[Devel] Re: [RFC 4/4] net: ppp_generic - introduce net-namespace functionality
Cyrill Gorcunov
gorcunov at gmail.com
Sat Jan 10 01:28:30 PST 2009
[Cyrill Gorcunov - Sat, Jan 10, 2009 at 12:22:58PM +0300]
| [Cyrill Gorcunov - Fri, Jan 09, 2009 at 10:51:58PM +0300]
| | - Each namespace contain ppp channels and units separately
| | with appropriate locks
| |
| | CC: Paul Mackerras <paulus at samba.org>
| | Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
| ...
|
| Please ignore this one -- I forgot to update
| ppp_init while was porting the patch. Will
| fix.
|
| - Cyrill -
ok, here is an updated version
- Cyrill -
---
From: Cyrill Gorcunov <gorcunov at gmail.com>
Subecjt: [RFC] net: ppp_generic - introduce net-namespace functionality
- Each namespace contain ppp channels and units separately
with appropriate locks
CC: Paul Mackerras <paulus at samba.org>
Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
---
drivers/net/ppp_generic.c | 279 ++++++++++++++++++++++++++++++++--------------
1 file changed, 199 insertions(+), 80 deletions(-)
Index: linux-2.6.git/drivers/net/ppp_generic.c
===================================================================
--- linux-2.6.git.orig/drivers/net/ppp_generic.c
+++ linux-2.6.git/drivers/net/ppp_generic.c
@@ -49,6 +49,10 @@
#include <net/slhc_vj.h>
#include <asm/atomic.h>
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
#define PPP_VERSION "2.4.2"
/*
@@ -89,6 +93,8 @@ struct ppp_file {
#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
+struct ppp_net;
+
/*
* Data structure describing one ppp unit.
* A ppp unit corresponds to a ppp network interface device
@@ -131,6 +137,7 @@ struct ppp {
struct sock_filter *active_filter;/* filter for pkts to reset idle */
unsigned pass_len, active_len;
#endif /* CONFIG_PPP_FILTER */
+ struct net *ppp_net; /* the net we belong to */
};
/*
@@ -173,25 +180,36 @@ struct channel {
* channel.downl.
*/
-/*
- * all_ppp_mutex 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 DEFINE_MUTEX(all_ppp_mutex);
static atomic_t ppp_unit_count = ATOMIC_INIT(0);
-static DEFINE_IDR(ppp_units_idr);
+static atomic_t channel_count = ATOMIC_INIT(0);
/*
- * all_channels_lock protects all_channels and last_channel_index,
- * and the atomicity of find a channel and updating its file.refcnt
- * field.
+ * per net-namespace data for this module
*/
-static DEFINE_SPINLOCK(all_channels_lock);
-static LIST_HEAD(all_channels);
-static LIST_HEAD(new_channels);
-static int last_channel_index;
-static atomic_t channel_count = ATOMIC_INIT(0);
+static unsigned int ppp_net_id;
+struct ppp_net {
+ /* units to ppp mapping */
+ struct idr units_idr;
+
+ /* channels */
+ struct list_head all_channels;
+ struct list_head new_channels;
+ int last_channel_index;
+
+ /*
+ * all_ppp_mutex protects the units_idr mapping.
+ * It also ensures that finding a ppp unit in the units_idr
+ * map and updating its file.refcnt field is atomic.
+ */
+ struct mutex all_ppp_mutex;
+
+ /*
+ * all_channels_lock protects all_channels and
+ * last_channel_index, and the atomicity of find
+ * a channel and updating its file.refcnt field.
