> Ok, where's a "system dependent hack" :)

> It seems that win9x doesn't have the "netmsg.dll" so it defaults to "normal"
> FormatMessage.
> I wonder if one could load wsock32.dll or winsock.dll on those systems
> instead of netmsg.dll.
>
> Mikhail, could you please test this code on your nt4 system?
> Could someone else test this code on a win98/95 system?
>
> It works on win2k over here.

It works on win2k here too but not on win98/95 or winNT.
Anyway, attached is the patch which uses Magnus's my_sock_strerror
function (renamed to winsock_strerror). The only difference is that
I put the code to load and unload netmsg.dll in the libpqdll.c
(is this OK Magnus?).

Mikhail Terekhov

src/interfaces/libpq/fe-connect.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.175 2001/08/17 15:11:15 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.176 2001/08/21 20:39:52 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -703,7 +703,7 @@ connectMakeNonblocking(PGconn *conn)
 	{
 		printfPQExpBuffer(&conn->errorMessage,
 						  libpq_gettext("could not set socket to non-blocking mode: %s\n"),
-						  strerror(errno));
+						  SOCK_STRERROR(SOCK_ERRNO));
 		return 0;
 	}
 
@@ -727,7 +727,7 @@ connectNoDelay(PGconn *conn)
 	{
 		printfPQExpBuffer(&conn->errorMessage,
 						  libpq_gettext("could not set socket to TCP no delay mode: %s\n"),
-						  strerror(errno));
+						  SOCK_STRERROR(SOCK_ERRNO));
 		return 0;
 	}
 
@@ -750,7 +750,7 @@ connectFailureMessage(PGconn *conn, int errorno)
 							  "\tIs the server running locally and accepting\n"
 							  "\tconnections on Unix domain socket \"%s\"?\n"
 							  ),
-						  strerror(errorno),
+						  SOCK_STRERROR(errorno),
 						  conn->raddr.un.sun_path);
 	else
 		printfPQExpBuffer(&conn->errorMessage,
@@ -759,7 +759,7 @@ connectFailureMessage(PGconn *conn, int errorno)
 							  "\tIs the server running on host %s and accepting\n"
 							  "\tTCP/IP connections on port %s?\n"
 							  ),
-						  strerror(errorno),
+						  SOCK_STRERROR(errorno),
 						  conn->pghost
 						  ? conn->pghost
 						  : (conn->pghostaddr
@@ -882,7 +882,7 @@ connectDBStart(PGconn *conn)
 	{
 		printfPQExpBuffer(&conn->errorMessage,
 						  libpq_gettext("could not create socket: %s\n"),
-						  strerror(errno));
+						  SOCK_STRERROR(SOCK_ERRNO));
 		goto connect_errReturn;
 	}
 
@@ -914,7 +914,7 @@ connectDBStart(PGconn *conn)
 	 */
 	if (connect(conn->sock, &conn->raddr.sa, conn->raddr_len) < 0)
 	{
-		if (errno == EINPROGRESS || errno == EWOULDBLOCK || errno == 0)
+		if (SOCK_ERRNO == EINPROGRESS || SOCK_ERRNO == EWOULDBLOCK || SOCK_ERRNO == 0)
 		{
 			/*
 			 * This is fine - we're in non-blocking mode, and the
@@ -925,7 +925,7 @@ connectDBStart(PGconn *conn)
 		else
 		{
 			/* Something's gone wrong */
-			connectFailureMessage(conn, errno);
+			connectFailureMessage(conn, SOCK_ERRNO);
 			goto connect_errReturn;
 		}
 	}
@@ -945,7 +945,7 @@ connectDBStart(PGconn *conn)
 		{
 			printfPQExpBuffer(&conn->errorMessage,
 							  libpq_gettext("could not send SSL negotiation packet: %s\n"),
-							  strerror(errno));
+							  SOCK_STRERROR(SOCK_ERRNO));
 			goto connect_errReturn;
 		}
 		/* Now receive the postmasters response */
@@ -953,7 +953,7 @@ connectDBStart(PGconn *conn)
 		{
 			printfPQExpBuffer(&conn->errorMessage,
 							  libpq_gettext("could not receive server response to SSL negotiation packet: %s\n"),
-							  strerror(errno));
+							  SOCK_STRERROR(SOCK_ERRNO));
 			goto connect_errReturn;
 		}
 		if (SSLok == 'S')
@@ -1203,7 +1203,7 @@ keep_going:						/* We will come back to here until there
 				{
 					printfPQExpBuffer(&conn->errorMessage,
 									  libpq_gettext("could not get socket error status: %s\n"),
-									  strerror(errno));
+									  SOCK_STRERROR(SOCK_ERRNO));
 					goto error_return;
 				}
 				else if (optval != 0)
@@ -1223,7 +1223,7 @@ keep_going:						/* We will come back to here until there
 				{
 					printfPQExpBuffer(&conn->errorMessage,
 									  libpq_gettext("could not get client address from socket: %s\n"),
-									  strerror(errno));
+									  SOCK_STRERROR(SOCK_ERRNO));
 					goto error_return;
 				}
 
