Provided by: libconfig-model-systemd-perl_0.249.1-1_all bug

NAME

       Config::Model::models::Systemd::Section::Socket - Configuration class Systemd::Section::Socket

DESCRIPTION

       Configuration classes used by Config::Model

       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 systemd.unit(5) for the
       common options of all unit configuration files. The common configuration items are configured in the
       generic [Unit] and [Install] sections. The socket specific configuration options are configured in the
       [Socket] section.

       Additional options are listed in systemd.exec(5), which define the execution environment the
       "ExecStartPre", "ExecStartPost", "ExecStopPre" and "ExecStopPost" commands are executed in, and in
       systemd.kill(5), which define the way the processes are terminated, and in systemd.resource-control(5),
       which configure resource control settings for the processes of the socket.

       For each socket unit, a matching service unit must exist, describing the service to start on incoming
       traffic on the socket (see systemd.service(5) for more information about .service units). The name of the
       .service unit is by default the same as the name of the .socket unit, but can be altered with the
       "Service" option described below. Depending on the setting of the "Accept" option described below, this
       .service unit must either be named like the .socket unit, but with the suffix replaced, unless overridden
       with "Service"; or it must be a template unit named the same way. Example: a socket file "foo.socket"
       needs a matching service "foo.service" if "Accept=no" is set. If "Accept=yes" is set, a service template
       "foo@.service" must exist from which services are instantiated for each incoming connection.

       No implicit "WantedBy" or "RequiredBy" dependency from the socket to the service is added. This means
       that the service may be started without the socket, in which case it must be able to open sockets by
       itself. To prevent this, an explicit "Requires" dependency may be added.

       Socket units may be used to implement on-demand starting of services, as well as parallelized starting of
       services. See the blog stories linked at the end for an introduction.

       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_fds(3)
       for details about the precise protocol used and the order in which the file descriptors are passed) or
       via traditional inetd(8)-style socket passing (i.e. sockets passed in via standard input and output,
       using "StandardInput=socket" in the service file).

       All network sockets allocated through ".socket" units are allocated in the host's network namespace (see
       network_namespaces(7)). This does not mean however that the service activated by a configured socket unit
       has to be part of the host's network namespace as well.  It is supported and even good practice to run
       services in their own network namespace (for example through "PrivateNetwork", see systemd.exec(5)),
       receiving only the sockets configured through socket-activation from the host's namespace. In such a set-
       up communication within the host's network namespace is only permitted through the activation sockets
       passed in while all sockets allocated from the service code itself will be associated with the service's
       own namespace, and thus possibly subject to a restrictive configuration.  This configuration class was
       generated from systemd documentation.  by parse-man.pl <https://github.com/dod38fr/config-model-
       systemd/contrib/parse-man.pl>

Elements

   ListenStream
       Specifies an address to listen on for a stream ("SOCK_STREAM"), datagram ("SOCK_DGRAM"), or sequential
       packet ("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
       family.

       If the address starts with an 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, see unix(7).

       If the address string is a single number, it is read as port number to listen on via IPv6. Depending on
       the value of "BindIPv6Only" (see below) this might result in the service being available via both IPv6
       and IPv4 (default) or just via IPv6.

       If the address string is a string in the format "v.w.x.y:z", it is interpreted as IPv4 address v.w.x.y
       and port z.

       If the address string is a string in the format "[x]:y", it is interpreted as IPv6 address x and port y.
       An optional interface scope (interface name or number) may be specified after a "%" symbol: "[x]:y%dev".
       Interface scopes are only useful with link-local addresses, because the kernel ignores them in other
       cases. Note that if an address is specified as IPv6, it might still make the service available via IPv4
       too, depending on the "BindIPv6Only" setting (see below).

       If the address string is a string in the format "vsock:x:y", it is read as CID x on a port y address in
       the "AF_VSOCK" family.  The CID is a unique 32-bit integer identifier in "AF_VSOCK" analogous to an IP
       address.  Specifying the CID is optional, and may be set to the empty string.

       Note that "SOCK_SEQPACKET" (i.e.  "ListenSequentialPacket") is only available for "AF_UNIX" sockets.
       "SOCK_STREAM" (i.e.  "ListenStream") when used for IP sockets refers to TCP 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 of 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.

