Add a regression suite for mkstemp(), verifying that it neither overruns

no underruns the supplied template buffer, that it can generate names that
don't contain any X's, and that all open() calls that pass O_CREAT also
pass O_EXCL

2 files changed, 114 insertions, 0 deletions

diff --git a/regress/lib/libc/mkstemp/Makefile b/regress/lib/libc/mkstemp/Makefile
new file mode 100644
index 00000000000..dc7eb281a9f
--- /dev/null
+++ b/regress/lib/libc/mkstemp/Makefile
@@ -0,0 +1,19 @@
+#	$OpenBSD: Makefile,v 1.1 2010/02/11 07:35:38 guenther Exp $
+
+PROG=mkstemp_test
+CLEANFILES+= ; rm -rf output
+
+O = output
+
+# The ktrace/kdump/perl combo verifies that all open() calls that
+# were passed O_CREAT were also passed O_EXCL
+run-regress-${PROG}: ${PROG}
+	mkdir -p $O && cd $O && ktrace ../${PROG}
+	cd $O && kdump | perl -mFcntl -nl \
+		-e '/ open\([^,]*,([^,]+)/	or next;'	\
+		-e '$$f = oct($$1);'				\
+		-e 'if ($$f & O_CREAT && !($$f & O_EXCL)) {'	\
+		-e '	print "FAIL"; exit 1'			\
+		-e '}'
+
+.include <bsd.regress.mk>
diff --git a/regress/lib/libc/mkstemp/mkstemp_test.c b/regress/lib/libc/mkstemp/mkstemp_test.c
new file mode 100644
index 00000000000..d8311cbf351
--- /dev/null
+++ b/regress/lib/libc/mkstemp/mkstemp_test.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2010  Philip Guenther <guenther@openbsd.org>
+ *
+ * Public domain.
+ *
+ * Verify that mkstemp() doesn't overrun or underrun the template buffer
+ * and that it can generate names that don't contain any X's
+ */
+
+#include <sys/param.h>
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#define MAX_TEMPLATE_LEN	10
+#define MAX_TRIES		100
+
+long pg;
+
+void
+try(char *p, const char *prefix, int len)
+{
+	struct stat sb, fsb;
+	char *q;
+	size_t plen = strlen(prefix);
+	int tries, fd;
+
+	for (tries = 0; tries < MAX_TRIES; tries++) {
+		memcpy(p, prefix, plen);
+		memset(p + plen, 'X', len);
+		p[plen + len] = '\0';
+		fd = mkstemp(p);
+		if (fd < 0)
+			err(1, "mkstemp");
+		if (stat(p, &sb))
+			err(1, "stat(%s)", p);
+		if (fstat(fd, &fsb))
+			err(1, "fstat(%d==%s)", fd, p);
+		if (sb.st_dev != fsb.st_dev || sb.st_ino != fsb.st_ino)
+			errx(1, "stat mismatch");
+		close(fd);
+		for (q = p + plen; *q != 'X'; q++) {
+			if (*q == '\0') {
+				if (q != p + plen + len)
+					errx(1, "unexpected truncation");
+				return;
+			}
+		}
+		if (q >= p + plen + len)
+			errx(1, "overrun?");
+	}
+	errx(1, "exceeded MAX_TRIES");
+}
+
+int
+main(void)
+{
+	struct stat sb, fsb;
+	char cwd[MAXPATHLEN + 1];
+	char *p;
+	size_t clen;
+	int i;
+
+	pg = sysconf(_SC_PAGESIZE);
+	if (getcwd(cwd, sizeof cwd - 1) == NULL)
+		err(1, "getcwd");
+	clen = strlen(cwd);
+	cwd[clen++] = '/';
+	cwd[clen] = '\0';
+	p = mmap(NULL, pg * 3, PROT_READ | PROT_WRITE, MAP_ANON, -1, 0);
+	if (p == NULL)
+		err(1, "mmap");
+	if (mprotect(p, pg, PROT_NONE) || mprotect(p + pg * 2, pg, PROT_NONE))
+		err(1, "mprotect");
+	p += pg;
+
+	i = MAX_TEMPLATE_LEN + 1;
+	while (i-- > 1) {
+		/* try first at the start of a page, no prefix */
+		try(p, "", i);
+		/* now at the end of the page, no prefix */
+		try(p + pg - i - 1, "", i);
+		/* start of the page, prefixed with the cwd */
+		try(p, cwd, i);
+		/* how about at the end of the page, prefixed with cwd? */
+		try(p + pg - i - 1 - clen, cwd, i);
+	}
+
+	return 0;
+}