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net: pppol2tp - introduce net-namespace functionality
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- Each tunnel and appropriate lock are inside own namespace now.
- pppox code allows to create per-namespace sockets for
  both PX_PROTO_OE and PX_PROTO_OL2TP protocols. Actually since
  now pppox_create support net-namespaces new PPPo... protocols
  (if they ever will be) should support net-namespace too otherwise
  explicit check for &init_net would be needed.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Cyrill Gorcunov authored and David S. Miller committed Jan 21, 2009
1 parent a6bcf1c commit 4e9fb80
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Showing 2 changed files with 117 additions and 47 deletions.
160 changes: 117 additions & 43 deletions drivers/net/pppol2tp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -90,7 +90,9 @@
#include <linux/hash.h>
#include <linux/sort.h>
#include <linux/proc_fs.h>
#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/dst.h>
#include <net/ip.h>
#include <net/udp.h>
Expand Down Expand Up @@ -204,6 +206,7 @@ struct pppol2tp_tunnel
struct sock *sock; /* Parent socket */
struct list_head list; /* Keep a list of all open
* prepared sockets */
struct net *pppol2tp_net; /* the net we belong to */

atomic_t ref_count;
};
Expand All @@ -227,8 +230,20 @@ static atomic_t pppol2tp_tunnel_count;
static atomic_t pppol2tp_session_count;
static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL };
static struct proto_ops pppol2tp_ops;
static LIST_HEAD(pppol2tp_tunnel_list);
static DEFINE_RWLOCK(pppol2tp_tunnel_list_lock);

/* per-net private data for this module */
static unsigned int pppol2tp_net_id;
struct pppol2tp_net {
struct list_head pppol2tp_tunnel_list;
rwlock_t pppol2tp_tunnel_list_lock;
};

static inline struct pppol2tp_net *pppol2tp_pernet(struct net *net)
{
BUG_ON(!net);

return net_generic(net, pppol2tp_net_id);
}

/* Helpers to obtain tunnel/session contexts from sockets.
*/
Expand Down Expand Up @@ -321,18 +336,19 @@ pppol2tp_session_find(struct pppol2tp_tunnel *tunnel, u16 session_id)

/* Lookup a tunnel by id
*/
static struct pppol2tp_tunnel *pppol2tp_tunnel_find(u16 tunnel_id)
static struct pppol2tp_tunnel *pppol2tp_tunnel_find(struct net *net, u16 tunnel_id)
{
struct pppol2tp_tunnel *tunnel = NULL;
struct pppol2tp_tunnel *tunnel;
struct pppol2tp_net *pn = pppol2tp_pernet(net);

read_lock_bh(&pppol2tp_tunnel_list_lock);
list_for_each_entry(tunnel, &pppol2tp_tunnel_list, list) {
read_lock_bh(&pn->pppol2tp_tunnel_list_lock);
list_for_each_entry(tunnel, &pn->pppol2tp_tunnel_list, list) {
if (tunnel->stats.tunnel_id == tunnel_id) {
read_unlock_bh(&pppol2tp_tunnel_list_lock);
read_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
return tunnel;
}
}
read_unlock_bh(&pppol2tp_tunnel_list_lock);
read_unlock_bh(&pn->pppol2tp_tunnel_list_lock);

return NULL;
}
Expand Down Expand Up @@ -1287,10 +1303,12 @@ static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel)
*/
static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel)
{
struct pppol2tp_net *pn = pppol2tp_pernet(tunnel->pppol2tp_net);

/* Remove from socket list */
write_lock_bh(&pppol2tp_tunnel_list_lock);
write_lock_bh(&pn->pppol2tp_tunnel_list_lock);
list_del_init(&tunnel->list);
write_unlock_bh(&pppol2tp_tunnel_list_lock);
write_unlock_bh(&pn->pppol2tp_tunnel_list_lock);

atomic_dec(&pppol2tp_tunnel_count);
kfree(tunnel);
Expand Down Expand Up @@ -1444,13 +1462,14 @@ static int pppol2tp_release(struct socket *sock)
/* Internal function to prepare a tunnel (UDP) socket to have PPPoX
* sockets attached to it.
*/
static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id,
int *error)
static struct sock *pppol2tp_prepare_tunnel_socket(struct net *net,
int fd, u16 tunnel_id, int *error)
{
int err;
struct socket *sock = NULL;
struct sock *sk;
struct pppol2tp_tunnel *tunnel;
struct pppol2tp_net *pn;
struct sock *ret = NULL;

