[PPPOX]: Fix assignment into const proto_ops.
[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(skb, sizeof(struct pppoe_hdr));
341                 skb_postpull_rcsum(skb, ph, sizeof(*ph));
342                 if (pskb_trim_rcsum(skb, len))
343                         goto abort_kfree;
344
345                 ppp_input(&po->chan, skb);
346         } else if (sk->sk_state & PPPOX_RELAY) {
347                 relay_po = get_item_by_addr(&po->pppoe_relay);
348
349                 if (relay_po == NULL)
350                         goto abort_kfree;
351
352                 if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0)
353                         goto abort_put;
354
355                 skb_pull(skb, sizeof(struct pppoe_hdr));
356                 if (!__pppoe_xmit(sk_pppox(relay_po), skb))
357                         goto abort_put;
358         } else {
359                 if (sock_queue_rcv_skb(sk, skb))
360                         goto abort_kfree;
361         }
362
363         return NET_RX_SUCCESS;
364
365 abort_put:
366         sock_put(sk_pppox(relay_po));
367
368 abort_kfree:
369         kfree_skb(skb);
370         return NET_RX_DROP;
371 }
372
373 /************************************************************************
374  *
375  * Receive wrapper called in BH context.
376  *
377  ***********************************************************************/
378 static int pppoe_rcv(struct sk_buff *skb,
379                      struct net_device *dev,
380                      struct packet_type *pt,
381                      struct net_device *orig_dev)
382
383 {
384         struct pppoe_hdr *ph;
385         struct pppox_sock *po;
386
387         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
388                 goto drop;
389
390         if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
391                 goto out;
392
393         ph = (struct pppoe_hdr *) skb->nh.raw;
394
395         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source);
396         if (po != NULL) 
397                 return sk_receive_skb(sk_pppox(po), skb);
398 drop:
399         kfree_skb(skb);
400 out:
401         return NET_RX_DROP;
402 }
403
404 /************************************************************************
405  *
406  * Receive a PPPoE Discovery frame.
407  * This is solely for detection of PADT frames
408  *
409  ***********************************************************************/
410 static int pppoe_disc_rcv(struct sk_buff *skb,
411                           struct net_device *dev,
412                           struct packet_type *pt,
413                           struct net_device *orig_dev)
414
415 {
416         struct pppoe_hdr *ph;
417         struct pppox_sock *po;
418
419         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
420                 goto abort;
421
422         if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
423                 goto out;
424
425         ph = (struct pppoe_hdr *) skb->nh.raw;
426         if (ph->code != PADT_CODE)
427                 goto abort;
428
429         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source);
430         if (po) {
431                 struct sock *sk = sk_pppox(po);
432
433                 bh_lock_sock(sk);
434
435                 /* If the user has locked the socket, just ignore
436                  * the packet.  With the way two rcv protocols hook into
437                  * one socket family type, we cannot (easily) distinguish
438                  * what kind of SKB it is during backlog rcv.
439                  */
440                 if (sock_owned_by_user(sk) == 0) {
441                         /* We're no longer connect at the PPPOE layer,
442                          * and must wait for ppp channel to disconnect us.
443                          */
444                         sk->sk_state = PPPOX_ZOMBIE;
445                 }
446
447                 bh_unlock_sock(sk);
448                 sock_put(sk);
449         }
450
451 abort:
452         kfree_skb(skb);
453 out:
454         return NET_RX_SUCCESS; /* Lies... :-) */
455 }
456
457 static struct packet_type pppoes_ptype = {
458         .type   = __constant_htons(ETH_P_PPP_SES),
459         .func   = pppoe_rcv,
460 };
461
462 static struct packet_type pppoed_ptype = {
463         .type   = __constant_htons(ETH_P_PPP_DISC),
464         .func   = pppoe_disc_rcv,
465 };
466
467 static struct proto pppoe_sk_proto = {
468         .name     = "PPPOE",
469         .owner    = THIS_MODULE,
470         .obj_size = sizeof(struct pppox_sock),
471 };
472
473 /***********************************************************************
474  *
475  * Initialize a new struct sock.
