[PPPOE]: Missing result check in __pppoe_xmit().
[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  * 220102 :     Fix module use count on failure in pppoe_create, pppox_sk -acme
11  * 030700 :     Fixed connect logic to allow for disconnect.
12  * 270700 :     Fixed potential SMP problems; we must protect against
13  *              simultaneous invocation of ppp_input
14  *              and ppp_unregister_channel.
15  * 040800 :     Respect reference count mechanisms on net-devices.
16  * 200800 :     fix kfree(skb) in pppoe_rcv (acme)
17  *              Module reference count is decremented in the right spot now,
18  *              guards against sock_put not actually freeing the sk
19  *              in pppoe_release.
20  * 051000 :     Initialization cleanup.
21  * 111100 :     Fix recvmsg.
22  * 050101 :     Fix PADT procesing.
23  * 140501 :     Use pppoe_rcv_core to handle all backlog. (Alexey)
24  * 170701 :     Do not lock_sock with rwlock held. (DaveM)
25  *              Ignore discovery frames if user has socket
26  *              locked. (DaveM)
27  *              Ignore return value of dev_queue_xmit in __pppoe_xmit
28  *              or else we may kfree an SKB twice. (DaveM)
29  * 190701 :     When doing copies of skb's in __pppoe_xmit, always delete
30  *              the original skb that was passed in on success, never on
31  *              failure.  Delete the copy of the skb on failure to avoid
32  *              a memory leak.
33  * 081001 :     Misc. cleanup (licence string, non-blocking, prevent
34  *              reference of device on close).
35  * 121301 :     New ppp channels interface; cannot unregister a channel
36  *              from interrupts.  Thus, we mark the socket as a ZOMBIE
37  *              and do the unregistration later.
38  * 081002 :     seq_file support for proc stuff -acme
39  * 111602 :     Merge all 2.4 fixes into 2.5/2.6 tree.  Label 2.5/2.6
40  *              as version 0.7.  Spacing cleanup.
41  * Author:      Michal Ostrowski <mostrows@speakeasy.net>
42  * Contributors:
43  *              Arnaldo Carvalho de Melo <acme@conectiva.com.br>
44  *              David S. Miller (davem@redhat.com)
45  *
46  * License:
47  *              This program is free software; you can redistribute it and/or
48  *              modify it under the terms of the GNU General Public License
49  *              as published by the Free Software Foundation; either version
50  *              2 of the License, or (at your option) any later version.
51  *
52  */
53
54 #include <linux/string.h>
55 #include <linux/module.h>
56 #include <linux/kernel.h>
57 #include <linux/slab.h>
58 #include <linux/errno.h>
59 #include <linux/netdevice.h>
60 #include <linux/net.h>
61 #include <linux/inetdevice.h>
62 #include <linux/etherdevice.h>
63 #include <linux/skbuff.h>
64 #include <linux/init.h>
65 #include <linux/if_ether.h>
66 #include <linux/if_pppox.h>
67 #include <linux/ppp_channel.h>
68 #include <linux/ppp_defs.h>
69 #include <linux/if_ppp.h>
70 #include <linux/notifier.h>
71 #include <linux/file.h>
72 #include <linux/proc_fs.h>
73 #include <linux/seq_file.h>
74
75 #include <net/sock.h>
76
77 #include <asm/uaccess.h>
78
79 #define PPPOE_HASH_BITS 4
80 #define PPPOE_HASH_SIZE (1<<PPPOE_HASH_BITS)
81
82 static struct ppp_channel_ops pppoe_chan_ops;
83
84 static int pppoe_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
85 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb);
86 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
87
88 static const struct proto_ops pppoe_ops;
89 static DEFINE_RWLOCK(pppoe_hash_lock);
90
91 static struct ppp_channel_ops pppoe_chan_ops;
92
93 static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
94 {
95         return (a->sid == b->sid &&
96                 (memcmp(a->remote, b->remote, ETH_ALEN) == 0));
97 }
98
99 static inline int cmp_addr(struct pppoe_addr *a, unsigned long sid, char *addr)
100 {
101         return (a->sid == sid &&
102                 (memcmp(a->remote,addr,ETH_ALEN) == 0));
103 }
104
105 static int hash_item(unsigned long sid, unsigned char *addr)
106 {
107         char hash = 0;
108         int i, j;
109
110         for (i = 0; i < ETH_ALEN ; ++i) {
111                 for (j = 0; j < 8/PPPOE_HASH_BITS ; ++j) {
112                         hash ^= addr[i] >> ( j * PPPOE_HASH_BITS );
113                 }
114         }
115
116         for (i = 0; i < (sizeof(unsigned long)*8) / PPPOE_HASH_BITS ; ++i)
