sysklogd/ChangeLog.md

Change Log

All relevant changes to the project are documented in this file.

v2.4.1 - 2022-08-01

Changes

• Fake microsecond timestamp to allow for improved log sorting:
  • in RFC3164 messages (that don't have this resolution)
  • in untrusted kernel messages
• Dropped debian/ directory (moved to separate branch), to ease re-packaging by downstream
• libsyslog now supports logging to remote servers, bypassing syslogd
• Major updates to logger:
  • Support for logging to a remote host, -h HOST and -P PORT
  • Support for logging in RFC3164 format, -b, mostly for remote logging to syslog servers that do not support RFC5424
  • Support for overriding hostname -H NAME
  • Support for custom PID, e.g., a shell scripts PID, -I PID

Fixes

• Fix #52: Prevent over-read when scanning a new-style kernel message. Found and fixed by Edward K. McGuire
• Fix #53: prevent log file corruption when kernel messages contain control codes, notably \n. Instead, preserve kernel protective C-style hex encoding. For example, \n embedded in a message by a kernel-level facility is received as \x0a. Found and fixed by Edward K. McGuire
• Fix #56: logging to remote machine stops after receiving a few SIGHUPs. Open remote socket count was not reset properly on SIGHUP. Problem introduced in v2.4.0. Reported by Edward K. McGuire
• Fix gettimeofday() error handling to use same fallback to time()
• Fix libsyslog opening and connecting to syslogd when LOG_NLOG is set
• Fix libsyslog so it honors LOG_PTRIM when logging to stderr
• Fix issue in RFC3164 output where the tag field could overflow. Spec. mandates tag never exceeds 32 characters

v2.4.0 - 2022-05-29

Changes

• Add support for secure_mode=[0,1,2] to syslog.conf, same as -s but easier to use and activate with SIGHUP
• Enable secure_mode=1 (only log to remote servers) in default syslog.conf
• Disable debug messages, in default syslog.conf, from /var/log/syslog
• Rename option -K to -t for trusting kernel timestamp, issue #42
• Add option -K to disable kernel logging, issue #48
• Rudimentary support for detecting if running in a container and then disable kernel logging automatically, issue #48
• Add support for notify PATH option to syslog.conf, for calling an external script on log rotation, by Steffen Nurpmeso, issue #45
• Add support for log rotation on SIGUSR2, by Steffen Nurpmeso, issue #46
• Update manual page for -b option description

Fixes

• Issue #41: add missing -H option to usage text
• Issue #44: option misspelled in man page
• Issue #47: do not lose file mode on rotated files, by Steffen Nurpmeso
• Issue #48: verify kernel log FIFO is a proper character device, for running in certain container setups
• Issue #49: add support for -8 command line option to allow 8-bit data to be logged -- this is a temporary fix until we have support for parsing the Unicode BOM, as defined in RFC5424
• Issue #50: fix issue with wall message, by Edward K. McGuire

v2.3.0 - 2021-11-27

Changes

• Add support for logger -k, early log to /dev/kmsg. Useful when logging from early system startup scripts before syslogd has started
• Support for extracting non-kernel log messages from /dev/kmsg
• Ignore EINVAL from kernel, caused warning message at first startup
• Use journald socket on systemd systems, not /dev/log
• Issue #38: add support for syslogd -C file to use file for caching the last seen kernel sequence number, default: /run/syslogd.cache. Note: syslogd relies on the location of this file to be wiped at system boot. The default, /run, is a RAM disk on modern systems

