libbpf: Introduce libbpf_bpf_prog_type_str

This change introduces a new function, libbpf_bpf_prog_type_str, to the
public libbpf API. The function allows users to get a string
representation for a bpf_prog_type variant.
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220523230428.3077108-2-deso@posteo.net

tools/lib/bpf/libbpf.c

@@ -72,6 +72,41 @@
 static struct bpf_map *bpf_object__add_map(struct bpf_object *obj);
 static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog);
 
+static const char * const prog_type_name[] = {
+	[BPF_PROG_TYPE_UNSPEC]			= "unspec",
+	[BPF_PROG_TYPE_SOCKET_FILTER]		= "socket_filter",
+	[BPF_PROG_TYPE_KPROBE]			= "kprobe",
+	[BPF_PROG_TYPE_SCHED_CLS]		= "sched_cls",
+	[BPF_PROG_TYPE_SCHED_ACT]		= "sched_act",
+	[BPF_PROG_TYPE_TRACEPOINT]		= "tracepoint",
+	[BPF_PROG_TYPE_XDP]			= "xdp",
+	[BPF_PROG_TYPE_PERF_EVENT]		= "perf_event",
+	[BPF_PROG_TYPE_CGROUP_SKB]		= "cgroup_skb",
+	[BPF_PROG_TYPE_CGROUP_SOCK]		= "cgroup_sock",
+	[BPF_PROG_TYPE_LWT_IN]			= "lwt_in",
+	[BPF_PROG_TYPE_LWT_OUT]			= "lwt_out",
+	[BPF_PROG_TYPE_LWT_XMIT]		= "lwt_xmit",
+	[BPF_PROG_TYPE_SOCK_OPS]		= "sock_ops",
+	[BPF_PROG_TYPE_SK_SKB]			= "sk_skb",
+	[BPF_PROG_TYPE_CGROUP_DEVICE]		= "cgroup_device",
+	[BPF_PROG_TYPE_SK_MSG]			= "sk_msg",
+	[BPF_PROG_TYPE_RAW_TRACEPOINT]		= "raw_tracepoint",
+	[BPF_PROG_TYPE_CGROUP_SOCK_ADDR]	= "cgroup_sock_addr",
+	[BPF_PROG_TYPE_LWT_SEG6LOCAL]		= "lwt_seg6local",
+	[BPF_PROG_TYPE_LIRC_MODE2]		= "lirc_mode2",
+	[BPF_PROG_TYPE_SK_REUSEPORT]		= "sk_reuseport",
+	[BPF_PROG_TYPE_FLOW_DISSECTOR]		= "flow_dissector",
+	[BPF_PROG_TYPE_CGROUP_SYSCTL]		= "cgroup_sysctl",
+	[BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE]	= "raw_tracepoint_writable",
+	[BPF_PROG_TYPE_CGROUP_SOCKOPT]		= "cgroup_sockopt",
+	[BPF_PROG_TYPE_TRACING]			= "tracing",
+	[BPF_PROG_TYPE_STRUCT_OPS]		= "struct_ops",
+	[BPF_PROG_TYPE_EXT]			= "ext",
+	[BPF_PROG_TYPE_LSM]			= "lsm",
+	[BPF_PROG_TYPE_SK_LOOKUP]		= "sk_lookup",
+	[BPF_PROG_TYPE_SYSCALL]			= "syscall",
+};
+
 static int __base_pr(enum libbpf_print_level level, const char *format,
 		     va_list args)
 {
@@ -9300,6 +9335,14 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
 	return libbpf_err(-ESRCH);
 }
 
+const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t)
+{
+	if (t < 0 || t >= ARRAY_SIZE(prog_type_name))
+		return NULL;
+
+	return prog_type_name[t];
+}
+
 static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj,
 						     size_t offset)
 {

tools/lib/bpf/libbpf.h

@@ -51,6 +51,15 @@ enum libbpf_errno {
 
 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
 
+/**
+ * @brief **libbpf_bpf_prog_type_str()** converts the provided program type
+ * value into a textual representation.
+ * @param t The program type.
+ * @return Pointer to a static string identifying the program type. NULL is
+ * returned for unknown **bpf_prog_type** values.
+ */
+LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t);
+
 enum libbpf_print_level {
         LIBBPF_WARN,
         LIBBPF_INFO,

tools/lib/bpf/libbpf.map

@@ -461,5 +461,8 @@ LIBBPF_0.8.0 {
 } LIBBPF_0.7.0;
 
 LIBBPF_1.0.0 {
+	global:
+		libbpf_bpf_prog_type_str;
+
 	local: *;
 };