Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 458 insertions, 0 deletions

diff --git a/src/backend/tcop/fastpath.c b/src/backend/tcop/fastpath.c
new file mode 100644
index 0000000..6343dd2
--- /dev/null
+++ b/src/backend/tcop/fastpath.c
@@ -0,0 +1,458 @@
+/*-------------------------------------------------------------------------
+ *
+ * fastpath.c
+ *	  routines to handle function requests from the frontend
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/tcop/fastpath.c
+ *
+ * NOTES
+ *	  This cruft is the server side of PQfn.
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/htup_details.h"
+#include "access/xact.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_proc.h"
+#include "libpq/libpq.h"
+#include "libpq/pqformat.h"
+#include "mb/pg_wchar.h"
+#include "miscadmin.h"
+#include "port/pg_bswap.h"
+#include "tcop/fastpath.h"
+#include "tcop/tcopprot.h"
+#include "utils/acl.h"
+#include "utils/lsyscache.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+
+
+/*
+ * Formerly, this code attempted to cache the function and type info
+ * looked up by fetch_fp_info, but only for the duration of a single
+ * transaction command (since in theory the info could change between
+ * commands).  This was utterly useless, because postgres.c executes
+ * each fastpath call as a separate transaction command, and so the
+ * cached data could never actually have been reused.  If it had worked
+ * as intended, it would have had problems anyway with dangling references
+ * in the FmgrInfo struct.  So, forget about caching and just repeat the
+ * syscache fetches on each usage.  They're not *that* expensive.
+ */
+struct fp_info
+{
+	Oid			funcid;
+	FmgrInfo	flinfo;			/* function lookup info for funcid */
+	Oid			namespace;		/* other stuff from pg_proc */
+	Oid			rettype;
+	Oid			argtypes[FUNC_MAX_ARGS];
+	char		fname[NAMEDATALEN]; /* function name for logging */
+};
+
+
+static int16 parse_fcall_arguments(StringInfo msgBuf, struct fp_info *fip,
+								   FunctionCallInfo fcinfo);
+
+/* ----------------
+ *		SendFunctionResult
+ * ----------------
+ */
+static void
+SendFunctionResult(Datum retval, bool isnull, Oid rettype, int16 format)
+{
+	StringInfoData buf;
+
+	pq_beginmessage(&buf, 'V');
+
+	if (isnull)
+	{
+		pq_sendint32(&buf, -1);
+	}
+	else
+	{
+		if (format == 0)
+		{
+			Oid			typoutput;
+			bool		typisvarlena;
+			char	   *outputstr;
+
+			getTypeOutputInfo(rettype, &typoutput, &typisvarlena);
+			outputstr = OidOutputFunctionCall(typoutput, retval);
+			pq_sendcountedtext(&buf, outputstr, strlen(outputstr), false);
+			pfree(outputstr);
+		}
+		else if (format == 1)
+		{
+			Oid			typsend;
+			bool		typisvarlena;
+			bytea	   *outputbytes;
+
+			getTypeBinaryOutputInfo(rettype, &typsend, &typisvarlena);
+			outputbytes = OidSendFunctionCall(typsend, retval);
+			pq_sendint32(&buf, VARSIZE(outputbytes) - VARHDRSZ);
+			pq_sendbytes(&buf, VARDATA(outputbytes),
+						 VARSIZE(outputbytes) - VARHDRSZ);
+			pfree(outputbytes);
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("unsupported format code: %d", format)));
+	}
+
+	pq_endmessage(&buf);
+}
+
+/*
+ * fetch_fp_info
+ *
+ * Performs catalog lookups to load a struct fp_info 'fip' for the
+ * function 'func_id'.
+ */
+static void
+fetch_fp_info(Oid func_id, struct fp_info *fip)
+{
+	HeapTuple	func_htp;
+	Form_pg_proc pp;
+
+	Assert(fip != NULL);
+
+	/*
+	 * Since the validity of this structure is determined by whether the
+	 * funcid is OK, we clear the funcid here.  It must not be set to the
+	 * correct value until we are about to return with a good struct fp_info,
+	 * since we can be interrupted (i.e., with an ereport(ERROR, ...)) at any
+	 * time.  [No longer really an issue since we don't save the struct
+	 * fp_info across transactions anymore, but keep it anyway.]