       It is also possible to have more than one socket unit for the same service when using "Service", and the
       service will receive all the sockets configured in all the socket units. Sockets configured in one unit
       are passed in the order of configuration, but no ordering between socket units is specified.

       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 of whether it will be up and running at any point.
       To deal with this, it is recommended to set the "FreeBind" option described below.  Optional. Type list
       of uniline.

   ListenDatagram
       Specifies an address to listen on for a stream ("SOCK_STREAM"), datagram ("SOCK_DGRAM"), or sequential
       packet ("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
       family.

       If the address starts with an 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, see unix(7).

       If the address string is a single number, it is read as port number to listen on via IPv6. Depending on
       the value of "BindIPv6Only" (see below) this might result in the service being available via both IPv6
       and IPv4 (default) or just via IPv6.

       If the address string is a string in the format "v.w.x.y:z", it is interpreted as IPv4 address v.w.x.y
       and port z.

       If the address string is a string in the format "[x]:y", it is interpreted as IPv6 address x and port y.
       An optional interface scope (interface name or number) may be specified after a "%" symbol: "[x]:y%dev".
       Interface scopes are only useful with link-local addresses, because the kernel ignores them in other
       cases. Note that if an address is specified as IPv6, it might still make the service available via IPv4
       too, depending on the "BindIPv6Only" setting (see below).

       If the address string is a string in the format "vsock:x:y", it is read as CID x on a port y address in
       the "AF_VSOCK" family.  The CID is a unique 32-bit integer identifier in "AF_VSOCK" analogous to an IP
       address.  Specifying the CID is optional, and may be set to the empty string.

       Note that "SOCK_SEQPACKET" (i.e.  "ListenSequentialPacket") is only available for "AF_UNIX" sockets.
       "SOCK_STREAM" (i.e.  "ListenStream") when used for IP sockets refers to TCP 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 of 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.

       It is also possible to have more than one socket unit for the same service when using "Service", and the
       service will receive all the sockets configured in all the socket units. Sockets configured in one unit
       are passed in the order of configuration, but no ordering between socket units is specified.

       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 of whether it will be up and running at any point.
       To deal with this, it is recommended to set the "FreeBind" option described below.  Optional. Type list
       of uniline.

   ListenSequentialPacket
       Specifies an address to listen on for a stream ("SOCK_STREAM"), datagram ("SOCK_DGRAM"), or sequential
       packet ("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
       family.

       If the address starts with an 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, see unix(7).

       If the address string is a single number, it is read as port number to listen on via IPv6. Depending on
       the value of "BindIPv6Only" (see below) this might result in the service being available via both IPv6
       and IPv4 (default) or just via IPv6.

       If the address string is a string in the format "v.w.x.y:z", it is interpreted as IPv4 address v.w.x.y
       and port z.

       If the address string is a string in the format "[x]:y", it is interpreted as IPv6 address x and port y.
       An optional interface scope (interface name or number) may be specified after a "%" symbol: "[x]:y%dev".
       Interface scopes are only useful with link-local addresses, because the kernel ignores them in other
       cases. Note that if an address is specified as IPv6, it might still make the service available via IPv4
       too, depending on the "BindIPv6Only" setting (see below).

       If the address string is a string in the format "vsock:x:y", it is read as CID x on a port y address in
       the "AF_VSOCK" family.  The CID is a unique 32-bit integer identifier in "AF_VSOCK" analogous to an IP
       address.  Specifying the CID is optional, and may be set to the empty string.

       Note that "SOCK_SEQPACKET" (i.e.  "ListenSequentialPacket") is only available for "AF_UNIX" sockets.
       "SOCK_STREAM" (i.e.  "ListenStream") when used for IP sockets refers to TCP 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 of 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.

       It is also possible to have more than one socket unit for the same service when using "Service", and the
       service will receive all the sockets configured in all the socket units. Sockets configured in one unit
       are passed in the order of configuration, but no ordering between socket units is specified.

       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 of whether it will be up and running at any point.
       To deal with this, it is recommended to set the "FreeBind" option described below.  Optional. Type list
       of uniline.

