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v6.13.7
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/** -*- linux-c -*- ***********************************************************
   3 * Linux PPP over Ethernet (PPPoX/PPPoE) Sockets
   4 *
   5 * PPPoX --- Generic PPP encapsulation socket family
   6 * PPPoE --- PPP over Ethernet (RFC 2516)
   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 processing.
  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 */
  54
  55#include <linux/string.h>
  56#include <linux/module.h>
  57#include <linux/kernel.h>
  58#include <linux/slab.h>
  59#include <linux/errno.h>
  60#include <linux/netdevice.h>
  61#include <linux/net.h>
  62#include <linux/inetdevice.h>
  63#include <linux/etherdevice.h>
  64#include <linux/skbuff.h>
  65#include <linux/init.h>
  66#include <linux/if_ether.h>
  67#include <linux/if_pppox.h>
  68#include <linux/ppp_channel.h>
  69#include <linux/ppp_defs.h>
  70#include <linux/ppp-ioctl.h>
  71#include <linux/notifier.h>
  72#include <linux/file.h>
  73#include <linux/proc_fs.h>
  74#include <linux/seq_file.h>
  75
  76#include <linux/nsproxy.h>
  77#include <net/net_namespace.h>
  78#include <net/netns/generic.h>
  79#include <net/sock.h>
  80
  81#include <linux/uaccess.h>
  82
  83#define PPPOE_HASH_BITS CONFIG_PPPOE_HASH_BITS
  84#define PPPOE_HASH_SIZE (1 << PPPOE_HASH_BITS)
  85#define PPPOE_HASH_MASK	(PPPOE_HASH_SIZE - 1)
  86
  87static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
  88
  89static const struct proto_ops pppoe_ops;
  90static const struct ppp_channel_ops pppoe_chan_ops;
  91
  92/* per-net private data for this module */
  93static unsigned int pppoe_net_id __read_mostly;
  94struct pppoe_net {
  95	/*
  96	 * we could use _single_ hash table for all
  97	 * nets by injecting net id into the hash but
  98	 * it would increase hash chains and add
  99	 * a few additional math comparisons messy
 100	 * as well, moreover in case of SMP less locking
 101	 * controversy here
 102	 */
 103	struct pppox_sock *hash_table[PPPOE_HASH_SIZE];
 104	rwlock_t hash_lock;
 105};
 106
 107/*
 108 * PPPoE could be in the following stages:
 109 * 1) Discovery stage (to obtain remote MAC and Session ID)
 110 * 2) Session stage (MAC and SID are known)
 111 *
 112 * Ethernet frames have a special tag for this but
 113 * we use simpler approach based on session id
 114 */
 115static inline bool stage_session(__be16 sid)
 116{
 117	return sid != 0;
 118}
 119
 120static inline struct pppoe_net *pppoe_pernet(struct net *net)
 121{
 
 
 122	return net_generic(net, pppoe_net_id);
 123}
 124
 125static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
 126{
 127	return a->sid == b->sid && ether_addr_equal(a->remote, b->remote);
 128}
 129
 130static inline int cmp_addr(struct pppoe_addr *a, __be16 sid, char *addr)
 131{
 132	return a->sid == sid && ether_addr_equal(a->remote, addr);
 133}
 134
 135#if 8 % PPPOE_HASH_BITS
 136#error 8 must be a multiple of PPPOE_HASH_BITS
 137#endif
 138
 139static int hash_item(__be16 sid, unsigned char *addr)
 140{
 141	unsigned char hash = 0;
 142	unsigned int i;
 143
 144	for (i = 0; i < ETH_ALEN; i++)
 145		hash ^= addr[i];
 146	for (i = 0; i < sizeof(sid_t) * 8; i += 8)
 147		hash ^= (__force __u32)sid >> i;
 148	for (i = 8; (i >>= 1) >= PPPOE_HASH_BITS;)
 149		hash ^= hash >> i;
 150
 151	return hash & PPPOE_HASH_MASK;
 152}
 153
 154/**********************************************************************
 155 *
 156 *  Set/get/delete/rehash items  (internal versions)
 157 *
 158 **********************************************************************/
 159static struct pppox_sock *__get_item(struct pppoe_net *pn, __be16 sid,
 160				unsigned char *addr, int ifindex)
 161{
 162	int hash = hash_item(sid, addr);
 163	struct pppox_sock *ret;
 164
 165	ret = pn->hash_table[hash];
 166	while (ret) {
 167		if (cmp_addr(&ret->pppoe_pa, sid, addr) &&
 168		    ret->pppoe_ifindex == ifindex)
 169			return ret;
 170
 171		ret = ret->next;
 172	}
 173
 174	return NULL;
 175}
 176
 177static int __set_item(struct pppoe_net *pn, struct pppox_sock *po)
 178{
 179	int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
 180	struct pppox_sock *ret;
 181
 182	ret = pn->hash_table[hash];
 183	while (ret) {
 184		if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) &&
 185		    ret->pppoe_ifindex == po->pppoe_ifindex)
 186			return -EALREADY;
 187
 188		ret = ret->next;
 189	}
 190
 191	po->next = pn->hash_table[hash];
 192	pn->hash_table[hash] = po;
 193
 194	return 0;
 195}
 196
 197static void __delete_item(struct pppoe_net *pn, __be16 sid,
 198					char *addr, int ifindex)
 199{
 200	int hash = hash_item(sid, addr);
 201	struct pppox_sock *ret, **src;
 202
 203	ret = pn->hash_table[hash];
 204	src = &pn->hash_table[hash];
 205
 206	while (ret) {
 207		if (cmp_addr(&ret->pppoe_pa, sid, addr) &&
 208		    ret->pppoe_ifindex == ifindex) {
 209			*src = ret->next;
 210			break;
 211		}
 212
 213		src = &ret->next;
 214		ret = ret->next;
 215	}
 216}
 217
 218/**********************************************************************
 219 *
 220 *  Set/get/delete/rehash items
 221 *
 222 **********************************************************************/
