drivers/net/pppoe.c

   1 /** -*- linux-c -*- ***********************************************************
   2  * Linux PPP over Ethernet (PPPoX/PPPoE) Sockets
   3  *
   4  * PPPoX --- Generic PPP encapsulation socket family
   5  * PPPoE --- PPP over Ethernet (RFC 2516)
   6  *
   7  *
   8  * Version:     0.7.0
   9  *
  10  * 220102 :     Fix module use count on failure in pppoe_create, pppox_sk -acme
  11  * 030700 :     Fixed connect logic to allow for disconnect.
  12  * 270700 :     Fixed potential SMP problems; we must protect against
  13  *              simultaneous invocation of ppp_input
  14  *              and ppp_unregister_channel.
  15  * 040800 :     Respect reference count mechanisms on net-devices.
  16  * 200800 :     fix kfree(skb) in pppoe_rcv (acme)
  17  *              Module reference count is decremented in the right spot now,
  18  *              guards against sock_put not actually freeing the sk
  19  *              in pppoe_release.
  20  * 051000 :     Initialization cleanup.
  21  * 111100 :     Fix recvmsg.
  22  * 050101 :     Fix PADT procesing.
  23  * 140501 :     Use pppoe_rcv_core to handle all backlog. (Alexey)
  24  * 170701 :     Do not lock_sock with rwlock held. (DaveM)
  25  *              Ignore discovery frames if user has socket
  26  *              locked. (DaveM)
  27  *              Ignore return value of dev_queue_xmit in __pppoe_xmit
  28  *              or else we may kfree an SKB twice. (DaveM)
  29  * 190701 :     When doing copies of skb's in __pppoe_xmit, always delete
  30  *              the original skb that was passed in on success, never on
  31  *              failure.  Delete the copy of the skb on failure to avoid
  32  *              a memory leak.
  33  * 081001 :     Misc. cleanup (licence string, non-blocking, prevent
  34  *              reference of device on close).
  35  * 121301 :     New ppp channels interface; cannot unregister a channel
  36  *              from interrupts.  Thus, we mark the socket as a ZOMBIE
  37  *              and do the unregistration later.
  38  * 081002 :     seq_file support for proc stuff -acme
  39  * 111602 :     Merge all 2.4 fixes into 2.5/2.6 tree.  Label 2.5/2.6
  40  *              as version 0.7.  Spacing cleanup.
  41  * Author:      Michal Ostrowski <mostrows@speakeasy.net>
  42  * Contributors:
  43  *              Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  44  *              David S. Miller (davem@redhat.com)
  45  *
  46  * License:
  47  *              This program is free software; you can redistribute it and/or
  48  *              modify it under the terms of the GNU General Public License
  49  *              as published by the Free Software Foundation; either version
  50  *              2 of the License, or (at your option) any later version.
  51  *
  52  */
  53
  54 #include <linux/string.h>
  55 #include <linux/module.h>
  56 #include <linux/kernel.h>
  57 #include <linux/slab.h>
  58 #include <linux/errno.h>
  59 #include <linux/netdevice.h>
  60 #include <linux/net.h>
  61 #include <linux/inetdevice.h>
  62 #include <linux/etherdevice.h>
  63 #include <linux/skbuff.h>
  64 #include <linux/init.h>
  65 #include <linux/if_ether.h>
  66 #include <linux/if_pppox.h>
  67 #include <linux/ppp_channel.h>
  68 #include <linux/ppp_defs.h>
  69 #include <linux/if_ppp.h>
  70 #include <linux/notifier.h>
  71 #include <linux/file.h>
  72 #include <linux/proc_fs.h>
  73 #include <linux/seq_file.h>
  74
  75 #include <net/sock.h>
  76
  77 #include <asm/uaccess.h>
  78
  79 #define PPPOE_HASH_BITS 4
  80 #define PPPOE_HASH_SIZE (1<<PPPOE_HASH_BITS)
  81
  82 static struct ppp_channel_ops pppoe_chan_ops;
  83
  84 static int pppoe_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
  85 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb);
  86 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
  87
  88 static const struct proto_ops pppoe_ops;
  89 static DEFINE_RWLOCK(pppoe_hash_lock);
  90
  91 static struct ppp_channel_ops pppoe_chan_ops;
  92
  93 static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
  94 {
  95         return (a->sid == b->sid &&
  96                 (memcmp(a->remote, b->remote, ETH_ALEN) == 0));
  97 }
  98
  99 static inline int cmp_addr(struct pppoe_addr *a, unsigned long sid, char *addr)
 100 {
 101         return (a->sid == sid &&
 102                 (memcmp(a->remote,addr,ETH_ALEN) == 0));
 103 }
 104
 105 static int hash_item(unsigned long sid, unsigned char *addr)
 106 {
 107         char hash = 0;
 108         int i, j;
 109
 110         for (i = 0; i < ETH_ALEN ; ++i) {
 111                 for (j = 0; j < 8/PPPOE_HASH_BITS ; ++j) {
 112                         hash ^= addr[i] >> ( j * PPPOE_HASH_BITS );
