open-dsi
/
postgres
mirror of https://github.com/postgres/postgres
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Add support for using SQL/MED compliant FOREIGN DATA WRAPPER, SERVER,

Browse Source 
and USER MAPPING as method to supply dblink connect parameters. Per
mailing list and PGCon discussions.
REL8_5_ALPHA1_BRANCH
Joe Conway 17 years ago
parent af98bb2ad7
commit 4334695b30
4 changed files with 228 additions and 5 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 104
      contrib/dblink/dblink.c
  2. 43
      contrib/dblink/expected/dblink.out
  3. 25
      contrib/dblink/sql/dblink.sql
  4. 61
      doc/src/sgml/dblink.sgml

104
contrib/dblink/dblink.c
Unescape View File

@ -8,7 +8,7 @@
* Darko Prenosil <Darko.Prenosil@finteh.hr>
* Shridhar Daithankar <shridhar_daithankar@persistent.co.in>
*
* $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.78 2009/06/02 03:21:56 joe Exp $
* $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.79 2009/06/06 21:27:56 joe Exp $
* Copyright (c) 2001-2009, PostgreSQL Global Development Group
* ALL RIGHTS RESERVED;
*
@ -46,6 +46,7 @@
#include "catalog/pg_type.h"
#include "executor/executor.h"
#include "executor/spi.h"
#include "foreign/foreign.h"
#include "lib/stringinfo.h"
#include "miscadmin.h"
#include "nodes/execnodes.h"
@ -96,6 +97,8 @@ static char *generate_relation_name(Oid relid);
static void dblink_connstr_check(const char *connstr);
static void dblink_security_check(PGconn *conn, remoteConn *rconn);
static void dblink_res_error(const char *conname, PGresult *res, const char *dblink_context_msg, bool fail);
static char *get_connect_string(const char *servername);
static char *escape_param_str(const char *from);
/* Global */
static remoteConn *pconn = NULL;
@ -165,7 +168,11 @@ typedef struct remoteConnHashEnt
} \
else \
{ \
connstr = conname_or_str; \
connstr = get_connect_string(conname_or_str); \
if (connstr == NULL) \
{ \
connstr = conname_or_str; \
} \
dblink_connstr_check(connstr); \
conn = PQconnectdb(connstr); \
if (PQstatus(conn) == CONNECTION_BAD) \
@ -210,6 +217,7 @@ PG_FUNCTION_INFO_V1(dblink_connect);
Datum
dblink_connect(PG_FUNCTION_ARGS)
{
char *conname_or_str = NULL;
char *connstr = NULL;
char *connname = NULL;
char *msg;
@ -220,16 +228,21 @@ dblink_connect(PG_FUNCTION_ARGS)
if (PG_NARGS() == 2)
{
connstr = text_to_cstring(PG_GETARG_TEXT_PP(1));
conname_or_str = text_to_cstring(PG_GETARG_TEXT_PP(1));
connname = text_to_cstring(PG_GETARG_TEXT_PP(0));
}
else if (PG_NARGS() == 1)
connstr = text_to_cstring(PG_GETARG_TEXT_PP(0));
conname_or_str = text_to_cstring(PG_GETARG_TEXT_PP(0));
if (connname)
rconn = (remoteConn *) MemoryContextAlloc(TopMemoryContext,
sizeof(remoteConn));
/* first check for valid foreign data server */
connstr = get_connect_string(conname_or_str);
if (connstr == NULL)
connstr = conname_or_str;
/* check password in connection string if not superuser */
dblink_connstr_check(connstr);
conn = PQconnectdb(connstr);
@ -2353,3 +2366,86 @@ dblink_res_error(const char *conname, PGresult *res, const char *dblink_context_
errcontext("Error occurred on dblink connection named \"%s\": %s.",
dblink_context_conname, dblink_context_msg)));
}
/*
* Obtain connection string for a foreign server
*/
static char *
get_connect_string(const char *servername)
{
ForeignServer *foreign_server = NULL;
UserMapping *user_mapping;
ListCell *cell;
StringInfo buf = makeStringInfo();
ForeignDataWrapper *fdw;
AclResult aclresult;
/* first gather the server connstr options */
if (strlen(servername) < NAMEDATALEN)
foreign_server = GetForeignServerByName(servername, true);
if (foreign_server)
{
Oid serverid = foreign_server->serverid;
Oid fdwid = foreign_server->fdwid;
Oid userid = GetUserId();
user_mapping = GetUserMapping(userid, serverid);
fdw = GetForeignDataWrapper(fdwid);
/* Check permissions, user must have usage on the server. */
aclresult = pg_foreign_server_aclcheck(serverid, userid, ACL_USAGE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_FOREIGN_SERVER, foreign_server->servername);
foreach (cell, fdw->options)
{
DefElem *def = lfirst(cell);
appendStringInfo(buf, "%s='%s' ", def->defname,
escape_param_str(strVal(def->arg)));
}
foreach (cell, foreign_server->options)
{
DefElem *def = lfirst(cell);
appendStringInfo(buf, "%s='%s' ", def->defname,
escape_param_str(strVal(def->arg)));
}
foreach (cell, user_mapping->options)
{
DefElem *def = lfirst(cell);
appendStringInfo(buf, "%s='%s' ", def->defname,
escape_param_str(strVal(def->arg)));
}
return buf->data;
}
else
return NULL;
}
/*
* Escaping libpq connect parameter strings.
*
* Replaces "'" with "\'" and "\" with "\\".
*/
static char *
escape_param_str(const char *str)
{
const char *cp;
StringInfo buf = makeStringInfo();
for (cp = str; *cp; cp++)
{
if (*cp == '\\' || *cp == '\'')
appendStringInfoChar(buf, '\\');
appendStringInfoChar(buf, *cp);
}
return buf->data;
}

