Reverse zones: other views' addresses aren't missing PTRs

A reverse zone's missing PTR count covers only its own view's A and
AAAA records. Addresses only other views' records use are counted apart
(ptr_other_views, 'Other views' in zone show, a note on the zone page)
and filled only when asked: fill-ptr --other-views, zone create
--fill --other-views, or the New reverse zone dialog's checkbox. This
keeps one view's host names out of another view's reverse zones.

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

internal/api/types.go

@@ -48,6 +48,10 @@ type Zone struct {
 	// PTRMissingList are the first 25 of them: the PTR records adding
 	// them would create.
 	PTRMissingList []PTRFill `json:"ptr_missing_list,omitempty"`
+	// PTROtherViews counts the addresses in it, without a PTR record,
+	// that only other views' records use: not missing, but fill-ptr with
+	// other_views=1 can name them from there.
+	PTROtherViews int `json:"ptr_other_views,omitempty"`
 	// Pending is set when listing with a changeset: add, change or delete.
 	Pending string `json:"pending,omitempty"`
 }

internal/engine/expand.go

@@ -471,8 +471,8 @@ func (x *expander) zoneCreate(req Request) ([]model.Op, error) {
 			}
 		}
 	}
-	fill := in.Fill
-	in.Fill = false
+	fill, fillOther := in.Fill, in.FillOtherViews
+	in.Fill, in.FillOtherViews = false, false
 	if fill {
 		if zt != model.ZonePrimary {
 			return nil, errf(KindBadRequest, "fill only applies to primary zones")
@@ -484,10 +484,15 @@ func (x *expander) zoneCreate(req Request) ([]model.Op, error) {
 		if in.ViewID != nil {
 			vid = *in.ViewID
 		}
-		fills := PTRFills(x.st, vid, name, moved)
+		fills := PTRFills(x.st, vid, name, moved, fillOther)
 		if len(fills) == 0 {
 			x.warnings = append(x.warnings, fmt.Sprintf("no A or AAAA record of %s has an address in %s, so there was nothing to fill it with", viewOrServer(x.st, vid), dnsname.Display(name)))
 		}
+		if !fillOther {
+			if h := otherViewsHint(x.st, vid, name, moved, len(fills), "to name them from there, fill it with other views (jarl zone fill-ptr ZONE --other-views)"); h != "" {
+				x.warnings = append(x.warnings, h)
+			}
+		}
 		x.warnings = append(x.warnings, fillWarnings(fills)...)
 		for _, f := range fills {
 			in.Records = append(in.Records, RecordInput{Name: model.Ptr(f.Name), Type: model.Ptr("PTR"), Data: model.Ptr(f.Target)})

internal/engine/inputs.go

@@ -163,8 +163,11 @@ type ZoneInput struct {
 	// step (docs/reverse.md).
 	AutoPTR *bool `json:"auto_ptr,omitempty"`
 	// Fill (create only, reverse zones) adds a PTR record for every
-	// address of the view's A and AAAA records in the zone's range.
-	Fill bool `json:"fill,omitempty"`
+	// address of the view's A and AAAA records in the zone's range;
+	// FillOtherViews also for the addresses only other views' records
+	// use, named from there.
+	Fill           bool `json:"fill,omitempty"`
+	FillOtherViews bool `json:"fill_other_views,omitempty"`
 
 	// Create only: name servers for the apex NS records (default: the
 	// configured default name servers), additional records, and a zone to
@@ -224,6 +227,13 @@ type LinkInput struct {
 	With []string `json:"with,omitempty"`
 }
 
+// FillPTRInput is zone.fill_ptr: OtherViews also fills the addresses only
+// other views' records use, naming them from there.
+type FillPTRInput struct {
+	ZoneID     int64 `json:"zone_id,omitempty"`
+	OtherViews bool  `json:"other_views,omitempty"`
+}
+
 // RRSetInput replaces all records of one name and type.
 type RRSetInput struct {
 	ZoneID  int64             `json:"zone_id,omitempty"`

