ppp: Move the PPP drivers

Move the PPP drivers into drivers/net/ppp/ and make the
necessary Kconfig and Makefile changes.

CC: Paul Mackerras <paulus@samba.org>
CC: Frank Cusack <fcusack@fcusack.com>
CC: Michal Ostrowski <mostrows@speakeasy.net>
CC: Michal Ostrowski <mostrows@earthlink.net>
CC: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

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 000000000000..bc9a4bb31980
--- /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);