xdp_redirect_cpu has a 6 different XDP programs that can be attached to
network interface. This sample has a option --prognum that allows user
for specifying which particular program from a given set will be
attached to network interface.
In order to make it easier when converting the mentioned sample to
libbpf usage, add a function to libbpf that will return program's fd for
a given index.
Note that there is already a bpf_object__find_prog_by_idx, which could
be exported and might be used for that purpose, but it operates on the
number of ELF section and here we need an index from a programs array
within the bpf_object.
Signed-off-by: Maciej Fijalkowski <maciejromanfijalkow...@gmail.com>
Reviewed-by: Jakub Kicinski <jakub.kicin...@netronome.com>
---
tools/lib/bpf/libbpf.c | 8 ++++++++
tools/lib/bpf/libbpf.h | 3 +++
tools/lib/bpf/libbpf.map | 1 +
3 files changed, 12 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index dc838bea403f..21c84d0f6128 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -935,6 +935,14 @@ static int bpf_object__elf_collect(struct bpf_object *obj,
int flags)
return err;
}
+int
+bpf_object__get_prog_fd_by_num(struct bpf_object *obj, int idx)
+{
+ if (idx >= 0 && idx < obj->nr_programs)
+ return bpf_program__fd(&obj->programs[idx]);
+ return -ENOENT;
+}
+
static struct bpf_program *
bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
{
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 7f10d36abdde..ca1b381cb3ad 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -95,6 +95,9 @@ LIBBPF_API int bpf_object__btf_fd(const struct bpf_object
*obj);
LIBBPF_API struct bpf_program *
bpf_object__find_program_by_title(struct bpf_object *obj, const char *title);
+LIBBPF_API int
+bpf_object__get_prog_fd_by_num(struct bpf_object *obj, int idx);
+
LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev);
#define bpf_object__for_each_safe(pos, tmp) \
for ((pos) = bpf_object__next(NULL), \
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 7c59e4f64082..871d2fc07150 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -127,4 +127,5 @@ LIBBPF_0.0.1 {
LIBBPF_0.0.2 {
global:
bpf_object__find_map_fd_by_name;
+ bpf_object__get_prog_fd_by_num;
} LIBBPF_0.0.1;
--
2.16.1
