Use BTF maps if BPF_ANNOTATE_KV_PAIR is defined.

Signed-off-by: fruffy <[email protected]>

backends/ebpf/runtime/ebpf_kernel.h

@@ -23,6 +23,7 @@ limitations under the License.
 
 #include "ebpf_common.h"
 
+#include <iproute2/bpf_elf.h> // Exports BPF_ANNOTATE_KV_PAIR in newer versions.
 #include <bpf/bpf_endian.h> // definitions for bpf_ntohs etc...
 
 #undef htonl
@@ -79,6 +80,9 @@ struct bpf_elf_map {
 /// Simple descriptor which replaces the kernel sk_buff structure.
 #define SK_BUFF struct __sk_buff
 
+
+#define REGISTER_START()
+#ifndef BPF_ANNOTATE_KV_PAIR
 /// From iproute2, annotate table with BTF which allows to read types at runtime.
 #define BPF_ANNOTATE_KV_PAIR(name, type_key, type_val)  \
     struct ____btf_map_##name {                         \
@@ -89,8 +93,6 @@ struct bpf_elf_map {
         __attribute__ ((section(".maps." #name), used)) \
         ____btf_map_##name = {};
 
-#define REGISTER_START()
-#ifndef BTF
 /// Note: pinning exports the table name globally, do not remove.
 #define REGISTER_TABLE(NAME, TYPE, KEY_TYPE, VALUE_TYPE, MAX_ENTRIES) \
 struct bpf_elf_map SEC("maps") NAME = {          \

testdata/extern_modules/extern-conntrack-ebpf.c

@@ -29,7 +29,7 @@ struct connInfo {
 };
 
 REGISTER_START()
-REGISTER_TABLE(tcp_reg, BPF_MAP_TYPE_HASH, sizeof(u32), sizeof(struct connInfo), MAX_ENTRIES)
+REGISTER_TABLE(tcp_reg, BPF_MAP_TYPE_HASH, u32, struct connInfo, MAX_ENTRIES)
 REGISTER_END()
 
 static inline u8 tcp_conntrack(struct Headers_t hdrs)