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 <asm/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 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 | PPPOX_ZOMBIE)) { 315 pppox_unbind_sock(sk); 316 sk->sk_state = PPPOX_ZOMBIE; 317 sk->sk_state_change(sk); 318 po->pppoe_dev = NULL; 319 dev_put(dev); 320 } 321 322 release_sock(sk); 323 sock_put(sk); 324 325 /* Restart the process from the start of the current 326 * hash chain. We dropped locks so the world may have 327 * change from underneath us. 328 */ 329 330 BUG_ON(pppoe_pernet(dev_net(dev)) == NULL); 331 write_lock_bh(&pn->hash_lock); 332 po = pn->hash_table[i]; 333 } 334 } 335 write_unlock_bh(&pn->hash_lock); 336 } 337 338 static int pppoe_device_event(struct notifier_block *this, 339 unsigned long event, void *ptr) 340 { 341 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 342 343 /* Only look at sockets that are using this specific device. */ 344 switch (event) { 345 case NETDEV_CHANGEADDR: 346 case NETDEV_CHANGEMTU: 347 /* A change in mtu or address is a bad thing, requiring 348 * LCP re-negotiation. 349 */ 350 351 case NETDEV_GOING_DOWN: 352 case NETDEV_DOWN: 353 /* Find every socket on this device and kill it. */ 354 pppoe_flush_dev(dev); 355 break; 356 357 default: 358 break; 359 } 360 361 return NOTIFY_DONE; 362 } 363 364 static struct notifier_block pppoe_notifier = { 365 .notifier_call = pppoe_device_event, 366 }; 367 368 /************************************************************************ 369 * 370 * Do the real work of receiving a PPPoE Session frame. 371 * 372 ***********************************************************************/ 373 static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb) 374 { 375 struct pppox_sock *po = pppox_sk(sk); 376 struct pppox_sock *relay_po; 377 378 /* Backlog receive. Semantics of backlog rcv preclude any code from 379 * executing in lock_sock()/release_sock() bounds; meaning sk->sk_state 380 * can't change. 381 */ 382 383 if (skb->pkt_type == PACKET_OTHERHOST) 384 goto abort_kfree; 385 386 if (sk->sk_state & PPPOX_BOUND) { 387 ppp_input(&po->chan, skb); 388 } else if (sk->sk_state & PPPOX_RELAY) { 389 relay_po = get_item_by_addr(sock_net(sk), 390 &po->pppoe_relay); 391 if (relay_po == NULL) 392 goto abort_kfree; 393 394 if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0) 395 goto abort_put; 396 397 if (!__pppoe_xmit(sk_pppox(relay_po), skb)) 398 goto abort_put; 399 } else { 400 if (sock_queue_rcv_skb(sk, skb)) 401 goto abort_kfree; 402 } 403 404 return NET_RX_SUCCESS; 405 406 abort_put: 407 sock_put(sk_pppox(relay_po)); 408 409 abort_kfree: 410 kfree_skb(skb); 411 return NET_RX_DROP; 412 } 413 414 /************************************************************************ 415 * 416 * Receive wrapper called in BH context. 