Rename blocklists to IP lists, add IP lookup flags, raise the download limit to 200 MiB (closes #233)

The lists are not only used for blocking, so the package, the `blocklists` field of the IP lookup answer and the state directory are now IP lists (`internal/iplist`, `ip_lists`, `iplists`). Every result gains a `flags` object with `is_tor` and `is_bogon`. The largest list file accepted is 200 MiB.

Judgement call: the dated 2026-10-27 `TODO.md` entry keeps the old word.
Rule suppressed: `tagliatelle` on the two result structs, for snake_case keys.

Model: opus-5-5

internal/iplist/download.go

@@ -1,4 +1,4 @@
-package blocklist
+package iplist
 
 import (
 	"context"
@@ -22,7 +22,7 @@ const (
 
 	// maxDownloadSize is the size of the largest list file accepted, in
 	// bytes. The largest list, FireHOL abusers, is about 2.5 MiB.
-	maxDownloadSize = 16 << 20
+	maxDownloadSize = 200 << 20
 )
 
 // The request headers a download sets.
@@ -78,10 +78,10 @@ var (
 // downloads each list once its copy is older than its Interval, and a list
 // with no copy at once. The goroutine runs until Stop: the end of ctx does
 // not stop it.
-func (b *Blocklists) Start(ctx context.Context) {
+func (b *IPLists) Start(ctx context.Context) {
 	err := os.MkdirAll(b.dir, dirPermissions)
 	if err != nil {
-		b.logger.Error("Failed to create the blocklists directory",
+		b.logger.Error("Failed to create the IP lists directory",
 			"dir", b.dir, "error", err)
 	}
 
@@ -90,7 +90,7 @@ func (b *Blocklists) Start(ctx context.Context) {
 	for i, list := range b.lists {
 		loadErr := b.loadCopy(list)
 		if loadErr != nil && !errors.Is(loadErr, fs.ErrNotExist) {
-			b.logger.Error("Failed to load a blocklist copy",
+			b.logger.Error("Failed to load an IP list copy",
 				"list", list.Name, "error", loadErr)
 		}
 
@@ -104,20 +104,20 @@ func (b *Blocklists) Start(ctx context.Context) {
 		b.run(ctx, nextDownload)
 	}()
 
-	b.logger.Info("Blocklist downloads started", "dir", b.dir)
+	b.logger.Info("IP list downloads started", "dir", b.dir)
 }
 
 // Stop stops the downloads, cancelling one in progress, and waits until the
 // goroutine has returned or ctx ends. The copies in memory stay, so Lookup
 // still answers.
-func (b *Blocklists) Stop(ctx context.Context) {
+func (b *IPLists) Stop(ctx context.Context) {
 	b.stop()
 
 	select {
 	case <-b.done:
-		b.logger.Info("Blocklist downloads stopped")
+		b.logger.Info("IP list downloads stopped")
 	case <-ctx.Done():
-		b.logger.Warn("Stop deadline passed before the blocklist downloads " +
+		b.logger.Warn("Stop deadline passed before the IP list downloads " +
 			"stopped")
 	}
 }
@@ -125,7 +125,7 @@ func (b *Blocklists) Stop(ctx context.Context) {
 // run downloads each list when nextDownload says, until ctx ends. After each
 // try, whether it worked or not, the list's next download is an Interval
 // later.
-func (b *Blocklists) run(ctx context.Context, nextDownload []time.Time) {
+func (b *IPLists) run(ctx context.Context, nextDownload []time.Time) {
 	defer close(b.done)
 
 	if len(nextDownload) == 0 {
@@ -155,7 +155,7 @@ func (b *Blocklists) run(ctx context.Context, nextDownload []time.Time) {
 			}
 
 			if err != nil {
-				b.logger.Error("Blocklist download failed; keeping the "+
+				b.logger.Error("IP list download failed; keeping the "+
 					"previous copy", "list", list.Name, "error", err)
 			}
 
@@ -169,7 +169,7 @@ func (b *Blocklists) run(ctx context.Context, nextDownload []time.Time) {
 // on disk and in memory. An answer that the copy is still current marks the
 // copy as updated now. Anything else leaves the copy as it is and returns an
 // error.
-func (b *Blocklists) download(ctx context.Context, list List) error {
+func (b *IPLists) download(ctx context.Context, list List) error {
 	ctx, cancel := context.WithTimeout(ctx, downloadTimeout)
 	defer cancel()
 
@@ -212,7 +212,7 @@ func (b *Blocklists) download(ctx context.Context, list List) error {
 // replaceCopy writes a new version of list, read from body, beside the list's
 // copy. Only when it parses does it replace the copy, on disk and in memory.
 // sent are the validators the publisher sent with the new version.
-func (b *Blocklists) replaceCopy(list List, body io.Reader, sent validators) error {
+func (b *IPLists) replaceCopy(list List, body io.Reader, sent validators) error {
 	root, err := os.OpenRoot(b.dir)
 	if err != nil {
 		return err
@@ -244,13 +244,13 @@ func (b *Blocklists) replaceCopy(list List, body io.Reader, sent validators) err
 	b.setCopy(list.Name, listCopy{
 		addresses: addresses, updated: time.Now().UTC(), validators: sent,
 	})
-	b.logger.Info("Downloaded a new version of a blocklist", "list", list.Name)
+	b.logger.Info("Downloaded a new version of an IP list", "list", list.Name)
 
