X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.socket.xml;h=8a12e25cf4f4474e434ce852fc95b1514ee4725b;hp=f187fe3bdf97e6319ad689b4b2fbac39518fdbd5;hb=96342de68d0d6de71a062d984dafd2a0905ed9fe;hpb=1f812feafb4b98d5cfa2934886bbdd43325780bb diff --git a/man/systemd.socket.xml b/man/systemd.socket.xml index f187fe3bd..8a12e25cf 100644 --- a/man/systemd.socket.xml +++ b/man/systemd.socket.xml @@ -9,16 +9,16 @@ Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or + 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. systemd 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 - General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License + You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . --> @@ -44,7 +44,7 @@ systemd.socket - systemd socket configuration files + Socket unit configuration @@ -54,10 +54,11 @@ Description - A unit configuration file whose name ends in .socket - encodes information about an IPC or network socket or - a file system FIFO controlled and supervised by systemd, - for socket-based activation. + A unit configuration file whose name ends in + .socket encodes information about + an IPC or network socket or a file system FIFO + controlled and supervised by systemd, for socket-based + activation. This man page lists the configuration options specific to this unit type. See @@ -65,19 +66,30 @@ for the common options of all unit configuration files. The common configuration items are configured in the generic [Unit] and [Install] sections. The - service specific configuration options are configured + socket specific configuration options are configured in the [Socket] section. Additional options are listed in - systemd.exec5. - - For each socket file a matching service file (see systemd.service5 for details) - must exist, describing the service to start on - incoming traffic on the socket. Depending on the - setting of (see below) this - must either be named like the socket unit, but with - the suffix replaced; or it must be a template file - named the same way. Example: a socket file + systemd.exec5, + which define the execution environment the + , + , + and + commands are executed + in, and in + systemd.kill5 + which define the way the processes are + terminated. + + For each socket file a matching service file + (see + systemd.service5 + for details) must exist, describing the service to + start on incoming traffic on the socket. Depending on + the setting of (see below), + this must either be named like the socket unit, but + with the suffix replaced; or it must be a template + file named the same way. Example: a socket file foo.socket needs a matching service foo.service if is set. If @@ -85,6 +97,36 @@ file foo@.service must exist from which services are instantiated for each incoming connection. + + Unless DefaultDependencies= + is set to , socket units will + implicitly have dependencies of type + Requires= and + After= on + sysinit.target as well as + dependencies of type Conflicts= and + Before= on + shutdown.target. These ensure + that socket units pull in basic system + initialization, and are terminated cleanly prior to + system shutdown. Only sockets involved with early + boot or late system shutdown should disable this + option. + + Socket units may be used to implement on-demand + starting of services, as well as parallelized starting + of services. + + Note that the daemon software configured for + socket activation with socket units needs to be able + to accept sockets from systemd, either via systemd's + native socket passing interface (see + sd_listen_fds3 + for details) or via the traditional + inetd8-style + socket passing (i.e. sockets passed in via STDIN and + STDOUT, using StandardInput=socket + in the service file). @@ -95,8 +137,10 @@ supervises. A number of options that may be used in this section are shared with other unit types. These options are documented in - systemd.exec5. The - options specific to the [Socket] section of service + systemd.exec5 + and + systemd.kill5. The + options specific to the [Socket] section of socket units are the following: @@ -117,7 +161,7 @@ family. If the address starts with an - ampersand (@) it is read as abstract + at symbol (@) it is read as abstract namespace socket in the AF_UNIX family. The @ is replaced with a NUL character before binding. For details @@ -157,7 +201,7 @@ regardless whether there is incoming traffic on them or not. - If an IP address is used here it + If an IP address is used here, it is often desirable to listen on it before the interface it is configured on is up and running, and even @@ -179,6 +223,51 @@ directive above. + + ListenSpecial= + Specifies a special + file in the file system to listen + on. This expects an absolute file + system path as argument. Behaviour + otherwise is very similar to the + ListenFIFO= + directive above. Use this to open + character device nodes as well as + special files in + /proc and + /sys. + + + + ListenNetlink= + Specifies a Netlink + family to create a socket for to + listen on. This expects a short string + referring to the AF_NETLINK family + name (such as audit + or kobject-uevent) + as argument, optionally suffixed by a + whitespace followed by a multicast + group integer. Behaviour otherwise is + very similar to the + ListenDatagram= + directive above. + + + + ListenMessageQueue= + Specifies a POSIX + message queue name to listen on. This + expects a valid message queue name + (i.e. beginning with /). Behaviour + otherwise is very similar to the + ListenFIFO= + directive above. On Linux message + queue descriptors are actually file + descriptors and can be inherited + between processes. + + BindIPv6Only= Takes a one of @@ -223,7 +312,7 @@ interfaces. This controls the SO_BINDTODEVICE