Merge branch 'master' into for-next

Sync with Linus tree to have 157550ff ("mtd: add GPMI-NAND driver
in the config and Makefile") as I have patch depending on that one.

1 files changed, 1208 insertions, 0 deletions

diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
new file mode 100644
index 00000000000..bc9a4bb3198
--- /dev/null
+++ b/drivers/net/ppp/pppoe.c
@@ -0,0 +1,1208 @@
+/** -*- linux-c -*- ***********************************************************
+ * Linux PPP over Ethernet (PPPoX/PPPoE) Sockets
+ *
+ * PPPoX --- Generic PPP encapsulation socket family
+ * PPPoE --- PPP over Ethernet (RFC 2516)
+ *
+ *
+ * Version:	0.7.0
+ *
+ * 070228 :	Fix to allow multiple sessions with same remote MAC and same
+ *		session id by including the local device ifindex in the
+ *		tuple identifying a session. This also ensures packets can't
+ *		be injected into a session from interfaces other than the one
+ *		specified by userspace. Florian Zumbiehl <florz@florz.de>
+ *		(Oh, BTW, this one is YYMMDD, in case you were wondering ...)
+ * 220102 :	Fix module use count on failure in pppoe_create, pppox_sk -acme
+ * 030700 :	Fixed connect logic to allow for disconnect.
+ * 270700 :	Fixed potential SMP problems; we must protect against
+ *		simultaneous invocation of ppp_input
+ *		and ppp_unregister_channel.
+ * 040800 :	Respect reference count mechanisms on net-devices.
+ * 200800 :	fix kfree(skb) in pppoe_rcv (acme)
+ *		Module reference count is decremented in the right spot now,
+ *		guards against sock_put not actually freeing the sk
+ *		in pppoe_release.
+ * 051000 :	Initialization cleanup.
+ * 111100 :	Fix recvmsg.
+ * 050101 :	Fix PADT procesing.
+ * 140501 :	Use pppoe_rcv_core to handle all backlog. (Alexey)
+ * 170701 :	Do not lock_sock with rwlock held. (DaveM)
+ *		Ignore discovery frames if user has socket
+ *		locked. (DaveM)
+ *		Ignore return value of dev_queue_xmit in __pppoe_xmit
+ *		or else we may kfree an SKB twice. (DaveM)
+ * 190701 :	When doing copies of skb's in __pppoe_xmit, always delete
+ *		the original skb that was passed in on success, never on
+ *		failure.  Delete the copy of the skb on failure to avoid
+ *		a memory leak.
+ * 081001 :	Misc. cleanup (licence string, non-blocking, prevent
+ *		reference of device on close).
+ * 121301 :	New ppp channels interface; cannot unregister a channel
+ *		from interrupts.  Thus, we mark the socket as a ZOMBIE
+ *		and do the unregistration later.
+ * 081002 :	seq_file support for proc stuff -acme
+ * 111602 :	Merge all 2.4 fixes into 2.5/2.6 tree.  Label 2.5/2.6
+ *		as version 0.7.  Spacing cleanup.
+ * Author:	Michal Ostrowski <mostrows@speakeasy.net>
+ * Contributors:
+ * 		Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *		David S. Miller (davem@redhat.com)
+ *
+ * License:
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/string.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/net.h>
+#include <linux/inetdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/if_ether.h>
+#include <linux/if_pppox.h>
+#include <linux/ppp_channel.h>
+#include <linux/ppp_defs.h>
+#include <linux/if_ppp.h>
+#include <linux/notifier.h>
+#include <linux/file.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/sock.h>
+
+#include <asm/uaccess.h>
+
+#define PPPOE_HASH_BITS 4
+#define PPPOE_HASH_SIZE (1 << PPPOE_HASH_BITS)
+#define PPPOE_HASH_MASK	(PPPOE_HASH_SIZE - 1)
+
+static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
+
+static const struct proto_ops pppoe_ops;
+static const struct ppp_channel_ops pppoe_chan_ops;
+
+/* per-net private data for this module */
+static int pppoe_net_id __read_mostly;
+struct pppoe_net {
+	/*
+	 * we could use _single_ hash table for all
+	 * nets by injecting net id into the hash but
+	 * it would increase hash chains and add
+	 * a few additional math comparations messy
+	 * as well, moreover in case of SMP less locking
+	 * controversy here
+	 */
+	struct pppox_sock *hash_table[PPPOE_HASH_SIZE];
+	rwlock_t hash_lock;
+};
+
+/*
