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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 (dev->nd_net != &init_net)
 393                 goto drop;
 394
 395         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
 396                 goto drop;
 397
 398         ph = pppoe_hdr(skb);
 399
 400         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
 401         if (po != NULL)
 402                 return sk_receive_skb(sk_pppox(po), skb, 0);
 403 drop:
 404         kfree_skb(skb);
 405 out:
 406         return NET_RX_DROP;
 407 }
 408
 409 /************************************************************************
 410  *
 411  * Receive a PPPoE Discovery frame.
 412  * This is solely for detection of PADT frames
 413  *
 414  ***********************************************************************/
 415 static int pppoe_disc_rcv(struct sk_buff *skb,
 416                           struct net_device *dev,
 417                           struct packet_type *pt,
 418                           struct net_device *orig_dev)
 419
 420 {
 421         struct pppoe_hdr *ph;
 422         struct pppox_sock *po;
 423
 424         if (dev->nd_net != &init_net)
 425                 goto abort;
 426
 427         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
 428                 goto abort;
 429
 430         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
 431                 goto out;
 432
 433         ph = pppoe_hdr(skb);
 434         if (ph->code != PADT_CODE)
 435                 goto abort;
 436
 437         po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
 438         if (po) {
 439                 struct sock *sk = sk_pppox(po);
 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 (sock_owned_by_user(sk) == 0) {
 449                         /* We're no longer connect at the PPPOE layer,
 450                          * and must wait for ppp channel to disconnect us.
 451                          */
 452                         sk->sk_state = PPPOX_ZOMBIE;
 453                 }
 454
 455                 bh_unlock_sock(sk);
 456                 sock_put(sk);
 457         }
 458
 459 abort:
 460         kfree_skb(skb);
 461 out:
 462         return NET_RX_SUCCESS; /* Lies... :-) */
 463 }
 464
 465 static struct packet_type pppoes_ptype = {
 466         .type   = __constant_htons(ETH_P_PPP_SES),
 467         .func   = pppoe_rcv,
 468 };
 469
 470 static struct packet_type pppoed_ptype = {
 471         .type   = __constant_htons(ETH_P_PPP_DISC),
 472         .func   = pppoe_disc_rcv,
 473 };
 474
 475 static struct proto pppoe_sk_proto = {
 476         .name     = "PPPOE",
 477         .owner    = THIS_MODULE,
 478         .obj_size = sizeof(struct pppox_sock),
 479 };
 480
 481 /***********************************************************************
 482  *
 483  * Initialize a new struct sock.
 484  *
 485  **********************************************************************/
 486 static int pppoe_create(struct net *net, struct socket *sock)
 487 {
 488         int error = -ENOMEM;
 489         struct sock *sk;
 490
 491         sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, 1);
 492         if (!sk)
 493                 goto out;
 494
 495         sock_init_data(sock, sk);
 496
 497         sock->state = SS_UNCONNECTED;
 498         sock->ops   = &pppoe_ops;
 499
 500         sk->sk_backlog_rcv = pppoe_rcv_core;
 501         sk->sk_state       = PPPOX_NONE;
 502         sk->sk_type        = SOCK_STREAM;
 503         sk->sk_family      = PF_PPPOX;
 504         sk->sk_protocol    = PX_PROTO_OE;
 505
 506         error = 0;
 507 out:    return error;
 508 }
 509
 510 static int pppoe_release(struct socket *sock)
 511 {
 512         struct sock *sk = sock->sk;
 513         struct pppox_sock *po;
 514
 515         if (!sk)
 516                 return 0;
 517
 518         lock_sock(sk);
 519         if (sock_flag(sk, SOCK_DEAD)){
 520                 release_sock(sk);
 521                 return -EBADF;
 522         }
 523
 524         pppox_unbind_sock(sk);
 525
 526         /* Signal the death of the socket. */
 527         sk->sk_state = PPPOX_DEAD;
 528
 529
 530         /* Write lock on hash lock protects the entire "po" struct from
 531          * concurrent updates via pppoe_flush_dev. The "po" struct should
 532          * be considered part of the hash table contents, thus protected
 533          * by the hash table lock */
 534         write_lock_bh(&pppoe_hash_lock);
 535
 536         po = pppox_sk(sk);
 537         if (po->pppoe_pa.sid) {
 538                 __delete_item(po->pppoe_pa.sid,
 539                               po->pppoe_pa.remote, po->pppoe_ifindex);
 540         }
 541
 542         if (po->pppoe_dev) {
 543                 dev_put(po->pppoe_dev);
 544                 po->pppoe_dev = NULL;
 545         }
 546
 547         write_unlock_bh(&pppoe_hash_lock);
 548
