ci: validate ASN sync changes on push

.github/workflows/sync-asn-metadata.yml

@@ -0,0 +1,51 @@
+name: Sync ASN metadata
+
+on:
+  schedule:
+    - cron: "29 3 * * *"
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+    paths:
+      - ".github/workflows/sync-asn-metadata.yml"
+      - "cmd/update-asn-metadata/**"
+      - "bgptools/data/**"
+      - "bgptools/asn_metadata.go"
+      - "bgptools/asn_metadata_test.go"
+      - "model/model.go"
+      - "go.mod"
+      - "go.sum"
+
+concurrency:
+  group: backtrace-asn-metadata-sync
+  cancel-in-progress: false
+
+permissions:
+  contents: write
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: actions/setup-go@v7
+        with:
+          go-version-file: go.mod
+          cache: true
+      - name: Update snapshot
+        run: go run ./cmd/update-asn-metadata
+      - name: Validate updater and runtime loader
+        run: go test -race ./cmd/update-asn-metadata ./bgptools
+      - name: Vet updater and runtime loader
+        run: go vet ./cmd/update-asn-metadata ./bgptools
+      - name: Commit semantic changes
+        run: |
+          if git diff --quiet -- bgptools/data/bgp-asn-map.json bgptools/data/bgp-asn-map.manifest.json; then
+            exit 0
+          fi
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git add bgptools/data/bgp-asn-map.json bgptools/data/bgp-asn-map.manifest.json
+          git commit -m "chore(data): update ASN metadata"
+          git push

