1 /* -*- buffer-read-only: t -*- vi: set ro: */
2 /* DO NOT EDIT! GENERATED AUTOMATICALLY! */
3 /* Create /proc/self/fd-related names for subfiles of open directories.
5 Copyright (C) 2006, 2009-2010 Free Software Foundation, Inc.
7 This program is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 /* Written by Paul Eggert. */
24 #include "openat-priv.h"
26 #include <sys/types.h>
36 #include "same-inode.h"
39 /* The results of open() in this file are not used with fchdir,
40 and we do not leak fds to any single-threaded code that could use stdio,
41 therefore save some unnecessary work in fchdir.c.
42 FIXME - if the kernel ever adds support for multi-thread safety for
43 avoiding standard fds, then we should use open_safer. */
47 #define PROC_SELF_FD_FORMAT "/proc/self/fd/%d/%s"
49 #define PROC_SELF_FD_NAME_SIZE_BOUND(len) \
50 (sizeof PROC_SELF_FD_FORMAT - sizeof "%d%s" \
51 + INT_STRLEN_BOUND (int) + (len) + 1)
54 /* Set BUF to the expansion of PROC_SELF_FD_FORMAT, using FD and FILE
55 respectively for %d and %s. If successful, return BUF if the
56 result fits in BUF, dynamically allocated memory otherwise. But
57 return NULL if /proc is not reliable. */
59 openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file)
61 static int proc_status = 0;
63 /* Make sure the caller gets ENOENT when appropriate. */
72 /* Set PROC_STATUS to a positive value if /proc/self/fd is
73 reliable, and a negative value otherwise. Solaris 10
74 /proc/self/fd mishandles "..", and any file name might expand
75 to ".." after symbolic link expansion, so avoid /proc/self/fd
76 if it mishandles "..". Solaris 10 has openat, but this
77 problem is exhibited on code that built on Solaris 8 and
78 running on Solaris 10. */
80 int proc_self_fd = open ("/proc/self/fd", O_RDONLY);
85 struct stat proc_self_fd_dotdot_st;
86 struct stat proc_self_st;
87 char dotdot_buf[PROC_SELF_FD_NAME_SIZE_BOUND (sizeof ".." - 1)];
88 sprintf (dotdot_buf, PROC_SELF_FD_FORMAT, proc_self_fd, "..");
90 ((stat (dotdot_buf, &proc_self_fd_dotdot_st) == 0
91 && stat ("/proc/self", &proc_self_st) == 0
92 && SAME_INODE (proc_self_fd_dotdot_st, proc_self_st))
102 size_t bufsize = PROC_SELF_FD_NAME_SIZE_BOUND (strlen (file));
103 char *result = (bufsize < OPENAT_BUFFER_SIZE ? buf : xmalloc (bufsize));
104 sprintf (result, PROC_SELF_FD_FORMAT, fd, file);