samples: bpf: make the use of xdp samples consistent

Currently, each xdp samples are inconsistent in the use.
Most of the samples fetch the interface with it's name.
(ex. xdp1, xdp2skb, xdp_redirect_cpu, xdp_sample_pkts, etc.)

But some of the xdp samples are fetching the interface with
ifindex by command argument.

This commit enables xdp samples to fetch interface with it's name
without changing the original index interface fetching.
(<ifname|ifindex> fetching in the same way as xdp_sample_pkts_user.c does.)

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 10 insertions, 2 deletions

diff --git a/samples/bpf/xdp_adjust_tail_user.c b/samples/bpf/xdp_adjust_tail_user.c
index 586ff751aba9..a3596b617c4c 100644
--- a/samples/bpf/xdp_adjust_tail_user.c
+++ b/samples/bpf/xdp_adjust_tail_user.c
@@ -13,6 +13,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <net/if.h>
 #include <sys/resource.h>
 #include <arpa/inet.h>
 #include <netinet/ether.h>
@@ -69,7 +70,7 @@ static void usage(const char *cmd)
 	printf("Start a XDP prog which send ICMP \"packet too big\" \n"
 		"messages if ingress packet is bigger then MAX_SIZE bytes\n");
 	printf("Usage: %s [...]\n", cmd);
-	printf("    -i <ifindex> Interface Index\n");
+	printf("    -i <ifname|ifindex> Interface\n");
 	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
 	printf("    -S use skb-mode\n");
 	printf("    -N enforce native mode\n");
@@ -102,7 +103,9 @@ int main(int argc, char **argv)
 
 		switch (opt) {
 		case 'i':
-			ifindex = atoi(optarg);
+			ifindex = if_nametoindex(optarg);
+			if (!ifindex)
+				ifindex = atoi(optarg);
 			break;
 		case 'T':
 			kill_after_s = atoi(optarg);
@@ -136,6 +139,11 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
+	if (!ifindex) {
+		fprintf(stderr, "Invalid ifname\n");
+		return 1;
+	}
+
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 	prog_load_attr.file = filename;