#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
+#include <netdb.h>
#include <string.h>
#include <sys/socket.h>
#include "Permission.h"
#include "TetherController.h"
+namespace {
+
+static const char BP_TOOLS_MODE[] = "bp-tools";
+static const char IPV4_FORWARDING_PROC_FILE[] = "/proc/sys/net/ipv4/ip_forward";
+static const char IPV6_FORWARDING_PROC_FILE[] = "/proc/sys/net/ipv6/conf/all/forwarding";
+static const char SEPARATOR[] = "|";
+
+bool writeToFile(const char* filename, const char* value) {
+ int fd = open(filename, O_WRONLY);
+ 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;
+}
+
+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
+
TetherController::TetherController() {
mInterfaces = new InterfaceCollection();
mDnsNetId = 0;
mDnsForwarders = new NetAddressCollection();
mDaemonFd = -1;
mDaemonPid = 0;
+ if (inBpToolsMode()) {
+ enableForwarding(BP_TOOLS_MODE);
+ } else {
+ setIpFwdEnabled();
+ }
}
TetherController::~TetherController() {
mInterfaces->clear();
mDnsForwarders->clear();
+ mForwardingRequests.clear();
}
-int TetherController::setIpFwdEnabled(bool enable) {
-
- ALOGD("Setting IP forward enable = %d", enable);
-
- // In BP tools mode, do not disable IP forwarding
- char bootmode[PROPERTY_VALUE_MAX] = {0};
- property_get("ro.bootmode", bootmode, "unknown");
- if ((enable == false) && (0 == strcmp("bp-tools", bootmode))) {
- return 0;
- }
-
- int fd = open("/proc/sys/net/ipv4/ip_forward", O_WRONLY);
- if (fd < 0) {
- ALOGE("Failed to open ip_forward (%s)", strerror(errno));
- return -1;
- }
-
- if (write(fd, (enable ? "1" : "0"), 1) != 1) {
- ALOGE("Failed to write ip_forward (%s)", strerror(errno));
- close(fd);
- return -1;
- }
- close(fd);
- return 0;
+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::getIpFwdEnabled() {
- int fd = open("/proc/sys/net/ipv4/ip_forward", O_RDONLY);
-
- if (fd < 0) {
- ALOGE("Failed to open ip_forward (%s)", strerror(errno));
- return false;
- }
+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();
+}
- char enabled;
- if (read(fd, &enabled, 1) != 1) {
- ALOGE("Failed to read ip_forward (%s)", strerror(errno));
- close(fd);
- return -1;
- }
+bool TetherController::disableForwarding(const char* requester) {
+ mForwardingRequests.erase(requester);
+ return setIpFwdEnabled();
+}
- close(fd);
- return (enabled == '1' ? true : false);
+size_t TetherController::forwardingRequestCount() {
+ return mForwardingRequests.size();
}
#define TETHER_START_CONST_ARG 8
-int TetherController::startTethering(int num_addrs, struct in_addr* addrs) {
+int TetherController::startTethering(int num_addrs, char **dhcp_ranges) {
if (mDaemonPid != 0) {
ALOGE("Tethering already started");
errno = EBUSY;
args[7] = (char *)"";
int nextArg = TETHER_START_CONST_ARG;
- for (int addrIndex=0; addrIndex < num_addrs;) {
- char *start = strdup(inet_ntoa(addrs[addrIndex++]));
- char *end = strdup(inet_ntoa(addrs[addrIndex++]));
- asprintf(&(args[nextArg++]),"--dhcp-range=%s,%s,1h", start, end);
- free(start);
- free(end);
+ 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)) {
fwmark.protectedFromVpn = true;
fwmark.permission = PERMISSION_SYSTEM;
- snprintf(daemonCmd, sizeof(daemonCmd), "update_dns:0x%x", fwmark.intValue);
+ 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]);
- struct in_addr a;
-
- if (!inet_aton(servers[i], &a)) {
+ 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;
}
break;
}
- strcat(daemonCmd, ":");
+ strcat(daemonCmd, SEPARATOR);
strcat(daemonCmd, servers[i]);
- mDnsForwarders->push_back(a);
+ mDnsForwarders->push_back(servers[i]);
}
mDnsNetId = netId;
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;
}
}
break;
}
- strcat(daemonCmd, ":");
+ strcat(daemonCmd, SEPARATOR);
strcat(daemonCmd, *it);
haveInterfaces = true;
}