peer addresses and unconnected interfaces

munet/base.py

@@ -1611,6 +1611,7 @@ def __init__(self, *args, **kwargs):
         # logging.warning("InterfaceMixin: args: %s kwargs: %s", args, kwargs)
 
         self._intf_addrs = defaultdict(lambda: [None, None])
+        self._peer_intf_addrs = defaultdict(lambda: [None, None])
         self.net_intfs = {}
         self.next_intf_index = 0
         self.basename = "eth"
@@ -1630,9 +1631,16 @@ def get_intf_addr(self, ifname, ipv6=False):
             return None
         return self._intf_addrs[ifname][bool(ipv6)]
 
-    def set_intf_addr(self, ifname, ifaddr):
+    def get_peer_intf_addr(self, ifname, ipv6=False):
+        if ifname not in self._peer_intf_addrs:
+            return None
+        return self._peer_intf_addrs[ifname][bool(ipv6)]
+
+    def set_intf_addr(self, ifname, ifaddr, peer_ifaddr=None):
         ifaddr = ipaddress.ip_interface(ifaddr)
         self._intf_addrs[ifname][ifaddr.version == 6] = ifaddr
+        if peer_ifaddr is not None:
+            self._peer_intf_addrs[ifname][peer_ifaddr.version == 6] = peer_ifaddr
 
     def net_addr(self, netname, ipv6=False):
         if netname not in self.net_intfs:
@@ -2883,6 +2891,33 @@ def add_host(self, name, cls=LinuxNamespace, **kwargs):
 
         return self.hosts[name]
 
+    def add_dummy(self, node1, if1, mtu=None, **intf_constraints):
+        """Add a dummy for an interface with no link."""
+        try:
+            name1 = node1.name
+        except AttributeError:
+            if node1 in self.switches:
+                node1 = self.switches[node1]
+            else:
+                node1 = self.hosts[node1]
+            name1 = node1.name
+
+        lname = "{}:{}".format(name1, if1)
+        self.logger.debug("%s: add_dummy %s", self, lname)
+        lhost = self.hosts[name1]
+
+        nsif1 = lhost.get_ns_ifname(if1)
+        lhost.cmd_raises_nsonly(f"ip link add name {nsif1} type dummy")
+
+        if mtu:
+            lhost.cmd_raises_nsonly(f"ip link set {nsif1} mtu {mtu}")
+        lhost.cmd_raises_nsonly(f"ip link set {nsif1} up")
+        lhost.register_interface(if1)
+
+        # Setup interface constraints if provided
+        if intf_constraints:
+            node1.set_intf_constraints(if1, **intf_constraints)
+
     def add_link(self, node1, node2, if1, if2, mtu=None, **intf_constraints):
         """Add a link between switch and node or 2 nodes.
 

munet/native.py

@@ -980,6 +980,31 @@ def get_ifname(self, netname):
                 return c["name"]
         return None
 
+    def set_dummy_addr(self, cconf):
+        if ip := cconf.get("ip"):
+            ipaddr = ipaddress.ip_interface(ip)
+            assert ipaddr.version == 4
+        else:
+            ipaddr = None
+
+        if ip := cconf.get("ipv6"):
+            ip6addr = ipaddress.ip_interface(ip)
+            assert ip6addr.version == 6
+        else:
+            ip6addr = None
+
+        if "physical" in cconf or self.is_vm:
+            return
+
+        ifname = cconf["name"]
+        for ip in (ipaddr, ip6addr):
+            if ip is None:
+                continue
+            self.set_intf_addr(ifname, ip)
+            ipcmd = "ip " if ip.version == 4 else "ip -6 "
+            self.logger.debug("%s: adding %s to unconnected intf %s", self, ip, ifname)
+            self.intf_ip_cmd(ifname, ipcmd + f"addr add {ip} dev {ifname}")
+
     def set_lan_addr(self, switch, cconf):
         if ip := cconf.get("ip"):
             ipaddr = ipaddress.ip_interface(ip)
@@ -1055,20 +1080,42 @@ def _set_p2p_addr(self, other, cconf, occonf, ipv6=False):
                 return
 
         if ipaddr:
+            # Check if the two sides of this link are assigned
+            # different subnets.  If so, set the peer address.
+            set_peer = False
+            if oipaddr and ipaddr.network != oipaddr.network:
+                set_peer = True
             ifname = cconf["name"]
-            self.set_intf_addr(ifname, ipaddr)
+            self.set_intf_addr(ifname, ipaddr, oipaddr)
             self.logger.debug("%s: adding %s to p2p intf %s", self, ipaddr, ifname)
             if "physical" not in cconf and not self.is_vm:
-                self.intf_ip_cmd(ifname, f"ip addr add {ipaddr} dev {ifname}")
+                if set_peer:
+                    self.logger.debug("%s: setting peer address %s", self, oipaddr)
+                    self.intf_ip_cmd(
+                        ifname,
+                        f"ip addr add {ipaddr.ip} peer {oipaddr.network} dev {ifname}",
+                    )
+                else:
+                    self.intf_ip_cmd(ifname, f"ip addr add {ipaddr} dev {ifname}")
 