internal/engine/reverse.go

@@ -87,11 +87,12 @@ type PTRFill struct {
 // PTRFills returns the PTR records a reverse zone named zoneName in a view
 // lacks for the addresses of the view's A and AAAA records: one per
 // address, naming its mail or name server host when it is one, otherwise
-// a host rather than the domain itself, then the shortest name. An
-// address no record of the view uses is named from another view's
-// records (fillAddresses), marked From. existing are the zone's records
-// (none for a new zone).
-func PTRFills(st *model.State, viewID int64, zoneName string, existing []*model.Record) []PTRFill {
+// a host rather than the domain itself, then the shortest name. With
+// otherViews, an address no record of the view uses is named from another
+// view's records (fillAddresses), marked From; that is only on request,
+// since it publishes one view's host names in another. existing are the
+// zone's records (none for a new zone).
+func PTRFills(st *model.State, viewID int64, zoneName string, existing []*model.Record, otherViews bool) []PTRFill {
 	prefix, ok := dnsname.PrefixFromReverse(zoneName)
 	if !ok {
 		return nil
@@ -105,7 +106,11 @@ func PTRFills(st *model.State, viewID int64, zoneName string, existing []*model.
 	servers := serverNames(st, viewID)
 	byAddr := map[netip.Addr][]addrUse{}
 	var order []netip.Addr
-	for _, u := range fillAddresses(st, viewID) {
+	addrs := forwardAddresses(st, viewID)
+	if otherViews {
+		addrs = fillAddresses(st, viewID)
+	}
+	for _, u := range addrs {
 		if !prefix.Contains(u.addr) {
 			continue
 		}
@@ -195,9 +200,23 @@ func displayAll(names []string) []string {
 	return out
 }
 
+// otherViewsHint says how many addresses only other views' records use in
+// a reverse zone, and how to add them; "" when there are none.
+func otherViewsHint(st *model.State, viewID int64, zoneName string, existing []*model.Record, own int, how string) string {
+	n := len(PTRFills(st, viewID, zoneName, existing, true)) - own
+	if n <= 0 {
+		return ""
+	}
+	what := "addresses"
+	if n == 1 {
+		what = "address"
+	}
+	return fmt.Sprintf("%d %s in %s only other views' records use; %s", n, what, dnsname.Display(zoneName), how)
+}
+
 // zoneFillPTR expands zone.fill_ptr: the PTR records a reverse zone lacks.
 func (x *expander) zoneFillPTR(req Request) ([]model.Op, error) {
-	var in LinkInput
+	var in FillPTRInput
 	if err := decode(req.Data, &in); err != nil {
 		return nil, err
 	}
@@ -215,9 +234,15 @@ func (x *expander) zoneFillPTR(req Request) ([]model.Op, error) {
 	if _, ok := dnsname.PrefixFromReverse(z.Name); !ok {
 		return nil, errf(KindBadRequest, "zone %s isn't a reverse zone of whole octets or nibbles (like 10.0.10.in-addr.arpa)", zoneDesc(x.st, z))
 	}
-	fills := PTRFills(x.st, z.ViewID, z.Name, x.st.ZoneRecords(z.ID))
+	fills := PTRFills(x.st, z.ViewID, z.Name, x.st.ZoneRecords(z.ID), in.OtherViews)
 	if len(fills) == 0 {
-		return nil, errf(KindBadRequest, "nothing to add: every address of %s's A and AAAA records in %s has a PTR record", viewOrServer(x.st, z.ViewID), zoneDesc(x.st, z))
+		msg := fmt.Sprintf("nothing to add: every address of %s's A and AAAA records in %s has a PTR record", viewOrServer(x.st, z.ViewID), zoneDesc(x.st, z))
+		if !in.OtherViews {
+			if h := otherViewsHint(x.st, z.ViewID, z.Name, x.st.ZoneRecords(z.ID), 0, "to name them from there, fill with other views (--other-views)"); h != "" {
+				msg += "; " + h
+			}
+		}
+		return nil, errf(KindBadRequest, "%s", msg)
 	}
 	x.warnings = append(x.warnings, fillWarnings(fills)...)
 	ids, err := x.ids(len(fills))
@@ -415,7 +440,7 @@ func ReverseCandidates(st *model.State, exposures []validate.Exposure, local []n
 				continue
 			}
 			s := ReverseSuggestion{ViewID: sc.id, View: viewName(st, sc.id), Prefix: p.String(), Zone: strings.TrimSuffix(name, "."), Group: group, Hidden: hidden, Why: why, Samples: []string{}}
-			fills := PTRFills(st, sc.id, name, nil)
+			fills := PTRFills(st, sc.id, name, nil, opt.All && opt.View != "")
 			s.Fill = len(fills)
 			for i, f := range fills {
 				if i == 3 {

