Consolidate and improve checking of key-column-attnum arguments for

dblink_build_sql_insert() and related functions.  In particular, be sure to
reject references to dropped and out-of-range column numbers.  The numbers
are still interpreted as physical column numbers, though, for backward
compatibility.

This patch replaces Joe's patch of 2010-02-03, which handled only some aspects
of the problem.

diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
index 91f652a55bd19ed830817903ef1e4a5ff2eb7c02..b737c68003afd5cae72beb8dcae06ad5375fc468 100644 (file)
--- a/contrib/dblink/dblink.c
+++ b/contrib/dblink/dblink.c
@@ -76,18 +76,20 @@ static HTAB *createConnHash(void);
 static void createNewConnection(const char *name, remoteConn * rconn);
 static void deleteConnection(const char *name);
 static char **get_pkey_attnames(Relation rel, int16 *numatts);
-static char *get_sql_insert(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals);
-static char *get_sql_delete(Relation rel, int2vector *pkattnums, int16 pknumatts, char **tgt_pkattvals);
-static char *get_sql_update(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals);
+static char *get_sql_insert(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals);
+static char *get_sql_delete(Relation rel, int *pkattnums, int pknumatts, char **tgt_pkattvals);
+static char *get_sql_update(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals);
 static char *quote_literal_cstr(char *rawstr);
 static char *quote_ident_cstr(char *rawstr);
-static int16 get_attnum_pk_pos(int2vector *pkattnums, int16 pknumatts, int16 key);
-static HeapTuple get_tuple_of_interest(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_pkattvals);
+static int     get_attnum_pk_pos(int *pkattnums, int pknumatts, int key);
+static HeapTuple get_tuple_of_interest(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals);
 static Relation get_rel_from_relname(text *relname_text, LOCKMODE lockmode, AclMode aclmode);
 static char *generate_relation_name(Relation rel);
 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(Relation rel);
+static void validate_pkattnums(Relation rel,
+                                  int2vector *pkattnums_arg, int32 pknumatts_arg,
+                                  int **pkattnums, int *pknumatts);
 
 /* Global */
 static remoteConn *pconn = NULL;
@@ -1150,9 +1152,10 @@ dblink_build_sql_insert(PG_FUNCTION_ARGS)
 {
        Relation        rel;
        text       *relname_text;
-       int2vector *pkattnums;
-       int                     pknumatts_tmp;
-       int16           pknumatts = 0;
+       int2vector *pkattnums_arg;
+       int32           pknumatts_arg;
+       int                *pkattnums;
+       int                     pknumatts;
        char      **src_pkattvals;
        char      **tgt_pkattvals;
        ArrayType  *src_pkattvals_arry;
@@ -1169,7 +1172,6 @@ dblink_build_sql_insert(PG_FUNCTION_ARGS)
        int16           typlen;
        bool            typbyval;
        char            typalign;
-       int                     nondropped_natts;
 
        relname_text = PG_GETARG_TEXT_P(0);
 
@@ -1178,36 +1180,17 @@ dblink_build_sql_insert(PG_FUNCTION_ARGS)
         */
        rel = get_rel_from_relname(relname_text, AccessShareLock, ACL_SELECT);
 
-       pkattnums = (int2vector *) PG_GETARG_POINTER(1);
-       pknumatts_tmp = PG_GETARG_INT32(2);
-       if (pknumatts_tmp <= SHRT_MAX)
-               pknumatts = pknumatts_tmp;
-       else
-               ereport(ERROR,
-                               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-                                errmsg("input for number of primary key " \
-                                               "attributes too large")));
-
        /*
-        * There should be at least one key attribute
+        * Process pkattnums argument.
         */
-       if (pknumatts == 0)
-               ereport(ERROR,
-                               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-                                errmsg("number of key attributes must be > 0")));
+       pkattnums_arg = (int2vector *) PG_GETARG_POINTER(1);
+       pknumatts_arg = PG_GETARG_INT32(2);
+       validate_pkattnums(rel, pkattnums_arg, pknumatts_arg,
+                                          &pkattnums, &pknumatts);
 
