Resolve PTR names over DNS-over-HTTPS and cache them for the record TTL (closes #238)

`internal/ptr` asks Google, Cloudflare, AdGuard and Quad9 in turn, 2 seconds in all per address. It keeps answers in memory and writes them through to `cache.db`, opened by the new `internal/cachedb`. A reserved address is not sent to the resolvers.

Judgement calls:
- Each resolver gets an equal share of the time left, so a hung resolver does not use up the 2 seconds.
- The negative TTL is the smaller of the SOA minimum and the SOA's own TTL (RFC 2308).
- Names that are not host names are dropped, as `net.Resolver.LookupAddr` does.

Model: opus-5-5

README.md

@@ -285,12 +285,8 @@ address. Every entry has the same fields:
   lookups), or an empty list when it has none
 - `flags`: yes-or-no facts about the address:
     - `is_tor`: true when the address is on the `tor_exits` list
-    - `is_vpn`: true when the address is on any list of VPN servers (see IP
-      lists)
     - `is_bogon`: true when the address is reserved, so that no network should
       announce it on the internet
-- `vpn_providers`: the names of the lists of VPN servers the address is on, or
-  an empty list when it is on none
 - `ip_lists`: the public IP lists the address is on (see IP lists), or an empty
   list when it is on none
 
@@ -421,16 +417,6 @@ The lists:
   last 30 days. From
   [FireHOL](https://iplists.firehol.org/?ipset=firehol_level3), downloaded every
   3 hours.
-- `ivpn`: VPN servers run by IVPN. From
-  [IVPN](https://api.ivpn.net/v5/servers.json), downloaded once a day.
-- `mullvad`: VPN servers run by Mullvad. From
-  [Mullvad](https://api.mullvad.net/www/relays/all/), downloaded once a day.
-- `nordvpn`: VPN servers run by NordVPN. From
-  [NordVPN](https://api.nordvpn.com/v1/servers?limit=0&fields[servers.station]&fields[servers.ipv6_station]&fields[servers.hostname]),
-  downloaded once a day.
-- `pia`: VPN servers run by Private Internet Access. From
-  [Private Internet Access](https://serverlist.piaservers.net/vpninfo/servers/v6),
-  downloaded once a day.
 - `spamhaus_drop` and `spamhaus_dropv6`: IPv4 and IPv6 networks hijacked or
   leased by spammers or cyber criminals, according to Spamhaus. From
   [Spamhaus DROP](https://www.spamhaus.org/blocklists/do-not-route-or-peer/),
@@ -439,9 +425,6 @@ The lists:
   the Tor network leaves. From the Tor Project's
   [Onionoo](https://metrics.torproject.org/onionoo.html) service, downloaded
   every hour.
-- `x4bnet` and `x4bnet_v6`: IPv4 and IPv6 networks of VPN services, according to
-  a community list that names no service. From
-  [X4BNet](https://github.com/X4BNet/lists_vpn), downloaded once a day.
 
 No list is downloaded more often than its publisher updates it or allows. Each
 can be downloaded whole without an account or a key.
@@ -498,8 +481,6 @@ How RouteWatch keeps the answers:
   whose SOA record has a TTL or minimum field of 0.
 - A failed lookup is not kept, so the next lookup of the address asks again.
 - Every 10 minutes it deletes expired answers from memory and from `cache.db`.
-- It keeps answers for at most 250,000 addresses, and keeps no answer for a new
-  address while it holds that many.
 
 ## Configuration
 

TODO.md

@@ -56,13 +56,6 @@ problem the run finds.
 - 2026-11-10: the IP lookup finds PTR names over DNS-over-HTTPS and caches them
   for the record's TTL, in memory and in `cache.db` (closes
   https://git.eeqj.de/sneak/routewatch/issues/238).
-- 2026-11-10: the tests no longer fail when a busy host stalls for several
-  seconds. Most such waits are now 15 seconds. The test of the stream's idle
-  timeout runs on a fake clock (closes #240)
-- 2026-11-10: the IP lookup checks the public VPN server lists of Mullvad,
-  NordVPN, Private Internet Access and IVPN, and X4BNet's community list. Each
-  result has `flags.is_vpn` and `vpn_providers` (closes
-  https://git.eeqj.de/sneak/routewatch/issues/235).
 - 2026-11-10: `tor_exits` comes from Onionoo, so it holds IPv6 exits and
   `is_tor` is true for them (closes
   https://git.eeqj.de/sneak/routewatch/issues/234).

cmd/asinfo-gen/main_test.go

@@ -12,7 +12,7 @@ import (
 
 // parseTimeLimit is how long a test waits for parseCSV to return before it
 // fails.
-const parseTimeLimit = 15 * time.Second
+const parseTimeLimit = 2 * time.Second
 
 // TestParseCSVReadsTodaysLayout parses an as.csv with the country code column
 // that the source added after the description. It expects each AS with its

internal/bogon/bogon.go

@@ -1,5 +1,5 @@
-// Package bogon tells whether a prefix, an address or an AS number is reserved:
-// set aside for a special purpose, so that no network should announce it on the
+// Package bogon tells whether a prefix or an AS number is reserved: set aside
+// for a special purpose, so that no network should announce it on the
 // internet. A route is a bogon announcement when its prefix is reserved or its
 // origin AS is.
 //
@@ -42,15 +42,6 @@ func Prefix(prefix netip.Prefix) (string, bool) {
 	return holder.name + " (" + holder.prefix.String() + ")", true
 }
 
-// Addr returns why addr is reserved, and true, when it lies inside a reserved
-// block, as Prefix decides. An IPv4 address written in IPv6 form counts as the
-// IPv4 address it holds. It returns "" and false when addr is not reserved.
-func Addr(addr netip.Addr) (string, bool) {
-	addr = addr.Unmap()
-
-	return Prefix(netip.PrefixFrom(addr, addr.BitLen()))
-}
-
 // ASN returns why asn is reserved, and true, when it is. It returns "" and
 // false when asn is not reserved.
 func ASN(asn int) (string, bool) {

internal/bogon/bogon_test.go

@@ -8,9 +8,6 @@ import (
 	"git.eeqj.de/sneak/routewatch/internal/bogon"
 )
 
-// privateUseTen is why a prefix or an address inside 10.0.0.0/8 is reserved.
-const privateUseTen = "Private-Use (10.0.0.0/8)"
-
 func TestPrefix(t *testing.T) {
 	t.Parallel()
 
@@ -19,8 +16,8 @@ func TestPrefix(t *testing.T) {
 		// want is why the prefix is reserved, or "" when it is not.
 		want string
 	}{
-		{"10.1.2.0/24", privateUseTen},
-		{"10.0.0.0/8", privateUseTen},
+		{"10.1.2.0/24", "Private-Use (10.0.0.0/8)"},
+		{"10.0.0.0/8", "Private-Use (10.0.0.0/8)"},
 		{"192.0.2.0/24", "Documentation (TEST-NET-1) (192.0.2.0/24)"},
 		{"2001:db8:1::/48", "Documentation (2001:db8::/32)"},
 		{"fd00::/8", "Unique-Local (fc00::/7)"},
@@ -59,39 +56,6 @@ func TestPrefix(t *testing.T) {
 	}
 }
 
-func TestAddr(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		addr string
-		// want is why the address is reserved, or "" when it is not.
-		want string
-	}{
-		{"10.0.0.1", privateUseTen},
-		{"fd00::1", "Unique-Local (fc00::/7)"},
-		// An IPv4 address written in IPv6 form counts as the IPv4 address.
-		{"::ffff:10.0.0.1", privateUseTen},
-		{"::ffff:8.8.8.8", ""},
-		// An address that may be announced, inside a reserved block.
-		{"192.0.0.9", ""},
-		// Addresses anyone may announce.
-		{"8.8.8.8", ""},
-		{"2001:4860:4860::8888", ""},
-	}
-
-	for _, tc := range tests {
-		t.Run(tc.addr, func(t *testing.T) {
-			t.Parallel()
-
-			reason, reserved := bogon.Addr(netip.MustParseAddr(tc.addr))
-			if reason != tc.want || reserved != (tc.want != "") {
-				t.Errorf("Addr(%s) = %q, %v; want %q", tc.addr, reason,
-					reserved, tc.want)
-			}
-		})
-	}
-}
-
 func TestASN(t *testing.T) {
 	t.Parallel()
 

internal/database/database_internal_test.go

@@ -72,34 +72,17 @@ const (
 	// lockTestPrefix is the prefix the batch writes in the checkpoint tests
 	// store.
 	lockTestPrefix = "192.0.2.0/24"
-	// longBusyTimeoutMs is the busy timeout setLongBusyTimeout gives the
-	// writing connection. A checkpoint that waits for an open read takes this
-	// long.
-	longBusyTimeoutMs = 30000
 	// readerCheckpointLimit is how long a checkpoint, and a batch write
-	// waiting for it, may take while a reader is open: well under
-	// longBusyTimeoutMs, with room for a stall on a busy host.
-	readerCheckpointLimit = 15 * time.Second
+	// waiting for it, may take while a reader is open: well under the busy
+	// timeout, which a checkpoint that waits for the reader takes.
+	readerCheckpointLimit = time.Second
 	// truncateCheckpointLimit is how long a checkpoint of a WAL file over
 	// sqliteWALSizeLimitBytes may take to give up while a reader is open: its
-	// wait for the reader plus readerCheckpointLimit.
+	// wait for the reader plus a second, well under the busy timeout.
 	truncateCheckpointLimit = truncateBusyTimeoutMs*time.Millisecond +
-		readerCheckpointLimit
+		time.Second
 )
 
-// setLongBusyTimeout gives the writing connection of db longBusyTimeoutMs, so
-// that a checkpoint that waits for an open read takes far longer than a stall
-// on a busy host.
-func setLongBusyTimeout(ctx context.Context, t *testing.T, db *Database) {
-	t.Helper()
-
-	_, err := db.writer.ExecContext(ctx,
-		fmt.Sprintf("PRAGMA busy_timeout=%d", longBusyTimeoutMs))
-	if err != nil {
-		t.Fatalf("failed to set the busy timeout: %v", err)
-	}
-}
-
 // TestConnectionPoolPragmas holds several pooled connections open at once and
 // checks each one carries the per-connection settings from the DSN, plus the
 // process-wide heap limits, and sees the new file with auto_vacuum
@@ -596,8 +579,6 @@ func TestCheckpointDoesNotWaitForReader(t *testing.T) {
 	ctx := context.Background()
 	ts := time.Now().UTC()
 
