bump go version

.github/workflows/go.yaml

@@ -12,10 +12,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - name: Set up Go 1.19
+    - name: Set up Go ${{vars.GO_VERSION}}
       uses: actions/setup-go@v5
       with:
-        go-version: 1.19
+        go-version: ${{vars.GO_VERSION}}
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/golangci-lint.yaml

@@ -23,13 +23,13 @@ jobs:
         run: sudo apt-get update && sudo apt-get install -y libpcap0.8 libpcap0.8-dev
       - uses: actions/setup-go@v5
         with:
-          go-version: '1.18'
+          go-version: ${{vars.GO_VERSION}}
       - uses: actions/checkout@v4
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v6
         with:
           # Optional: version of golangci-lint to use in form of v1.2 or v1.2.3 or `latest` to use the latest version
-          version: v1.51.2
+          version: v1.63.4
 
           # Optional: working directory, useful for monorepos
           # working-directory: somedir

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.22-alpine as builder
+FROM golang:1.23-alpine as builder
 
 ARG VERSION
 

README.md

@@ -61,10 +61,11 @@ manager.  Then edit `/etc/udp-proxy-2020.conf` and start via:
 `systemctl start udp-proxy-2020`.
 
 ### Docker
-
+<!-- markdown-link-check-disable -->
 There is also a [docker image available](
 https://hub.docker.com/repository/docker/synfinatic/udp-proxy-2020) for Linux on
 AMD64 and ARM64 (like the Ubiquiti UDM).
+<!-- markdown-link-check-enable -->
 
 Note that for Docker deployments, you should be using [host networking](
 https://docs.docker.com/network/host/).

cmd/udp-proxy-2020/listen.go

@@ -10,6 +10,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ccoveille/go-safecast"
 	"github.com/davecgh/go-spew/spew"
 	"github.com/google/gopacket"
 	"github.com/google/gopacket/layers"
@@ -307,11 +308,16 @@ func (l *Listen) buildPacket(sndpkt Send, dstip net.IP, eth layers.Ethernet, loo
 	// UDP checksums can't be calculated via SerializeOptions
 	// because it requires the IP pseudo-header:
 	// https://en.wikipedia.org/wiki/User_Datagram_Protocol#IPv4_pseudo_header
+	payload_len, err := safecast.ToUint16(len(payload))
+	if err != nil {
+		log.Fatalf("invalid payload length: %d", len(payload))
+	}
+
 	new_udp := layers.UDP{
 		SrcPort:  udp.SrcPort,
 		DstPort:  udp.DstPort,
 		Checksum: 0, // but 0 is always valid for UDP
-		Length:   uint16(8 + len(payload)),
+		Length:   payload_len,
 	}
 
 	if err := new_udp.SerializeTo(buffer, opts); err != nil {

go.mod

@@ -1,6 +1,6 @@
 module github.com/synfinatic/udp-proxy-2020
 
-go 1.18
+go 1.23
 
 require (
 	github.com/alecthomas/kong v0.9.0
@@ -10,6 +10,8 @@ require (
 	golang.org/x/net v0.23.0 // indirect; security
 )
 
+require github.com/ccoveille/go-safecast v1.5.0
+
 require golang.org/x/sys v0.18.0 // indirect
 
 // see: https://github.com/sirupsen/logrus/issues/1275

go.sum

@@ -1,13 +1,18 @@
 github.com/alecthomas/assert/v2 v2.6.0 h1:o3WJwILtexrEUk3cUVal3oiQY2tfgr/FHWiz/v2n4FU=
+github.com/alecthomas/assert/v2 v2.6.0/go.mod h1:Bze95FyfUr7x34QZrjL+XP+0qgp/zg8yS+TtBj1WA3k=
 github.com/alecthomas/kong v0.9.0 h1:G5diXxc85KvoV2f0ZRVuMsi45IrBgx9zDNGNj165aPA=
 github.com/alecthomas/kong v0.9.0/go.mod h1:Y47y5gKfHp1hDc7CH7OeXgLIpp+Q2m1Ni0L5s3bI8Os=
 github.com/alecthomas/repr v0.4.0 h1:GhI2A8MACjfegCPVq9f1FLvIBS+DrQ2KQBFZP1iFzXc=
+github.com/alecthomas/repr v0.4.0/go.mod h1:Fr0507jx4eOXV7AlPV6AVZLYrLIuIeSOWtW57eE/O/4=
+github.com/ccoveille/go-safecast v1.5.0 h1:cT/3uVQ/i5PTiJvhvkSU81HeKNurtyQtBndXEH3hDg4=
+github.com/ccoveille/go-safecast v1.5.0/go.mod h1:QqwNjxQ7DAqY0C721OIO9InMk9zCwcsO7tnRuHytad8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/google/gopacket v1.1.19 h1:ves8RnFZPGiFnTS0uPQStjwru6uO6h+nlr9j6fL7kF8=
 github.com/google/gopacket v1.1.19/go.mod h1:iJ8V8n6KS+z2U1A8pUwu8bW5SyEMkXJB8Yo/Vo+TKTo=
 github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
+github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=