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:    0.6.11
   9  *
  10  * 030700 :     Fixed connect logic to allow for disconnect.
  11  * 270700 :     Fixed potential SMP problems; we must protect against
  12  *              simultaneous invocation of ppp_input
  13  *              and ppp_unregister_channel.
  14  * 040800 :     Respect reference count mechanisms on net-devices.
  15  * 200800 :     fix kfree(skb) in pppoe_rcv (acme)
  16  *              Module reference count is decremented in the right spot now,
  17  *              guards against sock_put not actually freeing the sk
  18  *              in pppoe_release.
  19  * 051000 :     Initialization cleanup.
  20  * 111100 :     Fix recvmsg.
  21  * 050101 :     Fix PADT procesing.
  22  * 140501 :     Use pppoe_rcv_core to handle all backlog. (Alexey)
  23  * 170701 :     Do not lock_sock with rwlock held. (DaveM)
  24  *              Ignore discovery frames if user has socket
  25  *              locked. (DaveM)
  26  *              Ignore return value of dev_queue_xmit in __pppoe_xmit
  27  *              or else we may kfree an SKB twice. (DaveM)
  28  * 190701 :     When doing copies of skb's in __pppoe_xmit, always delete
  29  *              the original skb that was passed in on success, never on
  30  *              failure.  Delete the copy of the skb on failure to avoid
  31  *              a memory leak.
  32  * 081001 :     Misc. cleanup (licence string, non-blocking, prevent
  33  *              reference of device on close).
  34  * 121301 :     New ppp channels interface; cannot unregister a channel
  35  *              from interrupts.  Thus, we mark the socket as a ZOMBIE
  36  *              and do the unregistration later.
  37  * 071502 :     When a connection is being torn down, we must remember that
  38  *              ZOMBIE state connections are still connected and thus
  39  *              pppox_unbind_sock must unbind them (in pppoe_release).
  40  *
  41  * Author:      Michal Ostrowski <mostrows@speakeasy.net>
  42  * Contributors:
  43  *              Arnaldo Carvalho de Melo <acme@xconectiva.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
  57 #include <asm/uaccess.h>
  58
  59 #include <linux/kernel.h>
  60 #include <linux/sched.h>
  61 #include <linux/slab.h>
  62 #include <linux/errno.h>
  63
  64 #include <linux/netdevice.h>
  65 #include <linux/net.h>
  66 #include <linux/inetdevice.h>
  67 #include <linux/etherdevice.h>
  68 #include <linux/skbuff.h>
  69 #include <linux/init.h>
  70 #include <linux/if_ether.h>
  71 #include <linux/if_pppox.h>
  72 #include <net/sock.h>
  73 #include <linux/ppp_channel.h>
  74 #include <linux/ppp_defs.h>
  75 #include <linux/if_ppp.h>
  76 #include <linux/if_pppvar.h>
  77 #include <linux/notifier.h>
  78 #include <linux/file.h>
  79 #include <linux/proc_fs.h>
  80
  81
  82
  83 static int __attribute__((unused)) pppoe_debug = 7;
  84 #define PPPOE_HASH_BITS 4
  85 #define PPPOE_HASH_SIZE (1<<PPPOE_HASH_BITS)
  86
  87 int pppoe_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
  88 int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb);
  89 int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
  90
  91 struct proto_ops pppoe_ops;
  92
  93
  94 #if 0
  95 #define CHECKPTR(x,y) do { if (!(x) && pppoe_debug &7 ){ printk(KERN_CRIT "PPPoE Invalid pointer : %s , %p\n",#x,(x)); error=-EINVAL; goto y; }} while (0)
  96 #define DEBUG(s,args...) do { if( pppoe_debug & (s) ) printk(KERN_CRIT args ); } while (0)
  97 #else
  98 #define CHECKPTR(x,y) do { } while (0)
  99 #define DEBUG(s,args...) do { } while (0)
 100 #endif
 101
 102
 103
 104 static rwlock_t pppoe_hash_lock = RW_LOCK_UNLOCKED;
 105
 106
 107 static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
 108 {
 109         return (a->sid == b->sid &&
 110                 (memcmp(a->remote, b->remote, ETH_ALEN) == 0));
 111 }
 112
 113 static inline int cmp_addr(struct pppoe_addr *a, unsigned long sid, char *addr)
 114 {
 115         return (a->sid == sid &&
 116                 (memcmp(a->remote,addr,ETH_ALEN) == 0));