bgptools/asn_metadata.go

@@ -0,0 +1,226 @@
+package bgptools
+
+import (
+	"context"
+	"crypto/sha256"
+	_ "embed"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const (
+	ASNMetadataSchema         = "backtrace.asn-metadata/v1"
+	ASNMetadataManifestSchema = "backtrace.asn-metadata-manifest/v1"
+	ASNMetadataMinimum        = 50
+)
+
+var asnMetadataSnapshotURLs = []string{
+	"https://cdn.spiritlhl.net/https://raw.githubusercontent.com/oneclickvirt/backtrace/main/bgptools/data/bgp-asn-map.json",
+	"https://raw.githubusercontent.com/oneclickvirt/backtrace/main/bgptools/data/bgp-asn-map.json",
+}
+
+//go:embed data/bgp-asn-map.json
+var embeddedASNMetadata []byte
+
+//go:embed data/bgp-asn-map.manifest.json
+var embeddedASNMetadataManifest []byte
+
+type ASNMetadata struct {
+	ASN  uint32 `json:"asn"`
+	Name string `json:"name"`
+}
+
+type ASNMetadataSource struct {
+	Schema      string    `json:"schema"`
+	Count       int       `json:"count"`
+	GeneratedAt time.Time `json:"generated_at,omitempty"`
+	Source      string    `json:"source"`
+	Fallback    bool      `json:"fallback"`
+}
+
+type asnMetadataDocument struct {
+	Schema      string        `json:"schema"`
+	GeneratedAt time.Time     `json:"generated_at"`
+	Entries     []ASNMetadata `json:"entries"`
+}
+
+type asnMetadataManifest struct {
+	Schema      string    `json:"schema"`
+	File        string    `json:"file"`
+	Count       int       `json:"count"`
+	SHA256      string    `json:"sha256"`
+	GeneratedAt time.Time `json:"generated_at"`
+}
+
+// LoadASNMetadata prefers the component's validated remote snapshot and
+// falls back to the compile-time snapshot. Upstream registry URLs and parsing
+// rules are intentionally not exposed to callers.
+func LoadASNMetadata(ctx context.Context, client *http.Client) ([]ASNMetadata, ASNMetadataSource, error) {
+	return loadASNMetadata(ctx, client, asnMetadataSnapshotURLs, embeddedASNMetadata, embeddedASNMetadataManifest, ASNMetadataMinimum)
+}
+
+// EmbeddedASNMetadata returns the validated compile-time snapshot without
+// performing network access.
+func EmbeddedASNMetadata() ([]ASNMetadata, ASNMetadataSource, error) {
+	entries, generatedAt, err := parseASNMetadataDocument(embeddedASNMetadata, ASNMetadataMinimum)
+	if err != nil {
+		return nil, ASNMetadataSource{}, err
+	}
+	if err := validateASNMetadataManifest(embeddedASNMetadataManifest, embeddedASNMetadata, len(entries), generatedAt); err != nil {
+		return nil, ASNMetadataSource{}, fmt.Errorf("validate embedded ASN metadata manifest: %w", err)
+	}
+	return entries, ASNMetadataSource{Schema: ASNMetadataSchema, Count: len(entries), GeneratedAt: generatedAt, Source: "embedded", Fallback: true}, nil
+}
+
+// LookupASNMetadata resolves one ASN from the current component registry.
+func LookupASNMetadata(ctx context.Context, client *http.Client, asn string) (ASNMetadata, ASNMetadataSource, bool, error) {
+	normalized, err := normalizeASN(asn)
+	if err != nil {
+		return ASNMetadata{}, ASNMetadataSource{}, false, err
+	}
+	number, _ := strconv.ParseUint(normalized, 10, 32)
+	entries, source, err := LoadASNMetadata(ctx, client)
+	if err != nil {
+		return ASNMetadata{}, ASNMetadataSource{}, false, err
+	}
+	index := sort.Search(len(entries), func(index int) bool { return entries[index].ASN >= uint32(number) })
+	if index >= len(entries) || entries[index].ASN != uint32(number) {
+		return ASNMetadata{}, source, false, nil
+	}
+	return entries[index], source, true, nil
+}
+
+func loadASNMetadata(ctx context.Context, client *http.Client, urls []string, embedded, embeddedManifest []byte, minimum int) ([]ASNMetadata, ASNMetadataSource, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	embeddedEntries, embeddedAt, err := parseASNMetadataDocument(embedded, minimum)
+	if err != nil {
+		return nil, ASNMetadataSource{}, fmt.Errorf("invalid embedded ASN metadata: %w", err)
+	}
+	if err := validateASNMetadataManifest(embeddedManifest, embedded, len(embeddedEntries), embeddedAt); err != nil {
+		return nil, ASNMetadataSource{}, fmt.Errorf("invalid embedded ASN metadata manifest: %w", err)
+	}
+	if client == nil {
+		client = &http.Client{Timeout: 6 * time.Second}
+	}
+	minimumRemote := max(minimum, len(embeddedEntries)*65/100)
+	for index, snapshotURL := range urls {
