* Fixes the deadlock and scheduling-in-interrupt problems in the
ppp_generic code and the async-tty and sync-tty PPP line
disciplines.
* Fixes a memory leak when packet decompression errors occur (fix from
Andrew Morton).
* Uses an efficient data structure to index the ppp units, reducing
the overhead when large numbers of ppp interfaces are used.
There is a small change to the API in that ppp_unregister_channel may
now only be called from process context, not from interrupt or softirq
context. The patch includes changes to pppoe.c and if_pppox.h from
Michal Ostrowski which make the pppoe code conform to this
requirement.
Dave, if this looks OK to you, could you pass it on to Linus?
Paul.
diff -urN linux-2.5.4-pre1/drivers/net/ppp_async.c linux/drivers/net/ppp_async.c
--- linux-2.5.4-pre1/drivers/net/ppp_async.c Mon Oct 1 05:26:07 2001
+++ linux/drivers/net/ppp_async.c Thu Feb 7 10:04:38 2002
@@ -17,7 +17,7 @@
* PPP driver, written by Michael Callahan and Al Longyear, and
* subsequently hacked by Paul Mackerras.
*
- * ==FILEVERSION 20000227==
+ * ==FILEVERSION 20020125==
*/
#include <linux/module.h>
@@ -33,7 +33,7 @@
#include <linux/init.h>
#include <asm/uaccess.h>
-#define PPP_VERSION "2.4.1"
+#define PPP_VERSION "2.4.2"
#define OBUFSIZE 256
@@ -62,6 +62,8 @@
struct sk_buff *rpkt;
int lcp_fcs;
+ atomic_t refcnt;
+ struct semaphore dead_sem;
struct ppp_channel chan; /* interface to generic ppp layer */
unsigned char obuf[OBUFSIZE];
};
@@ -108,6 +110,35 @@
*/
/*
+ * We have a potential race on dereferencing tty->disc_data,
+ * because the tty layer provides no locking at all - thus one
+ * cpu could be running ppp_asynctty_receive while another
+ * calls ppp_asynctty_close, which zeroes tty->disc_data and
+ * frees the memory that ppp_asynctty_receive is using. The best
+ * way to fix this is to use a rwlock in the tty struct, but for now
+ * we use a single global rwlock for all ttys in ppp line discipline.
+ */
+static rwlock_t disc_data_lock = RW_LOCK_UNLOCKED;
+
+static struct asyncppp *ap_get(struct tty_struct *tty)
+{
+ struct asyncppp *ap;
+
+ read_lock(&disc_data_lock);
+ ap = tty->disc_data;
+ if (ap != NULL)
+ atomic_inc(&ap->refcnt);
+ read_unlock(&disc_data_lock);
+ return ap;
+}
+
+static void ap_put(struct asyncppp *ap)
+{
+ if (atomic_dec_and_test(&ap->refcnt))
+ up(&ap->dead_sem);
+}
+
+/*
* Called when a tty is put into PPP line discipline.
*/
static int
@@ -135,6 +166,9 @@
ap->olim = ap->obuf;
ap->lcp_fcs = -1;
+ atomic_set(&ap->refcnt, 1);
+ init_MUTEX_LOCKED(&ap->dead_sem);
+
ap->chan.private = ap;
ap->chan.ops = &async_ops;
ap->chan.mtu = PPP_MRU;
@@ -155,19 +189,34 @@
/*
* Called when the tty is put into another line discipline
- * or it hangs up.
- * We assume that while we are in this routine, the tty layer
- * won't call any of the other line discipline entries for the
- * same tty.
+ * or it hangs up. We have to wait for any cpu currently
+ * executing in any of the other ppp_asynctty_* routines to
+ * finish before we can call ppp_unregister_channel and free
+ * the asyncppp struct. This routine must be called from
+ * process context, not interrupt or softirq context.
*/
static void
ppp_asynctty_close(struct tty_struct *tty)
{
- struct asyncppp *ap = tty->disc_data;
+ struct asyncppp *ap;
+ write_lock(&disc_data_lock);
+ ap = tty->disc_data;
+ tty->disc_data = 0;
+ write_unlock(&disc_data_lock);
if (ap == 0)
return;
- tty->disc_data = 0;
+
+ /*
+ * We have now ensured that nobody can start using ap from now
+ * on, but we have to wait for all existing users to finish.
+ * Note that ppp_unregister_channel ensures that no calls to
+ * our channel ops (i.e. ppp_async_send/ioctl) are in progress
+ * by the time it returns.
+ */
+ if (!atomic_dec_and_test(&ap->refcnt))
+ down(&ap->dead_sem);
+
ppp_unregister_channel(&ap->chan);
if (ap->rpkt != 0)
kfree_skb(ap->rpkt);
@@ -203,9 +252,11 @@
ppp_asynctty_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
- struct asyncppp *ap = tty->disc_data;
+ struct asyncppp *ap = ap_get(tty);
int err, val;
+ if (ap == 0)
+ return -ENXIO;
err = -EFAULT;
switch (cmd) {
case PPPIOCGCHAN:
@@ -251,6 +302,7 @@
err = -ENOIOCTLCMD;
}
+ ap_put(ap);
return err;
}
@@ -271,13 +323,14 @@
ppp_asynctty_receive(struct tty_struct *tty, const unsigned char *buf,
char *flags, int count)
{
- struct asyncppp *ap = tty->disc_data;
+ struct asyncppp *ap = ap_get(tty);
if (ap == 0)
return;
spin_lock_bh(&ap->recv_lock);
ppp_async_input(ap, buf, flags, count);
spin_unlock_bh(&ap->recv_lock);
+ ap_put(ap);
if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
&& tty->driver.unthrottle)
tty->driver.unthrottle(tty);
@@ -286,13 +339,14 @@
static void
ppp_asynctty_wakeup(struct tty_struct *tty)
{
- struct asyncppp *ap = tty->disc_data;
+ struct asyncppp *ap = ap_get(tty);
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
if (ap == 0)
return;
if (ppp_async_push(ap))
ppp_output_wakeup(&ap->chan);
+ ap_put(ap);
}
diff -urN linux-2.5.4-pre1/drivers/net/ppp_generic.c linux/drivers/net/ppp_generic.c
--- linux-2.5.4-pre1/drivers/net/ppp_generic.c Tue Jan 22 19:44:15 2002
+++ linux/drivers/net/ppp_generic.c Thu Feb 7 10:19:11 2002
@@ -1,7 +1,7 @@
/*
* Generic PPP layer for Linux.
