zapret/init.d/sysv/custom-nfqws-quic4all-complex

# this custom script in addition to MODE=nfqws runs desync to all QUIC initial packets, without ipset/hostlist filtering
# and also sends special fake on the first outgoing packet with short header and udp.length>600
# need to add to config : NFQWS_OPT_DESYNC_QUIC="--dpi-desync=fake"
# need to add to config : NFQWS_OPT_DESYNC_QUIC_SHORT_HEADER="--dpi-desync=fake --dpi-desync-any-protocol --dpi-desync-fake-unknown-udp=/opt/zapret/files/fake/quic_short_header.bin --dpi-desync-cutoff=n2"
# NOTE : do not use TTL fooling. chromium QUIC engine breaks sessions if TTL expired in transit received

# this hack was first intended for TSPU but it appeared that it's overkill
# it's enough to send short header fake before initial

QNUM2=$(($QNUM+10))
QNUM3=$(($QNUM+11))

zapret_custom_daemons()
{
	# stop logic is managed by procd

	local MODE_OVERRIDE=nfqws
	local opt

	zapret_do_daemons $1

	opt="--qnum=$QNUM2 $NFQWS_OPT_BASE $NFQWS_OPT_DESYNC_QUIC"
	do_nfqws $1 100 "$opt"
	
	opt="--qnum=$QNUM3 $NFQWS_OPT_BASE $NFQWS_OPT_DESYNC_QUIC_SHORT_HEADER"
	do_nfqws $1 101 "$opt"
}
zapret_custom_firewall()
{
	# $1 - 1 - run, 0 - stop

	local MODE_OVERRIDE=nfqws
	local f
	local first_packets_only="-m connbytes --connbytes-dir=original --connbytes-mode=packets --connbytes 1:3"
	local desync="-m mark ! --mark $DESYNC_MARK/$DESYNC_MARK"
	local udplen="-m length --length 601:1500"
	local short_header4="-m u32 --u32 0>>22&0x3C@8>>24&0xC0=0x40"

	zapret_do_firewall_rules_ipt $1

	f="-p udp --dport 443"
	fw_nfqws_post $1 "$f $desync $first_packets_only" "$f $desync $first_packets_only" $QNUM2
	# this for ipv4 only. do not have access to ipv6 enabled TSPU to test
	fw_nfqws_post $1 "$f $desync $udplen $short_header4" "" $QNUM3

}
zapret_custom_firewall_nft()
{
	# stop logic is not required

	local MODE_OVERRIDE=nfqws
	local f
	local first_packets_only="ct original packets 1-3"
	local desync="mark and $DESYNC_MARK == 0"
	local udplen="udp length 601-1500"
	local short_header4="@th,64,2 1"

	zapret_apply_firewall_rules_nft

	f="udp dport 443"
	nft_fw_nfqws_post $1 "$f $desync $first_packets_only" "$f $desync $first_packets_only" $QNUM2
	# this for ipv4 only. do not have access to ipv6 enabled TSPU to test
	nft_fw_nfqws_post $1 "$f $desync $udplen $short_header4" "" $QNUM3
	# add flow offload exemption for the whole stream because we dont know when short_header rule triggers
	nft_add_flow_offload_exemption "$f" "" "QUIC exemption for complex TSPU hack"
}