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v3.15
 
   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 && ether_addr_equal(a->remote, b->remote);
 135}
 136
 137static 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
 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 = 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
 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 | 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
 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	if (skb) {
 983		total_len = min_t(size_t, total_len, skb->len);
 984		error = skb_copy_datagram_iovec(skb, 0, m->msg_iov, total_len);
 985		if (error == 0) {
 986			consume_skb(skb);
 987			return total_len;
 988		}
 989	}
 990
 991	kfree_skb(skb);
 992end:
 993	return error;
 994}
 995
 996#ifdef CONFIG_PROC_FS
 997static 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);
1012out:
1013	return 0;
1014}
1015
1016static 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
1030out:
1031	return po;
1032}
1033
1034static 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
1044static 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
1068out:
1069	return po;
1070}
1071
1072static 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
1079static 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
1086static 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
1092static 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
1102static 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
1122static const struct pppox_proto pppoe_proto = {
1123	.create	= pppoe_create,
1124	.ioctl	= pppoe_ioctl,
1125	.owner	= THIS_MODULE,
1126};
1127
1128static __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
1144static __net_exit void pppoe_exit_net(struct net *net)
1145{
1146	remove_proc_entry("pppoe", net->proc_net);
1147}
1148
1149static 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
1156static 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
1178out_unregister_pppoe_proto:
1179	proto_unregister(&pppoe_sk_proto);
1180out_unregister_net_ops:
1181	unregister_pernet_device(&pppoe_net_ops);
1182out:
1183	return err;
1184}
1185
1186static 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
1196module_init(pppoe_init);
1197module_exit(pppoe_exit);
1198
1199MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
1200MODULE_DESCRIPTION("PPP over Ethernet driver");
1201MODULE_LICENSE("GPL");
1202MODULE_ALIAS_NETPROTO(PF_PPPOX);
v5.4
   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 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 */
  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 4
  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 comparations 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	BUG_ON(!net);
 123
 124	return net_generic(net, pppoe_net_id);
 125}
 126
 127static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
 128{
 129	return a->sid == b->sid && ether_addr_equal(a->remote, b->remote);
 130}
 131
 132static inline int cmp_addr(struct pppoe_addr *a, __be16 sid, char *addr)
 133{
 134	return a->sid == sid && ether_addr_equal(a->remote, addr);
 135}
 136
 137#if 8 % PPPOE_HASH_BITS
 138#error 8 must be a multiple of PPPOE_HASH_BITS
 139#endif
 140
 141static int hash_item(__be16 sid, unsigned char *addr)
 142{
 143	unsigned char hash = 0;
 144	unsigned int i;
 145
 146	for (i = 0; i < ETH_ALEN; i++)
 147		hash ^= addr[i];
 148	for (i = 0; i < sizeof(sid_t) * 8; i += 8)
 149		hash ^= (__force __u32)sid >> i;
 150	for (i = 8; (i >>= 1) >= PPPOE_HASH_BITS;)
 151		hash ^= hash >> i;
 152
 153	return hash & PPPOE_HASH_MASK;
 154}
 155
 156/**********************************************************************
 157 *
 158 *  Set/get/delete/rehash items  (internal versions)
 159 *
 160 **********************************************************************/
 161static struct pppox_sock *__get_item(struct pppoe_net *pn, __be16 sid,
 162				unsigned char *addr, int ifindex)
 163{
 164	int hash = hash_item(sid, addr);
 165	struct pppox_sock *ret;
 166
 167	ret = pn->hash_table[hash];
 168	while (ret) {