internal/engine/reverse_test.go

@@ -69,11 +69,11 @@ func TestReverseFillAndSuggest(t *testing.T) {
 	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("fdab:abab:abab::/48")}))
 	st := env.state()
 	z6 := st.FindZone("b.a.b.a.b.a.b.a.b.a.d.f.ip6.arpa.", st.ViewByName("internal").ID)
-	env.submit(env.admin, NewRequest(OpZoneFillPTR, z6.ID, LinkInput{}))
+	env.submit(env.admin, NewRequest(OpZoneFillPTR, z6.ID, FillPTRInput{}))
 	if p := env.ptrs("internal", z6.Name); len(p) != 1 || !strings.HasSuffix(p[0], " nas.example.com.") {
 		t.Errorf("ip6 fill: %q", p)
 	}
-	if e := env.submitErr(env.admin, NewRequest(OpZoneFillPTR, z6.ID, LinkInput{})); !strings.Contains(e.Message, "nothing to add") {
+	if e := env.submitErr(env.admin, NewRequest(OpZoneFillPTR, z6.ID, FillPTRInput{})); !strings.Contains(e.Message, "nothing to add") {
 		t.Errorf("second fill: %v", e)
 	}
 
@@ -288,15 +288,38 @@ func TestReverseFromOtherView(t *testing.T) {
 			t.Errorf("suggested unasked: %+v", s)
 		}
 	}
-	res := env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("2600:3c01::f03c:93ff:fe2b:1/128"), View: model.Ptr("internal"), Fill: true}))
-	st := env.state()
-	var zone string
-	for _, z := range st.ZonesInView(st.ViewByName("internal").ID) {
-		if strings.HasSuffix(z.Name, ".ip6.arpa.") {
-			zone = z.Name
+	for _, s := range ReverseCandidates(env.state(), env.e.Exposures(env.state()), nil, ReverseOptions{All: true, View: "internal"}) {
+		if strings.HasPrefix(s.Prefix, "2600:") && (s.Fill != 1 || len(s.Samples) != 1) {
+			t.Errorf("candidate counts the other view's address: %+v", s)
 		}
 	}
-	if p := env.ptrs("internal", zone); len(p) != 1 || !strings.HasSuffix(p[0], " vps.example.com.") {
+	// Filling doesn't take names from other views unasked: it would
+	// publish one view's host names in another. It says how to.
+	res := env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("2600:3c01::f03c:93ff:fe2b:1/128"), View: model.Ptr("internal"), Fill: true}))
+	st := env.state()
+	var z *model.Zone
+	for _, o := range st.ZonesInView(st.ViewByName("internal").ID) {
+		if strings.HasSuffix(o.Name, ".ip6.arpa.") {
+			z = o
+		}
+	}
+	if p := env.ptrs("internal", z.Name); len(p) != 0 {
+		t.Errorf("filled from another view unasked: %q", p)
+	}
+	if !slices.ContainsFunc(res.Warnings, func(w string) bool {
+		return strings.Contains(w, "1 address in") && strings.Contains(w, "--other-views")
+	}) {
+		t.Errorf("warnings %q", res.Warnings)
+	}
+	// Not missing: no record of the zone's own view uses the address.
+	if f := PTRFills(st, z.ViewID, z.Name, st.ZoneRecords(z.ID), false); len(f) != 0 {
+		t.Errorf("missing %+v", f)
+	}
+	if e := env.submitErr(env.admin, NewRequest(OpZoneFillPTR, z.ID, FillPTRInput{})); !strings.Contains(e.Message, "nothing to add") || !strings.Contains(e.Message, "--other-views") {
+		t.Errorf("fill-ptr: %v", e)
+	}
+	res = env.submit(env.admin, NewRequest(OpZoneFillPTR, z.ID, FillPTRInput{OtherViews: true}))
+	if p := env.ptrs("internal", z.Name); len(p) != 1 || !strings.HasSuffix(p[0], " vps.example.com.") {
 		t.Errorf("filled %q", p)
 	}
 	if !slices.ContainsFunc(res.Warnings, func(w string) bool { return strings.Contains(w, "only view external has a record for it") }) {