Fixes

• Issue #34: regression in v2.2.3, causing loss of syslogd log messages like syslogd v2.2.3: restart.
• Issue #35: man pages lists -v as verbose mode, is actually version
• Issue #36: retry DNS lookup of remote syslog servers with res_init() to ensure name resolution at bootup when a remote DNS may temporarily be unreachable. Retry at most every five seconds, to prevent syslogd from monopolizing the CPU when emptying the kernel ring buffer
• Issue #39: update tests to use -P fn and -C fn
• Issue #40: improve documentation for syslogd.cache file requirements
• Issue #41: add missing documentation for -H option
• Issue #42: add option (-K) to always trust kernel timestamp. By default syslogd only trusts the kernel timestamp for the initial emptying of the kernel ring buffer
• Issue #43: avoid asserting (exiting) on and around Jan 19, 2038, when the UNIX epoch wraps around on 32-bit time_t systems
• libsyslog: handle EOVERFLOW from gettimeofday() on Jan 19, 2038
• Avoid NULL pointers to internal logit() function, only triggered when in debug mode
• Replace \m with \n (missing newline) in logger usage text

v2.2.3 - 2021-05-11

Bug fix release. The focus is still on tackling the fallout resulting in migrating from the old kernel log interface in /proc/kmsg to /dev/kmsg, introduced in v2.2.0.

Fixes

• Issue #28: log messages stuck in 1969. When not using libsyslog, or the bundled logger, the syslog() API in the C library is used, which may not necessarily set the timestamp. When sysklogd infers timestamp it was offset by the number of years since 1969, i.e., boot_time
• Issue #29: kernel messages repeated if syslogd is restarted at runtime. This introduces a new state file, /var/run/syslogd.cache, which saves the last seen/logged sequence id read from /dev/kmsg
• Issue #31: log message time calculation issue on 32-bit systems
• Issue #32: remote kernel messages being mapped to uucp instead of user
• Fix syslogd(8) manual page name of the syslogd PID file

v2.2.2 - 2021-03-08

Bug fix release.

Changes

• Load and reload timezone, with tzset(), on init/SIGHUP
• Logging from remote servers enabled by default in syslogd.service use /etc/default/syslogd to disable
• Initial Debian/Ubuntu packaging

Fixes

• Fix issue with parsing /dev/kmsg time, off by one error
• Fix spelling issues in syslogd and man pages, found by lintian

v2.2.1 - 2021-01-30

Bug fix release.

Fixes

• Issue #26: Liunx sends EPIPE when reading from /dev/kmsg if the kernel internal buffers are overrun. EPIPE is a heads-up message to userspace that at least one log message has been lost. Usually caused by a too small CONFIG_LOG_BUF_SHIFT value. sysklogd v2.2.0 treated the descriptor as faulty and closed it. The fix is to log the event and restart polling for more messages
• Issue #27: Linux log messages read from /dev/kmsg are formatted in a different way than its predecessor /proc/kmsg. sysklogd v2.2.0 failed to parse the priority field correctly, which caused matching problems with rules in /etc/syslog.conf
• Restore default install prefix, from / to /usr/local, which is the default for GNU configure based applications
• Drop %m gnuism from internal log macro (portability)
• logger: drop extra error message string, on error logging to a file

v2.2.0 - 2021-01-15

Minor feature and bug fix release.

Changes

• Issue #19: use /dev/kmsg instead of /proc/kmsg on Linux

Fixes

• Issue #17: Finally fix long-standing parallel build issue, thanks to Windriver for sticking with it and finding a really good fix!
• Issue #24: O_CLOEXEC not available on all systems
• Fix build error; allow loop initial declarations, enable C99
• Fix build warning; missing initializer for field 'usec'

v2.1.2 - 2020-03-22

Bug fix release.

Fixes

• Issue #17: Windriver found and fixed a race between building lib/*.o files with and without -fPIC. This should be the final parallel build issue.

v2.1.1 - 2020-01-19

Bug fix release.

Changes

• Add unit test to verify rule option parsing
• Minor code cleanup and code de-duplication

Fixes

• Issue #11: Some users still reported problems with parallel build, which was worked-around with .NOTPARALLEL in v2.1. This v2 fix is a refactor of src/Makefile.am which removes libcompat and use the same objects for linking both syslogd and the user libsyslog API. Yet still protecting against symbol poisoning
• A Westermo customer reported problems sending to remove syslog sinks at startup. Turns out the handling if sendmsg() fails was the same as that if syslogd fails to resolve the IP from a DNS name. The fix is to just let sendmsg() retry on the next syslog message for all benign/common network errors; EHOSTUNREACHABLE, ENETUNREACH, etc.
• Fix timer reset for suspended remote sinks. For all new incoming syslog messages all suspended (remote) sinks had their timeout mistakenly reset

v2.1 - 2020-01-05

Relicensed under the 3-clause BSD license.

