display the provisioned subnet

index.html

@@ -111,16 +111,12 @@
 			</figure>
 		</details>
 
+		<h2><code>{{ .Api.Root }}</code></h2>
+
 		<div id="control" hx-swap="none">
-			<button hx-get="/api/alloc/32">/32</button>
-			<button hx-get="/api/alloc/31">/31</button>
-			<button hx-get="/api/alloc/30">/30</button>
-			<button hx-get="/api/alloc/29">/29</button>
-			<button hx-get="/api/alloc/28">/28</button>
-			<button hx-get="/api/alloc/27">/27</button>
-			<button hx-get="/api/alloc/26">/26</button>
-			<button hx-get="/api/alloc/25">/25</button>
-			<button hx-get="/api/alloc/24">/24</button>
+			{{- range .Api.AllowedLengths }}
+			<button hx-get="/api/alloc/{{ . }}">/{{ . }}</button>
+			{{- end }}
 		</div>
 
 		{{ block "update" .Update }}<div id="updatemsg" class="card {{ .Type }}" hx-swap-oob="morph">{{ with .Content }}{{ . }}{{ end }}</div>{{ end }}
@@ -154,7 +150,7 @@
 		{{- end }}
 		{{ block "used" .Api }}
 		<div id="state" hx-swap-oob="morph" hx-swap="none">
-			<h2>grouped</h2>
+			<h3>grouped</h3>
 			<div id="used-grouped">
 			{{- range .UsedGrouped }}
 				{{- $first := index . 0 }}
@@ -170,7 +166,7 @@
 			{{ end -}}
 			</div>
 
-			<h2>all</h2>
+			<h3>all</h3>
 			<div id="used">
 				<table>
 					{{- range .Used }}

ipalloc/ipalloc.go

@@ -266,13 +266,21 @@ func (t *tree) Dot() string {
 
 type DB struct {
 	sync.Mutex
-	provisions *tree
+	provisions     *tree
+	allowedLengths []int
 }
 
-func NewDB(prefix string) *DB {
-	return &DB{provisions: &tree{prefix: netip.MustParsePrefix(prefix)}}
+func NewDB(prefix string, allowedLengths ...int) *DB {
+	p := netip.MustParsePrefix(prefix)
+	if canonical := p.Masked(); p.Addr() != canonical.Addr() {
+		log.Fatalf("Prefix %q is not in canonical form, use: %q", p, canonical)
+	}
+	return &DB{provisions: &tree{prefix: p}, allowedLengths: allowedLengths}
 }
 
+func (db *DB) AllowedLengths() []int {
+	return slices.Clip(db.allowedLengths)
+}
 func (db *DB) Used() []netip.Prefix {
 	db.Lock()
 	defer db.Unlock()
@@ -319,6 +327,9 @@ func (db *DB) All() []*tree {
 	})
 	return ret
 }
+func (db *DB) Dot() string {
+	return db.provisions.Dot()
+}
 func (db *DB) Alloc(bits int) (*tree, error) {
 	db.Lock()
 	defer db.Unlock()
@@ -399,7 +410,7 @@ func prefixShape(p netip.Prefix) Rect {
 	return Rect{
 		Y: 0,
 		X: 0,
-		H: 1 << (bits / 2),
+		H: 1 << (bits / 2), // TODO: handle overflow for normal ipv6 subnet sizes :)
 		W: 1 << ((bits + 1) / 2),
 	}
 }

main.go

@@ -4,6 +4,7 @@ import (
 	"embed"
 	"fmt"
 	"html/template"
+	"io"
 	"log"
 	"net/http"
 	"net/netip"
@@ -30,9 +31,13 @@ func (s *server) setup() {
 
 	s.mux.HandleFunc("/api/used/", s.apiUsed)
 	s.mux.HandleFunc("/api/print/", s.apiPrint)
+	s.mux.HandleFunc("/api/treemap.dot", s.apiDot)
 	//s.mux.HandleFunc("/api/provision/", s.apiProvision)
 
-	s.ipdb = ipalloc.NewDB("10.83.46.0/23")
+	s.ipdb = ipalloc.NewDB("10.83.46.0/23", 32, 29, 28, 27, 26)
+	//s.ipdb = ipalloc.NewDB("fd43:5602:29bd:fffe::/64", 128, 127, 126)
+	//s.ipdb = ipalloc.NewDB("fd43:5602:29bd:ffff:ffff:ffff:0:0/96", 128, 127, 126)
+	//s.ipdb = ipalloc.NewDB("fd43:5602:29bd:ffff:ffff:ffff:ffff:0/112", 128)
 	s.tmpl = template.Must(template.ParseFS(webcontent, "index.html"))
 }
 
@@ -59,7 +64,23 @@ type UpdateMessage struct {
 }
 
 func (s *server) template(w http.ResponseWriter, r *http.Request) {
-	err := s.tmpl.Execute(w, PageContent{Api: s.ipdb, Treemap: s.ipdb.Treemap()})
+	err := s.tmpl.Execute(w,
+		PageContent{
+			Api: s.ipdb,
+			Update: UpdateMessage{
+				Type:    "hint",
+				Content: template.HTML(" "),
+			},
+			Treemap: s.ipdb.Treemap(),
+		},
+	)
+
+	if err != nil {
+		log.Println(err)
+	}
+}
+func (s *server) apiDot(w http.ResponseWriter, r *http.Request) {
+	_, err := io.WriteString(w, s.ipdb.Dot())
 	if err != nil {
 		log.Println(err)
 	}