Exclude the IP where sshuttle is really listening

We were always excluding 127.0.0.1/8 but sshuttle might be listening on
other IP, e.g., ::1 for IPv6 or any other defined with -l

sshuttle/client.py

@@ -549,6 +549,7 @@ def main(listenip_v6, listenip_v4,
             listenip_v6 = None
 
     required.ipv6 = len(subnets_v6) > 0 or listenip_v6 is not None
+    required.ipv4 = len(subnets_v4) > 0 or listenip_v4 is not None
     required.udp = avail.udp
     required.dns = len(nslist) > 0
 
@@ -571,6 +572,14 @@ def main(listenip_v6, listenip_v4,
     if listenip_v4 == "auto":
         listenip_v4 = ('127.0.0.1', 0)
 
+    if required.ipv4 and \
+            not any(listenip_v4[0] == sex[1] for sex in subnets_v4):
+        subnets_exclude.append((socket.AF_INET, listenip_v4[0], 32))
+
+    if required.ipv6 and \
+            not any(listenip_v6[0] == sex[1] for sex in subnets_v6):
+        subnets_exclude.append((socket.AF_INET6, listenip_v6[0], 128))
+
     if listenip_v6 and listenip_v6[1] and listenip_v4 and listenip_v4[1]:
         # if both ports given, no need to search for a spare port
         ports = [0, ]

sshuttle/options.py

@@ -187,7 +187,7 @@ parser.add_argument(
     "-x", "--exclude",
     metavar="IP/MASK",
     action="append",
-    default=[parse_subnet('127.0.0.1/8')],
+    default=[],
     type=parse_subnet,
     help="""
     exclude this subnet (can be used more than once)