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25#include <linux/seqlock.h>
26#include <linux/sysctl.h>
27#include <linux/errno.h>
28#include <linux/init.h>
29
30#define DYNAMIC_PORT_MIN 0x40
31#define DYNAMIC_PORT_MAX 0x7f
32
33static DEFINE_SEQLOCK(local_port_range_lock);
34static int local_port_range_min[2] = {0, 0};
35static int local_port_range_max[2] = {1023, 1023};
36static int local_port_range[2] = {DYNAMIC_PORT_MIN, DYNAMIC_PORT_MAX};
37static struct ctl_table_header *phonet_table_hrd;
38
39static void set_local_port_range(int range[2])
40{
41 write_seqlock(&local_port_range_lock);
42 local_port_range[0] = range[0];
43 local_port_range[1] = range[1];
44 write_sequnlock(&local_port_range_lock);
45}
46
47void phonet_get_local_port_range(int *min, int *max)
48{
49 unsigned seq;
50 do {
51 seq = read_seqbegin(&local_port_range_lock);
52 if (min)
53 *min = local_port_range[0];
54 if (max)
55 *max = local_port_range[1];
56 } while (read_seqretry(&local_port_range_lock, seq));
57}
58
59static int proc_local_port_range(ctl_table *table, int write,
60 void __user *buffer,
61 size_t *lenp, loff_t *ppos)
62{
63 int ret;
64 int range[2] = {local_port_range[0], local_port_range[1]};
65 ctl_table tmp = {
66 .data = &range,
67 .maxlen = sizeof(range),
68 .mode = table->mode,
69 .extra1 = &local_port_range_min,
70 .extra2 = &local_port_range_max,
71 };
72
73 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
74
75 if (write && ret == 0) {
76 if (range[1] < range[0])
77 ret = -EINVAL;
78 else
79 set_local_port_range(range);
80 }
81
82 return ret;
83}
84
85static struct ctl_table phonet_table[] = {
86 {
87 .ctl_name = CTL_UNNUMBERED,
88 .procname = "local_port_range",
89 .data = &local_port_range,
90 .maxlen = sizeof(local_port_range),
91 .mode = 0644,
92 .proc_handler = proc_local_port_range,
93 .strategy = NULL,
94 },
95 { .ctl_name = 0 }
96};
97
98static struct ctl_path phonet_ctl_path[] = {
99 { .procname = "net", .ctl_name = CTL_NET, },
100 { .procname = "phonet", .ctl_name = CTL_UNNUMBERED, },
101 { },
102};
103
104int __init phonet_sysctl_init(void)
105{
106 phonet_table_hrd = register_sysctl_paths(phonet_ctl_path, phonet_table);
107 return phonet_table_hrd == NULL ? -ENOMEM : 0;
108}
109
110void phonet_sysctl_exit(void)
111{
112 unregister_sysctl_table(phonet_table_hrd);
113}
114