Delete a forwarded opening the way ufw accepts it, and read a fresh machine's resolver as not in use — both measured on a lab machine (hq ADR 0100)

internal/bootstrap/inuse.go

@@ -10,13 +10,11 @@ import (
 	"github.com/novox/mesh-host/internal/store"
 )
 
-// quietUDP are processes whose UDP sockets every fresh machine has — name resolution, address
+// quiet are the processes every fresh machine runs that serve nobody: name resolution (whose
-// configuration, time — and which serve nobody. ss names a process by its first fifteen characters,
+// link-local resolver listens on TCP as well as UDP, on every address), address configuration and
-// so both spellings are here.
+// time. ss names a process by its first fifteen characters, so both spellings are here. Measured
-//
+// on a freshly installed lab machine (testdata/fresh-machine-listeners.txt): these and nothing else.
-// **Still to be measured** (novox/hq ADR 0100): this list is what a fresh machine is expected to
+var quiet = map[string]bool{
-// hold, and it must be checked against a freshly installed lab machine before it is trusted.
-var quietUDP = map[string]bool{
 	"systemd-resolved": true, "systemd-resolve": true,
 	"systemd-networkd": true, "systemd-network": true,
 	"systemd-timesyncd": true, "systemd-timesyn": true,
@@ -24,8 +22,8 @@ var quietUDP = map[string]bool{
 }
 
 // InUse says what makes this machine a machine in use (novox/hq ADR 0100): every running container
-// no host made, and every socket listening on an address other than loopback that is not ssh's — a
+// no host made, and every socket listening on an address other than loopback that is neither ssh's
-// UDP one only when it is held by something other than what every fresh machine runs. ours names
+// nor held by what every fresh machine runs. ours names
 // what the mesh itself runs, which a re-run of genesis finds and does not count.
 func InUse(ctx context.Context, run Runner, ours func(name string) bool) ([]string, []reachable.Reach, error) {
 	var containers []string
@@ -61,9 +59,9 @@ func counts(r reachable.Reach) bool {
 	}
 	switch r.Protocol {
 	case "tcp":
-		return r.By != "sshd" && !(r.By == "" && r.Port == 22)
+		return r.By != "sshd" && !(r.By == "" && r.Port == 22) && !quiet[r.By]
 	case "udp":
-		return !quietUDP[r.By]
+		return !quiet[r.By]
 	}
 	return false
 }

internal/bootstrap/inuse_test.go

@@ -2,6 +2,7 @@ package bootstrap
 
 import (
 	"context"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -13,8 +14,8 @@ import (
 // and listener it counted.
 
 // Lines as `ss -Hltunp` prints them. The ssh, samba, loopback and proxy lines are captured from a
-// real machine; the resolver, DHCP and time lines are written in the same shape for the processes a
+// real machine; the resolver, DHCP and time lines are written in the same shape. What a fresh machine
-// fresh machine runs, and still need measuring against one.
+// actually runs is measured in testdata/fresh-machine-listeners.txt.
 const inUseSockets = `tcp LISTEN 0      128                                        0.0.0.0:22    0.0.0.0:* users:(("sshd",pid=1188536,fd=6))
 tcp LISTEN 0      128                                           [::]:22       [::]:* users:(("sshd",pid=1188536,fd=7))
 tcp LISTEN 0      32                                       127.0.0.1:53    0.0.0.0:* users:(("dnsmasq",pid=1189392,fd=7))
@@ -97,3 +98,25 @@ func TestARerunOfGenesisIsNotAMachineInUse(t *testing.T) {
 		t.Errorf("what an earlier genesis raised was counted as a machine in use: %v", err)
 	}
 }
+
+func TestAFreshlyInstalledMachineAsMeasuredIsNotInUse(t *testing.T) {
+	// Captured with `ss -Hltunp` on a freshly installed lab machine: its resolver listens on TCP on
+	// every address, which the record's words alone would count.
+	raw, err := os.ReadFile("testdata/fresh-machine-listeners.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	run := func(ctx context.Context, name string, args ...string) (string, error) {
+		if name == "ss" {
+			return string(raw), nil
+		}
+		return "", nil
+	}
+	containers, listeners, err := InUse(context.Background(), run, func(string) bool { return false })
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(containers) != 0 || len(listeners) != 0 {
+		t.Errorf("a fresh machine read as in use: containers %v, listeners %v", containers, listeners)
+	}
+}

