Config.py: Use some interfaces even if other fail (#12)

Allow to run PIM, IGMP or MLD on working interfaces even if it failed for other
interfaces listed in the configuration file.

pimdm/Config.py

-import yaml
+import sys, yaml
+from functools import partial
 from pimdm.tree import pim_globals
 from igmp.igmp2 import igmp_globals
 from mld.mld1 import mld_globals
@@ -34,18 +35,22 @@ def parse_config_file(file_path):
             pim_globals.T_LIMIT = pim_config["DefaultTimers"].get("T_LIMIT", pim_globals.T_LIMIT)
 
         if "Interfaces" in pim_config:
-            interfaces = pim_config["Interfaces"]  # type: dict
-
-            for if_name, if_value in interfaces.items():
-                if if_value.get("ipv4", False):
-                    if_ipv4 = if_value["ipv4"]
-                    if if_ipv4.get("enabled", False):
-                        Main.add_pim_interface(interface_name=if_name, state_refresh_capable=if_ipv4.get("state_refresh", False), ipv4=True, ipv6=False)
+            interface_dict = pim_config["Interfaces"]
+            add_pim_interface_dict = {
+                'ipv4': partial(Main.add_pim_interface, ipv4=True, ipv6=False),
+                'ipv6': partial(Main.add_pim_interface, ipv4=False, ipv6=True),
+            }
 
-                if if_value.get("ipv6", False):
-                    if_ipv6 = if_value["ipv6"]
-                    if if_ipv6.get("enabled", False):
-                        Main.add_pim_interface(interface_name=if_name, state_refresh_capable=if_ipv6.get("state_refresh", False), ipv4=False, ipv6=True)
+            for if_name, ip_family_dict in interface_dict.items():
+                for ip_family, if_dict in ip_family_dict.items():
+                    if if_dict.get("enabled", False):
+                        try:
+                            add_pim_interface_dict[ip_family](
+                                interface_name=if_name,
+                                state_refresh_capable=if_dict.get("state_refresh", False),
+                            )
+                        except Exception as e:
+                            print(e, file=sys.stderr)
 
 
         ##### IGMP config #######
@@ -65,11 +70,14 @@ def parse_config_file(file_path):
             igmp_globals.VERSION_1_ROUTER_PRESENT_TIMEOUT = igmp_config["Settings"].get("VERSION_1_ROUTER_PRESENT_TIMEOUT", igmp_globals.VERSION_1_ROUTER_PRESENT_TIMEOUT)
 
         if "Interfaces" in igmp_config:
-            interfaces = igmp_config["Interfaces"]  # type: dict
+            interface_dict = igmp_config["Interfaces"]
 
-            for if_name, if_value in interfaces.items():
+            for if_name, if_value in interface_dict.items():
+                try:
                     if if_value.get("enabled", False):
                         Main.add_membership_interface(interface_name=if_name, ipv4=True, ipv6=False)
+                except Exception as e:
+                    print(e, file=sys.stderr)
 
         ##### MLD config #######
         if "Settings" in mld_config:
@@ -85,11 +93,14 @@ def parse_config_file(file_path):
             mld_globals.UNSOLICITED_REPORT_INTERVAL = mld_config["Settings"].get("UNSOLICITED_REPORT_INTERVAL", mld_globals.UNSOLICITED_REPORT_INTERVAL)
 
         if "Interfaces" in mld_config:
-            interfaces = mld_config["Interfaces"]  # type: dict
+            interface_dict = mld_config["Interfaces"]
 
-            for if_name, if_value in interfaces.items():
+            for if_name, if_value in interface_dict.items():
+                try:
                     if if_value.get("enabled", False):
                         Main.add_membership_interface(interface_name=if_name, ipv4=False, ipv6=True)
+                except Exception as e:
+                    print(e, file=sys.stderr)
 
 
 def get_yaml_file():

pimdm/InterfacePIM.py

@@ -54,7 +54,11 @@ class InterfacePim(Interface):
         self.interface_logger = logging.LoggerAdapter(InterfacePim.LOGGER, {'vif': vif_index, 'interfacename': interface_name})
 
         # SOCKET
-        ip_interface = netifaces.ifaddresses(interface_name)[netifaces.AF_INET][0]['addr']
+        if_addr_dict = netifaces.ifaddresses(interface_name)
+        if not netifaces.AF_INET in if_addr_dict:
+            raise Exception("Adding PIM interface failed because %s does not "
+                            "have any ipv4 address" % interface_name)
+        ip_interface = if_addr_dict[netifaces.AF_INET][0]['addr']
         self.ip_interface = ip_interface
 
         s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_PIM)

pimdm/InterfacePIM6.py

@@ -46,12 +46,16 @@ class InterfacePim6(InterfacePim):
         s = socket.socket(socket.AF_INET6, socket.SOCK_RAW, socket.IPPROTO_PIM)
 
         ip_interface = ""
-        for if_addr in netifaces.ifaddresses(interface_name)[netifaces.AF_INET6]:
-            ip_interface = if_addr["addr"]
-            if ipaddress.IPv6Address(if_addr['addr'].split("%")[0]).is_link_local:
-                ip_interface = if_addr['addr'].split("%")[0]
+        if_addr_dict = netifaces.ifaddresses(interface_name)
+        if not netifaces.AF_INET6 in if_addr_dict:
+            raise Exception("Adding PIM interface failed because %s does not "
+                            "have any ipv6 address" % interface_name)
+        for network_dict in if_addr_dict[netifaces.AF_INET6]:
+            full_ip_interface = network_dict["addr"]
+            ip_interface = full_ip_interface.split("%")[0]
+            if ipaddress.IPv6Address(ip_interface).is_link_local:
                 # bind to interface
-                s.bind(socket.getaddrinfo(if_addr['addr'], None, 0, socket.SOCK_RAW, 0, socket.AI_PASSIVE)[0][4])
+                s.bind(socket.getaddrinfo(full_ip_interface, None, 0, socket.SOCK_RAW, 0, socket.AI_PASSIVE)[0][4])
                 break
 
         self.ip_interface = ip_interface