         if oipaddr:
+            set_peer = False
+            if ipaddr and ipaddr.network != oipaddr.network:
+                set_peer = True
             oifname = occonf["name"]
-            other.set_intf_addr(oifname, oipaddr)
+            other.set_intf_addr(oifname, oipaddr, ipaddr)
             self.logger.debug(
                 "%s: adding %s to other p2p intf %s", other, oipaddr, oifname
             )
             if "physical" not in occonf and not other.is_vm:
-                other.intf_ip_cmd(oifname, f"ip addr add {oipaddr} dev {oifname}")
+                if set_peer:
+                    other.logger.debug("%s: setting peer address %s", other, ipaddr)
+                    other.intf_ip_cmd(
+                        oifname,
+                        f"ip addr add {oipaddr.ip} peer {ipaddr.network} dev {oifname}",
+                    )
+                else:
+                    other.intf_ip_cmd(oifname, f"ip addr add {oipaddr} dev {oifname}")
 
     def set_p2p_addr(self, other, cconf, occonf):
         self._set_p2p_addr(other, cconf, occonf, ipv6=False)
@@ -2225,13 +2272,33 @@ async def renumber_interfaces(self):
             con.cmd_raises(f"ip -4 addr flush dev {ifname}")
             sw_is_nat = switch and hasattr(switch, "is_nat") and switch.is_nat
             if ifaddr := self.get_intf_addr(ifname, ipv6=False):
-                con.cmd_raises(f"ip addr add {ifaddr} dev {ifname}")
+                oifaddr = self.get_peer_intf_addr(ifname, ipv6=False)
+                if (
+                    not switch
+                    and oifaddr is not None
+                    and ifaddr.network != oifaddr.network
+                ):
+                    con.cmd_raises(
+                        f"ip addr add {ifaddr.ip} peer {oifaddr.network} dev {ifname}"
+                    )
+                else:
+                    con.cmd_raises(f"ip addr add {ifaddr} dev {ifname}")
                 if sw_is_nat:
                     # In case there was some preconfig e.g., cloud-init
                     con.cmd_raises("ip route flush exact default")
                     con.cmd_raises(f"ip route add default via {switch.ip_address}")
             if ifaddr := self.get_intf_addr(ifname, ipv6=True):
-                con.cmd_raises(f"ip -6 addr add {ifaddr} dev {ifname}")
+                oifaddr = self.get_peer_intf_addr(ifname, ipv6=True)
+                if (
+                    not switch
+                    and oifaddr is not None
+                    and ifaddr.network != oifaddr.network
+                ):
+                    con.cmd_raises(
+                        f"ip addr add {ifaddr.ip} peer {oifaddr.network} dev {ifname}"
+                    )
+                else:
+                    con.cmd_raises(f"ip -6 addr add {ifaddr} dev {ifname}")
                 if sw_is_nat:
                     # In case there was some preconfig e.g., cloud-init
                     con.cmd_raises("ip -6 route flush exact default")
@@ -3204,8 +3271,9 @@ async def _async_build(self, logger=None):
             if "connections" not in nconf:
                 continue
             for cconf in nconf["connections"]:
-                # Eventually can add support for unconnected intf here.
                 if "to" not in cconf:
+                    # unconnected intf
+                    await self.add_dummy_link(node, cconf)
                     continue
                 to = cconf["to"]
                 if to in self.switches:
@@ -3236,6 +3304,25 @@ def autonumber(self):
     def autonumber(self, value):
         self.topoconf["networks-autonumber"] = bool(value)
 