 169		if (cmp_addr(&ret->pppoe_pa, sid, addr) &&
 170		    ret->pppoe_ifindex == ifindex)
 171			return ret;
 172
 173		ret = ret->next;
 174	}
 175
 176	return NULL;
 177}
 178
 179static int __set_item(struct pppoe_net *pn, struct pppox_sock *po)
 180{
 181	int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
 182	struct pppox_sock *ret;
 183
 184	ret = pn->hash_table[hash];
 185	while (ret) {
 186		if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) &&
 187		    ret->pppoe_ifindex == po->pppoe_ifindex)
 188			return -EALREADY;
 189
 190		ret = ret->next;
 191	}
 192
 193	po->next = pn->hash_table[hash];
 194	pn->hash_table[hash] = po;
 195
 196	return 0;
 197}
 198
 199static void __delete_item(struct pppoe_net *pn, __be16 sid,
 200					char *addr, int ifindex)
 201{
 202	int hash = hash_item(sid, addr);
 203	struct pppox_sock *ret, **src;
 204
 205	ret = pn->hash_table[hash];
 206	src = &pn->hash_table[hash];
 207
 208	while (ret) {
 209		if (cmp_addr(&ret->pppoe_pa, sid, addr) &&
 210		    ret->pppoe_ifindex == ifindex) {
 211			*src = ret->next;
 212			break;
 213		}
 214
 215		src = &ret->next;
 216		ret = ret->next;
 217	}
 218}
 219
 220/**********************************************************************
 221 *
 222 *  Set/get/delete/rehash items
 223 *
 224 **********************************************************************/
 225static inline struct pppox_sock *get_item(struct pppoe_net *pn, __be16 sid,
 226					unsigned char *addr, int ifindex)
 227{
 228	struct pppox_sock *po;
 229
 230	read_lock_bh(&pn->hash_lock);
 231	po = __get_item(pn, sid, addr, ifindex);
 232	if (po)
 233		sock_hold(sk_pppox(po));
 234	read_unlock_bh(&pn->hash_lock);
 235
 236	return po;
 237}
 238
 239static inline struct pppox_sock *get_item_by_addr(struct net *net,
 240						struct sockaddr_pppox *sp)
 241{
 242	struct net_device *dev;
 243	struct pppoe_net *pn;
 244	struct pppox_sock *pppox_sock = NULL;
 245
 246	int ifindex;
 247
 248	rcu_read_lock();
 249	dev = dev_get_by_name_rcu(net, sp->sa_addr.pppoe.dev);
 250	if (dev) {
 251		ifindex = dev->ifindex;
 252		pn = pppoe_pernet(net);
 253		pppox_sock = get_item(pn, sp->sa_addr.pppoe.sid,
 254				sp->sa_addr.pppoe.remote, ifindex);
 255	}
 256	rcu_read_unlock();
 257	return pppox_sock;
 258}
 259
 260static inline void delete_item(struct pppoe_net *pn, __be16 sid,
 261					char *addr, int ifindex)
 262{
 263	write_lock_bh(&pn->hash_lock);
 264	__delete_item(pn, sid, addr, ifindex);
 265	write_unlock_bh(&pn->hash_lock);
 266}
 267
 268/***************************************************************************
 269 *
 270 *  Handler for device events.
 271 *  Certain device events require that sockets be unconnected.
 272 *
 273 **************************************************************************/
 274
 275static void pppoe_flush_dev(struct net_device *dev)
 276{
 277	struct pppoe_net *pn;
 278	int i;
 279
 280	pn = pppoe_pernet(dev_net(dev));
 281	write_lock_bh(&pn->hash_lock);
 282	for (i = 0; i < PPPOE_HASH_SIZE; i++) {
 283		struct pppox_sock *po = pn->hash_table[i];
 284		struct sock *sk;
 285
 286		while (po) {
 287			while (po && po->pppoe_dev != dev) {
 288				po = po->next;
 289			}
 290
 291			if (!po)
 292				break;
 293
 294			sk = sk_pppox(po);
 295
 296			/* We always grab the socket lock, followed by the
 297			 * hash_lock, in that order.  Since we should hold the
 298			 * sock lock while doing any unbinding, we need to
 299			 * release the lock we're holding.  Hold a reference to
 300			 * the sock so it doesn't disappear as we're jumping
 301			 * between locks.
 302			 */
 303
 304			sock_hold(sk);
 305			write_unlock_bh(&pn->hash_lock);
 306			lock_sock(sk);
 307
 308			if (po->pppoe_dev == dev &&
 309			    sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
 310				pppox_unbind_sock(sk);
 
 311				sk->sk_state_change(sk);
 312				po->pppoe_dev = NULL;
 313				dev_put(dev);
 314			}
 315
 316			release_sock(sk);
 317			sock_put(sk);
 318
 319			/* Restart the process from the start of the current
 320			 * hash chain. We dropped locks so the world may have
 321			 * change from underneath us.
