Rename blocklists to IP lists and add IP lookup flags (closes #233)

The answer field is now ip_lists, the package internal/iplist and the
state directory iplists. No compatibility is kept for the old names.

Every IP lookup result gains a flags object with is_tor and is_bogon.
The largest list file accepted is now 200 MiB.

Model: opus-5-5

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))
 }