coreutils-8.25HEADcoreutils-8.25master

1 files changed, 164 insertions, 134 deletions

diff --git a/lib/tempname.c b/lib/tempname.c
index e213600..31ecc50 100644
--- a/lib/tempname.c
+++ b/lib/tempname.c
@@ -1,28 +1,26 @@
 /* tempname.c - generate the name of a temporary file.
 
-   Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-   2000, 2001, 2002, 2003, 2005, 2006, 2007 Free Software Foundation,
-   Inc.
+   Copyright (C) 1991-2003, 2005-2007, 2009-2016 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program 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 General Public License for more details.
 
-   You should have received a copy of the GNU General Public License along
-   with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* Extracted from glibc sysdeps/posix/tempname.c.  See also tmpdir.c.  */
 
 #if !_LIBC
 # include <config.h>
 # include "tempname.h"
+# include "randint.h"
 #endif
 
 #include <sys/types.h>
@@ -41,12 +39,16 @@
 # define TMP_MAX 238328
 #endif
 #ifndef __GT_FILE
-# define __GT_FILE	0
-# define __GT_BIGFILE	1
-# define __GT_DIR	2
-# define __GT_NOCREATE	3
+# define __GT_FILE      0
+# define __GT_DIR       1
+# define __GT_NOCREATE  2
+#endif
+#if !_LIBC && (GT_FILE != __GT_FILE || GT_DIR != __GT_DIR       \
+               || GT_NOCREATE != __GT_NOCREATE)
+# error report this to bug-gnulib@gnu.org
 #endif
 
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
@@ -60,39 +62,33 @@
 
 #if _LIBC
 # define struct_stat64 struct stat64
-# define small_open __open
-# define large_open __open64
 #else
 # define struct_stat64 struct stat
-# define small_open open
-# define large_open open
+# define __try_tempname try_tempname
 # define __gen_tempname gen_tempname
 # define __getpid getpid
 # define __gettimeofday gettimeofday
 # define __mkdir mkdir
+# define __open open
 # define __lxstat64(version, file, buf) lstat (file, buf)
-# define __xstat64(version, file, buf) stat (file, buf)
-#endif
-
-#if ! (HAVE___SECURE_GETENV || _LIBC)
-# define __secure_getenv getenv
+# define __secure_getenv secure_getenv
 #endif
 
 #ifdef _LIBC
 # include <hp-timing.h>
 # if HP_TIMING_AVAIL
 #  define RANDOM_BITS(Var) \
-  if (__builtin_expect (value == UINT64_C (0), 0))			      \
-    {									      \
-      /* If this is the first time this function is used initialize	      \
-	 the variable we accumulate the value in to some somewhat	      \
-	 random value.  If we'd not do this programs at startup time	      \
-	 might have a reduced set of possible names, at least on slow	      \
-	 machines.  */							      \
-      struct timeval tv;						      \
-      __gettimeofday (&tv, NULL);					      \
-      value = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;		      \
-    }									      \
+  if (__builtin_expect (value == UINT64_C (0), 0))                            \
+    {                                                                         \
+      /* If this is the first time this function is used initialize           \
+         the variable we accumulate the value in to some somewhat             \
+         random value.  If we'd not do this programs at startup time          \
+         might have a reduced set of possible names, at least on slow         \
+         machines.  */                                                        \
+      struct timeval tv;                                                      \
+      __gettimeofday (&tv, NULL);                                             \
+      value = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;                      \
+    }                                                                         \
   HP_TIMING_NOW (Var)
 # endif
 #endif
@@ -123,7 +119,7 @@ direxists (const char *dir)
    enough space in TMPL. */
 int
 __path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
-	       int try_tmpdir)
+               int try_tmpdir)
 {
   const char *d;
   size_t dlen, plen;
@@ -137,35 +133,35 @@ __path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
     {
       plen = strlen (pfx);
       if (plen > 5)
-	plen = 5;
+        plen = 5;
     }
 
   if (try_tmpdir)
     {
       d = __secure_getenv ("TMPDIR");
       if (d != NULL && direxists (d))
-	dir = d;
+        dir = d;
       else if (dir != NULL && direxists (dir))
-	/* nothing */ ;
+        /* nothing */ ;
       else
-	dir = NULL;
+        dir = NULL;
     }
   if (dir == NULL)
     {
       if (direxists (P_tmpdir))
-	dir = P_tmpdir;
+        dir = P_tmpdir;
       else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
-	dir = "/tmp";
+        dir = "/tmp";
       else
-	{
-	  __set_errno (ENOENT);
-	  return -1;
-	}
+        {
+          __set_errno (ENOENT);
+          return -1;
+        }
     }
 
   dlen = strlen (dir);
   while (dlen > 1 && dir[dlen - 1] == '/')
-    dlen--;			/* remove trailing slashes */
+    dlen--;                     /* remove trailing slashes */
 
   /* check we have room for "${dir}/${pfx}XXXXXX\0" */
   if (tmpl_len < dlen + 1 + plen + 6 + 1)
@@ -179,42 +175,34 @@ __path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
 }
 #endif /* _LIBC */
 
