fix: macOS server crash when client disconnects abruptly - #9331

Summary

Fixes server crash with exit code 13 (SIGPIPE) on macOS when a Windows client disconnects abruptly (e.g., shutdown/restart without stopping Deskflow first).

Problem

When a client disconnects unexpectedly, the server attempts to write to the closed socket (via OpenSSL's SSL_write or SSL_shutdown), which generates a SIGPIPE signal that terminates the process.

Related log output:

ERROR: tls error occurred (system call failure)
IPC: client "windows-pc" has disconnected
WARNING: desktop process exited with code: 13

Solution

Two-layer fix:

1. SO_NOSIGPIPE socket option on macOS (ArchNetworkBSD.cpp)

   • Set on newly created sockets in newSocket()
   • Set on accepted client connections in acceptSocket()
   • Prevents SIGPIPE from being generated; returns EPIPE error instead

2. Quiet TLS shutdown (SecureSocket.cpp)

   • Added SSL_set_quiet_shutdown() before SSL_shutdown() in freeSSL()
   • Skips writing close_notify alert when connection is already broken

Related Issues

Fixes #9141
Fixes #9314

Contribution by Gittensor, see my contribution statistics at https://gittensor.io/miners/details?githubId=132382032