 322			 */
 323
 324			BUG_ON(pppoe_pernet(dev_net(dev)) == NULL);
 325			write_lock_bh(&pn->hash_lock);
 326			po = pn->hash_table[i];
 327		}
 328	}
 329	write_unlock_bh(&pn->hash_lock);
 330}
 331
 332static int pppoe_device_event(struct notifier_block *this,
 333			      unsigned long event, void *ptr)
 334{
 335	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 336
 337	/* Only look at sockets that are using this specific device. */
 338	switch (event) {
 339	case NETDEV_CHANGEADDR:
 340	case NETDEV_CHANGEMTU:
 341		/* A change in mtu or address is a bad thing, requiring
 342		 * LCP re-negotiation.
 343		 */
 344
 345	case NETDEV_GOING_DOWN:
 346	case NETDEV_DOWN:
 347		/* Find every socket on this device and kill it. */
 348		pppoe_flush_dev(dev);
 349		break;
 350
 351	default:
 352		break;
 353	}
 354
 355	return NOTIFY_DONE;
 356}
 357
 358static struct notifier_block pppoe_notifier = {
 359	.notifier_call = pppoe_device_event,
 360};
 361
 362/************************************************************************
 363 *
 364 * Do the real work of receiving a PPPoE Session frame.
 365 *
 366 ***********************************************************************/
 367static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb)
 368{
 369	struct pppox_sock *po = pppox_sk(sk);
 370	struct pppox_sock *relay_po;
 371
 372	/* Backlog receive. Semantics of backlog rcv preclude any code from
 373	 * executing in lock_sock()/release_sock() bounds; meaning sk->sk_state
 374	 * can't change.
 375	 */
 376
 377	if (skb->pkt_type == PACKET_OTHERHOST)
 378		goto abort_kfree;
 379
 380	if (sk->sk_state & PPPOX_BOUND) {
 381		ppp_input(&po->chan, skb);
 382	} else if (sk->sk_state & PPPOX_RELAY) {
 383		relay_po = get_item_by_addr(sock_net(sk),
 384					    &po->pppoe_relay);
 385		if (relay_po == NULL)
 386			goto abort_kfree;
 387
 388		if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0)
 389			goto abort_put;
 390
 391		if (!__pppoe_xmit(sk_pppox(relay_po), skb))
 392			goto abort_put;
 393
 394		sock_put(sk_pppox(relay_po));
 395	} else {
 396		if (sock_queue_rcv_skb(sk, skb))
 397			goto abort_kfree;
 398	}
 399
 400	return NET_RX_SUCCESS;
 401
 402abort_put:
 403	sock_put(sk_pppox(relay_po));
 404
 405abort_kfree:
 406	kfree_skb(skb);
 407	return NET_RX_DROP;
 408}
 409
 410/************************************************************************
 411 *
 412 * Receive wrapper called in BH context.
 413 *
 414 ***********************************************************************/
 415static int pppoe_rcv(struct sk_buff *skb, struct net_device *dev,
 416		     struct packet_type *pt, struct net_device *orig_dev)
 417{
 418	struct pppoe_hdr *ph;
 419	struct pppox_sock *po;
 420	struct pppoe_net *pn;
 421	int len;
 422
 423	skb = skb_share_check(skb, GFP_ATOMIC);
 424	if (!skb)
 425		goto out;
 426
 427	if (skb_mac_header_len(skb) < ETH_HLEN)
 428		goto drop;
 429
 430	if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
 431		goto drop;
 432
 433	ph = pppoe_hdr(skb);
 434	len = ntohs(ph->length);
 435
 436	skb_pull_rcsum(skb, sizeof(*ph));
 437	if (skb->len < len)
 438		goto drop;
 439
 440	if (pskb_trim_rcsum(skb, len))
 441		goto drop;
 442
 443	ph = pppoe_hdr(skb);
 444	pn = pppoe_pernet(dev_net(dev));
 445
 446	/* Note that get_item does a sock_hold(), so sk_pppox(po)
 447	 * is known to be safe.
 448	 */
 449	po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
 450	if (!po)
 451		goto drop;
 452
 453	return sk_receive_skb(sk_pppox(po), skb, 0);
 454
 455drop:
 456	kfree_skb(skb);
 457out:
 458	return NET_RX_DROP;
 459}
 460
 461static void pppoe_unbind_sock_work(struct work_struct *work)
 462{
 463	struct pppox_sock *po = container_of(work, struct pppox_sock,
 464					     proto.pppoe.padt_work);
 465	struct sock *sk = sk_pppox(po);
 466
 467	lock_sock(sk);
 468	if (po->pppoe_dev) {
 469		dev_put(po->pppoe_dev);
 470		po->pppoe_dev = NULL;
 471	}
 472	pppox_unbind_sock(sk);
 473	release_sock(sk);
 474	sock_put(sk);
 475}
 476
 477/************************************************************************
 478 *
 479 * Receive a PPPoE Discovery frame.
