test the IP address and subnet generation

Test the IP address and subnet generation to avoid breaking the existing
generation when updating or refactoring it. Given that the subnet
generation uses some binary operations, it is hard to spot potential
errors.

For this usecase the function generating the subnet was externalized to
be accessible from the test code instead of an inlined function.

.github/workflows/build.yml

@@ -20,8 +20,9 @@ jobs:
           git diff --exit-code
           go vet ./...
 
-      - name: Build project
+      - name: Build and test project
         run: |
+          go test ./...
           mkdir bin
           GOBIN="$PWD/bin" CGO_ENABLED=0 go install ./...
 

etcdconfigweb/config.go

@@ -34,6 +34,31 @@ var MISSING_V6MTU = errors.New("Missing v6mtu query parameter")
 var MISSING_PUBKEY = errors.New("Missing pubkey query parameter")
 var MISSING_NONCE = errors.New("Missing nonce query parameter")
 
+func generateNodeAddressesAndRanges(info *ffbs.NodeInfo) {
+	const V4_BASE uint32 = 10 << 24
+	const V4_RANGE_SIZE uint8 = 10
+	const V6_BASE_HIGH uint64 = 0x20010bf70381 << 16
+
+	num := *info.ID
+
+	var v4Addr [net.IPv4len]byte
+	binary.BigEndian.PutUint32(v4Addr[:], V4_BASE|(uint32(num)<<V4_RANGE_SIZE))
+	v4range := fmt.Sprintf("%s/%d", net.IP(v4Addr[:]), 8*net.IPv4len-V4_RANGE_SIZE)
+	v4Addr[net.IPv4len-1] = 1
+	v4addr := net.IP(v4Addr[:]).String()
+
+	var v6Addr [net.IPv6len]byte
+	binary.BigEndian.PutUint64(v6Addr[:8], V6_BASE_HIGH|uint64(num))
+	v6range := fmt.Sprintf("%s/64", net.IP(v6Addr[:]))
+	v6Addr[net.IPv6len-1] = 1
+	v6addr := net.IP(v6Addr[:]).String()
+
+	info.Address4 = &v4addr
+	info.Range4 = &v4range
+	info.Address6 = &v6addr
+	info.Range6 = &v6range
+}
+
 func (ch ConfigHandler) handleRequest(ctx context.Context, query url.Values, headers http.Header) (*ConfigResponse, error) {
 	var v6mtu uint64
 	var err error
@@ -80,30 +105,7 @@ func (ch ConfigHandler) handleRequest(ctx context.Context, query url.Values, hea
 		}
 
 		// insert new node
-		err := ch.etcdHandler.CreateNode(ctx, pubkey, func(info *ffbs.NodeInfo) {
-			const V4_BASE uint32 = 10 << 24
-			const V4_RANGE_SIZE uint8 = 10
-			const V6_BASE_HIGH uint64 = 0x20010bf70381 << 16
-
-			num := *info.ID
-
-			var v4Addr [net.IPv4len]byte
-			binary.BigEndian.PutUint32(v4Addr[:], V4_BASE|(uint32(num)<<V4_RANGE_SIZE))
-			v4range := fmt.Sprintf("%s/%d", net.IP(v4Addr[:]), 8*net.IPv4len-V4_RANGE_SIZE)
-			v4Addr[net.IPv4len-1] = 1
-			v4addr := net.IP(v4Addr[:]).String()
-
-			var v6Addr [net.IPv6len]byte
-			binary.BigEndian.PutUint64(v6Addr[:8], V6_BASE_HIGH|uint64(num))
-			v6range := fmt.Sprintf("%s/64", net.IP(v6Addr[:]))
-			v6Addr[net.IPv6len-1] = 1
-			v6addr := net.IP(v6Addr[:]).String()
-
-			info.Address4 = &v4addr
-			info.Range4 = &v4range
-			info.Address6 = &v6addr
-			info.Range6 = &v6range
-		})
+		err := ch.etcdHandler.CreateNode(ctx, pubkey, generateNodeAddressesAndRanges)
 		if err != nil {
 			return nil, err
 		}

etcdconfigweb/config_test.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/ffbs/etcd-tools/ffbs"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGenerateAddressesAndRanges(t *testing.T) {
+	// Using https://freifunk-bs.de/map/#!/de/map/f4068dcf9fe1 as an example
+	id := uint64(30)
+	node := ffbs.NodeInfo{ID: &id}
+	generateNodeAddressesAndRanges(&node)
+	assert.Equal(t, "10.0.120.1", *node.Address4)
+	assert.Equal(t, "10.0.120.0/22", *node.Range4)
+	assert.Equal(t, "2001:bf7:381:1e::1", *node.Address6)
+	assert.Equal(t, "2001:bf7:381:1e::/64", *node.Range6)
+}
+
+func TestGenerateHighestAddressesAndRanges(t *testing.T) {
+	// IPv4 base range is /8. Range of every subnet is /22 => 22-8 = 14 bits of freedom
+	id := uint64(16383)
+	node := ffbs.NodeInfo{ID: &id}
+	generateNodeAddressesAndRanges(&node)
+	assert.Equal(t, "10.255.252.1", *node.Address4)
+	assert.Equal(t, "10.255.252.0/22", *node.Range4)
+	assert.Equal(t, "2001:bf7:381:3fff::1", *node.Address6)
+	assert.Equal(t, "2001:bf7:381:3fff::/64", *node.Range6)
+}

go.mod

@@ -6,6 +6,7 @@ toolchain go1.22.9
 
 require (
 	github.com/spf13/cobra v1.8.1
+	github.com/stretchr/testify v1.9.0
 	go.etcd.io/etcd/client/v3 v3.5.17
 	go.seankhliao.com/signify v0.0.0-20200507101447-944db0e32d56
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6
@@ -14,6 +15,7 @@ require (
 require (
 	github.com/coreos/go-semver v0.3.0 // indirect
 	github.com/coreos/go-systemd/v22 v22.3.2 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/ebfe/bcrypt_pbkdf v0.0.0-20140212075826-3c8d2dcb253a // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
@@ -23,6 +25,7 @@ require (
 	github.com/mdlayher/genetlink v1.3.2 // indirect
 	github.com/mdlayher/netlink v1.7.2 // indirect
 	github.com/mdlayher/socket v0.4.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	go.etcd.io/etcd/api/v3 v3.5.17 // indirect
 	go.etcd.io/etcd/client/pkg/v3 v3.5.17 // indirect
@@ -40,4 +43,5 @@ require (
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20230822172742-b8732ec3820d // indirect
 	google.golang.org/grpc v1.59.0 // indirect
 	google.golang.org/protobuf v1.33.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -108,6 +108,7 @@ google.golang.org/grpc v1.59.0 h1:Z5Iec2pjwb+LEOqzpB2MR12/eKFhDPhuqW91O+4bwUk=
 google.golang.org/grpc v1.59.0/go.mod h1:aUPDwccQo6OTjy7Hct4AfBPD1GptF4fyUjIkQ9YtF98=
 google.golang.org/protobuf v1.33.0 h1:uNO2rsAINq/JlFpSdYEKIZ0uKD/R9cpdv0T+yoGwGmI=
 google.golang.org/protobuf v1.33.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=