
875         ph->length = htons(data_len);
876
877         skb->protocol = __constant_htons(ETH_P_PPP_SES);
878         skb->dev = dev;
879
880         dev->hard_header(skb, dev, ETH_P_PPP_SES,
881                          po->pppoe_pa.remote, NULL, data_len);
882
883         dev_queue_xmit(skb);
884
885         return 1;
886
887 abort:
888         kfree_skb(skb);
889         return 1;
890 }
891
892
893 /************************************************************************
894  *
895  * xmit function called by generic PPP driver
896  * sends PPP frame over PPPoE socket
897  *
898  ***********************************************************************/
899 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
900 {
901         struct sock *sk = (struct sock *) chan->private;
902         return __pppoe_xmit(sk, skb);
903 }
904
905
906 static struct ppp_channel_ops pppoe_chan_ops = {
907         .start_xmit = pppoe_xmit,
908 };
909
910 static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
911                   struct msghdr *m, size_t total_len, int flags)
912 {
913         struct sock *sk = sock->sk;
914         struct sk_buff *skb;
915         int error = 0;
916
917         if (sk->sk_state & PPPOX_BOUND) {
918                 error = -EIO;
919                 goto end;
920         }
921
922         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
923                                 flags & MSG_DONTWAIT, &error);
924
925         if (error < 0)
926                 goto end;
927
928         m->msg_namelen = 0;
929
930         if (skb) {
931                 struct pppoe_hdr *ph = pppoe_hdr(skb);
932                 const int len = ntohs(ph->length);
933
934                 error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
935                 if (error == 0)
936                         error = len;
937         }
938
939         kfree_skb(skb);
940 end:
941         return error;
942 }
943
944 #ifdef CONFIG_PROC_FS
945 static int pppoe_seq_show(struct seq_file *seq, void *v)
946 {
947         struct pppox_sock *po;
948         char *dev_name;
949
950         if (v == SEQ_START_TOKEN) {
951                 seq_puts(seq, "Id       Address              Device\n");
952                 goto out;
953         }
954
955         po = v;
956         dev_name = po->pppoe_pa.dev;
957
958         seq_printf(seq, "%08X %02X:%02X:%02X:%02X:%02X:%02X %8s\n",
959                    po->pppoe_pa.sid,
960                    po->pppoe_pa.remote[0], po->pppoe_pa.remote[1],
961                    po->pppoe_pa.remote[2], po->pppoe_pa.remote[3],
962                    po->pppoe_pa.remote[4], po->pppoe_pa.remote[5], dev_name);
963 out:
964         return 0;
965 }
966
967 static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
968 {
969         struct pppox_sock *po;
970         int i = 0;
971
972         for (; i < PPPOE_HASH_SIZE; i++) {
973                 po = item_hash_table[i];
974                 while (po) {
975                         if (!pos--)
976                                 goto out;
977                         po = po->next;
978                 }
979         }
980 out:
981         return po;
982 }
983
984 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
985 {
986         loff_t l = *pos;
987
988         read_lock_bh(&pppoe_hash_lock);
989         return l ? pppoe_get_idx(--l) : SEQ_START_TOKEN;
990 }
991
992 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
993 {
994         struct pppox_sock *po;
995
996         ++*pos;
997         if (v == SEQ_START_TOKEN) {
998                 po = pppoe_get_idx(0);
999                 goto out;
1000         }
1001         po = v;
1002         if (po->next)
1003                 po = po->next;
1004         else {
1005                 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
1006
1007                 while (++hash < PPPOE_HASH_SIZE) {