*
- * Copyright 1999-2000 Paul Mackerras.
+ * Copyright 1999-2002 Paul Mackerras.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -19,7 +19,7 @@
* PPP driver, written by Michael Callahan and Al Longyear, and
* subsequently hacked by Paul Mackerras.
*
- * ==FILEVERSION 20000902==
+ * ==FILEVERSION 20020205==
*/
#include <linux/config.h>
@@ -43,10 +43,12 @@
#include <linux/tcp.h>
#include <linux/spinlock.h>
#include <linux/smp_lock.h>
+#include <linux/rwsem.h>
+#include <linux/stddef.h>
#include <net/slhc_vj.h>
#include <asm/atomic.h>
-#define PPP_VERSION "2.4.1"
+#define PPP_VERSION "2.4.2"
/*
* Network protocols we support.
@@ -75,11 +77,11 @@
wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
int hdrlen; /* space to leave for headers */
- struct list_head list; /* link in all_* list */
int index; /* interface unit / channel number */
+ int dead; /* unit/channel has been shut down */
};
-#define PF_TO_X(pf, X) ((X *)((char *)(pf)-(unsigned long)(&((X *)0)->file)))
+#define PF_TO_X(pf, X) ((X *)((char *)(pf) - offsetof(X, file)))
#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
@@ -93,26 +95,27 @@
* It can have 0 or more ppp channels connected to it.
*/
struct ppp {
- struct ppp_file file; /* stuff for read/write/poll */
- struct list_head channels; /* list of attached channels */
- int n_channels; /* how many channels are attached */
- spinlock_t rlock; /* lock for receive side */
- spinlock_t wlock; /* lock for transmit side */
- int mru; /* max receive unit */
- unsigned int flags; /* control bits */
- unsigned int xstate; /* transmit state bits */
- unsigned int rstate; /* receive state bits */
- int debug; /* debug flags */
+ struct ppp_file file; /* stuff for read/write/poll 0 */
+ struct file *owner; /* file that owns this unit 48 */
+ struct list_head channels; /* list of attached channels 4c */
+ int n_channels; /* how many channels are attached 54 */
+ spinlock_t rlock; /* lock for receive side 58 */
+ spinlock_t wlock; /* lock for transmit side 5c */
+ int mru; /* max receive unit 60 */
+ unsigned int flags; /* control bits 64 */
+ unsigned int xstate; /* transmit state bits 68 */
+ unsigned int rstate; /* receive state bits 6c */
+ int debug; /* debug flags 70 */
struct slcompress *vj; /* state for VJ header compression */
- enum NPmode npmode[NUM_NP]; /* what to do with each net proto */
- struct sk_buff *xmit_pending; /* a packet ready to go out */
- struct compressor *xcomp; /* transmit packet compressor */
- void *xc_state; /* its internal state */
- struct compressor *rcomp; /* receive decompressor */
- void *rc_state; /* its internal state */
- unsigned long last_xmit; /* jiffies when last pkt sent */
- unsigned long last_recv; /* jiffies when last pkt rcvd */
- struct net_device *dev; /* network interface device */
+ enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
+ struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
+ struct compressor *xcomp; /* transmit packet compressor 8c */
+ void *xc_state; /* its internal state 90 */
+ struct compressor *rcomp; /* receive decompressor 94 */
+ void *rc_state; /* its internal state 98 */
+ unsigned long last_xmit; /* jiffies when last pkt sent 9c */
+ unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
+ struct net_device *dev; /* network interface device a4 */
#ifdef CONFIG_PPP_MULTILINK
int nxchan; /* next channel to send something on */
u32 nxseq; /* next sequence number to send */
@@ -144,11 +147,13 @@
*/
struct channel {
struct ppp_file file; /* stuff for read/write/poll */
+ struct list_head list; /* link in all/new_channels list */
struct ppp_channel *chan; /* public channel data structure */
+ struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
spinlock_t downl; /* protects `chan', file.xq dequeue */
struct ppp *ppp; /* ppp unit we're connected to */
struct list_head clist; /* link in list of channels per unit */
- rwlock_t upl; /* protects `ppp' and `ulist' */
+ rwlock_t upl; /* protects `ppp' */
#ifdef CONFIG_PPP_MULTILINK
u8 avail; /* flag used in multilink stuff */
u8 had_frag; /* >= 1 fragments have been sent */
@@ -166,12 +171,35 @@
*/
/*
- * all_ppp_lock protects the all_ppp_units.
- * It also ensures that finding a ppp unit in the all_ppp_units list
+ * A cardmap represents a mapping from unsigned integers to pointers,
+ * and provides a fast "find lowest unused number" operation.
+ * It uses a broad (32-way) tree with a bitmap at each level.
+ * It is designed to be space-efficient for small numbers of entries
+ * and time-efficient for large numbers of entries.
+ */
+#define CARDMAP_ORDER 5
+#define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
+#define CARDMAP_MASK (CARDMAP_WIDTH - 1)
+
+struct cardmap {
+ int shift;
+ unsigned long inuse;
+ struct cardmap *parent;
+ void *ptr[CARDMAP_WIDTH];
+};
+static void *cardmap_get(struct cardmap *map, unsigned int nr);
+static void cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
+static unsigned int cardmap_find_first_free(struct cardmap *map);
+static void cardmap_destroy(struct cardmap **map);
+
+/*
+ * all_ppp_sem protects the all_ppp_units mapping.
+ * It also ensures that finding a ppp unit in the all_ppp_units map
* and updating its file.refcnt field is atomic.
