383 lines
11 KiB
C++
383 lines
11 KiB
C++
/*
|
|
* 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 <netdb.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>
|
|
|
|
#define LOG_TAG "TetherController"
|
|
#include <cutils/log.h>
|
|
#include <cutils/properties.h>
|
|
|
|
#include "Fwmark.h"
|
|
#include "NetdConstants.h"
|
|
#include "Permission.h"
|
|
#include "InterfaceController.h"
|
|
#include "NetworkController.h"
|
|
#include "TetherController.h"
|
|
|
|
namespace {
|
|
|
|
const char BP_TOOLS_MODE[] = "bp-tools";
|
|
const char IPV4_FORWARDING_PROC_FILE[] = "/proc/sys/net/ipv4/ip_forward";
|
|
const char IPV6_FORWARDING_PROC_FILE[] = "/proc/sys/net/ipv6/conf/all/forwarding";
|
|
const char SEPARATOR[] = "|";
|
|
constexpr const char kTcpBeLiberal[] = "/proc/sys/net/netfilter/nf_conntrack_tcp_be_liberal";
|
|
|
|
bool writeToFile(const char* filename, const char* value) {
|
|
int fd = open(filename, O_WRONLY | O_CLOEXEC);
|
|
if (fd < 0) {
|
|
ALOGE("Failed to open %s: %s", filename, strerror(errno));
|
|
return false;
|
|
}
|
|
|
|
const ssize_t len = strlen(value);
|
|
if (write(fd, value, len) != len) {
|
|
ALOGE("Failed to write %s to %s: %s", value, filename, strerror(errno));
|
|
close(fd);
|
|
return false;
|
|
}
|
|
close(fd);
|
|
return true;
|
|
}
|
|
|
|
// TODO: Consider altering TCP and UDP timeouts as well.
|
|
void configureForTethering(bool enabled) {
|
|
writeToFile(kTcpBeLiberal, enabled ? "1" : "0");
|
|
}
|
|
|
|
bool configureForIPv6Router(const char *interface) {
|
|
return (InterfaceController::setEnableIPv6(interface, 0) == 0)
|
|
&& (InterfaceController::setAcceptIPv6Ra(interface, 0) == 0)
|
|
&& (InterfaceController::setAcceptIPv6Dad(interface, 0) == 0)
|
|
&& (InterfaceController::setIPv6DadTransmits(interface, "0") == 0)
|
|
&& (InterfaceController::setEnableIPv6(interface, 1) == 0);
|
|
}
|
|
|
|
void configureForIPv6Client(const char *interface) {
|
|
InterfaceController::setAcceptIPv6Ra(interface, 1);
|
|
InterfaceController::setAcceptIPv6Dad(interface, 1);
|
|
InterfaceController::setIPv6DadTransmits(interface, "1");
|
|
InterfaceController::setEnableIPv6(interface, 0);
|
|
}
|
|
|
|
bool inBpToolsMode() {
|
|
// In BP tools mode, do not disable IP forwarding
|
|
char bootmode[PROPERTY_VALUE_MAX] = {0};
|
|
property_get("ro.bootmode", bootmode, "unknown");
|
|
return !strcmp(BP_TOOLS_MODE, bootmode);
|
|
}
|
|
|
|
} // namespace
|
|
|
|
namespace android {
|
|
namespace net {
|
|
|
|
TetherController::TetherController() {
|
|
mDnsNetId = 0;
|
|
mDaemonFd = -1;
|
|
mDaemonPid = 0;
|
|
if (inBpToolsMode()) {
|
|
enableForwarding(BP_TOOLS_MODE);
|
|
} else {
|
|
setIpFwdEnabled();
|
|
}
|
|
}
|
|
|
|
TetherController::~TetherController() {
|
|
mInterfaces.clear();
|
|
mDnsForwarders.clear();
|
|
mForwardingRequests.clear();
|
|
}
|
|
|
|
bool TetherController::setIpFwdEnabled() {
|
|
bool success = true;
|
|
const char* value = mForwardingRequests.empty() ? "0" : "1";
|
|
ALOGD("Setting IP forward enable = %s", value);
|
|
success &= writeToFile(IPV4_FORWARDING_PROC_FILE, value);
|
|
success &= writeToFile(IPV6_FORWARDING_PROC_FILE, value);
|
|
return success;
|
|
}
|
|
|
|
bool TetherController::enableForwarding(const char* requester) {
|
|
// Don't return an error if this requester already requested forwarding. Only return errors for
|
|
// things that the caller caller needs to care about, such as "couldn't write to the file to
|
|
// enable forwarding".
