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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <resolv_netid.h>
#define LOG_TAG "SecondaryTablController"
#include <cutils/log.h>
#include <cutils/properties.h>
#include <logwrap/logwrap.h>
#include "ResponseCode.h"
#include "NetdConstants.h"
#include "SecondaryTableController.h"
const char* SecondaryTableController::LOCAL_MANGLE_OUTPUT = "st_mangle_OUTPUT";
const char* SecondaryTableController::LOCAL_MANGLE_EXEMPT = "st_mangle_EXEMPT";
const char* SecondaryTableController::LOCAL_MANGLE_IFACE_FORMAT = "st_mangle_%s_OUTPUT";
const char* SecondaryTableController::LOCAL_NAT_POSTROUTING = "st_nat_POSTROUTING";
const char* SecondaryTableController::LOCAL_FILTER_OUTPUT = "st_filter_OUTPUT";
SecondaryTableController::SecondaryTableController(NetworkController* controller) :
mNetCtrl(controller) {
}
SecondaryTableController::~SecondaryTableController() {
}
int SecondaryTableController::setupIptablesHooks() {
int res = execIptables(V4V6,
"-t",
"mangle",
"-F",
LOCAL_MANGLE_OUTPUT,
NULL);
res |= execIptables(V4V6,
"-t",
"mangle",
"-F",
LOCAL_MANGLE_EXEMPT,
NULL);
// rule for skipping anything marked with the PROTECT_MARK
char protect_mark_str[11];
snprintf(protect_mark_str, sizeof(protect_mark_str), "%d", PROTECT_MARK);
res |= execIptables(V4V6,
"-t",
"mangle",
"-A",
LOCAL_MANGLE_OUTPUT,
"-m",
"mark",
"--mark",
protect_mark_str,
"-j",
"RETURN",
NULL);
// protect the legacy VPN daemons from routes.
// TODO: Remove this when legacy VPN's are removed.
res |= execIptables(V4V6,
"-t",
"mangle",
"-A",
LOCAL_MANGLE_OUTPUT,
"-m",
"owner",
"--uid-owner",
"vpn",
"-j",
"RETURN",
NULL);
return res;
}
int SecondaryTableController::addRoute(SocketClient *cli, char *iface, char *dest, int prefix,
char *gateway) {
return modifyRoute(cli, ADD, iface, dest, prefix, gateway, mNetCtrl->getNetworkId(iface));
}
int SecondaryTableController::modifyRoute(SocketClient *cli, const char *action, char *iface,
char *dest, int prefix, char *gateway, unsigned netId) {
char dest_str[44]; // enough to store an IPv6 address + 3 character bitmask
char tableIndex_str[11];
int ret;
// IP tool doesn't like "::" - the equiv of 0.0.0.0 that it accepts for ipv4
snprintf(dest_str, sizeof(dest_str), "%s/%d", dest, prefix);
snprintf(tableIndex_str, sizeof(tableIndex_str), "%u", netId + BASE_TABLE_NUMBER);
if (strcmp("::", gateway) == 0) {
const char *cmd[] = {
IP_PATH,
"route",
action,
dest_str,
"dev",
iface,
"table",
tableIndex_str
};
ret = runCmd(ARRAY_SIZE(cmd), cmd);
} else {
const char *cmd[] = {
IP_PATH,
"route",
action,
dest_str,
"via",
gateway,
"dev",
iface,
"table",
tableIndex_str
};
ret = runCmd(ARRAY_SIZE(cmd), cmd);
}
if (ret) {
ALOGE("ip route %s failed: %s route %s %s/%d via %s dev %s table %u", action,
IP_PATH, action, dest, prefix, gateway, iface, netId + BASE_TABLE_NUMBER);
errno = ENODEV;
cli->sendMsg(ResponseCode::OperationFailed, "ip route modification failed", true);
return -1;
}
modifyRuleCount(netId, action);
cli->sendMsg(ResponseCode::CommandOkay, "Route modified", false);
return 0;
}
void SecondaryTableController::modifyRuleCount(unsigned netId, const char *action) {
if (strcmp(action, ADD) == 0) {
if (mNetIdRuleCount.count(netId) == 0)
mNetIdRuleCount[netId] = 0;
mNetIdRuleCount[netId]++;
} else {
if (mNetIdRuleCount.count(netId) > 0) {
if (--mNetIdRuleCount[netId] < 1) {
mNetIdRuleCount.erase(mNetIdRuleCount.find(netId));
}
}
}
}
const char *SecondaryTableController::getVersion(const char *addr) {
if (strchr(addr, ':') != NULL) {
return "-6";
} else {
return "-4";
}
}
IptablesTarget SecondaryTableController::getIptablesTarget(const char *addr) {
if (strchr(addr, ':') != NULL) {
return V6;
} else {
return V4;
}
}
int SecondaryTableController::removeRoute(SocketClient *cli, char *iface, char *dest, int prefix,
char *gateway) {
return modifyRoute(cli, DEL, iface, dest, prefix, gateway, mNetCtrl->getNetworkId(iface));
}
int SecondaryTableController::modifyFromRule(unsigned netId, const char *action,
const char *addr) {
char tableIndex_str[11];
snprintf(tableIndex_str, sizeof(tableIndex_str), "%u", netId + BASE_TABLE_NUMBER);
const char *cmd[] = {
IP_PATH,
getVersion(addr),
"rule",
action,
"from",
addr,
"table",
tableIndex_str
};
if (runCmd(ARRAY_SIZE(cmd), cmd)) {
return -1;
}
modifyRuleCount(netId, action);
return 0;
}
int SecondaryTableController::modifyLocalRoute(unsigned netId, const char *action,
const char *iface, const char *addr) {
char tableIndex_str[11];
modifyRuleCount(netId, action); // some del's will fail as the iface is already gone.