   ListenFIFO
       Specifies a file system FIFO (see fifo(7) for details) to listen on.  This expects an absolute file
       system path as argument.  Behavior otherwise is very similar to the "ListenDatagram" directive above.
       Optional. Type list of uniline.

   ListenSpecial
       Specifies a special file in the file system to listen on. This expects an absolute file system path as
       argument. Behavior 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/".  Optional. Type list of uniline.

   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. Behavior otherwise is very similar to the
       "ListenDatagram" directive above.  Optional. Type list of uniline.

   ListenMessageQueue
       Specifies a POSIX message queue name to listen on (see mq_overview(7) for details). This expects a valid
       message queue name (i.e. beginning with "/"). Behavior otherwise is very similar to the "ListenFIFO"
       directive above. On Linux message queue descriptors are actually file descriptors and can be inherited
       between processes.  Optional. Type list of uniline.

   ListenUSBFunction
       Specifies a USB FunctionFS <https://www.kernel.org/doc/Documentation/usb/functionfs.txt> endpoints
       location to listen on, for implementation of USB gadget functions. This expects an absolute file system
       path of a FunctionFS mount point as the argument.  Behavior otherwise is very similar to the "ListenFIFO"
       directive above. Use this to open the FunctionFS endpoint "ep0". When using this option, the activated
       service has to have the "USBFunctionDescriptors" and "USBFunctionStrings" options set.   Optional. Type
       list of uniline.

   SocketProtocol
       Takes one of "udplite" or "sctp". The socket will use the UDP-Lite ("IPPROTO_UDPLITE") or SCTP
       ("IPPROTO_SCTP") protocol, respectively.  Optional. Type enum. choice: 'udplite', 'sctp'.

   BindIPv6Only
       Takes one of "default", "both" or "ipv6-only". Controls the IPV6_V6ONLY socket option (see ipv6(7) for
       details). If "both", IPv6 sockets bound will be accessible via both IPv4 and IPv6. If "ipv6-only", they
       will be accessible via IPv6 only. If "default" (which is the default, surprise!), the system wide default
       setting is used, as controlled by "/proc/sys/net/ipv6/bindv6only", which in turn defaults to the
       equivalent of "both".  Optional. Type enum. choice: 'default', 'both', 'ipv6-only'.

   Backlog
       Takes an unsigned integer argument. Specifies the number of connections to queue that have not been
       accepted yet. This setting matters only for stream and sequential packet sockets. See listen(2) for
       details. Defaults to SOMAXCONN (128).  Optional. Type uniline.

   BindToDevice
       Specifies a network interface name to bind this socket to. If set, traffic will only be accepted from the
       specified network interfaces. This controls the "SO_BINDTODEVICE" socket option (see socket(7) for
       details). If this option is used, an implicit dependency from this socket unit on the network interface
       device unit is created (see systemd.device(5)).  Note that setting this parameter might result in
       additional dependencies to be added to the unit (see above).  Optional. Type uniline.

   SocketUser
       Takes a UNIX user/group name. When specified, all "AF_UNIX" sockets and FIFO nodes in the file system are
       owned by the specified user and group. If unset (the default), the nodes are owned by the root user/group
       (if run in system context) or the invoking user/group (if run in user context).  If only a user is
       specified but no group, then the group is derived from the user's default group.  Optional. Type uniline.

   SocketGroup
       Takes a UNIX user/group name. When specified, all "AF_UNIX" sockets and FIFO nodes in the file system are
       owned by the specified user and group. If unset (the default), the nodes are owned by the root user/group
       (if run in system context) or the invoking user/group (if run in user context).  If only a user is
       specified but no group, then the group is derived from the user's default group.  Optional. Type uniline.

   SocketMode
       If listening on a file system socket or FIFO, this option specifies the file system access mode used when
       creating the file node. Takes an access mode in octal notation. Defaults to 0666.  Optional. Type
       uniline.

   DirectoryMode
       If listening on a file system socket or FIFO, the parent directories are automatically created if needed.
       This option specifies the file system access mode used when creating these directories. Takes an access
       mode in octal notation. Defaults to 0755.  Optional. Type uniline.