 117 }
 118
 119 static int hash_item(unsigned long sid, unsigned char *addr)
 120 {
 121         char hash = 0;
 122         int i, j;
 123
 124         for (i = 0; i < ETH_ALEN ; ++i) {
 125                 for (j = 0; j < 8/PPPOE_HASH_BITS ; ++j) {
 126                         hash ^= addr[i] >> ( j * PPPOE_HASH_BITS );
 127                 }
 128         }
 129
 130         for (i = 0; i < (sizeof(unsigned long)*8) / PPPOE_HASH_BITS ; ++i)
 131                 hash ^= sid >> (i*PPPOE_HASH_BITS);
 132
 133         return hash & ( PPPOE_HASH_SIZE - 1 );
 134 }
 135
 136 static struct pppox_opt *item_hash_table[PPPOE_HASH_SIZE] = { 0, };
 137
 138 /**********************************************************************
 139  *
 140  *  Set/get/delete/rehash items  (internal versions)
 141  *
 142  **********************************************************************/
 143 static struct pppox_opt *__get_item(unsigned long sid, unsigned char *addr)
 144 {
 145         int hash = hash_item(sid, addr);
 146         struct pppox_opt *ret;
 147
 148         ret = item_hash_table[hash];
 149
 150         while (ret && !cmp_addr(&ret->pppoe_pa, sid, addr))
 151                 ret = ret->next;
 152
 153         return ret;
 154 }
 155
 156 static int __set_item(struct pppox_opt *po)
 157 {
 158         int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
 159         struct pppox_opt *ret;
 160
 161         ret = item_hash_table[hash];
 162         while (ret) {
 163                 if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa))
 164                         return -EALREADY;
 165
 166                 ret = ret->next;
 167         }
 168
 169         if (!ret) {
 170                 po->next = item_hash_table[hash];
 171                 item_hash_table[hash] = po;
 172         }
 173
 174         return 0;
 175 }
 176
 177 static struct pppox_opt *__delete_item(unsigned long sid, char *addr)
 178 {
 179         int hash = hash_item(sid, addr);
 180         struct pppox_opt *ret, **src;
 181
 182         ret = item_hash_table[hash];
 183         src = &item_hash_table[hash];
 184
 185         while (ret) {
 186                 if (cmp_addr(&ret->pppoe_pa, sid, addr)) {
 187                         *src = ret->next;
 188                         break;
 189                 }
 190
 191                 src = &ret->next;
 192                 ret = ret->next;
 193         }
 194
 195         return ret;
 196 }
 197
 198 /**********************************************************************
 199  *
 200  *  Set/get/delete/rehash items
 201  *
 202  **********************************************************************/
 203 static inline struct pppox_opt *get_item(unsigned long sid,
 204                                          unsigned char *addr)
 205 {
 206         struct pppox_opt *po;
 207
 208         read_lock_bh(&pppoe_hash_lock);
 209         po = __get_item(sid, addr);
 210         if (po)
 211                 sock_hold(po->sk);
 212         read_unlock_bh(&pppoe_hash_lock);
 213
 214         return po;
 215 }
 216
 217 static inline struct pppox_opt *get_item_by_addr(struct sockaddr_pppox *sp)
 218 {
 219         return get_item(sp->sa_addr.pppoe.sid, sp->sa_addr.pppoe.remote);
 220 }
 221
 222 static inline int set_item(struct pppox_opt *po)
 223 {
 224         int i;
 225
 226         if (!po)
 227                 return -EINVAL;
 228
 229         write_lock_bh(&pppoe_hash_lock);
 230         i = __set_item(po);
 231         write_unlock_bh(&pppoe_hash_lock);
 232
 233         return i;
 234 }
 235
 236 static inline struct pppox_opt *delete_item(unsigned long sid, char *addr)
 237 {
 238         struct pppox_opt *ret;
 239
 240         write_lock_bh(&pppoe_hash_lock);
 241         ret = __delete_item(sid, addr);
 242         write_unlock_bh(&pppoe_hash_lock);
 243
 244         return ret;
 245 }
 246
 247
 248
 249 /***************************************************************************
 250  *
 251  *  Handler for device events.
 252  *  Certain device events require that sockets be unconnected.