-	setLongBusyTimeout(ctx, t, db)
-
 	err = db.UpdatePrefixesBatch(map[string]time.Time{"198.51.100.0/24": ts})
 	if err != nil {
 		t.Fatalf("failed to store the prefix the reader reads: %v", err)
@@ -709,7 +690,6 @@ func TestCheckpointEmptiesWALOnceNoReadIsOpen(t *testing.T) {
 	}
 
 	fillWALPastLimit(ctx, t, db)
-	setLongBusyTimeout(ctx, t, db)
 
 	started := time.Now()
 

internal/iplist/iplist.go

@@ -34,23 +34,6 @@ const (
 	// addresses in two fields: exit_addresses, which has IPv4 only, and
 	// or_addresses, which has IPv4 and IPv6, each with a port.
 	FormatOnionooJSON
-
-	// FormatMullvadJSON is Mullvad's JSON list of relays. A relay's addresses
-	// are in ipv4_addr_in, ipv6_addr_in and ipv4_v2ray.
-	FormatMullvadJSON
-
-	// FormatNordVPNJSON is NordVPN's JSON list of servers. A server's
-	// addresses are in station and ipv6_station.
-	FormatNordVPNJSON
-
-	// FormatPIAJSON is Private Internet Access's JSON server list, then a
-	// blank line and a signature. Each region's servers has lists of servers
-	// by protocol, and each server has its address in ip.
-	FormatPIAJSON
-
-	// FormatIVPNJSON is IVPN's JSON server list. The hosts of its wireguard
-	// and openvpn gateways have their addresses in host and v2ray.
-	FormatIVPNJSON
 )
 
 // List is one public IP list.
@@ -70,9 +53,6 @@ type List struct {
 
 	// Format is how the list's file is written.
 	Format Format
-
-	// VPN says that the list holds servers of VPN services.
-	VPN bool
 }
 
 // Listing says that a list contains an address.
@@ -83,10 +63,6 @@ type Listing struct {
 	// Updated is when routewatch last downloaded the list, or last heard from
 	// its publisher that its copy was still current.
 	Updated time.Time `json:"updated"`
-
-	// VPN says that the list holds servers of VPN services. A lookup answer
-	// reports it through is_vpn and vpn_providers.
-	VPN bool `json:"-"`
 }
 
 // listCopy is a list's last good copy in memory.
@@ -153,7 +129,6 @@ func (b *IPLists) Lookup(addr netip.Addr) []Listing {
 				Name:        list.Name,
 				Description: list.Description,
 				Updated:     c.updated,
-				VPN:         list.VPN,
 			})
 		}
 	}

internal/iplist/iplist_internal_test.go

@@ -43,36 +43,6 @@ const (
 	],"bridges":[]}`
 )
 
-// Small documents in the VPN services' formats. PIA's and IVPN's have no
-// public IPv6 addresses, and IVPN's holds addresses that are not its servers,
-// which must not be read.
-const (
-	mullvadBody = `[
-		{"hostname":"a-wg-001","ipv4_addr_in":"192.0.2.40","ipv6_addr_in":"2001:db8::40"},
-		{"hostname":"a-br-001","ipv4_addr_in":"192.0.2.41","ipv6_addr_in":null,
-		 "ipv4_v2ray":"192.0.2.42"}
-	]`
-	nordVPNBody = `[
-		{"hostname":"a1.example.com","station":"192.0.2.50","ipv6_station":""},
-		{"hostname":"a2.example.com","station":"192.0.2.51","ipv6_station":"2001:db8::51"}
-	]`
-	piaBody = `{"groups":{"wg":[{"name":"wireguard","ports":[1337]}]},"regions":[
-		{"id":"a","servers":{
-			"wg":[{"ip":"192.0.2.60","cn":"a1"}],
-			"ikev2":[{"ip":"192.0.2.61","cn":"a1"}]}},
-		{"id":"b","servers":{"meta":[{"ip":"192.0.2.62","cn":"b1","van":true}]}}
-	]}` + "\n\nc2lnbmF0dXJl\nbGluZSB0d28=\n"
-	ivpnBody = `{"wireguard":[{"gateway":"a.wg.example.com","hosts":[
-		{"hostname":"a1","host":"192.0.2.70","v2ray":"192.0.2.71",
-		 "ipv6":{"local_ip":"2001:db8::70/96"}}]}],
-	"openvpn":[{"gateway":"a.gw.example.com","hosts":[
-		{"hostname":"a1","host":"192.0.2.72"}]}],
-	"config":{"api":{"ips":["192.0.2.73"]}}}`
-)
-
-// errorPage is a file that is no list, as a publisher's error page is.
-const errorPage = "<!DOCTYPE html>\n<html></html>\n"
-
 // testETag is the ETag a publisher sends with a version of the test list.
 const testETag = `"v1"`
 
@@ -188,7 +158,13 @@ func lookup(t *testing.T, b *IPLists, addr string) []Listing {
 func TestLookupFindsListedAddresses(t *testing.T) {
 	t.Parallel()
 
-	runLookupCases(t, []lookupCase{
+	tests := []struct {
+		name     string
+		format   Format
+		body     string
+		listed   []string
+		unlisted []string
+	}{
 		{
 			name:     "single addresses",
 			format:   FormatLines,
@@ -230,60 +206,9 @@ func TestLookupFindsListedAddresses(t *testing.T) {
 			},
 			unlisted: []string{"192.0.2.12", "2001:db8::2"},
 		},
-	})
-}
+	}
 
-// TestLookupFindsVPNServers downloads a list in each VPN service's format and
-// looks up addresses on it and off it.
-func TestLookupFindsVPNServers(t *testing.T) {
-	t.Parallel()
-
-	runLookupCases(t, []lookupCase{
-		{
-			name:     "Mullvad relays",
-			format:   FormatMullvadJSON,
-			body:     mullvadBody,
-			listed:   []string{"192.0.2.40", "192.0.2.41", "192.0.2.42", "2001:db8::40"},
-			unlisted: []string{"192.0.2.43", "2001:db8::41"},
-		},
-		{
-			name:     "NordVPN servers",
-			format:   FormatNordVPNJSON,
-			body:     nordVPNBody,
-			listed:   []string{"192.0.2.50", "192.0.2.51", "2001:db8::51"},
-			unlisted: []string{"192.0.2.52", "2001:db8::50"},
-		},
-		{
-			name:     "PIA servers, with the signature after the JSON",
-			format:   FormatPIAJSON,
-			body:     piaBody,
-			listed:   []string{"192.0.2.60", "192.0.2.61", "192.0.2.62"},
-			unlisted: []string{"192.0.2.63", "2001:db8::60"},
-		},
-		{
-			name:     "IVPN hosts",
-			format:   FormatIVPNJSON,
-			body:     ivpnBody,
-			listed:   []string{"192.0.2.70", "192.0.2.71", "192.0.2.72"},
-			unlisted: []string{"192.0.2.73", "2001:db8::70"},
-		},
-	})
-}
-
-// lookupCase is a list file, the addresses it holds and some it does not.
-type lookupCase struct {
-	name     string
-	format   Format
-	body     string
-	listed   []string
-	unlisted []string
-}
-
-// runLookupCases downloads each case's list file and checks its addresses.
-func runLookupCases(t *testing.T, cases []lookupCase) {
-	t.Helper()
-
-	for _, tt := range cases {
+	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
 
@@ -335,7 +260,7 @@ func TestFailedDownloadKeepsThePreviousCopy(t *testing.T) {
 		body   string
 	}{
 		{"server error", http.StatusInternalServerError, "unavailable"},
-		{"not a list", http.StatusOK, errorPage},
+		{"not a list", http.StatusOK, "<!DOCTYPE html>\n<html></html>\n"},
 	}
 
 	for _, tt := range tests {
@@ -381,7 +306,7 @@ func TestFileThatIsNotAnOnionooDocumentKeepsThePreviousCopy(t *testing.T) {
 		name string
 		body string
 	}{
-		{"not JSON", errorPage},
+		{"not JSON", "<!DOCTYPE html>\n<html></html>\n"},
 		{"other JSON", `{"status":"ok","data":{"relays_count":1}}`},
 		{"JSON array", `[{"or_addresses":["192.0.2.1:443"]}]`},
 		{"no relays", `{"relays":[],"bridges":[]}`},
@@ -423,112 +348,6 @@ func TestFileThatIsNotAnOnionooDocumentKeepsThePreviousCopy(t *testing.T) {
 	}
 }
 
-// TestWrongVPNDocumentFailsToParse parses documents that are not a VPN
-// service's list. Each fails, so none can replace a good copy.
-func TestWrongVPNDocumentFailsToParse(t *testing.T) {
-	t.Parallel()
-
-	formats := []struct {
-		name       string
-		format     Format
-		good       string
-		empty      string
-		badAddress string
-	}{
-		{
-			"Mullvad", FormatMullvadJSON, mullvadBody,
-			`[{"hostname":"a"}]`, `[{"ipv4_addr_in":"example"}]`,
-		},
-		{
-			"NordVPN", FormatNordVPNJSON, nordVPNBody,
-			`[{"hostname":"a","station":"","ipv6_station":""}]`,
-			`[{"station":"example"}]`,
-		},
-		{
-			"PIA", FormatPIAJSON, piaBody,
-			`{"regions":[{"id":"a","servers":{}}]}`,
-			`{"regions":[{"servers":{"wg":[{"ip":"example"}]}}]}`,
-		},
-		{
-			"IVPN", FormatIVPNJSON, ivpnBody,
-			`{"wireguard":[{"hosts":[]}],"openvpn":[]}`,
-			`{"wireguard":[{"hosts":[{"host":"example"}]}]}`,
-		},
-	}
-
-	for _, f := range formats {
-		bodies := map[string]string{
-			"not JSON":      errorPage,
-			"other JSON":    `{"status":"ok","data":{"count":1}}`,
-			"no addresses":  f.empty,
-			"bad address":   f.badAddress,
-			"cut off":       f.good[:len(f.good)/2],
-			"an empty file": "",
-		}
-
-		for name, body := range bodies {
-			t.Run(f.name+" "+name, func(t *testing.T) {
-				t.Parallel()
-
-				addresses, err := parse(strings.NewReader(body), f.format)
-				if err == nil {
-					t.Errorf("parse returned %v and no error", addresses.Ranges())
-				}
-			})
-		}
-	}
-}
-
-// TestLookupMarksVPNLists looks up an address on a VPN list and on another
-// list. Only the VPN list's listing says it is one.
-func TestLookupMarksVPNLists(t *testing.T) {
-	t.Parallel()
-
-	_, url := newPublisher(t, goodListBody)
-	vpnList := testList(url, FormatLines)
-	vpnList.Name = "test_vpn_list"
-	vpnList.VPN = true
-	otherList := testList(url, FormatLines)
-
-	b := New(Params{
-		Dir:    t.TempDir(),
-		Lists:  []List{vpnList, otherList},
-		Logger: slog.New(slog.DiscardHandler),
-	})
-
-	for _, list := range b.lists {
-		err := b.download(t.Context(), list)
-		if err != nil {
-			t.Fatalf("download of %s: %v", list.Name, err)
-		}
-	}
-
-	listings := lookup(t, b, listedAddr)
-	if len(listings) != 2 || !listings[0].VPN || listings[1].VPN {
-		t.Errorf("listings %+v, want the first of two marked as a VPN list",
-			listings)
-	}
-}
-
-// TestPublicListsMarkTheVPNLists checks which public lists are VPN lists,
-// since their names are what vpn_providers reports.
-func TestPublicListsMarkTheVPNLists(t *testing.T) {
-	t.Parallel()
-
-	var got []string
-
-	for _, list := range Lists() {
-		if list.VPN {
-			got = append(got, list.Name)
-		}
-	}
-
-	want := []string{"ivpn", "mullvad", "nordvpn", "pia", "x4bnet", "x4bnet_v6"}
-	if !slices.Equal(got, want) {
-		t.Errorf("VPN lists %v, want %v", got, want)
-	}
-}
-
 // 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) {
@@ -646,13 +465,9 @@ func TestRestartLoadsCopiesFromDisk(t *testing.T) {
 	second.Start(t.Context())
 	second.Stop(t.Context())
 
