Check to ensure the number of primary key fields supplied does not

exceed the total number of non-dropped source table fields for
dblink_build_sql_*(). Addresses bug report from Rushabh Lathia.

Backpatch all the way to the 7.3 branch.

diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
index d672edfc7772cf7a83932d761cb0fc1d643b7a96..69bf982a1df478c02acad606d21e2b2dac3a53b9 100644 (file)
--- a/contrib/dblink/dblink.c
+++ b/contrib/dblink/dblink.c
@@ -85,6 +85,7 @@ static Oid    get_relid_from_relname(text *relname_text);
 static char *generate_relation_name(Oid relid);
 static char *connstr_strip_password(const char *connstr);
 static void dblink_security_check(PGconn *conn, remoteConn *rconn, const char *connstr);
+static int get_nondropped_natts(Oid relid);
 
 /* Global */
 static remoteConn *pconn = NULL;
@@ -1169,6 +1170,7 @@ dblink_build_sql_insert(PG_FUNCTION_ARGS)
    int16       typlen;
    bool        typbyval;
    char        typalign;
+   int         nondropped_natts;
 
    relname_text = PG_GETARG_TEXT_P(0);
 
@@ -1203,6 +1205,15 @@ dblink_build_sql_insert(PG_FUNCTION_ARGS)
    src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
    tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
 
+   /*
+    * ensure we don't ask for more pk attributes than we have
+    * non-dropped columns
+    */
+   nondropped_natts = get_nondropped_natts(relid);
+   if (pknumatts > nondropped_natts)
+       ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
+               errmsg("number of primary key fields exceeds number of specified relation attributes")));
+
    /*
     * Source array is made up of key values that will be used to locate the
     * tuple of interest from the local system.
@@ -1316,6 +1327,7 @@ dblink_build_sql_delete(PG_FUNCTION_ARGS)
    int16       typlen;
    bool        typbyval;
    char        typalign;
+   int         nondropped_natts;
 
    relname_text = PG_GETARG_TEXT_P(0);
 
@@ -1349,6 +1361,15 @@ dblink_build_sql_delete(PG_FUNCTION_ARGS)
 
    tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
 
+   /*
+    * ensure we don't ask for more pk attributes than we have
+    * non-dropped columns
+    */
+   nondropped_natts = get_nondropped_natts(relid);
+   if (pknumatts > nondropped_natts)
+       ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
+               errmsg("number of primary key fields exceeds number of specified relation attributes")));
+
    /*
     * Target array is made up of key values that will be used to build the
     * SQL string for use on the remote system.
@@ -1438,6 +1459,7 @@ dblink_build_sql_update(PG_FUNCTION_ARGS)
    int16       typlen;
    bool        typbyval;
    char        typalign;
+   int         nondropped_natts;
 
    relname_text = PG_GETARG_TEXT_P(0);
 
@@ -1472,6 +1494,15 @@ dblink_build_sql_update(PG_FUNCTION_ARGS)
    src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
    tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
 
+   /*
+    * ensure we don't ask for more pk attributes than we have
+    * non-dropped columns
+    */
+   nondropped_natts = get_nondropped_natts(relid);
+   if (pknumatts > nondropped_natts)
+       ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
+               errmsg("number of primary key fields exceeds number of specified relation attributes")));
+
    /*
     * Source array is made up of key values that will be used to locate the
     * tuple of interest from the local system.
@@ -2304,3 +2335,28 @@ dblink_security_check(PGconn *conn, remoteConn *rconn, const char *connstr)
            PQfinish(conn);
    }
 }
+
+static int
+get_nondropped_natts(Oid relid)
+{
+   int         nondropped_natts = 0;
+   TupleDesc   tupdesc;
+   Relation    rel;
+   int         natts;
+   int         i;
+
+   rel = relation_open(relid, AccessShareLock);
+   tupdesc = rel->rd_att;
+   natts = tupdesc->natts;
+
+   for (i = 0; i < natts; i++)
+   {
+       if (tupdesc->attrs[i]->attisdropped)
+           continue;
+       nondropped_natts++;
+   }
+
+   relation_close(rel, AccessShareLock);
+   return nondropped_natts;
+}
+