 253  *
 254  **************************************************************************/
 255
 256 static void pppoe_flush_dev(struct net_device *dev)
 257 {
 258         int hash;
 259
 260         if (dev == NULL)
 261                 BUG();
 262
 263         read_lock_bh(&pppoe_hash_lock);
 264         for (hash = 0; hash < PPPOE_HASH_SIZE; hash++) {
 265                 struct pppox_opt *po = item_hash_table[hash];
 266
 267                 while (po != NULL) {
 268                         if (po->pppoe_dev == dev) {
 269                                 struct sock *sk = po->sk;
 270
 271                                 sock_hold(sk);
 272                                 po->pppoe_dev = NULL;
 273
 274                                 /* We hold a reference to SK, now drop the
 275                                  * hash table lock so that we may attempt
 276                                  * to lock the socket (which can sleep).
 277                                  */
 278                                 read_unlock_bh(&pppoe_hash_lock);
 279
 280                                 lock_sock(sk);
 281
 282                                 if (sk->state & (PPPOX_CONNECTED|PPPOX_BOUND)){
 283                                         pppox_unbind_sock(sk);
 284                                         dev_put(dev);
 285                                         sk->state = PPPOX_ZOMBIE;
 286                                         sk->state_change(sk);
 287                                 }
 288
 289                                 release_sock(sk);
 290
 291                                 sock_put(sk);
 292
 293                                 read_lock_bh(&pppoe_hash_lock);
 294
 295                                 /* Now restart from the beginning of this
 296                                  * hash chain.  We always NULL out pppoe_dev
 297                                  * so we are guarenteed to make forward
 298                                  * progress.
 299                                  */
 300                                 po = item_hash_table[hash];
 301                                 continue;
 302                         }
 303                         po = po->next;
 304                 }
 305         }
 306         read_unlock_bh(&pppoe_hash_lock);
 307 }
 308
 309 static int pppoe_device_event(struct notifier_block *this,
 310                               unsigned long event, void *ptr)
 311 {
 312         struct net_device *dev = (struct net_device *) ptr;
 313
 314         /* Only look at sockets that are using this specific device. */
 315         switch (event) {
 316         case NETDEV_CHANGEMTU:
 317                 /* A change in mtu is a bad thing, requiring
 318                  * LCP re-negotiation.
 319                  */
 320
 321         case NETDEV_GOING_DOWN:
 322         case NETDEV_DOWN:
 323                 /* Find every socket on this device and kill it. */
 324                 pppoe_flush_dev(dev);
 325                 break;
 326
 327         default:
 328                 break;
 329         };
 330
 331         return NOTIFY_DONE;
 332 }
 333
 334
 335 static struct notifier_block pppoe_notifier = {
 336         notifier_call: pppoe_device_event,
 337 };
 338
 339
 340
 341
 342 /************************************************************************
 343  *
 344  * Do the real work of receiving a PPPoE Session frame.
 345  *
 346  ***********************************************************************/
 347 int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb)
 348 {
 349         struct pppox_opt *po = sk->protinfo.pppox;
 350         struct pppox_opt *relay_po = NULL;
 351
 352         if (sk->state & PPPOX_BOUND) {
 353                 skb_pull(skb, sizeof(struct pppoe_hdr));
 354                 ppp_input(&po->chan, skb);
 355         } else if (sk->state & PPPOX_RELAY) {
 356                 relay_po = get_item_by_addr(&po->pppoe_relay);
 357
 358                 if (relay_po == NULL)
 359                         goto abort_kfree;
 360
 361                 if ((relay_po->sk->state & PPPOX_CONNECTED) == 0)
 362                         goto abort_put;
 363
 364                 skb_pull(skb, sizeof(struct pppoe_hdr));
 365                 if (!__pppoe_xmit( relay_po->sk , skb))
 366                         goto abort_put;
 367         } else {
 368                 sock_queue_rcv_skb(sk, skb);
 369         }
 370
 371         return NET_RX_SUCCESS;
 372
 373 abort_put:
 374         sock_put(relay_po->sk);
 375
 376 abort_kfree:
 377         kfree_skb(skb);
 378         return NET_RX_DROP;
 379 }
 380
 381 /************************************************************************
 382  *
 383  * Receive wrapper called in BH context.
