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linux/drivers/net/pppoe.c
Michal Ostrowski 42dc9cd54b [PPPOE]: Fix device tear-down notification. 
pppoe_flush_dev() kicks all sockets bound to a device that is going down.
In doing so, locks must be taken in the right order consistently (sock lock,
followed by the pppoe_hash_lock).  However, the scan process is based on
us holding the sock lock.  So, when something is found in the scan we must
release the lock we're holding and grab the sock lock.

This patch fixes race conditions between this code and pppoe_release(),
both of which perform similar functions but would naturally prefer to grab
locks in opposing orders.  Both code paths are now going after these locks
in a consistent manner.

pppoe_hash_lock protects the contents of the "pppox_sock" objects that reside
inside the hash.  Thus, NULL'ing out the pppoe_dev field should be done
under the protection of this lock.

Signed-off-by: Michal Ostrowski <mostrows@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:29:21 -07:00

1149 lines
26 KiB
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/** -*- 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 <net/sock.h>
#include <asm/uaccess.h>
#define PPPOE_HASH_BITS 4
#define PPPOE_HASH_SIZE (1<<PPPOE_HASH_BITS)
static struct ppp_channel_ops pppoe_chan_ops;
static int pppoe_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb);
static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
static const struct proto_ops pppoe_ops;
static DEFINE_RWLOCK(pppoe_hash_lock);
static struct ppp_channel_ops pppoe_chan_ops;
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) == 0));
}
static inline int cmp_addr(struct pppoe_addr *a, unsigned long sid, char *addr)
{
return (a->sid == sid &&
(memcmp(a->remote,addr,ETH_ALEN) == 0));
}
static int hash_item(unsigned long sid, unsigned char *addr)
{
char hash = 0;
int i, j;
for (i = 0; i < ETH_ALEN ; ++i) {
for (j = 0; j < 8/PPPOE_HASH_BITS ; ++j) {
hash ^= addr[i] >> ( j * PPPOE_HASH_BITS );
}
}
for (i = 0; i < (sizeof(unsigned long)*8) / PPPOE_HASH_BITS ; ++i)
hash ^= sid >> (i*PPPOE_HASH_BITS);
return hash & ( PPPOE_HASH_SIZE - 1 );
}
/* zeroed because its in .bss */
static struct pppox_sock *item_hash_table[PPPOE_HASH_SIZE];
/**********************************************************************
*
* Set/get/delete/rehash items (internal versions)
*
**********************************************************************/
static struct pppox_sock *__get_item(unsigned long sid, unsigned char *addr, int ifindex)
{
int hash = hash_item(sid, addr);
struct pppox_sock *ret;
ret = item_hash_table[hash];
while (ret && !(cmp_addr(&ret->pppoe_pa, sid, addr) && ret->pppoe_ifindex == ifindex))
ret = ret->next;
return ret;
}
static int __set_item(struct pppox_sock *po)
{
int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
struct pppox_sock *ret;
ret = item_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 = item_hash_table[hash];
item_hash_table[hash] = po;
return 0;
}
static struct pppox_sock *__delete_item(unsigned long sid, char *addr, int ifindex)
{
int hash = hash_item(sid, addr);
struct pppox_sock *ret, **src;
ret = item_hash_table[hash];
src = &item_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(unsigned long sid,
unsigned char *addr, int ifindex)
{
struct pppox_sock *po;
read_lock_bh(&pppoe_hash_lock);
po = __get_item(sid, addr, ifindex);
if (po)
sock_hold(sk_pppox(po));
read_unlock_bh(&pppoe_hash_lock);
return po;
}
static inline struct pppox_sock *get_item_by_addr(struct sockaddr_pppox *sp)
{
struct net_device *dev;
int ifindex;
dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
if(!dev)
return NULL;
ifindex = dev->ifindex;
dev_put(dev);
return get_item(sp->sa_addr.pppoe.sid, sp->sa_addr.pppoe.remote, ifindex);
}
static inline struct pppox_sock *delete_item(unsigned long sid, char *addr, int ifindex)
{
struct pppox_sock *ret;
write_lock_bh(&pppoe_hash_lock);
ret = __delete_item(sid, addr, ifindex);
write_unlock_bh(&pppoe_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)
{
int hash;
BUG_ON(dev == NULL);
write_lock_bh(&pppoe_hash_lock);
for (hash = 0; hash < PPPOE_HASH_SIZE; hash++) {
struct pppox_sock *po = item_hash_table[hash];
while (po != NULL) {
struct sock *sk = sk_pppox(po);
if (po->pppoe_dev != dev) {
po = po->next;
continue;
}
po->pppoe_dev = NULL;
dev_put(dev);
/* We always grab the socket lock, followed by the
* pppoe_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(&pppoe_hash_lock);
lock_sock(sk);
if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
pppox_unbind_sock(sk);
sk->sk_state = PPPOX_ZOMBIE;
sk->sk_state_change(sk);
}
release_sock(sk);
sock_put(sk);
/* Restart scan at the beginning of this hash chain.
