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solaris:dns-server.8s

dns-server


NAME

dns-server - Domain Name Server service

DESCRIPTION

The dns-server service is a service management facility, under the service identifier:

svc:/network/dns/server:default

The service starts, monitors and manages an instance of named(8) with command line options as per service properties configured in the SMF configuration repository. Use svcprop(1) to list the properties and svccfg(8) to make changes. See EXAMPLES below.

Administrative actions on this service, such as enabling, disabling, or requesting restart, can be performed using svcadm(8). The service’s status can be queried using the svcs(1) command.

SERVICE

The dns-server SMF service supports the start, stop, refresh and restart methods. The methods are invoked using svcadm(8).

start

Reads SMF properties and creates relevant command line, checks for existence of configuration file, and for rndc configuration (/etc/rndc.conf) or key (/etc/rndc.key) file (creating them if neither exist), starts named(8) with created options and monitors process.

stop

stops instance.

refresh

Refreshes SMF options and sends named(8) instance a SIGHUP signal, causing it to reload named.conf. Note, a running instance will not pickup any SMF option changes until a restart.

restart

stops and the restarts instance.

SMF PROPERTIES

The following application configuration properties are available to administrators:

options/chroot_dir

This option is not recommended and may be removed in a future release! Using zones(7) and Role-Based Access Control, rbac(7), is recommended rather than chroot environments.

chroot_dir specifies the directory to be used as the root directory after processing SMF properties and the command line arguments but before reading the configuration file. Use this property when using a chroot(2) environment. Synonymous to command line option -t directory.

This option should be used in conjunction with the start/user option (see below), as chrooting a process running as root does not enhance security on most systems; the way chroot() is defined allows a process with root privileges to escape a chroot jail.

When using chroot(2), named(8) is unable to disable itself when receiving rndc(8) stop or halt commands. Instead, you must use the svcadm(8) disable command.

options/configuration_file

Specifies the configuration file to be used instead of the default, /etc/named.conf. A directory option might be specified in the configuration file. To ensure that reloading the configuration file continues to work in such a situation, configuration_file should be specified as an absolute pathname. This pathname should not include the chroot_dir pathname. This property is the equivalent of the -c config-file option.

options/crypto_engine

Specify an alternative crypto hardware (OpenSSL engine) for the crypto operations. Equivalent command line option -E engine-name.

options/debug_level

Specifies the default debug level. The default is 0, which means no debugging. The higher the number the more verbose debug information becomes. Equivalent of the command line option -d debug_level.

options/ip_interfaces

Specifies over which IP transport, IPv4 or IPv6, BIND will transmit. Possible values are IPv4 or IPv6. Any other setting assumes all, the default. This property is the equivalent of command line option -4 or -6

options/listen_on_port

Specifies the default UDP and TCP port to be used for listening to DNS requests. This property is the equivalent of the command line option -p port.

options/listener_threads

Specifies the number of listener worker threads to listen for incoming UDP packets on each address. If not specified, named will calculate a default value based on the number of detected CPUs: 1 for 1 CPU, 2 for 2-4 CPUs, and the number of detected CPUs divided by 2 for values higher than 4. If options/threads has been set to a higher value than the number of detected CPUs, then listener_threads may be increased as high as that value, but no higher. Equivalent command line option -U #listeners’.

options/server

Specifies the server executable to be used instead of the default server, /usr/sbin/named.

options/threads

Specifies the number of CPU worker threads to create. The default of 0 causes named to try and determine the number of CPUs present and create one thread per CPU. Equivalent of command line option -n #cpus.

In the event of a configuration error originating in one of the above SMF application options, an error message is logged which provides information about the error and the parameters that need correcting. dns-server then exits with exit code SMF_EXIT_ERR_CONFIG. In the event of an error other than a configuration error, dns-server exits with exit code SMF_EXIT_ERR_FATAL. Both non-successful exit codes cause the start method, smf_method(7), to place the service in the maintenance state, which can be observed with the svcs(1) command svcs -x.

In addition to the properties listed above, the following property can be used to invoke named as a user other than root:

start/user

Specifies the identity of the user that is invoking named. See smf_method(7). Note that the user must have solaris.smf.manage.bind authorization. Without this role the named will be unable to manage its SMF FMRI and named will automatically be restarted by the SMF after an rndc(8) stop or halt command. See EXAMPLES for a sequence of commands that establishes the correct authorization.

EXAMPLES

Example 1 Configuring named to Transmit Only over IPv4 Networks

The following command sequence configures named such that it will transmit only over IPv4 networks.

# svccfg -s svc:network/dns/server:default setprop \

> options/ip_interfaces=IPv4

# svcadm refresh svc:network/dns/server:default

#

Example 2 Listing Current Configuration File and Setting an Alternative File

The following sequence of commands lists the current named configuration file and sets an alternative file.

# svcprop -p options/configuration_file dns/server:default

/etc/named.conf

# svccfg -s dns/server:default setprop \

> options/configuration_file=/var/named/named.conf

# svcadm refresh dns/server:default

# svcprop -p options/configuration_file dns/server:default

/var/named/named.conf

Example 3 Establishing Appropriate Authorization for named

To have named start with the solaris.smf.manage.bind authorization, perform the steps shown below.

Add the user dnsadmin to the solaris.smf.manage.bind role:

# usermod -A solaris.smf.manage.bind dnsadmin

Observe effect of command:

# tail -1 /etc/user_attr

dnsadmin::::type=normal;auths=solaris.smf.manage.bind

Modify the service properties:

# svccfg

svc:> select svc:/network/dns/server:default

svc:/network/dns/server:default> setprop start/user = dnsadmin

svc:/network/dns/server:default> setprop start/group = dnsadmin

svc:/network/dns/server:default> exit

# svcadm refresh svc:/network/dns/server:default

# svcadm restart svc:/network/dns/server:default

Because only root has write access to create the default process-ID file, /var/run/named/named.pid, named must be configured to use an alternative path for the user dnsadmin. Here is an example of how to accomplish this:

# mkdir /var/named/tmp

# chown dnsadmin /var/named/tmp

Shown below is what you must add to named.conf to make use of the directory created above.

# head /etc/named.conf

options {

directory “/var/named”;

pid-file “/var/named/tmp/named.pid”;

};

FILES

/etc/named.conf

default configuration file

/etc/rndc.conf

Configuration file for rndc(8)

/etc/rndc.key

default key file used by rndc(8)

/var/run/named/named.pid

default process-ID file

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

SEE ALSO

svcs(1), named(8), named-checkconf(8), named-checkzone(8), rndc(8), rndc-confgen(8), svcadm(8), svccfg(8), svcprop(1), chroot(2), setuid(2), bind(3c), attributes(7), smf(7), smf_method(7)

See the BIND 9 Administrator’s Reference Manual. As of the date of publication of this man page, this document is available at https://kb.isc.org/article/AA-01031.


solaris/dns-server.8s.txt · Last modified: 2023/07/19 08:58 by A User Not Logged in