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 "-F",
41 "oem_out"
42 };
43 runIptablesCmd(ARRAY_SIZE(cmd1), cmd1);
44
45 const char *cmd2[] = {
46 IPTABLES_PATH,
47 "-F",
48 "oem_fwd"
49 };
50 runIptablesCmd(ARRAY_SIZE(cmd2), cmd2);
51
52 const char *cmd3[] = {
53 IPTABLES_PATH,
54 "-t",
55 "nat",
56 "-F",
57 "oem_nat_pre"
58 };
59 runIptablesCmd(ARRAY_SIZE(cmd3), cmd3);
60 return true;
61 }
62
oemInitChains()63 static bool oemInitChains() {
64 int ret = system(OEM_SCRIPT_PATH);
65 if ((-1 == ret) || (0 != WEXITSTATUS(ret))) {
66 ALOGE("%s failed: %s", OEM_SCRIPT_PATH, strerror(errno));
67 oemCleanupHooks();
68 return false;
69 }
70 return true;
71 }
72
73
setupOemIptablesHook()74 void setupOemIptablesHook() {
75 if (0 == access(OEM_SCRIPT_PATH, R_OK | X_OK)) {
76 // The call to oemCleanupHooks() is superfluous when done on bootup,
77 // but is needed for the case where netd has crashed/stopped and is
78 // restarted.
79 if (oemCleanupHooks() && oemInitChains()) {
80 ALOGI("OEM iptable hook installed.");
81 }
82 }
83 }
84