*/
-static spinlock_t all_ppp_lock = SPIN_LOCK_UNLOCKED;
-static LIST_HEAD(all_ppp_units);
+static DECLARE_MUTEX(all_ppp_sem);
+static struct cardmap *all_ppp_units;
+static atomic_t ppp_unit_count = ATOMIC_INIT(0);
/*
* all_channels_lock protects all_channels and last_channel_index,
@@ -180,7 +208,9 @@
*/
static spinlock_t all_channels_lock = SPIN_LOCK_UNLOCKED;
static LIST_HEAD(all_channels);
+static LIST_HEAD(new_channels);
static int last_channel_index;
+static atomic_t channel_count = ATOMIC_INIT(0);
/* Get the PPP protocol number from a skb */
#define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
@@ -205,10 +235,6 @@
#define seq_after(a, b) ((s32)((a) - (b)) > 0)
/* Prototypes. */
-static ssize_t ppp_file_read(struct ppp_file *pf, struct file *file,
- char *buf, size_t count);
-static ssize_t ppp_file_write(struct ppp_file *pf, const char *buf,
- size_t count);
static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
unsigned int cmd, unsigned long arg);
static void ppp_xmit_process(struct ppp *ppp);
@@ -235,6 +261,7 @@
static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
static struct ppp *ppp_create_interface(int unit, int *retp);
static void init_ppp_file(struct ppp_file *pf, int kind);
+static void ppp_shutdown_interface(struct ppp *ppp);
static void ppp_destroy_interface(struct ppp *ppp);
static struct ppp *ppp_find_unit(int unit);
static struct channel *ppp_find_channel(int unit);
@@ -303,7 +330,6 @@
#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
ppp_xmit_unlock(ppp); } while (0)
-
/*
* /dev/ppp device routines.
* The /dev/ppp device is used by pppd to control the ppp unit.
@@ -323,10 +349,16 @@
static int ppp_release(struct inode *inode, struct file *file)
{
- struct ppp_file *pf = (struct ppp_file *) file->private_data;
+ struct ppp_file *pf = file->private_data;
+ struct ppp *ppp;
if (pf != 0) {
file->private_data = 0;
+ if (pf->kind == INTERFACE) {
+ ppp = PF_TO_PPP(pf);
+ if (file == ppp->owner)
+ ppp_shutdown_interface(ppp);
+ }
if (atomic_dec_and_test(&pf->refcnt)) {
switch (pf->kind) {
case INTERFACE:
@@ -344,30 +376,21 @@
static ssize_t ppp_read(struct file *file, char *buf,
size_t count, loff_t *ppos)
{
- struct ppp_file *pf = (struct ppp_file *) file->private_data;
-
- return ppp_file_read(pf, file, buf, count);
-}
-
-static ssize_t ppp_file_read(struct ppp_file *pf, struct file *file,
- char *buf, size_t count)
-{
+ struct ppp_file *pf = file->private_data;
DECLARE_WAITQUEUE(wait, current);
ssize_t ret;
struct sk_buff *skb = 0;
- ret = -ENXIO;
if (pf == 0)
- goto out; /* not currently attached */
-
+ return -ENXIO;
add_wait_queue(&pf->rwait, &wait);
- current->state = TASK_INTERRUPTIBLE;
for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
skb = skb_dequeue(&pf->rq);
if (skb)
break;
ret = 0;
- if (pf->kind == CHANNEL && PF_TO_CHANNEL(pf)->chan == 0)
+ if (pf->dead)
break;
ret = -EAGAIN;
if (file->f_flags & O_NONBLOCK)
@@ -377,7 +400,7 @@
break;
schedule();
}
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&pf->rwait, &wait);
if (skb == 0)
@@ -400,21 +423,12 @@
static ssize_t ppp_write(struct file *file, const char *buf,
size_t count, loff_t *ppos)
{
- struct ppp_file *pf = (struct ppp_file *) file->private_data;
-
- return ppp_file_write(pf, buf, count);
-}
-
-static ssize_t ppp_file_write(struct ppp_file *pf, const char *buf,
- size_t count)
-{
+ struct ppp_file *pf = file->private_data;
struct sk_buff *skb;
ssize_t ret;
- ret = -ENXIO;
if (pf == 0)
- goto out;
-
+ return -ENXIO;
ret = -ENOMEM;
skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
if (skb == 0)
@@ -446,7 +460,7 @@
/* No kernel lock - fine */
static unsigned int ppp_poll(struct file *file, poll_table *wait)
{
- struct ppp_file *pf = (struct ppp_file *) file->private_data;
+ struct ppp_file *pf = file->private_data;
unsigned int mask;
if (pf == 0)
@@ -455,18 +469,15 @@
mask = POLLOUT | POLLWRNORM;
if (skb_peek(&pf->rq) != 0)
mask |= POLLIN | POLLRDNORM;
- if (pf->kind == CHANNEL) {
- struct channel *pch = PF_TO_CHANNEL(pf);
- if (pch->chan == 0)
- mask |= POLLHUP;
- }
+ if (pf->dead)
+ mask |= POLLHUP;
return mask;
}
static int ppp_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
- struct ppp_file *pf = (struct ppp_file *) file->private_data;
+ struct ppp_file *pf = file->private_data;
struct ppp *ppp;
int err = -EFAULT, val, val2, i;
struct ppp_idle idle;
@@ -477,6 +488,33 @@
if (pf == 0)
return ppp_unattached_ioctl(pf, file, cmd, arg);
+ if (cmd == PPPIOCDETACH) {
+ /*
+ * We have to be careful here... if the file descriptor
+ * has been dup'd, we could have another process in the
+ * middle of a poll using the same file *, so we had
+ * better not free the interface data structures -
+ * instead we fail the ioctl. Even in this case, we
+ * shut down the interface if we are the owner of it.
+ * Actually, we should get rid of PPPIOCDETACH, userland
+ * (i.e. pppd) could achieve the same effect by closing
+ * this fd and reopening /dev/ppp.
