Upgrade mktemp.c to the current upstream version.

Yet another archaic relic containing bugs that had been fixed years before the
Android project even started...

Bug: 9935113
Change-Id: I3c9d019a216efd609ee568cf8c70bc360f357403

2 files changed, 193 insertions, 0 deletions

diff --git a/libc/upstream-freebsd/lib/libc/stdio/mktemp.c b/libc/upstream-freebsd/lib/libc/stdio/mktemp.c
new file mode 100644
index 0000000..58783dd
--- /dev/null
+++ b/libc/upstream-freebsd/lib/libc/stdio/mktemp.c
@@ -0,0 +1,191 @@
+/*
+ * Copyright (c) 1987, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)mktemp.c	8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "namespace.h"
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+#include "un-namespace.h"
+
+char *_mktemp(char *);
+
+static int _gettemp(char *, int *, int, int);
+
+static const unsigned char padchar[] =
+"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+int
+mkstemps(char *path, int slen)
+{
+	int fd;
+
+	return (_gettemp(path, &fd, 0, slen) ? fd : -1);
+}
+
+int
+mkstemp(char *path)
+{
+	int fd;
+
+	return (_gettemp(path, &fd, 0, 0) ? fd : -1);
+}
+
+char *
+mkdtemp(char *path)
+{
+	return (_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL);
+}
+
+char *
+_mktemp(char *path)
+{
+	return (_gettemp(path, (int *)NULL, 0, 0) ? path : (char *)NULL);
+}
+
+__warn_references(mktemp,
+    "warning: mktemp() possibly used unsafely; consider using mkstemp()");
+
+char *
+mktemp(char *path)
+{
+	return (_mktemp(path));
+}
+
+static int
+_gettemp(char *path, int *doopen, int domkdir, int slen)
+{
+	char *start, *trv, *suffp, *carryp;
+	char *pad;
+	struct stat sbuf;
+	int rval;
+	uint32_t rand;
+	char carrybuf[MAXPATHLEN];
+
+	if ((doopen != NULL && domkdir) || slen < 0) {
+		errno = EINVAL;
+		return (0);
+	}
+
+	for (trv = path; *trv != '\0'; ++trv)
+		;
+	if (trv - path >= MAXPATHLEN) {
+		errno = ENAMETOOLONG;
+		return (0);
+	}
+	trv -= slen;
+	suffp = trv;
+	--trv;
+	if (trv < path || NULL != strchr(suffp, '/')) {
+		errno = EINVAL;
+		return (0);
+	}
+
+	/* Fill space with random characters */
+	while (trv >= path && *trv == 'X') {
+		rand = arc4random_uniform(sizeof(padchar) - 1);
+		*trv-- = padchar[rand];
+	}
+	start = trv + 1;
+
+	/* save first combination of random characters */
+	memcpy(carrybuf, start, suffp - start);
+
+	/*
+	 * check the target directory.
+	 */
+	if (doopen != NULL || domkdir) {
+		for (; trv > path; --trv) {
+			if (*trv == '/') {
+				*trv = '\0';
+				rval = stat(path, &sbuf);
+				*trv = '/';
+				if (rval != 0)
+					return (0);
+				if (!S_ISDIR(sbuf.st_mode)) {
+					errno = ENOTDIR;
+					return (0);
+				}
+				break;
+			}
+		}
+	}
+
+	for (;;) {
+		if (doopen) {
+			if ((*doopen =
+			    _open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
+				return (1);
+			if (errno != EEXIST)
+				return (0);
+		} else if (domkdir) {
+			if (mkdir(path, 0700) == 0)
+				return (1);
+			if (errno != EEXIST)
+				return (0);
+		} else if (lstat(path, &sbuf))
+			return (errno == ENOENT);
+
+		/* If we have a collision, cycle through the space of filenames */
+		for (trv = start, carryp = carrybuf;;) {
+			/* have we tried all possible permutations? */
+			if (trv == suffp)
+				return (0); /* yes - exit with EEXIST */
+			pad = strchr(padchar, *trv);
+			if (pad == NULL) {
+				/* this should never happen */
+				errno = EIO;
+				return (0);
+			}
+			/* increment character */
+			*trv = (*++pad == '\0') ? padchar[0] : *pad;
+			/* carry to next position? */
+			if (*trv == *carryp) {
+				/* increment position and loop */
+				++trv;
+				++carryp;
+			} else {
+				/* try with new name */
+				break;
+			}
+		}
+	}
+	/*NOTREACHED*/
+}
diff --git a/libc/upstream-freebsd/namespace.h b/libc/upstream-freebsd/namespace.h
index a3f850e..a980b57 100644
--- a/libc/upstream-freebsd/namespace.h
+++ b/libc/upstream-freebsd/namespace.h
@@ -17,4 +17,6 @@
 #ifndef _BIONIC_FREEBSD_NAMESPACE_H_included
 #define _BIONIC_FREEBSD_NAMESPACE_H_included
 
+__attribute__((visibility("hidden"))) char* _mktemp(char*);
+
 #endif