libpq can now talk to either 3.0 or 2.0 protocol servers. It first tries

protocol 3, then falls back to 2 if postmaster rejects the startup packet
with an old-format error message.  A side benefit of the rewrite is that
SSL-encrypted connections can now be made without blocking.  (I think,
anyway, but do not have a good way to test.)

1 files changed, 1247 insertions, 0 deletions

diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
new file mode 100644
index 00000000000..2fbfa01566e
--- /dev/null
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -0,0 +1,1247 @@
+/*-------------------------------------------------------------------------
+ *
+ * fe-protocol3.c
+ *	  functions that are specific to frontend/backend protocol version 3
+ *
+ * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-protocol3.c,v 1.1 2003/06/08 17:43:00 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres_fe.h"
+
+#include <errno.h>
+#include <ctype.h>
+#include <fcntl.h>
+
+#include "libpq-fe.h"
+#include "libpq-int.h"
+
+#include "mb/pg_wchar.h"
+
+#ifdef WIN32
+#include "win32.h"
+#else
+#include <unistd.h>
+#include <netinet/in.h>
+#ifdef HAVE_NETINET_TCP_H
+#include <netinet/tcp.h>
+#endif
+#include <arpa/inet.h>
+#endif
+
+
+static void handleSyncLoss(PGconn *conn, char id, int msgLength);
+static int	getRowDescriptions(PGconn *conn);
+static int	getAnotherTuple(PGconn *conn, int msgLength);
+static int	getParameterStatus(PGconn *conn);
+static int	getNotify(PGconn *conn);
+static int	build_startup_packet(const PGconn *conn, char *packet,
+								 const PQEnvironmentOption *options);
+
+
+/*
+ * parseInput: if appropriate, parse input data from backend
+ * until input is exhausted or a stopping state is reached.
+ * Note that this function will NOT attempt to read more data from the backend.
+ */
+void
+pqParseInput3(PGconn *conn)
+{
+	char		id;
+	int			msgLength;
+	int			avail;
+	char		noticeWorkspace[128];
+
+	/*
+	 * Loop to parse successive complete messages available in the buffer.
+	 */
+	for (;;)
+	{
+		/*
+		 * Try to read a message.  First get the type code and length.
+		 * Return if not enough data.
+		 */
+		conn->inCursor = conn->inStart;
+		if (pqGetc(&id, conn))
+			return;
+		if (pqGetInt(&msgLength, 4, conn))
+			return;
+
+		/*
+		 * Try to validate message type/length here.  A length less than 4
+		 * is definitely broken.  Large lengths should only be believed
+		 * for a few message types.
+		 */
+		if (msgLength < 4)
+		{
+			handleSyncLoss(conn, id, msgLength);
+			return;
+		}
+		if (msgLength > 30000 &&
+			!(id == 'T' || id == 'D' || id == 'd'))
+		{
+			handleSyncLoss(conn, id, msgLength);
+			return;
+		}
+
+		/*
+		 * Can't process if message body isn't all here yet.
+		 */
+		msgLength -= 4;
+		avail = conn->inEnd - conn->inCursor;
+		if (avail < msgLength)
+		{
+			/*
+			 * Before returning, enlarge the input buffer if needed to hold
+			 * the whole message.  This is better than leaving it to
+			 * pqReadData because we can avoid multiple cycles of realloc()
+			 * when the message is large; also, we can implement a reasonable
+			 * recovery strategy if we are unable to make the buffer big
+			 * enough.
+			 */
+			if (pqCheckInBufferSpace(conn->inCursor + msgLength, conn))
+			{
+				/*
+				 * XXX add some better recovery code... plan is to skip
+				 * over the message using its length, then report an error.
+				 * For the moment, just treat this like loss of sync (which
+				 * indeed it might be!)
+				 */
+				handleSyncLoss(conn, id, msgLength);
+			}
+			return;
+		}
+
+		/*
+		 * NOTIFY and NOTICE messages can happen in any state; always process
+		 * them right away.
+		 *
+		 * Most other messages should only be processed while in BUSY state.
+		 * (In particular, in READY state we hold off further parsing
+		 * until the application collects the current PGresult.)
+		 *
+		 * However, if the state is IDLE then we got trouble; we need to deal
+		 * with the unexpected message somehow.
+		 *
+		 * ParameterStatus ('S') messages are a special case: in IDLE state
+		 * we must process 'em (this case could happen if a new value was
+		 * adopted from config file due to SIGHUP), but otherwise we hold
+		 * off until BUSY state.
+		 */
+		if (id == 'A')
+		{
+			if (getNotify(conn))
+				return;
+		}
+		else if (id == 'N')
+		{
+			if (pqGetErrorNotice3(conn, false))
+				return;
+		}
+		else if (conn->asyncStatus != PGASYNC_BUSY)
+		{
+			/* If not IDLE state, just wait ... */
+			if (conn->asyncStatus != PGASYNC_IDLE)
+				return;
+
+			/*
+			 * Unexpected message in IDLE state; need to recover somehow.