 223static inline struct pppox_sock *get_item(struct pppoe_net *pn, __be16 sid,
 224					unsigned char *addr, int ifindex)
 225{
 226	struct pppox_sock *po;
 227
 228	read_lock_bh(&pn->hash_lock);
 229	po = __get_item(pn, sid, addr, ifindex);
 230	if (po)
 231		sock_hold(sk_pppox(po));
 232	read_unlock_bh(&pn->hash_lock);
 233
 234	return po;
 235}
 236
 237static inline struct pppox_sock *get_item_by_addr(struct net *net,
 238						struct sockaddr_pppox *sp)
 239{
 240	struct net_device *dev;
 241	struct pppoe_net *pn;
 242	struct pppox_sock *pppox_sock = NULL;
 243
 244	int ifindex;
 245
 246	rcu_read_lock();
 247	dev = dev_get_by_name_rcu(net, sp->sa_addr.pppoe.dev);
 248	if (dev) {
 249		ifindex = dev->ifindex;
 250		pn = pppoe_pernet(net);
 251		pppox_sock = get_item(pn, sp->sa_addr.pppoe.sid,
 252				sp->sa_addr.pppoe.remote, ifindex);
 253	}
 254	rcu_read_unlock();
 255	return pppox_sock;
 256}
 257
 258static inline void delete_item(struct pppoe_net *pn, __be16 sid,
 259					char *addr, int ifindex)
 260{
 261	write_lock_bh(&pn->hash_lock);
 262	__delete_item(pn, sid, addr, ifindex);
 263	write_unlock_bh(&pn->hash_lock);
 264}
 265
 266/***************************************************************************
 267 *
 268 *  Handler for device events.
 269 *  Certain device events require that sockets be unconnected.
 270 *
 271 **************************************************************************/
 272
 273static void pppoe_flush_dev(struct net_device *dev)
 274{
 275	struct pppoe_net *pn;
 276	int i;
 277
 278	pn = pppoe_pernet(dev_net(dev));
 279	write_lock_bh(&pn->hash_lock);
 280	for (i = 0; i < PPPOE_HASH_SIZE; i++) {
 281		struct pppox_sock *po = pn->hash_table[i];
 282		struct sock *sk;
 283
 284		while (po) {
 285			while (po && po->pppoe_dev != dev) {
 286				po = po->next;
 287			}
 288
 289			if (!po)
 290				break;
 291
 292			sk = sk_pppox(po);
 293
 294			/* We always grab the socket lock, followed by the
 295			 * hash_lock, in that order.  Since we should hold the
 296			 * sock lock while doing any unbinding, we need to
 297			 * release the lock we're holding.  Hold a reference to
 298			 * the sock so it doesn't disappear as we're jumping
 299			 * between locks.
 300			 */
 301
 302			sock_hold(sk);
 303			write_unlock_bh(&pn->hash_lock);
 304			lock_sock(sk);
 305
 306			if (po->pppoe_dev == dev &&
 307			    sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
 308				pppox_unbind_sock(sk);
 
 309				sk->sk_state_change(sk);
 310				po->pppoe_dev = NULL;
 311				dev_put(dev);
 312			}
 313
 314			release_sock(sk);
 315			sock_put(sk);
 316
 317			/* Restart the process from the start of the current
 318			 * hash chain. We dropped locks so the world may have
 319			 * change from underneath us.
 320			 */
 321
 322			BUG_ON(pppoe_pernet(dev_net(dev)) == NULL);
 323			write_lock_bh(&pn->hash_lock);
 324			po = pn->hash_table[i];
 325		}
 326	}
 327	write_unlock_bh(&pn->hash_lock);
 328}
 329
 330static int pppoe_device_event(struct notifier_block *this,
 331			      unsigned long event, void *ptr)
 332{
 333	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 334
 335	/* Only look at sockets that are using this specific device. */
 336	switch (event) {
 337	case NETDEV_CHANGEADDR:
 338	case NETDEV_CHANGEMTU:
 339		/* A change in mtu or address is a bad thing, requiring
 340		 * LCP re-negotiation.
 341		 */
 342
 343	case NETDEV_GOING_DOWN:
 344	case NETDEV_DOWN:
 345		/* Find every socket on this device and kill it. */
 346		pppoe_flush_dev(dev);
 347		break;
 348
 349	default:
 350		break;
 351	}
 352
 353	return NOTIFY_DONE;
 354}
 355
 356static struct notifier_block pppoe_notifier = {
 357	.notifier_call = pppoe_device_event,
 358};
 359
 360/************************************************************************
 361 *
 362 * Do the real work of receiving a PPPoE Session frame.
 363 *
 364 ***********************************************************************/
 365static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb)
 366{
 367	struct pppox_sock *po = pppox_sk(sk);
 368	struct pppox_sock *relay_po;
 369
 370	/* Backlog receive. Semantics of backlog rcv preclude any code from
 371	 * executing in lock_sock()/release_sock() bounds; meaning sk->sk_state
 372	 * can't change.
 373	 */
 374
 375	if (skb->pkt_type == PACKET_OTHERHOST)
 376		goto abort_kfree;
 377
 378	if (sk->sk_state & PPPOX_BOUND) {
 379		ppp_input(&po->chan, skb);
 380	} else if (sk->sk_state & PPPOX_RELAY) {
 381		relay_po = get_item_by_addr(sock_net(sk),
 382					    &po->pppoe_relay);
 383		if (relay_po == NULL)
 384			goto abort_kfree;
 385
 386		if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0)
 387			goto abort_put;
 388
 389		if (!__pppoe_xmit(sk_pppox(relay_po), skb))
 390			goto abort_put;
 391
 392		sock_put(sk_pppox(relay_po));
 393	} else {
 394		if (sock_queue_rcv_skb(sk, skb))
 395			goto abort_kfree;
 396	}
 397
 398	return NET_RX_SUCCESS;
 399
 400abort_put:
 401	sock_put(sk_pppox(relay_po));
 402
 403abort_kfree:
 404	kfree_skb(skb);
 405	return NET_RX_DROP;
 406}
 407
 408/************************************************************************
 409 *
 410 * Receive wrapper called in BH context.
