SecureComms: Add support for inbound namespace

Support opening inbound ports in configrable network namespaces.
This allows opening an inbound port inside the pod network namespace of the podvm.
The traffic will be forwarded via the SecureComms ssh channel to the outbound at the worker node.

Signed-off-by: David Hadas <david.hadas@gmail.com>

src/cloud-api-adaptor/docs/SecureComms.md

@@ -27,7 +27,7 @@ Once the "Kubernetes Phase" SSH channel is established, Secure Comms connects th
 
 See [Secure Comms Architecture Slides](./SecureComms.pdf) for more details.
 
-## Setup
+## Setup for CoCo with Trustee
 
 ### Deploy CAA
 Use any of the option for installing CAA depending on the cloud driver used.
@@ -53,8 +53,7 @@ kubectl get secret kbs-client -n trustee-operator-system -o json|jq --arg ns "co
 For a testing environment, you may need to change the policy of the KBS and AS using the KBS Client to allow all or fit your own policy. One way to do that is:
 
 ```sh
-kubectl -n trustee-operator-system exec deployment/trustee-deployment --container as -it -- /bin/bash
-        sed -i.bak 's/^default allow = false/default allow = true/' /opt/confidential-containers/attestation-service/opa/default.rego
+kubectl -n trustee-operator-system exec deployment/trustee-deployment --container as -it -- sed -i.bak 's/^default allow = false/default allow = true/' /opt/confidential-containers/attestation-service/opa/default.rego
 
 kubectl -n trustee-operator-system get cm resource-policy -o yaml | sed "s/default allow = false/default allow = true/"|kubectl apply -f -
 ```
@@ -66,18 +65,61 @@ Change the `src/cloud-api-adaptor/podvm/files/etc/systemd/system/agent-protocol-
 ExecStart=/usr/local/bin/agent-protocol-forwarder -pod-namespace /run/netns/podns -secure-comms -kata-agent-socket /run/kata-containers/agent.sock $TLS_OPTIONS $OPTIONS
 ```
 
-You may also include additional Inbounds and Outbounds configurations to the Forwarder using the `-secure-comms-inbounds` and `-secure-comms-outbounds` flags. See more details regarding Inbounds and Outbounds below.
+You may also include additional Inbounds and Outbounds configurations to the Forwarder using the `-secure-comms-inbounds` and `-secure-comms-outbounds` flags.  [See more details regarding Inbounds and Outbounds below.](#adding-named-tunnels-to-the-ssh-channel)
+
+For example:
+```sh
+ExecStart=/usr/local/bin/agent-protocol-forwarder -kata-agent-namespace /run/netns/podns -secure-comms -secure-comms-inbounds KUBERNETES_PHASE:mytunnel:podns:6666 -kata-agent-socket /run/kata-containers/agent.sock $TLS_OPTIONS $OPTIONS
+```
 
 Once you changed `podvm/files/etc/systemd/system/agent-protocol-forwarder.service`, you will need to [rebuild the podvm](./../podvm/README.md).
 
 
 ### Activate CAA Secure-Comms feature
-Use `kubectl edit cm peer-pods-cm -n confidential-containers-system` to add to the `peer-pods-cm` config map at the `confidential-containers-system` namespace:
+Activate Secure-Comms of CAA by changing the `SECURE_COMMS` parameter of the `peer-pods-cm` configMap in the `confidential-containers-system` namespace to `"true"`.  
+
+```sh
+kubectl -n confidential-containers-system  get cm peer-pods-cm  -o yaml | sed "s/SECURE_COMMS: \"false\"/SECURE_COMMS: \"true\"/"|kubectl apply -f -
+```
+
+Set InitData to point KBC services to IP address 127.0.0.1 
+```sh
+cat <<EOF > /tmp/initdata.txt
+algorithm = "sha384"
+version = "0.1.0"
+
+[data]
+"aa.toml" = '''
+[token_configs]
+[token_configs.coco_as]
+url = 'http://127.0.0.1:8080'
+
+[token_configs.kbs]
+url = 'http://127.0.0.1:8080'
+'''
+"cdh.toml"  = '''
+socket = 'unix:///run/confidential-containers/cdh.sock'
+credentials = []
+
+[kbc]
+name = 'cc_kbc'
+url = 'http://127.0.0.1:8080'
+'''
+EOF
+export INITDATA=`base64 -w 0 /tmp/initdata.txt`
+kubectl -n confidential-containers-system  get cm peer-pods-cm  -o yaml | sed 's/\s*^INITDATA: .*/  INITDATA: '$INITDATA'/'|kubectl apply -f -
+
+```
+
+You may also include additional Inbounds and Outbounds configurations to the Adaptor using the `SECURE_COMMS_INBOUNDS` and `SECURE_COMMS_OUTBOUNDS` config points. [See more details regarding Inbounds and Outbounds below.](#adding-named-tunnels-to-the-ssh-channel)
+
+Use `kubectl edit cm peer-pods-cm -n confidential-containers-system` to make such changes in the configMap, for example:
 ```sh
 apiVersion: v1
 data:
     ...
     SECURE_COMMS: "true"
+    SECURE_COMMS_OUTBOUNDS: "KUBERNETES_PHASE:mytunnel:149.81.64.62:7777"
     ...
 ```
 
@@ -120,7 +162,8 @@ You may also set the KBS address using the `SECURE_COMMS_KBS_ADDR` config point.
 >
 
 
-### Adding named tunnels to the SSH channel
+
+## Adding named tunnels to the SSH channel