+ */
+ spinlock_t all_channels_lock;
+};
/* Get the PPP protocol number from a skb */
#define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
@@ -240,21 +258,28 @@ static void ppp_ccp_peek(struct ppp *ppp
static void ppp_ccp_closed(struct ppp *ppp);
static struct compressor *find_compressor(int type);
static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
-static struct ppp *ppp_create_interface(int unit, int *retp);
+static struct ppp *ppp_create_interface(struct net *net, 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);
+static struct channel *ppp_find_channel(struct net *net, int unit);
static int ppp_connect_channel(struct channel *pch, int unit);
static int ppp_disconnect_channel(struct channel *pch);
static void ppp_destroy_channel(struct channel *pch);
-static int unit_get(struct idr *p, void *ptr);
-static void unit_put(struct idr *p, int n);
-static void *unit_find(struct idr *p, int n);
+static int unit_get(struct net *net, void *ptr);
+static void unit_put(struct net *net, int n);
+static void *unit_find(struct net *net, int n);
static struct class *ppp_class;
+/* per net-namespace data */
+static inline struct ppp_net *ppp_pernet(struct net *net)
+{
+ BUG_ON(!net);
+
+ return net_generic(net, ppp_net_id);
+}
+
/* Translates a PPP protocol number to a NP index (NP == network protocol) */
static inline int proto_to_npindex(int proto)
{
@@ -343,6 +368,7 @@ static int ppp_open(struct inode *inode,
*/
if (!capable(CAP_NET_ADMIN))
return -EPERM;
+
return 0;
}
@@ -768,6 +794,7 @@ static int ppp_unattached_ioctl(struct p
int unit, err = -EFAULT;
struct ppp *ppp;
struct channel *chan;
+ struct ppp_net *pn;
int __user *p = (int __user *)arg;
lock_kernel();
@@ -776,7 +803,7 @@ static int ppp_unattached_ioctl(struct p
/* Create a new ppp unit */
if (get_user(unit, p))
break;
- ppp = ppp_create_interface(unit, &err);
+ ppp = ppp_create_interface(current->nsproxy->net_ns, unit, &err);
if (!ppp)
break;
file->private_data = &ppp->file;
@@ -791,29 +818,31 @@ static int ppp_unattached_ioctl(struct p
/* Attach to an existing ppp unit */
if (get_user(unit, p))
break;
- mutex_lock(&all_ppp_mutex);
+ pn = ppp_pernet(current->nsproxy->net_ns);
+ mutex_lock(&pn->all_ppp_mutex);
err = -ENXIO;
- ppp = ppp_find_unit(unit);
+ ppp = unit_find(current->nsproxy->net_ns, unit);
if (ppp) {
atomic_inc(&ppp->file.refcnt);
file->private_data = &ppp->file;
err = 0;
}
- mutex_unlock(&all_ppp_mutex);
+ mutex_unlock(&pn->all_ppp_mutex);
break;
case PPPIOCATTCHAN:
if (get_user(unit, p))
break;
- spin_lock_bh(&all_channels_lock);
+ pn = ppp_pernet(current->nsproxy->net_ns);
+ spin_lock_bh(&pn->all_channels_lock);
err = -ENXIO;
- chan = ppp_find_channel(unit);
+ chan = ppp_find_channel(current->nsproxy->net_ns, unit);
if (chan) {
atomic_inc(&chan->file.refcnt);
file->private_data = &chan->file;
err = 0;
}
- spin_unlock_bh(&all_channels_lock);
+ spin_unlock_bh(&pn->all_channels_lock);
break;
default:
@@ -833,6 +862,54 @@ static const struct file_operations ppp_
.release = ppp_release
};
+static __net_init int ppp_init_net(struct net *net)
+{
+ struct ppp_net *pn;
+ int err;
+
+ pn = kzalloc(sizeof(*pn), GFP_KERNEL);
+ if (!pn)
+ return -ENOMEM;
+
+ idr_init(&pn->units_idr);
+
+ INIT_LIST_HEAD(&pn->all_channels);
+ INIT_LIST_HEAD(&pn->new_channels);
+
+ mutex_init(&pn->all_ppp_mutex);
+ spin_lock_init(&pn->all_channels_lock);
+
+ err = net_assign_generic(net, ppp_net_id, pn);
+ if (err) {
+ kfree(pn);
+ return err;
+ }
+
+ try_module_get(THIS_MODULE);
+ return 0;
+}
+
+static __net_exit void ppp_exit_net(struct net *net)
+{
+ struct ppp_net *pn;
+
+ pn = net_generic(net, ppp_net_id);
+ idr_destroy(&pn->units_idr);
+ /*
+ * if someone has cached our net then
+ * further net_generic call will return NULL
+ */
+ net_assign_generic(net, ppp_net_id, NULL);
+ kfree(pn);
+
+ module_put(THIS_MODULE);
+}
+
+static __net_initdata struct pernet_operations ppp_net_ops = {
+ .init = ppp_init_net,
+ .exit = ppp_exit_net,
+};
+
#define PPP_MAJOR 108
/* Called at boot time if ppp is compiled into the kernel,
@@ -842,25 +919,36 @@ static int __init ppp_init(void)
int err;
printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
- err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
- if (!err) {
- ppp_class = class_create(THIS_MODULE, "ppp");
- if (IS_ERR(ppp_class)) {
- err = PTR_ERR(ppp_class);
- goto out_chrdev;
- }
- device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL,
- "ppp");
+
+ err = register_pernet_gen_device(&ppp_net_id, &ppp_net_ops);
+ if (err) {
+ printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
+ goto out;
}
-out:
- if (err)
+ err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
