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; 623 624 if (sockaddr_len != sizeof(struct sockaddr_pppox)) 625 goto end; 626 627 if (sp->sa_protocol != PX_PROTO_OE) 628 goto end; 629 630 /* Check for already bound sockets */ 631 error = -EBUSY; 632 if ((sk->sk_state & PPPOX_CONNECTED) && 633 stage_session(sp->sa_addr.pppoe.sid)) 634 goto end; 635 636 /* Check for already disconnected sockets, on attempts to disconnect */ 637 error = -EALREADY; 638 if ((sk->sk_state & PPPOX_DEAD) && 639 !stage_session(sp->sa_addr.pppoe.sid)) 640 goto end; 641 642 error = 0; 643 644 /* Delete the old binding */ 645 if (stage_session(po->pppoe_pa.sid)) { 646 pppox_unbind_sock(sk); 647 pn = pppoe_pernet(sock_net(sk)); 648 delete_item(pn, po->pppoe_pa.sid, 649 po->pppoe_pa.remote, po->pppoe_ifindex); 650 if (po->pppoe_dev) { 651 dev_put(po->pppoe_dev); 652 po->pppoe_dev = NULL; 653 } 654 655 po->pppoe_ifindex = 0; 656 memset(&po->pppoe_pa, 0, sizeof(po->pppoe_pa)); 657 memset(&po->pppoe_relay, 0, sizeof(po->pppoe_relay)); 658 memset(&po->chan, 0, sizeof(po->chan)); 659 po->next = NULL; 660 po->num = 0; 661 662 sk->sk_state = PPPOX_NONE; 663 } 664 665 /* Re-bind in session stage only */ 666 if (stage_session(sp->sa_addr.pppoe.sid)) { 667 error = -ENODEV; 668 net = sock_net(sk); 669 dev = dev_get_by_name(net, sp->sa_addr.pppoe.dev); 670 if (!dev) 671 goto err_put; 672 673 po->pppoe_dev = dev; 674 po->pppoe_ifindex = dev->ifindex; 675 pn = pppoe_pernet(net); 676 if (!(dev->flags & IFF_UP)) { 677 goto err_put; 678 } 679 680 memcpy(&po->pppoe_pa, 681 &sp->sa_addr.pppoe, 682 sizeof(struct pppoe_addr)); 683 684 write_lock_bh(&pn->hash_lock); 685 error = __set_item(pn, po); 686 write_unlock_bh(&pn->hash_lock); 687 if (error < 0) 688 goto err_put; 689 690 po->chan.hdrlen = (sizeof(struct pppoe_hdr) + 691 dev->hard_header_len); 692 693 po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr) - 2; 694 po->chan.private = sk; 695 po->chan.ops = &pppoe_chan_ops; 696 697 error = ppp_register_net_channel(dev_net(dev), &po->chan); 698 if (error) { 699 delete_item(pn, po->pppoe_pa.sid, 700 po->pppoe_pa.remote, po->pppoe_ifindex); 701 goto err_put; 702 } 703 704 sk->sk_state = PPPOX_CONNECTED; 705 } 706 707 po->num = sp->sa_addr.pppoe.sid; 708 709 end: 710 release_sock(sk); 711 return error; 712 err_put: 713 if (po->pppoe_dev) { 714 dev_put(po->pppoe_dev); 715 po->pppoe_dev = NULL; 716 } 717 goto end; 718 } 719 720 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr, 721 int peer) 722 { 723 int len = sizeof(struct sockaddr_pppox); 724 struct sockaddr_pppox sp; 725 726 sp.sa_family = AF_PPPOX; 727 sp.sa_protocol = PX_PROTO_OE; 728 memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa, 729 sizeof(struct pppoe_addr)); 730 731 memcpy(uaddr, &sp, len); 732 733 return len; 734 } 735 736 static int pppoe_ioctl(struct socket *sock, unsigned int cmd, 737 unsigned long arg) 738 { 739 struct sock *sk = sock->sk; 740 struct pppox_sock *po = pppox_sk(sk); 741 int val; 742 int err; 743 744 switch (cmd) { 745 case PPPIOCGMRU: 746 err = -ENXIO; 747 if (!(sk->sk_state & PPPOX_CONNECTED)) 748 break; 749 750 err = -EFAULT; 751 if (put_user(po->pppoe_dev->mtu - 752 sizeof(struct pppoe_hdr) - 753 PPP_HDRLEN, 754 (int __user *)arg)) 755 break; 756 err = 0; 757 break; 758 759 case PPPIOCSMRU: 760 err = -ENXIO; 761 if (!