+			 * ERROR messages are displayed using the notice processor;
+			 * ParameterStatus is handled normally;
+			 * anything else is just dropped on the floor after displaying
+			 * a suitable warning notice.  (An ERROR is very possibly the
+			 * backend telling us why it is about to close the connection,
+			 * so we don't want to just discard it...)
+			 */
+			if (id == 'E')
+			{
+				if (pqGetErrorNotice3(conn, false /* treat as notice */))
+					return;
+			}
+			else if (id == 'S')
+			{
+				if (getParameterStatus(conn))
+					return;
+			}
+			else
+			{
+				snprintf(noticeWorkspace, sizeof(noticeWorkspace),
+						 libpq_gettext("message type 0x%02x arrived from server while idle\n"),
+						 id);
+				PGDONOTICE(conn, noticeWorkspace);
+				/* Discard the unexpected message */
+				conn->inCursor += msgLength;
+			}
+		}
+		else
+		{
+			/*
+			 * In BUSY state, we can process everything.
+			 */
+			switch (id)
+			{
+				case 'C':		/* command complete */
+					if (pqGets(&conn->workBuffer, conn))
+						return;
+					if (conn->result == NULL)
+						conn->result = PQmakeEmptyPGresult(conn,
+													   PGRES_COMMAND_OK);
+					strncpy(conn->result->cmdStatus, conn->workBuffer.data,
+							CMDSTATUS_LEN);
+					conn->asyncStatus = PGASYNC_READY;
+					break;
+				case 'E':		/* error return */
+					if (pqGetErrorNotice3(conn, true))
+						return;
+					conn->asyncStatus = PGASYNC_READY;
+					break;
+				case 'Z':		/* backend is ready for new query */
+					if (pqGetc(&conn->xact_status, conn))
+						return;
+					conn->asyncStatus = PGASYNC_IDLE;
+					break;
+				case 'I':		/* empty query */
+					if (conn->result == NULL)
+						conn->result = PQmakeEmptyPGresult(conn,
+													  PGRES_EMPTY_QUERY);
+					conn->asyncStatus = PGASYNC_READY;
+					break;
+				case 'S':		/* parameter status */
+					if (getParameterStatus(conn))
+						return;
+					break;
+				case 'K':		/* secret key data from the backend */
+
+					/*
+					 * This is expected only during backend startup, but
+					 * it's just as easy to handle it as part of the main
+					 * loop.  Save the data and continue processing.
+					 */
+					if (pqGetInt(&(conn->be_pid), 4, conn))
+						return;
+					if (pqGetInt(&(conn->be_key), 4, conn))
+						return;
+					break;
+				case 'T':		/* row descriptions (start of query
+								 * results) */
+					if (conn->result == NULL)
+					{
+						/* First 'T' in a query sequence */
+						if (getRowDescriptions(conn))
+							return;
+					}
+					else
+					{
+						/*
+						 * A new 'T' message is treated as the start of
+						 * another PGresult.  (It is not clear that this
+						 * is really possible with the current backend.)
+						 * We stop parsing until the application accepts
+						 * the current result.
+						 */
+						conn->asyncStatus = PGASYNC_READY;
+						return;
+					}
+					break;
+				case 'D':		/* Data Row */
+					if (conn->result != NULL &&
+						conn->result->resultStatus == PGRES_TUPLES_OK)
+					{
+						/* Read another tuple of a normal query response */
+						if (getAnotherTuple(conn, msgLength))
+							return;
+					}
+					else if (conn->result != NULL &&
+							 conn->result->resultStatus == PGRES_FATAL_ERROR)
+					{
+						/*
+						 * We've already choked for some reason.  Just discard
+						 * tuples till we get to the end of the query.
+						 */
+						conn->inCursor += msgLength;
+					}
+					else
+					{
+						/* Set up to report error at end of query */
+						printfPQExpBuffer(&conn->errorMessage,
+								 libpq_gettext("server sent data (\"D\" message) without prior row description (\"T\" message)\n"));
+						pqSaveErrorResult(conn);
+						/* Discard the unexpected message */
+						conn->inCursor += msgLength;
+					}
+					break;
+				case 'G':		/* Start Copy In */
+					if (pqGetc(&conn->copy_is_binary, conn))
+						return;
+					/* XXX we currently ignore the rest of the message */
+					conn->inCursor = conn->inStart + 5 + msgLength;
+					conn->asyncStatus = PGASYNC_COPY_IN;
+					break;
+				case 'H':		/* Start Copy Out */
+					if (pqGetc(&conn->copy_is_binary, conn))
+						return;
+					/* XXX we currently ignore the rest of the message */
+					conn->inCursor = conn->inStart + 5 + msgLength;
+					conn->asyncStatus = PGASYNC_COPY_OUT;
+					conn->copy_already_done = 0;
+					break;
+				case 'd':		/* Copy Data */
+					/*
+					 * If we see Copy Data, just silently drop it.  This
+					 * would only occur if application exits COPY OUT mode
+					 * too early.
+					 */
+					conn->inCursor += msgLength;
+					break;
+				case 'c':		/* Copy Done */
+					/*
+					 * If we see Copy Done, just silently drop it.  This
+					 * is the normal case during PQendcopy.  We will keep
+					 * swallowing data, expecting to see command-complete
+					 * for the COPY command.