 384  *
 385  ***********************************************************************/
 386 static int pppoe_rcv(struct sk_buff *skb,
 387                       struct net_device *dev,
 388                       struct packet_type *pt)
 389
 390 {
 391         struct pppoe_hdr *ph = (struct pppoe_hdr *) skb->nh.raw;
 392         struct pppox_opt *po;
 393         struct sock *sk ;
 394         int ret;
 395
 396         po = get_item((unsigned long) ph->sid, skb->mac.ethernet->h_source);
 397
 398         if (!po) {
 399                 kfree_skb(skb);
 400                 return NET_RX_DROP;
 401         }
 402
 403         sk = po->sk;
 404         bh_lock_sock(sk);
 405
 406         /* Socket state is unknown, must put skb into backlog. */
 407         if (sk->lock.users != 0) {
 408                 sk_add_backlog(sk, skb);
 409                 ret = NET_RX_SUCCESS;
 410         } else {
 411                 ret = pppoe_rcv_core(sk, skb);
 412         }
 413
 414         bh_unlock_sock(sk);
 415         sock_put(sk);
 416
 417         return ret;
 418 }
 419
 420 /************************************************************************
 421  *
 422  * Receive a PPPoE Discovery frame.
 423  * This is solely for detection of PADT frames
 424  *
 425  ***********************************************************************/
 426 static int pppoe_disc_rcv(struct sk_buff *skb,
 427                           struct net_device *dev,
 428                           struct packet_type *pt)
 429
 430 {
 431         struct pppoe_hdr *ph = (struct pppoe_hdr *) skb->nh.raw;
 432         struct pppox_opt *po;
 433
 434         if (ph->code != PADT_CODE)
 435                 goto abort;
 436
 437         po = get_item((unsigned long) ph->sid, skb->mac.ethernet->h_source);
 438         if (po) {
 439                 struct sock *sk = po->sk;
 440
 441                 bh_lock_sock(sk);
 442
 443                 /* If the user has locked the socket, just ignore
 444                  * the packet.  With the way two rcv protocols hook into
 445                  * one socket family type, we cannot (easily) distinguish
 446                  * what kind of SKB it is during backlog rcv.
 447                  */
 448                 if (sk->lock.users == 0) {
 449                         /* We're no longer connect at the PPPOE layer,
 450                          * and must wait for ppp channel to disconnect us.
 451                          */
 452                         sk->state = PPPOX_ZOMBIE;
 453                 }
 454
 455                 bh_unlock_sock(sk);
 456                 sock_put(sk);
 457         }
 458
 459 abort:
 460         kfree_skb(skb);
 461         return NET_RX_SUCCESS; /* Lies... :-) */
 462 }
 463
 464 struct packet_type pppoes_ptype = {
 465         type:   __constant_htons(ETH_P_PPP_SES),
 466         func:   pppoe_rcv,
 467 };
 468
 469 struct packet_type pppoed_ptype = {
 470         type:   __constant_htons(ETH_P_PPP_DISC),
 471         func:   pppoe_disc_rcv,
 472 };
 473
 474 /***********************************************************************
 475  *
 476  * Really kill the socket. (Called from sock_put if refcnt == 0.)
 477  *
 478  **********************************************************************/
 479 void pppoe_sock_destruct(struct sock *sk)
 480 {
 481         if (sk->protinfo.destruct_hook)
 482                 kfree(sk->protinfo.destruct_hook);
 483         MOD_DEC_USE_COUNT;
 484 }
 485
 486
 487 /***********************************************************************
 488  *
 489  * Initialize a new struct sock.
 490  *
 491  **********************************************************************/
 492 static int pppoe_create(struct socket *sock)
 493 {
 494         int error = 0;
 495         struct sock *sk;
 496
 497         MOD_INC_USE_COUNT;
 498
 499         sk = sk_alloc(PF_PPPOX, GFP_KERNEL, 1);
 500         if (!sk)
 501                 return -ENOMEM;
 502
 503         sock_init_data(sock, sk);
 504
 505         sock->state = SS_UNCONNECTED;
 506         sock->ops   = &pppoe_ops;
 507
 508         sk->protocol = PX_PROTO_OE;
 509         sk->family = PF_PPPOX;
 510
 511         sk->backlog_rcv = pppoe_rcv_core;
 512         sk->next = NULL;
 513         sk->pprev = NULL;
 514         sk->state = PPPOX_NONE;
 515         sk->type = SOCK_STREAM;
 516         sk->destruct = pppoe_sock_destruct;
 517
 518         sk->protinfo.pppox = kmalloc(sizeof(struct pppox_opt), GFP_KERNEL);
 519         if (!sk->protinfo.pppox) {
 520                 error = -ENOMEM;
 521                 goto free_sk;
 522         }
 523
 524         memset((void *) sk->protinfo.pppox, 0, sizeof(struct pppox_opt));
 525         sk->protinfo.pppox->sk = sk;
 526
 527         /* Delete the protinfo when it is time to do so. */
 528         sk->protinfo.destruct_hook = sk->protinfo.pppox;
 529         sock->sk = sk;
 530
 531         return 0;
 532
 533 free_sk:
 534         sk_free(sk);
 535         return error;
 536 }
