iptables-workstation.sh: enable DHCPv4 offers and more SSDP communication

When trying to connect to a Panasonic Lumix DMC-G6 camera in direct mode
the current rules are too strict to fully enable DHCP communication and
SSDP discovery.

Accept the traffic required for these functionality.

diff --git a/iptables-workstation.sh b/iptables-workstation.sh
index a00aa51..2ec87ce 100755 (executable)
--- a/iptables-workstation.sh
+++ b/iptables-workstation.sh
@@ -37,6 +37,9 @@ flush_ruleset
 
 ip46t -N in-new
 
+# Accept DHCPv4 Offer
+ipt -A in-new -p udp -m udp --sport bootps --dport bootpc -j ACCEPT
+
 # Silently drop DHCPv4 Discover and Request packets from other clients.
 ipt -A in-new -s 0.0.0.0 -d 255.255.255.255 -p udp -m udp --sport bootpc --dport bootps -j DROP
 
@@ -48,11 +51,12 @@ ipt  -A in-new -d 224.0.0.251 -p udp -m udp --dport 5353 -j ACCEPT
 ip6t -A in-new -d ff02::fb    -p udp -m udp --dport 5353 -j ACCEPT
 
 # SSDP: https://en.wikipedia.org/wiki/Simple_Service_Discovery_Protocol
-ipt  -A in-new -d 239.255.255.250 -p udp -m udp --dport 1900 -j ACCEPT
-ip6t -A in-new -d ff02::c         -p udp -m udp --dport 1900 -j ACCEPT
-ip6t -A in-new -d ff05::c         -p udp -m udp --dport 1900 -j ACCEPT
-ip6t -A in-new -d ff08::c         -p udp -m udp --dport 1900 -j ACCEPT
-ip6t -A in-new -d ff0e::c         -p udp -m udp --dport 1900 -j ACCEPT
+ipt   -A in-new -d 239.255.255.250 -p udp -m udp --dport 1900 -j ACCEPT
+ip6t  -A in-new -d ff02::c         -p udp -m udp --dport 1900 -j ACCEPT
+ip6t  -A in-new -d ff05::c         -p udp -m udp --dport 1900 -j ACCEPT
+ip6t  -A in-new -d ff08::c         -p udp -m udp --dport 1900 -j ACCEPT
+ip6t  -A in-new -d ff0e::c         -p udp -m udp --dport 1900 -j ACCEPT
+ip46t -A in-new                    -p udp -m udp --sport 1900 -j ACCEPT
 
 
 for port in "${TCP_OPEN_PORTS[@]}";