it is defined in linux asm/sockios.h since commit
ae40eb1ef30ab4120bd3c8b7e3da99ee53d27a23 (linux v2.6.22)
but was missing from musl by accident.
in musl the sockios macros are exposed in sys/ioctl.h together
with other ioctl requests instead of in sys/socket.h because of
namespace rules. (glibc has them in sys/socket.h under _GNU_SOURCE.)
#define SIOCGPGRP 0x8904
#define SIOCATMARK 0x8905
#define SIOCGSTAMP 0x8906
+#define SIOCGSTAMPNS 0x8907
#define SIOCADDRT 0x890B
#define SIOCDELRT 0x890C
#define SIOCSPGRP _IOW('s', 8, pid_t)
#define SIOCGPGRP _IOR('s', 9, pid_t)
#define SIOCGSTAMP 0x8906
+#define SIOCGSTAMPNS 0x8907
#define SIOCADDRT 0x890B
#define SIOCDELRT 0x890C
#define SIOCSPGRP _IOW('s', 8, pid_t)
#define SIOCGPGRP _IOR('s', 9, pid_t)
#define SIOCGSTAMP 0x8906
+#define SIOCGSTAMPNS 0x8907
#define SIOCADDRT 0x890B
#define SIOCDELRT 0x890C
#define SIOCSPGRP _IOW('s', 8, pid_t)
#define SIOCGPGRP _IOR('s', 9, pid_t)
#define SIOCGSTAMP 0x8906
+#define SIOCGSTAMPNS 0x8907
#define SIOCADDRT 0x890B
#define SIOCDELRT 0x890C
#define SIOCGPGRP 0x8904
#define SIOCATMARK 0x8905
#define SIOCGSTAMP 0x8906
+#define SIOCGSTAMPNS 0x8907
#define SIOCADDRT 0x890B
#define SIOCDELRT 0x890C
#define SIOCGPGRP 0x8904
#define SIOCATMARK 0x8905
#define SIOCGSTAMP 0x8906
+#define SIOCGSTAMPNS 0x8907
#define SIOCADDRT 0x890B
#define SIOCDELRT 0x890C
#define SIOCGPGRP 0x8904
#define SIOCATMARK 0x8905
#define SIOCGSTAMP 0x8906
+#define SIOCGSTAMPNS 0x8907
#define SIOCADDRT 0x890B
#define SIOCDELRT 0x890C
#define SIOCSPGRP _IOW('s', 8, int)
#define SIOCGPGRP _IOW('s', 9, int)
#define SIOCGSTAMP _IOR('s', 100, char[8])
+#define SIOCGSTAMPNS _IOR('s', 101, char[8])
#define SIOCADDRT 0x890B
#define SIOCDELRT 0x890C