 537
 538 int pppoe_release(struct socket *sock)
 539 {
 540         struct sock *sk = sock->sk;
 541         struct pppox_opt *po;
 542         int error = 0;
 543
 544         if (!sk)
 545                 return 0;
 546
 547         if (sk->dead != 0)
 548                 return -EBADF;
 549
 550         pppox_unbind_sock(sk);
 551
 552         /* Signal the death of the socket. */
 553         sk->state = PPPOX_DEAD;
 554
 555         po = sk->protinfo.pppox;
 556         if (po->pppoe_pa.sid) {
 557                 delete_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
 558         }
 559
 560         if (po->pppoe_dev)
 561                 dev_put(po->pppoe_dev);
 562
 563         po->pppoe_dev = NULL;
 564
 565         sock_orphan(sk);
 566         sock->sk = NULL;
 567
 568         skb_queue_purge(&sk->receive_queue);
 569         sock_put(sk);
 570
 571         return error;
 572 }
 573
 574
 575 int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
 576                   int sockaddr_len, int flags)
 577 {
 578         struct sock *sk = sock->sk;
 579         struct net_device *dev = NULL;
 580         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
 581         struct pppox_opt *po = sk->protinfo.pppox;
 582         int error;
 583
 584         lock_sock(sk);
 585
 586         error = -EINVAL;
 587         if (sp->sa_protocol != PX_PROTO_OE)
 588                 goto end;
 589
 590         /* Check for already bound sockets */
 591         error = -EBUSY;
 592         if ((sk->state & PPPOX_CONNECTED) && sp->sa_addr.pppoe.sid)
 593                 goto end;
 594
 595         /* Check for already disconnected sockets,
 596            on attempts to disconnect */
 597         error = -EALREADY;
 598         if((sk->state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
 599                 goto end;
 600
 601         error = 0;
 602         if (po->pppoe_pa.sid) {
 603                 pppox_unbind_sock(sk);
 604
 605                 /* Delete the old binding */
 606                 delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote);
 607
 608                 dev_put(po->pppoe_dev);
 609
 610                 memset(po, 0, sizeof(struct pppox_opt));
 611                 po->sk = sk;
 612
 613                 sk->state = PPPOX_NONE;
 614         }
 615
 616         /* Don't re-bind if sid==0 */
 617         if (sp->sa_addr.pppoe.sid != 0) {
 618                 dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
 619
 620                 error = -ENODEV;
 621                 if (!dev)
 622                         goto end;
 623
 624                 po->pppoe_dev = dev;
 625
 626                 if (!(dev->flags & IFF_UP))
 627                         goto err_put;
 628
 629                 memcpy(&po->pppoe_pa,
 630                        &sp->sa_addr.pppoe,
 631                        sizeof(struct pppoe_addr));
 632
 633                 error = set_item(po);
 634                 if (error < 0)
 635                         goto err_put;
 636
 637                 po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
 638                                    dev->hard_header_len);
 639
 640                 po->chan.private = sk;
 641                 po->chan.ops = &pppoe_chan_ops;
 642
 643                 error = ppp_register_channel(&po->chan);
 644                 if (error)
 645                         goto err_put;
 646
 647                 sk->state = PPPOX_CONNECTED;
 648         }
 649
 650         sk->num = sp->sa_addr.pppoe.sid;
 651
 652  end:
 653         release_sock(sk);
 654         return error;
 655 err_put:
 656         dev_put(po->pppoe_dev);
 657         po->pppoe_dev = NULL;
 658         goto end;
 659 }
 660
 661
 662 int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
 663                   int *usockaddr_len, int peer)
 664 {
 665         int len = sizeof(struct sockaddr_pppox);
 666         struct sockaddr_pppox sp;
 667
 668         sp.sa_family    = AF_PPPOX;
 669         sp.sa_protocol  = PX_PROTO_OE;
 670         memcpy(&sp.sa_addr.pppoe, &sock->sk->protinfo.pppox->pppoe_pa,
 671                sizeof(struct pppoe_addr));
 672
 673         memcpy(uaddr, &sp, len);
 674
 675         *usockaddr_len = len;
 676
 677         return 0;
 678 }
 679
 680
 681 int pppoe_ioctl(struct socket *sock, unsigned int cmd,
 682                 unsigned long arg)
 683 {
 684         struct sock *sk = sock->sk;
 685         struct pppox_opt *po;
 686         int val = 0;
 687         int err = 0;
 688
 689         po = sk->protinfo.pppox;
 690         switch (cmd) {
 691         case PPPIOCGMRU:
 692                 err = -ENXIO;
 693
 694                 if (!(sk->state & PPPOX_CONNECTED))
 695                         break;
 696
 697                 err = -EFAULT;
 698                 if (put_user(po->pppoe_dev->mtu -
 699                              sizeof(struct pppoe_hdr) -
 700                              PPP_HDRLEN,
 701                              (int *) arg))