snprintf(tableIndex_str, sizeof(tableIndex_str), "%u", netId + BASE_TABLE_NUMBER);
const char *cmd[] = {
IP_PATH,
"route",
action,
addr,
"dev",
iface,
"table",
tableIndex_str
};
return runCmd(ARRAY_SIZE(cmd), cmd);
}
int SecondaryTableController::addFwmarkRule(const char *iface) {
return setFwmarkRule(iface, true);
}
int SecondaryTableController::removeFwmarkRule(const char *iface) {
return setFwmarkRule(iface, false);
}
int SecondaryTableController::setFwmarkRule(const char *iface, bool add) {
unsigned netId = mNetCtrl->getNetworkId(iface);
// Fail fast if any rules already exist for this interface
if (mNetIdRuleCount.count(netId) > 0) {
errno = EBUSY;
return -1;
}
int ret;
char mark_str[11];
snprintf(mark_str, sizeof(mark_str), "%u", netId + BASE_TABLE_NUMBER);
//add the catch all route to the tun. Route rules will make sure the right packets hit the table
const char *route_cmd[] = {
IP_PATH,
"route",
add ? "add" : "del",
"default",
"dev",
iface,
"table",
mark_str
};
ret = runCmd(ARRAY_SIZE(route_cmd), route_cmd);
const char *fwmark_cmd[] = {
IP_PATH,
"rule",
add ? "add" : "del",
"prio",
RULE_PRIO,
"fwmark",
mark_str,
"table",
mark_str
};
ret = runCmd(ARRAY_SIZE(fwmark_cmd), fwmark_cmd);
if (ret) return ret;
//add rules for v6
const char *route6_cmd[] = {
IP_PATH,
"-6",
"route",
add ? "add" : "del",
"default",
"dev",
iface,
"table",
mark_str
};
ret = runCmd(ARRAY_SIZE(route6_cmd), route6_cmd);
const char *fwmark6_cmd[] = {
IP_PATH,
"-6",
"rule",
add ? "add" : "del",
"prio",
RULE_PRIO,
"fwmark",
mark_str,
"table",
mark_str
};
ret = runCmd(ARRAY_SIZE(fwmark6_cmd), fwmark6_cmd);
if (ret) return ret;
//create the route rule chain
char chain_str[IFNAMSIZ + 18];
snprintf(chain_str, sizeof(chain_str), LOCAL_MANGLE_IFACE_FORMAT, iface);
//code split due to ordering requirements
if (add) {
ret = execIptables(V4V6,
"-t",
"mangle",
"-N",
chain_str,
NULL);
//set up the rule for sending premarked packets to the VPN chain
//Insert these at the top of the chain so they trigger before any UID rules
ret |= execIptables(V4V6,
"-t",
"mangle",
"-I",
LOCAL_MANGLE_OUTPUT,
"3",
"-m",
"mark",
"--mark",
mark_str,
"-g",
chain_str,
NULL);
//add a rule to clear the mark in the VPN chain
//packets marked with SO_MARK already have the iface's mark set but unless they match a
//route they should hit the network instead of the VPN
ret |= execIptables(V4V6,
"-t",
"mangle",
"-A",
chain_str,
"-j",
"MARK",
"--set-mark",
"0",
NULL);
} else {
ret = execIptables(V4V6,
"-t",
"mangle",
"-D",
LOCAL_MANGLE_OUTPUT,
"-m",
"mark",
"--mark",
mark_str,
"-g",
chain_str,
NULL);
//clear and delete the chain
ret |= execIptables(V4V6,
"-t",
"mangle",
"-F",
chain_str,
NULL);
ret |= execIptables(V4V6,
"-t",
"mangle",
"-X",
chain_str,
NULL);
}
//set up the needed source IP rewriting
//NOTE: Without ipv6 NAT in the kernel <3.7 only support V4 NAT
ret = execIptables(V4,
"-t",
"nat",
add ? "-A" : "-D",
LOCAL_NAT_POSTROUTING,
"-o",
iface,
"-m",
"mark",
"--mark",
mark_str,
"-j",
"MASQUERADE",
NULL);
if (ret) return ret;
//try and set up for ipv6. ipv6 nat came in the kernel only in 3.7, so this can fail
ret = execIptables(V6,
"-t",
"nat",
add ? "-A" : "-D",
LOCAL_NAT_POSTROUTING,
"-o",
iface,
"-m",
"mark",
"--mark",
mark_str,
"-j",
"MASQUERADE",
NULL);
if (ret) {
//Without V6 NAT we can't do V6 over VPNs.