+static inline bool _GL_ATTRIBUTE_PURE
+check_x_suffix (char const *s, size_t len)
+{
+  return len <= strspn (s, "X");
+}
+
 /* These are the characters used in temporary file names.  */
 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)
+try_tempname_len (char *tmpl, int suffixlen, void *args,
+                  int (*tryfunc) (char *, void *), size_t x_suffix_len)
 {
-  int len;
+  size_t len;
   char *XXXXXX;
-  static uint64_t value;
-  uint64_t random_time_bits;
   unsigned int count;
   int fd = -1;
   int save_errno = errno;
-  struct_stat64 st;
+  struct randint_source *rand_src;
 
   /* A lower bound on the number of temporary files to attempt to
      generate.  The maximum total number of temporary file names that
      can exist for a given template is 62**6.  It should never be
-     necessary to try all these combinations.  Instead if a reasonable
+     necessary to try all of these combinations.  Instead if a reasonable
      number of names is tried (we define reasonable as 62**3) fail to
-     give the system administrator the chance to remove the problems.  */
+     give the system administrator the chance to remove the problems.
+     This value requires that X_SUFFIX_LEN be at least 3.  */
 #define ATTEMPTS_MIN (62 * 62 * 62)
 
   /* The number of times to attempt to generate a temporary file.  To
@@ -226,90 +214,132 @@ __gen_tempname (char *tmpl, int kind)
 #endif
 
   len = strlen (tmpl);
-  if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX"))
+  if (len < x_suffix_len + suffixlen
+      || ! check_x_suffix (&tmpl[len - x_suffix_len - suffixlen],
+                           x_suffix_len))
     {
       __set_errno (EINVAL);
       return -1;
     }
 
   /* This is where the Xs start.  */
-  XXXXXX = &tmpl[len - 6];
+  XXXXXX = &tmpl[len - x_suffix_len - suffixlen];
 
   /* Get some more or less random data.  */
-#ifdef RANDOM_BITS
-  RANDOM_BITS (random_time_bits);
-#else
-  {
-    struct timeval tv;
-    __gettimeofday (&tv, NULL);
-    random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
-  }
-#endif
-  value += random_time_bits ^ __getpid ();
+  rand_src = randint_all_new (NULL, x_suffix_len);
+  if (! rand_src)
+    return -1;
 
-  for (count = 0; count < attempts; value += 7777, ++count)
+  for (count = 0; count < attempts; ++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 = small_open (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
-	  break;
-
-	case __GT_BIGFILE:
-	  fd = large_open (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");
-	}
+      size_t i;
+
+      for (i = 0; i < x_suffix_len; i++)
+        XXXXXX[i] = letters[randint_genmax (rand_src, sizeof letters - 2)];
 
+      fd = tryfunc (tmpl, args);
       if (fd >= 0)
-	{
-	  __set_errno (save_errno);
-	  return fd;
-	}
+        {
+          __set_errno (save_errno);
+          goto done;
+        }
       else if (errno != EEXIST)
-	return -1;
+        {
+          fd = -1;
+          goto done;
+        }
     }
 
+  randint_all_free (rand_src);
+
   /* We got out of the loop because we ran out of combinations to try.  */
   __set_errno (EEXIST);
   return -1;
+
+ done:
+  {
+    int saved_errno = errno;
+    randint_all_free (rand_src);
+    __set_errno (saved_errno);
+  }
+  return fd;
+}
+
+static int
+try_file (char *tmpl, void *flags)
+{
+  int *openflags = flags;
+  return __open (tmpl,
+                 (*openflags & ~O_ACCMODE)
+                 | O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+}
+
+static int
+try_dir (char *tmpl, void *flags _GL_UNUSED)
+{
+  return __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR);
+}
+
+static int
+try_nocreate (char *tmpl, void *flags _GL_UNUSED)
+{
+  struct_stat64 st;
+
+  if (__lxstat64 (_STAT_VER, tmpl, &st) == 0)
+    __set_errno (EEXIST);
+  return errno == ENOENT ? 0 : -1;
+}
+
+/* Generate a temporary file name based on TMPL.  TMPL must match the
+   rules for mk[s]temp (i.e., end in at least X_SUFFIX_LEN "X"s,
+   possibly with a suffix).
+   The name constructed does not exist at the time of the call to
+   this function.  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_DIR:            create a directory, which will be mode 0700.
+
+   We use a clever algorithm to get hard-to-predict names. */
+int
+gen_tempname_len (char *tmpl, int suffixlen, int flags, int kind,
+                  size_t x_suffix_len)
+{
+  int (*tryfunc) (char *, void *);
+
+  switch (kind)
+    {
+    case __GT_FILE:
+      tryfunc = try_file;
+      break;
+
+    case __GT_DIR:
+      tryfunc = try_dir;
+      break;
+
+    case __GT_NOCREATE:
+      tryfunc = try_nocreate;
+      break;
+
+    default:
+      assert (! "invalid KIND in __gen_tempname");
+      abort ();
+    }
+  return try_tempname_len (tmpl, suffixlen, &flags, tryfunc, x_suffix_len);
+}
+
+int
+__gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
+{
+  return gen_tempname_len (tmpl, suffixlen, flags, kind, 6);
+}
+
+int
+__try_tempname (char *tmpl, int suffixlen, void *args,
+                int (*tryfunc) (char *, void *))
+{
+  return try_tempname_len (tmpl, suffixlen, args, tryfunc, 6);
 }