 702                         break;
 703                 err = 0;
 704                 break;
 705
 706         case PPPIOCSMRU:
 707                 err = -ENXIO;
 708                 if (!(sk->state & PPPOX_CONNECTED))
 709                         break;
 710
 711                 err = -EFAULT;
 712                 if (get_user(val,(int *) arg))
 713                         break;
 714
 715                 if (val < (po->pppoe_dev->mtu
 716                            - sizeof(struct pppoe_hdr)
 717                            - PPP_HDRLEN))
 718                         err = 0;
 719                 else
 720                         err = -EINVAL;
 721                 break;
 722
 723         case PPPIOCSFLAGS:
 724                 err = -EFAULT;
 725                 if (get_user(val, (int *) arg))
 726                         break;
 727                 err = 0;
 728                 break;
 729
 730         case PPPOEIOCSFWD:
 731         {
 732                 struct pppox_opt *relay_po;
 733
 734                 err = -EBUSY;
 735                 if (sk->state & (PPPOX_BOUND|PPPOX_ZOMBIE|PPPOX_DEAD))
 736                         break;
 737
 738                 err = -ENOTCONN;
 739                 if (!(sk->state & PPPOX_CONNECTED))
 740                         break;
 741
 742                 /* PPPoE address from the user specifies an outbound
 743                    PPPoE address to which frames are forwarded to */
 744                 err = -EFAULT;
 745                 if (copy_from_user(&po->pppoe_relay,
 746                                    (void*)arg,
 747                                    sizeof(struct sockaddr_pppox)))
 748                         break;
 749
 750                 err = -EINVAL;
 751                 if (po->pppoe_relay.sa_family != AF_PPPOX ||
 752                     po->pppoe_relay.sa_protocol!= PX_PROTO_OE)
 753                         break;
 754
 755                 /* Check that the socket referenced by the address
 756                    actually exists. */
 757                 relay_po = get_item_by_addr(&po->pppoe_relay);
 758
 759                 if (!relay_po)
 760                         break;
 761
 762                 sock_put(relay_po->sk);
 763                 sk->state |= PPPOX_RELAY;
 764                 err = 0;
 765                 break;
 766         }
 767
 768         case PPPOEIOCDFWD:
 769                 err = -EALREADY;
 770                 if (!(sk->state & PPPOX_RELAY))
 771                         break;
 772
 773                 sk->state &= ~PPPOX_RELAY;
 774                 err = 0;
 775                 break;
 776
 777         default:;
 778         };
 779
 780         return err;
 781 }
 782
 783
 784 int pppoe_sendmsg(struct socket *sock, struct msghdr *m,
 785                   int total_len, struct scm_cookie *scm)
 786 {
 787         struct sk_buff *skb = NULL;
 788         struct sock *sk = sock->sk;
 789         int error = 0;
 790         struct pppoe_hdr hdr;
 791         struct pppoe_hdr *ph;
 792         struct net_device *dev;
 793         char *start;
 794
 795         if (sk->dead || !(sk->state & PPPOX_CONNECTED)) {
 796                 error = -ENOTCONN;
 797                 goto end;
 798         }
 799
 800         hdr.ver = 1;
 801         hdr.type = 1;
 802         hdr.code = 0;
 803         hdr.sid = sk->num;
 804
 805         lock_sock(sk);
 806
 807         dev = sk->protinfo.pppox->pppoe_dev;
 808
 809         error = -EMSGSIZE;
 810         if (total_len > (dev->mtu + dev->hard_header_len))
 811                 goto end;
 812
 813
 814         skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32,
 815                            0, GFP_KERNEL);
 816         if (!skb) {
 817                 error = -ENOMEM;
 818                 goto end;
 819         }
 820
 821         /* Reserve space for headers. */
 822         skb_reserve(skb, dev->hard_header_len);
 823         skb->nh.raw = skb->data;
 824
 825         skb->dev = dev;
 826
 827         skb->priority = sk->priority;
 828         skb->protocol = __constant_htons(ETH_P_PPP_SES);
 829
 830         ph = (struct pppoe_hdr *) skb_put(skb, total_len + sizeof(struct pppoe_hdr));
 831         start = (char *) &ph->tag[0];
 832
 833         error = memcpy_fromiovec(start, m->msg_iov, total_len);
 834
 835         if (error < 0) {
 836                 kfree_skb(skb);
 837                 goto end;
 838         }
 839
 840         error = total_len;
 841         dev->hard_header(skb, dev, ETH_P_PPP_SES,
 842                          sk->protinfo.pppox->pppoe_pa.remote,
 843                          NULL, total_len);
 844
 845         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
 846
 847         ph->length = htons(total_len);
 848
 849         dev_queue_xmit(skb);
 850
 851 end:
 852         release_sock(sk);
 853         return error;
 854 }
 855
 856
 857 /************************************************************************
 858  *
 859  * xmit function for internal use.