@@ -1262,7 +1262,7 @@ keep_going:						/* We will come back to here until there
 				{
 					printfPQExpBuffer(&conn->errorMessage,
 									  libpq_gettext("could not send startup packet: %s\n"),
-									  strerror(errno));
+									  SOCK_STRERROR(SOCK_ERRNO));
 					goto error_return;
 				}
 
@@ -2097,7 +2097,7 @@ PQresetPoll(PGconn *conn)
 int
 PQrequestCancel(PGconn *conn)
 {
-	int			save_errno = errno;
+	int			save_errno = SOCK_ERRNO;
 	int			tmpsock = -1;
 	struct
 	{
@@ -2169,7 +2169,7 @@ PQrequestCancel(PGconn *conn)
 	return TRUE;
 
 cancel_errReturn:
-	strcat(conn->errorMessage.data, strerror(errno));
+	strcat(conn->errorMessage.data, SOCK_STRERROR(SOCK_ERRNO));
 	strcat(conn->errorMessage.data, "\n");
 	conn->errorMessage.len = strlen(conn->errorMessage.data);
 	if (tmpsock >= 0)

src/interfaces/libpq/fe-exec.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v 1.107 2001/08/17 15:11:15 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v 1.108 2001/08/21 20:39:53 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2038,10 +2038,6 @@ PQoidStatus(const PGresult *res)
 	return buf;
 }
 
-#ifdef WIN32					/* need to get at normal errno here */
-#undef errno
-#endif
-
 /*
   PQoidValue -
 		a perhaps preferable form of the above which just returns
@@ -2056,7 +2052,11 @@ PQoidValue(const PGresult *res)
 	if (!res || !res->cmdStatus || strncmp(res->cmdStatus, "INSERT ", 7) != 0)
 		return InvalidOid;
 
+#ifdef WIN32
+    SetLastError(0);
+#else
 	errno = 0;
+#endif
 	result = strtoul(res->cmdStatus + 7, &endptr, 10);
 
 	if (!endptr || (*endptr != ' ' && *endptr != '\0') || errno == ERANGE)
@@ -2065,9 +2065,6 @@ PQoidValue(const PGresult *res)
 		return (Oid) result;
 }
 
-#ifdef WIN32					/* back to socket errno */
-#define errno WSAGetLastError()
-#endif
 
 /*
    PQcmdTuples -

src/interfaces/libpq/fe-lobj.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-lobj.c,v 1.37 2001/08/17 15:11:15 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-lobj.c,v 1.38 2001/08/21 20:39:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,12 +30,6 @@
 
 #include "libpq/libpq-fs.h"		/* must come after sys/stat.h */
 
-
-#ifdef WIN32					/* need to use normal errno in this file */
-#undef errno
-#endif
-
-
 #define LO_BUFSIZE		  8192
 
 static int	lo_initialize(PGconn *conn);

src/interfaces/libpq/fe-misc.c

@@ -25,7 +25,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.53 2001/08/17 15:11:15 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.54 2001/08/21 20:39:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -347,13 +347,13 @@ retry:
 	if (select(conn->sock + 1, &input_mask, (fd_set *) NULL, (fd_set *) NULL,
 			   &timeout) < 0)
 	{
-		if (errno == EINTR)
+		if (SOCK_ERRNO == EINTR)
 			/* Interrupted system call - we'll just try again */
 			goto retry;
 
 		printfPQExpBuffer(&conn->errorMessage,
 						  libpq_gettext("select() failed: %s\n"),
-						  strerror(errno));
+						  SOCK_STRERROR(SOCK_ERRNO));
 		return -1;
 	}
 
