Add l2xc support, including extensive tests to validate correct usage of the feature

schema.yaml

@@ -27,6 +27,7 @@ interface:
   mtu: int(min=128,max=9216,required=False)
   addresses: list(ip_interface(),min=1,max=6,required=False)
   sub-interfaces: map(include('sub-interface'),key=int(min=1,max=4294967295),required=False)
+  l2xc: str(required=False)
 ---
 sub-interface:
   description: str(exclude='\'"',required=False)
@@ -34,6 +35,7 @@ sub-interface:
   mtu: int(min=128,max=9216,required=False)
   addresses: list(ip_interface(),required=False)
   encapsulation: include('encapsulation',required=False)
+  l2xc: str(required=False)
 ---
 encapsulation:
   dot1q: int(min=1,max=4095,required=False)

unittest/correct-l2xc.yaml

@@ -0,0 +1,41 @@
+test:
+  description: "A few correct ways of setting L2 cross connects"
+  errors:
+    count: 0
+---
+bondethernets:
+  BondEthernet0:
+    interfaces: [ GigabitEthernet3/0/0, GigabitEthernet3/0/1 ]
+
+interfaces:
+  GigabitEthernet1/0/0:
+    description: "Cross connected to Gi1/0/1"
+    l2xc: GigabitEthernet1/0/1
+  GigabitEthernet1/0/1:
+    description: "Cross connected to Gi1/0/0"
+    l2xc: GigabitEthernet1/0/0
+
+  GigabitEthernet2/0/0:
+    description: "Cross connected to Gi2/0/1.100"
+    l2xc: GigabitEthernet2/0/1.100
+  GigabitEthernet2/0/1:
+    description: "Main phy with a subint"
+    sub-interfaces:
+      100:
+        description: "Cross connected to Gi2/0/0"
+        l2xc: GigabitEthernet2/0/0
+
+  GigabitEthernet3/0/0:
+    mtu: 3000
+  GigabitEthernet3/0/1:
+    mtu: 3000
+
+  BondEthernet0:
+    description: "BE0 with two xconnected sub-ints"
+    sub-interfaces:
+      100:
+        description: "Cross connected to BE0.101"
+        l2xc: BondEthernet0.101
+      101:
+        description: "Cross connected to BE0.100"
+        l2xc: BondEthernet0.100

unittest/error-bridgedomain7.yaml

@@ -0,0 +1,22 @@
+test:
+  description: "An interface that is in a bridgedomain, cannot also be an l2 cross connect"
+  errors:
+    expected:
+     - "interface .* l2xc target .* is in a bridgedomain"
+    count: 1
+---
+interfaces:
+  GigabitEthernet1/0/0:
+    mtu: 3000
+  GigabitEthernet1/0/1:
+    mtu: 3000
+
+  GigabitEthernet1/0/1:
+    mtu: 3000
+    l2xc: GigabitEthernet1/0/0
+
+bridgedomains:
+  bd10:
+    description: "Bridge Domain 10 has Gi1/0/0 which is also a target of an L2XC"
+    mtu: 3000
+    interfaces: [ GigabitEthernet1/0/0, GigabitEthernet1/0/1 ]

unittest/error-l2xc1.yaml

@@ -0,0 +1,18 @@
+test:
+  description: "L2 cross connect targets cannot occur more than once"
+  errors:
+    expected:
+     - "interface .* l2xc target .* is not unique"
+    count: 2
+---
+interfaces:
+  GigabitEthernet1/0/0:
+    description: "Cross connected to Gi1/0/1"
+    l2xc: GigabitEthernet1/0/1
+  GigabitEthernet1/0/1:
+    description: "Cross connected to Gi1/0/0"
+    l2xc: GigabitEthernet1/0/0
+
+  GigabitEthernet2/0/0:
+    description: "Cross connected to Gi1/0/0 as well"
+    l2xc: GigabitEthernet1/0/0

