iptables是Linux的一个命令行工具,经过设置一些规则能够直接把指定uid或网址的数据包从ip层过滤掉，从而实现网络防火墙的功能，这部分已经比较成熟,android或厂商只是对iptables命令进行了封装,让android app能够经过iptables命令进行防火墙设置，iptables有不少复杂的功能,咱们主要看看怎么设置白名单只让指定的uid app能够联网和设置黑名单让指定的uid app不能联网,咱们经过代码流程来分析,代码是mtk android8.1。java
root后经过adb shell iptables -L能够查看当前的规则列表，Chain INPUT，OUTPUT就是控制数据包的输入输出，没作任何设置前应该张下面这个样子，Chain OUTPUT的数据包经过Chain fw_OUTPUT控制, Chain fw_OUTPUT的规则是空的，因此当前对网络不作限制。android
$ adb shell iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
bw_INPUT all -- anywhere anywhere
fw_INPUT all -- anywhere anywhere shell
Chain FORWARD (policy ACCEPT)
target prot opt source destination
oem_fwd all -- anywhere anywhere
fw_FORWARD all -- anywhere anywhere
bw_FORWARD all -- anywhere anywhere
natctrl_FORWARD all -- anywhere anywhere 网络
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
oem_out all -- anywhere anywhere
firewall all -- anywhere anywhere
fw_OUTPUT all -- anywhere anywhere
st_OUTPUT all -- anywhere anywhere
bw_OUTPUT all -- anywhere anywhere app
Chain fw_FORWARD (1 references)
target prot opt source destination ide
Chain fw_INPUT (1 references)
target prot opt source destination 函数
Chain fw_OUTPUT (1 references)
target prot opt source destination 工具
//android app层ui
INetworkManagementService networkService = INetworkManagementService.Stub.asInterface(ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE));this
public void WhiteListMode(INetworkManagementService networkService) {
FireWallUtils.setFirewallEnabled(networkService, true);//白名单模式
FireWallUtils.setFirewallUidRule(networkService, 0, 1016, 0); //重置vpn uid rule
FireWallUtils.setFirewallUidRule(networkService, 0, 1016, 1); //设置vpn uid为白名单
FireWallUtils.setFirewallUidRule(networkService, 0, 0, 0); //重置root uid rule
FireWallUtils.setFirewallUidRule(networkService, 0, 0, 1); //设置root uid为白名单
// List<String> whitelistApp = new ArrayList<>();
// whitelistApp.add("com.nuts.extremspeedup");
// PackageManager pm = mContext.getPackageManager();
// for (String pkgName : whitelistApp) {
// int uid = FireWallUtils.getUidFromPackageName(pm, pkgName);
// if (uid > 0) {
// FireWallUtils.setFirewallUidRule(networkService, 0, uid, 0); //重置 uid rule
// FireWallUtils.setFirewallUidRule(networkService, 0, uid, 1); //设置白名单
// }
// }
}
public void BlackListMode(INetworkManagementService networkService) {
FireWallUtils.setFirewallEnabled(networkService, false); //黑名单模式
List<String> whitelistApp = new ArrayList<>();
whitelistApp.add("com.iflytek.inputmethod");//com.iflytek.inputmethod
PackageManager pm = getPackageManager();
for (String pkgName : whitelistApp) {
int uid = FireWallUtils.getUidFromPackageName(pm, pkgName); //获取app的uid
if (uid > 0) {
FireWallUtils.setFirewallUidRule(networkService, 0, uid, 0); //重置 uid rule
FireWallUtils.setFirewallUidRule(networkService, 0, uid, 2); //设置uid为黑名单
}
}
}
public void DisableMobileMode(INetworkManagementService networkService) {
FireWallUtils.setFirewallEnabled(networkService, false); //黑名单模式
List<String> whitelistApp = new ArrayList<>();
whitelistApp.add("com.iflytek.inputmethod");//com.iflytek.inputmethod
PackageManager pm = getPackageManager();
for (String pkgName : whitelistApp) {
int uid = FireWallUtils.getUidFromPackageName(pm, pkgName);
if (uid > 0) {
FireWallUtils.setFirewallUidChainRule(networkService, uid, 0, false); //(networkType == 1) ? WIFI : MOBILE; , 禁止此uid连mobile
}
}
}
import android.content.BroadcastReceiver;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.os.INetworkManagementService;
import android.os.Process;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.os.SystemProperties;
import android.provider.Settings;
import android.util.Log;
import java.util.ArrayList;
import java.util.List;
public class FireWallUtils {
private static final String TAG = "FireWallUtils";
