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