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/ppp-ioctl.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 <linux/nsproxy.h> 82 #include <net/net_namespace.h> 83 #include <net/netns/generic.h> 84 #include <net/sock.h> 85 86 #include <linux/uaccess.h> 87 88 #define PPPOE_HASH_BITS 4 89 #define PPPOE_HASH_SIZE (1 << PPPOE_HASH_BITS) 90 #define PPPOE_HASH_MASK (PPPOE_HASH_SIZE - 1) 91 92 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb); 93 94 static const struct proto_ops pppoe_ops; 95 static const struct ppp_channel_ops pppoe_chan_ops; 96 97 /* per-net private data for this module */ 98 static unsigned int pppoe_net_id __read_mostly; 99 struct pppoe_net { 100 /* 101 * we could use _single_ hash table for all 102 * nets by injecting net id into the hash but 103 * it would increase hash chains and add 104 * a few additional math comparations messy 105 * as well, moreover in case of SMP less locking 106 * controversy here 107 */ 108 struct pppox_sock *hash_table[PPPOE_HASH_SIZE]; 109 rwlock_t hash_lock; 110 }; 111 112 /* 113 * PPPoE could be in the following stages: 114 * 1) Discovery stage (to obtain remote MAC and Session ID) 115 * 2) Session stage (MAC and SID are known) 116 * 117 * Ethernet frames have a special tag for this but 118 * we use simpler approach based on session id 119 */ 120 static inline bool stage_session(__be16 sid) 121 { 122 return sid != 0; 123 } 124 125 static inline struct pppoe_net *pppoe_pernet(struct net *net) 126 { 127 BUG_ON(!net); 128 129 return net_generic(net, pppoe_net_id); 130 } 131 132 static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b) 133 { 134 return a->sid == b->sid && ether_addr_equal(a->remote, b->remote); 135 } 136 137 static inline int cmp_addr(struct pppoe_addr *a, __be16 sid, char *addr) 138 { 139 return a->sid == sid && ether_addr_equal(a->remote, addr); 140 } 141 142 #if 8 % PPPOE_HASH_BITS 143 #error 8 must be a multiple of PPPOE_HASH_BITS 144 #endif 145 146 static int hash_item(__be16 sid, unsigned char *addr) 147 { 148 unsigned char hash = 0; 149 unsigned int i; 150 151 for (i = 0; i < ETH_ALEN; i++) 152 hash ^= addr[i]; 153 for (i = 0; i < sizeof(sid_t) * 8; i += 8) 154 hash ^= (__force __u32)sid >> i; 155 for (i = 8; (i >>= 1) >= PPPOE_HASH_BITS;) 156 hash ^= hash >> i; 157 158 return hash & PPPOE_HASH_MASK; 159 } 160 161 /********************************************************************** 162 * 163 * Set/get/delete/rehash items (internal versions) 164 * 165 **********************************************************************/ 166 static struct pppox_sock *__get_item(struct pppoe_net *pn, __be16 sid, 167 unsigned char *addr, int ifindex) 168 { 169 int hash = hash_item(sid, addr); 170 struct pppox_sock *ret; 171 172 ret = pn->hash_table[hash]; 173 while (ret) { 174 if (cmp_addr(&ret->pppoe_pa, sid, addr) && 175 ret->pppoe_ifindex == ifindex) 176 return ret; 177 178 ret = ret->next; 179 } 180 181 return NULL; 182 } 183 184 static int __set_item(struct pppoe_net *pn, struct pppox_sock *po) 185 { 186 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); 187 struct pppox_sock *ret; 188 189 ret = pn->hash_table[hash]; 190 while (ret) { 191 if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) && 192 ret->pppoe_ifindex == po->pppoe_ifindex) 193 return -EALREADY; 194 195 ret = ret->next; 196 } 197 198 po->next = pn->hash_table[hash]; 199 pn->hash_table[hash] = po; 200 201 return 0; 202 } 203 204 static void __delete_item(struct pppoe_net *pn, __be16 sid, 205 char *addr, int ifindex) 