 549         sock_orphan(sk);
 550         sock->sk = NULL;
 551
 552         skb_queue_purge(&sk->sk_receive_queue);
 553         release_sock(sk);
 554         sock_put(sk);
 555
 556         return 0;
 557 }
 558
 559
 560 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
 561                   int sockaddr_len, int flags)
 562 {
 563         struct sock *sk = sock->sk;
 564         struct net_device *dev;
 565         struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
 566         struct pppox_sock *po = pppox_sk(sk);
 567         int error;
 568
 569         lock_sock(sk);
 570
 571         error = -EINVAL;
 572         if (sp->sa_protocol != PX_PROTO_OE)
 573                 goto end;
 574
 575         /* Check for already bound sockets */
 576         error = -EBUSY;
 577         if ((sk->sk_state & PPPOX_CONNECTED) && sp->sa_addr.pppoe.sid)
 578                 goto end;
 579
 580         /* Check for already disconnected sockets, on attempts to disconnect */
 581         error = -EALREADY;
 582         if ((sk->sk_state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
 583                 goto end;
 584
 585         error = 0;
 586         if (po->pppoe_pa.sid) {
 587                 pppox_unbind_sock(sk);
 588
 589                 /* Delete the old binding */
 590                 delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote,po->pppoe_ifindex);
 591
 592                 if(po->pppoe_dev)
 593                         dev_put(po->pppoe_dev);
 594
 595                 memset(sk_pppox(po) + 1, 0,
 596                        sizeof(struct pppox_sock) - sizeof(struct sock));
 597
 598                 sk->sk_state = PPPOX_NONE;
 599         }
 600
 601         /* Don't re-bind if sid==0 */
 602         if (sp->sa_addr.pppoe.sid != 0) {
 603                 dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
 604
 605                 error = -ENODEV;
 606                 if (!dev)
 607                         goto end;
 608
 609                 po->pppoe_dev = dev;
 610                 po->pppoe_ifindex = dev->ifindex;
 611
 612                 write_lock_bh(&pppoe_hash_lock);
 613                 if (!(dev->flags & IFF_UP)){
 614                         write_unlock_bh(&pppoe_hash_lock);
 615                         goto err_put;
 616                 }
 617
 618                 memcpy(&po->pppoe_pa,
 619                        &sp->sa_addr.pppoe,
 620                        sizeof(struct pppoe_addr));
 621
 622                 error = __set_item(po);
 623                 write_unlock_bh(&pppoe_hash_lock);
 624                 if (error < 0)
 625                         goto err_put;
 626
 627                 po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
 628                                    dev->hard_header_len);
 629
 630                 po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr);
 631                 po->chan.private = sk;
 632                 po->chan.ops = &pppoe_chan_ops;
 633
 634                 error = ppp_register_channel(&po->chan);
 635                 if (error)
 636                         goto err_put;
 637
 638                 sk->sk_state = PPPOX_CONNECTED;
 639         }
 640
 641         po->num = sp->sa_addr.pppoe.sid;
 642
 643  end:
 644         release_sock(sk);
 645         return error;
 646 err_put:
 647         if (po->pppoe_dev) {
 648                 dev_put(po->pppoe_dev);
 649                 po->pppoe_dev = NULL;
 650         }
 651         goto end;
 652 }
 653
 654
 655 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
 656                   int *usockaddr_len, int peer)
 657 {
 658         int len = sizeof(struct sockaddr_pppox);
 659         struct sockaddr_pppox sp;
 660
 661         sp.sa_family    = AF_PPPOX;
 662         sp.sa_protocol  = PX_PROTO_OE;
 663         memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
 664                sizeof(struct pppoe_addr));
 665
 666         memcpy(uaddr, &sp, len);
 667
 668         *usockaddr_len = len;
 669
 670         return 0;
 671 }
 672
 673
 674 static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
 675                 unsigned long arg)
 676 {
 677         struct sock *sk = sock->sk;
 678         struct pppox_sock *po = pppox_sk(sk);
 679         int val;
 680         int err;
 681
 682         switch (cmd) {
 683         case PPPIOCGMRU:
 684                 err = -ENXIO;
 685
 686                 if (!(sk->sk_state & PPPOX_CONNECTED))
 687                         break;
 688
 689                 err = -EFAULT;
 690                 if (put_user(po->pppoe_dev->mtu -
 691                              sizeof(struct pppoe_hdr) -
 692                              PPP_HDRLEN,
 693                              (int __user *) arg))
 694                         break;
 695                 err = 0;
 696                 break;
 697
 698         case PPPIOCSMRU:
 699                 err = -ENXIO;