 480 * This is solely for detection of PADT frames
 481 *
 482 ***********************************************************************/
 483static int pppoe_disc_rcv(struct sk_buff *skb, struct net_device *dev,
 484			  struct packet_type *pt, struct net_device *orig_dev)
 485
 486{
 487	struct pppoe_hdr *ph;
 488	struct pppox_sock *po;
 489	struct pppoe_net *pn;
 490
 491	skb = skb_share_check(skb, GFP_ATOMIC);
 492	if (!skb)
 493		goto out;
 494
 495	if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
 496		goto abort;
 497
 498	ph = pppoe_hdr(skb);
 499	if (ph->code != PADT_CODE)
 500		goto abort;
 501
 502	pn = pppoe_pernet(dev_net(dev));
 503	po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
 504	if (po)
 505		if (!schedule_work(&po->proto.pppoe.padt_work))
 506			sock_put(sk_pppox(po));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 507
 508abort:
 509	kfree_skb(skb);
 510out:
 511	return NET_RX_SUCCESS; /* Lies... :-) */
 512}
 513
 514static struct packet_type pppoes_ptype __read_mostly = {
 515	.type	= cpu_to_be16(ETH_P_PPP_SES),
 516	.func	= pppoe_rcv,
 517};
 518
 519static struct packet_type pppoed_ptype __read_mostly = {
 520	.type	= cpu_to_be16(ETH_P_PPP_DISC),
 521	.func	= pppoe_disc_rcv,
 522};
 523
 524static struct proto pppoe_sk_proto __read_mostly = {
 525	.name	  = "PPPOE",
 526	.owner	  = THIS_MODULE,
 527	.obj_size = sizeof(struct pppox_sock),
 528};
 529
 530/***********************************************************************
 531 *
 532 * Initialize a new struct sock.
 533 *
 534 **********************************************************************/
 535static int pppoe_create(struct net *net, struct socket *sock, int kern)
 536{
 537	struct sock *sk;
 538
 539	sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, kern);
 540	if (!sk)
 541		return -ENOMEM;
 542
 543	sock_init_data(sock, sk);
 544
 545	sock->state	= SS_UNCONNECTED;
 546	sock->ops	= &pppoe_ops;
 547
 548	sk->sk_backlog_rcv	= pppoe_rcv_core;
 549	sk->sk_state		= PPPOX_NONE;
 550	sk->sk_type		= SOCK_STREAM;
 551	sk->sk_family		= PF_PPPOX;
 552	sk->sk_protocol		= PX_PROTO_OE;
 553
 554	INIT_WORK(&pppox_sk(sk)->proto.pppoe.padt_work,
 555		  pppoe_unbind_sock_work);
 556
 557	return 0;
 558}
 559
 560static int pppoe_release(struct socket *sock)
 561{
 562	struct sock *sk = sock->sk;
 563	struct pppox_sock *po;
 564	struct pppoe_net *pn;
 565	struct net *net = NULL;
 566
 567	if (!sk)
 568		return 0;
 569
 570	lock_sock(sk);
 571	if (sock_flag(sk, SOCK_DEAD)) {
 572		release_sock(sk);
 573		return -EBADF;
 574	}
 575
 576	po = pppox_sk(sk);
 577
 578	if (po->pppoe_dev) {
 579		dev_put(po->pppoe_dev);
 580		po->pppoe_dev = NULL;
 581	}
 582
 583	pppox_unbind_sock(sk);
 584
 585	/* Signal the death of the socket. */
 586	sk->sk_state = PPPOX_DEAD;
 587
 588	net = sock_net(sk);
 589	pn = pppoe_pernet(net);
 590
 591	/*
 592	 * protect "po" from concurrent updates
 593	 * on pppoe_flush_dev
 594	 */
 595	delete_item(pn, po->pppoe_pa.sid, po->pppoe_pa.remote,
 596		    po->pppoe_ifindex);
 597
 598	sock_orphan(sk);
 599	sock->sk = NULL;
 600
 601	skb_queue_purge(&sk->sk_receive_queue);
 602	release_sock(sk);
 603	sock_put(sk);
 604
 605	return 0;
 606}
 607
 608static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
 609		  int sockaddr_len, int flags)
 610{
 611	struct sock *sk = sock->sk;