 411 *
 412 ***********************************************************************/
 413static int pppoe_rcv(struct sk_buff *skb, struct net_device *dev,
 414		     struct packet_type *pt, struct net_device *orig_dev)
 415{
 416	struct pppoe_hdr *ph;
 417	struct pppox_sock *po;
 418	struct pppoe_net *pn;
 419	int len;
 420
 421	skb = skb_share_check(skb, GFP_ATOMIC);
 422	if (!skb)
 423		goto out;
 424
 425	if (skb_mac_header_len(skb) < ETH_HLEN)
 426		goto drop;
 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	ph = pppoe_hdr(skb);
 442	pn = pppoe_pernet(dev_net(dev));
 443
 444	/* Note that get_item does a sock_hold(), so sk_pppox(po)
 445	 * is known to be safe.
 446	 */
 447	po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
 448	if (!po)
 449		goto drop;
 450
 451	return sk_receive_skb(sk_pppox(po), skb, 0);
 452
 453drop:
 454	kfree_skb(skb);
 455out:
 456	return NET_RX_DROP;
 457}
 458
 459static void pppoe_unbind_sock_work(struct work_struct *work)
 460{
 461	struct pppox_sock *po = container_of(work, struct pppox_sock,
 462					     proto.pppoe.padt_work);
 463	struct sock *sk = sk_pppox(po);
 464
 465	lock_sock(sk);
 466	if (po->pppoe_dev) {
 467		dev_put(po->pppoe_dev);
 468		po->pppoe_dev = NULL;
 469	}
 470	pppox_unbind_sock(sk);
 471	release_sock(sk);
 472	sock_put(sk);
 473}
 474
 475/************************************************************************
 476 *
 477 * Receive a PPPoE Discovery frame.
 478 * This is solely for detection of PADT frames
 479 *
 480 ***********************************************************************/
 481static int pppoe_disc_rcv(struct sk_buff *skb, struct net_device *dev,
 482			  struct packet_type *pt, struct net_device *orig_dev)
 483
 484{
 485	struct pppoe_hdr *ph;
 486	struct pppox_sock *po;
 487	struct pppoe_net *pn;
 488
 489	skb = skb_share_check(skb, GFP_ATOMIC);
 490	if (!skb)
 491		goto out;
 492
 493	if (skb->pkt_type != PACKET_HOST)
 494		goto abort;
 495
 496	if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
 497		goto abort;
 498
 499	ph = pppoe_hdr(skb);
 500	if (ph->code != PADT_CODE)
 501		goto abort;
 502
 503	pn = pppoe_pernet(dev_net(dev));
 504	po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
 505	if (po)
 506		if (!schedule_work(&po->proto.pppoe.padt_work))
 507			sock_put(sk_pppox(po));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 508
 509abort:
 510	kfree_skb(skb);
 511out:
 512	return NET_RX_SUCCESS; /* Lies... :-) */
 513}
 514
 515static struct packet_type pppoes_ptype __read_mostly = {
 516	.type	= cpu_to_be16(ETH_P_PPP_SES),
 517	.func	= pppoe_rcv,
 518};
 519
 520static struct packet_type pppoed_ptype __read_mostly = {
 521	.type	= cpu_to_be16(ETH_P_PPP_DISC),
 522	.func	= pppoe_disc_rcv,
 523};
 524
 525static struct proto pppoe_sk_proto __read_mostly = {
 526	.name	  = "PPPOE",
 527	.owner	  = THIS_MODULE,
 528	.obj_size = sizeof(struct pppox_sock),
 529};
 530
 531/***********************************************************************
 532 *
 533 * Initialize a new struct sock.
 534 *
 535 **********************************************************************/
 536static int pppoe_create(struct net *net, struct socket *sock, int kern)
 537{
 538	struct sock *sk;
 539
 540	sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, kern);
 541	if (!sk)
 542		return -ENOMEM;
 543
 544	sock_init_data(sock, sk);
 545
 546	sock->state	= SS_UNCONNECTED;
 547	sock->ops	= &pppoe_ops;
 548
 549	sk->sk_backlog_rcv	= pppoe_rcv_core;
 550	sk->sk_state		= PPPOX_NONE;
 551	sk->sk_type		= SOCK_STREAM;
 552	sk->sk_family		= PF_PPPOX;
 553	sk->sk_protocol		= PX_PROTO_OE;
 554
 555	INIT_WORK(&pppox_sk(sk)->proto.pppoe.padt_work,
 556		  pppoe_unbind_sock_work);
 557
 558	return 0;
 559}
 560
 561static int pppoe_release(struct socket *sock)
 562{
 563	struct sock *sk = sock->sk;
 564	struct pppox_sock *po;
 565	struct pppoe_net *pn;
 566	struct net *net = NULL;
 567
 568	if (!sk)
 569		return 0;
 570
 571	lock_sock(sk);
 572	if (sock_flag(sk, SOCK_DEAD)) {
 573		release_sock(sk);
 574		return -EBADF;
 575	}
 576
 577	po = pppox_sk(sk);
 578
 579	if (po->pppoe_dev) {
 580		dev_put(po->pppoe_dev);
 581		po->pppoe_dev = NULL;
 582	}
 583
 584	pppox_unbind_sock(sk);
 585
 586	/* Signal the death of the socket. */
 587	sk->sk_state = PPPOX_DEAD;
 588
 589	net = sock_net(sk);
 590	pn = pppoe_pernet(net);
