[SK_BUFF]: Introduce skb_reset_network_header(skb)
[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/sock.h>
82
83 #include <asm/uaccess.h>
84
85 #define PPPOE_HASH_BITS 4
86 #define PPPOE_HASH_SIZE (1<<PPPOE_HASH_BITS)
87
88 static struct ppp_channel_ops pppoe_chan_ops;
89
90 static int pppoe_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
91 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb);
92 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
93
94 static const struct proto_ops pppoe_ops;
95 static DEFINE_RWLOCK(pppoe_hash_lock);
96
97 static struct ppp_channel_ops pppoe_chan_ops;
98
99 static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
100 {
101         return (a->sid == b->sid &&
102                 (memcmp(a->remote, b->remote, ETH_ALEN) == 0));
103 }
104
105 static inline int cmp_addr(struct pppoe_addr *a, unsigned long sid, char *addr)
106 {
107         return (a->sid == sid &&
108                 (memcmp(a->remote,addr,ETH_ALEN) == 0));
109 }
110
111 static int hash_item(unsigned long sid, unsigned char *addr)
112 {
113         char hash = 0;
114         int i, j;
115
116         for (i = 0; i < ETH_ALEN ; ++i) {
117                 for (j = 0; j < 8/PPPOE_HASH_BITS ; ++j) {
118                         hash ^= addr[i] >> ( j * PPPOE_HASH_BITS );
119                 }
120         }
121
122         for (i = 0; i < (sizeof(unsigned long)*8) / PPPOE_HASH_BITS ; ++i)
123                 hash ^= sid >> (i*PPPOE_HASH_BITS);
124
125         return hash & ( PPPOE_HASH_SIZE - 1 );
126 }
127
128 /* zeroed because its in .bss */
129 static struct pppox_sock *item_hash_table[PPPOE_HASH_SIZE];
130
131 /**********************************************************************
132  *
133  *  Set/get/delete/rehash items  (internal versions)
134  *
135  **********************************************************************/
136 static struct pppox_sock *__get_item(unsigned long sid, unsigned char *addr, int ifindex)
137 {
138         int hash = hash_item(sid, addr);
139         struct pppox_sock *ret;
140
141         ret = item_hash_table[hash];
142
143         while (ret && !(cmp_addr(&ret->pppoe_pa, sid, addr) && ret->pppoe_ifindex == ifindex))
144                 ret = ret->next;
145
146         return ret;
147 }
148
149 static int __set_item(struct pppox_sock *po)
150 {
151         int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
152         struct pppox_sock *ret;
153
154         ret = item_hash_table[hash];
155         while (ret) {
156                 if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) && ret->pppoe_ifindex == po->pppoe_ifindex)
157                         return -EALREADY;
158
159                 ret = ret->next;
160         }
161
162         po->next = item_hash_table[hash];
163         item_hash_table[hash] = po;
164
165         return 0;
166 }
167
168 static struct pppox_sock *__delete_item(unsigned long sid, char *addr, int ifindex)
169 {
170         int hash = hash_item(sid, addr);
171         struct pppox_sock *ret, **src;
172
173         ret = item_hash_table[hash];
174         src = &item_hash_table[hash];
175
176         while (ret) {
177                 if (cmp_addr(&ret->pppoe_pa, sid, addr) && ret->pppoe_ifindex == ifindex) {
178                         *src = ret->next;
179                         break;
180                 }
181
182                 src = &ret->next;
183                 ret = ret->next;
184         }
185
186         return ret;
187 }
188
189 /**********************************************************************
190  *
191  *  Set/get/delete/rehash items
192  *
193  **********************************************************************/
194 static inline struct pppox_sock *get_item(unsigned long sid,
195                                          unsigned char *addr, int ifindex)
196 {
197         struct pppox_sock *po;
198
199         read_lock_bh(&pppoe_hash_lock);
200         po = __get_item(sid, addr, ifindex);
201         if (po)
202                 sock_hold(sk_pppox(po));
203         read_unlock_bh(&pppoe_hash_lock);
204
205         return po;
206 }
207
208 static inline struct pppox_sock *get_item_by_addr(struct sockaddr_pppox *sp)
209 {
210         struct net_device *dev = NULL;
211         int ifindex;
212
213         dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
214         if(!dev)