+					 */
+					break;
+				default:
+					printfPQExpBuffer(&conn->errorMessage,
+									  libpq_gettext(
+													"unexpected response from server; first received character was \"%c\"\n"),
+									  id);
+					/* build an error result holding the error message */
+					pqSaveErrorResult(conn);
+					/* not sure if we will see more, so go to ready state */
+					conn->asyncStatus = PGASYNC_READY;
+					/* Discard the unexpected message */
+					conn->inCursor += msgLength;
+					break;
+			}					/* switch on protocol character */
+		}
+		/* Successfully consumed this message */
+		if (conn->inCursor == conn->inStart + 5 + msgLength)
+		{
+			/* Normal case: parsing agrees with specified length */
+			conn->inStart = conn->inCursor;
+		}
+		else
+		{
+			/* Trouble --- report it */
+			printfPQExpBuffer(&conn->errorMessage,
+							  libpq_gettext("Message contents do not agree with length in message type \"%c\"\n"),
+							  id);
+			/* build an error result holding the error message */
+			pqSaveErrorResult(conn);
+			conn->asyncStatus = PGASYNC_READY;
+			/* trust the specified message length as what to skip */
+			conn->inStart += 5 + msgLength;
+		}
+	}
+}
+
+/*
+ * handleSyncLoss: clean up after loss of message-boundary sync
+ *
+ * There isn't really a lot we can do here except abandon the connection.
+ */
+static void
+handleSyncLoss(PGconn *conn, char id, int msgLength)
+{
+	printfPQExpBuffer(&conn->errorMessage,
+					  libpq_gettext(
+						  "lost synchronization with server: got message type \"%c\", length %d\n"),
+					  id, msgLength);
+	/* build an error result holding the error message */
+	pqSaveErrorResult(conn);
+	conn->asyncStatus = PGASYNC_READY; /* drop out of GetResult wait loop */
+
+	pqsecure_close(conn);
+	closesocket(conn->sock);
+	conn->sock = -1;
+	conn->status = CONNECTION_BAD;		/* No more connection to backend */
+}
+
+/*
+ * parseInput subroutine to read a 'T' (row descriptions) message.
+ * We build a PGresult structure containing the attribute data.
+ * Returns: 0 if completed message, EOF if not enough data yet.
+ *
+ * Note that if we run out of data, we have to release the partially
+ * constructed PGresult, and rebuild it again next time.  Fortunately,
+ * that shouldn't happen often, since 'T' messages usually fit in a packet.
+ */
+static int
+getRowDescriptions(PGconn *conn)
+{
+	PGresult   *result;
+	int			nfields;
+	int			i;
+
+	result = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK);
+
+	/* parseInput already read the 'T' label and message length. */
+	/* the next two bytes are the number of fields	*/
+	if (pqGetInt(&(result->numAttributes), 2, conn))
+	{
+		PQclear(result);
+		return EOF;
+	}
+	nfields = result->numAttributes;
+
+	/* allocate space for the attribute descriptors */
+	if (nfields > 0)
+	{
+		result->attDescs = (PGresAttDesc *)
+			pqResultAlloc(result, nfields * sizeof(PGresAttDesc), TRUE);
+		MemSet((char *) result->attDescs, 0, nfields * sizeof(PGresAttDesc));
+	}
+
+	/* get type info */
+	for (i = 0; i < nfields; i++)
+	{
+		int			tableid;
+		int			columnid;
+		int			typid;
+		int			typlen;
+		int			atttypmod;
+		int			format;
+
+		if (pqGets(&conn->workBuffer, conn) ||
+			pqGetInt(&tableid, 4, conn) ||
+			pqGetInt(&columnid, 2, conn) ||
+			pqGetInt(&typid, 4, conn) ||
+			pqGetInt(&typlen, 2, conn) ||
+			pqGetInt(&atttypmod, 4, conn) ||
+			pqGetInt(&format, 2, conn))
+		{
+			PQclear(result);
+			return EOF;
+		}
+
+		/*
+		 * Since pqGetInt treats 2-byte integers as unsigned, we need to
+		 * coerce these results to signed form.
+		 */
+		columnid = (int) ((int16) columnid);
+		typlen = (int) ((int16) typlen);
+		format = (int) ((int16) format);
+
+		result->attDescs[i].name = pqResultStrdup(result,
+												  conn->workBuffer.data);
+		result->attDescs[i].typid = typid;
+		result->attDescs[i].typlen = typlen;
+		result->attDescs[i].atttypmod = atttypmod;
+		/* XXX todo: save tableid/columnid, format too */
+	}
+
+	/* Success! */
+	conn->result = result;
+	return 0;
+}
+
+/*
+ * parseInput subroutine to read a 'D' (row data) message.
+ * We add another tuple to the existing PGresult structure.
+ * Returns: 0 if completed message, EOF if error or not enough data yet.
+ *
+ * Note that if we run out of data, we have to suspend and reprocess
+ * the message after more data is received.  We keep a partially constructed
+ * tuple in conn->curTuple, and avoid reallocating already-allocated storage.