   Accept
       Takes a boolean argument. If yes, a service instance is spawned for each incoming connection and only the
       connection socket is passed to it. If no, 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 a single service unit unconditionally handles all incoming
       traffic. Defaults to "no". For performance reasons, it is recommended to write new daemons only in a way
       that is suitable for "Accept=no". A daemon listening on an "AF_UNIX" socket may, but does not need to,
       call close(2) on the received socket before exiting. However, it must not unlink the socket from a file
       system. It should not invoke shutdown(2) on sockets it got with "Accept=no", but it may do so for sockets
       it got with "Accept=yes" set. Setting "Accept=yes" is mostly useful to allow daemons designed for usage
       with inetd(8) to work unmodified with systemd socket activation.

       For IPv4 and IPv6 connections, the "REMOTE_ADDR" environment variable will contain the remote IP address,
       and "REMOTE_PORT" will contain the remote port. This is the same as the format used by CGI. For
       "SOCK_RAW", the port is the IP protocol.  Optional. Type boolean.

   Writable
       Takes a boolean argument. May only be used in conjunction with "ListenSpecial". If true, the specified
       special file is opened in read-write mode, if false, in read-only mode. Defaults to false.  Optional.
       Type boolean.

   FlushPending
       Takes a boolean argument. May only be used when "Accept=no". If yes, the socket's buffers are cleared
       after the triggered service exited. This causes any pending data to be flushed and any pending incoming
       connections to be rejected. If no, the socket's buffers won't be cleared, permitting the service to
       handle any pending connections after restart, which is the usually expected behaviour.  Defaults to "no".
        Optional. Type boolean.

   MaxConnections
       The maximum number of connections to simultaneously run services instances for, when "Accept=yes" is set.
       If more concurrent connections are coming in, they will be refused until at least one existing connection
       is terminated. This setting has no effect on sockets configured with "Accept=no" or datagram sockets.
       Defaults to 64.  Optional. Type uniline.

   MaxConnectionsPerSource
       The maximum number of connections for a service per source IP address.  This is very similar to the
       "MaxConnections" directive above. Disabled by default.  Optional. Type uniline.

   KeepAlive
       Takes a boolean argument. If true, the TCP/IP stack will send a keep alive message after 2h (depending on
       the configuration of "/proc/sys/net/ipv4/tcp_keepalive_time") for all TCP streams accepted on this
       socket. This controls the "SO_KEEPALIVE" socket option (see socket(7) and the TCP Keepalive HOWTO
       <http://www.tldp.org/HOWTO/html_single/TCP-Keepalive-HOWTO/> for details.) Defaults to "false".
       Optional. Type boolean.

   KeepAliveTimeSec
       Takes time (in seconds) as argument. The connection needs to remain idle before TCP starts sending
       keepalive probes. This controls the TCP_KEEPIDLE socket option (see socket(7) and the TCP Keepalive HOWTO
       <http://www.tldp.org/HOWTO/html_single/TCP-Keepalive-HOWTO/> for details.)  Defaults value is 7200
       seconds (2 hours).  Optional. Type integer.

   KeepAliveIntervalSec
       Takes time (in seconds) as argument between individual keepalive probes, if the socket option
       "SO_KEEPALIVE" has been set on this socket. This controls the "TCP_KEEPINTVL" socket option (see
       socket(7) and the TCP Keepalive HOWTO <http://www.tldp.org/HOWTO/html_single/TCP-Keepalive-HOWTO/> for
       details.) Defaults value is 75 seconds.  Optional. Type integer.

   KeepAliveProbes
       Takes an integer as argument. It is the number of unacknowledged probes to send before considering the
       connection dead and notifying the application layer. This controls the TCP_KEEPCNT socket option (see
       socket(7) and the TCP Keepalive HOWTO <http://www.tldp.org/HOWTO/html_single/TCP-Keepalive-HOWTO/> for
       details.) Defaults value is 9.  Optional. Type integer.

   NoDelay
       Takes a boolean argument. TCP Nagle's algorithm works by combining a number of small outgoing messages,
       and sending them all at once. This controls the TCP_NODELAY socket option (see tcp(7)).  Defaults to
       "false".  Optional. Type boolean.

