samples/bpf: fix SKB_MODE flag to be a 32-bit unsigned int

The kernel side of XDP_FLAGS_SKB_MODE is unsigned, and the rtnetlink
IFLA_XDP_FLAGS is defined as NLA_U32. Thus, userspace programs under
samples/bpf/ should use the correct type.

Fixes: 3993f2cb98 ("samples/bpf: Add support for SKB_MODE to xdp1 and xdp_tx_iptunnel")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

samples/bpf/bpf_load.c

@@ -14,6 +14,7 @@
 #include <linux/perf_event.h>
 #include <linux/netlink.h>
 #include <linux/rtnetlink.h>
+#include <linux/types.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/syscall.h>
@@ -585,7 +586,7 @@ struct ksym *ksym_search(long key)
 	return &syms[0];
 }
 
-int set_link_xdp_fd(int ifindex, int fd, int flags)
+int set_link_xdp_fd(int ifindex, int fd, __u32 flags)
 {
 	struct sockaddr_nl sa;
 	int sock, seq = 0, len, ret = -1;

samples/bpf/bpf_load.h

@@ -47,5 +47,5 @@ struct ksym {
 
 int load_kallsyms(void);
 struct ksym *ksym_search(long key);
-int set_link_xdp_fd(int ifindex, int fd, int flags);
+int set_link_xdp_fd(int ifindex, int fd, __u32 flags);
 #endif

samples/bpf/xdp1_user.c

@@ -20,11 +20,11 @@
 #include "libbpf.h"
 
 static int ifindex;
-static int flags;
+static __u32 xdp_flags;
 
 static void int_exit(int sig)
 {
-	set_link_xdp_fd(ifindex, -1, flags);
+	set_link_xdp_fd(ifindex, -1, xdp_flags);
 	exit(0);
 }
 
@@ -75,7 +75,7 @@ int main(int argc, char **argv)
 	while ((opt = getopt(argc, argv, optstr)) != -1) {
 		switch (opt) {
 		case 'S':
-			flags |= XDP_FLAGS_SKB_MODE;
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
 			break;
 		default:
 			usage(basename(argv[0]));
@@ -103,7 +103,7 @@ int main(int argc, char **argv)
 
 	signal(SIGINT, int_exit);
 
-	if (set_link_xdp_fd(ifindex, prog_fd[0], flags) < 0) {
+	if (set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {
 		printf("link set xdp fd failed\n");
 		return 1;
 	}

samples/bpf/xdp_tx_iptunnel_user.c

@@ -142,8 +142,8 @@ int main(int argc, char **argv)
 	struct iptnl_info tnl = {};
 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	struct vip vip = {};
+	__u32 xdp_flags = 0;
 	char filename[256];
-	int flags = 0;
 	int opt;
 	int i;
 
@@ -204,7 +204,7 @@ int main(int argc, char **argv)
 			kill_after_s = atoi(optarg);
 			break;
 		case 'S':
-			flags |= XDP_FLAGS_SKB_MODE;
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
 			break;
 		default:
 			usage(argv[0]);
@@ -248,14 +248,14 @@ int main(int argc, char **argv)
 		}
 	}
 
-	if (set_link_xdp_fd(ifindex, prog_fd[0], flags) < 0) {
+	if (set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {
 		printf("link set xdp fd failed\n");
 		return 1;
 	}
 
 	poll_stats(kill_after_s);
 
-	set_link_xdp_fd(ifindex, -1, flags);
+	set_link_xdp_fd(ifindex, -1, xdp_flags);
 
 	return 0;
 }