+	 */
+	MemSet(fip, 0, sizeof(struct fp_info));
+	fip->funcid = InvalidOid;
+
+	func_htp = SearchSysCache1(PROCOID, ObjectIdGetDatum(func_id));
+	if (!HeapTupleIsValid(func_htp))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_FUNCTION),
+				 errmsg("function with OID %u does not exist", func_id)));
+	pp = (Form_pg_proc) GETSTRUCT(func_htp);
+
+	/* reject pg_proc entries that are unsafe to call via fastpath */
+	if (pp->prokind != PROKIND_FUNCTION || pp->proretset)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot call function \"%s\" via fastpath interface",
+						NameStr(pp->proname))));
+
+	/* watch out for catalog entries with more than FUNC_MAX_ARGS args */
+	if (pp->pronargs > FUNC_MAX_ARGS)
+		elog(ERROR, "function %s has more than %d arguments",
+			 NameStr(pp->proname), FUNC_MAX_ARGS);
+
+	fip->namespace = pp->pronamespace;
+	fip->rettype = pp->prorettype;
+	memcpy(fip->argtypes, pp->proargtypes.values, pp->pronargs * sizeof(Oid));
+	strlcpy(fip->fname, NameStr(pp->proname), NAMEDATALEN);
+
+	ReleaseSysCache(func_htp);
+
+	fmgr_info(func_id, &fip->flinfo);
+
+	/*
+	 * This must be last!
+	 */
+	fip->funcid = func_id;
+}
+
+
+/*
+ * HandleFunctionRequest
+ *
+ * Server side of PQfn (fastpath function calls from the frontend).
+ * This corresponds to the libpq protocol symbol "F".
+ *
+ * INPUT:
+ *		postgres.c has already read the message body and will pass it in
+ *		msgBuf.
+ *
+ * Note: palloc()s done here and in the called function do not need to be
+ * cleaned up explicitly.  We are called from PostgresMain() in the
+ * MessageContext memory context, which will be automatically reset when
+ * control returns to PostgresMain.
+ */
+void
+HandleFunctionRequest(StringInfo msgBuf)
+{
+	LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
+	Oid			fid;
+	AclResult	aclresult;
+	int16		rformat;
+	Datum		retval;
+	struct fp_info my_fp;
+	struct fp_info *fip;
+	bool		callit;
+	bool		was_logged = false;
+	char		msec_str[32];
+
+	/*
+	 * We only accept COMMIT/ABORT if we are in an aborted transaction, and
+	 * COMMIT/ABORT cannot be executed through the fastpath interface.
+	 */
+	if (IsAbortedTransactionBlockState())
+		ereport(ERROR,
+				(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
+				 errmsg("current transaction is aborted, "
+						"commands ignored until end of transaction block")));
+
+	/*
+	 * Now that we know we are in a valid transaction, set snapshot in case
+	 * needed by function itself or one of the datatype I/O routines.
+	 */
+	PushActiveSnapshot(GetTransactionSnapshot());
+
+	/*
+	 * Begin parsing the buffer contents.
+	 */
+	fid = (Oid) pq_getmsgint(msgBuf, 4);	/* function oid */
+
+	/*
+	 * There used to be a lame attempt at caching lookup info here. Now we
+	 * just do the lookups on every call.
+	 */
+	fip = &my_fp;
+	fetch_fp_info(fid, fip);
+
+	/* Log as soon as we have the function OID and name */
+	if (log_statement == LOGSTMT_ALL)
+	{
+		ereport(LOG,
+				(errmsg("fastpath function call: \"%s\" (OID %u)",
+						fip->fname, fid)));
+		was_logged = true;
+	}
+
+	/*
+	 * Check permission to access and call function.  Since we didn't go
+	 * through a normal name lookup, we need to check schema usage too.
+	 */
+	aclresult = pg_namespace_aclcheck(fip->namespace, GetUserId(), ACL_USAGE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, OBJECT_SCHEMA,
+					   get_namespace_name(fip->namespace));
+	InvokeNamespaceSearchHook(fip->namespace, true);
+
+	aclresult = pg_proc_aclcheck(fid, GetUserId(), ACL_EXECUTE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, OBJECT_FUNCTION,
+					   get_func_name(fid));
+	InvokeFunctionExecuteHook(fid);
+
+	/*
+	 * Prepare function call info block and insert arguments.
+	 *
+	 * Note: for now we pass collation = InvalidOid, so collation-sensitive
+	 * functions can't be called this way.  Perhaps we should pass
+	 * DEFAULT_COLLATION_OID, instead?
+	 */
+	InitFunctionCallInfoData(*fcinfo, &fip->flinfo, 0, InvalidOid, NULL, NULL);
+
+	rformat = parse_fcall_arguments(msgBuf, fip, fcinfo);
+
+	/* Verify we reached the end of the message where expected. */
+	pq_getmsgend(msgBuf);
+
+	/*
+	 * If func is strict, must not call it for null args.
+	 */
+	callit = true;
+	if (fip->flinfo.fn_strict)
+	{
+		int			i;
+
+		for (i = 0; i < fcinfo->nargs; i++)
+		{
+			if (fcinfo->args[i].isnull)
+			{
+				callit = false;
+				break;
+			}
+		}
+	}
+
+	if (callit)
+	{
+		/* Okay, do it ... */
+		retval = FunctionCallInvoke(fcinfo);
+	}
+	else
+	{
+		fcinfo->isnull = true;
+		retval = (Datum) 0;
+	}
+
+	/* ensure we do at least one CHECK_FOR_INTERRUPTS per function call */
+	CHECK_FOR_INTERRUPTS();
+
+	SendFunctionResult(retval, fcinfo->isnull, fip->rettype, rformat);
+
+	/* We no longer need the snapshot */
+	PopActiveSnapshot();
+
+	/*
+	 * Emit duration logging if appropriate.
