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freebsd-skq/libexec/ulog-helper/ulog-helper.c

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Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of <utmpx.h>, but I think we should at least try to add parts of it. Unfortunately we cannot implement <utmpx.h>, because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with <utmpx.h>, so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use <utmp.h>. 2. Remove <utmp.h>, implement <utmpx.h> and reimplement this library on top. 3. Port as many applications as possible back to <utmpx.h>.
2009-12-03 15:48:24 +00:00
/*-
libexec: adoption of SPDX licensing ID tags. Mainly focus on files that use BSD 2-Clause license, however the tool I was using misidentified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. No functional change intended.
2017-11-27 15:25:02 +00:00
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of <utmpx.h>, but I think we should at least try to add parts of it. Unfortunately we cannot implement <utmpx.h>, because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with <utmpx.h>, so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use <utmp.h>. 2. Remove <utmp.h>, implement <utmpx.h> and reimplement this library on top. 3. Port as many applications as possible back to <utmpx.h>.
2009-12-03 15:48:24 +00:00
* Copyright (c) 2009 Ed Schouten <ed@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <pwd.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <ulog.h>
/*
* This setuid helper utility writes user login records to disk.
Minor cleanups to ulog-helper: - Remove unneeded linking against libmd. libulog depends on this library, but the ulog-helper tool itself does not. - Change the comment at the top to mention utmpx instead of utmp, wtmp and lastlog. - Simply use user_from_uid() to translate to a username string. - Put variable declarations together.
2011-06-21 17:59:51 +00:00
* Unprivileged processes are not capable of writing records to utmpx,
* but we do want to allow this for pseudo-terminals. Because a file
* descriptor to a pseudo-terminal master device can only be obtained by
* processes using the pseudo-terminal, we expect such a descriptor on
* stdin.
Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of <utmpx.h>, but I think we should at least try to add parts of it. Unfortunately we cannot implement <utmpx.h>, because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with <utmpx.h>, so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use <utmp.h>. 2. Remove <utmp.h>, implement <utmpx.h> and reimplement this library on top. 3. Port as many applications as possible back to <utmpx.h>.
2009-12-03 15:48:24 +00:00
*
* It uses the real user ID of the calling process to determine the
* username. It does allow users to log arbitrary hostnames.
*/
Do a better job at determining the username of the login session. When multiple users share the same UID, the old code will simply pick an arbitrary username to attach to the utmpx entries. Make the code a bit more accurate by first checking whether getlogin() returns a username which corresponds to the uid of the calling process. If this fails, simply fall back to picking an arbitrary username. Reported by: saurik on GitHub MFC after: 2 weeks
2012-04-19 21:12:08 +00:00
static const char *
get_username(void)
{
const struct passwd *pw;
const char *login;
uid_t uid;
/*
* Attempt to determine the username corresponding to this login
* session. First, validate the results of getlogin() against
* the password database. If getlogin() returns invalid data,
* return an arbitrary username corresponding to this uid.
*/
uid = getuid();
if ((login = getlogin()) != NULL && (pw = getpwnam(login)) != NULL &&
pw->pw_uid == uid)
return (login);
if ((pw = getpwuid(uid)) != NULL)
return (pw->pw_name);
return (NULL);
}
Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of <utmpx.h>, but I think we should at least try to add parts of it. Unfortunately we cannot implement <utmpx.h>, because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with <utmpx.h>, so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use <utmp.h>. 2. Remove <utmp.h>, implement <utmpx.h> and reimplement this library on top. 3. Port as many applications as possible back to <utmpx.h>.
2009-12-03 15:48:24 +00:00
int
main(int argc, char *argv[])
{
Minor cleanups to ulog-helper: - Remove unneeded linking against libmd. libulog depends on this library, but the ulog-helper tool itself does not. - Change the comment at the top to mention utmpx instead of utmp, wtmp and lastlog. - Simply use user_from_uid() to translate to a username string. - Put variable declarations together.