socket option (see socket7 - for details). If this option is used + for details). If this option is used, an automatic dependency from this socket unit on the network interface device unit @@ -234,48 +323,51 @@ DirectoryMode= If listening on a file - system socket of FIFO the parent + system socket of FIFO, the parent directories are automatically created if needed. This option specifies the file system access mode used when - creating these directories. Defaults - to 0755. + creating these directories. Takes an + access mode in octal + notation. Defaults to + 0755. SocketMode= If listening on a file - system socket of FIFO this option + system socket of FIFO, this option specifies the file system access mode used when creating the file - node. Defaults to + node. Takes an access mode in octal + notation. Defaults to 0666. Accept= Takes a boolean - argument. If true a service instance + argument. If true, a service instance is spawned for each incoming connection and only the connection - socket is passed to it. If false all + socket is passed to it. If false, all listening sockets themselves are passed to the started service unit, and only one service unit is spawned for all connections (also see above). This value is ignored for datagram sockets and FIFOs where - unconditionally a single service unit + a single service unit unconditionally handles all incoming traffic. Defaults to . For - performance reasons it is recommended + performance reasons, it is recommended to write new daemons only in a way that is suitable for . This option is mostly useful to allow daemons designed for usage with - inetd8 - to work unmodified with system socket + inetd8, + to work unmodified with systemd socket activation. @@ -286,7 +378,7 @@ services instances for, when is set. If more concurrent connections - are coming in they will be refused, + are coming in, they will be refused until at least one existing connection is terminated. This setting has no effect for sockets configured with @@ -389,6 +481,19 @@ for details. + + MessageQueueMaxMessages=, + MessageQueueMessageSize= + These two settings + take integer values and control the + mq_maxmsg resp. mq_msgsize field when + creating the message queue. Note that + either none or both of these variables + need to be set. See + mq_setattr3 + for details. + + FreeBind= Takes a boolean @@ -406,23 +511,73 @@ address. Defaults to . - + + Transparent= + Takes a boolean + value. Controls the IP_TRANSPARENT + socket option. Defaults to + . + + + + Broadcast= + Takes a boolean + value. This controls the SO_BROADCAST + socket option, which allows broadcast + datagrams to be sent from this + socket. Defaults to + . + + + + PassCredentials= + Takes a boolean + value. This controls the SO_PASSCRED + socket option, which allows AF_UNIX sockets to + receive the credentials of the sending + process in an ancillary message. + Defaults to + . + + + + PassSecurity= + Takes a boolean + value. This controls the SO_PASSSEC + socket option, which allows AF_UNIX + sockets to receive the security + context of the sending process in an + ancillary message. Defaults to + . + + + + TCPCongestion= + Takes a string + value. Controls the TCP congestion + algorithm used by this socket. Should + be one of "westwood", "veno", "cubic", + "lp" or any other available algorithm + supported by the IP stack. This + setting applies only to stream + sockets. + + ExecStartPre= ExecStartPost= - Takes a command line - that is executed before (resp. after) - the listening sockets/FIFOs are created and + Takes one or more + command lines, which are executed + before (resp. after) the listening + sockets/FIFOs are created and bound. The first token of the command line must be an absolute file name, then followed by arguments for the - process. If specified more than once, - all commands are executed one after - the other, serially. Use of these - settings is optional. + process. Multiple command lines may be + specified following the same scheme as + used for + ExecStartPre= of + service unit files. @@ -431,14 +586,13 @@ Additional commands that are executed before (resp. after) the listening sockets/FIFOs are closed - and removed. If specified more than - once, all commands are executed one - after the other, serially. Use of - these settings is - optional. + and removed. Multiple command lines + may be specified following the same + scheme as used for + ExecStartPre= of + service unit files. - TimeoutSec= Configures the time to @@ -447,50 +601,50 @@ ExecStartPost=, ExecStopPre= and ExecStopPost= to - finish. If a comand does not exit - within the configured time the socket + finish. If a command does not exit + within the configured time, the socket will be considered failed and be shut - down again. All commands still running + down again. All commands still running, will be terminated forcibly via SIGTERM, and after another delay of this time with SIGKILL. (See - below.) + in systemd.kill5.) Takes a unit-less value in seconds, or a time span value such as "5min 20s". Pass 0 to disable the timeout logic. Defaults to - 60s. + 90s. - - KillMode= - Specifies how - processes of this service shall be - killed. One of - , - , - , - . - - This option is mostly equivalent - to the - option of service files. See - systemd.service5 - for details. + Service= + Specifies the service + unit name to activate on incoming + traffic. This defaults to the service + that bears the same name as the socket + (ignoring the different suffixes). In + most cases it should not be necessary + to use this option. - + + Check + systemd.exec5 + and + systemd.kill5 + for more settings. + See Also - systemd8, + systemd1, systemctl8, systemd.unit5, systemd.exec5, + systemd.kill5, systemd.service5