diff -rBu nmap-5.51-orig//configure.ac nmap-5.51/configure.ac
--- nmap-5.51-orig//configure.ac	2010-09-29 18:09:26.000000000 +0200
+++ nmap-5.51/configure.ac	2011-09-27 04:14:49.669996252 +0200
@@ -8,6 +8,10 @@
 dnl installed. This gets replaced with AM_GNU_GETTEXT for full gettext support.
 AM_NLS
 
+AC_ARG_VAR([SYSETCDIR], [system config directory location, Default = "/etc"])
+AS_IF([test "x$SYSETCDIR" = x], [SYSETCDIR="/etc"])
+AC_DEFINE_UNQUOTED([SYS_ETC_DIR], ["$SYSETCDIR"])
+
 AC_ARG_WITH(localdirs,
 AC_HELP_STRING([--with-localdirs], [Explicitly ask compiler to use /usr/local/{include,libs} if they exist ]),
   [ case "$with_localdirs" in
diff -rBu nmap-5.51-orig//nmap_config.h.in nmap-5.51/nmap_config.h.in
--- nmap-5.51-orig//nmap_config.h.in	2011-01-21 01:04:16.000000000 +0100
+++ nmap-5.51/nmap_config.h.in	2011-09-27 04:08:55.328239161 +0200
@@ -190,4 +190,6 @@
 #undef NETBSD
 #undef MACOSX
 
+#undef SYS_ETC_DIR
+
 #endif /* CONFIG_H */
diff -rBu nmap-5.51-orig//nmap_dns.cc nmap-5.51/nmap_dns.cc
--- nmap-5.51-orig//nmap_dns.cc	2011-01-21 01:04:16.000000000 +0100
+++ nmap-5.51/nmap_dns.cc	2011-09-27 16:22:50.790512326 +0200
@@ -940,9 +940,9 @@
   char fmt[32];
   char ipaddr[INET6_ADDRSTRLEN];
 
-  fp = fopen("/etc/resolv.conf", "r");
+  fp = fopen(SYS_ETC_DIR "/resolv.conf", "r");
   if (fp == NULL) {
-    if (firstrun) error("mass_dns: warning: Unable to open /etc/resolv.conf. Try using --system-dns or specify valid servers with --dns-servers");
+    if (firstrun) error("mass_dns: warning: Unable to open %s/resolv.conf. Try using --system-dns or specify valid servers with --dns-servers", SYS_ETC_DIR);
     return;
   }
 
@@ -1101,7 +1101,7 @@
   parse_etchosts(tpbuf);
 
 #else
-  parse_etchosts("/etc/hosts");
+  parse_etchosts(SYS_ETC_DIR "/hosts");
 #endif
 }
 
diff -rBu nmap-5.51-orig//nmap_rpc.cc nmap-5.51/nmap_rpc.cc
--- nmap-5.51-orig//nmap_rpc.cc	2011-01-21 01:04:16.000000000 +0100
+++ nmap-5.51/nmap_rpc.cc	2011-09-27 16:23:30.454709015 +0200
@@ -131,8 +131,8 @@
   ri.numbers = (unsigned long *) cp_alloc(ri.num_alloc * sizeof(unsigned long));
 
   if (nmap_fetchfile(filename, sizeof(filename), "nmap-rpc") != 1) {
-    error("Unable to find nmap-rpc!  Resorting to /etc/rpc");
-    strcpy(filename, "/etc/rpc");
+    error("Unable to find nmap-rpc!  Resorting to %s/rpc", SYS_ETC_DIR);
+    strncpy(filename, SYS_ETC_DIR "/rpc", 511);
   }
 
   fp = fopen(filename, "r");
diff -rBu nmap-5.51-orig//protocols.cc nmap-5.51/protocols.cc
--- nmap-5.51-orig//protocols.cc	2011-01-21 01:04:16.000000000 +0100
+++ nmap-5.51/protocols.cc	2011-09-27 16:24:34.107024643 +0200
@@ -116,8 +116,8 @@
   int res;
 
   if (nmap_fetchfile(filename, sizeof(filename), "nmap-protocols") != 1) {
-    error("Unable to find nmap-protocols!  Resorting to /etc/protocols");
-    strcpy(filename, "/etc/protocols");
+    error("Unable to find nmap-protocols!  Resorting to %s/protocols", SYS_ETC_DIR);
+    strncpy(filename, SYS_ETC_DIR "/protocols", 511);
   }
 
   fp = fopen(filename, "r");
diff -rBu nmap-5.51-orig//services.cc nmap-5.51/services.cc
--- nmap-5.51-orig//services.cc	2011-01-21 01:04:16.000000000 +0100
+++ nmap-5.51/services.cc	2011-09-27 16:25:13.115218075 +0200
@@ -162,8 +162,8 @@
 
   if (nmap_fetchfile(filename, sizeof(filename), "nmap-services") != 1) {
 #ifndef WIN32
-    error("Unable to find nmap-services!  Resorting to /etc/services");
-    strcpy(filename, "/etc/services");
+    error("Unable to find nmap-services!  Resorting to %s/services", SYS_ETC_DIR);
+    strncpy(filename, SYS_ETC_DIR "/services", 511);
 #else
 	int len, wnt = GetVersion() < 0x80000000;
     error("Unable to find nmap-services!  Resorting to /etc/services");