forked from DGNum/liminix
125 lines
4.5 KiB
Nix
125 lines
4.5 KiB
Nix
let
|
|
drop = expr : "${expr} drop";
|
|
accept = expr : "${expr} accept";
|
|
mcast-scope = 8;
|
|
allow-incoming = false;
|
|
bogons-ip6 = {
|
|
type = "filter";
|
|
family = "ip6";
|
|
policy = "accept";
|
|
hook = "prerouting";
|
|
rules = [
|
|
(drop "ip6 saddr ff00::/8") # multicast saddr is illegal
|
|
|
|
(drop "ip6 saddr ::/128") # unspecified address
|
|
(drop "ip6 daddr ::/128")
|
|
(drop "ip6 saddr 2001:db8::/32") # documentation addresses
|
|
(drop "ip6 daddr 2001:db8::/32")
|
|
|
|
# I think this means "check FIB for (saddr, iif) to see if we
|
|
# could route a packet to that address using that interface",
|
|
# and if we can't then it was an inapproppriate source address
|
|
# for packets received _from_ said interface
|
|
(drop "fib saddr . iif oif eq 0")
|
|
|
|
(drop "icmpv6 type router-renumbering")
|
|
(drop "icmpv6 type 139") # Node Information Query
|
|
(drop "icmpv6 type 140") # Node Information Response
|
|
(drop "icmpv6 type 100")
|
|
(drop "icmpv6 type 101")
|
|
(drop "icmpv6 type 200")
|
|
(drop "icmpv6 type 201")
|
|
(drop "icmpv6 type 127")
|
|
(drop "icmpv6 type 255")
|
|
(drop "icmpv6 type destination-unreachable ct state invalid,untracked")
|
|
];
|
|
};
|
|
forward-ip6 = {
|
|
type = "filter";
|
|
family = "ip6";
|
|
policy = "drop";
|
|
hook = "forward";
|
|
rules = [
|
|
(drop "ip6 saddr ::1/128") # loopback address [RFC4291]
|
|
(drop "ip6 daddr ::1/128")
|
|
(drop "ip6 saddr ::FFFF:0:0/96")# IPv4-mapped addresses
|
|
(drop "ip6 daddr ::FFFF:0:0/96")
|
|
(drop "ip6 saddr fe80::/10") # link-local unicast
|
|
(drop "ip6 daddr fe80::/10")
|
|
(drop "ip6 saddr fc00::/7") # unique-local addresses
|
|
(drop "ip6 daddr fc00::/7")
|
|
(drop "ip6 saddr 2001:10::/28") # ORCHID [RFC4843].
|
|
(drop "ip6 daddr 2001:10::/28")
|
|
|
|
(drop "ip6 saddr fc00::/7") # unique local source
|
|
(drop "ip6 daddr fc00::/7") # and/or dst addresses [RFC4193]
|
|
|
|
# multicast with wrong scopes
|
|
(drop
|
|
# dest addr first byte 0xff, low nibble of second byte <= scope
|
|
# https://www.mankier.com/8/nft#Payload_Expressions-Raw_Payload_Expression
|
|
"@nh,192,8 eq 0xff @nh,204,4 le ${toString mcast-scope}")
|
|
|
|
(accept "oifname \"int\" iifname \"ppp0\" meta l4proto udp ct state established,related")
|
|
(accept "iifname \"int\" oifname \"ppp0\" meta l4proto udp")
|
|
|
|
(accept "meta l4proto icmpv6")
|
|
(accept "meta l4proto ah")
|
|
(accept "meta l4proto esp")
|
|
|
|
# does this ever get used or does the preceding general udp accept
|
|
# already grab anything that might get here?
|
|
(accept "oifname \"ppp0\" udp dport 500") # IKE Protocol [RFC5996]. haha zyxel
|
|
(accept "ip6 nexthdr 139") # Host Identity Protocol
|
|
|
|
## FIXME no support yet for recs 27-30 Mobility Header
|
|
|
|
(accept "oifname \"int\" iifname \"ppp0\" meta l4proto tcp ct state established,related")
|
|
(accept "iifname \"int\" oifname \"ppp0\" meta l4proto tcp")
|
|
|
|
(accept "oifname \"int\" iifname \"ppp0\" meta l4proto sctp ct state established,related")
|
|
(accept "iifname \"int\" oifname \"ppp0\" meta l4proto sctp")
|
|
|
|
(accept "oifname \"int\" iifname \"ppp0\" meta l4proto dccp ct state established,related")
|
|
(accept "iifname \"int\" oifname \"ppp0\" meta l4proto dccp")
|
|
|
|
# we can allow all reasonable inbound, or we can use an explicit
|
|
# allowlist to enumerate the endpoints that are allowed to
|
|
# accept inbound from the WAN
|
|
(if allow-incoming
|
|
then accept "oifname \"int\" iifname \"ppp0\""
|
|
else "oifname \"int\" iifname \"ppp0\" jump incoming-allowed-ip6"
|
|
)
|
|
# allow all outbound and any inbound that's part of a
|
|
# recognised (outbound-initiated) flow
|
|
(accept "oifname \"int\" iifname \"ppp0\" ct state established,related")
|
|
(accept "iifname \"int\" oifname \"ppp0\" ")
|
|
];
|
|
};
|
|
input-ip6 = {
|
|
type = "filter";
|
|
family = "ip6";
|
|
policy = "drop";
|
|
hook = "input";
|
|
rules = [
|
|
(accept "meta l4proto icmpv6")
|
|
(if allow-incoming
|
|
then accept "oifname \"int\" iifname \"ppp0\""
|
|
else "oifname \"int\" iifname \"ppp0\" jump incoming-allowed-ip6"
|
|
)
|
|
(accept "oifname \"int\" iifname \"ppp0\" ct state established,related")
|
|
(accept "iifname \"int\" oifname \"ppp0\" ")
|
|
];
|
|
};
|
|
|
|
incoming-allowed-ip6 = {
|
|
type = "filter";
|
|
family = "ip6";
|
|
rules = [
|
|
# this is where you put permitted incoming connections
|
|
# "oifname \"int\" ip6 daddr 2001:8b0:de3a:40de::e9d tcp dport 22"
|
|
];
|
|
};
|
|
in {
|
|
inherit input-ip6 forward-ip6 bogons-ip6 incoming-allowed-ip6;
|
|
}
|