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2.3.2 SPA Messages

The fwknop system (and subsequently libfko), support a specific set of message types. The message type value is used by fwknop to help determine the correct message format and content. These message types are:

Variable: int fko_message_type_t ¶

FKO_COMMAND_MSG

A request to have the fwknop server execute the given command. The format for this type is: ‘<ip of requestor>,<command text>’.

"192.168.1.2,uname -a"

FKO_ACCESS_MSG

A basic access request. This is the most common type in use. The format for this type is: ‘<ip of requestor>,<protocol>/<port>’. Note that multiple protocol/port entries are allowed.

"192.168.1.2,tcp/22"
"192.168.1.2,tcp/22,udp/5005"

FKO_NAT_ACCESS_MSG

An access request that also provide information for the fwknop server to create a Network Address Translation (NAT to an internal address. The format for this string is: ‘<internal ip>,<ext nat port>’.

"10.10.1.2,9922"

FKO_CLIENT_TIMEOUT_ACCESS_MSG

This is an FKO_ACCESS_REQUEST with a timeout parameter for the fwknop server. The timeout value is provided via the client_timeout data field.

FKO_CLIENT_TIMEOUT_NAT_ACCESS_MSG

This is an FKO_NAT_ACCESS_REQUEST with a timeout parameter for the fwknop server. The timeout value is provided via the client_timeout data field.

FKO_LOCAL_NAT_ACCESS_MSG

This is similar to the FKO_NAT_ACCESS request except the NAT is to the local to the server (i.e. a service listening on 127.0.0.1).

FKO_CLIENT_TIMEOUT_LOCAL_NAT_ACCESS_MSG

This is an FKO_LOCAL_NAT_ACCESS_REQUEST with a timeout parameter for the fwknop server. The timeout value is provided via the client_timeout data field.