+ if (err) {
printk(KERN_ERR "failed to register PPP device (%d)\n", err);
- return err;
+ goto out_net;
+ }
+
+ ppp_class = class_create(THIS_MODULE, "ppp");
+ if (IS_ERR(ppp_class)) {
+ err = PTR_ERR(ppp_class);
+ goto out_chrdev;
+ }
+
+ /* not a big deal if we fail here :-) */
+ device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
+
+ return 0;
out_chrdev:
unregister_chrdev(PPP_MAJOR, "ppp");
- goto out;
+out_net:
+ unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
+out:
+ return err;
}
/*
@@ -1992,10 +2080,14 @@ int
ppp_register_channel(struct ppp_channel *chan)
{
struct channel *pch;
+ struct ppp_net *pn;
pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
if (!pch)
return -ENOMEM;
+
+ pn = ppp_pernet(current->nsproxy->net_ns);
+
pch->ppp = NULL;
pch->chan = chan;
chan->ppp = pch;
@@ -2007,11 +2099,11 @@ ppp_register_channel(struct ppp_channel
init_rwsem(&pch->chan_sem);
spin_lock_init(&pch->downl);
rwlock_init(&pch->upl);
- spin_lock_bh(&all_channels_lock);
- pch->file.index = ++last_channel_index;
- list_add(&pch->list, &new_channels);
+ spin_lock_bh(&pn->all_channels_lock);
+ pch->file.index = ++pn->last_channel_index;
+ list_add(&pch->list, &pn->new_channels);
atomic_inc(&channel_count);
- spin_unlock_bh(&all_channels_lock);
+ spin_unlock_bh(&pn->all_channels_lock);
return 0;
}
@@ -2052,11 +2144,17 @@ void
ppp_unregister_channel(struct ppp_channel *chan)
{
struct channel *pch = chan->ppp;
+ struct ppp_net *pn;
if (!pch)
return; /* should never happen */
chan->ppp = NULL;
+ if (pch->ppp->ppp_net)
+ pn = ppp_pernet(pch->ppp->ppp_net);
+ else
+ pn = ppp_pernet(current->nsproxy->net_ns);
+
/*
* This ensures that we have returned from any calls into the
* the channel's start_xmit or ioctl routine before we proceed.
@@ -2067,9 +2165,9 @@ ppp_unregister_channel(struct ppp_channe
spin_unlock_bh(&pch->downl);
up_write(&pch->chan_sem);
ppp_disconnect_channel(pch);
- spin_lock_bh(&all_channels_lock);
+ spin_lock_bh(&pn->all_channels_lock);
list_del(&pch->list);
- spin_unlock_bh(&all_channels_lock);
+ spin_unlock_bh(&pn->all_channels_lock);
pch->file.dead = 1;
wake_up_interruptible(&pch->file.rwait);
if (atomic_dec_and_test(&pch->file.refcnt))
@@ -2394,10 +2492,11 @@ ppp_get_stats(struct ppp *ppp, struct pp
* unit == -1 means allocate a new number.
*/
static struct ppp *
-ppp_create_interface(int unit, int *retp)
+ppp_create_interface(struct net *net, int unit, int *retp)
{
struct ppp *ppp;
- struct net_device *dev = NULL;
+ struct net_device *dev;
+ struct ppp_net *pn;
int ret = -ENOMEM;
int i;
@@ -2408,6 +2507,7 @@ ppp_create_interface(int unit, int *retp
ppp = netdev_priv(dev);
ppp->dev = dev;
ppp->mru = PPP_MRU;
+ ppp->ppp_net = net;
init_ppp_file(&ppp->file, INTERFACE);
ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
for (i = 0; i < NUM_NP; ++i)
@@ -2421,19 +2521,21 @@ ppp_create_interface(int unit, int *retp
#endif /* CONFIG_PPP_MULTILINK */
ret = -EEXIST;
- mutex_lock(&all_ppp_mutex);
+
+ pn = ppp_pernet(net);
+ mutex_lock(&pn->all_ppp_mutex);
if (unit < 0) {
- unit = unit_get(&ppp_units_idr, ppp);
+ unit = unit_get(net, ppp);
if (unit < 0) {
*retp = unit;
goto out2;
}
} else {
- if (unit_find(&ppp_units_idr, unit))
+ if (unit_find(net, unit))
goto out2; /* unit already exists */
else {
- /* darn, someone is cheating us? */
+ /* darn, someone is cheatting us? */
*retp = -EINVAL;
goto out2;
}
@@ -2445,20 +2547,20 @@ ppp_create_interface(int unit, int *retp
ret = register_netdev(dev);
if (ret != 0) {
- unit_put(&ppp_units_idr, unit);
+ unit_put(net, unit);
printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
dev->name, ret);
goto out2;
}
atomic_inc(&ppp_unit_count);
- mutex_unlock(&all_ppp_mutex);
+ mutex_unlock(&pn->all_ppp_mutex);
*retp = 0;
return ppp;
out2:
- mutex_unlock(&all_ppp_mutex);
+ mutex_unlock(&pn->all_ppp_mutex);
free_netdev(dev);
out1:
*retp = ret;
@@ -2484,7 +2586,9 @@ init_ppp_file(struct ppp_file *pf, int k
*/
static void ppp_shutdown_interface(struct ppp *ppp)
{
- mutex_lock(&all_ppp_mutex);
+ struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
+
+ mutex_lock(&pn->all_ppp_mutex);
/* This will call dev_close() for us. */
ppp_lock(ppp);
if (!ppp->closing) {
@@ -2494,11 +2598,11 @@ static void ppp_shutdown_interface(struc
} else
ppp_unlock(ppp);
- unit_put(&ppp_units_idr, ppp->file.index);
+ unit_put(ppp->ppp_net, ppp->file.index);
ppp->file.dead = 1;
ppp->owner = NULL;
wake_up_interruptible(&ppp->file.rwait);
- mutex_unlock(&all_ppp_mutex);
+ mutex_unlock(&pn->all_ppp_mutex);
}
/*
@@ -2542,16 +2646,6 @@ static void ppp_destroy_interface(struct
}
/*
- * Locate an existing ppp unit.