+ */
+static int
+getAnotherTuple(PGconn *conn, int msgLength)
+{
+	PGresult   *result = conn->result;
+	int			nfields = result->numAttributes;
+	PGresAttValue *tup;
+	int			tupnfields;		/* # fields from tuple */
+	int			vlen;			/* length of the current field value */
+	int			i;
+
+	/* Allocate tuple space if first time for this data message */
+	if (conn->curTuple == NULL)
+	{
+		conn->curTuple = (PGresAttValue *)
+			pqResultAlloc(result, nfields * sizeof(PGresAttValue), TRUE);
+		if (conn->curTuple == NULL)
+			goto outOfMemory;
+		MemSet((char *) conn->curTuple, 0, nfields * sizeof(PGresAttValue));
+	}
+	tup = conn->curTuple;
+
+	/* Get the field count and make sure it's what we expect */
+	if (pqGetInt(&tupnfields, 2, conn))
+		return EOF;
+
+	if (tupnfields != nfields)
+	{
+		/* Replace partially constructed result with an error result */
+		printfPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("unexpected field count in D message\n"));
+		pqSaveErrorResult(conn);
+		/* Discard the failed message by pretending we read it */
+		conn->inCursor = conn->inStart + 5 + msgLength;
+		return 0;
+	}
+
+	/* Scan the fields */
+	for (i = 0; i < nfields; i++)
+	{
+		/* get the value length */
+		if (pqGetInt(&vlen, 4, conn))
+			return EOF;
+		if (vlen == -1)
+		{
+			/* null field */
+			tup[i].value = result->null_field;
+			tup[i].len = NULL_LEN;
+			continue;
+		}
+		if (vlen < 0)
+			vlen = 0;
+		if (tup[i].value == NULL)
+		{
+			tup[i].value = (char *) pqResultAlloc(result, vlen + 1, false);
+			if (tup[i].value == NULL)
+				goto outOfMemory;
+		}
+		tup[i].len = vlen;
+		/* read in the value */
+		if (vlen > 0)
+			if (pqGetnchar((char *) (tup[i].value), vlen, conn))
+				return EOF;
+		/* we have to terminate this ourselves */
+		tup[i].value[vlen] = '\0';
+	}
+
+	/* Success!  Store the completed tuple in the result */
+	if (!pqAddTuple(result, tup))
+		goto outOfMemory;
+	/* and reset for a new message */
+	conn->curTuple = NULL;
+
+	return 0;
+
+outOfMemory:
+	/*
+	 * Replace partially constructed result with an error result.
+	 * First discard the old result to try to win back some memory.
+	 */
+	pqClearAsyncResult(conn);
+	printfPQExpBuffer(&conn->errorMessage,
+					  libpq_gettext("out of memory for query result\n"));
+	pqSaveErrorResult(conn);
+
+	/* Discard the failed message by pretending we read it */
+	conn->inCursor = conn->inStart + 5 + msgLength;
+	return 0;
+}
+
+
+/*
+ * Attempt to read an Error or Notice response message.
+ * This is possible in several places, so we break it out as a subroutine.
+ * Entry: 'E' or 'N' message type and length have already been consumed.
+ * Exit: returns 0 if successfully consumed message.
+ *		 returns EOF if not enough data.
+ */
+int
+pqGetErrorNotice3(PGconn *conn, bool isError)
+{
+	PGresult   *res;
+	PQExpBufferData workBuf;
+	char		id;
+
+	/*
+	 * Make a PGresult to hold the accumulated fields.  We temporarily
+	 * lie about the result status, so that PQmakeEmptyPGresult doesn't
+	 * uselessly copy conn->errorMessage.
+	 */
+	res = PQmakeEmptyPGresult(conn, PGRES_EMPTY_QUERY);
+	res->resultStatus = isError ? PGRES_FATAL_ERROR : PGRES_NONFATAL_ERROR;
+	/*
+	 * Since the fields might be pretty long, we create a temporary
+	 * PQExpBuffer rather than using conn->workBuffer.	workBuffer is
+	 * intended for stuff that is expected to be short.  We shouldn't
+	 * use conn->errorMessage either, since this might be only a notice.
+	 */
+	initPQExpBuffer(&workBuf);
+
+	/*
+	 * Read the fields and save into res.
+	 */
+	for (;;)
+	{
+		if (pqGetc(&id, conn))
+			goto fail;
+		if (id == '\0')
+			break;				/* terminator found */
+		if (pqGets(&workBuf, conn))
+			goto fail;
+		switch (id)
+		{
+			case 'S':
+				res->errSeverity = pqResultStrdup(res, workBuf.data);
+				break;
+			case 'C':
+				res->errCode = pqResultStrdup(res, workBuf.data);
+				break;
+			case 'M':
+				res->errPrimary = pqResultStrdup(res, workBuf.data);
+				break;
+			case 'D':
+				res->errDetail = pqResultStrdup(res, workBuf.data);
+				break;
+			case 'H':
+				res->errHint = pqResultStrdup(res, workBuf.data);
+				break;
+			case 'P':
+				res->errPosition = pqResultStrdup(res, workBuf.data);
+				break;
+			case 'W':
+				res->errContext = pqResultStrdup(res, workBuf.data);
+				break;
+			case 'F':
+				res->errFilename = pqResultStrdup(res, workBuf.data);
+				break;
+			case 'L':
+				res->errLineno = pqResultStrdup(res, workBuf.data);
+				break;
+			case 'R':
+				res->errFuncname = pqResultStrdup(res, workBuf.data);
+				break;
+			default:
+				/* silently ignore any other field type */
+				break;
+		}
+	}
+
+	/*
+	 * Now build the "overall" error message for PQresultErrorMessage.