 113                 }
 114         }
 115
 116         for (i = 0; i < (sizeof(unsigned long)*8) / PPPOE_HASH_BITS ; ++i)
 117                 hash ^= sid >> (i*PPPOE_HASH_BITS);
 118
 119         return hash & ( PPPOE_HASH_SIZE - 1 );
 120 }
 121
 122 /* zeroed because its in .bss */
 123 static struct pppox_sock *item_hash_table[PPPOE_HASH_SIZE];
 124
 125 /**********************************************************************
 126  *
 127  *  Set/get/delete/rehash items  (internal versions)
 128  *
 129  **********************************************************************/
 130 static struct pppox_sock *__get_item(unsigned long sid, unsigned char *addr)
 131 {
 132         int hash = hash_item(sid, addr);
 133         struct pppox_sock *ret;
 134
 135         ret = item_hash_table[hash];
 136
 137         while (ret && !cmp_addr(&ret->pppoe_pa, sid, addr))
 138                 ret = ret->next;
 139
 140         return ret;
 141 }
 142
 143 static int __set_item(struct pppox_sock *po)
 144 {
 145         int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
 146         struct pppox_sock *ret;
 147
 148         ret = item_hash_table[hash];
 149         while (ret) {
 150                 if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa))
 151                         return -EALREADY;
 152
 153                 ret = ret->next;
 154         }
 155
 156         if (!ret) {
 157                 po->next = item_hash_table[hash];
 158                 item_hash_table[hash] = po;
 159         }
 160
 161         return 0;
 162 }
 163
 164 static struct pppox_sock *__delete_item(unsigned long sid, char *addr)
 165 {
 166         int hash = hash_item(sid, addr);
 167         struct pppox_sock *ret, **src;
 168
 169         ret = item_hash_table[hash];
 170         src = &item_hash_table[hash];
 171
 172         while (ret) {
 173                 if (cmp_addr(&ret->pppoe_pa, sid, addr)) {
 174                         *src = ret->next;
 175                         break;
 176                 }
 177
 178                 src = &ret->next;
 179                 ret = ret->next;
 180         }
 181
 182         return ret;
 183 }
 184
 185 /**********************************************************************
 186  *
 187  *  Set/get/delete/rehash items
 188  *
 189  **********************************************************************/
 190 static inline struct pppox_sock *get_item(unsigned long sid,
 191                                          unsigned char *addr)
 192 {
 193         struct pppox_sock *po;
 194
 195         read_lock_bh(&pppoe_hash_lock);
 196         po = __get_item(sid, addr);
 197         if (po)
 198                 sock_hold(sk_pppox(po));
 199         read_unlock_bh(&pppoe_hash_lock);
 200
 201         return po;
 202 }
 203
 204 static inline struct pppox_sock *get_item_by_addr(struct sockaddr_pppox *sp)
 205 {
 206         return get_item(sp->sa_addr.pppoe.sid, sp->sa_addr.pppoe.remote);
 207 }
 208
 209 static inline int set_item(struct pppox_sock *po)
 210 {
 211         int i;
 212
 213         if (!po)
 214                 return -EINVAL;
 215
 216         write_lock_bh(&pppoe_hash_lock);
 217         i = __set_item(po);
 218         write_unlock_bh(&pppoe_hash_lock);
 219
 220         return i;
 221 }
 222
 223 static inline struct pppox_sock *delete_item(unsigned long sid, char *addr)
 224 {
 225         struct pppox_sock *ret;
 226
 227         write_lock_bh(&pppoe_hash_lock);
 228         ret = __delete_item(sid, addr);
 229         write_unlock_bh(&pppoe_hash_lock);
 230
 231         return ret;
 232 }
 233
 234
 235
 236 /***************************************************************************
 237  *
 238  *  Handler for device events.
 239  *  Certain device events require that sockets be unconnected.
 240  *
 241  **************************************************************************/
 242
 243 static void pppoe_flush_dev(struct net_device *dev)
 244 {
 245         int hash;
 246
 247         BUG_ON(dev == NULL);
 248
 249         read_lock_bh(&pppoe_hash_lock);
 250         for (hash = 0; hash < PPPOE_HASH_SIZE; hash++) {
 251                 struct pppox_sock *po = item_hash_table[hash];
 252
 253                 while (po != NULL) {
 254                         if (po->pppoe_dev == dev) {
 255                                 struct sock *sk = sk_pppox(po);
 256
 257                                 sock_hold(sk);
 258                                 po->pppoe_dev = NULL;
 259
 260                                 /* We hold a reference to SK, now drop the
 261                                  * hash table lock so that we may attempt
 262                                  * to lock the socket (which can sleep).
