From b484ddf4d2eb81736512efa35ed3e5d2a72993d8 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 30 Sep 2021 14:16:08 -0400
Subject: [PATCH] Treat ETIMEDOUT as indicating a non-recoverable connection
 failure.

Add ETIMEDOUT to ALL_CONNECTION_FAILURE_ERRNOS' list of "errnos that
identify hard failure of a previously-established network connection".
While one could imagine that this is sometimes recoverable, the same
could be said of other entries such as ENETDOWN.

In support of this, handle ETIMEDOUT on par with other socket errors
in relevant infrastructure, such as TranslateSocketError().
(I made a couple of cosmetic adjustments in TranslateSocketError(),
too.)  The code now assumes that ETIMEDOUT is defined everywhere,
which it should be given that POSIX has required it since SUSv2.

Perhaps this should be back-patched, but I'm hesitant to do so given
the lack of previous complaints, and the hazard that there's a small
ABI break on Windows from redefining the symbol.  Even if we decide
to do that, it'd be prudent to let this bake awhile in HEAD first.

Jelte Fennema

Discussion: https://postgr.es/m/AM5PR83MB01782BFF2978505F6D6C559AF7AA9@AM5PR83MB0178.EURPRD83.prod.outlook.com
---
 src/backend/port/win32/socket.c | 11 ++++++++---
 src/include/port.h              |  3 ++-
 src/include/port/win32_port.h   |  2 ++
 src/port/strerror.c             |  2 --
 4 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/backend/port/win32/socket.c b/src/backend/port/win32/socket.c
index af151e8470..70592afe54 100644
--- a/src/backend/port/win32/socket.c
+++ b/src/backend/port/win32/socket.c
@@ -47,8 +47,8 @@ int			pgwin32_noblock = 0;
  *
  * Note: where there is a direct correspondence between a WSAxxx error code
  * and a Berkeley error symbol, this mapping is actually a no-op, because
- * in win32.h we redefine the network-related Berkeley error symbols to have
- * the values of their WSAxxx counterparts.  The point of the switch is
+ * in win32_port.h we redefine the network-related Berkeley error symbols to
+ * have the values of their WSAxxx counterparts.  The point of the switch is
  * mostly to translate near-miss error codes into something that's sensible
  * in the Berkeley universe.
  */
@@ -141,10 +141,15 @@ TranslateSocketError(void)
 		case WSAEDISCON:
 			errno = ENOTCONN;
 			break;
+		case WSAETIMEDOUT:
+			errno = ETIMEDOUT;
+			break;
 		default:
 			ereport(NOTICE,
-					(errmsg_internal("unrecognized win32 socket error code: %d", WSAGetLastError())));
+					(errmsg_internal("unrecognized win32 socket error code: %d",
+									 WSAGetLastError())));
 			errno = EINVAL;
+			break;
 	}
 }
 
diff --git a/src/include/port.h b/src/include/port.h
index 82f63de325..2ff529fa59 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -119,7 +119,8 @@ extern void pgfnames_cleanup(char **filenames);
 	case EHOSTUNREACH: \
 	case ENETDOWN: \
 	case ENETRESET: \
-	case ENETUNREACH
+	case ENETUNREACH: \
+	case ETIMEDOUT
 
 /* Portable locale initialization (in exec.c) */
 extern void set_pglocale_pgservice(const char *argv0, const char *app);
diff --git a/src/include/port/win32_port.h b/src/include/port/win32_port.h
index 05c5a53442..093a009aee 100644
--- a/src/include/port/win32_port.h
+++ b/src/include/port/win32_port.h
@@ -381,6 +381,8 @@ extern int	_pgstat64(const char *name, struct stat *buf);
 #define ENETUNREACH WSAENETUNREACH
 #undef ENOTCONN
 #define ENOTCONN WSAENOTCONN
+#undef ETIMEDOUT
+#define ETIMEDOUT WSAETIMEDOUT
 
 /*
  * Locale stuff.
diff --git a/src/port/strerror.c b/src/port/strerror.c
index c07c983e75..9b98f77b42 100644
--- a/src/port/strerror.c
+++ b/src/port/strerror.c
@@ -250,10 +250,8 @@ get_errno_symbol(int errnum)
 #endif
 		case ESRCH:
 			return "ESRCH";
-#ifdef ETIMEDOUT
 		case ETIMEDOUT:
 			return "ETIMEDOUT";
-#endif
 #ifdef ETXTBSY
 		case ETXTBSY:
 			return "ETXTBSY";