 612	struct sockaddr_pppox *sp = (struct sockaddr_pppox *)uservaddr;
 613	struct pppox_sock *po = pppox_sk(sk);
 614	struct net_device *dev = NULL;
 615	struct pppoe_net *pn;
 616	struct net *net = NULL;
 617	int error;
 618
 619	lock_sock(sk);
 620
 621	error = -EINVAL;
 622
 623	if (sockaddr_len != sizeof(struct sockaddr_pppox))
 624		goto end;
 625
 626	if (sp->sa_protocol != PX_PROTO_OE)
 627		goto end;
 628
 629	/* Check for already bound sockets */
 630	error = -EBUSY;
 631	if ((sk->sk_state & PPPOX_CONNECTED) &&
 632	     stage_session(sp->sa_addr.pppoe.sid))
 633		goto end;
 634
 635	/* Check for already disconnected sockets, on attempts to disconnect */
 636	error = -EALREADY;
 637	if ((sk->sk_state & PPPOX_DEAD) &&
 638	     !stage_session(sp->sa_addr.pppoe.sid))
 639		goto end;
 640
 641	error = 0;
 642
 643	/* Delete the old binding */
 644	if (stage_session(po->pppoe_pa.sid)) {
 645		pppox_unbind_sock(sk);
 646		pn = pppoe_pernet(sock_net(sk));
 647		delete_item(pn, po->pppoe_pa.sid,
 648			    po->pppoe_pa.remote, po->pppoe_ifindex);
 649		if (po->pppoe_dev) {
 650			dev_put(po->pppoe_dev);
 651			po->pppoe_dev = NULL;
 652		}
 653
 654		po->pppoe_ifindex = 0;
 655		memset(&po->pppoe_pa, 0, sizeof(po->pppoe_pa));
 656		memset(&po->pppoe_relay, 0, sizeof(po->pppoe_relay));
 657		memset(&po->chan, 0, sizeof(po->chan));
 658		po->next = NULL;
 659		po->num = 0;
 660
 661		sk->sk_state = PPPOX_NONE;
 662	}
 663
 664	/* Re-bind in session stage only */
 665	if (stage_session(sp->sa_addr.pppoe.sid)) {
 666		error = -ENODEV;
 667		net = sock_net(sk);
 668		dev = dev_get_by_name(net, sp->sa_addr.pppoe.dev);
 669		if (!dev)
 670			goto err_put;
 671
 672		po->pppoe_dev = dev;
 673		po->pppoe_ifindex = dev->ifindex;
 674		pn = pppoe_pernet(net);
 675		if (!(dev->flags & IFF_UP)) {
 676			goto err_put;
 677		}
 678
 679		memcpy(&po->pppoe_pa,
 680		       &sp->sa_addr.pppoe,
 681		       sizeof(struct pppoe_addr));
 682
 683		write_lock_bh(&pn->hash_lock);
 684		error = __set_item(pn, po);
 685		write_unlock_bh(&pn->hash_lock);
 686		if (error < 0)
 687			goto err_put;
 688
 689		po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
 690				   dev->hard_header_len);
 691
 692		po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr) - 2;
 693		po->chan.private = sk;
 694		po->chan.ops = &pppoe_chan_ops;
 695
 696		error = ppp_register_net_channel(dev_net(dev), &po->chan);
 697		if (error) {
 698			delete_item(pn, po->pppoe_pa.sid,
 699				    po->pppoe_pa.remote, po->pppoe_ifindex);
 700			goto err_put;
 701		}
 702
 703		sk->sk_state = PPPOX_CONNECTED;
 704	}
 705
 706	po->num = sp->sa_addr.pppoe.sid;
 707
 708end:
 709	release_sock(sk);
 710	return error;
 711err_put:
 712	if (po->pppoe_dev) {
 713		dev_put(po->pppoe_dev);
 714		po->pppoe_dev = NULL;
 715	}
 716	goto end;
 717}
 718
 719static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
 720		  int peer)
 721{
 722	int len = sizeof(struct sockaddr_pppox);
 723	struct sockaddr_pppox sp;
 724
 725	sp.sa_family	= AF_PPPOX;
 726	sp.sa_protocol	= PX_PROTO_OE;
 727	memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
 728	       sizeof(struct pppoe_addr));
 729
 730	memcpy(uaddr, &sp, len);
 731
 732	return len;
 
 
 733}
 734
 735static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
 736		unsigned long arg)
 737{
 738	struct sock *sk = sock->sk;
