changes to support outbound-addr

Fixes #6064

Signed-off-by: Bohumil Cervenka <5eraph@protonmail.com>

4 files changed, 149 insertions, 13 deletions

diff --git a/docs/source/markdown/podman-create.1.md b/docs/source/markdown/podman-create.1.md
index b4456225e..d57af0a06 100644
--- a/docs/source/markdown/podman-create.1.md
+++ b/docs/source/markdown/podman-create.1.md
@@ -560,9 +560,14 @@ Valid values are:
 - `ns:<path>`: path to a network namespace to join
 - `private`: create a new namespace for the container (default)
 - `slirp4netns[:OPTIONS,...]`: use slirp4netns to create a user network stack.  This is the default for rootless containers.  It is possible to specify these additional options:
-  **port_handler=rootlesskit**: Use rootlesskit for port forwarding.  Default.
-  **port_handler=slirp4netns**: Use the slirp4netns port forwarding.
-  **allow_host_loopback=true|false**: Allow the slirp4netns to reach the host loopback IP (`10.0.2.2`).  Default to false.
+  - **allow_host_loopback=true|false**: Allow the slirp4netns to reach the host loopback IP (`10.0.2.2`). Default is false.
+  - **enable_ipv6=true|false**: Enable IPv6. Default is false. (Required for `outbound_addr6`).
+  - **outbound_addr=INTERFACE**: Specify the outbound interface slirp should bind to (ipv4 traffic only).
+  - **outbound_addr=IPv4**: Specify the outbound ipv4 address slirp should bind to.
+  - **outbound_addr6=INTERFACE**: Specify the outbound interface slirp should bind to (ipv6 traffic only).
+  - **outbound_addr6=IPv6**: Specify the outbound ipv6 address slirp should bind to.
+  - **port_handler=rootlesskit**: Use rootlesskit for port forwarding. Default.
+  - **port_handler=slirp4netns**: Use the slirp4netns port forwarding.
 
 **--network-alias**=*alias*
 
diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go
index 844748970..ed8f82c46 100644
--- a/libpod/networking_linux.go
+++ b/libpod/networking_linux.go
@@ -171,6 +171,8 @@ type slirpFeatures struct {
 	HasMTU                 bool
 	HasEnableSandbox       bool
 	HasEnableSeccomp       bool
+	HasOutboundAddr        bool
+	HasIPv6                bool
 }
 
 type slirp4netnsCmdArg struct {
@@ -197,6 +199,8 @@ func checkSlirpFlags(path string) (*slirpFeatures, error) {
 		HasMTU:                 strings.Contains(string(out), "--mtu"),
 		HasEnableSandbox:       strings.Contains(string(out), "--enable-sandbox"),
 		HasEnableSeccomp:       strings.Contains(string(out), "--enable-seccomp"),
+		HasOutboundAddr:        strings.Contains(string(out), "--outbound-addr"),
+		HasIPv6:                strings.Contains(string(out), "--enable-ipv6"),
 	}, nil
 }
 
@@ -225,21 +229,64 @@ func (r *Runtime) setupRootlessNetNS(ctr *Container) error {
 
