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
28 namespace android {
29 namespace wifi_system {
30 namespace {
31
32 const char kWlan0InterfaceName[] = "wlan0";
33
GetIfState(const char * if_name,int sock,struct ifreq * ifr)34 bool 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
GetUpState(const char * if_name)53 bool 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
SetUpState(const char * if_name,bool request_up)69 bool 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
SetWifiUpState(bool request_up)102 bool InterfaceTool::SetWifiUpState(bool request_up) {
103 return SetUpState(kWlan0InterfaceName, request_up);
104 }
105
106 } // namespace wifi_system
107 } // namespace android
108