Implement cache for networks

README.md

@@ -298,7 +298,7 @@ However, a few points are left before go-away can be called v1.0.0:
 * [ ] Replace Anubis-like default template with own one.
 * [ ] Define strings and multi-language support for quick modification by operators without custom templates.
 * [ ] Have highly tested paths that match examples.
-* [ ] Caching of temporary fetches, for example, network ranges.
+* [x] Caching of temporary fetches, for example, network ranges.
 * [x] Allow live and dynamic policy reloading.
 * [x] Multiple domains / subdomains -> one backend handling, CEL rules for backends
 * [ ] Merge all rules and conditions into one large AST for higher performance.

cmd/go-away/main.go

@@ -223,11 +223,23 @@ func main() {
 		log.Fatal(fmt.Errorf("no backends defined in policy file"))
 	}
 
+	var cache utils.Cache
 	if *cachePath != "" {
 		err = os.MkdirAll(*cachePath, 0755)
 		if err != nil {
 			log.Fatal(fmt.Errorf("failed to create cache directory: %w", err))
 		}
+		for _, n := range []string{"networks", "acme"} {
+			err = os.MkdirAll(path.Join(*cachePath, n), 0755)
+			if err != nil {
+				log.Fatal(fmt.Errorf("failed to create cache sub directory %s: %w", n, err))
+			}
+		}
+
+		cache, err = utils.CacheDirectory(*cachePath)
+		if err != nil {
+			log.Fatal(fmt.Errorf("failed to open cache directory: %w", err))
+		}
 	}
 
 	var tlsConfig *tls.Config
@@ -293,6 +305,7 @@ func main() {
 		}
 
 		settings := policy.Settings{
+			Cache:                  cache,
 			Backends:               createdBackends,
 			Debug:                  *debugMode,
 			PackageName:            *packageName,

lib/policy/network.go

@@ -27,6 +27,7 @@ type Network struct {
 }
 
 func (n Network) FetchPrefixes(c *http.Client, whois *utils.RADb) (output []net.IPNet, err error) {
+
 	if len(n.Prefixes) > 0 {
 		for _, prefix := range n.Prefixes {
 			ipNet, err := parseCIDROrIP(prefix)

lib/policy/options.go

@@ -1,10 +1,12 @@
 package policy
 
 import (
+	"git.gammaspectra.live/git/go-away/utils"
 	"net/http"
 )
 
 type Settings struct {
+	Cache                  utils.Cache
 	Backends               map[string]http.Handler
 	PrivateKeySeed         []byte
 	Debug                  bool

lib/state.go

@@ -3,6 +3,7 @@ package lib
 import (
 	"crypto/ed25519"
 	"crypto/rand"
+	"encoding/json"
 	"fmt"
 	"git.gammaspectra.live/git/go-away/lib/challenge"
 	"git.gammaspectra.live/git/go-away/lib/condition"
@@ -11,11 +12,13 @@ import (
 	"github.com/google/cel-go/cel"
 	"github.com/yl2chen/cidranger"
 	"log/slog"
+	"net"
 	"net/http"
 	"net/http/httputil"
 	"os"
 	"path"
 	"strings"
+	"time"
 )
 
 type State struct {
@@ -105,26 +108,72 @@ func NewState(p policy.Policy, settings policy.Settings) (handler http.Handler,
 	}
 