+		manifest, fetchErr := fetchASNMetadata(ctx, client, asnMetadataManifestURL(snapshotURL))
+		if fetchErr != nil {
+			continue
+		}
+		data, fetchErr := fetchASNMetadata(ctx, client, snapshotURL)
+		if fetchErr != nil {
+			continue
+		}
+		entries, generatedAt, parseErr := parseASNMetadataDocument(data, minimumRemote)
+		if parseErr == nil && validateASNMetadataManifest(manifest, data, len(entries), generatedAt) == nil {
+			return entries, ASNMetadataSource{Schema: ASNMetadataSchema, Count: len(entries), GeneratedAt: generatedAt, Source: metadataRemoteSource(index), Fallback: index > 0}, nil
+		}
+	}
+	return embeddedEntries, ASNMetadataSource{Schema: ASNMetadataSchema, Count: len(embeddedEntries), GeneratedAt: embeddedAt, Source: "embedded", Fallback: true}, nil
+}
+
+func metadataRemoteSource(index int) string {
+	if index == 0 {
+		return "cdn"
+	}
+	if index == 1 {
+		return "raw"
+	}
+	return "remote"
+}
+
+func asnMetadataManifestURL(snapshotURL string) string {
+	return strings.TrimSuffix(snapshotURL, ".json") + ".manifest.json"
+}
+
+func validateASNMetadataManifest(data, snapshot []byte, count int, generatedAt time.Time) error {
+	var manifest asnMetadataManifest
+	decoder := json.NewDecoder(strings.NewReader(string(data)))
+	decoder.DisallowUnknownFields()
+	if err := decoder.Decode(&manifest); err != nil {
+		return fmt.Errorf("decode manifest: %w", err)
+	}
+	var extra any
+	if err := decoder.Decode(&extra); err != io.EOF {
+		return errors.New("manifest contains trailing JSON")
+	}
+	if manifest.Schema != ASNMetadataManifestSchema || manifest.File != "bgp-asn-map.json" || manifest.Count != count || manifest.GeneratedAt.IsZero() || !manifest.GeneratedAt.Equal(generatedAt) {
+		return errors.New("manifest schema, file, count, or generated_at is invalid")
+	}
+	hash := sha256.Sum256(snapshot)
+	if !strings.EqualFold(manifest.SHA256, hex.EncodeToString(hash[:])) {
+		return errors.New("manifest SHA-256 does not match snapshot")
+	}
+	return nil
+}
+
+func fetchASNMetadata(ctx context.Context, client *http.Client, snapshotURL string) ([]byte, error) {
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, snapshotURL, nil)
+	if err != nil {
+		return nil, err
+	}
+	request.Header.Set("Accept", "application/json")
+	request.Header.Set("User-Agent", "oneclickvirt-backtrace-asn-metadata/1")
+	response, err := client.Do(request)
+	if err != nil {
+		return nil, err
+	}
+	defer response.Body.Close()
+	if response.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("HTTP %d", response.StatusCode)
+	}
+	const maximumSize = 4 << 20
+	data, err := io.ReadAll(io.LimitReader(response.Body, maximumSize+1))
+	if err != nil {
+		return nil, err
+	}
+	if len(data) > maximumSize {
+		return nil, fmt.Errorf("ASN metadata exceeds %d bytes", maximumSize)
+	}
+	return data, nil
+}
+
+func parseASNMetadataDocument(data []byte, minimum int) ([]ASNMetadata, time.Time, error) {
+	var document asnMetadataDocument
+	decoder := json.NewDecoder(strings.NewReader(string(data)))
+	decoder.DisallowUnknownFields()
+	if err := decoder.Decode(&document); err != nil {
+		return nil, time.Time{}, err
+	}
+	var extra any
+	if err := decoder.Decode(&extra); err != io.EOF {
+		return nil, time.Time{}, errors.New("ASN metadata contains trailing JSON")
+	}
+	if document.Schema != ASNMetadataSchema || document.GeneratedAt.IsZero() {
+		return nil, time.Time{}, errors.New("ASN metadata schema or generated_at is invalid")
+	}
+	seen := make(map[uint32]struct{}, len(document.Entries))
+	entries := make([]ASNMetadata, 0, len(document.Entries))
+	for _, entry := range document.Entries {
+		entry.Name = strings.TrimSpace(entry.Name)
+		if entry.ASN == 0 || entry.Name == "" {
+			return nil, time.Time{}, errors.New("ASN metadata contains an invalid entry")
+		}
+		if _, exists := seen[entry.ASN]; exists {
+			return nil, time.Time{}, fmt.Errorf("ASN metadata contains duplicate AS%d", entry.ASN)
+		}
+		seen[entry.ASN] = struct{}{}
+		entries = append(entries, entry)
+	}
+	if len(entries) < minimum {
+		return nil, time.Time{}, fmt.Errorf("ASN metadata count %d is below minimum %d", len(entries), minimum)
+	}
+	sort.Slice(entries, func(i, j int) bool { return entries[i].ASN < entries[j].ASN })
+	return entries, document.GeneratedAt, nil
+}