476  *
477  **********************************************************************/
478 static int pppoe_create(struct socket *sock)
479 {
480         int error = -ENOMEM;
481         struct sock *sk;
482
483         sk = sk_alloc(PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, 1);
484         if (!sk)
485                 goto out;
486
487         sock_init_data(sock, sk);
488
489         sock->state = SS_UNCONNECTED;
490         sock->ops   = &pppoe_ops;
491
492         sk->sk_backlog_rcv = pppoe_rcv_core;
493         sk->sk_state       = PPPOX_NONE;
494         sk->sk_type        = SOCK_STREAM;
495         sk->sk_family      = PF_PPPOX;
496         sk->sk_protocol    = PX_PROTO_OE;
497
498         error = 0;
499 out:    return error;
500 }
501
502 static int pppoe_release(struct socket *sock)
503 {
504         struct sock *sk = sock->sk;
505         struct pppox_sock *po;
506         int error = 0;
507
508         if (!sk)
509                 return 0;
510
511         if (sock_flag(sk, SOCK_DEAD))
512                 return -EBADF;
513
514         pppox_unbind_sock(sk);
515
516         /* Signal the death of the socket. */
517         sk->sk_state = PPPOX_DEAD;
518
519         po = pppox_sk(sk);
520         if (po->pppoe_pa.sid) {
521                 delete_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
522         }
523
524         if (po->pppoe_dev)
525                 dev_put(po->pppoe_dev);
526
527         po->pppoe_dev = NULL;
528
529         sock_orphan(sk);
530         sock->sk = NULL;
531
532         skb_queue_purge(&sk->sk_receive_queue);
533         sock_put(sk);
534
535         return error;
536 }
537
538
539 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
540                   int sockaddr_len, int flags)
541 {
542         struct sock *sk = sock->sk;
543         struct net_device *dev = NULL;
544         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
545         struct pppox_sock *po = pppox_sk(sk);
546         int error;
547
548         lock_sock(sk);
549
550         error = -EINVAL;
551         if (sp->sa_protocol != PX_PROTO_OE)
552                 goto end;
553
554         /* Check for already bound sockets */
555         error = -EBUSY;
556         if ((sk->sk_state & PPPOX_CONNECTED) && sp->sa_addr.pppoe.sid)
557                 goto end;
558
559         /* Check for already disconnected sockets, on attempts to disconnect */
560         error = -EALREADY;
561         if ((sk->sk_state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
562                 goto end;
563
564         error = 0;
565         if (po->pppoe_pa.sid) {
566                 pppox_unbind_sock(sk);
567
568                 /* Delete the old binding */
569                 delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote);
570
571                 if(po->pppoe_dev)
572                         dev_put(po->pppoe_dev);
573
574                 memset(sk_pppox(po) + 1, 0,
575                        sizeof(struct pppox_sock) - sizeof(struct sock));
576
577                 sk->sk_state = PPPOX_NONE;
578         }
579
580         /* Don't re-bind if sid==0 */
581         if (sp->sa_addr.pppoe.sid != 0) {
582                 dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
583
584                 error = -ENODEV;
585                 if (!dev)
586                         goto end;
587
588                 po->pppoe_dev = dev;
589
590                 if (!(dev->flags & IFF_UP))
591                         goto err_put;
592
593                 memcpy(&po->pppoe_pa,
594                        &sp->sa_addr.pppoe,
595                        sizeof(struct pppoe_addr));
596
597                 error = set_item(po);
598                 if (error < 0)
599                         goto err_put;
600
601                 po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
602                                    dev->hard_header_len);
603
604                 po->chan.private = sk;
605                 po->chan.ops = &pppoe_chan_ops;
606
607                 error = ppp_register_channel(&po->chan);
608                 if (error)
609                         goto err_put;
610
611                 sk->sk_state = PPPOX_CONNECTED;
612         }
613
614         po->num = sp->sa_addr.pppoe.sid;
615
616  end:
617         release_sock(sk);
