diff -urN ../exim-p0f3-dlfunc-0.1.orig/exim-p0f3-dlfunc.c ./exim-p0f3-dlfunc.c
--- ../exim-p0f3-dlfunc-0.1.orig/exim-p0f3-dlfunc.c	2012-07-04 12:34:14.000000000 +0300
+++ ./exim-p0f3-dlfunc.c	2020-02-22 03:17:03.015245000 +0200
@@ -45,6 +45,19 @@
 /* Exim4 dlfunc API header: */
 #include "local_scan.h"
 
+# define string_copy(s) string_copy_function(s)
+# define string_copyn(s, n) string_copyn_function((s), (n))
+# define string_copy_taint(s, t) string_copy_taint_function((s), (t))
+
+extern uschar * string_copy_function(const uschar *);
+extern uschar * string_copyn_function(const uschar *, int n);
+extern uschar * string_copy_taint_function(const uschar *, BOOL tainted);
+
+#define string_sprintf(fmt, ...) \
+	string_sprintf_trc(fmt, US __FUNCTION__, __LINE__, __VA_ARGS__)
+extern uschar *string_sprintf_trc(const char *, const uschar *, unsigned, ...) ALMOST_PRINTF(1,4);
+
+
 /*****************************************************************************
  * Configuration settings:
  *****************************************************************************/
@@ -140,7 +153,7 @@
 		return ERROR;
 	}
 
-	if (strlen(argv[0]) >= sizeof sun.sun_path - 1) { /* - 1 for \0 */
+	if (strlen((const char *)argv[0]) >= sizeof sun.sun_path - 1) { /* - 1 for \0 */
 		*yield = string_copy(US"Socket path is too long.");
 		return ERROR;
 	}
@@ -163,19 +176,19 @@
 
 	s = socket(PF_UNIX, SOCK_STREAM, 0);
 	if (s < 0) {
-		*yield = string_sprintf(US"Call to socket() failed"
+		*yield = string_sprintf("Call to socket() failed"
 					" (errno = %d).", errno);
 		return FAIL;
 	}
 
 	memset(&sun, 0, sizeof sun);
 	sun.sun_family = AF_UNIX;
-	strcpy(sun.sun_path, argv[0]);
+	strcpy(sun.sun_path, (const char *)argv[0]);
 	/* Note: We ignore sun.sun_len which only exists on some platforms.
 	 * It is poorly documented and ignored by most(?) OSes anyway. */
 
 	if (connect(s, (struct sockaddr *) &sun, sizeof sun) != 0) {
-		log_write(0, LOG_MAIN, US"p0f: Can't connect to API socket %s"
+		log_write(0, LOG_MAIN, "p0f: Can't connect to API socket %s"
 			  " (errno = %d)."
 			  " p0f daemon down or socket name incorrect?",
 			  argv[0], errno);
@@ -192,11 +205,11 @@
 	if (ret != sizeof q) {
 		if (ret < 0)
 			log_write(0, LOG_MAIN,
-				  US"p0f: Error %d writing to API socket.",
+				  "p0f: Error %d writing to API socket.",
 				  errno);
 		else
 			log_write(0, LOG_MAIN,
-				  US"p0f: Short write to API socket.");
+				  "p0f: Short write to API socket.");
 
 		*yield = string_copy(P0F_OS_LOOKUP_FAILED);
 		close(s);
@@ -209,11 +222,11 @@
 	if (ret != sizeof r) {
 		if (ret < 0)
 			log_write(0, LOG_MAIN,
-				  US"p0f: Error %d reading from API socket.",
+				  "p0f: Error %d reading from API socket.",
 				  errno);
 		else
 			log_write(0, LOG_MAIN,
-				  US"p0f: Short read from API socket.");
+				  "p0f: Short read from API socket.");
 
 		*yield = string_copy(P0F_OS_LOOKUP_FAILED);
 		close(s);
@@ -224,13 +237,13 @@
 	/* check response status: */
 
 	if (r.magic != P0F3_RESP_MAGIC) {
-		log_write(0, LOG_MAIN, US"p0f: Bad response magic.");
+		log_write(0, LOG_MAIN, "p0f: Bad response magic.");
 		*yield = string_copy(P0F_OS_LOOKUP_FAILED);
 		return OK;
 	}
 
 	if (r.status == P0F3_STATUS_BADQUERY) {
-		log_write(0, LOG_MAIN, US"p0f: We were misunderstood.");
+		log_write(0, LOG_MAIN, "p0f: We were misunderstood.");
 		*yield = string_copy(P0F_OS_LOOKUP_FAILED);
 		return OK;
 	}