Adding upstream version 15.5.upstream/15.5

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

1 files changed, 558 insertions, 0 deletions

diff --git a/contrib/postgres_fdw/option.c b/contrib/postgres_fdw/option.c
new file mode 100644
index 0000000..2e0e8ee
--- /dev/null
+++ b/contrib/postgres_fdw/option.c
@@ -0,0 +1,558 @@
+/*-------------------------------------------------------------------------
+ *
+ * option.c
+ *		  FDW and GUC option handling for postgres_fdw
+ *
+ * Portions Copyright (c) 2012-2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		  contrib/postgres_fdw/option.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/reloptions.h"
+#include "catalog/pg_foreign_server.h"
+#include "catalog/pg_foreign_table.h"
+#include "catalog/pg_user_mapping.h"
+#include "commands/defrem.h"
+#include "commands/extension.h"
+#include "libpq/libpq-be.h"
+#include "postgres_fdw.h"
+#include "utils/builtins.h"
+#include "utils/guc.h"
+#include "utils/varlena.h"
+
+/*
+ * Describes the valid options for objects that this wrapper uses.
+ */
+typedef struct PgFdwOption
+{
+	const char *keyword;
+	Oid			optcontext;		/* OID of catalog in which option may appear */
+	bool		is_libpq_opt;	/* true if it's used in libpq */
+} PgFdwOption;
+
+/*
+ * Valid options for postgres_fdw.
+ * Allocated and filled in InitPgFdwOptions.
+ */
+static PgFdwOption *postgres_fdw_options;
+
+/*
+ * Valid options for libpq.
+ * Allocated and filled in InitPgFdwOptions.
+ */
+static PQconninfoOption *libpq_options;
+
+/*
+ * GUC parameters
+ */
+char	   *pgfdw_application_name = NULL;
+
+void		_PG_init(void);
+
+/*
+ * Helper functions
+ */
+static void InitPgFdwOptions(void);
+static bool is_valid_option(const char *keyword, Oid context);
+static bool is_libpq_option(const char *keyword);
+
+#include "miscadmin.h"
+
+/*
+ * Validate the generic options given to a FOREIGN DATA WRAPPER, SERVER,
+ * USER MAPPING or FOREIGN TABLE that uses postgres_fdw.
+ *
+ * Raise an ERROR if the option or its value is considered invalid.
+ */
+PG_FUNCTION_INFO_V1(postgres_fdw_validator);
+
+Datum
+postgres_fdw_validator(PG_FUNCTION_ARGS)
+{
+	List	   *options_list = untransformRelOptions(PG_GETARG_DATUM(0));
+	Oid			catalog = PG_GETARG_OID(1);
+	ListCell   *cell;
+
+	/* Build our options lists if we didn't yet. */
+	InitPgFdwOptions();
+
+	/*
+	 * Check that only options supported by postgres_fdw, and allowed for the
+	 * current object type, are given.
+	 */
+	foreach(cell, options_list)
+	{
+		DefElem    *def = (DefElem *) lfirst(cell);
+
+		if (!is_valid_option(def->defname, catalog))
+		{
+			/*
+			 * Unknown option specified, complain about it. Provide a hint
+			 * with list of valid options for the object.
+			 */
+			PgFdwOption *opt;
+			StringInfoData buf;
+
+			initStringInfo(&buf);
+			for (opt = postgres_fdw_options; opt->keyword; opt++)
+			{
+				if (catalog == opt->optcontext)
+					appendStringInfo(&buf, "%s%s", (buf.len > 0) ? ", " : "",
+									 opt->keyword);
+			}
+
+			ereport(ERROR,
+					(errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
+					 errmsg("invalid option \"%s\"", def->defname),
+					 buf.len > 0
+					 ? errhint("Valid options in this context are: %s",
+							   buf.data)
+					 : errhint("There are no valid options in this context.")));
+		}
+
+		/*
+		 * Validate option value, when we can do so without any context.
+		 */
+		if (strcmp(def->defname, "use_remote_estimate") == 0 ||
+			strcmp(def->defname, "updatable") == 0 ||
+			strcmp(def->defname, "truncatable") == 0 ||
+			strcmp(def->defname, "async_capable") == 0 ||
+			strcmp(def->defname, "parallel_commit") == 0 ||
+			strcmp(def->defname, "keep_connections") == 0)
+		{
+			/* these accept only boolean values */
+			(void) defGetBoolean(def);
+		}
+		else if (strcmp(def->defname, "fdw_startup_cost") == 0 ||
+				 strcmp(def->defname, "fdw_tuple_cost") == 0)
+		{
+			/*
+			 * These must have a floating point value greater than or equal to
+			 * zero.
