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: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200731182830.286260-5-andriin@fb.com
This commit is contained in:
Andrii Nakryiko 2020-07-31 11:28:29 -07:00 committed by Alexei Starovoitov
parent 90806ccc90
commit 0e8c7c07f0

View file

@ -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 }
};