Changes

• klogd removed, replaced by native syslogd functionality
• Import pristine FreeBSD versions of syslogd and syslog.conf man pages, both under the 3-clause BSD license.
• With klogd removed and the original man pages replaced with FreeBSD versions, the only remaining GPL'ed material was the build system, which the copyright owner (undersigned) agrees to change to BSD as well. Hence, the GNU GPL could be dropped in favor of 3-clause BSD

Fixes

• Issue #8: Kernel messages duplicated to console. syslogd on Linux now calls klogctl() to disable kernel logging to console
• Earlier versions were slightly sensitive to time skips. I.e., when recording the last-change time on a log file and wall time changed backwards, syslogd would consider that log file to have a date in the future. This only affected buffering of multiple messages, and -- MARK -- so most users never would have noticed
• Issue #9: Kernel logging broken if syslogd started without -F
• Issue #10: Fix build on non-GLIBC Linux systems, by Khem Raj
• Issue #11: Fix nasty parallel build problem. Also reported by the Gentoo project, and Westermo
• Make sure log rotation cannot be enabled for non-file targets
• Use snprintf() rather than sprintf() in log rotation
• Fix variable names shadowing global/local defs, found by clang-tidy
• Handle multiple invocations of SIGHUP, respond to all of them
• Use correct #ifdef for checking on Linux or not

v2.0.3 - 2019-12-01

Changes

• Always run domark() timer, regardless of -m interval setting, it is used for internal housekeeping, runs every 15 sec
• Handle DNS lookup of unknown remote syslog hosts in domark()
• Only enable debug mode when -d is given on the command line
• Always create PID file, even in debug mode
• Add -F, as alias for -n, to klogd for compat. with syslogd

Fixes

• When logging to a remote host using @FQDN previous releases of syslogd gave up after 10 tries. In many industrial cases intermittent access to the DNS is very likely, so this release includes a fix to retry the IP address lookup forever. The interval for retries is configurable
• Fix accidental blocking of SIGHUP/SIGALRM when an invalid facility is found in the internal logmsg() function
• Fix leaking of internal error messages (like DNS lookup failure) to /dev/console during reconfiguration, i.e. after initial start

v2.0.2 - 2019-11-28

Changes

• Add missing remote:port info in error message when failing to send to a remote syslog server.

Fixes

• Fix assert() in fprintlog_successive(), caused by never being reset in fprintlog_first(), found by Westermo
• Issue #6: Workaround for systems with vanilla autoconf 2.69 that does not support --runstatedir=PATH, e.g. CRUX https://crux.nu/

v2.0.1 - 2019-11-25

Minor bug fix release.

Changes

• Make logger tool and man page optional in build, by Lars Wendler
• Expand resulting directories in configure summary

Fixes

• Add missing -k and -T command line flags to getopt()
• Issue #3: Don't guess PID file location, use configre's $runstatedir

v2.0 - 2019-11-15

This release represents a major refresh of the sysklogd project. The venerable syslogd gets an infusion of new blood from NetBSD and FreeBSD to fully support RFC3164 and RFC5424. Also included is a user library and a replacement for syslog.h to enable new features in RFC5424.

Note: as of this release klogd is disabled by default, syslogd can read Linux kernel messages on its own now.