 700                 if (!(sk->sk_state & PPPOX_CONNECTED))
 701                         break;
 702
 703                 err = -EFAULT;
 704                 if (get_user(val,(int __user *) arg))
 705                         break;
 706
 707                 if (val < (po->pppoe_dev->mtu
 708                            - sizeof(struct pppoe_hdr)
 709                            - PPP_HDRLEN))
 710                         err = 0;
 711                 else
 712                         err = -EINVAL;
 713                 break;
 714
 715         case PPPIOCSFLAGS:
 716                 err = -EFAULT;
 717                 if (get_user(val, (int __user *) arg))
 718                         break;
 719                 err = 0;
 720                 break;
 721
 722         case PPPOEIOCSFWD:
 723         {
 724                 struct pppox_sock *relay_po;
 725
 726                 err = -EBUSY;
 727                 if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD))
 728                         break;
 729
 730                 err = -ENOTCONN;
 731                 if (!(sk->sk_state & PPPOX_CONNECTED))
 732                         break;
 733
 734                 /* PPPoE address from the user specifies an outbound
 735                    PPPoE address which frames are forwarded to */
 736                 err = -EFAULT;
 737                 if (copy_from_user(&po->pppoe_relay,
 738                                    (void __user *)arg,
 739                                    sizeof(struct sockaddr_pppox)))
 740                         break;
 741
 742                 err = -EINVAL;
 743                 if (po->pppoe_relay.sa_family != AF_PPPOX ||
 744                     po->pppoe_relay.sa_protocol!= PX_PROTO_OE)
 745                         break;
 746
 747                 /* Check that the socket referenced by the address
 748                    actually exists. */
 749                 relay_po = get_item_by_addr(&po->pppoe_relay);
 750
 751                 if (!relay_po)
 752                         break;
 753
 754                 sock_put(sk_pppox(relay_po));
 755                 sk->sk_state |= PPPOX_RELAY;
 756                 err = 0;
 757                 break;
 758         }
 759
 760         case PPPOEIOCDFWD:
 761                 err = -EALREADY;
 762                 if (!(sk->sk_state & PPPOX_RELAY))
 763                         break;
 764
 765                 sk->sk_state &= ~PPPOX_RELAY;
 766                 err = 0;
 767                 break;
 768
 769         default:
 770                 err = -ENOTTY;
 771         }
 772
 773         return err;
 774 }
 775
 776
 777 static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
 778                   struct msghdr *m, size_t total_len)
 779 {
 780         struct sk_buff *skb;
 781         struct sock *sk = sock->sk;
 782         struct pppox_sock *po = pppox_sk(sk);
 783         int error;
 784         struct pppoe_hdr hdr;
 785         struct pppoe_hdr *ph;
 786         struct net_device *dev;
 787         char *start;
 788
 789         lock_sock(sk);
 790         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
 791                 error = -ENOTCONN;
 792                 goto end;
 793         }
 794
 795         hdr.ver = 1;
 796         hdr.type = 1;
 797         hdr.code = 0;
 798         hdr.sid = po->num;
 799
 800         dev = po->pppoe_dev;
 801
 802         error = -EMSGSIZE;
 803         if (total_len > (dev->mtu + dev->hard_header_len))
 804                 goto end;
 805
 806
 807         skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32,
 808                            0, GFP_KERNEL);
 809         if (!skb) {
 810                 error = -ENOMEM;
 811                 goto end;
 812         }
 813
 814         /* Reserve space for headers. */
 815         skb_reserve(skb, dev->hard_header_len);
 816         skb_reset_network_header(skb);
 817
 818         skb->dev = dev;
 819
 820         skb->priority = sk->sk_priority;
 821         skb->protocol = __constant_htons(ETH_P_PPP_SES);
 822
 823         ph = (struct pppoe_hdr *) skb_put(skb, total_len + sizeof(struct pppoe_hdr));
 824         start = (char *) &ph->tag[0];
 825
 826         error = memcpy_fromiovec(start, m->msg_iov, total_len);
 827
 828         if (error < 0) {
 829                 kfree_skb(skb);
 830                 goto end;
 831         }
 832
 833         error = total_len;
 834         dev->hard_header(skb, dev, ETH_P_PPP_SES,
 835                          po->pppoe_pa.remote, NULL, total_len);
 836
 837         memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
 838
 839         ph->length = htons(total_len);
 840
 841         dev_queue_xmit(skb);
 842
 843 end:
 844         release_sock(sk);
 845         return error;
 846 }
 847
 848
 849 /************************************************************************
 850  *
 851  * xmit function for internal use.
