ClatdController.cpp revision 69261cb65186e27dfbdc1e3eec796437f9968ff9 
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 "NetdConstants.h"
25#include "ClatdController.h"
26#include "Fwmark.h"
27#include "NetdConstants.h"
28#include "NetworkController.h"
29
30ClatdController::ClatdController(NetworkController* controller)
31        : mNetCtrl(controller), mClatdPid(0) {
32}
33
34ClatdController::~ClatdController() {
35}
36
37int ClatdController::startClatd(char *interface) {
38    pid_t pid;
39
40    if(mClatdPid != 0) {
41        ALOGE("clatd already running");
42        errno = EBUSY;
43        return -1;
44    }
45
46    if (!isIfaceName(interface)) {
47        errno = ENOENT;
48        return -1;
49    }
50
51    ALOGD("starting clatd");
52
53    if ((pid = fork()) < 0) {
54        ALOGE("fork failed (%s)", strerror(errno));
55        return -1;
56    }
57
58    if (!pid) {
59        // Pass in the interface, a netid to use for DNS lookups, and a fwmark for outgoing packets.
60        unsigned netId = mNetCtrl->getNetworkId(interface);
61        char netIdString[UINT32_STRLEN];
62        snprintf(netIdString, sizeof(netIdString), "%u", netId);
63
64        Fwmark fwmark = { netId, true, true, PERMISSION_CONNECTIVITY_INTERNAL };
65        char fwmarkString[UINT32_HEX_STRLEN];
66        snprintf(fwmarkString, sizeof(fwmarkString), "0x%x", fwmark.intValue);
67
68        char *args[] = {
69            (char *) "/system/bin/clatd",
70            (char *) "-i",
71            interface,
72            (char *) "-n",
73            netIdString,
74            (char *) "-m",
75            fwmarkString,
76            NULL
77        };
78
79        if (execv(args[0], args)) {
80            ALOGE("execv failed (%s)", strerror(errno));
81        }
82        ALOGE("Should never get here!");
83        _exit(0);
84    } else {
85        mClatdPid = pid;
86        ALOGD("clatd started");
87    }
88
89    return 0;
90}
91
92int ClatdController::stopClatd() {
93    if (mClatdPid == 0) {
94        ALOGE("clatd already stopped");
95        return -1;
96    }
97
98    ALOGD("Stopping clatd");
99
100    kill(mClatdPid, SIGTERM);
101    waitpid(mClatdPid, NULL, 0);
102    mClatdPid = 0;
103
104    ALOGD("clatd stopped");
105
106    return 0;
107}
108
109bool ClatdController::isClatdStarted() {
110    pid_t waitpid_status;
111    if(mClatdPid == 0) {
112        return false;
113    }
114    waitpid_status = waitpid(mClatdPid, NULL, WNOHANG);
115    if(waitpid_status != 0) {
116        mClatdPid = 0; // child exited, don't call waitpid on it again
117    }
118    return waitpid_status == 0; // 0 while child is running
119}
120