@@ -381,13 +381,13 @@ retry:
 	if (select(conn->sock + 1, (fd_set *) NULL, &input_mask, (fd_set *) NULL,
 			   &timeout) < 0)
 	{
-		if (errno == EINTR)
+		if (SOCK_ERRNO == EINTR)
 			/* Interrupted system call - we'll just try again */
 			goto retry;
 
 		printfPQExpBuffer(&conn->errorMessage,
 						  libpq_gettext("select() failed: %s\n"),
-						  strerror(errno));
+						  SOCK_STRERROR(SOCK_ERRNO));
 		return -1;
 	}
 	return FD_ISSET(conn->sock, &input_mask) ? 1 : 0;
@@ -467,25 +467,25 @@ tryAgain:
 					 conn->inBufSize - conn->inEnd, 0);
 	if (nread < 0)
 	{
-		if (errno == EINTR)
+		if (SOCK_ERRNO == EINTR)
 			goto tryAgain;
 		/* Some systems return EAGAIN/EWOULDBLOCK for no data */
 #ifdef EAGAIN
-		if (errno == EAGAIN)
+		if (SOCK_ERRNO == EAGAIN)
 			return someread;
 #endif
 #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
-		if (errno == EWOULDBLOCK)
+		if (SOCK_ERRNO == EWOULDBLOCK)
 			return someread;
 #endif
 		/* We might get ECONNRESET here if using TCP and backend died */
 #ifdef ECONNRESET
-		if (errno == ECONNRESET)
+		if (SOCK_ERRNO == ECONNRESET)
 			goto definitelyFailed;
 #endif
 		printfPQExpBuffer(&conn->errorMessage,
 						  libpq_gettext("could not receive data from server: %s\n"),
-						  strerror(errno));
+						  SOCK_STRERROR(SOCK_ERRNO));
 		return -1;
 	}
 	if (nread > 0)
@@ -553,25 +553,25 @@ tryAgain2:
 					 conn->inBufSize - conn->inEnd, 0);
 	if (nread < 0)
 	{
-		if (errno == EINTR)
+		if (SOCK_ERRNO == EINTR)
 			goto tryAgain2;
 		/* Some systems return EAGAIN/EWOULDBLOCK for no data */
 #ifdef EAGAIN
-		if (errno == EAGAIN)
+		if (SOCK_ERRNO == EAGAIN)
 			return 0;
 #endif
 #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
-		if (errno == EWOULDBLOCK)
+		if (SOCK_ERRNO == EWOULDBLOCK)
 			return 0;
 #endif
 		/* We might get ECONNRESET here if using TCP and backend died */
 #ifdef ECONNRESET
-		if (errno == ECONNRESET)
+		if (SOCK_ERRNO == ECONNRESET)
 			goto definitelyFailed;
 #endif
 		printfPQExpBuffer(&conn->errorMessage,
 						  libpq_gettext("could not receive data from server: %s\n"),
-						  strerror(errno));
+						  SOCK_STRERROR(SOCK_ERRNO));
 		return -1;
 	}
 	if (nread > 0)
@@ -653,7 +653,7 @@ pqFlush(PGconn *conn)
 			 * EPIPE or ECONNRESET, assume we've lost the backend
 			 * connection permanently.
 			 */
-			switch (errno)
+			switch (SOCK_ERRNO)
 			{
 #ifdef EAGAIN
 				case EAGAIN:
@@ -689,7 +689,7 @@ pqFlush(PGconn *conn)
 				default:
 					printfPQExpBuffer(&conn->errorMessage,
 									  libpq_gettext("could not send data to server: %s\n"),
-									  strerror(errno));
+									  SOCK_STRERROR(SOCK_ERRNO));
 					/* We don't assume it's a fatal error... */
 					return EOF;
 			}
@@ -772,11 +772,11 @@ retry:
 		if (select(conn->sock + 1, &input_mask, &output_mask, &except_mask,
 				   (struct timeval *) NULL) < 0)
 		{
-			if (errno == EINTR)
+			if (SOCK_ERRNO == EINTR)
 				goto retry;
 			printfPQExpBuffer(&conn->errorMessage,
 							  libpq_gettext("select() failed: %s\n"),
-							  strerror(errno));
+							  SOCK_STRERROR(SOCK_ERRNO));
 			return EOF;
 		}
 	}
@@ -851,3 +851,27 @@ libpq_gettext(const char *msgid)
 	return dgettext("libpq", msgid);
 }
 #endif /* ENABLE_NLS */
+
+#ifdef WIN32
+/*
+ * strerror replacement for windows:
+ */
+const char*
+winsock_strerror(DWORD eno)
+{
+	if (!FormatMessage( 
+		FORMAT_MESSAGE_IGNORE_INSERTS |
+        FORMAT_MESSAGE_FROM_SYSTEM | /* always consider system table */
+        ((netmsgModule != NULL) ? FORMAT_MESSAGE_FROM_HMODULE : 0),
+        netmsgModule, /* module to get message from (NULL == system) */
+		eno,
+        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+        winsock_strerror_buf,sizeof(winsock_strerror_buf)-1,
+        NULL
+       )){
+      sprintf(winsock_strerror_buf,"Unknown socket error(%u)",eno);
+    }
+    winsock_strerror_buf[sizeof(winsock_strerror_buf)-1]='\0';
+    return winsock_strerror_buf;
+}
+#endif