618         return error;
619 err_put:
620         if (po->pppoe_dev) {
621                 dev_put(po->pppoe_dev);
622                 po->pppoe_dev = NULL;
623         }
624         goto end;
625 }
626
627
628 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
629                   int *usockaddr_len, int peer)
630 {
631         int len = sizeof(struct sockaddr_pppox);
632         struct sockaddr_pppox sp;
633
634         sp.sa_family    = AF_PPPOX;
635         sp.sa_protocol  = PX_PROTO_OE;
636         memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
637                sizeof(struct pppoe_addr));
638
639         memcpy(uaddr, &sp, len);
640
641         *usockaddr_len = len;
642
643         return 0;
644 }
645
646
647 static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
648                 unsigned long arg)
649 {
650         struct sock *sk = sock->sk;
651         struct pppox_sock *po = pppox_sk(sk);
652         int val = 0;
653         int err = 0;
654
655         switch (cmd) {
656         case PPPIOCGMRU:
657                 err = -ENXIO;
658
659                 if (!(sk->sk_state & PPPOX_CONNECTED))
660                         break;
661
662                 err = -EFAULT;
663                 if (put_user(po->pppoe_dev->mtu -
664                              sizeof(struct pppoe_hdr) -
665                              PPP_HDRLEN,
666                              (int __user *) arg))
667                         break;
668                 err = 0;
669                 break;
670
671         case PPPIOCSMRU:
672                 err = -ENXIO;
673                 if (!(sk->sk_state & PPPOX_CONNECTED))
674                         break;
675
676                 err = -EFAULT;
677                 if (get_user(val,(int __user *) arg))
678                         break;
679
680                 if (val < (po->pppoe_dev->mtu
681                            - sizeof(struct pppoe_hdr)
682                            - PPP_HDRLEN))
683                         err = 0;
684                 else
685                         err = -EINVAL;
686                 break;
687
688         case PPPIOCSFLAGS:
689                 err = -EFAULT;
690                 if (get_user(val, (int __user *) arg))
691                         break;
692                 err = 0;
693                 break;
694
695         case PPPOEIOCSFWD:
696         {
697                 struct pppox_sock *relay_po;
698
699                 err = -EBUSY;
700                 if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD))
701                         break;
702
703                 err = -ENOTCONN;
704                 if (!(sk->sk_state & PPPOX_CONNECTED))
705                         break;
706
707                 /* PPPoE address from the user specifies an outbound
708                    PPPoE address to which frames are forwarded to */
709                 err = -EFAULT;
710                 if (copy_from_user(&po->pppoe_relay,
711                                    (void __user *)arg,
712                                    sizeof(struct sockaddr_pppox)))
713                         break;
714
715                 err = -EINVAL;
716                 if (po->pppoe_relay.sa_family != AF_PPPOX ||
717                     po->pppoe_relay.sa_protocol!= PX_PROTO_OE)
718                         break;
719
720                 /* Check that the socket referenced by the address
721                    actually exists. */
722                 relay_po = get_item_by_addr(&po->pppoe_relay);
723
724                 if (!relay_po)
725                         break;
726
727                 sock_put(sk_pppox(relay_po));
728                 sk->sk_state |= PPPOX_RELAY;
729                 err = 0;
730                 break;
731         }
732
733         case PPPOEIOCDFWD:
734                 err = -EALREADY;
735                 if (!(sk->sk_state & PPPOX_RELAY))
736                         break;
737
738                 sk->sk_state &= ~PPPOX_RELAY;
739                 err = 0;
740                 break;
741
742         default:;
743         };
744
745         return err;
746 }
747
748
749 static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock, 
750                   struct msghdr *m, size_t total_len)
751 {
752         struct sk_buff *skb = NULL;
753         struct sock *sk = sock->sk;
