Files
moby/daemon/libnetwork/iptables/iptables_test.go
Paweł Gronowski 3df05205f4 modernize: Use range int
Added in Go 1.22

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
2025-12-15 18:56:34 +01:00

349 lines
8.3 KiB
Go

//go:build linux
package iptables
import (
"fmt"
"net"
"net/netip"
"os/exec"
"strconv"
"strings"
"testing"
"github.com/moby/moby/v2/internal/testutil/netnsutils"
"golang.org/x/sync/errgroup"
"gotest.tools/v3/assert"
"gotest.tools/v3/skip"
)
const (
chainName = "DOCKEREST"
bridgeName = "lo"
)
func createNewChain(t *testing.T) (*IPTable, *ChainInfo, *ChainInfo) {
t.Helper()
iptable := GetIptable(IPv4)
natChain, err := iptable.NewChain(chainName, Nat)
if err != nil {
t.Fatal(err)
}
filterChain, err := iptable.NewChain(chainName, Filter)
if err != nil {
t.Fatal(err)
}
return iptable, natChain, filterChain
}
func TestNewChain(t *testing.T) {
createNewChain(t)
}
func TestLink(t *testing.T) {
iptable, _, filterChain := createNewChain(t)
ip1 := netip.MustParseAddr("192.168.1.1")
ip2 := netip.MustParseAddr("192.168.1.2")
port := 1234
proto := "tcp"
err := filterChain.Link(Append, ip1, ip2, port, proto, bridgeName)
if err != nil {
t.Fatal(err)
}
rule1 := []string{
"-i", bridgeName,
"-o", bridgeName,
"-p", proto,
"-s", ip1.String(),
"-d", ip2.String(),
"--dport", strconv.Itoa(port),
"-j", "ACCEPT",
}
if !iptable.Exists(filterChain.Table, filterChain.Name, rule1...) {
t.Fatal("rule1 does not exist")
}
rule2 := []string{
"-i", bridgeName,
"-o", bridgeName,
"-p", proto,
"-s", ip2.String(),
"-d", ip1.String(),
"--sport", strconv.Itoa(port),
"-j", "ACCEPT",
}
if !iptable.Exists(filterChain.Table, filterChain.Name, rule2...) {
t.Fatal("rule2 does not exist")
}
}
func TestPrerouting(t *testing.T) {
iptable, natChain, _ := createNewChain(t)
args := []string{"-i", "lo", "-d", "192.168.1.1"}
err := natChain.Prerouting(Insert, args...)
if err != nil {
t.Fatal(err)
}
if !iptable.Exists(natChain.Table, "PREROUTING", args...) {
t.Fatal("rule does not exist")
}
delRule := append([]string{"-D", "PREROUTING", "-t", string(Nat)}, args...)
if _, err = iptable.Raw(delRule...); err != nil {
t.Fatal(err)
}
}
func TestOutput(t *testing.T) {
iptable, natChain, _ := createNewChain(t)
args := []string{"-o", "lo", "-d", "192.168.1.1"}
err := natChain.Output(Insert, args...)
if err != nil {
t.Fatal(err)
}
if !iptable.Exists(natChain.Table, "OUTPUT", args...) {
t.Fatal("rule does not exist")
}
delRule := append([]string{
"-D", "OUTPUT", "-t",
string(natChain.Table),
}, args...)
if _, err = iptable.Raw(delRule...); err != nil {
t.Fatal(err)
}
}
// Runs 10 concurrent rule additions. This will fail if iptables
// is actually invoked simultaneously without --wait.
func TestConcurrencyWithWait(t *testing.T) {
_, natChain, _ := createNewChain(t)
ip := net.ParseIP("192.168.1.1")
port := 1234
dstAddr := "172.17.0.1"
dstPort := 4321
proto := "tcp"
group := new(errgroup.Group)
for range 10 {
group.Go(func() error {
return addSomeRules(natChain, ip, port, proto, dstAddr, dstPort)
})
}
if err := group.Wait(); err != nil {
t.Fatal(err)
}
}
// addSomeRules adds arbitrary iptable rules. RunConcurrencyTest previously used
// iptables.Forward to create rules, that function has been removed. To preserve
// the test, this function creates similar rules.
func addSomeRules(c *ChainInfo, ip net.IP, port int, proto, destAddr string, destPort int) error {
iptable := GetIptable(c.IPVersion)
daddr := ip.String()
args := []string{
"-p", proto,
"-d", daddr,
"--dport", strconv.Itoa(port),
"-j", "DNAT",
"--to-destination", net.JoinHostPort(destAddr, strconv.Itoa(destPort)),
}
if err := iptable.ProgramRule(Nat, c.Name, Append, args); err != nil {
return err
}
args = []string{
"!", "-i", "lo",
"-o", "lo",
"-p", proto,
"-d", destAddr,
"--dport", strconv.Itoa(destPort),
"-j", "ACCEPT",
}
if err := iptable.ProgramRule(Filter, c.Name, Append, args); err != nil {
return err
}
args = []string{
"-p", proto,
"-s", destAddr,
"-d", destAddr,
"--dport", strconv.Itoa(destPort),
"-j", "MASQUERADE",
}
if err := iptable.ProgramRule(Nat, "POSTROUTING", Append, args); err != nil {
return err
}
return nil
}
func TestCleanup(t *testing.T) {
iptable, _, filterChain := createNewChain(t)