(sk->sk_state & PPPOX_CONNECTED)) 762 break; 763 764 err = -EFAULT; 765 if (get_user(val, (int __user *)arg)) 766 break; 767 768 if (val < (po->pppoe_dev->mtu 769 - sizeof(struct pppoe_hdr) 770 - PPP_HDRLEN)) 771 err = 0; 772 else 773 err = -EINVAL; 774 break; 775 776 case PPPIOCSFLAGS: 777 err = -EFAULT; 778 if (get_user(val, (int __user *)arg)) 779 break; 780 err = 0; 781 break; 782 783 case PPPOEIOCSFWD: 784 { 785 struct pppox_sock *relay_po; 786 787 err = -EBUSY; 788 if (sk->sk_state & (PPPOX_BOUND | PPPOX_DEAD)) 789 break; 790 791 err = -ENOTCONN; 792 if (!(sk->sk_state & PPPOX_CONNECTED)) 793 break; 794 795 /* PPPoE address from the user specifies an outbound 796 PPPoE address which frames are forwarded to */ 797 err = -EFAULT; 798 if (copy_from_user(&po->pppoe_relay, 799 (void __user *)arg, 800 sizeof(struct sockaddr_pppox))) 801 break; 802 803 err = -EINVAL; 804 if (po->pppoe_relay.sa_family != AF_PPPOX || 805 po->pppoe_relay.sa_protocol != PX_PROTO_OE) 806 break; 807 808 /* Check that the socket referenced by the address 809 actually exists. */ 810 relay_po = get_item_by_addr(sock_net(sk), &po->pppoe_relay); 811 if (!relay_po) 812 break; 813 814 sock_put(sk_pppox(relay_po)); 815 sk->sk_state |= PPPOX_RELAY; 816 err = 0; 817 break; 818 } 819 820 case PPPOEIOCDFWD: 821 err = -EALREADY; 822 if (!(sk->sk_state & PPPOX_RELAY)) 823 break; 824 825 sk->sk_state &= ~PPPOX_RELAY; 826 err = 0; 827 break; 828 829 default: 830 err = -ENOTTY; 831 } 832 833 return err; 834 } 835 836 static int pppoe_sendmsg(struct socket *sock, struct msghdr *m, 837 size_t total_len) 838 { 839 struct sk_buff *skb; 840 struct sock *sk = sock->sk; 841 struct pppox_sock *po = pppox_sk(sk); 842 int error; 843 struct pppoe_hdr hdr; 844 struct pppoe_hdr *ph; 845 struct net_device *dev; 846 char *start; 847 int hlen; 848 849 lock_sock(sk); 850 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) { 851 error = -ENOTCONN; 852 goto end; 853 } 854 855 hdr.ver = 1; 856 hdr.type = 1; 857 hdr.code = 0; 858 hdr.sid = po->num; 859 860 dev = po->pppoe_dev; 861 862 error = -EMSGSIZE; 863 if (total_len > (dev->mtu + dev->hard_header_len)) 864 goto end; 865 866 hlen = LL_RESERVED_SPACE(dev); 867 skb = sock_wmalloc(sk, hlen + sizeof(*ph) + total_len + 868 dev->needed_tailroom, 0, GFP_KERNEL); 869 if (!skb) { 870 error = -ENOMEM; 871 goto end; 872 } 873 874 /* Reserve space for headers. */ 875 skb_reserve(skb, hlen); 876 skb_reset_network_header(skb); 877 878 skb->dev = dev; 879 880 skb->priority = sk->sk_priority; 881 skb->protocol = cpu_to_be16(ETH_P_PPP_SES); 882 883 ph = skb_put(skb, total_len + sizeof(struct pppoe_hdr)); 884 start = (char *)&ph->tag[0]; 885 886 error = memcpy_from_msg(start, m, total_len); 887 if (error < 0) { 888 kfree_skb(skb); 889 goto end; 890 } 891 892 error = total_len; 893 dev_hard_header(skb, dev, ETH_P_PPP_SES, 894 po->pppoe_pa.remote, NULL, total_len); 895 896 memcpy(ph, &hdr, sizeof(struct pppoe_hdr)); 897 898 ph->length = htons(total_len); 899 900 dev_queue_xmit(skb); 901 902 end: 903 release_sock(sk); 904 return error; 905 } 906 907 /************************************************************************ 908 * 909 * xmit function for internal use. 910 * 911 ***********************************************************************/ 912 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb) 913 { 914 struct pppox_sock *po = pppox_sk(sk); 915 struct net_device *dev = po->pppoe_dev; 916 struct pppoe_hdr *ph; 917 int data_len = skb->len; 918 919 /* The higher-level PPP code (ppp_unregister_channel()) ensures the PPP 920 * xmit operations conclude prior to an unregistration call. Thus 921 * sk->sk_state cannot change, so we don't need to do lock_sock(). 