43
contrib/dblink/expected/dblink.out
Unescape View File

@ -784,3 +784,46 @@ SELECT dblink_disconnect('dtest1');
OK
(1 row)
-- test foreign data wrapper functionality
CREATE USER dblink_regression_test;
CREATE FOREIGN DATA WRAPPER postgresql;
CREATE SERVER fdtest FOREIGN DATA WRAPPER postgresql OPTIONS (dbname 'contrib_regression');
CREATE USER MAPPING FOR public SERVER fdtest;
GRANT USAGE ON FOREIGN SERVER fdtest TO dblink_regression_test;
GRANT EXECUTE ON FUNCTION dblink_connect_u(text, text) TO dblink_regression_test;
\set ORIGINAL_USER :USER
\c - dblink_regression_test
-- should fail
SELECT dblink_connect('myconn', 'fdtest');
ERROR: password is required
DETAIL: Non-superusers must provide a password in the connection string.
-- should succeed
SELECT dblink_connect_u('myconn', 'fdtest');
dblink_connect_u
------------------
OK
(1 row)
SELECT * FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[]);
a | b | c
----+---+---------------
0 | a | {a0,b0,c0}
1 | b | {a1,b1,c1}
2 | c | {a2,b2,c2}
3 | d | {a3,b3,c3}
4 | e | {a4,b4,c4}
5 | f | {a5,b5,c5}
6 | g | {a6,b6,c6}
7 | h | {a7,b7,c7}
8 | i | {a8,b8,c8}
9 | j | {a9,b9,c9}
10 | k | {a10,b10,c10}
(11 rows)
\c - :ORIGINAL_USER
REVOKE USAGE ON FOREIGN SERVER fdtest FROM dblink_regression_test;
REVOKE EXECUTE ON FUNCTION dblink_connect_u(text, text) FROM dblink_regression_test;
DROP USER dblink_regression_test;
DROP USER MAPPING FOR public SERVER fdtest;
DROP SERVER fdtest;
DROP FOREIGN DATA WRAPPER postgresql;