public static void setFirewallEnabled(INetworkManagementService networkService, boolean enable) {
try {
networkService.setFirewallEnabled(enable);
} catch (RemoteException e) {
Log.e(TAG, "setFirewallEnabled RemoteException e:" + Log.getStackTraceString(e));
} catch (Exception e) {
Log.e(TAG, "setFirewallEnabled Exception e:" + Log.getStackTraceString(e));
}
}
public static void setFirewallUidRule(INetworkManagementService networkService, int chain, int uid, int rule) {
try {
networkService.setFirewallUidRule(chain, uid, rule);
} catch (RemoteException e) {
Log.e(TAG, "setFirewallUidRule RemoteException e:" + Log.getStackTraceString(e));
} catch (Exception e) {
Log.e(TAG, "setFirewallUidRule Exception e:" + Log.getStackTraceString(e));
}
}
public static int getUidFromPackageName(PackageManager pm, String pkgName) {
try {
ApplicationInfo appInfo = pm.getApplicationInfo(pkgName, PackageManager.MATCH_ALL);
if (appInfo != null) {
return appInfo.uid;
}
} catch (PackageManager.NameNotFoundException e) {
//e.printStackTrace();
}
return -1;
}
}
public static void setFirewallUidChainRule(INetworkManagementService networkService, int uid, int networkType, boolean allow) {
try {
networkService.setFirewallUidChainRule(uid, networkType, allow);
} catch (RemoteException e) {
Log.d(TAG, "setFirewallEnabled RemoteException e:" + Log.getStackTraceString(e));
} catch (Exception e) {
Log.d(TAG, "setFirewallEnabled Exception e:" + Log.getStackTraceString(e));
}
}
public static void clearFirewallChain(INetworkManagementService networkService, String chain) {
try {
networkService.clearFirewallChain(chain);
} catch (RemoteException e) {
Log.d(TAG, "setFirewallEnabled RemoteException e:" + Log.getStackTraceString(e));
} catch (Exception e) {
Log.d(TAG, "setFirewallEnabled Exception e:" + Log.getStackTraceString(e));
}
}
frameworks/base/core/java/android/os/INetworkManagementService.aidl
void setFirewallEnabled(boolean enabled);
boolean isFirewallEnabled();
void setFirewallInterfaceRule(String iface, boolean allow);
void setFirewallUidRule(int chain, int uid, int rule);
void setFirewallUidRules(int chain, in int[] uids, in int[] rules);
void setFirewallChainEnabled(int chain, boolean enable);
/**
* agold
* Cnfigure firewall rule by uid and chain
* @hide
*/
void setFirewallUidChainRule(int uid, int networkType, boolean allow);
/** @} */
/**
* agold
* Delete all rules in chain or all chains
* @hide
*/
void clearFirewallChain(String chain);
frameworks/base/services/core/java/com/android/server/NetworkManagementService.java
@Override
public void setFirewallEnabled(boolean enabled) {
enforceSystemUid();
try {
mConnector.execute("firewall", "enable", enabled ? "whitelist" : "blacklist");
mFirewallEnabled = enabled;
} catch (NativeDaemonConnectorException e) {
throw e.rethrowAsParcelableException();
}
}
@Override
public void setFirewallUidRule(int chain, int uid, int rule) {
enforceSystemUid();
synchronized (mQuotaLock) {
setFirewallUidRuleLocked(chain, uid, rule);
}
}
private void setFirewallUidRuleLocked(int chain, int uid, int rule) {
if (updateFirewallUidRuleLocked(chain, uid, rule)) {
try {
mConnector.execute("firewall", "set_uid_rule", getFirewallChainName(chain), uid,
getFirewallRuleName(chain, rule));
} catch (NativeDaemonConnectorException e) {
throw e.rethrowAsParcelableException();
}
}
}
/**
* agold
* @Configure firewall rule by uid and chain
* @hide
*/
public void setFirewallUidChainRule(int uid, int networkType, boolean allow) {
android.util.Log.i("linyuan_NMS", "setFirewallUidChainRule uid = " + uid + ", networkType = " + networkType + ", allow = " + allow);
//enforceSystemUid();
final String MOBILE = "mobile";
final String WIFI = "wifi";
final String rule = allow ? "allow" : "deny";
final String chain = (networkType == 1) ? WIFI : MOBILE;
try {