+ * PPPoE could be in the following stages:
+ * 1) Discovery stage (to obtain remote MAC and Session ID)
+ * 2) Session stage (MAC and SID are known)
+ *
+ * Ethernet frames have a special tag for this but
+ * we use simpler approach based on session id
+ */
+static inline bool stage_session(__be16 sid)
+{
+	return sid != 0;
+}
+
+static inline struct pppoe_net *pppoe_pernet(struct net *net)
+{
+	BUG_ON(!net);
+
+	return net_generic(net, pppoe_net_id);
+}
+
+static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
+{
+	return a->sid == b->sid && !memcmp(a->remote, b->remote, ETH_ALEN);
+}
+
+static inline int cmp_addr(struct pppoe_addr *a, __be16 sid, char *addr)
+{
+	return a->sid == sid && !memcmp(a->remote, addr, ETH_ALEN);
+}
+
+#if 8 % PPPOE_HASH_BITS
+#error 8 must be a multiple of PPPOE_HASH_BITS
+#endif
+
+static int hash_item(__be16 sid, unsigned char *addr)
+{
+	unsigned char hash = 0;
+	unsigned int i;
+
+	for (i = 0; i < ETH_ALEN; i++)
+		hash ^= addr[i];
+	for (i = 0; i < sizeof(sid_t) * 8; i += 8)
+		hash ^= (__force __u32)sid >> i;
+	for (i = 8; (i >>= 1) >= PPPOE_HASH_BITS;)
+		hash ^= hash >> i;
+
+	return hash & PPPOE_HASH_MASK;
+}
+
+/**********************************************************************
+ *
+ *  Set/get/delete/rehash items  (internal versions)
+ *
+ **********************************************************************/
+static struct pppox_sock *__get_item(struct pppoe_net *pn, __be16 sid,
+				unsigned char *addr, int ifindex)
+{
+	int hash = hash_item(sid, addr);
+	struct pppox_sock *ret;
+
+	ret = pn->hash_table[hash];
+	while (ret) {
+		if (cmp_addr(&ret->pppoe_pa, sid, addr) &&
+		    ret->pppoe_ifindex == ifindex)
+			return ret;
+
+		ret = ret->next;
+	}
+
+	return NULL;
+}
+
+static int __set_item(struct pppoe_net *pn, struct pppox_sock *po)
+{
+	int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
+	struct pppox_sock *ret;
+
+	ret = pn->hash_table[hash];
+	while (ret) {
+		if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) &&
+		    ret->pppoe_ifindex == po->pppoe_ifindex)
+			return -EALREADY;
+
+		ret = ret->next;
+	}
+
+	po->next = pn->hash_table[hash];
+	pn->hash_table[hash] = po;
+
+	return 0;
+}
+
+static struct pppox_sock *__delete_item(struct pppoe_net *pn, __be16 sid,
+					char *addr, int ifindex)
+{
+	int hash = hash_item(sid, addr);
+	struct pppox_sock *ret, **src;
+
+	ret = pn->hash_table[hash];
+	src = &pn->hash_table[hash];
+
+	while (ret) {
+		if (cmp_addr(&ret->pppoe_pa, sid, addr) &&
+		    ret->pppoe_ifindex == ifindex) {
+			*src = ret->next;
+			break;
+		}
+
+		src = &ret->next;
+		ret = ret->next;
+	}
+
+	return ret;
+}
+
+/**********************************************************************
+ *
+ *  Set/get/delete/rehash items
+ *
+ **********************************************************************/
+static inline struct pppox_sock *get_item(struct pppoe_net *pn, __be16 sid,
+					unsigned char *addr, int ifindex)
+{
+	struct pppox_sock *po;
+
+	read_lock_bh(&pn->hash_lock);
+	po = __get_item(pn, sid, addr, ifindex);
+	if (po)
+		sock_hold(sk_pppox(po));
+	read_unlock_bh(&pn->hash_lock);
+
+	return po;
+}
+
+static inline struct pppox_sock *get_item_by_addr(struct net *net,
+						struct sockaddr_pppox *sp)
+{
+	struct net_device *dev;
+	struct pppoe_net *pn;
+	struct pppox_sock *pppox_sock = NULL;
+
+	int ifindex;
+
+	rcu_read_lock();
+	dev = dev_get_by_name_rcu(net, sp->sa_addr.pppoe.dev);
+	if (dev) {
+		ifindex = dev->ifindex;
+		pn = pppoe_pernet(net);
+		pppox_sock = get_item(pn, sp->sa_addr.pppoe.sid,
+				sp->sa_addr.pppoe.remote, ifindex);
+	}
+	rcu_read_unlock();
+	return pppox_sock;
+}
+
+static inline struct pppox_sock *delete_item(struct pppoe_net *pn, __be16 sid,
+					char *addr, int ifindex)
+{
+	struct pppox_sock *ret;
+
+	write_lock_bh(&pn->hash_lock);
+	ret = __delete_item(pn, sid, addr, ifindex);
+	write_unlock_bh(&pn->hash_lock);
+
+	return ret;
+}
+
+/***************************************************************************
+ *
+ *  Handler for device events.
