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
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <signal.h>
20 #include <errno.h>
21 #include <string.h>
22 #include <sys/stat.h>
23 #include <sys/types.h>
24 #include <sys/wait.h>
25
26 #include <fcntl.h>
27 #include <dirent.h>
28
29 #define LOG_TAG "Netd"
30
31 #include "cutils/log.h"
32
33 #include "CommandListener.h"
34 #include "NetlinkManager.h"
35 #include "DnsProxyListener.h"
36 #include "MDnsSdListener.h"
37 #include "FwmarkServer.h"
38
39 static void blockSigpipe();
40 static void remove_pid_file();
41 static bool write_pid_file();
42
43 const char* const PID_FILE_PATH = "/data/misc/net/netd_pid";
44 const int PID_FILE_FLAGS = O_CREAT | O_TRUNC | O_WRONLY | O_NOFOLLOW | O_CLOEXEC;
45 const mode_t PID_FILE_MODE = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH; // mode 0644, rw-r--r--
46
main()47 int main() {
48
49 CommandListener *cl;
50 NetlinkManager *nm;
51 DnsProxyListener *dpl;
52 MDnsSdListener *mdnsl;
53 FwmarkServer* fwmarkServer;
54
55 ALOGI("Netd 1.0 starting");
56 remove_pid_file();
57
58 blockSigpipe();
59
60 if (!(nm = NetlinkManager::Instance())) {
61 ALOGE("Unable to create NetlinkManager");
62 exit(1);
63 };
64
65 cl = new CommandListener();
66 nm->setBroadcaster((SocketListener *) cl);
67
68 if (nm->start()) {
69 ALOGE("Unable to start NetlinkManager (%s)", strerror(errno));
70 exit(1);
71 }
72
73 // Set local DNS mode, to prevent bionic from proxying
74 // back to this service, recursively.
75 setenv("ANDROID_DNS_MODE", "local", 1);
76 dpl = new DnsProxyListener(CommandListener::sNetCtrl);
77 if (dpl->startListener()) {
78 ALOGE("Unable to start DnsProxyListener (%s)", strerror(errno));
79 exit(1);
80 }
81
82 mdnsl = new MDnsSdListener();
83 if (mdnsl->startListener()) {
84 ALOGE("Unable to start MDnsSdListener (%s)", strerror(errno));
85 exit(1);
86 }
87
88 fwmarkServer = new FwmarkServer(CommandListener::sNetCtrl);
89 if (fwmarkServer->startListener()) {
90 ALOGE("Unable to start FwmarkServer (%s)", strerror(errno));
91 exit(1);
92 }
93
94 /*
95 * Now that we're up, we can respond to commands
96 */
97 if (cl->startListener()) {
98 ALOGE("Unable to start CommandListener (%s)", strerror(errno));
99 exit(1);
100 }
101
102 bool wrote_pid = write_pid_file();
103
104 while(1) {
105 sleep(30); // 30 sec
106 if (!wrote_pid) {
107 wrote_pid = write_pid_file();
108 }
109 }
110
111 ALOGI("Netd exiting");
112 remove_pid_file();
113 exit(0);
114 }
115
write_pid_file()116 static bool write_pid_file() {
117 char pid_buf[20]; // current pid_max is 32768, so plenty of room
118 snprintf(pid_buf, sizeof(pid_buf), "%ld\n", (long)getpid());
119
120 int fd = open(PID_FILE_PATH, PID_FILE_FLAGS, PID_FILE_MODE);
121 if (fd == -1) {
122 ALOGE("Unable to create pid file (%s)", strerror(errno));
123 return false;
124 }
125
126 // File creation is affected by umask, so make sure the right mode bits are set.
127 if (fchmod(fd, PID_FILE_MODE) == -1) {
128 ALOGE("failed to set mode 0%o on %s (%s)", PID_FILE_MODE, PID_FILE_PATH, strerror(errno));
129 close(fd);
130 remove_pid_file();
131 return false;
132 }
133
134 if (write(fd, pid_buf, strlen(pid_buf)) != (ssize_t)strlen(pid_buf)) {
135 ALOGE("Unable to write to pid file (%s)", strerror(errno));
136 close(fd);
137 remove_pid_file();
138 return false;
139 }
140 close(fd);
141 return true;
142 }
143
remove_pid_file()144 static void remove_pid_file() {
145 unlink(PID_FILE_PATH);
146 }
147
blockSigpipe()148 static void blockSigpipe()
149 {
150 sigset_t mask;
151
152 sigemptyset(&mask);
153 sigaddset(&mask, SIGPIPE);
154 if (sigprocmask(SIG_BLOCK, &mask, NULL) != 0)
155 ALOGW("WARNING: SIGPIPE not blocked\n");
156 }
157