1 files changed, 331 insertions, 0 deletions
diff --git a/server/TetherController.cpp b/server/TetherController.cpp
new file mode 100644
index 00000000..fb51c06c
--- /dev/null
+++ b/server/TetherController.cpp
@@ -0,0 +1,331 @@
+/*
+ * 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>
+
+#define LOG_TAG "TetherController"
+#include <cutils/log.h>
+#include <cutils/properties.h>
+
+#include "Fwmark.h"
+#include "NetdConstants.h"
+#include "Permission.h"
+#include "TetherController.h"
+
+TetherController::TetherController() {
+    mInterfaces = new InterfaceCollection();
+    mDnsNetId = 0;
+    mDnsForwarders = new NetAddressCollection();
+    mDaemonFd = -1;
+    mDaemonPid = 0;
+}
+
+TetherController::~TetherController() {
+    InterfaceCollection::iterator it;
+
+    for (it = mInterfaces->begin(); it != mInterfaces->end(); ++it) {
+        free(*it);
+    }
+    mInterfaces->clear();
+
+    mDnsForwarders->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::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;
+    }
+
+    char enabled;
+    if (read(fd, &enabled, 1) != 1) {
+        ALOGE("Failed to read ip_forward (%s)", strerror(errno));
+        close(fd);
+        return -1;
+    }
+
+    close(fd);
+    return (enabled  == '1' ? true : false);
+}
+
+#define TETHER_START_CONST_ARG        8
+
+int TetherController::startTethering(int num_addrs, struct in_addr* addrs) {
+    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]);
+        }
+
+        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 *)"";
+
+        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);
+        }
+
+        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];
+        applyDnsInterfaces();
+        ALOGD("Tethering services running");
+    }
+
+    return 0;
+}
+
+int TetherController::stopTethering() {
+
+    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:0x%x", 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)) {
+            ALOGE("Failed to parse DNS server '%s'", servers[i]);
+            mDnsForwarders->clear();
+            return -1;
+        }
+
+        cmdLen += (strlen(servers[i]) + 1);
+        if (cmdLen + 1 >= MAX_CMD_SIZE) {
+            ALOGD("Too many DNS servers listed");
+            break;
+        }
+
+        strcat(daemonCmd, ":");
+        strcat(daemonCmd, servers[i]);
+        mDnsForwarders->push_back(a);
+    }
+
+    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();
+            return -1;
+        }
+    }
+    return 0;
+}
+
+unsigned TetherController::getDnsNetId() {
+    return mDnsNetId;
+}
+
+NetAddressCollection *TetherController::getDnsForwarders() {
+    return mDnsForwarders;
+}
+
+int TetherController::applyDnsInterfaces() {
+    char daemonCmd[MAX_CMD_SIZE];
+
+    strcpy(daemonCmd, "update_ifaces");
+    int cmdLen = strlen(daemonCmd);
+    InterfaceCollection::iterator it;
+    bool haveInterfaces = false;
+
+    for (it = mInterfaces->begin(); it != mInterfaces->end(); ++it) {
+        cmdLen += (strlen(*it) + 1);
+        if (cmdLen + 1 >= MAX_CMD_SIZE) {
+            ALOGD("Too many DNS ifaces listed");
+            break;
+        }
+
+        strcat(daemonCmd, ":");
+        strcat(daemonCmd, *it);
+        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 -1;
+        }
+    }
+    return 0;
+}
+
+int TetherController::tetherInterface(const char *interface) {
+    ALOGD("tetherInterface(%s)", interface);
+    if (!isIfaceName(interface)) {
+        errno = ENOENT;
+        return -1;
+    }
+    mInterfaces->push_back(strdup(interface));
+
+    if (applyDnsInterfaces()) {
+        InterfaceCollection::iterator it;
+        for (it = mInterfaces->begin(); it != mInterfaces->end(); ++it) {
+            if (!strcmp(interface, *it)) {
+                free(*it);
+                mInterfaces->erase(it);
+                break;
+            }
+        }
+        return -1;
+    } else {
+        return 0;
+    }
+}
+
+int TetherController::untetherInterface(const char *interface) {
+    InterfaceCollection::iterator it;
+
+    ALOGD("untetherInterface(%s)", interface);
+
+    for (it = mInterfaces->begin(); it != mInterfaces->end(); ++it) {
+        if (!strcmp(interface, *it)) {
+            free(*it);
+            mInterfaces->erase(it);
+
+            return applyDnsInterfaces();
+        }
+    }
+    errno = ENOENT;
+    return -1;
+}
+
+InterfaceCollection *TetherController::getTetheredInterfaceList() {
+    return mInterfaces;
+}