internal/server/dsat_test.go

@@ -93,3 +93,27 @@ func TestPTRMissingList(t *testing.T) {
 		t.Errorf("ptr_missing %v, list %v", z["ptr_missing"], z["ptr_missing_list"])
 	}
 }
+
+// An address only another view's records use isn't missing from a
+// reverse zone: it is counted apart, and filled only when asked.
+func TestPTROtherViews(t *testing.T) {
+	e := newAPIEnv(t)
+	e.do("POST", "/views", e.token, map[string]any{"name": "internal", "match_clients": []string{"10.0.0.0/8"}}, 201)
+	e.do("POST", "/views", e.token, map[string]any{"name": "vps"}, 201)
+	e.do("POST", "/zones", e.token, map[string]any{"name": "adbraun.lol", "view": "internal", "nameservers": []string{"ns1.example.net."},
+		"records": []map[string]any{{"name": "claude", "type": "A", "data": "10.0.10.101"}}}, 201)
+	for _, v := range []string{"internal", "vps"} {
+		e.do("POST", "/zones", e.token, map[string]any{"name": "10.0.10.0/24", "view": v, "nameservers": []string{"ns1.example.net."}}, 201)
+	}
+	if z := e.do("GET", "/zones/10.0.10.in-addr.arpa?view=internal", e.token, nil, 200); z["ptr_missing"] != float64(1) || z["ptr_other_views"] != nil {
+		t.Errorf("internal: ptr_missing %v, ptr_other_views %v", z["ptr_missing"], z["ptr_other_views"])
+	}
+	if z := e.do("GET", "/zones/10.0.10.in-addr.arpa?view=vps", e.token, nil, 200); z["ptr_missing"] != nil || z["ptr_other_views"] != float64(1) {
+		t.Errorf("vps: ptr_missing %v, ptr_other_views %v", z["ptr_missing"], z["ptr_other_views"])
+	}
+	e.do("POST", "/zones/10.0.10.in-addr.arpa/fill-ptr?view=vps", e.token, nil, 400)
+	e.do("POST", "/zones/10.0.10.in-addr.arpa/fill-ptr?view=vps&other_views=1", e.token, nil, 201)
+	if z := e.do("GET", "/zones/10.0.10.in-addr.arpa?view=vps", e.token, nil, 200); z["ptr_other_views"] != nil {
+		t.Errorf("vps after filling: ptr_other_views %v", z["ptr_other_views"])
+	}
+}

internal/server/h_reverse.go

@@ -8,7 +8,8 @@ import (
 )
 
 // zoneFillPTR: POST /zones/{zone}/fill-ptr adds the PTR records a reverse
-// zone lacks for its view's A and AAAA records (docs/reverse.md).
+// zone lacks for its view's A and AAAA records; ?other_views=1 also for
+// the addresses only other views' records use (docs/reverse.md).
 func (s *Server) zoneFillPTR(w http.ResponseWriter, r *http.Request, p *auth.Principal) error {
 	st, err := s.state(r)
 	if err != nil {
@@ -18,7 +19,7 @@ func (s *Server) zoneFillPTR(w http.ResponseWriter, r *http.Request, p *auth.Pri
 	if err != nil {
 		return err
 	}
-	return s.mutate(w, r, p, "", []engine.Request{engine.NewRequest(engine.OpZoneFillPTR, z.ID, engine.LinkInput{ZoneID: z.ID})}, nil)
+	return s.mutate(w, r, p, "", []engine.Request{engine.NewRequest(engine.OpZoneFillPTR, z.ID, engine.FillPTRInput{ZoneID: z.ID, OtherViews: queryBool(r, "other_views")})}, nil)
 }
 
 // reverseSuggestions: GET /reverse-zones/suggestions lists the reverse

internal/server/present.go

@@ -41,8 +41,11 @@ func (s *Server) presentZone(st *model.State, z *model.Zone, counts map[int64]re
 	if pf, ok := dnsname.PrefixFromReverse(z.Name); ok {
 		out.Prefix = pf.String()
 		if z.Type == model.ZonePrimary {
-			fills := engine.PTRFills(st, z.ViewID, z.Name, st.ZoneRecords(z.ID))
+			fills := engine.PTRFills(st, z.ViewID, z.Name, st.ZoneRecords(z.ID), false)
 			out.PTRMissing = len(fills)
+			if z.ViewID != 0 {
+				out.PTROtherViews = len(engine.PTRFills(st, z.ViewID, z.Name, st.ZoneRecords(z.ID), true)) - len(fills)
+			}
 			for _, f := range fills[:min(len(fills), 25)] {
 				out.PTRMissingList = append(out.PTRMissingList, api.PTRFill(f))
 			}