 739	struct pppox_sock *po = pppox_sk(sk);
 740	int val;
 741	int err;
 742
 743	switch (cmd) {
 744	case PPPIOCGMRU:
 745		err = -ENXIO;
 746		if (!(sk->sk_state & PPPOX_CONNECTED))
 747			break;
 748
 749		err = -EFAULT;
 750		if (put_user(po->pppoe_dev->mtu -
 751			     sizeof(struct pppoe_hdr) -
 752			     PPP_HDRLEN,
 753			     (int __user *)arg))
 754			break;
 755		err = 0;
 756		break;
 757
 758	case PPPIOCSMRU:
 759		err = -ENXIO;
 760		if (!(sk->sk_state & PPPOX_CONNECTED))
 761			break;
 762
 763		err = -EFAULT;
 764		if (get_user(val, (int __user *)arg))
 765			break;
 766
 767		if (val < (po->pppoe_dev->mtu
 768			   - sizeof(struct pppoe_hdr)
 769			   - PPP_HDRLEN))
 770			err = 0;
 771		else
 772			err = -EINVAL;
 773		break;
 774
 775	case PPPIOCSFLAGS:
 776		err = -EFAULT;
 777		if (get_user(val, (int __user *)arg))
 778			break;
 779		err = 0;
 780		break;
 781
 782	case PPPOEIOCSFWD:
 783	{
 784		struct pppox_sock *relay_po;
 785
 786		err = -EBUSY;
 787		if (sk->sk_state & (PPPOX_BOUND | PPPOX_DEAD))
 788			break;
 789
 790		err = -ENOTCONN;
 791		if (!(sk->sk_state & PPPOX_CONNECTED))
 792			break;
 793
 794		/* PPPoE address from the user specifies an outbound
 795		   PPPoE address which frames are forwarded to */
 796		err = -EFAULT;
 797		if (copy_from_user(&po->pppoe_relay,
 798				   (void __user *)arg,
 799				   sizeof(struct sockaddr_pppox)))
 800			break;
 801
 802		err = -EINVAL;
 803		if (po->pppoe_relay.sa_family != AF_PPPOX ||
 804		    po->pppoe_relay.sa_protocol != PX_PROTO_OE)
 805			break;
 806
 807		/* Check that the socket referenced by the address
 808		   actually exists. */
 809		relay_po = get_item_by_addr(sock_net(sk), &po->pppoe_relay);
 810		if (!relay_po)
 811			break;
 812
 813		sock_put(sk_pppox(relay_po));
 814		sk->sk_state |= PPPOX_RELAY;
 815		err = 0;
 816		break;
 817	}
 818
 819	case PPPOEIOCDFWD:
 820		err = -EALREADY;
 821		if (!(sk->sk_state & PPPOX_RELAY))
 822			break;
 823
 824		sk->sk_state &= ~PPPOX_RELAY;
 825		err = 0;
 826		break;
 827
 828	default:
 829		err = -ENOTTY;
 830	}
 831
 832	return err;
 833}
 834
 835static int pppoe_sendmsg(struct socket *sock, struct msghdr *m,
 836			 size_t total_len)
 837{
 838	struct sk_buff *skb;
 839	struct sock *sk = sock->sk;
 840	struct pppox_sock *po = pppox_sk(sk);
 841	int error;
 842	struct pppoe_hdr hdr;
 843	struct pppoe_hdr *ph;
 844	struct net_device *dev;
 845	char *start;
 846	int hlen;
 847
 848	lock_sock(sk);
 849	if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
 850		error = -ENOTCONN;
 851		goto end;
 852	}
 853
 854	hdr.ver = 1;
 855	hdr.type = 1;
 856	hdr.code = 0;
 857	hdr.sid = po->num;
 858
 859	dev = po->pppoe_dev;
 860
 861	error = -EMSGSIZE;
 862	if (total_len > (dev->mtu + dev->hard_header_len))
 863		goto end;
 864
 865	hlen = LL_RESERVED_SPACE(dev);
 866	skb = sock_wmalloc(sk, hlen + sizeof(*ph) + total_len +
 867			   dev->needed_tailroom, 0, GFP_KERNEL);
 868	if (!skb) {
 869		error = -ENOMEM;
 870		goto end;
 871	}
 872
 873	/* Reserve space for headers. */
 874	skb_reserve(skb, hlen);
 875	skb_reset_network_header(skb);
 876
 877	skb->dev = dev;
 878
 879	skb->priority = sk->sk_priority;
 880	skb->protocol = cpu_to_be16(ETH_P_PPP_SES);
 881
 882	ph = skb_put(skb, total_len + sizeof(struct pppoe_hdr));
 883	start = (char *)&ph->tag[0];
 884
 885	error = memcpy_from_msg(start, m, total_len);
