Guest environment (DF-3316 + DF-3317 verification)
=====================================================

Baseline kernel (all reproductions):
  DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0:
  Thu Jul  2 06:02:54 UTC 2026  root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC
  x86_64, stock INVARIANTS X86_64_GENERIC, 6 vCPUs, netisr_ncpus=6

Fix-validation kernel (DF-3317 only):
  DragonFly dfbsd 6.5-DEVELOPMENT #1: Thu Sep 10 17:27:19 UTC 2026
  (fix.diff applied to /usr/src/sys/netinet/tcp_subr.c in-guest,
   make -j6 nativekernel + make installkernel)

Network: lo0 mtu 16384, inet 127.0.0.1/8, inet6 ::1/128

Sysctls observed (defaults):
  net.inet.tcp.sendspace: 57344
  net.inet.tcp.recvspace: 57344
  kern.ipc.maxsockbuf: 524288
  (SO_SNDBUF 524288 on lo0 clamps ssb_hiwat to 419430)

DF-3317 runs as root ONLY for raw ICMPv6 injection (stand-in for the
off-path remote forger; /sbin/ping-style setuid would do the same).
DF-3316 readers and churner run as user 'nobody'.