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

@@ -72,7 +72,10 @@ export async function render(el, params, query) {
         h("span", { class: "mono" }, f.address), " → ", h("span", { class: "mono" }, display(f.target)),
         f.from ? h("span", { class: "muted" }, " (from view " + f.from + ")") : null,
         f.others && f.others.length ? h("span", { class: "muted" }, " (also " + f.others.map(display).join(", ") + ")") : null)),
-        zone.ptr_missing > (zone.ptr_missing_list || []).length ? h("li", { class: "muted" }, "and " + (zone.ptr_missing - zone.ptr_missing_list.length) + " more") : null)) : null;
+        zone.ptr_missing > (zone.ptr_missing_list || []).length ? h("li", { class: "muted" }, "and " + (zone.ptr_missing - zone.ptr_missing_list.length) + " more") : null))
+    : zone.ptr_other_views && can("zones", true) ? h("div", { class: "muted small" },
+      plural(zone.ptr_other_views, "address", "addresses") + " in " + zone.prefix + " only other views' records use, without a PTR record here. ",
+      h("button", { class: "small", title: "Adds PTR records naming them from the other views' records, publishing those names in view " + zone.view, onclick: () => fillPTR(zone, true) }, "Name them from there")) : null;
   const tabBar = h("div", { class: "tabs" }, tabs.map(([k, label]) => h("a", { href: "#/zones/" + id + "/" + k, class: k === tab ? "active" : "" }, label)));
   // The header and tabs show at once. Below them, switching tabs keeps the
   // previous tab's content (faded) until the new one is loaded, rather
@@ -951,9 +954,9 @@ async function toggleZone(zone) {
 }
 
 // fillPTR adds the PTR records a reverse zone lacks (docs/reverse.md).
-async function fillPTR(zone) {
+async function fillPTR(zone, otherViews) {
   try {
-    const r = await change("POST", "/zones/" + zone.id + "/fill-ptr");
+    const r = await change("POST", "/zones/" + zone.id + "/fill-ptr", undefined, otherViews ? { query: { other_views: "1" } } : {});
     toast(describeResult(r));
     (r.warnings || []).forEach((w) => toast(w, "warn", 10000));
     rerender();

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

@@ -103,7 +103,10 @@ export async function newZoneDialog(views, zones, settings, preset = {}) {
   cloneSel.addEventListener("change", syncLink);
   const comment = input();
   const fill = checkbox("Add a PTR record for each address the view's A and AAAA records use in this network", true);
-  const fillRow = field("PTR records", fill, "Names already in your zones, so the reverse zone answers from the start. Leave it off to add them yourself.");
+  // Off unless asked (or a network only other views use is picked): it
+  // publishes one view's host names in another.
+  const fillOther = checkbox("Also for addresses only other views' records use, named from there", false);
+  const fillRow = field("PTR records", h("div", null, fill, views.length ? fillOther : null), "Names already in your zones, so the reverse zone answers from the start. Leave it off to add them yourself.");
   const updateClones = () => {
     // Records can only be copied into a single zone.
     const n = (kind === "reverse" ? reverseZoneFor(name.value).name || "-" : name.value.trim().toLowerCase().replace(/\.$/, "")) + ".";
@@ -206,6 +209,7 @@ export async function newZoneDialog(views, zones, settings, preset = {}) {
           name.value = c.prefix;
           sizeFrom = c.samples.length ? c.samples[0].split(" ")[0] : null;
           if (views.length && c.view) view.value = c.view;
+          if ((c.hidden || "").startsWith("records in ")) { fill.input.checked = true; fillOther.input.checked = true; }
           changed();
         } },
           h("span", { class: "mono" }, c.prefix),
@@ -273,7 +277,10 @@ export async function newZoneDialog(views, zones, settings, preset = {}) {
       if (view.value) data.view = view.value;
       const opts = [];
       const list = (ta) => lines(ta.value).map((l) => l.replace(/;$/, "") + ";").join(" ");
-      if (t === "primary" && kind === "reverse" && fill.input.checked) data.fill = true;
+      if (t === "primary" && kind === "reverse" && fill.input.checked) {
+        data.fill = true;
+        if (fillOther.input.checked) data.fill_other_views = true;
+      }
       if (t === "primary") {
         data.nameservers = lines(ns.value);
         if (contact.value.trim()) data.soa = { rname: contact.value.trim() };