lint: actually lint all go files

.golangci.yaml

@@ -6,6 +6,9 @@ output:
 linters-settings:
   goimports:
     local-prefixes: "github.com/chihaya/chihaya"
+  gosec:
+    excludes:
+      - "G404" # Allow the usage of math/rand
 linters:
   enable:
     - "bidichk"
@@ -26,7 +29,6 @@ linters:
     - "makezero"
     - "prealloc"
     - "predeclared"
-    - "promlinter"
     - "revive"
     - "rowserrcheck"
     - "staticcheck"

cmd/chihaya/main.go

@@ -100,7 +100,7 @@ func (r *Run) Start(ps storage.PeerStore) error {
 }
 
 func combineErrors(prefix string, errs []error) error {
-	var errStrs []string
+	errStrs := make([]string, 0, len(errs))
 	for _, err := range errs {
 		errStrs = append(errStrs, err.Error())
 	}

frontend/http/bencode/encoder.go

@@ -66,7 +66,7 @@ func marshal(w io.Writer, data interface{}) (err error) {
 		err = marshalInt(w, int64(v))
 
 	case int64:
-		err = marshalInt(w, int64(v))
+		err = marshalInt(w, v)
 
 	case uint:
 		err = marshalUint(w, uint64(v))
@@ -78,7 +78,7 @@ func marshal(w io.Writer, data interface{}) (err error) {
 		err = marshalUint(w, uint64(v))
 
 	case uint64:
-		err = marshalUint(w, uint64(v))
+		err = marshalUint(w, v)
 
 	case time.Duration: // Assume seconds
 		err = marshalInt(w, int64(v/time.Second))

frontend/http/frontend.go

@@ -164,6 +164,7 @@ func NewFrontend(logic frontend.TrackerLogic, provided Config) (*Frontend, error
 	if cfg.TLSCertPath != "" && cfg.TLSKeyPath != "" {
 		var err error
 		f.tlsCfg = &tls.Config{
+			MinVersion:   tls.VersionTLS12,
 			Certificates: make([]tls.Certificate, 1),
 		}
 		f.tlsCfg.Certificates[0], err = tls.LoadX509KeyPair(cfg.TLSCertPath, cfg.TLSKeyPath)
@@ -265,7 +266,7 @@ func (f *Frontend) serveHTTP(l net.Listener) error {
 	f.srv.SetKeepAlivesEnabled(f.EnableKeepAlive)
 
 	// Start the HTTP server.
-	if err := f.srv.Serve(l); err != http.ErrServerClosed {
+	if err := f.srv.Serve(l); !errors.Is(err, http.ErrServerClosed) {
 		return err
 	}
 	return nil
@@ -285,7 +286,7 @@ func (f *Frontend) serveHTTPS(l net.Listener) error {
 	f.tlsSrv.SetKeepAlivesEnabled(f.EnableKeepAlive)
 
 	// Start the HTTP server.
-	if err := f.tlsSrv.ServeTLS(l, "", ""); err != http.ErrServerClosed {
+	if err := f.tlsSrv.ServeTLS(l, "", ""); !errors.Is(err, http.ErrServerClosed) {
 		return err
 	}
 	return nil

frontend/http/parser.go

@@ -1,6 +1,7 @@
 package http
 
 import (
+	"errors"
 	"net"
 	"net/http"
 
@@ -92,7 +93,7 @@ func ParseAnnounce(r *http.Request, opts ParseOptions) (*bittorrent.AnnounceRequ
 
 	// Determine the number of peers the client wants in the response.
 	numwant, err := qp.Uint64("numwant", 32)
-	if err != nil && err != bittorrent.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, bittorrent.ErrKeyNotFound) {
 		return nil, bittorrent.ClientError("failed to parse parameter: numwant")
 	}
 	// If there were no errors, the user actually provided the numwant.

frontend/http/prometheus.go

@@ -1,6 +1,7 @@
 package http
 
 import (
+	"errors"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -26,8 +27,9 @@ var promResponseDurationMilliseconds = prometheus.NewHistogramVec(
 func recordResponseDuration(action string, af *bittorrent.AddressFamily, err error, duration time.Duration) {
 	var errString string
 	if err != nil {
-		if _, ok := err.(bittorrent.ClientError); ok {
+		var clientErr bittorrent.ClientError
-			errString = err.Error()
+		if errors.As(err, &clientErr) {
+			errString = clientErr.Error()
 		} else {
 			errString = "internal error"
 		}

frontend/http/writer.go

@@ -1,6 +1,7 @@
 package http
 
 import (
+	"errors"
 	"net/http"
 