internal/bootstrap/testdata/fresh-machine-listeners.txt

@@ -0,0 +1,12 @@
+udp UNCONN 0      0                                 0.0.0.0:5353  0.0.0.0:* users:(("systemd-resolve",pid=262,fd=17))
+udp UNCONN 0      0                                 0.0.0.0:5355  0.0.0.0:* users:(("systemd-resolve",pid=262,fd=13))
+udp UNCONN 0      0                              127.0.0.54:53    0.0.0.0:* users:(("systemd-resolve",pid=262,fd=24))
+udp UNCONN 0      0                           127.0.0.53%lo:53    0.0.0.0:* users:(("systemd-resolve",pid=262,fd=22))
+udp UNCONN 0      0                                    [::]:5353     [::]:* users:(("systemd-resolve",pid=262,fd=18))
+udp UNCONN 0      0                                    [::]:5355     [::]:* users:(("systemd-resolve",pid=262,fd=15))
+udp UNCONN 0      0      [fe80::1266:6aff:fe24:628d]%enp5s0:546      [::]:* users:(("systemd-network",pid=272,fd=36))
+tcp LISTEN 0      4096                            127.0.0.1:39473 0.0.0.0:* users:(("containerd",pid=394,fd=14))
+tcp LISTEN 0      4096                              0.0.0.0:5355  0.0.0.0:* users:(("systemd-resolve",pid=262,fd=14))
+tcp LISTEN 0      4096                        127.0.0.53%lo:53    0.0.0.0:* users:(("systemd-resolve",pid=262,fd=23))
+tcp LISTEN 0      4096                           127.0.0.54:53    0.0.0.0:* users:(("systemd-resolve",pid=262,fd=25))
+tcp LISTEN 0      4096                                 [::]:5355     [::]:* users:(("systemd-resolve",pid=262,fd=16))

internal/firewall/firewall.go

@@ -38,6 +38,17 @@ const (
 	Unsupported Kind = "unsupported"
 )
 
+// deletion is the arguments that delete a rule as `ufw show added` printed it. A route rule is
+// deleted with `route delete …`: ufw refuses `delete route …` as invalid syntax. And ufw answers
+// success when asked to delete a rule it does not hold, so every deletion is read back.
+func deletion(rule string) []string {
+	w := words(rule)
+	if len(w) > 0 && w[0] == "route" {
+		return append([]string{"route", "delete"}, w[1:]...)
+	}
+	return append([]string{"delete"}, w...)
+}
+
 // MeshInterface is the private network's interface, the way an opening from the mesh is known.
 // It must be the controller's overlay interface name.
 const MeshInterface = "mesh0"
@@ -335,7 +346,7 @@ func Converge(ctx context.Context, run Runner, o *declaration.Opening) (string,
 		return "unchanged", nil
 	}
 	for _, rule := range stale {
-		if _, err := run(ctx, "ufw", append([]string{"delete"}, words(rule)...)...); err != nil {
+		if _, err := run(ctx, "ufw", deletion(rule)...); err != nil {
 			return "", fmt.Errorf("deleting the mesh's stale ufw rule %q: %w", rule, err)
 		}
 	}
@@ -381,7 +392,7 @@ func Remove(ctx context.Context, run Runner, id string) (int, error) {
 		if !markedFor(comment(rule), id) {
 			continue
 		}
-		if _, err := run(ctx, "ufw", append([]string{"delete"}, words(rule)...)...); err != nil {
+		if _, err := run(ctx, "ufw", deletion(rule)...); err != nil {
 			return removed, fmt.Errorf("deleting the mesh's ufw rule %q: %w", rule, err)
 		}
 		removed++

