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diff --git a/lib/tempname.c b/lib/tempname.c
index 26a38ce..5944ee0 100644
--- a/lib/tempname.c
+++ b/lib/tempname.c
@@ -20,6 +20,7 @@
#if !_LIBC
# include <config.h>
# include "tempname.h"
+# include "randint.h"
#endif
#include <sys/types.h>
@@ -47,6 +48,7 @@
# error report this to bug-gnulib@gnu.org
#endif
+#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
@@ -175,14 +177,21 @@ __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", possibly with a suffix).
+ 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
- __gen_tempname. TMPL is overwritten with the result.
+ this function. TMPL is overwritten with the result.
KIND may be one of:
__GT_NOCREATE: simply verify that the name does not exist
@@ -193,23 +202,24 @@ static const char letters[] =
We use a clever algorithm to get hard-to-predict names. */
int
-__gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
+gen_tempname_len (char *tmpl, int suffixlen, int flags, int kind,
+ 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 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
@@ -221,43 +231,28 @@ __gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
#endif
len = strlen (tmpl);
- if (len < 6 + suffixlen || memcmp (&tmpl[len - 6 - suffixlen], "XXXXXX", 6))
+ 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 - suffixlen];
+ 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];
+ size_t i;
+
+ for (i = 0; i < x_suffix_len; i++)
+ XXXXXX[i] = letters[randint_genmax (rand_src, sizeof letters - 2)];
switch (kind)
{
@@ -272,7 +267,7 @@ __gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
break;
case __GT_NOCREATE:
- /* This case is backward from the other three. __gen_tempname
+ /* This case is backward from the other three. This function
succeeds if __xstat fails because the name does not exist.
Note the continue to bypass the common logic at the bottom
of the loop. */
@@ -281,11 +276,15 @@ __gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
if (errno == ENOENT)
{
__set_errno (save_errno);
- return 0;
+ fd = 0;
+ goto done;
}
else
- /* Give up now. */
- return -1;
+ {
+ /* Give up now. */
+ fd = -1;
+ goto done;
+ }
}
continue;
@@ -297,13 +296,32 @@ __gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
if (fd >= 0)
{
__set_errno (save_errno);
- return fd;
+ 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;
+}
+
+int
+__gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
+{
+ return gen_tempname_len (tmpl, suffixlen, flags, kind, 6);
}
|
