blob: acc6eafaa2d2d94edd5f821d008ecfdcd2c40a2b [file] [log] [blame]
#include <linux/proc_fs.h>
#include <linux/nsproxy.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/fs_struct.h>
#include <linux/mount.h>
#include <linux/path.h>
#include <linux/namei.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <net/net_namespace.h>
#include <linux/mnt_namespace.h>
#include <linux/ipc_namespace.h>
#include <linux/pid_namespace.h>
#include "internal.h"
static const struct proc_ns_operations *ns_entries[] = {
#ifdef CONFIG_NET_NS
&netns_operations,
#endif
#ifdef CONFIG_UTS_NS
&utsns_operations,
#endif
#ifdef CONFIG_IPC_NS
&ipcns_operations,
#endif
#ifdef CONFIG_USER_NS
&userns_operations,
#endif
};
static const struct file_operations ns_file_operations = {
.llseek = no_llseek,
};
static struct dentry *proc_ns_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, const void *ptr)
{
const struct proc_ns_operations *ns_ops = ptr;
struct inode *inode;
struct proc_inode *ei;
struct dentry *error = ERR_PTR(-ENOENT);
void *ns;
inode = proc_pid_make_inode(dir->i_sb, task);
if (!inode)
goto out;
ns = ns_ops->get(task);
if (!ns)
goto out_iput;
ei = PROC_I(inode);
inode->i_mode = S_IFREG|S_IRUSR;
inode->i_fop = &ns_file_operations;
ei->ns_ops = ns_ops;
ei->ns = ns;
dentry->d_op = &pid_dentry_operations;
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
error = NULL;
out:
return error;
out_iput:
iput(inode);
goto out;
}
static int proc_ns_fill_cache(struct file *filp, void *dirent,
filldir_t filldir, struct task_struct *task,
const struct proc_ns_operations *ops)
{
return proc_fill_cache(filp, dirent, filldir,
ops->name, strlen(ops->name),
proc_ns_instantiate, task, ops);
}
static int proc_ns_dir_readdir(struct file *filp, void *dirent,
filldir_t filldir)
{
int i;
struct dentry *dentry = filp->f_path.dentry;
struct inode *inode = dentry->d_inode;
struct task_struct *task = get_proc_task(inode);
const struct proc_ns_operations **entry, **last;
ino_t ino;
int ret;
ret = -ENOENT;
if (!task)
goto out_no_task;
ret = -EPERM;
if (!ptrace_may_access(task, PTRACE_MODE_READ))
goto out;
ret = 0;
i = filp->f_pos;
switch (i) {
case 0:
ino = inode->i_ino;
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
goto out;
i++;
filp->f_pos++;
/* fall through */
case 1:
ino = parent_ino(dentry);
if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
goto out;
i++;
filp->f_pos++;
/* fall through */
default:
i -= 2;
if (i >= ARRAY_SIZE(ns_entries)) {
ret = 1;
goto out;
}
entry = ns_entries + i;
last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
while (entry <= last) {
if (proc_ns_fill_cache(filp, dirent, filldir,
task, *entry) < 0)
goto out;
filp->f_pos++;
entry++;
}
}
ret = 1;
out:
put_task_struct(task);
out_no_task:
return ret;
}
const struct file_operations proc_ns_dir_operations = {
.read = generic_read_dir,
.readdir = proc_ns_dir_readdir,
};
static struct dentry *proc_ns_dir_lookup(struct inode *dir,
struct dentry *dentry, struct nameidata *nd)
{
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
const struct proc_ns_operations **entry, **last;
unsigned int len = dentry->d_name.len;
error = ERR_PTR(-ENOENT);
if (!task)
goto out_no_task;
error = ERR_PTR(-EPERM);
if (!ptrace_may_access(task, PTRACE_MODE_READ))
goto out;
last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
for (entry = ns_entries; entry <= last; entry++) {
if (strlen((*entry)->name) != len)
continue;
if (!memcmp(dentry->d_name.name, (*entry)->name, len))
break;
}
error = ERR_PTR(-ENOENT);
if (entry > last)
goto out;
error = proc_ns_instantiate(dir, dentry, task, *entry);
out:
put_task_struct(task);
out_no_task:
return error;
}
const struct inode_operations proc_ns_dir_inode_operations = {
.lookup = proc_ns_dir_lookup,
.getattr = pid_getattr,
.setattr = proc_setattr,
};
struct file *proc_ns_fget(int fd)
{
struct file *file;
file = fget(fd);
if (!file)
return ERR_PTR(-EBADF);
if (file->f_op != &ns_file_operations)
goto out_invalid;
return file;
out_invalid:
fput(file);
return ERR_PTR(-EINVAL);
}