117                 hash ^= sid >> (i*PPPOE_HASH_BITS);
118
119         return hash & ( PPPOE_HASH_SIZE - 1 );
120 }
121
122 /* zeroed because its in .bss */
123 static struct pppox_sock *item_hash_table[PPPOE_HASH_SIZE];
124
125 /**********************************************************************
126  *
127  *  Set/get/delete/rehash items  (internal versions)
128  *
129  **********************************************************************/
130 static struct pppox_sock *__get_item(unsigned long sid, unsigned char *addr)
131 {
132         int hash = hash_item(sid, addr);
133         struct pppox_sock *ret;
134
135         ret = item_hash_table[hash];
136
137         while (ret && !cmp_addr(&ret->pppoe_pa, sid, addr))
138                 ret = ret->next;
139
140         return ret;
141 }
142
143 static int __set_item(struct pppox_sock *po)
144 {
145         int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
146         struct pppox_sock *ret;
147
148         ret = item_hash_table[hash];
149         while (ret) {
150                 if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa))
151                         return -EALREADY;
152
153                 ret = ret->next;
154         }
155
156         if (!ret) {
157                 po->next = item_hash_table[hash];
158                 item_hash_table[hash] = po;
159         }
160
161         return 0;
162 }
163
164 static struct pppox_sock *__delete_item(unsigned long sid, char *addr)
165 {
166         int hash = hash_item(sid, addr);
167         struct pppox_sock *ret, **src;
168
169         ret = item_hash_table[hash];
170         src = &item_hash_table[hash];
171
172         while (ret) {
173                 if (cmp_addr(&ret->pppoe_pa, sid, addr)) {
174                         *src = ret->next;
175                         break;
176                 }
177
178                 src = &ret->next;
179                 ret = ret->next;
180         }
181
182         return ret;
183 }
184
185 /**********************************************************************
186  *
187  *  Set/get/delete/rehash items
188  *
189  **********************************************************************/
190 static inline struct pppox_sock *get_item(unsigned long sid,
191                                          unsigned char *addr)
192 {
193         struct pppox_sock *po;
194
195         read_lock_bh(&pppoe_hash_lock);
196         po = __get_item(sid, addr);
197         if (po)
198                 sock_hold(sk_pppox(po));
199         read_unlock_bh(&pppoe_hash_lock);
200
201         return po;
202 }
203
204 static inline struct pppox_sock *get_item_by_addr(struct sockaddr_pppox *sp)
205 {
206         return get_item(sp->sa_addr.pppoe.sid, sp->sa_addr.pppoe.remote);
207 }
208
209 static inline int set_item(struct pppox_sock *po)
210 {
211         int i;
212
213         if (!po)
214                 return -EINVAL;
215
216         write_lock_bh(&pppoe_hash_lock);
217         i = __set_item(po);
218         write_unlock_bh(&pppoe_hash_lock);
219
220         return i;
221 }
222
223 static inline struct pppox_sock *delete_item(unsigned long sid, char *addr)
224 {
225         struct pppox_sock *ret;
226
227         write_lock_bh(&pppoe_hash_lock);
228         ret = __delete_item(sid, addr);
229         write_unlock_bh(&pppoe_hash_lock);
230
231         return ret;
232 }
233
234
235
236 /***************************************************************************
237  *
238  *  Handler for device events.
239  *  Certain device events require that sockets be unconnected.
240  *
241  **************************************************************************/
242
243 static void pppoe_flush_dev(struct net_device *dev)
244 {
245         int hash;
246
247         BUG_ON(dev == NULL);
248
249         read_lock_bh(&pppoe_hash_lock);
250         for (hash = 0; hash < PPPOE_HASH_SIZE; hash++) {
251                 struct pppox_sock *po = item_hash_table[hash];
252
253                 while (po != NULL) {
254                         if (po->pppoe_dev == dev) {
255                                 struct sock *sk = sk_pppox(po);
256
257                                 sock_hold(sk);
258                                 po->pppoe_dev = NULL;
259
260                                 /* We hold a reference to SK, now drop the
261                                  * hash table lock so that we may attempt
262                                  * to lock the socket (which can sleep).
