linux-stable/fs/proc/proc_net.c
Linus Torvalds 590dce2d49 Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs 'statx()' update from Al Viro.

This adds the new extended stat() interface that internally subsumes our
previous stat interfaces, and allows user mode to specify in more detail
what kind of information it wants.

It also allows for some explicit synchronization information to be
passed to the filesystem, which can be relevant for network filesystems:
is the cached value ok, or do you need open/close consistency, or what?

From David Howells.

Andreas Dilger points out that the first version of the extended statx
interface was posted June 29, 2010:

    https://www.spinics.net/lists/linux-fsdevel/msg33831.html

* 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  statx: Add a system call to make enhanced file info available
2017-03-03 11:38:56 -08:00

247 lines
4.6 KiB
C

/*
* linux/fs/proc/net.c
*
* Copyright (C) 2007
*
* Author: Eric Biederman <ebiederm@xmission.com>
*
* proc net directory handling functions
*/
#include <linux/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/sched/task.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/mount.h>
#include <linux/nsproxy.h>
#include <linux/uidgid.h>
#include <net/net_namespace.h>
#include <linux/seq_file.h>
#include "internal.h"
static inline struct net *PDE_NET(struct proc_dir_entry *pde)
{
return pde->parent->data;
}
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) {
task_lock(task);
ns = task->nsproxy;
if (ns != NULL)
net = get_net(ns->net_ns);
task_unlock(task);
}
rcu_read_unlock();
return net;
}
static struct dentry *proc_tgid_net_lookup(struct inode *dir,
struct dentry *dentry, unsigned int flags)
{
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(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int query_flags)
{
struct inode *inode = d_inode(path->dentry);
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 *file, struct dir_context *ctx)
{
int ret;
struct net *net;
ret = -EINVAL;
net = get_proc_task_net(file_inode(file));
if (net != NULL) {
ret = proc_readdir_de(net->proc_net, file, ctx);
put_net(net);
}
return ret;
}
const struct file_operations proc_net_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate_shared = proc_tgid_net_readdir,
};
static __net_init int proc_net_ns_init(struct net *net)
{
struct proc_dir_entry *netd, *net_statd;
kuid_t uid;
kgid_t gid;
int err;
err = -ENOMEM;
netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL);
if (!netd)
goto out;
netd->subdir = RB_ROOT;
netd->data = net;
netd->nlink = 2;
netd->namelen = 3;
netd->parent = &proc_root;
memcpy(netd->name, "net", 4);
uid = make_kuid(net->user_ns, 0);
if (!uid_valid(uid))
uid = netd->uid;
gid = make_kgid(net->user_ns, 0);
if (!gid_valid(gid))
gid = netd->gid;
proc_set_user(netd, uid, gid);
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);
}