 591
 592	/*
 593	 * protect "po" from concurrent updates
 594	 * on pppoe_flush_dev
 595	 */
 596	delete_item(pn, po->pppoe_pa.sid, po->pppoe_pa.remote,
 597		    po->pppoe_ifindex);
 598
 599	sock_orphan(sk);
 600	sock->sk = NULL;
 601
 602	skb_queue_purge(&sk->sk_receive_queue);
 603	release_sock(sk);
 604	sock_put(sk);
 605
 606	return 0;
 607}
 608
 609static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
 610		  int sockaddr_len, int flags)
 611{
 612	struct sock *sk = sock->sk;
 613	struct sockaddr_pppox *sp = (struct sockaddr_pppox *)uservaddr;
 614	struct pppox_sock *po = pppox_sk(sk);
 615	struct net_device *dev = NULL;
 616	struct pppoe_net *pn;
 617	struct net *net = NULL;
 618	int error;
 619
 620	lock_sock(sk);
 621
 622	error = -EINVAL;
 623
 624	if (sockaddr_len != sizeof(struct sockaddr_pppox))
 625		goto end;
 626
 627	if (sp->sa_protocol != PX_PROTO_OE)
 628		goto end;
 629
 630	/* Check for already bound sockets */
 631	error = -EBUSY;
 632	if ((sk->sk_state & PPPOX_CONNECTED) &&
 633	     stage_session(sp->sa_addr.pppoe.sid))
 634		goto end;
 635
 636	/* Check for already disconnected sockets, on attempts to disconnect */
 637	error = -EALREADY;
 638	if ((sk->sk_state & PPPOX_DEAD) &&
 639	     !stage_session(sp->sa_addr.pppoe.sid))
 640		goto end;
 641
 642	error = 0;
 643
 644	/* Delete the old binding */
 645	if (stage_session(po->pppoe_pa.sid)) {
 646		pppox_unbind_sock(sk);
 647		pn = pppoe_pernet(sock_net(sk));
 648		delete_item(pn, po->pppoe_pa.sid,
 649			    po->pppoe_pa.remote, po->pppoe_ifindex);
 650		if (po->pppoe_dev) {
 651			dev_put(po->pppoe_dev);
 652			po->pppoe_dev = NULL;
 653		}
 654
 655		po->pppoe_ifindex = 0;
 656		memset(&po->pppoe_pa, 0, sizeof(po->pppoe_pa));
 657		memset(&po->pppoe_relay, 0, sizeof(po->pppoe_relay));
 658		memset(&po->chan, 0, sizeof(po->chan));
 659		po->next = NULL;
 660		po->num = 0;
 661
 662		sk->sk_state = PPPOX_NONE;
 663	}
 664
 665	/* Re-bind in session stage only */
 666	if (stage_session(sp->sa_addr.pppoe.sid)) {
 667		error = -ENODEV;
 668		net = sock_net(sk);
 669		dev = dev_get_by_name(net, sp->sa_addr.pppoe.dev);
 670		if (!dev)
 671			goto err_put;
 672
 673		po->pppoe_dev = dev;
 674		po->pppoe_ifindex = dev->ifindex;
 675		pn = pppoe_pernet(net);
 676		if (!(dev->flags & IFF_UP)) {
 677			goto err_put;
 678		}
 679
 680		memcpy(&po->pppoe_pa,
 681		       &sp->sa_addr.pppoe,
 682		       sizeof(struct pppoe_addr));
 683
 684		write_lock_bh(&pn->hash_lock);
 685		error = __set_item(pn, po);
 686		write_unlock_bh(&pn->hash_lock);
 687		if (error < 0)
 688			goto err_put;
 689
 690		po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
 691				   dev->hard_header_len);
 692
 693		po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr) - 2;
 694		po->chan.private = sk;
 695		po->chan.ops = &pppoe_chan_ops;
 696
 697		error = ppp_register_net_channel(dev_net(dev), &po->chan);
 698		if (error) {
 699			delete_item(pn, po->pppoe_pa.sid,
 700				    po->pppoe_pa.remote, po->pppoe_ifindex);
 701			goto err_put;
 702		}
 703
 704		sk->sk_state = PPPOX_CONNECTED;
 705	}
 706
 707	po->num = sp->sa_addr.pppoe.sid;
 708
 709end:
 710	release_sock(sk);
 711	return error;
 712err_put:
 713	if (po->pppoe_dev) {
 714		dev_put(po->pppoe_dev);
 715		po->pppoe_dev = NULL;
 716	}
 717	goto end;
 718}
 719
 720static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
 721		  int peer)
 722{
 723	int len = sizeof(struct sockaddr_pppox);
 724	struct sockaddr_pppox sp;
 725
 726	sp.sa_family	= AF_PPPOX;
 727	sp.sa_protocol	= PX_PROTO_OE;
 728	memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
 729	       sizeof(struct pppoe_addr));
 730
 731	memcpy(uaddr, &sp, len);
 732
 733	return len;
 
 
 734}
 735
 736static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
 737		unsigned long arg)
 738{
 739	struct sock *sk = sock->sk;
 740	struct pppox_sock *po = pppox_sk(sk);
 741	int val;
 742	int err;
 743
 744	switch (cmd) {
 745	case PPPIOCGMRU:
 746		err = -ENXIO;
 747		if (!(sk->sk_state & PPPOX_CONNECTED))
 748			break;
 749
 750		err = -EFAULT;
 751		if (put_user(po->pppoe_dev->mtu -
 752			     sizeof(struct pppoe_hdr) -
 753			     PPP_HDRLEN,
 754			     (int __user *)arg))
 755			break;
 756		err = 0;
 757		break;
 758
 759	case PPPIOCSMRU:
 760		err = -ENXIO;
 761		if (!(sk->sk_state & PPPOX_CONNECTED))