2011-06-21 17:59:51 +00:00
const char *line, *user, *host;
Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of <utmpx.h>, but I think we should at least try to add parts of it. Unfortunately we cannot implement <utmpx.h>, because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with <utmpx.h>, so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use <utmp.h>. 2. Remove <utmp.h>, implement <utmpx.h> and reimplement this library on top. 3. Port as many applications as possible back to <utmpx.h>.
2009-12-03 15:48:24 +00:00
/* Device line name. */
if ((line = ptsname(STDIN_FILENO)) == NULL)
return (EX_USAGE);
if ((argc == 2 || argc == 3) && strcmp(argv[1], "login") == 0) {
/* Username. */
Do a better job at determining the username of the login session. When multiple users share the same UID, the old code will simply pick an arbitrary username to attach to the utmpx entries. Make the code a bit more accurate by first checking whether getlogin() returns a username which corresponds to the uid of the calling process. If this fails, simply fall back to picking an arbitrary username. Reported by: saurik on GitHub MFC after: 2 weeks
2012-04-19 21:12:08 +00:00
user = get_username();
Minor cleanups to ulog-helper: - Remove unneeded linking against libmd. libulog depends on this library, but the ulog-helper tool itself does not. - Change the comment at the top to mention utmpx instead of utmp, wtmp and lastlog. - Simply use user_from_uid() to translate to a username string. - Put variable declarations together.
2011-06-21 17:59:51 +00:00
if (user == NULL)
Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of <utmpx.h>, but I think we should at least try to add parts of it. Unfortunately we cannot implement <utmpx.h>, because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with <utmpx.h>, so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use <utmp.h>. 2. Remove <utmp.h>, implement <utmpx.h> and reimplement this library on top. 3. Port as many applications as possible back to <utmpx.h>.
2009-12-03 15:48:24 +00:00
return (EX_OSERR);
/* Hostname. */
Minor cleanups to ulog-helper: - Remove unneeded linking against libmd. libulog depends on this library, but the ulog-helper tool itself does not. - Change the comment at the top to mention utmpx instead of utmp, wtmp and lastlog. - Simply use user_from_uid() to translate to a username string. - Put variable declarations together.
2011-06-21 17:59:51 +00:00
host = argc == 3 ? argv[2] : NULL;
Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of <utmpx.h>, but I think we should at least try to add parts of it. Unfortunately we cannot implement <utmpx.h>, because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with <utmpx.h>, so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use <utmp.h>. 2. Remove <utmp.h>, implement <utmpx.h> and reimplement this library on top. 3. Port as many applications as possible back to <utmpx.h>.
2009-12-03 15:48:24 +00:00
Minor cleanups to ulog-helper: - Remove unneeded linking against libmd. libulog depends on this library, but the ulog-helper tool itself does not. - Change the comment at the top to mention utmpx instead of utmp, wtmp and lastlog. - Simply use user_from_uid() to translate to a username string. - Put variable declarations together.
2011-06-21 17:59:51 +00:00
ulog_login(line, user, host);
Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of <utmpx.h>, but I think we should at least try to add parts of it. Unfortunately we cannot implement <utmpx.h>, because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with <utmpx.h>, so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use <utmp.h>. 2. Remove <utmp.h>, implement <utmpx.h> and reimplement this library on top. 3. Port as many applications as possible back to <utmpx.h>.
2009-12-03 15:48:24 +00:00
return (EX_OK);
} else if (argc == 2 && strcmp(argv[1], "logout") == 0) {
Repair breakage to last-minute API change. I changed ulog_log{in,out} to return a void, but forgot to change ulog-helper as well. Reported by: stefanf
2009-12-03 21:44:41 +00:00
ulog_logout(line);
Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of <utmpx.h>, but I think we should at least try to add parts of it. Unfortunately we cannot implement <utmpx.h>, because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with <utmpx.h>, so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use <utmp.h>. 2. Remove <utmp.h>, implement <utmpx.h> and reimplement this library on top. 3. Port as many applications as possible back to <utmpx.h>.
2009-12-03 15:48:24 +00:00
return (EX_OK);
}
return (EX_USAGE);
}
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