+ */
+ err = -EINVAL;
+ if (pf->kind == INTERFACE) {
+ ppp = PF_TO_PPP(pf);
+ if (file == ppp->owner)
+ ppp_shutdown_interface(ppp);
+ }
+ if (atomic_read(&file->f_count) <= 2) {
+ ppp_release(inode, file);
+ err = 0;
+ } else
+ printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
+ atomic_read(&file->f_count));
+ return err;
+ }
+
if (pf->kind == CHANNEL) {
struct channel *pch = PF_TO_CHANNEL(pf);
struct ppp_channel *chan;
@@ -492,20 +530,13 @@
err = ppp_disconnect_channel(pch);
break;
- case PPPIOCDETACH:
- file->private_data = 0;
- if (atomic_dec_and_test(&pf->refcnt))
- ppp_destroy_channel(pch);
- err = 0;
- break;
-
default:
- spin_lock_bh(&pch->downl);
+ down_read(&pch->chan_sem);
chan = pch->chan;
err = -ENOTTY;
if (chan && chan->ops->ioctl)
err = chan->ops->ioctl(chan, cmd, arg);
- spin_unlock_bh(&pch->downl);
+ up_read(&pch->chan_sem);
}
return err;
}
@@ -518,13 +549,6 @@
ppp = PF_TO_PPP(pf);
switch (cmd) {
- case PPPIOCDETACH:
- file->private_data = 0;
- if (atomic_dec_and_test(&pf->refcnt))
- ppp_destroy_interface(ppp);
- err = 0;
- break;
-
case PPPIOCSMRU:
if (get_user(val, (int *) arg))
break;
@@ -675,6 +699,7 @@
default:
err = -ENOTTY;
}
+
return err;
}
@@ -694,6 +719,7 @@
if (ppp == 0)
break;
file->private_data = &ppp->file;
+ ppp->owner = file;
err = -EFAULT;
if (put_user(ppp->file.index, (int *) arg))
break;
@@ -704,31 +730,29 @@
/* Attach to an existing ppp unit */
if (get_user(unit, (int *) arg))
break;
- spin_lock(&all_ppp_lock);
+ down(&all_ppp_sem);
+ err = -ENXIO;
ppp = ppp_find_unit(unit);
- if (ppp != 0)
+ if (ppp != 0) {
atomic_inc(&ppp->file.refcnt);
- spin_unlock(&all_ppp_lock);
- err = -ENXIO;
- if (ppp == 0)
- break;
- file->private_data = &ppp->file;
- err = 0;
+ file->private_data = &ppp->file;
+ err = 0;
+ }
+ up(&all_ppp_sem);
break;
case PPPIOCATTCHAN:
if (get_user(unit, (int *) arg))
break;
spin_lock_bh(&all_channels_lock);
+ err = -ENXIO;
chan = ppp_find_channel(unit);
- if (chan != 0)
+ if (chan != 0) {
atomic_inc(&chan->file.refcnt);
+ file->private_data = &chan->file;
+ err = 0;
+ }
spin_unlock_bh(&all_channels_lock);
- err = -ENXIO;
- if (chan == 0)
- break;
- file->private_data = &chan->file;
- err = 0;
break;
default:
@@ -905,15 +929,16 @@
struct sk_buff *skb;
ppp_xmit_lock(ppp);
- ppp_push(ppp);
- while (ppp->xmit_pending == 0
- && (skb = skb_dequeue(&ppp->file.xq)) != 0)
- ppp_send_frame(ppp, skb);
- /* If there's no work left to do, tell the core net
- code that we can accept some more. */
- if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0
- && ppp->dev != 0)
- netif_wake_queue(ppp->dev);
+ if (ppp->dev != 0) {
+ ppp_push(ppp);
+ while (ppp->xmit_pending == 0
+ && (skb = skb_dequeue(&ppp->file.xq)) != 0)
+ ppp_send_frame(ppp, skb);
+ /* If there's no work left to do, tell the core net
+ code that we can accept some more. */
+ if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
+ netif_wake_queue(ppp->dev);
+ }
ppp_xmit_unlock(ppp);
}
@@ -1526,6 +1551,7 @@
error indication. */
if (len == DECOMP_FATALERROR)
ppp->rstate |= SC_DC_FERROR;
+ kfree_skb(ns);
goto err;
}
@@ -1797,7 +1823,7 @@
{
struct channel *pch;
- pch = kmalloc(sizeof(struct channel), GFP_ATOMIC);
+ pch = kmalloc(sizeof(struct channel), GFP_KERNEL);
if (pch == 0)
return -ENOMEM;
memset(pch, 0, sizeof(struct channel));
@@ -1809,11 +1835,13 @@
#ifdef CONFIG_PPP_MULTILINK
pch->lastseq = -1;
#endif /* CONFIG_PPP_MULTILINK */
+ init_rwsem(&pch->chan_sem);
spin_lock_init(&pch->downl);
pch->upl = RW_LOCK_UNLOCKED;
spin_lock_bh(&all_channels_lock);
pch->file.index = ++last_channel_index;
- list_add(&pch->file.list, &all_channels);
+ list_add(&pch->list, &new_channels);
+ atomic_inc(&channel_count);
spin_unlock_bh(&all_channels_lock);
MOD_INC_USE_COUNT;
return 0;
@@ -1826,7 +1854,9 @@
{
struct channel *pch = chan->ppp;
- return pch->file.index;
+ if (pch != 0)
+ return pch->file.index;
+ return -1;
}
/*
@@ -1848,7 +1878,7 @@
/*
* Disconnect a channel from the generic layer.
- * This can be called from mainline or BH/softirq level.
+ * This must be called in process context.
*/
void
ppp_unregister_channel(struct ppp_channel *chan)
@@ -1863,14 +1893,17 @@
* This ensures that we have returned from any calls into the
* the channel's start_xmit or ioctl routine before we proceed.