 263                                  */
 264                                 read_unlock_bh(&pppoe_hash_lock);
 265
 266                                 lock_sock(sk);
 267
 268                                 if (sk->sk_state &
 269                                     (PPPOX_CONNECTED | PPPOX_BOUND)) {
 270                                         pppox_unbind_sock(sk);
 271                                         dev_put(dev);
 272                                         sk->sk_state = PPPOX_ZOMBIE;
 273                                         sk->sk_state_change(sk);
 274                                 }
 275
 276                                 release_sock(sk);
 277
 278                                 sock_put(sk);
 279
 280                                 read_lock_bh(&pppoe_hash_lock);
 281
 282                                 /* Now restart from the beginning of this
 283                                  * hash chain.  We always NULL out pppoe_dev
 284                                  * so we are guaranteed to make forward
 285                                  * progress.
 286                                  */
 287                                 po = item_hash_table[hash];
 288                                 continue;
 289                         }
 290                         po = po->next;
 291                 }
 292         }
 293         read_unlock_bh(&pppoe_hash_lock);
 294 }
 295
 296 static int pppoe_device_event(struct notifier_block *this,
 297                               unsigned long event, void *ptr)
 298 {
 299         struct net_device *dev = (struct net_device *) ptr;
 300
 301         /* Only look at sockets that are using this specific device. */
 302         switch (event) {
 303         case NETDEV_CHANGEMTU:
 304                 /* A change in mtu is a bad thing, requiring
 305                  * LCP re-negotiation.
 306                  */
 307
 308         case NETDEV_GOING_DOWN:
 309         case NETDEV_DOWN:
 310                 /* Find every socket on this device and kill it. */
 311                 pppoe_flush_dev(dev);
 312                 break;
 313
 314         default:
 315                 break;
 316         };
 317
 318         return NOTIFY_DONE;
 319 }
 320
 321
 322 static struct notifier_block pppoe_notifier = {
 323         .notifier_call = pppoe_device_event,
 324 };
 325
 326
 327 /************************************************************************
 328  *
 329  * Do the real work of receiving a PPPoE Session frame.
 330  *
 331  ***********************************************************************/
 332 static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb)
 333 {
 334         struct pppox_sock *po = pppox_sk(sk);
 335         struct pppox_sock *relay_po = NULL;
 336
 337         if (sk->sk_state & PPPOX_BOUND) {
 338                 struct pppoe_hdr *ph = (struct pppoe_hdr *) skb->nh.raw;
 339                 int len = ntohs(ph->length);
 340                 skb_pull(skb, sizeof(struct pppoe_hdr));
 341                 skb_postpull_rcsum(skb, ph, sizeof(*ph));
 342                 if (pskb_trim_rcsum(skb, len))
 343                         goto abort_kfree;
 344
 345                 ppp_input(&po->chan, skb);
 346         } else if (sk->sk_state & PPPOX_RELAY) {
 347                 relay_po = get_item_by_addr(&po->pppoe_relay);
 348
 349                 if (relay_po == NULL)
 350                         goto abort_kfree;
 351
 352                 if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0)
 353                         goto abort_put;
 354
 355                 skb_pull(skb, sizeof(struct pppoe_hdr));
 356                 if (!__pppoe_xmit(sk_pppox(relay_po), skb))
 357                         goto abort_put;
 358         } else {
 359                 if (sock_queue_rcv_skb(sk, skb))
 360                         goto abort_kfree;
 361         }
 362
 363         return NET_RX_SUCCESS;
 364
 365 abort_put:
 366         sock_put(sk_pppox(relay_po));
 367
 368 abort_kfree:
 369         kfree_skb(skb);
 370         return NET_RX_DROP;
 371 }
 372
 373 /************************************************************************
 374  *
 375  * Receive wrapper called in BH context.
 376  *
 377  ***********************************************************************/
 378 static int pppoe_rcv(struct sk_buff *skb,
 379                      struct net_device *dev,
 380                      struct packet_type *pt,
 381                      struct net_device *orig_dev)
 382
 383 {
 384         struct pppoe_hdr *ph;
 385         struct pppox_sock *po;
 386
 387         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
 388                 goto drop;
 389
 390         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
 391                 goto out;
 392
 393         ph = (struct pppoe_hdr *) skb->nh.raw;
 394
 395         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source);
 396         if (po != NULL)
 397                 return sk_receive_skb(sk_pppox(po), skb);
 398 drop:
 399         kfree_skb(skb);
 400 out:
 401         return NET_RX_DROP;
 402 }
 403
 404 /************************************************************************
 405  *
 406  * Receive a PPPoE Discovery frame.
