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>

1 files changed, 48 insertions, 13 deletions

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 98695585bbb6..2bdd5ecd1aad 100644
--- 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)