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