X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=man%2Fsystemd.socket.xml;h=0d5652b8347d16fd517f1e884bb4aa65c48093b3;hb=1e158d273bb63883566358cbb886cd4167421df6;hp=4b1fcc8b0cf725d5b85f7472e17e7d4bfb7328b7;hpb=f274ece0f76b5709408821e317e87aef76123db6;p=elogind.git diff --git a/man/systemd.socket.xml b/man/systemd.socket.xml index 4b1fcc8b0..0d5652b83 100644 --- a/man/systemd.socket.xml +++ b/man/systemd.socket.xml @@ -48,7 +48,7 @@ - systemd.socket + socket.socket @@ -75,7 +75,7 @@ , , and - commands are executed + commands are executed in, and in systemd.kill5 which define the way the processes are @@ -143,26 +143,26 @@ options specific to the [Socket] section of socket units are the following: - + ListenStream= ListenDatagram= ListenSequentialPacket= Specifies an address to listen on for a stream - (SOCK_STREAM), datagram (SOCK_DGRAM), + (SOCK_STREAM), datagram (SOCK_DGRAM), or sequential packet - (SOCK_SEQPACKET) socket, respectively. The address + (SOCK_SEQPACKET) socket, respectively. The address can be written in various formats: If the address starts with a slash (/), it is read as file system - socket in the AF_UNIX socket + socket in the AF_UNIX socket family. If the address starts with an at symbol (@) it is read as abstract - namespace socket in the AF_UNIX + namespace socket in the AF_UNIX family. The @ is replaced with a NUL character before binding. For details see @@ -193,31 +193,36 @@ setting (see below). - Note that SOCK_SEQPACKET + Note that SOCK_SEQPACKET (i.e. ListenSequentialPacket=) - is only available for AF_UNIX - sockets. SOCK_STREAM + is only available for AF_UNIX + sockets. SOCK_STREAM (i.e. ListenStream=) when used for IP sockets refers to TCP - sockets, SOCK_DGRAM + sockets, SOCK_DGRAM (i.e. ListenDatagram=) to UDP. These options may be specified more than once in which case incoming - traffic on any of the sockets will trigger - service activation, and all listed - sockets will be passed to the service, - regardless whether there is incoming - traffic on them or not. - - If an IP address is used here, it - is often desirable to listen on it + traffic on any of the sockets will + trigger service activation, and all + listed sockets will be passed to the + service, regardless whether there is + incoming traffic on them or not. If + the empty string is assigned to any of + these options, the list of addresses + to listen on is reset, all prior uses + of any of these options will have no + effect. + + 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 regardless whether it will be up and - running ever at all. To deal with this it is - recommended to set the + running ever at all. To deal with this + it is recommended to set the FreeBind= option described below. @@ -253,7 +258,7 @@ Specifies a Netlink family to create a socket for to listen on. This expects a short string - referring to the AF_NETLINK family + referring to the AF_NETLINK family name (such as audit or kobject-uevent) as argument, optionally suffixed by a @@ -369,17 +374,30 @@ and only one service unit is spawned for all connections (also see above). This value is ignored for - datagram sockets and FIFOs where - a single service unit unconditionally + datagram sockets and FIFOs where a + single service unit unconditionally handles all incoming traffic. Defaults to . For 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, + . A + daemon listening on an AF_UNIX socket + may, but does not need to, call + close2 + on the received socket before + exiting. However, it must not unlink + the socket from a filesystem. It + should note invoke + shutdown2 + on sockets it got with + Accept=false, but + it may do so for sockets it got with + Accept=true set. + Setting Accept=true + is mostly useful to allow daemons + designed for usage with + inetd8 to work unmodified with systemd socket activation. @@ -566,7 +584,7 @@ PassCredentials= Takes a boolean value. This controls the SO_PASSCRED - socket option, which allows AF_UNIX sockets to + socket option, which allows AF_UNIX sockets to receive the credentials of the sending process in an ancillary message. Defaults to @@ -577,7 +595,7 @@ PassSecurity= Takes a boolean value. This controls the SO_PASSSEC - socket option, which allows AF_UNIX + socket option, which allows AF_UNIX sockets to receive the security context of the sending process in an ancillary message. Defaults to @@ -678,7 +696,16 @@ systemd.unit5, systemd.exec5, systemd.kill5, - systemd.service5 + systemd.service5, + systemd.directives7 + + + + For more extensive descriptions see the "Systemd for Developers" series: + Socket Activation, + Socket Activation, part II, + Converting inetd Services, + Socket Activated Internet Services and OS Containers.