From c569826ff1ced6a664737416aa34f27566391fa2 Mon Sep 17 00:00:00 2001
From: Jarrod Johnson <jjohnson2@lenovo.com>
Date: Mon, 4 Oct 2021 16:22:12 -0400
Subject: [PATCH] Improve scan result with missing neigh entries

If no neigh table is present for
a given address, send a packet to
induce kernel activity.

Then wait for a bit over 2 seconds to allow for
2 retries (at default settings)
and then proceed assuming all findable neighbor table
entries will be found.
---
 .../confluent/discovery/protocols/slp.py      | 29 ++++++++++++++-----
 .../confluent/discovery/protocols/ssdp.py     | 11 +++----
 confluent_server/confluent/neighutil.py       |  2 ++
 3 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/confluent_server/confluent/discovery/protocols/slp.py b/confluent_server/confluent/discovery/protocols/slp.py
index 1fc92558..2a049674 100644
--- a/confluent_server/confluent/discovery/protocols/slp.py
+++ b/confluent_server/confluent/discovery/protocols/slp.py
@@ -104,8 +104,6 @@ def _parse_slp_packet(packet, peer, rsps, xidmap):
     if not parsed:
         return
     addr = peer[0]
-    if '%' in addr:
-        addr = addr[:addr.index('%')]
     mac = neighutil.get_hwaddr(addr)
     if mac:
         identifier = mac
@@ -413,8 +411,7 @@ def rescan(handler):
         for addr in scanned['addresses']:
             if addr in known_peers:
                 break
-            ip = addr[0].partition('%')[0]  # discard scope if present
-            macaddr = neighutil.get_hwaddr(ip)
+            macaddr = neighutil.get_hwaddr(addr[0])
             if not macaddr:
                 continue
             known_peers.add(addr)
@@ -478,10 +475,9 @@ def snoop(handler, protocol=None):
             while r:
                 for s in r:
                     (rsp, peer) = s.recvfrom(9000)
-                    ip = peer[0].partition('%')[0]
                     if peer in known_peers:
                         continue
-                    mac = neighutil.get_hwaddr(ip)
+                    mac = neighutil.get_hwaddr(peer[0])
                     if not mac:
                         continue
                     known_peers.add(peer)
@@ -534,14 +530,31 @@ def snoop(handler, protocol=None):
 
 def active_scan(handler, protocol=None):
     known_peers = set([])
+    net4 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    net6 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    toprocess = []
+    # Implement a warmup, inducing neighbor table activity
+    # by kernel and giving 2 seconds for a retry or two if
+    # needed
     for scanned in scan():
+        toprocess.append(scanned)
+        for addr in scanned['addresses']:
+            macaddr = neighutil.get_hwaddr(addr[0])
+            if not macaddr:
+                if ':' in addr[0]:
+                    net6.sendto(b'\x00', (addr[0], 8989))
+                else:
+                    net4.sendto(b'\x00', (addr[0], 8989))
+    eventlet.sleep(2.2)
+    for scanned in toprocess:
         for addr in scanned['addresses']:
             if addr in known_peers:
                 break
-            ip = addr[0].partition('%')[0]  # discard scope if present
-            macaddr = neighutil.get_hwaddr(ip)
+            macaddr = neighutil.get_hwaddr(addr[0])
             if not macaddr:
                 continue
+            if not scanned.get('hwaddr', None):
+                scanned['hwaddr'] = macaddr
             known_peers.add(addr)
         else:
             scanned['protocol'] = protocol
diff --git a/confluent_server/confluent/discovery/protocols/ssdp.py b/confluent_server/confluent/discovery/protocols/ssdp.py
index 2f6aa822..d9e5e13d 100644
--- a/confluent_server/confluent/discovery/protocols/ssdp.py
+++ b/confluent_server/confluent/discovery/protocols/ssdp.py
@@ -63,8 +63,7 @@ def active_scan(handler, protocol=None):
         for addr in scanned['addresses']:
             if addr in known_peers:
                 break
-            ip = addr[0].partition('%')[0]  # discard scope if present
-            hwaddr = neighutil.get_hwaddr(ip)
+            hwaddr = neighutil.get_hwaddr(addr[0])
             if not hwaddr:
                 continue
             known_peers.add(addr)
@@ -130,10 +129,9 @@ def snoop(handler, byehandler=None, protocol=None, uuidlookup=None):
                     rsp = rsp.split(b'\r\n')
                     method, _, _ = rsp[0].split(b' ', 2)
                     if method == b'NOTIFY':
-                        ip = peer[0].partition('%')[0]
                         if peer in known_peers:
                             continue
-                        mac = neighutil.get_hwaddr(ip)
+                        mac = neighutil.get_hwaddr(peer[0])
                         if not mac:
                             continue
                         known_peers.add(peer)
@@ -309,10 +307,9 @@ def check_cpstorage(urldata):
 
 
 def _parse_ssdp(peer, rsp, peerdata):
-    ip = peer[0].partition('%')[0]
-    nid = ip
+    nid = peer[0]
     mac = None
-    mac = neighutil.get_hwaddr(ip)
+    mac = neighutil.get_hwaddr(peer[0])
     if mac:
         nid = mac
     headlines = rsp.split(b'\r\n')
diff --git a/confluent_server/confluent/neighutil.py b/confluent_server/confluent/neighutil.py
index ded62ea3..72f1106c 100644
--- a/confluent_server/confluent/neighutil.py
+++ b/confluent_server/confluent/neighutil.py
@@ -76,6 +76,8 @@ def _update_neigh():
 
 
 def get_hwaddr(ipaddr):
+    if '%' in ipaddr:
+        ipaddr, _ = ipaddr.split('%', 1)
     hwaddr = None
     if os.name == 'nt':
         return hwaddr