From: Dave Hart <hart@ntp.org>
Date: Sun, 19 Mar 2023 05:05:11 +0000 (-0400)
Subject: Don't cast size_t to int, update contract for followlink().
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d7e82c4adda4bd800cd09ebb8709868a8dc16652;p=thirdparty%2Fntp.git

Don't cast size_t to int, update contract for followlink().
Make ssize_t size match size_t, provide SSIZE_MAX on Windows.

bk: 64169807wtm82iCy2AhNAbmk6IX4_Q
---

diff --git a/ports/winnt/include/config.h b/ports/winnt/include/config.h
index 17526c266..4439b1cdd 100644
--- a/ports/winnt/include/config.h
+++ b/ports/winnt/include/config.h
@@ -309,8 +309,7 @@ extern void arc4random_buf(void *buf, size_t nbytes);
  */
 #define __func__	__FUNCTION__
 
-typedef int pid_t;		/* PID is an int */
-typedef int ssize_t;	/* ssize is an int */
+typedef int	pid_t;	/* PID is an int */
 
 /*
  * Map the stream to the file number
@@ -502,6 +501,13 @@ typedef unsigned long uintptr_t;
   typedef unsigned __int64 uint64_t;
 #endif
 
+#ifdef _WIN64		/* mirroring SIZE_MAX from limits.h */
+  typedef SSIZE_T	ssize_t;
+#define SSIZE_MAX	_I64_MAX
+#else
+  typedef int		ssize_t;
+#define SSIZE_MAX	INT_MAX
+#endif
 
 /* Directory separator, usually / or \ */
 #define	DIR_SEP	'\\'
diff --git a/util/ntp-keygen.c b/util/ntp-keygen.c
index c40a85298..ff9d6cad8 100644
--- a/util/ntp-keygen.c
+++ b/util/ntp-keygen.c
@@ -277,16 +277,16 @@ followlink(
 	ssize_t	len;
 	char *	target;
 
-	REQUIRE(bufsiz > 0);
+	REQUIRE(bufsiz > 0 && bufsiz <= SSIZE_MAX);
 
 	target = emalloc(bufsiz);
 	len = readlink(fname, target, bufsiz);
-	if (len < 0 ) {
+	if (len < 0) {
 		fname[0] = '\0';
 		return;
 	}
-	if (len > (int)bufsiz - 1)
-		len = (int)bufsiz - 1;
+	if ((size_t)len > bufsiz - 1)
+		len = bufsiz - 1;
 	memcpy(fname, target, len);
 	fname[len] = '\0';
 	free(target);