 852  *
 853  ***********************************************************************/
 854 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
 855 {
 856         struct pppox_sock *po = pppox_sk(sk);
 857         struct net_device *dev = po->pppoe_dev;
 858         struct pppoe_hdr *ph;
 859         int data_len = skb->len;
 860
 861         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
 862                 goto abort;
 863
 864         if (!dev)
 865                 goto abort;
 866
 867         /* Copy the data if there is no space for the header or if it's
 868          * read-only.
 869          */
 870         if (skb_cow_head(skb, sizeof(*ph) + dev->hard_header_len))
 871                 goto abort;
 872
 873         __skb_push(skb, sizeof(*ph));
 874         skb_reset_network_header(skb);
 875
 876         ph = pppoe_hdr(skb);
 877         ph->ver = 1;
 878         ph->type = 1;
 879         ph->code = 0;
 880         ph->sid = po->num;
 881         ph->length = htons(data_len);
 882
 883         skb->protocol = __constant_htons(ETH_P_PPP_SES);
 884         skb->dev = dev;
 885
 886         dev->hard_header(skb, dev, ETH_P_PPP_SES,
 887                          po->pppoe_pa.remote, NULL, data_len);
 888
 889         dev_queue_xmit(skb);
 890
 891         return 1;
 892
 893 abort:
 894         kfree_skb(skb);
 895         return 1;
 896 }
 897
 898
 899 /************************************************************************
 900  *
 901  * xmit function called by generic PPP driver
 902  * sends PPP frame over PPPoE socket
 903  *
 904  ***********************************************************************/
 905 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 906 {
 907         struct sock *sk = (struct sock *) chan->private;
 908         return __pppoe_xmit(sk, skb);
 909 }
 910
 911
 912 static struct ppp_channel_ops pppoe_chan_ops = {
 913         .start_xmit = pppoe_xmit,
 914 };
 915
 916 static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
 917                   struct msghdr *m, size_t total_len, int flags)
 918 {
 919         struct sock *sk = sock->sk;
 920         struct sk_buff *skb;
 921         int error = 0;
 922
 923         if (sk->sk_state & PPPOX_BOUND) {
 924                 error = -EIO;
 925                 goto end;
 926         }
 927
 928         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
 929                                 flags & MSG_DONTWAIT, &error);
 930
 931         if (error < 0)
 932                 goto end;
 933
 934         m->msg_namelen = 0;
 935
 936         if (skb) {
 937                 struct pppoe_hdr *ph = pppoe_hdr(skb);
 938                 const int len = ntohs(ph->length);
 939
 940                 error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
 941                 if (error == 0)
 942                         error = len;
 943         }
 944
 945         kfree_skb(skb);
 946 end:
 947         return error;
 948 }
 949
 950 #ifdef CONFIG_PROC_FS
 951 static int pppoe_seq_show(struct seq_file *seq, void *v)
 952 {
 953         struct pppox_sock *po;
 954         char *dev_name;
 955
 956         if (v == SEQ_START_TOKEN) {
 957                 seq_puts(seq, "Id       Address              Device\n");
 958                 goto out;
 959         }
 960
 961         po = v;
 962         dev_name = po->pppoe_pa.dev;
 963
 964         seq_printf(seq, "%08X %02X:%02X:%02X:%02X:%02X:%02X %8s\n",
 965                    po->pppoe_pa.sid,
 966                    po->pppoe_pa.remote[0], po->pppoe_pa.remote[1],
 967                    po->pppoe_pa.remote[2], po->pppoe_pa.remote[3],
 968                    po->pppoe_pa.remote[4], po->pppoe_pa.remote[5], dev_name);
 969 out:
 970         return 0;
 971 }
 972
 973 static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
 974 {
 975         struct pppox_sock *po;
 976         int i = 0;
 977
 978         for (; i < PPPOE_HASH_SIZE; i++) {
 979                 po = item_hash_table[i];
 980                 while (po) {
 981                         if (!pos--)
 982                                 goto out;
 983                         po = po->next;
 984                 }
 985         }
 986 out:
 987         return po;
 988 }
 989
 990 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
 991 {
 992         loff_t l = *pos;
 993
 994         read_lock_bh(&pppoe_hash_lock);
 995         return l ? pppoe_get_idx(--l) : SEQ_START_TOKEN;