 	// Without this file, the first download after a restart asks for the
 	// whole list.
 	err = writeValidators(root, list.Name, sent)
 	if err != nil {
-		b.logger.Error("Failed to keep the validators of a blocklist copy",
+		b.logger.Error("Failed to keep the validators of an IP list copy",
 			"list", list.Name, "error", err)
 	}
 
@@ -288,7 +288,7 @@ func writeAndParse(
 
 // markCurrent records that the publisher says the list's copy is still
 // current: the copy, on disk and in memory, is marked as updated now.
-func (b *Blocklists) markCurrent(list List) error {
+func (b *IPLists) markCurrent(list List) error {
 	root, err := os.OpenRoot(b.dir)
 	if err != nil {
 		return err
@@ -304,7 +304,7 @@ func (b *Blocklists) markCurrent(list List) error {
 	}
 
 	b.setUpdated(list.Name, now)
-	b.logger.Debug("Blocklist copy is still current", "list", list.Name)
+	b.logger.Debug("IP list copy is still current", "list", list.Name)
 
 	return nil
 }
@@ -312,7 +312,7 @@ func (b *Blocklists) markCurrent(list List) error {
 // loadCopy makes the list's copy on disk, with the validators kept beside it,
 // its copy in memory. The file's modification time is when the copy was
 // updated.
-func (b *Blocklists) loadCopy(list List) error {
+func (b *IPLists) loadCopy(list List) error {
 	root, err := os.OpenRoot(b.dir)
 	if err != nil {
 		return err

internal/iplist/iplist.go

@@ -1,7 +1,7 @@
-// Package blocklist downloads public IP blocklists on a schedule, keeps the
-// last good copy of each on disk and in memory, and answers which lists
-// contain an address.
-package blocklist
+// Package iplist downloads public IP lists on a schedule, keeps the last good
+// copy of each on disk and in memory, and answers which lists contain an
+// address.
+package iplist
 
 import (
 	"context"
@@ -31,7 +31,7 @@ const (
 	FormatDShield
 )
 
-// List is one public blocklist.
+// List is one public IP list.
 type List struct {
 	// Name names the list in lookup answers, and names its copy on disk.
 	Name string
@@ -80,9 +80,9 @@ type Params struct {
 	Logger *slog.Logger
 }
 
-// Blocklists keeps a copy of each list and answers which lists contain an
+// IPLists keeps a copy of each list and answers which lists contain an
 // address. Start loads the copies from disk and starts downloading the lists.
-type Blocklists struct {
+type IPLists struct {
 	dir    string
 	lists  []List
 	logger *slog.Logger
@@ -97,12 +97,12 @@ type Blocklists struct {
 	done chan struct{}
 }
 
-// New returns a Blocklists with no copies. Start loads them.
-func New(params Params) *Blocklists {
-	return &Blocklists{
+// New returns an IPLists with no copies. Start loads them.
+func New(params Params) *IPLists {
+	return &IPLists{
 		dir:    params.Dir,
 		lists:  params.Lists,
-		logger: params.Logger.With("component", "blocklists"),
+		logger: params.Logger.With("component", "iplists"),
 		copies: make(map[string]listCopy),
 		done:   make(chan struct{}),
 	}
@@ -111,7 +111,7 @@ func New(params Params) *Blocklists {
 // Lookup returns a Listing for each list whose copy contains addr, in the
 // order of the lists given to New. It makes no outside request. When no list
 // contains addr, it returns an empty list, not nil.
-func (b *Blocklists) Lookup(addr netip.Addr) []Listing {
+func (b *IPLists) Lookup(addr netip.Addr) []Listing {
 	b.mu.RLock()
 	defer b.mu.RUnlock()
 
@@ -133,7 +133,7 @@ func (b *Blocklists) Lookup(addr netip.Addr) []Listing {
 
 // ShortestInterval returns the shortest Interval of the lists. That is the
 // soonest a copy can change, and so how long a lookup answer stays current.
-func (b *Blocklists) ShortestInterval() time.Duration {
+func (b *IPLists) ShortestInterval() time.Duration {
 	var shortest time.Duration
 
 	for i, list := range b.lists {
@@ -147,7 +147,7 @@ func (b *Blocklists) ShortestInterval() time.Duration {
 
 // updated returns when the named list's copy was last downloaded or found
 // current, or the zero time when the list has no copy.
-func (b *Blocklists) updated(name string) time.Time {
+func (b *IPLists) updated(name string) time.Time {
 	b.mu.RLock()
 	defer b.mu.RUnlock()
 
@@ -156,7 +156,7 @@ func (b *Blocklists) updated(name string) time.Time {
 
 // copyValidators returns the validators of the named list's copy. They are
 // empty when the list has no copy.
-func (b *Blocklists) copyValidators(name string) validators {
+func (b *IPLists) copyValidators(name string) validators {
 	b.mu.RLock()
 	defer b.mu.RUnlock()
 
@@ -164,7 +164,7 @@ func (b *Blocklists) copyValidators(name string) validators {
 }
 
 // setCopy makes c the named list's copy.
-func (b *Blocklists) setCopy(name string, c listCopy) {
+func (b *IPLists) setCopy(name string, c listCopy) {
 	b.mu.Lock()
 	defer b.mu.Unlock()
 
@@ -172,7 +172,7 @@ func (b *Blocklists) setCopy(name string, c listCopy) {
 }
 
 // setUpdated records that the named list's copy was found current at t.
-func (b *Blocklists) setUpdated(name string, t time.Time) {
+func (b *IPLists) setUpdated(name string, t time.Time) {
 	b.mu.Lock()
 	defer b.mu.Unlock()
 

internal/iplist/iplist_internal_test.go

@@ -1,4 +1,4 @@
-package blocklist
+package iplist
 
 import (
 	"context"
@@ -121,7 +121,7 @@ func testList(url string, format Format) List {
 	}
 }
 