-	// The download takes its time after writing the file, and the restart
-	// reads the file's time. A busy host can put seconds between the two.
-	const maxUpdatedDifference = 15 * time.Second
-
 	listings := lookup(t, second, listedAddr)
 	if len(listings) != 1 ||
-		listings[0].Updated.Sub(downloaded).Abs() > maxUpdatedDifference {
+		listings[0].Updated.Sub(downloaded).Abs() > time.Second {
 		t.Errorf("after the restart, listings %+v, want one updated at %s",
 			listings, downloaded)
 	}

internal/iplist/lists.go

@@ -1,9 +1,6 @@
 package iplist
 
-import (
-	"slices"
-	"time"
-)
+import "time"
 
 // TorExitsList is the name of the list of Tor exit nodes.
 const TorExitsList = "tor_exits"
@@ -35,20 +32,12 @@ const (
 	// Onionoo sets no download limit:
 	// https://metrics.torproject.org/onionoo.html
 	torExitsInterval = time.Hour
-
-	// A VPN service's servers change slowly, so once a day is enough.
-	vpnListInterval = 24 * time.Hour
 )
 
 // 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 {
-	return slices.Concat(nonVPNLists(), vpnLists())
-}
-
-// nonVPNLists returns the public lists that are not lists of VPN servers.
-func nonVPNLists() []List {
 	return []List{
 		{
 			Name: "dshield",
@@ -107,64 +96,3 @@ func nonVPNLists() []List {
 		},
 	}
 }
-
-// vpnLists returns the public lists of VPN servers. Their names are what
-// vpn_providers reports.
-func vpnLists() []List {
-	return []List{
-		{
-			Name:        "ivpn",
-			Description: "A server of the IVPN service",
-			URL:         "https://api.ivpn.net/v5/servers.json",
-			Interval:    vpnListInterval,
-			Format:      FormatIVPNJSON,
-			VPN:         true,
-		},
-		{
-			Name:        "mullvad",
-			Description: "A server of the Mullvad VPN service",
-			URL:         "https://api.mullvad.net/www/relays/all/",
-			Interval:    vpnListInterval,
-			Format:      FormatMullvadJSON,
-			VPN:         true,
-		},
-		{
-			Name:        "nordvpn",
-			Description: "A server of the NordVPN service",
-			URL: "https://api.nordvpn.com/v1/servers?limit=0" +
-				"&fields[servers.station]&fields[servers.ipv6_station]" +
-				"&fields[servers.hostname]",
-			Interval: vpnListInterval,
-			Format:   FormatNordVPNJSON,
-			VPN:      true,
-		},
-		{
-			Name:        "pia",
-			Description: "A server of the Private Internet Access VPN service",
-			URL:         "https://serverlist.piaservers.net/vpninfo/servers/v6",
-			Interval:    vpnListInterval,
-			Format:      FormatPIAJSON,
-			VPN:         true,
-		},
-		{
-			Name: "x4bnet",
-			Description: "In an IPv4 network of a VPN service, according to " +
-				"X4BNet's community list",
-			URL: "https://raw.githubusercontent.com/X4BNet/lists_vpn/main/" +
-				"output/vpn/ipv4.txt",
-			Interval: vpnListInterval,
-			Format:   FormatLines,
-			VPN:      true,
-		},
-		{
-			Name: "x4bnet_v6",
-			Description: "In an IPv6 network of a VPN service, according to " +
-				"X4BNet's community list",
-			URL: "https://raw.githubusercontent.com/X4BNet/lists_vpn/main/" +
-				"output/vpn/ipv6.txt",
-			Interval: vpnListInterval,
-			Format:   FormatLines,
-			VPN:      true,
-		},
-	}
-}

internal/iplist/parse.go

@@ -8,7 +8,6 @@ import (
 	"io"
 	"net"
 	"net/netip"
-	"slices"
 	"strings"
 
 	"go4.org/netipx"
@@ -34,7 +33,7 @@ var (
 	errUnknownFormat = errors.New("unknown list format")
 	errNoNetwork     = errors.New("no network on the line")
 	errBadRange      = errors.New("first and last address make no range")
-	errNoAddresses   = errors.New("no addresses in the document")
+	errNoAddresses   = errors.New("no relay addresses in the document")
 )
 
 // parse reads a list file written in format and returns the addresses it
@@ -50,14 +49,6 @@ func parse(r io.Reader, format Format) (*netipx.IPSet, error) {
 		return parseLines(r, addDShieldNetwork)
 	case FormatOnionooJSON:
 		return parseOnionoo(r)
-	case FormatMullvadJSON:
-		return parseMullvad(r)
-	case FormatNordVPNJSON:
-		return parseNordVPN(r)
-	case FormatPIAJSON:
-		return parsePIA(r)
-	case FormatIVPNJSON:
-		return parseIVPN(r)
 	default:
 		return nil, errUnknownFormat
 	}
@@ -177,6 +168,11 @@ func addDShieldNetwork(builder *netipx.IPSetBuilder, line string) error {
 // fields of the relays in an Onionoo details document. A document with no
 // addresses fails, because the Tor network always has relays.
 func parseOnionoo(r io.Reader) (*netipx.IPSet, error) {
+	data, err := io.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+
 	//nolint:tagliatelle // Onionoo's own field names
 	var details struct {
 		Relays []struct {
@@ -185,7 +181,7 @@ func parseOnionoo(r io.Reader) (*netipx.IPSet, error) {
 		} `json:"relays"`
 	}
 
-	err := readJSON(r, &details)
+	err = json.Unmarshal(data, &details)
 	if err != nil {
 		return nil, err
 	}
@@ -220,153 +216,6 @@ func parseOnionoo(r io.Reader) (*netipx.IPSet, error) {
 	return addresses, nil
 }
 
-// parseMullvad returns the addresses of the relays in a Mullvad document. A
-// relay with no IPv6 address has null for it, and only bridges have
-// ipv4_v2ray.
-func parseMullvad(r io.Reader) (*netipx.IPSet, error) {
-	//nolint:tagliatelle // Mullvad's own field names
-	var relays []struct {
-		IPv4      string `json:"ipv4_addr_in"`
-		IPv6      string `json:"ipv6_addr_in"`
-		IPv4V2Ray string `json:"ipv4_v2ray"`
-	}
-
-	err := readJSON(r, &relays)
-	if err != nil {
-		return nil, err
-	}
-
-	var texts []string
-
-	for _, relay := range relays {
-		texts = append(texts, relay.IPv4, relay.IPv6, relay.IPv4V2Ray)
-	}
-
-	return addressSet(texts)
-}
-
-// parseNordVPN returns the addresses of the servers in a NordVPN document. A
-// server with no IPv6 address has an empty ipv6_station.
-func parseNordVPN(r io.Reader) (*netipx.IPSet, error) {
-	//nolint:tagliatelle // NordVPN's own field names
-	var servers []struct {
-		Station     string `json:"station"`
-		IPv6Station string `json:"ipv6_station"`
-	}
-
-	err := readJSON(r, &servers)
-	if err != nil {
-		return nil, err
-	}
-
-	var texts []string
-
-	for _, server := range servers {
-		texts = append(texts, server.Station, server.IPv6Station)
-	}
-
-	return addressSet(texts)
-}
-
-// parsePIA returns the addresses of the servers in a Private Internet Access
-// document. json.Decoder stops at the end of the JSON, so the signature after
-// it is not read.
-func parsePIA(r io.Reader) (*netipx.IPSet, error) {
-	var list struct {
-		Regions []struct {
-			Servers map[string][]struct {
-				IP string `json:"ip"`
-			} `json:"servers"`
-		} `json:"regions"`
-	}
-
-	err := json.NewDecoder(r).Decode(&list)
-	if err != nil {
-		return nil, err
-	}
-
-	var texts []string
-
-	for _, region := range list.Regions {
-		for _, servers := range region.Servers {
-			for _, server := range servers {
-				texts = append(texts, server.IP)
-			}
-		}
-	}
-
-	return addressSet(texts)
-}
-
-// parseIVPN returns the addresses of the hosts in an IVPN document. A host's
-// ipv6 object holds only an address inside the VPN, so it is not read.
-func parseIVPN(r io.Reader) (*netipx.IPSet, error) {
-	type gateway struct {
-		Hosts []struct {
-			Host  string `json:"host"`
-			V2Ray string `json:"v2ray"`
-		} `json:"hosts"`
-	}
-
-	var list struct {
-		WireGuard []gateway `json:"wireguard"`
-		OpenVPN   []gateway `json:"openvpn"`
-	}
-
-	err := readJSON(r, &list)
-	if err != nil {
-		return nil, err
-	}
-
-	var texts []string
-
-	for _, gw := range slices.Concat(list.WireGuard, list.OpenVPN) {
-		for _, host := range gw.Hosts {
-			texts = append(texts, host.Host, host.V2Ray)
-		}
-	}
-
-	return addressSet(texts)
-}
-
-// readJSON reads r to its end and decodes it, as one JSON document, into v.
-func readJSON(r io.Reader, v any) error {
-	data, err := io.ReadAll(r)
-	if err != nil {
-		return err
-	}
-
-	return json.Unmarshal(data, v)
-}
-
-// addressSet returns the set of the addresses in texts, skipping empty ones.
-// A list with no addresses fails, because every VPN service has servers.
-func addressSet(texts []string) (*netipx.IPSet, error) {
-	var builder netipx.IPSetBuilder
-
-	for _, text := range texts {
-		if text == "" {
-			continue
-		}
-
-		err := addAddress(&builder, text)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	addresses, err := builder.IPSet()
-	if err != nil {
-		return nil, err
-	}
-
-	if len(addresses.Ranges()) == 0 {
-		return nil, errNoAddresses
-	}
-
-	return addresses, nil
-}
-
 // addAddress adds an address, such as 192.0.2.1, to builder.
 func addAddress(builder *netipx.IPSetBuilder, text string) error {
 	addr, err := netip.ParseAddr(text)

internal/ptr/cache.go

@@ -1,6 +1,6 @@
 // Package ptr looks up the PTR names of addresses over DNS-over-HTTPS. It
-// keeps answers in memory for as long as DNS allows, and in cache.db so that
-// the answers survive a restart.
+// keeps each answer in memory for as long as DNS allows, and in cache.db so
+// that the answers survive a restart.
 package ptr
 
 import (
@@ -29,10 +29,6 @@ const (
 
 	// nameSeparator separates the names in a row of the hostnames table.
 	nameSeparator = " "
-
-	// maxAddresses limits how many addresses the cache holds, so that a public
-	// lookup cannot grow memory and cache.db without bound.
-	maxAddresses = 250_000
 )
 