754         struct pppox_sock *po = pppox_sk(sk);
755         int error = 0;
756         struct pppoe_hdr hdr;
757         struct pppoe_hdr *ph;
758         struct net_device *dev;
759         char *start;
760
761         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
762                 error = -ENOTCONN;
763                 goto end;
764         }
765
766         hdr.ver = 1;
767         hdr.type = 1;
768         hdr.code = 0;
769         hdr.sid = po->num;
770
771         lock_sock(sk);
772
773         dev = po->pppoe_dev;
774
775         error = -EMSGSIZE;
776         if (total_len > (dev->mtu + dev->hard_header_len))
777                 goto end;
778
779
780         skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32,
781                            0, GFP_KERNEL);
782         if (!skb) {
783                 error = -ENOMEM;
784                 goto end;
785         }
786
787         /* Reserve space for headers. */
788         skb_reserve(skb, dev->hard_header_len);
789         skb->nh.raw = skb->data;
790
791         skb->dev = dev;
792
793         skb->priority = sk->sk_priority;
794         skb->protocol = __constant_htons(ETH_P_PPP_SES);
795
796         ph = (struct pppoe_hdr *) skb_put(skb, total_len + sizeof(struct pppoe_hdr));
797         start = (char *) &ph->tag[0];
798
799         error = memcpy_fromiovec(start, m->msg_iov, total_len);
800
801         if (error < 0) {
802                 kfree_skb(skb);
803                 goto end;
804         }
805
806         error = total_len;
807         dev->hard_header(skb, dev, ETH_P_PPP_SES,
808                          po->pppoe_pa.remote, NULL, total_len);
809
810         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
811
812         ph->length = htons(total_len);
813
814         dev_queue_xmit(skb);
815
816 end:
817         release_sock(sk);
818         return error;
819 }
820
821
822 /************************************************************************
823  *
824  * xmit function for internal use.
825  *
826  ***********************************************************************/
827 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
828 {
829         struct pppox_sock *po = pppox_sk(sk);
830         struct net_device *dev = po->pppoe_dev;
831         struct pppoe_hdr hdr;
832         struct pppoe_hdr *ph;
833         int headroom = skb_headroom(skb);
834         int data_len = skb->len;
835         struct sk_buff *skb2;
836
837         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
838                 goto abort;
839
840         hdr.ver = 1;
841         hdr.type = 1;
842         hdr.code = 0;
843         hdr.sid = po->num;
844         hdr.length = htons(skb->len);
845
846         if (!dev)
847                 goto abort;
848
849         /* Copy the skb if there is no space for the header. */
850         if (headroom < (sizeof(struct pppoe_hdr) + dev->hard_header_len)) {
851                 skb2 = dev_alloc_skb(32+skb->len +
852                                      sizeof(struct pppoe_hdr) +
853                                      dev->hard_header_len);
854
855                 if (skb2 == NULL)
856                         goto abort;
857
858                 skb_reserve(skb2, dev->hard_header_len + sizeof(struct pppoe_hdr));
859                 memcpy(skb_put(skb2, skb->len), skb->data, skb->len);
860         } else {
861                 /* Make a clone so as to not disturb the original skb,
862                  * give dev_queue_xmit something it can free.
863                  */
864                 skb2 = skb_clone(skb, GFP_ATOMIC);
865         }
866
867         ph = (struct pppoe_hdr *) skb_push(skb2, sizeof(struct pppoe_hdr));
868         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
869         skb2->protocol = __constant_htons(ETH_P_PPP_SES);
870
871         skb2->nh.raw = skb2->data;
872
873         skb2->dev = dev;
874
875         dev->hard_header(skb2, dev, ETH_P_PPP_SES,
876                          po->pppoe_pa.remote, NULL, data_len);
877
878         /* We're transmitting skb2, and assuming that dev_queue_xmit
879          * will free it.  The generic ppp layer however, is expecting
880          * that we give back 'skb' (not 'skb2') in case of failure,
881          * but free it in case of success.