-func newTestBlocklists(dir string, list List) *Blocklists {
+func newTestIPLists(dir string, list List) *IPLists {
 	return New(Params{
 		Dir:    dir,
 		Lists:  []List{list},
@@ -130,7 +130,7 @@ func newTestBlocklists(dir string, list List) *Blocklists {
 }
 
 // lookup looks addr up in b.
-func lookup(t *testing.T, b *Blocklists, addr string) []Listing {
+func lookup(t *testing.T, b *IPLists, addr string) []Listing {
 	t.Helper()
 
 	return b.Lookup(netip.MustParseAddr(addr))
@@ -188,7 +188,7 @@ func TestLookupFindsListedAddresses(t *testing.T) {
 			t.Parallel()
 
 			_, url := newPublisher(t, tt.body)
-			b := newTestBlocklists(t.TempDir(), testList(url, tt.format))
+			b := newTestIPLists(t.TempDir(), testList(url, tt.format))
 
 			err := b.download(t.Context(), b.lists[0])
 			if err != nil {
@@ -228,10 +228,6 @@ func TestFailedDownloadKeepsThePreviousCopy(t *testing.T) {
 	}{
 		{"server error", http.StatusInternalServerError, "unavailable"},
 		{"not a list", http.StatusOK, "<!DOCTYPE html>\n<html></html>\n"},
-		{
-			"over the size limit", http.StatusOK,
-			strings.Repeat(listedAddr+"\n", maxDownloadSize/len(listedAddr)),
-		},
 	}
 
 	for _, tt := range tests {
@@ -240,7 +236,7 @@ func TestFailedDownloadKeepsThePreviousCopy(t *testing.T) {
 
 			dir := t.TempDir()
 			p, url := newPublisher(t, goodListBody)
-			b := newTestBlocklists(dir, testList(url, FormatLines))
+			b := newTestIPLists(dir, testList(url, FormatLines))
 
 			err := b.download(t.Context(), b.lists[0])
 			if err != nil {
@@ -262,23 +258,106 @@ func TestFailedDownloadKeepsThePreviousCopy(t *testing.T) {
 				t.Errorf("listings %+v after the failure, want %+v", after, before)
 			}
 
-			copies := os.DirFS(dir)
-
-			onDisk, err := fs.ReadFile(copies, testListName)
-			if err != nil || string(onDisk) != goodListBody {
-				t.Errorf("copy on disk %q (%v), want %q", onDisk, err, goodListBody)
-			}
-
-			_, err = fs.Stat(copies, testListName+downloadSuffix)
-			if !errors.Is(err, fs.ErrNotExist) {
-				t.Errorf("the failed download's file is still there (%v)", err)
-			}
+			checkGoodCopyOnDisk(t, dir)
 		})
 	}
 }
 
+// checkGoodCopyOnDisk checks that dir holds the good version of the test list
+// and no part of a failed download.
+func checkGoodCopyOnDisk(t *testing.T, dir string) {
+	t.Helper()
+
+	copies := os.DirFS(dir)
+
+	onDisk, err := fs.ReadFile(copies, testListName)
+	if err != nil || string(onDisk) != goodListBody {
+		t.Errorf("copy on disk %q (%v), want %q", onDisk, err, goodListBody)
+	}
+
+	_, err = fs.Stat(copies, testListName+downloadSuffix)
+	if !errors.Is(err, fs.ErrNotExist) {
+		t.Errorf("the failed download's file is still there (%v)", err)
+	}
+}
+
+// commentLines is an endless io.Reader of comment lines. It lets a test send
+// a large list file without holding the file in memory.
+type commentLines struct {
+	offset int
+}
+
+func (c *commentLines) Read(p []byte) (int, error) {
+	const line = "# a comment line that pads a large list file\n"
+
+	for filled := 0; filled < len(p); {
+		copied := copy(p[filled:], line[c.offset:])
+		filled += copied
+		c.offset = (c.offset + copied) % len(line)
+	}
+
+	return len(p), nil
+}
+
+// largeListFile returns a reader of a list file of size bytes: comment lines,
+// then newListedAddr on the last line.
+func largeListFile(size int64) io.Reader {
+	lastLine := "\n" + newListedAddr + "\n"
+
+	return io.MultiReader(
+		io.LimitReader(&commentLines{}, size-int64(len(lastLine))),
+		strings.NewReader(lastLine),
+	)
+}
+
+// TestLargeFileUnderTheSizeLimitIsAccepted replaces a list with a 199 MiB
+// file. The address on its last line is listed, so the whole file was read.
+func TestLargeFileUnderTheSizeLimitIsAccepted(t *testing.T) {
+	t.Parallel()
+
+	const size = 199 << 20
+
+	b := newTestIPLists(t.TempDir(), testList("", FormatLines))
+
+	err := b.replaceCopy(b.lists[0], largeListFile(size), validators{})
+	if err != nil {
+		t.Fatalf("replaceCopy: %v", err)
+	}
+
+	if listings := lookup(t, b, newListedAddr); len(listings) != 1 {
+		t.Errorf("listings %+v, want one", listings)
+	}
+}
+
+// TestFileOverTheSizeLimitKeepsThePreviousCopy downloads a good version of a
+// list, then replaces it with a file one byte over the limit. The attempt
+// fails, and the good copy stays in memory and on disk.
+func TestFileOverTheSizeLimitKeepsThePreviousCopy(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	_, url := newPublisher(t, goodListBody)
+	b := newTestIPLists(dir, testList(url, FormatLines))
+
+	err := b.download(t.Context(), b.lists[0])
+	if err != nil {
+		t.Fatalf("download: %v", err)
+	}
+
+	err = b.replaceCopy(b.lists[0], largeListFile(maxDownloadSize+1), validators{})
+	if !errors.Is(err, errTooLarge) {
+		t.Fatalf("replaceCopy: %v, want %v", err, errTooLarge)
+	}
+
+	if listings := lookup(t, b, listedAddr); len(listings) != 1 {
+		t.Errorf("listings of %s %+v, want one", listedAddr, listings)
+	}
+
+	checkGoodCopyOnDisk(t, dir)
+}
+
 // TestRestartLoadsCopiesFromDisk downloads a list, then starts a new
-// Blocklists on the same directory, as a restart does. The new one answers
+// IPLists on the same directory, as a restart does. The new one answers
 // from the copy on disk at once, and does not download the list again while
 // the copy is younger than the list's interval.
 func TestRestartLoadsCopiesFromDisk(t *testing.T) {
@@ -288,7 +367,7 @@ func TestRestartLoadsCopiesFromDisk(t *testing.T) {
 	p, url := newPublisher(t, goodListBody)
 	list := testList(url, FormatLines)
 
