mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-14 17:11:06 +00:00
123 lines
3.1 KiB
C
123 lines
3.1 KiB
C
/* Copyright (C) 2010-2013 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; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <pwd.h>
|
|
#include <unistd.h>
|
|
#include <not-cancel.h>
|
|
|
|
#define STATIC static
|
|
static int getlogin_r_fd0 (char *name, size_t namesize);
|
|
#define getlogin_r getlogin_r_fd0
|
|
#include <sysdeps/unix/getlogin_r.c>
|
|
#undef getlogin_r
|
|
|
|
|
|
/* Try to determine login name from /proc/self/loginuid and return 0
|
|
if successful. If /proc/self/loginuid cannot be read return -1.
|
|
Otherwise return the error number. */
|
|
|
|
int
|
|
attribute_hidden
|
|
__getlogin_r_loginuid (name, namesize)
|
|
char *name;
|
|
size_t namesize;
|
|
{
|
|
int fd = open_not_cancel_2 ("/proc/self/loginuid", O_RDONLY);
|
|
if (fd == -1)
|
|
return -1;
|
|
|
|
/* We are reading a 32-bit number. 12 bytes are enough for the text
|
|
representation. If not, something is wrong. */
|
|
char uidbuf[12];
|
|
ssize_t n = TEMP_FAILURE_RETRY (read_not_cancel (fd, uidbuf,
|
|
sizeof (uidbuf)));
|
|
close_not_cancel_no_status (fd);
|
|
|
|
uid_t uid;
|
|
char *endp;
|
|
if (n <= 0
|
|
|| n == sizeof (uidbuf)
|
|
|| (uidbuf[n] = '\0',
|
|
uid = strtoul (uidbuf, &endp, 10),
|
|
endp == uidbuf || *endp != '\0'))
|
|
return -1;
|
|
|
|
size_t buflen = 1024;
|
|
char *buf = alloca (buflen);
|
|
bool use_malloc = false;
|
|
struct passwd pwd;
|
|
struct passwd *tpwd;
|
|
int result = 0;
|
|
int res;
|
|
|
|
while ((res = __getpwuid_r (uid, &pwd, buf, buflen, &tpwd)) == ERANGE)
|
|
if (__libc_use_alloca (2 * buflen))
|
|
buf = extend_alloca (buf, buflen, 2 * buflen);
|
|
else
|
|
{
|
|
buflen *= 2;
|
|
char *newp = realloc (use_malloc ? buf : NULL, buflen);
|
|
if (newp == NULL)
|
|
{
|
|
result = ENOMEM;
|
|
goto out;
|
|
}
|
|
buf = newp;
|
|
use_malloc = true;
|
|
}
|
|
|
|
if (res != 0 || tpwd == NULL)
|
|
{
|
|
result = -1;
|
|
goto out;
|
|
}
|
|
|
|
size_t needed = strlen (pwd.pw_name) + 1;
|
|
if (needed > namesize)
|
|
{
|
|
__set_errno (ERANGE);
|
|
result = ERANGE;
|
|
goto out;
|
|
}
|
|
|
|
memcpy (name, pwd.pw_name, needed);
|
|
|
|
out:
|
|
if (use_malloc)
|
|
free (buf);
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
/* Return at most NAME_LEN characters of the login name of the user in NAME.
|
|
If it cannot be determined or some other error occurred, return the error
|
|
code. Otherwise return 0. */
|
|
|
|
int
|
|
getlogin_r (name, namesize)
|
|
char *name;
|
|
size_t namesize;
|
|
{
|
|
int res = __getlogin_r_loginuid (name, namesize);
|
|
if (res >= 0)
|
|
return res;
|
|
|
|
return getlogin_r_fd0 (name, namesize);
|
|
}
|
|
libc_hidden_def (getlogin_r)
|