+	 *
+	 * XXX this should be configurable somehow.
+	 */
+	resetPQExpBuffer(&workBuf);
+	if (res->errSeverity)
+		appendPQExpBuffer(&workBuf, "%s:  ", res->errSeverity);
+	if (res->errPrimary)
+		appendPQExpBufferStr(&workBuf, res->errPrimary);
+	/* translator: %s represents a digit string */
+	if (res->errPosition)
+		appendPQExpBuffer(&workBuf, libpq_gettext(" at character %s"),
+						  res->errPosition);
+	appendPQExpBufferChar(&workBuf, '\n');
+	if (res->errDetail)
+		appendPQExpBuffer(&workBuf, libpq_gettext("DETAIL:  %s\n"),
+						  res->errDetail);
+	if (res->errHint)
+		appendPQExpBuffer(&workBuf, libpq_gettext("HINT:  %s\n"),
+						  res->errHint);
+	if (res->errContext)
+		appendPQExpBuffer(&workBuf, libpq_gettext("CONTEXT:  %s\n"),
+						  res->errContext);
+
+	/*
+	 * Either save error as current async result, or just emit the notice.
+	 */
+	if (isError)
+	{
+		res->errMsg = pqResultStrdup(res, workBuf.data);
+		pqClearAsyncResult(conn);
+		conn->result = res;
+		resetPQExpBuffer(&conn->errorMessage);
+		appendPQExpBufferStr(&conn->errorMessage, workBuf.data);
+	}
+	else
+	{
+		PGDONOTICE(conn, workBuf.data);
+		PQclear(res);
+	}
+
+	termPQExpBuffer(&workBuf);
+	return 0;
+
+fail:
+	PQclear(res);
+	termPQExpBuffer(&workBuf);
+	return EOF;
+}
+
+
+/*
+ * Attempt to read a ParameterStatus message.
+ * This is possible in several places, so we break it out as a subroutine.
+ * Entry: 'S' message type and length have already been consumed.
+ * Exit: returns 0 if successfully consumed message.
+ *		 returns EOF if not enough data.
+ */
+static int
+getParameterStatus(PGconn *conn)
+{
+	PQExpBufferData valueBuf;
+
+	/* Get the parameter name */
+	if (pqGets(&conn->workBuffer, conn))
+		return EOF;
+	/* Get the parameter value (could be large) */
+	initPQExpBuffer(&valueBuf);
+	if (pqGets(&valueBuf, conn))
+	{
+		termPQExpBuffer(&valueBuf);
+		return EOF;
+	}
+	/* And save it */
+	pqSaveParameterStatus(conn, conn->workBuffer.data, valueBuf.data);
+	termPQExpBuffer(&valueBuf);
+	return 0;
+}
+
+
+/*
+ * Attempt to read a Notify response message.
+ * This is possible in several places, so we break it out as a subroutine.
+ * Entry: 'A' message type and length have already been consumed.
+ * Exit: returns 0 if successfully consumed Notify message.
+ *		 returns EOF if not enough data.
+ */
+static int
+getNotify(PGconn *conn)
+{
+	int			be_pid;
+	PGnotify   *newNotify;
+
+	if (pqGetInt(&be_pid, 4, conn))
+		return EOF;
+	if (pqGets(&conn->workBuffer, conn))
+		return EOF;
+
+	/*
+	 * Store the relation name right after the PQnotify structure so it
+	 * can all be freed at once.  We don't use NAMEDATALEN because we
+	 * don't want to tie this interface to a specific server name length.
+	 */
+	newNotify = (PGnotify *) malloc(sizeof(PGnotify) +
+									strlen(conn->workBuffer.data) +1);
+	if (newNotify)
+	{
+		newNotify->relname = (char *) newNotify + sizeof(PGnotify);
+		strcpy(newNotify->relname, conn->workBuffer.data);
+		newNotify->be_pid = be_pid;
+		DLAddTail(conn->notifyList, DLNewElem(newNotify));
+	}
+
+	/* Swallow extra string (not presently used) */
+	if (pqGets(&conn->workBuffer, conn))
+		return EOF;
+
+	return 0;
+}
+
+
+/*
+ * PQgetline - gets a newline-terminated string from the backend.
+ *
+ * See fe-exec.c for documentation.
