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 (skb_mac_header_len(skb) < ETH_HLEN) 433 goto drop; 434 435 if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr))) 436 goto drop; 437 438 ph = pppoe_hdr(skb); 439 len = ntohs(ph->length); 440 441 skb_pull_rcsum(skb, sizeof(*ph)); 442 if (skb->len < len) 443 goto drop; 444 445 if (pskb_trim_rcsum(skb, len)) 446 goto drop; 447 448 pn = pppoe_pernet(dev_net(dev)); 449 450 /* Note that get_item does a sock_hold(), so sk_pppox(po) 451 * is known to be safe. 452 */ 453 po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex); 454 if (!po) 455 goto drop; 456 457 return sk_receive_skb(sk_pppox(po), skb, 0); 458 459 drop: 460 kfree_skb(skb); 461 out: 462 return NET_RX_DROP; 463 } 464 465 static void pppoe_unbind_sock_work(struct work_struct *work) 466 { 467 struct pppox_sock *po = container_of(work, struct pppox_sock, 468 proto.pppoe.padt_work); 469 struct sock *sk = sk_pppox(po); 470 471 lock_sock(sk); 472 if (po->pppoe_dev) { 473 dev_put(po->pppoe_dev); 474 po->pppoe_dev = NULL; 475 } 476 pppox_unbind_sock(sk); 477 release_sock(sk); 478 sock_put(sk); 479 } 480 481 /************************************************************************ 482 * 483 * Receive a PPPoE Discovery frame. 484 * This is solely for detection of PADT frames 485 * 486 ***********************************************************************/ 487 static int pppoe_disc_rcv(struct sk_buff *skb, struct net_device *dev, 488 struct packet_type *pt, struct net_device *orig_dev) 489 490 { 491 struct pppoe_hdr *ph; 492 struct pppox_sock *po; 493 struct pppoe_net *pn; 494 495 skb = skb_share_check(skb, GFP_ATOMIC); 496 if (!skb) 497 goto out; 498 499 if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr))) 500 goto abort; 501 502 ph = pppoe_hdr(skb); 503 if (ph->code != PADT_CODE) 504 goto abort; 505 506 pn = pppoe_pernet(dev_net(dev)); 507 po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex); 508 if (po) 509 if (!schedule_work(&po->proto.pppoe.padt_work)) 510 sock_put(sk_pppox(po)); 511 512 abort: 513 kfree_skb(skb); 514 out: 515 return NET_RX_SUCCESS; /* Lies... :-) */ 516 } 517 518 static struct packet_type pppoes_ptype __read_mostly = { 519 .type = cpu_to_be16(ETH_P_PPP_SES), 520 .func = pppoe_rcv, 521 }; 522 523 static struct packet_type pppoed_ptype __read_mostly = { 524 .type = cpu_to_be16(ETH_P_PPP_DISC), 525 .func = pppoe_disc_rcv, 526 }; 527 528 static struct proto pppoe_sk_proto __read_mostly = { 529 .name = "PPPOE", 530 .owner = THIS_MODULE, 531 .obj_size = sizeof(struct pppox_sock), 532 }; 533 534 /*********************************************************************** 535 * 536 * Initialize a new struct sock. 537 * 538 **********************************************************************/ 539 static int pppoe_create(struct net *net, struct socket *sock, int kern) 540 { 541 struct sock *sk; 542 543 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, kern); 544 if (!sk) 545 return -ENOMEM; 546 547 sock_init_data(sock, sk); 548 549 sock->state = SS_UNCONNECTED; 550 sock->ops = &pppoe_ops; 551 552 sk->sk_backlog_rcv = pppoe_rcv_core; 553 sk->sk_state = PPPOX_NONE; 554 sk->sk_type = SOCK_STREAM; 555 sk->sk_family = PF_PPPOX; 556 sk->sk_protocol = PX_PROTO_OE; 557 558 INIT_WORK(&pppox_sk(sk)->proto.pppoe.padt_work, 559 pppoe_unbind_sock_work); 560 561 return 0; 562 } 563 564 static int pppoe_release(struct socket *sock) 