*/
+ down_write(&pch->chan_sem);
spin_lock_bh(&pch->downl);
pch->chan = 0;
spin_unlock_bh(&pch->downl);
+ up_write(&pch->chan_sem);
ppp_disconnect_channel(pch);
- wake_up_interruptible(&pch->file.rwait);
spin_lock_bh(&all_channels_lock);
- list_del(&pch->file.list);
+ list_del(&pch->list);
spin_unlock_bh(&all_channels_lock);
+ pch->file.dead = 1;
+ wake_up_interruptible(&pch->file.rwait);
if (atomic_dec_and_test(&pch->file.refcnt))
ppp_destroy_channel(pch);
MOD_DEC_USE_COUNT;
@@ -1927,20 +1960,21 @@
#endif /* CONFIG_KMOD */
if (cp == 0)
goto out;
+ /*
+ * XXX race: the compressor module could get unloaded between
+ * here and when we do the comp_alloc or decomp_alloc call below.
+ */
err = -ENOBUFS;
if (data.transmit) {
- ppp_xmit_lock(ppp);
- ppp->xstate &= ~SC_COMP_RUN;
- if (ppp->xc_state != 0) {
- ppp->xcomp->comp_free(ppp->xc_state);
- ppp->xc_state = 0;
- }
- ppp_xmit_unlock(ppp);
-
state = cp->comp_alloc(ccp_option, data.length);
if (state != 0) {
ppp_xmit_lock(ppp);
+ ppp->xstate &= ~SC_COMP_RUN;
+ if (ppp->xc_state != 0) {
+ ppp->xcomp->comp_free(ppp->xc_state);
+ ppp->xc_state = 0;
+ }
ppp->xcomp = cp;
ppp->xc_state = state;
ppp_xmit_unlock(ppp);
@@ -1948,17 +1982,14 @@
}
} else {
- ppp_recv_lock(ppp);
- ppp->rstate &= ~SC_DECOMP_RUN;
- if (ppp->rc_state != 0) {
- ppp->rcomp->decomp_free(ppp->rc_state);
- ppp->rc_state = 0;
- }
- ppp_recv_unlock(ppp);
-
state = cp->decomp_alloc(ccp_option, data.length);
if (state != 0) {
ppp_recv_lock(ppp);
+ ppp->rstate &= ~SC_DECOMP_RUN;
+ if (ppp->rc_state != 0) {
+ ppp->rcomp->decomp_free(ppp->rc_state);
+ ppp->rc_state = 0;
+ }
ppp->rcomp = cp;
ppp->rc_state = state;
ppp_recv_unlock(ppp);
@@ -2191,39 +2222,27 @@
ppp_create_interface(int unit, int *retp)
{
struct ppp *ppp;
- struct net_device *dev;
- struct list_head *list;
- int last_unit = -1;
- int ret = -EEXIST;
+ struct net_device *dev = NULL;
+ int ret = -ENOMEM;
int i;
- spin_lock(&all_ppp_lock);
- list = &all_ppp_units;
- while ((list = list->next) != &all_ppp_units) {
- ppp = list_entry(list, struct ppp, file.list);
- if ((unit < 0 && ppp->file.index > last_unit + 1)
- || (unit >= 0 && unit < ppp->file.index))
- break;
- if (unit == ppp->file.index)
- goto out; /* unit already exists */
- last_unit = ppp->file.index;
- }
- if (unit < 0)
- unit = last_unit + 1;
-
- /* Create a new ppp structure and link it before `list'. */
- ret = -ENOMEM;
- ppp = kmalloc(sizeof(struct ppp), GFP_ATOMIC);
+ ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL);
if (ppp == 0)
- goto out;
+ goto err;
+ dev = kmalloc(sizeof(struct net_device), GFP_KERNEL);
+ if (dev == 0)
+ goto err;
memset(ppp, 0, sizeof(struct ppp));
- dev = kmalloc(sizeof(struct net_device), GFP_ATOMIC);
- if (dev == 0) {
- kfree(ppp);
- goto out;
- }
memset(dev, 0, sizeof(struct net_device));
+ ret = -EEXIST;
+ down(&all_ppp_sem);
+ if (unit < 0)
+ unit = cardmap_find_first_free(all_ppp_units);
+ else if (cardmap_get(all_ppp_units, unit) != NULL)
+ goto err_unlock; /* unit already exists */
+
+ /* Initialize the new ppp unit */
ppp->file.index = unit;
ppp->mru = PPP_MRU;
init_ppp_file(&ppp->file, INTERFACE);
@@ -2248,19 +2267,26 @@
ret = register_netdevice(dev);
rtnl_unlock();
if (ret != 0) {
- printk(KERN_ERR "PPP: couldn't register device (%d)\n", ret);
- kfree(dev);
- kfree(ppp);
- goto out;
+ printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
+ dev->name, ret);
+ goto err_unlock;
}
- list_add(&ppp->file.list, list->prev);
- out:
- spin_unlock(&all_ppp_lock);
- *retp = ret;
- if (ret != 0)
- ppp = 0;
+ atomic_inc(&ppp_unit_count);
+ cardmap_set(&all_ppp_units, unit, ppp);
+ up(&all_ppp_sem);
+ *retp = 0;
return ppp;
+
+ err_unlock:
+ up(&all_ppp_sem);
+ err:
+ *retp = ret;
+ if (ppp)
+ kfree(ppp);
+ if (dev)
+ kfree(dev);
+ return NULL;
}
/*
@@ -2277,19 +2303,48 @@
}
/*
- * Free up all the resources used by a ppp interface unit.
+ * Take down a ppp interface unit - called when the owning file
+ * (the one that created the unit) is closed or detached.
*/
-static void ppp_destroy_interface(struct ppp *ppp)
+static void ppp_shutdown_interface(struct ppp *ppp)
{
struct net_device *dev;
- int n_channels ;
-
- spin_lock(&all_ppp_lock);
- list_del(&ppp->file.list);
- /* Last fd open to this ppp unit is being closed or detached:
- mark the interface down, free the ppp unit */
+ down(&all_ppp_sem);
ppp_lock(ppp);
+ dev = ppp->dev;
+ ppp->dev = 0;
+ ppp_unlock(ppp);
+ if (dev) {
+ rtnl_lock();
+ dev_close(dev);
+ unregister_netdevice(dev);
+ rtnl_unlock();
+ }
+ cardmap_set(&all_ppp_units, ppp->file.index, NULL);
+ ppp->file.dead = 1;
+ ppp->owner = NULL;
+ wake_up_interruptible(&ppp->file.rwait);
+ up(&all_ppp_sem);
+}
+
+/*
+ * Free the memory used by a ppp unit. This is only called once
+ * there are no channels connected to the unit and no file structs
+ * that reference the unit.
