Release 4.15 kernel/nsproxy.c

/*
 *  Copyright (C) 2006 IBM Corporation
 *
 *  Author: Serge Hallyn <serue@us.ibm.com>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation, version 2 of the
 *  License.
 *
 *  Jun 2006 - namespaces support
 *             OpenVZ, SWsoft Inc.
 *             Pavel Emelianov <xemul@openvz.org>
 */

#include <linux/slab.h>
#include <linux/export.h>
#include <linux/nsproxy.h>
#include <linux/init_task.h>
#include <linux/mnt_namespace.h>
#include <linux/utsname.h>
#include <linux/pid_namespace.h>
#include <net/net_namespace.h>
#include <linux/ipc_namespace.h>
#include <linux/proc_ns.h>
#include <linux/file.h>
#include <linux/syscalls.h>
#include <linux/cgroup.h>
#include <linux/perf_event.h>


static struct kmem_cache *nsproxy_cachep;


struct nsproxy init_nsproxy = {
	.count			= ATOMIC_INIT(1),
	.uts_ns			= &init_uts_ns,
#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
	.ipc_ns			= &init_ipc_ns,
#endif
	.mnt_ns			= NULL,
	.pid_ns_for_children	= &init_pid_ns,
#ifdef CONFIG_NET
	.net_ns			= &init_net,
#endif
#ifdef CONFIG_CGROUPS
	.cgroup_ns		= &init_cgroup_ns,
#endif
};



static inline struct nsproxy *create_nsproxy(void)
{
	struct nsproxy *nsproxy;

	nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
	if (nsproxy)
		atomic_set(&nsproxy->count, 1);
	return nsproxy;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Serge E. Hallyn
26
61.90%
1
33.33%
Cédric Le Goater
9
21.43%
1
33.33%
Alexey Dobriyan
7
16.67%
1
33.33%
Total
42
100.00%
3
100.00%

/*
 * Create new nsproxy and all of its the associated namespaces.
 * Return the newly created nsproxy.  Do not attach this to the task,
 * leave it to the caller to do proper locking and attach it to task.
 */


static struct nsproxy *create_new_namespaces(unsigned long flags,
	struct task_struct *tsk, struct user_namespace *user_ns,
	struct fs_struct *new_fs)
{
	struct nsproxy *new_nsp;
	int err;

	new_nsp = create_nsproxy();
	if (!new_nsp)
		return ERR_PTR(-ENOMEM);

	new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs);
	if (IS_ERR(new_nsp->mnt_ns)) {
		err = PTR_ERR(new_nsp->mnt_ns);
		goto out_ns;
	}

	new_nsp->uts_ns = copy_utsname(flags, user_ns, tsk->nsproxy->uts_ns);
	if (IS_ERR(new_nsp->uts_ns)) {
		err = PTR_ERR(new_nsp->uts_ns);
		goto out_uts;
	}

	new_nsp->ipc_ns = copy_ipcs(flags, user_ns, tsk->nsproxy->ipc_ns);
	if (IS_ERR(new_nsp->ipc_ns)) {
		err = PTR_ERR(new_nsp->ipc_ns);
		goto out_ipc;
	}

	new_nsp->pid_ns_for_children =
		copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children);
	if (IS_ERR(new_nsp->pid_ns_for_children)) {
		err = PTR_ERR(new_nsp->pid_ns_for_children);
		goto out_pid;
	}

	new_nsp->cgroup_ns = copy_cgroup_ns(flags, user_ns,
					    tsk->nsproxy->cgroup_ns);
	if (IS_ERR(new_nsp->cgroup_ns)) {
		err = PTR_ERR(new_nsp->cgroup_ns);
		goto out_cgroup;
	}

	new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns);
	if (IS_ERR(new_nsp->net_ns)) {
		err = PTR_ERR(new_nsp->net_ns);
		goto out_net;
	}

	return new_nsp;