263                                  */
264                                 read_unlock_bh(&pppoe_hash_lock);
265
266                                 lock_sock(sk);
267
268                                 if (sk->sk_state &
269                                     (PPPOX_CONNECTED | PPPOX_BOUND)) {
270                                         pppox_unbind_sock(sk);
271                                         dev_put(dev);
272                                         sk->sk_state = PPPOX_ZOMBIE;
273                                         sk->sk_state_change(sk);
274                                 }
275
276                                 release_sock(sk);
277
278                                 sock_put(sk);
279
280                                 read_lock_bh(&pppoe_hash_lock);
281
282                                 /* Now restart from the beginning of this
283                                  * hash chain.  We always NULL out pppoe_dev
284                                  * so we are guaranteed to make forward
285                                  * progress.
286                                  */
287                                 po = item_hash_table[hash];
288                                 continue;
289                         }
290                         po = po->next;
291                 }
292         }
293         read_unlock_bh(&pppoe_hash_lock);
294 }
295
296 static int pppoe_device_event(struct notifier_block *this,
297                               unsigned long event, void *ptr)
298 {
299         struct net_device *dev = (struct net_device *) ptr;
300
301         /* Only look at sockets that are using this specific device. */
302         switch (event) {
303         case NETDEV_CHANGEMTU:
304                 /* A change in mtu is a bad thing, requiring
305                  * LCP re-negotiation.
306                  */
307
308         case NETDEV_GOING_DOWN:
309         case NETDEV_DOWN:
310                 /* Find every socket on this device and kill it. */
311                 pppoe_flush_dev(dev);
312                 break;
313
314         default:
315                 break;
316         };
317
318         return NOTIFY_DONE;
319 }
320
321
322 static struct notifier_block pppoe_notifier = {
323         .notifier_call = pppoe_device_event,
324 };
325
326
327 /************************************************************************
328  *
329  * Do the real work of receiving a PPPoE Session frame.
330  *
331  ***********************************************************************/
332 static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb)
333 {
334         struct pppox_sock *po = pppox_sk(sk);
335         struct pppox_sock *relay_po = NULL;
336
337         if (sk->sk_state & PPPOX_BOUND) {
338                 struct pppoe_hdr *ph = (struct pppoe_hdr *) skb->nh.raw;
339                 int len = ntohs(ph->length);
340                 skb_pull_rcsum(skb, sizeof(struct pppoe_hdr));
341                 if (pskb_trim_rcsum(skb, len))
342                         goto abort_kfree;
343
344                 ppp_input(&po->chan, skb);
345         } else if (sk->sk_state & PPPOX_RELAY) {
346                 relay_po = get_item_by_addr(&po->pppoe_relay);
347
348                 if (relay_po == NULL)
349                         goto abort_kfree;
350
351                 if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0)
352                         goto abort_put;
353
354                 skb_pull(skb, sizeof(struct pppoe_hdr));
355                 if (!__pppoe_xmit(sk_pppox(relay_po), skb))
356                         goto abort_put;
357         } else {
358                 if (sock_queue_rcv_skb(sk, skb))
359                         goto abort_kfree;
360         }
361
362         return NET_RX_SUCCESS;
363
364 abort_put:
365         sock_put(sk_pppox(relay_po));
366
367 abort_kfree:
368         kfree_skb(skb);
369         return NET_RX_DROP;
370 }
371
372 /************************************************************************
373  *
374  * Receive wrapper called in BH context.
375  *
376  ***********************************************************************/
377 static int pppoe_rcv(struct sk_buff *skb,
378                      struct net_device *dev,
379                      struct packet_type *pt,
380                      struct net_device *orig_dev)
381
382 {
383         struct pppoe_hdr *ph;
384         struct pppox_sock *po;
385
386         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
387                 goto drop;
388
389         if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
390                 goto out;
391
392         ph = (struct pppoe_hdr *) skb->nh.raw;
393
394         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source);
395         if (po != NULL) 
396                 return sk_receive_skb(sk_pppox(po), skb);
397 drop:
398         kfree_skb(skb);
399 out:
400         return NET_RX_DROP;
401 }
402
403 /************************************************************************
404  *
405  * Receive a PPPoE Discovery frame.