 // Params is what New needs.
@@ -56,16 +52,15 @@ type entry struct {
 // Cache answers PTR lookups from memory, and asks the resolvers for an address
 // it holds no current answer for. Start loads it from cache.db.
 type Cache struct {
-	db         *sql.DB
-	resolvers  []string
-	timeLimit  time.Duration
-	maxEntries int
-	logger     *slog.Logger
-	client     *http.Client
-	now        func() time.Time
+	db        *sql.DB
+	resolvers []string
+	timeLimit time.Duration
+	logger    *slog.Logger
+	client    *http.Client
+	now       func() time.Time
 
-	// entries holds the kept answers by address, at most maxEntries of them.
-	// pending holds those that cache.db does not have yet.
+	// entries holds every answer by address. pending holds those that
+	// cache.db does not have yet.
 	mu      sync.RWMutex
 	entries map[string]entry
 	pending map[string]entry
@@ -78,16 +73,15 @@ type Cache struct {
 // New returns an empty Cache. Start loads it.
 func New(params Params) *Cache {
 	return &Cache{
-		db:         params.DB,
-		resolvers:  params.Resolvers,
-		timeLimit:  LookupTimeout,
-		maxEntries: maxAddresses,
-		logger:     params.Logger.With("component", "ptr"),
-		client:     &http.Client{},
-		now:        time.Now,
-		entries:    make(map[string]entry),
-		pending:    make(map[string]entry),
-		done:       make(chan struct{}),
+		db:        params.DB,
+		resolvers: params.Resolvers,
+		timeLimit: LookupTimeout,
+		logger:    params.Logger.With("component", "ptr"),
+		client:    &http.Client{},
+		now:       time.Now,
+		entries:   make(map[string]entry),
+		pending:   make(map[string]entry),
+		done:      make(chan struct{}),
 	}
 }
 
@@ -101,12 +95,14 @@ func (c *Cache) LookupAddr(ctx context.Context, addr string) ([]string, error) {
 		return nil, fmt.Errorf("parsing the address: %w", err)
 	}
 
-	_, reserved := bogon.Addr(parsed)
+	parsed = parsed.Unmap()
+
+	_, reserved := bogon.Prefix(netip.PrefixFrom(parsed, parsed.BitLen()))
 	if reserved {
 		return []string{}, nil
 	}
 
-	address := parsed.Unmap().String()
+	address := parsed.String()
 
 	cached, ok := c.current(address)
 	if ok {
@@ -174,18 +170,11 @@ func (c *Cache) current(address string) (entry, bool) {
 	return found, true
 }
 
-// store keeps an answer in memory and queues it for cache.db. Once entries
-// holds maxEntries addresses it keeps no new address. It still replaces the
-// answer of an address already held.
+// store keeps an answer in memory and queues it for cache.db.
 func (c *Cache) store(address string, answer entry) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	_, held := c.entries[address]
-	if !held && len(c.entries) >= c.maxEntries {
-		return
-	}
-
 	c.entries[address] = answer
 	c.pending[address] = answer
 }

internal/ptr/cache_internal_test.go

@@ -880,72 +880,3 @@ func TestFlushKeepsAnswersItCouldNotWrite(t *testing.T) {
 		t.Errorf("%d rows after the second write, want 1", got)
 	}
 }
-
-// TestNewAddressIsNotKeptAtTheLimit fills a cache that holds one address. A
-// lookup of a second address still returns its answer, and the cache keeps
-// nothing for it until the sweep has deleted the first address's expired
-// answer.
-func TestNewAddressIsNotKeptAtTheLimit(t *testing.T) {
-	t.Parallel()
-
-	db := openTestDB(t, t.TempDir())
-	resolver := newFakeResolver(t, ptrReply(300, testName))
-	cache, clock := newTestCache(t, db, resolver)
-	cache.maxEntries = 1
-
-	lookupOK(t, cache, testAddress)
-
-	names := lookupOK(t, cache, otherAddress)
-	if !slices.Equal(names, []string{testName}) {
-		t.Errorf("names %v at the limit, want %s", names, testName)
-	}
-
-	_, inEntries := cache.entries[otherAddress]
-	_, inPending := cache.pending[otherAddress]
-
-	if inEntries || inPending {
-		t.Errorf("a new address was kept at the limit: in entries %t, in pending %t",
-			inEntries, inPending)
-	}
-
-	cache.flush(t.Context())
-
-	if got := countRows(t, db); got != 1 {
-		t.Errorf("%d rows at the limit, want 1", got)
-	}
-
-	clock.advance(300 * time.Second)
-	cache.sweep(t.Context())
-	lookupOK(t, cache, otherAddress)
-
-	_, inEntries = cache.entries[otherAddress]
-	if !inEntries {
-		t.Error("a new address was not kept after the sweep made room")
-	}
-}
-
-// TestHeldAddressIsReplacedAtTheLimit lets the answer of the only address a
-// cache holds expire. The new answer replaces it in memory and is queued for
-// cache.db.
-func TestHeldAddressIsReplacedAtTheLimit(t *testing.T) {
-	t.Parallel()
-
-	resolver := newFakeResolver(t, ptrReply(300, testName))
-	cache, clock := newTestCache(t, openTestDB(t, t.TempDir()), resolver)
-	cache.maxEntries = 1
-
-	lookupOK(t, cache, testAddress)
-	clock.advance(300 * time.Second)
-	resolver.setReply(ptrReply(300, otherName))
-	lookupOK(t, cache, testAddress)
-
-	want := []string{otherName}
-
-	if got := cache.entries[testAddress].names; !slices.Equal(got, want) {
-		t.Errorf("entries holds %v, want %v", got, want)
-	}
-
-	if got := cache.pending[testAddress].names; !slices.Equal(got, want) {
-		t.Errorf("pending holds %v, want %v", got, want)
-	}
-}

internal/routewatch/app_integration_internal_test.go

@@ -8,8 +8,6 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/netip"
-	"os"
-	"path/filepath"
 	"slices"
 	"strconv"
 	"strings"
@@ -785,74 +783,3 @@ func TestShutdownCheckpointsAndClosesTheDatabaseLast(t *testing.T) {
 		t.Errorf("Shutdown made the calls %q, want %q", store.calls, want)
 	}
 }
-
-// TestPTRCacheAnswersTheIPLookup starts the PTR cache and the HTTP server as
-// Run does, and looks up a reserved address, which asks no resolver. Without
-// the PTR cache the server has no PTR resolver, and every IP lookup answers
-// 500.
-func TestPTRCacheAnswersTheIPLookup(t *testing.T) {
-	t.Parallel()
-
-	store := newMockStore()
-	log := logger.New()
-	port := freePort(t)
-	cfg := &config.Config{Port: port, StateDir: t.TempDir()}
-	s := streamer.New(log, metrics.New())
-
-	// A started server reads its routing table in the background, so it
-	// needs one.
-	rw := New(Dependencies{
-		DB:       store,
-		Streamer: s,
-		Server: server.New(store, routetable.New(routetable.Params{}), s, log,
-			cfg),
-		Logger: log,
-		Config: cfg,
-	})
-
-	err := rw.startPTRCache(t.Context())
-	if err != nil {
-		t.Fatalf("failed to start the PTR cache: %v", err)
-	}
-
-	defer rw.stopPTRCache(t.Context())
-
-	err = rw.server.Start(t.Context())
-	if err != nil {
-		t.Fatalf("failed to start the HTTP server: %v", err)
-	}
-
-	defer func() { _ = rw.server.Stop(t.Context()) }()
-
-	req, err := http.NewRequestWithContext(t.Context(), http.MethodGet,
-		"http://"+net.JoinHostPort("127.0.0.1", strconv.Itoa(port))+
-			"/api/v1/ip/10.0.0.1", nil)
-	if err != nil {
-		t.Fatalf("failed to build the request: %v", err)
-	}
-
-	resp, err := http.DefaultClient.Do(req)
-	if err != nil {
-		t.Fatalf("the IP lookup failed: %v", err)
-	}
-
-	defer func() { _ = resp.Body.Close() }()
-
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		t.Fatalf("failed to read the answer: %v", err)
-	}
-
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("status %d, want %d; body %s", resp.StatusCode, http.StatusOK, body)
-	}
-
-	if !strings.Contains(string(body), `"ptr":[]`) {
-		t.Errorf("answer %s, want an empty ptr", body)
-	}
-
-	_, err = os.Stat(filepath.Join(cfg.StateDir, "cache.db"))
-	if err != nil {
-		t.Errorf("cache.db is not in the state directory: %v", err)
-	}
-}

internal/server/handlers.go

@@ -778,10 +778,6 @@ type IPLookupResult struct {
 
 	Flags IPLookupFlags `json:"flags"`
 
-	// VPNProviders names the VPN lists the address is on. It is empty, never
-	// nil, when there are none.
-	VPNProviders []string `json:"vpn_providers"`
-
 	// IPLists has one entry for each IP list the address is on.
 	IPLists []iplist.Listing `json:"ip_lists"`
 }
@@ -794,9 +790,6 @@ type IPLookupFlags struct {
 	// IsTor says that the address is on the Tor exit list.
 	IsTor bool `json:"is_tor"`
 
-	// IsVPN says that the address is on a list of VPN servers.
-	IsVPN bool `json:"is_vpn"`
-
 	// IsBogon says that the address is reserved, as package bogon tells.
 	IsBogon bool `json:"is_bogon"`
 }
@@ -981,30 +974,14 @@ func (s *Server) ipLookupResult(ip string, ptrs []string, info IPInfo) IPLookupR
 	listings := s.ipListListings(ip)
 
 	return IPLookupResult{
-		IP:           ip,
-		PTR:          ptrs,
-		IPInfo:       info,
-		Flags:        ipLookupFlags(ip, listings),
-		VPNProviders: vpnProviders(listings),
-		IPLists:      listings,
+		IP:      ip,
+		PTR:     ptrs,
+		IPInfo:  info,
+		Flags:   ipLookupFlags(ip, listings),
+		IPLists: listings,
 	}
 }
 
