1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
//
// Copyright (C) 2014 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 "apmanager/dhcp_server.h"
#include <net/if.h>
#include <signal.h>
#include <base/strings/stringprintf.h>
#include "apmanager/daemon.h"
using std::string;
namespace apmanager {
// static.
#if !defined(__ANDROID__)
const char DHCPServer::kDnsmasqPath[] = "/usr/sbin/dnsmasq";
const char DHCPServer::kDnsmasqConfigFilePathFormat[] =
"/var/run/apmanager/dnsmasq/dhcpd-%d.conf";
const char DHCPServer::kDHCPLeasesFilePathFormat[] =
"/var/run/apmanager/dnsmasq/dhcpd-%d.leases";
#else
const char DHCPServer::kDnsmasqPath[] = "/system/bin/dnsmasq";
const char DHCPServer::kDnsmasqConfigFilePathFormat[] =
"/data/misc/apmanager/dnsmasq/dhcpd-%d.conf";
const char DHCPServer::kDHCPLeasesFilePathFormat[] =
"/data/misc/apmanager/dnsmasq/dhcpd-%d.leases";
const char DHCPServer::kDnsmasqPidFilePath[] =
"/data/misc/apmanager/dnsmasq/dnsmasq.pid";
#endif // __ANDROID__
const char DHCPServer::kServerAddressFormat[] = "192.168.%d.254";
const char DHCPServer::kAddressRangeLowFormat[] = "192.168.%d.1";
const char DHCPServer::kAddressRangeHighFormat[] = "192.168.%d.128";
const int DHCPServer::kServerAddressPrefix = 24;
const int DHCPServer::kTerminationTimeoutSeconds = 2;
DHCPServer::DHCPServer(uint16_t server_address_index,
const string& interface_name)
: server_address_index_(server_address_index),
interface_name_(interface_name),
server_address_(shill::IPAddress::kFamilyIPv4),
rtnl_handler_(shill::RTNLHandler::GetInstance()),
file_writer_(FileWriter::GetInstance()),
process_factory_(ProcessFactory::GetInstance()) {}
DHCPServer::~DHCPServer() {
if (dnsmasq_process_) {
// The destructor of the Process will send a SIGKILL signal if it is not
// already terminated.
dnsmasq_process_->Kill(SIGTERM, kTerminationTimeoutSeconds);
dnsmasq_process_.reset();
rtnl_handler_->RemoveInterfaceAddress(
rtnl_handler_->GetInterfaceIndex(interface_name_), server_address_);
}
}
bool DHCPServer::Start() {
if (dnsmasq_process_) {
LOG(ERROR) << "DHCP Server already running";
return false;
}
// Generate dnsmasq config file.
string config_str = GenerateConfigFile();
string file_name = base::StringPrintf(kDnsmasqConfigFilePathFormat,
server_address_index_);
if (!file_writer_->Write(file_name, config_str)) {
LOG(ERROR) << "Failed to write configuration to a file";
return false;
}
// Setup local server address and bring up the interface in case it is down.
server_address_.SetAddressFromString(
base::StringPrintf(kServerAddressFormat, server_address_index_));
server_address_.set_prefix(kServerAddressPrefix);
int interface_index = rtnl_handler_->GetInterfaceIndex(interface_name_);
rtnl_handler_->AddInterfaceAddress(
interface_index,
server_address_,
server_address_.GetDefaultBroadcast(),
shill::IPAddress(shill::IPAddress::kFamilyIPv4));
rtnl_handler_->SetInterfaceFlags(interface_index, IFF_UP, IFF_UP);
// Start a dnsmasq process.
dnsmasq_process_.reset(process_factory_->CreateProcess());
dnsmasq_process_->AddArg(kDnsmasqPath);
dnsmasq_process_->AddArg(base::StringPrintf("--conf-file=%s",
file_name.c_str()));
#if defined(__ANDROID__)
// dnsmasq normally creates a pid file in /var/run/dnsmasq.pid. Overwrite
// this file path for Android.
dnsmasq_process_->AddArg(
base::StringPrintf("--pid-file=%s", kDnsmasqPidFilePath));
#endif // __ANDROID__
if (!dnsmasq_process_->Start()) {
rtnl_handler_->RemoveInterfaceAddress(interface_index, server_address_);
dnsmasq_process_.reset();
LOG(ERROR) << "Failed to start dnsmasq process";
return false;
}
return true;
}
string DHCPServer::GenerateConfigFile() {
string server_address = base::StringPrintf(kServerAddressFormat,
server_address_index_);
string address_low = base::StringPrintf(kAddressRangeLowFormat,
server_address_index_);
string address_high = base::StringPrintf(kAddressRangeHighFormat,
server_address_index_);
string lease_file_path = base::StringPrintf(kDHCPLeasesFilePathFormat,
server_address_index_);
string config;
config += "port=0\n";
config += "bind-interfaces\n";
config += "log-dhcp\n";
// By default, dnsmasq process will spawn off another process to run the
// dnsmasq task in the "background" and exit the current process immediately.
// This means the daemon would not have any knowledge of the background
// dnsmasq process, and it will continue to run even after the AP service is
// terminated. Configure dnsmasq to run in "foreground" so no extra process
// will be spawned.
config += "keep-in-foreground\n";
base::StringAppendF(
&config, "dhcp-range=%s,%s\n", address_low.c_str(), address_high.c_str());
base::StringAppendF(&config, "interface=%s\n", interface_name_.c_str());
// Explicitly set the user to apmanager. If not set, dnsmasq will default to
// run as "nobody".
base::StringAppendF(&config, "user=%s\n", Daemon::kAPManagerUserName);
base::StringAppendF(&config, "dhcp-leasefile=%s\n", lease_file_path.c_str());
return config;
}
} // namespace apmanager
|