+ *  Certain device events require that sockets be unconnected.
+ *
+ **************************************************************************/
+
+static void pppoe_flush_dev(struct net_device *dev)
+{
+	struct pppoe_net *pn;
+	int i;
+
+	pn = pppoe_pernet(dev_net(dev));
+	write_lock_bh(&pn->hash_lock);
+	for (i = 0; i < PPPOE_HASH_SIZE; i++) {
+		struct pppox_sock *po = pn->hash_table[i];
+		struct sock *sk;
+
+		while (po) {
+			while (po && po->pppoe_dev != dev) {
+				po = po->next;
+			}
+
+			if (!po)
+				break;
+
+			sk = sk_pppox(po);
+
+			/* We always grab the socket lock, followed by the
+			 * hash_lock, in that order.  Since we should hold the
+			 * sock lock while doing any unbinding, we need to
+			 * release the lock we're holding.  Hold a reference to
+			 * the sock so it doesn't disappear as we're jumping
+			 * between locks.
+			 */
+
+			sock_hold(sk);
+			write_unlock_bh(&pn->hash_lock);
+			lock_sock(sk);
+
+			if (po->pppoe_dev == dev &&
+			    sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND | PPPOX_ZOMBIE)) {
+				pppox_unbind_sock(sk);
+				sk->sk_state = PPPOX_ZOMBIE;
+				sk->sk_state_change(sk);
+				po->pppoe_dev = NULL;
+				dev_put(dev);
+			}
+
+			release_sock(sk);
+			sock_put(sk);
+
+			/* Restart the process from the start of the current
+			 * hash chain. We dropped locks so the world may have
+			 * change from underneath us.
+			 */
+
+			BUG_ON(pppoe_pernet(dev_net(dev)) == NULL);
+			write_lock_bh(&pn->hash_lock);
+			po = pn->hash_table[i];
+		}
+	}
+	write_unlock_bh(&pn->hash_lock);
+}
+
+static int pppoe_device_event(struct notifier_block *this,
+			      unsigned long event, void *ptr)
+{
+	struct net_device *dev = (struct net_device *)ptr;
+
+	/* Only look at sockets that are using this specific device. */
+	switch (event) {
+	case NETDEV_CHANGEADDR:
+	case NETDEV_CHANGEMTU:
+		/* A change in mtu or address is a bad thing, requiring
+		 * LCP re-negotiation.
+		 */
+
+	case NETDEV_GOING_DOWN:
+	case NETDEV_DOWN:
+		/* Find every socket on this device and kill it. */
+		pppoe_flush_dev(dev);
+		break;
+
+	default:
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block pppoe_notifier = {
+	.notifier_call = pppoe_device_event,
+};
+
+/************************************************************************
+ *
+ * Do the real work of receiving a PPPoE Session frame.
+ *
+ ***********************************************************************/
+static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb)
+{
+	struct pppox_sock *po = pppox_sk(sk);
+	struct pppox_sock *relay_po;
+
+	/* Backlog receive. Semantics of backlog rcv preclude any code from
+	 * executing in lock_sock()/release_sock() bounds; meaning sk->sk_state
+	 * can't change.
+	 */
+
+	if (sk->sk_state & PPPOX_BOUND) {
+		ppp_input(&po->chan, skb);
+	} else if (sk->sk_state & PPPOX_RELAY) {
+		relay_po = get_item_by_addr(sock_net(sk),
+					    &po->pppoe_relay);
+		if (relay_po == NULL)
+			goto abort_kfree;
+
+		if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0)
+			goto abort_put;
+
+		if (!__pppoe_xmit(sk_pppox(relay_po), skb))
+			goto abort_put;
+	} else {
+		if (sock_queue_rcv_skb(sk, skb))
+			goto abort_kfree;
+	}
+
+	return NET_RX_SUCCESS;
+
+abort_put:
+	sock_put(sk_pppox(relay_po));
+
+abort_kfree:
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+/************************************************************************
+ *
+ * Receive wrapper called in BH context.
