Include bpf program in APEXes

bpf program is put to an APEX via 'bpfs' property. It is
placed under etc/bpf directory in it.

Fix: 167530625
Test: m
Change-Id: Ia36b486f0cffb619ecc4f7a318cde881abc5baf4
diff --git a/bpf/bpf.go b/bpf/bpf.go
index 4cdfb31..297e13a 100644
--- a/bpf/bpf.go
+++ b/bpf/bpf.go
@@ -26,7 +26,7 @@
 )
 
 func init() {
-	android.RegisterModuleType("bpf", bpfFactory)
+	android.RegisterModuleType("bpf", BpfFactory)
 	pctx.Import("android/soong/cc/config")
 }
 
@@ -43,6 +43,13 @@
 		"ccCmd", "cFlags")
 )
 
+// BpfModule interface is used by the apex package to gather information from a bpf module.
+type BpfModule interface {
+	android.Module
+
+	OutputFiles(tag string) (android.Paths, error)
+}
+
 type BpfProperties struct {
 	Srcs         []string `android:"path"`
 	Cflags       []string
@@ -141,7 +148,7 @@
 
 var _ android.OutputFileProducer = (*bpf)(nil)
 
-func bpfFactory() android.Module {
+func BpfFactory() android.Module {
 	module := &bpf{}
 
 	module.AddProperties(&module.properties)
diff --git a/bpf/bpf_test.go b/bpf/bpf_test.go
index eeca057..d06d7d1 100644
--- a/bpf/bpf_test.go
+++ b/bpf/bpf_test.go
@@ -59,7 +59,7 @@
 
 func testContext(config android.Config) *android.TestContext {
 	ctx := cc.CreateTestContext()
-	ctx.RegisterModuleType("bpf", bpfFactory)
+	ctx.RegisterModuleType("bpf", BpfFactory)
 	ctx.Register(config)
 
 	return ctx