internal/firewall/firewall_test.go

@@ -180,9 +180,17 @@ func (f *fakeUFW) run(_ context.Context, name string, args ...string) (string, e
 	case args[0] == "disable":
 		f.active = false
 		return "Firewall stopped and disabled on system startup\n", nil
-	case args[0] == "delete":
+	case args[0] == "delete" && len(args) > 1 && args[1] == "route":
+		// As the real ufw answers it (captured in testdata/ufw-delete.txt): a route rule is
+		// deleted with `route delete`, never `delete route`.
+		return "", errors.New("ERROR: Invalid syntax")
+	case args[0] == "delete", args[0] == "route" && len(args) > 1 && args[1] == "delete":
+		rest := args[1:]
+		if args[0] == "route" {
+			rest = append([]string{"route"}, args[2:]...)
+		}
 		for i, r := range f.rules {
-			if strings.Join(words(r), "\x00") == strings.Join(args[1:], "\x00") {
+			if strings.Join(words(r), "\x00") == strings.Join(rest, "\x00") {
 				f.rules = append(f.rules[:i], f.rules[i+1:]...)
 				return "Rule deleted\n", nil
 			}
@@ -333,3 +341,86 @@ func TestDetectingTheFoundFirewall(t *testing.T) {
 		}
 	}
 }
+
+// The fixtures below were captured from a real ufw 0.36.2 on a lab machine, not written by hand:
+// ufw prints a rule back in its own shorter form, so the mark in the comment is the only thing the
+// host relies on.
+
+func TestTheMarksAreReadFromWhatUfwReallyPrints(t *testing.T) {
+	raw, err := os.ReadFile("testdata/ufw-show-added.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	run := func(ctx context.Context, name string, args ...string) (string, error) { return string(raw), nil }
+	rules, err := added(context.Background(), run)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rules) != 7 {
+		t.Fatalf("read %d rules, want 7: %q", len(rules), rules)
+	}
+	marked := 0
+	for _, r := range rules {
+		if strings.HasPrefix(comment(r), "mesh-host ") {
+			marked++
+		}
+	}
+	if marked != 5 {
+		t.Errorf("read %d marked rules, want 5", marked)
+	}
+	if !markedFor(comment(rules[5]), "adoption.opening-tcp-8443-forwarded") {
+		t.Errorf("the forwarded rule from the mesh lost its mark: %q", rules[5])
+	}
+}
+
+func TestEveryRealRuleIsDeletedInTheFormUfwAccepts(t *testing.T) {
+	raw, err := os.ReadFile("testdata/ufw-show-added.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	run := func(ctx context.Context, name string, args ...string) (string, error) { return string(raw), nil }
+	rules, _ := added(context.Background(), run)
+	// Each of these was run on the lab machine and answered "Rule deleted" (testdata/ufw-delete.txt).
+	want := map[string]string{
+		"allow 5671/tcp comment 'mesh-host adoption.opening-tcp-5671-incoming 1a2b3c4d'":                                     "delete allow 5671/tcp comment|mesh-host adoption.opening-tcp-5671-incoming 1a2b3c4d",
+		"allow in on mesh0 to any port 5432 proto tcp comment 'mesh-host adoption.opening-tcp-5432-incoming deadbeef'":       "delete allow in on mesh0 to any port 5432 proto tcp comment|mesh-host adoption.opening-tcp-5432-incoming deadbeef",
+		"route allow 80/tcp comment 'mesh-host adoption.opening-tcp-8081-forwarded 0badf00d'":                                "route delete allow 80/tcp comment|mesh-host adoption.opening-tcp-8081-forwarded 0badf00d",
+		"route allow in on mesh0 to any port 443 proto tcp comment 'mesh-host adoption.opening-tcp-8443-forwarded cafe0001'": "route delete allow in on mesh0 to any port 443 proto tcp comment|mesh-host adoption.opening-tcp-8443-forwarded cafe0001",
+	}
+	seen := 0
+	for _, r := range rules {
+		w, ok := want[r]
+		if !ok {
+			continue
+		}
+		seen++
+		d := deletion(r)
+		got := strings.Join(d[:len(d)-1], " ") + "|" + d[len(d)-1]
+		if got != w {
+			t.Errorf("deleting %q\n got  %s\n want %s", r, got, w)
+		}
+	}
+	if seen != len(want) {
+		t.Errorf("matched %d of %d captured rules", seen, len(want))
+	}
+}
+
+func TestARealUfwRulesetIsUfw(t *testing.T) {
+	raw, err := os.ReadFile("testdata/ufw-active.nft")
+	if err != nil {
+		t.Fatal(err)
+	}
+	status, err := os.ReadFile("testdata/ufw-status-active.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !statusActive(string(status)) {
+		t.Fatal("the captured status does not read as active")
+	}
+	if refusing := Refusing(string(raw), true); len(refusing) > 0 {
+		t.Errorf("a machine with ufw active and nothing else read as refusing in %v", refusing)
+	}
+	if refusing := Refusing(string(raw), false); len(refusing) == 0 {
+		t.Error("ufw's drop chains, with ufw not known to be active, read as refusing nothing")
+	}
+}