565 { 566 struct sock *sk = sock->sk; 567 struct pppox_sock *po; 568 struct pppoe_net *pn; 569 struct net *net = NULL; 570 571 if (!sk) 572 return 0; 573 574 lock_sock(sk); 575 if (sock_flag(sk, SOCK_DEAD)) { 576 release_sock(sk); 577 return -EBADF; 578 } 579 580 po = pppox_sk(sk); 581 582 if (po->pppoe_dev) { 583 dev_put(po->pppoe_dev); 584 po->pppoe_dev = NULL; 585 } 586 587 pppox_unbind_sock(sk); 588 589 /* Signal the death of the socket. */ 590 sk->sk_state = PPPOX_DEAD; 591 592 net = sock_net(sk); 593 pn = pppoe_pernet(net); 594 595 /* 596 * protect "po" from concurrent updates 597 * on pppoe_flush_dev 598 */ 599 delete_item(pn, po->pppoe_pa.sid, po->pppoe_pa.remote, 600 po->pppoe_ifindex); 601 602 sock_orphan(sk); 603 sock->sk = NULL; 604 605 skb_queue_purge(&sk->sk_receive_queue); 606 release_sock(sk); 607 sock_put(sk); 608 609 return 0; 610 } 611 612 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr, 613 int sockaddr_len, int flags) 614 { 615 struct sock *sk = sock->sk; 616 struct sockaddr_pppox *sp = (struct sockaddr_pppox *)uservaddr; 617 struct pppox_sock *po = pppox_sk(sk); 618 struct net_device *dev = NULL; 619 struct pppoe_net *pn; 620 struct net *net = NULL; 621 int error; 622 623 lock_sock(sk); 624 625 error = -EINVAL; 626 627 if (sockaddr_len != sizeof(struct sockaddr_pppox)) 628 goto end; 629 630 if (sp->sa_protocol != PX_PROTO_OE) 631 goto end; 632 633 /* Check for already bound sockets */ 634 error = -EBUSY; 635 if ((sk->sk_state & PPPOX_CONNECTED) && 636 stage_session(sp->sa_addr.pppoe.sid)) 637 goto end; 638 639 /* Check for already disconnected sockets, on attempts to disconnect */ 640 error = -EALREADY; 641 if ((sk->sk_state & PPPOX_DEAD) && 642 !stage_session(sp->sa_addr.pppoe.sid)) 643 goto end; 644 645 error = 0; 646 647 /* Delete the old binding */ 648 if (stage_session(po->pppoe_pa.sid)) { 649 pppox_unbind_sock(sk); 650 pn = pppoe_pernet(sock_net(sk)); 651 delete_item(pn, po->pppoe_pa.sid, 652 po->pppoe_pa.remote, po->pppoe_ifindex); 653 if (po->pppoe_dev) { 654 dev_put(po->pppoe_dev); 655 po->pppoe_dev = NULL; 656 } 657 658 po->pppoe_ifindex = 0; 659 memset(&po->pppoe_pa, 0, sizeof(po->pppoe_pa)); 660 memset(&po->pppoe_relay, 0, sizeof(po->pppoe_relay)); 661 memset(&po->chan, 0, sizeof(po->chan)); 662 po->next = NULL; 663 po->num = 0; 664 665 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 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 return len; 737 } 738 739 static int pppoe_ioctl(struct socket *sock, unsigned int cmd, 740 unsigned long arg) 741 { 742 struct sock *sk = sock->sk; 743 struct pppox_sock *po = pppox_sk(sk); 744 int val; 745 int err; 746 747 switch (cmd) { 748 case PPPIOCGMRU: 749 err = -ENXIO; 750 if (!(sk->sk_state & PPPOX_CONNECTED)) 751 break; 752 753 err = -EFAULT; 754 if (put_user(po->pppoe_dev->mtu - 755 sizeof(struct pppoe_hdr) - 756 PPP_HDRLEN, 757 (int __user *)arg)) 758 break; 759 err = 0; 760 break; 761 762 case PPPIOCSMRU: 763 err = -ENXIO; 764 if (!(sk->sk_state & PPPOX_CONNECTED)) 765 break; 766 767 err = -EFAULT; 768 if (get_user(val, (int __user *)arg)) 769 break; 770 771 if (val < (po->pppoe_dev->mtu 772 - sizeof(struct pppoe_hdr) 773 - PPP_HDRLEN)) 774 err = 0; 775 else 776 err = -EINVAL; 777 break; 778 779 case PPPIOCSFLAGS: 780 err = -EFAULT; 781 if (get_user(val, (int __user *)arg)) 782 break; 783 err = 0; 784 break; 785 786 case PPPOEIOCSFWD: 787 { 788 struct pppox_sock *relay_po; 789 790 err = -EBUSY; 791 if (sk->sk_state & (PPPOX_BOUND | PPPOX_DEAD)) 792 break; 793 794 err = -ENOTCONN; 795 if (!