tools: bpftool: reimplement bpf_prog_load() for prog load

bpf_prog_load() is a very useful helper but it doesn't give us full
flexibility of modifying the BPF objects before loading.  Open code
bpf_prog_load() in bpftool so we can add extra logic in following
commits.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 9869558..2bdd5ec 100644 (file)
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -43,6 +43,8 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
+#include <linux/err.h>
+
 #include <bpf.h>
 #include <libbpf.h>
 
@@ -682,17 +684,20 @@ static int do_pin(int argc, char **argv)
 
 static int do_load(int argc, char **argv)
 {
-       struct bpf_prog_load_attr attr = {
+       enum bpf_attach_type expected_attach_type;
+       struct bpf_object_open_attr attr = {
                .prog_type      = BPF_PROG_TYPE_UNSPEC,
        };
-       const char *objfile, *pinfile;
+       struct bpf_program *prog;
        struct bpf_object *obj;
-       int prog_fd;
+       struct bpf_map *map;
+       const char *pinfile;
+       __u32 ifindex = 0;
        int err;
 
        if (!REQ_ARGS(2))
                return -1;
-       objfile = GET_ARG();
+       attr.file = GET_ARG();
        pinfile = GET_ARG();
 
        while (argc) {
@@ -719,7 +724,7 @@ static int do_load(int argc, char **argv)
                        strcat(type, "/");
 
                        err = libbpf_prog_type_by_name(type, &attr.prog_type,
-                                                      &attr.expected_attach_type);
+                                                      &expected_attach_type);
                        free(type);
                        if (err < 0) {
                                p_err("unknown program type '%s'", *argv);
@@ -729,15 +734,15 @@ static int do_load(int argc, char **argv)
                } else if (is_prefix(*argv, "dev")) {
                        NEXT_ARG();
 
-                       if (attr.ifindex) {
+                       if (ifindex) {
                                p_err("offload device already specified");
                                return -1;
                        }
                        if (!REQ_ARGS(1))
                                return -1;
 
-                       attr.ifindex = if_nametoindex(*argv);
-                       if (!attr.ifindex) {
+                       ifindex = if_nametoindex(*argv);
+                       if (!ifindex) {
                                p_err("unrecognized netdevice '%s': %s",
                                      *argv, strerror(errno));
                                return -1;
@@ -750,14 +755,44 @@ static int do_load(int argc, char **argv)
                }
        }
 
-       attr.file = objfile;
-
-       if (bpf_prog_load_xattr(&attr, &obj, &prog_fd)) {
-               p_err("failed to load program");
+       obj = bpf_object__open_xattr(&attr);
+       if (IS_ERR_OR_NULL(obj)) {
+               p_err("failed to open object file");
                return -1;
        }
 
-       if (do_pin_fd(prog_fd, pinfile))
+       prog = bpf_program__next(NULL, obj);
+       if (!prog) {
+               p_err("object file doesn't contain any bpf program");
+               goto err_close_obj;
+       }
+
+       bpf_program__set_ifindex(prog, ifindex);
+       if (attr.prog_type == BPF_PROG_TYPE_UNSPEC) {
+               const char *sec_name = bpf_program__title(prog, false);
+
+               err = libbpf_prog_type_by_name(sec_name, &attr.prog_type,
+                                              &expected_attach_type);
+               if (err < 0) {
+                       p_err("failed to guess program type based on section name %s\n",
+                             sec_name);
+                       goto err_close_obj;
+               }
+       }
+       bpf_program__set_type(prog, attr.prog_type);
+       bpf_program__set_expected_attach_type(prog, expected_attach_type);
+
+       bpf_map__for_each(map, obj)
+               if (!bpf_map__is_offload_neutral(map))
+                       bpf_map__set_ifindex(map, ifindex);
+
+       err = bpf_object__load(obj);
+       if (err) {
+               p_err("failed to load object file");
+               goto err_close_obj;
+       }
+
+       if (do_pin_fd(bpf_program__fd(prog), pinfile))
                goto err_close_obj;
 
        if (json_output)