Solaris 2.6 has the prototypes for inet_pton() and inet_ntop() in

resolv.h.

config.h.in

@@ -975,6 +975,10 @@
    */
 #undef MAX_UID_T_LEN
 
+/* Define to 1 if resolv.h must be included to get the `inet_ntop' or
+   `inet_pton' function prototypes. */
+#undef NEED_RESOLV_H
+
 /* Define to 1 if you don't want sudo to prompt for a password by default. */
 #undef NO_AUTHENTICATION
 

configure

@@ -20349,6 +20349,12 @@ $as_echo "yes" >&6; }
 
 	    NET_LIBS="${NET_LIBS} $libs"
 	    INET_PTON_LIBS="$libs"
+	    case "$libs" in
+		*-lresolv*)
+		    $as_echo "#define NEED_RESOLV_H 1" >>confdefs.h
+
+		    ;;
+	    esac
 	    break
 
     else
@@ -26790,5 +26796,6 @@ fi
 
 
 
+
 
 

configure.ac

@@ -2790,6 +2790,11 @@ AC_CHECK_FUNC([inet_pton], [
 	    AC_DEFINE(HAVE_INET_PTON)
 	    NET_LIBS="${NET_LIBS} $libs"
 	    INET_PTON_LIBS="$libs"
+	    case "$libs" in
+		*-lresolv*)
+		    AC_DEFINE(NEED_RESOLV_H)
+		    ;;
+	    esac
 	    break
 	], [], [$extralibs])
     done
@@ -4336,6 +4341,7 @@ AH_TEMPLATE(HAVE__NSS_INITF_GROUP, [Define to 1 if you have the `_nss_initf_grou
 AH_TEMPLATE(HAVE___NSS_INITF_GROUP, [Define to 1 if you have the `__nss_initf_group' function.])
 AH_TEMPLATE(HAVE__NSS_XBYY_BUF_ALLOC, [Define to 1 if you have the `_nss_XbyY_buf_alloc' function.])
 AH_TEMPLATE(HAVE___NSS_XBYY_BUF_ALLOC, [Define to 1 if you have the `__nss_XbyY_buf_alloc' function.])
+AH_TEMPLATE(NEED_RESOLV_H, [Define to 1 if resolv.h must be included to get the `inet_ntop' or `inet_pton' function prototypes.])
 AH_TEMPLATE(HAVE_STRNLEN, [Define to 1 if you have the `strnlen' function.])
 
 dnl

lib/util/getaddrinfo.c

@@ -51,6 +51,10 @@
 
 #include <arpa/inet.h>
 #include <netinet/in.h>
+#ifdef NEED_RESOLV_H
+# include <arpa/nameser.h>
+# include <resolv.h>
+#endif /* NEED_RESOLV_H */
 
 #include "sudo_compat.h"
 #include "compat/getaddrinfo.h"

plugins/sudoers/interfaces.c

@@ -29,6 +29,10 @@
 #include <unistd.h>
 #include <netinet/in.h>  
 #include <arpa/inet.h>
+#ifdef NEED_RESOLV_H
+# include <arpa/nameser.h>
+# include <resolv.h>
+#endif /* NEED_RESOLV_H */
 #include <netdb.h>
 #include <errno.h>
 

plugins/sudoers/match_addr.c

@@ -36,6 +36,10 @@
 #include <unistd.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#ifdef NEED_RESOLV_H
+# include <arpa/nameser.h>
+# include <resolv.h>
+#endif /* NEED_RESOLV_H */
 
 #include "sudoers.h"
 #include "interfaces.h"

src/net_ifs.c

@@ -67,6 +67,10 @@ struct rtentry;
 #endif /* _MIPS */
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#ifdef NEED_RESOLV_H
+# include <arpa/nameser.h>
+# include <resolv.h>
+#endif /* NEED_RESOLV_H */
 #include <net/if.h>
 #ifdef HAVE_GETIFADDRS
 # include <ifaddrs.h>