 	isSlirpHostForward := false
 	disableHostLoopback := true
+	enableIPv6 := false
+	outboundAddr := ""
+	outboundAddr6 := ""
+
 	if ctr.config.NetworkOptions != nil {
 		slirpOptions := ctr.config.NetworkOptions["slirp4netns"]
 		for _, o := range slirpOptions {
-			switch o {
-			case "port_handler=slirp4netns":
-				isSlirpHostForward = true
-			case "port_handler=rootlesskit":
-				isSlirpHostForward = false
-			case "allow_host_loopback=true":
-				disableHostLoopback = false
-			case "allow_host_loopback=false":
-				disableHostLoopback = true
+			parts := strings.Split(o, "=")
+			option, value := parts[0], parts[1]
+
+			switch option {
+			case "port_handler":
+				switch value {
+				case "slirp4netns":
+					isSlirpHostForward = true
+				case "rootlesskit":
+					isSlirpHostForward = false
+				default:
+					return errors.Errorf("unknown port_handler for slirp4netns: %q", value)
+				}
+			case "allow_host_loopback":
+				switch value {
+				case "true":
+					disableHostLoopback = false
+				case "false":
+					disableHostLoopback = true
+				default:
+					return errors.Errorf("invalid value of allow_host_loopback for slirp4netns: %q", value)
+				}
+			case "enable_ipv6":
+				switch value {
+				case "true":
+					enableIPv6 = true
+				case "false":
+					enableIPv6 = false
+				default:
+					return errors.Errorf("invalid value of enable_ipv6 for slirp4netns: %q", value)
+				}
+			case "outbound_addr":
+				ipv4 := net.ParseIP(value)
+				if ipv4 == nil || ipv4.To4() == nil {
+					_, err := net.InterfaceByName(value)
+					if err != nil {
+						return errors.Errorf("invalid outbound_addr %q", value)
+					}
+				}
+				outboundAddr = value
+			case "outbound_addr6":
+				ipv6 := net.ParseIP(value)
+				if ipv6 == nil || ipv6.To4() != nil {
+					_, err := net.InterfaceByName(value)
+					if err != nil {
+						return errors.Errorf("invalid outbound_addr6: %q", value)
+					}
+				}
+				outboundAddr6 = value
 			default:
 				return errors.Errorf("unknown option for slirp4netns: %q", o)
-
 			}
 		}
 	}
@@ -262,6 +309,30 @@ func (r *Runtime) setupRootlessNetNS(ctr *Container) error {
 		cmdArgs = append(cmdArgs, "--enable-seccomp")
 	}
 
+	if enableIPv6 {
+		if !slirpFeatures.HasIPv6 {
+			return errors.Errorf("enable_ipv6 not supported")
+		}
+		cmdArgs = append(cmdArgs, "--enable-ipv6")
+	}
+
+	if outboundAddr != "" {
+		if !slirpFeatures.HasOutboundAddr {
+			return errors.Errorf("outbound_addr not supported")
+		}
+		cmdArgs = append(cmdArgs, fmt.Sprintf("--outbound-addr=%s", outboundAddr))
+	}
+
+	if outboundAddr6 != "" {
+		if !slirpFeatures.HasOutboundAddr || !slirpFeatures.HasIPv6 {
+			return errors.Errorf("outbound_addr6 not supported")
+		}
+		if !enableIPv6 {
+			return errors.Errorf("enable_ipv6=true is required for outbound_addr6")
+		}
+		cmdArgs = append(cmdArgs, fmt.Sprintf("--outbound-addr6=%s", outboundAddr6))
+	}
+
 	var apiSocket string
 	if havePortMapping && isSlirpHostForward {
 		apiSocket = filepath.Join(ctr.runtime.config.Engine.TmpDir, fmt.Sprintf("%s.net", ctr.config.ID))
diff --git a/test/e2e/run_networking_test.go b/test/e2e/run_networking_test.go
index 87b74052a..d37b3510e 100644
--- a/test/e2e/run_networking_test.go
+++ b/test/e2e/run_networking_test.go
@@ -1,11 +1,14 @@
 package integration
 
 import (
+	"fmt"
 	"os"
+	"strings"
 
 	. "github.com/containers/podman/v2/test/utils"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
+	"github.com/uber/jaeger-client-go/utils"
 )
 
 var _ = Describe("Podman run networking", func() {
@@ -278,6 +281,53 @@ var _ = Describe("Podman run networking", func() {
 		Expect(session.ExitCode()).To(Equal(0))
 	})
 
