x/mobile: Calling net.InterfaceAddrs() fails on Android SDK 30

[halseth]

What version of Go are you using (go version)?

$ go version
go version go1.14.6 darwin/amd64

$gomobile version
gomobile version +973feb4 Sat Aug 1 11:21:45 2020 +0000 (android,ios); androidSDK=/sdk/platforms/android-30

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/user/Library/Caches/go-build"
GOENV="/Users/user/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/user/golang"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.14.6/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.14.6/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/user/golang/src/golang.org/x/mobile/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/kq/3436m_v11sg0l7zqtmv2r1gw0000gn/T/go-build713467523=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

Calling net.InterfaceAddrs() fails on Android app targetting SDK version 30. With build.gradle looking like:

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.0"
    defaultConfig {
        applicationId "com.example.testapp"
        minSdkVersion 29
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

Building the exact same app targetting SDK 29 works, and returns no error:

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.0"
    defaultConfig {
        applicationId "com.example.testapp"
        minSdkVersion 29
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

What did you expect to see?

Targetting SDK 30 would behave no differently.

What did you see instead?

Calling net.InterfaceAddrs() results in error route ip+net: netlinkrib: permission denied when embedded in Android app targetting SDK 30 (R):

2020-08-04 15:10:21.386 15754-15754/? W/Thread-2: type=1400 audit(0.0:616): avc: denied { bind } for scontext=u:r:untrusted_app:s0:c158,c256,c512,c768 tcontext=u:r:untrusted_app:s0:c158,c256,c512,c768 tclass=netlink_route_socket permissive=0 b/155595000 app=com.example.testapp

[toothrot]

/cc @hyangah

[hsjoberg]

Any more updates on this one? Android 11 was released today.

[vikulin]

Reproduced in Yggdrasil project for net.Interfaces():
https://github.com/yggdrasil-network/yggdrasil-go/blob/master/src/multicast/multicast.go#L192

[vikulin]

Any updates?

[rschulman]

I'd also love an update, if possible. This is blocking a project of mine right now.

[halseth]

Anybody looking into this?

[bt90]

Seems to be caused by these new restrictions in Android 11:

The following is a list of the ways that apps are affected by this change:

• NetworkInterface.getHardwareAddress() returns null for every interface.
• Apps cannot use the bind() function on NETLINK_ROUTE sockets.
• The ip command does not return information about interfaces.
• Apps cannot send RTM_GETLINK messages.

https://developer.android.com/training/articles/user-data-ids#mac-11-plus

[Catfriend1]

Fix: Catfriend1/syncthing-android#800

[DentonGentry]

https://developer.android.com/distribute/best-practices/develop/target-sdk

In August 2021, new apps in the Google Play Store will be required to target API level 30.
In November 2021, updates to existing apps in the Google Play Store will be required to target API level 30.

[uburoiubu]

Any updates on this one? This fix did not work for us: Catfriend1/syncthing-android#800

[simbadMarino]

Hello golang dev team, any update on this issue? This is blocking the Android 11 compatibility of my app :/. Thanks!

[DentonGentry]

We ended up developing an alternative using Android APIs, which we call instead of getInterfaceAddrs().
tailscale/tailscale-android#21

[simbadMarino]

Great, will take a look and see if I can circumvent my issue with this . Thanks! Sent from myMail for iOS Thursday, 9 December 2021 14:39 -0600 from ***@***.*** ***@***.***>:

…

We ended up developing an alternative using Android APIs, which we call instead of getInterfaceAddrs(). tailscale/tailscale-android#21 — You are receiving this because you commented. Reply to this email directly, view it on GitHub , or unsubscribe . Triage notifications on the go with GitHub Mobile for iOS or Android .

[neilyoung]

I'm having a question: This problem is open since 2020. There is no workaround. Basically it means, that all Android apps, relying on GO in some way and "doing network things", will not work if they are running Android 11 or higher (at least the latter is for sure not that exotic anymore as it was in 2020)

I'm wondering why this issue is not making bigger waves, but most likely the relevance of gomobile for Android is lower than expected (which is kind of a pity, since it is in some limited ways a perfect replacement of C++).

