from GNU libc

1 files changed, 297 insertions, 0 deletions

diff --git a/lib/tempname.c b/lib/tempname.c
new file mode 100644
index 000000000..d008c982f
--- /dev/null
+++ b/lib/tempname.c
@@ -0,0 +1,297 @@
+/* Copyright (C) 1991-1999, 2000 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <assert.h>
+
+#include <errno.h>
+#ifndef __set_errno
+# define __set_errno(Val) errno = (Val)
+#endif
+
+#include <stdio.h>
+#ifndef P_tmpdir
+# define P_tmpdir "/tmp"
+#endif
+#ifndef TMP_MAX
+# define TMP_MAX 238328
+#endif
+#ifndef __GT_FILE
+# define __GT_FILE	0
+# define __GT_BIGFILE	1
+# define __GT_DIR	2
+# define __GT_NOCREATE	3
+#endif
+
+#if STDC_HEADERS || _LIBC
+# include <stddef.h>
+# include <stdlib.h>
+# include <string.h>
+#endif
+
+#if HAVE_FCNTL_H || _LIBC
+# include <fcntl.h>
+#endif
+
+#if HAVE_SYS_TIME_H || _LIBC
+# include <sys/time.h>
+#endif
+
+#if HAVE_STDINT_H || _LIBC
+# include <stdint.h>
+#endif
+
+#if HAVE_UNISTD_H || _LIBC
+# include <unistd.h>
+#endif
+
+#include <sys/stat.h>
+#if STAT_MACROS_BROKEN
+# undef S_ISDIR
+#endif
+#if !defined S_ISDIR && defined S_IFDIR
+# define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
+#endif
+#if !S_IRUSR && S_IREAD
+# define S_IRUSR S_IREAD
+#endif
+#if !S_IRUSR
+# define S_IRUSR 00400
+#endif
+#if !S_IWUSR && S_IWRITE
+# define S_IWUSR S_IWRITE
+#endif
+#if !S_IWUSR
+# define S_IWUSR 00200
+#endif
+#if !S_IXUSR && S_IEXEC
+# define S_IXUSR S_IEXEC
+#endif
+#if !S_IXUSR
+# define S_IXUSR 00100
+#endif
+
+#if _LIBC
+# define struct_stat64 struct stat64
+#else
+# define struct_stat64 struct stat
+# define __getpid getpid
+# define __gettimeofday gettimeofday
+# define __mkdir mkdir
+# define __open open
+# define __open64 open
+# define __lxstat64(version, path, buf) lstat (path, buf)
+# define __xstat64(version, path, buf) stat (path, buf)
+#endif
+
+#if ! (HAVE___SECURE_GETENV || _LIBC)
+# define __secure_getenv getenv
+#endif
+
+/* Return nonzero if DIR is an existent directory.  */
+static int
+direxists (const char *dir)
+{
+  struct_stat64 buf;
+  return __xstat64 (_STAT_VER, dir, &buf) == 0 && S_ISDIR (buf.st_mode);
+}
+
+/* Path search algorithm, for tmpnam, tmpfile, etc.  If DIR is
+   non-null and exists, uses it; otherwise uses the first of $TMPDIR,
+   P_tmpdir, /tmp that exists.  Copies into TMPL a template suitable
+   for use with mk[s]temp.  Will fail (-1) if DIR is non-null and
+   doesn't exist, none of the searched dirs exists, or there's not
+   enough space in TMPL. */
+int
+__path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
+	       int try_tmpdir)
+{
+  const char *d;
+  size_t dlen, plen;
+
+  if (!pfx || !pfx[0])
+    {
+      pfx = "file";
+      plen = 4;
+    }
+  else
+    {
+      plen = strlen (pfx);
+      if (plen > 5)
+	plen = 5;
+    }
+
+  if (try_tmpdir)
+    {
+      d = __secure_getenv ("TMPDIR");
+      if (d != NULL && direxists (d))
+	dir = d;
+      else if (dir != NULL && direxists (dir))
+	/* nothing */ ;
+      else
+	dir = NULL;
+    }
+  if (dir == NULL)
+    {
+      if (direxists (P_tmpdir))
+	dir = P_tmpdir;
+      else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
+	dir = "/tmp";
+      else
+	{
+	  __set_errno (ENOENT);
+	  return -1;
+	}
+    }
+
+  dlen = strlen (dir);
+  while (dlen > 1 && dir[dlen - 1] == '/')
+    dlen--;			/* remove trailing slashes */
+
+  /* check we have room for "${dir}/${pfx}XXXXXX\0" */
+  if (tmpl_len < dlen + 1 + plen + 6 + 1)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  sprintf (tmpl, "%.*s/%.*sXXXXXX", (int) dlen, dir, (int) plen, pfx);
+  return 0;
+}
+
+/* These are the characters used in temporary filenames.  */
+static const char letters[] =
+"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+
+/* Generate a temporary file name based on TMPL.  TMPL must match the
+   rules for mk[s]temp (i.e. end in "XXXXXX").  The name constructed
+   does not exist at the time of the call to __gen_tempname.  TMPL is
+   overwritten with the result.