        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(rel);
-       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.
@@ -1312,9 +1295,10 @@ dblink_build_sql_delete(PG_FUNCTION_ARGS)
 {
        Relation        rel;
        text       *relname_text;
-       int2vector *pkattnums;
-       int                     pknumatts_tmp;
-       int16           pknumatts = 0;
+       int2vector *pkattnums_arg;
+       int32           pknumatts_arg;
+       int                *pkattnums;
+       int                     pknumatts;
        char      **tgt_pkattvals;
        ArrayType  *tgt_pkattvals_arry;
        int                     tgt_ndim;
@@ -1326,7 +1310,6 @@ dblink_build_sql_delete(PG_FUNCTION_ARGS)
        int16           typlen;
        bool            typbyval;
        char            typalign;
-       int                     nondropped_natts;
 
        relname_text = PG_GETARG_TEXT_P(0);
 
@@ -1335,35 +1318,16 @@ dblink_build_sql_delete(PG_FUNCTION_ARGS)
         */
        rel = get_rel_from_relname(relname_text, AccessShareLock, ACL_SELECT);
 
-       pkattnums = (int2vector *) PG_GETARG_POINTER(1);
-       pknumatts_tmp = PG_GETARG_INT32(2);
-       if (pknumatts_tmp <= SHRT_MAX)
-               pknumatts = pknumatts_tmp;
-       else
-               ereport(ERROR,
-                               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-                                errmsg("input for number of primary key " \
-                                               "attributes too large")));
-
        /*
-        * There should be at least one key attribute
+        * Process pkattnums argument.
         */
-       if (pknumatts == 0)
-               ereport(ERROR,
-                               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-                                errmsg("number of key attributes must be > 0")));
+       pkattnums_arg = (int2vector *) PG_GETARG_POINTER(1);
+       pknumatts_arg = PG_GETARG_INT32(2);
+       validate_pkattnums(rel, pkattnums_arg, pknumatts_arg,
+                                          &pkattnums, &pknumatts);
 
        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(rel);
-       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.
@@ -1439,9 +1403,10 @@ dblink_build_sql_update(PG_FUNCTION_ARGS)
 {
        Relation        rel;
        text       *relname_text;
-       int2vector *pkattnums;
-       int                     pknumatts_tmp;
-       int16           pknumatts = 0;
+       int2vector *pkattnums_arg;
+       int32           pknumatts_arg;
+       int                *pkattnums;
+       int                     pknumatts;
        char      **src_pkattvals;
        char      **tgt_pkattvals;
        ArrayType  *src_pkattvals_arry;
@@ -1458,7 +1423,6 @@ dblink_build_sql_update(PG_FUNCTION_ARGS)
        int16           typlen;
        bool            typbyval;
        char            typalign;
-       int                     nondropped_natts;
 
        relname_text = PG_GETARG_TEXT_P(0);
 
@@ -1467,36 +1431,17 @@ dblink_build_sql_update(PG_FUNCTION_ARGS)
         */
        rel = get_rel_from_relname(relname_text, AccessShareLock, ACL_SELECT);
 
-       pkattnums = (int2vector *) PG_GETARG_POINTER(1);
-       pknumatts_tmp = PG_GETARG_INT32(2);
-       if (pknumatts_tmp <= SHRT_MAX)
-               pknumatts = pknumatts_tmp;
-       else
-               ereport(ERROR,
-                               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-                                errmsg("input for number of primary key " \
-                                               "attributes too large")));
-
        /*
-        * There should be one source array key values for each key attnum
+        * Process pkattnums argument.
         */
-       if (pknumatts == 0)
-               ereport(ERROR,
-                               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-                                errmsg("number of key attributes must be > 0")));
+       pkattnums_arg = (int2vector *) PG_GETARG_POINTER(1);
+       pknumatts_arg = PG_GETARG_INT32(2);
+       validate_pkattnums(rel, pkattnums_arg, pknumatts_arg,
+                                          &pkattnums, &pknumatts);
 
        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(rel);
-       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.
@@ -1653,7 +1598,7 @@ get_pkey_attnames(Relation rel, int16 *numatts)
 }
 
 static char *
-get_sql_insert(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals)
+get_sql_insert(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals)
 {
        char       *relname;
        HeapTuple       tuple;
@@ -1662,7 +1607,7 @@ get_sql_insert(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_
        StringInfo      str = makeStringInfo();
        char       *sql;
        char       *val;
-       int16           key;
+       int                     key;
        int                     i;
        bool            needComma;
 