 	"github.com/chihaya/chihaya/bittorrent"
@@ -11,8 +12,9 @@ import (
 // WriteError communicates an error to a BitTorrent client over HTTP.
 func WriteError(w http.ResponseWriter, err error) error {
 	message := "internal server error"
-	if _, clientErr := err.(bittorrent.ClientError); clientErr {
+	var clientErr bittorrent.ClientError
-		message = err.Error()
+	if errors.As(err, &clientErr) {
+		message = clientErr.Error()
 	} else {
 		log.Error("http: internal error", log.Err(err))
 	}
@@ -57,7 +59,7 @@ func WriteAnnounceResponse(w http.ResponseWriter, resp *bittorrent.AnnounceRespo
 	}
 
 	// Add the peers to the dictionary.
-	var peers []bencode.Dict
+	peers := make([]bencode.Dict, 0, len(resp.IPv4Peers)+len(resp.IPv6Peers))
 	for _, peer := range resp.IPv4Peers {
 		peers = append(peers, dict(peer))
 	}

frontend/udp/frontend.go

@@ -6,6 +6,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/binary"
+	"errors"
 	"fmt"
 	"math/rand"
 	"net"
@@ -123,8 +124,7 @@ func NewFrontend(logic frontend.TrackerLogic, provided Config) (*Frontend, error
 		},
 	}
 
-	err := f.listen()
+	if err := f.listen(); err != nil {
-	if err != nil {
 		return nil, err
 	}
 
@@ -188,7 +188,8 @@ func (t *Frontend) serve() error {
 		n, addr, err := t.socket.ReadFromUDP(*buffer)
 		if err != nil {
 			pool.Put(buffer)
-			if netErr, ok := err.(net.Error); ok && netErr.Temporary() {
+			var netErr net.Error
+			if errors.As(err, &netErr); netErr.Temporary() {
 				// A temporary failure is not fatal; just pretend it never happened.
 				continue
 			}

frontend/udp/parser.go

@@ -115,7 +115,7 @@ func ParseAnnounce(r Request, v6Action bool, opts ParseOptions) (*bittorrent.Ann
 	request := &bittorrent.AnnounceRequest{
 		Event:           eventIDs[eventID],
 		InfoHash:        bittorrent.InfoHashFromBytes(infohash),
-		NumWant:         uint32(numWant),
+		NumWant:         numWant,
 		Left:            left,
 		Downloaded:      downloaded,
 		Uploaded:        uploaded,

frontend/udp/parser_test.go

@@ -1,6 +1,7 @@
 package udp
 
 import (
+	"errors"
 	"fmt"
 	"testing"
 )
@@ -51,7 +52,7 @@ func TestHandleOptionalParameters(t *testing.T) {
 	for _, tt := range table {
 		t.Run(fmt.Sprintf("%#v as %#v", tt.data, tt.values), func(t *testing.T) {
 			params, err := handleOptionalParameters(tt.data)
-			if err != tt.err {
+			if !errors.Is(err, tt.err) {
 				if tt.err == nil {
 					t.Fatalf("expected no parsing error for %x but got %s", tt.data, err)
 				} else {

frontend/udp/prometheus.go

@@ -1,6 +1,7 @@
 package udp
 
 import (
+	"errors"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -26,8 +27,9 @@ var promResponseDurationMilliseconds = prometheus.NewHistogramVec(
 func recordResponseDuration(action string, af *bittorrent.AddressFamily, err error, duration time.Duration) {
 	var errString string
 	if err != nil {
-		if _, ok := err.(bittorrent.ClientError); ok {
+		var clientErr bittorrent.ClientError
-			errString = err.Error()
+		if errors.As(err, &clientErr) {
+			errString = clientErr.Error()
 		} else {
 			errString = "internal error"
 		}

frontend/udp/writer.go

@@ -2,6 +2,7 @@ package udp
 
 import (
 	"encoding/binary"
+	"errors"
 	"fmt"
 	"io"
 	"time"
@@ -12,8 +13,9 @@ import (
 // WriteError writes the failure reason as a null-terminated string.
 func WriteError(w io.Writer, txID []byte, err error) {
 	// If the client wasn't at fault, acknowledge it.
-	if _, ok := err.(bittorrent.ClientError); !ok {
+	var clientErr bittorrent.ClientError
-		err = fmt.Errorf("internal error occurred: %s", err.Error())
+	if !errors.As(err, &clientErr) {
+		err = fmt.Errorf("internal error occurred: %w", err)
 	}
 
 	buf := newBuffer()

middleware/clientapproval/clientapproval.go

@@ -28,7 +28,7 @@ func (d driver) NewHook(optionBytes []byte) (middleware.Hook, error) {
 	var cfg Config
 	err := yaml.Unmarshal(optionBytes, &cfg)
 	if err != nil {
-		return nil, fmt.Errorf("invalid options for middleware %s: %s", Name, err)
+		return nil, fmt.Errorf("invalid options for middleware %s: %w", Name, err)
 	}
 
 	return NewHook(cfg)

middleware/hooks.go

@@ -2,6 +2,7 @@ package middleware
 
 import (
 	"context"
+	"errors"
 