-// vpnProviders returns the names of the VPN lists among listings. It returns
-// an empty list, never nil, so that an answer's vpn_providers is [] rather
-// than null.
-func vpnProviders(listings []iplist.Listing) []string {
-	names := []string{}
-
-	for _, listing := range listings {
-		if listing.VPN {
-			names = append(names, listing.Name)
-		}
-	}
-
-	return names
-}
-
 // 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 {
@@ -1022,21 +999,20 @@ func ipLookupFlags(ip string, listings []iplist.Listing) IPLookupFlags {
 		IsTor: slices.ContainsFunc(listings, func(l iplist.Listing) bool {
 			return l.Name == iplist.TorExitsList
 		}),
-		IsVPN: slices.ContainsFunc(listings, func(l iplist.Listing) bool {
-			return l.VPN
-		}),
 		IsBogon: isBogon(ip),
 	}
 }
 
-// isBogon says whether the address ip is reserved, as package bogon tells.
+// 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
 	}
 
-	_, reserved := bogon.Addr(addr)
+	addr = addr.Unmap()
+	_, reserved := bogon.Prefix(netip.PrefixFrom(addr, addr.BitLen()))
 
 	return reserved
 }

internal/server/handlers_internal_test.go

@@ -17,7 +17,6 @@ import (
 	"strings"
 	"sync/atomic"
 	"testing"
-	"testing/synctest"
 	"time"
 
 	"git.eeqj.de/sneak/routewatch/internal/config"
@@ -175,9 +174,6 @@ type tableStats struct {
 // carried 203.0.113.0/24, the two with kept routes withdrew it, so its origin
 // keeps no route. The oldest and newest routes are those of the other two
 // prefixes.
-//
-// The requests run in a synctest bubble, whose clock is fake, so a stall on
-// the host does not use up the handlers' 4-second limit.
 func TestStatsHandlersAnswerFromMemory(t *testing.T) {
 	t.Parallel()
 
@@ -223,11 +219,7 @@ func TestStatsHandlersAnswerFromMemory(t *testing.T) {
 
 	for name, handler := range handlers {
 		rec := httptest.NewRecorder()
-
-		synctest.Test(t, func(t *testing.T) {
-			handler(rec,
-				httptest.NewRequestWithContext(t.Context(), http.MethodGet, "/", nil))
-		})
+		handler(rec, httptest.NewRequestWithContext(t.Context(), http.MethodGet, "/", nil))
 
 		if rec.Code != http.StatusOK {
 			t.Errorf("%s: status %d, want %d; body %s",
@@ -262,20 +254,15 @@ func TestStatsHandlersAnswerFromMemory(t *testing.T) {
 // TestStatsAnswerCarriesChurnPerMinute checks that the stream object of the
 // /api/v1/stats answer holds route_churn_per_min as a whole number, and no
 // longer route_churn_per_sec, the moving average it replaces
-// (https://git.eeqj.de/sneak/routewatch/issues/160). The request runs in a
-// synctest bubble, whose clock is fake, so a stall on the host does not use up
-// the handler's 4-second limit.
+// (https://git.eeqj.de/sneak/routewatch/issues/160).
 func TestStatsAnswerCarriesChurnPerMinute(t *testing.T) {
 	t.Parallel()
 
 	s := newServerWithTestRoutes(t)
 
 	rec := httptest.NewRecorder()
-
-	synctest.Test(t, func(t *testing.T) {
-		s.handleStats()(rec,
-			httptest.NewRequestWithContext(t.Context(), http.MethodGet, statsPath, nil))
-	})
+	s.handleStats()(rec,
+		httptest.NewRequestWithContext(t.Context(), http.MethodGet, statsPath, nil))
 
 	if rec.Code != http.StatusOK {
 		t.Fatalf("status %d, want %d; body %s", rec.Code, http.StatusOK, rec.Body)
@@ -323,26 +310,18 @@ func (heldBackHandler) HeldBackCount() int                 { return heldBackMess
 
 // TestStatsAnswerGivesHowManyMessagesAHandlerHoldsBack registers a handler
 // that holds back messages. Its figures in /api/v1/stats, which the status
-// page shows, must give how many. The request runs in a synctest bubble, whose
-// clock is fake, so a stall on the host does not use up the handler's 4-second
-// limit.
+// page shows, must give how many.
 func TestStatsAnswerGivesHowManyMessagesAHandlerHoldsBack(t *testing.T) {
 	t.Parallel()
 
 	s := newServerWithTestRoutes(t)
 	s.streamer.RegisterHandler(heldBackHandler{})
 
-	var answer []byte
-
-	synctest.Test(t, func(t *testing.T) {
-		answer = get(t, s, statsPath).Body.Bytes()
-	})
-
 	var body struct {
 		Data StatsResponse `json:"data"`
 	}
 
-	err := json.Unmarshal(answer, &body)
+	err := json.Unmarshal(get(t, s, statsPath).Body.Bytes(), &body)
 	if err != nil {
 		t.Fatalf("decoding the answer: %v", err)
 	}
@@ -386,9 +365,7 @@ type unitStats struct {
 // names. They used to be strings with the unit in them, such as "1h18m34s" or
 // "1.1 GB" (https://git.eeqj.de/sneak/routewatch/issues/199). The stream has
 // never connected, so the uptime is 0. The memory use in /api/v1/stats is the
-// same number of bytes as its gc.heap_alloc_bytes. The requests run in a
-// synctest bubble, whose clock is fake, so a stall on the host does not use up
-// the handlers' 4-second limit.
+// same number of bytes as its gc.heap_alloc_bytes.
 func TestStatsAnswersGiveUnitsInFieldNames(t *testing.T) {
 	t.Parallel()
 
@@ -398,11 +375,7 @@ func TestStatsAnswersGiveUnitsInFieldNames(t *testing.T) {
 	s.SetASNFetcher(fixedIntervalASNFetcher{interval: fetchInterval})
 
 	for _, path := range []string{statusJSONPath, statsPath} {
-		var answer []byte
-
-		synctest.Test(t, func(t *testing.T) {
-			answer = get(t, s, path).Body.Bytes()
-		})
+		answer := get(t, s, path).Body.Bytes()
 
 		var body struct {
 			Data unitStats `json:"data"`
@@ -443,89 +416,82 @@ func TestStatsAnswersGiveUnitsInFieldNames(t *testing.T) {
 // connection_duration_seconds of /api/v1/stats is null while the stream is not
 // connected, and a whole number of seconds once it is. It used to be the
 // string "disconnected", or a Go duration such as "1h18m34s"
-// (https://git.eeqj.de/sneak/routewatch/issues/199). The test runs in a
-// synctest bubble, whose clock is fake, so a stall on the host does not use up
-// the handler's 4-second limit.
+// (https://git.eeqj.de/sneak/routewatch/issues/199).
 func TestStatsAnswerGivesConnectionDurationInSeconds(t *testing.T) {
 	t.Parallel()
 
 	s := newServerWithTestRoutes(t)
 
-	synctest.Test(t, func(t *testing.T) {
-		connectionDuration := func() json.RawMessage {
-			answer := get(t, s, statsPath).Body.Bytes()
+	connectionDuration := func() json.RawMessage {
+		answer := get(t, s, statsPath).Body.Bytes()
 
-			var body struct {
-				Data map[string]json.RawMessage `json:"data"`
-			}
-
-			err := json.Unmarshal(answer, &body)
-			if err != nil {
-				t.Fatalf("decoding the answer: %v; answer %s", err, answer)
-			}
-
-			duration, ok := body.Data["connection_duration_seconds"]
-			if !ok {
-				t.Fatalf("no connection_duration_seconds: %s", answer)
-			}
-
-			return duration
+		var body struct {
+			Data map[string]json.RawMessage `json:"data"`
 		}
 
-		disconnected := connectionDuration()
-		if string(disconnected) != "null" {
-			t.Errorf("disconnected: connection_duration_seconds = %s, want null",
-				disconnected)
+		err := json.Unmarshal(answer, &body)
+		if err != nil {
+			t.Fatalf("decoding the answer: %v; answer %s", err, answer)
 		}
 
-		s.streamer.GetMetricsTracker().SetConnected(true)
-
-		var seconds int64
-
-		connected := connectionDuration()
-
-		err := json.Unmarshal(connected, &seconds)
-		if err != nil || seconds != 0 {
-			t.Errorf("just connected: connection_duration_seconds = %s, want 0",
-				connected)
+		duration, ok := body.Data["connection_duration_seconds"]
+		if !ok {
+			t.Fatalf("no connection_duration_seconds: %s", answer)
 		}
-	})
+
+		return duration
+	}
+
+	disconnected := connectionDuration()
+	if string(disconnected) != "null" {
+		t.Errorf("disconnected: connection_duration_seconds = %s, want null",
+			disconnected)
+	}
+
+	s.streamer.GetMetricsTracker().SetConnected(true)
+
+	var seconds int64
+
+	connected := connectionDuration()
+
+	err := json.Unmarshal(connected, &seconds)
+	if err != nil || seconds != 0 {
+		t.Errorf("just connected: connection_duration_seconds = %s, want 0",
+			connected)
+	}
 }
 
 // TestStreamDurationsCountSeconds checks that the uptime and the connection
 // duration of a stream that connected 90 seconds ago are both 90. A stream
 // that has never connected has an uptime of 0, and one that is not connected
-// has no connection duration. The test runs in a synctest bubble, whose clock
-// is fake, so a stall on the host does not add to the 90 seconds.
+// has no connection duration.
 func TestStreamDurationsCountSeconds(t *testing.T) {
 	t.Parallel()
 
-	synctest.Test(t, func(t *testing.T) {
-		const connectedFor = 90 * time.Second
+	const connectedFor = 90 * time.Second
 
-		connectedSince := time.Now().Add(-connectedFor)
-		want := int64(connectedFor / time.Second)
+	connectedSince := time.Now().Add(-connectedFor)
+	want := int64(connectedFor / time.Second)
 
-		if got := uptimeSeconds(connectedSince); got != want {
-			t.Errorf("uptimeSeconds = %d, want %d", got, want)
-		}
+	if got := uptimeSeconds(connectedSince); got != want {
+		t.Errorf("uptimeSeconds = %d, want %d", got, want)
+	}
 
-		if got := uptimeSeconds(time.Time{}); got != 0 {
-			t.Errorf("uptimeSeconds before any connection = %d, want 0", got)
-		}
+	if got := uptimeSeconds(time.Time{}); got != 0 {
+		t.Errorf("uptimeSeconds before any connection = %d, want 0", got)
+	}
 