 886	if (error < 0) {
 887		kfree_skb(skb);
 888		goto end;
 889	}
 890
 891	error = total_len;
 892	dev_hard_header(skb, dev, ETH_P_PPP_SES,
 893			po->pppoe_pa.remote, NULL, total_len);
 894
 895	memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
 896
 897	ph->length = htons(total_len);
 898
 899	dev_queue_xmit(skb);
 900
 901end:
 902	release_sock(sk);
 903	return error;
 904}
 905
 906/************************************************************************
 907 *
 908 * xmit function for internal use.
 909 *
 910 ***********************************************************************/
 911static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
 912{
 913	struct pppox_sock *po = pppox_sk(sk);
 914	struct net_device *dev = po->pppoe_dev;
 915	struct pppoe_hdr *ph;
 916	int data_len = skb->len;
 917
 918	/* The higher-level PPP code (ppp_unregister_channel()) ensures the PPP
 919	 * xmit operations conclude prior to an unregistration call.  Thus
 920	 * sk->sk_state cannot change, so we don't need to do lock_sock().
 921	 * But, we also can't do a lock_sock since that introduces a potential
 922	 * deadlock as we'd reverse the lock ordering used when calling
 923	 * ppp_unregister_channel().
 924	 */
 925
 926	if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
 927		goto abort;
 928
 929	if (!dev)
 930		goto abort;
 931
 932	/* Copy the data if there is no space for the header or if it's
 933	 * read-only.
 934	 */
 935	if (skb_cow_head(skb, LL_RESERVED_SPACE(dev) + sizeof(*ph)))
 936		goto abort;
 937
 938	__skb_push(skb, sizeof(*ph));
 939	skb_reset_network_header(skb);
 940
 941	ph = pppoe_hdr(skb);
 942	ph->ver	= 1;
 943	ph->type = 1;
 944	ph->code = 0;
 945	ph->sid	= po->num;
 946	ph->length = htons(data_len);
 947
 948	skb->protocol = cpu_to_be16(ETH_P_PPP_SES);
 949	skb->dev = dev;
 950
 951	dev_hard_header(skb, dev, ETH_P_PPP_SES,
 952			po->pppoe_pa.remote, NULL, data_len);
 953
 954	dev_queue_xmit(skb);
 955	return 1;
 956
 957abort:
 958	kfree_skb(skb);
 959	return 1;
 960}
 961
 962/************************************************************************
 963 *
 964 * xmit function called by generic PPP driver
 965 * sends PPP frame over PPPoE socket
 966 *
 967 ***********************************************************************/
 968static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 969{
 970	struct sock *sk = (struct sock *)chan->private;
 971	return __pppoe_xmit(sk, skb);
 972}
 973
 974static const struct ppp_channel_ops pppoe_chan_ops = {
 975	.start_xmit = pppoe_xmit,
 976};
 977
 978static int pppoe_recvmsg(struct socket *sock, struct msghdr *m,
 979			 size_t total_len, int flags)
 980{
 981	struct sock *sk = sock->sk;
 982	struct sk_buff *skb;
 983	int error = 0;
 984
 985	if (sk->sk_state & PPPOX_BOUND) {
 986		error = -EIO;
 987		goto end;
 988	}
 989
 990	skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
 991				flags & MSG_DONTWAIT, &error);
 992	if (error < 0)
 993		goto end;
 994
 995	if (skb) {
 996		total_len = min_t(size_t, total_len, skb->len);
 997		error = skb_copy_datagram_msg(skb, 0, m, total_len);
 998		if (error == 0) {
 999			consume_skb(skb);
1000			return total_len;
1001		}
1002	}
1003
1004	kfree_skb(skb);
1005end:
1006	return error;
1007}
1008
1009#ifdef CONFIG_PROC_FS
1010static int pppoe_seq_show(struct seq_file *seq, void *v)
1011{