internal/firewall/testdata/ufw-active.nft

@@ -0,0 +1,478 @@
+table ip nat {
+	chain DOCKER {
+	}
+
+	chain PREROUTING {
+		type nat hook prerouting priority dstnat; policy accept;
+		xt match "addrtype" counter packets 2 bytes 1160 jump DOCKER
+	}
+
+	chain OUTPUT {
+		type nat hook output priority dstnat; policy accept;
+		ip daddr != 127.0.0.0/8 xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain POSTROUTING {
+		type nat hook postrouting priority srcnat; policy accept;
+		ip saddr 172.17.0.0/16 oifname != "docker0" counter packets 0 bytes 0 xt target "MASQUERADE"
+	}
+}
+table ip filter {
+	chain DOCKER {
+		iifname != "docker0" oifname "docker0" counter packets 0 bytes 0 drop
+	}
+
+	chain DOCKER-FORWARD {
+		counter packets 0 bytes 0 jump DOCKER-CT
+		counter packets 0 bytes 0 jump DOCKER-INTERNAL
+		counter packets 0 bytes 0 jump DOCKER-BRIDGE
+		iifname "docker0" counter packets 0 bytes 0 accept
+	}
+
+	chain DOCKER-BRIDGE {
+		oifname "docker0" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain DOCKER-CT {
+		oifname "docker0" xt match "conntrack" counter packets 0 bytes 0 accept
+	}
+
+	chain DOCKER-INTERNAL {
+	}
+
+	chain FORWARD {
+		type filter hook forward priority filter; policy drop;
+		counter packets 0 bytes 0 jump DOCKER-USER
+		counter packets 0 bytes 0 jump DOCKER-FORWARD
+		counter packets 0 bytes 0 jump ufw-before-logging-forward
+		counter packets 0 bytes 0 jump ufw-before-forward
+		counter packets 0 bytes 0 jump ufw-after-forward
+		counter packets 0 bytes 0 jump ufw-after-logging-forward
+		counter packets 0 bytes 0 jump ufw-reject-forward
+		counter packets 0 bytes 0 jump ufw-track-forward
+	}
+
+	chain DOCKER-USER {
+	}
+
+	chain ufw-before-logging-input {
+	}
+
+	chain ufw-before-logging-output {
+	}
+
+	chain ufw-before-logging-forward {
+	}
+
+	chain ufw-before-input {
+		iifname "lo" counter packets 0 bytes 0 accept
+		xt match "conntrack" counter packets 0 bytes 0 accept
+		xt match "conntrack" counter packets 0 bytes 0 jump ufw-logging-deny
+		xt match "conntrack" counter packets 0 bytes 0 drop
+		ip protocol icmp xt match "icmp" counter packets 0 bytes 0 accept
+		ip protocol icmp xt match "icmp" counter packets 0 bytes 0 accept
+		ip protocol icmp xt match "icmp" counter packets 0 bytes 0 accept
+		ip protocol icmp xt match "icmp" counter packets 0 bytes 0 accept
+		udp sport 67 udp dport 68 counter packets 0 bytes 0 accept
+		counter packets 0 bytes 0 jump ufw-not-local
+		ip daddr 224.0.0.251 udp dport 5353 counter packets 0 bytes 0 accept
+		ip daddr 239.255.255.250 udp dport 1900 counter packets 0 bytes 0 accept
+		counter packets 0 bytes 0 jump ufw-user-input
+	}
+
+	chain ufw-before-output {
+		oifname "lo" counter packets 0 bytes 0 accept
+		xt match "conntrack" counter packets 0 bytes 0 accept
+		counter packets 0 bytes 0 jump ufw-user-output
+	}
+
+	chain ufw-before-forward {
+		xt match "conntrack" counter packets 0 bytes 0 accept
+		ip protocol icmp xt match "icmp" counter packets 0 bytes 0 accept
+		ip protocol icmp xt match "icmp" counter packets 0 bytes 0 accept
+		ip protocol icmp xt match "icmp" counter packets 0 bytes 0 accept
+		ip protocol icmp xt match "icmp" counter packets 0 bytes 0 accept