406  * This is solely for detection of PADT frames
407  *
408  ***********************************************************************/
409 static int pppoe_disc_rcv(struct sk_buff *skb,
410                           struct net_device *dev,
411                           struct packet_type *pt,
412                           struct net_device *orig_dev)
413
414 {
415         struct pppoe_hdr *ph;
416         struct pppox_sock *po;
417
418         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
419                 goto abort;
420
421         if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
422                 goto out;
423
424         ph = (struct pppoe_hdr *) skb->nh.raw;
425         if (ph->code != PADT_CODE)
426                 goto abort;
427
428         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source);
429         if (po) {
430                 struct sock *sk = sk_pppox(po);
431
432                 bh_lock_sock(sk);
433
434                 /* If the user has locked the socket, just ignore
435                  * the packet.  With the way two rcv protocols hook into
436                  * one socket family type, we cannot (easily) distinguish
437                  * what kind of SKB it is during backlog rcv.
438                  */
439                 if (sock_owned_by_user(sk) == 0) {
440                         /* We're no longer connect at the PPPOE layer,
441                          * and must wait for ppp channel to disconnect us.
442                          */
443                         sk->sk_state = PPPOX_ZOMBIE;
444                 }
445
446                 bh_unlock_sock(sk);
447                 sock_put(sk);
448         }
449
450 abort:
451         kfree_skb(skb);
452 out:
453         return NET_RX_SUCCESS; /* Lies... :-) */
454 }
455
456 static struct packet_type pppoes_ptype = {
457         .type   = __constant_htons(ETH_P_PPP_SES),
458         .func   = pppoe_rcv,
459 };
460
461 static struct packet_type pppoed_ptype = {
462         .type   = __constant_htons(ETH_P_PPP_DISC),
463         .func   = pppoe_disc_rcv,
464 };
465
466 static struct proto pppoe_sk_proto = {
467         .name     = "PPPOE",
468         .owner    = THIS_MODULE,
469         .obj_size = sizeof(struct pppox_sock),
470 };
471
472 /***********************************************************************
473  *
474  * Initialize a new struct sock.
475  *
476  **********************************************************************/
477 static int pppoe_create(struct socket *sock)
478 {
479         int error = -ENOMEM;
480         struct sock *sk;
481
482         sk = sk_alloc(PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, 1);
483         if (!sk)
484                 goto out;
485
486         sock_init_data(sock, sk);
487
488         sock->state = SS_UNCONNECTED;
489         sock->ops   = &pppoe_ops;
490
491         sk->sk_backlog_rcv = pppoe_rcv_core;
492         sk->sk_state       = PPPOX_NONE;
493         sk->sk_type        = SOCK_STREAM;
494         sk->sk_family      = PF_PPPOX;
495         sk->sk_protocol    = PX_PROTO_OE;
496
497         error = 0;
498 out:    return error;
499 }
500
501 static int pppoe_release(struct socket *sock)
502 {
503         struct sock *sk = sock->sk;
504         struct pppox_sock *po;
505         int error = 0;
506
507         if (!sk)
508                 return 0;
509
510         if (sock_flag(sk, SOCK_DEAD))
511                 return -EBADF;
512
513         pppox_unbind_sock(sk);
514
515         /* Signal the death of the socket. */
516         sk->sk_state = PPPOX_DEAD;
517
518         po = pppox_sk(sk);
519         if (po->pppoe_pa.sid) {
520                 delete_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
521         }
522
523         if (po->pppoe_dev)
524                 dev_put(po->pppoe_dev);
525
526         po->pppoe_dev = NULL;
527
528         sock_orphan(sk);
529         sock->sk = NULL;
530
531         skb_queue_purge(&sk->sk_receive_queue);
532         sock_put(sk);
533
534         return error;
535 }
536
537
538 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
539                   int sockaddr_len, int flags)
540 {
541         struct sock *sk = sock->sk;
542         struct net_device *dev = NULL;
543         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
544         struct pppox_sock *po = pppox_sk(sk);
545         int error;
546
547         lock_sock(sk);
548
549         error = -EINVAL;
550         if (sp->sa_protocol != PX_PROTO_OE)
551                 goto end;
552
553         /* Check for already bound sockets */
554         error = -EBUSY;
555         if ((sk->sk_state & PPPOX_CONNECTED) && sp->sa_addr.pppoe.sid)
556                 goto end;
557
558         /* Check for already disconnected sockets, on attempts to disconnect */
559         error = -EALREADY;