Changes

• Support for true RFC3164 formatted log messages to remote log servers, including timestamp and hostname. Use ;RFC3164 rule option
• Support for RFC5424 from UNIX domain socket, from remote servers and also to remote servers. Requires new API syslogp() to unlock these features on the UNIX socket. Still compatible with GLIBC/musl/uClibc
• Support for options to syslog.conf rules. E.g. ;RFC5424 to enable sending/writing log messages with RFC3339 style timestamps, and more
• Support for include /etc/syslog.d/*.conf in syslog.conf
• New tool logger from the Finit project, BSD licensed. Supports all the features of RFC5424, so very useful for trying out the "new" standard
• Support for reading from a custom UNIX domain socket path, -p SOCK, for unit testing with logger -u /path/to/sock
• Support for sending to a custom port on a remote server, @host:port
• New syslogp() API from NetBSD, for applications wanting to use RFC5424 features like MsgID or structured data
• Many incompatible changes to command line options in syslogd and klogd for compatiblity with FreeBSD and NetBSD syslogd. Examples:
  • In syslogd: -b and -c have been replaced with -r for global log rotation, -a has been replaced with the new -p support. The -r flag and -s HOST has also been dropped in favor of the BSD -s flag to control two levels of secure mode. The -n flag is now -F and -n means something else entirely ... there's more
  • In klogd: -i and -I have been removed
• klogd is not built by default anymore, syslogd can read /proc/kmsg on Linux on its own. Reduces complexity and gives you one daemon less
• When systemd support is detected by the configure script the unit file(s) are now installed into the systemd system services folder
• Update COPYING file to GPL 2 rev 2, with new FSF address and other minor stuff
• Update license header in all files:
  • Sync 3-clause BSD license change with upstream NetBSD and FreeBSD sources
  • Sync GPL license header, new FSF address
  • Add SPDX license identifiers to all source files

Fixes

• Fix GCC 8 warnings; "too small destination buffer in snprintf()"
• Major code cleanup and rewrite inspired by both NetBSD and FreeBSD sources, e.g. removed all previous unit TESTING #ifdefs

v1.6 - 2018-09-25

Changes

• IPv6 support forward ported from FreeBSD, by John Haxby john.haxby@oracle.com
• Built-in log rotation support from BusyBox syslogd, disabled by default
  • Enable from command line using '-b SIZE' and '-c COUNT', or
  • Per log file in syslog.conf using 'SIZE:COUNT'
• Automatic compression (gzip) of rotated files from .1
• Only read /etc/services when needed, by Martin Schulze joey@infodrom.org
• Improved sleep/alarm/mark implementation,
  by Alan Jenkins alan-jenkins@tuffmail.co.uk
• Move hostname setting code from main() into init() so it is re-read on SIGHUP, by Thomas Jarosch thomas.jarosch@intra2net.com
• Documentation update by Martin Schulze joey@infodrom.org
• Re-indent code to Linux KNF
• Touch PID file on SIGHUP, for integration with Finit
• Add systemd unit files
• Add GNU configure & build system
  • Add configure flags to enable features and control behavior
  • Detect systemd PATHs

Fixes

• Flush log files independent of MARK, by Martin Schulze joey@infodrom.org
• Fix segfault, remove faulty fclose(), found by Andrea Morandi and Sean Young. Fixed by Martin Schulze joey@infodrom.org
• Correct continuation line problems on 64bit architecture,
  by David Couture glowplugrelayw0rks@gmail.com
• Bugfix against invalid PRI values (CVE-2014-3634), by mancha mancha1@zoho.com
• Ignore backed up (low baud rate) console, and do not close it. Instead, continue writing when its unclogged
• Increase socket receive buffer size (double), patch from FreeBSD

