1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef _NAT_CONTROLLER_H
18 #define _NAT_CONTROLLER_H
19 
20 #include <linux/in.h>
21 #include <list>
22 #include <string>
23 
24 #include "NetdConstants.h"
25 
26 class NatController {
27 public:
28     NatController();
29     virtual ~NatController();
30 
31     int enableNat(const char* intIface, const char* extIface);
32     int disableNat(const char* intIface, const char* extIface);
33     int setupIptablesHooks();
34 
35     static const char* LOCAL_FORWARD;
36     static const char* LOCAL_MANGLE_FORWARD;
37     static const char* LOCAL_NAT_POSTROUTING;
38     static const char* LOCAL_RAW_PREROUTING;
39     static const char* LOCAL_TETHER_COUNTERS_CHAIN;
40 
41     // List of strings of interface pairs.
42     std::list<std::string> ifacePairList;
43 
44 private:
45     int natCount;
46 
47     bool checkTetherCountingRuleExist(const char *pair_name);
48 
49     int setDefaults();
50     int runCmd(int argc, const char **argv);
51     int setForwardRules(bool set, const char *intIface, const char *extIface);
52     int setTetherCountingRules(bool add, const char *intIface, const char *extIface);
53 
54     // For testing.
55     friend class NatControllerTest;
56     static int (*execFunction)(int, char **, int *, bool, bool);
57     static int (*iptablesRestoreFunction)(IptablesTarget, const std::string&);
58 };
59 
60 #endif
61