560         if ((sk->sk_state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
561                 goto end;
562
563         error = 0;
564         if (po->pppoe_pa.sid) {
565                 pppox_unbind_sock(sk);
566
567                 /* Delete the old binding */
568                 delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote);
569
570                 if(po->pppoe_dev)
571                         dev_put(po->pppoe_dev);
572
573                 memset(sk_pppox(po) + 1, 0,
574                        sizeof(struct pppox_sock) - sizeof(struct sock));
575
576                 sk->sk_state = PPPOX_NONE;
577         }
578
579         /* Don't re-bind if sid==0 */
580         if (sp->sa_addr.pppoe.sid != 0) {
581                 dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
582
583                 error = -ENODEV;
584                 if (!dev)
585                         goto end;
586
587                 po->pppoe_dev = dev;
588
589                 if (!(dev->flags & IFF_UP))
590                         goto err_put;
591
592                 memcpy(&po->pppoe_pa,
593                        &sp->sa_addr.pppoe,
594                        sizeof(struct pppoe_addr));
595
596                 error = set_item(po);
597                 if (error < 0)
598                         goto err_put;
599
600                 po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
601                                    dev->hard_header_len);
602
603                 po->chan.private = sk;
604                 po->chan.ops = &pppoe_chan_ops;
605
606                 error = ppp_register_channel(&po->chan);
607                 if (error)
608                         goto err_put;
609
610                 sk->sk_state = PPPOX_CONNECTED;
611         }
612
613         po->num = sp->sa_addr.pppoe.sid;
614
615  end:
616         release_sock(sk);
617         return error;
618 err_put:
619         if (po->pppoe_dev) {
620                 dev_put(po->pppoe_dev);
621                 po->pppoe_dev = NULL;
622         }
623         goto end;
624 }
625
626
627 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
628                   int *usockaddr_len, int peer)
629 {
630         int len = sizeof(struct sockaddr_pppox);
631         struct sockaddr_pppox sp;
632
633         sp.sa_family    = AF_PPPOX;
634         sp.sa_protocol  = PX_PROTO_OE;
635         memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
636                sizeof(struct pppoe_addr));
637
638         memcpy(uaddr, &sp, len);
639
640         *usockaddr_len = len;
641
642         return 0;
643 }
644
645
646 static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
647                 unsigned long arg)
648 {
649         struct sock *sk = sock->sk;
650         struct pppox_sock *po = pppox_sk(sk);
651         int val = 0;
652         int err = 0;
653
654         switch (cmd) {
655         case PPPIOCGMRU:
656                 err = -ENXIO;
657
658                 if (!(sk->sk_state & PPPOX_CONNECTED))
659                         break;
660
661                 err = -EFAULT;
662                 if (put_user(po->pppoe_dev->mtu -
663                              sizeof(struct pppoe_hdr) -
664                              PPP_HDRLEN,
665                              (int __user *) arg))
666                         break;
667                 err = 0;
668                 break;
669
670         case PPPIOCSMRU:
671                 err = -ENXIO;
672                 if (!(sk->sk_state & PPPOX_CONNECTED))
673                         break;
674
675                 err = -EFAULT;
676                 if (get_user(val,(int __user *) arg))
677                         break;
678
679                 if (val < (po->pppoe_dev->mtu
680                            - sizeof(struct pppoe_hdr)
681                            - PPP_HDRLEN))
682                         err = 0;
683                 else
684                         err = -EINVAL;
685                 break;
686
687         case PPPIOCSFLAGS:
688                 err = -EFAULT;
689                 if (get_user(val, (int __user *) arg))
690                         break;
691                 err = 0;
692                 break;
693
694         case PPPOEIOCSFWD:
695         {
696                 struct pppox_sock *relay_po;
697
698                 err = -EBUSY;
699                 if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD))
700                         break;
701
702                 err = -ENOTCONN;
703                 if (!(sk->sk_state & PPPOX_CONNECTED))
704                         break;
705
706                 /* PPPoE address from the user specifies an outbound
707                    PPPoE address to which frames are forwarded to */
708                 err = -EFAULT;
709                 if (copy_from_user(&po->pppoe_relay,
710                                    (void __user *)arg,