+	It("podman run network bind to 127.0.0.1", func() {
+		slirp4netnsHelp := SystemExec("slirp4netns", []string{"--help"})
+		Expect(slirp4netnsHelp.ExitCode()).To(Equal(0))
+		networkConfiguration := "slirp4netns:outbound_addr=127.0.0.1,allow_host_loopback=true"
+
+		if strings.Contains(slirp4netnsHelp.OutputToString(), "outbound-addr") {
+			ncListener := StartSystemExec("nc", []string{"-v", "-n", "-l", "-p", "8083"})
+			session := podmanTest.Podman([]string{"run", "--network", networkConfiguration, "-dt", ALPINE, "nc", "-w", "2", "10.0.2.2", "8083"})
+			session.Wait(30)
+			ncListener.Wait(30)
+
+			Expect(session.ExitCode()).To(Equal(0))
+			Expect(ncListener.ExitCode()).To(Equal(0))
+			Expect(ncListener.ErrorToString()).To(ContainSubstring("127.0.0.1"))
+		} else {
+			session := podmanTest.Podman([]string{"run", "--network", networkConfiguration, "-dt", ALPINE, "nc", "-w", "2", "10.0.2.2", "8083"})
+			session.Wait(30)
+			Expect(session.ExitCode()).ToNot(Equal(0))
+			Expect(session.ErrorToString()).To(ContainSubstring("outbound_addr not supported"))
+		}
+	})
+
+	It("podman run network bind to HostIP", func() {
+		ip, err := utils.HostIP()
+		Expect(err).To(BeNil())
+
+		slirp4netnsHelp := SystemExec("slirp4netns", []string{"--help"})
+		Expect(slirp4netnsHelp.ExitCode()).To(Equal(0))
+		networkConfiguration := fmt.Sprintf("slirp4netns:outbound_addr=%s,allow_host_loopback=true", ip.String())
+
+		if strings.Contains(slirp4netnsHelp.OutputToString(), "outbound-addr") {
+			ncListener := StartSystemExec("nc", []string{"-v", "-n", "-l", "-p", "8084"})
+			session := podmanTest.Podman([]string{"run", "--network", networkConfiguration, "-dt", ALPINE, "nc", "-w", "2", "10.0.2.2", "8084"})
+			session.Wait(30)
+			ncListener.Wait(30)
+
+			Expect(session.ExitCode()).To(Equal(0))
+			Expect(ncListener.ExitCode()).To(Equal(0))
+			Expect(ncListener.ErrorToString()).To(ContainSubstring(ip.String()))
+		} else {
+			session := podmanTest.Podman([]string{"run", "--network", networkConfiguration, "-dt", ALPINE, "nc", "-w", "2", "10.0.2.2", "8084"})
+			session.Wait(30)
+			Expect(session.ExitCode()).ToNot(Equal(0))
+			Expect(session.ErrorToString()).To(ContainSubstring("outbound_addr not supported"))
+		}
+	})
+
 	It("podman run network expose ports in image metadata", func() {
 		session := podmanTest.Podman([]string{"create", "--name", "test", "-dt", "-P", nginx})
 		session.Wait(90)
diff --git a/test/utils/utils.go b/test/utils/utils.go
index 2c454f532..8ee702423 100644
--- a/test/utils/utils.go
+++ b/test/utils/utils.go
@@ -341,6 +341,16 @@ func SystemExec(command string, args []string) *PodmanSession {
 	return &PodmanSession{session}
 }
 
+// StartSystemExec is used to start exec a system command
+func StartSystemExec(command string, args []string) *PodmanSession {
+	c := exec.Command(command, args...)
+	session, err := gexec.Start(c, GinkgoWriter, GinkgoWriter)
+	if err != nil {
+		Fail(fmt.Sprintf("unable to run command: %s %s", command, strings.Join(args, " ")))
+	}
+	return &PodmanSession{session}
+}
+
 // StringInSlice determines if a string is in a string slice, returns bool
 func StringInSlice(s string, sl []string) bool {
 	for _, i := range sl {