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Diffstat (limited to 'samples/bpf/xdp_sample_pkts_user.c')
-rw-r--r--samples/bpf/xdp_sample_pkts_user.c34
1 files changed, 29 insertions, 5 deletions
diff --git a/samples/bpf/xdp_sample_pkts_user.c b/samples/bpf/xdp_sample_pkts_user.c
index 62f34827c775..dc66345a929a 100644
--- a/samples/bpf/xdp_sample_pkts_user.c
+++ b/samples/bpf/xdp_sample_pkts_user.c
@@ -24,25 +24,49 @@ static int pmu_fds[MAX_CPUS], if_idx;
static struct perf_event_mmap_page *headers[MAX_CPUS];
static char *if_name;
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static __u32 prog_id;
static int do_attach(int idx, int fd, const char *name)
{
+ struct bpf_prog_info info = {};
+ __u32 info_len = sizeof(info);
int err;
err = bpf_set_link_xdp_fd(idx, fd, xdp_flags);
- if (err < 0)
+ if (err < 0) {
printf("ERROR: failed to attach program to %s\n", name);
+ return err;
+ }
+
+ err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
+ if (err) {
+ printf("can't get prog info - %s\n", strerror(errno));
+ return err;
+ }
+ prog_id = info.id;
return err;
}
static int do_detach(int idx, const char *name)
{
- int err;
+ __u32 curr_prog_id = 0;
+ int err = 0;
- err = bpf_set_link_xdp_fd(idx, -1, 0);
- if (err < 0)
- printf("ERROR: failed to detach program from %s\n", name);
+ err = bpf_get_link_xdp_id(idx, &curr_prog_id, 0);
+ if (err) {
+ printf("bpf_get_link_xdp_id failed\n");
+ return err;
+ }
+ if (prog_id == curr_prog_id) {
+ err = bpf_set_link_xdp_fd(idx, -1, 0);
+ if (err < 0)
+ printf("ERROR: failed to detach prog from %s\n", name);
+ } else if (!curr_prog_id) {
+ printf("couldn't find a prog id on a %s\n", name);
+ } else {
+ printf("program on interface changed, not removing\n");
+ }
return err;
}