ClatdController.cpp revision 45d3dd0ad99d566ea589d9d5d37102ef35ca8fb2 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16#include <unistd.h>
17#include <errno.h>
18#include <sys/types.h>
19#include <sys/wait.h>
20
21#define LOG_TAG "ClatdController"
22#include <cutils/log.h>
23
24#include "ClatdController.h"
25#include "Fwmark.h"
26#include "NetdConstants.h"
27#include "NetworkController.h"
28
29ClatdController::ClatdController(NetworkController* controller)
30        : mNetCtrl(controller), mClatdPid(0) {
31}
32
33ClatdController::~ClatdController() {
34}
35
36int ClatdController::startClatd(char *interface) {
37    pid_t pid;
38
39    if(mClatdPid != 0) {
40        ALOGE("clatd already running");
41        errno = EBUSY;
42        return -1;
43    }
44
45    ALOGD("starting clatd");
46
47    if ((pid = fork()) < 0) {
48        ALOGE("fork failed (%s)", strerror(errno));
49        return -1;
50    }
51
52    if (!pid) {
53        // Pass in the interface, a netid to use for DNS lookups, and a fwmark for outgoing packets.
54        unsigned netId = mNetCtrl->getNetworkId(interface);
55        char netIdString[UINT32_STRLEN];
56        snprintf(netIdString, sizeof(netIdString), "%u", netId);
57
58        Fwmark fwmark = { netId, true, true, PERMISSION_CONNECTIVITY_INTERNAL };
59        char fwmarkString[UINT32_HEX_STRLEN];
60        snprintf(fwmarkString, sizeof(fwmarkString), "0x%x", fwmark.intValue);
61
62        char *args[] = {
63            (char *) "/system/bin/clatd",
64            (char *) "-i",
65            interface,
66            (char *) "-n",
67            netIdString,
68            (char *) "-m",
69            fwmarkString,
70            NULL
71        };
72
73        if (execv(args[0], args)) {
74            ALOGE("execv failed (%s)", strerror(errno));
75        }
76        ALOGE("Should never get here!");
77        _exit(0);
78    } else {
79        mClatdPid = pid;
80        ALOGD("clatd started");
81    }
82
83    return 0;
84}
85
86int ClatdController::stopClatd() {
87    if (mClatdPid == 0) {
88        ALOGE("clatd already stopped");
89        return -1;
90    }
91
92    ALOGD("Stopping clatd");
93
94    kill(mClatdPid, SIGTERM);
95    waitpid(mClatdPid, NULL, 0);
96    mClatdPid = 0;
97
98    ALOGD("clatd stopped");
99
100    return 0;
101}
102
103bool ClatdController::isClatdStarted() {
104    pid_t waitpid_status;
105    if(mClatdPid == 0) {
106        return false;
107    }
108    waitpid_status = waitpid(mClatdPid, NULL, WNOHANG);
109    if(waitpid_status != 0) {
110        mClatdPid = 0; // child exited, don't call waitpid on it again
111    }
112    return waitpid_status == 0; // 0 while child is running
113}
114