4 files changed, 209 insertions, 5 deletions

diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index bce38e3f06cb..ebaba0213546 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -11,6 +11,7 @@ proc-y       += inode.o root.o base.o generic.o array.o \
 		proc_tty.o proc_misc.o
 
 proc-$(CONFIG_PROC_SYSCTL)	+= proc_sysctl.o
+proc-$(CONFIG_NET)		+= proc_net.o
 proc-$(CONFIG_PROC_KCORE)	+= kcore.o
 proc-$(CONFIG_PROC_VMCORE)	+= vmcore.o
 proc-$(CONFIG_PROC_DEVICETREE)	+= proc_devtree.o
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index b215c3524fa6..1820eb2ef762 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -16,6 +16,11 @@ extern int proc_sys_init(void);
 #else
 static inline void proc_sys_init(void) { }
 #endif
+#ifdef CONFIG_NET
+extern int proc_net_init(void);
+#else
+static inline int proc_net_init(void) { return 0; }
+#endif
 
 struct vmalloc_info {
 	unsigned long	used;
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
new file mode 100644
index 000000000000..2e91fb756e9a
--- /dev/null
+++ b/fs/proc/proc_net.c
@@ -0,0 +1,200 @@
+/*
+ *  linux/fs/proc/net.c
+ *
+ *  Copyright (C) 2007
+ *
+ *  Author: Eric Biederman <ebiederm@xmission.com>
+ *
+ *  proc net directory handling functions
+ */
+
+#include <asm/uaccess.h>
+
+#include <linux/errno.h>
+#include <linux/time.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/smp_lock.h>
+#include <linux/mount.h>
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
+
+#include "internal.h"
+
+
+struct proc_dir_entry *proc_net_create(struct net *net,
+	const char *name, mode_t mode, get_info_t *get_info)
+{
+	return create_proc_info_entry(name,mode, net->proc_net, get_info);
+}
+EXPORT_SYMBOL_GPL(proc_net_create);
+
+struct proc_dir_entry *proc_net_fops_create(struct net *net,
+	const char *name, mode_t mode, const struct file_operations *fops)
+{
+	struct proc_dir_entry *res;
+
+	res = create_proc_entry(name, mode, net->proc_net);
+	if (res)
+		res->proc_fops = fops;
+	return res;
+}
+EXPORT_SYMBOL_GPL(proc_net_fops_create);
+
+void proc_net_remove(struct net *net, const char *name)
+{
+	remove_proc_entry(name, net->proc_net);
+}
+EXPORT_SYMBOL_GPL(proc_net_remove);
+
+struct net *get_proc_net(const struct inode *inode)
+{
+	return maybe_get_net(PDE_NET(PDE(inode)));
+}
+EXPORT_SYMBOL_GPL(get_proc_net);
+
+static struct proc_dir_entry *proc_net_shadow;
+
+static struct dentry *proc_net_shadow_dentry(struct dentry *parent,
+						struct proc_dir_entry *de)
+{
+	struct dentry *shadow = NULL;
+	struct inode *inode;
+	if (!de)
+		goto out;
+	de_get(de);
+	inode = proc_get_inode(parent->d_inode->i_sb, de->low_ino, de);
+	if (!inode)
+		goto out_de_put;
+	shadow = d_alloc_name(parent, de->name);
+	if (!shadow)
+		goto out_iput;
+	shadow->d_op = parent->d_op; /* proc_dentry_operations */
+	d_instantiate(shadow, inode);
+out:
+	return shadow;
+out_iput:
+	iput(inode);
+out_de_put:
+	de_put(de);
+	goto out;
+}
+
+static void *proc_net_follow_link(struct dentry *parent, struct nameidata *nd)
+{
+	struct net *net = current->nsproxy->net_ns;
+	struct dentry *shadow;
+	shadow = proc_net_shadow_dentry(parent, net->proc_net);
+	if (!shadow)
+		return ERR_PTR(-ENOENT);
+
+	dput(nd->dentry);
+	/* My dentry count is 1 and that should be enough as the
