From 9c830e9dd22485f8f8990ae811875a4971552133 Mon Sep 17 00:00:00 2001 From: Peifeng Qiu Date: Thu, 27 Mar 2025 16:01:23 +0800 Subject: [PATCH] Extensible user mapping handler Add the following syntax: CREATE USER MAPPING FOR user_name SERVER server_name [ USING user_mapping_handler ] [ OPTIONS ( ... ) ] When "user_mapping_handler" is present, options of a user mapping is retrieved through this function. The extension "dummy_um" is a proof of concept for this. A basic test using postgres_fdw is also included. --- contrib/dummy_um/Makefile | 11 ++++++++ contrib/dummy_um/dummy_um--1.0.sql | 4 +++ contrib/dummy_um/dummy_um.c | 23 +++++++++++++++++ contrib/dummy_um/dummy_um.control | 4 +++ contrib/dummy_um/expected/basic.out | 35 +++++++++++++++++++++++++ contrib/dummy_um/sql/basic.sql | 37 +++++++++++++++++++++++++++ src/backend/commands/foreigncmds.c | 16 +++++++++++- src/backend/foreign/foreign.c | 13 ++++++++-- src/backend/parser/gram.y | 12 +++++++-- src/include/catalog/pg_user_mapping.h | 1 + src/include/nodes/parsenodes.h | 1 + 11 files changed, 152 insertions(+), 5 deletions(-) create mode 100644 contrib/dummy_um/Makefile create mode 100644 contrib/dummy_um/dummy_um--1.0.sql create mode 100644 contrib/dummy_um/dummy_um.c create mode 100644 contrib/dummy_um/dummy_um.control create mode 100644 contrib/dummy_um/expected/basic.out create mode 100644 contrib/dummy_um/sql/basic.sql diff --git a/contrib/dummy_um/Makefile b/contrib/dummy_um/Makefile new file mode 100644 index 00000000000..808935e82ac --- /dev/null +++ b/contrib/dummy_um/Makefile @@ -0,0 +1,11 @@ +# Makefile for the dummy_um PostgreSQL extension + +MODULES = dummy_um +EXTENSION = dummy_um +DATA = dummy_um--1.0.sql +PG_CONFIG = pg_config +PGXS = $(shell $(PG_CONFIG) --pgxs) +REGRESS = basic +include $(PGXS) + +# Additional build instructions can be added here if necessary. \ No newline at end of file diff --git a/contrib/dummy_um/dummy_um--1.0.sql b/contrib/dummy_um/dummy_um--1.0.sql new file mode 100644 index 00000000000..aed8f7e9a80 --- /dev/null +++ b/contrib/dummy_um/dummy_um--1.0.sql @@ -0,0 +1,4 @@ +CREATE FUNCTION dummy_user_mapping_handler(um internal) +RETURNS internal +AS 'MODULE_PATHNAME' +LANGUAGE C STRICT; \ No newline at end of file diff --git a/contrib/dummy_um/dummy_um.c b/contrib/dummy_um/dummy_um.c new file mode 100644 index 00000000000..79036a1f865 --- /dev/null +++ b/contrib/dummy_um/dummy_um.c @@ -0,0 +1,23 @@ +#include "postgres.h" +#include "fmgr.h" +#include "foreign/foreign.h" +#include "nodes/makefuncs.h" + +PG_MODULE_MAGIC; + +PG_FUNCTION_INFO_V1(dummy_user_mapping_handler); + +Datum +dummy_user_mapping_handler(PG_FUNCTION_ARGS) +{ + UserMapping *um = (UserMapping *)PG_GETARG_POINTER(0); + List *options = NIL; + + /* handler can use the options from catalog */ + (void)um->options; + + options = lappend(options, makeDefElem("user", (Node *)makeString("dummy_test"), -1)); + options = lappend(options, makeDefElem("password", (Node *)makeString("123"), -1)); + + PG_RETURN_POINTER(options); +} \ No newline at end of file diff --git a/contrib/dummy_um/dummy_um.control b/contrib/dummy_um/dummy_um.control new file mode 100644 index 00000000000..6f90bc27942 --- /dev/null +++ b/contrib/dummy_um/dummy_um.control @@ -0,0 +1,4 @@ +# dummy_um.control file contents +default_version = '1.0' +module_pathname = '$libdir/dummy_um' +relocatable = true diff --git a/contrib/dummy_um/expected/basic.out b/contrib/dummy_um/expected/basic.out new file mode 100644 index 00000000000..143807b9ccc --- /dev/null +++ b/contrib/dummy_um/expected/basic.out @@ -0,0 +1,35 @@ +CREATE EXTENSION dummy_um; +CREATE EXTENSION