unittest/error-l2xc2.yaml

@@ -0,0 +1,14 @@
+test:
+  description: "L2 cross connect targets must exist"
+  errors:
+    expected:
+     - "interface .* l2xc target .* does not exist"
+    count: 1
+---
+interfaces:
+  GigabitEthernet1/0/0:
+    description: "Cross connected to Gi1/0/1"
+    l2xc: GigabitEthernet1/0/1
+  GigabitEthernet1/0/1:
+    description: "Cross connected to Gi1/0/2, which does not exist"
+    l2xc: GigabitEthernet1/0/2

unittest/error-l2xc3.yaml

@@ -0,0 +1,18 @@
+test:
+  description: "L2 cross connect targets cannot also occur in a bridgedomain"
+  errors:
+    expected:
+     - "interface .* l2xc target .* in a bridgedomain"
+    count: 1
+---
+interfaces:
+  GigabitEthernet1/0/0:
+    description: "Cross connected to Gi1/0/1"
+    l2xc: GigabitEthernet1/0/1
+  GigabitEthernet1/0/1:
+    description: "In a Bridge Domain, so cannot be a target of L2XC"
+
+bridgedomains:
+  bd10:
+    description: "A Bridge with gi1/0/0 which also occurs as an L2XC target"
+    interfaces: [ GigabitEthernet1/0/1 ]

unittest/error-l2xc4.yaml

@@ -0,0 +1,18 @@
+test:
+  description: "L2 cross connect targets cannot have an IP address or LCP"
+  errors:
+    expected:
+     - "interface .* l2xc so it cannot be an LCP"
+     - "interface .* l2xc so it cannot have an address"
+    count: 3
+---
+interfaces:
+  GigabitEthernet1/0/0:
+    description: "Cross connected to Gi1/0/1, but should not have an LCP"
+    l2xc: GigabitEthernet1/0/1
+    lcp: "e1-0-0"
+  GigabitEthernet1/0/1:
+    description: "Cross connected to Gi1/0/0, but should not have address and LCP"
+    l2xc: GigabitEthernet1/0/0
+    lcp: "e1-0-1"
+    addresses: [ 192.0.2.1/30 ]

unittest/error-l2xc5.yaml

@@ -0,0 +1,18 @@
+test:
+  description: "L2 cross connect from a phy cannot also have sub-interfaces"
+  errors:
+    expected:
+     - "interface .* l2xc so it cannot have sub-interfaces"
+    count: 1
+---
+interfaces:
+  GigabitEthernet1/0/0:
+    l2xc: GigabitEthernet1/0/1.100
+    sub-interfaces:
+      100:
+        description: "If the parent is cross connected, it should not have sub-interfaces"
+
+  GigabitEthernet1/0/1:
+    sub-interfaces:
+      100:
+        l2xc: GigabitEthernet1/0/0