417 * 418 ***********************************************************************/ 419 static int pppoe_rcv(struct sk_buff *skb, struct net_device *dev, 420 struct packet_type *pt, struct net_device *orig_dev) 421 { 422 struct pppoe_hdr *ph; 423 struct pppox_sock *po; 424 struct pppoe_net *pn; 425 int len; 426 427 skb = skb_share_check(skb, GFP_ATOMIC); 428 if (!skb) 429 goto out; 430 431 if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr))) 432 goto drop; 433 434 ph = pppoe_hdr(skb); 435 len = ntohs(ph->length); 436 437 skb_pull_rcsum(skb, sizeof(*ph)); 438 if (skb->len < len) 439 goto drop; 440 441 if (pskb_trim_rcsum(skb, len)) 442 goto drop; 443 444 pn = pppoe_pernet(dev_net(dev)); 445 446 /* Note that get_item does a sock_hold(), so sk_pppox(po) 447 * is known to be safe. 448 */ 449 po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex); 450 if (!po) 451 goto drop; 452 453 return sk_receive_skb(sk_pppox(po), skb, 0); 454 455 drop: 456 kfree_skb(skb); 457 out: 458 return NET_RX_DROP; 459 } 460 461 static void pppoe_unbind_sock_work(struct work_struct *work) 462 { 463 struct pppox_sock *po = container_of(work, struct pppox_sock, 464 proto.pppoe.padt_work); 465 struct sock *sk = sk_pppox(po); 466 467 lock_sock(sk); 468 if (po->pppoe_dev) { 469 dev_put(po->pppoe_dev); 470 po->pppoe_dev = NULL; 471 } 472 pppox_unbind_sock(sk); 473 release_sock(sk); 474 sock_put(sk); 475 } 476 477 /************************************************************************ 478 * 479 * Receive a PPPoE Discovery frame. 480 * This is solely for detection of PADT frames 481 * 482 ***********************************************************************/ 483 static int pppoe_disc_rcv(struct sk_buff *skb, struct net_device *dev, 484 struct packet_type *pt, struct net_device *orig_dev) 485 486 { 487 struct pppoe_hdr *ph; 488 struct pppox_sock *po; 489 struct pppoe_net *pn; 490 491 skb = skb_share_check(skb, GFP_ATOMIC); 492 if (!skb) 493 goto out; 494 495 if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr))) 496 goto abort; 497 498 ph = pppoe_hdr(skb); 499 if (ph->code != PADT_CODE) 500 goto abort; 501 502 pn = pppoe_pernet(dev_net(dev)); 503 po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex); 504 if (po) { 505 struct sock *sk = sk_pppox(po); 506 507 bh_lock_sock(sk); 508 509 /* If the user has locked the socket, just ignore 510 * the packet. With the way two rcv protocols hook into 511 * one socket family type, we cannot (easily) distinguish 512 * what kind of SKB it is during backlog rcv. 513 */ 514 if (sock_owned_by_user(sk) == 0) { 515 /* We're no longer connect at the PPPOE layer, 516 * and must wait for ppp channel to disconnect us. 517 */ 518 sk->sk_state = PPPOX_ZOMBIE; 519 } 520 521 bh_unlock_sock(sk); 522 if (!schedule_work(&po->proto.pppoe.padt_work)) 523 sock_put(sk); 524 } 525 526 abort: 527 kfree_skb(skb); 528 out: 529 return NET_RX_SUCCESS; /* Lies... :-) */ 530 } 531 532 static struct packet_type pppoes_ptype __read_mostly = { 533 .type = cpu_to_be16(ETH_P_PPP_SES), 534 .func = pppoe_rcv, 535 }; 536 537 static struct packet_type pppoed_ptype __read_mostly = { 538 .type = cpu_to_be16(ETH_P_PPP_DISC), 539 .func = pppoe_disc_rcv, 540 }; 541 542 static struct proto pppoe_sk_proto __read_mostly = { 543 .name = "PPPOE", 544 .owner = THIS_MODULE, 545 .obj_size = sizeof(struct pppox_sock), 546 }; 547 548 /*********************************************************************** 549 * 550 * Initialize a new struct sock. 551 * 552 **********************************************************************/ 553 static int pppoe_create(struct