 	"github.com/chihaya/chihaya/bittorrent"
 	"github.com/chihaya/chihaya/storage"
@@ -37,12 +38,12 @@ func (h *swarmInteractionHook) HandleAnnounce(ctx context.Context, req *bittorre
 	switch {
 	case req.Event == bittorrent.Stopped:
 		err = h.store.DeleteSeeder(req.InfoHash, req.Peer)
-		if err != nil && err != storage.ErrResourceDoesNotExist {
+		if err != nil && !errors.Is(err, storage.ErrResourceDoesNotExist) {
 			return ctx, err
 		}
 
 		err = h.store.DeleteLeecher(req.InfoHash, req.Peer)
-		if err != nil && err != storage.ErrResourceDoesNotExist {
+		if err != nil && !errors.Is(err, storage.ErrResourceDoesNotExist) {
 			return ctx, err
 		}
 	case req.Event == bittorrent.Completed:
@@ -106,7 +107,7 @@ func (h *responseHook) HandleAnnounce(ctx context.Context, req *bittorrent.Annou
 func (h *responseHook) appendPeers(req *bittorrent.AnnounceRequest, resp *bittorrent.AnnounceResponse) error {
 	seeding := req.Left == 0
 	peers, err := h.store.AnnouncePeers(req.InfoHash, seeding, int(req.NumWant), req.Peer)
-	if err != nil && err != storage.ErrResourceDoesNotExist {
+	if err != nil && !errors.Is(err, storage.ErrResourceDoesNotExist) {
 		return err
 	}
 

middleware/jwt/jwt.go

@@ -44,7 +44,7 @@ func (d driver) NewHook(optionBytes []byte) (middleware.Hook, error) {
 	var cfg Config
 	err := yaml.Unmarshal(optionBytes, &cfg)
 	if err != nil {
-		return nil, fmt.Errorf("invalid options for middleware %s: %s", Name, err)
+		return nil, fmt.Errorf("invalid options for middleware %s: %w", Name, err)
 	}
 
 	return NewHook(cfg)
@@ -93,8 +93,7 @@ func NewHook(cfg Config) (middleware.Hook, error) {
 	}
 
 	log.Debug("performing initial fetch of JWKs")
-	err := h.updateKeys()
+	if err := h.updateKeys(); err != nil {
-	if err != nil {
 		return nil, errors.New("failed to fetch initial JWK Set: " + err.Error())
 	}
 

middleware/pkg/random/entropy.go

@@ -11,7 +11,7 @@ import (
 //
 // Calling DeriveEntropyFromRequest multiple times yields the same values.
 func DeriveEntropyFromRequest(req *bittorrent.AnnounceRequest) (uint64, uint64) {
-	v0 := binary.BigEndian.Uint64([]byte(req.InfoHash[:8])) + binary.BigEndian.Uint64([]byte(req.InfoHash[8:16]))
+	v0 := binary.BigEndian.Uint64(req.InfoHash[:8]) + binary.BigEndian.Uint64(req.InfoHash[8:16])
-	v1 := binary.BigEndian.Uint64([]byte(req.Peer.ID[:8])) + binary.BigEndian.Uint64([]byte(req.Peer.ID[8:16]))
+	v1 := binary.BigEndian.Uint64(req.Peer.ID[:8]) + binary.BigEndian.Uint64(req.Peer.ID[8:16])
 	return v0, v1
 }

middleware/torrentapproval/torrentapproval.go

@@ -28,7 +28,7 @@ func (d driver) NewHook(optionBytes []byte) (middleware.Hook, error) {
 	var cfg Config
 	err := yaml.Unmarshal(optionBytes, &cfg)
 	if err != nil {
-		return nil, fmt.Errorf("invalid options for middleware %s: %s", Name, err)
+		return nil, fmt.Errorf("invalid options for middleware %s: %w", Name, err)
 	}
 
 	return NewHook(cfg)

middleware/varinterval/varinterval.go

@@ -29,7 +29,7 @@ func (d driver) NewHook(optionBytes []byte) (middleware.Hook, error) {
 	var cfg Config
 	err := yaml.Unmarshal(optionBytes, &cfg)
 	if err != nil {
-		return nil, fmt.Errorf("invalid options for middleware %s: %s", Name, err)
+		return nil, fmt.Errorf("invalid options for middleware %s: %w", Name, err)
 	}
 
 	return NewHook(cfg)
@@ -77,8 +77,7 @@ type hook struct {
 // NewHook creates a middleware to randomly modify the announce interval from
 // the given config.
 func NewHook(cfg Config) (middleware.Hook, error) {
-	err := checkConfig(cfg)
+	if err := checkConfig(cfg); err != nil {
-	if err != nil {
 		return nil, err
 	}
 