/* Get the tunnel UDP socket from the fd, which was opened by
Expand Down Expand Up @@ -1524,11 +1543,15 @@ static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id,
/* Misc init */
rwlock_init(&tunnel->hlist_lock);

/* The net we belong to */
tunnel->pppol2tp_net = net;
pn = pppol2tp_pernet(net);

/* Add tunnel to our list */
INIT_LIST_HEAD(&tunnel->list);
write_lock_bh(&pppol2tp_tunnel_list_lock);
list_add(&tunnel->list, &pppol2tp_tunnel_list);
write_unlock_bh(&pppol2tp_tunnel_list_lock);
write_lock_bh(&pn->pppol2tp_tunnel_list_lock);
list_add(&tunnel->list, &pn->pppol2tp_tunnel_list);
write_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
atomic_inc(&pppol2tp_tunnel_count);

/* Bump the reference count. The tunnel context is deleted
Expand Down Expand Up @@ -1629,15 +1652,16 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
* tunnel id.
*/
if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) {
tunnel_sock = pppol2tp_prepare_tunnel_socket(sp->pppol2tp.fd,
tunnel_sock = pppol2tp_prepare_tunnel_socket(sock_net(sk),
sp->pppol2tp.fd,
sp->pppol2tp.s_tunnel,
&error);
if (tunnel_sock == NULL)
goto end;

tunnel = tunnel_sock->sk_user_data;
} else {
tunnel = pppol2tp_tunnel_find(sp->pppol2tp.s_tunnel);
tunnel = pppol2tp_tunnel_find(sock_net(sk), sp->pppol2tp.s_tunnel);

/* Error if we can't find the tunnel */
error = -ENOENT;
Expand Down Expand Up @@ -2347,8 +2371,9 @@ static int pppol2tp_getsockopt(struct socket *sock, int level,
#include <linux/seq_file.h>

struct pppol2tp_seq_data {
struct pppol2tp_tunnel *tunnel; /* current tunnel */
struct pppol2tp_session *session; /* NULL means get first session in tunnel */
struct net *seq_net; /* net of inode */
struct pppol2tp_tunnel *tunnel; /* current tunnel */
struct pppol2tp_session *session; /* NULL means get first session in tunnel */
};

static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr)
Expand Down Expand Up @@ -2384,39 +2409,42 @@ static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, str
return session;
}

static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_tunnel *curr)
static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_net *pn,
struct pppol2tp_tunnel *curr)
{
struct pppol2tp_tunnel *tunnel = NULL;

read_lock_bh(&pppol2tp_tunnel_list_lock);
if (list_is_last(&curr->list, &pppol2tp_tunnel_list)) {
read_lock_bh(&pn->pppol2tp_tunnel_list_lock);
if (list_is_last(&curr->list, &pn->pppol2tp_tunnel_list)) {
goto out;
}
tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list);
out:
read_unlock_bh(&pppol2tp_tunnel_list_lock);
read_unlock_bh(&pn->pppol2tp_tunnel_list_lock);

return tunnel;
}

static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
{
struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
struct pppol2tp_net *pn;
loff_t pos = *offs;

if (!pos)
goto out;

BUG_ON(m->private == NULL);
pd = m->private;
pn = pppol2tp_pernet(pd->seq_net);

if (pd->tunnel == NULL) {
if (!list_empty(&pppol2tp_tunnel_list))
pd->tunnel = list_entry(pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list);
if (!list_empty(&pn->pppol2tp_tunnel_list))
pd->tunnel = list_entry(pn->pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list);
} else {
pd->session = next_session(pd->tunnel, pd->session);
if (pd->session == NULL) {
pd->tunnel = next_tunnel(pd->tunnel);
pd->tunnel = next_tunnel(pn, pd->tunnel);
}
}

Expand Down Expand Up @@ -2532,6 +2560,7 @@ static int pppol2tp_proc_open(struct inode *inode, struct file *file)
{
struct seq_file *m;
struct pppol2tp_seq_data *pd;
struct net *net;
int ret = 0;

ret = seq_open(file, &pppol2tp_seq_ops);
Expand All @@ -2542,12 +2571,15 @@ static int pppol2tp_proc_open(struct inode *inode, struct file *file)