   Priority
       Takes an integer argument controlling the priority for all traffic sent from this socket. This controls
       the "SO_PRIORITY" socket option (see socket(7) for details.).  Optional. Type integer.

   DeferAcceptSec
       Takes time (in seconds) as argument. If set, the listening process will be awakened only when data
       arrives on the socket, and not immediately when connection is established. When this option is set, the
       "TCP_DEFER_ACCEPT" socket option will be used (see tcp(7)), and the kernel will ignore initial ACK
       packets without any data. The argument specifies the approximate amount of time the kernel should wait
       for incoming data before falling back to the normal behavior of honoring empty ACK packets. This option
       is beneficial for protocols where the client sends the data first (e.g. HTTP, in contrast to SMTP),
       because the server process will not be woken up unnecessarily before it can take any action.

       If the client also uses the "TCP_DEFER_ACCEPT" option, the latency of the initial connection may be
       reduced, because the kernel will send data in the final packet establishing the connection (the third
       packet in the "three-way handshake").

       Disabled by default.  Optional. Type integer.

   ReceiveBuffer
       Takes an integer argument controlling the receive or send buffer sizes of this socket, respectively.
       This controls the "SO_RCVBUF" and "SO_SNDBUF" socket options (see socket(7) for details.). The usual
       suffixes K, M, G are supported and are understood to the base of 1024.  Optional. Type uniline.

   SendBuffer
       Takes an integer argument controlling the receive or send buffer sizes of this socket, respectively.
       This controls the "SO_RCVBUF" and "SO_SNDBUF" socket options (see socket(7) for details.). The usual
       suffixes K, M, G are supported and are understood to the base of 1024.  Optional. Type uniline.

   IPTOS
       Takes an integer argument controlling the IP Type-Of-Service field for packets generated from this
       socket.  This controls the "IP_TOS" socket option (see ip(7) for details.). Either a numeric string or
       one of "low-delay", "throughput", "reliability" or "low-cost" may be specified.  Optional. Type integer.

   IPTTL
       Takes an integer argument controlling the IPv4 Time-To-Live/IPv6 Hop-Count field for packets generated
       from this socket. This sets the "IP_TTL"/"IPV6_UNICAST_HOPS" socket options (see ip(7) and ipv6(7) for
       details.)  Optional. Type integer.

   Mark
       Takes an integer value. Controls the firewall mark of packets generated by this socket. This can be used
       in the firewall logic to filter packets from this socket. This sets the "SO_MARK" socket option. See
       iptables(8) for details.  Optional. Type integer.

   ReusePort
       Takes a boolean value. If true, allows multiple bind(2)s to this TCP or UDP port. This controls the
       "SO_REUSEPORT" socket option. See socket(7) for details.  Optional. Type boolean.

   SmackLabel
       Takes a string value. Controls the extended attributes "security.SMACK64", "security.SMACK64IPIN" and
       "security.SMACK64IPOUT", respectively, i.e.  the security label of the FIFO, or the security label for
       the incoming or outgoing connections of the socket, respectively.  See Smack.txt
       <https://www.kernel.org/doc/Documentation/security/Smack.txt> for details.  Optional. Type uniline.

   SmackLabelIPIn
       Takes a string value. Controls the extended attributes "security.SMACK64", "security.SMACK64IPIN" and
       "security.SMACK64IPOUT", respectively, i.e.  the security label of the FIFO, or the security label for
       the incoming or outgoing connections of the socket, respectively.  See Smack.txt
       <https://www.kernel.org/doc/Documentation/security/Smack.txt> for details.  Optional. Type uniline.

   SmackLabelIPOut
       Takes a string value. Controls the extended attributes "security.SMACK64", "security.SMACK64IPIN" and
       "security.SMACK64IPOUT", respectively, i.e.  the security label of the FIFO, or the security label for
       the incoming or outgoing connections of the socket, respectively.  See Smack.txt
       <https://www.kernel.org/doc/Documentation/security/Smack.txt> for details.  Optional. Type uniline.