out_net:
	put_cgroup_ns(new_nsp->cgroup_ns);
out_cgroup:
	if (new_nsp->pid_ns_for_children)
		put_pid_ns(new_nsp->pid_ns_for_children);
out_pid:
	if (new_nsp->ipc_ns)
		put_ipc_ns(new_nsp->ipc_ns);
out_ipc:
	if (new_nsp->uts_ns)
		put_uts_ns(new_nsp->uts_ns);
out_uts:
	if (new_nsp->mnt_ns)
		put_mnt_ns(new_nsp->mnt_ns);
out_ns:
	kmem_cache_free(nsproxy_cachep, new_nsp);
	return ERR_PTR(err);
}

Contributors
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Commits
CommitProp
Badari Pulavarty
146
38.32%
1
5.00%
Eric W. Biedermann
70
18.37%
7
35.00%
Cédric Le Goater
67
17.59%
4
20.00%
Aditya Kali
49
12.86%
1
5.00%
Serge E. Hallyn
32
8.40%
3
15.00%
Kirill Korotaev
9
2.36%
2
10.00%
Andrew Lutomirski
6
1.57%
1
5.00%
Alexey Dobriyan
2
0.52%
1
5.00%
Total
381
100.00%
20
100.00%

/*
 * called from clone.  This now handles copy for nsproxy and all
 * namespaces therein.
 */


int copy_namespaces(unsigned long flags, struct task_struct *tsk)
{
	struct nsproxy *old_ns = tsk->nsproxy;
	struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);
	struct nsproxy *new_ns;

	if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
			      CLONE_NEWPID | CLONE_NEWNET |
			      CLONE_NEWCGROUP)))) {
		get_nsproxy(old_ns);
		return 0;
	}

	if (!ns_capable(user_ns, CAP_SYS_ADMIN))
		return -EPERM;

	/*
         * CLONE_NEWIPC must detach from the undolist: after switching
         * to a new ipc namespace, the semaphore arrays from the old
         * namespace are unreachable.  In clone parlance, CLONE_SYSVSEM
         * means share undolist with parent, so we must forbid using
         * it along with CLONE_NEWIPC.
         */
	if ((flags & (CLONE_NEWIPC | CLONE_SYSVSEM)) ==
		(CLONE_NEWIPC | CLONE_SYSVSEM)) 
		return -EINVAL;

	new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs);
	if (IS_ERR(new_ns))
		return  PTR_ERR(new_ns);

	tsk->nsproxy = new_ns;
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Serge E. Hallyn
75
50.68%
6
35.29%
Eric W. Biedermann
36
24.32%
5
29.41%
Badari Pulavarty
17
11.49%
1
5.88%
Kirill Korotaev
8
5.41%
1
5.88%
Raphael S. Carvalho
6
4.05%
1
5.88%
Pavel Emelyanov
2
1.35%
1
5.88%
Cédric Le Goater
2
1.35%
1
5.88%
Aditya Kali
2
1.35%
1
5.88%
Total
148
100.00%
17
100.00%



void free_nsproxy(struct nsproxy *ns)
{
	if (ns->mnt_ns)
		put_mnt_ns(ns->mnt_ns);
	if (ns->uts_ns)
		put_uts_ns(ns->uts_ns);
	if (ns->ipc_ns)
		put_ipc_ns(ns->ipc_ns);
	if (ns->pid_ns_for_children)
		put_pid_ns(ns->pid_ns_for_children);
	put_cgroup_ns(ns->cgroup_ns);
	put_net(ns->net_ns);
	kmem_cache_free(nsproxy_cachep, ns);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Serge E. Hallyn
37
44.58%
3
30.00%
Kirill Korotaev
16
19.28%
2
20.00%
Cédric Le Goater
14
16.87%
2
20.00%
Eric W. Biedermann
7
8.43%
1
10.00%
Aditya Kali
7
8.43%
1
10.00%
Andrew Lutomirski
2
2.41%
1
10.00%
Total
83
100.00%
10
100.00%

