2019-07-24 17:44:46

by Brian Vazquez

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

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 <[email protected]>
Signed-off-by: Brian Vazquez <[email protected]>
---
tools/lib/bpf/bpf.c | 28 ++++++++++++++++++++++++++++
tools/lib/bpf/bpf.h | 4 ++++
2 files changed, 32 insertions(+)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index c7d7993c44bb0..c1139b7db756a 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 ff42ca043dc8f..86496443440e9 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);
--
2.22.0.657.g960e92d24f-goog

2019-07-24 20:18:49

by Willem de Bruijn

Subject: Re: [PATCH bpf-next 4/6] libbpf: support BPF_MAP_DUMP command

On Wed, Jul 24, 2019 at 1:10 PM Brian Vazquez <[email protected]> wrote:
>
> 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 <[email protected]>
> Signed-off-by: Brian Vazquez <[email protected]>
> ---
> tools/lib/bpf/bpf.c | 28 ++++++++++++++++++++++++++++
> tools/lib/bpf/bpf.h | 4 ++++
> 2 files changed, 32 insertions(+)
>
> diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> index c7d7993c44bb0..c1139b7db756a 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));
> +}

This can call bpf_map_dump_flags internally to avoid code duplication?

> +
> +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));
> +}
> +