 860  *
 861  ***********************************************************************/
 862 int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
 863 {
 864         struct net_device *dev = sk->protinfo.pppox->pppoe_dev;
 865         struct pppoe_hdr hdr;
 866         struct pppoe_hdr *ph;
 867         int headroom = skb_headroom(skb);
 868         int data_len = skb->len;
 869         struct sk_buff *skb2;
 870
 871         if (sk->dead  || !(sk->state & PPPOX_CONNECTED))
 872                 goto abort;
 873
 874         hdr.ver = 1;
 875         hdr.type = 1;
 876         hdr.code = 0;
 877         hdr.sid = sk->num;
 878         hdr.length = htons(skb->len);
 879
 880         if (!dev)
 881                 goto abort;
 882
 883         /* Copy the skb if there is no space for the header. */
 884         if (headroom < (sizeof(struct pppoe_hdr) + dev->hard_header_len)) {
 885                 skb2 = dev_alloc_skb(32+skb->len +
 886                                      sizeof(struct pppoe_hdr) +
 887                                      dev->hard_header_len);
 888
 889                 if (skb2 == NULL)
 890                         goto abort;
 891
 892                 skb_reserve(skb2, dev->hard_header_len + sizeof(struct pppoe_hdr));
 893                 memcpy(skb_put(skb2, skb->len), skb->data, skb->len);
 894         } else {
 895                 /* Make a clone so as to not disturb the original skb,
 896                  * give dev_queue_xmit something it can free.
 897                  */
 898                 skb2 = skb_clone(skb, GFP_ATOMIC);
 899         }
 900
 901         ph = (struct pppoe_hdr *) skb_push(skb2, sizeof(struct pppoe_hdr));
 902         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
 903         skb2->protocol = __constant_htons(ETH_P_PPP_SES);
 904
 905         skb2->nh.raw = skb2->data;
 906
 907         skb2->dev = dev;
 908
 909         dev->hard_header(skb2, dev, ETH_P_PPP_SES,
 910                          sk->protinfo.pppox->pppoe_pa.remote,
 911                          NULL, data_len);
 912
 913         /* We're transmitting skb2, and assuming that dev_queue_xmit
 914          * will free it.  The generic ppp layer however, is expecting
 915          * that we give back 'skb' (not 'skb2') in case of failure,
 916          * but free it in case of success.
