libbpf: Open code raw_tp_open and link_create commands.

Open code raw_tracepoint_open and link_create used by light skeleton
to be able to avoid full libbpf eventually.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220131220528.98088-4-alexei.starovoitov@gmail.com

diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 8eacfc7..eacfc6a 100644 (file)
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -381,13 +381,13 @@ static void codegen_attach_detach(struct bpf_object *obj, const char *obj_name)
                switch (bpf_program__type(prog)) {
                case BPF_PROG_TYPE_RAW_TRACEPOINT:
                        tp_name = strchr(bpf_program__section_name(prog), '/') + 1;
-                       printf("\tint fd = bpf_raw_tracepoint_open(\"%s\", prog_fd);\n", tp_name);
+                       printf("\tint fd = skel_raw_tracepoint_open(\"%s\", prog_fd);\n", tp_name);
                        break;
                case BPF_PROG_TYPE_TRACING:
                        if (bpf_program__expected_attach_type(prog) == BPF_TRACE_ITER)
-                               printf("\tint fd = bpf_link_create(prog_fd, 0, BPF_TRACE_ITER, NULL);\n");
+                               printf("\tint fd = skel_link_create(prog_fd, 0, BPF_TRACE_ITER);\n");
                        else
-                               printf("\tint fd = bpf_raw_tracepoint_open(NULL, prog_fd);\n");
+                               printf("\tint fd = skel_raw_tracepoint_open(NULL, prog_fd);\n");
                        break;
                default:
                        printf("\tint fd = ((void)prog_fd, 0); /* auto-attach not supported */\n");

diff --git a/tools/lib/bpf/skel_internal.h b/tools/lib/bpf/skel_internal.h
index 57507f1..dcd3336 100644 (file)
--- a/tools/lib/bpf/skel_internal.h
+++ b/tools/lib/bpf/skel_internal.h
@@ -110,6 +110,32 @@ static inline int skel_map_update_elem(int fd, const void *key,
        return skel_sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, attr_sz);
 }
 
+static inline int skel_raw_tracepoint_open(const char *name, int prog_fd)
+{
+       const size_t attr_sz = offsetofend(union bpf_attr, raw_tracepoint.prog_fd);
+       union bpf_attr attr;
+
+       memset(&attr, 0, attr_sz);
+       attr.raw_tracepoint.name = (long) name;
+       attr.raw_tracepoint.prog_fd = prog_fd;
+
+       return skel_sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, attr_sz);
+}
+
+static inline int skel_link_create(int prog_fd, int target_fd,
+                                  enum bpf_attach_type attach_type)
+{
+       const size_t attr_sz = offsetofend(union bpf_attr, link_create.iter_info_len);
+       union bpf_attr attr;
+
+       memset(&attr, 0, attr_sz);
+       attr.link_create.prog_fd = prog_fd;
+       attr.link_create.target_fd = target_fd;
+       attr.link_create.attach_type = attach_type;
+
+       return skel_sys_bpf(BPF_LINK_CREATE, &attr, attr_sz);
+}
+
 static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
 {
        int map_fd = -1, prog_fd = -1, key = 0, err;