Modules are done, this instance you would do this first
$this->bbcode_second_pass_code('', 'modprobe iptable_filter')
Here is a list of other potential modules
$this->bbcode_second_pass_code('', 'nfnetlink
loadmodule x_tables
ip_tables
loadmodule iptable_filter
iptable_mangle
ip_conntrack
nf_conntrack
nf_conntrack_ipv4
iptable_nat
iptable_raw
xt_state
loadmodule xt_tcpudp
ipt_LOG
loadmodule xt_AUDIT
xt_CLASSIFY
xt_connmark
xt_CONNMARK
xt_conntrack
xt_dccp
loadmodule xt_dscp
xt_DSCP
loadmodule xt_hashlimit
xt_helper
loadmodule xt_ipp2p
xt_iprange
xt_length
loadmodule xt_limit
xt_mac
loadmodule xt_mark
xt_MARK
loadmodule xt_multiport
xt_NFLOG
loadmodule xt_NFQUEUE
xt_owner
loadmodule xt_physdev
xt_pkttype
xt_policy
loadmodule xt_sctp
xt_tcpmss
loadmodule xt_TCPMSS
xt_time
loadmodule xt_IPMARK
xt_TPROXY
loadmodule xt_condition
xt_geoip
loadmodule xt_ipp2p
xt_LOGMARK
xt_RAWNAT
loadmodule ip_conntrack_amanda
ip_conntrack_ftp
ip_conntrack_h323
ip_conntrack_irc
ip_conntrack_netbios_ns
ip_conntrack_pptp
ip_conntrack_sip
ip_conntrack_tftp
ip_nat_amanda
ip_nat_ftp
ip_nat_h323
ip_nat_irc
ip_nat_pptp
ip_nat_sip
ip_nat_snmp_basic
ip_nat_tftp
nf_conntrack_ftp
nf_conntrack_h323
nf_conntrack_irc
nf_conntrack_netbios_ns
nf_conntrack_netlink
nf_conntrack_pptp
nf_conntrack_proto_gre
nf_conntrack_proto_sctp
nf_conntrack_proto_udplite
nf_conntrack_sip sip_direct_media=0
nf_conntrack_tftp
nf_conntrack_sane
nf_nat_amanda
nf_nat_ftp
nf_nat_h323
nf_nat_irc
nf_nat
loadmodule nf_nat_pptp
nf_nat_proto_gre
nf_nat_sip
nf_nat_snmp_basic
nf_nat_tftp
xt_set
loadmodule ip_set
ip_set_iphash
ip_set_ipmap
ip_set_ipporthash
ip_set_iptree
ip_set_iptreemap
ip_set_macipmap
ip_set_nethash
ip_set_portmap
ipt_SET
loadmodule ipt_set
sch_sfq
loadmodule sch_ingress
sch_hfsc
loadmodule sch_htb
sch_prio
loadmodule sch_tbf
sch_fq_codel
cls_u32
loadmodule cls_fw
cls_flow
loadmodule cls_basic
act_police
ipt_addrtype
ipt_ah
loadmodule ipt_CLASSIFY
ipt_CLUSTERIP
ipt_comment
ipt_connmark
ipt_CONNMARK
ipt_conntrack
ipt_dscp
loadmodule ipt_DSCP
ipt_ecn
loadmodule ipt_ECN
ipt_esp
loadmodule ipt_hashlimit
ipt_helper
ipt_ipp2p
loadmodule ipt_iprange
ipt_length
ipt_limit
loadmodule ipt_LOG
ipt_mac
loadmodule ipt_mark
ipt_MARK
loadmodule ipt_MASQUERADE
ipt_multiport
ipt_NETMAP
ipt_NOTRACK
ipt_owner
loadmodule ipt_physdev
ipt_pkttype
ipt_policy
ipt_realm
loadmodule ipt_recent
ipt_REDIRECT
ipt_REJECT
ipt_SAME
loadmodule ipt_sctp
ipt_set
loadmodule ipt_state
ipt_tcpmss
ipt_TCPMSS
ipt_tos
loadmodule ipt_TOS
ipt_ttl
loadmodule ipt_TTL
ipt_ULOG
')
If you installed and used something like shorewall, that would take care of modules