711                                    sizeof(struct sockaddr_pppox)))
712                         break;
713
714                 err = -EINVAL;
715                 if (po->pppoe_relay.sa_family != AF_PPPOX ||
716                     po->pppoe_relay.sa_protocol!= PX_PROTO_OE)
717                         break;
718
719                 /* Check that the socket referenced by the address
720                    actually exists. */
721                 relay_po = get_item_by_addr(&po->pppoe_relay);
722
723                 if (!relay_po)
724                         break;
725
726                 sock_put(sk_pppox(relay_po));
727                 sk->sk_state |= PPPOX_RELAY;
728                 err = 0;
729                 break;
730         }
731
732         case PPPOEIOCDFWD:
733                 err = -EALREADY;
734                 if (!(sk->sk_state & PPPOX_RELAY))
735                         break;
736
737                 sk->sk_state &= ~PPPOX_RELAY;
738                 err = 0;
739                 break;
740
741         default:;
742         };
743
744         return err;
745 }
746
747
748 static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock, 
749                   struct msghdr *m, size_t total_len)
750 {
751         struct sk_buff *skb = NULL;
752         struct sock *sk = sock->sk;
753         struct pppox_sock *po = pppox_sk(sk);
754         int error = 0;
755         struct pppoe_hdr hdr;
756         struct pppoe_hdr *ph;
757         struct net_device *dev;
758         char *start;
759
760         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
761                 error = -ENOTCONN;
762                 goto end;
763         }
764
765         hdr.ver = 1;
766         hdr.type = 1;
767         hdr.code = 0;
768         hdr.sid = po->num;
769
770         lock_sock(sk);
771
772         dev = po->pppoe_dev;
773
774         error = -EMSGSIZE;
775         if (total_len > (dev->mtu + dev->hard_header_len))
776                 goto end;
777
778
779         skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32,
780                            0, GFP_KERNEL);
781         if (!skb) {
782                 error = -ENOMEM;
783                 goto end;
784         }
785
786         /* Reserve space for headers. */
787         skb_reserve(skb, dev->hard_header_len);
788         skb->nh.raw = skb->data;
789
790         skb->dev = dev;
791
792         skb->priority = sk->sk_priority;
793         skb->protocol = __constant_htons(ETH_P_PPP_SES);
794
795         ph = (struct pppoe_hdr *) skb_put(skb, total_len + sizeof(struct pppoe_hdr));
796         start = (char *) &ph->tag[0];
797
798         error = memcpy_fromiovec(start, m->msg_iov, total_len);
799
800         if (error < 0) {
801                 kfree_skb(skb);
802                 goto end;
803         }
804
805         error = total_len;
806         dev->hard_header(skb, dev, ETH_P_PPP_SES,
807                          po->pppoe_pa.remote, NULL, total_len);
808
809         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
810
811         ph->length = htons(total_len);
812
813         dev_queue_xmit(skb);
814
815 end:
816         release_sock(sk);
817         return error;
818 }
819
820
821 /************************************************************************
822  *
823  * xmit function for internal use.
824  *
825  ***********************************************************************/
826 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
827 {
828         struct pppox_sock *po = pppox_sk(sk);
829         struct net_device *dev = po->pppoe_dev;
830         struct pppoe_hdr hdr;
831         struct pppoe_hdr *ph;
832         int headroom = skb_headroom(skb);
833         int data_len = skb->len;
834         struct sk_buff *skb2;
835
836         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
837                 goto abort;
838
839         hdr.ver = 1;
840         hdr.type = 1;
841         hdr.code = 0;
842         hdr.sid = po->num;
843         hdr.length = htons(skb->len);
844
845         if (!dev)
846                 goto abort;
847
848         /* Copy the skb if there is no space for the header. */
849         if (headroom < (sizeof(struct pppoe_hdr) + dev->hard_header_len)) {
850                 skb2 = dev_alloc_skb(32+skb->len +
851                                      sizeof(struct pppoe_hdr) +
852                                      dev->hard_header_len);
853
854                 if (skb2 == NULL)
855                         goto abort;
856
857                 skb_reserve(skb2, dev->hard_header_len + sizeof(struct pppoe_hdr));
858                 memcpy(skb_put(skb2, skb->len), skb->data, skb->len);
859         } else {
860                 /* Make a clone so as to not disturb the original skb,
861                  * give dev_queue_xmit something it can free.