-	first := newTestBlocklists(dir, list)
+	first := newTestIPLists(dir, list)
 
 	err := first.download(t.Context(), list)
 	if err != nil {
@@ -297,7 +376,7 @@ func TestRestartLoadsCopiesFromDisk(t *testing.T) {
 
 	downloaded := lookup(t, first, listedAddr)[0].Updated
 
-	second := newTestBlocklists(dir, list)
+	second := newTestIPLists(dir, list)
 	second.Start(t.Context())
 	second.Stop(t.Context())
 
@@ -328,7 +407,7 @@ func TestStartRefreshesAnOldCopy(t *testing.T) {
 	lastModified := time.Now().Add(-3 * list.Interval).UTC().Truncate(time.Second)
 	p.publish(goodListBody, lastModified, testETag)
 
-	err := newTestBlocklists(dir, list).download(t.Context(), list)
+	err := newTestIPLists(dir, list).download(t.Context(), list)
 	if err != nil {
 		t.Fatalf("download: %v", err)
 	}
@@ -340,7 +419,7 @@ func TestStartRefreshesAnOldCopy(t *testing.T) {
 		t.Fatalf("Chtimes: %v", err)
 	}
 
-	b := newTestBlocklists(dir, list)
+	b := newTestIPLists(dir, list)
 	b.Start(t.Context())
 
 	deadline := time.Now().Add(maxWait)
@@ -381,7 +460,7 @@ func TestNewVersionOlderThanTheLastDownloadReplacesTheCopy(t *testing.T) {
 
 	p, url := newPublisher(t, goodListBody)
 	list := testList(url, FormatLines)
-	b := newTestBlocklists(t.TempDir(), list)
+	b := newTestIPLists(t.TempDir(), list)
 
 	firstVersion := time.Now().Add(-2 * list.Interval).UTC().Truncate(time.Second)
 	p.publish(goodListBody, firstVersion, "")
@@ -418,7 +497,7 @@ func TestDownloadWithoutLastModifiedOrETagSendsNoCondition(t *testing.T) {
 
 	p, url := newPublisher(t, goodListBody)
 	list := testList(url, FormatLines)
-	b := newTestBlocklists(t.TempDir(), list)
+	b := newTestIPLists(t.TempDir(), list)
 
 	err := b.download(t.Context(), list)
 	if err != nil {
@@ -455,7 +534,7 @@ func TestStopCancelsADownloadInProgress(t *testing.T) {
 		}))
 	t.Cleanup(srv.Close)
 
-	b := newTestBlocklists(t.TempDir(), testList(srv.URL, FormatLines))
+	b := newTestIPLists(t.TempDir(), testList(srv.URL, FormatLines))
 	b.Start(t.Context())
 
 	select {

internal/iplist/lists.go

@@ -1,7 +1,10 @@
-package blocklist
+package iplist
 
 import "time"
 
+// TorExitsList is the name of the list of Tor exit nodes.
+const TorExitsList = "tor_exits"
+
 // How often each list is downloaded. No list is downloaded more often than
 // its publisher updates it or allows.
 const (
@@ -30,7 +33,7 @@ const (
 	torExitsInterval = time.Hour
 )
 
-// Lists returns the public blocklists routewatch downloads. Each can be
+// Lists returns the public IP lists routewatch downloads. Each can be
 // downloaded whole without an account or a key. Spamhaus merged its EDROP
 // list into DROP, so DROP covers both.
 func Lists() []List {
@@ -83,7 +86,7 @@ func Lists() []List {
 			Format:   FormatSpamhausJSON,
 		},
 		{
-			Name:        "tor_exits",
+			Name:        TorExitsList,
 			Description: "A Tor exit node, where traffic from the Tor network leaves",
 			URL:         "https://check.torproject.org/torbulkexitlist",
 			Interval:    torExitsInterval,

internal/iplist/parse.go

@@ -1,4 +1,4 @@
-package blocklist
+package iplist
 
 import (
 	"bufio"

internal/routewatch/app.go

@@ -15,9 +15,9 @@ import (
 	"sync"
 	"time"
 
