Fix "update PTR": add a missing PTR, also in linked views

Ticking update PTR alone did nothing: the web UI didn't send it, and the engine only acted when the name or address changed. Alone it now adds a missing PTR record (or enables it); for linked zones every linked view's reverse zone counts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/engine/expand.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/netip"
+	"slices"
 	"strings"
 	"time"
 
@@ -642,11 +643,42 @@ func (x *expander) ptrCreate(z *model.Zone, owner string, p *rr.Parsed) ([]model
 	if !ok {
 		return nil, errf(KindBadRequest, "ptr only applies to A and AAAA records")
 	}
-	rz, ptrName := reverseZoneFor(x.st, z.ViewID, addr)
-	if rz == nil {
-		x.warnings = append(x.warnings, fmt.Sprintf("no reverse zone for %s in this view, so no PTR record was added", addr))
-		return nil, nil
+	var ops []model.Op
+	found := false
+	for _, vid := range ptrViews(x.st, z) {
+		rz, ptrName := reverseZoneFor(x.st, vid, addr)
+		if rz == nil {
+			continue
+		}
+		found = true
+		more, err := x.ptrCreateIn(rz, ptrName, owner)
+		if err != nil {
+			return nil, err
+		}
+		ops = append(ops, more...)
 	}
+	if !found {
+		x.warnings = append(x.warnings, fmt.Sprintf("no reverse zone for %s in this view, so no PTR record was added (create one: jarl zone create %s/%d)", addr, addr, addr.BitLen()))
+	}
+	return ops, nil
+}
+
+// ptrViews are the views whose reverse zones get the PTR records of zone
+// z's address records: z's own, and, for a linked zone, the other views
+// of the link (the record is in all of them).
+func ptrViews(st *model.State, z *model.Zone) []int64 {
+	out := []int64{z.ViewID}
+	for _, o := range st.LinkedWith(z) {
+		if !slices.Contains(out, o.ViewID) {
+			out = append(out, o.ViewID)
+		}
+	}
+	return out
+}
+
+// ptrCreateIn returns operations creating the PTR record ptrName -> owner
+// in reverse zone rz (none when it is there; enabling it when disabled).
+func (x *expander) ptrCreateIn(rz *model.Zone, ptrName, owner string) ([]model.Op, error) {
 	for _, r := range x.st.ZoneRecords(rz.ID) {
 		if r.Name == ptrName && r.Type == "PTR" {
 			if strings.EqualFold(r.Data, owner) {
@@ -674,10 +706,18 @@ func (x *expander) ptrSetDisabled(z *model.Zone, owner string, p *rr.Parsed, dis
 	if !ok {
 		return nil
 	}
-	rz, ptrName := reverseZoneFor(x.st, z.ViewID, addr)
-	if rz == nil {
-		return nil
+	var ops []model.Op
+	for _, vid := range ptrViews(x.st, z) {
+		rz, ptrName := reverseZoneFor(x.st, vid, addr)
+		if rz == nil {
+			continue
+		}
+		ops = append(ops, x.ptrSetDisabledIn(rz, ptrName, owner, disabled)...)
 	}
+	return ops
+}
+
+func (x *expander) ptrSetDisabledIn(rz *model.Zone, ptrName, owner string, disabled bool) []model.Op {
 	var ops []model.Op
 	for _, r := range x.st.ZoneRecords(rz.ID) {
 		if r.Name == ptrName && r.Type == "PTR" && strings.EqualFold(r.Data, owner) && r.Disabled != disabled {
@@ -700,12 +740,16 @@ func (x *expander) ptrDelete(z *model.Zone, owner string, p *rr.Parsed) []model.
 	if !ok {
 		return nil
 	}
-	rz, ptrName := reverseZoneFor(x.st, z.ViewID, addr)
-	if rz == nil {
-		return nil
+	var ops []model.Op
+	for _, vid := range ptrViews(x.st, z) {
+		rz, ptrName := reverseZoneFor(x.st, vid, addr)
+		if rz == nil {
+			continue
+		}
+		in := RecordInput{ZoneID: rz.ID, Name: model.Ptr(ptrName), Type: model.Ptr("PTR"), Data: model.Ptr(owner), MissingOK: true}
+		ops = append(ops, newOp(OpRecordDelete, 0, 0, in, fmt.Sprintf("delete %s IN PTR %s (if present)", ptrName, owner)))
 	}
-	in := RecordInput{ZoneID: rz.ID, Name: model.Ptr(ptrName), Type: model.Ptr("PTR"), Data: model.Ptr(owner), MissingOK: true}
-	return []model.Op{newOp(OpRecordDelete, 0, 0, in, fmt.Sprintf("delete %s IN PTR %s (if present)", ptrName, owner))}
+	return ops
 }
 