diff --git a/contrib/dblink/expected/dblink.out b/contrib/dblink/expected/dblink.out
index f2e364a9423e872416bda12b1c45c1ed4525dbca..d224755e20a489b61732a0d39144bed590ed9da9 100644 (file)
--- a/contrib/dblink/expected/dblink.out
+++ b/contrib/dblink/expected/dblink.out
@@ -44,6 +44,9 @@ SELECT dblink_build_sql_insert('foo','1 2',2,'{"0", "a"}','{"99", "xyz"}');
  INSERT INTO foo(f1,f2,f3) VALUES('99','xyz','{a0,b0,c0}')
 (1 row)
 
+-- too many pk fields, should fail
+SELECT dblink_build_sql_insert('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}','{"99", "xyz", "{za0,zb0,zc0}"}');
+ERROR:  number of primary key fields exceeds number of specified relation attributes
 -- build an update statement based on a local tuple,
 -- replacing the primary key values with new ones
 SELECT dblink_build_sql_update('foo','1 2',2,'{"0", "a"}','{"99", "xyz"}');
@@ -52,6 +55,9 @@ SELECT dblink_build_sql_update('foo','1 2',2,'{"0", "a"}','{"99", "xyz"}');
  UPDATE foo SET f1 = '99', f2 = 'xyz', f3 = '{a0,b0,c0}' WHERE f1 = '99' AND f2 = 'xyz'
 (1 row)
 
+-- too many pk fields, should fail
+SELECT dblink_build_sql_update('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}','{"99", "xyz", "{za0,zb0,zc0}"}');
+ERROR:  number of primary key fields exceeds number of specified relation attributes
 -- build a delete statement based on a local tuple,
 SELECT dblink_build_sql_delete('foo','1 2',2,'{"0", "a"}');
            dblink_build_sql_delete           
@@ -59,6 +65,9 @@ SELECT dblink_build_sql_delete('foo','1 2',2,'{"0", "a"}');
  DELETE FROM foo WHERE f1 = '0' AND f2 = 'a'
 (1 row)
 
+-- too many pk fields, should fail
+SELECT dblink_build_sql_delete('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}');
+ERROR:  number of primary key fields exceeds number of specified relation attributes
 -- retest using a quoted and schema qualified table
 CREATE SCHEMA "MySchema";
 CREATE TABLE "MySchema"."Foo"(f1 int, f2 text, f3 text[], primary key (f1,f2));

diff --git a/contrib/dblink/sql/dblink.sql b/contrib/dblink/sql/dblink.sql
index 66e2607cfee667bbe8c226da4c0f4bb66ec39669..1987da8da27b9dc308bd1fedc7bb05ee57608b89 100644 (file)
--- a/contrib/dblink/sql/dblink.sql
+++ b/contrib/dblink/sql/dblink.sql
@@ -35,13 +35,19 @@ FROM dblink_get_pkey('foo');
 -- build an insert statement based on a local tuple,
 -- replacing the primary key values with new ones
 SELECT dblink_build_sql_insert('foo','1 2',2,'{"0", "a"}','{"99", "xyz"}');
+-- too many pk fields, should fail
+SELECT dblink_build_sql_insert('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}','{"99", "xyz", "{za0,zb0,zc0}"}');
 
 -- build an update statement based on a local tuple,
 -- replacing the primary key values with new ones
 SELECT dblink_build_sql_update('foo','1 2',2,'{"0", "a"}','{"99", "xyz"}');
+-- too many pk fields, should fail
+SELECT dblink_build_sql_update('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}','{"99", "xyz", "{za0,zb0,zc0}"}');
 
 -- build a delete statement based on a local tuple,
 SELECT dblink_build_sql_delete('foo','1 2',2,'{"0", "a"}');
+-- too many pk fields, should fail
+SELECT dblink_build_sql_delete('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}');
 
 -- retest using a quoted and schema qualified table
 CREATE SCHEMA "MySchema";