linux/fs/proc/proc_net.c

248 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);
}