206 { 207 int hash = hash_item(sid, addr); 208 struct pppox_sock *ret, **src; 209 210 ret = pn->hash_table[hash]; 211 src = &pn->hash_table[hash]; 212 213 while (ret) { 214 if (cmp_addr(&ret->pppoe_pa, sid, addr) && 215 ret->pppoe_ifindex == ifindex) { 216 *src = ret->next; 217 break; 218 } 219 220 src = &ret->next; 221 ret = ret->next; 222 } 223 } 224 225 /********************************************************************** 226 * 227 * Set/get/delete/rehash items 228 * 229 **********************************************************************/ 230 static inline struct pppox_sock *get_item(struct pppoe_net *pn, __be16 sid, 231 unsigned char *addr, int ifindex) 232 { 233 struct pppox_sock *po; 234 235 read_lock_bh(&pn->hash_lock); 236 po = __get_item(pn, sid, addr, ifindex); 237 if (po) 238 sock_hold(sk_pppox(po)); 239 read_unlock_bh(&pn->hash_lock); 240 241 return po; 242 } 243 244 static inline struct pppox_sock *get_item_by_addr(struct net *net, 245 struct sockaddr_pppox *sp) 246 { 247 struct net_device *dev; 248 struct pppoe_net *pn; 249 struct pppox_sock *pppox_sock = NULL; 250 251 int ifindex; 252 253 rcu_read_lock(); 254 dev = dev_get_by_name_rcu(net, sp->sa_addr.pppoe.dev); 255 if (dev) { 256 ifindex = dev->ifindex; 257 pn = pppoe_pernet(net); 258 pppox_sock = get_item(pn, sp->sa_addr.pppoe.sid, 259 sp->sa_addr.pppoe.remote, ifindex); 260 } 261 rcu_read_unlock(); 262 return pppox_sock; 263 } 264 265 static inline void delete_item(struct pppoe_net *pn, __be16 sid, 266 char *addr, int ifindex) 267 { 268 write_lock_bh(&pn->hash_lock); 269 __delete_item(pn, sid, addr, ifindex); 270 write_unlock_bh(&pn->hash_lock); 271 } 272 273 /*************************************************************************** 274 * 275 * Handler for device events. 276 * Certain device events require that sockets be unconnected. 277 * 278 **************************************************************************/ 279 280 static void pppoe_flush_dev(struct net_device *dev) 281 { 282 struct pppoe_net *pn; 283 int i; 284 285 pn = pppoe_pernet(dev_net(dev)); 286 write_lock_bh(&pn->hash_lock); 287 for (i = 0; i < PPPOE_HASH_SIZE; i++) { 288 struct pppox_sock *po = pn->hash_table[i]; 289 struct sock *sk; 290 291 while (po) { 292 while (po && po->pppoe_dev != dev) { 293 po = po->next; 294 } 295 296 if (!po) 297 break; 298 299 sk = sk_pppox(po); 300 301 /* We always grab the socket lock, followed by the 302 * hash_lock, in that order. Since we should hold the 303 * sock lock while doing any unbinding, we need to 304 * release the lock we're holding. Hold a reference to 305 * the sock so it doesn't disappear as we're jumping 306 * between locks. 307 */ 308 309 sock_hold(sk); 310 write_unlock_bh(&pn->hash_lock); 311 lock_sock(sk); 312 313 if (po->pppoe_dev == dev && 314 sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) { 315 pppox_unbind_sock(sk); 316 sk->sk_state_change(sk); 317 po->pppoe_dev = NULL; 318 dev_put(dev); 319 } 320 321 release_sock(sk); 322 sock_put(sk); 323 324 /* Restart the process from the start of the current 325 * hash chain. We dropped locks so the world may have 326 * change from underneath us. 327 */ 328 329 BUG_ON(pppoe_pernet(dev_net(dev)) == NULL); 330 write_lock_bh(&pn->hash_lock); 331 po = pn->hash_table[i]; 332 } 333 } 334 write_unlock_bh(&pn->hash_lock); 335 } 336 337 static int pppoe_device_event(struct notifier_block *this, 338 unsigned long event, void *ptr) 339 { 340 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 341 342 /* Only look at sockets that are using this specific device. */ 343 switch (event) { 344 case NETDEV_CHANGEADDR: 345 case NETDEV_CHANGEMTU: 346 /* A change in mtu or address is a bad thing, requiring 347 * LCP re-negotiation. 