 762			break;
 763
 764		err = -EFAULT;
 765		if (get_user(val, (int __user *)arg))
 766			break;
 767
 768		if (val < (po->pppoe_dev->mtu
 769			   - sizeof(struct pppoe_hdr)
 770			   - PPP_HDRLEN))
 771			err = 0;
 772		else
 773			err = -EINVAL;
 774		break;
 775
 776	case PPPIOCSFLAGS:
 777		err = -EFAULT;
 778		if (get_user(val, (int __user *)arg))
 779			break;
 780		err = 0;
 781		break;
 782
 783	case PPPOEIOCSFWD:
 784	{
 785		struct pppox_sock *relay_po;
 786
 787		err = -EBUSY;
 788		if (sk->sk_state & (PPPOX_BOUND | PPPOX_DEAD))
 789			break;
 790
 791		err = -ENOTCONN;
 792		if (!(sk->sk_state & PPPOX_CONNECTED))
 793			break;
 794
 795		/* PPPoE address from the user specifies an outbound
 796		   PPPoE address which frames are forwarded to */
 797		err = -EFAULT;
 798		if (copy_from_user(&po->pppoe_relay,
 799				   (void __user *)arg,
 800				   sizeof(struct sockaddr_pppox)))
 801			break;
 802
 803		err = -EINVAL;
 804		if (po->pppoe_relay.sa_family != AF_PPPOX ||
 805		    po->pppoe_relay.sa_protocol != PX_PROTO_OE)
 806			break;
 807
 808		/* Check that the socket referenced by the address
 809		   actually exists. */
 810		relay_po = get_item_by_addr(sock_net(sk), &po->pppoe_relay);
 811		if (!relay_po)
 812			break;
 813
 814		sock_put(sk_pppox(relay_po));
 815		sk->sk_state |= PPPOX_RELAY;
 816		err = 0;
 817		break;
 818	}
 819
 820	case PPPOEIOCDFWD:
 821		err = -EALREADY;
 822		if (!(sk->sk_state & PPPOX_RELAY))
 823			break;
 824
 825		sk->sk_state &= ~PPPOX_RELAY;
 826		err = 0;
 827		break;
 828
 829	default:
 830		err = -ENOTTY;
 831	}
 832
 833	return err;
 834}
 835
 836static int pppoe_sendmsg(struct socket *sock, struct msghdr *m,
 837			 size_t total_len)
 838{
 839	struct sk_buff *skb;
 840	struct sock *sk = sock->sk;
 841	struct pppox_sock *po = pppox_sk(sk);
 842	int error;
 843	struct pppoe_hdr hdr;
 844	struct pppoe_hdr *ph;
 845	struct net_device *dev;
 846	char *start;
 847	int hlen;
 848
 849	lock_sock(sk);
 850	if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
 851		error = -ENOTCONN;
 852		goto end;
 853	}
 854
 855	hdr.ver = 1;
 856	hdr.type = 1;
 857	hdr.code = 0;
 858	hdr.sid = po->num;
 859
 860	dev = po->pppoe_dev;
 861
 862	error = -EMSGSIZE;
 863	if (total_len > (dev->mtu + dev->hard_header_len))
 864		goto end;
 865
 866	hlen = LL_RESERVED_SPACE(dev);
 867	skb = sock_wmalloc(sk, hlen + sizeof(*ph) + total_len +
 868			   dev->needed_tailroom, 0, GFP_KERNEL);
 869	if (!skb) {
 870		error = -ENOMEM;
 871		goto end;
 872	}
 873
 874	/* Reserve space for headers. */
 875	skb_reserve(skb, hlen);
 876	skb_reset_network_header(skb);
 877
 878	skb->dev = dev;
 879
 880	skb->priority = READ_ONCE(sk->sk_priority);
 881	skb->protocol = cpu_to_be16(ETH_P_PPP_SES);
 882
 883	ph = skb_put(skb, total_len + sizeof(struct pppoe_hdr));
 884	start = (char *)&ph->tag[0];
 885
 886	error = memcpy_from_msg(start, m, total_len);
 887	if (error < 0) {
 888		kfree_skb(skb);
 889		goto end;
 890	}
 891
 892	error = total_len;
 893	dev_hard_header(skb, dev, ETH_P_PPP_SES,
 894			po->pppoe_pa.remote, NULL, total_len);
 895
 896	memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
 897
 898	ph->length = htons(total_len);
 899
 900	dev_queue_xmit(skb);
 901
 902end:
 903	release_sock(sk);
 904	return error;
 905}
 906
 907/************************************************************************
 908 *
 909 * xmit function for internal use.
 910 *
 911 ***********************************************************************/
 912static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
 913{
 914	struct pppox_sock *po = pppox_sk(sk);
 915	struct net_device *dev = po->pppoe_dev;
 916	struct pppoe_hdr *ph;
 917	int data_len = skb->len;
 918
 919	/* The higher-level PPP code (ppp_unregister_channel()) ensures the PPP
 920	 * xmit operations conclude prior to an unregistration call.  Thus
 921	 * sk->sk_state cannot change, so we don't need to do lock_sock().
 922	 * But, we also can't do a lock_sock since that introduces a potential
 923	 * deadlock as we'd reverse the lock ordering used when calling
 924	 * ppp_unregister_channel().
 925	 */
 926
 927	if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
 928		goto abort;
 929
 930	if (!dev)
 931		goto abort;
 932
 933	/* Copy the data if there is no space for the header or if it's
 934	 * read-only.
