[PATCH v6 bpf-next 2/3] bpf: extend libbpf with bpf_map_lookup_and_delete_elem_flags

[Denis Salopek <denis.salopek@xxxxxxxxxx>]

Add bpf_map_lookup_and_delete_elem_flags() libbpf API in order to use
the BPF_F_LOCK flag with the map_lookup_and_delete_elem() function.

Cc: Juraj Vijtiuk <juraj.vijtiuk@xxxxxxxxxx>
Cc: Luka Oreskovic <luka.oreskovic@xxxxxxxxxx>
Cc: Luka Perkov <luka.perkov@xxxxxxxxxx>
Cc: Yonghong Song <yhs@xxxxxx>
Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Signed-off-by: Denis Salopek <denis.salopek@xxxxxxxxxx>
Acked-by: Yonghong Song <yhs@xxxxxx>
---
v5: Move to the newest libbpf version (0.4.0).
v6: Add Acked-by.
---
 tools/lib/bpf/bpf.c      | 13 +++++++++++++
 tools/lib/bpf/bpf.h      |  2 ++
 tools/lib/bpf/libbpf.map |  1 +
 3 files changed, 16 insertions(+)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index bba48ff4c5c0..b7c2cc12034c 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -458,6 +458,19 @@ int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value)
 	return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
 }
 
+int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, __u64 flags)
+{
+	union bpf_attr attr;
+
+	memset(&attr, 0, sizeof(attr));
+	attr.map_fd = fd;
+	attr.key = ptr_to_u64(key);
+	attr.value = ptr_to_u64(value);
+	attr.flags = flags;
+
+	return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
+}
+
 int bpf_map_delete_elem(int fd, const void *key)
 {
 	union bpf_attr attr;
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 875dde20d56e..4f758f8f50cd 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -124,6 +124,8 @@ LIBBPF_API int bpf_map_lookup_elem_flags(int fd, const void *key, void *value,
 					 __u64 flags);
 LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key,
 					      void *value);
+LIBBPF_API int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key,
+						    void *value, __u64 flags);
 LIBBPF_API int bpf_map_delete_elem(int fd, const void *key);
 LIBBPF_API int bpf_map_get_next_key(int fd, const void *key, void *next_key);
 LIBBPF_API int bpf_map_freeze(int fd);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index b9b29baf1df8..6c06267c020e 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -360,5 +360,6 @@ LIBBPF_0.4.0 {
 		bpf_linker__free;
 		bpf_linker__new;
 		bpf_map__inner_map;
+		bpf_map_lookup_and_delete_elem_flags;
 		bpf_object__set_kversion;
 } LIBBPF_0.3.0;
-- 
2.26.2