changed to use slprintf() instead of sprintf() just about

everywhere. I've implemented slprintf() as a bounds checked sprintf()
using mprotect() and a non-writeable page.

This should prevent any sprintf based security holes.

source/lib/slprintf.c

@@ -0,0 +1,88 @@
+/* 
+   Unix SMB/Netbios implementation.
+   Version 1.9.
+   snprintf replacement
+   Copyright (C) Andrew Tridgell 1998
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+extern int DEBUGLEVEL;
+
+int vslprintf(char *str, int n, char *format, va_list ap)
+{
+#ifdef HAVE_VSNPRINTF
+	int ret = vsnprintf(str, n, format, ap);
+	if (ret >= 0) str[ret] = 0;
+	return ret;
+#else
+	static char *buf;
+	static int len;
+	static int pagesize;
+	int ret;
+
+	if (!len || !buf || (len-pagesize) < n) {
+		pagesize = getpagesize();
+		len = (2+(n/pagesize))*pagesize;
+		/* note: we don't free the old memory (if any) as we don't 
+		   want a malloc lib to reuse the memory as it will
+		   have the wrong permissions */
+		buf = memalign(pagesize, len);
+		if (buf) {
+			if (mprotect(buf+(len-pagesize), pagesize, PROT_READ) != 0) {
+				exit(1);
+				return -1;
+			}
+		}
+	}
+
+	if (!buf) {
+		exit(1);
+	}
+
+	ret = vsprintf(str, format, ap);
+	/* we will have got a seg fault here if we overflowed the buffer */
+	return ret;
+#endif
+}
+
+#ifdef __STDC__
+int slprintf(char *str, int n, char *format, ...)
+{
+#else
+ int slprintf(va_alist)
+va_dcl
+{
+	char *str, *format;
+	int n;
+#endif
+	va_list ap;  
+	int ret;
+
+#ifdef __STDC__
+	va_start(ap, format);
+#else
+	va_start(ap);
+	str = va_arg(ap,char *);
+	n = va_arg(ap,int);
+	format = va_arg(ap,char *);
+#endif
+
+	ret = vslprintf(str,n,format,ap);
+	va_end(ap);
+	return ret;
+}