215                 return NULL;
216         ifindex = dev->ifindex;
217         dev_put(dev);
218         return get_item(sp->sa_addr.pppoe.sid, sp->sa_addr.pppoe.remote, ifindex);
219 }
220
221 static inline int set_item(struct pppox_sock *po)
222 {
223         int i;
224
225         if (!po)
226                 return -EINVAL;
227
228         write_lock_bh(&pppoe_hash_lock);
229         i = __set_item(po);
230         write_unlock_bh(&pppoe_hash_lock);
231
232         return i;
233 }
234
235 static inline struct pppox_sock *delete_item(unsigned long sid, char *addr, int ifindex)
236 {
237         struct pppox_sock *ret;
238
239         write_lock_bh(&pppoe_hash_lock);
240         ret = __delete_item(sid, addr, ifindex);
241         write_unlock_bh(&pppoe_hash_lock);
242
243         return ret;
244 }
245
246
247
248 /***************************************************************************
249  *
250  *  Handler for device events.
251  *  Certain device events require that sockets be unconnected.
252  *
253  **************************************************************************/
254
255 static void pppoe_flush_dev(struct net_device *dev)
256 {
257         int hash;
258
259         BUG_ON(dev == NULL);
260
261         read_lock_bh(&pppoe_hash_lock);
262         for (hash = 0; hash < PPPOE_HASH_SIZE; hash++) {
263                 struct pppox_sock *po = item_hash_table[hash];
264
265                 while (po != NULL) {
266                         if (po->pppoe_dev == dev) {
267                                 struct sock *sk = sk_pppox(po);
268
269                                 sock_hold(sk);
270                                 po->pppoe_dev = NULL;
271
272                                 /* We hold a reference to SK, now drop the
273                                  * hash table lock so that we may attempt
274                                  * to lock the socket (which can sleep).
275                                  */
276                                 read_unlock_bh(&pppoe_hash_lock);
277
278                                 lock_sock(sk);
279
280                                 if (sk->sk_state &
281                                     (PPPOX_CONNECTED | PPPOX_BOUND)) {
282                                         pppox_unbind_sock(sk);
283                                         dev_put(dev);
284                                         sk->sk_state = PPPOX_ZOMBIE;
285                                         sk->sk_state_change(sk);
286                                 }
287
288                                 release_sock(sk);
289
290                                 sock_put(sk);
291
292                                 read_lock_bh(&pppoe_hash_lock);
293
294                                 /* Now restart from the beginning of this
295                                  * hash chain.  We always NULL out pppoe_dev
296                                  * so we are guaranteed to make forward
297                                  * progress.
298                                  */
299                                 po = item_hash_table[hash];
300                                 continue;
301                         }
302                         po = po->next;
303                 }
304         }
305         read_unlock_bh(&pppoe_hash_lock);
306 }
307
308 static int pppoe_device_event(struct notifier_block *this,
309                               unsigned long event, void *ptr)
310 {
311         struct net_device *dev = (struct net_device *) ptr;
312
313         /* Only look at sockets that are using this specific device. */
314         switch (event) {
315         case NETDEV_CHANGEMTU:
316                 /* A change in mtu is a bad thing, requiring
317                  * LCP re-negotiation.
318                  */
319
320         case NETDEV_GOING_DOWN:
321         case NETDEV_DOWN:
322                 /* Find every socket on this device and kill it. */
323                 pppoe_flush_dev(dev);
324                 break;
325
326         default:
327                 break;
328         };
329
330         return NOTIFY_DONE;
331 }
332
333
334 static struct notifier_block pppoe_notifier = {
335         .notifier_call = pppoe_device_event,
336 };
337
338
339 /************************************************************************
340  *
341  * Do the real work of receiving a PPPoE Session frame.