 935	 */
 936	if (skb_cow_head(skb, LL_RESERVED_SPACE(dev) + sizeof(*ph)))
 937		goto abort;
 938
 939	__skb_push(skb, sizeof(*ph));
 940	skb_reset_network_header(skb);
 941
 942	ph = pppoe_hdr(skb);
 943	ph->ver	= 1;
 944	ph->type = 1;
 945	ph->code = 0;
 946	ph->sid	= po->num;
 947	ph->length = htons(data_len);
 948
 949	skb->protocol = cpu_to_be16(ETH_P_PPP_SES);
 950	skb->dev = dev;
 951
 952	dev_hard_header(skb, dev, ETH_P_PPP_SES,
 953			po->pppoe_pa.remote, NULL, data_len);
 954
 955	dev_queue_xmit(skb);
 956	return 1;
 957
 958abort:
 959	kfree_skb(skb);
 960	return 1;
 961}
 962
 963/************************************************************************
 964 *
 965 * xmit function called by generic PPP driver
 966 * sends PPP frame over PPPoE socket
 967 *
 968 ***********************************************************************/
 969static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 970{
 971	struct sock *sk = chan->private;
 972	return __pppoe_xmit(sk, skb);
 973}
 974
 975static int pppoe_fill_forward_path(struct net_device_path_ctx *ctx,
 976				   struct net_device_path *path,
 977				   const struct ppp_channel *chan)
 978{
 979	struct sock *sk = chan->private;
 980	struct pppox_sock *po = pppox_sk(sk);
 981	struct net_device *dev = po->pppoe_dev;
 982
 983	if (sock_flag(sk, SOCK_DEAD) ||
 984	    !(sk->sk_state & PPPOX_CONNECTED) || !dev)
 985		return -1;
 986
 987	path->type = DEV_PATH_PPPOE;
 988	path->encap.proto = htons(ETH_P_PPP_SES);
 989	path->encap.id = be16_to_cpu(po->num);
 990	memcpy(path->encap.h_dest, po->pppoe_pa.remote, ETH_ALEN);
 991	memcpy(ctx->daddr, po->pppoe_pa.remote, ETH_ALEN);
 992	path->dev = ctx->dev;
 993	ctx->dev = dev;
 994
 995	return 0;
 996}
 997
 998static const struct ppp_channel_ops pppoe_chan_ops = {
 999	.start_xmit = pppoe_xmit,
1000	.fill_forward_path = pppoe_fill_forward_path,
1001};
1002
1003static int pppoe_recvmsg(struct socket *sock, struct msghdr *m,
1004			 size_t total_len, int flags)
1005{
1006	struct sock *sk = sock->sk;
1007	struct sk_buff *skb;
1008	int error = 0;
1009
1010	if (sk->sk_state & PPPOX_BOUND)
1011		return -EIO;
 
 
1012
1013	skb = skb_recv_datagram(sk, flags, &error);
1014	if (!skb)
1015		return error;
 
 
 
1016
1017	total_len = min_t(size_t, total_len, skb->len);
1018	error = skb_copy_datagram_msg(skb, 0, m, total_len);
1019	if (error == 0) {
1020		consume_skb(skb);
1021		return total_len;
 
 
1022	}
1023
1024	kfree_skb(skb);
 
1025	return error;
1026}
1027
1028#ifdef CONFIG_PROC_FS
1029static int pppoe_seq_show(struct seq_file *seq, void *v)
1030{
1031	struct pppox_sock *po;
1032	char *dev_name;
1033
1034	if (v == SEQ_START_TOKEN) {
1035		seq_puts(seq, "Id       Address              Device\n");
1036		goto out;
1037	}
1038
1039	po = v;
1040	dev_name = po->pppoe_pa.dev;
1041
1042	seq_printf(seq, "%08X %pM %8s\n",
1043		po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name);
1044out:
1045	return 0;
1046}
1047
1048static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos)
1049{
1050	struct pppox_sock *po;
1051	int i;
1052
1053	for (i = 0; i < PPPOE_HASH_SIZE; i++) {
1054		po = pn->hash_table[i];
1055		while (po) {
1056			if (!pos--)
1057				goto out;
1058			po = po->next;
1059		}
1060	}
1061
1062out:
1063	return po;
1064}
1065
1066static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
1067	__acquires(pn->hash_lock)
1068{
1069	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
1070	loff_t l = *pos;
1071
1072	read_lock_bh(&pn->hash_lock);
1073	return l ? pppoe_get_idx(pn, --l) : SEQ_START_TOKEN;
1074}
1075
1076static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1077{
1078	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
1079	struct pppox_sock *po;
1080
1081	++*pos;
1082	if (v == SEQ_START_TOKEN) {
1083		po = pppoe_get_idx(pn, 0);
1084		goto out;
1085	}
1086	po = v;
1087	if (po->next)
1088		po = po->next;
1089	else {
1090		int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
1091
1092		po = NULL;
1093		while (++hash < PPPOE_HASH_SIZE) {
1094			po = pn->hash_table[hash];
1095			if (po)
1096				break;
1097		}
1098	}
1099
1100out:
1101	return po;
1102}
1103
1104static void pppoe_seq_stop(struct seq_file *seq, void *v)
1105	__releases(pn->hash_lock)
1106{
1107	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
1108	read_unlock_bh(&pn->hash_lock);
1109}
1110
1111static const struct seq_operations pppoe_seq_ops = {
1112	.start		= pppoe_seq_start,
1113	.next		= pppoe_seq_next,
1114	.stop		= pppoe_seq_stop,
1115	.show		= pppoe_seq_show,
1116};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1117#endif /* CONFIG_PROC_FS */
1118
1119static const struct proto_ops pppoe_ops = {
1120	.family		= AF_PPPOX,
1121	.owner		= THIS_MODULE,
1122	.release	= pppoe_release,
1123	.bind		= sock_no_bind,
1124	.connect	= pppoe_connect,
1125	.socketpair	= sock_no_socketpair,
1126	.accept		= sock_no_accept,
1127	.getname	= pppoe_getname,
1128	.poll		= datagram_poll,
1129	.listen		= sock_no_listen,
1130	.shutdown	= sock_no_shutdown,
 
 
1131	.sendmsg	= pppoe_sendmsg,
1132	.recvmsg	= pppoe_recvmsg,
1133	.mmap		= sock_no_mmap,
1134	.ioctl		= pppox_ioctl,
1135#ifdef CONFIG_COMPAT
1136	.compat_ioctl	= pppox_compat_ioctl,
1137#endif
1138};
1139
1140static const struct pppox_proto pppoe_proto = {
1141	.create	= pppoe_create,
1142	.ioctl	= pppoe_ioctl,
1143	.owner	= THIS_MODULE,
1144};
1145
1146static __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_net("pppoe", 0444, net->proc_net,
1154			&pppoe_seq_ops, sizeof(struct seq_net_private));
1155#ifdef CONFIG_PROC_FS
1156	if (!pde)
1157		return -ENOMEM;
1158#endif
1159
1160	return 0;
1161}
1162
1163static __net_exit void pppoe_exit_net(struct net *net)
