1 files changed, 107 insertions, 22 deletions

diff --git a/db/clib/snprintf.c b/db/clib/snprintf.c
index e41272dde..e1bc5d112 100644
--- a/db/clib/snprintf.c
+++ b/db/clib/snprintf.c
@@ -1,24 +1,30 @@
 /*-
  * See the file LICENSE for redistribution information.
  *
- * Copyright (c) 1996-2003
+ * Copyright (c) 1996-2004
  *	Sleepycat Software.  All rights reserved.
+ *
+ * $Id: snprintf.c,v 11.18 2004/09/22 03:32:43 bostic Exp $
  */
 
 #include "db_config.h"
 
-#ifndef lint
-static const char revid[] = "$Id: snprintf.c,v 11.12 2003/05/02 16:10:41 bostic Exp $";
-#endif /* not lint */
-
 #ifndef NO_SYSTEM_INCLUDES
 #include <sys/types.h>
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>				/* Declare STDERR_FILENO. */
 #endif
 
 #include "db_int.h"
 
+#if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF)
+static void sprintf_overflow __P((void));
+static int  sprintf_retcharpnt __P((void));
+#endif
+
 /*
  * snprintf --
  *	Bounded version of sprintf.
@@ -41,9 +47,98 @@ snprintf(str, n, fmt, va_alist)
 {
 	static int ret_charpnt = -1;
 	va_list ap;
-	int len;
+	size_t len;
+
+	if (ret_charpnt == -1)
+		ret_charpnt = sprintf_retcharpnt();
+
+#ifdef STDC_HEADERS
+	va_start(ap, fmt);
+#else
+	va_start(ap);
+#endif
+	len = (size_t)vsprintf(str, fmt, ap);
+	if (ret_charpnt)
+		len = strlen(str);
+
+	va_end(ap);
+
+	if (len >= n) {
+		sprintf_overflow();
+		/* NOTREACHED */
+	}
+	return ((int)len);
+}
+#endif
+
+/*
+ * vsnprintf --
+ *	Bounded version of vsprintf.
+ *
+ * PUBLIC: #ifndef HAVE_VSNPRINTF
+ * PUBLIC: int vsnprintf __P((char *, size_t, const char *, va_list));
+ * PUBLIC: #endif
+ */
+#ifndef HAVE_VSNPRINTF
+int
+vsnprintf(str, n, fmt, ap)
+	char *str;
+	size_t n;
+	const char *fmt;
+	va_list ap;
+{
+	static int ret_charpnt = -1;
+	size_t len;
+
+	if (ret_charpnt == -1)
+		ret_charpnt = sprintf_retcharpnt();
+
+	len = (size_t)vsprintf(str, fmt, ap);
+	if (ret_charpnt)
+		len = strlen(str);
+
+	if (len >= n) {
+		sprintf_overflow();
+		/* NOTREACHED */
+	}
+	return ((int)len);
+}
+#endif
+
+#if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF)
+static void
+sprintf_overflow()
+{
+	/*
+	 * !!!
+	 * We're potentially manipulating strings handed us by the application,
+	 * and on systems without a real snprintf() the sprintf() calls could
+	 * have overflowed the buffer.  We can't do anything about it now, but
+	 * we don't want to return control to the application, we might have
+	 * overwritten the stack with a Trojan horse.  We're not trying to do
+	 * anything recoverable here because systems without snprintf support
+	 * are pretty rare anymore.
+	 */
+#define	OVERFLOW_ERROR	"internal buffer overflow, process ended\n"
+#ifndef	STDERR_FILENO
+#define	STDERR_FILENO	2
+#endif
+	(void)write(STDERR_FILENO, OVERFLOW_ERROR, sizeof(OVERFLOW_ERROR) - 1);
+
+	/* Be polite. */
+	exit(1);
 
-	COMPQUIET(n, 0);
+	/* But firm. */
+	abort();
+
+	/* NOTREACHED */
+}
+
+static int
+sprintf_retcharpnt()
+{
+	int ret_charpnt;
+	char buf[10];
 
 	/*
 	 * Some old versions of sprintf return a pointer to the first argument
@@ -53,22 +148,12 @@ snprintf(str, n, fmt, va_alist)
 	 * We do this test at run-time because it's not a test we can do in a
 	 * cross-compilation environment.
 	 */
-	if (ret_charpnt == -1) {
-		char buf[10];
 
-		ret_charpnt =
-		    sprintf(buf, "123") != 3 ||
-		    sprintf(buf, "123456789") != 9 ||
-		    sprintf(buf, "1234") != 4;
-	}
+	ret_charpnt =
+	    (int)sprintf(buf, "123") != 3 ||
+	    (int)sprintf(buf, "123456789") != 9 ||
+	    (int)sprintf(buf, "1234") != 4;
 
-#ifdef STDC_HEADERS
-	va_start(ap, fmt);
-#else
-	va_start(ap);
-#endif
-	len = vsprintf(str, fmt, ap);
-	va_end(ap);
-	return (ret_charpnt ? (int)strlen(str) : len);
+	return (ret_charpnt);
 }
 #endif