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/* Copyright (C) 1991-2023 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <https://www.gnu.org/licenses/>. */
#include <unistd.h>
#include <hurd.h>
#include <hurd/paths.h>
#include <hurd/fd.h>
#include <fcntl.h>
#include <string.h>
/* Read the contents of the symbolic link FILE_NAME relative to FD into no more
than LEN bytes of BUF. The contents are not null-terminated.
Returns the number of characters read, or -1 for errors. */
ssize_t
__readlinkat (int fd, const char *file_name, char *buf, size_t len)
{
error_t err;
file_t file_stat;
struct stat64 st;
enum retry_type doretry;
char retryname[1024];
file_t file;
char *rbuf = buf;
mach_msg_type_number_t nread = len;
file_stat = __file_name_lookup_at (fd, 0, file_name, O_NOLINK, 0);
if (file_stat == MACH_PORT_NULL)
return -1;
err = __io_stat (file_stat, &st);
if (err)
goto out;
if (!S_ISLNK (st.st_mode))
{
err = EINVAL;
goto out;
}
err = __dir_lookup (file_stat, "", O_READ | O_NOLINK,
0, &doretry, retryname, &file);
if (err)
goto out;
if (doretry != FS_RETRY_NORMAL || retryname[0] != '\0')
{
err = EGRATUITOUS;
goto out;
}
err = __io_read (file, &rbuf, &nread, 0, len);
__mach_port_deallocate (__mach_task_self (), file);
if (err)
goto out;
len = nread;
if (rbuf != buf)
{
memcpy (buf, rbuf, len);
__vm_deallocate (__mach_task_self (), (vm_address_t) rbuf, nread);
}
out:
__mach_port_deallocate (__mach_task_self (), file_stat);
return err ? __hurd_fail (err) : len;
}
weak_alias (__readlinkat, readlinkat)
libc_hidden_def (readlinkat)
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