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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/*
* �Anytun
*
* �Anytun is a tiny implementation of SATP. Unlike Anytun which is a full
* featured implementation �Anytun has no support for multiple connections
* or synchronisation. It is a small single threaded implementation intended
* to act as a client on small platforms.
* The secure anycast tunneling protocol (satp) defines a protocol used
* for communication between any combination of unicast and anycast
* tunnel endpoints. It has less protocol overhead than IPSec in Tunnel
* mode and allows tunneling of every ETHER TYPE protocol (e.g.
* ethernet, ip, arp ...). satp directly includes cryptography and
* message authentication based on the methodes used by SRTP. It is
* intended to deliver a generic, scaleable and secure solution for
* tunneling and relaying of packets of any protocol.
*
*
* Copyright (C) 2007-2008 Christian Pointner <equinox@anytun.org>
*
* This file is part of �Anytun.
*
* �Anytun is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* �Anytun is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with �Anytun. If not, see <http://www.gnu.org/licenses/>.
*/
#include "datatypes.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "log.h"
#include "signal.h"
#include "options.h"
#include "tun.h"
#include "udp.h"
#include "plain_packet.h"
#include "encrypted_packet.h"
#include "cipher.h"
#include "daemon.h"
#include "sysexec.h"
void main_loop(tun_device_t* dev, udp_socket_t* sock, options_t* opt)
{
log_printf(INFO, "entering main loop");
plain_packet_t plain_packet;
plain_packet_init(&plain_packet);
encrypted_packet_t encrypted_packet;
encrypted_packet_init(&encrypted_packet);
u_int32_t len = 0;
udp_endpoint_t remote;
seq_nr_t seq_nr = 0;
while(1) {
plain_packet_set_payload_length(&plain_packet, -1);
encrypted_packet_set_length(&encrypted_packet, -1);
// TODO: add select
// if dev->fd_ is ready:
len = tun_read(dev, plain_packet_get_payload(&plain_packet), plain_packet_get_payload_length(&plain_packet));
plain_packet_set_payload_length(&plain_packet, len);
// TODO: cipher packet
// TODO: add auth-tag
encrypted_packet_set_seq_nr(&encrypted_packet, seq_nr);
encrypted_packet_set_sender_id(&encrypted_packet, opt->sender_id_);
encrypted_packet_set_mux(&encrypted_packet, opt->mux_);
udp_write(sock, encrypted_packet_get_packet(&encrypted_packet), encrypted_packet_get_length(&encrypted_packet));
// if sock->fd_ is ready:
len = udp_read(sock, encrypted_packet_get_packet(&encrypted_packet), encrypted_packet_get_length(&encrypted_packet), &remote);
encrypted_packet_set_length(&encrypted_packet, len);
// TODO: check auth-tag
if(encrypted_packet_get_mux(&encrypted_packet) != opt->mux_)
continue;
// TODO: check seq nr for sender id
if(memcmp(&remote, &(sock->remote_end_), sizeof(remote))) {
memcpy(&(sock->remote_end_), &remote, sizeof(remote));
char* addrstring = udp_endpoint_to_string(remote);
log_printf(NOTICE, "autodetected remote host changed %s", addrstring);
free(addrstring);
}
// TODO: decipher packet
tun_write(dev, plain_packet_get_payload(&plain_packet), plain_packet_get_payload_length(&plain_packet));
}
}
void print_hex_dump(const u_int8_t* buf, u_int32_t len)
{
u_int32_t i;
for(i=0; i < len; i++) {
printf("%02X ", buf[i]);
if(!((i+1)%8))
printf(" ");
if(!((i+1)%16))
printf("\n");
}
printf("\n");
}
int main(int argc, char* argv[])
{
log_init("uanytun", DAEMON);
signal_init();
options_t* opt;
int ret = options_parse(&opt, argc, argv);
if(ret) {
options_print_usage();
log_printf(ERR, "error on options_parse, exitting");
exit(ret);
}
tun_device_t* dev;
tun_init(&dev, opt->dev_name_, opt->dev_type_, opt->ifconfig_param_local_, opt->ifconfig_param_remote_netmask_);
if(!dev) {
log_printf(ERR, "error on tun_init, exitting");
exit(-1);
}
log_printf(NOTICE, "dev of type '%s' opened, actual name is '%s'", tun_get_type_string(dev), dev->actual_name_);
if(opt->post_up_script_) {
int ret = exec_script(opt->post_up_script_, dev->actual_name_);
log_printf(NOTICE, "post-up script returned %d", ret);
}
udp_socket_t* sock;
udp_init(&sock, opt->local_addr_, opt->local_port_);
if(!sock) {
log_printf(ERR, "error on udp_init, exitting");
exit(-1);
}
char* local_string = udp_get_local_end_string(sock);
log_printf(NOTICE, "listening on: %s", local_string);
free(local_string);
if(opt->remote_addr_) {
udp_set_remote(sock, opt->remote_addr_, opt->remote_port_);
char* remote_string = udp_get_remote_end_string(sock);
log_printf(NOTICE, "set remote end to: %s", remote_string);
free(remote_string);
}
FILE* pid_file = NULL;
if(opt->pid_file_) {
pid_file = fopen(opt->pid_file_, "w");
if(!pid_file) {
log_printf(WARNING, "unable to open pid file: %m");
}
}
if(opt->chroot_)
chrootAndDrop("/var/run/", "nobody");
if(opt->daemonize_) {
pid_t oldpid = getpid();
daemonize();
log_printf(INFO, "running in background now (old pid: %d)", oldpid);
}
if(pid_file) {
pid_t pid = getpid();
fprintf(pid_file, "%d", pid);
fclose(pid_file);
}
main_loop(dev, sock, opt);
tun_close(&dev);
udp_close(&sock);
options_clear(&opt);
log_printf(NOTICE, "normal shutdown");
return 0;
}
|