1164{
1165	remove_proc_entry("pppoe", net->proc_net);
1166}
1167
1168static struct pernet_operations pppoe_net_ops = {
1169	.init = pppoe_init_net,
1170	.exit = pppoe_exit_net,
1171	.id   = &pppoe_net_id,
1172	.size = sizeof(struct pppoe_net),
1173};
1174
1175static int __init pppoe_init(void)
1176{
1177	int err;
1178
1179	err = register_pernet_device(&pppoe_net_ops);
1180	if (err)
1181		goto out;
1182
1183	err = proto_register(&pppoe_sk_proto, 0);
1184	if (err)
1185		goto out_unregister_net_ops;
1186
1187	err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
1188	if (err)
1189		goto out_unregister_pppoe_proto;
1190
1191	dev_add_pack(&pppoes_ptype);
1192	dev_add_pack(&pppoed_ptype);
1193	register_netdevice_notifier(&pppoe_notifier);
1194
1195	return 0;
1196
1197out_unregister_pppoe_proto:
1198	proto_unregister(&pppoe_sk_proto);
1199out_unregister_net_ops:
1200	unregister_pernet_device(&pppoe_net_ops);
1201out:
1202	return err;
1203}
1204
1205static void __exit pppoe_exit(void)
1206{
1207	unregister_netdevice_notifier(&pppoe_notifier);
1208	dev_remove_pack(&pppoed_ptype);
1209	dev_remove_pack(&pppoes_ptype);
1210	unregister_pppox_proto(PX_PROTO_OE);
1211	proto_unregister(&pppoe_sk_proto);
1212	unregister_pernet_device(&pppoe_net_ops);
1213}
1214
1215module_init(pppoe_init);
1216module_exit(pppoe_exit);
1217
1218MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1219MODULE_DESCRIPTION("PPP over Ethernet driver");
1220MODULE_LICENSE("GPL");
1221MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OE);
v3.5.6
 
   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
  92static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
  93
  94static const struct proto_ops pppoe_ops;
  95static const struct ppp_channel_ops pppoe_chan_ops;
  96
  97/* per-net private data for this module */
  98static int pppoe_net_id __read_mostly;
  99struct 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 */
 120static inline bool stage_session(__be16 sid)
 121{
 122	return sid != 0;
 123}
 124
 125static 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
 132static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
 133{
 134	return a->sid == b->sid && !memcmp(a->remote, b->remote, ETH_ALEN);
 135}
 136
 137static inline int cmp_addr(struct pppoe_addr *a, __be16 sid, char *addr)
 138{
 139	return a->sid == sid && !memcmp(a->remote, addr, ETH_ALEN);
 140}
 141
 142#if 8 % PPPOE_HASH_BITS
 143#error 8 must be a multiple of PPPOE_HASH_BITS
 144#endif
 145
 146static 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 **********************************************************************/
 166static 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
 184static 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
 204static 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 **********************************************************************/
 230static 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
 244static 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
 265static 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
 280static 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
 338static int pppoe_device_event(struct notifier_block *this,
 339			      unsigned long event, void *ptr)
 340{
 341	struct net_device *dev = (struct net_device *)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
 364static 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 ***********************************************************************/
 373static 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
 403abort_put:
 404	sock_put(sk_pppox(relay_po));
 405
 406abort_kfree:
 407	kfree_skb(skb);
 408	return NET_RX_DROP;
 409}
 410
 411/************************************************************************
 412 *
 413 * Receive wrapper called in BH context.
 414 *
 415 ***********************************************************************/
 416static 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
 452drop:
 453	kfree_skb(skb);
 454out:
 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 ***********************************************************************/
 464static 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
 506abort:
 507	kfree_skb(skb);
 508out:
 509	return NET_RX_SUCCESS; /* Lies... :-) */
 510}
 511
 512static struct packet_type pppoes_ptype __read_mostly = {
 513	.type	= cpu_to_be16(ETH_P_PPP_SES),
 514	.func	= pppoe_rcv,
 515};
 516
 517static struct packet_type pppoed_ptype __read_mostly = {
 518	.type	= cpu_to_be16(ETH_P_PPP_DISC),
 519	.func	= pppoe_disc_rcv,
 520};
 521
 522static 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 **********************************************************************/
 533static 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
 555static 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)) {
 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
 603static 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);
 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
 694end:
 695	release_sock(sk);
 696	return error;
 697err_put:
 698	if (po->pppoe_dev) {
 699		dev_put(po->pppoe_dev);
 700		po->pppoe_dev = NULL;
 701	}
 702	goto end;
 703}
 704
 705static 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
 723static 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
 823static 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_fromiovec(start, m->msg_iov, 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
 888end:
 889	release_sock(sk);
 890	return error;
 891}
 892
 893/************************************************************************
 894 *
 895 * xmit function for internal use.
