1 /*
2 * File: sysctl.c
3 *
4 * Phonet /proc/sys/net/phonet interface implementation
5 *
6 * Copyright (C) 2008 Nokia Corporation.
7 *
8 * Author: Rémi Denis-Courmont
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * version 2 as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22 * 02110-1301 USA
23 */
24
25 #include <linux/seqlock.h>
26 #include <linux/sysctl.h>
27 #include <linux/errno.h>
28 #include <linux/init.h>
29
30 #include <net/sock.h>
31 #include <linux/phonet.h>
32 #include <net/phonet/phonet.h>
33
34 #define DYNAMIC_PORT_MIN 0x40
35 #define DYNAMIC_PORT_MAX 0x7f
36
37 static DEFINE_SEQLOCK(local_port_range_lock);
38 static int local_port_range_min[2] = {0, 0};
39 static int local_port_range_max[2] = {1023, 1023};
40 static int local_port_range[2] = {DYNAMIC_PORT_MIN, DYNAMIC_PORT_MAX};
41 static struct ctl_table_header *phonet_table_hrd;
42
set_local_port_range(int range[2])43 static void set_local_port_range(int range[2])
44 {
45 write_seqlock(&local_port_range_lock);
46 local_port_range[0] = range[0];
47 local_port_range[1] = range[1];
48 write_sequnlock(&local_port_range_lock);
49 }
50
phonet_get_local_port_range(int * min,int * max)51 void phonet_get_local_port_range(int *min, int *max)
52 {
53 unsigned int seq;
54
55 do {
56 seq = read_seqbegin(&local_port_range_lock);
57 if (min)
58 *min = local_port_range[0];
59 if (max)
60 *max = local_port_range[1];
61 } while (read_seqretry(&local_port_range_lock, seq));
62 }
63
proc_local_port_range(ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)64 static int proc_local_port_range(ctl_table *table, int write,
65 void __user *buffer,
66 size_t *lenp, loff_t *ppos)
67 {
68 int ret;
69 int range[2] = {local_port_range[0], local_port_range[1]};
70 ctl_table tmp = {
71 .data = &range,
72 .maxlen = sizeof(range),
73 .mode = table->mode,
74 .extra1 = &local_port_range_min,
75 .extra2 = &local_port_range_max,
76 };
77
78 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
79
80 if (write && ret == 0) {
81 if (range[1] < range[0])
82 ret = -EINVAL;
83 else
84 set_local_port_range(range);
85 }
86
87 return ret;
88 }
89
90 static struct ctl_table phonet_table[] = {
91 {
92 .procname = "local_port_range",
93 .data = &local_port_range,
94 .maxlen = sizeof(local_port_range),
95 .mode = 0644,
96 .proc_handler = proc_local_port_range,
97 },
98 { }
99 };
100
phonet_sysctl_init(void)101 int __init phonet_sysctl_init(void)
102 {
103 phonet_table_hrd = register_net_sysctl(&init_net, "net/phonet", phonet_table);
104 return phonet_table_hrd == NULL ? -ENOMEM : 0;
105 }
106
phonet_sysctl_exit(void)107 void phonet_sysctl_exit(void)
108 {
109 unregister_net_sysctl_table(phonet_table_hrd);
110 }
111