1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <resolv.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "config.h"
static int fd;
static void open_kmem(void)
{
fd = open("/dev/kmem", O_RDONLY);
if (fd < 0) {
perror("open(/dev/kmem)");
exit(errno);
}
}
static void read_kmem(void *buffer, size_t len, unsigned long addr)
{
if (lseek(fd, addr, SEEK_SET) == (off_t)-1) {
perror("lseek");
exit(errno);
}
if (read(fd, buffer, len) != len) {
perror("read");
exit(errno);
}
}
static inline unsigned int read_int(unsigned long addr)
{
unsigned int ret;
read_kmem(&ret, sizeof(ret), addr);
return ret;
}
static inline unsigned long read_long(unsigned long addr)
{
unsigned long ret;
read_kmem(&ret, sizeof(ret), addr);
return ret;
}
static unsigned long find_interface(const char *interface)
{
FILE *f = fopen("/proc/net/udp", "r");
char line[256], *ptr;
unsigned long addr = 0;
char name[IFNAMSIZ + 1] = { 0 };
if (!f) {
perror("fopen(/proc/net/udp)");
exit(errno);
}
if (!fgets(line, 256, f))
goto out;
while (fgets(line, 256, f)) {
ptr = line + strlen(line) - 1;
while (*--ptr == ' ');
while (*--ptr != ' ');
while (*(--ptr - 1) != ' ');
addr = strtoul(ptr, NULL, 16);
if (!addr)
continue;
addr = read_long(addr + SOCK_DEVICE_OFFSET);
if (!addr)
continue;
read_kmem(name, IFNAMSIZ, addr + DEVICE_NAME_OFFSET);
if (!strcmp(name, interface))
goto out;
}
addr = 0;
out:
fclose(f);
return addr;
}
static bool print_key(unsigned long key)
{
unsigned char sending[32], receiving[32];
char sending_b64[45], receiving_b64[45];
unsigned int local_index, remote_index;
if (!key)
return false;
local_index = le32toh(read_int(key + KEY_LOCALID_OFFSET));
remote_index = le32toh(read_int(key + KEY_REMOTEID_OFFSET));
read_kmem(sending, 32, key + KEY_SENDING_OFFSET);
read_kmem(receiving, 32, key + KEY_RECEIVING_OFFSET);
b64_ntop(sending, 32, sending_b64, 45);
b64_ntop(receiving, 32, receiving_b64, 45);
printf("0x%08x %s\n", local_index, receiving_b64);
printf("0x%08x %s\n", remote_index, sending_b64);
return true;
}
static bool walk_peers(unsigned long peer_head)
{
unsigned long peer, peer_entry;
bool found = false;
for (peer_entry = read_long(peer_head); peer_entry != peer_head; peer_entry = read_long(peer_entry)) {
peer = peer_entry + PEERS_PEER_OFFSET;
if (print_key(read_long(peer + PEER_CURRENTKEY_OFFSET)))
found = true;
if (print_key(read_long(peer + PEER_PREVIOUSKEY_OFFSET)))
found = true;
if (print_key(read_long(peer + PEER_NEXTKEY_OFFSET)))
found = true;
}
return found;
}
int main(int argc, char *argv[])
{
unsigned long wireguard_device;
if (argc < 2) {
fprintf(stderr, "Usage: %s WIREGUARD_INTERFACE\n", argv[0]);
return EINVAL;
}
open_kmem();
wireguard_device = find_interface(argv[1]);
if (!wireguard_device) {
fprintf(stderr, "Could not find interface %s\n", argv[1]);
return EBADSLT;
}
if (!walk_peers(wireguard_device + DEVICE_PEERS_OFFSET)) {
fprintf(stderr, "No active sessions\n");
return ENOKEY;
}
return 0;
}
|