 917          */
 918
 919         if (dev_queue_xmit(skb2) < 0)
 920                 goto abort;
 921
 922         kfree_skb(skb);
 923         return 1;
 924
 925 abort:
 926         return 0;
 927 }
 928
 929
 930 /************************************************************************
 931  *
 932  * xmit function called by generic PPP driver
 933  * sends PPP frame over PPPoE socket
 934  *
 935  ***********************************************************************/
 936 int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 937 {
 938         struct sock *sk = (struct sock *) chan->private;
 939         return __pppoe_xmit(sk, skb);
 940 }
 941
 942
 943 struct ppp_channel_ops pppoe_chan_ops = { pppoe_xmit , NULL };
 944
 945 int pppoe_rcvmsg(struct socket *sock, struct msghdr *m, int total_len, int flags, struct scm_cookie *scm)
 946 {
 947         struct sock *sk = sock->sk;
 948         struct sk_buff *skb = NULL;
 949         int error = 0;
 950         int len;
 951         struct pppoe_hdr *ph = NULL;
 952
 953         if (sk->state & PPPOX_BOUND) {
 954                 error = -EIO;
 955                 goto end;
 956         }
 957
 958         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
 959                                 flags & MSG_DONTWAIT, &error);
 960
 961         if (error < 0) {
 962                 goto end;
 963         }
 964
 965         m->msg_namelen = 0;
 966
 967         if (skb) {
 968                 error = 0;
 969                 ph = (struct pppoe_hdr *) skb->nh.raw;
 970                 len = ntohs(ph->length);
 971
 972                 error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
 973                 if (error < 0)
 974                         goto do_skb_free;
 975                 error = len;
 976         }
 977
 978 do_skb_free:
 979         if (skb)
 980                 kfree_skb(skb);
 981 end:
 982         return error;
 983 }
 984
 985 int pppoe_proc_info(char *buffer, char **start, off_t offset, int length)
 986 {
 987         struct pppox_opt *po;
 988         int len = 0;
 989         off_t pos = 0;
 990         off_t begin = 0;
 991         int size;
 992         int i;
 993
 994         len += sprintf(buffer,
 995                        "Id       Address              Device\n");
 996         pos = len;
 997
 998         write_lock_bh(&pppoe_hash_lock);
 999
1000         for (i = 0; i < PPPOE_HASH_SIZE; i++) {
1001                 po = item_hash_table[i];
1002                 while (po) {
1003                         char *dev = po->pppoe_pa.dev;
1004
1005                         size = sprintf(buffer + len,
1006                                        "%08X %02X:%02X:%02X:%02X:%02X:%02X %8s\n",
1007                                        po->pppoe_pa.sid,
1008                                        po->pppoe_pa.remote[0],
1009                                        po->pppoe_pa.remote[1],
1010                                        po->pppoe_pa.remote[2],
1011                                        po->pppoe_pa.remote[3],
1012                                        po->pppoe_pa.remote[4],
1013                                        po->pppoe_pa.remote[5],
1014                                        dev);
1015                         len += size;
1016                         pos += size;
1017                         if (pos < offset) {
1018                                 len = 0;
1019                                 begin = pos;
1020                         }
1021
1022                         if (pos > offset + length)
1023                                 break;
1024
1025                         po = po->next;
1026                 }
1027
1028                 if (po)
1029                         break;
1030         }
1031         write_unlock_bh(&pppoe_hash_lock);
1032
1033         *start = buffer + (offset - begin);
1034         len -= (offset - begin);
1035         if (len > length)
1036                 len = length;
1037         if (len < 0)
1038                 len = 0;
1039         return len;
1040 }
1041
1042
1043 struct proto_ops pppoe_ops = {
1044     family:             AF_PPPOX,
1045     release:            pppoe_release,
1046     bind:               sock_no_bind,
1047     connect:            pppoe_connect,
1048     socketpair:         sock_no_socketpair,
1049     accept:             sock_no_accept,
1050     getname:            pppoe_getname,
1051     poll:               datagram_poll,
1052     ioctl:              pppoe_ioctl,
1053     listen:             sock_no_listen,
1054     shutdown:           sock_no_shutdown,
1055     setsockopt:         sock_no_setsockopt,
1056     getsockopt:         sock_no_getsockopt,
1057     sendmsg:            pppoe_sendmsg,
1058     recvmsg:            pppoe_rcvmsg,
1059     mmap:               sock_no_mmap
1060 };
1061
1062 struct pppox_proto pppoe_proto = {
1063     create:     pppoe_create,
1064     ioctl:      pppoe_ioctl
1065 };
1066
1067
1068 int __init pppoe_init(void)
1069 {
1070         int err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
1071
1072         if (err == 0) {
1073                 dev_add_pack(&pppoes_ptype);
1074                 dev_add_pack(&pppoed_ptype);
1075                 register_netdevice_notifier(&pppoe_notifier);
1076                 proc_net_create("pppoe", 0, pppoe_proc_info);
1077         }
1078         return err;
1079 }
1080
1081 void __exit pppoe_exit(void)
1082 {
1083         unregister_pppox_proto(PX_PROTO_OE);
1084         dev_remove_pack(&pppoes_ptype);
1085         dev_remove_pack(&pppoed_ptype);
1086         unregister_netdevice_notifier(&pppoe_notifier);
1087         proc_net_remove("pppoe");
1088 }
1089
1090 module_init(pppoe_init);
1091 module_exit(pppoe_exit);
1092
1093 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1094 MODULE_DESCRIPTION("PPP over Ethernet driver");
1095 MODULE_LICENSE("GPL");