+		counter packets 0 bytes 0 jump ufw-user-forward
+	}
+
+	chain ufw-after-input {
+		udp dport 137 counter packets 0 bytes 0 jump ufw-skip-to-policy-input
+		udp dport 138 counter packets 0 bytes 0 jump ufw-skip-to-policy-input
+		tcp dport 139 counter packets 0 bytes 0 jump ufw-skip-to-policy-input
+		tcp dport 445 counter packets 0 bytes 0 jump ufw-skip-to-policy-input
+		udp dport 67 counter packets 0 bytes 0 jump ufw-skip-to-policy-input
+		udp dport 68 counter packets 0 bytes 0 jump ufw-skip-to-policy-input
+		xt match "addrtype" counter packets 0 bytes 0 jump ufw-skip-to-policy-input
+	}
+
+	chain ufw-after-output {
+	}
+
+	chain ufw-after-forward {
+	}
+
+	chain ufw-after-logging-input {
+		limit rate 3/minute burst 10 packets counter packets 0 bytes 0 xt target "LOG"
+	}
+
+	chain ufw-after-logging-output {
+	}
+
+	chain ufw-after-logging-forward {
+		limit rate 3/minute burst 10 packets counter packets 0 bytes 0 xt target "LOG"
+	}
+
+	chain ufw-reject-input {
+	}
+
+	chain ufw-reject-output {
+	}
+
+	chain ufw-reject-forward {
+	}
+
+	chain ufw-track-input {
+	}
+
+	chain ufw-track-output {
+		ip protocol tcp xt match "conntrack" counter packets 0 bytes 0 accept
+		ip protocol udp xt match "conntrack" counter packets 0 bytes 0 accept
+	}
+
+	chain ufw-track-forward {
+	}
+
+	chain INPUT {
+		type filter hook input priority filter; policy drop;
+		counter packets 1 bytes 76 jump ufw-before-logging-input
+		counter packets 1 bytes 76 jump ufw-before-input
+		counter packets 0 bytes 0 jump ufw-after-input
+		counter packets 0 bytes 0 jump ufw-after-logging-input
+		counter packets 0 bytes 0 jump ufw-reject-input
+		counter packets 0 bytes 0 jump ufw-track-input
+	}
+
+	chain OUTPUT {
+		type filter hook output priority filter; policy accept;
+		counter packets 1 bytes 76 jump ufw-before-logging-output
+		counter packets 1 bytes 76 jump ufw-before-output
+		counter packets 1 bytes 76 jump ufw-after-output
+		counter packets 1 bytes 76 jump ufw-after-logging-output
+		counter packets 1 bytes 76 jump ufw-reject-output
+		counter packets 1 bytes 76 jump ufw-track-output
+	}
+
+	chain ufw-logging-deny {
+		xt match "conntrack" limit rate 3/minute burst 10 packets counter packets 0 bytes 0 return
+		limit rate 3/minute burst 10 packets counter packets 0 bytes 0 xt target "LOG"
+	}
+
+	chain ufw-logging-allow {
+		limit rate 3/minute burst 10 packets counter packets 0 bytes 0 xt target "LOG"
+	}
+
+	chain ufw-skip-to-policy-input {
+		counter packets 0 bytes 0 drop
+	}
+
+	chain ufw-skip-to-policy-output {
+		counter packets 0 bytes 0 accept
+	}
+
+	chain ufw-skip-to-policy-forward {
+		counter packets 0 bytes 0 drop
+	}
+
+	chain ufw-not-local {
+		xt match "addrtype" counter packets 0 bytes 0 return
+		xt match "addrtype" counter packets 0 bytes 0 return
+		xt match "addrtype" counter packets 0 bytes 0 return
+		limit rate 3/minute burst 10 packets counter packets 0 bytes 0 jump ufw-logging-deny
+		counter packets 0 bytes 0 drop
+	}
+
+	chain ufw-user-input {
+		tcp dport 22 counter packets 0 bytes 0 accept
+		tcp dport 8080 counter packets 0 bytes 0 accept
+		udp dport 51820 counter packets 0 bytes 0 accept
+	}
+
+	chain ufw-user-output {
+	}
+