348 */ 349 350 case NETDEV_GOING_DOWN: 351 case NETDEV_DOWN: 352 /* Find every socket on this device and kill it. */ 353 pppoe_flush_dev(dev); 354 break; 355 356 default: 357 break; 358 } 359 360 return NOTIFY_DONE; 361 } 362 363 static struct notifier_block pppoe_notifier = { 364 .notifier_call = pppoe_device_event, 365 }; 366 367 /************************************************************************ 368 * 369 * Do the real work of receiving a PPPoE Session frame. 370 * 371 ***********************************************************************/ 372 static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb) 373 { 374 struct pppox_sock *po = pppox_sk(sk); 375 struct pppox_sock *relay_po; 376 377 /* Backlog receive. Semantics of backlog rcv preclude any code from 378 * executing in lock_sock()/release_sock() bounds; meaning sk->sk_state 379 * can't change. 380 */ 381 382 if (skb->pkt_type == PACKET_OTHERHOST) 383 goto abort_kfree; 384 385 if (sk->sk_state & PPPOX_BOUND) { 386 ppp_input(&po->chan, skb); 387 } else if (sk->sk_state & PPPOX_RELAY) { 388 relay_po = get_item_by_addr(sock_net(sk), 389 &po->pppoe_relay); 390 if (relay_po == NULL) 391 goto abort_kfree; 392 393 if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0) 394 goto abort_put; 395 396 if (!__pppoe_xmit(sk_pppox(relay_po), skb)) 397 goto abort_put; 398 399 sock_put(sk_pppox(relay_po)); 400 } else { 401 if (sock_queue_rcv_skb(sk, skb)) 402 goto abort_kfree; 403 } 404 405 return NET_RX_SUCCESS; 406 407 abort_put: 408 sock_put(sk_pppox(relay_po)); 409 410 abort_kfree: 411 kfree_skb(skb); 412 return NET_RX_DROP; 413 } 414 415 /************************************************************************ 416 * 417 * Receive wrapper called in BH context. 418 * 419 ***********************************************************************/ 420 static int pppoe_rcv(struct sk_buff *skb, struct net_device *dev, 421 struct packet_type *pt, struct net_device *orig_dev) 422 { 423 struct pppoe_hdr *ph; 424 struct pppox_sock *po; 425 struct pppoe_net *pn; 426 int len; 427 428 skb = skb_share_check(skb, GFP_ATOMIC); 429 if (!skb) 430 goto out; 431 432 if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr))) 433 goto drop; 434 435 ph = pppoe_hdr(skb); 436 len = ntohs(ph->length); 437 438 skb_pull_rcsum(skb, sizeof(*ph)); 439 if (skb->len < len) 440 goto drop; 441 442 if (pskb_trim_rcsum(skb, len)) 443 goto drop; 444 445 pn = pppoe_pernet(dev_net(dev)); 446 447 /* Note that get_item does a sock_hold(), so sk_pppox(po) 448 * is known to be safe. 449 */ 450 po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex); 451 if (!po) 452 goto drop; 453 454 return sk_receive_skb(sk_pppox(po), skb, 0); 455 456 drop: 457 kfree_skb(skb); 458 out: 459 return NET_RX_DROP; 460 } 461 462 static void pppoe_unbind_sock_work(struct work_struct *work) 463 { 464 struct pppox_sock *po = container_of(work, struct pppox_sock, 465 proto.pppoe.padt_work); 466 struct sock *sk = sk_pppox(po); 467 468 lock_sock(sk); 469 if (po->pppoe_dev) { 470 dev_put(po->pppoe_dev); 471 po->pppoe_dev = NULL; 472 } 473 pppox_unbind_sock(sk); 474 release_sock(sk); 475 sock_put(sk); 476 } 477 478 /************************************************************************ 479 * 480 * Receive a PPPoE Discovery frame. 