interface_tool.cpp revision 929c0d1d2abb1df2c9997c60da7941d6c44cdb2d 
1/*
2 * Copyright (C) 2016 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 "wifi_system/interface_tool.h"
18
19#include <netinet/in.h>
20#include <sys/socket.h>
21/* We need linux/if.h for flags like IFF_UP.  Sadly, it forward declares
22   struct sockaddr and must be included after sys/socket.h. */
23#include <linux/if.h>
24
25#include <android-base/logging.h>
26#include <android-base/unique_fd.h>
27
28namespace android {
29namespace wifi_system {
30namespace {
31
32const char kWlan0InterfaceName[] = "wlan0";
33
34bool GetIfState(const char* if_name, int sock, struct ifreq* ifr) {
35  memset(ifr, 0, sizeof(*ifr));
36  if (strlcpy(ifr->ifr_name, if_name, sizeof(ifr->ifr_name)) >=
37      sizeof(ifr->ifr_name)) {
38    LOG(ERROR) << "Interface name is too long: " << if_name;
39    return false;
40  }
41
42  if (TEMP_FAILURE_RETRY(ioctl(sock, SIOCGIFFLAGS, ifr)) != 0) {
43    LOG(ERROR) << "Could not read interface state for " << if_name
44               << " (" << strerror(errno) << ")";
45    return false;
46  }
47
48  return true;
49}
50
51}  // namespace
52
53bool InterfaceTool::GetUpState(const char* if_name) {
54  base::unique_fd sock(socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0));
55  if (sock.get() < 0) {
56    LOG(ERROR) << "Failed to open socket to set up/down state ("
57               << strerror(errno) << ")";
58    return false;
59  }
60
61  struct ifreq ifr;
62  if (!GetIfState(if_name, sock.get(), &ifr)) {
63    return false;  // logging done internally
64  }
65
66  return ifr.ifr_flags & IFF_UP;
67}
68
69bool InterfaceTool::SetUpState(const char* if_name, bool request_up) {
70  base::unique_fd sock(socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0));
71  if (sock.get() < 0) {
72    LOG(ERROR) << "Failed to open socket to set up/down state ("
73               << strerror(errno) << ")";
74    return false;
75  }
76
77  struct ifreq ifr;
78  if (!GetIfState(if_name, sock.get(), &ifr)) {
79    return false;  // logging done internally
80  }
81
82  const bool currently_up = ifr.ifr_flags & IFF_UP;
83  if (currently_up == request_up) {
84    return true;
85  }
86
87  if (request_up) {
88    ifr.ifr_flags |= IFF_UP;
89  } else {
90    ifr.ifr_flags &= ~IFF_UP;
91  }
92
93  if (TEMP_FAILURE_RETRY(ioctl(sock.get(), SIOCSIFFLAGS, &ifr)) != 0) {
94    LOG(ERROR) << "Could not set interface flags for " << if_name
95               << " (" << strerror(errno) << ")";
96    return false;
97  }
98
99  return true;
100}
101
102bool InterfaceTool::SetWifiUpState(bool request_up) {
103  return SetUpState(kWlan0InterfaceName, request_up);
104}
105
106}  // namespace wifi_system
107}  // namespace android
108