ci: use golangci-lint v2, fix issues

Author: dmke

.github/workflows/build.yml

@@ -9,15 +9,11 @@ jobs:
     name: Tests
     runs-on: ubuntu-latest
     steps:
-
-    - name: Set up Go 1.x
-      uses: actions/setup-go@v2
+    - uses: actions/setup-go@v5
       with:
-        go-version: ^1.24
-      id: go
+        go-version: stable
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - name: Get go-acc
       run: go install github.com/ory/go-acc@latest

.github/workflows/golangci-lint.yml

@@ -9,9 +9,9 @@ jobs:
     name: lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
+
       - name: golangci-lint
-        uses: golangci/golangci-lint-action@v2
+        uses: golangci/golangci-lint-action@v8
         with:
-          # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.
-          version: v1.30
+          version: v2.1

.golangci.yml

@@ -1,7 +1,14 @@
-issues:
-  # Excluding configuration per-path, per-linter, per-text and per-source
-  exclude-rules:
-    # Exclude some linters from running on tests files.
-    - path: \.go
-      linters:
-        - errcheck
+version: "2"
+
+linters:
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
+
+formatters:
+  exclusions:
+    generated: lax

cmd/pingnet/main.go

@@ -180,7 +180,7 @@ func main() {
 
 	// yield all IP addresses
 	for _, g := range generator {
-		g.each(func(ip net.IP) error {
+		_ = g.each(func(ip net.IP) error {
 			ips <- net.IPAddr{IP: ip, Zone: ifname}
 			time.Sleep(interval)
 			return nil

internal/conn.go

@@ -98,7 +98,7 @@ func (c *Conn) receiver(proto int, conn net.PacketConn) {
 	// read incoming packets
 	for {
 		if n, source, err := conn.ReadFrom(rb); err != nil {
-			if netErr, ok := err.(net.Error); !ok || !netErr.Temporary() {
+			if netErr, ok := err.(net.Error); !ok || !netErr.Temporary() { //nolint:staticcheck // needs investigation
 				break // socket gone
 			}
 		} else {
@@ -215,7 +215,7 @@ func (c *Conn) WriteTo(addr *net.IPAddr, seq int, data []byte) error {
 	if c.Privileged {
 		_, err = conn.WriteTo(wb, addr)
 	} else {
-		conn.WriteTo(wb, &net.UDPAddr{
+		_, _ = conn.WriteTo(wb, &net.UDPAddr{
 			IP:   addr.IP,
 			Zone: addr.Zone,
 		})

internal/payload.go

@@ -1,7 +1,8 @@
 package internal
 
 import (
-	"math/rand"
+	"encoding/binary"
+	"math/rand/v2"
 	"time"
 
 	"github.com/digineo/go-logwrap"
@@ -13,10 +14,14 @@ var (
 	// SetLogger allows updating the Logger. For details, see
 	// "github.com/digineo/go-logwrap".Instance.SetLogger.
 	SetLogger = Logger.SetLogger
+
+	rnd *rand.ChaCha8
 )
 
 func init() {
-	rand.Seed(time.Now().UnixNano())
+	seed := [32]byte{}
+	binary.NativeEndian.PutUint64(seed[:], uint64(time.Now().UnixNano()))
+	rnd = rand.NewChaCha8(seed)
 }
 
 // Payload represents additional data appended to outgoing ICMP Echo
@@ -26,9 +31,6 @@ type Payload []byte
 // Resize will assign a new payload of the given size to p.
 func (p *Payload) Resize(size uint16) {
 	buf := make([]byte, size)
-	if _, err := rand.Read(buf); err != nil {
-		Logger.Errorf("error resizing payload: %v", err)
-		return
-	}
+	_, _ = rnd.Read(buf)
 	*p = Payload(buf)
 }

monitor/history.go

@@ -102,7 +102,8 @@ func (h *History) compute() *Metrics {
 		size := numTotal - numFailure
 		mean = total / float64(size)
 		for _, rtt := range data {
-			sumSquares += math.Pow(rtt-mean, 2)
+			d := rtt - mean
+			sumSquares += d * d
 		}
 		stddev = time.Duration(math.Sqrt(sumSquares / float64(size)))
 

request.go

@@ -55,7 +55,7 @@ func (req *simpleRequest) close() {
 	defer func() {
 		// Double-closing is very unlikely, but a race condition may
 		// happen when sending fails and a reply is received anyway.
-		recover()
+		_ = recover()
 	}()
 
 	close(req.wait)