+	 */
+	switch (check_log_duration(msec_str, was_logged))
+	{
+		case 1:
+			ereport(LOG,
+					(errmsg("duration: %s ms", msec_str)));
+			break;
+		case 2:
+			ereport(LOG,
+					(errmsg("duration: %s ms  fastpath function call: \"%s\" (OID %u)",
+							msec_str, fip->fname, fid)));
+			break;
+	}
+}
+
+/*
+ * Parse function arguments in a 3.0 protocol message
+ *
+ * Argument values are loaded into *fcinfo, and the desired result format
+ * is returned.
+ */
+static int16
+parse_fcall_arguments(StringInfo msgBuf, struct fp_info *fip,
+					  FunctionCallInfo fcinfo)
+{
+	int			nargs;
+	int			i;
+	int			numAFormats;
+	int16	   *aformats = NULL;
+	StringInfoData abuf;
+
+	/* Get the argument format codes */
+	numAFormats = pq_getmsgint(msgBuf, 2);
+	if (numAFormats > 0)
+	{
+		aformats = (int16 *) palloc(numAFormats * sizeof(int16));
+		for (i = 0; i < numAFormats; i++)
+			aformats[i] = pq_getmsgint(msgBuf, 2);
+	}
+
+	nargs = pq_getmsgint(msgBuf, 2);	/* # of arguments */
+
+	if (fip->flinfo.fn_nargs != nargs || nargs > FUNC_MAX_ARGS)
+		ereport(ERROR,
+				(errcode(ERRCODE_PROTOCOL_VIOLATION),
+				 errmsg("function call message contains %d arguments but function requires %d",
+						nargs, fip->flinfo.fn_nargs)));
+
+	fcinfo->nargs = nargs;
+
+	if (numAFormats > 1 && numAFormats != nargs)
+		ereport(ERROR,
+				(errcode(ERRCODE_PROTOCOL_VIOLATION),
+				 errmsg("function call message contains %d argument formats but %d arguments",
+						numAFormats, nargs)));
+
+	initStringInfo(&abuf);
+
+	/*
+	 * Copy supplied arguments into arg vector.
+	 */
+	for (i = 0; i < nargs; ++i)
+	{
+		int			argsize;
+		int16		aformat;
+
+		argsize = pq_getmsgint(msgBuf, 4);
+		if (argsize == -1)
+		{
+			fcinfo->args[i].isnull = true;
+		}
+		else
+		{
+			fcinfo->args[i].isnull = false;
+			if (argsize < 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_PROTOCOL_VIOLATION),
+						 errmsg("invalid argument size %d in function call message",
+								argsize)));
+
+			/* Reset abuf to empty, and insert raw data into it */
+			resetStringInfo(&abuf);
+			appendBinaryStringInfo(&abuf,
+								   pq_getmsgbytes(msgBuf, argsize),
+								   argsize);
+		}
+
+		if (numAFormats > 1)
+			aformat = aformats[i];
+		else if (numAFormats > 0)
+			aformat = aformats[0];
+		else
+			aformat = 0;		/* default = text */
+
+		if (aformat == 0)
+		{
+			Oid			typinput;
+			Oid			typioparam;
+			char	   *pstring;
+
+			getTypeInputInfo(fip->argtypes[i], &typinput, &typioparam);
+
+			/*
+			 * Since stringinfo.c keeps a trailing null in place even for
+			 * binary data, the contents of abuf are a valid C string.  We
+			 * have to do encoding conversion before calling the typinput
+			 * routine, though.
+			 */
+			if (argsize == -1)
+				pstring = NULL;
+			else
+				pstring = pg_client_to_server(abuf.data, argsize);
+
+			fcinfo->args[i].value = OidInputFunctionCall(typinput, pstring,
+														 typioparam, -1);
+			/* Free result of encoding conversion, if any */
+			if (pstring && pstring != abuf.data)
+				pfree(pstring);
+		}
+		else if (aformat == 1)
+		{
+			Oid			typreceive;
+			Oid			typioparam;
+			StringInfo	bufptr;
+
+			/* Call the argument type's binary input converter */
+			getTypeBinaryInputInfo(fip->argtypes[i], &typreceive, &typioparam);
+
+			if (argsize == -1)
+				bufptr = NULL;
+			else
+				bufptr = &abuf;
+
+			fcinfo->args[i].value = OidReceiveFunctionCall(typreceive, bufptr,
+														   typioparam, -1);
+
+			/* Trouble if it didn't eat the whole buffer */
+			if (argsize != -1 && abuf.cursor != abuf.len)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+						 errmsg("incorrect binary data format in function argument %d",
+								i + 1)));
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("unsupported format code: %d", aformat)));
+	}
+
+	/* Return result format code */
+	return (int16) pq_getmsgint(msgBuf, 2);
+}