 Named tunnels can be added to the SSH channel. Adding a named tunnel requires adding an Inbound at one of the SSH channel peers and an Outbound at the other SSH channel peer. The Inbound and Outbound both carry the name of the tunnel being created.
 
             |---------Tunnel----------| 
@@ -129,9 +172,11 @@ Named tunnels can be added to the SSH channel. Adding a named tunnel requires ad
 
 Inbounds and Outbounds take the form of a comma separated inbound/outbound tags such that Inbounds are formed as "InboundTag1,InboundTag2,InboundTag3,..." and Outbounds are formed as "OutboundTag1,OutboundTag2,outboundTag3,..."
 
-Each Inbound tag is structured as `Phase:Name:Port` where:
+
+Each Inbound tag is structured as `Phase:Name:Namespace:Port` or `Phase:Name:Port` where:
 - Phase can be 'KUBERNETES_PHASE' to represent an outbound available during the Kubernetes phase, 'ATTESTATION_PHASE' to represent an outbound available during the Attestation phase, or 'BOTH_PHASES' to represent an outbound available during both phases.
 - Name is the name of the tunnel
+- Namespace (if available) is a linux network namespace where the local service should be available.
 - Port is the local service port being opened to serve as ingress of the tunnel.
 
 Each outbound tag is structured as `Phase:Name:Host:Port` or `Phase:Name:Port` where:

src/cloud-api-adaptor/pkg/securecomms/sshproxy/sshproxy.go

@@ -9,11 +9,13 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"net/url"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"sync"
 
 	"github.com/confidential-containers/cloud-api-adaptor/src/cloud-api-adaptor/pkg/securecomms/sshutil"
+	"github.com/confidential-containers/cloud-api-adaptor/src/cloud-api-adaptor/pkg/util/netops"
 	"golang.org/x/crypto/ssh"
 )
 
@@ -102,11 +104,11 @@ func (inbounds *Inbounds) AddTags(tags []string, inboundPorts map[string]string,
 		if tag == "" {
 			continue
 		}
-		inPort, _, name, phase, err := ParseTag(tag)
+		inPort, namespace, name, phase, err := ParseTag(tag)
 		if err != nil {
 			return fmt.Errorf("failed to parse inbound tag %s: %v", tag, err)
 		}
-		retPort, err := inbounds.Add(inPort, name, phase, wg)
+		retPort, err := inbounds.Add(namespace, inPort, name, phase, wg)
 		if err != nil {
 			return fmt.Errorf("failed to add inbound: %v", err)
 		}
@@ -117,12 +119,34 @@ func (inbounds *Inbounds) AddTags(tags []string, inboundPorts map[string]string,
 	return nil
 }
 
-func (inbounds *Inbounds) Add(inPort int, name, phase string, wg *sync.WaitGroup) (string, error) {
+func (inbounds *Inbounds) listen(namespace string, tcpAddr *net.TCPAddr, name string) (tcpListener *net.TCPListener, err error) {
+	if namespace == "" {
+		return net.ListenTCP("tcp", tcpAddr)
+	}
+
+	var ns netops.Namespace
+	ns, netopsErr := netops.OpenNamespace(filepath.Join("/run/netns", namespace))
+	if netopsErr != nil {
+		return nil, fmt.Errorf("inbound %s failed to OpenNamespace '%s': %w", name, namespace, netopsErr)
+	}
+	defer ns.Close()
+
+	netopsErr = ns.Run(func() error {
+		tcpListener, err = net.ListenTCP("tcp", tcpAddr)
+		return err
+	})
+	if netopsErr != nil {
+		return nil, fmt.Errorf("inbound %s failed to ListenTCP '%s': %w", name, namespace, netopsErr)
+	}
+	return
+}
+
+func (inbounds *Inbounds) Add(namespace string, inPort int, name, phase string, wg *sync.WaitGroup) (string, error) {
 	tcpAddr := &net.TCPAddr{
 		IP:   net.IPv4(127, 0, 0, 1),
 		Port: inPort,
 	}
-	tcpListener, err := net.ListenTCP("tcp", tcpAddr)
+	tcpListener, err := inbounds.listen(namespace, tcpAddr, name)
 	if err != nil {
 		return "", fmt.Errorf("inbound failed to listen to host: %s port '%d' - err: %v", name, inPort, err)
 	}
@@ -162,6 +186,22 @@ func (inbounds *Inbounds) DelAll() {
 	inbounds.list = [](*Inbound){}
 }
 
+// ParseTag() parses an inbound or outbound tag
+// Outbound tags with structure <Phase>:<Name>:<Port>
+//
+//	are interperted to approach 127.0.0.1:<Port>
+//
+// Outbound tags with structure <Phase>:<Name>:<Host>:<Port>
+//
+//	are interperted to approach <Host>:<Port>
+//
+// Inbound tags with structure <Phase>:<Name>:<Port>
+//
+//	are interperted to serve 127.0.0.1:<Port> on host network namespace
+//
+// Inbound tags with structure <Phase>:<Name>:<Namespace>:<Port>
+//
+//	are interperted to serve 127.0.0.1:<Port> on <Namespace> network namepsace
 func ParseTag(tag string) (port int, host, name, phase string, err error) {
 	var inPort string
 	var uint64port uint64
@@ -174,7 +214,7 @@ func ParseTag(tag string) (port int, host, name, phase string, err error) {
 	} else if len(splits) == 4 {
 		phase = splits[0]
 		name = splits[1]
-		host = splits[2]
+		host = splits[2] // host for outbound or network namespace for inbound
 		inPort = splits[3]
 	} else {
 		err = fmt.Errorf("illegal tag: %s", tag)