filterChain.Remove()
err := iptable.RemoveExistingChain(chainName, Nat)
if err != nil {
t.Fatal(err)
}
rules, err := exec.Command("iptables-save").Output()
if err != nil {
t.Fatal(err)
}
if strings.Contains(string(rules), chainName) {
t.Fatalf("Removing chain failed. %s found in iptables-save", chainName)
}
}
func TestExistsRaw(t *testing.T) {
const testChain1 = "ABCD"
const testChain2 = "EFGH"
iptable := GetIptable(IPv4)
_, err := iptable.NewChain(testChain1, Filter)
if err != nil {
t.Fatal(err)
}
defer func() {
iptable.RemoveExistingChain(testChain1, Filter)
}()
_, err = iptable.NewChain(testChain2, Filter)
if err != nil {
t.Fatal(err)
}
defer func() {
iptable.RemoveExistingChain(testChain2, Filter)
}()
// Test detection over full and truncated rule string
input := []struct{ rule []string }{
{[]string{"-s", "172.8.9.9/32", "-j", "ACCEPT"}},
{[]string{"-d", "172.8.9.0/24", "-j", "DROP"}},
{[]string{"-s", "172.0.3.0/24", "-d", "172.17.0.0/24", "-p", "tcp", "-m", "tcp", "--dport", "80", "-j", testChain2}},
{[]string{"-j", "RETURN"}},
}
for i, r := range input {
ruleAdd := append([]string{"-t", string(Filter), "-A", testChain1}, r.rule...)
err = iptable.RawCombinedOutput(ruleAdd...)
if err != nil {
t.Fatalf("i=%d, err: %v", i, err)
}
if !iptable.exists(true, Filter, testChain1, r.rule...) {
t.Fatalf("Failed to detect rule. i=%d", i)
}
// Truncate the rule
trg := r.rule[len(r.rule)-1]
trg = trg[:len(trg)-2]
r.rule[len(r.rule)-1] = trg
if iptable.exists(true, Filter, testChain1, r.rule...) {
t.Fatalf("Invalid detection. i=%d", i)
}
}
}
func TestRule(t *testing.T) {
skip.If(t, UsingFirewalld(), "firewalld is running in the host netns, it can't modify rules in the test's netns")
defer netnsutils.SetupTestOSContext(t)()
assert.NilError(t, exec.Command("iptables", "-N", "TESTCHAIN").Run())
rule := Rule{IPVer: IPv4, Table: Filter, Chain: "TESTCHAIN", Args: []string{"-j", "RETURN"}}
assert.NilError(t, rule.Insert())
assert.Equal(t, rule.Exists(), true)
assert.Equal(t, mustDumpChain(t, Filter, "TESTCHAIN"), `-N TESTCHAIN
-A TESTCHAIN -j RETURN
`)
// Test that Insert is idempotent
assert.NilError(t, rule.Insert())
assert.Equal(t, mustDumpChain(t, Filter, "TESTCHAIN"), `-N TESTCHAIN
-A TESTCHAIN -j RETURN
`)
rule = Rule{IPVer: IPv4, Table: Filter, Chain: "TESTCHAIN", Args: []string{"-j", "ACCEPT"}}
assert.NilError(t, rule.Append())
assert.Equal(t, rule.Exists(), true)
assert.Equal(t, mustDumpChain(t, Filter, "TESTCHAIN"), `-N TESTCHAIN
-A TESTCHAIN -j RETURN
-A TESTCHAIN -j ACCEPT
`)
// Test that Append is idempotent
assert.NilError(t, rule.Append())
assert.Equal(t, mustDumpChain(t, Filter, "TESTCHAIN"), `-N TESTCHAIN
-A TESTCHAIN -j RETURN
-A TESTCHAIN -j ACCEPT
`)
assert.NilError(t, rule.Delete())
assert.Equal(t, rule.Exists(), false)
assert.Equal(t, mustDumpChain(t, Filter, "TESTCHAIN"), `-N TESTCHAIN
-A TESTCHAIN -j RETURN
`)
// Test that Delete is idempotent
assert.NilError(t, rule.Delete())
}
func mustDumpChain(t *testing.T, table Table, chain string) string {
t.Helper()
out, err := exec.Command("iptables", "-t", string(table), "-S", chain).CombinedOutput()
assert.NilError(t, err, "output:\n%s", out)
return string(out)
}
func TestFlushChain(t *testing.T) {
_ = firewalldInit()
if UsingFirewalld() {
t.Skip("firewalld in host netns cannot create rules in the test's netns")
}
defer netnsutils.SetupTestOSContext(t)()
iptable := GetIptable(IPv4)
chain := "TESTFLUSHCHAIN"
table := Filter
// Ensure the chain exists
assert.NilError(t, iptable.RemoveExistingChain(chain, table))
_, err := iptable.NewChain(chain, table)
assert.NilError(t, err)
// Add a rule to the chain
rule := Rule{
IPVer: IPv4, Table: table, Chain: chain,
Args: []string{"-j", "ACCEPT"},
}
assert.NilError(t, rule.Insert())
// Flush the chain
assert.NilError(t, iptable.FlushChain(table, chain))
// Check that the chain exists and is empty (only the chain definition remains)
out, err := exec.Command("iptables", "-t", string(table), "-S", chain).CombinedOutput()
assert.NilError(t, err)
rulesCount := strings.Count(string(out), fmt.Sprintf("-A %s ", chain))
assert.Check(t, rulesCount == 0)
// Cleanup
_ = iptable.RemoveExistingChain(chain, table)
}