@@ -1709,7 +1654,7 @@ get_sql_insert(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_
                        appendStringInfo(str, ",");
 
                if (tgt_pkattvals != NULL)
-                       key = get_attnum_pk_pos(pkattnums, pknumatts, i + 1);
+                       key = get_attnum_pk_pos(pkattnums, pknumatts, i);
                else
                        key = -1;
 
@@ -1737,11 +1682,10 @@ get_sql_insert(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_
 }
 
 static char *
-get_sql_delete(Relation rel, int2vector *pkattnums, int16 pknumatts, char **tgt_pkattvals)
+get_sql_delete(Relation rel, int *pkattnums, int pknumatts, char **tgt_pkattvals)
 {
        char       *relname;
        TupleDesc       tupdesc;
-       int                     natts;
        StringInfo      str = makeStringInfo();
        char       *sql;
        char       *val = NULL;
@@ -1751,18 +1695,17 @@ get_sql_delete(Relation rel, int2vector *pkattnums, int16 pknumatts, char **tgt_
        relname = generate_relation_name(rel);
 
        tupdesc = rel->rd_att;
-       natts = tupdesc->natts;
 
        appendStringInfo(str, "DELETE FROM %s WHERE ", relname);
        for (i = 0; i < pknumatts; i++)
        {
-               int16           pkattnum = pkattnums->values[i];
+               int                     pkattnum = pkattnums[i];
 
                if (i > 0)
                        appendStringInfo(str, " AND ");
 
                appendStringInfo(str, "%s",
-                  quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum - 1]->attname)));
+                  quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum]->attname)));
 
                if (tgt_pkattvals != NULL)
                        val = pstrdup(tgt_pkattvals[i]);
@@ -1787,7 +1730,7 @@ get_sql_delete(Relation rel, int2vector *pkattnums, int16 pknumatts, char **tgt_
 }
 
 static char *
-get_sql_update(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals)
+get_sql_update(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals)
 {
        char       *relname;
        HeapTuple       tuple;
@@ -1796,7 +1739,7 @@ get_sql_update(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_
        StringInfo      str = makeStringInfo();
        char       *sql;
        char       *val;
-       int16           key;
+       int                     key;
        int                     i;
        bool            needComma;
 
@@ -1827,7 +1770,7 @@ get_sql_update(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_
                                          quote_ident_cstr(NameStr(tupdesc->attrs[i]->attname)));
 
                if (tgt_pkattvals != NULL)
-                       key = get_attnum_pk_pos(pkattnums, pknumatts, i + 1);
+                       key = get_attnum_pk_pos(pkattnums, pknumatts, i);
                else
                        key = -1;
 
@@ -1850,18 +1793,18 @@ get_sql_update(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_
 
        for (i = 0; i < pknumatts; i++)
        {
-               int16           pkattnum = pkattnums->values[i];
+               int                     pkattnum = pkattnums[i];
 
                if (i > 0)
                        appendStringInfo(str, " AND ");
 
                appendStringInfo(str, "%s",
-                  quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum - 1]->attname)));
+                  quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum]->attname)));
 
                if (tgt_pkattvals != NULL)
                        val = pstrdup(tgt_pkattvals[i]);
                else
-                       val = SPI_getvalue(tuple, tupdesc, pkattnum);
+                       val = SPI_getvalue(tuple, tupdesc, pkattnum + 1);
 
                if (val != NULL)
                {
@@ -1915,8 +1858,8 @@ quote_ident_cstr(char *rawstr)
        return result;
 }
 
-static int16
-get_attnum_pk_pos(int2vector *pkattnums, int16 pknumatts, int16 key)
+static int
+get_attnum_pk_pos(int *pkattnums, int pknumatts, int key)
 {
        int                     i;
 