+	chain ufw-user-forward {
+		tcp dport 80 counter packets 0 bytes 0 accept
+		iifname "mesh0" tcp dport 443 counter packets 0 bytes 0 accept
+	}
+
+	chain ufw-user-logging-input {
+	}
+
+	chain ufw-user-logging-output {
+	}
+
+	chain ufw-user-logging-forward {
+	}
+
+	chain ufw-user-limit {
+		limit rate 3/minute burst 5 packets counter packets 0 bytes 0 xt target "LOG"
+		counter packets 0 bytes 0 xt target "REJECT"
+	}
+
+	chain ufw-user-limit-accept {
+		counter packets 0 bytes 0 accept
+	}
+}
+table ip6 nat {
+	chain DOCKER {
+	}
+
+	chain PREROUTING {
+		type nat hook prerouting priority dstnat; policy accept;
+		xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+
+	chain OUTPUT {
+		type nat hook output priority dstnat; policy accept;
+		ip6 daddr != ::1 xt match "addrtype" counter packets 0 bytes 0 jump DOCKER
+	}
+}
+table ip6 filter {
+	chain DOCKER {
+	}
+
+	chain DOCKER-FORWARD {
+		counter packets 0 bytes 0 jump DOCKER-CT
+		counter packets 0 bytes 0 jump DOCKER-INTERNAL
+		counter packets 0 bytes 0 jump DOCKER-BRIDGE
+	}
+
+	chain DOCKER-BRIDGE {
+	}
+
+	chain DOCKER-CT {
+	}
+
+	chain DOCKER-INTERNAL {
+	}
+
+	chain FORWARD {
+		type filter hook forward priority filter; policy drop;
+		counter packets 0 bytes 0 jump DOCKER-USER
+		counter packets 0 bytes 0 jump DOCKER-FORWARD
+		counter packets 0 bytes 0 jump ufw6-before-logging-forward
+		counter packets 0 bytes 0 jump ufw6-before-forward
+		counter packets 0 bytes 0 jump ufw6-after-forward
+		counter packets 0 bytes 0 jump ufw6-after-logging-forward
+		counter packets 0 bytes 0 jump ufw6-reject-forward
+		counter packets 0 bytes 0 jump ufw6-track-forward
+	}
+
+	chain DOCKER-USER {
+	}
+
+	chain ufw6-before-logging-input {
+	}
+
+	chain ufw6-before-logging-output {
+	}
+
+	chain ufw6-before-logging-forward {
+	}
+
+	chain ufw6-before-input {
+		iifname "lo" counter packets 0 bytes 0 accept
+		xt match "rt" counter packets 0 bytes 0 drop
+		xt match "conntrack" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		xt match "conntrack" counter packets 0 bytes 0 jump ufw6-logging-deny
+		xt match "conntrack" counter packets 0 bytes 0 drop
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 ip6 daddr fe80::/10 udp sport 547 udp dport 546 counter packets 0 bytes 0 accept
+		ip6 daddr ff02::fb udp dport 5353 counter packets 0 bytes 0 accept
+		ip6 daddr ff02::f udp dport 1900 counter packets 0 bytes 0 accept
+		counter packets 0 bytes 0 jump ufw6-user-input
+	}
+
+	chain ufw6-before-output {
+		oifname "lo" counter packets 0 bytes 0 accept
+		xt match "rt" counter packets 0 bytes 0 drop
+		xt match "conntrack" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		ip6 saddr fe80::/10 meta l4proto ipv6-icmp xt match "icmp6" xt match "hl" counter packets 0 bytes 0 accept
+		counter packets 0 bytes 0 jump ufw6-user-output
+	}
+
+	chain ufw6-before-forward {
+		xt match "rt" counter packets 0 bytes 0 drop
+		xt match "conntrack" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		meta l4proto ipv6-icmp xt match "icmp6" counter packets 0 bytes 0 accept
+		counter packets 0 bytes 0 jump ufw6-user-forward
+	}
+
+	chain ufw6-after-input {
+		udp dport 137 counter packets 0 bytes 0 jump ufw6-skip-to-policy-input
