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 <map>
17 #include <string>
18
19 #include <unistd.h>
20 #include <errno.h>
21 #include <sys/types.h>
22 #include <sys/wait.h>
23
24 #define LOG_TAG "ClatdController"
25 #include <cutils/log.h>
26
27 #include <resolv_netid.h>
28
29 #include "NetdConstants.h"
30 #include "ClatdController.h"
31 #include "Fwmark.h"
32 #include "NetdConstants.h"
33 #include "NetworkController.h"
34
35 static const char* kClatdPath = "/system/bin/clatd";
36
37 namespace android {
38 namespace net {
39
ClatdController(NetworkController * controller)40 ClatdController::ClatdController(NetworkController* controller)
41 : mNetCtrl(controller) {
42 }
43
~ClatdController()44 ClatdController::~ClatdController() {
45 }
46
47 // Returns the PID of the clatd running on interface |interface|, or 0 if clatd is not running on
48 // |interface|.
getClatdPid(char * interface)49 pid_t ClatdController::getClatdPid(char* interface) {
50 auto it = mClatdPids.find(interface);
51 return (it == mClatdPids.end() ? 0 : it->second);
52 }
53
startClatd(char * interface)54 int ClatdController::startClatd(char* interface) {
55 pid_t pid = getClatdPid(interface);
56
57 if (pid != 0) {
58 ALOGE("clatd pid=%d already started on %s", pid, interface);
59 errno = EBUSY;
60 return -1;
61 }
62
63 // Pass in the interface, a netid to use for DNS lookups, and a fwmark for outgoing packets.
64 unsigned netId = mNetCtrl->getNetworkForInterface(interface);
65 if (netId == NETID_UNSET) {
66 ALOGE("interface %s not assigned to any netId", interface);
67 errno = ENODEV;
68 return -1;
69 }
70
71 char netIdString[UINT32_STRLEN];
72 snprintf(netIdString, sizeof(netIdString), "%u", netId);
73
74 Fwmark fwmark;
75 fwmark.netId = netId;
76 fwmark.explicitlySelected = true;
77 fwmark.protectedFromVpn = true;
78 fwmark.permission = PERMISSION_SYSTEM;
79
80 char fwmarkString[UINT32_HEX_STRLEN];
81 snprintf(fwmarkString, sizeof(fwmarkString), "0x%x", fwmark.intValue);
82
83 ALOGD("starting clatd on %s", interface);
84
85 std::string progname("clatd-");
86 progname += interface;
87
88 if ((pid = fork()) < 0) {
89 ALOGE("fork failed (%s)", strerror(errno));
90 return -1;
91 }
92
93 if (!pid) {
94 char *args[] = {
95 (char *) progname.c_str(),
96 (char *) "-i",
97 interface,
98 (char *) "-n",
99 netIdString,
100 (char *) "-m",
101 fwmarkString,
102 NULL
103 };
104
105 if (execv(kClatdPath, args)) {
106 ALOGE("execv failed (%s)", strerror(errno));
107 _exit(1);
108 }
109 ALOGE("Should never get here!");
110 _exit(1);
111 } else {
112 mClatdPids[interface] = pid;
113 ALOGD("clatd started on %s", interface);
114 }
115
116 return 0;
117 }
118
stopClatd(char * interface)119 int ClatdController::stopClatd(char* interface) {
120 pid_t pid = getClatdPid(interface);
121
122 if (pid == 0) {
123 ALOGE("clatd already stopped");
124 return -1;
125 }
126
127 ALOGD("Stopping clatd pid=%d on %s", pid, interface);
128
129 kill(pid, SIGTERM);
130 waitpid(pid, NULL, 0);
131 mClatdPids.erase(interface);
132
133 ALOGD("clatd on %s stopped", interface);
134
135 return 0;
136 }
137
isClatdStarted(char * interface)138 bool ClatdController::isClatdStarted(char* interface) {
139 pid_t waitpid_status;
140 pid_t pid = getClatdPid(interface);
141 if (pid == 0) {
142 return false;
143 }
144 waitpid_status = waitpid(pid, NULL, WNOHANG);
145 if (waitpid_status != 0) {
146 mClatdPids.erase(interface); // child exited, don't call waitpid on it again
147 }
148 return waitpid_status == 0; // 0 while child is running
149 }
150
151 } // namespace net
152 } // namespace android
153