diff options
| -rw-r--r-- | .mailmap | 6 | ||||
| -rw-r--r-- | NEWS | 209 | ||||
| -rw-r--r-- | man/resolved.conf.xml | 20 |
3 files changed, 209 insertions, 26 deletions
@@ -64,3 +64,9 @@ Tom Rini <trini@kernel.crashing.org> Paul Mundt <lethal@linux-sh.org> Atul Sabharwal <atul.sabharwal@intel.com> Daniel Machon <Danielmachon@live.dk> +Thomas Blume <Thomas.Blume@suse.com> +Pablo Lezaeta Reyes <prflr88@gmail.com> +Otto Wallenius <otto_026@hotmail.com> +Tom Yan <tom.ty89@gmail.com> +Marty Plummer <ntzrmtthihu777@gmail.com> +Brian Boylston <brian.boylston@hpe.com> @@ -2,23 +2,206 @@ systemd System and Service Manager CHANGES WITH 231: - * When using systemd's default tmp.mount for /tmp, this will now be - mounted with the "nosuid" and "nodev" options. This avoids - privilege escalation attacks that put traps and exploits into /tmp. - However, this might cause some problems if you e. g. put container + * In service units the various ExecXYZ= settings have been extended + with an additional special character as first argument of the + assigned value: if the character '!' is used the specified command + line it will be run with full privileges, regardless of User=, + Group=, CapabilityBoundingSet= and similar options. The effect is + similar to the existing PermissionsStartOnly= option, but allows + configuration of this concept for each executed command line + independently. + + * Services may now alter the service watchdog timeout at runtime by + sending a WATCHDOG_USEC= message via sd_notify(). + + * MemoryLimit= and related unit settings now optionally take percentage + specifications. The percentage is taken relative to the amount of + physical memory in the system (or in case of containers, the assigned + amount of memory). This allows scaling service resources neatly with + the amount of RAM available on the system. Similarly, systemd-logind's + RuntimeDirectorySize= option now also optionally takes percentage + values. + + * In similar fashion TasksMax= takes percentage values now, too. The + value is taken relative to the configured maximum number of processes + on the system. The per-service task maximum has been changed to 15% + using this functionality. (Effectively this is an increase of 512 → + 4915 for service units, given the kernel's default pid_max setting.) + + * Calendar time specifications in .timer units now understand a ".." + syntax for time ranges. Example: "4..7:10" may now be used for + defining a timer that is triggered at 4:10am, 5:10am, 6:10am and + 7:10am every day. + + * The InaccessableDirectories=, ReadOnlyDirectories= and + ReadWriteDirectories= unit file settings have been renamed to + InaccessablePaths=, ReadOnlyPaths= and ReadWritePaths= and may now be + applied to all kinds of file nodes, and not just directories, with + the exception of symlinks. Specifically these settings may now be + used on block and character device nodes, UNIX sockets and FIFOS as + well as regular files. The old names of these settings remain + available for compatibility. + + * systemd will now log about all service processes it kills forcibly + (using SIGKILL) because they remained after the clean shutdown phase + of the service completed. This should help identifying services that + shut down uncleanly. Moreover if KillUserProcesses= is enabled in + systemd-logind's configuration a similar log message is generated for + processes killed at the end of each session due to this setting. + + * systemd will now set the $JOURNAL_STREAM environment variable for all + services whose stdout/stderr are connected to the Journal (which + effectively means by default: all services). The variable contains + the device and inode number of the file descriptor used for + stdout/stderr. This may be used by invoked programs to detect whether + their stdout/stderr is connected to the Journal, in which case they + can switch over to direct Journal communication, thus being able to + pass extended, structured metadata along with their log messages. As + one example, this is now used by glib's logging primitives. + + * When using systemd's default tmp.mount unit for /tmp, the mount point + will now be established with the "nosuid" and "nodev" options. This + avoids privilege escalation attacks that put traps and exploits into + /tmp. However, this might cause problems if you e. g. put container images or overlays into /tmp; if you need this, override tmp.mount's "Options=" with a drop-in, or mount /tmp from /etc/fstab with your desired options. - * systemd-resolved gained a new "Cache=" option in resolved.conf. - Local caching makes DNS poisoning attacks slightly easier and allows - a local user to detect whether any other user on the same machine has - recently visited a given DNS name (privacy). If that is a concern, - you can disable local caching with this option at the cost of slower - DNS resolution (which is particularly expensive with DNSSEC). The - default continues to be "yes" (i. e. caching is enabled). - - Contributions from: ... + * systemd now supports the "memory" cgroup controller also on + cgroupsv2. + + * The systemd-cgtop tool now optionally takes a control group path as + command line argument. If specified, the control group list shown is + limited to subgroups of that group. + + * The SystemCallFilter= unit file setting gained support for + pre-defined, named system call filter sets. For example + SystemCallFilter=@clock is now an effective way to make all clock + changing-related system calls unavailable to a service. A number of + similar pre-defined groups are defined. Writing system call filters + for system services is simplified substantially with this new + concept. Accordingly, all of systemd's own, long-running services now + enable system call filtering based on this, by default. + + * A new service setting MemoryDenyWriteExecute= has been added, taking + a boolean value. If turned on, a service may no longer create memory + mappings that are writable and executable at the same time. This + enhances security for services where this is enabled as it becomes + harder to dynamically write and then execute memory in exploited + service processes. This option has been enabled for all of systemd's + own long-running services. + + * A new RestrictRealtime= service setting has been added, taking a + boolean argument. If set the service's processes may no longer + acquire realtime scheduling. This improves security as realtime + scheduling may otherwise be used to easily freeze the system. + + * systemd-nspawn gained a new switch --notify-ready= taking a boolean + value. This may be used for requesting that the system manager inside + of the container reports start-up completion to nspawn which then + propagates this notification further to the service manager + supervising nspawn itself. A related option NotifyReady= in .nspawn + files has been added too. This functionality allows ordering of the + start-up of multiple containers using the usual systemd ordering + primitives. + + * machinectl gained a new command "stop" that is an alias for + "terminate". + + * systemd-resolved gained support for contacting DNS servers on + link-local IPv6 addresses. + + * If systemd-resolved receives the SIGUSR2 signal it will now flush all + its caches. A method call for requesting the same operation has been + added to the bus API too, and is made available via "systemd-resolve + --flush-caches". + + * systemd-resolve gained a new --status switch. If passed a brief + summary of the used DNS configuration with per-interface information + is shown. + + * resolved.conf gained a new Cache= boolean option, defaulting to + on. If turned off local DNS caching is disabled. This comes with a + performance penalty in particular when DNSSEC is enabled. Note that + resolved disables its internal caching implicitly anyway, when the + configured DNS server is on a host-local IP address such as ::1 or + 127.0.0.1, thus automatically avoiding double local caching. + + * systemd-resolved now listens on the local IP address 127.0.0.53:53 + for DNS requests. This improves compatibility with local programs + that do not use the libc NSS or systemd-resolved's bus APIs for name + resolution. This minimal DNS service is only available to local + programs and does not implement the full DNS protocol, but enough to + cover local DNS clients. A new, static resolv.conf file, listing just + this DNS server is now shipped in /usr/lib/systemd/resolv.conf. It is + now recommended to make /etc/resolv.conf a symlink to this file in + order to route all DNS lookups to systemd-resolved, regardless if + done via NSS, the bus API or raw DNS packets. Note that this local + DNS service is not as fully featured as the libc NSS or + systemd-resolved's bus APIs. For example, as unicast DNS cannot be + used to deliver link-local address information (as this implies + sending a local interface index along), LLMNR/mDNS support via this + interface is severely restricted. It is thus strongly recommended for + all applications to use the libc NSS API or native systemd-resolved + bus API instead. + + * systemd-networkd's bridge support learned a new setting + VLANFiltering= for controlling VLAN filtering. Moreover a new section + in .network files has been added for configuring