bgptools/asn_metadata_test.go

@@ -0,0 +1,83 @@
+package bgptools
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestLoadASNMetadataPrefersValidatedRemote(t *testing.T) {
+	payload := `{"schema":"backtrace.asn-metadata/v1","generated_at":"2026-07-20T00:00:00Z","entries":[{"asn":2,"name":"Two"},{"asn":1,"name":"One"}]}`
+	manifest := manifestFor([]byte(payload), "bgp-asn-map.json", 2)
+	if err := validateASNMetadataManifest(manifest, []byte(payload), 2, time.Date(2026, 7, 20, 0, 0, 0, 0, time.UTC)); err != nil {
+		t.Fatal(err)
+	}
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, request *http.Request) {
+		if strings.HasSuffix(request.URL.Path, ".manifest.json") {
+			_, _ = w.Write(manifest)
+			return
+		}
+		_, _ = w.Write([]byte(payload))
+	}))
+	defer server.Close()
+	entries, source, err := loadASNMetadata(context.Background(), server.Client(), []string{server.URL + "/bgp-asn-map.json"}, []byte(payload), manifest, 1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if source.Source != "cdn" || source.Fallback || source.Count != 2 || entries[0].ASN != 1 {
+		t.Fatalf("unexpected result: %#v %#v", entries, source)
+	}
+}
+
+func TestLoadASNMetadataFallsBackOnSchemaFailure(t *testing.T) {
+	embedded := `{"schema":"backtrace.asn-metadata/v1","generated_at":"2026-07-20T00:00:00Z","entries":[{"asn":1,"name":"One"}]}`
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) { _, _ = w.Write([]byte(`{"schema":"wrong"}`)) }))
+	defer server.Close()
+	manifest := manifestFor([]byte(embedded), "bgp-asn-map.json", 1)
+	entries, source, err := loadASNMetadata(context.Background(), server.Client(), []string{server.URL + "/bgp-asn-map.json"}, []byte(embedded), manifest, 1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if source.Source != "embedded" || !source.Fallback || len(entries) != 1 {
+		t.Fatalf("unexpected fallback: %#v %#v", entries, source)
+	}
+}
+
+func TestLoadASNMetadataFallsBackFromCDNToRaw(t *testing.T) {
+	payload := []byte(`{"schema":"backtrace.asn-metadata/v1","generated_at":"2026-07-20T00:00:00Z","entries":[{"asn":1,"name":"One"}]}`)
+	validManifest := manifestFor(payload, "bgp-asn-map.json", 1)
+	server := httptest.NewServer(http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
+		if request.URL.Path == "/cdn/bgp-asn-map.manifest.json" {
+			_, _ = writer.Write([]byte(`{"schema":"backtrace.asn-metadata-manifest/v1","file":"bgp-asn-map.json","count":1,"sha256":"bad","generated_at":"2026-07-20T00:00:00Z"}`))
+			return
+		}
+		if request.URL.Path == "/raw/bgp-asn-map.manifest.json" {
+			_, _ = writer.Write(validManifest)
+			return
+		}
+		_, _ = writer.Write(payload)
+	}))
+	defer server.Close()
+	entries, source, err := loadASNMetadata(context.Background(), server.Client(), []string{server.URL + "/cdn/bgp-asn-map.json", server.URL + "/raw/bgp-asn-map.json"}, payload, validManifest, 1)
+	if err != nil || len(entries) != 1 || source.Source != "raw" || !source.Fallback {
+		t.Fatalf("unexpected raw fallback: entries=%#v source=%#v err=%v", entries, source, err)
+	}
+}
+
+func manifestFor(snapshot []byte, file string, count int) []byte {
+	hash := sha256.Sum256(snapshot)
+	return []byte(fmt.Sprintf(`{"schema":"backtrace.asn-metadata-manifest/v1","file":"%s","count":%d,"sha256":"%s","generated_at":"2026-07-20T00:00:00Z"}`, file, count, hex.EncodeToString(hash[:])))
+}
+
+func TestParseASNMetadataRejectsDuplicateAndDrop(t *testing.T) {
+	payload := []byte(`{"schema":"backtrace.asn-metadata/v1","generated_at":"2026-07-20T00:00:00Z","entries":[{"asn":1,"name":"One"},{"asn":1,"name":"Again"}]}`)
+	if _, _, err := parseASNMetadataDocument(payload, 1); err == nil {
+		t.Fatal("duplicate ASN unexpectedly accepted")
+	}
+}

