Changeset 8212638 for fedd/federation

Timestamp:

Sep 19, 2012 4:03:06 PM (12 years ago)

Author:

Ted Faber <faber@…>

Branches:

master

Children:

319fb0a

Parents:

b9ec635

Message:

Recognize and respect user allocated IP addresses

File:

• fedd/federation/experiment_control.py (modified) (2 diffs)

fedd/federation/experiment_control.py

@@ -1314 +1314 @@
     def allocate_ips_to_topo(self, top):
         """
-        Add an ip4_address attribute to all the hosts in the topology, based on
-        the shared substrates on which they sit.  An /etc/hosts file is also
-        created and returned as a list of hostfiles entries.  We also return
-        the allocator, because we may need to allocate IPs to portals
+        Add an ip4_address attribute to all the hosts in the topology that have
+        not already been assigned one by the user, based on the shared
+        substrates on which they sit.  An /etc/hosts file is also created and
+        returned as a list of hostfiles entries.  We also return the allocator,
+        because we may need to allocate IPs to portals
         (specifically DRAGON portals).
         """
@@ -1327 +1328 @@
         hosts = [ ]
 
+        assigned = { }
+        assigned_subs = set()
+        # Look for IP networks that were already assigned to the experiment by
+        # the user.  We assume that users are smart in making that assignment,
+        # but we check them later.
+        for e in top.elements:
+            if not isinstance(e, topdl.Computer): continue
+            for inf in e.interface:
+                a = inf.get_attribute('ip4_address')
+                if not a: continue
+                for s in inf.substrate:
+                    assigned_subs.add(s)
+                a = ip_addr(a)
+                n = ip_addr(inf.get_attribute('ip4_netmask'))
+
+                sz = 0x100000000 - long(n)
+                net = (long(a) & long(n)) & 0xffffffff
+                if net in assigned:
+                    if sz > assigned[net]: assigned[net] = sz
+                assigned[net] = sz
+
+        # Walk all substrates, smallest to largest, assigning IP addresses to
+        # the unassigned and checking the assigned.  Build an /etc/hosts file
+        # as well.
         for idx, s in enumerate(subs):
-            net_size = len(s.interfaces)+2
-
-            a = ips.allocate(net_size)
-            if a :
-                base, num = a
-                if num < net_size: 
-                    raise service_error(service_error.internal,
-                            "Allocator returned wrong number of IPs??")
+            if s.name not in assigned_subs:
+                net_size = len(s.interfaces)+2
+
+                # Get an ip allocation for this substrate.  Make sure the
+                # allocation does not collide with any user allocations.
+                ok = False
+                while not ok:
+                    a = ips.allocate(net_size)
+                    if not a:
+                        raise service_error(service_error.req, 
+                                "Cannot allocate IP addresses")
+                    base, num = a
+                    if num < net_size: 
+                        raise service_error(service_error.internal,
+                                "Allocator returned wrong number of IPs??")
+                    # Check for overlap.  An assigned network could contain an
+                    # endpoint of the new allocation or the new allocation
+                    # could contain an endpoint of an assigned network.
+                    # NB the else is attached to the for - if the loop is not
+                    # exited by a break, ok = True.
+                    for n, sz in assigned.items():
+                        if base >= n and base < n + sz:
+                            ok = False
+                            break
+                        if base + num > n and base + num  < n + sz:
+                            ok = False
+                            break
+                        if n >= base and n < base + num:
+                            ok = False
+                            break
+                        if n+sz > base and n+sz < base + num:
+                            ok = False
+                            break
+                    else:
+                        ok = True
+                            
+                mask = ips.min_alloc
+                while mask < net_size:
+                    mask *= 2
+
+                netmask = ((2**32-1) ^ (mask-1))
             else:
-                raise service_error(service_error.req, 
-                        "Cannot allocate IP addresses")
-            mask = ips.min_alloc
-            while mask < net_size:
-                mask *= 2
-
-            netmask = ((2**32-1) ^ (mask-1))
-
+                base = 0
+
+            # Add the attributes and build hosts
             base += 1
             for i in s.interfaces:
-                i.attribute.append(
-                        topdl.Attribute('ip4_address', 
-                            "%s" % ip_addr(base)))
-                i.attribute.append(
-                        topdl.Attribute('ip4_netmask', 
-                            "%s" % ip_addr(int(netmask))))
-
+                # Add address and masks to interfaces on unassigned substrates
+                if s.name not in assigned_subs:
+                    i.attribute.append(
+                            topdl.Attribute('ip4_address', 
+                                "%s" % ip_addr(base)))
+                    i.attribute.append(
+                            topdl.Attribute('ip4_netmask', 
+                                "%s" % ip_addr(int(netmask))))
+
+                # Make /etc/hosts entries
+                addr = i.get_attribute('ip4_address')
+                if addr is None:
+                    raise service_error(service_error.req, 
+                            "Partially assigned substrate %s" %s.name)
                 hname = i.element.name
-                if ifs.has_key(hname):
+                if hname in ifs:
                     hosts.append("%s\t%s-%s %s-%d" % \
-                            (ip_addr(base), hname, s.name, hname,
-                                ifs[hname]))
+                            (addr, hname, s.name, hname, ifs[hname]))
                 else:
+                    # First IP allocated it the default ip according to hosts,
+                    # so the extra alias is here.
                     ifs[hname] = 0
                     hosts.append("%s\t%s-%s %s-%d %s" % \
-                            (ip_addr(base), hname, s.name, hname,
-                                ifs[hname], hname))
+                            (addr, hname, s.name, hname, ifs[hname], hname))
 
                 ifs[hname] += 1