+ */
+static void ppp_destroy_interface(struct ppp *ppp)
+{
+ atomic_dec(&ppp_unit_count);
+
+ if (!ppp->file.dead || ppp->n_channels) {
+ /* "can't happen" */
+ printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
+ "n_channels=%d !\n", ppp, ppp->file.dead,
+ ppp->n_channels);
+ return;
+ }
+
ppp_ccp_closed(ppp);
if (ppp->vj) {
slhc_free(ppp->vj);
@@ -2310,52 +2365,27 @@
ppp->active_filter.filter = 0;
}
#endif /* CONFIG_PPP_FILTER */
- dev = ppp->dev;
- ppp->dev = 0;
- n_channels = ppp->n_channels ;
- ppp_unlock(ppp);
-
- if (dev) {
- rtnl_lock();
- dev_close(dev);
- unregister_netdevice(dev);
- rtnl_unlock();
- }
- /*
- * We can't acquire any new channels (since we have the
- * all_ppp_lock) so if n_channels is 0, we can free the
- * ppp structure. Otherwise we leave it around until the
- * last channel disconnects from it.
- */
- if (n_channels == 0)
- kfree(ppp);
-
- spin_unlock(&all_ppp_lock);
+ kfree(ppp);
}
/*
* Locate an existing ppp unit.
- * The caller should have locked the all_ppp_lock.
+ * The caller should have locked the all_ppp_sem.
*/
static struct ppp *
ppp_find_unit(int unit)
{
- struct ppp *ppp;
- struct list_head *list;
-
- list = &all_ppp_units;
- while ((list = list->next) != &all_ppp_units) {
- ppp = list_entry(list, struct ppp, file.list);
- if (ppp->file.index == unit)
- return ppp;
- }
- return 0;
+ return cardmap_get(all_ppp_units, unit);
}
/*
* Locate an existing ppp channel.
* The caller should have locked the all_channels_lock.
+ * First we look in the new_channels list, then in the
+ * all_channels list. If found in the new_channels list,
+ * we move it to the all_channels list. This is for speed
+ * when we have a lot of channels in use.
*/
static struct channel *
ppp_find_channel(int unit)
@@ -2363,9 +2393,18 @@
struct channel *pch;
struct list_head *list;
+ list = &new_channels;
+ while ((list = list->next) != &new_channels) {
+ pch = list_entry(list, struct channel, list);
+ if (pch->file.index == unit) {
+ list_del(&pch->list);
+ list_add(&pch->list, &all_channels);
+ return pch;
+ }
+ }
list = &all_channels;
while ((list = list->next) != &all_channels) {
- pch = list_entry(list, struct channel, file.list);
+ pch = list_entry(list, struct channel, list);
if (pch->file.index == unit)
return pch;
}
@@ -2382,19 +2421,16 @@
int ret = -ENXIO;
int hdrlen;
- spin_lock(&all_ppp_lock);
+ down(&all_ppp_sem);
ppp = ppp_find_unit(unit);
if (ppp == 0)
goto out;
write_lock_bh(&pch->upl);
ret = -EINVAL;
if (pch->ppp != 0)
- goto outwl;
- ppp_lock(ppp);
- spin_lock_bh(&pch->downl);
- if (pch->chan == 0) /* need to check this?? */
- goto outr;
+ goto outl;
+ ppp_lock(ppp);
if (pch->file.hdrlen > ppp->file.hdrlen)
ppp->file.hdrlen = pch->file.hdrlen;
hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
@@ -2403,15 +2439,14 @@
list_add_tail(&pch->clist, &ppp->channels);
++ppp->n_channels;
pch->ppp = ppp;
+ atomic_inc(&ppp->file.refcnt);
+ ppp_unlock(ppp);
ret = 0;
- outr:
- spin_unlock_bh(&pch->downl);
- ppp_unlock(ppp);
- outwl:
+ outl:
write_unlock_bh(&pch->upl);
out:
- spin_unlock(&all_ppp_lock);
+ up(&all_ppp_sem);
return ret;
}
@@ -2423,25 +2458,21 @@
{
struct ppp *ppp;
int err = -EINVAL;
- int dead;
write_lock_bh(&pch->upl);
ppp = pch->ppp;
+ pch->ppp = NULL;
+ write_unlock_bh(&pch->upl);
if (ppp != 0) {
/* remove it from the ppp unit's list */
- pch->ppp = NULL;
ppp_lock(ppp);
list_del(&pch->clist);
--ppp->n_channels;
- dead = ppp->dev == 0 && ppp->n_channels == 0;
ppp_unlock(ppp);
- if (dead)
- /* Last disconnect from a ppp unit
- that is already dead: free it. */
- kfree(ppp);
+ if (atomic_dec_and_test(&ppp->file.refcnt))
+ ppp_destroy_interface(ppp);
err = 0;
}
- write_unlock_bh(&pch->upl);
return err;
}
@@ -2450,6 +2481,14 @@
*/
static void ppp_destroy_channel(struct channel *pch)
{
+ atomic_dec(&channel_count);
+
+ if (!pch->file.dead) {
+ /* "can't happen" */
+ printk(KERN_ERR "ppp: destroying undead channel %p !\n",
+ pch);
+ return;
+ }
skb_queue_purge(&pch->file.xq);
skb_queue_purge(&pch->file.rq);
kfree(pch);
@@ -2458,12 +2497,123 @@
static void __exit ppp_cleanup(void)
{
/* should never happen */
- if (!list_empty(&all_ppp_units) || !list_empty(&all_channels))
+ if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
printk(KERN_ERR "PPP: removing module but units remain!\n");
+ cardmap_destroy(&all_ppp_units);
if (devfs_unregister_chrdev(PPP_MAJOR, "ppp") != 0)
printk(KERN_ERR "PPP: failed to unregister PPP device\n");
devfs_unregister(devfs_handle);
}
+
+/*
+ * Cardmap implementation.
