Move ebpf code to its own package to avoid crash issues in Android (#1033)

* Move ebpf code to its own package to avoid crash issues in Android

Older versions of android crashes because of the bytecode files
Even when they aren't loaded as it was our case

* move c file to own folder

* fix lint

client/internal/wgproxy/ebpf/bpf_bpfeb.go

@@ -2,7 +2,7 @@
 //go:build arm64be || armbe || mips || mips64 || mips64p32 || ppc64 || s390 || s390x || sparc || sparc64
 // +build arm64be armbe mips mips64 mips64p32 ppc64 s390 s390x sparc sparc64
 
-package wgproxy
+package ebpf
 
 import (
 	"bytes"

client/internal/wgproxy/ebpf/bpf_bpfel.go

@@ -2,7 +2,7 @@
 //go:build 386 || amd64 || amd64p32 || arm || arm64 || mips64le || mips64p32le || mipsle || ppc64le || riscv64
 // +build 386 amd64 amd64p32 arm arm64 mips64le mips64p32le mipsle ppc64le riscv64
 
-package wgproxy
+package ebpf
 
 import (
 	"bytes"

client/internal/wgproxy/ebpf/loader.go

@@ -1,6 +1,6 @@
 //go:build linux && !android
 
-package wgproxy
+package ebpf
 
 import (
 	_ "embed"
@@ -15,17 +15,20 @@ const (
 	mapKeyWgPort    uint32 = 1
 )
 
-//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -cc clang-14 bpf bpf/portreplace.c --
+//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -cc clang-14 bpf src/portreplace.c --
 
-type eBPF struct {
+// EBPF is a wrapper for eBPF program
+type EBPF struct {
 	link link.Link
 }
 
-func newEBPF() *eBPF {
-	return &eBPF{}
+// NewEBPF create new EBPF instance
+func NewEBPF() *EBPF {
+	return &EBPF{}
 }
 
-func (l *eBPF) load(proxyPort, wgPort int) error {
+// Load load ebpf program
+func (l *EBPF) Load(proxyPort, wgPort int) error {
 	// it required for Docker
 	err := rlimit.RemoveMemlock()
 	if err != nil {
@@ -72,7 +75,8 @@ func (l *eBPF) load(proxyPort, wgPort int) error {
 	return err
 }
 
-func (l *eBPF) free() error {
+// Free free ebpf program
+func (l *EBPF) Free() error {
 	if l.link != nil {
 		return l.link.Close()
 	}

client/internal/wgproxy/ebpf/loader_test.go

@@ -1,16 +1,16 @@
 //go:build linux
 
-package wgproxy
+package ebpf
 
 import (
 	"testing"
 )
 
 func Test_newEBPF(t *testing.T) {
-	ebpf := newEBPF()
-	err := ebpf.load(1234, 51892)
+	ebpf := NewEBPF()
+	err := ebpf.Load(1234, 51892)
 	defer func() {
-		_ = ebpf.free()
+		_ = ebpf.Free()
 	}()
 	if err != nil {
 		t.Errorf("%s", err)

client/internal/wgproxy/proxy_ebpf.go

@@ -14,11 +14,13 @@ import (
 	"github.com/google/gopacket/layers"
 
 	log "github.com/sirupsen/logrus"
+
+	ebpf2 "github.com/netbirdio/netbird/client/internal/wgproxy/ebpf"
 )
 
-// WGEBPFProxy definition for proxy with eBPF support
+// WGEBPFProxy definition for proxy with EBPF support
 type WGEBPFProxy struct {
-	ebpf              *eBPF
+	ebpf              *ebpf2.EBPF
 	lastUsedPort      uint16
 	localWGListenPort int
 
@@ -34,7 +36,7 @@ func NewWGEBPFProxy(wgPort int) *WGEBPFProxy {
 	log.Debugf("instantiate ebpf proxy")
 	wgProxy := &WGEBPFProxy{
 		localWGListenPort: wgPort,
-		ebpf:              newEBPF(),
+		ebpf:              ebpf2.NewEBPF(),
 		lastUsedPort:      0,
 		turnConnStore:     make(map[uint16]net.Conn),
 	}
@@ -54,7 +56,7 @@ func (p *WGEBPFProxy) Listen() error {
 		return err
 	}
 
-	err = p.ebpf.load(wgPorxyPort, p.localWGListenPort)
+	err = p.ebpf.Load(wgPorxyPort, p.localWGListenPort)
 	if err != nil {
 		return err
 	}
@@ -107,7 +109,7 @@ func (p *WGEBPFProxy) Free() error {
 		err1 = p.conn.Close()
 	}
 
-	err2 = p.ebpf.free()
+	err2 = p.ebpf.Free()
 	if p.rawConn != nil {
 		err3 = p.rawConn.Close()
 	}