342  *
343  ***********************************************************************/
344 static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb)
345 {
346         struct pppox_sock *po = pppox_sk(sk);
347         struct pppox_sock *relay_po = NULL;
348
349         if (sk->sk_state & PPPOX_BOUND) {
350                 struct pppoe_hdr *ph = pppoe_hdr(skb);
351                 int len = ntohs(ph->length);
352                 skb_pull_rcsum(skb, sizeof(struct pppoe_hdr));
353                 if (pskb_trim_rcsum(skb, len))
354                         goto abort_kfree;
355
356                 ppp_input(&po->chan, skb);
357         } else if (sk->sk_state & PPPOX_RELAY) {
358                 relay_po = get_item_by_addr(&po->pppoe_relay);
359
360                 if (relay_po == NULL)
361                         goto abort_kfree;
362
363                 if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0)
364                         goto abort_put;
365
366                 skb_pull(skb, sizeof(struct pppoe_hdr));
367                 if (!__pppoe_xmit(sk_pppox(relay_po), skb))
368                         goto abort_put;
369         } else {
370                 if (sock_queue_rcv_skb(sk, skb))
371                         goto abort_kfree;
372         }
373
374         return NET_RX_SUCCESS;
375
376 abort_put:
377         sock_put(sk_pppox(relay_po));
378
379 abort_kfree:
380         kfree_skb(skb);
381         return NET_RX_DROP;
382 }
383
384 /************************************************************************
385  *
386  * Receive wrapper called in BH context.
387  *
388  ***********************************************************************/
389 static int pppoe_rcv(struct sk_buff *skb,
390                      struct net_device *dev,
391                      struct packet_type *pt,
392                      struct net_device *orig_dev)
393
394 {
395         struct pppoe_hdr *ph;
396         struct pppox_sock *po;
397
398         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
399                 goto drop;
400
401         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
402                 goto out;
403
404         ph = pppoe_hdr(skb);
405
406         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
407         if (po != NULL)
408                 return sk_receive_skb(sk_pppox(po), skb, 0);
409 drop:
410         kfree_skb(skb);
411 out:
412         return NET_RX_DROP;
413 }
414
415 /************************************************************************
416  *
417  * Receive a PPPoE Discovery frame.
418  * This is solely for detection of PADT frames
419  *
420  ***********************************************************************/
421 static int pppoe_disc_rcv(struct sk_buff *skb,
422                           struct net_device *dev,
423                           struct packet_type *pt,
424                           struct net_device *orig_dev)
425
426 {
427         struct pppoe_hdr *ph;
428         struct pppox_sock *po;
429
430         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
431                 goto abort;
432
433         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
434                 goto out;
435
436         ph = pppoe_hdr(skb);
437         if (ph->code != PADT_CODE)
438                 goto abort;
439
440         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
441         if (po) {
442                 struct sock *sk = sk_pppox(po);
443
444                 bh_lock_sock(sk);
445
446                 /* If the user has locked the socket, just ignore
447                  * the packet.  With the way two rcv protocols hook into
448                  * one socket family type, we cannot (easily) distinguish
449                  * what kind of SKB it is during backlog rcv.
450                  */
451                 if (sock_owned_by_user(sk) == 0) {
452                         /* We're no longer connect at the PPPOE layer,
453                          * and must wait for ppp channel to disconnect us.
454                          */
455                         sk->sk_state = PPPOX_ZOMBIE;
456                 }
457
458                 bh_unlock_sock(sk);
459                 sock_put(sk);
460         }
461
462 abort:
463         kfree_skb(skb);
464 out:
465         return NET_RX_SUCCESS; /* Lies... :-) */
466 }
467
468 static struct packet_type pppoes_ptype = {
469         .type   = __constant_htons(ETH_P_PPP_SES),
470         .func   = pppoe_rcv,
471 };
472
473 static struct packet_type pppoed_ptype = {
474         .type   = __constant_htons(ETH_P_PPP_DISC),
475         .func   = pppoe_disc_rcv,
476 };
477
478 static struct proto pppoe_sk_proto = {
479         .name     = "PPPOE",
480         .owner    = THIS_MODULE,
481         .obj_size = sizeof(struct pppox_sock),
482 };
483
484 /***********************************************************************
485  *
486  * Initialize a new struct sock.