-	"git.eeqj.de/sneak/routewatch/internal/blocklist"
 	"git.eeqj.de/sneak/routewatch/internal/config"
 	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/iplist"
 	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
 	"git.eeqj.de/sneak/routewatch/internal/routetable"
@@ -61,12 +61,12 @@ type RouteWatch struct {
 	peeringHandler *PeeringHandler
 	asnFetcher     *ASNFetcher
 	dbMaintainer   *DBMaintainer
-	blocklists     *blocklist.Blocklists
+	ipLists        *iplist.IPLists
 }
 
-// blocklistsDirName is the directory in the state directory that holds the
-// blocklist copies.
-const blocklistsDirName = "blocklists"
+// ipListsDirName is the directory in the state directory that holds the IP
+// list copies.
+const ipListsDirName = "iplists"
 
 // New creates a new RouteWatch instance
 func New(deps Dependencies) *RouteWatch {
@@ -138,17 +138,17 @@ func (rw *RouteWatch) Run(ctx context.Context) error {
 	rw.asnFetcher.Start(ctx)
 	rw.server.SetASNFetcher(rw.asnFetcher)
 
-	// Load the blocklist copies from disk and start downloading the lists.
-	// The HTTP handlers read the server's blocklists without a lock, so they
+	// Load the IP list copies from disk and start downloading the lists.
+	// The HTTP handlers read the server's IP lists without a lock, so they
 	// are set before the handlers run.
-	blocklists := blocklist.New(blocklist.Params{
-		Dir:    filepath.Join(rw.config.StateDir, blocklistsDirName),
-		Lists:  blocklist.Lists(),
+	ipLists := iplist.New(iplist.Params{
+		Dir:    filepath.Join(rw.config.StateDir, ipListsDirName),
+		Lists:  iplist.Lists(),
 		Logger: rw.logger.Logger,
 	})
-	blocklists.Start(ctx)
-	rw.blocklists = blocklists
-	rw.server.SetBlocklists(blocklists)
+	ipLists.Start(ctx)
+	rw.ipLists = ipLists
+	rw.server.SetIPLists(ipLists)
 
 	// Start HTTP server
 	err = rw.server.Start(ctx)
@@ -168,7 +168,7 @@ func (rw *RouteWatch) Run(ctx context.Context) error {
 
 // Shutdown stops all services in order: the streamer, the handlers, which
 // write what they hold, the WHOIS fetcher, the database maintainer, the
-// blocklist downloads and the HTTP server, and last the database, which it
+// IP list downloads and the HTTP server, and last the database, which it
 // checkpoints and closes. Each stage waits at most until ctx ends, so
 // Shutdown returns soon after: a handler logs what it could not write by
 // then, and the HTTP server closes the connections of requests still
@@ -219,8 +219,8 @@ func (rw *RouteWatch) Shutdown(ctx context.Context) {
 		rw.dbMaintainer.Stop(ctx)
 	}
 
-	if rw.blocklists != nil {
-		rw.blocklists.Stop(ctx)
+	if rw.ipLists != nil {
+		rw.ipLists.Stop(ctx)
 	}
 
 	err := rw.server.Stop(ctx)

internal/routewatch/app_integration_internal_test.go

@@ -418,7 +418,7 @@ func TestRouteWatchLiveFeed(t *testing.T) {
 	// Create streamer
 	s := streamer.New(logger, metricsTracker)
 
-	// The state directory holds the blocklist copies Run downloads.
+	// The state directory holds the IP list copies Run downloads.
 	cfg := &config.Config{
 		StateDir:                    t.TempDir(),
 		MaxRuntime:                  5 * time.Second,

internal/server/handlers.go

@@ -15,8 +15,9 @@ import (
 	"strings"
 	"time"
 
-	"git.eeqj.de/sneak/routewatch/internal/blocklist"
+	"git.eeqj.de/sneak/routewatch/internal/bogon"
 	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/iplist"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
 	"git.eeqj.de/sneak/routewatch/internal/ristypes"
 	"git.eeqj.de/sneak/routewatch/internal/routetable"
@@ -765,9 +766,12 @@ type IPLookupResponse struct {
 	Errors  []string         `json:"errors,omitempty"`
 }
 
-// IPLookupResult is the answer for one address: its PTR names, its live route
-// and that route's AS, and the blocklists that list it. Every result has every
-// field. The fields of IPInfo are null when the address has no live route.
+// IPLookupResult is the answer for one address: its PTR names, its flags, its
+// live route and that route's AS, and the IP lists that contain it. Every
+// result has every field. The fields of IPInfo are null when the address has
+// no live route.
+//
+//nolint:tagliatelle // snake_case keys, as the Go style guide asks
 type IPLookupResult struct {
 	IPInfo
 
@@ -775,8 +779,22 @@ type IPLookupResult struct {
 	// PTR is empty, never nil, when the address has no PTR names.
 	PTR []string `json:"ptr"`
 
-	// Blocklists has one entry for each blocklist the address is on.
-	Blocklists []blocklist.Listing `json:"blocklists"`
+	Flags IPLookupFlags `json:"flags"`
+
+	// IPLists has one entry for each IP list the address is on.
+	IPLists []iplist.Listing `json:"ip_lists"`
+}
+
+// IPLookupFlags are the yes-or-no facts about an address. Every result has
+// them, whether or not the address has a live route.
+//
+//nolint:tagliatelle // snake_case keys, as the Go style guide asks
+type IPLookupFlags struct {
+	// IsTor says that the address is on the Tor exit list.
+	IsTor bool `json:"is_tor"`
+
+	// IsBogon says that the address is reserved, as package bogon tells.
+	IsBogon bool `json:"is_bogon"`
 }
 
