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