In response to the modifications made to the permissions for accessing system MAC addresses in Android 11, ordinary applications encounter several main issues when using NETLINK sockets:
- Not allowing bind operations on
NETLINK
sockets. - Not permitting the use of the
RTM_GETLINK
functionality.
For detailed information, please refer to: https://developer.android.com/training/articles/user-data-ids#mac-11-plus
As a result of the aforementioned reasons, using net.Interfaces()
and net.InterfaceAddrs()
from the Go net package in the Android environment leads to the route ip+net: netlinkrib: permission denied
error.
You can find specific issue details here: golang/go#40569
To address the issue of using the Go net package in the Android environment, we have made partial modifications to its source code to ensure proper functionality on Android.
I have fully resolved the issues with net.InterfaceAddrs()
.
However, for net.Interfaces()
, we have only addressed some problems, as the following issues still remain:
- It can only return interfaces with IP addresses.
- It cannot return hardware MAC addresses.
Nevertheless, the fixed net.Interfaces()
function now aligns with the Android API's NetworkInterface.getNetworkInterfaces()
and can be used normally in most scenarios.
The specific fix logic includes:
Removing the Bind()
operation on Netlink
sockets in the NetlinkRIB()
function.
Using ioctl
based on the Index number returned by RTM_GETADDR
to retrieve the network card's name, MTU, and flags.
There are two implementations of the net
package: one from the Go standard library and another from the golang.org/x/net module. Both of these implementations have the same issues in the Android environment. The anet
package should be compatible with both of them.
use net.Interface()
:
func RawInterface() {
interfaces, err := net.Interfaces()
if err != nil {
panic(err)
}
for _, i := range interfaces {
log.Println(i)
}
}
result:
panic: route ip+net: netlinkrib: permission denied
use anet.Interface()
:
func AnetInterface() {
interfaces, err := anet.Interfaces()
if err != nil {
panic(err)
}
for _, i := range interfaces {
log.Println(i)
}
}
result:
{1 65536 lo up|loopback|running}
{15 1400 rmnet_data1 up|running}
{24 1500 wlan0 up|broadcast|multicast|running}
{3 1500 dummy0 up|broadcast|running}
{4 1500 ifb0 up|broadcast|running}
{5 1500 ifb1 up|broadcast|running}
{12 1500 ifb2 up|broadcast|running}
{14 1500 rmnet_data0 up|running}
{16 1400 rmnet_data2 up|running}
{17 1400 rmnet_data3 up|running}
use net.InterfaceAddrs()
:
func NetInterfaceAddrs() {
addrs, err := net.InterfaceAddrs()
if err != nil {
panic(err)
}
for _, addr := range addrs {
log.Println(addr)
}
}
result:
panic: route ip+net: netlinkrib: permission denied
use anet.InterfaceAddrs()
:
func AnetInterfaceAddrs() {
addrs, err := anet.InterfaceAddrs()
if err != nil {
panic(err)
}
for _, addr := range addrs {
log.Println(addr)
}
}
result:
127.0.0.1/8
::1/128
...
192.168.6.143/24
fe80::7e4f:4446:eb3:1eb8/64