Commit 0e8c7c07 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

tools/bpftool: Add `link detach` subcommand 



Add ability to force-detach BPF link. Also add missing error message, if
specified link ID is wrong.

Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200731182830.286260-5-andriin@fb.com
parent 90806ccc

tools/bpf/bpftool/link.c

+36 −1
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ static const char * const link_type_name[] = { 


static int link_parse_fd(int *argc, char ***argv)

{

	int fd;



	if (is_prefix(**argv, "id")) {

		unsigned int id;

		char *endptr;
@@ -35,7 +37,10 @@ static int link_parse_fd(int *argc, char ***argv) 
		}

		NEXT_ARGP();



		return bpf_link_get_fd_by_id(id);

		fd = bpf_link_get_fd_by_id(id);

		if (fd < 0)

			p_err("failed to get link with ID %d: %s", id, strerror(errno));

		return fd;

	} else if (is_prefix(**argv, "pinned")) {

		char *path;
@@ -316,6 +321,34 @@ static int do_pin(int argc, char **argv) 
	return err;

}



static int do_detach(int argc, char **argv)

{

	int err, fd;



	if (argc != 2) {

		p_err("link specifier is invalid or missing\n");

		return 1;

	}



	fd = link_parse_fd(&argc, &argv);

	if (fd < 0)

		return 1;



	err = bpf_link_detach(fd);

	if (err)

		err = -errno;

	close(fd);

	if (err) {

		p_err("failed link detach: %s", strerror(-err));

		return 1;

	}



	if (json_output)

		jsonw_null(json_wtr);



	return 0;

}



static int do_help(int argc, char **argv)

{

	if (json_output) {
@@ -326,6 +359,7 @@ static int do_help(int argc, char **argv) 
	fprintf(stderr,

		"Usage: %1$s %2$s { show | list }   [LINK]\n"

		"       %1$s %2$s pin        LINK  FILE\n"

		"       %1$s %2$s detach     LINK\n"

		"       %1$s %2$s help\n"

		"\n"

		"       " HELP_SPEC_LINK "\n"
@@ -341,6 +375,7 @@ static const struct cmd cmds[] = { 
	{ "list",	do_show },

	{ "help",	do_help },

	{ "pin",	do_pin },

	{ "detach",	do_detach },

	{ 0 }

};