postgres_fdw; +CREATE USER dummy_test LOGIN PASSWORD '1234'; +CREATE SCHEMA AUTHORIZATION dummy_test; +CREATE TABLE dummy_test.dummy_table ( + id SERIAL PRIMARY KEY, + name VARCHAR(255) NOT NULL +); +INSERT INTO dummy_test.dummy_table (name) VALUES ('dummy'); +GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA dummy_test TO dummy_test; +DO $d$ + BEGIN + EXECUTE $$CREATE SERVER loopback FOREIGN DATA WRAPPER postgres_fdw + OPTIONS (dbname '$$||current_database()||$$', + host '127.0.0.1', + port '$$||current_setting('port')||$$' + )$$; + END; +$d$; +CREATE USER MAPPING FOR CURRENT_USER SERVER loopback +USING dummy_user_mapping_handler +OPTIONS (id 'xxx'); +CREATE FOREIGN TABLE dummy_table_fdw ( + id int NOT NULL, + name VARCHAR(255) NOT NULL +) SERVER loopback OPTIONS (schema_name 'dummy_test', table_name 'dummy_table'); +SELECT * FROM dummy_table_fdw; + id | name +----+------- + 1 | dummy +(1 row) + +DROP SCHEMA dummy_test CASCADE; +NOTICE: drop cascades to table dummy_test.dummy_table +DROP USER dummy_test; diff --git a/contrib/dummy_um/sql/basic.sql b/contrib/dummy_um/sql/basic.sql new file mode 100644 index 00000000000..cc1cd729ccd --- /dev/null +++ b/contrib/dummy_um/sql/basic.sql @@ -0,0 +1,37 @@ +CREATE EXTENSION dummy_um; +CREATE EXTENSION postgres_fdw; +CREATE USER dummy_test LOGIN PASSWORD '1234'; +CREATE SCHEMA AUTHORIZATION dummy_test; + +CREATE TABLE dummy_test.dummy_table ( + id SERIAL PRIMARY KEY, + name VARCHAR(255) NOT NULL +); + +INSERT INTO dummy_test.dummy_table (name) VALUES ('dummy'); +GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA dummy_test TO dummy_test; + + +DO $d$ + BEGIN + EXECUTE $$CREATE SERVER loopback FOREIGN DATA WRAPPER postgres_fdw + OPTIONS (dbname '$$||current_database()||$$', + host '127.0.0.1', + port '$$||current_setting('port')||$$' + )$$; + END; +$d$; + +CREATE USER MAPPING FOR CURRENT_USER SERVER loopback +USING dummy_user_mapping_handler +OPTIONS (id 'xxx'); + +CREATE FOREIGN TABLE dummy_table_fdw ( + id int NOT NULL, + name VARCHAR(255) NOT NULL +) SERVER loopback OPTIONS (schema_name 'dummy_test', table_name 'dummy_table'); + +SELECT * FROM dummy_table_fdw; + +DROP SCHEMA dummy_test CASCADE; +DROP USER dummy_test; \ No newline at end of file diff --git a/src/backend/commands/foreigncmds.c b/src/backend/commands/foreigncmds.c index c14e038d54f..25d7bc24646 100644 --- a/src/backend/commands/foreigncmds.c +++ b/src/backend/commands/foreigncmds.c @@ -1111,6 +1111,8 @@ CreateUserMapping(CreateUserMappingStmt *stmt) ForeignServer *srv; ForeignDataWrapper *fdw; RoleSpec *role = (RoleSpec *) stmt->user; + Oid umHandler; + Oid fdwvalidator; rel = table_open(UserMappingRelationId, RowExclusiveLock); @@ -1157,6 +1159,17 @@ CreateUserMapping(CreateUserMappingStmt *stmt) } fdw = GetForeignDataWrapper(srv->fdwid); + if (stmt->um_handler) + { + umHandler = DatumGetObjectId(DirectFunctionCall1(regprocin, + CStringGetDatum(stmt->um_handler))); + fdwvalidator = InvalidOid; + } + else + { + umHandler = InvalidOid; + fdwvalidator = fdw->fdwvalidator; + } /* * Insert tuple into pg_user_mapping. @@ -1169,12 +1182,13 @@ CreateUserMapping(CreateUserMappingStmt *stmt) values[Anum_pg_user_mapping_oid - 1] = ObjectIdGetDatum(umId); values[Anum_pg_user_mapping_umuser - 1] = ObjectIdGetDatum(useId); values[Anum_pg_user_mapping_umserver - 1] = ObjectIdGetDatum(srv->serverid); + values[Anum_pg_user_mapping_umhandler - 1] = ObjectIdGetDatum(umHandler); /* Add user options */ useoptions = transformGenericOptions(UserMappingRelationId, PointerGetDatum(NULL), stmt->options, - fdw->fdwvalidator); + fdwvalidator); if (PointerIsValid(DatumGetPointer(useoptions))) values[Anum_pg_user_mapping_umoptions - 1] = useoptions; diff --git a/src/backend/foreign/foreign.c b/src/backend/foreign/foreign.c index f0835fc3070..2e066efea24 100644 --- a/src/backend/foreign/foreign.c +++ b/src/backend/foreign/foreign.c @@ -203,6 +203,7 @@ GetUserMapping(Oid userid, Oid serverid) HeapTuple tp; bool isnull; UserMapping *um; + Form_pg_user_mapping form_um; tp = SearchSysCache2(USERMAPPINGUSERSERVER, ObjectIdGetDatum(userid), @@ -225,12 +226,14 @@ GetUserMapping(Oid userid, Oid serverid) errmsg("user mapping not found for user \"%s\", server \"%s\"", MappingUserName(userid), server->servername))); } - + form_um = (Form_pg_user_mapping) GETSTRUCT(tp); um = (UserMapping *) palloc(sizeof(UserMapping)); - um->umid = ((Form_pg_user_mapping) GETSTRUCT(tp))->oid; + um->umid = (form_um)->oid; um->userid = userid; um->serverid = serverid; + + /* Extract the umoptions */ datum = SysCacheGetAttr(USERMAPPINGUSERSERVER, tp, @@ -241,6 +244,12 @@ GetUserMapping(Oid userid, Oid serverid) else um->options = untransformRelOptions(datum); + if (OidIsValid(form_um->umhandler)) + { + /* custom user mapping handler exist, override options */ + Datum result = OidFunctionCall1(form_um->umhandler, PointerGetDatum(um)); + um->options = (List *)result; + } ReleaseSysCache(tp); return um; diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 271ae26cbaf..cf130ed6f66 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -382,6 +382,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); access_method_clause attr_name table_access_method_clause name cursor_name file_name cluster_index_specification + user_mapping_handler %type func_name handler_name qual_Op qual_all_Op subquery_Op opt_inline_handler opt_validator validator_clause @@ -5812,13 +5813,14 @@ import_qualification: * *****************************************************************************/ -CreateUserMappingStmt: CREATE USER MAPPING FOR auth_ident SERVER name create_generic_options +CreateUserMappingStmt: CREATE USER MAPPING FOR auth_ident SERVER name user_mapping_handler create_generic_options { CreateUserMappingStmt *n = makeNode(CreateUserMappingStmt); n->user = $5; n->servername = $7; - n->options = $8; + n->um_handler = $8; + n->options = $9; n->if_not_exists = false; $$ = (Node *) n; } @@ -5839,6 +5841,12 @@ auth_ident: RoleSpec { $$ = $1; } | USER { $$ = makeRoleSpec(ROLESPEC_CURRENT_USER, @1); } ; +/* Custom user mapping handler */ +user_mapping_handler: + USING name { $$ = $2; } + | /*EMPTY*/ { $$ = NULL; } + ; + /***************************************************************************** * * QUERY : diff --git a/src/include/catalog/pg_user_mapping.h b/src/include/catalog/pg_user_mapping.h index 7a0465c4d97..158c088ee90 100644 --- a/src/include/catalog/pg_user_mapping.h +++ b/src/include/catalog/pg_user_mapping.h @@ -34,6 +34,7 @@ CATALOG(pg_user_mapping,1418,UserMappingRelationId) * wanted */ Oid umserver BKI_LOOKUP(pg_foreign_server); /* server of this * mapping */ + Oid umhandler BKI_LOOKUP_OPT(pg_proc); /* Id of the handler */ #ifdef CATALOG_VARLEN /* variable-length fields start here */ text umoptions[1]; /* user mapping options */ diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index df331b1c0d9..563c00670c8 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -3001,6 +3001,7 @@ typedef struct CreateUserMappingStmt NodeTag type; RoleSpec *user; /* user role */ char *servername; /* server name */ + char *um_handler; /* custom handler name */ bool if_not_exists; /* just do nothing if it already exists? */ List *options; /* generic options to server */ } CreateUserMappingStmt; -- 2.34.1