net *net, struct socket *sock, int kern) 554 { 555 struct sock *sk; 556 557 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, kern); 558 if (!sk) 559 return -ENOMEM; 560 561 sock_init_data(sock, sk); 562 563 sock->state = SS_UNCONNECTED; 564 sock->ops = &pppoe_ops; 565 566 sk->sk_backlog_rcv = pppoe_rcv_core; 567 sk->sk_state = PPPOX_NONE; 568 sk->sk_type = SOCK_STREAM; 569 sk->sk_family = PF_PPPOX; 570 sk->sk_protocol = PX_PROTO_OE; 571 572 return 0; 573 } 574 575 static int pppoe_release(struct socket *sock) 576 { 577 struct sock *sk = sock->sk; 578 struct pppox_sock *po; 579 struct pppoe_net *pn; 580 struct net *net = NULL; 581 582 if (!sk) 583 return 0; 584 585 lock_sock(sk); 586 if (sock_flag(sk, SOCK_DEAD)) { 587 release_sock(sk); 588 return -EBADF; 589 } 590 591 po = pppox_sk(sk); 592 593 if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND | PPPOX_ZOMBIE)) { 594 dev_put(po->pppoe_dev); 595 po->pppoe_dev = NULL; 596 } 597 598 pppox_unbind_sock(sk); 599 600 /* Signal the death of the socket. */ 601 sk->sk_state = PPPOX_DEAD; 602 603 net = sock_net(sk); 604 pn = pppoe_pernet(net); 605 606 /* 607 * protect "po" from concurrent updates 608 * on pppoe_flush_dev 609 */ 610 delete_item(pn, po->pppoe_pa.sid, po->pppoe_pa.remote, 611 po->pppoe_ifindex); 612 613 sock_orphan(sk); 614 sock->sk = NULL; 615 616 skb_queue_purge(&sk->sk_receive_queue); 617 release_sock(sk); 618 sock_put(sk); 619 620 return 0; 621 } 622 623 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr, 624 int sockaddr_len, int flags) 625 { 626 struct sock *sk = sock->sk; 627 struct sockaddr_pppox *sp = (struct sockaddr_pppox *)uservaddr; 628 struct pppox_sock *po = pppox_sk(sk); 629 struct net_device *dev = NULL; 630 struct pppoe_net *pn; 631 struct net *net = NULL; 632 int error; 633 634 lock_sock(sk); 635 636 INIT_WORK(&po->proto.pppoe.padt_work, pppoe_unbind_sock_work); 637 638 error = -EINVAL; 639 if (sp->sa_protocol != PX_PROTO_OE) 640 goto end; 641 642 /* Check for already bound sockets */ 643 error = -EBUSY; 644 if ((sk->sk_state & PPPOX_CONNECTED) && 645 stage_session(sp->sa_addr.pppoe.sid)) 646 goto end; 647 648 /* Check for already disconnected sockets, on attempts to disconnect */ 649 error = -EALREADY; 650 if ((sk->sk_state & PPPOX_DEAD) && 651 !stage_session(sp->sa_addr.pppoe.sid)) 652 goto end; 653 654 error = 0; 655 656 /* Delete the old binding */ 657 if (stage_session(po->pppoe_pa.sid)) { 658 pppox_unbind_sock(sk); 659 pn = pppoe_pernet(sock_net(sk)); 660 delete_item(pn, po->pppoe_pa.sid, 661 po->pppoe_pa.remote, po->pppoe_ifindex); 662 if (po->pppoe_dev) { 663 dev_put(po->pppoe_dev); 664 po->pppoe_dev = NULL; 665 } 666 667 memset(sk_pppox(po) + 1, 0, 668 sizeof(struct pppox_sock) - sizeof(struct sock)); 669 sk->sk_state = PPPOX_NONE; 670 } 671 672 /* Re-bind in session stage only */ 673 if (stage_session(sp->sa_addr.pppoe.sid)) { 674 error = -ENODEV; 675 net = sock_net(sk); 676 dev = dev_get_by_name(net, sp->sa_addr.pppoe.dev); 677 if (!dev) 678 goto err_put; 679 680 po->pppoe_dev = dev; 681 po->pppoe_ifindex = dev->ifindex; 682 pn = pppoe_pernet(net); 683 if (!