+ */
+static void *cardmap_get(struct cardmap *map, unsigned int nr)
+{
+ struct cardmap *p;
+ int i;
+
+ for (p = map; p != NULL; ) {
+ if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
+ return NULL;
+ if (p->shift == 0)
+ return p->ptr[i];
+ nr &= ~(CARDMAP_MASK << p->shift);
+ p = p->ptr[i];
+ }
+ return NULL;
+}
+
+static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
+{
+ struct cardmap *p;
+ int i;
+
+ p = *pmap;
+ if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
+ do {
+ /* need a new top level */
+ struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
+ memset(np, 0, sizeof(*np));
+ np->ptr[0] = p;
+ if (p != NULL) {
+ np->shift = p->shift + CARDMAP_ORDER;
+ p->parent = np;
+ } else
+ np->shift = 0;
+ p = np;
+ } while ((nr >> p->shift) >= CARDMAP_WIDTH);
+ *pmap = p;
+ }
+ while (p->shift > 0) {
+ i = (nr >> p->shift) & CARDMAP_MASK;
+ if (p->ptr[i] == NULL) {
+ struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
+ memset(np, 0, sizeof(*np));
+ np->shift = p->shift - CARDMAP_ORDER;
+ np->parent = p;
+ p->ptr[i] = np;
+ }
+ if (ptr == NULL)
+ clear_bit(i, &p->inuse);
+ p = p->ptr[i];
+ }
+ i = nr & CARDMAP_MASK;
+ p->ptr[i] = ptr;
+ if (ptr != NULL)
+ set_bit(i, &p->inuse);
+ else
+ clear_bit(i, &p->inuse);
+}
+
+static unsigned int cardmap_find_first_free(struct cardmap *map)
+{
+ struct cardmap *p;
+ unsigned int nr = 0;
+ int i;
+
+ if ((p = map) == NULL)
+ return 0;
+ for (;;) {
+ i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
+ if (i >= CARDMAP_WIDTH) {
+ if (p->parent == NULL)
+ return CARDMAP_WIDTH << p->shift;
+ p = p->parent;
+ i = (nr >> p->shift) & CARDMAP_MASK;
+ set_bit(i, &p->inuse);
+ continue;
+ }
+ nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
+ if (p->shift == 0 || p->ptr[i] == NULL)
+ return nr;
+ p = p->ptr[i];
+ }
+}
+
+static void cardmap_destroy(struct cardmap **pmap)
+{
+ struct cardmap *p, *np;
+ int i;
+
+ for (p = *pmap; p != NULL; p = np) {
+ if (p->shift != 0) {
+ for (i = 0; i < CARDMAP_WIDTH; ++i)
+ if (p->ptr[i] != NULL)
+ break;
+ if (i < CARDMAP_WIDTH) {
+ np = p->ptr[i];
+ p->ptr[i] = NULL;
+ continue;
+ }
+ }
+ np = p->parent;
+ kfree(p);
+ }
+ *pmap = NULL;
+}
+
+/* Module/initialization stuff */
module_init(ppp_init);
module_exit(ppp_cleanup);
diff -urN linux-2.5.4-pre1/drivers/net/ppp_synctty.c linux/drivers/net/ppp_synctty.c
--- linux-2.5.4-pre1/drivers/net/ppp_synctty.c Fri Oct 12 04:17:22 2001
+++ linux/drivers/net/ppp_synctty.c Thu Feb 7 10:04:38 2002
@@ -25,11 +25,11 @@
* the generic PPP layer to give it frames to send and to process
* received frames. It implements the PPP line discipline.
*
- * Part of the code in this driver was inspired by the old sync-only
+ * Part of the code in this driver was inspired by the old async-only
* PPP driver, written by Michael Callahan and Al Longyear, and
* subsequently hacked by Paul Mackerras.
*
- * ==FILEVERSION 20000322==
+ * ==FILEVERSION 20020125==
*/
#include <linux/module.h>
@@ -41,10 +41,12 @@
#include <linux/ppp_defs.h>
#include <linux/if_ppp.h>
#include <linux/ppp_channel.h>
+#include <linux/spinlock.h>
#include <linux/init.h>
#include <asm/uaccess.h>
+#include <asm/semaphore.h>
-#define PPP_VERSION "2.4.1"
+#define PPP_VERSION "2.4.2"
/* Structure for storing local state. */
struct syncppp {
@@ -65,6 +67,8 @@
struct sk_buff *rpkt;
+ atomic_t refcnt;
+ struct semaphore dead_sem;
struct ppp_channel chan; /* interface to generic ppp layer */
};
@@ -161,7 +165,36 @@
*/
/*
- * Called when a tty is put into line discipline.
+ * We have a potential race on dereferencing tty->disc_data,
+ * because the tty layer provides no locking at all - thus one
+ * cpu could be running ppp_synctty_receive while another
+ * calls ppp_synctty_close, which zeroes tty->disc_data and
+ * frees the memory that ppp_synctty_receive is using. The best
+ * way to fix this is to use a rwlock in the tty struct, but for now
+ * we use a single global rwlock for all ttys in ppp line discipline.
+ */
+static rwlock_t disc_data_lock = RW_LOCK_UNLOCKED;
+
+static struct syncppp *sp_get(struct tty_struct *tty)
+{
+ struct syncppp *ap;
+
+ read_lock(&disc_data_lock);
+ ap = tty->disc_data;
+ if (ap != NULL)
+ atomic_inc(&ap->refcnt);
+ read_unlock(&disc_data_lock);
+ return ap;
+}
+
+static void sp_put(struct syncppp *ap)
+{
+ if (atomic_dec_and_test(&ap->refcnt))
+ up(&ap->dead_sem);
+}
+
+/*
+ * Called when a tty is put into sync-PPP line discipline.
