building by gcc on Arch Linux fix

iputils/ping.h

@@ -8,7 +8,6 @@
 #include <sys/socket.h>
 #include <linux/types.h>
 #include <linux/sockios.h>
-#include <linux/ipv6.h>
 # define __USE_KERNEL_IPV6_DEFS
 #include <sys/file.h>
 #include <sys/time.h>
@@ -68,6 +67,7 @@
 
 #include <ifaddrs.h>
 #include <netinet/in.h>
+#include <linux/ipv6.h>
 #include <arpa/inet.h>
 #include <linux/types.h>
 #include <linux/errqueue.h>

iputils/ping6_common.c

@@ -60,6 +60,13 @@
 
 #include "ping.h"
 
+/* IPv6 packet information.  */
+struct in6_pktinfo
+  {
+    struct in6_addr ipi6_addr;	/* src/dst IPv6 address */
+    unsigned int ipi6_ifindex;	/* send/recv interface index */
+  };
+
 ping_func_set_st ping6_func_set = {
     .send_probe = ping6_send_probe,
     .receive_error_msg = ping6_receive_error_msg,