(dev->flags & IFF_UP)) { 684 goto err_put; 685 } 686 687 memcpy(&po->pppoe_pa, 688 &sp->sa_addr.pppoe, 689 sizeof(struct pppoe_addr)); 690 691 write_lock_bh(&pn->hash_lock); 692 error = __set_item(pn, po); 693 write_unlock_bh(&pn->hash_lock); 694 if (error < 0) 695 goto err_put; 696 697 po->chan.hdrlen = (sizeof(struct pppoe_hdr) + 698 dev->hard_header_len); 699 700 po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr) - 2; 701 po->chan.private = sk; 702 po->chan.ops = &pppoe_chan_ops; 703 704 error = ppp_register_net_channel(dev_net(dev), &po->chan); 705 if (error) { 706 delete_item(pn, po->pppoe_pa.sid, 707 po->pppoe_pa.remote, po->pppoe_ifindex); 708 goto err_put; 709 } 710 711 sk->sk_state = PPPOX_CONNECTED; 712 } 713 714 po->num = sp->sa_addr.pppoe.sid; 715 716 end: 717 release_sock(sk); 718 return error; 719 err_put: 720 if (po->pppoe_dev) { 721 dev_put(po->pppoe_dev); 722 po->pppoe_dev = NULL; 723 } 724 goto end; 725 } 726 727 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr, 728 int *usockaddr_len, int peer) 729 { 730 int len = sizeof(struct sockaddr_pppox); 731 struct sockaddr_pppox sp; 732 733 sp.sa_family = AF_PPPOX; 734 sp.sa_protocol = PX_PROTO_OE; 735 memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa, 736 sizeof(struct pppoe_addr)); 737 738 memcpy(uaddr, &sp, len); 739 740 *usockaddr_len = len; 741 742 return 0; 743 } 744 745 static int pppoe_ioctl(struct socket *sock, unsigned int cmd, 746 unsigned long arg) 747 { 748 struct sock *sk = sock->sk; 749 struct pppox_sock *po = pppox_sk(sk); 750 int val; 751 int err; 752 753 switch (cmd) { 754 case PPPIOCGMRU: 755 err = -ENXIO; 756 if (!(sk->sk_state & PPPOX_CONNECTED)) 757 break; 758 759 err = -EFAULT; 760 if (put_user(po->pppoe_dev->mtu - 761 sizeof(struct pppoe_hdr) - 762 PPP_HDRLEN, 763 (int __user *)arg)) 764 break; 765 err = 0; 766 break; 767 768 case PPPIOCSMRU: 769 err = -ENXIO; 770 if (!(sk->sk_state & PPPOX_CONNECTED)) 771 break; 772 773 err = -EFAULT; 774 if (get_user(val, (int __user *)arg)) 775 break; 776 777 if (val < (po->pppoe_dev->mtu 778 - sizeof(struct pppoe_hdr) 779 - PPP_HDRLEN)) 780 err = 0; 781 else 782 err = -EINVAL; 783 break; 784 785 case PPPIOCSFLAGS: 786 err = -EFAULT; 787 if (get_user(val, (int __user *)arg)) 788 break; 789 err = 0; 790 break; 791 792 case PPPOEIOCSFWD: 793 { 794 struct pppox_sock *relay_po; 795 796 err = -EBUSY; 797 if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD)) 798 break; 799 800 err = -ENOTCONN; 801 if (!(sk->sk_state & PPPOX_CONNECTED)) 802 break; 803 804 /* PPPoE address from the user specifies an outbound 805 PPPoE address which frames are forwarded to */ 806 err = -EFAULT; 807 if (copy_from_user(&po->pppoe_relay, 808 (void __user *)arg, 809 sizeof(struct sockaddr_pppox))) 810 break; 811 812 err = -EINVAL; 813 if (po->pppoe_relay.sa_family != AF_PPPOX || 814 po->pppoe_relay.sa_protocol != PX_PROTO_OE) 815 break; 816 817 /* Check that the socket referenced by the address 818 actually exists. */ 819 relay_po = get_item_by_addr(sock_net(sk), &po->pppoe_relay); 820 if (!relay_po) 821 break; 822 823 sock_put(sk_pppox(relay_po)); 824 sk->sk_state |= PPPOX_RELAY; 825 err = 0; 826 break; 827 } 828 829 case PPPOEIOCDFWD: 830 err = -EALREADY; 831 if (!