SoW-2019-0002: Dynamic Snapshot

[lttng-tools.git] / src / common / filter / filter-visitor-ir-validate-globbing.c

diff --git a/src/common/filter/filter-visitor-ir-validate-globbing.c b/src/common/filter/filter-visitor-ir-validate-globbing.c
new file mode 100644 (file)
index 0000000..3e749a4
--- /dev/null
+++ b/src/common/filter/filter-visitor-ir-validate-globbing.c
@@ -0,0 +1,112 @@
+/*
+ * filter-visitor-ir-validate-globbing.c
+ *
+ * LTTng filter IR validate globbing
+ *
+ * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+
+#include <common/macros.h>
+
+#include "filter-ast.h"
+#include "filter-parser.h"
+#include "filter-ir.h"
+
+static
+int validate_globbing(struct ir_op *node)
+{
+       int ret;
+
+       switch (node->op) {
+       case IR_OP_UNKNOWN:
+       default:
+               fprintf(stderr, "[error] %s: unknown op type\n", __func__);
+               return -EINVAL;
+
+       case IR_OP_ROOT:
+               return validate_globbing(node->u.root.child);
+       case IR_OP_LOAD:
+               return 0;
+       case IR_OP_UNARY:
+               return validate_globbing(node->u.unary.child);
+       case IR_OP_BINARY:
+       {
+               struct ir_op *left = node->u.binary.left;
+               struct ir_op *right = node->u.binary.right;
+
+               if (left->op == IR_OP_LOAD && right->op == IR_OP_LOAD &&
+                               left->data_type == IR_DATA_STRING &&
+                               right->data_type == IR_DATA_STRING) {
+                       /* Test 1. */
+                       if (left->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR &&
+                                       right->u.load.u.string.type != IR_LOAD_STRING_TYPE_PLAIN) {
+                               fprintf(stderr, "[error] Cannot compare two globbing patterns\n");
+                               return -1;
+                       }
+
+                       if (right->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR &&
+                                       left->u.load.u.string.type != IR_LOAD_STRING_TYPE_PLAIN) {
+                               fprintf(stderr, "[error] Cannot compare two globbing patterns\n");
+                               return -1;
+                       }
+               }
+
+               if ((left->op == IR_OP_LOAD && left->data_type == IR_DATA_STRING) ||
+                               (right->op == IR_OP_LOAD && right->data_type == IR_DATA_STRING)) {
+                       if ((left->op == IR_OP_LOAD && left->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR) ||
+                                       (right->op == IR_OP_LOAD && right->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR)) {
+                               /* Test 2. */
+                               if (node->u.binary.type != AST_OP_EQ &&
+                                               node->u.binary.type != AST_OP_NE) {
+                                       fprintf(stderr, "[error] Only the `==` and `!=` operators are allowed with a globbing pattern\n");
+                                       return -1;
+                               }
+                       }
+               }
+
+               ret = validate_globbing(left);
+               if (ret) {
+                       return ret;
+               }
+
+               return validate_globbing(right);
+       }
+       case IR_OP_LOGICAL:
+               ret = validate_globbing(node->u.logical.left);
+               if (ret)
+                       return ret;
+               return validate_globbing(node->u.logical.right);
+       }
+}
+
+/*
+ * This function recursively validates that:
+ *
+ * 1. When there's a binary operation between two literal strings,
+ *    if one of them has the IR_LOAD_STRING_TYPE_GLOB_STAR type,
+ *    the other one has the IR_LOAD_STRING_TYPE_PLAIN type.
+ *
+ *    In other words, you cannot compare two globbing patterns, except
+ *    for two globbing patterns with only a star at the end for backward
+ *    compatibility reasons.
+ *
+ * 2. When there's a binary operation between two literal strings, if
+ *    one of them is a (full) star globbing pattern, the binary
+ *    operation is either == or !=.
+ */
+LTTNG_HIDDEN
+int filter_visitor_ir_validate_globbing(struct filter_parser_ctx *ctx)
+{
+       return validate_globbing(ctx->ir_root);
+}