+			 */
+			char	   *value;
+			double		real_val;
+			bool		is_parsed;
+
+			value = defGetString(def);
+			is_parsed = parse_real(value, &real_val, 0, NULL);
+
+			if (!is_parsed)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("invalid value for floating point option \"%s\": %s",
+								def->defname, value)));
+
+			if (real_val < 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("\"%s\" must be a floating point value greater than or equal to zero",
+								def->defname)));
+		}
+		else if (strcmp(def->defname, "extensions") == 0)
+		{
+			/* check list syntax, warn about uninstalled extensions */
+			(void) ExtractExtensionList(defGetString(def), true);
+		}
+		else if (strcmp(def->defname, "fetch_size") == 0 ||
+				 strcmp(def->defname, "batch_size") == 0)
+		{
+			char	   *value;
+			int			int_val;
+			bool		is_parsed;
+
+			value = defGetString(def);
+			is_parsed = parse_int(value, &int_val, 0, NULL);
+
+			if (!is_parsed)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("invalid value for integer option \"%s\": %s",
+								def->defname, value)));
+
+			if (int_val <= 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("\"%s\" must be an integer value greater than zero",
+								def->defname)));
+		}
+		else if (strcmp(def->defname, "password_required") == 0)
+		{
+			bool		pw_required = defGetBoolean(def);
+
+			/*
+			 * Only the superuser may set this option on a user mapping, or
+			 * alter a user mapping on which this option is set. We allow a
+			 * user to clear this option if it's set - in fact, we don't have
+			 * a choice since we can't see the old mapping when validating an
+			 * alter.
+			 */
+			if (!superuser() && !pw_required)
+				ereport(ERROR,
+						(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+						 errmsg("password_required=false is superuser-only"),
+						 errhint("User mappings with the password_required option set to false may only be created or modified by the superuser.")));
+		}
+		else if (strcmp(def->defname, "sslcert") == 0 ||
+				 strcmp(def->defname, "sslkey") == 0)
+		{
+			/* similarly for sslcert / sslkey on user mapping */
+			if (catalog == UserMappingRelationId && !superuser())
+				ereport(ERROR,
+						(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+						 errmsg("sslcert and sslkey are superuser-only"),
+						 errhint("User mappings with the sslcert or sslkey options set may only be created or modified by the superuser.")));
+		}
+	}
+
+	PG_RETURN_VOID();
+}
+
+/*
+ * Initialize option lists.
+ */
+static void
+InitPgFdwOptions(void)
+{
+	int			num_libpq_opts;
+	PQconninfoOption *lopt;
+	PgFdwOption *popt;
+
+	/* non-libpq FDW-specific FDW options */
+	static const PgFdwOption non_libpq_options[] = {
+		{"schema_name", ForeignTableRelationId, false},
+		{"table_name", ForeignTableRelationId, false},
+		{"column_name", AttributeRelationId, false},
+		/* use_remote_estimate is available on both server and table */
+		{"use_remote_estimate", ForeignServerRelationId, false},
+		{"use_remote_estimate", ForeignTableRelationId, false},
+		/* cost factors */
+		{"fdw_startup_cost", ForeignServerRelationId, false},
+		{"fdw_tuple_cost", ForeignServerRelationId, false},
+		/* shippable extensions */
+		{"extensions", ForeignServerRelationId, false},
+		/* updatable is available on both server and table */
+		{"updatable", ForeignServerRelationId, false},
+		{"updatable", ForeignTableRelationId, false},
+		/* truncatable is available on both server and table */
+		{"truncatable", ForeignServerRelationId, false},
+		{"truncatable", ForeignTableRelationId, false},
+		/* fetch_size is available on both server and table */
+		{"fetch_size", ForeignServerRelationId, false},
+		{"fetch_size", ForeignTableRelationId, false},
+		/* batch_size is available on both server and table */
+		{"batch_size", ForeignServerRelationId, false},
+		{"batch_size", ForeignTableRelationId, false},
+		/* async_capable is available on both server and table */
+		{"async_capable", ForeignServerRelationId, false},
+		{"async_capable", ForeignTableRelationId, false},
+		{"parallel_commit", ForeignServerRelationId, false},
+		{"keep_connections", ForeignServerRelationId, false},
+		{"password_required", UserMappingRelationId, false},
+
+		/*
+		 * sslcert and sslkey are in fact libpq options, but we repeat them
+		 * here to allow them to appear in both foreign server context (when
+		 * we generate libpq options) and user mapping context (from here).