481 * This is solely for detection of PADT frames 482 * 483 ***********************************************************************/ 484 static int pppoe_disc_rcv(struct sk_buff *skb, struct net_device *dev, 485 struct packet_type *pt, struct net_device *orig_dev) 486 487 { 488 struct pppoe_hdr *ph; 489 struct pppox_sock *po; 490 struct pppoe_net *pn; 491 492 skb = skb_share_check(skb, GFP_ATOMIC); 493 if (!skb) 494 goto out; 495 496 if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr))) 497 goto abort; 498 499 ph = pppoe_hdr(skb); 500 if (ph->code != PADT_CODE) 501 goto abort; 502 503 pn = pppoe_pernet(dev_net(dev)); 504 po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex); 505 if (po) 506 if (!schedule_work(&po->proto.pppoe.padt_work)) 507 sock_put(sk_pppox(po)); 508 509 abort: 510 kfree_skb(skb); 511 out: 512 return NET_RX_SUCCESS; /* Lies... :-) */ 513 } 514 515 static struct packet_type pppoes_ptype __read_mostly = { 516 .type = cpu_to_be16(ETH_P_PPP_SES), 517 .func = pppoe_rcv, 518 }; 519 520 static struct packet_type pppoed_ptype __read_mostly = { 521 .type = cpu_to_be16(ETH_P_PPP_DISC), 522 .func = pppoe_disc_rcv, 523 }; 524 525 static struct proto pppoe_sk_proto __read_mostly = { 526 .name = "PPPOE", 527 .owner = THIS_MODULE, 528 .obj_size = sizeof(struct pppox_sock), 529 }; 530 531 /*********************************************************************** 532 * 533 * Initialize a new struct sock. 534 * 535 **********************************************************************/ 536 static int pppoe_create(struct net *net, struct socket *sock, int kern) 537 { 538 struct sock *sk; 539 540 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, kern); 541 if (!sk) 542 return -ENOMEM; 543 544 sock_init_data(sock, sk); 545 546 sock->state = SS_UNCONNECTED; 547 sock->ops = &pppoe_ops; 548 549 sk->sk_backlog_rcv = pppoe_rcv_core; 550 sk->sk_state = PPPOX_NONE; 551 sk->sk_type = SOCK_STREAM; 552 sk->sk_family = PF_PPPOX; 553 sk->sk_protocol = PX_PROTO_OE; 554 555 INIT_WORK(&pppox_sk(sk)->proto.pppoe.padt_work, 556 pppoe_unbind_sock_work); 557 558 return 0; 559 } 560 561 static int pppoe_release(struct socket *sock) 562 { 563 struct sock *sk = sock->sk; 564 struct pppox_sock *po; 565 struct pppoe_net *pn; 566 struct net *net = NULL; 567 568 if (!sk) 569 return 0; 570 571 lock_sock(sk); 572 if (sock_flag(sk, SOCK_DEAD)) { 573 release_sock(sk); 574 return -EBADF; 575 } 576 577 po = pppox_sk(sk); 578 579 if (po->pppoe_dev) { 580 dev_put(po->pppoe_dev); 581 po->pppoe_dev = NULL; 582 } 583 584 pppox_unbind_sock(sk); 585 586 /* Signal the death of the socket. */ 587 sk->sk_state = PPPOX_DEAD; 588 589 net = sock_net(sk); 590 pn = pppoe_pernet(net); 591 592 /* 593 * protect "po" from concurrent updates 594 * on pppoe_flush_dev 595 */ 596 delete_item(pn, po->pppoe_pa.sid, po->pppoe_pa.remote, 597 po->pppoe_ifindex); 598 599 sock_orphan(sk); 600 sock->sk = NULL; 601 602 skb_queue_purge(&sk->sk_receive_queue); 603 release_sock(sk); 604 sock_put(sk); 605 606 return 0; 607 } 608 609 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr, 610 int sockaddr_len, int flags) 611 { 612 struct sock *sk = sock->sk; 613 struct sockaddr_pppox *sp = (struct sockaddr_pppox *)uservaddr; 614 struct pppox_sock *po = pppox_sk(sk); 615 struct net_device *dev = NULL; 616 struct pppoe_net *pn; 617 struct net *net = NULL; 618 int error; 619 620 lock_sock(sk); 621 622 error = -EINVAL; 623 if (sp->sa_protocol != PX_PROTO_OE) 624 goto end; 625 626 /* Check for already bound sockets */ 627 error = -EBUSY; 628 if ((sk->sk_state & PPPOX_CONNECTED) && 629 stage_session(sp->sa_addr.pppoe.sid)) 630 goto end; 631 632 /* Check for already disconnected sockets, on attempts to disconnect */ 633 error = -EALREADY; 634 if ((sk->sk_state & PPPOX_DEAD) && 635 !stage_session(sp->sa_addr.pppoe.sid)) 636 goto end; 637 638 error = 0; 639 640 /* Delete the old binding */ 641 if (stage_session(po->pppoe_pa.sid)) { 642 pppox_unbind_sock(sk); 643 pn = pppoe_pernet(sock_net(sk)); 644 delete_item(pn, po->pppoe_pa.sid, 645 po->pppoe_pa.remote, po->pppoe_ifindex); 646 if (po->pppoe_dev) { 647 dev_put(po->pppoe_dev); 648 po->pppoe_dev = NULL; 649 } 650 651 po->pppoe_ifindex = 0; 652 memset(&po->pppoe_pa, 0, sizeof(po->pppoe_pa)); 653 memset(&po->pppoe_relay, 0, sizeof(po->pppoe_relay)); 654 memset(&po->chan, 0, sizeof(po->chan)); 655 po->next = NULL; 656 po->num = 0; 657 658 sk->sk_state = PPPOX_NONE; 659 } 660 661 /* Re-bind in session stage only */ 662 if (stage_session(sp->sa_addr.pppoe.sid)) { 663 error = -ENODEV; 664 net = sock_net(sk); 665 dev = dev_get_by_name(net, sp->sa_addr.pppoe.dev); 666 if (!dev) 667 goto err_put; 668 669 po->pppoe_dev = dev; 670 po->pppoe_ifindex = dev->ifindex; 671 pn = pppoe_pernet(net); 672 if (!(dev->flags & IFF_UP)) { 673 goto err_put; 674 } 675 676 memcpy(&po->pppoe_pa, 677 &sp->sa_addr.pppoe, 678 sizeof(struct pppoe_addr)); 679 680 write_lock_bh(&pn->hash_lock); 681 error = __set_item(pn, po); 682 write_unlock_bh(&pn->hash_lock); 683 if (error < 0) 684 goto err_put; 685 686 po->chan.hdrlen = (sizeof(struct pppoe_hdr) + 687 dev->hard_header_len); 688 689 po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr) - 2; 690 po->chan.private = sk; 691 po->chan.ops = &pppoe_chan_ops; 692 693 error = ppp_register_net_channel(dev_net(dev), &po->chan); 694 if (error) { 695 delete_item(pn, po->pppoe_pa.sid, 696 po->pppoe_pa.remote, po->pppoe_ifindex); 697 goto err_put; 698 } 699 700 sk->sk_state = PPPOX_CONNECTED; 701 } 702 703 po->num = sp->sa_addr.pppoe.sid; 704 705 end: 706 release_sock(sk); 707 return error; 708 err_put: 709 if (po->pppoe_dev) { 710 dev_put(po->pppoe_dev); 711 po->pppoe_dev = NULL; 712 } 713 goto end; 714 } 715 716 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr, 717 int peer) 718 { 719 int len = sizeof(struct sockaddr_pppox); 720 struct sockaddr_pppox sp; 721 722 sp.sa_family = AF_PPPOX; 723 sp.sa_protocol = PX_PROTO_OE; 724 memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa, 725 sizeof(struct pppoe_addr)); 726 727 memcpy(uaddr, &sp, len); 728 729 return len; 730 } 731 732 static int pppoe_ioctl(struct socket *sock, unsigned int cmd, 733 unsigned long arg) 734 { 735 struct sock *sk = sock->sk; 736 struct pppox_sock *po = pppox_sk(sk); 737 int val; 738 int err; 739 740 switch (cmd) { 741 case PPPIOCGMRU: 742 err = -ENXIO; 743 if (!(sk->sk_state & PPPOX_CONNECTED)) 744 break; 745 746 err = -EFAULT; 747 if (put_user(po->pppoe_dev->mtu - 748 sizeof(struct pppoe_hdr) - 749 PPP_HDRLEN, 750 (int __user *)arg)) 751 break; 752 err = 0; 753 break; 754 755 case PPPIOCSMRU: 756 err = -ENXIO; 757 if (!(sk->sk_state & PPPOX_CONNECTED)) 758 break; 759 760 err = -EFAULT; 761 if (get_user(val, (int __user *)arg)) 762 break; 763 764 if (val < (po->pppoe_dev->mtu 765 - sizeof(struct pppoe_hdr) 766 - PPP_HDRLEN)) 767 err = 0; 768 else 769 err = -EINVAL; 770 break; 771 772 case PPPIOCSFLAGS: 773 err = -EFAULT; 774 if (get_user(val, (int __user *)arg)) 775 break; 776 err = 0; 777 break; 778 779 case PPPOEIOCSFWD: 780 { 781 struct pppox_sock *relay_po; 782 783 err = -EBUSY; 784 if (sk->sk_state & (PPPOX_BOUND | PPPOX_DEAD)) 785 break; 786 787 err = -ENOTCONN; 788 if (!