-		switch got := connectionDurationSeconds(true, connectedSince); {
-		case got == nil:
-			t.Errorf("connectionDurationSeconds = nil, want %d", want)
-		case *got != want:
-			t.Errorf("connectionDurationSeconds = %d, want %d", *got, want)
-		}
+	switch got := connectionDurationSeconds(true, connectedSince); {
+	case got == nil:
+		t.Errorf("connectionDurationSeconds = nil, want %d", want)
+	case *got != want:
+		t.Errorf("connectionDurationSeconds = %d, want %d", *got, want)
+	}
 
-		if got := connectionDurationSeconds(false, connectedSince); got != nil {
-			t.Errorf("connectionDurationSeconds while not connected = %d, want nil",
-				*got)
-		}
-	})
+	if got := connectionDurationSeconds(false, connectedSince); got != nil {
+		t.Errorf("connectionDurationSeconds while not connected = %d, want nil",
+			*got)
+	}
 }
 
 // newTestTable returns a routing table that holds a route for testPrefixV4,
@@ -1172,9 +1138,7 @@ func (failingDB) GetPrefixFirstSeen(
 // with the driver's error text. It also sends a prefix that does not parse.
 // No answer may carry the driver's or the prefix parser's text. Before the fix
 // the answers sent it to the client
-// (https://git.eeqj.de/sneak/routewatch/issues/108). The requests run in a
-// synctest bubble, whose clock is fake, so a stall on the host does not use up
-// the stats handlers' 4-second limit.
+// (https://git.eeqj.de/sneak/routewatch/issues/108).
 func TestJSONRoutesDoNotSendErrorDetails(t *testing.T) {
 	t.Parallel()
 
@@ -1195,11 +1159,8 @@ func TestJSONRoutesDoNotSendErrorDetails(t *testing.T) {
 
 	for _, tt := range tests {
 		rec := httptest.NewRecorder()
-
-		synctest.Test(t, func(t *testing.T) {
-			s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
-				t.Context(), http.MethodGet, tt.path, nil))
-		})
+		s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, tt.path, nil))
 
 		if rec.Code != tt.wantCode {
 			t.Errorf("%s: status %d, want %d; body %s",
@@ -1292,19 +1253,16 @@ func TestIPLookupAnswers500WhenDatabaseReadFails(t *testing.T) {
 	}
 }
 
-// errNoSuchHost is what fakeResolver answers a host name lookup it has no
-// addresses for with.
+// errNoSuchHost is what fakeResolver answers a lookup it has no answer for
+// with.
 var errNoSuchHost = errors.New("no such host")
 
 // fakeResolver answers a host name lookup with the addresses hosts lists for
-// the name. It answers a PTR lookup with the names ptrs lists for the address,
-// and with no names and no error, as the real one does, when ptrs lists none.
-// When ptrNeverAnswers is set, a PTR lookup fails after ptr.LookupTimeout, as
-// the real one does when no resolver answers. hostLookups counts the host name
-// lookups.
+// the name, and a PTR lookup with no names or, when ptrNeverAnswers is set,
+// with a failure after ptr.LookupTimeout, as the real one does when no
+// resolver answers. hostLookups counts the host name lookups.
 type fakeResolver struct {
 	hosts           map[string][]string
-	ptrs            map[string][]string
 	ptrNeverAnswers bool
 
 	hostLookups atomic.Int64
@@ -1321,7 +1279,7 @@ func (r *fakeResolver) LookupHost(_ context.Context, host string) ([]string, err
 	return addrs, nil
 }
 
-func (r *fakeResolver) LookupAddr(ctx context.Context, addr string) ([]string, error) {
+func (r *fakeResolver) LookupAddr(ctx context.Context, _ string) ([]string, error) {
 	if r.ptrNeverAnswers {
 		ctx, cancel := context.WithTimeout(ctx, ptr.LookupTimeout)
 		defer cancel()
@@ -1331,7 +1289,7 @@ func (r *fakeResolver) LookupAddr(ctx context.Context, addr string) ([]string, e
 		return nil, ctx.Err()
 	}
 
-	return r.ptrs[addr], nil
+	return nil, errNoSuchHost
 }
 
 // useFakeResolver makes r answer the server's host name and PTR lookups.
@@ -1443,21 +1401,17 @@ const addrInTestPrefixV4 = "192.0.2.1"
 
 // TestIPLookupKeepsRouteWhenPTRLookupDoesNotAnswer looks up a routed address
 // with a resolver that never answers its PTR lookup. Once the PTR lookup's own
-// limit passes, the lookup answers 200 with the route and an empty ptr. Before
-// the fix the PTR lookup ran until the request's time limit, and the lookup
-// answered 504 without the route
-// (https://git.eeqj.de/sneak/routewatch/issues/110).
+// limit passes, the lookup answers 200 with the route. Before the fix the PTR
+// lookup ran until the request's time limit, and the lookup answered 504
+// without the route (https://git.eeqj.de/sneak/routewatch/issues/110).
 func TestIPLookupKeepsRouteWhenPTRLookupDoesNotAnswer(t *testing.T) {
 	t.Parallel()
 
 	s := newServerWithTestRoutes(t)
 	useFakeResolver(s, &fakeResolver{ptrNeverAnswers: true})
 
-	// The request's time limit passes well after the PTR lookup's, so that a
-	// stall on a busy host does not use up the difference.
-	const requestTimeLimit = ptr.LookupTimeout + 15*time.Second
-
-	ctx, cancel := context.WithTimeout(t.Context(), requestTimeLimit)
+	// The request's time limit passes after the PTR lookup's.
+	ctx, cancel := context.WithTimeout(t.Context(), 2*ptr.LookupTimeout)
 	defer cancel()
 
 	rec := httptest.NewRecorder()
@@ -1481,10 +1435,6 @@ func TestIPLookupKeepsRouteWhenPTRLookupDoesNotAnswer(t *testing.T) {
 		*body.Data.Results[0].Netblock != testPrefixV4 {
 		t.Errorf("answer %s, want one result in %s", rec.Body, testPrefixV4)
 	}
-
-	if !strings.Contains(rec.Body.String(), `"ptr":[]`) {
-		t.Errorf("answer %s, want an empty ptr list", rec.Body)
-	}
 }
 
 // addrInTestPrefixV6 is an address in testPrefixV6, which
@@ -1504,19 +1454,8 @@ const listedUnroutedAddr = "203.0.113.1"
 // torExitAddr is the address that fakeIPLists lists on the Tor exit list.
 const torExitAddr = "203.0.113.2"
 
-// The addresses that fakeIPLists lists on one and on two VPN lists, and the
-// names of those lists.
-const (
-	oneVPNListAddr  = "203.0.113.3"
-	twoVPNListsAddr = "203.0.113.4"
-	testVPNList     = "test_vpn"
-	otherTestVPN    = "other_test_vpn"
-)
-
-// fakeIPLists has four lists. The test list holds addrInTestPrefixV4,
-// listedUnroutedAddr and twoVPNListsAddr. The Tor exit list holds torExitAddr.
-// The test VPN list holds oneVPNListAddr and twoVPNListsAddr, and the other
-// test VPN list holds twoVPNListsAddr.
+// 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 {
@@ -1537,18 +1476,6 @@ func (fakeIPLists) Lookup(addr netip.Addr) []iplist.Listing {
 		return []iplist.Listing{{Name: iplist.TorExitsList}}
 	}
 
-	if addr == netip.MustParseAddr(oneVPNListAddr) {
-		return []iplist.Listing{{Name: testVPNList, VPN: true}}
-	}
-
-	if addr == netip.MustParseAddr(twoVPNListsAddr) {
-		return []iplist.Listing{
-			{Name: otherTestVPN, VPN: true},
-			testListing(),
-			{Name: testVPNList, VPN: true},
-		}
-	}
-
 	return []iplist.Listing{}
 }
 
@@ -1557,7 +1484,7 @@ func (fakeIPLists) ShortestInterval() time.Duration {
 }
 
 // TestIPLookupFlags looks up addresses with and without a route. Every result
-// has every flag, under the JSON keys the API documents.
+// has both flags, under the JSON keys the API documents.
 func TestIPLookupFlags(t *testing.T) {
 	t.Parallel()
 
@@ -1603,9 +1530,7 @@ func TestIPLookupFlags(t *testing.T) {
 				t.Fatalf("%s: decoding flags %s: %v", path, results[0]["flags"], err)
 			}
 
-			want := map[string]bool{
-				"is_tor": tt.tor, "is_vpn": false, "is_bogon": tt.bogon,
-			}
+			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)
 			}
@@ -1613,61 +1538,6 @@ func TestIPLookupFlags(t *testing.T) {
 	}
 }
 
-// TestIPLookupReportsVPNProviders looks up addresses on no list, on a list
-// that is not a VPN list, on one VPN list and on two. is_vpn says whether any
-// VPN list holds the address, and vpn_providers names only those lists. An
-// address on none has [], not null.
-func TestIPLookupReportsVPNProviders(t *testing.T) {
-	t.Parallel()
-
-	s := newServerWithTestRoutes(t)
-	s.resolver = &fakeResolver{}
-	s.SetIPLists(fakeIPLists{})
-
-	tests := []struct {
-		name      string
-		addr      string
-		isVPN     string
-		providers string
-	}{
-		{"on no list", "1.1.1.1", "false", `[]`},
-		{"on a list that is not a VPN list", listedUnroutedAddr, "false", `[]`},
-		{"on one VPN list", oneVPNListAddr, "true", `["` + testVPNList + `"]`},
-		{
-			"on two VPN lists", twoVPNListsAddr, "true",
-			`["` + otherTestVPN + `","` + testVPNList + `"]`,
-		},
-	}
-
-	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 flags map[string]json.RawMessage
-
-			err := json.Unmarshal(results[0]["flags"], &flags)
-			if err != nil {
-				t.Fatalf("%s: decoding flags %s: %v", path, results[0]["flags"], err)
-			}
-
-			if got := string(flags["is_vpn"]); got != tt.isVPN {
-				t.Errorf("%s: is_vpn %s, want %s", path, got, tt.isVPN)
-			}
-
-			if got := string(results[0]["vpn_providers"]); got != tt.providers {
-				t.Errorf("%s: vpn_providers %s, want %s", path, got, tt.providers)
-			}
-		})
-	}
-}
-
 // 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.
@@ -1887,32 +1757,6 @@ func TestIPLookupOfAnAddressWithoutPTRNamesOrStoredNetblock(t *testing.T) {
 	}
 }
 
