shim/ is an LD_PRELOAD guard around close/fclose/dup2/dup3:
- before each close it resolves /proc/self/fd/N;
- it reports, with a backtrace, a non-owner close of wallet.dat,
database/log.* or blocks/*.dat, and every close that fails with EBADF
(the second half of a double close);
- FDGUARD_ABORT=1 aborts on the first hit;
- run_tests.sh self-tests it (51 checks).
repro/ runs a shimmed dragonxd on isolated regtest. Each run gets its
own unprivileged network namespace (loopback only). The loads are:
- rpc: a hammer with impatient/RST/half-open clients, work-queue
bursts and long-polls;
- p2p: TLS peers churned by disconnectnode, ban and kill, plus a raw
TCP/TLS misbehaver;
- tor: a fake control port;
- mine: mining with blocknotify and autoshield.
tools/tally.py groups the reports by closer. tools/scan_bdb.py finds BDB
pages written into block files.
With the wolfSSL CloseSocket macro in effect:
- p2pmin (300 s) gives one EBADF double close per disconnect;
- the full load (1200 s) gives 930 EBADF closes, 186 non-owner closes
(37 of wallet/log/blk files) and a 632 KB db.log with BDB0060 PANIC;
- RPC-only and Tor-only loads give none.
After the fix, every count is 0 and db.log stays empty. The README has
the commands and the numbers.
Paths come from the environment (GOLDEN, BIN, RUNS, SHIM, ASMAP and the
Sapling params). Run output goes to $RUNS, outside the tree.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