(sk->sk_state & PPPOX_CONNECTED)) 789 break; 790 791 /* PPPoE address from the user specifies an outbound 792 PPPoE address which frames are forwarded to */ 793 err = -EFAULT; 794 if (copy_from_user(&po->pppoe_relay, 795 (void __user *)arg, 796 sizeof(struct sockaddr_pppox))) 797 break; 798 799 err = -EINVAL; 800 if (po->pppoe_relay.sa_family != AF_PPPOX || 801 po->pppoe_relay.sa_protocol != PX_PROTO_OE) 802 break; 803 804 /* Check that the socket referenced by the address 805 actually exists. */ 806 relay_po = get_item_by_addr(sock_net(sk), &po->pppoe_relay); 807 if (!relay_po) 808 break; 809 810 sock_put(sk_pppox(relay_po)); 811 sk->sk_state |= PPPOX_RELAY; 812 err = 0; 813 break; 814 } 815 816 case PPPOEIOCDFWD: 817 err = -EALREADY; 818 if (!(sk->sk_state & PPPOX_RELAY)) 819 break; 820 821 sk->sk_state &= ~PPPOX_RELAY; 822 err = 0; 823 break; 824 825 default: 826 err = -ENOTTY; 827 } 828 829 return err; 830 } 831 832 static int pppoe_sendmsg(struct socket *sock, struct msghdr *m, 833 size_t total_len) 834 { 835 struct sk_buff *skb; 836 struct sock *sk = sock->sk; 837 struct pppox_sock *po = pppox_sk(sk); 838 int error; 839 struct pppoe_hdr hdr; 840 struct pppoe_hdr *ph; 841 struct net_device *dev; 842 char *start; 843 int hlen; 844 845 lock_sock(sk); 846 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) { 847 error = -ENOTCONN; 848 goto end; 849 } 850 851 hdr.ver = 1; 852 hdr.type = 1; 853 hdr.code = 0; 854 hdr.sid = po->num; 855 856 dev = po->pppoe_dev; 857 858 error = -EMSGSIZE; 859 if (total_len > (dev->mtu + dev->hard_header_len)) 860 goto end; 861 862 hlen = LL_RESERVED_SPACE(dev); 863 skb = sock_wmalloc(sk, hlen + sizeof(*ph) + total_len + 864 dev->needed_tailroom, 0, GFP_KERNEL); 865 if (!skb) { 866 error = -ENOMEM; 867 goto end; 868 } 869 870 /* Reserve space for headers. */ 871 skb_reserve(skb, hlen); 872 skb_reset_network_header(skb); 873 874 skb->dev = dev; 875 876 skb->priority = sk->sk_priority; 877 skb->protocol = cpu_to_be16(ETH_P_PPP_SES); 878 879 ph = skb_put(skb, total_len + sizeof(struct pppoe_hdr)); 880 start = (char *)&ph->tag[0]; 881 882 error = memcpy_from_msg(start, m, total_len); 883 if (error < 0) { 884 kfree_skb(skb); 885 goto end; 886 } 887 888 error = total_len; 889 dev_hard_header(skb, dev, ETH_P_PPP_SES, 890 po->pppoe_pa.remote, NULL, total_len); 891 892 memcpy(ph, &hdr, sizeof(struct pppoe_hdr)); 893 894 ph->length = htons(total_len); 895 896 dev_queue_xmit(skb); 897 898 end: 899 release_sock(sk); 900 return error; 901 } 902 903 /************************************************************************ 904 * 905 * xmit function for internal use. 906 * 907 ***********************************************************************/ 908 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb) 909 { 910 struct pppox_sock *po = pppox_sk(sk); 911 struct net_device *dev = po->pppoe_dev; 912 struct pppoe_hdr *ph; 913 int data_len = skb->len; 914 915 /* The higher-level PPP code (ppp_unregister_channel()) ensures the PPP 916 * xmit operations conclude prior to an unregistration call. Thus 917 * sk->sk_state cannot change, so we don't need to do lock_sock(). 918 * But, we also can't do a lock_sock since that introduces a potential 919 * deadlock as we'd reverse the lock ordering used when calling 920 * ppp_unregister_channel(). 