   SELinuxContextFromNet
       Takes a boolean argument. When true, systemd will attempt to figure out the SELinux label used for the
       instantiated service from the information handed by the peer over the network. Note that only the
       security level is used from the information provided by the peer. Other parts of the resulting SELinux
       context originate from either the target binary that is effectively triggered by socket unit or from the
       value of the "SELinuxContext" option.  This configuration option applies only when activated service is
       passed in single socket file descriptor, i.e. service instances that have standard input connected to a
       socket or services triggered by exactly one socket unit. Also note that this option is useful only when
       MLS/MCS SELinux policy is deployed. Defaults to "false".  Optional. Type boolean.

   PipeSize
       Takes a size in bytes. Controls the pipe buffer size of FIFOs configured in this socket unit. See
       fcntl(2) for details. The usual suffixes K, M, G are supported and are understood to the base of 1024.
       Optional. Type uniline.

   MessageQueueMaxMessages
       These two settings take integer values and control the mq_maxmsg field or the mq_msgsize field,
       respectively, when creating the message queue. Note that either none or both of these variables need to
       be set. See mq_setattr(3) for details.  Optional. Type uniline.

   FreeBind
       Takes a boolean value. Controls whether the socket can be bound to non-local IP addresses. This is useful
       to configure sockets listening on specific IP addresses before those IP addresses are successfully
       configured on a network interface. This sets the "IP_FREEBIND"/"IPV6_FREEBIND" socket option. For
       robustness reasons it is recommended to use this option whenever you bind a socket to a specific IP
       address. Defaults to "false".  Optional. Type boolean.

   Transparent
       Takes a boolean value. Controls the "IP_TRANSPARENT"/"IPV6_TRANSPARENT" socket option. Defaults to
       "false".  Optional. Type boolean.

   Broadcast
       Takes a boolean value. This controls the "SO_BROADCAST" socket option, which allows broadcast datagrams
       to be sent from this socket. Defaults to "false".  Optional. Type boolean.

   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 "false".  Optional.
       Type boolean.

   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 "false".
       Optional. Type boolean.

   PassPacketInfo
       Takes a boolean value. This controls the "IP_PKTINFO", "IPV6_RECVPKTINFO", "NETLINK_PKTINFO" or
       "PACKET_AUXDATA" socket options, which enable reception of additional per-packet metadata as ancillary
       message, on "AF_INET", "AF_INET6", "AF_UNIX" and "AF_PACKET" sockets.  Defaults to "false".  Optional.
       Type boolean.

   Timestamping
       Takes one of "off", "us" (alias: "usec", "Xs") or "ns" (alias: "nsec"). This controls the "SO_TIMESTAMP"
       or "SO_TIMESTAMPNS" socket options, and enables whether ingress network traffic shall carry timestamping
       metadata. Defaults to "off".  Optional. Type enum. choice: 'off', 'us', 'usec', 'Xs', 'ns', 'nsec'.

   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.  Optional. Type uniline.

   ExecStartPre
       Takes one or more command lines, which are executed before or after the listening sockets/FIFOs are
       created and bound, respectively. The first token of the command line must be an absolute filename, then
       followed by arguments for the process. Multiple command lines may be specified following the same scheme
       as used for "ExecStartPre" of service unit files.  Optional. Type list of uniline.

   ExecStartPost
       Takes one or more command lines, which are executed before or after the listening sockets/FIFOs are
       created and bound, respectively. The first token of the command line must be an absolute filename, then
       followed by arguments for the process. Multiple command lines may be specified following the same scheme
       as used for "ExecStartPre" of service unit files.  Optional. Type list of uniline.

   ExecStopPre
       Additional commands that are executed before or after the listening sockets/FIFOs are closed and removed,
       respectively. Multiple command lines may be specified following the same scheme as used for
       "ExecStartPre" of service unit files.  Optional. Type list of uniline.

   ExecStopPost
       Additional commands that are executed before or after the listening sockets/FIFOs are closed and removed,
       respectively. Multiple command lines may be specified following the same scheme as used for
       "ExecStartPre" of service unit files.  Optional. Type list of uniline.

