| /* Reentrant function to return the current login name. Unix version. |
| Copyright (C) 1991-2018 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 <errno.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <limits.h> |
| #include <fcntl.h> |
| |
| #include <utmp.h> |
| #include "../login/utmp-private.h" |
| |
| /* 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. */ |
| |
| #ifdef STATIC |
| STATIC |
| #endif |
| int |
| __getlogin_r (char *name, size_t name_len) |
| { |
| char tty_pathname[2 + 2 * NAME_MAX]; |
| char *real_tty_path = tty_pathname; |
| int result; |
| struct utmp *ut, line, buffer; |
| |
| /* Get name of tty connected to fd 0. Return if not a tty or |
| if fd 0 isn't open. Note that a lot of documentation says that |
| getlogin() is based on the controlling terminal---what they |
| really mean is "the terminal connected to standard input". The |
| getlogin() implementation of DEC Unix, SunOS, Solaris, HP-UX all |
| return NULL if fd 0 has been closed, so this is the compatible |
| thing to do. Note that ttyname(open("/dev/tty")) on those |
| systems returns /dev/tty, so that is not a possible solution for |
| getlogin(). */ |
| |
| result = __ttyname_r (0, real_tty_path, sizeof (tty_pathname)); |
| |
| if (result != 0) |
| return result; |
| |
| real_tty_path += 5; /* Remove "/dev/". */ |
| strncpy (line.ut_line, real_tty_path, sizeof line.ut_line); |
| |
| /* We don't use the normal entry points __setutent et al, because we |
| want setutent + getutline_r + endutent all to happen with the lock |
| held so that our search is thread-safe. */ |
| |
| __libc_lock_lock (__libc_utmp_lock); |
| (*__libc_utmp_jump_table->setutent) (); |
| result = (*__libc_utmp_jump_table->getutline_r) (&line, &buffer, &ut); |
| if (result < 0) |
| { |
| if (errno == ESRCH) |
| /* The caller expects ENOENT if nothing is found. */ |
| result = ENOENT; |
| else |
| result = errno; |
| } |
| (*__libc_utmp_jump_table->endutent) (); |
| __libc_utmp_jump_table = &__libc_utmp_unknown_functions; |
| __libc_lock_unlock (__libc_utmp_lock); |
| |
| if (result == 0) |
| { |
| size_t needed = __strnlen (ut->ut_user, UT_NAMESIZE) + 1; |
| |
| if (needed > name_len) |
| { |
| __set_errno (ERANGE); |
| result = ERANGE; |
| } |
| else |
| { |
| memcpy (name, ut->ut_user, needed - 1); |
| name[needed - 1] = 0; |
| result = 0; |
| } |
| } |
| |
| return result; |
| } |
| #ifndef STATIC |
| libc_hidden_def (__getlogin_r) |
| weak_alias (__getlogin_r, getlogin_r) |
| libc_hidden_weak (getlogin_r) |
| #endif |