487  *
488  **********************************************************************/
489 static int pppoe_create(struct socket *sock)
490 {
491         int error = -ENOMEM;
492         struct sock *sk;
493
494         sk = sk_alloc(PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, 1);
495         if (!sk)
496                 goto out;
497
498         sock_init_data(sock, sk);
499
500         sock->state = SS_UNCONNECTED;
501         sock->ops   = &pppoe_ops;
502
503         sk->sk_backlog_rcv = pppoe_rcv_core;
504         sk->sk_state       = PPPOX_NONE;
505         sk->sk_type        = SOCK_STREAM;
506         sk->sk_family      = PF_PPPOX;
507         sk->sk_protocol    = PX_PROTO_OE;
508
509         error = 0;
510 out:    return error;
511 }
512
513 static int pppoe_release(struct socket *sock)
514 {
515         struct sock *sk = sock->sk;
516         struct pppox_sock *po;
517         int error = 0;
518
519         if (!sk)
520                 return 0;
521
522         if (sock_flag(sk, SOCK_DEAD))
523                 return -EBADF;
524
525         pppox_unbind_sock(sk);
526
527         /* Signal the death of the socket. */
528         sk->sk_state = PPPOX_DEAD;
529
530         po = pppox_sk(sk);
531         if (po->pppoe_pa.sid) {
532                 delete_item(po->pppoe_pa.sid, po->pppoe_pa.remote, po->pppoe_ifindex);
533         }
534
535         if (po->pppoe_dev)
536                 dev_put(po->pppoe_dev);
537
538         po->pppoe_dev = NULL;
539
540         sock_orphan(sk);
541         sock->sk = NULL;
542
543         skb_queue_purge(&sk->sk_receive_queue);
544         sock_put(sk);
545
546         return error;
547 }
548
549
550 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
551                   int sockaddr_len, int flags)
552 {
553         struct sock *sk = sock->sk;
554         struct net_device *dev;
555         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
556         struct pppox_sock *po = pppox_sk(sk);
557         int error;
558
559         lock_sock(sk);
560
561         error = -EINVAL;
562         if (sp->sa_protocol != PX_PROTO_OE)
563                 goto end;
564
565         /* Check for already bound sockets */
566         error = -EBUSY;
567         if ((sk->sk_state & PPPOX_CONNECTED) && sp->sa_addr.pppoe.sid)
568                 goto end;
569
570         /* Check for already disconnected sockets, on attempts to disconnect */
571         error = -EALREADY;
572         if ((sk->sk_state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
573                 goto end;
574
575         error = 0;
576         if (po->pppoe_pa.sid) {
577                 pppox_unbind_sock(sk);
578
579                 /* Delete the old binding */
580                 delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote,po->pppoe_ifindex);
581
582                 if(po->pppoe_dev)
583                         dev_put(po->pppoe_dev);
584
585                 memset(sk_pppox(po) + 1, 0,
586                        sizeof(struct pppox_sock) - sizeof(struct sock));
587
588                 sk->sk_state = PPPOX_NONE;
589         }
590
591         /* Don't re-bind if sid==0 */
592         if (sp->sa_addr.pppoe.sid != 0) {
593                 dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
594
595                 error = -ENODEV;
596                 if (!dev)
597                         goto end;
598
599                 po->pppoe_dev = dev;
600                 po->pppoe_ifindex = dev->ifindex;
601
602                 if (!(dev->flags & IFF_UP))
603                         goto err_put;
604
605                 memcpy(&po->pppoe_pa,
606                        &sp->sa_addr.pppoe,
607                        sizeof(struct pppoe_addr));
608
609                 error = set_item(po);
610                 if (error < 0)
611                         goto err_put;
612
613                 po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
614                                    dev->hard_header_len);
615
616                 po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr);
617                 po->chan.private = sk;
618                 po->chan.ops = &pppoe_chan_ops;
619
620                 error = ppp_register_channel(&po->chan);
621                 if (error)
622                         goto err_put;
623
624                 sk->sk_state = PPPOX_CONNECTED;
625         }
626