+		 */
+		{"sslcert", UserMappingRelationId, true},
+		{"sslkey", UserMappingRelationId, true},
+
+		{NULL, InvalidOid, false}
+	};
+
+	/* Prevent redundant initialization. */
+	if (postgres_fdw_options)
+		return;
+
+	/*
+	 * Get list of valid libpq options.
+	 *
+	 * To avoid unnecessary work, we get the list once and use it throughout
+	 * the lifetime of this backend process.  We don't need to care about
+	 * memory context issues, because PQconndefaults allocates with malloc.
+	 */
+	libpq_options = PQconndefaults();
+	if (!libpq_options)			/* assume reason for failure is OOM */
+		ereport(ERROR,
+				(errcode(ERRCODE_FDW_OUT_OF_MEMORY),
+				 errmsg("out of memory"),
+				 errdetail("Could not get libpq's default connection options.")));
+
+	/* Count how many libpq options are available. */
+	num_libpq_opts = 0;
+	for (lopt = libpq_options; lopt->keyword; lopt++)
+		num_libpq_opts++;
+
+	/*
+	 * Construct an array which consists of all valid options for
+	 * postgres_fdw, by appending FDW-specific options to libpq options.
+	 *
+	 * We use plain malloc here to allocate postgres_fdw_options because it
+	 * lives as long as the backend process does.  Besides, keeping
+	 * libpq_options in memory allows us to avoid copying every keyword
+	 * string.
+	 */
+	postgres_fdw_options = (PgFdwOption *)
+		malloc(sizeof(PgFdwOption) * num_libpq_opts +
+			   sizeof(non_libpq_options));
+	if (postgres_fdw_options == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FDW_OUT_OF_MEMORY),
+				 errmsg("out of memory")));
+
+	popt = postgres_fdw_options;
+	for (lopt = libpq_options; lopt->keyword; lopt++)
+	{
+		/* Hide debug options, as well as settings we override internally. */
+		if (strchr(lopt->dispchar, 'D') ||
+			strcmp(lopt->keyword, "fallback_application_name") == 0 ||
+			strcmp(lopt->keyword, "client_encoding") == 0)
+			continue;
+
+		/* We don't have to copy keyword string, as described above. */
+		popt->keyword = lopt->keyword;
+
+		/*
+		 * "user" and any secret options are allowed only on user mappings.
+		 * Everything else is a server option.
+		 */
+		if (strcmp(lopt->keyword, "user") == 0 || strchr(lopt->dispchar, '*'))
+			popt->optcontext = UserMappingRelationId;
+		else
+			popt->optcontext = ForeignServerRelationId;
+		popt->is_libpq_opt = true;
+
+		popt++;
+	}
+
+	/* Append FDW-specific options and dummy terminator. */
+	memcpy(popt, non_libpq_options, sizeof(non_libpq_options));
+}
+
+/*
+ * Check whether the given option is one of the valid postgres_fdw options.
+ * context is the Oid of the catalog holding the object the option is for.
+ */
+static bool
+is_valid_option(const char *keyword, Oid context)
+{
+	PgFdwOption *opt;
+
+	Assert(postgres_fdw_options);	/* must be initialized already */
+
+	for (opt = postgres_fdw_options; opt->keyword; opt++)
+	{
+		if (context == opt->optcontext && strcmp(opt->keyword, keyword) == 0)
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * Check whether the given option is one of the valid libpq options.
+ */
+static bool
+is_libpq_option(const char *keyword)
+{
+	PgFdwOption *opt;
+
+	Assert(postgres_fdw_options);	/* must be initialized already */
+
+	for (opt = postgres_fdw_options; opt->keyword; opt++)
+	{
+		if (opt->is_libpq_opt && strcmp(opt->keyword, keyword) == 0)
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * Generate key-value arrays which include only libpq options from the
+ * given list (which can contain any kind of options).  Caller must have
+ * allocated large-enough arrays.  Returns number of options found.
