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freebsd-dev/lib/libc/gen/utxdb.h

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Implement <utmpx.h>. The utmpx interface is the standardized interface of the user accounting database. The standard only defines a subset of the functions that were present in System V-like systems. I'd like to highlight some of the traits my implementation has: - The standard allows the on-disk format to be different than the in-memory representation (struct utmpx). Most operating systems don't do this, but we do. This allows us to keep our ABI more stable, while giving us the opportunity to modify the on-disk format. It also allows us to use a common file format across different architectures (i.e. byte ordering). - Our implementation of pututxline() also updates wtmp and lastlog (now called utx.log and utx.lastlogin). This means the databases are more likely to be in sync. - Care must be taken that our implementation discard any fields that are not applicable. For example, our DEAD_PROCESS records do not hold a TTY name. Just a time stamp, a record identifier and a process identifier. It also guarantees that strings (ut_host, ut_line and ut_user) are null terminated. ut_id is obviously not null terminated, because it's not a string. - The API and its behaviour should be conformant to POSIX, but there may be things that slightly deviate from the standard. This implementation uses separate file descriptors when writing to the log files. It also doesn't use getutxid() to search for a field to overwrite. It uses an allocation strategy similar to getutxid(), but prevents DEAD_PROCESS records from accumulating. Make sure libulog doesn't overwrite the manpages shipped with our C library. Also keep the symbol list in Symbol.map sorted. I'll bump __FreeBSD_version later this evening. I first want to convert everything to <utmpx.h> and get rid of <utmp.h>.
2010-01-13 17:29:55 +00:00
/*-
libc: further adoption of SPDX licensing ID tags. Mainly focus on files that use BSD 2-Clause license, however the tool I was using mis-identified 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.
2017-11-25 17:12:48 +00:00
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
Implement <utmpx.h>. The utmpx interface is the standardized interface of the user accounting database. The standard only defines a subset of the functions that were present in System V-like systems. I'd like to highlight some of the traits my implementation has: - The standard allows the on-disk format to be different than the in-memory representation (struct utmpx). Most operating systems don't do this, but we do. This allows us to keep our ABI more stable, while giving us the opportunity to modify the on-disk format. It also allows us to use a common file format across different architectures (i.e. byte ordering). - Our implementation of pututxline() also updates wtmp and lastlog (now called utx.log and utx.lastlogin). This means the databases are more likely to be in sync. - Care must be taken that our implementation discard any fields that are not applicable. For example, our DEAD_PROCESS records do not hold a TTY name. Just a time stamp, a record identifier and a process identifier. It also guarantees that strings (ut_host, ut_line and ut_user) are null terminated. ut_id is obviously not null terminated, because it's not a string. - The API and its behaviour should be conformant to POSIX, but there may be things that slightly deviate from the standard. This implementation uses separate file descriptors when writing to the log files. It also doesn't use getutxid() to search for a field to overwrite. It uses an allocation strategy similar to getutxid(), but prevents DEAD_PROCESS records from accumulating. Make sure libulog doesn't overwrite the manpages shipped with our C library. Also keep the symbol list in Symbol.map sorted. I'll bump __FreeBSD_version later this evening. I first want to convert everything to <utmpx.h> and get rid of <utmp.h>.
2010-01-13 17:29:55 +00:00
* Copyright (c) 2010 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.
*
* $FreeBSD$
*/
#ifndef _UTXDB_H_
#define _UTXDB_H_
#include <stdint.h>
#define _PATH_UTX_ACTIVE "/var/run/utx.active"
#define _PATH_UTX_LASTLOGIN "/var/log/utx.lastlogin"
#define _PATH_UTX_LOG "/var/log/utx.log"
/*
* Entries in struct futx are ordered by how often they are used. In
* utx.log only entries will be written until the last non-zero byte,
* which means we want to put the hostname at the end. Most primitive
* records only store a ut_type and ut_tv, which means we want to store
* those at the front.
*/
struct utmpx;
struct futx {
uint8_t fu_type;
uint64_t fu_tv;
char fu_id[8];
uint32_t fu_pid;
char fu_user[32];
char fu_line[16];
char fu_host[128];
} __packed;
void utx_to_futx(const struct utmpx *, struct futx *);
Perform several small cleanups to the utmpx code. - Massively reduce BSS usage. Let futx_to_utx() dynamically allocate the structure. There is only a very small amount of applications out there that needs to use the utmpx database. Wasting 1 KB on unused structures makes little sense. - Just let getutxid() search for matching ut_id's for any *PROCESS-type. This makes the code a bit more future-proof. - Fix a POSIX-mistake: when reading POSIX and the OpenSolaris implementation, getutxline() must return USER_PROCESS and LOGIN_PROCESS records whose ut_lines match. When reading POSIX, it seems LOGIN_PROCESS should not use ut_line at the first place. I have reported this issue.
2010-01-17 21:40:05 +00:00
struct utmpx *futx_to_utx(const struct futx *);
Implement <utmpx.h>. The utmpx interface is the standardized interface of the user accounting database. The standard only defines a subset of the functions that were present in System V-like systems. I'd like to highlight some of the traits my implementation has: - The standard allows the on-disk format to be different than the in-memory representation (struct utmpx). Most operating systems don't do this, but we do. This allows us to keep our ABI more stable, while giving us the opportunity to modify the on-disk format. It also allows us to use a common file format across different architectures (i.e. byte ordering). - Our implementation of pututxline() also updates wtmp and lastlog (now called utx.log and utx.lastlogin). This means the databases are more likely to be in sync. - Care must be taken that our implementation discard any fields that are not applicable. For example, our DEAD_PROCESS records do not hold a TTY name. Just a time stamp, a record identifier and a process identifier. It also guarantees that strings (ut_host, ut_line and ut_user) are null terminated. ut_id is obviously not null terminated, because it's not a string. - The API and its behaviour should be conformant to POSIX, but there may be things that slightly deviate from the standard. This implementation uses separate file descriptors when writing to the log files. It also doesn't use getutxid() to search for a field to overwrite. It uses an allocation strategy similar to getutxid(), but prevents DEAD_PROCESS records from accumulating. Make sure libulog doesn't overwrite the manpages shipped with our C library. Also keep the symbol list in Symbol.map sorted. I'll bump __FreeBSD_version later this evening. I first want to convert everything to <utmpx.h> and get rid of <utmp.h>.
2010-01-13 17:29:55 +00:00
#endif /* !_UTXDB_H_ */
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