edgeguard-native/internal/firewall/ruleset.nft.tpl

#!/usr/sbin/nft -f
# Generated by edgeguard-api — DO NOT EDIT.
# Source: internal/firewall/firewall.go.
# Re-generate via `edgeguard-ctl render-config` or via API mutations.

flush ruleset

table inet edgeguard {
    set peer_ipv4 {
        type ipv4_addr; flags interval
        {{- if .PeerIPv4}}
        elements = { {{range $i, $ip := .PeerIPv4}}{{if $i}}, {{end}}{{$ip}}{{end}} }
        {{- end}}
    }
    set peer_ipv6 {
        type ipv6_addr; flags interval
        {{- if .PeerIPv6}}
        elements = { {{range $i, $ip := .PeerIPv6}}{{if $i}}, {{end}}{{$ip}}{{end}} }
        {{- end}}
    }

    chain input {
        type filter hook input priority 0; policy drop;

        # ── ANTI-LOCKOUT (immer aktiv, kann von keiner Custom-Rule overruled werden) ──
        # nft input-chain wird top-down evaluiert; eine accept-Action terminiert.
        # Diese Block kommt VOR den Custom-Rules — d.h. selbst wenn ein
        # Operator versehentlich „drop alles" baut, bleibt SSH + Admin-UI
        # erreichbar.
        tcp dport 22   ct state new limit rate 10/minute accept comment "anti-lockout: SSH (rate-limited)"
        tcp dport 443  accept comment "anti-lockout: HAProxy public HTTPS"
        tcp dport 3443 accept comment "anti-lockout: Management-UI (HAProxy admin HTTPS)"

        # Stateful baseline
        ct state established,related accept
        ct state invalid drop
        iif lo accept

        # ICMP — keep PMTUD and basic diagnostics
        ip  protocol icmp   icmp   type { echo-request, destination-unreachable, time-exceeded, parameter-problem } accept
        ip6 nexthdr  icmpv6 icmpv6 type { echo-request, destination-unreachable, packet-too-big, time-exceeded, parameter-problem, nd-router-solicit, nd-router-advert, nd-neighbor-solicit, nd-neighbor-advert } accept

        # Public ingress: HAProxy serves :80 (ACME + redirect)
        tcp dport 80 accept

        # Cluster-internal: peers reach edgeguard-api over mTLS on :8443
        tcp dport 8443 ip  saddr @peer_ipv4 accept
        tcp dport 8443 ip6 saddr @peer_ipv6 accept

        # ── Operator-defined rules ──
{{range .Legs}}
        # rule {{.RuleID}}{{if .Name}} ({{.Name}}){{end}}{{if .Comment}} — {{.Comment}}{{end}}
        {{- /* Body MUSS auf EIGENER Zeile starten (nicht via {{- }} an
                 die Comment-Zeile angehängt — sonst frisst nft die rule
                 als Teil des # Kommentars). */ -}}
        {{""}}
        {{if .SrcIfaces}}iifname { {{join .SrcIfaces ", "}} } {{end}}{{if .DstIfaces}}oifname { {{join .DstIfaces ", "}} } {{end}}{{if .SrcAddrs}}ip saddr { {{join .SrcAddrs ", "}} } {{end}}{{if .DstAddrs}}ip daddr { {{join .DstAddrs ", "}} } {{end}}{{with .Service}}{{if and (or (eq .Proto "tcp") (eq .Proto "udp")) .PortStart}}{{.Proto}} dport {{.PortStart}}{{if and .PortEnd (ne .PortEnd .PortStart)}}-{{.PortEnd}}{{end}} {{else if eq .Proto "icmp"}}ip protocol icmp {{else if eq .Proto "icmpv6"}}ip6 nexthdr icmpv6 {{end}}{{end}}{{if .Log}}log prefix "edgeguard:{{.RuleID}} " {{end}}{{.Action}}
{{end}}
    }

    chain forward {
        type filter hook forward priority 0; policy drop;

        ct state established,related accept
        ct state invalid drop

        # DNAT-rewrites aus prerouting_nat haben den ct.status DNAT-Bit
        # gesetzt — die müssen forward-passieren dürfen, sonst kommen
        # Port-Forwards (z.B. :2030 → 10.10.20.12:22) zwar durch das
        # NAT-Rewrite, scheitern aber an policy=drop. Equivalent zu
        # iptables -m conntrack --ctstate DNAT.
        ct status dnat accept