 996 }
 997
 998 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 999 {
1000         struct pppox_sock *po;
1001
1002         ++*pos;
1003         if (v == SEQ_START_TOKEN) {
1004                 po = pppoe_get_idx(0);
1005                 goto out;
1006         }
1007         po = v;
1008         if (po->next)
1009                 po = po->next;
1010         else {
1011                 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
1012
1013                 while (++hash < PPPOE_HASH_SIZE) {
1014                         po = item_hash_table[hash];
1015                         if (po)
1016                                 break;
1017                 }
1018         }
1019 out:
1020         return po;
1021 }
1022
1023 static void pppoe_seq_stop(struct seq_file *seq, void *v)
1024 {
1025         read_unlock_bh(&pppoe_hash_lock);
1026 }
1027
1028 static struct seq_operations pppoe_seq_ops = {
1029         .start          = pppoe_seq_start,
1030         .next           = pppoe_seq_next,
1031         .stop           = pppoe_seq_stop,
1032         .show           = pppoe_seq_show,
1033 };
1034
1035 static int pppoe_seq_open(struct inode *inode, struct file *file)
1036 {
1037         return seq_open(file, &pppoe_seq_ops);
1038 }
1039
1040 static const struct file_operations pppoe_seq_fops = {
1041         .owner          = THIS_MODULE,
1042         .open           = pppoe_seq_open,
1043         .read           = seq_read,
1044         .llseek         = seq_lseek,
1045         .release        = seq_release,
1046 };
1047
1048 static int __init pppoe_proc_init(void)
1049 {
1050         struct proc_dir_entry *p;
1051
1052         p = create_proc_entry("pppoe", S_IRUGO, init_net.proc_net);
1053         if (!p)
1054                 return -ENOMEM;
1055
1056         p->proc_fops = &pppoe_seq_fops;
1057         return 0;
1058 }
1059 #else /* CONFIG_PROC_FS */
1060 static inline int pppoe_proc_init(void) { return 0; }
1061 #endif /* CONFIG_PROC_FS */
1062
1063 static const struct proto_ops pppoe_ops = {
1064     .family             = AF_PPPOX,
1065     .owner              = THIS_MODULE,
1066     .release            = pppoe_release,
1067     .bind               = sock_no_bind,
1068     .connect            = pppoe_connect,
1069     .socketpair         = sock_no_socketpair,
1070     .accept             = sock_no_accept,
1071     .getname            = pppoe_getname,
1072     .poll               = datagram_poll,
1073     .listen             = sock_no_listen,
1074     .shutdown           = sock_no_shutdown,
1075     .setsockopt         = sock_no_setsockopt,
1076     .getsockopt         = sock_no_getsockopt,
1077     .sendmsg            = pppoe_sendmsg,
1078     .recvmsg            = pppoe_recvmsg,
1079     .mmap               = sock_no_mmap,
1080     .ioctl              = pppox_ioctl,
1081 };
1082
1083 static struct pppox_proto pppoe_proto = {
1084     .create     = pppoe_create,
1085     .ioctl      = pppoe_ioctl,
1086     .owner      = THIS_MODULE,
1087 };
1088
1089
1090 static int __init pppoe_init(void)
1091 {
1092         int err = proto_register(&pppoe_sk_proto, 0);
1093
1094         if (err)
1095                 goto out;
1096
1097         err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
1098         if (err)
1099                 goto out_unregister_pppoe_proto;
1100
1101         err = pppoe_proc_init();
1102         if (err)
1103                 goto out_unregister_pppox_proto;
1104
1105         dev_add_pack(&pppoes_ptype);
1106         dev_add_pack(&pppoed_ptype);
1107         register_netdevice_notifier(&pppoe_notifier);
1108 out:
1109         return err;
1110 out_unregister_pppox_proto:
1111         unregister_pppox_proto(PX_PROTO_OE);
1112 out_unregister_pppoe_proto:
1113         proto_unregister(&pppoe_sk_proto);
1114         goto out;
1115 }
1116
1117 static void __exit pppoe_exit(void)
1118 {
1119         unregister_pppox_proto(PX_PROTO_OE);
1120         dev_remove_pack(&pppoes_ptype);
1121         dev_remove_pack(&pppoed_ptype);
1122         unregister_netdevice_notifier(&pppoe_notifier);
1123         remove_proc_entry("pppoe", init_net.proc_net);
1124         proto_unregister(&pppoe_sk_proto);
1125 }
1126
1127 module_init(pppoe_init);
1128 module_exit(pppoe_exit);
1129
1130 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1131 MODULE_DESCRIPTION("PPP over Ethernet driver");
1132 MODULE_LICENSE("GPL");
1133 MODULE_ALIAS_NETPROTO(PF_PPPOX);