 407  * This is solely for detection of PADT frames
 408  *
 409  ***********************************************************************/
 410 static int pppoe_disc_rcv(struct sk_buff *skb,
 411                           struct net_device *dev,
 412                           struct packet_type *pt,
 413                           struct net_device *orig_dev)
 414
 415 {
 416         struct pppoe_hdr *ph;
 417         struct pppox_sock *po;
 418
 419         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
 420                 goto abort;
 421
 422         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
 423                 goto out;
 424
 425         ph = (struct pppoe_hdr *) skb->nh.raw;
 426         if (ph->code != PADT_CODE)
 427                 goto abort;
 428
 429         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source);
 430         if (po) {
 431                 struct sock *sk = sk_pppox(po);
 432
 433                 bh_lock_sock(sk);
 434
 435                 /* If the user has locked the socket, just ignore
 436                  * the packet.  With the way two rcv protocols hook into
 437                  * one socket family type, we cannot (easily) distinguish
 438                  * what kind of SKB it is during backlog rcv.
 439                  */
 440                 if (sock_owned_by_user(sk) == 0) {
 441                         /* We're no longer connect at the PPPOE layer,
 442                          * and must wait for ppp channel to disconnect us.
 443                          */
 444                         sk->sk_state = PPPOX_ZOMBIE;
 445                 }
 446
 447                 bh_unlock_sock(sk);
 448                 sock_put(sk);
 449         }
 450
 451 abort:
 452         kfree_skb(skb);
 453 out:
 454         return NET_RX_SUCCESS; /* Lies... :-) */
 455 }
 456
 457 static struct packet_type pppoes_ptype = {
 458         .type   = __constant_htons(ETH_P_PPP_SES),
 459         .func   = pppoe_rcv,
 460 };
 461
 462 static struct packet_type pppoed_ptype = {
 463         .type   = __constant_htons(ETH_P_PPP_DISC),
 464         .func   = pppoe_disc_rcv,
 465 };
 466
 467 static struct proto pppoe_sk_proto = {
 468         .name     = "PPPOE",
 469         .owner    = THIS_MODULE,
 470         .obj_size = sizeof(struct pppox_sock),
 471 };
 472
 473 /***********************************************************************
 474  *
 475  * Initialize a new struct sock.
 476  *
 477  **********************************************************************/
 478 static int pppoe_create(struct socket *sock)
 479 {
 480         int error = -ENOMEM;
 481         struct sock *sk;
 482
 483         sk = sk_alloc(PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, 1);
 484         if (!sk)
 485                 goto out;
 486
 487         sock_init_data(sock, sk);
 488
 489         sock->state = SS_UNCONNECTED;
 490         sock->ops   = &pppoe_ops;
 491
 492         sk->sk_backlog_rcv = pppoe_rcv_core;
 493         sk->sk_state       = PPPOX_NONE;
 494         sk->sk_type        = SOCK_STREAM;
 495         sk->sk_family      = PF_PPPOX;
 496         sk->sk_protocol    = PX_PROTO_OE;
 497
 498         error = 0;
 499 out:    return error;
 500 }
 501
 502 static int pppoe_release(struct socket *sock)
 503 {
 504         struct sock *sk = sock->sk;
 505         struct pppox_sock *po;
 506         int error = 0;
 507
 508         if (!sk)
 509                 return 0;
 510
 511         if (sock_flag(sk, SOCK_DEAD))
 512                 return -EBADF;
 513
 514         pppox_unbind_sock(sk);
 515
 516         /* Signal the death of the socket. */
 517         sk->sk_state = PPPOX_DEAD;
 518
 519         po = pppox_sk(sk);
 520         if (po->pppoe_pa.sid) {
 521                 delete_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
 522         }
 523
 524         if (po->pppoe_dev)
 525                 dev_put(po->pppoe_dev);
 526
 527         po->pppoe_dev = NULL;
 528
 529         sock_orphan(sk);
 530         sock->sk = NULL;
 531
 532         skb_queue_purge(&sk->sk_receive_queue);
 533         sock_put(sk);
 534
 535         return error;
 536 }
 537
 538
 539 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
 540                   int sockaddr_len, int flags)
 541 {
 542         struct sock *sk = sock->sk;
 543         struct net_device *dev = NULL;
 544         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
 545         struct pppox_sock *po = pppox_sk(sk);
 546         int error;
 547
 548         lock_sock(sk);
 549
 550         error = -EINVAL;
 551         if (sp->sa_protocol != PX_PROTO_OE)
 552                 goto end;
 553
 554         /* Check for already bound sockets */
 555         error = -EBUSY;
 556         if ((sk->sk_state & PPPOX_CONNECTED) && sp->sa_addr.pppoe.sid)
 557                 goto end;
 558
 559         /* Check for already disconnected sockets, on attempts to disconnect */
 560         error = -EALREADY;