(sk->sk_state & PPPOX_CONNECTED)) 796 break; 797 798 /* PPPoE address from the user specifies an outbound 799 PPPoE address which frames are forwarded to */ 800 err = -EFAULT; 801 if (copy_from_user(&po->pppoe_relay, 802 (void __user *)arg, 803 sizeof(struct sockaddr_pppox))) 804 break; 805 806 err = -EINVAL; 807 if (po->pppoe_relay.sa_family != AF_PPPOX || 808 po->pppoe_relay.sa_protocol != PX_PROTO_OE) 809 break; 810 811 /* Check that the socket referenced by the address 812 actually exists. */ 813 relay_po = get_item_by_addr(sock_net(sk), &po->pppoe_relay); 814 if (!relay_po) 815 break; 816 817 sock_put(sk_pppox(relay_po)); 818 sk->sk_state |= PPPOX_RELAY; 819 err = 0; 820 break; 821 } 822 823 case PPPOEIOCDFWD: 824 err = -EALREADY; 825 if (!(sk->sk_state & PPPOX_RELAY)) 826 break; 827 828 sk->sk_state &= ~PPPOX_RELAY; 829 err = 0; 830 break; 831 832 default: 833 err = -ENOTTY; 834 } 835 836 return err; 837 } 838 839 static int pppoe_sendmsg(struct socket *sock, struct msghdr *m, 840 size_t total_len) 841 { 842 struct sk_buff *skb; 843 struct sock *sk = sock->sk; 844 struct pppox_sock *po = pppox_sk(sk); 845 int error; 846 struct pppoe_hdr hdr; 847 struct pppoe_hdr *ph; 848 struct net_device *dev; 849 char *start; 850 int hlen; 851 852 lock_sock(sk); 853 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) { 854 error = -ENOTCONN; 855 goto end; 856 } 857 858 hdr.ver = 1; 859 hdr.type = 1; 860 hdr.code = 0; 861 hdr.sid = po->num; 862 863 dev = po->pppoe_dev; 864 865 error = -EMSGSIZE; 866 if (total_len > (dev->mtu + dev->hard_header_len)) 867 goto end; 868 869 hlen = LL_RESERVED_SPACE(dev); 870 skb = sock_wmalloc(sk, hlen + sizeof(*ph) + total_len + 871 dev->needed_tailroom, 0, GFP_KERNEL); 872 if (!skb) { 873 error = -ENOMEM; 874 goto end; 875 } 876 877 /* Reserve space for headers. */ 878 skb_reserve(skb, hlen); 879 skb_reset_network_header(skb); 880 881 skb->dev = dev; 882 883 skb->priority = sk->sk_priority; 884 skb->protocol = cpu_to_be16(ETH_P_PPP_SES); 885 886 ph = skb_put(skb, total_len + sizeof(struct pppoe_hdr)); 887 start = (char *)&ph->tag[0]; 888 889 error = memcpy_from_msg(start, m, total_len); 890 if (error < 0) { 891 kfree_skb(skb); 892 goto end; 893 } 894 895 error = total_len; 896 dev_hard_header(skb, dev, ETH_P_PPP_SES, 897 po->pppoe_pa.remote, NULL, total_len); 898 899 memcpy(ph, &hdr, sizeof(struct pppoe_hdr)); 900 901 ph->length = htons(total_len); 902 903 dev_queue_xmit(skb); 904 905 end: 906 release_sock(sk); 907 return error; 908 } 909 910 /************************************************************************ 911 * 912 * xmit function for internal use. 913 * 914 ***********************************************************************/ 915 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb) 916 { 917 struct pppox_sock *po = pppox_sk(sk); 918 struct net_device *dev = po->pppoe_dev; 919 struct pppoe_hdr *ph; 920 int data_len = skb->len; 921 922 /* The higher-level PPP code (ppp_unregister_channel()) ensures the PPP 923 * xmit operations conclude prior to an unregistration call. Thus 924 * sk->sk_state cannot change, so we don't need to do lock_sock(). 925 * But, we also can't do a lock_sock since that introduces a potential 926 * deadlock as we'd reverse the lock ordering used when calling 927 * ppp_unregister_channel(). 