[PATCH bpf-next RFC v3 4/6] libbpf: support BPF_MAP_DUMP command

[Brian Vazquez]

Make libbpf aware of new BPF_MAP_DUMP command and add bpf_map_dump and
bpf_map_dump_flags to use them from the library.

Suggested-by: Stanislav Fomichev <s...@google.com>
Signed-off-by: Brian Vazquez <bria...@google.com>
---
 tools/lib/bpf/bpf.c      | 28 ++++++++++++++++++++++++++++
 tools/lib/bpf/bpf.h      |  4 ++++
 tools/lib/bpf/libbpf.map |  2 ++
 3 files changed, 34 insertions(+)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index c7d7993c44bb..c1139b7db756 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -368,6 +368,34 @@ int bpf_map_update_elem(int fd, const void *key, const 
void *value,
        return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
 }
 
+int bpf_map_dump(int fd, const void *prev_key, void *buf, void *buf_len)
+{
+       union bpf_attr attr;
+
+       memset(&attr, 0, sizeof(attr));
+       attr.dump.map_fd = fd;
+       attr.dump.prev_key = ptr_to_u64(prev_key);
+       attr.dump.buf = ptr_to_u64(buf);
+       attr.dump.buf_len = ptr_to_u64(buf_len);
+
+       return sys_bpf(BPF_MAP_DUMP, &attr, sizeof(attr));
+}
+
+int bpf_map_dump_flags(int fd, const void *prev_key, void *buf, void *buf_len,
+                      __u64 flags)
+{
+       union bpf_attr attr;
+
+       memset(&attr, 0, sizeof(attr));
+       attr.dump.map_fd = fd;
+       attr.dump.prev_key = ptr_to_u64(prev_key);
+       attr.dump.buf = ptr_to_u64(buf);
+       attr.dump.buf_len = ptr_to_u64(buf_len);
+       attr.dump.flags = flags;
+
+       return sys_bpf(BPF_MAP_DUMP, &attr, sizeof(attr));
+}
+
 int bpf_map_lookup_elem(int fd, const void *key, void *value)
 {
        union bpf_attr attr;
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index ff42ca043dc8..86496443440e 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -112,6 +112,10 @@ LIBBPF_API int bpf_verify_program(enum bpf_prog_type type,
 LIBBPF_API int bpf_map_update_elem(int fd, const void *key, const void *value,
                                   __u64 flags);
 
+LIBBPF_API int bpf_map_dump(int fd, const void *prev_key, void *buf,
+                               void *buf_len);
+LIBBPF_API int bpf_map_dump_flags(int fd, const void *prev_key, void *buf,
+                               void *buf_len, __u64 flags);
 LIBBPF_API int bpf_map_lookup_elem(int fd, const void *key, void *value);
 LIBBPF_API int bpf_map_lookup_elem_flags(int fd, const void *key, void *value,
                                         __u64 flags);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 2c6d835620d2..e7641773cfb0 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -173,4 +173,6 @@ LIBBPF_0.0.4 {
                btf__parse_elf;
                bpf_object__load_xattr;
                libbpf_num_possible_cpus;
+               bpf_map_dump;
+               bpf_map_dump_flags;
 } LIBBPF_0.0.3;
-- 
2.22.0.410.gd8fdbe21b5-goog