+	 * shadow dentry is thrown away immediately.
+	 */
+	nd->dentry = shadow;
+	return NULL;
+}
+
+static struct dentry *proc_net_lookup(struct inode *dir, struct dentry *dentry,
+				      struct nameidata *nd)
+{
+	struct net *net = current->nsproxy->net_ns;
+	struct dentry *shadow;
+
+	shadow = proc_net_shadow_dentry(nd->dentry, net->proc_net);
+	if (!shadow)
+		return ERR_PTR(-ENOENT);
+
+	dput(nd->dentry);
+	nd->dentry = shadow;
+
+	return shadow->d_inode->i_op->lookup(shadow->d_inode, dentry, nd);
+}
+
+static int proc_net_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+	struct net *net = current->nsproxy->net_ns;
+	struct dentry *shadow;
+	int ret;
+
+	shadow = proc_net_shadow_dentry(dentry->d_parent, net->proc_net);
+	if (!shadow)
+		return -ENOENT;
+	ret = shadow->d_inode->i_op->setattr(shadow, iattr);
+	dput(shadow);
+	return ret;
+}
+
+static const struct file_operations proc_net_dir_operations = {
+	.read			= generic_read_dir,
+};
+
+static struct inode_operations proc_net_dir_inode_operations = {
+	.follow_link	= proc_net_follow_link,
+	.lookup		= proc_net_lookup,
+	.setattr	= proc_net_setattr,
+};
+
+static __net_init int proc_net_ns_init(struct net *net)
+{
+	struct proc_dir_entry *root, *netd, *net_statd;
+	int err;
+
+	err = -ENOMEM;
+	root = kzalloc(sizeof(*root), GFP_KERNEL);
+	if (!root)
+		goto out;
+
+	err = -EEXIST;
+	netd = proc_mkdir("net", root);
+	if (!netd)
+		goto free_root;
+
+	err = -EEXIST;
+	net_statd = proc_mkdir("stat", netd);
+	if (!net_statd)
+		goto free_net;
+
+	root->data = net;
+	netd->data = net;
+	net_statd->data = net;
+
+	net->proc_net_root = root;
+	net->proc_net = netd;
+	net->proc_net_stat = net_statd;
+	err = 0;
+
+out:
+	return err;
+free_net:
+	remove_proc_entry("net", root);
+free_root:
+	kfree(root);
+	goto out;
+}
+
+static __net_exit void proc_net_ns_exit(struct net *net)
+{
+	remove_proc_entry("stat", net->proc_net);
+	remove_proc_entry("net", net->proc_net_root);
+	kfree(net->proc_net_root);
+}
+
+struct pernet_operations __net_initdata proc_net_ns_ops = {
+	.init = proc_net_ns_init,
+	.exit = proc_net_ns_exit,
+};
+
+int __init proc_net_init(void)
+{
+	proc_net_shadow = proc_mkdir("net", NULL);
+	proc_net_shadow->proc_iops = &proc_net_dir_inode_operations;
+	proc_net_shadow->proc_fops = &proc_net_dir_operations;
+
+	return register_pernet_subsys(&proc_net_ns_ops);
+}
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 41f17037f738..cf3046638b09 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -21,7 +21,7 @@
 
 #include "internal.h"
 
-struct proc_dir_entry *proc_net, *proc_net_stat, *proc_bus, *proc_root_fs, *proc_root_driver;
+struct proc_dir_entry *proc_bus, *proc_root_fs, *proc_root_driver;
 
 static int proc_get_sb(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
@@ -61,8 +61,8 @@ void __init proc_root_init(void)
 		return;
 	}
 	proc_misc_init();
-	proc_net = proc_mkdir("net", NULL);
-	proc_net_stat = proc_mkdir("net/stat", NULL);
+
+	proc_net_init();
 
 #ifdef CONFIG_SYSVIPC
 	proc_mkdir("sysvipc", NULL);
@@ -159,7 +159,5 @@ EXPORT_SYMBOL(create_proc_entry);
 EXPORT_SYMBOL(remove_proc_entry);
 EXPORT_SYMBOL(proc_root);
 EXPORT_SYMBOL(proc_root_fs);
-EXPORT_SYMBOL(proc_net);
-EXPORT_SYMBOL(proc_net_stat);
 EXPORT_SYMBOL(proc_bus);
 EXPORT_SYMBOL(proc_root_driver);