Terminating connection with server without terminating connection with client

[awrenn]

Hello,

I have been having issues with redsocks as a socks5 transparent proxy with the iptables redirector, only when using Rust's Cargo.

As soon as cargo reaches out to crates.io, redsocks sends the following log messages:
redsocks.c:439 redsocks_event_error(...) [...] client error, code EVBUFFER_READ|0|0|EVBUFFER_ERROR|0|0x0: No error information
[warn] Epoll MOD(4) on fd 22 failed. Old events were 6; read change was 2 (del); write change was 0 (none): Bad file descriptor [warn] Epoll MOD(1) on fd 22 failed. Old events were 6; read change was 0 (none); write change was 2 (del): Bad file descriptor

This causes the server connection to terminate, but it does not terminate the connection to cargo, which then blocks forever. Any ideas on what might be causing this/how I can fix it? Hopefully it is just a configuration issue.

[awrenn]

Adding the following strace from redsocks:
close(42) = 0
epoll_ctl(3, EPOLL_CTL_MOD, 42, {EPOLLOUT, {u32=42, u64=42}}) = -1 EBADF (Bad file descriptor)
Proof that redsocks is closing the fd prematurely. I'll dig into source soon and see if I can find culprit.