627         po->num = sp->sa_addr.pppoe.sid;
628
629  end:
630         release_sock(sk);
631         return error;
632 err_put:
633         if (po->pppoe_dev) {
634                 dev_put(po->pppoe_dev);
635                 po->pppoe_dev = NULL;
636         }
637         goto end;
638 }
639
640
641 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
642                   int *usockaddr_len, int peer)
643 {
644         int len = sizeof(struct sockaddr_pppox);
645         struct sockaddr_pppox sp;
646
647         sp.sa_family    = AF_PPPOX;
648         sp.sa_protocol  = PX_PROTO_OE;
649         memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
650                sizeof(struct pppoe_addr));
651
652         memcpy(uaddr, &sp, len);
653
654         *usockaddr_len = len;
655
656         return 0;
657 }
658
659
660 static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
661                 unsigned long arg)
662 {
663         struct sock *sk = sock->sk;
664         struct pppox_sock *po = pppox_sk(sk);
665         int val = 0;
666         int err = 0;
667
668         switch (cmd) {
669         case PPPIOCGMRU:
670                 err = -ENXIO;
671
672                 if (!(sk->sk_state & PPPOX_CONNECTED))
673                         break;
674
675                 err = -EFAULT;
676                 if (put_user(po->pppoe_dev->mtu -
677                              sizeof(struct pppoe_hdr) -
678                              PPP_HDRLEN,
679                              (int __user *) arg))
680                         break;
681                 err = 0;
682                 break;
683
684         case PPPIOCSMRU:
685                 err = -ENXIO;
686                 if (!(sk->sk_state & PPPOX_CONNECTED))
687                         break;
688
689                 err = -EFAULT;
690                 if (get_user(val,(int __user *) arg))
691                         break;
692
693                 if (val < (po->pppoe_dev->mtu
694                            - sizeof(struct pppoe_hdr)
695                            - PPP_HDRLEN))
696                         err = 0;
697                 else
698                         err = -EINVAL;
699                 break;
700
701         case PPPIOCSFLAGS:
702                 err = -EFAULT;
703                 if (get_user(val, (int __user *) arg))
704                         break;
705                 err = 0;
706                 break;
707
708         case PPPOEIOCSFWD:
709         {
710                 struct pppox_sock *relay_po;
711
712                 err = -EBUSY;
713                 if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD))
714                         break;
715
716                 err = -ENOTCONN;
717                 if (!(sk->sk_state & PPPOX_CONNECTED))
718                         break;
719
720                 /* PPPoE address from the user specifies an outbound
721                    PPPoE address which frames are forwarded to */
722                 err = -EFAULT;
723                 if (copy_from_user(&po->pppoe_relay,
724                                    (void __user *)arg,
725                                    sizeof(struct sockaddr_pppox)))
726                         break;
727
728                 err = -EINVAL;
729                 if (po->pppoe_relay.sa_family != AF_PPPOX ||
730                     po->pppoe_relay.sa_protocol!= PX_PROTO_OE)
731                         break;
732
733                 /* Check that the socket referenced by the address
734                    actually exists. */
735                 relay_po = get_item_by_addr(&po->pppoe_relay);
736
737                 if (!relay_po)
738                         break;
739
740                 sock_put(sk_pppox(relay_po));
741                 sk->sk_state |= PPPOX_RELAY;
742                 err = 0;
743                 break;
744         }
745
746         case PPPOEIOCDFWD:
747                 err = -EALREADY;
748                 if (!(sk->sk_state & PPPOX_RELAY))
749                         break;
750
751                 sk->sk_state &= ~PPPOX_RELAY;
752                 err = 0;
753                 break;
754
755         default:;
756         };
757
758         return err;
759 }
760
761
762 static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
763                   struct msghdr *m, size_t total_len)
764 {
765         struct sk_buff *skb = NULL;
766         struct sock *sk = sock->sk;
