Warn that wildcards must be used as the last character in a string

[lttng-tools.git] / src / lib / lttng-ctl / filter / filter-visitor-ir-validate-string.c

diff --git a/src/lib/lttng-ctl/filter/filter-visitor-ir-validate-string.c b/src/lib/lttng-ctl/filter/filter-visitor-ir-validate-string.c
new file mode 100644 (file)
index 0000000..34b4b19
--- /dev/null
+++ b/src/lib/lttng-ctl/filter/filter-visitor-ir-validate-string.c
@@ -0,0 +1,148 @@
+/*
+ * filter-visitor-ir-validate-string.c
+ *
+ * LTTng filter IR validate string
+ *
+ * Copyright 2014 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License, version 2.1 only,
+ * as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+#include "filter-ast.h"
+#include "filter-parser.h"
+#include "filter-ir.h"
+
+enum parse_char_result {
+       PARSE_CHAR_UNKNOWN = -2,
+       PARSE_CHAR_WILDCARD = -1,
+       PARSE_CHAR_NORMAL = 0,
+};
+
+static
+enum parse_char_result parse_char(const char **p)
+{
+       switch (**p) {
+       case '\\':
+               (*p)++;
+               switch (**p) {
+               case '\\':
+               case '*':
+                       return PARSE_CHAR_NORMAL;
+               default:
+                       return PARSE_CHAR_UNKNOWN;
+               }
+       case '*':
+               return PARSE_CHAR_WILDCARD;
+       default:
+               return PARSE_CHAR_NORMAL;
+       }
+}
+
+static
+int validate_string(struct ir_op *node)
+{
+       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_string(node->u.root.child);
+       case IR_OP_LOAD:
+       {
+               int ret = 0;
+
+               if (node->data_type == IR_DATA_STRING) {
+                       const char *str;
+
+                       assert(node->u.load.u.string);
+                       str = node->u.load.u.string;
+
+                       /*
+                        * Make sure that if a non-escaped wildcard is
+                        * present, it is the last character of the string.
+                        */
+                       for (;;) {
+                               enum parse_char_result res;
+
+                               if (!(*str)) {
+                                       break;
+                               }
+
+                               res = parse_char(&str);
+                               str++;
+
+                               switch (res) {
+                               case PARSE_CHAR_WILDCARD:
+                               {
+                                       if (*str) {
+                                               /*
+                                                * Found a wildcard followed by non-null
+                                                * character; unsupported.
+                                                */
+                                               ret = -EINVAL;
+                                               fprintf(stderr,
+                                                       "Wildcards may only be used as the last character of a string in a filter.\n");
+                                               goto end_load;
+                                       }
+                                       break;
+                               }
+                               case PARSE_CHAR_UNKNOWN:
+                                       ret = -EINVAL;
+                                       fprintf(stderr,
+                                               "Unsupported escape character detected.\n");
+                                       goto end_load;
+                               case PARSE_CHAR_NORMAL:
+                               default:
+                                       break;
+                               }
+                       }
+               }
+end_load:
+               return ret;
+       }
+       case IR_OP_UNARY:
+               return validate_string(node->u.unary.child);
+       case IR_OP_BINARY:
+       {
+               int ret = validate_string(node->u.binary.left);
+
+               if (ret)
+                       return ret;
+               return validate_string(node->u.binary.right);
+       }
+       case IR_OP_LOGICAL:
+       {
+               int ret;
+
+               ret = validate_string(node->u.logical.left);
+               if (ret)
+                       return ret;
+               return validate_string(node->u.logical.right);
+       }
+       }
+}
+
+int filter_visitor_ir_validate_string(struct filter_parser_ctx *ctx)
+{
+       return validate_string(ctx->ir_root);
+}