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