* While the lock was dropped the chain contents may
* have changed.
*/
write_lock_bh(&pppoe_hash_lock);
po = item_hash_table[hash];
}
}
write_unlock_bh(&pppoe_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_CHANGEMTU:
/* A change in mtu 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;
if (sk->sk_state & PPPOX_BOUND) {
struct pppoe_hdr *ph = pppoe_hdr(skb);
int len = ntohs(ph->length);
skb_pull_rcsum(skb, sizeof(struct pppoe_hdr));
if (pskb_trim_rcsum(skb, len))
goto abort_kfree;
ppp_input(&po->chan, skb);
} else if (sk->sk_state & PPPOX_RELAY) {
relay_po = get_item_by_addr(&po->pppoe_relay);
if (relay_po == NULL)
goto abort_kfree;
if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0)
goto abort_put;
skb_pull(skb, sizeof(struct pppoe_hdr));
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;
if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
goto drop;
if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
goto out;
ph = pppoe_hdr(skb);
po = get_item((unsigned long) ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
if (po != NULL)
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;
if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
goto abort;
if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
goto out;
ph = pppoe_hdr(skb);
if (ph->code != PADT_CODE)
goto abort;
po = get_item((unsigned long) 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 = {
.type = __constant_htons(ETH_P_PPP_SES),
.func = pppoe_rcv,
};
static struct packet_type pppoed_ptype = {
.type = __constant_htons(ETH_P_PPP_DISC),
.func = pppoe_disc_rcv,
};
static struct proto pppoe_sk_proto = {
.name = "PPPOE",
.owner = THIS_MODULE,
.obj_size = sizeof(struct pppox_sock),
};
/***********************************************************************
*
* Initialize a new struct sock.
*
**********************************************************************/
static int pppoe_create(struct socket *sock)
{
int error = -ENOMEM;
struct sock *sk;
sk = sk_alloc(PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto, 1);
if (!sk)
goto out;
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;
error = 0;
out: return error;
}
static int pppoe_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct pppox_sock *po;
if (!sk)
return 0;
lock_sock(sk);
if (sock_flag(sk, SOCK_DEAD)){
release_sock(sk);
return -EBADF;
}
pppox_unbind_sock(sk);
/* Signal the death of the socket. */
sk->sk_state = PPPOX_DEAD;
/* Write lock on hash lock protects the entire "po" struct from
* concurrent updates via pppoe_flush_dev. The "po" struct should
* be considered part of the hash table contents, thus protected
* by the hash table lock */
write_lock_bh(&pppoe_hash_lock);
po = pppox_sk(sk);
if (po->pppoe_pa.sid) {
__delete_item(po->pppoe_pa.sid,
po->pppoe_pa.remote, po->pppoe_ifindex);
}
if (po->pppoe_dev) {
dev_put(po->pppoe_dev);
po->pppoe_dev = NULL;
}
write_unlock_bh(&pppoe_hash_lock);
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 net_device *dev;
struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
struct pppox_sock *po = pppox_sk(sk);
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) && sp->sa_addr.pppoe.sid)
goto end;
/* Check for already disconnected sockets, on attempts to disconnect */
error = -EALREADY;
if ((sk->sk_state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
goto end;
error = 0;
if (po->pppoe_pa.sid) {
pppox_unbind_sock(sk);
/* Delete the old binding */
delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote,po->pppoe_ifindex);
if(po->pppoe_dev)
dev_put(po->pppoe_dev);
memset(sk_pppox(po) + 1, 0,
sizeof(struct pppox_sock) - sizeof(struct sock));
sk->sk_state = PPPOX_NONE;
}
/* Don't re-bind if sid==0 */
if (sp->sa_addr.pppoe.sid != 0) {
dev = dev_get_by_name(sp->sa_addr.pppoe.dev);
error = -ENODEV;
if (!dev)
goto end;
po->pppoe_dev = dev;
po->pppoe_ifindex = dev->ifindex;
write_lock_bh(&pppoe_hash_lock);
if (!(dev->flags & IFF_UP)){
write_unlock_bh(&pppoe_hash_lock);
goto err_put;
}
memcpy(&po->pppoe_pa,
&sp->sa_addr.pppoe,
sizeof(struct pppoe_addr));
error = __set_item(po);
write_unlock_bh(&pppoe_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_channel(&po->chan);
if (error)
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 = 0;
int err = 0;
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(&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:;
};
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;
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;
lock_sock(sk);
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 = __constant_htons(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 hdr;
struct pppoe_hdr *ph;
int headroom = skb_headroom(skb);
int data_len = skb->len;
struct sk_buff *skb2;
if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
goto abort;
hdr.ver = 1;
hdr.type = 1;
hdr.code = 0;
hdr.sid = po->num;
hdr.length = htons(skb->len);
if (!dev)
goto abort;
/* Copy the skb if there is no space for the header. */
if (headroom < (sizeof(struct pppoe_hdr) + dev->hard_header_len)) {
skb2 = dev_alloc_skb(32+skb->len +
sizeof(struct pppoe_hdr) +
dev->hard_header_len);
if (skb2 == NULL)
goto abort;
skb_reserve(skb2, dev->hard_header_len + sizeof(struct pppoe_hdr));
skb_copy_from_linear_data(skb, skb_put(skb2, skb->len),
skb->len);
} else {
/* Make a clone so as to not disturb the original skb,
* give dev_queue_xmit something it can free.