 // handleIPInfo returns a handler that provides comprehensive IP information.
@@ -852,12 +870,7 @@ func (s *Server) handleIPInfo() http.HandlerFunc {
 				return
 			}
 
-			response.Results = append(response.Results, IPLookupResult{
-				IP:         ip,
-				PTR:        ptrs,
-				IPInfo:     ipInfo,
-				Blocklists: s.blocklistListings(ip),
-			})
+			response.Results = append(response.Results, s.ipLookupResult(ip, ptrs, ipInfo))
 
 			if ipInfo.NeedsWHOISRefresh {
 				refreshASNs[*ipInfo.ASN] = true
@@ -958,23 +971,61 @@ func ipVersionOf(prefix netip.Prefix) int {
 	return ipVersionV6
 }
 
-// blocklistListings returns the blocklists that list ip. It returns an empty
-// list, never nil, so that an answer's blocklists is [] rather than null.
-func (s *Server) blocklistListings(ip string) []blocklist.Listing {
+// ipLookupResult returns the result for ip, adding its flags and IP lists to
+// its PTR names and route.
+func (s *Server) ipLookupResult(ip string, ptrs []string, info IPInfo) IPLookupResult {
+	listings := s.ipListListings(ip)
+
+	return IPLookupResult{
+		IP:      ip,
+		PTR:     ptrs,
+		IPInfo:  info,
+		Flags:   ipLookupFlags(ip, listings),
+		IPLists: listings,
+	}
+}
+
+// ipListListings returns the IP lists that contain ip. It returns an empty
+// list, never nil, so that an answer's ip_lists is [] rather than null.
+func (s *Server) ipListListings(ip string) []iplist.Listing {
 	addr, err := netip.ParseAddr(ip)
-	if s.blocklists == nil || err != nil {
-		return []blocklist.Listing{}
+	if s.ipLists == nil || err != nil {
+		return []iplist.Listing{}
 	}
 
-	return s.blocklists.Lookup(addr)
+	return s.ipLists.Lookup(addr)
+}
+
+// ipLookupFlags returns the flags of ip, whose IP list entries are listings.
+func ipLookupFlags(ip string, listings []iplist.Listing) IPLookupFlags {
+	return IPLookupFlags{
+		IsTor: slices.ContainsFunc(listings, func(l iplist.Listing) bool {
+			return l.Name == iplist.TorExitsList
+		}),
+		IsBogon: isBogon(ip),
+	}
+}
+
+// isBogon says whether the address ip is reserved. An IPv4 address written in
+// IPv6 form counts as the IPv4 address it holds.
+func isBogon(ip string) bool {
+	addr, err := netip.ParseAddr(ip)
+	if err != nil {
+		return false
+	}
+
+	addr = addr.Unmap()
+	_, reserved := bogon.Prefix(netip.PrefixFrom(addr, addr.BitLen()))
+
+	return reserved
 }
 
 // setIPLookupCacheControl lets caches keep an IP lookup answer for the
-// shortest blocklist interval, the soonest a blocklist copy can change. The
+// shortest IP list interval, the soonest an IP list copy can change. The
 // answer about the caller's own address is private, so that a shared cache
-// does not give it to another caller. Without blocklists it sets nothing.
+// does not give it to another caller. Without IP lists it sets nothing.
 func (s *Server) setIPLookupCacheControl(w http.ResponseWriter, ownAddress bool) {
-	if s.blocklists == nil {
+	if s.ipLists == nil {
 		return
 	}
 
@@ -983,7 +1034,7 @@ func (s *Server) setIPLookupCacheControl(w http.ResponseWriter, ownAddress bool)
 		visibility = cacheControlPrivate
 	}
 
-	maxAgeSeconds := int(s.blocklists.ShortestInterval().Seconds())
+	maxAgeSeconds := int(s.ipLists.ShortestInterval().Seconds())
 	w.Header().Set(cacheControlHeader,
 		visibility+cacheControlMaxAge+strconv.Itoa(maxAgeSeconds))
 }

internal/server/handlers_internal_test.go

@@ -19,9 +19,9 @@ import (
 	"testing"
 	"time"
 
-	"git.eeqj.de/sneak/routewatch/internal/blocklist"
 	"git.eeqj.de/sneak/routewatch/internal/config"
 	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/iplist"
 	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
 	"git.eeqj.de/sneak/routewatch/internal/ristypes"
@@ -1428,50 +1428,112 @@ func TestIPLookupKeepsRouteWhenPTRLookupDoesNotAnswer(t *testing.T) {
 // newServerWithTestRoutes stores a route for.
 const addrInTestPrefixV6 = "2001:db8::1"
 
-// testBlocklistInterval is fakeBlocklists' shortest interval.
-const testBlocklistInterval = 15 * time.Minute
+// testIPListInterval is fakeIPLists' shortest interval.
+const testIPListInterval = 15 * time.Minute
 
 // ownAddressPath is the IP lookup of the caller's own address.
 const ownAddressPath = "/ip/"
 
-// listedUnroutedAddr is an address that fakeBlocklists lists, outside the
-// routes newServerWithTestRoutes stores.
+// listedUnroutedAddr is an address that fakeIPLists lists, outside the routes
+// newServerWithTestRoutes stores.
 const listedUnroutedAddr = "203.0.113.1"
 