+ */
+int
+ExtractConnectionOptions(List *defelems, const char **keywords,
+						 const char **values)
+{
+	ListCell   *lc;
+	int			i;
+
+	/* Build our options lists if we didn't yet. */
+	InitPgFdwOptions();
+
+	i = 0;
+	foreach(lc, defelems)
+	{
+		DefElem    *d = (DefElem *) lfirst(lc);
+
+		if (is_libpq_option(d->defname))
+		{
+			keywords[i] = d->defname;
+			values[i] = defGetString(d);
+			i++;
+		}
+	}
+	return i;
+}
+
+/*
+ * Parse a comma-separated string and return a List of the OIDs of the
+ * extensions named in the string.  If any names in the list cannot be
+ * found, report a warning if warnOnMissing is true, else just silently
+ * ignore them.
+ */
+List *
+ExtractExtensionList(const char *extensionsString, bool warnOnMissing)
+{
+	List	   *extensionOids = NIL;
+	List	   *extlist;
+	ListCell   *lc;
+
+	/* SplitIdentifierString scribbles on its input, so pstrdup first */
+	if (!SplitIdentifierString(pstrdup(extensionsString), ',', &extlist))
+	{
+		/* syntax error in name list */
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("parameter \"%s\" must be a list of extension names",
+						"extensions")));
+	}
+
+	foreach(lc, extlist)
+	{
+		const char *extension_name = (const char *) lfirst(lc);
+		Oid			extension_oid = get_extension_oid(extension_name, true);
+
+		if (OidIsValid(extension_oid))
+		{
+			extensionOids = lappend_oid(extensionOids, extension_oid);
+		}
+		else if (warnOnMissing)
+		{
+			ereport(WARNING,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("extension \"%s\" is not installed",
+							extension_name)));
+		}
+	}
+
+	list_free(extlist);
+	return extensionOids;
+}
+
+/*
+ * Replace escape sequences beginning with % character in the given
+ * application_name with status information, and return it.
+ *
+ * This function always returns a palloc'd string, so the caller is
+ * responsible for pfreeing it.
+ */
+char *
+process_pgfdw_appname(const char *appname)
+{
+	const char *p;
+	StringInfoData buf;
+
+	initStringInfo(&buf);
+
+	for (p = appname; *p != '\0'; p++)
+	{
+		if (*p != '%')
+		{
+			/* literal char, just copy */
+			appendStringInfoChar(&buf, *p);
+			continue;
+		}
+
+		/* must be a '%', so skip to the next char */
+		p++;
+		if (*p == '\0')
+			break;				/* format error - ignore it */
+		else if (*p == '%')
+		{
+			/* string contains %% */
+			appendStringInfoChar(&buf, '%');
+			continue;
+		}
+
+		/* process the option */
+		switch (*p)
+		{
+			case 'a':
+				appendStringInfoString(&buf, application_name);
+				break;
+			case 'c':
+				appendStringInfo(&buf, "%lx.%x", (long) (MyStartTime), MyProcPid);
+				break;
+			case 'C':
+				appendStringInfoString(&buf, cluster_name);
+				break;
+			case 'd':
+				if (MyProcPort)
+				{
+					const char *dbname = MyProcPort->database_name;
+
+					if (dbname)
+						appendStringInfoString(&buf, dbname);
+					else
+						appendStringInfoString(&buf, "[unknown]");
+				}
+				break;
+			case 'p':
+				appendStringInfo(&buf, "%d", MyProcPid);
+				break;
+			case 'u':
+				if (MyProcPort)
+				{
+					const char *username = MyProcPort->user_name;
+
+					if (username)
+						appendStringInfoString(&buf, username);
+					else
+						appendStringInfoString(&buf, "[unknown]");
+				}
+				break;
+			default:
+				/* format error - ignore it */
+				break;
+		}
+	}
+
+	return buf.data;
+}
+
+/*
+ * Module load callback
+ */
+void
+_PG_init(void)
+{
+	/*
+	 * Unlike application_name GUC, don't set GUC_IS_NAME flag nor check_hook
+	 * to allow postgres_fdw.application_name to be any string more than
+	 * NAMEDATALEN characters and to include non-ASCII characters. Instead,
+	 * remote server truncates application_name of remote connection to less
+	 * than NAMEDATALEN and replaces any non-ASCII characters in it with a '?'
+	 * character.
+	 */
+	DefineCustomStringVariable("postgres_fdw.application_name",
+							   "Sets the application name to be used on the remote server.",
+							   NULL,
+							   &pgfdw_application_name,
+							   NULL,
+							   PGC_USERSET,
+							   0,
+							   NULL,
+							   NULL,
+							   NULL);
+
+	MarkGUCPrefixReserved("postgres_fdw");
+}