 561         if ((sk->sk_state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
 562                 goto end;
 563
 564         error = 0;
 565         if (po->pppoe_pa.sid) {
 566                 pppox_unbind_sock(sk);
 567
 568                 /* Delete the old binding */
 569                 delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote);
 570
 571                 if(po->pppoe_dev)
 572                         dev_put(po->pppoe_dev);
 573
 574                 memset(sk_pppox(po) + 1, 0,
 575                        sizeof(struct pppox_sock) - sizeof(struct sock));
 576
 577                 sk->sk_state = PPPOX_NONE;
 578         }
 579
 580         /* Don't re-bind if sid==0 */
 581         if (sp->sa_addr.pppoe.sid != 0) {
 582                 dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
 583
 584                 error = -ENODEV;
 585                 if (!dev)
 586                         goto end;
 587
 588                 po->pppoe_dev = dev;
 589
 590                 if (!(dev->flags & IFF_UP))
 591                         goto err_put;
 592
 593                 memcpy(&po->pppoe_pa,
 594                        &sp->sa_addr.pppoe,
 595                        sizeof(struct pppoe_addr));
 596
 597                 error = set_item(po);
 598                 if (error < 0)
 599                         goto err_put;
 600
 601                 po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
 602                                    dev->hard_header_len);
 603
 604                 po->chan.private = sk;
 605                 po->chan.ops = &pppoe_chan_ops;
 606
 607                 error = ppp_register_channel(&po->chan);
 608                 if (error)
 609                         goto err_put;
 610
 611                 sk->sk_state = PPPOX_CONNECTED;
 612         }
 613
 614         po->num = sp->sa_addr.pppoe.sid;
 615
 616  end:
 617         release_sock(sk);
 618         return error;
 619 err_put:
 620         if (po->pppoe_dev) {
 621                 dev_put(po->pppoe_dev);
 622                 po->pppoe_dev = NULL;
 623         }
 624         goto end;
 625 }
 626
 627
 628 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
 629                   int *usockaddr_len, int peer)
 630 {
 631         int len = sizeof(struct sockaddr_pppox);
 632         struct sockaddr_pppox sp;
 633
 634         sp.sa_family    = AF_PPPOX;
 635         sp.sa_protocol  = PX_PROTO_OE;
 636         memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
 637                sizeof(struct pppoe_addr));
 638
 639         memcpy(uaddr, &sp, len);
 640
 641         *usockaddr_len = len;
 642
 643         return 0;
 644 }
 645
 646
 647 static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
 648                 unsigned long arg)
 649 {
 650         struct sock *sk = sock->sk;
 651         struct pppox_sock *po = pppox_sk(sk);
 652         int val = 0;
 653         int err = 0;
 654
 655         switch (cmd) {
 656         case PPPIOCGMRU:
 657                 err = -ENXIO;
 658
 659                 if (!(sk->sk_state & PPPOX_CONNECTED))
 660                         break;
 661
 662                 err = -EFAULT;
 663                 if (put_user(po->pppoe_dev->mtu -
 664                              sizeof(struct pppoe_hdr) -
 665                              PPP_HDRLEN,
 666                              (int __user *) arg))
 667                         break;
 668                 err = 0;
 669                 break;
 670
 671         case PPPIOCSMRU:
 672                 err = -ENXIO;
 673                 if (!(sk->sk_state & PPPOX_CONNECTED))
 674                         break;
 675
 676                 err = -EFAULT;
 677                 if (get_user(val,(int __user *) arg))
 678                         break;
 679
 680                 if (val < (po->pppoe_dev->mtu
 681                            - sizeof(struct pppoe_hdr)
 682                            - PPP_HDRLEN))
 683                         err = 0;
 684                 else
 685                         err = -EINVAL;
 686                 break;
 687
 688         case PPPIOCSFLAGS:
 689                 err = -EFAULT;
 690                 if (get_user(val, (int __user *) arg))
 691                         break;
 692                 err = 0;
 693                 break;
 694
 695         case PPPOEIOCSFWD:
 696         {
 697                 struct pppox_sock *relay_po;
 698
 699                 err = -EBUSY;
 700                 if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD))
 701                         break;
 702
 703                 err = -ENOTCONN;
 704                 if (!(sk->sk_state & PPPOX_CONNECTED))
 705                         break;
 706
 707                 /* PPPoE address from the user specifies an outbound
 708                    PPPoE address to which frames are forwarded to */
 709                 err = -EFAULT;
 710                 if (copy_from_user(&po->pppoe_relay,
 711                                    (void __user *)arg,