*/
skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2 == NULL)
goto abort;
}
ph = (struct pppoe_hdr *) skb_push(skb2, sizeof(struct pppoe_hdr));
memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
skb2->protocol = __constant_htons(ETH_P_PPP_SES);
skb_reset_network_header(skb2);
skb2->dev = dev;
dev->hard_header(skb2, dev, ETH_P_PPP_SES,
po->pppoe_pa.remote, NULL, data_len);
/* We're transmitting skb2, and assuming that dev_queue_xmit
* will free it. The generic ppp layer however, is expecting
* that we give back 'skb' (not 'skb2') in case of failure,
* but free it in case of success.
*/
if (dev_queue_xmit(skb2) < 0)
goto abort;
kfree_skb(skb);
return 1;
abort:
return 0;
}
/************************************************************************
*
* 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 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) {
struct pppoe_hdr *ph = pppoe_hdr(skb);
const int len = ntohs(ph->length);
error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
if (error == 0)
error = 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 %02X:%02X:%02X:%02X:%02X:%02X %8s\n",
po->pppoe_pa.sid,
po->pppoe_pa.remote[0], po->pppoe_pa.remote[1],
po->pppoe_pa.remote[2], po->pppoe_pa.remote[3],
po->pppoe_pa.remote[4], po->pppoe_pa.remote[5], dev_name);
out:
return 0;
}
static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
{
struct pppox_sock *po;
int i = 0;
for (; i < PPPOE_HASH_SIZE; i++) {
po = item_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)
{
loff_t l = *pos;
read_lock_bh(&pppoe_hash_lock);
return l ? pppoe_get_idx(--l) : SEQ_START_TOKEN;
}
static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct pppox_sock *po;
++*pos;
if (v == SEQ_START_TOKEN) {
po = pppoe_get_idx(0);
goto out;
}
po = v;
if (po->next)
po = po->next;
else {
int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);
while (++hash < PPPOE_HASH_SIZE) {
po = item_hash_table[hash];
if (po)
break;
}
}
out:
return po;
}
static void pppoe_seq_stop(struct seq_file *seq, void *v)
{
read_unlock_bh(&pppoe_hash_lock);
}
static 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(file, &pppoe_seq_ops);
}
static const struct file_operations pppoe_seq_fops = {
.owner = THIS_MODULE,
.open = pppoe_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init pppoe_proc_init(void)
{
struct proc_dir_entry *p;
p = create_proc_entry("net/pppoe", S_IRUGO, NULL);
if (!p)
return -ENOMEM;
p->proc_fops = &pppoe_seq_fops;
return 0;
}
#else /* CONFIG_PROC_FS */
static inline int pppoe_proc_init(void) { return 0; }
#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 struct pppox_proto pppoe_proto = {
.create = pppoe_create,
.ioctl = pppoe_ioctl,
.owner = THIS_MODULE,
};
static int __init pppoe_init(void)
{
int err = proto_register(&pppoe_sk_proto, 0);
if (err)
goto out;
err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
if (err)
goto out_unregister_pppoe_proto;
err = pppoe_proc_init();
if (err)
goto out_unregister_pppox_proto;
dev_add_pack(&pppoes_ptype);
dev_add_pack(&pppoed_ptype);
register_netdevice_notifier(&pppoe_notifier);
out:
return err;
out_unregister_pppox_proto:
unregister_pppox_proto(PX_PROTO_OE);
out_unregister_pppoe_proto:
proto_unregister(&pppoe_sk_proto);
goto out;
}
static void __exit pppoe_exit(void)
{
unregister_pppox_proto(PX_PROTO_OE);
dev_remove_pack(&pppoes_ptype);
dev_remove_pack(&pppoed_ptype);
unregister_netdevice_notifier(&pppoe_notifier);
remove_proc_entry("net/pppoe", NULL);
proto_unregister(&pppoe_sk_proto);
}
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);
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