src/interfaces/libpq/libpq-fe.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: libpq-fe.h,v 1.71 2001/03/22 04:01:27 momjian Exp $
+ * $Id: libpq-fe.h,v 1.72 2001/08/21 20:39:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,10 +21,21 @@ extern		"C"
 #endif
 
 #include <stdio.h>
+
+#ifdef WIN32
+    #define SOCK_ERRNO (WSAGetLastError ())
+	#define SOCK_STRERROR winsock_strerror
+#else
+    #define SOCK_ERRNO errno
+	#define SOCK_STRERROR strerror
+#endif
+
+
 /* postgres_ext.h defines the backend's externally visible types,
  * such as Oid.
  */
 #include "postgres_ext.h"
+
 #ifdef USE_SSL
 #include <openssl/ssl.h>
 #endif

src/interfaces/libpq/libpqdll.c

@@ -1,6 +1,7 @@
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #include <winsock.h>
+#include "win32.h"
 
 BOOL		WINAPI
 DllMain(HINSTANCE hinstDLL, DWORD fdwReason,
@@ -20,8 +21,13 @@ DllMain(HINSTANCE hinstDLL, DWORD fdwReason,
 				 */
 				return FALSE;
 			}
+		    if (netmsgModule == NULL){
+				netmsgModule=LoadLibraryEx("netmsg.dll",NULL,LOAD_LIBRARY_AS_DATAFILE);
+			}
 			break;
 		case DLL_PROCESS_DETACH:
+		    if (netmsgModule != NULL)
+				FreeLibrary(netmsgModule);
 			WSACleanup();
 			break;
 	}

src/interfaces/libpq/win32.h

@@ -23,19 +23,17 @@
  */
 #define crypt(a,b) (a)
 
-/*
- * Most of libpq uses "errno" to access error conditions from socket calls,
- * so on Windows we want to redirect those usages to WSAGetLastError().
- * Rather than #ifdef'ing every single place that has "errno", hack it up
- * with a macro instead.  But there are a few places that do need to touch
- * the regular errno variable.  For them, we #undef and then redefine errno.
- */
-
-#define errno WSAGetLastError()
-
 #undef EAGAIN	/* doesn't apply on sockets */
 #undef EINTR
 #define EINTR WSAEINTR
 #define EWOULDBLOCK WSAEWOULDBLOCK
 #define ECONNRESET WSAECONNRESET
 #define EINPROGRESS WSAEINPROGRESS
+
+/*
+ * Windows network messaging stuff:
+ */
+static HINSTANCE netmsgModule = NULL;
+
+static char winsock_strerror_buf[512];
+const char* winsock_strerror(DWORD eno);