928 */ 929 930 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 931 goto abort; 932 933 if (!dev) 934 goto abort; 935 936 /* Copy the data if there is no space for the header or if it's 937 * read-only. 938 */ 939 if (skb_cow_head(skb, LL_RESERVED_SPACE(dev) + sizeof(*ph))) 940 goto abort; 941 942 __skb_push(skb, sizeof(*ph)); 943 skb_reset_network_header(skb); 944 945 ph = pppoe_hdr(skb); 946 ph->ver = 1; 947 ph->type = 1; 948 ph->code = 0; 949 ph->sid = po->num; 950 ph->length = htons(data_len); 951 952 skb->protocol = cpu_to_be16(ETH_P_PPP_SES); 953 skb->dev = dev; 954 955 dev_hard_header(skb, dev, ETH_P_PPP_SES, 956 po->pppoe_pa.remote, NULL, data_len); 957 958 dev_queue_xmit(skb); 959 return 1; 960 961 abort: 962 kfree_skb(skb); 963 return 1; 964 } 965 966 /************************************************************************ 967 * 968 * xmit function called by generic PPP driver 969 * sends PPP frame over PPPoE socket 970 * 971 ***********************************************************************/ 972 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb) 973 { 974 struct sock *sk = (struct sock *)chan->private; 975 return __pppoe_xmit(sk, skb); 976 } 977 978 static const struct ppp_channel_ops pppoe_chan_ops = { 979 .start_xmit = pppoe_xmit, 980 }; 981 982 static int pppoe_recvmsg(struct socket *sock, struct msghdr *m, 983 size_t total_len, int flags) 984 { 985 struct sock *sk = sock->sk; 986 struct sk_buff *skb; 987 int error = 0; 988 989 if (sk->sk_state & PPPOX_BOUND) { 990 error = -EIO; 991 goto end; 992 } 993 994 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, 995 flags & MSG_DONTWAIT, &error); 996 if (error < 0) 997 goto end; 998 999 if (skb) { 1000 total_len = min_t(size_t, total_len, skb->len); 1001 error = skb_copy_datagram_msg(skb, 0, m, total_len); 1002 if (error == 0) { 1003 consume_skb(skb); 1004 return total_len; 1005 } 1006 } 1007 1008 kfree_skb(skb); 1009 end: 1010 return error; 1011 } 1012 1013 #ifdef CONFIG_PROC_FS 1014 static int pppoe_seq_show(struct seq_file *seq, void *v) 1015 { 1016 struct pppox_sock *po; 1017 char *dev_name; 1018 1019 if (v == SEQ_START_TOKEN) { 1020 seq_puts(seq, "Id Address Device\n"); 1021 goto out; 1022 } 1023 1024 po = v; 1025 dev_name = po->pppoe_pa.dev; 1026 1027 seq_printf(seq, "%08X %pM %8s\n", 1028 po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name); 1029 out: 1030 return 0; 1031 } 1032 1033 static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos) 1034 { 1035 struct pppox_sock *po; 1036 int i; 1037 1038 for (i = 0; i < PPPOE_HASH_SIZE; i++) { 1039 po = pn->hash_table[i]; 1040 while (po) { 1041 if (!pos--) 1042 goto out; 1043 po = po->next; 1044 } 1045 } 1046 1047 out: 1048 return po; 1049 } 1050 1051 static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos) 1052 __acquires(pn->hash_lock) 1053 { 1054 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1055 loff_t l = *pos; 1056 1057 read_lock_bh(&pn->hash_lock); 1058 return l ? pppoe_get_idx(pn, --l) : SEQ_START_TOKEN; 1059 } 1060 1061 static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1062 { 1063 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1064 struct pppox_sock *po; 1065 1066 ++*pos; 1067 if (v == SEQ_START_TOKEN) { 1068 po = pppoe_get_idx(pn, 0); 1069 goto out; 1070 } 1071 po = v; 1072 if (po->next) 1073 po = po->next; 1074 else { 1075 