feat: ipcohort filter with inbound/outbound/whitelist cohorts

Blacklist → IPFilter with three separate atomic cohorts: whitelist
(never blocked), inbound, and outbound. ContainsInbound/ContainsOutbound
each skip the whitelist. HTTP sync fetches all cachers before a single
reload to avoid double-load. Also fixes httpcache.Init calling c.Fetch().

net/httpcache/httpcache.go

@@ -37,23 +37,27 @@ func (c *Cacher) Register(fn func() error) {
 // Init fetches the URL unconditionally (no cached headers yet) and invokes
 // all callbacks, ensuring files are loaded on startup.
 func (c *Cacher) Init() error {
-	if _, err := c.fetch(); err != nil {
+	if _, err := c.Fetch(); err != nil {
 		return err
 	}
 	return c.invokeCallbacks()
 }
 
-// Sync sends a conditional GET. If the server returns new content, writes it
+// Sync sends a conditional GET, writes updated content, and invokes callbacks.
-// to Path and invokes callbacks. Returns whether the file was updated.
+// Returns whether the file was updated.
 func (c *Cacher) Sync() (updated bool, err error) {
-	updated, err = c.fetch()
+	updated, err = c.Fetch()
 	if err != nil || !updated {
 		return updated, err
 	}
 	return true, c.invokeCallbacks()
 }
 
-func (c *Cacher) fetch() (updated bool, err error) {
+// Fetch sends a conditional GET and writes new content to Path if the server
+// responds with 200. Returns whether the file was updated. Does not invoke
+// callbacks — use Sync for the single-cacher case, or call Fetch across
+// multiple cachers and handle the reload yourself.
+func (c *Cacher) Fetch() (updated bool, err error) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 

net/ipcohort/cmd/check-ip-blacklist/blacklist.go

@@ -19,70 +19,101 @@ type HTTPSource struct {
 	Path string
 }
 
-type Blacklist struct {
+// IPFilter holds up to three cohorts: a whitelist (IPs never blocked),
-	atomic.Pointer[ipcohort.Cohort]
+// an inbound blocklist, and an outbound blocklist.
-	paths []string
+type IPFilter struct {
+	whitelist atomic.Pointer[ipcohort.Cohort]
+	inbound   atomic.Pointer[ipcohort.Cohort]
+	outbound  atomic.Pointer[ipcohort.Cohort]
+
+	whitelistPaths []string
+	inboundPaths   []string
+	outboundPaths  []string
+
 	git         *gitshallow.Repo
-	http  []*httpcache.Cacher
+	httpInbound []*httpcache.Cacher
+	httpOutbound []*httpcache.Cacher
 }
 
-// NewBlacklist loads from one or more local files.
+// NewFileFilter loads inbound/outbound/whitelist from local files.
-func NewBlacklist(paths ...string) *Blacklist {
+func NewFileFilter(whitelist, inbound, outbound []string) *IPFilter {
-	return &Blacklist{paths: paths}
+	return &IPFilter{
+		whitelistPaths: whitelist,
+		inboundPaths:   inbound,
+		outboundPaths:  outbound,
+	}
 }
 
-// NewGitBlacklist clones/pulls gitURL into repoDir and loads relPaths on each update.
+// NewGitFilter clones/pulls gitURL into repoDir and loads the given relative
-func NewGitBlacklist(gitURL, repoDir string, relPaths ...string) *Blacklist {
+// paths for each cohort on each update.
+func NewGitFilter(gitURL, repoDir string, whitelist, inboundRel, outboundRel []string) *IPFilter {
 	repo := gitshallow.New(gitURL, repoDir, 1, "")
-	paths := make([]string, len(relPaths))
+	abs := func(rel []string) []string {
-	for i, p := range relPaths {
+		out := make([]string, len(rel))
-		paths[i] = filepath.Join(repoDir, p)
+		for i, p := range rel {
+			out[i] = filepath.Join(repoDir, p)
 		}
-	b := &Blacklist{paths: paths, git: repo}
+		return out
-	repo.Register(b.reload)
+	}
-	return b
+	f := &IPFilter{
+		whitelistPaths: whitelist,
+		inboundPaths:   abs(inboundRel),
+		outboundPaths:  abs(outboundRel),
+		git:            repo,
+	}
+	repo.Register(f.reloadAll)
+	return f
 }
 
-// NewHTTPBlacklist fetches each source URL to its local path, reloading on any change.
+// NewHTTPFilter fetches inbound and outbound sources via HTTP;
-func NewHTTPBlacklist(sources ...HTTPSource) *Blacklist {
+// whitelist is always loaded from local files.
-	b := &Blacklist{}
+func NewHTTPFilter(whitelist []string, inbound, outbound []HTTPSource) *IPFilter {
-	for _, src := range sources {
+	f := &IPFilter{whitelistPaths: whitelist}
-		b.paths = append(b.paths, src.Path)
+	for _, src := range inbound {
-		c := httpcache.New(src.URL, src.Path)
+		f.inboundPaths = append(f.inboundPaths, src.Path)
-		c.Register(b.reload)
+		f.httpInbound = append(f.httpInbound, httpcache.New(src.URL, src.Path))
-		b.http = append(b.http, c)
 	}
-	return b
+	for _, src := range outbound {
+		f.outboundPaths = append(f.outboundPaths, src.Path)
+		f.httpOutbound = append(f.httpOutbound, httpcache.New(src.URL, src.Path))
+	}
+	return f
 }
 
