@@ -47,17 +47,58 @@ static int do_attach(int idx, int prog_fd, int map_fd, const char *name)
return err;
}
-static int do_detach(int idx, const char *name)
+static int do_detach(int ifindex, const char *ifname, const char
+*app_name)
{
- int err;
+ LIBBPF_OPTS(bpf_xdp_attach_opts, opts);
+ struct bpf_prog_info prog_info = {};
+ char prog_name[BPF_OBJ_NAME_LEN];
+ __u32 info_len, curr_prog_id;
+ int prog_fd;
+ int err = 1;
+
+ if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) {
+ printf("ERROR: bpf_xdp_query_id failed (%s)\n",
+ strerror(errno));
+ return err;
+ }
+
+ if (!curr_prog_id) {
+ printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n",
+ xdp_flags, ifname);
+ return err;
+ }
- err = bpf_xdp_detach(idx, xdp_flags, NULL);
- if (err < 0)
- printf("ERROR: failed to detach program from %s\n", name);
+ info_len = sizeof(prog_info);
+ prog_fd = bpf_prog_get_fd_by_id(curr_prog_id);
+ if (prog_fd < 0) {
+ printf("ERROR: bpf_prog_get_fd_by_id failed (%s)\n",
+ strerror(errno));
+ return err;
+ }
+
+ err = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &info_len);
+ if (err) {
+ printf("ERROR: bpf_obj_get_info_by_fd failed (%s)\n",
+ strerror(errno));
+ return err;
+ }
+ snprintf(prog_name, sizeof(prog_name), "%s_prog", app_name);
+ prog_name[BPF_OBJ_NAME_LEN - 1] = '\0';
+
+ if (strcmp(prog_info.name, prog_name)) {
+ printf("ERROR: %s isn't attached to %s\n", app_name, ifname);
+ err = 1;
+ } else {
+ opts.old_prog_fd = prog_fd;
+ err = bpf_xdp_detach(ifindex, xdp_flags, &opts);
+ if (err < 0)
+ printf("ERROR: failed to detach program from %s (%s)\n",
+ ifname, strerror(errno));
+ /* TODO: Remember to cleanup map, when adding use of shared map
+ * bpf_map_delete_elem((map_fd, &idx);
+ */
+ }
- /* TODO: Remember to cleanup map, when adding use of shared map
- * bpf_map_delete_elem((map_fd, &idx);
- */
return err;
}
@@ -169,7 +210,7 @@ int main(int argc, char **argv)
return 1;
}
if (!attach) {
- err = do_detach(idx, argv[i]);
+ err = do_detach(idx, argv[i], prog_name);
if (err)
ret = err;
} else {
-----邮件原件----- 发件人: shaozhengchao 发送时间: 2022年5月21日 12:35 收件人: bpf@vger.kernel.org; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; ast@kernel.org; daniel@iogearbox.net; davem@davemloft.net; kuba@kernel.org; hawk@kernel.org; john.fastabend@gmail.com; andrii@kernel.org; kafai@fb.com; songliubraving@fb.com; yhs@fb.com; kpsingh@kernel.org 抄送: weiyongjun (A) <weiyongjun1@huawei.com>; shaozhengchao <shaozhengchao@huawei.com>; yuehaibing <yuehaibing@huawei.com> 主题: [PATCH v3,bpf-next] samples/bpf: check detach prog exist or not in xdp_fwd Before detach the prog, we should check detach prog exist or not. Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> --- samples/bpf/xdp_fwd_user.c | 59 ++++++++++++++++++++++++++++++++------ 1 file changed, 50 insertions(+), 9 deletions(-) -- 2.17.1 Hi Toke, Do you have any more feedback? Does it look better to you now?