Only define struct ucred if <sys/socket.h> does not provide it

Android.mk

@@ -79,7 +79,7 @@ LOCAL_CFLAGS += \
         -DHAVE_ERRNO_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRINGS_H=1 -DHAVE_UNISTD_H=1 \
         -DHAVE_STRING_H=1 -DHAVE_ARPA_INET_H=1 -DHAVE_SYS_SOCKET_H=1 \
         -DHAVE_SYS_MMAN_H=1 -DHAVE_SYS_TIME_H=1 -DHAVE_POLL_H=1 -DHAVE_NETDB_H=1 \
-	-DHAVE_JNI_H=1 -DBYTE_ORDER=_BYTE_ORDER \
+	-DHAVE_JNI_H=1 -DHAVE_STRUCT_UCRED=1 -DBYTE_ORDER=_BYTE_ORDER \
 	-I$(NACL_INC) \
 	-I$(SQLITE3_INC)
 LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog 

configure.in

@@ -37,6 +37,11 @@ dnl Math library functions for spandsp
 AC_CHECK_HEADERS([math.h], [INSERT_MATH_HEADER="#include <math.h>"])
 AC_CHECK_HEADERS([float.h])
 
+dnl Math library functions for spandsp
+AC_CHECK_MEMBER(struct ucred.uid,
+    [AC_DEFINE([HAVE_STRUCT_UCRED], 1)],,
+    [#include <sys/socket.h>])
+
 dnl Check for a working Java compiler, keep going if unsuccessful.
 dnl *** Kludge: override AC_MSG_ERROR because AC_PROG_JAVAC does not have
 dnl *** [if-found] and [if-not-found] action parameters.

monitor.c

@@ -26,14 +26,13 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include "serval.h"
 #include <sys/stat.h>
 
-/* Need a better way to do this! */
-#ifndef ANDROID
+#ifndef HAVE_STRUCT_UCRED
 struct ucred {
   pid_t pid;
   uid_t uid;
   gid_t gid;
 };
-#endif
+#endif // HAVE_STRUCT_UCRED
 
 /* really shouldn't need more than 2:
    1 for rhizome