767         struct pppox_sock *po = pppox_sk(sk);
768         int error = 0;
769         struct pppoe_hdr hdr;
770         struct pppoe_hdr *ph;
771         struct net_device *dev;
772         char *start;
773
774         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
775                 error = -ENOTCONN;
776                 goto end;
777         }
778
779         hdr.ver = 1;
780         hdr.type = 1;
781         hdr.code = 0;
782         hdr.sid = po->num;
783
784         lock_sock(sk);
785
786         dev = po->pppoe_dev;
787
788         error = -EMSGSIZE;
789         if (total_len > (dev->mtu + dev->hard_header_len))
790                 goto end;
791
792
793         skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32,
794                            0, GFP_KERNEL);
795         if (!skb) {
796                 error = -ENOMEM;
797                 goto end;
798         }
799
800         /* Reserve space for headers. */
801         skb_reserve(skb, dev->hard_header_len);
802         skb_reset_network_header(skb);
803
804         skb->dev = dev;
805
806         skb->priority = sk->sk_priority;
807         skb->protocol = __constant_htons(ETH_P_PPP_SES);
808
809         ph = (struct pppoe_hdr *) skb_put(skb, total_len + sizeof(struct pppoe_hdr));
810         start = (char *) &ph->tag[0];
811
812         error = memcpy_fromiovec(start, m->msg_iov, total_len);
813
814         if (error < 0) {
815                 kfree_skb(skb);
816                 goto end;
817         }
818
819         error = total_len;
820         dev->hard_header(skb, dev, ETH_P_PPP_SES,
821                          po->pppoe_pa.remote, NULL, total_len);
822
823         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
824
825         ph->length = htons(total_len);
826
827         dev_queue_xmit(skb);
828
829 end:
830         release_sock(sk);
831         return error;
832 }
833
834
835 /************************************************************************
836  *
837  * xmit function for internal use.
838  *
839  ***********************************************************************/
840 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
841 {
842         struct pppox_sock *po = pppox_sk(sk);
843         struct net_device *dev = po->pppoe_dev;
844         struct pppoe_hdr hdr;
845         struct pppoe_hdr *ph;
846         int headroom = skb_headroom(skb);
847         int data_len = skb->len;
848         struct sk_buff *skb2;
849
850         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
851                 goto abort;
852
853         hdr.ver = 1;
854         hdr.type = 1;
855         hdr.code = 0;
856         hdr.sid = po->num;
857         hdr.length = htons(skb->len);
858
859         if (!dev)
860                 goto abort;
861
862         /* Copy the skb if there is no space for the header. */
863         if (headroom < (sizeof(struct pppoe_hdr) + dev->hard_header_len)) {
864                 skb2 = dev_alloc_skb(32+skb->len +
865                                      sizeof(struct pppoe_hdr) +
866                                      dev->hard_header_len);
867
868                 if (skb2 == NULL)
869                         goto abort;
870
871                 skb_reserve(skb2, dev->hard_header_len + sizeof(struct pppoe_hdr));
872                 memcpy(skb_put(skb2, skb->len), skb->data, skb->len);
873         } else {
874                 /* Make a clone so as to not disturb the original skb,
875                  * give dev_queue_xmit something it can free.
876                  */
877                 skb2 = skb_clone(skb, GFP_ATOMIC);
878
879                 if (skb2 == NULL)
880                         goto abort;
881         }
882
883         ph = (struct pppoe_hdr *) skb_push(skb2, sizeof(struct pppoe_hdr));
884         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
885         skb2->protocol = __constant_htons(ETH_P_PPP_SES);
886
887         skb_reset_network_header(skb2);
888
889         skb2->dev = dev;
890
891         dev->hard_header(skb2, dev, ETH_P_PPP_SES,
892                          po->pppoe_pa.remote, NULL, data_len);
893
894         /* We're transmitting skb2, and assuming that dev_queue_xmit
895          * will free it.  The generic ppp layer however, is expecting
896          * that we give back 'skb' (not 'skb2') in case of failure,
897          * but free it in case of success.