*/
static int
ppp_sync_open(struct tty_struct *tty)
@@ -185,6 +218,9 @@
ap->xaccm[3] = 0x60000000U;
ap->raccm = ~0U;
+ atomic_set(&ap->refcnt, 1);
+ init_MUTEX_LOCKED(&ap->dead_sem);
+
ap->chan.private = ap;
ap->chan.ops = &sync_ops;
ap->chan.mtu = PPP_MRU;
@@ -206,16 +242,34 @@
/*
* Called when the tty is put into another line discipline
- * (or it hangs up).
+ * or it hangs up. We have to wait for any cpu currently
+ * executing in any of the other ppp_synctty_* routines to
+ * finish before we can call ppp_unregister_channel and free
+ * the syncppp struct. This routine must be called from
+ * process context, not interrupt or softirq context.
*/
static void
ppp_sync_close(struct tty_struct *tty)
{
- struct syncppp *ap = tty->disc_data;
+ struct syncppp *ap;
+ write_lock(&disc_data_lock);
+ ap = tty->disc_data;
+ tty->disc_data = 0;
+ write_unlock(&disc_data_lock);
if (ap == 0)
return;
- tty->disc_data = 0;
+
+ /*
+ * We have now ensured that nobody can start using ap from now
+ * on, but we have to wait for all existing users to finish.
+ * Note that ppp_unregister_channel ensures that no calls to
+ * our channel ops (i.e. ppp_sync_send/ioctl) are in progress
+ * by the time it returns.
+ */
+ if (!atomic_dec_and_test(&ap->refcnt))
+ down(&ap->dead_sem);
+
ppp_unregister_channel(&ap->chan);
if (ap->rpkt != 0)
kfree_skb(ap->rpkt);
@@ -251,9 +305,11 @@
ppp_synctty_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
- struct syncppp *ap = tty->disc_data;
+ struct syncppp *ap = sp_get(tty);
int err, val;
+ if (ap == 0)
+ return -ENXIO;
err = -EFAULT;
switch (cmd) {
case PPPIOCGCHAN:
@@ -299,6 +355,7 @@
err = -ENOIOCTLCMD;
}
+ sp_put(ap);
return err;
}
@@ -319,13 +376,14 @@
ppp_sync_receive(struct tty_struct *tty, const unsigned char *buf,
char *flags, int count)
{
- struct syncppp *ap = tty->disc_data;
+ struct syncppp *ap = sp_get(tty);
if (ap == 0)
return;
spin_lock_bh(&ap->recv_lock);
ppp_sync_input(ap, buf, flags, count);
spin_unlock_bh(&ap->recv_lock);
+ sp_put(ap);
if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
&& tty->driver.unthrottle)
tty->driver.unthrottle(tty);
@@ -334,13 +392,14 @@
static void
ppp_sync_wakeup(struct tty_struct *tty)
{
- struct syncppp *ap = tty->disc_data;
+ struct syncppp *ap = sp_get(tty);
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
if (ap == 0)
return;
if (ppp_sync_push(ap))
ppp_output_wakeup(&ap->chan);
+ sp_put(ap);
}
diff -urN linux-2.5.4-pre1/drivers/net/pppoe.c linux/drivers/net/pppoe.c
--- linux-2.5.4-pre1/drivers/net/pppoe.c Sat Nov 10 09:02:24 2001
+++ linux/drivers/net/pppoe.c Thu Feb 7 10:04:38 2002
@@ -5,7 +5,7 @@
* PPPoE --- PPP over Ethernet (RFC 2516)
*
*
- * Version: 0.6.9
+ * Version: 0.6.10
*
* 030700 : Fixed connect logic to allow for disconnect.
* 270700 : Fixed potential SMP problems; we must protect against
@@ -31,6 +31,9 @@
* 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.
*
* Author: Michal Ostrowski <mostrows@speakeasy.net>
* Contributors:
@@ -273,10 +276,10 @@
lock_sock(sk);
- if (sk->state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
+ if (sk->state & (PPPOX_CONNECTED|PPPOX_BOUND)){
pppox_unbind_sock(sk);
dev_put(dev);
- sk->state = PPPOX_DEAD;
+ sk->state = PPPOX_ZOMBIE;
sk->state_change(sk);
}
@@ -439,8 +442,10 @@
* one socket family type, we cannot (easily) distinguish
* what kind of SKB it is during backlog rcv.
*/
- if (sk->lock.users == 0)
+ if (sk->lock.users == 0) {
+ sk->state = PPPOX_ZOMBIE;
pppox_unbind_sock(sk);
+ }
bh_unlock_sock(sk);
sock_put(sk);
@@ -722,7 +727,7 @@
struct pppox_opt *relay_po;
err = -EBUSY;
- if (sk->state & PPPOX_BOUND)
+ if (sk->state & (PPPOX_BOUND|PPPOX_ZOMBIE|PPPOX_DEAD))
break;
err = -ENOTCONN;
diff -urN linux-2.5.4-pre1/include/linux/if_pppox.h linux/include/linux/if_pppox.h
--- linux-2.5.4-pre1/include/linux/if_pppox.h Fri Nov 23 06:47:14 2001
+++ linux/include/linux/if_pppox.h Thu Feb 7 10:04:38 2002
@@ -126,13 +126,14 @@
extern int pppox_channel_ioctl(struct ppp_channel *pc, unsigned int cmd,
unsigned long arg);
-/* PPPoE socket states */
+/* PPPoX socket states */
enum {
PPPOX_NONE = 0, /* initial state */
PPPOX_CONNECTED = 1, /* connection established ==TCP_ESTABLISHED */
PPPOX_BOUND = 2, /* bound to ppp device */
PPPOX_RELAY = 4, /* forwarding is enabled */
- PPPOX_DEAD = 8
+ PPPOX_ZOMBIE = 8, /* dead, but still bound to ppp device */
+ PPPOX_DEAD = 16 /* dead, useless, please clean me up!*/
};
extern struct ppp_channel_ops pppoe_chan_ops;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/