-func (b *Blacklist) Init(lightGC bool) error {
+func (f *IPFilter) Init(lightGC bool) error {
 	switch {
-	case b.git != nil:
+	case f.git != nil:
-		return b.git.Init(lightGC)
+		return f.git.Init(lightGC)
-	case len(b.http) > 0:
+	case len(f.httpInbound) > 0 || len(f.httpOutbound) > 0:
-		for _, c := range b.http {
+		for _, c := range f.httpInbound {
-			if err := c.Init(); err != nil {
+			if _, err := c.Fetch(); err != nil {
 				return err
 			}
 		}
-		return nil
+		for _, c := range f.httpOutbound {
+			if _, err := c.Fetch(); err != nil {
+				return err
+			}
+		}
+		return f.reloadAll()
 	default:
-		return b.reload()
+		return f.reloadAll()
 	}
 }
 
-func (b *Blacklist) Run(ctx context.Context, lightGC bool) {
+func (f *IPFilter) Run(ctx context.Context, lightGC bool) {
 	ticker := time.NewTicker(47 * time.Minute)
 	defer ticker.Stop()
 
 	for {
 		select {
 		case <-ticker.C:
-			updated, err := b.sync(lightGC)
+			updated, err := f.sync(lightGC)
 			if err != nil {
-				fmt.Fprintf(os.Stderr, "error: blacklist sync: %v\n", err)
+				fmt.Fprintf(os.Stderr, "error: filter sync: %v\n", err)
 			} else if updated {
-				fmt.Fprintf(os.Stderr, "blacklist: reloaded %d entries\n", b.Size())
+				fmt.Fprintf(os.Stderr, "filter: reloaded — inbound=%d outbound=%d\n",
+					f.InboundSize(), f.OutboundSize())
 			}
 		case <-ctx.Done():
 			return
@@ -90,38 +121,109 @@ func (b *Blacklist) Run(ctx context.Context, lightGC bool) {
 	}
 }
 
-func (b *Blacklist) sync(lightGC bool) (bool, error) {
+func (f *IPFilter) sync(lightGC bool) (bool, error) {
 	switch {
-	case b.git != nil:
+	case f.git != nil:
-		return b.git.Sync(lightGC)
+		return f.git.Sync(lightGC)
-	case len(b.http) > 0:
+	case len(f.httpInbound) > 0 || len(f.httpOutbound) > 0:
 		var anyUpdated bool
-		for _, c := range b.http {
+		for _, c := range f.httpInbound {
-			updated, err := c.Sync()
+			updated, err := c.Fetch()
 			if err != nil {
 				return anyUpdated, err
 			}
 			anyUpdated = anyUpdated || updated
 		}
-		return anyUpdated, nil
+		for _, c := range f.httpOutbound {
+			updated, err := c.Fetch()
+			if err != nil {
+				return anyUpdated, err
+			}
+			anyUpdated = anyUpdated || updated
+		}
+		if anyUpdated {
+			return true, f.reloadAll()
+		}
+		return false, nil
 	default:
 		return false, nil
 	}
 }
 
-func (b *Blacklist) Contains(ipStr string) bool {
+// ContainsInbound reports whether ip is in the inbound blocklist and not whitelisted.
-	return b.Load().Contains(ipStr)
+func (f *IPFilter) ContainsInbound(ip string) bool {
+	if wl := f.whitelist.Load(); wl != nil && wl.Contains(ip) {
+		return false
+	}
+	c := f.inbound.Load()
+	return c != nil && c.Contains(ip)
 }
 
-func (b *Blacklist) Size() int {
+// ContainsOutbound reports whether ip is in the outbound blocklist and not whitelisted.
-	return b.Load().Size()
+func (f *IPFilter) ContainsOutbound(ip string) bool {
+	if wl := f.whitelist.Load(); wl != nil && wl.Contains(ip) {
+		return false
+	}
+	c := f.outbound.Load()
+	return c != nil && c.Contains(ip)
 }
 
-func (b *Blacklist) reload() error {
+func (f *IPFilter) InboundSize() int {
-	c, err := ipcohort.LoadFiles(b.paths...)
+	if c := f.inbound.Load(); c != nil {
+		return c.Size()
+	}
+	return 0
+}
+
+func (f *IPFilter) OutboundSize() int {
+	if c := f.outbound.Load(); c != nil {
+		return c.Size()
+	}
+	return 0
+}
+
+func (f *IPFilter) reloadAll() error {
+	if err := f.reloadWhitelist(); err != nil {
+		return err
+	}
+	if err := f.reloadInbound(); err != nil {
+		return err
+	}
+	return f.reloadOutbound()
+}
+
+func (f *IPFilter) reloadWhitelist() error {
+	if len(f.whitelistPaths) == 0 {
+		return nil
+	}
+	c, err := ipcohort.LoadFiles(f.whitelistPaths...)
 	if err != nil {
 		return err
 	}
-	b.Store(c)
+	f.whitelist.Store(c)
+	return nil
+}
+
+func (f *IPFilter) reloadInbound() error {
+	if len(f.inboundPaths) == 0 {
+		return nil
+	}
+	c, err := ipcohort.LoadFiles(f.inboundPaths...)
+	if err != nil {
+		return err
+	}
+	f.inbound.Store(c)
+	return nil
+}
+
+func (f *IPFilter) reloadOutbound() error {
+	if len(f.outboundPaths) == 0 {
+		return nil
+	}
+	c, err := ipcohort.LoadFiles(f.outboundPaths...)
+	if err != nil {
+		return err
+	}
+	f.outbound.Store(c)
 	return nil
 }