bgptools/data/bgp-asn-map.json

@@ -0,0 +1,342 @@
+{
+  "schema": "backtrace.asn-metadata/v1",
+  "generated_at": "2026-07-21T15:33:49.459211Z",
+  "entries": [
+    {
+      "asn": 174,
+      "name": "Cogent"
+    },
+    {
+      "asn": 701,
+      "name": "Verizon"
+    },
+    {
+      "asn": 702,
+      "name": "Verizon"
+    },
+    {
+      "asn": 1239,
+      "name": "Sprint"
+    },
+    {
+      "asn": 1273,
+      "name": "Vodafone"
+    },
+    {
+      "asn": 1299,
+      "name": "Arelion"
+    },
+    {
+      "asn": 1729,
+      "name": "Telia"
+    },
+    {
+      "asn": 2497,
+      "name": "IIJ"
+    },
+    {
+      "asn": 2516,
+      "name": "KDDI"
+    },
+    {
+      "asn": 2914,
+      "name": "NTT"
+    },
+    {
+      "asn": 3209,
+      "name": "Vodafone"
+    },
+    {
+      "asn": 3257,
+      "name": "GTT"
+    },
+    {
+      "asn": 3258,
+      "name": "xTom"
+    },
+    {
+      "asn": 3301,
+      "name": "Telia"
+    },
+    {
+      "asn": 3308,
+      "name": "Telia"
+    },
+    {
+      "asn": 3320,
+      "name": "DTAG"
+    },
+    {
+      "asn": 3356,
+      "name": "Lumen"
+    },
+    {
+      "asn": 3462,
+      "name": "Hinet"
+    },
+    {
+      "asn": 3491,
+      "name": "PCCW"
+    },
+    {
+      "asn": 3786,
+      "name": "LG"
+    },
+    {
+      "asn": 4445,
+      "name": "Vodafone"
+    },
+    {
+      "asn": 4609,
+      "name": "CTM"
+    },
+    {
+      "asn": 4637,
+      "name": "Telstra"
+    },
+    {
+      "asn": 4657,
+      "name": "StarHub"
+    },
+    {
+      "asn": 4766,
+      "name": "KT"
+    },
+    {
+      "asn": 4788,
+      "name": "TMNet"
+    },
+    {
+      "asn": 5378,
+      "name": "Vodafone"
+    },
+    {
+      "asn": 5511,
+      "name": "Orange"
+    },
+    {
+      "asn": 6233,
+      "name": "xTom"
+    },
+    {
+      "asn": 6453,
+      "name": "TATA"
+    },
+    {
+      "asn": 6461,
+      "name": "Zayo"
+    },
+    {
+      "asn": 6762,
+      "name": "Sparkle"
+    },
+    {
+      "asn": 6830,
+      "name": "Liberty"
+    },
+    {
+      "asn": 6939,
+      "name": "HE"
+    },
+    {
+      "asn": 7018,
+      "name": "AT\u0026T"
+    },
+    {
+      "asn": 7473,
+      "name": "SingTel"
+    },
+    {
+      "asn": 7922,
+      "name": "Comcast"
+    },
+    {
+      "asn": 7979,
+      "name": "Servers"
+    },
+    {
+      "asn": 8075,
+      "name": "MS"
+    },
+    {
+      "asn": 8888,
+      "name": "xTom"
+    },
+    {
+      "asn": 9002,
+      "name": "RETN"
+    },
+    {
+      "asn": 9269,
+      "name": "HKBN"
+    },
+    {
+      "asn": 9304,
+      "name": "HGC"
+    },
+    {
+      "asn": 9505,
+      "name": "CHT"
+    },
+    {
+      "asn": 9644,
+      "name": "SK"
+    },
+    {
+      "asn": 9886,
+      "name": "CTCSCI"
+    },
+    {
+      "asn": 9924,
+      "name": "TFN"
+    },
+    {
+      "asn": 12389,
+      "name": "RT_RU"
+    },
+    {
+      "asn": 12876,
+      "name": "Scaleway"
+    },
+    {
+      "asn": 12956,
+      "name": "Telxius"
+    },
+    {
+      "asn": 13335,
+      "name": "CF"
+    },
+    {
+      "asn": 15169,
+      "name": "Google"
+    },
+    {
+      "asn": 15802,
+      "name": "DU"
+    },
+    {
+      "asn": 16276,
+      "name": "OVH"
+    },
+    {
+      "asn": 16509,
+      "name": "Amazon"
+    },
+    {
+      "asn": 17676,
+      "name": "Softbank"
+    },
+    {
+      "asn": 18403,
+      "name": "FPT"
+    },
+    {
+      "asn": 20473,
+      "name": "Vultr"
+    },
+    {
+      "asn": 20485,
+      "name": "TTK_RU"
+    },
+    {
+      "asn": 23961,
+      "name": "Misaka"
+    },
+    {
+      "asn": 24940,
+      "name": "Hetzner"
+    },
+    {
+      "asn": 25820,
+      "name": "IT7"
+    },
+    {
+      "asn": 30844,
+      "name": "Liquid"
+    },
+    {
+      "asn": 31898,
+      "name": "Oracle"
+    },
+    {
+      "asn": 37700,
+      "name": "JINX"
+    },
+    {
+      "asn": 38731,
+      "name": "CHT"
+    },
+    {
+      "asn": 45102,
+      "name": "Alibaba"
+    },
+    {
+      "asn": 45899,
+      "name": "VNPT"
+    },
+    {
+      "asn": 49304,
+      "name": "SAKURA"
+    },
+    {
+      "asn": 51847,
+      "name": "Nearoute"
+    },
+    {
+      "asn": 58652,
+      "name": "Level3"
+    },
+    {
+      "asn": 60068,
+      "name": "Datacamp"
+    },
+    {
+      "asn": 63150,
+      "name": "Bage"
+    },
+    {
+      "asn": 132203,
+      "name": "Tencent"
+    },
+    {
+      "asn": 133613,
+      "name": "MTel"
+    },
+    {
+      "asn": 136907,
+      "name": "Huawei"
+    },
+    {
+      "asn": 137409,
+      "name": "GSL"
+    },
+    {
+      "asn": 140096,
+      "name": "JINX"
+    },
+    {
+      "asn": 152672,
+      "name": "Aiyun"
+    },
+    {
+      "asn": 202662,
+      "name": "Hytron"
+    },
+    {
+      "asn": 209242,
+      "name": "CF"
+    },
+    {
+      "asn": 211392,
+      "name": "Dream"
+    },
+    {
+      "asn": 214996,
+      "name": "netcup"
+    },
+    {
+      "asn": 216382,
+      "name": "Layer"
+    }
+  ]
+}