-// fakeBlocklists has one list, which lists addrInTestPrefixV4 and
-// listedUnroutedAddr and no other address.
-type fakeBlocklists struct{}
+// torExitAddr is the address that fakeIPLists lists on the Tor exit list.
+const torExitAddr = "203.0.113.2"
 
-func testListing() blocklist.Listing {
-	return blocklist.Listing{
+// fakeIPLists has two lists. The test list holds addrInTestPrefixV4 and
+// listedUnroutedAddr, and the Tor exit list holds torExitAddr.
+type fakeIPLists struct{}
+
+func testListing() iplist.Listing {
+	return iplist.Listing{
 		Name:        "test_list",
 		Description: "On the test list",
 		Updated:     time.Date(2026, 10, 27, 4, 0, 0, 0, time.UTC),
 	}
 }
 
-func (fakeBlocklists) Lookup(addr netip.Addr) []blocklist.Listing {
+func (fakeIPLists) Lookup(addr netip.Addr) []iplist.Listing {
 	if addr == netip.MustParseAddr(addrInTestPrefixV4) ||
 		addr == netip.MustParseAddr(listedUnroutedAddr) {
-		return []blocklist.Listing{testListing()}
+		return []iplist.Listing{testListing()}
 	}
 
-	return []blocklist.Listing{}
+	if addr == netip.MustParseAddr(torExitAddr) {
+		return []iplist.Listing{{Name: iplist.TorExitsList}}
+	}
+
+	return []iplist.Listing{}
 }
 
-func (fakeBlocklists) ShortestInterval() time.Duration {
-	return testBlocklistInterval
+func (fakeIPLists) ShortestInterval() time.Duration {
+	return testIPListInterval
 }
 
-// TestIPLookupReportsBlocklists looks up two routed addresses, one of them on
-// a blocklist. The listed address's result names the list, says what it means
-// and when it was updated. The other's result has an empty list.
-func TestIPLookupReportsBlocklists(t *testing.T) {
+// TestIPLookupFlags looks up addresses with and without a route. Every result
+// has both flags, under the JSON keys the API documents.
+func TestIPLookupFlags(t *testing.T) {
 	t.Parallel()
 
 	s := newServerWithTestRoutes(t)
 	s.resolver = &fakeResolver{}
-	s.SetBlocklists(fakeBlocklists{})
+	s.SetIPLists(fakeIPLists{})
+
+	tests := []struct {
+		name  string
+		addr  string
+		tor   bool
+		bogon bool
+	}{
+		{"on the Tor exit list", torExitAddr, true, true},
+		{"on another list", listedUnroutedAddr, false, true},
+		{"routed IPv4", addrInTestPrefixV4, false, true},
+		{"routed IPv6", addrInTestPrefixV6, false, true},
+		{"private IPv4", "10.0.0.1", false, true},
+		{"loopback IPv4", "127.0.0.1", false, true},
+		{"public IPv4", "1.1.1.1", false, false},
+		{"private IPv6", "fd00::1", false, true},
+		{"loopback IPv6", "::1", false, true},
+		{"public IPv6", "2606:4700:4700::1111", false, false},
+		{"public IPv4 in IPv6 form", "::ffff:1.1.1.1", false, false},
+		{"private IPv4 in IPv6 form", "::ffff:10.0.0.1", false, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			path := "/api/v1/ip/" + tt.addr
+
+			results := resultFields(t, get(t, s, path).Body.Bytes())
+			if len(results) != 1 {
+				t.Fatalf("%s: %d results, want 1", path, len(results))
+			}
+
+			var got map[string]bool
+
+			err := json.Unmarshal(results[0]["flags"], &got)
+			if err != nil {
+				t.Fatalf("%s: decoding flags %s: %v", path, results[0]["flags"], err)
+			}
+
+			want := map[string]bool{"is_tor": tt.tor, "is_bogon": tt.bogon}
+			if !maps.Equal(got, want) {
+				t.Errorf("%s: flags %v, want %v", path, got, want)
+			}
+		})
+	}
+}
+
+// TestIPLookupReportsIPLists looks up two routed addresses, one of them on an
+// IP list. The listed address's result names the list, says what it means and
+// when it was updated. The other's result has an empty list.
+func TestIPLookupReportsIPLists(t *testing.T) {
+	t.Parallel()
+
+	s := newServerWithTestRoutes(t)
+	s.resolver = &fakeResolver{}
+	s.SetIPLists(fakeIPLists{})
 
 	rec := httptest.NewRecorder()
 	s.router.ServeHTTP(rec, httptest.NewRequestWithContext(t.Context(),
@@ -1498,15 +1560,15 @@ func TestIPLookupReportsBlocklists(t *testing.T) {
 
 	want := testListing()
 
-	listed := results[0].Blocklists
+	listed := results[0].IPLists
 	if len(listed) != 1 || listed[0].Name != want.Name ||
 		listed[0].Description != want.Description ||
 		!listed[0].Updated.Equal(want.Updated) {
-		t.Errorf("%s: blocklists %+v, want [%+v]", results[0].IP, listed, want)
+		t.Errorf("%s: ip_lists %+v, want [%+v]", results[0].IP, listed, want)
 	}
 
-	if !strings.Contains(rec.Body.String(), `"blocklists":[]`) {
-		t.Errorf("answer %s, want an empty blocklists list for %s",
+	if !strings.Contains(rec.Body.String(), `"ip_lists":[]`) {
+		t.Errorf("answer %s, want an empty ip_lists list for %s",
 			rec.Body, addrInTestPrefixV6)
 	}
 }
@@ -1536,20 +1598,19 @@ func resultFields(t *testing.T, answer []byte) []map[string]json.RawMessage {
 	return body.Data.Results
 }
 
