Handle NULL fields returned in unixodbc

ODBC uses the data length indicator to report NULL return values.

diff --git a/src/modules/rlm_sql/drivers/rlm_sql_unixodbc/rlm_sql_unixodbc.c b/src/modules/rlm_sql/drivers/rlm_sql_unixodbc/rlm_sql_unixodbc.c
index 4489511b2ea35916c87aab487a65c0caa81131bd..4ee7ce311137f1294c1105c87126d266905ecb02 100644 (file)
--- a/src/modules/rlm_sql/drivers/rlm_sql_unixodbc/rlm_sql_unixodbc.c
+++ b/src/modules/rlm_sql/drivers/rlm_sql_unixodbc/rlm_sql_unixodbc.c
@@ -36,6 +36,7 @@ typedef struct {
        SQLHSTMT                stmt;           /* Statement handle */
        SQLSMALLINT             colcount;       /* Number of columns in last result */
        rlm_sql_row_t           row;            /* Results row */
+       SQLLEN                  *ind;           /* Data length / NULL indicators */
        connection_t            *conn;          /* Generic connection structure for this connection */
        rlm_sql_config_t const  *config;        /* SQL instance configuration */
        SQLUSMALLINT            async_mode;     /* What Async mode does this driver support */
@@ -504,13 +505,14 @@ static unlang_action_t sql_select_query_resume(rlm_rcode_t *p_result, UNUSED int
 
        /* Reserving memory for result */
        conn->row = talloc_zero_array(conn, char *, conn->colcount + 1); /* Space for pointers */
+       conn->ind = talloc_zero_array(conn, SQLLEN, conn->colcount); /* Space for indicators */
 
        for (i = 1; i <= conn->colcount; i++) {
                len = 0;
                /* SQLColAttribute can in theory run Async */
                while (SQLColAttribute(conn->stmt, (SQLUSMALLINT) i, SQL_DESC_LENGTH, NULL, 0, NULL, &len) == SQL_STILL_EXECUTING);
                conn->row[i - 1] = talloc_array(conn->row, char, ++len);
-               SQLBindCol(conn->stmt, i, SQL_C_CHAR, (SQLCHAR *)conn->row[i - 1], len, NULL);
+               SQLBindCol(conn->stmt, i, SQL_C_CHAR, (SQLCHAR *)conn->row[i - 1], len, &conn->ind[i - 1]);
        }
 
        RETURN_MODULE_OK;
@@ -561,6 +563,7 @@ static unlang_action_t sql_fetch_row(rlm_rcode_t *p_result, UNUSED int *priority
        fr_sql_query_t          *query_ctx = talloc_get_type_abort(uctx, fr_sql_query_t);
        rlm_sql_unixodbc_conn_t *conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_unixodbc_conn_t);
        SQLRETURN               ret = SQL_STILL_EXECUTING;
+       SQLINTEGER              i;
 
        query_ctx->row = NULL;
 
@@ -575,6 +578,13 @@ static unlang_action_t sql_fetch_row(rlm_rcode_t *p_result, UNUSED int *priority
        query_ctx->rcode = sql_check_error(ret, SQL_HANDLE_STMT, conn->stmt);
        if (query_ctx->rcode != RLM_SQL_OK) RETURN_MODULE_FAIL;
 
+       /*
+        *      If the field is NULL, then SQLFetch doesn't touch pointer, so set it here
+        */
+       for (i = 0; i < conn->colcount; i++) {
+               if (conn->ind[i] == SQL_NULL_DATA) conn->row[i] = NULL;
+       }
+
        query_ctx->row = conn->row;
 
        query_ctx->rcode = RLM_SQL_OK;
@@ -586,6 +596,7 @@ static sql_rcode_t sql_free_result(fr_sql_query_t *query_ctx, UNUSED rlm_sql_con
        rlm_sql_unixodbc_conn_t *conn = query_ctx->tconn->conn->h;
 
        TALLOC_FREE(conn->row);
+       TALLOC_FREE(conn->ind);
        conn->colcount = 0;
 
        return RLM_SQL_OK;