--- /dev/null
+/*
+ * 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);
+}
+
+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;
+}
+
+void proc_net_remove(struct net *net, const char *name)
+{
+ remove_proc_entry(name, net->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 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 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 proc_net_ns_ops = {
+ .init = proc_net_ns_init,
+ .exit = proc_net_ns_exit,
+};
+
+int 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);
+}