(sk->sk_state & PPPOX_RELAY)) 832 break; 833 834 sk->sk_state &= ~PPPOX_RELAY; 835 err = 0; 836 break; 837 838 default: 839 err = -ENOTTY; 840 } 841 842 return err; 843 } 844 845 static int pppoe_sendmsg(struct socket *sock, struct msghdr *m, 846 size_t total_len) 847 { 848 struct sk_buff *skb; 849 struct sock *sk = sock->sk; 850 struct pppox_sock *po = pppox_sk(sk); 851 int error; 852 struct pppoe_hdr hdr; 853 struct pppoe_hdr *ph; 854 struct net_device *dev; 855 char *start; 856 857 lock_sock(sk); 858 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) { 859 error = -ENOTCONN; 860 goto end; 861 } 862 863 hdr.ver = 1; 864 hdr.type = 1; 865 hdr.code = 0; 866 hdr.sid = po->num; 867 868 dev = po->pppoe_dev; 869 870 error = -EMSGSIZE; 871 if (total_len > (dev->mtu + dev->hard_header_len)) 872 goto end; 873 874 875 skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32, 876 0, GFP_KERNEL); 877 if (!skb) { 878 error = -ENOMEM; 879 goto end; 880 } 881 882 /* Reserve space for headers. */ 883 skb_reserve(skb, dev->hard_header_len); 884 skb_reset_network_header(skb); 885 886 skb->dev = dev; 887 888 skb->priority = sk->sk_priority; 889 skb->protocol = cpu_to_be16(ETH_P_PPP_SES); 890 891 ph = (struct pppoe_hdr *)skb_put(skb, total_len + sizeof(struct pppoe_hdr)); 892 start = (char *)&ph->tag[0]; 893 894 error = memcpy_from_msg(start, m, total_len); 895 if (error < 0) { 896 kfree_skb(skb); 897 goto end; 898 } 899 900 error = total_len; 901 dev_hard_header(skb, dev, ETH_P_PPP_SES, 902 po->pppoe_pa.remote, NULL, total_len); 903 904 memcpy(ph, &hdr, sizeof(struct pppoe_hdr)); 905 906 ph->length = htons(total_len); 907 908 dev_queue_xmit(skb); 909 910 end: 911 release_sock(sk); 912 return error; 913 } 914 915 /************************************************************************ 916 * 917 * xmit function for internal use. 918 * 919 ***********************************************************************/ 920 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb) 921 { 922 struct pppox_sock *po = pppox_sk(sk); 923 struct net_device *dev = po->pppoe_dev; 924 struct pppoe_hdr *ph; 925 int data_len = skb->len; 926 927 /* The higher-level PPP code (ppp_unregister_channel()) ensures the PPP 928 * xmit operations conclude prior to an unregistration call. Thus 929 * sk->sk_state cannot change, so we don't need to do lock_sock(). 930 * But, we also can't do a lock_sock since that introduces a potential 931 * deadlock as we'd reverse the lock ordering used when calling 932 * ppp_unregister_channel(). 933 */ 934 935 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 936 goto abort; 937 938 if (!dev) 939 goto abort; 940 941 /* Copy the data if there is no space for the header or if it's 942 * read-only. 943 */ 944 if (skb_cow_head(skb, sizeof(*ph) + dev->hard_header_len)) 945 goto abort; 946 947 __skb_push(skb, sizeof(*ph)); 948 skb_reset_network_header(skb); 949 950 ph = pppoe_hdr(skb); 951 ph->ver = 1; 952 ph->type = 1; 953 ph->code = 0; 954 ph->sid = po->num; 955 ph->length = htons(data_len); 956 957 skb->protocol = cpu_to_be16(ETH_P_PPP_SES); 958 skb->dev = dev; 959 960 dev_hard_header(skb, dev, ETH_P_PPP_SES, 961 po->pppoe_pa.remote, NULL, data_len); 962 963 dev_queue_xmit(skb); 964 return 1; 