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-rw-r--r--libc/misc/internals/tempname.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/libc/misc/internals/tempname.c b/libc/misc/internals/tempname.c
new file mode 100644
index 000000000..3c43f9b85
--- /dev/null
+++ b/libc/misc/internals/tempname.c
@@ -0,0 +1,187 @@
+/* Copyright (C) 1991,92,93,94,95,96,97,98,99 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. */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/time.h>
+
+/* Return nonzero if DIR is an existent directory. */
+static int direxists (const char *dir)
+{
+ struct stat buf;
+ return stat(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 $TMPDIR,
+ P_tmpdir, /tmp that exists. Copies into TMPL a template suitable
+ for use with mk[s]temp. Will fail (-1) if DIR is non-null and
+ doesn't exist, none of the searched dirs exists, or there's not
+ enough space in TMPL. */
+int __path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
+ int try_tmpdir)
+{
+ //const char *d;
+ size_t dlen, plen;
+
+ if (!pfx || !pfx[0])
+ {
+ pfx = "file";
+ plen = 4;
+ }
+ else
+ {
+ plen = strlen (pfx);
+ if (plen > 5)
+ plen = 5;
+ }
+
+#if 0
+ if (try_tmpdir)
+ {
+ d = __secure_getenv ("TMPDIR");
+ if (d != NULL && direxists (d))
+ dir = d;
+ else if (dir != NULL && direxists (dir))
+ /* nothing */ ;
+ else
+ dir = NULL;
+ }
+#endif
+ if (dir == NULL)
+ {
+ if (direxists (P_tmpdir))
+ dir = P_tmpdir;
+ else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
+ dir = "/tmp";
+ else
+ {
+ __set_errno (ENOENT);
+ return -1;
+ }
+ }
+
+ dlen = strlen (dir);
+ while (dlen > 1 && dir[dlen - 1] == '/')
+ dlen--; /* remove trailing slashes */
+
+ /* check we have room for "${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. If OPENIT is nonzero, creates the
+ file and returns a read-write fd; the file is mode 0600 modulo
+ umask. If LARGEFILE is nonzero, uses open64() instead of open().
+
+ We use a clever algorithm to get hard-to-predict names. */
+int __gen_tempname (char *tmpl, int openit)
+{
+ int len;
+ char *XXXXXX;
+ static uint64_t value;
+ struct timeval tv;
+ int count, fd;
+ int save_errno = errno;
+
+ 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. */
+ gettimeofday (&tv, NULL);
+ value += ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec ^ 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];
+
+ if (openit)
+ {
+ fd = open (tmpl, O_RDWR | O_CREAT | O_EXCL, 0600);
+ if (fd >= 0)
+ {
+ __set_errno (save_errno);
+ return fd;
+ }
+ else if (errno != EEXIST)
+ /* Any other error will apply also to other names we might
+ try, and there are 2^32 or so of them, so give up now. */
+ return -1;
+ }
+ else
+ {
+ struct stat st;
+ if (stat (tmpl, &st) < 0)
+ {
+ if (errno == ENOENT)
+ {
+ __set_errno (save_errno);
+ return 0;
+ }
+ else
+ /* Give up now. */
+ return -1;
+ }
+ }
+ }
+
+ /* We got out of the loop because we ran out of combinations to try. */
+ __set_errno (EEXIST);
+ return -1;
+}