xref: /linux/net/unix/sysctl_net_unix.c (revision a6377d905913cf3bc855408373ff2022386f586f)
1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /*
3   * NET4:	Sysctl interface to net af_unix subsystem.
4   *
5   * Authors:	Mike Shaver.
6   */
7  
8  #include <linux/mm.h>
9  #include <linux/slab.h>
10  #include <linux/sysctl.h>
11  
12  #include <net/af_unix.h>
13  
14  static struct ctl_table unix_table[] = {
15  	{
16  		.procname	= "max_dgram_qlen",
17  		.data		= &init_net.unx.sysctl_max_dgram_qlen,
18  		.maxlen		= sizeof(int),
19  		.mode		= 0644,
20  		.proc_handler	= proc_dointvec
21  	},
22  	{ }
23  };
24  
25  int __net_init unix_sysctl_register(struct net *net)
26  {
27  	struct ctl_table *table;
28  
29  	table = kmemdup(unix_table, sizeof(unix_table), GFP_KERNEL);
30  	if (table == NULL)
31  		goto err_alloc;
32  
33  	/* Don't export sysctls to unprivileged users */
34  	if (net->user_ns != &init_user_ns)
35  		table[0].procname = NULL;
36  
37  	table[0].data = &net->unx.sysctl_max_dgram_qlen;
38  	net->unx.ctl = register_net_sysctl(net, "net/unix", table);
39  	if (net->unx.ctl == NULL)
40  		goto err_reg;
41  
42  	return 0;
43  
44  err_reg:
45  	kfree(table);
46  err_alloc:
47  	return -ENOMEM;
48  }
49  
50  void unix_sysctl_unregister(struct net *net)
51  {
52  	struct ctl_table *table;
53  
54  	table = net->unx.ctl->ctl_table_arg;
55  	unregister_net_sysctl_table(net->unx.ctl);
56  	kfree(table);
57  }
58