+ *
+ ***********************************************************************/
+static int pppoe_rcv(struct sk_buff *skb, struct net_device *dev,
+		     struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct pppoe_hdr *ph;
+	struct pppox_sock *po;
+	struct pppoe_net *pn;
+	int len;
+
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		goto out;
+
+	if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
+		goto drop;
+
+	ph = pppoe_hdr(skb);
+	len = ntohs(ph->length);
+
+	skb_pull_rcsum(skb, sizeof(*ph));
+	if (skb->len < len)
+		goto drop;
+
+	if (pskb_trim_rcsum(skb, len))
+		goto drop;
+
+	pn = pppoe_pernet(dev_net(dev));
+
+	/* Note that get_item does a sock_hold(), so sk_pppox(po)
+	 * is known to be safe.
+	 */
+	po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
+	if (!po)
+		goto drop;
+
+	return sk_receive_skb(sk_pppox(po), skb, 0);
+
+drop:
+	kfree_skb(skb);
+out:
+	return NET_RX_DROP;
+}
+
+/************************************************************************
+ *
+ * Receive a PPPoE Discovery frame.
+ * This is solely for detection of PADT frames
+ *
+ ***********************************************************************/
+static int pppoe_disc_rcv(struct sk_buff *skb, struct net_device *dev,
+			  struct packet_type *pt, struct net_device *orig_dev)
+
+{
+	struct pppoe_hdr *ph;
+	struct pppox_sock *po;
+	struct pppoe_net *pn;
+
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		goto out;
+
+	if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
+		goto abort;
+
+	ph = pppoe_hdr(skb);
+	if (ph->code != PADT_CODE)
+		goto abort;
+
+	pn = pppoe_pernet(dev_net(dev));
+	po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
+	if (po) {
+		struct sock *sk = sk_pppox(po);
+
+		bh_lock_sock(sk);
+
+		/* If the user has locked the socket, just ignore
+		 * the packet.  With the way two rcv protocols hook into
+		 * one socket family type, we cannot (easily) distinguish
+		 * what kind of SKB it is during backlog rcv.
+		 */
+		if (sock_owned_by_user(sk) == 0) {
+			/* We're no longer connect at the PPPOE layer,
+			 * and must wait for ppp channel to disconnect us.
+			 */
+			sk->sk_state = PPPOX_ZOMBIE;
+		}
+
+		bh_unlock_sock(sk);
+		sock_put(sk);
+	}
+
+abort:
+	kfree_skb(skb);
+out:
+	return NET_RX_SUCCESS; /* Lies... :-) */
+}
+
+static struct packet_type pppoes_ptype __read_mostly = {
+	.type	= cpu_to_be16(ETH_P_PPP_SES),
+	.func	= pppoe_rcv,
+};
+
+static struct packet_type pppoed_ptype __read_mostly = {
+	.type	= cpu_to_be16(ETH_P_PPP_DISC),
+	.func	= pppoe_disc_rcv,
+};
+
+static struct proto pppoe_sk_proto __read_mostly = {
+	.name	  = "PPPOE",
+	.owner	  = THIS_MODULE,
+	.obj_size = sizeof(struct pppox_sock),
+};
+
+/***********************************************************************
+ *
+ * Initialize a new struct sock.