+		udp dport 138 counter packets 0 bytes 0 jump ufw6-skip-to-policy-input
+		tcp dport 139 counter packets 0 bytes 0 jump ufw6-skip-to-policy-input
+		tcp dport 445 counter packets 0 bytes 0 jump ufw6-skip-to-policy-input
+		udp dport 546 counter packets 0 bytes 0 jump ufw6-skip-to-policy-input
+		udp dport 547 counter packets 0 bytes 0 jump ufw6-skip-to-policy-input
+	}
+
+	chain ufw6-after-output {
+	}
+
+	chain ufw6-after-forward {
+	}
+
+	chain ufw6-after-logging-input {
+		limit rate 3/minute burst 10 packets counter packets 0 bytes 0 xt target "LOG"
+	}
+
+	chain ufw6-after-logging-output {
+	}
+
+	chain ufw6-after-logging-forward {
+		limit rate 3/minute burst 10 packets counter packets 0 bytes 0 xt target "LOG"
+	}
+
+	chain ufw6-reject-input {
+	}
+
+	chain ufw6-reject-output {
+	}
+
+	chain ufw6-reject-forward {
+	}
+
+	chain ufw6-track-input {
+	}
+
+	chain ufw6-track-output {
+		meta l4proto tcp xt match "conntrack" counter packets 0 bytes 0 accept
+		meta l4proto udp xt match "conntrack" counter packets 0 bytes 0 accept
+	}
+
+	chain ufw6-track-forward {
+	}
+
+	chain INPUT {
+		type filter hook input priority filter; policy drop;
+		counter packets 1 bytes 128 jump ufw6-before-logging-input
+		counter packets 1 bytes 128 jump ufw6-before-input
+		counter packets 0 bytes 0 jump ufw6-after-input
+		counter packets 0 bytes 0 jump ufw6-after-logging-input
+		counter packets 0 bytes 0 jump ufw6-reject-input
+		counter packets 0 bytes 0 jump ufw6-track-input
+	}
+
+	chain OUTPUT {
+		type filter hook output priority filter; policy accept;
+		counter packets 4 bytes 304 jump ufw6-before-logging-output
+		counter packets 4 bytes 304 jump ufw6-before-output
+		counter packets 0 bytes 0 jump ufw6-after-output
+		counter packets 0 bytes 0 jump ufw6-after-logging-output
+		counter packets 0 bytes 0 jump ufw6-reject-output
+		counter packets 0 bytes 0 jump ufw6-track-output
+	}
+
+	chain ufw6-logging-deny {
+		xt match "conntrack" limit rate 3/minute burst 10 packets counter packets 0 bytes 0 return
+		limit rate 3/minute burst 10 packets counter packets 0 bytes 0 xt target "LOG"
+	}
+
+	chain ufw6-logging-allow {
+		limit rate 3/minute burst 10 packets counter packets 0 bytes 0 xt target "LOG"
+	}
+
+	chain ufw6-skip-to-policy-input {
+		counter packets 0 bytes 0 drop
+	}
+
+	chain ufw6-skip-to-policy-output {
+		counter packets 0 bytes 0 accept
+	}
+
+	chain ufw6-skip-to-policy-forward {
+		counter packets 0 bytes 0 drop
+	}
+
+	chain ufw6-user-input {
+		tcp dport 22 counter packets 0 bytes 0 accept
+		tcp dport 8080 counter packets 0 bytes 0 accept
+		udp dport 51820 counter packets 0 bytes 0 accept
+	}
+
+	chain ufw6-user-output {
+	}
+
+	chain ufw6-user-forward {
+		tcp dport 80 counter packets 0 bytes 0 accept
+		iifname "mesh0" tcp dport 443 counter packets 0 bytes 0 accept
+	}
+
+	chain ufw6-user-logging-input {
+	}
+
+	chain ufw6-user-logging-output {
+	}
+
+	chain ufw6-user-logging-forward {
+	}
+
+	chain ufw6-user-limit {
+		limit rate 3/minute burst 5 packets counter packets 0 bytes 0 xt target "LOG"
+		counter packets 0 bytes 0 xt target "REJECT"
+	}
+
+	chain ufw6-user-limit-accept {
+		counter packets 0 bytes 0 accept
+	}
+}