net/ipcohort/cmd/check-ip-blacklist/main.go

@@ -12,10 +12,16 @@ const (
 	inboundNetworkURL = "https://github.com/bitwire-it/ipblocklist/raw/refs/heads/main/tables/inbound/networks.txt"
 )
 
+// outbound blocklist
+const (
+	outboundSingleURL  = "https://github.com/bitwire-it/ipblocklist/raw/refs/heads/main/tables/outbound/single_ips.txt"
+	outboundNetworkURL = "https://github.com/bitwire-it/ipblocklist/raw/refs/heads/main/tables/outbound/networks.txt"
+)
+
 func main() {
 	if len(os.Args) < 3 {
-		fmt.Fprintf(os.Stderr, "Usage: %s <cache-dir|blacklist.csv> <ip-address> [git-url]\n", os.Args[0])
+		fmt.Fprintf(os.Stderr, "Usage: %s <cache-dir|blacklist.txt> <ip-address> [git-url]\n", os.Args[0])
-		fmt.Fprintf(os.Stderr, "  No remote:  load from <blacklist.csv>\n")
+		fmt.Fprintf(os.Stderr, "  No remote:  load from <blacklist.txt> (inbound only)\n")
 		fmt.Fprintf(os.Stderr, "  git URL:    clone/pull into <cache-dir>\n")
 		fmt.Fprintf(os.Stderr, "  (default):  fetch via HTTP into <cache-dir>\n")
 		os.Exit(1)
@@ -28,34 +34,52 @@ func main() {
 		gitURL = os.Args[3]
 	}
 
-	var bl *Blacklist
+	var f *IPFilter
 	switch {
 	case gitURL != "":
-		bl = NewGitBlacklist(gitURL, dataPath,
+		f = NewGitFilter(gitURL, dataPath,
-			"tables/inbound/single_ips.txt",
+			nil,
-			"tables/inbound/networks.txt",
+			[]string{"tables/inbound/single_ips.txt", "tables/inbound/networks.txt"},
+			[]string{"tables/outbound/single_ips.txt", "tables/outbound/networks.txt"},
 		)
 	case strings.HasSuffix(dataPath, ".txt") || strings.HasSuffix(dataPath, ".csv"):
-		bl = NewBlacklist(dataPath)
+		f = NewFileFilter(nil, []string{dataPath}, nil)
 	default:
 		// dataPath is a cache directory; fetch the pre-split files via HTTP
-		bl = NewHTTPBlacklist(
+		f = NewHTTPFilter(
-			HTTPSource{inboundSingleURL, dataPath + "/single_ips.txt"},
+			nil,
-			HTTPSource{inboundNetworkURL, dataPath + "/networks.txt"},
+			[]HTTPSource{
+				{inboundSingleURL, dataPath + "/inbound_single_ips.txt"},
+				{inboundNetworkURL, dataPath + "/inbound_networks.txt"},
+			},
+			[]HTTPSource{
+				{outboundSingleURL, dataPath + "/outbound_single_ips.txt"},
+				{outboundNetworkURL, dataPath + "/outbound_networks.txt"},
+			},
 		)
 	}
 
-	if err := bl.Init(false); err != nil {
+	if err := f.Init(false); err != nil {
 		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 		os.Exit(1)
 	}
 
-	fmt.Fprintf(os.Stderr, "Loaded %d entries\n", bl.Size())
+	fmt.Fprintf(os.Stderr, "Loaded inbound=%d outbound=%d\n", f.InboundSize(), f.OutboundSize())
 
-	if bl.Contains(ipStr) {
+	blockedInbound := f.ContainsInbound(ipStr)
-		fmt.Printf("%s is BLOCKED\n", ipStr)
+	blockedOutbound := f.ContainsOutbound(ipStr)
+
+	switch {
+	case blockedInbound && blockedOutbound:
+		fmt.Printf("%s is BLOCKED (inbound + outbound)\n", ipStr)
 		os.Exit(1)
-	}
+	case blockedInbound:
-
+		fmt.Printf("%s is BLOCKED (inbound)\n", ipStr)
+		os.Exit(1)
+	case blockedOutbound:
+		fmt.Printf("%s is BLOCKED (outbound)\n", ipStr)
+		os.Exit(1)
+	default:
 		fmt.Printf("%s is allowed\n", ipStr)
+	}
 }