 // parseWarnings keeps what parsing noticed (e.g. a name read as absolute).
@@ -885,7 +929,10 @@ func (x *expander) recordUpdate(req Request) ([]model.Op, error) {
 	if len(pre) > 0 {
 		base = 0 // the record was just updated by pre
 	}
-	ops := append(pre, newOp(OpRecordUpdate, r.ID, base, in, summary))
+	ops := pre
+	if string(mustJSON(in)) != "{}" || !ptr {
+		ops = append(ops, newOp(OpRecordUpdate, r.ID, base, in, summary))
+	}
 	disabled := r.Disabled
 	if in.Disabled != nil {
 		disabled = *in.Disabled
@@ -909,6 +956,15 @@ func (x *expander) recordUpdate(req Request) ([]model.Op, error) {
 		}
 		ops = append(ops, x.ptrSetDisabled(z, owner, p, disabled)...)
 	}
+	if ptr && !moved && !toggled && !disabled {
+		// Nothing else changes: make sure the PTR record is there (the
+		// reverse zone may be newer than the record).
+		more, err := x.ptrCreate(z, owner, p)
+		if err != nil {
+			return nil, err
+		}
+		ops = append(ops, more...)
+	}
 	return ops, nil
 }
 

internal/engine/inputs.go

@@ -174,7 +174,9 @@ type RecordInput struct {
 	// Disabled keeps the record in Jarl but out of the zone.
 	Disabled *bool `json:"disabled,omitempty"`
 	// PTR also creates (or deletes, disables or enables) the matching PTR
-	// record in the reverse zone, for A and AAAA records.
+	// record in the reverse zone, for A and AAAA records. On an update that
+	// changes nothing else it adds the PTR record if it is missing. In a
+	// linked zone, every linked view's reverse zone counts.
 	PTR bool `json:"ptr,omitempty"`
 	// MissingOK makes a delete-by-match succeed when nothing matches.
 	MissingOK bool `json:"missing_ok,omitempty"`

internal/engine/ptr_update_test.go

@@ -0,0 +1,53 @@
+package engine
+
+import (
+	"slices"
+	"strings"
+	"testing"
+
+	"jarl/internal/model"
+)
+
+// Ticking "update PTR" on an unchanged address record adds its PTR when
+// the reverse zone is there (it was created after the record).
+func TestUpdatePTRAddsMissing(t *testing.T) {
+	env := newEnv(t)
+	env.submit(env.admin, NewRequest(OpSettingsUpdate, 0, SettingsInput{Nameservers: &[]string{"ns1.example.net."}}))
+	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com")}))
+	env.submit(env.admin, rec("example.com", "ldn", "A", "139.144.144.154"))
+	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("139.144.144.154/32")}))
+	var id int64
+	for _, r := range env.state().Records {
+		if r.Name == "ldn.example.com." {
+			id = r.ID
+		}
+	}
+	env.submit(env.admin, NewRequest(OpRecordUpdate, id, RecordInput{PTR: true}))
+	got := env.records("154.144.144.139.in-addr.arpa.")
+	if !slices.ContainsFunc(got, func(s string) bool { return strings.Contains(s, "PTR ldn.example.com.") }) {
+		t.Errorf("reverse zone = %q", got)
+	}
+}
+
+// In linked zones the PTR goes to the reverse zone of whichever linked
+// view has one.
+func TestUpdatePTRLinked(t *testing.T) {
+	env := linkedEnv(t)
+	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com"), View: model.Ptr("external"), LinkWith: "internal"}))
+	env.submit(env.admin, recIn("internal", "ldn", "A", "139.144.144.154"))
+	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("139.144.144.154/32"), View: model.Ptr("external")}))
+	res := env.submit(env.admin, NewRequest(OpRecordUpdate, env.recordID("internal", "ldn", "A"), RecordInput{PTR: true}))
+	st := env.state()
+	z := st.FindZone("154.144.144.139.in-addr.arpa.", st.ViewByName("external").ID)
+	ok := false
+	for _, r := range st.ZoneRecords(z.ID) {
+		ok = ok || r.Type == "PTR" && r.Data == "ldn.example.com."
+	}
+	if !ok {
+		t.Errorf("no PTR in external's reverse zone (warnings %q)", res.Warnings)
+	}
+	// Again: already there, nothing to do.
+	if e := env.submitErr(env.admin, NewRequest(OpRecordUpdate, env.recordID("internal", "ldn", "A"), RecordInput{PTR: true})); !strings.Contains(e.Message, "nothing to do") {
+		t.Errorf("second time: %v", e)
+	}
+}

internal/web/static/assets/pages/zone.js

@@ -625,7 +625,7 @@ async function recordsTab(el, zone, query) {
     const eTTL = input({ type: "number", value: r.ttl ?? "", placeholder: "default", style: { width: "90px" } });
     const eData = input({ value: r.type === "TXT" && r.text !== undefined ? r.text : r.data, class: "mono", style: { width: "100%" } });
     const eComment = input({ value: r.comment || "", style: { width: "100%" } });
-    const ePTR = checkbox("update PTR", false);
+    const ePTR = checkbox("update PTR", false, { title: "Keep the PTR record in the reverse zone in step: moved with a new name or address, or added if it is missing" });
     const eErr = h("div");
     const save = async () => {
       const body = {};
@@ -638,7 +638,9 @@ async function recordsTab(el, zone, query) {
       else if (eTTL.value !== "" && Number(eTTL.value) !== r.ttl) body.ttl = Number(eTTL.value);
       if (eComment.value !== (r.comment || "")) body.comment = eComment.value;
       if (ePTR.input.checked) body.ptr = true;
-      if (Object.keys(body).length === 0 || (Object.keys(body).length === 1 && body.ptr)) { editing = null; draw(); return; }
+      // "update PTR" alone adds a missing PTR record (the reverse zone may
+      // be newer than the record).
+      if (Object.keys(body).length === 0) { editing = null; draw(); return; }
       try {
         const res = await change("PATCH", "/records/" + r.id, body);
         toast(describeResult(res));