VLAN bridging in + more detail: VLAN=, EgressUntagged=, PVID= in [BridgeVLAN]. + + * systemd-networkd's IPv6 Router Advertisement code now makes use of + the DNSSL and RDNSS options. This means IPv6 DNS configuration may + now be acquired without relying on DHCPv6. Two new options + UseDomains= and UseDNS= have been added to configure this behaviour. + + * systemd-networkd's IPv6AcceptRouterAdvertisements= option has been + renamed IPv6AcceptRA=, without altering its behaviour. The old + setting name remains available for compatibility reasons. + + * The systemd-networkd VTI/VTI6 tunneling support gained new options + Key=, InputKey= and OutputKey=. + + * systemd-networkd gained support for VRF ("Virtual Routing Function") + interface configuration. + + * "systemctl edit" may now be used to create new unit files by + specifying the --force switch. + + * sd-event gained a new function sd_event_get_iteration() for + requesting the current iteration counter of the event loop. It starts + at zero and is increased by one with each event loop iteration. + + * Configuration for "mkosi" is now part of the systemd + repository. mkosi is a tool to easily build legacy-free OS images, + and is available on github: https://github.com/systemd/mkosi. If + "mkosi" is invoked in the build tree a new raw OS image is generated + incorporating the systemd sources currently being worked on and a + clean, fresh distribution installation. The generated OS image may be + booted up with "systemd-nspawn -b -i", qemu-kvm or on any physcial + UEFI PC. This functionality is particularly useful to easily test + local changes made to systemd in a pristine, defined environment. See + HACKING for details. + + Contributions from: Alessandro Puccetti, Alessio Igor Bogani, + Alexander Kuleshov, Alexander Kurtz, Alex Gaynor, Andika Triwidada, + Andreas Pokorny, Andreas Rammhold, Andrew Jeddeloh, Ansgar Burchardt, + Atrotors, Benjamin Drung, Brian Boylston, Christian Hesse, Christian + Rebischke, Daniele Medri, Daniel Mack, Dave Reisner, David Herrmann, + David Michael, Djalal Harouni, Doug Christman, Elias Probst, Evgeny + Vereshchagin, Federico Mena Quintero, Felipe Sateler, Franck Bui, + Harald Hoyer, Ian Lee, Ivan Shapovalov, Jakub Wilk, Jan Janssen, + Jean-Sébastien Bour, John Paul Adrian Glaubitz, Jouke Witteveen, Kai + Ruhnau, kpengboy, Kyle Walker, Lénaïc Huard, Lennart Poettering, Luca + Bruno, Lukas Lösche, Lukáš Nykrýn, mahkoh, Marcel Holtmann, Martin + Pitt, Marty Plummer, Matthieu Codron, Max Prokhorov, Michael Biebl, + Michael Karcher, Michael Olbrich, Michał Bartoszkiewicz, Michal + Sekletar, Michal Soltys, Minkyung, Muhammet Kara, mulkieran, Otto + Wallenius, Pablo Lezaeta Reyes, Peter Hutterer, Ronny Chevalier, Rusty + Bird, Stef Walter, Susant Sahani, Tejun Heo, Thomas Blume, Thomas + Haller, Thomas H. P. Andersen, Tobias Jungel, Tom Gundersen, Tom Yan, + Topi Miettinen, Torstein Husebø, Valentin Vidić, Viktar Vaŭčkievič, + Weng Xuetian, Werner Fink, Zbigniew Jędrzejewski-Szmek — Somewhere, 2016-XX-XX diff --git a/man/resolved.conf.xml b/man/resolved.conf.xml index 024ad6a9c1..7556c6ff31 100644 --- a/man/resolved.conf.xml +++ b/man/resolved.conf.xml @@ -204,19 +204,13 @@ <varlistentry> <term><varname>Cache=</varname></term> - <listitem><para>Takes a boolean argument. If "yes" (the default), - resolving a domain name which already got queried earlier will re-use - the previous result as long as that is still valid, and thus does not - need to do an actual network request.</para> - - <para>However, local caching slightly increases the chance of a - successful DNS poisoning attack, and might also be a privacy problem in - some environments: By measuring the time it takes to resolve a - particular network name, a user can determine whether any other user on - the same machine recently visited that name. If either of these is a - concern, you may disable the local caching. Be aware that this comes at - a performance cost, which is <emphasis>very</emphasis> high with DNSSEC. - </para></listitem> + <listitem><para>Takes a boolean argument. If "yes" (the default), resolving a domain name which already got + queried earlier will return the previous result as long as it is still valid, and thus does not result in a new + network request. Be aware that that turning off caching comes at a performance penalty, which is particularly + high when DNSSEC is used.</para> + + <para>Note that caching is turned off implicitly if the configured DNS server is on a host-local IP address + (such as 127.0.0.1 or ::1), in order to avoid duplicate local caching.</para></listitem> </varlistentry> </variablelist> |