 896 *
 897 ***********************************************************************/
 898static 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
 944abort:
 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 ***********************************************************************/
 955static 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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 961static const struct ppp_channel_ops pppoe_chan_ops = {
 962	.start_xmit = pppoe_xmit,
 
 963};
 964
 965static 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	m->msg_namelen = 0;
 983
 984	if (skb) {
 985		total_len = min_t(size_t, total_len, skb->len);
 986		error = skb_copy_datagram_iovec(skb, 0, m->msg_iov, total_len);
 987		if (error == 0) {
 988			consume_skb(skb);
 989			return total_len;
 990		}
 991	}
 992
 993	kfree_skb(skb);
 994end:
 995	return error;
 996}
 997
 998#ifdef CONFIG_PROC_FS
 999static int pppoe_seq_show(struct seq_file *seq, void *v)
1000{
1001	struct pppox_sock *po;
1002	char *dev_name;
1003
1004	if (v == SEQ_START_TOKEN) {
1005		seq_puts(seq, "Id       Address              Device\n");
1006		goto out;
1007	}
1008
1009	po = v;
1010	dev_name = po->pppoe_pa.dev;
1011
1012	seq_printf(seq, "%08X %pM %8s\n",
1013		po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name);
1014out:
1015	return 0;
1016}
1017
1018static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos)
1019{
1020	struct pppox_sock *po;
1021	int i;
1022
1023	for (i = 0; i < PPPOE_HASH_SIZE; i++) {
1024		po = pn->hash_table[i];
1025		while (po) {
1026			if (!pos--)
1027				goto out;
1028			po = po->next;
1029		}
1030	}
1031
1032out:
1033	return po;
1034}
1035
1036static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
1037	__acquires(pn->hash_lock)
1038{
1039	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
1040	loff_t l = *pos;
1041
1042	read_lock_bh(&pn->hash_lock);
1043	return l ? pppoe_get_idx(pn, --l) : SEQ_START_TOKEN;
1044}
1045
1046static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1047{
1048	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
1049	struct pppox_sock *po;
1050
1051	++*pos;
1052	if (v == SEQ_START_TOKEN) {
1053		po = pppoe_get_idx(pn, 0);
1054		goto out;
1055	}
1056	po = v;
1057	if (po->next)
1058		po = po->next;
1059	else {
1060		int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
1061
1062		po = NULL;
1063		while (++hash < PPPOE_HASH_SIZE) {
1064			po = pn->hash_table[hash];
1065			if (po)
1066				break;
1067		}
1068	}
1069
1070out:
1071	return po;
1072}
1073
1074static void pppoe_seq_stop(struct seq_file *seq, void *v)
1075	__releases(pn->hash_lock)
1076{
1077	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
1078	read_unlock_bh(&pn->hash_lock);
1079}
1080
1081static const struct seq_operations pppoe_seq_ops = {
1082	.start		= pppoe_seq_start,
1083	.next		= pppoe_seq_next,
1084	.stop		= pppoe_seq_stop,
1085	.show		= pppoe_seq_show,
1086};
1087
1088static int pppoe_seq_open(struct inode *inode, struct file *file)
1089{
1090	return seq_open_net(inode, file, &pppoe_seq_ops,
1091			sizeof(struct seq_net_private));
1092}
1093
1094static const struct file_operations pppoe_seq_fops = {
1095	.owner		= THIS_MODULE,
1096	.open		= pppoe_seq_open,
1097	.read		= seq_read,
1098	.llseek		= seq_lseek,
1099	.release	= seq_release_net,
1100};
1101
1102#endif /* CONFIG_PROC_FS */
1103
1104static 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
1124static const struct pppox_proto pppoe_proto = {
1125	.create	= pppoe_create,
1126	.ioctl	= pppoe_ioctl,
1127	.owner	= THIS_MODULE,
1128};
1129
1130static __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_net_fops_create(net, "pppoe", S_IRUGO, &pppoe_seq_fops);
 
1138#ifdef CONFIG_PROC_FS
1139	if (!pde)
1140		return -ENOMEM;
1141#endif
1142
1143	return 0;
1144}
1145
1146static __net_exit void pppoe_exit_net(struct net *net)
1147{
1148	proc_net_remove(net, "pppoe");
1149}
1150
1151static struct pernet_operations pppoe_net_ops = {
1152	.init = pppoe_init_net,
1153	.exit = pppoe_exit_net,
1154	.id   = &pppoe_net_id,
1155	.size = sizeof(struct pppoe_net),
1156};
1157
1158static int __init pppoe_init(void)
1159{
1160	int err;
1161
1162	err = register_pernet_device(&pppoe_net_ops);
1163	if (err)
1164		goto out;
1165
1166	err = proto_register(&pppoe_sk_proto, 0);
1167	if (err)
1168		goto out_unregister_net_ops;
1169
1170	err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
1171	if (err)
1172		goto out_unregister_pppoe_proto;
1173
1174	dev_add_pack(&pppoes_ptype);
1175	dev_add_pack(&pppoed_ptype);
1176	register_netdevice_notifier(&pppoe_notifier);
1177
1178	return 0;
1179
1180out_unregister_pppoe_proto:
1181	proto_unregister(&pppoe_sk_proto);
1182out_unregister_net_ops:
1183	unregister_pernet_device(&pppoe_net_ops);
1184out:
1185	return err;
1186}
1187
1188static void __exit pppoe_exit(void)
1189{
1190	unregister_netdevice_notifier(&pppoe_notifier);
1191	dev_remove_pack(&pppoed_ptype);
1192	dev_remove_pack(&pppoes_ptype);
1193	unregister_pppox_proto(PX_PROTO_OE);
1194	proto_unregister(&pppoe_sk_proto);
1195	unregister_pernet_device(&pppoe_net_ops);
1196}
1197
1198module_init(pppoe_init);
1199module_exit(pppoe_exit);
1200
1201MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1202MODULE_DESCRIPTION("PPP over Ethernet driver");
1203MODULE_LICENSE("GPL");
1204MODULE_ALIAS_NETPROTO(PF_PPPOX);