-// TestIPLookupGivesPTRNamesWithoutTrailingDots looks up an address whose PTR
-// name the resolver gives fully qualified. The result's ptr holds the name
-// without its trailing dot.
-func TestIPLookupGivesPTRNamesWithoutTrailingDots(t *testing.T) {
-	t.Parallel()
-
-	s := newServerWithTestRoutes(t)
-	useFakeResolver(s, &fakeResolver{ptrs: map[string][]string{
-		addrInTestPrefixV4: {"host.example.com."},
-	}})
-
-	path := "/api/v1/ip/" + addrInTestPrefixV4
-
-	results := resultFields(t, get(t, s, path).Body.Bytes())
-	if len(results) != 1 {
-		t.Fatalf("%s: %d results, want 1", path, len(results))
-	}
-
-	got := string(results[0]["ptr"])
-
-	want := `["host.example.com"]`
-	if got != want {
-		t.Errorf("%s: ptr is %s, want %s", path, got, want)
-	}
-}
-
 // TestIPLookupAnswersMayBeCached checks the Cache-Control header of the IP
 // 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
@@ -2456,13 +2300,9 @@ func settledGoroutineCount() int {
 	return prev
 }
 
-// waitForGoroutines waits up to 15 seconds for the goroutine count to drop to
-// target or below.
+// waitForGoroutines waits until the goroutine count drops to target or below.
 func waitForGoroutines(target int) bool {
-	const maxWait = 15 * time.Second
-
-	deadline := time.Now().Add(maxWait)
-	for time.Now().Before(deadline) {
+	for range 100 {
 		if runtime.NumGoroutine() <= target {
 			return true
 		}

internal/server/home_internal_test.go

@@ -76,9 +76,7 @@ func asLink(asn int) string {
 }
 
 // TestHomePageCardsShowTheTableFigures fills a routing table and the asns
-// table, works out the cards, and checks that each card shows its figure. The
-// cards are worked out in a synctest bubble, whose clock is fake, so a stall on
-// the host does not use up the 4-second limit on their database read.
+// table, works out the cards, and checks that each card shows its figure.
 func TestHomePageCardsShowTheTableFigures(t *testing.T) {
 	t.Parallel()
 
@@ -97,9 +95,7 @@ func TestHomePageCardsShowTheTableFigures(t *testing.T) {
 		t.Fatalf("GetOrCreateASNBatch: %v", err)
 	}
 
-	synctest.Test(t, func(t *testing.T) {
-		s.refreshHomeCards(t.Context())
-	})
+	s.refreshHomeCards(t.Context())
 
 	page := get(t, s, "/").Body.String()
 
@@ -283,7 +279,7 @@ func TestKeepHomeCardsFreshWorksThemOutEveryInterval(t *testing.T) {
 
 	const (
 		interval = 10 * time.Millisecond
-		maxWait  = 15 * time.Second
+		maxWait  = 5 * time.Second
 	)
 
 	table := emptyTable()
@@ -325,7 +321,7 @@ func TestKeepHomeCardsFreshWorksThemOutEveryInterval(t *testing.T) {
 func TestStartedServerWorksOutTheCards(t *testing.T) {
 	t.Parallel()
 
-	const maxWait = 15 * time.Second
+	const maxWait = 5 * time.Second
 
 	s := newServerWithTable(t, newCardsTable())
 

internal/server/middleware_internal_test.go

@@ -14,7 +14,6 @@ import (
 	"regexp"
 	"strings"
 	"testing"
-	"testing/synctest"
 	"time"
 
 	"git.eeqj.de/sneak/routewatch/internal/config"
@@ -164,10 +163,6 @@ func TestJSONAnswersPutNoUnitInAString(t *testing.T) {
 // router and the middleware write. Before the fix a panic in a handler, and a
 // method /status.json or the health check does not take, answered with an
 // empty body (https://git.eeqj.de/sneak/routewatch/issues/201).
-//
-// The requests run in a synctest bubble, whose clock is fake, so a stall on
-// the host does not use up the 2-second limit of the health check or the
-// 4-second limit of the stats handlers.
 func TestJSONAnswersCarryMeta(t *testing.T) {
 	t.Parallel()
 
@@ -186,10 +181,6 @@ func TestJSONAnswersCarryMeta(t *testing.T) {
 	s.router.Get(panicsPath, JSONValidationMiddleware(http.HandlerFunc(
 		func(http.ResponseWriter, *http.Request) { panic(errDiskIO) })).ServeHTTP)
 
-	failing := New(failingDB{}, newTestTable(),
-		streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
-	useFakeResolver(failing, &fakeResolver{})
-
 	tests := []struct {
 		method   string
 		path     string
@@ -225,40 +216,42 @@ func TestJSONAnswersCarryMeta(t *testing.T) {
 		{http.MethodGet, panicsPath, http.StatusInternalServerError},
 	}
 
-	synctest.Test(t, func(t *testing.T) {
-		for _, tt := range tests {
-			checkAnswerCarriesMeta(t, s, httptest.NewRequestWithContext(
-				t.Context(), tt.method, tt.path, nil), tt.wantCode)
-		}
+	for _, tt := range tests {
+		checkAnswerCarriesMeta(t, s, httptest.NewRequestWithContext(
+			t.Context(), tt.method, tt.path, nil), tt.wantCode)
+	}
 
-		// A request whose time limit has already passed answers 504. The
-		// handlers write the answers of the first five routes, and the JSON
-		// check on the route writes the last.
-		pastTimeLimit, cancel := context.WithDeadline(t.Context(), time.Now())
-		defer cancel()
+	// A request whose time limit has already passed answers 504. The handlers
+	// write the answers of the first five routes, and the JSON check on the
+	// route writes the last.
+	pastTimeLimit, cancel := context.WithDeadline(t.Context(), time.Now())
+	defer cancel()
 
-		for _, path := range []string{
-			statusJSONPath, statsPath, "/ip/" + addrInTestPrefixV4,
-			"/api/v1/ip/" + addrInTestPrefixV4, asJSONPath, writesNothingPath,
-		} {
-			checkAnswerCarriesMeta(t, s, httptest.NewRequestWithContext(
-				pastTimeLimit, http.MethodGet, path, nil), http.StatusGatewayTimeout)
-		}
+	for _, path := range []string{
+		statusJSONPath, statsPath, "/ip/" + addrInTestPrefixV4,
+		"/api/v1/ip/" + addrInTestPrefixV4, asJSONPath, writesNothingPath,
+	} {
+		checkAnswerCarriesMeta(t, s, httptest.NewRequestWithContext(
+			pastTimeLimit, http.MethodGet, path, nil), http.StatusGatewayTimeout)
+	}
 
-		// With a store whose reads fail, the health check answers 503, and
-		// the handlers of the other routes 500.
+	// With a store whose reads fail, the health check answers 503, and the
+	// handlers of the other routes 500.
+	failing := New(failingDB{}, newTestTable(),
+		streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+	useFakeResolver(failing, &fakeResolver{})
+
+	checkAnswerCarriesMeta(t, failing, httptest.NewRequestWithContext(
+		t.Context(), http.MethodGet, healthCheckPath, nil),
+		http.StatusServiceUnavailable)
+
+	for _, path := range []string{
+		statusJSONPath, statsPath, asJSONPath,
+		"/api/v1/ip/" + addrInTestPrefixV4, "/ip/" + addrInTestPrefixV4,
+	} {
 		checkAnswerCarriesMeta(t, failing, httptest.NewRequestWithContext(
-			t.Context(), http.MethodGet, healthCheckPath, nil),
-			http.StatusServiceUnavailable)
-
-		for _, path := range []string{
-			statusJSONPath, statsPath, asJSONPath,
-			"/api/v1/ip/" + addrInTestPrefixV4, "/ip/" + addrInTestPrefixV4,
-		} {
-			checkAnswerCarriesMeta(t, failing, httptest.NewRequestWithContext(
-				t.Context(), http.MethodGet, path, nil), http.StatusInternalServerError)
-		}
-	})
+			t.Context(), http.MethodGet, path, nil), http.StatusInternalServerError)
+	}
 }
 
 // checkAnswerCarriesMeta serves req through the server's router, and checks

internal/server/routes_internal_test.go

@@ -5,7 +5,6 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"testing"
-	"testing/synctest"
 )
 
 // TestRoutesAnswerHEAD sends HEAD for a page and JSON routes through the
@@ -13,23 +12,15 @@ import (
 // lookup of the caller's own address, are in the list because chi's GetHead
 // does not reach them. Before the fix every route answered HEAD with 405
 // (https://git.eeqj.de/sneak/routewatch/issues/111).
-//
-// The requests run in a synctest bubble, whose clock is fake, so a stall on
-// the host does not use up the stats handlers' 4-second limit. The resolver
-// is fake because no time limit would cut off a real DNS lookup in a bubble.
 func TestRoutesAnswerHEAD(t *testing.T) {
 	t.Parallel()
 
 	s := newServerWithTestRoutes(t)
-	s.resolver = &fakeResolver{}
 
 	for _, path := range []string{"/", statusJSONPath, statsPath, "/ip", "/ip/"} {
 		rec := httptest.NewRecorder()
-
-		synctest.Test(t, func(t *testing.T) {
-			s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
-				t.Context(), http.MethodHead, path, nil))
-		})
+		s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
+			t.Context(), http.MethodHead, path, nil))
 
 		if rec.Code != http.StatusOK {
 			t.Errorf("HEAD %s: status %d, want %d; body %s",

internal/server/server.go

@@ -58,8 +58,8 @@ type dnsResolver interface {
 	LookupHost(ctx context.Context, host string) ([]string, error)
 }
 
-// PTRResolver looks up the PTR names of addresses, as *ptr.Cache does.
-type PTRResolver interface {
+// ptrResolver looks up the PTR names of addresses, as *ptr.Cache does.
+type ptrResolver interface {
 	LookupAddr(ctx context.Context, addr string) ([]string, error)
 }
 
@@ -84,7 +84,7 @@ type Server struct {
 	resolver dnsResolver
 
 	// ptrResolver looks up the IP lookup's PTR names. SetPTRResolver sets it.
-	ptrResolver PTRResolver
+	ptrResolver ptrResolver
 
 	// cards is the copy of the home page's cards that the pages serve, nil
 	// until the server first works them out
@@ -205,7 +205,7 @@ func (s *Server) Stop(ctx context.Context) error {
 
 // SetPTRResolver sets what looks up the IP lookup's PTR names. Call it before
 // Start: the handlers read it without a lock.
-func (s *Server) SetPTRResolver(resolver PTRResolver) {
+func (s *Server) SetPTRResolver(resolver ptrResolver) {
 	s.ptrResolver = resolver
 }
 

internal/server/server_internal_test.go

@@ -22,10 +22,10 @@ func TestStopClosesTheConnectionOfARequestStillRunning(t *testing.T) {
 		stopDeadline = 100 * time.Millisecond
 		// waitTimeout is how long the test waits for the request to reach
 		// the handler, and then for the client to see its connection closed.
-		waitTimeout = 15 * time.Second
+		waitTimeout = 2 * time.Second
 		// readHeaderTimeout bounds the test server's read of the request
 		// header, as every http.Server must.
-		readHeaderTimeout = waitTimeout
+		readHeaderTimeout = time.Second
 	)
 
 	release := make(chan struct{})

internal/streamer/streamer_internal_test.go

@@ -14,7 +14,6 @@ import (
 	"strings"
 	"sync/atomic"
 	"testing"
-	"testing/synctest"
 	"time"
 