 712                                    sizeof(struct sockaddr_pppox)))
 713                         break;
 714
 715                 err = -EINVAL;
 716                 if (po->pppoe_relay.sa_family != AF_PPPOX ||
 717                     po->pppoe_relay.sa_protocol!= PX_PROTO_OE)
 718                         break;
 719
 720                 /* Check that the socket referenced by the address
 721                    actually exists. */
 722                 relay_po = get_item_by_addr(&po->pppoe_relay);
 723
 724                 if (!relay_po)
 725                         break;
 726
 727                 sock_put(sk_pppox(relay_po));
 728                 sk->sk_state |= PPPOX_RELAY;
 729                 err = 0;
 730                 break;
 731         }
 732
 733         case PPPOEIOCDFWD:
 734                 err = -EALREADY;
 735                 if (!(sk->sk_state & PPPOX_RELAY))
 736                         break;
 737
 738                 sk->sk_state &= ~PPPOX_RELAY;
 739                 err = 0;
 740                 break;
 741
 742         default:;
 743         };
 744
 745         return err;
 746 }
 747
 748
 749 static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
 750                   struct msghdr *m, size_t total_len)
 751 {
 752         struct sk_buff *skb = NULL;
 753         struct sock *sk = sock->sk;
 754         struct pppox_sock *po = pppox_sk(sk);
 755         int error = 0;
 756         struct pppoe_hdr hdr;
 757         struct pppoe_hdr *ph;
 758         struct net_device *dev;
 759         char *start;
 760
 761         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
 762                 error = -ENOTCONN;
 763                 goto end;
 764         }
 765
 766         hdr.ver = 1;
 767         hdr.type = 1;
 768         hdr.code = 0;
 769         hdr.sid = po->num;
 770
 771         lock_sock(sk);
 772
 773         dev = po->pppoe_dev;
 774
 775         error = -EMSGSIZE;
 776         if (total_len > (dev->mtu + dev->hard_header_len))
 777                 goto end;
 778
 779
 780         skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32,
 781                            0, GFP_KERNEL);
 782         if (!skb) {
 783                 error = -ENOMEM;
 784                 goto end;
 785         }
 786
 787         /* Reserve space for headers. */
 788         skb_reserve(skb, dev->hard_header_len);
 789         skb->nh.raw = skb->data;
 790
 791         skb->dev = dev;
 792
 793         skb->priority = sk->sk_priority;
 794         skb->protocol = __constant_htons(ETH_P_PPP_SES);
 795
 796         ph = (struct pppoe_hdr *) skb_put(skb, total_len + sizeof(struct pppoe_hdr));
 797         start = (char *) &ph->tag[0];
 798
 799         error = memcpy_fromiovec(start, m->msg_iov, total_len);
 800
 801         if (error < 0) {
 802                 kfree_skb(skb);
 803                 goto end;
 804         }
 805
 806         error = total_len;
 807         dev->hard_header(skb, dev, ETH_P_PPP_SES,
 808                          po->pppoe_pa.remote, NULL, total_len);
 809
 810         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
 811
 812         ph->length = htons(total_len);
 813
 814         dev_queue_xmit(skb);
 815
 816 end:
 817         release_sock(sk);
 818         return error;
 819 }
 820
 821
 822 /************************************************************************
 823  *
 824  * xmit function for internal use.
 825  *
 826  ***********************************************************************/
 827 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
 828 {
 829         struct pppox_sock *po = pppox_sk(sk);
 830         struct net_device *dev = po->pppoe_dev;
 831         struct pppoe_hdr hdr;
 832         struct pppoe_hdr *ph;
 833         int headroom = skb_headroom(skb);
 834         int data_len = skb->len;
 835         struct sk_buff *skb2;
 836
 837         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
 838                 goto abort;
 839
 840         hdr.ver = 1;
 841         hdr.type = 1;
 842         hdr.code = 0;
 843         hdr.sid = po->num;
 844         hdr.length = htons(skb->len);
 845
 846         if (!dev)
 847                 goto abort;
 848
 849         /* Copy the skb if there is no space for the header. */
 850         if (headroom < (sizeof(struct pppoe_hdr) + dev->hard_header_len)) {
 851                 skb2 = dev_alloc_skb(32+skb->len +
 852                                      sizeof(struct pppoe_hdr) +
 853                                      dev->hard_header_len);
 854
 855                 if (skb2 == NULL)
 856                         goto abort;
 857
 858                 skb_reserve(skb2, dev->hard_header_len + sizeof(struct pppoe_hdr));
 859                 memcpy(skb_put(skb2, skb->len), skb->data, skb->len);
 860         } else {
 861                 /* Make a clone so as to not disturb the original skb,
 862                  * give dev_queue_xmit something it can free.
