1 /*
2 * Copyright (C) 2012 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 #include <stdio.h>
18 #include <stdlib.h>
19 #include <sys/types.h>
20 #include <sys/wait.h>
21 #include <errno.h>
22 #include <string.h>
23 #include <unistd.h>
24
25 #define LOG_TAG "OemIptablesHook"
26 #include <cutils/log.h>
27 #include <logwrap/logwrap.h>
28 #include "NetdConstants.h"
29
runIptablesCmd(int argc,const char ** argv)30 static int runIptablesCmd(int argc, const char **argv) {
31 int res;
32
33 res = android_fork_execvp(argc, (char **)argv, NULL, false, false);
34 return res;
35 }
36
oemCleanupHooks()37 static bool oemCleanupHooks() {
38 const char *cmd1[] = {
39 IPTABLES_PATH,
40 "-w",
41 "-F",
42 "oem_out"
43 };
44 runIptablesCmd(ARRAY_SIZE(cmd1), cmd1);
45
46 const char *cmd2[] = {
47 IPTABLES_PATH,
48 "-w",
49 "-F",
50 "oem_fwd"
51 };
52 runIptablesCmd(ARRAY_SIZE(cmd2), cmd2);
53
54 const char *cmd3[] = {
55 IPTABLES_PATH,
56 "-w",
57 "-t",
58 "nat",
59 "-F",
60 "oem_nat_pre"
61 };
62 runIptablesCmd(ARRAY_SIZE(cmd3), cmd3);
63 return true;
64 }
65
oemInitChains()66 static bool oemInitChains() {
67 int ret = system(OEM_SCRIPT_PATH);
68 if ((-1 == ret) || (0 != WEXITSTATUS(ret))) {
69 ALOGE("%s failed: %s", OEM_SCRIPT_PATH, strerror(errno));
70 oemCleanupHooks();
71 return false;
72 }
73 return true;
74 }
75
76
setupOemIptablesHook()77 void setupOemIptablesHook() {
78 if (0 == access(OEM_SCRIPT_PATH, R_OK | X_OK)) {
79 // The call to oemCleanupHooks() is superfluous when done on bootup,
80 // but is needed for the case where netd has crashed/stopped and is
81 // restarted.
82 if (oemCleanupHooks() && oemInitChains()) {
83 ALOGI("OEM iptable hook installed.");
84 }
85 }
86 }
87