middleware: remove sanitization mw

middleware/hooks.go

@@ -2,8 +2,6 @@ package middleware
 
 import (
 	"context"
-	"errors"
-	"net"
 
 	"github.com/chihaya/chihaya/bittorrent"
 	"github.com/chihaya/chihaya/storage"
@@ -67,56 +65,6 @@ func (h *swarmInteractionHook) HandleScrape(ctx context.Context, _ *bittorrent.S
 	return ctx, nil
 }
 
-// ErrInvalidIP indicates an invalid IP for an Announce.
-var ErrInvalidIP = errors.New("invalid IP")
-
-// sanitizationHook enforces semantic assumptions about requests that may have
-// not been accounted for in a tracker frontend.
-//
-// The SanitizationHook performs the following checks:
-// - maxNumWant: Checks whether the numWant parameter of an announce is below
-//     a limit. Sets it to the limit if the value is higher.
-// - defaultNumWant: Checks whether the numWant parameter of an announce is
-//     zero. Sets it to the default if it is.
-// - IP sanitization: Checks whether the announcing Peer's IP address is either
-//     IPv4 or IPv6. Returns ErrInvalidIP if the address is neither IPv4 nor
-//     IPv6. Sets the Peer.AddressFamily field accordingly. Truncates IPv4
-//     addresses to have a length of 4 bytes.
-type sanitizationHook struct {
-	maxNumWant          uint32
-	defaultNumWant      uint32
-	maxScrapeInfoHashes uint32
-}
-
-func (h *sanitizationHook) HandleAnnounce(ctx context.Context, req *bittorrent.AnnounceRequest, resp *bittorrent.AnnounceResponse) (context.Context, error) {
-	if req.NumWant > h.maxNumWant {
-		req.NumWant = h.maxNumWant
-	}
-
-	if req.NumWant == 0 {
-		req.NumWant = h.defaultNumWant
-	}
-
-	if ip := req.Peer.IP.To4(); ip != nil {
-		req.Peer.IP.IP = ip
-		req.Peer.IP.AddressFamily = bittorrent.IPv4
-	} else if len(req.Peer.IP.IP) == net.IPv6len { // implies req.Peer.IP.To4() == nil
-		req.Peer.IP.AddressFamily = bittorrent.IPv6
-	} else {
-		return ctx, ErrInvalidIP
-	}
-
-	return ctx, nil
-}
-
-func (h *sanitizationHook) HandleScrape(ctx context.Context, req *bittorrent.ScrapeRequest, resp *bittorrent.ScrapeResponse) (context.Context, error) {
-	if len(req.InfoHashes) > int(h.maxScrapeInfoHashes) {
-		req.InfoHashes = req.InfoHashes[:h.maxScrapeInfoHashes]
-	}
-
-	return ctx, nil
-}
-
 type skipResponseHook struct{}
 
 // SkipResponseHookKey is a key for the context of an Announce or Scrape to

middleware/middleware.go

@@ -15,10 +15,7 @@ import (
 
 // Config holds the configuration common across all middleware.
 type Config struct {
-	AnnounceInterval    time.Duration `yaml:"announce_interval"`
-	MaxNumWant          uint32        `yaml:"max_numwant"`
-	DefaultNumWant      uint32        `yaml:"default_numwant"`
-	MaxScrapeInfoHashes uint32        `yaml:"max_scrape_infohashes"`
+	AnnounceInterval time.Duration `yaml:"announce_interval"`
 }
 
 var _ frontend.TrackerLogic = &Logic{}
@@ -26,17 +23,12 @@ var _ frontend.TrackerLogic = &Logic{}
 // NewLogic creates a new instance of a TrackerLogic that executes the provided
 // middleware hooks.
 func NewLogic(cfg Config, peerStore storage.PeerStore, preHooks, postHooks []Hook) *Logic {
-	l := &Logic{
+	return &Logic{
 		announceInterval: cfg.AnnounceInterval,
 		peerStore:        peerStore,
-		preHooks:         []Hook{&sanitizationHook{cfg.MaxNumWant, cfg.DefaultNumWant, cfg.MaxScrapeInfoHashes}},
+		preHooks:         append(preHooks, &responseHook{store: peerStore}),
 		postHooks:        append(postHooks, &swarmInteractionHook{store: peerStore}),
 	}
-
-	l.preHooks = append(l.preHooks, preHooks...)
-	l.preHooks = append(l.preHooks, &responseHook{store: peerStore})
-
-	return l
 }
 
 // Logic is an implementation of the TrackerLogic that functions by

middleware/middleware_test.go

@@ -80,15 +80,4 @@ func BenchmarkHookOverhead(b *testing.B) {
 			benchHookListV6(b, nopHooks)
 		})
 	}
-
-	var sanHooks hookList
-	for i := 1; i < 4; i++ {
-		sanHooks = append(sanHooks, &sanitizationHook{maxNumWant: 50})
-		b.Run(fmt.Sprintf("%dsanitation-v4", i), func(b *testing.B) {
-			benchHookListV4(b, sanHooks)
-		})
-		b.Run(fmt.Sprintf("%dsanitation-v6", i), func(b *testing.B) {
-			benchHookListV6(b, sanHooks)
-		})
-	}
 }