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

From: Larysa Zaremba
Date: Thu May 11 2023 - 11:22:06 EST


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