   TimeoutSec
       Configures the time to wait for the commands specified in "ExecStartPre", "ExecStartPost", "ExecStopPre"
       and "ExecStopPost" to 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 will be terminated forcibly via
       "SIGTERM", and after another delay of this time with "SIGKILL". (See "KillMode" in systemd.kill(5).)
       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 "DefaultTimeoutStartSec" from the manager configuration file (see
       systemd-system.conf(5)).   Optional. Type uniline.

   Service
       Specifies the service unit name to activate on incoming traffic. This setting is only allowed for sockets
       with "Accept=no". It defaults to the service that bears the same name as the socket (with the suffix
       replaced). In most cases, it should not be necessary to use this option. Note that setting this parameter
       might result in additional dependencies to be added to the unit (see above).  Optional. Type uniline.

   RemoveOnStop
       Takes a boolean argument. If enabled, any file nodes created by this socket unit are removed when it is
       stopped. This applies to "AF_UNIX" sockets in the file system, POSIX message queues, FIFOs, as well as
       any symlinks to them configured with "Symlinks". Normally, it should not be necessary to use this option,
       and is not recommended as services might continue to run after the socket unit has been terminated and it
       should still be possible to communicate with them via their file system node. Defaults to off.  Optional.
       Type boolean.

   Symlinks
       Takes a list of file system paths. The specified paths will be created as symlinks to the "AF_UNIX"
       socket path or FIFO path of this socket unit. If this setting is used, only one "AF_UNIX" socket in the
       file system or one FIFO may be configured for the socket unit. Use this option to manage one or more
       symlinked alias names for a socket, binding their lifecycle together. Note that if creation of a symlink
       fails this is not considered fatal for the socket unit, and the socket unit may still start. If an empty
       string is assigned, the list of paths is reset. Defaults to an empty list.  Optional. Type uniline.

   FileDescriptorName
       Assigns a name to all file descriptors this socket unit encapsulates. This is useful to help activated
       services identify specific file descriptors, if multiple fds are passed. Services may use the
       sd_listen_fds_with_names(3) call to acquire the names configured for the received file descriptors. Names
       may contain any ASCII character, but must exclude control characters and ":", and must be at most 255
       characters in length. If this setting is not used, the file descriptor name defaults to the name of the
       socket unit, including its ".socket" suffix.  Optional. Type uniline.

   TriggerLimitIntervalSec
       Configures a limit on how often this socket unit my be activated within a specific time interval. The
       "TriggerLimitIntervalSec" may be used to configure the length of the time interval in the usual time
       units "us", "ms", "s", "min", "h", X and defaults to 2s (See systemd.time(7) for details on the various
       time units understood). The "TriggerLimitBurst" setting takes a positive integer value and specifies the
       number of permitted activations per time interval, and defaults to 200 for "Accept=yes" sockets (thus by
       default permitting 200 activations per 2s), and 20 otherwise (20 activations per 2s). Set either to 0 to
       disable any form of trigger rate limiting. If the limit is hit, the socket unit is placed into a failure
       mode, and will not be connectible anymore until restarted. Note that this limit is enforced before the
       service activation is enqueued.  Optional. Type uniline.

   TriggerLimitBurst
       Configures a limit on how often this socket unit my be activated within a specific time interval. The
       "TriggerLimitIntervalSec" may be used to configure the length of the time interval in the usual time
       units "us", "ms", "s", "min", "h", X and defaults to 2s (See systemd.time(7) for details on the various
       time units understood). The "TriggerLimitBurst" setting takes a positive integer value and specifies the
       number of permitted activations per time interval, and defaults to 200 for "Accept=yes" sockets (thus by
       default permitting 200 activations per 2s), and 20 otherwise (20 activations per 2s). Set either to 0 to
       disable any form of trigger rate limiting. If the limit is hit, the socket unit is placed into a failure
       mode, and will not be connectible anymore until restarted. Note that this limit is enforced before the
       service activation is enqueued.  Optional. Type uniline.

SEE ALSO

       •   cme

COPYRIGHT

       2010-2016 Lennart Poettering and others
       2016 Dominique Dumont

LICENSE

       LGPLv2.1+

perl v5.32.1                                       2021-11-2Config::Model::models::Systemd::Section::Socket(3pm)