25
contrib/dblink/sql/dblink.sql
Unescape View File

@ -364,3 +364,28 @@ SELECT * from
SELECT dblink_cancel_query('dtest1');
SELECT dblink_error_message('dtest1');
SELECT dblink_disconnect('dtest1');
-- test foreign data wrapper functionality
CREATE USER dblink_regression_test;
CREATE FOREIGN DATA WRAPPER postgresql;
CREATE SERVER fdtest FOREIGN DATA WRAPPER postgresql OPTIONS (dbname 'contrib_regression');
CREATE USER MAPPING FOR public SERVER fdtest;
GRANT USAGE ON FOREIGN SERVER fdtest TO dblink_regression_test;
GRANT EXECUTE ON FUNCTION dblink_connect_u(text, text) TO dblink_regression_test;
\set ORIGINAL_USER :USER
\c - dblink_regression_test
-- should fail
SELECT dblink_connect('myconn', 'fdtest');
-- should succeed
SELECT dblink_connect_u('myconn', 'fdtest');
SELECT * FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[]);
\c - :ORIGINAL_USER
REVOKE USAGE ON FOREIGN SERVER fdtest FROM dblink_regression_test;
REVOKE EXECUTE ON FUNCTION dblink_connect_u(text, text) FROM dblink_regression_test;
DROP USER dblink_regression_test;
DROP USER MAPPING FOR public SERVER fdtest;
DROP SERVER fdtest;
DROP FOREIGN DATA WRAPPER postgresql;

61
doc/src/sgml/dblink.sgml
Unescape View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/dblink.sgml,v 1.6 2008/11/12 15:52:44 petere Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/dblink.sgml,v 1.7 2009/06/06 21:27:56 joe Exp $ -->
<sect1 id="dblink">
<title>dblink</title>
@ -42,6 +42,18 @@
only one unnamed connection is permitted at a time. The connection
will persist until closed or until the database session is ended.
</para>
<para>
The connection string may also be the name of an existing foreign
server that utilizes the postgresql_fdw foreign data wrapper library.
See the example below, as well as the following:
<simplelist type="inline">
<member><xref linkend="sql-createforeigndatawrapper" endterm="sql-createforeigndatawrapper-title"></member>
<member><xref linkend="sql-createserver" endterm="sql-createserver-title"></member>
<member><xref linkend="sql-createusermapping" endterm="sql-createusermapping-title"></member>
</simplelist>
</para>
</refsect1>
<refsect1>
@ -113,6 +125,53 @@
----------------
OK
(1 row)
-- FOREIGN DATA WRAPPER functionality
-- Note: local connection must require password authentication for this to work properly
-- Otherwise, you will receive the following error from dblink_connect():
-- ----------------------------------------------------------------------
-- ERROR: password is required
-- DETAIL: Non-superuser cannot connect if the server does not request a password.
-- HINT: Target server's authentication method must be changed.
CREATE USER dblink_regression_test WITH PASSWORD 'secret';
CREATE FOREIGN DATA WRAPPER postgresql;
CREATE SERVER fdtest FOREIGN DATA WRAPPER postgresql OPTIONS (hostaddr '127.0.0.1', dbname 'contrib_regression');
CREATE USER MAPPING FOR dblink_regression_test SERVER fdtest OPTIONS (user 'dblink_regression_test', password 'secret');
GRANT USAGE ON FOREIGN SERVER fdtest TO dblink_regression_test;
GRANT SELECT ON TABLE foo TO dblink_regression_test;
\set ORIGINAL_USER :USER
\c - dblink_regression_test
SELECT dblink_connect('myconn', 'fdtest');
dblink_connect
----------------
OK
(1 row)
SELECT * FROM dblink('myconn','SELECT * FROM foo') AS t(a int, b text, c text[]);
a | b | c
----+---+---------------
0 | a | {a0,b0,c0}
1 | b | {a1,b1,c1}
2 | c | {a2,b2,c2}
3 | d | {a3,b3,c3}
4 | e | {a4,b4,c4}
5 | f | {a5,b5,c5}
6 | g | {a6,b6,c6}
7 | h | {a7,b7,c7}
8 | i | {a8,b8,c8}
9 | j | {a9,b9,c9}
10 | k | {a10,b10,c10}
(11 rows)
\c - :ORIGINAL_USER
REVOKE USAGE ON FOREIGN SERVER fdtest FROM dblink_regression_test;
REVOKE SELECT ON TABLE foo FROM dblink_regression_test;
DROP USER MAPPING FOR dblink_regression_test SERVER fdtest;
DROP USER dblink_regression_test;
DROP SERVER fdtest;
DROP FOREIGN DATA WRAPPER postgresql;
</programlisting>
</refsect1>
</refentry>

Write Preview
Loading…
Cancel
Save