882          */
883
884         if (dev_queue_xmit(skb2) < 0)
885                 goto abort;
886
887         kfree_skb(skb);
888         return 1;
889
890 abort:
891         return 0;
892 }
893
894
895 /************************************************************************
896  *
897  * xmit function called by generic PPP driver
898  * sends PPP frame over PPPoE socket
899  *
900  ***********************************************************************/
901 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
902 {
903         struct sock *sk = (struct sock *) chan->private;
904         return __pppoe_xmit(sk, skb);
905 }
906
907
908 static struct ppp_channel_ops pppoe_chan_ops = { 
909         .start_xmit = pppoe_xmit, 
910 };
911
912 static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
913                   struct msghdr *m, size_t total_len, int flags)
914 {
915         struct sock *sk = sock->sk;
916         struct sk_buff *skb = NULL;
917         int error = 0;
918         int len;
919         struct pppoe_hdr *ph = NULL;
920
921         if (sk->sk_state & PPPOX_BOUND) {
922                 error = -EIO;
923                 goto end;
924         }
925
926         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
927                                 flags & MSG_DONTWAIT, &error);
928
929         if (error < 0) {
930                 goto end;
931         }
932
933         m->msg_namelen = 0;
934
935         if (skb) {
936                 error = 0;
937                 ph = (struct pppoe_hdr *) skb->nh.raw;
938                 len = ntohs(ph->length);
939
940                 error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
941                 if (error < 0)
942                         goto do_skb_free;
943                 error = len;
944         }
945
946 do_skb_free:
947         if (skb)
948                 kfree_skb(skb);
949 end:
950         return error;
951 }
952
953 #ifdef CONFIG_PROC_FS
954 static int pppoe_seq_show(struct seq_file *seq, void *v)
955 {
956         struct pppox_sock *po;
957         char *dev_name;
958
959         if (v == SEQ_START_TOKEN) {
960                 seq_puts(seq, "Id       Address              Device\n");
961                 goto out;
962         }
963
964         po = v;
965         dev_name = po->pppoe_pa.dev;
966
967         seq_printf(seq, "%08X %02X:%02X:%02X:%02X:%02X:%02X %8s\n",
968                    po->pppoe_pa.sid,
969                    po->pppoe_pa.remote[0], po->pppoe_pa.remote[1],
970                    po->pppoe_pa.remote[2], po->pppoe_pa.remote[3],
971                    po->pppoe_pa.remote[4], po->pppoe_pa.remote[5], dev_name);
972 out:
973         return 0;
974 }
975
976 static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
977 {
978         struct pppox_sock *po = NULL;
979         int i = 0;
980
981         for (; i < PPPOE_HASH_SIZE; i++) {
982                 po = item_hash_table[i];
983                 while (po) {
984                         if (!pos--)
985                                 goto out;
986                         po = po->next;
987                 }
988         }
989 out:
990         return po;
991 }
992
993 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
994 {
995         loff_t l = *pos;
996
997         read_lock_bh(&pppoe_hash_lock);
998         return l ? pppoe_get_idx(--l) : SEQ_START_TOKEN;
999 }
1000
1001 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1002 {
1003         struct pppox_sock *po;
1004
1005         ++*pos;
1006         if (v == SEQ_START_TOKEN) {
1007                 po = pppoe_get_idx(0);
1008                 goto out;
1009         }
1010         po = v;
1011         if (po->next) 
1012                 po = po->next;
1013         else {
1014                 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
1015
1016                 while (++hash < PPPOE_HASH_SIZE) {