ret = execIptables(V6,
"-t",
"filter",
add ? "-A" : "-D",
LOCAL_FILTER_OUTPUT,
"-m",
"mark",
"--mark",
mark_str,
"-j",
"REJECT",
NULL);
}
return ret;
}
int SecondaryTableController::addFwmarkRoute(const char* iface, const char *dest, int prefix) {
return setFwmarkRoute(iface, dest, prefix, true);
}
int SecondaryTableController::removeFwmarkRoute(const char* iface, const char *dest, int prefix) {
return setFwmarkRoute(iface, dest, prefix, false);
}
int SecondaryTableController::setFwmarkRoute(const char* iface, const char *dest, int prefix,
bool add) {
unsigned netId = mNetCtrl->getNetworkId(iface);
char mark_str[11] = {0};
char chain_str[IFNAMSIZ + 18];
char dest_str[44]; // enough to store an IPv6 address + 3 character bitmask
snprintf(mark_str, sizeof(mark_str), "%u", netId + BASE_TABLE_NUMBER);
snprintf(chain_str, sizeof(chain_str), LOCAL_MANGLE_IFACE_FORMAT, iface);
snprintf(dest_str, sizeof(dest_str), "%s/%d", dest, prefix);
return execIptables(getIptablesTarget(dest),
"-t",
"mangle",
add ? "-A" : "-D",
chain_str,
"-d",
dest_str,
"-j",
"MARK",
"--set-mark",
mark_str,
NULL);
}
int SecondaryTableController::addUidRule(const char *iface, int uid_start, int uid_end) {
return setUidRule(iface, uid_start, uid_end, true);
}
int SecondaryTableController::removeUidRule(const char *iface, int uid_start, int uid_end) {
return setUidRule(iface, uid_start, uid_end, false);
}
int SecondaryTableController::setUidRule(const char *iface, int uid_start, int uid_end, bool add) {
unsigned netId = mNetCtrl->getNetworkId(iface);
if (!mNetCtrl->setNetworkForUidRange(uid_start, uid_end, add ? netId : 0, false)) {
errno = EINVAL;
return -1;
}
char uid_str[24] = {0};
char chain_str[IFNAMSIZ + 18];
snprintf(uid_str, sizeof(uid_str), "%d-%d", uid_start, uid_end);
snprintf(chain_str, sizeof(chain_str), LOCAL_MANGLE_IFACE_FORMAT, iface);
return execIptables(V4V6,
"-t",
"mangle",
add ? "-A" : "-D",
LOCAL_MANGLE_OUTPUT,
"-m",
"owner",
"--uid-owner",
uid_str,
"-g",
chain_str,
NULL);
}
int SecondaryTableController::addHostExemption(const char *host) {
return setHostExemption(host, true);
}
int SecondaryTableController::removeHostExemption(const char *host) {
return setHostExemption(host, false);
}
int SecondaryTableController::setHostExemption(const char *host, bool add) {
IptablesTarget target = !strcmp(getVersion(host), "-4") ? V4 : V6;
char protect_mark_str[11];
snprintf(protect_mark_str, sizeof(protect_mark_str), "%d", PROTECT_MARK);
int ret = execIptables(target,
"-t",
"mangle",
add ? "-A" : "-D",
LOCAL_MANGLE_EXEMPT,
"-d",
host,
"-j",
"MARK",
"--set-mark",
protect_mark_str,
NULL);
const char *cmd[] = {
IP_PATH,
getVersion(host),
"rule",
add ? "add" : "del",
"prio",
EXEMPT_PRIO,
"to",
host,
"table",
"main"
};
ret |= runCmd(ARRAY_SIZE(cmd), cmd);
return ret;
}
void SecondaryTableController::getUidMark(SocketClient *cli, int uid) {
unsigned netId = mNetCtrl->getNetwork(uid, NETID_UNSET, NetworkController::PID_UNSPECIFIED,
false);
char mark_str[11];
snprintf(mark_str, sizeof(mark_str), "%u", netId + BASE_TABLE_NUMBER);
cli->sendMsg(ResponseCode::GetMarkResult, mark_str, false);
}
void SecondaryTableController::getProtectMark(SocketClient *cli) {
char protect_mark_str[11];
snprintf(protect_mark_str, sizeof(protect_mark_str), "%d", PROTECT_MARK);
cli->sendMsg(ResponseCode::GetMarkResult, protect_mark_str, false);
}
int SecondaryTableController::runCmd(int argc, const char **argv) {
int ret = 0;
ret = android_fork_execvp(argc, (char **)argv, NULL, false, false);
return ret;
}