|
|
mForwardingRequests.insert(requester);
|
|
return setIpFwdEnabled();
|
|
}
|
|
|
|
bool TetherController::disableForwarding(const char* requester) {
|
|
mForwardingRequests.erase(requester);
|
|
return setIpFwdEnabled();
|
|
}
|
|
|
|
size_t TetherController::forwardingRequestCount() {
|
|
return mForwardingRequests.size();
|
|
}
|
|
|
|
#define TETHER_START_CONST_ARG 10
|
|
|
|
int TetherController::startTethering(int num_addrs, char **dhcp_ranges) {
|
|
if (mDaemonPid != 0) {
|
|
ALOGE("Tethering already started");
|
|
errno = EBUSY;
|
|
return -1;
|
|
}
|
|
|
|
ALOGD("Starting tethering services");
|
|
|
|
pid_t pid;
|
|
int pipefd[2];
|
|
|
|
if (pipe(pipefd) < 0) {
|
|
ALOGE("pipe failed (%s)", strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* TODO: Create a monitoring thread to handle and restart
|
|
* the daemon if it exits prematurely
|
|
*/
|
|
if ((pid = fork()) < 0) {
|
|
ALOGE("fork failed (%s)", strerror(errno));
|
|
close(pipefd[0]);
|
|
close(pipefd[1]);
|
|
return -1;
|
|
}
|
|
|
|
if (!pid) {
|
|
close(pipefd[1]);
|
|
if (pipefd[0] != STDIN_FILENO) {
|
|
if (dup2(pipefd[0], STDIN_FILENO) != STDIN_FILENO) {
|
|
ALOGE("dup2 failed (%s)", strerror(errno));
|
|
return -1;
|
|
}
|
|
close(pipefd[0]);
|
|
}
|
|
|
|
Fwmark fwmark;
|
|
fwmark.netId = NetworkController::LOCAL_NET_ID;
|
|
fwmark.explicitlySelected = true;
|
|
fwmark.protectedFromVpn = true;
|
|
fwmark.permission = PERMISSION_SYSTEM;
|
|
char markStr[UINT32_HEX_STRLEN];
|
|
snprintf(markStr, sizeof(markStr), "0x%x", fwmark.intValue);
|
|
|
|
int num_processed_args = TETHER_START_CONST_ARG + (num_addrs/2) + 1;
|
|
char **args = (char **)malloc(sizeof(char *) * num_processed_args);
|
|
args[num_processed_args - 1] = NULL;
|
|
args[0] = (char *)"/system/bin/dnsmasq";
|
|
args[1] = (char *)"--keep-in-foreground";
|
|
args[2] = (char *)"--no-resolv";
|
|
args[3] = (char *)"--no-poll";
|
|
args[4] = (char *)"--dhcp-authoritative";
|
|
// TODO: pipe through metered status from ConnService
|
|
args[5] = (char *)"--dhcp-option-force=43,ANDROID_METERED";
|
|
args[6] = (char *)"--pid-file";
|
|
args[7] = (char *)"--listen-mark";
|
|
args[8] = (char *)markStr;
|
|
args[9] = (char *)"";
|
|
|
|
int nextArg = TETHER_START_CONST_ARG;
|
|
for (int addrIndex = 0; addrIndex < num_addrs; addrIndex += 2) {
|
|
asprintf(&(args[nextArg++]),"--dhcp-range=%s,%s,1h",
|
|
dhcp_ranges[addrIndex], dhcp_ranges[addrIndex+1]);
|
|
}
|
|
|
|
if (execv(args[0], args)) {
|
|
ALOGE("execl failed (%s)", strerror(errno));
|
|
}
|
|
ALOGE("Should never get here!");
|
|
_exit(-1);
|
|
} else {
|
|
close(pipefd[0]);
|
|
mDaemonPid = pid;
|
|
mDaemonFd = pipefd[1];
|
|
configureForTethering(true);
|
|
applyDnsInterfaces();
|
|
ALOGD("Tethering services running");
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int TetherController::stopTethering() {
|
|
configureForTethering(false);
|
|
|
|
if (mDaemonPid == 0) {
|
|
ALOGE("Tethering already stopped");
|
|
return 0;
|
|
}
|
|
|
|
ALOGD("Stopping tethering services");
|
|
|
|
kill(mDaemonPid, SIGTERM);
|
|
waitpid(mDaemonPid, NULL, 0);
|
|
mDaemonPid = 0;
|
|
close(mDaemonFd);
|
|
mDaemonFd = -1;
|
|
ALOGD("Tethering services stopped");
|
|
return 0;
|
|
}
|
|
|
|
bool TetherController::isTetheringStarted() {
|
|
return (mDaemonPid == 0 ? false : true);
|
|
}
|
|
|
|
#define MAX_CMD_SIZE 1024
|
|
|
|
int TetherController::setDnsForwarders(unsigned netId, char **servers, int numServers) {
|
|
int i;
|
|