+
+   KIND may be one of:
+   __GT_NOCREATE:	simply verify that the name does not exist
+			at the time of the call.
+   __GT_FILE:		create the file using open(O_CREAT|O_EXCL)
+			and return a read-write fd.  The file is mode 0600.
+   __GT_BIGFILE:	same as __GT_FILE but use open64().
+   __GT_DIR:		create a directory, which will be mode 0700.
+
+   We use a clever algorithm to get hard-to-predict names. */
+int
+__gen_tempname (char *tmpl, int kind)
+{
+  int len;
+  char *XXXXXX;
+  static uint64_t value;
+  uint64_t random_time_bits;
+  int count, fd = -1;
+  int save_errno = errno;
+  struct_stat64 st;
+
+  len = strlen (tmpl);
+  if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX"))
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  /* This is where the Xs start.  */
+  XXXXXX = &tmpl[len - 6];
+
+  /* Get some more or less random data.  */
+#if HAVE_GETTIMEOFDAY || _LIBC
+  {
+    struct timeval tv;
+    __gettimeofday (&tv, NULL);
+    random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
+  }
+#else
+  random_time_bits = time (NULL);
+#endif
+  value += random_time_bits ^ __getpid ();
+
+  for (count = 0; count < TMP_MAX; value += 7777, ++count)
+    {
+      uint64_t v = value;
+
+      /* Fill in the random bits.  */
+      XXXXXX[0] = letters[v % 62];
+      v /= 62;
+      XXXXXX[1] = letters[v % 62];
+      v /= 62;
+      XXXXXX[2] = letters[v % 62];
+      v /= 62;
+      XXXXXX[3] = letters[v % 62];
+      v /= 62;
+      XXXXXX[4] = letters[v % 62];
+      v /= 62;
+      XXXXXX[5] = letters[v % 62];
+
+      switch (kind)
+	{
+	case __GT_FILE:
+	  fd = __open (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+	  break;
+
+	case __GT_BIGFILE:
+	  fd = __open64 (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+	  break;
+
+	case __GT_DIR:
+	  fd = __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR);
+	  break;
+
+	case __GT_NOCREATE:
+	  /* This case is backward from the other three.  __gen_tempname
+	     succeeds if __xstat fails because the name does not exist.
+	     Note the continue to bypass the common logic at the bottom
+	     of the loop.  */
+	  if (__lxstat64 (_STAT_VER, tmpl, &st) < 0)
+	    {
+	      if (errno == ENOENT)
+		{
+		  __set_errno (save_errno);
+		  return 0;
+		}
+	      else
+		/* Give up now. */
+		return -1;
+	    }
+	  continue;
+
+	default:
+	  assert (! "invalid KIND in __gen_tempname");
+	}
+
+      if (fd >= 0)
+	{
+	  __set_errno (save_errno);
+	  return fd;
+	}
+      else if (errno != EEXIST)
+	return -1;
+    }
+
+  /* We got out of the loop because we ran out of combinations to try.  */
+  __set_errno (EEXIST);
+  return -1;
+}