From 94f6070cbe78694c6b3f6419f4dd812a45ded3f2 Mon Sep 17 00:00:00 2001
From: Raja R Harinath <harinath@src.gnome.org>
Date: Wed, 11 Mar 1998 22:30:51 +0000
Subject: Importing <URL:http://theos.com/~deraadt/snprintf.c> as vsnprintf.c.

svn path=/branches/SNPRINTF_de_Raadt/; revision=133
---
 support/vsnprintf.c | 151 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 150 insertions(+), 1 deletion(-)

diff --git a/support/vsnprintf.c b/support/vsnprintf.c
index 6119346..4059113 100644
--- a/support/vsnprintf.c
+++ b/support/vsnprintf.c
@@ -1 +1,150 @@
-#error "Fill in the code"
+/*
+ * Revision 12: http://theos.com/~deraadt/snprintf.c
+ *
+ * Copyright (c) 1997 Theo de Raadt
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <signal.h>
+#include <stdio.h>
+#if __STDC__
+#include <stdarg.h>
+#include <stdlib.h>
+#else
+#include <varargs.h>
+#endif
+#include <setjmp.h>
+
+#ifndef roundup
+#define roundup (x, y) ((((x)+((y)-1))/(y))*(y))
+#endif
+
+static int pgsize;
+static char *curobj;
+static int caught;
+static sigjmp_buf bail;
+
+#define EXTRABYTES	2	/* XXX: why 2? you don't want to know */
+
+static char *
+msetup(str, n)
+	char *str;
+	size_t n;
+{
+	char *e;
+
+	if (n == 0)
+		return NULL;
+	if (pgsize == 0)
+		pgsize = getpagesize();
+	curobj = (char *)malloc(n + EXTRABYTES + pgsize * 2);
+	if (curobj == NULL)
+		return NULL;
+	e = curobj + n + EXTRABYTES;
+	e = (char *)roundup((unsigned long)e, pgsize);
+	if (mprotect(e, pgsize, PROT_NONE) == -1) {
+		free(curobj);
+		curobj = NULL;
+		return NULL;
+	}
+	e = e - n - EXTRABYTES;
+	*e = '\0';
+	return (e);
+}
+
+static void
+mcatch()
+{
+	siglongjmp(bail, 1);
+}
+
+static void
+mcleanup(str, n, p)
+	char *str;
+	size_t n;
+	char *p;
+{
+	strncpy(str, p, n-1);
+	str[n-1] = '\0';
+	if (mprotect((caddr_t)(p + n + EXTRABYTES), pgsize,
+	    PROT_READ|PROT_WRITE|PROT_EXEC) == -1)
+		mprotect((caddr_t)(p + n + EXTRABYTES), pgsize,
+		    PROT_READ|PROT_WRITE);
+	free(curobj);
+}
+
+int
+#if __STDC__
+snprintf(char *str, size_t n, char const *fmt, ...)
+#else
+snprintf(str, n, fmt, va_alist)
+	char *str;
+	size_t n;
+	char *fmt;
+	va_dcl
+#endif
+{
+	va_list ap;
+#if __STDC__
+	va_start(ap, fmt);
+#else
+	va_start(ap);
+#endif
+
+	return (vsnprintf(str, n, fmt, ap));
+	va_end(ap);
+}
+
+int
+vsnprintf(str, n, fmt, ap)
+	char *str;
+	size_t n;
+	char *fmt;
+	char *ap;
+{
+	struct sigaction osa, nsa;
+	char *p;
+	int ret = n + 1;	/* if we bail, indicated we overflowed */
+
+	memset(&nsa, 0, sizeof nsa);
+	nsa.sa_handler = mcatch;
+	sigemptyset(&nsa.sa_mask);
+
+	p = msetup(str, n);
+	if (p == NULL) {
+		*str = '\0';
+		return 0;
+	}
+	if (sigsetjmp(bail, 1) == 0) {
+		if (sigaction(SIGSEGV, &nsa, &osa) == -1) {
+			mcleanup(str, n, p);
+			return (0);
+		}
+		ret = vsprintf(p, fmt, ap);
+	}
+	mcleanup(str, n, p);
+	(void) sigaction(SIGSEGV, &osa, NULL);
+	return (ret);
+}
-- 
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