validator/interface.py

@@ -133,6 +133,65 @@ def is_bridge_interface(yaml, ifname):
     return False
 
 
+def get_l2xc_interfaces(yaml):
+    """ Returns a list of all interfaces that have an L2 CrossConnect """
+    ret = []
+    if not 'interfaces' in yaml:
+        return ret
+    for ifname, iface in yaml['interfaces'].items():
+        if 'l2xc' in iface:
+            ret.extend(ifname)
+        if 'sub-interfaces' in iface:
+            for sub_ifname, sub_iface in iface['sub-interfaces'].items():
+                if 'l2xc' in sub_iface:
+                    ret.extend(sub_ifname)
+
+    return ret
+
+
+def is_l2xc_interface(yaml, ifname):
+    """ Returns True if this interface has an L2 CrossConnect """
+
+    if ifname in get_l2xc_interfaces(yaml):
+        return True
+    return False
+
+
+def get_l2xc_target_interfaces(yaml):
+    """ Returns a list of all interfaces that are the target of an L2 CrossConnect """
+    ret = []
+    if not 'interfaces' in yaml:
+        return ret
+    for ifname, iface in yaml['interfaces'].items():
+        if 'l2xc' in iface:
+            ret.append(iface['l2xc'])
+        if 'sub-interfaces' in iface:
+            for sub_ifname, sub_iface in iface['sub-interfaces'].items():
+                if 'l2xc' in sub_iface:
+                    ret.append(sub_iface['l2xc'])
+
+    return ret
+
+
+def is_l2xc_target_interface(yaml, ifname):
+    """ Returns True if this interface is the target of an L2 CrossConnect """
+
+    if ifname in get_l2xc_target_interfaces(yaml):
+        return True
+    return False
+
+
+def is_l2xc_target_interface_unique(yaml, ifname):
+    """ Returns True if this interface is referenced as an l2xc target zero or one times """
+
+    ifs = get_l2xc_target_interfaces(yaml)
+    n = ifs.count(ifname)
+
+    if n == 0 or n == 1:
+        return True
+    return False
+
+
 def has_lcp(yaml, ifname):
     """ Returns True if this interface or sub-interface has an LCP """
     if not 'interfaces' in yaml:
@@ -322,6 +381,25 @@ def validate_interfaces(yaml):
                 if not address.is_allowed(yaml, ifname, iface['addresses'], a):
                     msgs.append("interface %s IP address %s conflicts with another" % (ifname, a))
                     result = False
+        if 'l2xc' in iface:
+            if has_sub(yaml, ifname):
+                msgs.append("interface %s is l2xc so it cannot have sub-interfaces" % (ifname))
+                result = False
+            if iface_lcp:
+                msgs.append("interface %s is l2xc so it cannot be an LCP" % (ifname))
+                result = False
+            if iface_address:
+                msgs.append("interface %s is l2xc so it cannot have an address" % (ifname))
+                result = False
+            if not get_by_name(yaml, iface['l2xc']):
+                msgs.append("interface %s l2xc target %s does not exist" % (ifname, iface['l2xc']))
+                result = False
+            if not is_l2xc_target_interface_unique(yaml, iface['l2xc']):
+                msgs.append("interface %s l2xc target %s is not unique" % (ifname, iface['l2xc']))
+                result = False
+            if is_bridge_interface(yaml, iface['l2xc']):
+                msgs.append("interface %s l2xc target %s is in a bridgedomain" % (ifname, iface['l2xc']))
+                result = False
 
         if has_sub(yaml, ifname):
             for sub_id, sub_iface in yaml['interfaces'][ifname]['sub-interfaces'].items():
@@ -362,5 +440,22 @@ def validate_interfaces(yaml):
                 elif not unique_encapsulation(yaml, sub_ifname):
                     msgs.append("sub-interface %s doesn't have unique encapsulation" % (sub_ifname))
                     result = False
+                if 'l2xc' in sub_iface:
+                    if has_lcp(yaml, sub_ifname):
+                        msgs.append("sub-interface %s is l2xc so it cannot be an LCP" % (sub_ifname))
+                        result = False
+                    if has_address(yaml, sub_ifname):
+                        msgs.append("sub-interface %s is l2xc so it cannot have an address" % (sub_ifname))
+                        result = False
+                    if not get_by_name(yaml, sub_iface['l2xc']):
+                        msgs.append("sub-interface %s l2xc target %s does not exist" % (ifname, sub_iface['l2xc']))
+                        result = False
+                    if not is_l2xc_target_interface_unique(yaml, sub_iface['l2xc']):
+                        msgs.append("sub-interface %s l2xc target %s is not unique" % (ifname, sub_iface['l2xc']))
+                        result = False
+                    if is_bridge_interface(yaml, sub_iface['l2xc']):
+                        msgs.append("sub-interface %s l2xc target %s is in a bridgedomain" % (ifname, sub_iface['l2xc']))
+                        result = False
+
 
     return result, msgs