mConnector.execute("firewall", "set_uid_fw_rule", uid, chain, rule);
} catch (NativeDaemonConnectorException e) {
throw e.rethrowAsParcelableException();
}
}
/**
* agold
* @Configure firewall rule by uid and chain
* @hide
*/
public void clearFirewallChain(String chain) {
//enforceSystemUid();
try {
mConnector.execute("firewall", "clear_fw_chain", chain);
} catch (NativeDaemonConnectorException e) {
throw e.rethrowAsParcelableException();
}
}
system/netd/server/CommandListener.cpp
int CommandListener::FirewallCmd::runCommand(SocketClient *cli, int argc,
char **argv) {
if (argc < 2) {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing command", false);
return 0;
}
if (!strcmp(argv[1], "enable")) {
if (argc != 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError,
"Usage: firewall enable <whitelist|blacklist>", false);
return 0;
}
FirewallType firewallType = parseFirewallType(argv[2]);
int res = gCtls->firewallCtrl.enableFirewall(firewallType);
return sendGenericOkFail(cli, res);
}
if (!strcmp(argv[1], "disable")) {
int res = gCtls->firewallCtrl.disableFirewall();
return sendGenericOkFail(cli, res);
}
if (!strcmp(argv[1], "is_enabled")) {
int res = gCtls->firewallCtrl.isFirewallEnabled();
return sendGenericOkFail(cli, res);
}
if (!strcmp(argv[1], "set_uid_rule")) {
if (argc != 5) {
cli->sendMsg(ResponseCode::CommandSyntaxError,
"Usage: firewall set_uid_rule <dozable|standby|none> <1000> <allow|deny>",
false);
return 0;
}
ChildChain childChain = parseChildChain(argv[2]);
if (childChain == INVALID_CHAIN) {
cli->sendMsg(ResponseCode::CommandSyntaxError,
"Invalid chain name. Valid names are: <dozable|standby|none>",
false);
return 0;
}
int uid = atoi(argv[3]);
FirewallRule rule = parseRule(argv[4]);
int res = gCtls->firewallCtrl.setUidRule(childChain, uid, rule);
return sendGenericOkFail(cli, res);
}
//agold start
if (!strcmp(argv[1], "set_uid_fw_rule")) {
ALOGD("set_uid_fw_rule");
if (argc != 5) {
cli->sendMsg(ResponseCode::CommandSyntaxError,
"Usage: firewall set_uid_fw_rule <uid> <mobile|wifi> <allow|deny>",
false);
return 0;
}
int uid = atoi(argv[2]);
FirewallChinaRule chain = parseChain(argv[3]);
FirewallRule rule = parseRule(argv[4]);
int res = gCtls->firewallCtrl.setUidFwRule(uid, chain, rule);
return sendGenericOkFail(cli, res);
}
if (!strcmp(argv[1], "clear_fw_chain")) {
if (argc != 3) {
cli->sendMsg(ResponseCode::CommandSyntaxError,
"Usage: firewall clear_fw_chain <chain>",
false);
return 0;
}
FirewallChinaRule chain = parseChain(argv[2]);
int res = gCtls->firewallCtrl.clearFwChain(chain);
return sendGenericOkFail(cli, res);
}
//agold end
cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown command", false);
return 0;
}
system/netd/server/FirewallController.cpp
int FirewallController::enableFirewall(FirewallType ftype) {
int res = 0;
if (mFirewallType != ftype) {
// flush any existing rules
disableFirewall();
if (ftype == WHITELIST) {
// create default rule to drop all traffic
std::string command =
"*filter\n"
"-A fw_INPUT -j DROP\n"
"-A fw_OUTPUT -j REJECT\n"
"-A fw_FORWARD -j REJECT\n"
"COMMIT\n";
res = execIptablesRestore(V4V6, command.c_str());
}
// Set this after calling disableFirewall(), since it defaults to WHITELIST there
mFirewallType = ftype;
}
return res;
}
int FirewallController::disableFirewall(void) {
mFirewallType = WHITELIST;
mIfaceRules.clear();
// flush any existing rules
std::string command =
"*filter\n"
":fw_INPUT -\n"
":fw_OUTPUT -\n"
":fw_FORWARD -\n"
"COMMIT\n";
return execIptablesRestore(V4V6, command.c_str());
}
int FirewallController::setUidRule(ChildChain chain, int uid, FirewallRule rule) {
const char* op;
const char* target;
FirewallType firewallType = getFirewallType(chain);
if (firewallType == WHITELIST) {
target = "RETURN";
// When adding, insert RETURN rules at the front, before the catch-all DROP at the end.
