Setting SIG_IGN for SIGPIPE errors (mitmproxy#6764)

* Setting SIG_IGN for SIGPIPE errors

    The issue was reported in mitmproxy#6744

    Problem description:
    When there is a sudden surge of requests, mitmproxy will hit SIGPIPE (broken pipe) errors because it was trying to write to a closed socket. The stacktrace is:
    File "asyncio/runners.py", line 44, in run
    File "asyncio/base_events.py", line 636, in run_until_complete
    File "asyncio/base_events.py", line 603, in run_forever
    File "asyncio/base_events.py", line 1909, in _run_once
    File "asyncio/events.py", line 80, in _run
    File "mitmproxy/proxy/server.py", line 294, in handle_connection
    File "mitmproxy/proxy/server.py", line 407, in server_event
    File "asyncio/streams.py", line 325, in write
    File "asyncio/selector_events.py", line 924, in write

    When this happens, the process terminates unless handled
    The fix will allow the process to continue to run.

* add changelog entry

* [autofix.ci] apply automated fixes

* Handling SIGPIPE only in non-Windows platforms

* [autofix.ci] apply automated fixes

* nit: make check platform-agnostic

---------

Co-authored-by: changsin <[email protected]>
Co-authored-by: Maximilian Hils <[email protected]>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -21,8 +21,12 @@
   ([#6747](https://github.com/mitmproxy/mitmproxy/pull/6747), @jlaine)
 * Fix a bug where async `client_connected` handlers would crash mitmproxy.
   ([#6749](https://github.com/mitmproxy/mitmproxy/pull/6749), @mhils)
-  * Add button to close flow details panel
+* Add button to close flow details panel
   ([#6734](https://github.com/mitmproxy/mitmproxy/pull/6734), @lups2000)
+* Ignore SIGPIPE signals when there is lots of traffic.
+  Socket errors are handled directly and do not require extra signals
+  that generate noise.
+  ([#6764](https://github.com/mitmproxy/mitmproxy/pull/6764), @changsin)
 * Add primitive websocket interception and modification
   ([#6766](https://github.com/mitmproxy/mitmproxy/pull/6766), @errorxyz)
 

mitmproxy/tools/main.py

@@ -120,6 +120,10 @@ def _sigterm(*_):
         # but signal.signal just works fine for our purposes.
         signal.signal(signal.SIGINT, _sigint)
         signal.signal(signal.SIGTERM, _sigterm)
+        # to fix the issue mentioned https://github.com/mitmproxy/mitmproxy/issues/6744
+        # by setting SIGPIPE to SIG_IGN, the process will not terminate and continue to run
+        if hasattr(signal, "SIGPIPE"):
+            signal.signal(signal.SIGPIPE, signal.SIG_IGN)
 
         await master.run()
         return master