Introduce SetKeySize, Autocreate and SetAutocreate

Co-authored-by: sc07kvm <[email protected]>

map.go

@@ -149,9 +149,16 @@ func (m *BPFMap) KeySize() int {
 	return int(C.bpf_map__key_size(m.bpfMap))
 }
 
-// TODO: implement `bpf_map__set_key_size` wrapper
-// func (m *BPFMap) SetKeySize(size uint32) error {
-// }
+// SetKeySize sets the key size to a BPFMap instance that is not yet associated
+// with a file descriptor.
+func (m *BPFMap) SetKeySize(size uint32) error {
+	retC := C.bpf_map__set_key_size(m.bpfMap, C.uint(size))
+	if retC < 0 {
+		return fmt.Errorf("could not set map key size: %w", syscall.Errno(-retC))
+	}
+
+	return nil
+}
 
 func (m *BPFMap) ValueSize() int {
 	return int(C.bpf_map__value_size(m.bpfMap))
@@ -168,6 +175,21 @@ func (m *BPFMap) SetValueSize(size uint32) error {
 	return nil
 }
 
+func (m *BPFMap) Autocreate() bool {
+	return bool(C.bpf_map__autocreate(m.bpfMap))
+}
+
+// Autocreate sets whether libbpf has to auto-create BPF map during BPF object
+// load phase.
+func (m *BPFMap) SetAutocreate(autocreate bool) error {
+	retC := C.bpf_map__set_autocreate(m.bpfMap, C.bool(autocreate))
+	if retC < 0 {
+		return fmt.Errorf("could not set map autocreate: %w", syscall.Errno(-retC))
+	}
+
+	return nil
+}
+
 func (m *BPFMap) BTFKeyTypeID() uint32 {
 	return uint32(C.bpf_map__btf_key_type_id(m.bpfMap))
 }

selftest/map-autocreate/Makefile

@@ -0,0 +1 @@
+../common/Makefile

selftest/map-autocreate/go.mod

@@ -0,0 +1,7 @@
+module github.com/aquasecurity/libbpfgo/selftest/map-update
+
+go 1.18
+
+require github.com/aquasecurity/libbpfgo v0.4.7-libbpf-1.2.0-b2e29a1
+
+replace github.com/aquasecurity/libbpfgo => ../../

selftest/map-autocreate/go.sum

@@ -0,0 +1,4 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

selftest/map-autocreate/main.bpf.c

@@ -0,0 +1,11 @@
+//+build ignore
+
+#include <vmlinux.h>
+
+#include <bpf/bpf_helpers.h>
+
+struct {
+    __uint(type, ~0U);
+} tester SEC(".maps");
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";

selftest/map-autocreate/main.go

@@ -0,0 +1,58 @@
+package main
+
+import "C"
+
+import (
+	"log"
+
+	bpf "github.com/aquasecurity/libbpfgo"
+)
+
+func main() {
+	bpfModuleWithAutocreate, err := bpf.NewModuleFromFile("main.bpf.o")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer bpfModuleWithAutocreate.Close()
+
+	testerMapWithAutocreate, err := bpfModuleWithAutocreate.GetMap("tester")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	isAutocreate := testerMapWithAutocreate.Autocreate()
+	if !isAutocreate {
+		log.Fatal("Autocreate is false")
+	}
+
+	err = bpfModuleWithAutocreate.BPFLoadObject()
+	if err == nil {
+		log.Fatal("Was able to load with a bad type of map")
+	}
+
+	bpfModuleWithoutAutocreate, err := bpf.NewModuleFromFile("main.bpf.o")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer bpfModuleWithoutAutocreate.Close()
+
+	testerMapWithoutAutocreate, err := bpfModuleWithoutAutocreate.GetMap("tester")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = testerMapWithoutAutocreate.SetAutocreate(false)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	isAutocreate = testerMapWithoutAutocreate.Autocreate()
+	if isAutocreate {
+		log.Fatal("Autocreate is true")
+	}
+
+	err = bpfModuleWithoutAutocreate.BPFLoadObject()
+	if err != nil {
+		log.Fatal(err)
+	}
+}

selftest/map-autocreate/run.sh

@@ -0,0 +1 @@
+../common/run.sh

selftest/map-keysize/Makefile

@@ -0,0 +1 @@
+../common/Makefile

selftest/map-keysize/go.mod

@@ -0,0 +1,7 @@
+module github.com/aquasecurity/libbpfgo/selftest/map-update
+
+go 1.18
+
+require github.com/aquasecurity/libbpfgo v0.4.7-libbpf-1.2.0-b2e29a1
+
+replace github.com/aquasecurity/libbpfgo => ../../

selftest/map-keysize/go.sum

@@ -0,0 +1,4 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

selftest/map-keysize/main.bpf.c

@@ -0,0 +1,14 @@
+//+build ignore
+
+#include <vmlinux.h>
+
+#include <bpf/bpf_helpers.h>
+
+struct {
+    __uint(type, BPF_MAP_TYPE_HASH);
+    __type(key, u32);
+    __type(value, u32);
+    __uint(max_entries, 1);
+} tester SEC(".maps");
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";

selftest/map-keysize/main.go

@@ -0,0 +1,39 @@
+package main
+
+import "C"
+
+import (
+	"log"
+
+	bpf "github.com/aquasecurity/libbpfgo"
+)
+
+func main() {
+	bpfModule, err := bpf.NewModuleFromFile("main.bpf.o")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer bpfModule.Close()
+
+	testerMap, err := bpfModule.GetMap("tester")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	keySize := testerMap.KeySize()
+	if keySize != 4 {
+		log.Fatal("keySize do not match")
+	}
+
+	err = testerMap.SetKeySize(8)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	keySize = testerMap.KeySize()
+	if keySize != 8 {
+		log.Fatal("keySize do not match")
+	}
+
+	bpfModule.BPFLoadObject()
+}

selftest/map-keysize/run.sh

@@ -0,0 +1 @@
+../common/run.sh