922 * But, we also can't do a lock_sock since that introduces a potential 923 * deadlock as we'd reverse the lock ordering used when calling 924 * ppp_unregister_channel(). 925 */ 926 927 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 928 goto abort; 929 930 if (!dev) 931 goto abort; 932 933 /* Copy the data if there is no space for the header or if it's 934 * read-only. 935 */ 936 if (skb_cow_head(skb, LL_RESERVED_SPACE(dev) + sizeof(*ph))) 937 goto abort; 938 939 __skb_push(skb, sizeof(*ph)); 940 skb_reset_network_header(skb); 941 942 ph = pppoe_hdr(skb); 943 ph->ver = 1; 944 ph->type = 1; 945 ph->code = 0; 946 ph->sid = po->num; 947 ph->length = htons(data_len); 948 949 skb->protocol = cpu_to_be16(ETH_P_PPP_SES); 950 skb->dev = dev; 951 952 dev_hard_header(skb, dev, ETH_P_PPP_SES, 953 po->pppoe_pa.remote, NULL, data_len); 954 955 dev_queue_xmit(skb); 956 return 1; 957 958 abort: 959 kfree_skb(skb); 960 return 1; 961 } 962 963 /************************************************************************ 964 * 965 * xmit function called by generic PPP driver 966 * sends PPP frame over PPPoE socket 967 * 968 ***********************************************************************/ 969 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb) 970 { 971 struct sock *sk = (struct sock *)chan->private; 972 return __pppoe_xmit(sk, skb); 973 } 974 975 static const struct ppp_channel_ops pppoe_chan_ops = { 976 .start_xmit = pppoe_xmit, 977 }; 978 979 static int pppoe_recvmsg(struct socket *sock, struct msghdr *m, 980 size_t total_len, int flags) 981 { 982 struct sock *sk = sock->sk; 983 struct sk_buff *skb; 984 int error = 0; 985 986 if (sk->sk_state & PPPOX_BOUND) { 987 error = -EIO; 988 goto end; 989 } 990 991 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, 992 flags & MSG_DONTWAIT, &error); 993 if (error < 0) 994 goto end; 995 996 if (skb) { 997 total_len = min_t(size_t, total_len, skb->len); 998 error = skb_copy_datagram_msg(skb, 0, m, total_len); 999 if (error == 0) { 1000 consume_skb(skb); 1001 return total_len; 1002 } 1003 } 1004 1005 kfree_skb(skb); 1006 end: 1007 return error; 1008 } 1009 1010 #ifdef CONFIG_PROC_FS 1011 static int pppoe_seq_show(struct seq_file *seq, void *v) 1012 { 1013 struct pppox_sock *po; 1014 char *dev_name; 1015 1016 if (v == SEQ_START_TOKEN) { 1017 seq_puts(seq, "Id Address Device\n"); 1018 goto out; 1019 } 1020 1021 po = v; 1022 dev_name = po->pppoe_pa.dev; 1023 1024 seq_printf(seq, "%08X %pM %8s\n", 1025 po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name); 1026 out: 1027 return 0; 1028 } 1029 1030 static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos) 1031 { 1032 struct pppox_sock *po; 1033 int i; 1034 1035 for (i = 0; i < PPPOE_HASH_SIZE; i++) { 1036 po = pn->hash_table[i]; 1037 while (po) { 1038 if (!pos--) 1039 goto out; 1040 po = po->next; 1041 } 1042 } 1043 1044 out: 1045 return po; 1046 } 1047 1048 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos) 1049 __acquires(pn->hash_lock) 1050 { 1051 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1052 loff_t l = *pos; 1053 1054 read_lock_bh(&pn->hash_lock); 1055 return l ? pppoe_get_idx(pn, --l) : SEQ_START_TOKEN; 1056 } 1057 1058 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1059 { 1060 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1061 struct pppox_sock *po; 1062 1063 ++*pos; 1064 if (v == SEQ_START_TOKEN) { 1065 po = pppoe_get_idx(pn, 0); 1066 goto out; 1067 } 1068 po = v; 1069 if (po->next) 1070 po = po->next; 1071 else { 1072 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); 1073 1074 po = NULL; 1075 while (++hash < PPPOE_HASH_SIZE) { 1076 po = pn->hash_table[hash]; 1077 if (po) 1078 break; 1079 } 1080 } 1081 1082 out: 1083 return po; 1084 } 1085 1086 static void pppoe_seq_stop(struct seq_file *seq, void *v) 1087 __releases(pn->hash_lock) 1088 { 1089 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1090 read_unlock_bh(&pn->hash_lock); 1091 } 1092 1093 static const struct seq_operations pppoe_seq_ops = { 1094 .start = pppoe_seq_start, 1095 .next = pppoe_seq_next, 1096 .stop = pppoe_seq_stop, 1097 .show = pppoe_seq_show, 1098 }; 1099 #endif /* CONFIG_PROC_FS */ 1100 1101 static const struct proto_ops pppoe_ops = { 1102 .family = AF_PPPOX, 1103 .owner = THIS_MODULE, 1104 .release = pppoe_release, 1105 .bind = sock_no_bind, 1106 .connect = pppoe_connect, 1107 .socketpair = sock_no_socketpair, 1108 .accept = sock_no_accept, 1109 .getname = pppoe_getname, 1110 .poll = datagram_poll, 1111 .listen = sock_no_listen, 1112 .shutdown = sock_no_shutdown, 1113 .setsockopt = sock_no_setsockopt, 1114 .getsockopt = sock_no_getsockopt, 1115 .sendmsg = pppoe_sendmsg, 1116 .recvmsg = pppoe_recvmsg, 1117 .mmap = sock_no_mmap, 1118 .ioctl = pppox_ioctl, 1119 }; 1120 1121 static const struct pppox_proto pppoe_proto = { 1122 .create = pppoe_create, 1123 .ioctl = pppoe_ioctl, 1124 .owner = THIS_MODULE, 1125 }; 1126 1127 static __net_init int pppoe_init_net(struct net *net) 1128 { 1129 struct pppoe_net *pn = pppoe_pernet(net); 1130 struct proc_dir_entry *pde; 1131 1132 rwlock_init(&pn->hash_lock); 1133 1134 pde = proc_create_net("pppoe", 0444, net->proc_net, 1135 &pppoe_seq_ops, sizeof(struct seq_net_private)); 1136 #ifdef CONFIG_PROC_FS 1137 if (!pde) 1138 return -ENOMEM; 1139 #endif 1140 1141 return 0; 1142 } 1143 1144 static __net_exit void pppoe_exit_net(struct net *net) 1145 { 1146 remove_proc_entry("pppoe", net->proc_net); 1147 } 1148 1149 static struct pernet_operations pppoe_net_ops = { 1150 .init = pppoe_init_net, 1151 .exit = pppoe_exit_net, 1152 .id = &pppoe_net_id, 1153 .size = sizeof(struct pppoe_net), 1154 }; 1155 1156 static int __init pppoe_init(void) 1157 { 1158 int err; 1159 1160 err = register_pernet_device(&pppoe_net_ops); 1161 if (err) 1162 goto out; 1163 1164 err = proto_register(&pppoe_sk_proto, 0); 1165 if (err) 1166 goto out_unregister_net_ops; 1167 1168 err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto); 1169 if (err) 1170 goto out_unregister_pppoe_proto; 1171 1172 dev_add_pack(&pppoes_ptype); 1173 dev_add_pack(&pppoed_ptype); 1174 register_netdevice_notifier(&pppoe_notifier); 1175 1176 return 0; 1177 1178 out_unregister_pppoe_proto: 1179 proto_unregister(&pppoe_sk_proto); 1180 out_unregister_net_ops: 1181 unregister_pernet_device(&pppoe_net_ops); 1182 out: 1183 return err; 1184 } 1185 1186 static void __exit pppoe_exit(void) 1187 { 1188 unregister_netdevice_notifier(&pppoe_notifier); 1189 dev_remove_pack(&pppoed_ptype); 1190 dev_remove_pack(&pppoes_ptype); 1191 unregister_pppox_proto(PX_PROTO_OE); 1192 proto_unregister(&pppoe_sk_proto); 1193 unregister_pernet_device(&pppoe_net_ops); 1194 } 1195 1196 module_init(pppoe_init); 1197 module_exit(pppoe_exit); 1198 1199 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>"); 1200 MODULE_DESCRIPTION("PPP over Ethernet driver"); 1201 MODULE_LICENSE("GPL"); 1202 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OE); 1203