+ *
+ **********************************************************************/
+static int pppoe_create(struct net *net, struct socket *sock)
+{
+	struct sock *sk;
+
+	sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto);
+	if (!sk)
+		return -ENOMEM;
+
+	sock_init_data(sock, sk);
+
+	sock->state	= SS_UNCONNECTED;
+	sock->ops	= &pppoe_ops;
+
+	sk->sk_backlog_rcv	= pppoe_rcv_core;
+	sk->sk_state		= PPPOX_NONE;
+	sk->sk_type		= SOCK_STREAM;
+	sk->sk_family		= PF_PPPOX;
+	sk->sk_protocol		= PX_PROTO_OE;
+
+	return 0;
+}
+
+static int pppoe_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct pppox_sock *po;
+	struct pppoe_net *pn;
+	struct net *net = NULL;
+
+	if (!sk)
+		return 0;
+
+	lock_sock(sk);
+	if (sock_flag(sk, SOCK_DEAD)) {
+		release_sock(sk);
+		return -EBADF;
+	}
+
+	po = pppox_sk(sk);
+
+	if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
+		dev_put(po->pppoe_dev);
+		po->pppoe_dev = NULL;
+	}
+
+	pppox_unbind_sock(sk);
+
+	/* Signal the death of the socket. */
+	sk->sk_state = PPPOX_DEAD;
+
+	net = sock_net(sk);
+	pn = pppoe_pernet(net);
+
+	/*
+	 * protect "po" from concurrent updates
+	 * on pppoe_flush_dev
+	 */
+	delete_item(pn, po->pppoe_pa.sid, po->pppoe_pa.remote,
+		    po->pppoe_ifindex);
+
+	sock_orphan(sk);
+	sock->sk = NULL;
+
+	skb_queue_purge(&sk->sk_receive_queue);
+	release_sock(sk);
+	sock_put(sk);
+
+	return 0;
+}
+
+static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
+		  int sockaddr_len, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct sockaddr_pppox *sp = (struct sockaddr_pppox *)uservaddr;
+	struct pppox_sock *po = pppox_sk(sk);
+	struct net_device *dev = NULL;
+	struct pppoe_net *pn;
+	struct net *net = NULL;
+	int error;
+
+	lock_sock(sk);
+
+	error = -EINVAL;
+	if (sp->sa_protocol != PX_PROTO_OE)
+		goto end;
+
+	/* Check for already bound sockets */
+	error = -EBUSY;
+	if ((sk->sk_state & PPPOX_CONNECTED) &&
+	     stage_session(sp->sa_addr.pppoe.sid))
+		goto end;
+
+	/* Check for already disconnected sockets, on attempts to disconnect */
+	error = -EALREADY;
+	if ((sk->sk_state & PPPOX_DEAD) &&
+	     !stage_session(sp->sa_addr.pppoe.sid))
+		goto end;
+
+	error = 0;
+
+	/* Delete the old binding */
+	if (stage_session(po->pppoe_pa.sid)) {
+		pppox_unbind_sock(sk);
+		pn = pppoe_pernet(sock_net(sk));
+		delete_item(pn, po->pppoe_pa.sid,
+			    po->pppoe_pa.remote, po->pppoe_ifindex);
+		if (po->pppoe_dev) {
+			dev_put(po->pppoe_dev);
+			po->pppoe_dev = NULL;
+		}
+
+		memset(sk_pppox(po) + 1, 0,
+		       sizeof(struct pppox_sock) - sizeof(struct sock));
+		sk->sk_state = PPPOX_NONE;
+	}
+
+	/* Re-bind in session stage only */
+	if (stage_session(sp->sa_addr.pppoe.sid)) {
+		error = -ENODEV;
+		net = sock_net(sk);
+		dev = dev_get_by_name(net, sp->sa_addr.pppoe.dev);
+		if (!dev)
+			goto err_put;
+
+		po->pppoe_dev = dev;
+		po->pppoe_ifindex = dev->ifindex;
+		pn = pppoe_pernet(net);
+		if (!(dev->flags & IFF_UP)) {
+			goto err_put;
+		}
+
+		memcpy(&po->pppoe_pa,
+		       &sp->sa_addr.pppoe,
+		       sizeof(struct pppoe_addr));
+
+		write_lock_bh(&pn->hash_lock);
+		error = __set_item(pn, po);
+		write_unlock_bh(&pn->hash_lock);
+		if (error < 0)
+			goto err_put;
+
+		po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
+				   dev->hard_header_len);
+
+		po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr);
+		po->chan.private = sk;
+		po->chan.ops = &pppoe_chan_ops;
+
+		error = ppp_register_net_channel(dev_net(dev), &po->chan);
+		if (error) {
+			delete_item(pn, po->pppoe_pa.sid,
+				    po->pppoe_pa.remote, po->pppoe_ifindex);
+			goto err_put;
+		}
+
+		sk->sk_state = PPPOX_CONNECTED;
+	}
+
+	po->num = sp->sa_addr.pppoe.sid;
+
+end:
+	release_sock(sk);
+	return error;
+err_put:
+	if (po->pppoe_dev) {
+		dev_put(po->pppoe_dev);
+		po->pppoe_dev = NULL;
+	}
+	goto end;
+}
+
+static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