int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); 1076 1077 po = NULL; 1078 while (++hash < PPPOE_HASH_SIZE) { 1079 po = pn->hash_table[hash]; 1080 if (po) 1081 break; 1082 } 1083 } 1084 1085 out: 1086 return po; 1087 } 1088 1089 static void pppoe_seq_stop(struct seq_file *seq, void *v) 1090 __releases(pn->hash_lock) 1091 { 1092 struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); 1093 read_unlock_bh(&pn->hash_lock); 1094 } 1095 1096 static const struct seq_operations pppoe_seq_ops = { 1097 .start = pppoe_seq_start, 1098 .next = pppoe_seq_next, 1099 .stop = pppoe_seq_stop, 1100 .show = pppoe_seq_show, 1101 }; 1102 #endif /* CONFIG_PROC_FS */ 1103 1104 static const struct proto_ops pppoe_ops = { 1105 .family = AF_PPPOX, 1106 .owner = THIS_MODULE, 1107 .release = pppoe_release, 1108 .bind = sock_no_bind, 1109 .connect = pppoe_connect, 1110 .socketpair = sock_no_socketpair, 1111 .accept = sock_no_accept, 1112 .getname = pppoe_getname, 1113 .poll = datagram_poll, 1114 .listen = sock_no_listen, 1115 .shutdown = sock_no_shutdown, 1116 .setsockopt = sock_no_setsockopt, 1117 .getsockopt = sock_no_getsockopt, 1118 .sendmsg = pppoe_sendmsg, 1119 .recvmsg = pppoe_recvmsg, 1120 .mmap = sock_no_mmap, 1121 .ioctl = pppox_ioctl, 1122 }; 1123 1124 static const struct pppox_proto pppoe_proto = { 1125 .create = pppoe_create, 1126 .ioctl = pppoe_ioctl, 1127 .owner = THIS_MODULE, 1128 }; 1129 1130 static __net_init int pppoe_init_net(struct net *net) 1131 { 1132 struct pppoe_net *pn = pppoe_pernet(net); 1133 struct proc_dir_entry *pde; 1134 1135 rwlock_init(&pn->hash_lock); 1136 1137 pde = proc_create_net("pppoe", 0444, net->proc_net, 1138 &pppoe_seq_ops, sizeof(struct seq_net_private)); 1139 #ifdef CONFIG_PROC_FS 1140 if (!pde) 1141 return -ENOMEM; 1142 #endif 1143 1144 return 0; 1145 } 1146 1147 static __net_exit void pppoe_exit_net(struct net *net) 1148 { 1149 remove_proc_entry("pppoe", net->proc_net); 1150 } 1151 1152 static struct pernet_operations pppoe_net_ops = { 1153 .init = pppoe_init_net, 1154 .exit = pppoe_exit_net, 1155 .id = &pppoe_net_id, 1156 .size = sizeof(struct pppoe_net), 1157 }; 1158 1159 static int __init pppoe_init(void) 1160 { 1161 int err; 1162 1163 err = register_pernet_device(&pppoe_net_ops); 1164 if (err) 1165 goto out; 1166 1167 err = proto_register(&pppoe_sk_proto, 0); 1168 if (err) 1169 goto out_unregister_net_ops; 1170 1171 err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto); 1172 if (err) 1173 goto out_unregister_pppoe_proto; 1174 1175 dev_add_pack(&pppoes_ptype); 1176 dev_add_pack(&pppoed_ptype); 1177 register_netdevice_notifier(&pppoe_notifier); 1178 1179 return 0; 1180 1181 out_unregister_pppoe_proto: 1182 proto_unregister(&pppoe_sk_proto); 1183 out_unregister_net_ops: 1184 unregister_pernet_device(&pppoe_net_ops); 1185 out: 1186 return err; 1187 } 1188 1189 static void __exit pppoe_exit(void) 1190 { 1191 unregister_netdevice_notifier(&pppoe_notifier); 1192 dev_remove_pack(&pppoed_ptype); 1193 dev_remove_pack(&pppoes_ptype); 1194 unregister_pppox_proto(PX_PROTO_OE); 1195 proto_unregister(&pppoe_sk_proto); 1196 unregister_pernet_device(&pppoe_net_ops); 1197 } 1198 1199 module_init(pppoe_init); 1200 module_exit(pppoe_exit); 1201 1202 MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>"); 1203 MODULE_DESCRIPTION("PPP over Ethernet driver"); 1204 MODULE_LICENSE("GPL"); 1205 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OE); 1206