From c573a780e98f9ae960008fd756af5e65912d9969 Mon Sep 17 00:00:00 2001
From: ed <s@ocv.me>
Date: Sat, 3 Dec 2022 16:37:14 +0000
Subject: [PATCH] some failsafes

---
 copyparty/multicast.py | 10 +++++++++-
 copyparty/tcpsrv.py    | 11 ++++++++++-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/copyparty/multicast.py b/copyparty/multicast.py
index 3d4e4fe4..cab9fb5d 100644
--- a/copyparty/multicast.py
+++ b/copyparty/multicast.py
@@ -8,7 +8,7 @@ import ipaddress
 from ipaddress import IPv4Address, IPv4Network, IPv6Address, IPv6Network
 
 from .__init__ import TYPE_CHECKING
-from .util import Netdev, min_ex, spack
+from .util import MACOS, Netdev, min_ex, spack
 
 if TYPE_CHECKING:
     from .svchub import SvcHub
@@ -216,6 +216,9 @@ class MCast(object):
 
             grp = self.grp6 if srv.idx else ""
             try:
+                if MACOS:
+                    raise Exception()
+
                 sck.bind((grp, self.port, 0, srv.idx))
             except:
                 sck.bind(("", self.port, 0, srv.idx))
@@ -243,6 +246,9 @@ class MCast(object):
 
             grp = self.grp4 if srv.idx else ""
             try:
+                if MACOS:
+                    raise Exception()
+
                 sck.bind((grp, self.port))
             except:
                 sck.bind(("", self.port))
@@ -289,6 +295,8 @@ class MCast(object):
             except:
                 pass
 
+            # t = "joining {} from ip {} idx {} with mreq {}"
+            # self.log(t.format(srv.grp, srv.ip, srv.idx, repr(srv.mreq)), 6)
             sck.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, req)
 
     def map_client(self, cip: str) -> Optional[MC_Sck]:
diff --git a/copyparty/tcpsrv.py b/copyparty/tcpsrv.py
index 655fcacf..f000be15 100644
--- a/copyparty/tcpsrv.py
+++ b/copyparty/tcpsrv.py
@@ -280,7 +280,16 @@ class TcpSrv(object):
                     # browsers dont impl linklocal
                     continue
 
-                eps[sip] = Netdev(sip, nic.index or 0, nic.nice_name, "")
+                nd = Netdev(sip, nic.index or 0, nic.nice_name, "")
+                eps[sip] = nd
+                try:
+                    idx = socket.if_nametoindex(nd.name)
+                    if idx and idx != nd.idx:
+                        t = "netdev idx mismatch; ifaddr={} cpython={}"
+                        self.log("tcpsrv", t.format(nd.idx, idx), 3)
+                        nd.idx = idx
+                except:
+                    pass
 
         if "0.0.0.0" not in listen_ips and "::" not in listen_ips:
             eps = {k: v for k, v in eps.items() if k.split("/")[0] in listen_ips}