/* *  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/slab.h>#include <linux/init.h>#include <linux/sched.h>#include <linux/module.h>#include <linux/bitops.h>#include <linux/mount.h>#include <linux/nsproxy.h>#include <net/net_namespace.h>#include <linux/seq_file.h> #include "internal.h"  static struct net *get_proc_net(const struct inode *inode){	return maybe_get_net(PDE_NET(PDE(inode)));} int seq_open_net(struct inode *ino, struct file *f,		 const struct seq_operations *ops, int size){	struct net *net;	struct seq_net_private *p; 	BUG_ON(size < sizeof(*p)); 	net = get_proc_net(ino);	if (net == NULL)		return -ENXIO; 	p = __seq_open_private(f, ops, size);	if (p == NULL) {		put_net(net);		return -ENOMEM;	}#ifdef CONFIG_NET_NS	p->net = net;#endif	return 0;}EXPORT_SYMBOL_GPL(seq_open_net); int single_open_net(struct inode *inode, struct file *file,		int (*show)(struct seq_file *, void *)){	int err;	struct net *net; 	err = -ENXIO;	net = get_proc_net(inode);	if (net == NULL)		goto err_net; 	err = single_open(file, show, net);	if (err < 0)		goto err_open; 	return 0; err_open:	put_net(net);err_net:	return err;}EXPORT_SYMBOL_GPL(single_open_net); int seq_release_net(struct inode *ino, struct file *f){	struct seq_file *seq; 	seq = f->private_data; 	put_net(seq_file_net(seq));	seq_release_private(ino, f);	return 0;}EXPORT_SYMBOL_GPL(seq_release_net); int single_release_net(struct inode *ino, struct file *f){	struct seq_file *seq = f->private_data;	put_net(seq->private);	return single_release(ino, f);}EXPORT_SYMBOL_GPL(single_release_net); static struct net *get_proc_task_net(struct inode *dir){	struct task_struct *task;	struct nsproxy *ns;	struct net *net = NULL; 	rcu_read_lock();	task = pid_task(proc_pid(dir), PIDTYPE_PID);	if (task != NULL) {		ns = task_nsproxy(task);		if (ns != NULL)			net = get_net(ns->net_ns);	}	rcu_read_unlock(); 	return net;} static struct dentry *proc_tgid_net_lookup(struct inode *dir,		struct dentry *dentry, struct nameidata *nd){	struct dentry *de;	struct net *net; 	de = ERR_PTR(-ENOENT);	net = get_proc_task_net(dir);	if (net != NULL) {		de = proc_lookup_de(net->proc_net, dir, dentry);		put_net(net);	}	return de;} static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry,		struct kstat *stat){	struct inode *inode = dentry->d_inode;	struct net *net; 	net = get_proc_task_net(inode); 	generic_fillattr(inode, stat); 	if (net != NULL) {		stat->nlink = net->proc_net->nlink;		put_net(net);	} 	return 0;} const struct inode_operations proc_net_inode_operations = {	.lookup		= proc_tgid_net_lookup,	.getattr	= proc_tgid_net_getattr,}; static int proc_tgid_net_readdir(struct file *filp, void *dirent,		filldir_t filldir){	int ret;	struct net *net; 	ret = -EINVAL;	net = get_proc_task_net(filp->f_path.dentry->d_inode);	if (net != NULL) {		ret = proc_readdir_de(net->proc_net, filp, dirent, filldir);		put_net(net);	}	return ret;} const struct file_operations proc_net_operations = {	.llseek		= generic_file_llseek,	.read		= generic_read_dir,	.readdir	= proc_tgid_net_readdir,};  struct proc_dir_entry *proc_net_fops_create(struct net *net,	const char *name, umode_t mode, const struct file_operations *fops){	return proc_create(name, mode, net->proc_net, fops);}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); static __net_init int proc_net_ns_init(struct net *net){	struct proc_dir_entry *netd, *net_statd;	int err; 	err = -ENOMEM;	netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL);	if (!netd)		goto out; 	netd->data = net;	netd->nlink = 2;	netd->namelen = 3;	netd->parent = &proc_root;	memcpy(netd->name, "net", 4); 	err = -EEXIST;	net_statd = proc_net_mkdir(net, "stat", netd);	if (!net_statd)		goto free_net; 	net->proc_net = netd;	net->proc_net_stat = net_statd;	return 0; free_net:	kfree(netd);out:	return err;} static __net_exit void proc_net_ns_exit(struct net *net){	remove_proc_entry("stat", net->proc_net);	kfree(net->proc_net);} static 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_symlink("net", NULL, "self/net"); 	return register_pernet_subsys(&proc_net_ns_ops);}