[PATCH bpf-next] samples/bpf: Fix sockex3: missing BPF prog type

From: Rong Tao
Date: Thu Oct 27 2022 - 09:38:42 EST


From: Rong Tao <rongtao@xxxxxxxx>

since commit 450b167fb9be("libbpf: clean up SEC() handling"),
sec_def_matches() does not recognize "socket/xxx" as "socket", therefore,
the BPF program type is not recognized, we should add a custom program
type handler for "socket/xxx".

$ cd samples/bpf
$ sudo ./sockex3
libbpf: prog 'bpf_func_PARSE_IP': missing BPF prog type, check ELF section name 'socket/3'
libbpf: prog 'bpf_func_PARSE_IP': failed to load: -22
libbpf: failed to load object './sockex3_kern.o'
ERROR: loading BPF object file failed

Signed-off-by: Rong Tao <rongtao@xxxxxxxx>
---
samples/bpf/sockex3_user.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/samples/bpf/sockex3_user.c b/samples/bpf/sockex3_user.c
index cd6fa79df900..d18d7a3600b0 100644
--- a/samples/bpf/sockex3_user.c
+++ b/samples/bpf/sockex3_user.c
@@ -22,6 +22,14 @@ struct pair {
__u64 bytes;
};

+static int socket_prog_type_id;
+
+__attribute__((destructor))
+static void unregister_socket_sec_handlers(void)
+{
+ libbpf_unregister_prog_handler(socket_prog_type_id);
+}
+
int main(int argc, char **argv)
{
int i, sock, key, fd, main_prog_fd, jmp_table_fd, hash_map_fd;
@@ -31,6 +39,13 @@ int main(int argc, char **argv)
char filename[256];
FILE *f;

+ LIBBPF_OPTS(libbpf_prog_handler_opts, socket_opts,
+ .cookie = 1,
+ );
+
+ socket_prog_type_id = libbpf_register_prog_handler("socket/",
+ BPF_PROG_TYPE_SOCKET_FILTER, 0, &socket_opts);
+
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);

obj = bpf_object__open_file(filename, NULL);
--
2.31.1