bgptools/data/bgp-asn-map.manifest.json

@@ -0,0 +1,7 @@
+{
+  "schema": "backtrace.asn-metadata-manifest/v1",
+  "file": "bgp-asn-map.json",
+  "count": 84,
+  "sha256": "f681dd78d55c27d4615d2e705de9bde24d111e8897d37a489b91e263f27f1a66",
+  "generated_at": "2026-07-21T15:33:49.459211Z"
+}

cmd/update-asn-metadata/main.go

@@ -0,0 +1,207 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/oneclickvirt/backtrace/bgptools"
+)
+
+const defaultSource = "https://raw.githubusercontent.com/xykt/NetQuality/main/ref/AS_Mapping.txt"
+
+type document struct {
+	Schema      string                 `json:"schema"`
+	GeneratedAt time.Time              `json:"generated_at"`
+	Entries     []bgptools.ASNMetadata `json:"entries"`
+}
+
+type manifest struct {
+	Schema      string    `json:"schema"`
+	File        string    `json:"file"`
+	Count       int       `json:"count"`
+	SHA256      string    `json:"sha256"`
+	GeneratedAt time.Time `json:"generated_at"`
+}
+
+func main() {
+	source := flag.String("source", defaultSource, "ASN name registry URL")
+	output := flag.String("output", "bgptools/data/bgp-asn-map.json", "snapshot output path")
+	minimum := flag.Int("min-count", bgptools.ASNMetadataMinimum, "minimum accepted ASN count")
+	timeout := flag.Duration("timeout", 30*time.Second, "fetch timeout")
+	flag.Parse()
+	ctx, cancel := context.WithTimeout(context.Background(), *timeout)
+	defer cancel()
+	entries, err := fetchEntries(ctx, http.DefaultClient, *source)
+	if err != nil {
+		fatal(err)
+	}
+	if err := updateSnapshot(*output, entries, *minimum); err != nil {
+		fatal(err)
+	}
+}
+
+func fetchEntries(ctx context.Context, client *http.Client, source string) ([]bgptools.ASNMetadata, error) {
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, source, nil)
+	if err != nil {
+		return nil, err
+	}
+	request.Header.Set("User-Agent", "oneclickvirt-backtrace-asn-sync/1")
+	response, err := client.Do(request)
+	if err != nil {
+		return nil, err
+	}
+	defer response.Body.Close()
+	if response.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("ASN registry returned HTTP %d", response.StatusCode)
+	}
+	return parseEntries(io.LimitReader(response.Body, 4<<20))
+}
+
+func parseEntries(reader io.Reader) ([]bgptools.ASNMetadata, error) {
+	seen := make(map[uint32]string)
+	scanner := bufio.NewScanner(reader)
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) < 2 || !strings.HasPrefix(strings.ToUpper(fields[0]), "AS") {
+			continue
+		}
+		number, err := strconv.ParseUint(strings.TrimPrefix(strings.ToUpper(fields[0]), "AS"), 10, 32)
+		if err != nil || number == 0 {
+			continue
+		}
+		if _, exists := seen[uint32(number)]; !exists {
+			seen[uint32(number)] = strings.Join(fields[1:], " ")
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+	entries := make([]bgptools.ASNMetadata, 0, len(seen))
+	for asn, name := range seen {
+		entries = append(entries, bgptools.ASNMetadata{ASN: asn, Name: name})
+	}
+	sort.Slice(entries, func(i, j int) bool { return entries[i].ASN < entries[j].ASN })
+	if len(entries) == 0 {
+		return nil, fmt.Errorf("ASN registry contains no valid entries")
+	}
+	return entries, nil