 863                  */
 864                 skb2 = skb_clone(skb, GFP_ATOMIC);
 865         }
 866
 867         ph = (struct pppoe_hdr *) skb_push(skb2, sizeof(struct pppoe_hdr));
 868         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
 869         skb2->protocol = __constant_htons(ETH_P_PPP_SES);
 870
 871         skb2->nh.raw = skb2->data;
 872
 873         skb2->dev = dev;
 874
 875         dev->hard_header(skb2, dev, ETH_P_PPP_SES,
 876                          po->pppoe_pa.remote, NULL, data_len);
 877
 878         /* We're transmitting skb2, and assuming that dev_queue_xmit
 879          * will free it.  The generic ppp layer however, is expecting
 880          * that we give back 'skb' (not 'skb2') in case of failure,
 881          * but free it in case of success.
 882          */
 883
 884         if (dev_queue_xmit(skb2) < 0)
 885                 goto abort;
 886
 887         kfree_skb(skb);
 888         return 1;
 889
 890 abort:
 891         return 0;
 892 }
 893
 894
 895 /************************************************************************
 896  *
 897  * xmit function called by generic PPP driver
 898  * sends PPP frame over PPPoE socket
 899  *
 900  ***********************************************************************/
 901 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 902 {
 903         struct sock *sk = (struct sock *) chan->private;
 904         return __pppoe_xmit(sk, skb);
 905 }
 906
 907
 908 static struct ppp_channel_ops pppoe_chan_ops = {
 909         .start_xmit = pppoe_xmit,
 910 };
 911
 912 static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
 913                   struct msghdr *m, size_t total_len, int flags)
 914 {
 915         struct sock *sk = sock->sk;
 916         struct sk_buff *skb = NULL;
 917         int error = 0;
 918         int len;
 919         struct pppoe_hdr *ph = NULL;
 920
 921         if (sk->sk_state & PPPOX_BOUND) {
 922                 error = -EIO;
 923                 goto end;
 924         }
 925
 926         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
 927                                 flags & MSG_DONTWAIT, &error);
 928
 929         if (error < 0) {
 930                 goto end;
 931         }
 932
 933         m->msg_namelen = 0;
 934
 935         if (skb) {
 936                 error = 0;
 937                 ph = (struct pppoe_hdr *) skb->nh.raw;
 938                 len = ntohs(ph->length);
 939
 940                 error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
 941                 if (error < 0)
 942                         goto do_skb_free;
 943                 error = len;
 944         }
 945
 946 do_skb_free:
 947         if (skb)
 948                 kfree_skb(skb);
 949 end:
 950         return error;
 951 }
 952
 953 #ifdef CONFIG_PROC_FS
 954 static int pppoe_seq_show(struct seq_file *seq, void *v)
 955 {
 956         struct pppox_sock *po;
 957         char *dev_name;
 958
 959         if (v == SEQ_START_TOKEN) {
 960                 seq_puts(seq, "Id       Address              Device\n");
 961                 goto out;
 962         }
 963
 964         po = v;
 965         dev_name = po->pppoe_pa.dev;
 966
 967         seq_printf(seq, "%08X %02X:%02X:%02X:%02X:%02X:%02X %8s\n",
 968                    po->pppoe_pa.sid,
 969                    po->pppoe_pa.remote[0], po->pppoe_pa.remote[1],
 970                    po->pppoe_pa.remote[2], po->pppoe_pa.remote[3],
 971                    po->pppoe_pa.remote[4], po->pppoe_pa.remote[5], dev_name);
 972 out:
 973         return 0;
 974 }
 975
 976 static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
 977 {
 978         struct pppox_sock *po = NULL;
 979         int i = 0;
 980
 981         for (; i < PPPOE_HASH_SIZE; i++) {
 982                 po = item_hash_table[i];
 983                 while (po) {
 984                         if (!pos--)
 985                                 goto out;
 986                         po = po->next;
 987                 }
 988         }
 989 out:
 990         return po;
 991 }
 992
 993 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
 994 {
 995         loff_t l = *pos;
 996
 997         read_lock_bh(&pppoe_hash_lock);
 998         return l ? pppoe_get_idx(--l) : SEQ_START_TOKEN;
 999 }
1000
1001 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1002 {