op = (rule == ALLOW)? "-I" : "-D";
} else { // BLACKLIST mode
target = "DROP";
// When adding, append DROP rules at the end, after the RETURN rule that matches TCP RSTs.
op = (rule == DENY)? "-A" : "-D";
}
std::vector<std::string> chainNames;
switch(chain) {
case DOZABLE:
chainNames = { LOCAL_DOZABLE };
break;
case STANDBY:
chainNames = { LOCAL_STANDBY };
break;
case POWERSAVE:
chainNames = { LOCAL_POWERSAVE };
break;
case NONE:
chainNames = { LOCAL_INPUT, LOCAL_OUTPUT };
break;
default:
ALOGW("Unknown child chain: %d", chain);
return -1;
}
std::string command = "*filter\n";
for (std::string chainName : chainNames) {
StringAppendF(&command, "%s %s -m owner --uid-owner %d -j %s\n",
op, chainName.c_str(), uid, target);
}
StringAppendF(&command, "COMMIT\n");
return execIptablesRestore(V4V6, command);
}
//agold start
const char* FirewallController::FIREWALL = "firewall";
const char* FirewallController::FIREWALL_MOBILE = "mobile";
const char* FirewallController::FIREWALL_WIFI = "wifi";
//agold end
int FirewallController::setupIptablesHooks(void) {
int res = 0;
//agold start
std::string command = "*filter\n";
StringAppendF(&command, "-F firewall \n");
StringAppendF(&command, "-A firewall -o ppp+ -j mobile\n");
StringAppendF(&command, "-A firewall -o ccmni+ -j mobile\n");
StringAppendF(&command, "-A firewall -o ccemni+ -j mobile\n");
StringAppendF(&command, "-A firewall -o usb+ -j mobile\n");
StringAppendF(&command, "-A firewall -o cc2mni+ -j mobile\n");
StringAppendF(&command, "-A firewall -o wlan+ -j wifi\n");
StringAppendF(&command, "COMMIT\n");
res |= execIptablesRestore(V4V6, command.c_str());
//agold end
res |= createChain(LOCAL_DOZABLE, getFirewallType(DOZABLE));
res |= createChain(LOCAL_STANDBY, getFirewallType(STANDBY));
res |= createChain(LOCAL_POWERSAVE, getFirewallType(POWERSAVE));
return res;
}
//agold start
int FirewallController::setUidFwRule(int uid, FirewallChinaRule chain, FirewallRule rule) {
ALOGD("setUidFwRule");
std::string command = "*filter\n";
char uidStr[16];
const char* op;
const char* fwChain;
sprintf(uidStr, "%d", uid);
if (rule == DENY) {
op = "-I";
} else {
op = "-D";
}
if(chain == MOBILE) {
fwChain = "mobile";
}else{
fwChain = "wifi";
}
/*
if(chain == MOBILE) {
if(rule == ALLOW)
blacklistUsers.insert(uid);
else
blacklistUsers.erase(uid);
}
*/
ALOGD("setUidFwRule op = %s, chain = %s, uid = %s", op, fwChain, uidStr);
StringAppendF(&command, "%s %s -m owner --uid-owner %s -j REJECT\n", op, fwChain, uidStr);
StringAppendF(&command, "COMMIT\n");
return execIptablesRestore(V4V6, command.c_str());
}
int FirewallController::clearFwChain(FirewallChinaRule chain) {
std::string command = "*filter\n";
const char* fwChain;
if(chain == MOBILE) {
fwChain = "mobile";
}else{
fwChain = "wifi";
}
StringAppendF(&command, "-F %s \n", fwChain);
StringAppendF(&command, "COMMIT\n");
return execIptablesRestore(V4V6, command.c_str());
}
//agold end
运行到最后就是调用iptables命令去添加或删除一些规则，若是没有接口能够参考上面的接口增长,熟悉下iptables的规则就知道怎么添加了。
WhiteListMode函数其实就调的下面的iptables命令
adb shell iptables -A fw_INPUT -j DROP ； // -A表示要添加规则到fw_INPUT链, -j DROP表示添加丢弃规则,丢弃全部输入包
adb shell iptables -A fw_OUTPUT -j REJECT // -A表示要添加规则到fw_OUTPU链, -j REJECT表示添加拒绝规则,拒绝全部输出包
adb shell iptables -A fw_FORWARD -j REJECT
adb shell iptables -I fw_OUTPUT -m owner --uid-owner 1016 -j ACCEPT // -I表示插入一条规则到fw_OUTPUT链,是一条白名单规则,容许uid 1016的数据包经过
adb shell iptables -I fw_INPUT -m owner --uid-owner 1016 -j ACCEPT
调用后iptables张下面这个样子，Chain OUTPUT的数据包经过Chain fw_OUTPUT控制, Chain fw_OUTPUT的规则是reject全部数据包,只容许uid 1016 vpn。