But at least network things should be working.

[invented-pro]

Same suffering here. 4 years old bug, unbelievable!

Findings, while using same gomobile arr in Android App,

• If App built with targetSdkVersion 29, it can run flawlessly on Android 11 device, but fail on Android 13 device.
• If App built with targetSdkVersion 30 and above, it fails on all devices, with err msg "netlinkrib: permission denied"

Is there any workaround available, even only with targetSdkVersion 29?

[neilyoung]

@invented-pro At least for me it is solved. Apply this PR to a source installation of GOLANG #61089

[invented-pro]

I'll take a try. Thanks @neilyoung

[bt90]

@wlynxg what's the current state of the PR?

[neilyoung]

Merging is blocked for some reasons.

[invented-pro]

I'll take a try. Thanks @neilyoung

src + PR build on macos failed due to some tests.
which platfrom did you manage? @neilyoung

[neilyoung]

@invented-pro I'm on macOS 14.2.1, M1

[invented-pro]

@invented-pro I'm on macOS 14.2.1, M1

cannot build on 14.2.1 M2

[neilyoung]

I had a recent binary installation on disk, then followed this gist https://go.dev/doc/install/source. Applied the patch manually. Made the patched GOLANG default then.

EDIT: Aarggh.... Realized right now, that I did it on Ubuntu 20.04. Sorry for this...

[invented-pro]

I had a recent binary installation on disk, then followed this gist https://go.dev/doc/install/source. Applied the patch manually. Made the patched GOLANG default then.

EDIT: Aarggh.... Realized right now, that I did it on Ubuntu 20.04. Sorry for this...

Thanks. I'll try on linux.

[invented-pro]

I built golang from src patched with PR61089, then used it to build aar file, finally it works as expected now on Android11 & 13, no "netlinkrib: permission denied" anymore.

Sincerely thank @wlynxg for the PR !!! Thank @neilyoung for guidance!!!

Hints to whom it may concern:

• Golang built from src failed on my Mac M2; it's done on a Debian11 host with no error.
• If you see error "zipdata redeclared in this block" during build, that's only because you build src multi times, time/tzdata/zzipdata.go is generated automatically, just delete it.
• For linux env, don't forget to config Android SDK, NDK, etc.
• GOROOT is your new go bin directory, don't point GOPATH to this GOROOT.
• New aar file from Go 1.21 makes my App crash on Android frequently, while Go 1.20 seams ok.

[neilyoung]

@invented-pro Thanks for letting me know. Yes, this PR is really worth to be merged finally.

Thanks also for the extra information, even though I cannot confirm your last issue.

[vikulin]

@invented-pro Thanks for letting me know. Yes, this PR is really worth to be merged finally.

Thanks also for the extra information, even though I cannot confirm your last issue.

Actually the PR is'nt ready yet

[vikulin]

Fix confirmed

[KellendF]

Yes, this problem exists since Android 11, if you need help, you can contact me. Yes, this problem exists since Android 11, if you need help, you can contact me.

Hi @wlynxg, thanks for the offer. Well, I see the changes linked above, but I wouldn't know how to apply them. I generally know how to apply a PR, but in this scenario I'm just a GOMOBILE user under Android, and my GOLANG is maybe three days old or so :) I basically don't know, where to apply the change. Hi, thanks for the quote. Ok, I see the changes linked above but I don't know how to apply them. I usually know how to apply a PR, but in this case I'm just a GOMOBILE user under Android, and my GOLANG is probably three days old or so :) I basically have no idea where to apply the changes.

The official has not accepted this change for the time being. My suggestion is to temporarily use a third-party library on the Android platform instead of the net package to obtain network card information. You can refer to my code: https:// github.com/wlynxg/anet. The official has not accepted this change for the time being. My suggestion is to temporarily use a third-party library on the Android platform instead of the net package to obtain network card information. You can refer to my code: https://github.com/wlynxg/anet.

He solved my problem thanks