+		  int *usockaddr_len, int peer)
+{
+	int len = sizeof(struct sockaddr_pppox);
+	struct sockaddr_pppox sp;
+
+	sp.sa_family	= AF_PPPOX;
+	sp.sa_protocol	= PX_PROTO_OE;
+	memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
+	       sizeof(struct pppoe_addr));
+
+	memcpy(uaddr, &sp, len);
+
+	*usockaddr_len = len;
+
+	return 0;
+}
+
+static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
+		unsigned long arg)
+{
+	struct sock *sk = sock->sk;
+	struct pppox_sock *po = pppox_sk(sk);
+	int val;
+	int err;
+
+	switch (cmd) {
+	case PPPIOCGMRU:
+		err = -ENXIO;
+		if (!(sk->sk_state & PPPOX_CONNECTED))
+			break;
+
+		err = -EFAULT;
+		if (put_user(po->pppoe_dev->mtu -
+			     sizeof(struct pppoe_hdr) -
+			     PPP_HDRLEN,
+			     (int __user *)arg))
+			break;
+		err = 0;
+		break;
+
+	case PPPIOCSMRU:
+		err = -ENXIO;
+		if (!(sk->sk_state & PPPOX_CONNECTED))
+			break;
+
+		err = -EFAULT;
+		if (get_user(val, (int __user *)arg))
+			break;
+
+		if (val < (po->pppoe_dev->mtu
+			   - sizeof(struct pppoe_hdr)
+			   - PPP_HDRLEN))
+			err = 0;
+		else
+			err = -EINVAL;
+		break;
+
+	case PPPIOCSFLAGS:
+		err = -EFAULT;
+		if (get_user(val, (int __user *)arg))
+			break;
+		err = 0;
+		break;
+
+	case PPPOEIOCSFWD:
+	{
+		struct pppox_sock *relay_po;
+
+		err = -EBUSY;
+		if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD))
+			break;
+
+		err = -ENOTCONN;
+		if (!(sk->sk_state & PPPOX_CONNECTED))
+			break;
+
+		/* PPPoE address from the user specifies an outbound
+		   PPPoE address which frames are forwarded to */
+		err = -EFAULT;
+		if (copy_from_user(&po->pppoe_relay,
+				   (void __user *)arg,
+				   sizeof(struct sockaddr_pppox)))
+			break;
+
+		err = -EINVAL;
+		if (po->pppoe_relay.sa_family != AF_PPPOX ||
+		    po->pppoe_relay.sa_protocol != PX_PROTO_OE)
+			break;
+
+		/* Check that the socket referenced by the address
+		   actually exists. */
+		relay_po = get_item_by_addr(sock_net(sk), &po->pppoe_relay);
+		if (!relay_po)
+			break;
+
+		sock_put(sk_pppox(relay_po));
+		sk->sk_state |= PPPOX_RELAY;
+		err = 0;
+		break;
+	}
+
+	case PPPOEIOCDFWD:
+		err = -EALREADY;
+		if (!(sk->sk_state & PPPOX_RELAY))
+			break;
+
+		sk->sk_state &= ~PPPOX_RELAY;
+		err = 0;
+		break;
+
+	default:
+		err = -ENOTTY;
+	}
+
+	return err;
+}
+
+static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
+		  struct msghdr *m, size_t total_len)
+{
+	struct sk_buff *skb;
+	struct sock *sk = sock->sk;
+	struct pppox_sock *po = pppox_sk(sk);
+	int error;
+	struct pppoe_hdr hdr;
+	struct pppoe_hdr *ph;
+	struct net_device *dev;
+	char *start;
+
+	lock_sock(sk);
+	if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
+		error = -ENOTCONN;
+		goto end;
+	}
+
+	hdr.ver = 1;
+	hdr.type = 1;
+	hdr.code = 0;
+	hdr.sid = po->num;
+
+	dev = po->pppoe_dev;
+
+	error = -EMSGSIZE;
+	if (total_len > (dev->mtu + dev->hard_header_len))
+		goto end;
+
+
+	skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32,
+			   0, GFP_KERNEL);
+	if (!skb) {
+		error = -ENOMEM;
+		goto end;
+	}
+
+	/* Reserve space for headers. */
+	skb_reserve(skb, dev->hard_header_len);
+	skb_reset_network_header(skb);
+
+	skb->dev = dev;
+
+	skb->priority = sk->sk_priority;
+	skb->protocol = cpu_to_be16(ETH_P_PPP_SES);
+
+	ph = (struct pppoe_hdr *)skb_put(skb, total_len + sizeof(struct pppoe_hdr));
+	start = (char *)&ph->tag[0];
+
+	error = memcpy_fromiovec(start, m->msg_iov, total_len);
+	if (error < 0) {
+		kfree_skb(skb);
+		goto end;
+	}
+
+	error = total_len;
+	dev_hard_header(skb, dev, ETH_P_PPP_SES,
+			po->pppoe_pa.remote, NULL, total_len);
+
+	memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
+
+	ph->length = htons(total_len);
+
+	dev_queue_xmit(skb);
+
+end:
+	release_sock(sk);
+	return error;
+}
+
+/************************************************************************
+ *
+ * xmit function for internal use.
