--- a/src/lib/Makefile.am	Wed Apr 11 14:19:25 2007 +0300
+++ b/src/lib/Makefile.am	Wed Apr 11 14:24:34 2007 +0300
@@ -74,6 +74,7 @@
 	restrict-process-size.c \
 	safe-memset.c \
 	safe-mkdir.c \
+	safe-mkstemp.c \
 	sendfile-util.c \
 	seq-range-array.c \
 	sha1.c \
@@ -153,6 +154,7 @@
 	restrict-process-size.h \
 	safe-memset.h \
 	safe-mkdir.h \
+	safe-mkstemp.h \
 	sendfile-util.h \
 	seq-range-array.h \
 	sha1.h \

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/safe-mkstemp.c	Wed Apr 11 14:24:34 2007 +0300
@@ -0,0 +1,59 @@
+/* Copyright (c) 2007 Timo Sirainen */
+
+#include "lib.h"
+#include "str.h"
+#include "hex-binary.h"
+#include "randgen.h"
+#include "hostpid.h"
+#include "safe-mkstemp.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+
+int safe_mkstemp(string_t *prefix, mode_t mode, uid_t uid, gid_t gid)
+{
+	size_t prefix_len;
+	struct stat st;
+	unsigned char randbuf[8];
+	int fd;
+
+	prefix_len = str_len(prefix);
+	for (;;) {
+		do {
+			random_fill_weak(randbuf, sizeof(randbuf));
+			str_truncate(prefix, prefix_len);
+			str_append(prefix,
+				   binary_to_hex(randbuf, sizeof(randbuf)));
+		} while (lstat(str_c(prefix), &st) == 0);
+
+		if (errno != ENOENT) {
+			i_error("stat(%s) failed: %m", str_c(prefix));
+			return -1;
+		}
+
+		fd = open(str_c(prefix), O_RDWR | O_EXCL | O_CREAT, mode);
+		if (fd != -1)
+			break;
+
+		if (errno != EEXIST) {
+			i_error("open(%s) failed: %m", str_c(prefix));
+			return -1;
+		}
+	}
+	if (uid != (uid_t)-1 || gid != (gid_t)-1) {
+		if (fchown(fd, uid, gid) < 0) {
+			i_error("fchown(%s) failed: %m", str_c(prefix));
+			(void)close(fd);
+			(void)unlink(str_c(prefix));
+			return -1;
+		}
+	}
+	return fd;
+}
+
+int safe_mkstemp_hostpid(string_t *prefix, mode_t mode, uid_t uid, gid_t gid)
+{
+	str_printfa(prefix, "%s.%s.", my_hostname, my_pid);
+	return safe_mkstemp(prefix, mode, uid, gid);
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/safe-mkstemp.h	Wed Apr 11 14:24:34 2007 +0300
@@ -0,0 +1,11 @@
+#ifndef __SAFE_MKSTEMP_H
+#define __SAFE_MKSTEMP_H
+
+/* Create a new file with a given prefix. The string is updated to contain the
+   created filename. uid and gid can be (uid_t)-1 and (gid_t)-1 to use the
+   defaults. */
+int safe_mkstemp(string_t *prefix, mode_t mode, uid_t uid, gid_t gid);
+/* Append host and PID to the prefix. */
+int safe_mkstemp_hostpid(string_t *prefix, mode_t mode, uid_t uid, gid_t gid);
+
+#endif