/*
 * Called from unshare. Unshare all the namespaces part of nsproxy.
 * On success, returns the new nsproxy.
 */


int unshare_nsproxy_namespaces(unsigned long unshare_flags,
	struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs)
{
	struct user_namespace *user_ns;
	int err = 0;

	if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
			       CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP)))
		return 0;

	user_ns = new_cred ? new_cred->user_ns : current_user_ns();
	if (!ns_capable(user_ns, CAP_SYS_ADMIN))
		return -EPERM;

	*new_nsp = create_new_namespaces(unshare_flags, current, user_ns,
					 new_fs ? new_fs : current->fs);
	if (IS_ERR(*new_nsp)) {
		err = PTR_ERR(*new_nsp);
		goto out;
	}

out:
	return err;
}

Contributors
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Commits
CommitProp
Badari Pulavarty
91
70.00%
1
12.50%
Eric W. Biedermann
29
22.31%
4
50.00%
Serge E. Hallyn
8
6.15%
2
25.00%
Aditya Kali
2
1.54%
1
12.50%
Total
130
100.00%
8
100.00%



void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
{
	struct nsproxy *ns;

	might_sleep();

	task_lock(p);
	ns = p->nsproxy;
	p->nsproxy = new;
	task_unlock(p);

	if (ns && atomic_dec_and_test(&ns->count))
		free_nsproxy(ns);
}

Contributors
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Pavel Emelyanov
52
83.87%
1
50.00%
Eric W. Biedermann
10
16.13%
1
50.00%
Total
62
100.00%
2
100.00%



void exit_task_namespaces(struct task_struct *p)
{
	switch_task_namespaces(p, NULL);
}

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Pavel Emelyanov
17
100.00%
1
100.00%
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17
100.00%
1
100.00%


SYSCALL_DEFINE2(setns, int, fd, int, nstype)
{
	struct task_struct *tsk = current;
	struct nsproxy *new_nsproxy;
	struct file *file;
	struct ns_common *ns;
	int err;

	file = proc_ns_fget(fd);
	if (IS_ERR(file))
		return PTR_ERR(file);

	err = -EINVAL;
	ns = get_proc_ns(file_inode(file));
	if (nstype && (ns->ops->type != nstype))
		goto out;

	new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
	if (IS_ERR(new_nsproxy)) {
		err = PTR_ERR(new_nsproxy);
		goto out;
	}

	err = ns->ops->install(new_nsproxy, ns);
	if (err) {
		free_nsproxy(new_nsproxy);
		goto out;
	}
	switch_task_namespaces(tsk, new_nsproxy);

	perf_event_namespaces(tsk);
out:
	fput(file);
	return err;
}



int __init nsproxy_cache_init(void)
{
	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
	return 0;
}
Contributors
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Tokens
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CommitProp
Cédric Le Goater
19
95.00%
1
50.00%
Pavel Emelyanov
1
5.00%
1
50.00%
Total
20
100.00%
2
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric W. Biedermann
319
26.97%
13
28.89%
Badari Pulavarty
255
21.56%
1
2.22%
Serge E. Hallyn
199
16.82%
8
17.78%
Cédric Le Goater
121
10.23%
5
11.11%
Pavel Emelyanov
75
6.34%
4
8.89%
Aditya Kali
74
6.26%
1
2.22%
Alexey Dobriyan
63
5.33%
2
4.44%
Kirill Korotaev
35
2.96%
2
4.44%
Al Viro
13
1.10%
3
6.67%
Andrew Lutomirski
9
0.76%
1
2.22%
Hari Bathini
8
0.68%
1
2.22%
Raphael S. Carvalho
6
0.51%
1
2.22%
Tejun Heo
3
0.25%
1
2.22%
David Howells
2
0.17%
1
2.22%
Paul Gortmaker
1
0.08%
1
2.22%
Total
1183
100.00%
45
100.00%
Directory: kernel

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