921 */ 922 923 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 924 goto abort; 925 926 if (!dev) 927 goto abort; 928 929 /* Copy the data if there is no space for the header or if it's 930 * read-only. 931 */ 932 if (skb_cow_head(skb, LL_RESERVED_SPACE(dev) + sizeof(*ph))) 933 goto abort; 934 935 __skb_push(skb, sizeof(*ph)); 936 skb_reset_network_header(skb); 937 938 ph = pppoe_hdr(skb); 939 ph->ver = 1; 940 ph->type = 1; 941 ph->code = 0; 942 ph->sid = po->num; 943 ph->length = htons(data_len); 944 945 skb->protocol = cpu_to_be16(ETH_P_PPP_SES); 946 skb->dev = dev; 947 948 dev_hard_header(skb, dev, ETH_P_PPP_SES, 949 po->pppoe_pa.remote, NULL, data_len); 950 951 dev_queue_xmit(skb); 952 return 1; 953 954 abort: 955 kfree_skb(skb); 956 return 1; 957 } 958 959 /************************************************************************ 960 * 961 * xmit function called by generic PPP driver 962 * sends PPP frame over PPPoE socket 963 * 964 ***********************************************************************/ 965 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb) 966 { 967 struct sock *sk = (struct sock *)chan->private; 968 return __pppoe_xmit(sk, skb); 969 } 970 971 static const struct ppp_channel_ops pppoe_chan_ops = { 972 .start_xmit = pppoe_xmit, 973 }; 974 975 static int pppoe_recvmsg(struct socket *sock, struct msghdr *m, 976 size_t total_len, int flags) 977 { 978 struct sock *sk = sock->sk; 979 struct sk_buff *skb; 980 int error = 0; 981 982 if (sk->sk_state & PPPOX_BOUND) { 983 error = -EIO; 984 goto end; 985 } 986 987 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, 988 flags & MSG_DONTWAIT, &error); 989 if (error < 0) 990 goto end; 991 992 if (skb) { 993 total_len = min_t(size_t, total_len, skb->len); 994 error = skb_copy_datagram_msg(skb, 0, m, total_len); 995 if (error == 0) { 996 consume_skb(skb); 997 return total_len; 998 } 999 } 1000 1001 kfree_skb(skb); 1002 end: 1003 return error; 1004 } 1005 1006 #ifdef CONFIG_PROC_FS 1007 static int pppoe_seq_show(struct seq_file *seq, void *v) 1008 { 1009 struct pppox_sock *po; 1010 char *dev_name; 1011 1012 if (v == SEQ_START_TOKEN) { 1013 seq_puts(seq, "Id Address Device\n"); 1014 goto out; 1015 } 1016 1017 po = v; 1018 dev_name = po->pppoe_pa.dev; 1019 1020 seq_printf(seq, "%08X %pM %8s\n", 1021 po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name); 1022 out: 1023 return 0; 1024 } 1025 1026 static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos) 1027 { 1028 struct pppox_sock *po; 1029 int i; 1030 1031 for (i = 0; i < PPPOE_HASH_SIZE; i++) { 1032 po = pn->hash_table[i]; 1033 while (po) { 1034 if (!pos--) 1035 goto out; 1036 po = po->next; 1037 } 1038 } 1039 1040 out: 1041 return po; 1042 } 1043 1044 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos) 1045 __acquires(pn->hash_lock) 1046 { 1047 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1048 loff_t l = *pos; 1049 1050 read_lock_bh(&pn->hash_lock); 1051 return l ? pppoe_get_idx(pn, --l) : SEQ_START_TOKEN; 1052 } 1053 1054 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1055 { 1056 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1057 struct pppox_sock *po; 1058 1059 ++*pos; 1060 if (v == SEQ_START_TOKEN) { 1061 po = pppoe_get_idx(pn, 0); 1062 goto out; 1063 } 1064 po = v; 1065 if (po->next) 1066 po = po->next; 1067 else { 1068 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); 1069 1070 po = NULL; 1071 while (++hash < PPPOE_HASH_SIZE) { 1072 po = pn->hash_table[hash]; 1073 if (po) 1074 break; 1075 } 1076 } 1077 1078 out: 1079 return po; 1080 } 1081 1082 static void pppoe_seq_stop(struct