862                  */
863                 skb2 = skb_clone(skb, GFP_ATOMIC);
864
865                 if (skb2 == NULL)
866                         goto abort;
867         }
868
869         ph = (struct pppoe_hdr *) skb_push(skb2, sizeof(struct pppoe_hdr));
870         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
871         skb2->protocol = __constant_htons(ETH_P_PPP_SES);
872
873         skb2->nh.raw = skb2->data;
874
875         skb2->dev = dev;
876
877         dev->hard_header(skb2, dev, ETH_P_PPP_SES,
878                          po->pppoe_pa.remote, NULL, data_len);
879
880         /* We're transmitting skb2, and assuming that dev_queue_xmit
881          * will free it.  The generic ppp layer however, is expecting
882          * that we give back 'skb' (not 'skb2') in case of failure,
883          * but free it in case of success.
884          */
885
886         if (dev_queue_xmit(skb2) < 0)
887                 goto abort;
888
889         kfree_skb(skb);
890         return 1;
891
892 abort:
893         return 0;
894 }
895
896
897 /************************************************************************
898  *
899  * xmit function called by generic PPP driver
900  * sends PPP frame over PPPoE socket
901  *
902  ***********************************************************************/
903 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
904 {
905         struct sock *sk = (struct sock *) chan->private;
906         return __pppoe_xmit(sk, skb);
907 }
908
909
910 static struct ppp_channel_ops pppoe_chan_ops = { 
911         .start_xmit = pppoe_xmit, 
912 };
913
914 static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
915                   struct msghdr *m, size_t total_len, int flags)
916 {
917         struct sock *sk = sock->sk;
918         struct sk_buff *skb = NULL;
919         int error = 0;
920         int len;
921         struct pppoe_hdr *ph = NULL;
922
923         if (sk->sk_state & PPPOX_BOUND) {
924                 error = -EIO;
925                 goto end;
926         }
927
928         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
929                                 flags & MSG_DONTWAIT, &error);
930
931         if (error < 0) {
932                 goto end;
933         }
934
935         m->msg_namelen = 0;
936
937         if (skb) {
938                 error = 0;
939                 ph = (struct pppoe_hdr *) skb->nh.raw;
940                 len = ntohs(ph->length);
941
942                 error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
943                 if (error < 0)
944                         goto do_skb_free;
945                 error = len;
946         }
947
948 do_skb_free:
949         if (skb)
950                 kfree_skb(skb);
951 end:
952         return error;
953 }
954
955 #ifdef CONFIG_PROC_FS
956 static int pppoe_seq_show(struct seq_file *seq, void *v)
957 {
958         struct pppox_sock *po;
959         char *dev_name;
960
961         if (v == SEQ_START_TOKEN) {
962                 seq_puts(seq, "Id       Address              Device\n");
963                 goto out;
964         }
965
966         po = v;
967         dev_name = po->pppoe_pa.dev;
968
969         seq_printf(seq, "%08X %02X:%02X:%02X:%02X:%02X:%02X %8s\n",
970                    po->pppoe_pa.sid,
971                    po->pppoe_pa.remote[0], po->pppoe_pa.remote[1],
972                    po->pppoe_pa.remote[2], po->pppoe_pa.remote[3],
973                    po->pppoe_pa.remote[4], po->pppoe_pa.remote[5], dev_name);
974 out:
975         return 0;
976 }
977
978 static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
979 {
980         struct pppox_sock *po = NULL;
981         int i = 0;
982
983         for (; i < PPPOE_HASH_SIZE; i++) {
984                 po = item_hash_table[i];
985                 while (po) {
986                         if (!pos--)
987                                 goto out;
988                         po = po->next;
989                 }
990         }
991 out:
992         return po;
993 }
994
995 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
996 {
997         loff_t l = *pos;
998
999         read_lock_bh(&pppoe_hash_lock);
1000         return l ? pppoe_get_idx(--l) : SEQ_START_TOKEN;
1001 }
1002
1003 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1004 {
1005         struct pppox_sock *po;
