From b10a8c3d8ffee143a0da007377fe641c24761782 Mon Sep 17 00:00:00 2001
Message-Id: <b10a8c3d8ffee143a0da007377fe641c24761782.1714049322.git.mdw@distorted.org.uk>
From: Mark Wooding <mdw@chiark.greenend.org.uk>
Date: Sat, 15 May 2010 19:41:07 +0100
Subject: [PATCH] svc/conntrack.in: Force reconnection on local IP address
 changes.
Organization: Straylight/Edgeware

From: Mark Wooding <mdw@distorted.org.uk>

ICd or NetworkManager might roam to a new network, and tell us about it;
but if we decided that we wanted to stick with the same peer
specification then our peer will continue with the wrong IP address until
watch gets a ping timeout.

Of course, this doesn't trap other reasons we might change IP addresses
without anyone noticing, such as roaming to a different 3G NAT thingummy.
---
 svc/conntrack.in | 36 +++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/svc/conntrack.in b/svc/conntrack.in
index 47f66f4d..b80f92ed 100644
--- a/svc/conntrack.in
+++ b/svc/conntrack.in
@@ -214,6 +214,7 @@ def localaddr(peer):
 
 _kick = T.Queue()
 def kickpeers():
+  lastip = {}
   while True:
     upness, reason = _kick.get()
 
@@ -233,35 +234,44 @@ def kickpeers():
       addr = localaddr(CF.testaddr)
       if addr is None:
         upness = False
+    else:
+      addr = None
 
     ## Now decide what to do.
     changes = []
     for g, pp in CF.groups:
 
       ## Find out which peer in the group ought to be active.
-      want = None                       # unequal to any string
-      if upness:
-        for t, p, a, m in pp:
-          if p is None:
-            aq = addr
-          else:
-            aq = localaddr(p)
-          if aq is not None and (aq & m) == a:
-            want = t
-            break
+      ip = None
+      map = {}
+      want = None
+      for t, p, a, m in pp:
+        if p is None or not upness:
+          ipq = addr
+        else:
+          ipq = localaddr(p)
+        if upness and ip is None and \
+              ipq is not None and (ipq & m) == a:
+          map[t] = 'up'
+          want = t
+          ip = ipq
+        else:
+          map[t] = 'down'
 
       ## Shut down the wrong ones.
       found = False
       for p in peers:
-        if p == want:
+        what = map.get(p, 'leave')
+        if what == 'up':
           found = True
-        elif p.startswith(g) and p != want:
+        elif what == 'down':
           changes.append(lambda p=p: SM.kill(p))
 
       ## Start the right one if necessary.
-      if want is not None and not found:
+      if want is not None and (not found or ip != lastip.get(g, None)):
         changes.append(lambda: T._simple(SM.svcsubmit('connect', 'active',
                                                       want)))
+      lastip[g] = ip
 
     ## Commit the changes.
     if changes:
-- 
[mdw]