glibc/bits/utmp.h
Florian Weimer 5361ad3910 login: Use unsigned 32-bit types for seconds-since-epoch
These fields store timestamps when the system was running.  No Linux
systems existed before 1970, so these values are unused.  Switching
to unsigned types allows continued use of the existing struct layouts
beyond the year 2038.

The intent is to give distributions more time to switch to improved
interfaces that also avoid locking/data corruption issues.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-04-19 14:38:17 +02:00

128 lines
4.0 KiB
C

/* The `struct utmp' type, describing entries in the utmp file.
Copyright (C) 1993-2024 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
<https://www.gnu.org/licenses/>. */
#ifndef _UTMP_H
# error "Never include <bits/utmp.h> directly; use <utmp.h> instead."
#endif
#include <paths.h>
#include <sys/time.h>
#include <sys/types.h>
#include <bits/wordsize.h>
#define UT_LINESIZE 32
#define UT_NAMESIZE 32
#define UT_HOSTSIZE 256
/* The structure describing an entry in the database of
previous logins. */
struct lastlog
{
#if __WORDSIZE_TIME64_COMPAT32
__uint32_t ll_time;
#else
__time_t ll_time;
#endif
char ll_line[UT_LINESIZE];
char ll_host[UT_HOSTSIZE];
};
/* The structure describing the status of a terminated process. This
type is used in `struct utmp' below. */
struct exit_status
{
short int e_termination; /* Process termination status. */
short int e_exit; /* Process exit status. */
};
/* The structure describing an entry in the user accounting database. */
struct utmp
{
short int ut_type; /* Type of login. */
pid_t ut_pid; /* Process ID of login process. */
char ut_line[UT_LINESIZE]
__attribute_nonstring__; /* Devicename. */
char ut_id[4]
__attribute_nonstring__; /* Inittab ID. */
char ut_user[UT_NAMESIZE]
__attribute_nonstring__; /* Username. */
char ut_host[UT_HOSTSIZE]
__attribute_nonstring__; /* Hostname for remote login. */
struct exit_status ut_exit; /* Exit status of a process marked
as DEAD_PROCESS. */
/* The ut_session and ut_tv fields must be the same size when compiled
32- and 64-bit. This allows data files and shared memory to be
shared between 32- and 64-bit applications. */
#if __WORDSIZE_TIME64_COMPAT32
int32_t ut_session; /* Session ID, used for windowing. */
struct
{
__uint32_t tv_sec; /* Seconds. */
int32_t tv_usec; /* Microseconds. */
} ut_tv; /* Time entry was made. */
#else
long int ut_session; /* Session ID, used for windowing. */
struct timeval ut_tv; /* Time entry was made. */
#endif
int32_t ut_addr_v6[4]; /* Internet address of remote host. */
char __glibc_reserved[20]; /* Reserved for future use. */
};
/* Backwards compatibility hacks. */
#define ut_name ut_user
#ifndef _NO_UT_TIME
/* We have a problem here: `ut_time' is also used otherwise. Define
_NO_UT_TIME if the compiler complains. */
# define ut_time ut_tv.tv_sec
#endif
#define ut_xtime ut_tv.tv_sec
#define ut_addr ut_addr_v6[0]
/* Values for the `ut_type' field of a `struct utmp'. */
#define EMPTY 0 /* No valid user accounting information. */
#define RUN_LVL 1 /* The system's runlevel. */
#define BOOT_TIME 2 /* Time of system boot. */
#define NEW_TIME 3 /* Time after system clock changed. */
#define OLD_TIME 4 /* Time when system clock changed. */
#define INIT_PROCESS 5 /* Process spawned by the init process. */
#define LOGIN_PROCESS 6 /* Session leader of a logged in user. */
#define USER_PROCESS 7 /* Normal process. */
#define DEAD_PROCESS 8 /* Terminated process. */
#define ACCOUNTING 9
/* Old Linux name for the EMPTY type. */
#define UT_UNKNOWN EMPTY
/* Tell the user that we have a modern system with UT_HOST, UT_PID,
UT_TYPE, UT_ID and UT_TV fields. */
#define _HAVE_UT_TYPE 1
#define _HAVE_UT_PID 1
#define _HAVE_UT_ID 1
#define _HAVE_UT_TV 1
#define _HAVE_UT_HOST 1