1008                         po = item_hash_table[hash];
1009                         if (po)
1010                                 break;
1011                 }
1012         }
1013 out:
1014         return po;
1015 }
1016
1017 static void pppoe_seq_stop(struct seq_file *seq, void *v)
1018 {
1019         read_unlock_bh(&pppoe_hash_lock);
1020 }
1021
1022 static struct seq_operations pppoe_seq_ops = {
1023         .start          = pppoe_seq_start,
1024         .next           = pppoe_seq_next,
1025         .stop           = pppoe_seq_stop,
1026         .show           = pppoe_seq_show,
1027 };
1028
1029 static int pppoe_seq_open(struct inode *inode, struct file *file)
1030 {
1031         return seq_open(file, &pppoe_seq_ops);
1032 }
1033
1034 static const struct file_operations pppoe_seq_fops = {
1035         .owner          = THIS_MODULE,
1036         .open           = pppoe_seq_open,
1037         .read           = seq_read,
1038         .llseek         = seq_lseek,
1039         .release        = seq_release,
1040 };
1041
1042 static int __init pppoe_proc_init(void)
1043 {
1044         struct proc_dir_entry *p;
1045
1046         p = create_proc_entry("pppoe", S_IRUGO, init_net.proc_net);
1047         if (!p)
1048                 return -ENOMEM;
1049
1050         p->proc_fops = &pppoe_seq_fops;
1051         return 0;
1052 }
1053 #else /* CONFIG_PROC_FS */
1054 static inline int pppoe_proc_init(void) { return 0; }
1055 #endif /* CONFIG_PROC_FS */
1056
1057 static const struct proto_ops pppoe_ops = {
1058     .family             = AF_PPPOX,
1059     .owner              = THIS_MODULE,
1060     .release            = pppoe_release,
1061     .bind               = sock_no_bind,
1062     .connect            = pppoe_connect,
1063     .socketpair         = sock_no_socketpair,
1064     .accept             = sock_no_accept,
1065     .getname            = pppoe_getname,
1066     .poll               = datagram_poll,
1067     .listen             = sock_no_listen,
1068     .shutdown           = sock_no_shutdown,
1069     .setsockopt         = sock_no_setsockopt,
1070     .getsockopt         = sock_no_getsockopt,
1071     .sendmsg            = pppoe_sendmsg,
1072     .recvmsg            = pppoe_recvmsg,
1073     .mmap               = sock_no_mmap,
1074     .ioctl              = pppox_ioctl,
1075 };
1076
1077 static struct pppox_proto pppoe_proto = {
1078     .create     = pppoe_create,
1079     .ioctl      = pppoe_ioctl,
1080     .owner      = THIS_MODULE,
1081 };
1082
1083
1084 static int __init pppoe_init(void)
1085 {
1086         int err = proto_register(&pppoe_sk_proto, 0);
1087
1088         if (err)
1089                 goto out;
1090
1091         err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
1092         if (err)
1093                 goto out_unregister_pppoe_proto;
1094
1095         err = pppoe_proc_init();
1096         if (err)
1097                 goto out_unregister_pppox_proto;
1098
1099         dev_add_pack(&pppoes_ptype);
1100         dev_add_pack(&pppoed_ptype);
1101         register_netdevice_notifier(&pppoe_notifier);
1102 out:
1103         return err;
1104 out_unregister_pppox_proto:
1105         unregister_pppox_proto(PX_PROTO_OE);
1106 out_unregister_pppoe_proto:
1107         proto_unregister(&pppoe_sk_proto);
1108         goto out;
1109 }
1110
1111 static void __exit pppoe_exit(void)
1112 {
1113         unregister_pppox_proto(PX_PROTO_OE);
1114         dev_remove_pack(&pppoes_ptype);
1115         dev_remove_pack(&pppoed_ptype);
1116         unregister_netdevice_notifier(&pppoe_notifier);
1117         remove_proc_entry("pppoe", init_net.proc_net);
1118         proto_unregister(&pppoe_sk_proto);
1119 }
1120
1121 module_init(pppoe_init);
1122 module_exit(pppoe_exit);
1123
1124 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1125 MODULE_DESCRIPTION("PPP over Ethernet driver");
1126 MODULE_LICENSE("GPL");
1127 MODULE_ALIAS_NETPROTO(PF_PPPOX);