- * The caller should have locked the all_ppp_mutex.
- */
-static struct ppp *
-ppp_find_unit(int unit)
-{
- return unit_find(&ppp_units_idr, 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
@@ -2560,20 +2654,25 @@ ppp_find_unit(int unit)
* when we have a lot of channels in use.
*/
static struct channel *
-ppp_find_channel(int unit)
+ppp_find_channel(struct net *net, int unit)
{
struct channel *pch;
+ struct ppp_net *pn;
+
+ pn = ppp_pernet(net);
- list_for_each_entry(pch, &new_channels, list) {
+ list_for_each_entry(pch, &pn->new_channels, list) {
if (pch->file.index == unit) {
- list_move(&pch->list, &all_channels);
+ list_move(&pch->list, &pn->all_channels);
return pch;
}
}
- list_for_each_entry(pch, &all_channels, list) {
+
+ list_for_each_entry(pch, &pn->all_channels, list) {
if (pch->file.index == unit)
return pch;
}
+
return NULL;
}
@@ -2584,11 +2683,14 @@ static int
ppp_connect_channel(struct channel *pch, int unit)
{
struct ppp *ppp;
+ struct ppp_net *pn;
int ret = -ENXIO;
int hdrlen;
- mutex_lock(&all_ppp_mutex);
- ppp = ppp_find_unit(unit);
+ pn = ppp_pernet(current->nsproxy->net_ns);
+
+ mutex_lock(&pn->all_ppp_mutex);
+ ppp = unit_find(current->nsproxy->net_ns, unit);
if (!ppp)
goto out;
write_lock_bh(&pch->upl);
@@ -2612,7 +2714,7 @@ ppp_connect_channel(struct channel *pch,
outl:
write_unlock_bh(&pch->upl);
out:
- mutex_unlock(&all_ppp_mutex);
+ mutex_unlock(&pn->all_ppp_mutex);
return ret;
}
@@ -2669,7 +2771,7 @@ static void __exit ppp_cleanup(void)
unregister_chrdev(PPP_MAJOR, "ppp");
device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
class_destroy(ppp_class);
- idr_destroy(&ppp_units_idr);
+ unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
}
/*
@@ -2678,9 +2780,14 @@ static void __exit ppp_cleanup(void)
*/
/* get new free unit number and associate pointer with it */
-static int unit_get(struct idr *p, void *ptr)
+static int unit_get(struct net *net, void *ptr)
{
int unit, err;
+ struct ppp_net *pn;
+ struct idr *p;
+
+ pn = ppp_pernet(net);
+ p = &pn->units_idr;
again:
if (idr_pre_get(p, GFP_KERNEL) == 0) {
@@ -2696,14 +2803,26 @@ again:
}
/* put unit number back to a pool */
-static void unit_put(struct idr *p, int n)
+static void unit_put(struct net *net, int n)
{
+ struct ppp_net *pn;
+ struct idr *p;
+
+ pn = ppp_pernet(net);
+ p = &pn->units_idr;
+
idr_remove(p, n);
}
/* get pointer associated with the number */
-static void *unit_find(struct idr *p, int n)
+static void *unit_find(struct net *net, int n)
{
+ struct ppp_net *pn;
+ struct idr *p;
+
+ pn = ppp_pernet(net);
+ p = &pn->units_idr;
+
return idr_find(p, n);
}
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