+}
+
+func updateSnapshot(path string, entries []bgptools.ASNMetadata, minimum int) error {
+	if len(entries) < minimum {
+		return fmt.Errorf("ASN count %d is below minimum %d", len(entries), minimum)
+	}
+	currentData, err := os.ReadFile(path)
+	if err != nil {
+		return err
+	}
+	var current document
+	if err := json.Unmarshal(currentData, &current); err != nil || current.Schema != bgptools.ASNMetadataSchema {
+		return fmt.Errorf("current ASN metadata schema is invalid")
+	}
+	if len(current.Entries) >= minimum && len(entries)*100 < len(current.Entries)*65 {
+		return fmt.Errorf("ASN count dropped from %d to %d", len(current.Entries), len(entries))
+	}
+	if sameEntries(current.Entries, entries) && !current.GeneratedAt.IsZero() {
+		return writeManifest(path, currentData, len(current.Entries))
+	}
+	next, err := json.MarshalIndent(document{Schema: bgptools.ASNMetadataSchema, GeneratedAt: time.Now().UTC(), Entries: entries}, "", "  ")
+	if err != nil {
+		return err
+	}
+	next = append(next, '\n')
+	temporary, err := os.CreateTemp(filepath.Dir(path), ".asn-metadata-*.json")
+	if err != nil {
+		return err
+	}
+	name := temporary.Name()
+	defer os.Remove(name)
+	if _, err := temporary.Write(next); err != nil {
+		temporary.Close()
+		return err
+	}
+	if err := temporary.Chmod(0o644); err != nil {
+		temporary.Close()
+		return err
+	}
+	if err := temporary.Close(); err != nil {
+		return err
+	}
+	if err := os.Rename(name, path); err != nil {
+		return err
+	}
+	return writeManifest(path, next, len(entries))
+}
+
+func writeManifest(snapshotPath string, snapshot []byte, count int) error {
+	var snapshotDocument document
+	if err := json.Unmarshal(snapshot, &snapshotDocument); err != nil {
+		return err
+	}
+	hash := sha256.Sum256(snapshot)
+	value := manifest{
+		Schema: bgptools.ASNMetadataManifestSchema, File: filepath.Base(snapshotPath), Count: count,
+		SHA256: hex.EncodeToString(hash[:]), GeneratedAt: snapshotDocument.GeneratedAt,
+	}
+	data, err := json.MarshalIndent(value, "", "  ")
+	if err != nil {
+		return err
+	}
+	data = append(data, '\n')
+	manifestPath := strings.TrimSuffix(snapshotPath, ".json") + ".manifest.json"
+	if current, readErr := os.ReadFile(manifestPath); readErr == nil && string(current) == string(data) {
+		return nil
+	}
+	return writeAtomic(manifestPath, data)
+}
+
+func writeAtomic(path string, data []byte) error {
+	temporary, err := os.CreateTemp(filepath.Dir(path), ".asn-metadata-manifest-*.json")
+	if err != nil {
+		return err
+	}
+	name := temporary.Name()
+	defer os.Remove(name)
+	if _, err := temporary.Write(data); err != nil {
+		temporary.Close()
+		return err
+	}
+	if err := temporary.Chmod(0o644); err != nil {
+		temporary.Close()
+		return err
+	}
+	if err := temporary.Close(); err != nil {
+		return err
+	}
+	return os.Rename(name, path)
+}
+
+func sameEntries(left, right []bgptools.ASNMetadata) bool {
+	if len(left) != len(right) {
+		return false
+	}
+	for index := range left {
+		if left[index] != right[index] {
+			return false
+		}
+	}
+	return true
+}
+
+func fatal(err error) {
+	fmt.Fprintln(os.Stderr, err)
+	os.Exit(1)
+}

