Keep fdb and arp tables state between fast reboots (sonic-net#57)

scripts/fast-reboot

@@ -30,6 +30,16 @@ esac
 # Load kernel into memory
 /sbin/kexec -l "$KERNEL_IMAGE" --initrd="$INITRD" --append="$BOOT_OPTIONS"
 
+# Save ARP and FDB table to files
+/usr/bin/fast-reboot-dump.py
+docker cp /tmp/fdb.json swss:/
+docker cp /tmp/arp.json swss:/
+
+# Kill bgpd to enable graceful restart of BGP
+docker exec -ti bgp killall -9 watchquagga
+docker exec -ti bgp killall -9 zebra
+docker exec -ti bgp killall -9 bgpd
+
 # Stop docker container engine. Otherwise will have broken docker storage
 systemctl stop docker.service
 

scripts/fast-reboot-dump.py

@@ -0,0 +1,128 @@
+#!/usr/bin/env python
+
+
+import swsssdk
+import json
+from pprint import pprint
+
+
+def generate_arp_entries(filename):
+    db = swsssdk.SonicV2Connector()
+    db.connect(db.APPL_DB, False)   # Make one attempt only
+
+    arp_output = []
+
+    keys = db.keys(db.APPL_DB, 'NEIGH_TABLE:*')
+    keys = [] if keys is None else keys
+    for key in keys:
+        obj = {
+          'OP': 'SET',
+          key: db.get_all(db.APPL_DB, key)
+        }
+        arp_output.append(obj)
+
+    db.close(db.APPL_DB)
+
+    with open(filename, 'w') as fp:
+        json.dump(arp_output, fp, indent=2, separators=(',', ': '))
+
+    return
+
+def is_mac_unicast(mac):
+    first_octet = mac.split(':')[0]
+
+    if int(first_octet, 16) & 0x01 == 0:
+        return True
+    else:
+        return False
+
+def get_vlan_ifaces():
+    vlans = []
+    with open('/proc/net/dev') as fp:
+        raw = fp.read()
+
+    for line in raw.split('\n'):
+        if 'Vlan' not in line:
+            continue
+        vlan_name = line.split(':')[0].strip()
+        vlans.append(vlan_name)
+
+    return vlans
+
+def get_map_port_id_2_iface_name(db):
+    port_id_2_iface = {}
+    keys = db.keys(db.ASIC_DB, 'ASIC_STATE:SAI_OBJECT_TYPE_HOSTIF:oid:*')
+    keys = [] if keys is None else keys
+    for key in keys:
+        value = db.get_all(db.ASIC_DB, key)
+        port_id = value['SAI_HOSTIF_ATTR_RIF_OR_PORT_ID']
+        iface_name = value['SAI_HOSTIF_ATTR_NAME']
+        port_id_2_iface[port_id] = iface_name
+
+    return port_id_2_iface
+
+def get_fdb(db, vlan_id, port_id_2_iface):
+    fdb_types = {
+      'SAI_FDB_ENTRY_TYPE_DYNAMIC': 'dynamic',
+      'SAI_FDB_ENTRY_TYPE_STATIC' : 'static'
+    }
+
+    entries = []
+    keys = db.keys(db.ASIC_DB, 'ASIC_STATE:SAI_OBJECT_TYPE_FDB_ENTRY:{*\"vlan\":\"%d\"}' % vlan_id)
+    keys = [] if keys is None else keys
+    for key in keys:
+        key_obj = json.loads(key.replace('ASIC_STATE:SAI_OBJECT_TYPE_FDB_ENTRY:', ''))
+        vlan = str(key_obj['vlan'])
+        mac = str(key_obj['mac'])
+        if not is_mac_unicast(mac):
+            continue
+        mac = mac.replace(':', '-')
+        # FIXME: mac is unicast
+        # get attributes
+        value = db.get_all(db.ASIC_DB, key)
+        type = fdb_types[value['SAI_FDB_ENTRY_ATTR_TYPE']]
+        port = port_id_2_iface[value['SAI_FDB_ENTRY_ATTR_PORT_ID']]
+
+        obj = {
+          'FDB_TABLE:Vlan%d:%s' % (vlan_id, mac) : {
+            'type': type,
+            'port': port,
+          },
+          'OP': 'SET'
+        }
+
+        entries.append(obj)
+
+    return entries
+
+
+def generate_fdb_entries(filename):
+    fdb_entries = []
+
+    db = swsssdk.SonicV2Connector()
+    db.connect(db.ASIC_DB, False)   # Make one attempt only
+
+    port_id_2_iface = get_map_port_id_2_iface_name(db)
+
+    vlan_ifaces = get_vlan_ifaces()
+
+    for vlan in vlan_ifaces:
+        vlan_id = int(vlan.replace('Vlan', ''))
+        fdb_entries.extend(get_fdb(db, vlan_id, port_id_2_iface))
+
+    db.close(db.ASIC_DB)
+
+    with open(filename, 'w') as fp:
+        json.dump(fdb_entries, fp, indent=2, separators=(',', ': '))
+
+    return
+
+def main():
+    generate_arp_entries('/tmp/arp.json')
+    generate_fdb_entries('/tmp/fdb.json')
+
+    return
+
+
+if __name__ == '__main__':
+    main()

setup.py

@@ -20,6 +20,7 @@
         'scripts/coredump-compress',
         'scripts/decode-syseeprom',
         'scripts/fast-reboot',
+        'scripts/fast-reboot-dump.py',
         'scripts/generate_dump',
         'scripts/lldpshow',
         'scripts/portstat',