@@ -1924,14 +1867,14 @@ get_attnum_pk_pos(int2vector *pkattnums, int16 pknumatts, int16 key)
         * Not likely a long list anyway, so just scan for the value
         */
        for (i = 0; i < pknumatts; i++)
-               if (key == pkattnums->values[i])
+               if (key == pkattnums[i])
                        return i;
 
        return -1;
 }
 
 static HeapTuple
-get_tuple_of_interest(Relation rel, int2vector *pkattnums, int16 pknumatts, char **src_pkattvals)
+get_tuple_of_interest(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals)
 {
        char       *relname;
        TupleDesc       tupdesc;
@@ -1962,13 +1905,13 @@ get_tuple_of_interest(Relation rel, int2vector *pkattnums, int16 pknumatts, char
 
        for (i = 0; i < pknumatts; i++)
        {
-               int16           pkattnum = pkattnums->values[i];
+               int                     pkattnum = pkattnums[i];
 
                if (i > 0)
                        appendStringInfo(str, " AND ");
 
                appendStringInfo(str, "%s",
-                  quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum - 1]->attname)));
+                  quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum]->attname)));
 
                val = pstrdup(src_pkattvals[i]);
                if (val != NULL)
@@ -2308,24 +2251,52 @@ dblink_security_check(PGconn *conn, remoteConn *rconn, const char *connstr)
        }
 }
 
-static int
-get_nondropped_natts(Relation rel)
+/*
+ * Validate the PK-attnums argument for dblink_build_sql_insert() and related
+ * functions, and translate to the internal representation.
+ *
+ * The user supplies an int2vector of 1-based physical attnums, plus a count
+ * argument (the need for the separate count argument is historical, but we
+ * still check it).  We check that each attnum corresponds to a valid,
+ * non-dropped attribute of the rel.  We do *not* prevent attnums from being
+ * listed twice, though the actual use-case for such things is dubious.
+ *
+ * The internal representation is a palloc'd int array of 0-based physical
+ * attnums.
+ */
+static void
+validate_pkattnums(Relation rel,
+                                  int2vector *pkattnums_arg, int32 pknumatts_arg,
+                                  int **pkattnums, int *pknumatts)
 {
-       int                     nondropped_natts = 0;
-       TupleDesc       tupdesc;
-       int                     natts;
+       TupleDesc       tupdesc = rel->rd_att;
+       int                     natts = tupdesc->natts;
        int                     i;
 
-       tupdesc = rel->rd_att;
-       natts = tupdesc->natts;
+       /* Don't take more array elements than there are */
+       pknumatts_arg = Min(pknumatts_arg, pkattnums_arg->dim1);
 
-       for (i = 0; i < natts; i++)
+       /* Must have at least one pk attnum selected */
+       if (pknumatts_arg <= 0)
+               ereport(ERROR,
+                               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                                errmsg("number of key attributes must be > 0")));
+
+       /* Allocate output array */
+       *pkattnums = (int *) palloc(pknumatts_arg * sizeof(int));
+       *pknumatts = pknumatts_arg;
+
+       /* Validate attnums and convert to internal form */
+       for (i = 0; i < pknumatts_arg; i++)
        {
-               if (tupdesc->attrs[i]->attisdropped)
-                       continue;
-               nondropped_natts++;
-       }
+               int             pkattnum = pkattnums_arg->values[i];
 
-       return nondropped_natts;
+               if (pkattnum <= 0 || pkattnum > natts ||
+                       tupdesc->attrs[pkattnum - 1]->attisdropped)
+                       ereport(ERROR,
+                                       (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                                        errmsg("invalid attribute number %d", pkattnum)));
+               (*pkattnums)[i] = pkattnum - 1;
+       }
 }
 

diff --git a/contrib/dblink/expected/dblink.out b/contrib/dblink/expected/dblink.out
index d224755e20a489b61732a0d39144bed590ed9da9..fa9a0feb28d54b223e9c4d678f5b731e6c8a796f 100644 (file)
--- a/contrib/dblink/expected/dblink.out
+++ b/contrib/dblink/expected/dblink.out
@@ -46,7 +46,7 @@ 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}"}');
-ERROR:  number of primary key fields exceeds number of specified relation attributes
+ERROR:  invalid attribute number 4
 -- 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"}');
@@ -57,7 +57,7 @@ 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}"}');
-ERROR:  number of primary key fields exceeds number of specified relation attributes
+ERROR:  invalid attribute number 4
 -- build a delete statement based on a local tuple,
 SELECT dblink_build_sql_delete('foo','1 2',2,'{"0", "a"}');
            dblink_build_sql_delete           
@@ -67,7 +67,7 @@ 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}"}');
-ERROR:  number of primary key fields exceeds number of specified relation attributes
+ERROR:  invalid attribute number 4
 -- 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));