cmd/update-asn-metadata/main_test.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/oneclickvirt/backtrace/bgptools"
+)
+
+func TestParseEntriesDeduplicatesAndSorts(t *testing.T) {
+	entries, err := parseEntries(strings.NewReader("AS3356 Lumen\nAS174 Cogent\nAS3356 Level3\ninvalid\n"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(entries) != 2 || entries[0] != (bgptools.ASNMetadata{ASN: 174, Name: "Cogent"}) || entries[1].Name != "Lumen" {
+		t.Fatalf("unexpected entries: %#v", entries)
+	}
+}
+
+func TestUpdateSnapshotWritesMatchingManifestWithoutRewritingSnapshot(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "asn.json")
+	current := []byte(`{"schema":"backtrace.asn-metadata/v1","generated_at":"2026-07-20T00:00:00Z","entries":[{"asn":1,"name":"One"},{"asn":2,"name":"Two"}]}`)
+	if err := os.WriteFile(path, current, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	entries := []bgptools.ASNMetadata{{ASN: 1, Name: "One"}, {ASN: 2, Name: "Two"}}
+	if err := updateSnapshot(path, entries, 1); err != nil {
+		t.Fatal(err)
+	}
+	after, _ := os.ReadFile(path)
+	if string(after) != string(current) {
+		t.Fatal("semantic no-op rewrote snapshot")
+	}
+	data, err := os.ReadFile(filepath.Join(filepath.Dir(path), "asn.manifest.json"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var value manifest
+	if err := json.Unmarshal(data, &value); err != nil {
+		t.Fatal(err)
+	}
+	hash := sha256.Sum256(current)
+	if value.Schema != bgptools.ASNMetadataManifestSchema || value.File != "asn.json" || value.Count != 2 || value.SHA256 != hex.EncodeToString(hash[:]) {
+		t.Fatalf("manifest mismatch: %#v", value)
+	}
+}
+
+func TestUpdateSnapshotRejectsCountDrop(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "asn.json")
+	current := `{"schema":"backtrace.asn-metadata/v1","generated_at":"2026-07-20T00:00:00Z","entries":[{"asn":1,"name":"One"},{"asn":2,"name":"Two"}]}`
+	if err := os.WriteFile(path, []byte(current), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := updateSnapshot(path, []bgptools.ASNMetadata{{ASN: 1, Name: "One"}}, 1); err == nil {
+		t.Fatal("count drop unexpectedly accepted")
+	}
+}

model/model.go

@@ -2,7 +2,7 @@ package model
 
 import "time"
 
-const BackTraceVersion = "v0.0.12"
+const BackTraceVersion = "v0.0.15"
 
 var EnableLoger = false