898          */
899
900         if (dev_queue_xmit(skb2) < 0)
901                 goto abort;
902
903         kfree_skb(skb);
904         return 1;
905
906 abort:
907         return 0;
908 }
909
910
911 /************************************************************************
912  *
913  * xmit function called by generic PPP driver
914  * sends PPP frame over PPPoE socket
915  *
916  ***********************************************************************/
917 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
918 {
919         struct sock *sk = (struct sock *) chan->private;
920         return __pppoe_xmit(sk, skb);
921 }
922
923
924 static struct ppp_channel_ops pppoe_chan_ops = {
925         .start_xmit = pppoe_xmit,
926 };
927
928 static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
929                   struct msghdr *m, size_t total_len, int flags)
930 {
931         struct sock *sk = sock->sk;
932         struct sk_buff *skb = NULL;
933         int error = 0;
934
935         if (sk->sk_state & PPPOX_BOUND) {
936                 error = -EIO;
937                 goto end;
938         }
939
940         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
941                                 flags & MSG_DONTWAIT, &error);
942
943         if (error < 0) {
944                 goto end;
945         }
946
947         m->msg_namelen = 0;
948
949         if (skb) {
950                 struct pppoe_hdr *ph = pppoe_hdr(skb);
951                 const int len = ntohs(ph->length);
952
953                 error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
954                 if (error == 0)
955                         error = len;
956         }
957
958         kfree_skb(skb);
959 end:
960         return error;
961 }
962
963 #ifdef CONFIG_PROC_FS
964 static int pppoe_seq_show(struct seq_file *seq, void *v)
965 {
966         struct pppox_sock *po;
967         char *dev_name;
968
969         if (v == SEQ_START_TOKEN) {
970                 seq_puts(seq, "Id       Address              Device\n");
971                 goto out;
972         }
973
974         po = v;
975         dev_name = po->pppoe_pa.dev;
976
977         seq_printf(seq, "%08X %02X:%02X:%02X:%02X:%02X:%02X %8s\n",
978                    po->pppoe_pa.sid,
979                    po->pppoe_pa.remote[0], po->pppoe_pa.remote[1],
980                    po->pppoe_pa.remote[2], po->pppoe_pa.remote[3],
981                    po->pppoe_pa.remote[4], po->pppoe_pa.remote[5], dev_name);
982 out:
983         return 0;
984 }
985
986 static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
987 {
988         struct pppox_sock *po = NULL;
989         int i = 0;
990
991         for (; i < PPPOE_HASH_SIZE; i++) {
992                 po = item_hash_table[i];
993                 while (po) {
994                         if (!pos--)
995                                 goto out;
996                         po = po->next;
997                 }
998         }
999 out:
1000         return po;
1001 }
1002
1003 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
1004 {
1005         loff_t l = *pos;
1006
1007         read_lock_bh(&pppoe_hash_lock);
1008         return l ? pppoe_get_idx(--l) : SEQ_START_TOKEN;
1009 }
1010
1011 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1012 {
1013         struct pppox_sock *po;
1014
1015         ++*pos;
1016         if (v == SEQ_START_TOKEN) {
1017                 po = pppoe_get_idx(0);
1018                 goto out;
1019         }
1020         po = v;
1021         if (po->next)
1022                 po = po->next;
1023         else {
1024                 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
1025
1026                 while (++hash < PPPOE_HASH_SIZE) {
1027                         po = item_hash_table[hash];
1028                         if (po)
