From fd7db2396109ae193355c78989712f1e4b0afe33 Mon Sep 17 00:00:00 2001
From: Brad Davidson <brad.davidson@rancher.com>
Date: Tue, 15 Nov 2022 08:10:12 +0000
Subject: [PATCH] Add rootless IPv6 support

Signed-off-by: Brad Davidson <brad.davidson@rancher.com>
(cherry picked from commit 6f2b21c5cd38c0cb3f36870a517a29736236449c)
Signed-off-by: Brad Davidson <brad.davidson@rancher.com>
---
 pkg/agent/run.go                 |  6 +++++-
 pkg/cli/server/server.go         |  6 +++++-
 pkg/rootless/rootless.go         | 17 +++++++++++++----
 pkg/rootless/rootless_windows.go |  4 ++--
 4 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/pkg/agent/run.go b/pkg/agent/run.go
index 7c4ba2112b..dacdf08f5c 100644
--- a/pkg/agent/run.go
+++ b/pkg/agent/run.go
@@ -258,7 +258,11 @@ func Run(ctx context.Context, cfg cmds.Agent) error {
 	}
 
 	if cfg.Rootless && !cfg.RootlessAlreadyUnshared {
-		if err := rootless.Rootless(cfg.DataDir); err != nil {
+		dualNode, err := utilsnet.IsDualStackIPStrings(cfg.NodeIP)
+		if err != nil {
+			return err
+		}
+		if err := rootless.Rootless(cfg.DataDir, dualNode); err != nil {
 			return err
 		}
 	}
diff --git a/pkg/cli/server/server.go b/pkg/cli/server/server.go
index 39b3afdb71..0fd4b3f6b2 100644
--- a/pkg/cli/server/server.go
+++ b/pkg/cli/server/server.go
@@ -81,7 +81,11 @@ func run(app *cli.Context, cfg *cmds.Server, leaderControllers server.CustomCont
 		}
 		cfg.DataDir = dataDir
 		if !cfg.DisableAgent {
-			if err := rootless.Rootless(dataDir); err != nil {
+			dualNode, err := utilsnet.IsDualStackIPStrings(cmds.AgentConfig.NodeIP)
+			if err != nil {
+				return err
+			}
+			if err := rootless.Rootless(dataDir, dualNode); err != nil {
 				return err
 			}
 		}
diff --git a/pkg/rootless/rootless.go b/pkg/rootless/rootless.go
index 4cc51d3bbe..1611d90f81 100644
--- a/pkg/rootless/rootless.go
+++ b/pkg/rootless/rootless.go
@@ -29,11 +29,12 @@ var (
 
 	mtuEnv             = "K3S_ROOTLESS_MTU"
 	cidrEnv            = "K3S_ROOTLESS_CIDR"
+	enableIPv6Env      = "K3S_ROOTLESS_ENABLE_IPV6"
 	portDriverEnv      = "K3S_ROOTLESS_PORT_DRIVER"
 	disableLoopbackEnv = "K3S_ROOTLESS_DISABLE_HOST_LOOPBACK"
 )
 
-func Rootless(stateDir string) error {
+func Rootless(stateDir string, enableIPv6 bool) error {
 	defer func() {
 		os.Unsetenv(pipeFD)
 		os.Unsetenv(childEnv)
@@ -66,7 +67,7 @@ func Rootless(stateDir string) error {
 	if err := validateSysctl(); err != nil {
 		logrus.Fatal(err)
 	}
-	parentOpt, err := createParentOpt(driver, rootlessDir)
+	parentOpt, err := createParentOpt(driver, rootlessDir, enableIPv6)
 	if err != nil {
 		logrus.Fatal(err)
 	}
@@ -127,7 +128,7 @@ func parseCIDR(s string) (*net.IPNet, error) {
 	return ipnet, nil
 }
 
-func createParentOpt(driver portDriver, stateDir string) (*parent.Opt, error) {
+func createParentOpt(driver portDriver, stateDir string, enableIPv6 bool) (*parent.Opt, error) {
 	if err := os.MkdirAll(stateDir, 0755); err != nil {
 		return nil, errors.Wrapf(err, "failed to mkdir %s", stateDir)
 	}
@@ -180,6 +181,14 @@ func createParentOpt(driver portDriver, stateDir string) (*parent.Opt, error) {
 		}
 	}
 
+	if val := os.Getenv(enableIPv6Env); val != "" {
+		if v, err := strconv.ParseBool(val); err != nil {
+			logrus.Warn("Failed to parse rootless enable-ipv6 value; using default")
+		} else {
+			enableIPv6 = v
+		}
+	}
+
 	cidr := "10.41.0.0/16"
 	if val := os.Getenv(cidrEnv); val != "" {
 		cidr = val
@@ -193,7 +202,7 @@ func createParentOpt(driver portDriver, stateDir string) (*parent.Opt, error) {
 	if _, err := exec.LookPath(binary); err != nil {
 		return nil, err
 	}
-	opt.NetworkDriver, err = slirp4netns.NewParentDriver(driver.LogWriter(), binary, mtu, ipnet, "tap0", disableHostLoopback, driver.APISocketPath(), false, false, false)
+	opt.NetworkDriver, err = slirp4netns.NewParentDriver(driver.LogWriter(), binary, mtu, ipnet, "tap0", disableHostLoopback, driver.APISocketPath(), false, false, enableIPv6)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/rootless/rootless_windows.go b/pkg/rootless/rootless_windows.go
index 4431d0ab73..1d8ad5b00a 100644
--- a/pkg/rootless/rootless_windows.go
+++ b/pkg/rootless/rootless_windows.go
@@ -1,5 +1,5 @@
 package rootless
 
-func Rootless(stateDir string) error {
-	panic("Rootless not supported on windows")
+func Rootless(stateDir string, enableIPv6 bool) error {
+	panic("Rootless is not supported on windows")
 }