seq_file *seq, void *v) 1083 __releases(pn->hash_lock) 1084 { 1085 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1086 read_unlock_bh(&pn->hash_lock); 1087 } 1088 1089 static const struct seq_operations pppoe_seq_ops = { 1090 .start = pppoe_seq_start, 1091 .next = pppoe_seq_next, 1092 .stop = pppoe_seq_stop, 1093 .show = pppoe_seq_show, 1094 }; 1095 1096 static int pppoe_seq_open(struct inode *inode, struct file *file) 1097 { 1098 return seq_open_net(inode, file, &pppoe_seq_ops, 1099 sizeof(struct seq_net_private)); 1100 } 1101 1102 static const struct file_operations pppoe_seq_fops = { 1103 .owner = THIS_MODULE, 1104 .open = pppoe_seq_open, 1105 .read = seq_read, 1106 .llseek = seq_lseek, 1107 .release = seq_release_net, 1108 }; 1109 1110 #endif /* CONFIG_PROC_FS */ 1111 1112 static const struct proto_ops pppoe_ops = { 1113 .family = AF_PPPOX, 1114 .owner = THIS_MODULE, 1115 .release = pppoe_release, 1116 .bind = sock_no_bind, 1117 .connect = pppoe_connect, 1118 .socketpair = sock_no_socketpair, 1119 .accept = sock_no_accept, 1120 .getname = pppoe_getname, 1121 .poll = datagram_poll, 1122 .listen = sock_no_listen, 1123 .shutdown = sock_no_shutdown, 1124 .setsockopt = sock_no_setsockopt, 1125 .getsockopt = sock_no_getsockopt, 1126 .sendmsg = pppoe_sendmsg, 1127 .recvmsg = pppoe_recvmsg, 1128 .mmap = sock_no_mmap, 1129 .ioctl = pppox_ioctl, 1130 }; 1131 1132 static const struct pppox_proto pppoe_proto = { 1133 .create = pppoe_create, 1134 .ioctl = pppoe_ioctl, 1135 .owner = THIS_MODULE, 1136 }; 1137 1138 static __net_init int pppoe_init_net(struct net *net) 1139 { 1140 struct pppoe_net *pn = pppoe_pernet(net); 1141 struct proc_dir_entry *pde; 1142 1143 rwlock_init(&pn->hash_lock); 1144 1145 pde = proc_create("pppoe", 0444, net->proc_net, &pppoe_seq_fops); 1146 #ifdef CONFIG_PROC_FS 1147 if (!pde) 1148 return -ENOMEM; 1149 #endif 1150 1151 return 0; 1152 } 1153 1154 static __net_exit void pppoe_exit_net(struct net *net) 1155 { 1156 remove_proc_entry("pppoe", net->proc_net); 1157 } 1158 1159 static struct pernet_operations pppoe_net_ops = { 1160 .init = pppoe_init_net, 1161 .exit = pppoe_exit_net, 1162 .id = &pppoe_net_id, 1163 .size = sizeof(struct pppoe_net), 1164 }; 1165 1166 static int __init pppoe_init(void) 1167 { 1168 int err; 1169 1170 err = register_pernet_device(&pppoe_net_ops); 1171 if (err) 1172 goto out; 1173 1174 err = proto_register(&pppoe_sk_proto, 0); 1175 if (err) 1176 goto out_unregister_net_ops; 1177 1178 err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto); 1179 if (err) 1180 goto out_unregister_pppoe_proto; 1181 1182 dev_add_pack(&pppoes_ptype); 1183 dev_add_pack(&pppoed_ptype); 1184 register_netdevice_notifier(&pppoe_notifier); 1185 1186 return 0; 1187 1188 out_unregister_pppoe_proto: 1189 proto_unregister(&pppoe_sk_proto); 1190 out_unregister_net_ops: 1191 unregister_pernet_device(&pppoe_net_ops); 1192 out: 1193 return err; 1194 } 1195 1196 static void __exit pppoe_exit(void) 1197 { 1198 unregister_netdevice_notifier(&pppoe_notifier); 1199 dev_remove_pack(&pppoed_ptype); 1200 dev_remove_pack(&pppoes_ptype); 1201 unregister_pppox_proto(PX_PROTO_OE); 1202 proto_unregister(&pppoe_sk_proto); 1203 unregister_pernet_device(&pppoe_net_ops); 1204 } 1205 1206 module_init(pppoe_init); 1207 module_exit(pppoe_exit); 1208 1209 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>"); 1210 MODULE_DESCRIPTION("PPP over Ethernet driver"); 1211 MODULE_LICENSE("GPL"); 1212 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OE); 1213