+ *
+ ***********************************************************************/
+static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
+{
+	struct pppox_sock *po = pppox_sk(sk);
+	struct net_device *dev = po->pppoe_dev;
+	struct pppoe_hdr *ph;
+	int data_len = skb->len;
+
+	/* The higher-level PPP code (ppp_unregister_channel()) ensures the PPP
+	 * xmit operations conclude prior to an unregistration call.  Thus
+	 * sk->sk_state cannot change, so we don't need to do lock_sock().
+	 * But, we also can't do a lock_sock since that introduces a potential
+	 * deadlock as we'd reverse the lock ordering used when calling
+	 * ppp_unregister_channel().
+	 */
+
+	if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
+		goto abort;
+
+	if (!dev)
+		goto abort;
+
+	/* Copy the data if there is no space for the header or if it's
+	 * read-only.
+	 */
+	if (skb_cow_head(skb, sizeof(*ph) + dev->hard_header_len))
+		goto abort;
+
+	__skb_push(skb, sizeof(*ph));
+	skb_reset_network_header(skb);
+
+	ph = pppoe_hdr(skb);
+	ph->ver	= 1;
+	ph->type = 1;
+	ph->code = 0;
+	ph->sid	= po->num;
+	ph->length = htons(data_len);
+
+	skb->protocol = cpu_to_be16(ETH_P_PPP_SES);
+	skb->dev = dev;
+
+	dev_hard_header(skb, dev, ETH_P_PPP_SES,
+			po->pppoe_pa.remote, NULL, data_len);
+
+	dev_queue_xmit(skb);
+	return 1;
+
+abort:
+	kfree_skb(skb);
+	return 1;
+}
+
+/************************************************************************
+ *
+ * xmit function called by generic PPP driver
+ * sends PPP frame over PPPoE socket
+ *
+ ***********************************************************************/
+static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
+{
+	struct sock *sk = (struct sock *)chan->private;
+	return __pppoe_xmit(sk, skb);
+}
+
+static const struct ppp_channel_ops pppoe_chan_ops = {
+	.start_xmit = pppoe_xmit,
+};
+
+static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
+		  struct msghdr *m, size_t total_len, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct sk_buff *skb;
+	int error = 0;
+
+	if (sk->sk_state & PPPOX_BOUND) {
+		error = -EIO;
+		goto end;
+	}
+
+	skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
+				flags & MSG_DONTWAIT, &error);
+	if (error < 0)
+		goto end;
+
+	m->msg_namelen = 0;
+
+	if (skb) {
+		total_len = min_t(size_t, total_len, skb->len);
+		error = skb_copy_datagram_iovec(skb, 0, m->msg_iov, total_len);
+		if (error == 0)
+			error = total_len;
+	}
+
+	kfree_skb(skb);
+end:
+	return error;
+}
+
+#ifdef CONFIG_PROC_FS
+static int pppoe_seq_show(struct seq_file *seq, void *v)
+{
+	struct pppox_sock *po;
+	char *dev_name;
+
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq, "Id       Address              Device\n");
+		goto out;
+	}
+
+	po = v;
+	dev_name = po->pppoe_pa.dev;
+
+	seq_printf(seq, "%08X %pM %8s\n",
+		po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name);
+out:
+	return 0;
+}
+
+static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos)
+{
+	struct pppox_sock *po;
+	int i;
+
+	for (i = 0; i < PPPOE_HASH_SIZE; i++) {
+		po = pn->hash_table[i];
+		while (po) {
+			if (!pos--)
+				goto out;
+			po = po->next;
+		}
+	}
+
+out:
+	return po;
+}
+
+static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(pn->hash_lock)
+{
+	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
+	loff_t l = *pos;
+
+	read_lock_bh(&pn->hash_lock);
+	return l ? pppoe_get_idx(pn, --l) : SEQ_START_TOKEN;
+}
+
+static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