965 966 abort: 967 kfree_skb(skb); 968 return 1; 969 } 970 971 /************************************************************************ 972 * 973 * xmit function called by generic PPP driver 974 * sends PPP frame over PPPoE socket 975 * 976 ***********************************************************************/ 977 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb) 978 { 979 struct sock *sk = (struct sock *)chan->private; 980 return __pppoe_xmit(sk, skb); 981 } 982 983 static const struct ppp_channel_ops pppoe_chan_ops = { 984 .start_xmit = pppoe_xmit, 985 }; 986 987 static int pppoe_recvmsg(struct socket *sock, struct msghdr *m, 988 size_t total_len, int flags) 989 { 990 struct sock *sk = sock->sk; 991 struct sk_buff *skb; 992 int error = 0; 993 994 if (sk->sk_state & PPPOX_BOUND) { 995 error = -EIO; 996 goto end; 997 } 998 999 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, 1000 flags & MSG_DONTWAIT, &error); 1001 if (error < 0) 1002 goto end; 1003 1004 if (skb) { 1005 total_len = min_t(size_t, total_len, skb->len); 1006 error = skb_copy_datagram_msg(skb, 0, m, total_len); 1007 if (error == 0) { 1008 consume_skb(skb); 1009 return total_len; 1010 } 1011 } 1012 1013 kfree_skb(skb); 1014 end: 1015 return error; 1016 } 1017 1018 #ifdef CONFIG_PROC_FS 1019 static int pppoe_seq_show(struct seq_file *seq, void *v) 1020 { 1021 struct pppox_sock *po; 1022 char *dev_name; 1023 1024 if (v == SEQ_START_TOKEN) { 1025 seq_puts(seq, "Id Address Device\n"); 1026 goto out; 1027 } 1028 1029 po = v; 1030 dev_name = po->pppoe_pa.dev; 1031 1032 seq_printf(seq, "%08X %pM %8s\n", 1033 po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name); 1034 out: 1035 return 0; 1036 } 1037 1038 static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos) 1039 { 1040 struct pppox_sock *po; 1041 int i; 1042 1043 for (i = 0; i < PPPOE_HASH_SIZE; i++) { 1044 po = pn->hash_table[i]; 1045 while (po) { 1046 if (!pos--) 1047 goto out; 1048 po = po->next; 1049 } 1050 } 1051 1052 out: 1053 return po; 1054 } 1055 1056 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos) 1057 __acquires(pn->hash_lock) 1058 { 1059 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1060 loff_t l = *pos; 1061 1062 read_lock_bh(&pn->hash_lock); 1063 return l ? pppoe_get_idx(pn, --l) : SEQ_START_TOKEN; 1064 } 1065 1066 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1067 { 1068 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1069 struct pppox_sock *po; 1070 1071 ++*pos; 1072 if (v == SEQ_START_TOKEN) { 1073 po = pppoe_get_idx(pn, 0); 1074 goto out; 1075 } 1076 po = v; 1077 if (po->next) 1078 po = po->next; 1079 else { 1080 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); 1081 1082 po = NULL; 1083 while (++hash < PPPOE_HASH_SIZE) { 1084 po = pn->hash_table[hash]; 1085 if (po) 1086 break; 1087 } 1088 } 1089 1090 out: 1091 return po; 1092 } 1093 1094 static void pppoe_seq_stop(struct seq_file *seq, void *v) 1095 __releases(pn->hash_lock) 1096 { 1097 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1098 read_unlock_bh(&pn->hash_lock); 1099 } 1100 1101 static const struct seq_operations pppoe_seq_ops = { 1102 .start = pppoe_seq_start, 1103 .next = pppoe_seq_next, 1104 .stop = pppoe_seq_stop, 1105 .show = pppoe_seq_show, 1106 }; 1107 1108 static int pppoe_seq_open(struct inode *inode, struct file *file) 1109 { 1110 return seq_open_net(inode, file, &pppoe_seq_ops, 1111 sizeof(struct seq_net_private)); 1112 } 1113 1114 static const struct file_operations pppoe_seq_fops = { 1115 .owner = THIS_MODULE, 1116 .open = pppoe_seq_open, 1117 .read = seq_read, 1118 .llseek = seq_lseek, 1119 .release = seq_release_net, 1120 }; 1121 1122 #endif /* CONFIG_PROC_FS */ 1123 1124 static const struct proto_ops pppoe_ops = { 1125 .family = AF_PPPOX, 1126 .owner = THIS_MODULE, 1127 .release = pppoe_release, 1128 .bind = sock_no_bind, 1129 .connect = pppoe_connect, 1130 .socketpair = sock_no_socketpair, 1131 .accept = sock_no_accept, 1132 .getname = pppoe_getname, 1133 .poll = datagram_poll, 1134 .listen = sock_no_listen, 1135 .shutdown = sock_no_shutdown, 1136 .setsockopt = sock_no_setsockopt, 1137 .getsockopt = sock_no_getsockopt, 1138 .sendmsg = pppoe_sendmsg, 1139 .recvmsg = pppoe_recvmsg, 1140 .mmap = sock_no_mmap, 1141 .ioctl = pppox_ioctl, 1142 }; 1143 1144 static const struct pppox_proto pppoe_proto = { 1145 .create = pppoe_create, 1146 .ioctl = pppoe_ioctl, 1147 .owner = THIS_MODULE, 1148 }; 1149 1150 static __net_init int pppoe_init_net(struct net *net) 1151 { 1152 struct pppoe_net *pn = pppoe_pernet(net); 1153 struct proc_dir_entry *pde; 1154 1155 rwlock_init(&pn->hash_lock); 1156 1157 pde = proc_create("pppoe", S_IRUGO, net->proc_net, &pppoe_seq_fops); 1158 #ifdef CONFIG_PROC_FS 1159 if (!pde) 1160 return -ENOMEM; 1161 #endif 1162 1163 return 0; 1164 } 1165 1166 static __net_exit void pppoe_exit_net(struct net *net) 1167 { 1168 remove_proc_entry("pppoe", net->proc_net); 1169 } 1170 1171 static struct pernet_operations pppoe_net_ops = { 1172 .init = pppoe_init_net, 1173 .exit = pppoe_exit_net, 1174 .id = &pppoe_net_id, 1175 .size = sizeof(struct pppoe_net), 1176 }; 1177 1178 static int __init pppoe_init(void) 1179 { 1180 int err; 1181 1182 err = register_pernet_device(&pppoe_net_ops); 1183 if (err) 1184 goto out; 1185 1186 err = proto_register(&pppoe_sk_proto, 0); 1187 if (err) 1188 goto out_unregister_net_ops; 1189 1190 err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto); 1191 if (err) 1192 goto out_unregister_pppoe_proto; 1193 1194 dev_add_pack(&pppoes_ptype); 1195 dev_add_pack(&pppoed_ptype); 1196 register_netdevice_notifier(&pppoe_notifier); 1197 1198 return 0; 1199 1200 out_unregister_pppoe_proto: 1201 proto_unregister(&pppoe_sk_proto); 1202 out_unregister_net_ops: 1203 unregister_pernet_device(&pppoe_net_ops); 1204 out: 1205 return err; 1206 } 1207 1208 static void __exit pppoe_exit(void) 1209 { 1210 unregister_netdevice_notifier(&pppoe_notifier); 1211 dev_remove_pack(&pppoed_ptype); 1212 dev_remove_pack(&pppoes_ptype); 1213 unregister_pppox_proto(PX_PROTO_OE); 1214 proto_unregister(&pppoe_sk_proto); 1215 unregister_pernet_device(&pppoe_net_ops); 1216 } 1217 1218 module_init(pppoe_init); 1219 module_exit(pppoe_exit); 1220 1221 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>"); 1222 MODULE_DESCRIPTION("PPP over Ethernet driver"); 1223 MODULE_LICENSE("GPL"); 1224 MODULE_ALIAS_NETPROTO(PF_PPPOX); 1225