/* Allocate and fill our proc_data for access later */
ret = -ENOMEM;
m->private = kzalloc(sizeof(struct pppol2tp_seq_data), GFP_KERNEL);
m->private = kzalloc(sizeof(*pd), GFP_KERNEL);
if (m->private == NULL)
goto out;

pd = m->private;
ret = 0;
net = maybe_get_net(PDE_NET(PDE(inode)));
BUG_ON(!net);
pd->seq_net = net;
return 0;

out:
return ret;
Expand All @@ -2558,6 +2590,9 @@ static int pppol2tp_proc_open(struct inode *inode, struct file *file)
static int pppol2tp_proc_release(struct inode *inode, struct file *file)
{
struct seq_file *m = (struct seq_file *)file->private_data;
struct pppol2tp_seq_data *pd = m->private;

put_net(pd->seq_net);

kfree(m->private);
m->private = NULL;
Expand All @@ -2573,8 +2608,6 @@ static const struct file_operations pppol2tp_proc_fops = {
.release = pppol2tp_proc_release,
};

static struct proc_dir_entry *pppol2tp_proc;

#endif /* CONFIG_PROC_FS */

/*****************************************************************************
Expand Down Expand Up @@ -2606,6 +2639,57 @@ static struct pppox_proto pppol2tp_proto = {
.ioctl = pppol2tp_ioctl
};

static __net_init int pppol2tp_init_net(struct net *net)
{
struct pppol2tp_net *pn;
struct proc_dir_entry *pde;
int err;

pn = kzalloc(sizeof(*pn), GFP_KERNEL);
if (!pn)
return -ENOMEM;

INIT_LIST_HEAD(&pn->pppol2tp_tunnel_list);
rwlock_init(&pn->pppol2tp_tunnel_list_lock);

err = net_assign_generic(net, pppol2tp_net_id, pn);
if (err)
goto out;

pde = proc_net_fops_create(net, "pppol2tp", S_IRUGO, &pppol2tp_proc_fops);
#ifdef CONFIG_PROC_FS
if (!pde) {
err = -ENOMEM;
goto out;
}
#endif

return 0;

out:
kfree(pn);
return err;
}

static __net_exit void pppol2tp_exit_net(struct net *net)
{
struct pppoe_net *pn;

proc_net_remove(net, "pppol2tp");
pn = net_generic(net, pppol2tp_net_id);
/*
* if someone has cached our net then
* further net_generic call will return NULL
*/
net_assign_generic(net, pppol2tp_net_id, NULL);
kfree(pn);
}

static __net_initdata struct pernet_operations pppol2tp_net_ops = {
.init = pppol2tp_init_net,
.exit = pppol2tp_exit_net,
};

static int __init pppol2tp_init(void)
{
int err;
Expand All @@ -2617,23 +2701,17 @@ static int __init pppol2tp_init(void)
if (err)
goto out_unregister_pppol2tp_proto;

#ifdef CONFIG_PROC_FS
pppol2tp_proc = proc_net_fops_create(&init_net, "pppol2tp", 0,
&pppol2tp_proc_fops);
if (!pppol2tp_proc) {
err = -ENOMEM;
err = register_pernet_gen_device(&pppol2tp_net_id, &pppol2tp_net_ops);
if (err)
goto out_unregister_pppox_proto;
}
#endif /* CONFIG_PROC_FS */

printk(KERN_INFO "PPPoL2TP kernel driver, %s\n",
PPPOL2TP_DRV_VERSION);

out:
return err;
#ifdef CONFIG_PROC_FS
out_unregister_pppox_proto:
unregister_pppox_proto(PX_PROTO_OL2TP);
#endif
out_unregister_pppol2tp_proto:
proto_unregister(&pppol2tp_sk_proto);
goto out;
Expand All @@ -2642,10 +2720,6 @@ static int __init pppol2tp_init(void)
static void __exit pppol2tp_exit(void)
{
unregister_pppox_proto(PX_PROTO_OL2TP);

#ifdef CONFIG_PROC_FS
remove_proc_entry("pppol2tp", init_net.proc_net);
#endif
proto_unregister(&pppol2tp_sk_proto);
}

Expand Down
4 changes: 0 additions & 4 deletions drivers/net/pppox.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,10 +111,6 @@ static int pppox_create(struct net *net, struct socket *sock, int protocol)
if (protocol < 0 || protocol > PX_MAX_PROTO)
goto out;

/* we support net-namespaces for PPPoE only (yet) */
if (protocol != PX_PROTO_OE && net != &init_net)
return -EAFNOSUPPORT;

rc = -EPROTONOSUPPORT;
if (!pppox_protos[protocol])
request_module("pppox-proto-%d", protocol);
Expand Down

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