3.2. Server configuration

3.2. Server configuration
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The server configuration is defined in the Server section. The server specifies the set of sockets a client can connect to. It defines rules for how and from where a client can connect and the properties of the connection.

It also defines some global settings listed in the following table:

Table 3.3. Global server settings

Name	Description
MaxConnections	The maximum number of total simultaneous connections (clients). If not specified the default is used. The default is the operating system limit.
Threads	Number of threads for serving client connections.

Here is an example configuration of the server global settings:

Server
{
    MaxConnections 12
    Threads 7
}

The server has two types of sockets to configure in the sections Listen and ListenSSL. ListenSSL is describing a secure connection with a transport layer encryption based on SSL/TLS. Listen on the other hand is describing a plain TCP/IP connection. In the following two sections they are introduced:

3.2.1. Listen

In the subsections named Listen of the server configuration we define sockets providing plain connections based on TCP/IP. The following table describes the attributes you can set for plain TCP/IP connections:

Table 3.4. Listen settings

Name	Description
Address	Listening address (IPv4 or IPv6) of the server. '127.0.0.1' and '::1' stand for the loopback address (IPv4 an IPv6 respectively). The listener wildcards '*' or '0.0.0.0' (IPv4) or '::' (IPv6) are also accepted.
Port	Connection port. Ports 7649-7671 and 7934-7966 are unassigned according to IANA (last updated 2010-03-11). The default ports are 7661 for unencrypted connections and 7961 for SSL connections. Note that 7654 seems to be used by Winamp.
Identifier	Identifier that can be referenced in authorization functions to classify connections and to define authorization based on it.
MaxConnections	(optional) The maximum number of simultaneus connections for this socket.
Restrictions	(optional) Defines the subsection containing IP restrictions on the connection. If not defined, the connection is allowed from everywhere. The configuration of IP restrictions will be defined in the section IP restrictions.

The following Listen configuration shows an example plain TCP/IP connection definition:

Server
{
    Listen
    {
        Address localhost
        Port 7661
        Identifier "Interface 1"
        Restrictions {
            allow 192.168.201.0/24
        }
    }
}

3.2.2. ListenSSL

In the subsections named ListenSSL of the server configuration we define sockets providing secured connections with full transport layer encryption based on SSL/TLS. The following table describes the attributes you can set for secured connections. The first five attributes are the same as for sockets configured as plain TCP/IP (Listen) as shown before:

Table 3.5. ListenSSL settings

Name	Description
Address	Listening address (IPv4 or IPv6) of the server. '127.0.0.1' and '::1' stand for the loopback address (IPv4 an IPv6 respectively). The listener wildcards '*' or '0.0.0.0' (IPv4) or '::' (IPv6) are also accepted.
Port	Connection port. Ports 7649-7671 and 7934-7966 are unassigned according to IANA (last updated 2010-03-11). The default ports are 7661 for unencrypted connections and 7961 for SSL connections. Note that 7654 seems to be used by Winamp.
Identifier	Identifier that can be referenced in authorization functions to classify connections and to define authorization based on it.
MaxConnections	The maximum number of simultaneus connections for this port.
Restrictions	Defines the subsection containing IP restrictions on the connection. If not defined, the connection is allowed from everywhere. The configuration of IP restrictions will be defined in the section IP restrictions.
Certificate	File with the SSL certificate
Key	File with the SSL key
CAdirectory	Directory holding the CA certificate files.
CAchainFile	SSL CA chain file
Verify	ON/OFF switch to enabe/disable client certificate verification.

The following configuration shows an example ListenSSL definition:

Server
{
    ListenSSL
    {
        Address localhost
        Port 7961
        Identifier "Interface 1"
        MaxConnections 2
        Certificate SSL/wolframed.crt
        key SSL/wolframed.key
        CAchainFile SSL/CAchain.pem
        Verify Off
    }
}

3.2.3. IP restrictions

IP restrictions are defined as sub section restrictions of the socket configurations (Listener and ListenerSSL) in the server configuration.

Table 3.6. Restrictions settings

Name	Argument	Description
Allow	IP address with optional network mask	Define an IP or network address as allowed to connect from, if not explicitely defined by a `Deny` directive. If no `allow` is specified then all IPs are allowed to connect from, if not explicitely excluded by a `deny` directive. So no `allow` is equivalent to `allow all`
Deny	IP address with optional network mask	Define an IP or network address as forbidden to connect from. If a `deny` directive refers to an IP explictely defined or part of an `allow` then the `deny` is stronger and overrides the `allow` declaration.

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