+ */
+int
+pqGetline3(PGconn *conn, char *s, int maxlen)
+{
+	int			status;
+
+	if (conn->sock < 0 ||
+		conn->asyncStatus != PGASYNC_COPY_OUT ||
+		conn->copy_is_binary)
+	{
+		printfPQExpBuffer(&conn->errorMessage,
+					libpq_gettext("PQgetline: not doing text COPY OUT\n"));
+		*s = '\0';
+		return EOF;
+	}
+
+	while ((status = PQgetlineAsync(conn, s, maxlen-1)) == 0)
+	{
+		/* need to load more data */
+		if (pqWait(TRUE, FALSE, conn) ||
+			pqReadData(conn) < 0)
+		{
+			*s = '\0';
+			return EOF;
+		}
+	}
+
+	if (status < 0)
+	{
+		/* End of copy detected; gin up old-style terminator */
+		strcpy(s, "\\.");
+		return 0;
+	}
+
+	/* Add null terminator, and strip trailing \n if present */
+	if (s[status-1] == '\n')
+	{
+		s[status-1] = '\0';
+		return 0;
+	}
+	else
+	{
+		s[status] = '\0';
+		return 1;
+	}
+}
+
+/*
+ * PQgetlineAsync - gets a COPY data row without blocking.
+ *
+ * See fe-exec.c for documentation.
+ */
+int
+pqGetlineAsync3(PGconn *conn, char *buffer, int bufsize)
+{
+	char		id;
+	int			msgLength;
+	int			avail;
+
+	if (conn->asyncStatus != PGASYNC_COPY_OUT)
+		return -1;				/* we are not doing a copy... */
+
+	/*
+	 * Recognize the next input message.  To make life simpler for async
+	 * callers, we keep returning 0 until the next message is fully available
+	 * even if it is not Copy Data.  This should keep PQendcopy from blocking.
+	 */
+	conn->inCursor = conn->inStart;
+	if (pqGetc(&id, conn))
+		return 0;
+	if (pqGetInt(&msgLength, 4, conn))
+		return 0;
+	avail = conn->inEnd - conn->inCursor;
+	if (avail < msgLength - 4)
+		return 0;
+
+	/*
+	 * Cannot proceed unless it's a Copy Data message.  Anything else means
+	 * end of copy mode.
+	 */
+	if (id != 'd')
+		return -1;
+
+	/*
+	 * Move data from libpq's buffer to the caller's.  In the case where
+	 * a prior call found the caller's buffer too small, we use
+	 * conn->copy_already_done to remember how much of the row was already
+	 * returned to the caller.
+	 */
+	conn->inCursor += conn->copy_already_done;
+	avail = msgLength - 4 - conn->copy_already_done;
+	if (avail <= bufsize)
+	{
+		/* Able to consume the whole message */
+		memcpy(buffer, &conn->inBuffer[conn->inCursor], avail);
+		/* Mark message consumed */
+		conn->inStart = conn->inCursor + avail;
+		/* Reset state for next time */
+		conn->copy_already_done = 0;
+		return avail;
+	}
+	else
+	{
+		/* We must return a partial message */
+		memcpy(buffer, &conn->inBuffer[conn->inCursor], bufsize);
+		/* The message is NOT consumed from libpq's buffer */
+		conn->copy_already_done += bufsize;
+		return bufsize;
+	}
+}
+
+/*
+ * PQendcopy
+ *
+ * See fe-exec.c for documentation.
+ */
+int
+pqEndcopy3(PGconn *conn)
+{
+	PGresult   *result;
+
+	if (conn->asyncStatus != PGASYNC_COPY_IN &&
+		conn->asyncStatus != PGASYNC_COPY_OUT)
+	{
+		printfPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("no COPY in progress\n"));
+		return 1;
+	}
+
+	/* Send the CopyDone message if needed */
+	if (conn->asyncStatus == PGASYNC_COPY_IN)
+	{
+		if (pqPutMsgStart('c', false, conn) < 0 ||
+			pqPutMsgEnd(conn) < 0)
+			return 1;
+	}
+
+	/*
+	 * make sure no data is waiting to be sent, abort if we are
+	 * non-blocking and the flush fails
+	 */
+	if (pqFlush(conn) && pqIsnonblocking(conn))
+		return (1);
+
+	/* Return to active duty */
+	conn->asyncStatus = PGASYNC_BUSY;
+	resetPQExpBuffer(&conn->errorMessage);
+
+	/*
+	 * Non blocking connections may have to abort at this point.  If everyone
+	 * played the game there should be no problem, but in error scenarios
+	 * the expected messages may not have arrived yet.  (We are assuming that
+	 * the backend's packetizing will ensure that CommandComplete arrives
+	 * along with the CopyDone; are there corner cases where that doesn't
+	 * happen?)
+	 */
+	if (pqIsnonblocking(conn) && PQisBusy(conn))
+		return (1);
+
+	/* Wait for the completion response */
+	result = PQgetResult(conn);
+
+	/* Expecting a successful result */
+	if (result && result->resultStatus == PGRES_COMMAND_OK)
+	{
+		PQclear(result);
+		return 0;
+	}
+
+	/*
+	 * Trouble. For backwards-compatibility reasons, we issue the error
+	 * message as if it were a notice (would be nice to get rid of this
+	 * silliness, but too many apps probably don't handle errors from
+	 * PQendcopy reasonably).  Note that the app can still obtain the
+	 * error status from the PGconn object.
