ltm rule command MQTT packet id

iRule(1)					  BIG-IP TMSH Manual					     iRule(1)

MQTT::packet_id
       Get or set packet-id of MQTT message

SYNOPSIS
       MQTT::packet_id (PACKETID)?

DESCRIPTION
       This command can be used to get or set packet-id field of MQTT message.	This command is valid only for
       following MQTT message types:

	   PUBLISH (if QoS > 0)
	   PUBACK
	   PUBREC
	   PUBREL
	   PUBCOMP
	   SUBSCRIBE
	   SUBACK
	   UNSUBSCRIBE
	   UNSUBACK
	   PINGREQ
	   PINGRESP
	   DISCONNECT

       Syntax

       MQTT::packet_id []

       MQTT::packet_id
	   * Returns the packet-id of the MQTT message.

       MQTT::packet_id 
	   * Replaces the packet-id of the MQTT message with . The value supplied must be less than
       65536.

RETURN VALUE
       When called without an argument, this command returns the packet-id of MQTT message

VALID DURING
       MQTT_CLIENT_INGRESS MQTT_SERVER_INGRESS MQTT_CLIENT_DATA MQTT_SERVER_DATA MQTT_CLIENT_EGRESS
       MQTT_SERVER_EGRESS

EXAMPLES
	#Example: Split SUBSCRIBE with multiple topics into separate SUBSCRIBE messages
	when MQTT_CLIENT_INGRESS {
	  set type [MQTT::type]
	  switch $type {
	     "SUBSCRIBE" {
		 set count [MQTT::topic count]
		 if { $count > 1 } {
		    set topiclist [MQTT::topic list]
		    set qoslist [list]
		    foreach topic $topiclist {
		       lappend qoslist [MQTT::topic qos $topic]
		    }
		    set packetid [MQTT::packet_id]
		    set i 0
		    foreach topic $topiclist {
			if { $i == 0 } {
			    MQTT::replace type SUBSCRIBE packet_id $packetid topic_list $topic [lindex $qoslist $i]
			    table add -subtable "outstanding_packetid_table" "[client_addr]_[client_port]_${packetid}" $count
			} else {
			    MQTT::insert after type SUBSCRIBE packet_id [expr { ($packetid + 1000 + $i)%65535}] topic_list $topic [lindex $qoslist $i]
			}
			set i [expr { $i + 1 }]
		    }
		 }
	     }
	  }
	}

	when SERVER_CONNECTED {
	   set suback_count 0
	   set rclist [list]
	}

	when MQTT_SERVER_INGRESS {
	   set type [MQTT::type]
	   switch $type {
	      "SUBACK" {
		 set packetid [MQTT::packet_id]
		 if { $suback_count == 0 } {
		     set count [table lookup -subtable "outstanding_packetid_table" "[client_addr]_[client_port]_${packetid}"]
		     if { $count != "" } {
			set suback_count $count
		     } elseif { [llength $rclist] > 0 } {
			MQTT::replace type SUBACK return_code_list $rclist
			set rclist [list]
		     }
		 }
		 if { $suback_count > 0 } {
		     set suback_count [expr { $suback_count - 1}]
		     lappend rclist [MQTT::return_code_list]
		     MQTT::drop
		 }
	      }
	   }
	}

HINTS
SEE ALSO
CHANGE LOG
       @BIGIP-13.0.0 --First introduced the command.

BIG-IP						      2020-06-23					     iRule(1)