internal/firewall/testdata/ufw-delete.txt

@@ -0,0 +1,40 @@
+Rule deleted
+Rule deleted (v6)
+rc=0
+Rule deleted
+Rule deleted (v6)
+rc=0
+ERROR: Invalid syntax
+rc=1
+===ADDED2
+Added user rules (see 'ufw status' for running firewall):
+ufw allow 22/tcp
+ufw allow 8080/tcp
+ufw route allow 80/tcp comment 'mesh-host adoption.opening-tcp-8081-forwarded 0badf00d'
+ufw route allow in on mesh0 to any port 443 proto tcp comment 'mesh-host adoption.opening-tcp-8443-forwarded cafe0001'
+ufw allow 51820/udp comment 'mesh-host adoption.opening-udp-51820-incoming 11112222'
+Firewall reloaded
+reload rc=0
+===AFTERRELOAD
+3
+Firewall stopped and disabled on system startup
+===DISABLED
+Status: inactive
+/etc/ufw/user.rules
+3
+Firewall is active and enabled on system startup
+Status: active
+Rule deleted
+Rule deleted (v6)
+rc=0
+Rule deleted
+Rule deleted (v6)
+rc=0
+Could not delete non-existent rule
+Could not delete non-existent rule (v6)
+wrongcomment rc=0
+Added user rules (see 'ufw status' for running firewall):
+ufw allow 22/tcp
+ufw allow 8080/tcp
+ufw allow 51820/udp comment 'mesh-host adoption.opening-udp-51820-incoming 11112222'
+Status: active

internal/firewall/testdata/ufw-show-added.txt

@@ -0,0 +1,8 @@
+Added user rules (see 'ufw status' for running firewall):
+ufw allow 22/tcp
+ufw allow 8080/tcp
+ufw allow 5671/tcp comment 'mesh-host adoption.opening-tcp-5671-incoming 1a2b3c4d'
+ufw allow in on mesh0 to any port 5432 proto tcp comment 'mesh-host adoption.opening-tcp-5432-incoming deadbeef'
+ufw route allow 80/tcp comment 'mesh-host adoption.opening-tcp-8081-forwarded 0badf00d'
+ufw route allow in on mesh0 to any port 443 proto tcp comment 'mesh-host adoption.opening-tcp-8443-forwarded cafe0001'
+ufw allow 51820/udp comment 'mesh-host adoption.opening-udp-51820-incoming 11112222'

internal/firewall/testdata/ufw-status-active.txt

@@ -0,0 +1,21 @@
+Status: active
+
+To                         Action      From
+--                         ------      ----
+22/tcp                     ALLOW       Anywhere                  
+8080/tcp                   ALLOW       Anywhere                  
+5671/tcp                   ALLOW       Anywhere                   # mesh-host adoption.opening-tcp-5671-incoming 1a2b3c4d
+5432/tcp on mesh0          ALLOW       Anywhere                   # mesh-host adoption.opening-tcp-5432-incoming deadbeef
+51820/udp                  ALLOW       Anywhere                   # mesh-host adoption.opening-udp-51820-incoming 11112222
+22/tcp (v6)                ALLOW       Anywhere (v6)             
+8080/tcp (v6)              ALLOW       Anywhere (v6)             
+5671/tcp (v6)              ALLOW       Anywhere (v6)              # mesh-host adoption.opening-tcp-5671-incoming 1a2b3c4d
+5432/tcp (v6) on mesh0     ALLOW       Anywhere (v6)              # mesh-host adoption.opening-tcp-5432-incoming deadbeef
+51820/udp (v6)             ALLOW       Anywhere (v6)              # mesh-host adoption.opening-udp-51820-incoming 11112222
+
+80/tcp                     ALLOW FWD   Anywhere                   # mesh-host adoption.opening-tcp-8081-forwarded 0badf00d
+443/tcp                    ALLOW FWD   Anywhere on mesh0          # mesh-host adoption.opening-tcp-8443-forwarded cafe0001
+80/tcp (v6)                ALLOW FWD   Anywhere (v6)              # mesh-host adoption.opening-tcp-8081-forwarded 0badf00d
+443/tcp (v6)               ALLOW FWD   Anywhere (v6) on mesh0     # mesh-host adoption.opening-tcp-8443-forwarded cafe0001
+
+===STATUSV