-// TestIPLookupReportsBlocklistsOfAnAddressWithNoRoute looks up a listed
-// address that has no live route, alone and beside a routed address. Each
-// answer is 200 and has a result for the address, with its blocklists and
-// every route field set to null. Before the fix the lookup of that address
-// alone answered 404, and beside a routed address it was only named in
-// errors, so its blocklists were never reported. After that fix the result
-// still left out the route fields
-// (https://git.eeqj.de/sneak/routewatch/issues/200).
-func TestIPLookupReportsBlocklistsOfAnAddressWithNoRoute(t *testing.T) {
+// TestIPLookupReportsIPListsOfAnAddressWithNoRoute looks up a listed address
+// that has no live route, alone and beside a routed address. Each answer is
+// 200 and has a result for the address, with its IP lists and every route
+// field set to null. Before the fix the lookup of that address alone answered
+// 404, and beside a routed address it was only named in errors, so its IP
+// lists were never reported. After that fix the result still left out the
+// route fields (https://git.eeqj.de/sneak/routewatch/issues/200).
+func TestIPLookupReportsIPListsOfAnAddressWithNoRoute(t *testing.T) {
 	t.Parallel()
 
 	s := newServerWithTestRoutes(t)
 	s.resolver = &fakeResolver{}
-	s.SetBlocklists(fakeBlocklists{})
+	s.SetIPLists(fakeIPLists{})
 
 	// routeFields are the fields of a result that come from the address's
 	// route and that route's origin AS.
@@ -1605,10 +1666,10 @@ func TestIPLookupReportsBlocklistsOfAnAddressWithNoRoute(t *testing.T) {
 		}
 
 		result := body.Data.Results[i]
-		if len(result.Blocklists) != 1 ||
-			result.Blocklists[0].Name != testListing().Name {
-			t.Errorf("%s: blocklists %+v, want [%+v]",
-				target, result.Blocklists, testListing())
+		if len(result.IPLists) != 1 ||
+			result.IPLists[0].Name != testListing().Name {
+			t.Errorf("%s: ip_lists %+v, want [%+v]",
+				target, result.IPLists, testListing())
 		}
 	}
 }
@@ -1629,7 +1690,7 @@ func TestIPLookupResultsHaveTheSameFields(t *testing.T) {
 	s.resolver = &fakeResolver{hosts: map[string][]string{
 		twoAddressHostName: {addrInTestPrefixV4, listedUnroutedAddr},
 	}}
-	s.SetBlocklists(fakeBlocklists{})
+	s.SetIPLists(fakeIPLists{})
 
 	// want is the fields of the first result.
 	var want []string
@@ -1684,7 +1745,7 @@ func TestIPLookupOfAnAddressWithoutPTRNamesOrStoredNetblock(t *testing.T) {
 }
 
 // TestIPLookupAnswersMayBeCached checks the Cache-Control header of the IP
-// lookup answers. Caches may keep them for the blocklists' shortest interval,
+// lookup answers. Caches may keep them for the IP lists' shortest interval,
 // and only the caller's own browser may keep the answer about the caller's
 // own address.
 func TestIPLookupAnswersMayBeCached(t *testing.T) {
@@ -1692,7 +1753,7 @@ func TestIPLookupAnswersMayBeCached(t *testing.T) {
 
 	s := newServerWithTestRoutes(t)
 	s.resolver = &fakeResolver{}
-	s.SetBlocklists(fakeBlocklists{})
+	s.SetIPLists(fakeIPLists{})
 
 	tests := []struct {
 		path string

internal/server/server.go

@@ -22,9 +22,9 @@ import (
 	"sync/atomic"
 	"time"
 
-	"git.eeqj.de/sneak/routewatch/internal/blocklist"
 	"git.eeqj.de/sneak/routewatch/internal/config"
 	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/iplist"
 	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/routetable"
 	"git.eeqj.de/sneak/routewatch/internal/streamer"
@@ -45,10 +45,10 @@ type ASNFetcher interface {
 	GetStats() ASNFetcherStats
 }
 
-// Blocklists tells which public blocklists list an address, from copies it
-// keeps in memory, as *blocklist.Blocklists does.
-type Blocklists interface {
-	Lookup(addr netip.Addr) []blocklist.Listing
+// IPLists tells which public IP lists contain an address, from copies it keeps
+// in memory, as *iplist.IPLists does.
+type IPLists interface {
+	Lookup(addr netip.Addr) []iplist.Listing
 	ShortestInterval() time.Duration
 }
 
@@ -69,7 +69,7 @@ type Server struct {
 	port       int
 	srv        *http.Server
 	asnFetcher ASNFetcher
-	blocklists Blocklists
+	ipLists    IPLists
 
 	// trustedProxies are the reverse proxies whose X-Forwarded-For header
 	// RealIPMiddleware believes
@@ -202,8 +202,8 @@ func (s *Server) SetASNFetcher(fetcher ASNFetcher) {
 	s.asnFetcher = fetcher
 }
 
-// SetBlocklists sets the blocklists the IP lookups report. Call it before
-// Start: the handlers read the blocklists without a lock.
-func (s *Server) SetBlocklists(blocklists Blocklists) {
-	s.blocklists = blocklists
+// SetIPLists sets the IP lists the IP lookups report. Call it before Start:
+// the handlers read the IP lists without a lock.
+func (s *Server) SetIPLists(ipLists IPLists) {
+	s.ipLists = ipLists
 }