 	state.networks = make(map[string]cidranger.Ranger)
+
+	networkCache := utils.CachePrefix(state.Settings().Cache, "networks/")
+
 	for k, network := range p.Networks {
+
 		ranger := cidranger.NewPCTrieRanger()
-		for _, e := range network {
-			if e.Url != nil {
-				slog.Debug("loading network url list", "network", k, "url", *e.Url)
-			}
-			if e.ASN != nil {
-				slog.Debug("loading ASN", "network", k, "asn", *e.ASN)
-			}
-			prefixes, err := e.FetchPrefixes(state.client, state.radb)
-			if err != nil {
-				slog.Error("error fetching network list", "network", k, "url", *e.Url)
-				continue
-			}
+		for i, e := range network {
+			prefixes, err := func() ([]net.IPNet, error) {
+				var useCache bool
+				if e.Url != nil {
+					slog.Debug("loading network url list", "network", k, "url", *e.Url)
+					useCache = true
+				} else if e.ASN != nil {
+					slog.Debug("loading ASN", "network", k, "asn", *e.ASN)
+					useCache = true
+				}
+
+				cacheKey := fmt.Sprintf("%s-%d", k, i)
+				var cached []net.IPNet
+				if useCache && networkCache != nil {
+					cachedData, err := networkCache.Get(cacheKey, time.Hour*24)
+					var l []string
+					_ = json.Unmarshal(cachedData, &l)
+					for _, n := range l {
+						_, ipNet, err := net.ParseCIDR(n)
+						if err == nil {
+							cached = append(cached, *ipNet)
+						}
+					}
+					if err == nil {
+						// use
+						return cached, nil
+
+					}
+				}
+
+				prefixes, err := e.FetchPrefixes(state.client, state.radb)
+				if err != nil {
+					if len(cached) > 0 {
+						// use cached meanwhile
+						return cached, err
+					}
+					return nil, err
+				}
+				if useCache && networkCache != nil {
+					var l []string
+					for _, n := range prefixes {
+						l = append(l, n.String())
+					}
+					cachedData, err := json.Marshal(l)
+					if err == nil {
+						_ = networkCache.Set(cacheKey, cachedData)
+					}
+				}
+				return prefixes, nil
+			}()
 			for _, prefix := range prefixes {
 				err = ranger.Insert(cidranger.NewBasicRangerEntry(prefix))
 				if err != nil {
 					return nil, fmt.Errorf("networks %s: error inserting prefix %s: %v", k, prefix.String(), err)
 				}
 			}
+			if err != nil {
+				slog.Error("error loading network list", "network", k, "url", *e.Url, "error", err)
+				continue
+			}
 		}
 
 		slog.Warn("loaded network prefixes", "network", k, "count", ranger.Len())

utils/cache.go

@@ -0,0 +1,86 @@
+package utils
+
+import (
+	"errors"
+	"os"
+	"path"
+	"time"
+)
+
+type Cache interface {
+	Get(key string, maxAge time.Duration) ([]byte, error)
+
+	Set(key string, value []byte) error
+}
+
+func CachePrefix(c Cache, prefix string) Cache {
+	if c == nil {
+		return nil
+	}
+	return prefixCache{
+		c:      c,
+		prefix: prefix,
+	}
+}
+
+func CacheDirectory(directory string) (Cache, error) {
+	if stat, err := os.Stat(directory); err != nil {
+		return nil, err
+	} else if !stat.IsDir() {
+		return nil, errors.New("not a directory")
+	}
+	return dirCache(directory), nil
+}
+
+type prefixCache struct {
+	c      Cache
+	prefix string
+}
+
+func (c prefixCache) Get(key string, maxAge time.Duration) ([]byte, error) {
+	return c.c.Get(c.prefix+key, maxAge)
+}
+
+func (c prefixCache) Set(key string, value []byte) error {
+	return c.c.Set(c.prefix+key, value)
+}
+
+type dirCache string
+
+var ErrExpired = errors.New("key expired")
+
+func (d dirCache) Get(key string, maxAge time.Duration) ([]byte, error) {
+	fname := path.Join(string(d), key)
+	stat, err := os.Stat(fname)
+	if err != nil {
+		return nil, err
+	}
+	if stat.IsDir() {
+		return nil, errors.New("key is directory")
+	}
+	data, err := os.ReadFile(fname)
+	if err != nil {
+		return nil, err
+	}
+
+	if stat.ModTime().Before(time.Now().Add(-maxAge)) {
+		return data, ErrExpired
+	} else {
+		return data, nil
+	}
+}
+
+func (d dirCache) Set(key string, value []byte) error {
+	fname := path.Join(string(d), key)
+	fs, err := os.Create(fname)
+	if err != nil {
+		return err
+	}
+	defer fs.Close()
+	_, err = fs.Write(value)
+	fs.Sync()
+	fs.Close()
+
+	_ = os.Chtimes(fname, time.Time{}, time.Now())
+	return err
+}