char daemonCmd[MAX_CMD_SIZE];
|
|
|
|
Fwmark fwmark;
|
|
fwmark.netId = netId;
|
|
fwmark.explicitlySelected = true;
|
|
fwmark.protectedFromVpn = true;
|
|
fwmark.permission = PERMISSION_SYSTEM;
|
|
|
|
snprintf(daemonCmd, sizeof(daemonCmd), "update_dns%s0x%x", SEPARATOR, fwmark.intValue);
|
|
int cmdLen = strlen(daemonCmd);
|
|
|
|
mDnsForwarders.clear();
|
|
for (i = 0; i < numServers; i++) {
|
|
ALOGD("setDnsForwarders(0x%x %d = '%s')", fwmark.intValue, i, servers[i]);
|
|
|
|
addrinfo *res, hints = { .ai_flags = AI_NUMERICHOST };
|
|
int ret = getaddrinfo(servers[i], NULL, &hints, &res);
|
|
freeaddrinfo(res);
|
|
if (ret) {
|
|
ALOGE("Failed to parse DNS server '%s'", servers[i]);
|
|
mDnsForwarders.clear();
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
cmdLen += (strlen(servers[i]) + 1);
|
|
if (cmdLen + 1 >= MAX_CMD_SIZE) {
|
|
ALOGD("Too many DNS servers listed");
|
|
break;
|
|
}
|
|
|
|
strcat(daemonCmd, SEPARATOR);
|
|
strcat(daemonCmd, servers[i]);
|
|
mDnsForwarders.push_back(servers[i]);
|
|
}
|
|
|
|
mDnsNetId = netId;
|
|
if (mDaemonFd != -1) {
|
|
ALOGD("Sending update msg to dnsmasq [%s]", daemonCmd);
|
|
if (write(mDaemonFd, daemonCmd, strlen(daemonCmd) +1) < 0) {
|
|
ALOGE("Failed to send update command to dnsmasq (%s)", strerror(errno));
|
|
mDnsForwarders.clear();
|
|
errno = EREMOTEIO;
|
|
return -1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
unsigned TetherController::getDnsNetId() {
|
|
return mDnsNetId;
|
|
}
|
|
|
|
const std::list<std::string> &TetherController::getDnsForwarders() const {
|
|
return mDnsForwarders;
|
|
}
|
|
|
|
bool TetherController::applyDnsInterfaces() {
|
|
char daemonCmd[MAX_CMD_SIZE];
|
|
|
|
strcpy(daemonCmd, "update_ifaces");
|
|
int cmdLen = strlen(daemonCmd);
|
|
bool haveInterfaces = false;
|
|
|
|
for (const auto &ifname : mInterfaces) {
|
|
cmdLen += (ifname.size() + 1);
|
|
if (cmdLen + 1 >= MAX_CMD_SIZE) {
|
|
ALOGD("Too many DNS ifaces listed");
|
|
break;
|
|
}
|
|
|
|
strcat(daemonCmd, SEPARATOR);
|
|
strcat(daemonCmd, ifname.c_str());
|
|
haveInterfaces = true;
|
|
}
|
|
|
|
if ((mDaemonFd != -1) && haveInterfaces) {
|
|
ALOGD("Sending update msg to dnsmasq [%s]", daemonCmd);
|
|
if (write(mDaemonFd, daemonCmd, strlen(daemonCmd) +1) < 0) {
|
|
ALOGE("Failed to send update command to dnsmasq (%s)", strerror(errno));
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
int TetherController::tetherInterface(const char *interface) {
|
|
ALOGD("tetherInterface(%s)", interface);
|
|
if (!isIfaceName(interface)) {
|
|
errno = ENOENT;
|
|
return -1;
|
|
}
|
|
|
|
if (!configureForIPv6Router(interface)) {
|
|
configureForIPv6Client(interface);
|
|
return -1;
|
|
}
|
|
mInterfaces.push_back(interface);
|
|
|
|
if (!applyDnsInterfaces()) {
|
|
mInterfaces.pop_back();
|
|
configureForIPv6Client(interface);
|
|
return -1;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
int TetherController::untetherInterface(const char *interface) {
|
|
ALOGD("untetherInterface(%s)", interface);
|
|
|
|
for (auto it = mInterfaces.cbegin(); it != mInterfaces.cend(); ++it) {
|
|
if (!strcmp(interface, it->c_str())) {
|
|
mInterfaces.erase(it);
|
|
|
|
configureForIPv6Client(interface);
|
|
return applyDnsInterfaces() ? 0 : -1;
|
|
}
|
|
}
|
|
errno = ENOENT;
|
|
return -1;
|
|
}
|
|
|
|
const std::list<std::string> &TetherController::getTetheredInterfaceList() const {
|
|
return mInterfaces;
|
|
}
|
|
|
|
} // namespace net
|
|
} // namespace android
|