Descobri:
CUSTOMPORT=$(netstat -tlpn | grep 0.0.0.0.*ssh | cut -d: -f2 | cut -f1 -d\ )
SOURCE_IP=1.2.3.4
firewall-cmd --zone=public --permanent --query-masquerade
firewall-cmd --zone=public --permanent --add-masquerade
firewall-cmd --zone=public --permanent --add-rich-rule="rule family=\"ipv4\" source address=\"${SOURCE_IP}\" forward-port port=\"22\" protocol=\"tcp\" to-port=\"${CUSTOMPORT}\""
firewall-cmd --reload