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
|
/*
* Copyright (C) 2009 Martin Willi
* Hochschule fuer Technik Rapperswil
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program 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.
*
* $Id$
*/
#include "resolv_conf_handler.h"
#include <unistd.h>
#include <daemon.h>
#include <utils/mutex.h>
typedef struct private_resolv_conf_handler_t private_resolv_conf_handler_t;
/**
* Private data of an resolv_conf_handler_t object.
*/
struct private_resolv_conf_handler_t {
/**
* Public resolv_conf_handler_t interface.
*/
resolv_conf_handler_t public;
/**
* resolv.conf file to use
*/
char *file;
/**
* Mutex to access file exclusively
*/
mutex_t *mutex;
};
/**
* Implementation of attribute_handler_t.handle
*/
static bool handle(private_resolv_conf_handler_t *this, ike_sa_t *ike_sa,
configuration_attribute_type_t type, chunk_t data)
{
FILE *in, *out;
char buf[1024];
host_t *addr;
int family;
size_t len;
bool handled = FALSE;
switch (type)
{
case INTERNAL_IP4_DNS:
family = AF_INET;
break;
case INTERNAL_IP6_DNS:
family = AF_INET6;
break;
default:
return FALSE;
}
this->mutex->lock(this->mutex);
in = fopen(this->file, "r");
/* allows us to stream from in to out */
unlink(this->file);
out = fopen(this->file, "w");
if (out)
{
addr = host_create_from_chunk(family, data, 0);
fprintf(out, "nameserver %H # by strongSwan, from %D\n",
addr, ike_sa->get_other_id(ike_sa));
DBG1(DBG_IKE, "installing DNS server %H to %s", addr, this->file);
addr->destroy(addr);
handled = TRUE;
/* copy rest of the file */
if (in)
{
while ((len = fread(buf, 1, sizeof(buf), in)))
{
ignore_result(fwrite(buf, 1, len, out));
}
fclose(in);
}
fclose(out);
}
if (!handled)
{
DBG1(DBG_IKE, "adding DNS server failed", this->file);
}
this->mutex->unlock(this->mutex);
return handled;
}
/**
* Implementation of attribute_handler_t.release
*/
static void release(private_resolv_conf_handler_t *this, ike_sa_t *ike_sa,
configuration_attribute_type_t type, chunk_t data)
{
FILE *in, *out;
char line[1024], matcher[512], *pos;
host_t *addr;
int family;
switch (type)
{
case INTERNAL_IP4_DNS:
family = AF_INET;
break;
case INTERNAL_IP6_DNS:
family = AF_INET6;
break;
default:
return;
}
this->mutex->lock(this->mutex);
in = fopen(this->file, "r");
if (in)
{
/* allows us to stream from in to out */
unlink(this->file);
out = fopen(this->file, "w");
if (out)
{
addr = host_create_from_chunk(family, data, 0);
snprintf(matcher, sizeof(matcher),
"nameserver %H # by strongSwan, from %D\n",
addr, ike_sa->get_other_id(ike_sa));
/* copy all, but matching line */
while ((pos = fgets(line, sizeof(line), in)))
{
if (strneq(line, matcher, strlen(matcher)))
{
DBG1(DBG_IKE, "removing DNS server %H from %s",
addr, this->file);
}
else
{
fputs(line, out);
}
}
addr->destroy(addr);
fclose(out);
}
fclose(in);
}
this->mutex->unlock(this->mutex);
}
/**
* Implementation of resolv_conf_handler_t.destroy.
*/
static void destroy(private_resolv_conf_handler_t *this)
{
this->mutex->destroy(this->mutex);
free(this);
}
/**
* See header
*/
resolv_conf_handler_t *resolv_conf_handler_create()
{
private_resolv_conf_handler_t *this = malloc_thing(private_resolv_conf_handler_t);
this->public.handler.handle = (bool(*)(attribute_handler_t*, ike_sa_t*, configuration_attribute_type_t, chunk_t))handle;
this->public.handler.release = (void(*)(attribute_handler_t*, ike_sa_t*, configuration_attribute_type_t, chunk_t))release;
this->public.destroy = (void(*)(resolv_conf_handler_t*))destroy;
this->mutex = mutex_create(MUTEX_DEFAULT);
this->file = lib->settings->get_str(lib->settings,
"charon.plugins.resolv-conf.file", RESOLV_CONF);
return &this->public;
}
|