+	struct pppox_sock *po;
+
+	++*pos;
+	if (v == SEQ_START_TOKEN) {
+		po = pppoe_get_idx(pn, 0);
+		goto out;
+	}
+	po = v;
+	if (po->next)
+		po = po->next;
+	else {
+		int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
+
+		po = NULL;
+		while (++hash < PPPOE_HASH_SIZE) {
+			po = pn->hash_table[hash];
+			if (po)
+				break;
+		}
+	}
+
+out:
+	return po;
+}
+
+static void pppoe_seq_stop(struct seq_file *seq, void *v)
+	__releases(pn->hash_lock)
+{
+	struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq));
+	read_unlock_bh(&pn->hash_lock);
+}
+
+static const struct seq_operations pppoe_seq_ops = {
+	.start		= pppoe_seq_start,
+	.next		= pppoe_seq_next,
+	.stop		= pppoe_seq_stop,
+	.show		= pppoe_seq_show,
+};
+
+static int pppoe_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &pppoe_seq_ops,
+			sizeof(struct seq_net_private));
+}
+
+static const struct file_operations pppoe_seq_fops = {
+	.owner		= THIS_MODULE,
+	.open		= pppoe_seq_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release_net,
+};
+
+#endif /* CONFIG_PROC_FS */
+
+static const struct proto_ops pppoe_ops = {
+	.family		= AF_PPPOX,
+	.owner		= THIS_MODULE,
+	.release	= pppoe_release,
+	.bind		= sock_no_bind,
+	.connect	= pppoe_connect,
+	.socketpair	= sock_no_socketpair,
+	.accept		= sock_no_accept,
+	.getname	= pppoe_getname,
+	.poll		= datagram_poll,
+	.listen		= sock_no_listen,
+	.shutdown	= sock_no_shutdown,
+	.setsockopt	= sock_no_setsockopt,
+	.getsockopt	= sock_no_getsockopt,
+	.sendmsg	= pppoe_sendmsg,
+	.recvmsg	= pppoe_recvmsg,
+	.mmap		= sock_no_mmap,
+	.ioctl		= pppox_ioctl,
+};
+
+static const struct pppox_proto pppoe_proto = {
+	.create	= pppoe_create,
+	.ioctl	= pppoe_ioctl,
+	.owner	= THIS_MODULE,
+};
+
+static __net_init int pppoe_init_net(struct net *net)
+{
+	struct pppoe_net *pn = pppoe_pernet(net);
+	struct proc_dir_entry *pde;
+
+	rwlock_init(&pn->hash_lock);
+
+	pde = proc_net_fops_create(net, "pppoe", S_IRUGO, &pppoe_seq_fops);
+#ifdef CONFIG_PROC_FS
+	if (!pde)
+		return -ENOMEM;
+#endif
+
+	return 0;
+}
+
+static __net_exit void pppoe_exit_net(struct net *net)
+{
+	proc_net_remove(net, "pppoe");
+}
+
+static struct pernet_operations pppoe_net_ops = {
+	.init = pppoe_init_net,
+	.exit = pppoe_exit_net,
+	.id   = &pppoe_net_id,
+	.size = sizeof(struct pppoe_net),
+};
+
+static int __init pppoe_init(void)
+{
+	int err;
+
+	err = register_pernet_device(&pppoe_net_ops);
+	if (err)
+		goto out;
+
+	err = proto_register(&pppoe_sk_proto, 0);
+	if (err)
+		goto out_unregister_net_ops;
+
+	err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
+	if (err)
+		goto out_unregister_pppoe_proto;
+
+	dev_add_pack(&pppoes_ptype);
+	dev_add_pack(&pppoed_ptype);
+	register_netdevice_notifier(&pppoe_notifier);
+
+	return 0;
+
+out_unregister_pppoe_proto:
+	proto_unregister(&pppoe_sk_proto);
+out_unregister_net_ops:
+	unregister_pernet_device(&pppoe_net_ops);
+out:
+	return err;
+}
+
+static void __exit pppoe_exit(void)
+{
+	unregister_netdevice_notifier(&pppoe_notifier);
+	dev_remove_pack(&pppoed_ptype);
+	dev_remove_pack(&pppoes_ptype);
+	unregister_pppox_proto(PX_PROTO_OE);
+	proto_unregister(&pppoe_sk_proto);
+	unregister_pernet_device(&pppoe_net_ops);
+}
+
+module_init(pppoe_init);
+module_exit(pppoe_exit);
+
+MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>");
+MODULE_DESCRIPTION("PPP over Ethernet driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(PF_PPPOX);