1006
1007         ++*pos;
1008         if (v == SEQ_START_TOKEN) {
1009                 po = pppoe_get_idx(0);
1010                 goto out;
1011         }
1012         po = v;
1013         if (po->next) 
1014                 po = po->next;
1015         else {
1016                 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
1017
1018                 while (++hash < PPPOE_HASH_SIZE) {
1019                         po = item_hash_table[hash];
1020                         if (po)
1021                                 break;
1022                 }
1023         }
1024 out:
1025         return po;
1026 }
1027
1028 static void pppoe_seq_stop(struct seq_file *seq, void *v)
1029 {
1030         read_unlock_bh(&pppoe_hash_lock);
1031 }
1032
1033 static struct seq_operations pppoe_seq_ops = {
1034         .start          = pppoe_seq_start,
1035         .next           = pppoe_seq_next,
1036         .stop           = pppoe_seq_stop,
1037         .show           = pppoe_seq_show,
1038 };
1039
1040 static int pppoe_seq_open(struct inode *inode, struct file *file)
1041 {
1042         return seq_open(file, &pppoe_seq_ops);
1043 }
1044
1045 static struct file_operations pppoe_seq_fops = {
1046         .owner          = THIS_MODULE,
1047         .open           = pppoe_seq_open,
1048         .read           = seq_read,
1049         .llseek         = seq_lseek,
1050         .release        = seq_release,
1051 };
1052
1053 static int __init pppoe_proc_init(void)
1054 {
1055         struct proc_dir_entry *p;
1056
1057         p = create_proc_entry("net/pppoe", S_IRUGO, NULL);
1058         if (!p)
1059                 return -ENOMEM;
1060
1061         p->proc_fops = &pppoe_seq_fops;
1062         return 0;
1063 }
1064 #else /* CONFIG_PROC_FS */
1065 static inline int pppoe_proc_init(void) { return 0; }
1066 #endif /* CONFIG_PROC_FS */
1067
1068 static const struct proto_ops pppoe_ops = {
1069     .family             = AF_PPPOX,
1070     .owner              = THIS_MODULE,
1071     .release            = pppoe_release,
1072     .bind               = sock_no_bind,
1073     .connect            = pppoe_connect,
1074     .socketpair         = sock_no_socketpair,
1075     .accept             = sock_no_accept,
1076     .getname            = pppoe_getname,
1077     .poll               = datagram_poll,
1078     .listen             = sock_no_listen,
1079     .shutdown           = sock_no_shutdown,
1080     .setsockopt         = sock_no_setsockopt,
1081     .getsockopt         = sock_no_getsockopt,
1082     .sendmsg            = pppoe_sendmsg,
1083     .recvmsg            = pppoe_recvmsg,
1084     .mmap               = sock_no_mmap,
1085     .ioctl              = pppox_ioctl,
1086 };
1087
1088 static struct pppox_proto pppoe_proto = {
1089     .create     = pppoe_create,
1090     .ioctl      = pppoe_ioctl,
1091     .owner      = THIS_MODULE,
1092 };
1093
1094
1095 static int __init pppoe_init(void)
1096 {
1097         int err = proto_register(&pppoe_sk_proto, 0);
1098
1099         if (err)
1100                 goto out;
1101
1102         err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
1103         if (err)
1104                 goto out_unregister_pppoe_proto;
1105
1106         err = pppoe_proc_init();
1107         if (err)
1108                 goto out_unregister_pppox_proto;
1109         
1110         dev_add_pack(&pppoes_ptype);
1111         dev_add_pack(&pppoed_ptype);
1112         register_netdevice_notifier(&pppoe_notifier);
1113 out:
1114         return err;
1115 out_unregister_pppox_proto:
1116         unregister_pppox_proto(PX_PROTO_OE);
1117 out_unregister_pppoe_proto:
1118         proto_unregister(&pppoe_sk_proto);
1119         goto out;
1120 }
1121
1122 static void __exit pppoe_exit(void)
1123 {
1124         unregister_pppox_proto(PX_PROTO_OE);
1125         dev_remove_pack(&pppoes_ptype);
1126         dev_remove_pack(&pppoed_ptype);
1127         unregister_netdevice_notifier(&pppoe_notifier);
1128         remove_proc_entry("net/pppoe", NULL);
1129         proto_unregister(&pppoe_sk_proto);
1130 }
1131
1132 module_init(pppoe_init);
1133 module_exit(pppoe_exit);
1134
1135 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1136 MODULE_DESCRIPTION("PPP over Ethernet driver");
1137 MODULE_LICENSE("GPL");
1138 MODULE_ALIAS_NETPROTO(PF_PPPOX);