[PATCH bpf-next] bpftool: specify XDP Hints ifname when loading program

[Larysa Zaremba <larysa.zaremba@xxxxxxxxx>]

Add ability to specify a network interface used to resolve
XDP Hints kfuncs when loading program through bpftool.

Usage:
bpftool prog load <bpf_obj_path> <pin_path> dev xdpmeta <ifname>

Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
---
 tools/bpf/bpftool/prog.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 91b6075b2db3..a9cb96d99277 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -1517,12 +1517,13 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
 	struct bpf_program *prog = NULL, *pos;
 	unsigned int old_map_fds = 0;
 	const char *pinmaps = NULL;
+	__u32 offload_ifindex = 0;
 	bool auto_attach = false;
+	__u32 meta_ifindex = 0;
 	struct bpf_object *obj;
 	struct bpf_map *map;
 	const char *pinfile;
 	unsigned int i, j;
-	__u32 ifindex = 0;
 	const char *file;
 	int idx, err;
 
@@ -1614,17 +1615,25 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
 			map_replace[old_map_fds].fd = fd;
 			old_map_fds++;
 		} else if (is_prefix(*argv, "dev")) {
+			__u32 *cur_ifindex;
+
 			NEXT_ARG();
 
-			if (ifindex) {
-				p_err("offload device already specified");
+			if (offload_ifindex || meta_ifindex) {
+				p_err("device already specified");
 				goto err_free_reuse_maps;
 			}
+			if (is_prefix(*argv, "xdpmeta")) {
+				cur_ifindex = &meta_ifindex;
+				NEXT_ARG();
+			} else {
+				cur_ifindex = &offload_ifindex;
+			}
 			if (!REQ_ARGS(1))
 				goto err_free_reuse_maps;
 
-			ifindex = if_nametoindex(*argv);
-			if (!ifindex) {
+			*cur_ifindex = if_nametoindex(*argv);
+			if (!(*cur_ifindex)) {
 				p_err("unrecognized netdevice '%s': %s",
 				      *argv, strerror(errno));
 				goto err_free_reuse_maps;
@@ -1671,7 +1680,12 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
 				goto err_close_obj;
 		}
 
-		bpf_program__set_ifindex(pos, ifindex);
+		if (prog_type == BPF_PROG_TYPE_XDP && meta_ifindex) {
+			bpf_program__set_flags(pos, BPF_F_XDP_DEV_BOUND_ONLY);
+			bpf_program__set_ifindex(pos, meta_ifindex);
+		} else {
+			bpf_program__set_ifindex(pos, offload_ifindex);
+		}
 		if (bpf_program__type(pos) != prog_type)
 			bpf_program__set_type(pos, prog_type);
 		bpf_program__set_expected_attach_type(pos, expected_attach_type);
@@ -1709,7 +1723,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
 	idx = 0;
 	bpf_object__for_each_map(map, obj) {
 		if (bpf_map__type(map) != BPF_MAP_TYPE_PERF_EVENT_ARRAY)
-			bpf_map__set_ifindex(map, ifindex);
+			bpf_map__set_ifindex(map, offload_ifindex);
 
 		if (j < old_map_fds && idx == map_replace[j].idx) {
 			err = bpf_map__reuse_fd(map, map_replace[j++].fd);
-- 
2.35.3