+	 */
+	if (conn->errorMessage.len > 0)
+		PGDONOTICE(conn, conn->errorMessage.data);
+
+	PQclear(result);
+
+	return 1;
+}
+
+
+/*
+ * PQfn - Send a function call to the POSTGRES backend.
+ *
+ * See fe-exec.c for documentation.
+ */
+PGresult *
+pqFunctionCall3(PGconn *conn, Oid fnid,
+				int *result_buf, int *actual_result_len,
+				int result_is_int,
+				const PQArgBlock *args, int nargs)
+{
+	bool		needInput = false;
+	ExecStatusType status = PGRES_FATAL_ERROR;
+	char		id;
+	int			msgLength;
+	int			avail;
+	int			i;
+
+	/* PQfn already validated connection state */
+
+	if (pqPutMsgStart('F', false, conn) < 0 || /* function call msg */
+		pqPutInt(fnid, 4, conn) < 0 ||		/* function id */
+		pqPutInt(1, 2, conn) < 0 ||			/* # of format codes */
+		pqPutInt(1, 2, conn) < 0 ||			/* format code: BINARY */
+		pqPutInt(nargs, 2, conn) < 0)		/* # of args */
+	{
+		pqHandleSendFailure(conn);
+		return NULL;
+	}
+
+	for (i = 0; i < nargs; ++i)
+	{							/* len.int4 + contents	   */
+		if (pqPutInt(args[i].len, 4, conn))
+		{
+			pqHandleSendFailure(conn);
+			return NULL;
+		}
+		if (args[i].len == -1)
+			continue;			/* it's NULL */
+
+		if (args[i].isint)
+		{
+			if (pqPutInt(args[i].u.integer, args[i].len, conn))
+			{
+				pqHandleSendFailure(conn);
+				return NULL;
+			}
+		}
+		else
+		{
+			if (pqPutnchar((char *) args[i].u.ptr, args[i].len, conn))
+			{
+				pqHandleSendFailure(conn);
+				return NULL;
+			}
+		}
+	}
+
+	if (pqPutInt(1, 2, conn) < 0)		/* result format code: BINARY */
+	{
+		pqHandleSendFailure(conn);
+		return NULL;
+	}
+
+	if (pqPutMsgEnd(conn) < 0 ||
+		pqFlush(conn))
+	{
+		pqHandleSendFailure(conn);
+		return NULL;
+	}
+
+	for (;;)
+	{
+		if (needInput)
+		{
+			/* Wait for some data to arrive (or for the channel to close) */
+			if (pqWait(TRUE, FALSE, conn) ||
+				pqReadData(conn) < 0)
+				break;
+		}
+
+		/*
+		 * Scan the message. If we run out of data, loop around to try
+		 * again.
+		 */
+		needInput = true;
+
+		conn->inCursor = conn->inStart;
+		if (pqGetc(&id, conn))
+			continue;
+		if (pqGetInt(&msgLength, 4, conn))
+			continue;
+
+		/*
+		 * Try to validate message type/length here.  A length less than 4
+		 * is definitely broken.  Large lengths should only be believed
+		 * for a few message types.
+		 */
+		if (msgLength < 4)
+		{
+			handleSyncLoss(conn, id, msgLength);
+			break;
+		}
+		if (msgLength > 30000 &&
+			!(id == 'T' || id == 'D' || id == 'd' || id == 'V'))
+		{
+			handleSyncLoss(conn, id, msgLength);
+			break;
+		}
+
+		/*
+		 * Can't process if message body isn't all here yet.
+		 */
+		msgLength -= 4;
+		avail = conn->inEnd - conn->inCursor;
+		if (avail < msgLength)
+		{
+			/*
+			 * Before looping, enlarge the input buffer if needed to hold
+			 * the whole message.  See notes in parseInput.
+			 */
+			if (pqCheckInBufferSpace(conn->inCursor + msgLength, conn))
+			{
+				/*
+				 * XXX add some better recovery code... plan is to skip
+				 * over the message using its length, then report an error.
+				 * For the moment, just treat this like loss of sync (which
+				 * indeed it might be!)
+				 */
+				handleSyncLoss(conn, id, msgLength);
+				break;
+			}
+			continue;
+		}
+
+		/*
+		 * We should see V or E response to the command, but might get N
+		 * and/or A notices first. We also need to swallow the final Z
+		 * before returning.