@@ -96,12 +95,12 @@ func (h *hook) HandleAnnounce(ctx context.Context, req *bittorrent.AnnounceReque
 	if h.cfg.ModifyResponseProbability == 1 || p < h.cfg.ModifyResponseProbability {
 		// Generate the increase delta.
 		v, _, _ = random.Intn(s0, s1, h.cfg.MaxIncreaseDelta)
-		addSeconds := time.Duration(v+1) * time.Second
+		deltaDuration := time.Duration(v+1) * time.Second
 
-		resp.Interval += addSeconds
+		resp.Interval += deltaDuration
 
 		if h.cfg.ModifyMinInterval {
-			resp.MinInterval += addSeconds
+			resp.MinInterval += deltaDuration
 		}
 
 		return ctx, nil

pkg/metrics/server.go

@@ -4,6 +4,7 @@ package metrics
 
 import (
 	"context"
+	"errors"
 	"net/http"
 	"net/http/pprof"
 
@@ -49,7 +50,7 @@ func NewServer(addr string) *Server {
 	}
 
 	go func() {
-		if err := s.srv.ListenAndServe(); err != http.ErrServerClosed {
+		if err := s.srv.ListenAndServe(); !errors.Is(err, http.ErrServerClosed) {
 			log.Fatal("failed while serving prometheus", log.Err(err))
 		}
 	}()

storage/redis/peer_store.go

@@ -25,6 +25,7 @@ package redis
 
 import (
 	"encoding/binary"
+	"errors"
 	"net"
 	"strconv"
 	"sync"
@@ -301,7 +302,7 @@ func (ps *peerStore) populateProm() {
 	defer conn.Close()
 
 	for _, group := range ps.groups() {
-		if n, err := redis.Int64(conn.Do("GET", ps.infohashCountKey(group))); err != nil && err != redis.ErrNil {
+		if n, err := redis.Int64(conn.Do("GET", ps.infohashCountKey(group))); err != nil && !errors.Is(err, redis.ErrNil) {
 			log.Error("storage: GET counter failure", log.Fields{
 				"key":   ps.infohashCountKey(group),
 				"error": err,
@@ -309,7 +310,7 @@ func (ps *peerStore) populateProm() {
 		} else {
 			numInfohashes += n
 		}
-		if n, err := redis.Int64(conn.Do("GET", ps.seederCountKey(group))); err != nil && err != redis.ErrNil {
+		if n, err := redis.Int64(conn.Do("GET", ps.seederCountKey(group))); err != nil && !errors.Is(err, redis.ErrNil) {
 			log.Error("storage: GET counter failure", log.Fields{
 				"key":   ps.seederCountKey(group),
 				"error": err,
@@ -317,7 +318,7 @@ func (ps *peerStore) populateProm() {
 		} else {
 			numSeeders += n
 		}
-		if n, err := redis.Int64(conn.Do("GET", ps.leecherCountKey(group))); err != nil && err != redis.ErrNil {
+		if n, err := redis.Int64(conn.Do("GET", ps.leecherCountKey(group))); err != nil && !errors.Is(err, redis.ErrNil) {
 			log.Error("storage: GET counter failure", log.Fields{
 				"key":   ps.leecherCountKey(group),
 				"error": err,
@@ -789,7 +790,7 @@ func (ps *peerStore) collectGarbage(cutoff time.Time) error {
 					_ = conn.Send("DECR", ps.infohashCountKey(group))
 				}
 				_, err = redis.Values(conn.Do("EXEC"))
-				if err != nil && err != redis.ErrNil {
+				if err != nil && !errors.Is(err, redis.ErrNil) {
 					log.Error("storage: Redis EXEC failure", log.Fields{
 						"group":    group,
 						"infohash": ihStr,
@@ -797,7 +798,7 @@ func (ps *peerStore) collectGarbage(cutoff time.Time) error {
 					})
 				}
 			} else {
-				if _, err = conn.Do("UNWATCH"); err != nil && err != redis.ErrNil {
+				if _, err = conn.Do("UNWATCH"); err != nil && !errors.Is(err, redis.ErrNil) {
 					log.Error("storage: Redis UNWATCH failure", log.Fields{"error": err})
 				}
 			}

storage/redis/redis.go

@@ -69,7 +69,7 @@ func (rc *redisConnector) NewPool() *redis.Pool {
 		},
 		// PINGs connections that have been idle more than 10 seconds
 		TestOnBorrow: func(c redis.Conn, t time.Time) error {
-			if time.Since(t) < time.Duration(10*time.Second) {
+			if time.Since(t) < 10*time.Second {
 				return nil
 			}
 			_, err := c.Do("PING")