Include netinet/{in.h, in_systm.h} when checking for netinet/ip.h

This solves warning messages of autoconf on e.g. FreeBSD 8:

configure: WARNING: netinet/ip.h: present but cannot be compiled
configure: WARNING: netinet/ip.h:   check for missing prerequisite headers?

diff --git a/configure.in b/configure.in
index 153ec579f702e184d91c54b22bdc21e14d579c8d..b053c416570f92167e90b43e2fcdb58a565f9c0c 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -101,12 +101,19 @@ AC_HEADER_TIME
 AC_HEADER_SYS_WAIT
 
 AC_CHECK_HEADERS([ \
-       ctype.h errno.h fcntl.h netdb.h netinet/in.h stdlib.h string.h \
-       strings.h sys/socket.h sys/time.h unistd.h \
+       ctype.h errno.h fcntl.h netdb.h netinet/in.h netinet/in_systm.h \
+       stdlib.h string.h strings.h sys/socket.h sys/time.h unistd.h \
        ],,AC_MSG_ERROR([required C header missing!]))
 
 AC_CHECK_HEADERS([ \
-       arpa/inet.h ctype.h malloc.h netinet/ip.h stdbool.h stddef.h varargs.h])
+       arpa/inet.h ctype.h malloc.h netinet/ip.h stdbool.h stddef.h varargs.h \
+       ],[],[],[[
+       #include <netinet/in.h>
+       #ifdef HAVE_NETINET_IN_SYSTM_H
+               #include <netinet/in_systm.h>
+       #endif
+       ]]
+)
 
 # -- Datatypes --