v1.5.1 - 2014-10-06

Fixes

• Bugfix against invalid PRI values (CVE-2014-3634), by mancha mancha1@zoho.com

v1.5 - 2007-07-27

• Dmitry V. Levin ldv@altlinux.org
  • Close file descriptor in FindSymbolFile() in ksym.c in order not to leak file descriptors.
• Solar Designer solar@openwall.com
  • improve crunch_list()
  • Prevent potential buffer overflow in reading messages from the kernel log ringbuffer.
  • Ensure that "len" is not placed in a register, and that the endtty() signal handler is not installed too early which could cause a segmentation fault or worse.
• Steve Grubb linux_4ever@yahoo.com
  • fix memory calculation in crunch_list()
• Martin Schulze joey@infodrom.org
  • klogd will reconnect to the logger (mostly syslogd) after it went away
  • On heavily loaded system syslog will not spit out error messages anymore when recvfrom() results in EAGAIN
  • Makefile improvements
  • Local copy of module.h
  • Improved sysklogd.8
  • Always log with syslogd's timezone and locale
  • Remove trailing newline when forwarding messages
  • Continue working properly if /etc/service is missing and ignore network activity
  • Continue writing to log files as soon as space becomes available again after a filled up disk
  • Removed test to detect control characters > 0x20 as this prevented characters encoded in UTF-8 to be properly passed through
  • Only resolve the local domain when accepting messages from remote
  • Properly accompany the MARK message with the facility
  • Improved daemonise routine in klogd to stabilise startup
  • klogd will not change the console log level anymore unless -c is given
  • Added back /usr/src/linux/System.map as fall-back location
  • Rewrote the module symbol parser to read from /proc/kallsyms
  • Notify the waiting parent process if the client dies so it doesn't wait the entire five minutes.
  • Complete rewrite of the oops kernel module for Linux 2.6
  • Only read kernel symbols from /proc/kallsyms if no System.map has been read
  • Improved symbol lookup
  • Prevent named pipes from becoming the controlling tty
• Jon Burgess Jon_Burgess@eur.3com.com
  • Moved the installation of the signal handler up a little bit so it guaranteed to be available when the child is forked, hence, fixing a race condition. This used to create problems with UML and fast machines.
• Greg Trounson gregt@maths.otago.ac.nz
  • Improved README.linux
• Ulf H<>rnhammar Ulf.Harnhammar.9485@student.uu.se
  • Boundary check for fscanf() in InitKsyms() and CheckMapVersion()
• Colin Phipps cph@cph.demon.co.uk
  • Don't block on the network socket in case of packet loss
• Dirk Mueller mueller@kde.org
  • Don't crash when filesize limit is reached (e.g. without LFS)
• Miquel van Smoorenburg miquels@cistron.nl
  • Fix spurious hanging syslogd in connection with futex and NPTL introduced in recent glibc versions and Linux 2.6 (Details: http://bugs.debian.org/301511)
• Eric Tucker et@tallmaple.com
  • Improved syslog.conf(5) manpage
• Mike Frysinger vapier@gentoo.org
  • use socklen_t where appropriate
• Kelledin kelledin@skarpsey.dyndns.org
  • use newer query_module function rather than stepping through /dev/kmem.
• Matthew Fischer futhark@vzavenue.net
  • Remove special treatment of the percent sign in klogd

[v1.4.1][] - 2001-03-11

• klogd will set the console log level only if -c' is given on the commandline, not overwriting local settings in /etc/sysctl.conf'.
• Bugfix: klogd will use SOCK_DGRM as well, re-enables kernel logging
• Bugfix: Don't make syslogd fail with broken `-a'
• Bugfix: klogd will skip zero bytes and not enter a busy loop anymore
• Thomas Roessler roessler@does-not-exist.org
  • Patch to prevent LogLine() from being invoked with a negative counter as an argument.

v1.4 - 2000-09-19

• Skip newline when reading in klog messages
• Use lseek64() instead of llseek() which is deprecated these days
• Close symbol file before returning with 0 when an error occurred while reading it. This will enable systems to umount that partition with no open file descriptor left over.
• Solar Designer solar@false.com
  • printline() fixes
  • priority decoding fix
• Daniel Jacobowitz dan@debian.org
  • printchopped() fix
• Keith Owens kaos@ocs.com.au
  • Fixed bug that caused klogd to die if there is no sym_array available.
  • When symbols are expanded, print the line twice. Once with addresses converted to symbols, once with the raw text. Allows external programs such as ksymoops do their own processing on the original data.
• Olaf Kirch okir@caldera.de
  • Remove Unix Domain Sockets and switch to Datagram Unix Sockets
• Several bugfixes and improvements, please refer to the .c files