+		 */
+		switch (id)
+		{
+			case 'V':			/* function result */
+				if (pqGetInt(actual_result_len, 4, conn))
+					continue;
+				if (*actual_result_len != -1)
+				{
+					if (result_is_int)
+					{
+						if (pqGetInt(result_buf, *actual_result_len, conn))
+							continue;
+					}
+					else
+					{
+						if (pqGetnchar((char *) result_buf,
+									   *actual_result_len,
+									   conn))
+							continue;
+					}
+				}
+				/* correctly finished function result message */
+				status = PGRES_COMMAND_OK;
+				break;
+			case 'E':			/* error return */
+				if (pqGetErrorNotice3(conn, true))
+					continue;
+				status = PGRES_FATAL_ERROR;
+				break;
+			case 'A':			/* notify message */
+				/* handle notify and go back to processing return values */
+				if (getNotify(conn))
+					continue;
+				break;
+			case 'N':			/* notice */
+				/* handle notice and go back to processing return values */
+				if (pqGetErrorNotice3(conn, false))
+					continue;
+				break;
+			case 'Z':			/* backend is ready for new query */
+				if (pqGetc(&conn->xact_status, conn))
+					continue;
+				/* consume the message and exit */
+				conn->inStart += 5 + msgLength;
+				/* if we saved a result object (probably an error), use it */
+				if (conn->result)
+					return pqPrepareAsyncResult(conn);
+				return PQmakeEmptyPGresult(conn, status);
+			case 'S':			/* parameter status */
+				if (getParameterStatus(conn))
+					continue;
+				break;
+			default:
+				/* The backend violates the protocol. */
+				printfPQExpBuffer(&conn->errorMessage,
+							  libpq_gettext("protocol error: id=0x%x\n"),
+								  id);
+				pqSaveErrorResult(conn);
+				/* trust the specified message length as what to skip */
+				conn->inStart += 5 + msgLength;
+				return pqPrepareAsyncResult(conn);
+		}
+		/* Completed this message, keep going */
+		/* trust the specified message length as what to skip */
+		conn->inStart += 5 + msgLength;
+		needInput = false;
+	}
+
+	/*
+	 * We fall out of the loop only upon failing to read data.
+	 * conn->errorMessage has been set by pqWait or pqReadData. We want to
+	 * append it to any already-received error message.
+	 */
+	pqSaveErrorResult(conn);
+	return pqPrepareAsyncResult(conn);
+}
+
+
+/*
+ * Construct startup packet
+ *
+ * Returns a malloc'd packet buffer, or NULL if out of memory
+ */
+char *
+pqBuildStartupPacket3(PGconn *conn, int *packetlen,
+					  const PQEnvironmentOption *options)
+{
+	char   *startpacket;
+
+	*packetlen = build_startup_packet(conn, NULL, options);
+	startpacket = (char *) malloc(*packetlen);
+	if (!startpacket)
+		return NULL;
+	*packetlen = build_startup_packet(conn, startpacket, options);
+	return startpacket;
+}
+
+/*
+ * Build a startup packet given a filled-in PGconn structure.
+ *
+ * We need to figure out how much space is needed, then fill it in.
+ * To avoid duplicate logic, this routine is called twice: the first time
+ * (with packet == NULL) just counts the space needed, the second time
+ * (with packet == allocated space) fills it in.  Return value is the number
+ * of bytes used.
+ */
+static int
+build_startup_packet(const PGconn *conn, char *packet,
+					 const PQEnvironmentOption *options)
+{
+	int		packet_len = 0;
+	const PQEnvironmentOption *next_eo;
+
+	/* Protocol version comes first. */
+	if (packet)
+	{
+		ProtocolVersion pv = htonl(conn->pversion);
+
+		memcpy(packet + packet_len, &pv, sizeof(ProtocolVersion));
+	}
+	packet_len += sizeof(ProtocolVersion);
+
+	/* Add user name, database name, options */
+	if (conn->pguser && conn->pguser[0])
+	{
+		if (packet)
+			strcpy(packet + packet_len, "user");
+		packet_len += strlen("user") + 1;
+		if (packet)
+			strcpy(packet + packet_len, conn->pguser);
+		packet_len += strlen(conn->pguser) + 1;
+	}
+	if (conn->dbName && conn->dbName[0])
+	{
+		if (packet)
+			strcpy(packet + packet_len, "database");
+		packet_len += strlen("database") + 1;
+		if (packet)
+			strcpy(packet + packet_len, conn->dbName);
+		packet_len += strlen(conn->dbName) + 1;
+	}
+	if (conn->pgoptions && conn->pgoptions[0])
+	{
+		if (packet)
+			strcpy(packet + packet_len, "options");
+		packet_len += strlen("options") + 1;
+		if (packet)
+			strcpy(packet + packet_len, conn->pgoptions);
+		packet_len += strlen(conn->pgoptions) + 1;
+	}
+
+	/* Add any environment-driven GUC settings needed */
+	for (next_eo = options; next_eo->envName; next_eo++)
+	{
+		const char *val;
+
+		if ((val = getenv(next_eo->envName)) != NULL)
+		{
+			if (strcasecmp(val, "default") != 0)
+			{
+				if (packet)
+					strcpy(packet + packet_len, next_eo->pgName);
+				packet_len += strlen(next_eo->pgName) + 1;
+				if (packet)
+					strcpy(packet + packet_len, val);
+				packet_len += strlen(val) + 1;
+			}
+		}
+	}
+
+	/* Add trailing terminator */
+	if (packet)
+		packet[packet_len] = '\0';
+	packet_len++;
+
+	return packet_len;
+}