+    async def add_dummy_link(self, node1, c1=None):
+        c1 = {} if c1 is None else c1
+
+        if "name" not in c1:
+            c1["name"] = node1.get_next_intf_name()
+        if1 = c1["name"]
+
+        do_add_dummy = True
+        if "hostintf" in c1:
+            await node1.add_host_intf(c1["hostintf"], c1["name"], mtu=c1.get("mtu"))
+            do_add_dummy = False
+        elif "physical" in c1:
+            await node1.add_phy_intf(c1["physical"], c1["name"])
+            do_add_dummy = False
+
+        if do_add_dummy:
+            super().add_dummy(node1, if1, **c1)
+            node1.set_dummy_addr(c1)
+
     async def add_native_link(self, node1, node2, c1=None, c2=None):
         """Add a link between switch and node or 2 nodes."""
         isp2p = False

tests/config/p2p-addr/munet.yaml

@@ -0,0 +1,28 @@
+version: 1
+topology:
+  ipv6-enable: true
+  nodes:
+    - name: r1
+      connections:
+        - to: r2
+          name: eth0
+          mtu: 4500
+          ip: 172.16.0.1/32
+          ipv6: 2001:db8::1/128
+      cmd: |
+        ip addr show
+        ip -6 addr show
+        which ping
+        tail -f /dev/null
+    - name: r2
+      connections:
+        - to: r1
+          name: eth0
+          mtu: 4500
+          ip: 172.16.1.2/24
+          ipv6: 2001:db8::1:1/112
+      cmd: |
+        ip addr show
+        ip -6 addr show
+        which ping
+        tail -f /dev/null

tests/config/p2p-addr/test_p2p_peer_addr.py

@@ -0,0 +1,34 @@
+# -*- coding: utf-8 eval: (blacken-mode 1) -*-
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# June 28 2023, Eric Kinzie <ekinzie@labn.net>
+#
+# Copyright 2023, LabN Consulting, L.L.C.
+#
+"Test p2p peer addresses"
+import logging
+import pytest
+
+# All tests are coroutines
+pytestmark = pytest.mark.asyncio
+
+
+async def test_peer_address(unet):
+    rc, o, e = await unet.hosts["r1"].async_cmd_status(f"ip addr show dev eth0")
+    assert rc == 0
+    assert o.find("mtu 4500") > -1
+    assert o.find("inet 172.16.0.1 peer 172.16.1.0/24") > -1
+    assert o.find("inet6 2001:db8::1 peer 2001:db8::1:0/112") > -1
+
+    rc, o, e = await unet.hosts["r2"].async_cmd_status(f"ip addr show dev eth0")
+    assert rc == 0
+    assert o.find("mtu 4500") > -1
+    assert o.find("inet 172.16.1.2 peer 172.16.0.1/32") > -1
+    assert o.find("inet6 2001:db8::1:1 peer 2001:db8::1/128") > -1
+
+
+async def test_peer_ping(unet):
+    r1eth0 = unet.hosts["r1"].get_intf_addr("eth0").ip
+    logging.debug("r1eth0 is %s", r1eth0)
+    o = await unet.hosts["r2"].async_cmd_raises(f"ping -w1 -c1 172.16.0.1")
+    logging.debug("ping r2 output: %s", o)

tests/config/unconnected/munet.yaml

@@ -0,0 +1,31 @@
+version: 1
+topology:
+  networks-autonumber: true
+  ipv6-enable: true
+  networks:
+    - name: net0
+      mtu: 5000
+  nodes:
+    - name: r1
+      connections:
+        - to: net0
+          name: eth0
+          mtu: 4500
+        - name: unconnected
+          ip: 172.16.0.1/24
+          mtu: 9000
+      cmd: |
+        ip addr show
+        ip -6 addr show
+        which ping
+        tail -f /dev/null
+    - name: r2
+      connections:
+        - to: "net0"
+          name: eth0
+          mtu: 4500
+      cmd: |
+        ip addr show
+        ip -6 addr show
+        which ping
+        tail -f /dev/null

tests/config/unconnected/test_unconnected.py

@@ -0,0 +1,32 @@
+# -*- coding: utf-8 eval: (blacken-mode 1) -*-
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# June 28 2023, Eric Kinzie <ekinzie@labn.net>
+#
+# Copyright 2023, LabN Consulting, L.L.C.
+#
+"Testing of unconnected interface."
+import logging
+
+import pytest
+
+# All tests are coroutines
+pytestmark = pytest.mark.asyncio
+
+
+async def test_unconnected_presence(unet):
+    rc, o, e = await unet.hosts["r1"].async_cmd_status(f"ip addr show dev unconnected")
+    assert rc == 0
+    assert o.find("mtu 9000") > -1
+    assert o.find("inet 172.16.0.1/24") > -1
+
+
+async def test_basic_ping(unet):
+    r1eth0 = unet.hosts["r1"].get_intf_addr("eth0").ip
+    logging.debug("r1eth0 is %s", r1eth0)
+    rc, o, e = await unet.hosts["r2"].async_cmd_status(
+        f"ip ro add 172.16.0.0/24 via {r1eth0}"
+    )
+    assert rc == 0
+    o = await unet.hosts["r2"].async_cmd_raises(f"ping -w1 -c1 172.16.0.1")
+    logging.debug("ping r2 output: %s", o)