1003         struct pppox_sock *po;
1004
1005         ++*pos;
1006         if (v == SEQ_START_TOKEN) {
1007                 po = pppoe_get_idx(0);
1008                 goto out;
1009         }
1010         po = v;
1011         if (po->next)
1012                 po = po->next;
1013         else {
1014                 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
1015
1016                 while (++hash < PPPOE_HASH_SIZE) {
1017                         po = item_hash_table[hash];
1018                         if (po)
1019                                 break;
1020                 }
1021         }
1022 out:
1023         return po;
1024 }
1025
1026 static void pppoe_seq_stop(struct seq_file *seq, void *v)
1027 {
1028         read_unlock_bh(&pppoe_hash_lock);
1029 }
1030
1031 static struct seq_operations pppoe_seq_ops = {
1032         .start          = pppoe_seq_start,
1033         .next           = pppoe_seq_next,
1034         .stop           = pppoe_seq_stop,
1035         .show           = pppoe_seq_show,
1036 };
1037
1038 static int pppoe_seq_open(struct inode *inode, struct file *file)
1039 {
1040         return seq_open(file, &pppoe_seq_ops);
1041 }
1042
1043 static struct file_operations pppoe_seq_fops = {
1044         .owner          = THIS_MODULE,
1045         .open           = pppoe_seq_open,
1046         .read           = seq_read,
1047         .llseek         = seq_lseek,
1048         .release        = seq_release,
1049 };
1050
1051 static int __init pppoe_proc_init(void)
1052 {
1053         struct proc_dir_entry *p;
1054
1055         p = create_proc_entry("net/pppoe", S_IRUGO, NULL);
1056         if (!p)
1057                 return -ENOMEM;
1058
1059         p->proc_fops = &pppoe_seq_fops;
1060         return 0;
1061 }
1062 #else /* CONFIG_PROC_FS */
1063 static inline int pppoe_proc_init(void) { return 0; }
1064 #endif /* CONFIG_PROC_FS */
1065
1066 static const struct proto_ops pppoe_ops = {
1067     .family             = AF_PPPOX,
1068     .owner              = THIS_MODULE,
1069     .release            = pppoe_release,
1070     .bind               = sock_no_bind,
1071     .connect            = pppoe_connect,
1072     .socketpair         = sock_no_socketpair,
1073     .accept             = sock_no_accept,
1074     .getname            = pppoe_getname,
1075     .poll               = datagram_poll,
1076     .listen             = sock_no_listen,
1077     .shutdown           = sock_no_shutdown,
1078     .setsockopt         = sock_no_setsockopt,
1079     .getsockopt         = sock_no_getsockopt,
1080     .sendmsg            = pppoe_sendmsg,
1081     .recvmsg            = pppoe_recvmsg,
1082     .mmap               = sock_no_mmap,
1083     .ioctl              = pppox_ioctl,
1084 };
1085
1086 static struct pppox_proto pppoe_proto = {
1087     .create     = pppoe_create,
1088     .ioctl      = pppoe_ioctl,
1089     .owner      = THIS_MODULE,
1090 };
1091
1092
1093 static int __init pppoe_init(void)
1094 {
1095         int err = proto_register(&pppoe_sk_proto, 0);
1096
1097         if (err)
1098                 goto out;
1099
1100         err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
1101         if (err)
1102                 goto out_unregister_pppoe_proto;
1103
1104         err = pppoe_proc_init();
1105         if (err)
1106                 goto out_unregister_pppox_proto;
1107
1108         dev_add_pack(&pppoes_ptype);
1109         dev_add_pack(&pppoed_ptype);
1110         register_netdevice_notifier(&pppoe_notifier);
1111 out:
1112         return err;
1113 out_unregister_pppox_proto:
1114         unregister_pppox_proto(PX_PROTO_OE);
1115 out_unregister_pppoe_proto:
1116         proto_unregister(&pppoe_sk_proto);
1117         goto out;
1118 }
1119
1120 static void __exit pppoe_exit(void)
1121 {
1122         unregister_pppox_proto(PX_PROTO_OE);
1123         dev_remove_pack(&pppoes_ptype);
1124         dev_remove_pack(&pppoed_ptype);
1125         unregister_netdevice_notifier(&pppoe_notifier);
1126         remove_proc_entry("net/pppoe", NULL);
1127         proto_unregister(&pppoe_sk_proto);
1128 }
1129
1130 module_init(pppoe_init);
1131 module_exit(pppoe_exit);
1132
1133 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1134 MODULE_DESCRIPTION("PPP over Ethernet driver");
1135 MODULE_LICENSE("GPL");
1136 MODULE_ALIAS_NETPROTO(PF_PPPOX);