        # Auto-Forward für SNAT/Masquerade-Origin-Pakete. Forward-chain
        # sieht das Paket VOR der postrouting-Translation; ct.status ist
        # also noch nicht "snat". Wir ziehen pro NAT-Rule das SrcCIDR
        # nach und erlauben new-state-Pakete von dort. Return-Pakete
        # gehen via ct state established schon durch.
{{range .NATRules}}{{if or (eq .Kind "snat") (eq .Kind "masquerade")}}{{if .SrcCIDR}}
        ip saddr {{.SrcCIDR}} ct state new accept comment "auto-forward for NAT rule {{.ID}}"
{{end}}{{end}}{{end}}
    }

    chain output {
        type filter hook output priority 0; policy accept;
    }

    chain prerouting_nat {
        type nat hook prerouting priority -100;
{{range .NATRules}}{{if eq .Kind "dnat"}}
        # NAT {{.ID}} (dnat{{if .Comment}} — {{.Comment}}{{end}})
        {{""}}
        {{/* nft-Syntax: erst L3-match (ip saddr/daddr), DANN L4 (tcp/udp dport).
             Sonst quittiert der parser '... unexpected ip' an dieser Stelle. */}}
        {{if .InIfaces}}iifname { {{join .InIfaces ", "}} } {{end}}{{if .SrcCIDR}}ip saddr {{.SrcCIDR}} {{end}}{{if .DstCIDR}}ip daddr {{.DstCIDR}} {{end}}{{if and .Proto (ne .Proto "any")}}{{.Proto}} {{else}}meta l4proto { tcp, udp } {{end}}{{if .DPortStart}}dport {{.DPortStart}}{{if and .DPortEnd (ne .DPortEnd .DPortStart)}}-{{.DPortEnd}}{{end}} {{end}}{{if .TargetAddr}}dnat to {{.TargetAddr}}{{if .TargetPortStart}}:{{.TargetPortStart}}{{if and .TargetPortEnd (ne .TargetPortEnd .TargetPortStart)}}-{{.TargetPortEnd}}{{end}}{{end}}{{end}}
{{end}}{{end}}
    }

    chain postrouting_nat {
        type nat hook postrouting priority 100;

        # Auto-Hairpin für DNAT-Pakete: alle in prerouting_nat
        # umgeschriebenen Pakete bekommen zusätzlich SNAT auf die
        # Box-IP des ausgehenden Iface (masquerade). Sonst antwortet
        # das DNAT-Ziel via seinem eigenen default-Gateway, das oft
        # nicht zur EdgeGuard-Box zeigt → SYN_SENT + UNREPLIED.
        # Trade-off: Backend sieht die Box-IP statt der echten
        # client-IP (für Logging / Geo-Block: später optional via
        # NAT-Rule-Flag preserve_client_ip).
        ct status dnat masquerade
{{range .NATRules}}{{if eq .Kind "snat"}}
        # NAT {{.ID}} (snat{{if .Comment}} — {{.Comment}}{{end}})
        {{""}}
        {{if .OutIfaces}}oifname { {{join .OutIfaces ", "}} } {{end}}{{if .SrcCIDR}}ip saddr {{.SrcCIDR}} {{end}}{{if .TargetAddr}}snat to {{.TargetAddr}}{{end}}
{{end}}{{if eq .Kind "masquerade"}}
        # NAT {{.ID}} (masquerade{{if .Comment}} — {{.Comment}}{{end}})
        {{""}}
        {{if .OutIfaces}}oifname { {{join .OutIfaces ", "}} } {{end}}{{if .SrcCIDR}}ip saddr {{.SrcCIDR}} {{end}}masquerade
{{end}}{{end}}
    }
}