--- dhcp-4.2.2/client/clparse.c
+++ dhcp-4.2.2/client/clparse.c
@@ -182,6 +182,10 @@ isc_result_t read_client_conf ()
 #endif
 	}
 
+	/* Read any extra configuration from stdin */
+	extern int read_client_conf_stdin (struct interface_info *ip, struct client_config *client);
+	read_client_conf_stdin (NULL, &top_level_config);
+
 	/* Set up state and config structures for clients that don't
 	   have per-interface configuration statements. */
 	config = (struct client_config *)0;
@@ -211,23 +215,13 @@ isc_result_t read_client_conf ()
 	return status;
 }
 
-int read_client_conf_file (const char *name, struct interface_info *ip,
+int read_client_conf_actual (struct parse *cfile, struct interface_info *ip,
 			   struct client_config *client)
 {
-	int file;
-	struct parse *cfile;
 	const char *val;
 	int token;
 	isc_result_t status;
 
-	if ((file = open (name, O_RDONLY)) < 0)
-		return uerr2isc (errno);
-
-	cfile = NULL;
-	status = new_parse(&cfile, file, NULL, 0, path_dhclient_conf, 0);
-	if (status != ISC_R_SUCCESS || cfile == NULL)
-		return status;
-
 	do {
 		token = peek_token (&val, (unsigned *)0, cfile);
 		if (token == END_OF_FILE)
@@ -238,10 +232,74 @@ int read_client_conf_file (const char *name, struct interface_info *ip,
 	status = (cfile -> warnings_occurred
 		  ? DHCP_R_BADPARSE
 		  : ISC_R_SUCCESS);
+	return status;
+}
+
+int read_client_conf_file (const char *name, struct interface_info *ip,
+			   struct client_config *client)
+{
+	int file;
+	struct parse *cfile;
+	isc_result_t status;
+	
+	if ((file = open (name, O_RDONLY)) < 0)
+		return uerr2isc (errno);
+
+	cfile = (struct parse *)0;
+	new_parse (&cfile, file, (char *)0, 0, path_dhclient_conf, 0);
+	status = read_client_conf_actual(cfile, ip, client);
 	end_parse (&cfile);
 	return status;
 }
 
+int read_client_conf_stdin (struct interface_info *ip,
+			    struct client_config *client)
+{
+	int file;
+	char *buffer = NULL, *p;
+	unsigned buflen, len = 0;
+	struct parse *cfile;
+	size_t bytes;
+	isc_result_t status;
+
+	file = fileno(stdin);
+	if (isatty (file))
+		return ISC_R_NOTFOUND;
+	if (fcntl (file, F_SETFL, O_NONBLOCK) < 0)
+		log_fatal ("could not set stdin to non blocking!");
+
+	buflen = BUFSIZ;
+	buffer = malloc (BUFSIZ + 1);
+	p = buffer;
+	do {
+		bytes = read (file, p, BUFSIZ);
+		if (bytes == 0)
+			break;
+		if (bytes == -1)
+			log_fatal ("failed to read stdin!");
+		if (bytes >= BUFSIZ) {
+			buflen += BUFSIZ;
+			len += BUFSIZ;
+			buffer = realloc (buffer, buflen + 1);
+			if (!buffer)
+				log_fatal ("not enough buffer to read stdin!");
+			p = buffer + len;
+		} else {
+			len += bytes;
+			break;
+		}
+	} while(1);
+	buffer[len] = '\0';
+
+	cfile = (struct parse *)0;
+	status = new_parse (&cfile, -1, buffer, len, "stdin", 0);
+	if (status == ISC_R_SUCCESS) {
+		status = read_client_conf_actual (cfile, ip, client);
+		end_parse (&cfile);
+	}
+	free(buffer);
+	return status;
+}
 
 /* lease-file :== client-lease-statements END_OF_FILE
    client-lease-statements :== <nil>