1029                                 break;
1030                 }
1031         }
1032 out:
1033         return po;
1034 }
1035
1036 static void pppoe_seq_stop(struct seq_file *seq, void *v)
1037 {
1038         read_unlock_bh(&pppoe_hash_lock);
1039 }
1040
1041 static struct seq_operations pppoe_seq_ops = {
1042         .start          = pppoe_seq_start,
1043         .next           = pppoe_seq_next,
1044         .stop           = pppoe_seq_stop,
1045         .show           = pppoe_seq_show,
1046 };
1047
1048 static int pppoe_seq_open(struct inode *inode, struct file *file)
1049 {
1050         return seq_open(file, &pppoe_seq_ops);
1051 }
1052
1053 static const struct file_operations pppoe_seq_fops = {
1054         .owner          = THIS_MODULE,
1055         .open           = pppoe_seq_open,
1056         .read           = seq_read,
1057         .llseek         = seq_lseek,
1058         .release        = seq_release,
1059 };
1060
1061 static int __init pppoe_proc_init(void)
1062 {
1063         struct proc_dir_entry *p;
1064
1065         p = create_proc_entry("net/pppoe", S_IRUGO, NULL);
1066         if (!p)
1067                 return -ENOMEM;
1068
1069         p->proc_fops = &pppoe_seq_fops;
1070         return 0;
1071 }
1072 #else /* CONFIG_PROC_FS */
1073 static inline int pppoe_proc_init(void) { return 0; }
1074 #endif /* CONFIG_PROC_FS */
1075
1076 static const struct proto_ops pppoe_ops = {
1077     .family             = AF_PPPOX,
1078     .owner              = THIS_MODULE,
1079     .release            = pppoe_release,
1080     .bind               = sock_no_bind,
1081     .connect            = pppoe_connect,
1082     .socketpair         = sock_no_socketpair,
1083     .accept             = sock_no_accept,
1084     .getname            = pppoe_getname,
1085     .poll               = datagram_poll,
1086     .listen             = sock_no_listen,
1087     .shutdown           = sock_no_shutdown,
1088     .setsockopt         = sock_no_setsockopt,
1089     .getsockopt         = sock_no_getsockopt,
1090     .sendmsg            = pppoe_sendmsg,
1091     .recvmsg            = pppoe_recvmsg,
1092     .mmap               = sock_no_mmap,
1093     .ioctl              = pppox_ioctl,
1094 };
1095
1096 static struct pppox_proto pppoe_proto = {
1097     .create     = pppoe_create,
1098     .ioctl      = pppoe_ioctl,
1099     .owner      = THIS_MODULE,
1100 };
1101
1102
1103 static int __init pppoe_init(void)
1104 {
1105         int err = proto_register(&pppoe_sk_proto, 0);
1106
1107         if (err)
1108                 goto out;
1109
1110         err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
1111         if (err)
1112                 goto out_unregister_pppoe_proto;
1113
1114         err = pppoe_proc_init();
1115         if (err)
1116                 goto out_unregister_pppox_proto;
1117
1118         dev_add_pack(&pppoes_ptype);
1119         dev_add_pack(&pppoed_ptype);
1120         register_netdevice_notifier(&pppoe_notifier);
1121 out:
1122         return err;
1123 out_unregister_pppox_proto:
1124         unregister_pppox_proto(PX_PROTO_OE);
1125 out_unregister_pppoe_proto:
1126         proto_unregister(&pppoe_sk_proto);
1127         goto out;
1128 }
1129
1130 static void __exit pppoe_exit(void)
1131 {
1132         unregister_pppox_proto(PX_PROTO_OE);
1133         dev_remove_pack(&pppoes_ptype);
1134         dev_remove_pack(&pppoed_ptype);
1135         unregister_netdevice_notifier(&pppoe_notifier);
1136         remove_proc_entry("net/pppoe", NULL);
1137         proto_unregister(&pppoe_sk_proto);
1138 }
1139
1140 module_init(pppoe_init);
1141 module_exit(pppoe_exit);
1142
1143 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1144 MODULE_DESCRIPTION("PPP over Ethernet driver");
1145 MODULE_LICENSE("GPL");
1146 MODULE_ALIAS_NETPROTO(PF_PPPOX);