1012	struct pppox_sock *po;
1013	char *dev_name;
1014
1015	if (v == SEQ_START_TOKEN) {
1016		seq_puts(seq, "Id       Address              Device\n");
1017		goto out;
1018	}
1019
1020	po = v;
1021	dev_name = po->pppoe_pa.dev;
1022
1023	seq_printf(seq, "%08X %pM %8s\n",
1024		po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name);
1025out:
1026	return 0;
1027}
1028
1029static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos)
1030{
1031	struct pppox_sock *po;
1032	int i;
1033
1034	for (i = 0; i < PPPOE_HASH_SIZE; i++) {
1035		po = pn->hash_table[i];
1036		while (po) {
1037			if (!pos--)
1038				goto out;
1039			po = po->next;
1040		}
1041	}
1042
1043out:
1044	return po;
1045}
1046
1047static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
1048	__acquires(pn->hash_lock)
1049{
1050	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
1051	loff_t l = *pos;
1052
1053	read_lock_bh(&pn->hash_lock);
1054	return l ? pppoe_get_idx(pn, --l) : SEQ_START_TOKEN;
1055}
1056
1057static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1058{
1059	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
1060	struct pppox_sock *po;
1061
1062	++*pos;
1063	if (v == SEQ_START_TOKEN) {
1064		po = pppoe_get_idx(pn, 0);
1065		goto out;
1066	}
1067	po = v;
1068	if (po->next)
1069		po = po->next;
1070	else {
1071		int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
1072
1073		po = NULL;
1074		while (++hash < PPPOE_HASH_SIZE) {
1075			po = pn->hash_table[hash];
1076			if (po)
1077				break;
1078		}
1079	}
1080
1081out:
1082	return po;
1083}
1084
1085static void pppoe_seq_stop(struct seq_file *seq, void *v)
1086	__releases(pn->hash_lock)
1087{
1088	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
1089	read_unlock_bh(&pn->hash_lock);
1090}
1091
1092static const struct seq_operations pppoe_seq_ops = {
1093	.start		= pppoe_seq_start,
1094	.next		= pppoe_seq_next,
1095	.stop		= pppoe_seq_stop,
1096	.show		= pppoe_seq_show,
1097};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1098#endif /* CONFIG_PROC_FS */
1099
1100static const struct proto_ops pppoe_ops = {
1101	.family		= AF_PPPOX,
1102	.owner		= THIS_MODULE,
1103	.release	= pppoe_release,
1104	.bind		= sock_no_bind,
1105	.connect	= pppoe_connect,
1106	.socketpair	= sock_no_socketpair,
1107	.accept		= sock_no_accept,
1108	.getname	= pppoe_getname,
1109	.poll		= datagram_poll,
1110	.listen		= sock_no_listen,
1111	.shutdown	= sock_no_shutdown,
1112	.setsockopt	= sock_no_setsockopt,
1113	.getsockopt	= sock_no_getsockopt,
1114	.sendmsg	= pppoe_sendmsg,
1115	.recvmsg	= pppoe_recvmsg,
1116	.mmap		= sock_no_mmap,
1117	.ioctl		= pppox_ioctl,
1118#ifdef CONFIG_COMPAT
1119	.compat_ioctl	= pppox_compat_ioctl,
1120#endif
1121};
1122
1123static const struct pppox_proto pppoe_proto = {
1124	.create	= pppoe_create,
1125	.ioctl	= pppoe_ioctl,
1126	.owner	= THIS_MODULE,
1127};
1128
1129static __net_init int pppoe_init_net(struct net *net)
1130{
1131	struct pppoe_net *pn = pppoe_pernet(net);
1132	struct proc_dir_entry *pde;
1133
1134	rwlock_init(&pn->hash_lock);
1135
1136	pde = proc_create_net("pppoe", 0444, net->proc_net,
1137			&pppoe_seq_ops, sizeof(struct seq_net_private));
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	remove_proc_entry("pppoe", net->proc_net);
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_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OE);