Repository navigation
IPv6 scope ids and IPV6_PKTINFO ifindex survive interface slot reuse #51
Description
Same stale-slot pattern as #42. IPv6 scope ids and the sticky IPV6_PKTINFO ifindex are stored as raw slot+1 at connect/bind/setsockopt (src/bsdsocket/socket.c:1440, :1451, :2432, :2455, :2506; src/bsdsocket/cmsg.c:641) and re-checked on each send only against nx_interface_valid (socket.c:2040-2066, cmsg.c:474-478); receive filtering compares the number only (src/bsdsocket/transfer.c:993-999).
Repro: UDP socket connect()s to fe80::1%k (or sets sticky IPV6_PKTINFO{ifindex=k}); RemoveNetInterface k; AddNetInterface another device into slot k; send() leaves by the new link to its fe80::1, and that router's datagrams are accepted. Expected: EADDRNOTAVAIL / ENETUNREACH.
Also, low: an IPv4 per-datagram IP_PKTINFO ifindex naming an empty slot is returned without a validity check (cmsg.c:515-521); the datagram is dropped later instead of failing with EADDRNOTAVAIL.
Fix after #48 lands: record netstack_interface_epoch() with the stored index and treat a changed epoch as gone. Test: emulator run modelled on run-mcastepoch.sh expecting the error after slot reuse.
🤖 Generated with Claude Code
Activity
bsdsocket: expire stored IPv6 zones across interface slot reuse (#51)
bsdsocket: expire stored IPv6 zones across interface slot reuse (#51) (…
tests: keep main's #51 stubs (4498196) over the duplicates from d6e47cb
transfer: resolve the connected peer's zone inside the bracket (#51)
transfer: snapshot the connected peer inside the bracket (#51 review)
test_cork: stub bsd_scope_live, which transfer.c calls since #51
test_transfer: stub bsd_scope_live too (#51)
integration: keep #51's bsd_scope_live stubs, drop #53's duplicates
image size: default bsdsocket budget 365000 for the review fixes
tinic commentedon Sep 26, 2026
Follow-up on main a213cfc: the connected peer's zone was still read before the NetX bracket in send/sendto/sendmsg, so a slot removed and reattached in that window was missed. It is now resolved inside the bracket, and the connected address, port and zone are copied together there (dfb64a3, 5d67ec9; tests 84b558f, d1d70cd, covering UDP and raw with a peer change during the allocate wait). The host32 test_transfer/test_cork link break from #83 is fixed in the same branch. CI 36241074109 green.