 	"git.eeqj.de/sneak/routewatch/internal/logger"
@@ -399,7 +398,7 @@ func TestStopQueuesTheHeldStateMessages(t *testing.T) {
 	const (
 		held    = 2
 		lines   = held + 1
-		maxWait = 15 * time.Second
+		maxWait = 5 * time.Second
 	)
 
 	srv := httptest.NewServer(http.HandlerFunc(
@@ -479,15 +478,15 @@ func TestStopQueuesTheHeldStateMessages(t *testing.T) {
 // TestStopReturnsByItsDeadline stops a streamer whose handler has a full queue
 // and a STATE message held for it, and a worker that stays busy until the test
 // ends, as one does whose handler waits for a database write. Stop must return
-// within its deadline plus a margin instead of waiting for room on the queue
-// and for the worker, and log as not handed over the held message and every
-// message on the queue.
+// within its deadline plus a small margin instead of waiting for room on the
+// queue and for the worker, and log as not handed over the held message and
+// every message on the queue.
 func TestStopReturnsByItsDeadline(t *testing.T) {
 	t.Parallel()
 
 	const (
 		deadline = 100 * time.Millisecond
-		margin   = 15 * time.Second
+		margin   = 2 * time.Second
 	)
 
 	var logs bytes.Buffer
@@ -578,7 +577,7 @@ func TestStopBeforeMessageReachesQueues(t *testing.T) {
 func TestReconnectWhenStreamEnds(t *testing.T) {
 	t.Parallel()
 
-	endResponse := pipeTransport{write: func(context.Context, io.Writer) {}}
+	endResponse := func(http.ResponseWriter, *http.Request) {}
 	checkReconnect(t, endResponse, streamIdleTimeout)
 }
 
@@ -590,8 +589,9 @@ func TestReconnectWhenStreamGoesIdle(t *testing.T) {
 
 	const idleTimeout = 50 * time.Millisecond
 
-	holdResponse := pipeTransport{
-		write: func(ctx context.Context, _ io.Writer) { <-ctx.Done() },
+	holdResponse := func(w http.ResponseWriter, r *http.Request) {
+		flush(w)
+		<-r.Context().Done()
 	}
 	checkReconnect(t, holdResponse, idleTimeout)
 }
@@ -604,51 +604,16 @@ func TestReconnectWhenServerNeverAnswers(t *testing.T) {
 
 	const idleTimeout = 50 * time.Millisecond
 
-	neverAnswer := roundTripFunc(
-		func(req *http.Request) (*http.Response, error) {
-			<-req.Context().Done()
-
-			return nil, req.Context().Err()
-		},
-	)
+	neverAnswer := func(_ http.ResponseWriter, r *http.Request) {
+		<-r.Context().Done()
+	}
 	checkReconnect(t, neverAnswer, idleTimeout)
 }
 
-// pipeTransport answers every request with a response whose body write fills.
-// The body fails when the request's context ends, as a connection's does.
-// write gets that context, so that it can end when the request does.
-type pipeTransport struct {
-	write func(context.Context, io.Writer)
-}
-
-func (p pipeTransport) RoundTrip(req *http.Request) (*http.Response, error) {
-	body, w := io.Pipe()
-
-	context.AfterFunc(req.Context(), func() {
-		_ = w.CloseWithError(req.Context().Err())
-	})
-
-	go func(ctx context.Context) {
-		p.write(ctx, w)
-
-		_ = w.Close()
-	}(req.Context())
-
-	return &http.Response{StatusCode: http.StatusOK, Body: body}, nil
-}
-
-// roundTripFunc makes a function an http.RoundTripper.
-type roundTripFunc func(*http.Request) (*http.Response, error)
-
-func (f roundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {
-	return f(req)
-}
-
-// TestStreamNotDroppedWhileLinesArrive has a response send lines well within
-// the idle timeout for several times the timeout, then end. Each line must
-// start the idle timeout over, so the stream lasts until the response ends
-// instead of being dropped as idle. It runs in a synctest bubble, whose clock
-// is fake, so a stall on the host does not use up the timeout.
+// TestStreamNotDroppedWhileLinesArrive has the server send lines well within
+// the idle timeout for several times the timeout, then end the response. Each
+// line must start the idle timeout over, so the stream lasts until the server
+// ends it instead of being dropped as idle.
 func TestStreamNotDroppedWhileLinesArrive(t *testing.T) {
 	t.Parallel()
 
@@ -658,35 +623,26 @@ func TestStreamNotDroppedWhileLinesArrive(t *testing.T) {
 		sendFor      = 5 * idleTimeout
 	)
 
-	// The streamer is made outside the bubble. Its metrics start a goroutine
-	// that never returns, and a bubble waits for each of its goroutines to
-	// return.
-	s := New(logger.New(), metrics.New())
-	s.idleTimeout = idleTimeout
-	s.client = &http.Client{Transport: pipeTransport{
-		write: func(ctx context.Context, w io.Writer) {
+	srv := httptest.NewServer(http.HandlerFunc(
+		func(w http.ResponseWriter, _ *http.Request) {
 			deadline := time.Now().Add(sendFor)
 			for time.Now().Before(deadline) {
 				_, _ = io.WriteString(w, updateLine)
 
-				// The wait ends with the stream. A bubble's clock stops when
-				// the test function returns, and a goroutine then still
-				// asleep panics the test binary.
-				select {
-				case <-ctx.Done():
-					return
-				case <-time.After(lineInterval):
-				}
+				flush(w)
+				time.Sleep(lineInterval)
 			}
-		},
-	}}
+		}))
+	defer srv.Close()
 
-	synctest.Test(t, func(t *testing.T) {
-		err := s.stream(context.Background())
-		if !errors.Is(err, errStreamEnded) {
-			t.Fatalf("stream returned %v, want %v", err, errStreamEnded)
-		}
-	})
+	s := New(logger.New(), metrics.New())
+	s.url = srv.URL
+	s.idleTimeout = idleTimeout
+
+	err := s.stream(context.Background())
+	if !errors.Is(err, errStreamEnded) {
+		t.Fatalf("stream returned %v, want %v", err, errStreamEnded)
+	}
 }
 
 // TestStreamReadsLongLine has the server send one UPDATE line of about
@@ -750,7 +706,7 @@ func TestHandlerStatsReadWhileMessagesAreDropped(t *testing.T) {
 	const (
 		lines       = 5
 		wantDropped = lines - 2
-		maxWait     = 15 * time.Second
+		maxWait     = 5 * time.Second
 	)
 
 	srv := httptest.NewServer(http.HandlerFunc(
@@ -864,70 +820,61 @@ func streamLines(t *testing.T, s *Streamer, lines string) {
 // line and then stays open. The streamer must come back for a second
 // response, must not be marked connected when it does, and must handle the
 // UPDATE in it.
-//
-// It runs in a synctest bubble, whose clock is fake, so a stall on the host
-// does not use up the idle timeout. The fake server gets the requests in the
-// order the streamer makes them, because no real connection carries them.
 func checkReconnect(
-	t *testing.T, firstResponse http.RoundTripper, idleTimeout time.Duration,
+	t *testing.T, firstResponse http.HandlerFunc, idleTimeout time.Duration,
 ) {
 	t.Helper()
 
-	const maxWait = 15 * time.Second
+	const maxWait = 5 * time.Second
 
-	// The tracker is made outside the bubble. It starts a goroutine that never
-	// returns, and a bubble waits for each of its goroutines to return.
 	tracker := metrics.New()
+	connectedAtReconnect := make(chan bool, 1)
 
-	synctest.Test(t, func(t *testing.T) {
-		connectedAtReconnect := make(chan bool, 1)
-		laterResponse := pipeTransport{
-			write: func(ctx context.Context, w io.Writer) {
-				_, _ = io.WriteString(w, updateLine)
+	var requests atomic.Int32
 
-				<-ctx.Done()
-			},
-		}
+	srv := httptest.NewServer(http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			if requests.Add(1) == 1 {
+				firstResponse(w, r)
 
-		var requests atomic.Int32
+				return
+			}
 
-		s := New(logger.New(), tracker)
-		s.client = &http.Client{Transport: roundTripFunc(
-			func(req *http.Request) (*http.Response, error) {
-				if requests.Add(1) == 1 {
-					return firstResponse.RoundTrip(req)
-				}
+			select {
+			case connectedAtReconnect <- tracker.IsConnected():
+			default:
+			}
 
-				select {
-				case connectedAtReconnect <- tracker.IsConnected():
-				default:
-				}
+			_, _ = io.WriteString(w, updateLine)
 
-				return laterResponse.RoundTrip(req)
-			},
-		)}
-		s.idleTimeout = idleTimeout
-		s.minBackoff = time.Millisecond
-		handler := updateHandler{handled: make(chan struct{}, 1)}
-		s.RegisterHandler(handler)
+			flush(w)
+			<-r.Context().Done()
+		}))
+	defer srv.Close()
 
-		err := s.Start(t.Context())
-		if err != nil {
-			t.Fatalf("Start returned error: %v", err)
-		}
-		defer s.Stop(t.Context())
+	s := New(logger.New(), tracker)
+	s.url = srv.URL
+	s.idleTimeout = idleTimeout
+	s.minBackoff = time.Millisecond
+	handler := updateHandler{handled: make(chan struct{}, 1)}
+	s.RegisterHandler(handler)
 
-		select {
-		case <-handler.handled:
-		case <-time.After(maxWait):
-			t.Fatalf("no message from a second response handled within %s", maxWait)
-		}
+	err := s.Start(t.Context())
+	if err != nil {
+		t.Fatalf("Start returned error: %v", err)
+	}
+	defer s.Stop(t.Context())
 
-		if <-connectedAtReconnect {
-			t.Error("streamer was still marked connected when it came back " +
-				"for a second response")
-		}
-	})
+	select {
+	case <-handler.handled:
+	case <-time.After(maxWait):
+		t.Fatalf("no message from a second response handled within %s", maxWait)
+	}
+
+	if <-connectedAtReconnect {
+		t.Error("streamer was still marked connected when it came back " +
+			"for a second response")
+	}
 }
 
 // settledGoroutineCount lets transient goroutines finish, then reports the
@@ -949,13 +896,9 @@ func settledGoroutineCount() int {
 	return prev
 }
 
-// waitForGoroutines waits up to 15 seconds for the goroutine count to drop to
-// target or below.
+// waitForGoroutines waits until the goroutine count drops to target or below.
 func waitForGoroutines(target int) bool {
-	const maxWait = 15 * time.Second
-
-	deadline := time.Now().Add(maxWait)
-	for time.Now().Before(deadline) {
+	for range 100 {
 		if runtime.NumGoroutine() <= target {
 			return true
 		}