Add check for shared dependents during building dependency list

Ticket: CM-5373
Reviewed By: sam
Testing Done: Tested with shared slaves in bridge and bonds

addons/bridge.py

@@ -221,6 +221,7 @@ class bridge(moduleBase):
         if ifaceobj.link_type != ifaceLinkType.LINK_NA:
            ifaceobj.link_type = ifaceLinkType.LINK_MASTER
         ifaceobj.link_kind = ifaceLinkKind.BRIDGE
+        ifaceobj.dependency_type = ifaceDependencyType.MASTER_SLAVE
         return self.parse_port_list(ifaceobj.get_attr_value_first(
                                     'bridge-ports'), ifacenames_all)
 

addons/ifenslave.py

@@ -118,7 +118,7 @@ class ifenslave(moduleBase):
             return None
         slave_list = self.parse_port_list(ifaceobj.get_attr_value_first(
                                     'bond-slaves'), ifacenames_all)
-
+        ifaceobj.dependency_type = ifaceDependencyType.MASTER_SLAVE
         # Also save a copy for future use
         ifaceobj.priv_data = list(slave_list)
         if ifaceobj.link_type != ifaceLinkType.LINK_NA:

ifupdown/iface.py

@@ -33,6 +33,36 @@ class ifaceLinkType():
     LINK_MASTER = 0x2
     LINK_NA = 0x3
 
+class ifaceDependencyType():
+    """ Indicates type of dependency.
+
+        This class enumerates types of dependency relationships
+        between interfaces.
+
+        iface dependency relationships can be classified
+        into:
+         - link
+         - master/slave
+
+        In a 'link' dependency relationship, dependency can be shared
+        between interfaces. example: swp1.100 and
+        swp1.200 can both have 'link' swp1. swp1 is also a dependency
+        of swp1.100 and swp1.200. As you can see dependency
+        swp1 is shared between swp1.100 and swp1.200.
+         
+        In a master/slave relationship like bridge and
+        its ports: eg: bridge br0 and its ports swp1 and swp2.
+        dependency swp1 and swp2 cannot be shared with any other
+        interface with the same dependency relationship.
+        ie, swp1 and swp2 cannot be in a slave relationship
+        with another interface. Understanding the dependency type is
+        required for any semantic checks between dependencies.
+
+    """
+    UNKNOWN = 0x0
+    LINK = 0x1
+    MASTER_SLAVE = 0x2
+
 class ifaceStatus():
     """Enumerates iface status """
 
@@ -230,6 +260,10 @@ class iface():
         self.link_type = ifaceLinkType.LINK_UNKNOWN
         self.link_kind = ifaceLinkKind.UNKNOWN
 
+        # The below attribute is used to disambiguate between various
+        # types of dependencies
+        self.dependency_type = ifaceDependencyType.UNKNOWN
+
     def _set_attrs_from_dict(self, attrdict):
         self.auto = attrdict.get('auto', False)
         self.name = attrdict.get('name')
@@ -416,6 +450,7 @@ class iface():
         del odict['env']
         del odict['link_type']
         del odict['link_kind']
+        del odict['dependency_type']
         return odict
 
     def __setstate__(self, dict):
@@ -434,6 +469,7 @@ class iface():
         self.flags |= self._PICKLED
         self.link_type = ifaceLinkType.LINK_NA
         self.link_kind = ifaceLinkKind.UNKNOWN
+        self.dependency_type = ifaceDependencyType.UNKNOWN
 
     def dump_raw(self, logger):
         indent = '  '

ifupdown/ifupdownmain.py

@@ -384,6 +384,27 @@ class ifupdownMain(ifupdownBase):
         if not ifaceobj: return True
         return self.is_ifaceobj_noconfig(ifaceobj)
 
+    def check_shared_dependents(self, ifaceobj, dlist):
+        """ Check if dlist intersects with any other
+            interface with slave dependents.
+            example: bond and bridges.
+            This function logs such errors """
+        setdlist = Set(dlist)
+        for ifacename, ifacedlist in self.dependency_graph.items():
+            if not ifacedlist:
+                continue
+            check_depends = False
+            iobjs = self.get_ifaceobjs(ifacename)
+            for i in iobjs:
+                if (i.dependency_type == ifaceDependencyType.MASTER_SLAVE):
+                    check_depends = True
+            if check_depends:
+                common = Set(ifacedlist).intersection(setdlist)
+                if common:
+                    self.logger.error('iface %s and %s '
+                            %(ifaceobj.name, ifacename) +
+                            'have common dependents %s' %str(list(common)))
+
     def preprocess_dependency_list(self, upperifaceobj, dlist, ops):
         """ We go through the dependency list and
             delete or add interfaces from the interfaces dict by
@@ -401,6 +422,10 @@ class ifupdownMain(ifupdownBase):
         """
         del_list = []
 
+        if (upperifaceobj.dependency_type ==
+                    ifaceDependencyType.MASTER_SLAVE):
+            self.check_shared_dependents(upperifaceobj, dlist)
+
         for d in dlist:
             dilist = self.get_ifaceobjs(d)
             if not dilist:
@@ -451,6 +476,7 @@ class ifupdownMain(ifupdownBase):
             if dlist: ret_dlist.extend(dlist)
         return list(set(ret_dlist))
 
+
     def populate_dependency_info(self, ops, ifacenames=None):
         """ recursive function to generate iface dependency info """