1 /* Change a port cell to a directory by looking up a name.
2    Copyright (C) 1999-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #include <errno.h>
20 #include <unistd.h>
21 #include <hurd.h>
22 #include <hurd/port.h>
23 #include <hurd/fd.h>
24 #include <fcntl.h>
25 #include <string.h>
26 
27 int
_hurd_change_directory_port_from_name(struct hurd_port * portcell,const char * name)28 _hurd_change_directory_port_from_name (struct hurd_port *portcell,
29 				       const char *name)
30 {
31   size_t len;
32   const char *lookup;
33   file_t dir;
34 
35   /* Append trailing "/." to directory name to force ENOTDIR if it's not a
36      directory and EACCES if we don't have search permission.  */
37   len = strlen (name);
38   if (len >= 2 && name[len - 2] == '/' && name[len - 1] == '.')
39     lookup = name;
40   else if (len == 0)
41     /* Special-case empty file name according to POSIX.  */
42     return __hurd_fail (ENOENT);
43   else
44     {
45       char *n = alloca (len + 3);
46       memcpy (n, name, len);
47       n[len] = '/';
48       n[len + 1] = '.';
49       n[len + 2] = '\0';
50       lookup = n;
51     }
52 
53   dir = __file_name_lookup (lookup, 0, 0);
54   if (dir == MACH_PORT_NULL)
55     return -1;
56 
57   _hurd_port_set (portcell, dir);
58   return 0;
59 }
60