1017                         po = item_hash_table[hash];
1018                         if (po)
1019                                 break;
1020                 }
1021         }
1022 out:
1023         return po;
1024 }
1025
1026 static void pppoe_seq_stop(struct seq_file *seq, void *v)
1027 {
1028         read_unlock_bh(&pppoe_hash_lock);
1029 }
1030
1031 static struct seq_operations pppoe_seq_ops = {
1032         .start          = pppoe_seq_start,
1033         .next           = pppoe_seq_next,
1034         .stop           = pppoe_seq_stop,
1035         .show           = pppoe_seq_show,
1036 };
1037
1038 static int pppoe_seq_open(struct inode *inode, struct file *file)
1039 {
1040         return seq_open(file, &pppoe_seq_ops);
1041 }
1042
1043 static struct file_operations pppoe_seq_fops = {
1044         .owner          = THIS_MODULE,
1045         .open           = pppoe_seq_open,
1046         .read           = seq_read,
1047         .llseek         = seq_lseek,
1048         .release        = seq_release,
1049 };
1050
1051 static int __init pppoe_proc_init(void)
1052 {
1053         struct proc_dir_entry *p;
1054
1055         p = create_proc_entry("net/pppoe", S_IRUGO, NULL);
1056         if (!p)
1057                 return -ENOMEM;
1058
1059         p->proc_fops = &pppoe_seq_fops;
1060         return 0;
1061 }
1062 #else /* CONFIG_PROC_FS */
1063 static inline int pppoe_proc_init(void) { return 0; }
1064 #endif /* CONFIG_PROC_FS */
1065
1066 static const struct proto_ops pppoe_ops = {
1067     .family             = AF_PPPOX,
1068     .owner              = THIS_MODULE,
1069     .release            = pppoe_release,
1070     .bind               = sock_no_bind,
1071     .connect            = pppoe_connect,
1072     .socketpair         = sock_no_socketpair,
1073     .accept             = sock_no_accept,
1074     .getname            = pppoe_getname,
1075     .poll               = datagram_poll,
1076     .listen             = sock_no_listen,
1077     .shutdown           = sock_no_shutdown,
1078     .setsockopt         = sock_no_setsockopt,
1079     .getsockopt         = sock_no_getsockopt,
1080     .sendmsg            = pppoe_sendmsg,
1081     .recvmsg            = pppoe_recvmsg,
1082     .mmap               = sock_no_mmap,
1083     .ioctl              = pppox_ioctl,
1084 };
1085
1086 static struct pppox_proto pppoe_proto = {
1087     .create     = pppoe_create,
1088     .ioctl      = pppoe_ioctl,
1089     .owner      = THIS_MODULE,
1090 };
1091
1092
1093 static int __init pppoe_init(void)
1094 {
1095         int err = proto_register(&pppoe_sk_proto, 0);
1096
1097         if (err)
1098                 goto out;
1099
1100         err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
1101         if (err)
1102                 goto out_unregister_pppoe_proto;
1103
1104         err = pppoe_proc_init();
1105         if (err)
1106                 goto out_unregister_pppox_proto;
1107         
1108         dev_add_pack(&pppoes_ptype);
1109         dev_add_pack(&pppoed_ptype);
1110         register_netdevice_notifier(&pppoe_notifier);
1111 out:
1112         return err;
1113 out_unregister_pppox_proto:
1114         unregister_pppox_proto(PX_PROTO_OE);
1115 out_unregister_pppoe_proto:
1116         proto_unregister(&pppoe_sk_proto);
1117         goto out;
1118 }
1119
1120 static void __exit pppoe_exit(void)
1121 {
1122         unregister_pppox_proto(PX_PROTO_OE);
1123         dev_remove_pack(&pppoes_ptype);
1124         dev_remove_pack(&pppoed_ptype);
1125         unregister_netdevice_notifier(&pppoe_notifier);
1126         remove_proc_entry("net/pppoe", NULL);
1127         proto_unregister(&pppoe_sk_proto);
1128 }
1129
1130 module_init(pppoe_init);
1131 module_exit(pppoe_exit);
1132
1133 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1134 MODULE_DESCRIPTION("PPP over Ethernet driver");
1135 MODULE_LICENSE("GPL");
1136 MODULE_ALIAS_NETPROTO(PF_PPPOX);