$ adb shell iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
bw_INPUT all -- anywhere anywhere
fw_INPUT all -- anywhere anywhere
Chain FORWARD (policy ACCEPT)
target prot opt source destination
oem_fwd all -- anywhere anywhere
fw_FORWARD all -- anywhere anywhere
bw_FORWARD all -- anywhere anywhere
natctrl_FORWARD all -- anywhere anywhere
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
oem_out all -- anywhere anywhere
firewall all -- anywhere anywhere
fw_OUTPUT all -- anywhere anywhere
st_OUTPUT all -- anywhere anywhere
bw_OUTPUT all -- anywhere anywhere
Chain fw_FORWARD (1 references)
target prot opt source destination
REJECT all -- anywhere anywhere reject-with icmp-port-unreachable
Chain fw_INPUT (1 references)
target prot opt source destination
RETURN all -- anywhere anywhere owner UID match vpn
DROP all -- anywhere anywhere
Chain fw_OUTPUT (1 references)
target prot opt source destination
RETURN all -- anywhere anywhere owner UID match vpn
REJECT all -- anywhere anywhere reject-with icmp-port-unreachable
BlackListMode函数其实就调的下面的iptables命令
adb shell iptables -F fw_INPUT
adb shell iptables -F fw_OUTPUT //清除fw_OUTPUT链上全部规则,容许全部数据包经过
adb shell iptables -D fw_INPUT -m owner --uid-owner 10086 -j DROP // -D表示删除一条规则
adb shell iptables -I fw_OUTPUT -m owner --uid-owner 10086 -j DROP // -I表示插入一条规则到fw_OUTPUT链,是一条黑名单规则,只禁止uid 10086的数据包经过
adb shell iptables -I fw_INPUT -m owner --uid-owner 10086 -j DROP
调用后iptables张下面这个样子，Chain OUTPUT的数据包经过Chain fw_OUTPUT控制, Chain fw_OUTPUT的规则是只丢弃
uid 为u11_a83(10086)的数据包，就是前面设置的app的uid 10086
~$adb shell iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
bw_INPUT all -- anywhere anywhere
fw_INPUT all -- anywhere anywhere
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
oem_out all -- anywhere anywhere
firewall all -- anywhere anywhere
fw_OUTPUT all -- anywhere anywhere
st_OUTPUT all -- anywhere anywhere
bw_OUTPUT all -- anywhere anywhere
Chain fw_INPUT (1 references)
target prot opt source destination
DROP all -- anywhere anywhere owner UID match u11_a83
Chain fw_OUTPUT (1 references)
target prot opt source destination
DROP all -- anywhere anywhere owner UID match u11_a83
若是须要单独控制wifi或移动数据，看DisableMobileMode里面setFirewallUidChainRule接口，这部分是厂商加的，若是没有能够按上面的内容进行添加，参考agold关键字，对照adb shell iptables -L的输出调试问题就不大了。
调用后iptables张下面这个样子，Chain OUTPUT的数据包经过Chain fw_OUTPUT 和Chain firewall控制, Chain fw_OUTPUT的规则为空就是不限制，Chain firewall经过mobile和wifi链控制wifi/mobile, Chain wifi为空，Chain mobile为reject owner UID match u0_a79
~$ adb shell iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
bw_INPUT all -- anywhere anywhere
fw_INPUT all -- anywhere anywhere
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
oem_out all -- anywhere anywhere
firewall all -- anywhere anywhere
fw_OUTPUT all -- anywhere anywhere
st_OUTPUT all -- anywhere anywhere
bw_OUTPUT all -- anywhere anywhere
Chain firewall (1 references)
target prot opt source destination
mobile all -- anywhere anywhere
mobile all -- anywhere anywhere
mobile all -- anywhere anywhere
mobile all -- anywhere anywhere
mobile all -- anywhere anywhere
wifi all -- anywhere anywhere
Chain fw_INPUT (1 references)
target prot opt source destination
Chain fw_OUTPUT (1 references)
target prot opt source destination
Chain mobile (5 references)
target prot opt source destination
REJECT all -- anywhere anywhere owner UID match u0_a79 reject-with icmp-port-unreachable
Chain wifi (1 references)
target prot opt source destination
iptables命令能够参考 https://blog.csdn.net/l1028386804/article/details/47356011