src/common/filter/filter-visitor-ir-validate-globbing.c

   1 /*
   2  * filter-visitor-ir-validate-globbing.c
   3  *
   4  * LTTng filter IR validate globbing
   5  *
   6  * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
   7  *
   8  * SPDX-License-Identifier: LGPL-2.1-only
   9  *
  10  */
  11
  12 #include <stdio.h>
  13 #include <unistd.h>
  14 #include <string.h>
  15 #include <stdlib.h>
  16 #include <assert.h>
  17 #include <errno.h>
  18 #include <inttypes.h>
  19
  20 #include <common/macros.h>
  21
  22 #include "filter-ast.h"
  23 #include "filter-parser.h"
  24 #include "filter-ir.h"
  25
  26 static
  27 int validate_globbing(struct ir_op *node)
  28 {
  29         int ret;
  30
  31         switch (node->op) {
  32         case IR_OP_UNKNOWN:
  33         default:
  34                 fprintf(stderr, "[error] %s: unknown op type\n", __func__);
  35                 return -EINVAL;
  36
  37         case IR_OP_ROOT:
  38                 return validate_globbing(node->u.root.child);
  39         case IR_OP_LOAD:
  40                 return 0;
  41         case IR_OP_UNARY:
  42                 return validate_globbing(node->u.unary.child);
  43         case IR_OP_BINARY:
  44         {
  45                 struct ir_op *left = node->u.binary.left;
  46                 struct ir_op *right = node->u.binary.right;
  47
  48                 if (left->op == IR_OP_LOAD && right->op == IR_OP_LOAD &&
  49                                 left->data_type == IR_DATA_STRING &&
  50                                 right->data_type == IR_DATA_STRING) {
  51                         /* Test 1. */
  52                         if (left->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR &&
  53                                         right->u.load.u.string.type != IR_LOAD_STRING_TYPE_PLAIN) {
  54                                 fprintf(stderr, "[error] Cannot compare two globbing patterns\n");
  55                                 return -1;
  56                         }
  57
  58                         if (right->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR &&
  59                                         left->u.load.u.string.type != IR_LOAD_STRING_TYPE_PLAIN) {
  60                                 fprintf(stderr, "[error] Cannot compare two globbing patterns\n");
  61                                 return -1;
  62                         }
  63                 }
  64
  65                 if ((left->op == IR_OP_LOAD && left->data_type == IR_DATA_STRING) ||
  66                                 (right->op == IR_OP_LOAD && right->data_type == IR_DATA_STRING)) {
  67                         if ((left->op == IR_OP_LOAD && left->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR) ||
  68                                         (right->op == IR_OP_LOAD && right->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR)) {
  69                                 /* Test 2. */
  70                                 if (node->u.binary.type != AST_OP_EQ &&
  71                                                 node->u.binary.type != AST_OP_NE) {
  72                                         fprintf(stderr, "[error] Only the `==` and `!=` operators are allowed with a globbing pattern\n");
  73                                         return -1;
  74                                 }
  75                         }
  76                 }
  77
  78                 ret = validate_globbing(left);
  79                 if (ret) {
  80                         return ret;
  81                 }
  82
  83                 return validate_globbing(right);
  84         }
  85         case IR_OP_LOGICAL:
  86                 ret = validate_globbing(node->u.logical.left);
  87                 if (ret)
  88                         return ret;
  89                 return validate_globbing(node->u.logical.right);
  90         }
  91 }
  92
  93 /*
  94  * This function recursively validates that:
  95  *
  96  * 1. When there's a binary operation between two literal strings,
  97  *    if one of them has the IR_LOAD_STRING_TYPE_GLOB_STAR type,
  98  *    the other one has the IR_LOAD_STRING_TYPE_PLAIN type.
  99  *
 100  *    In other words, you cannot compare two globbing patterns, except
 101  *    for two globbing patterns with only a star at the end for backward
 102  *    compatibility reasons.
 103  *
 104  * 2. When there's a binary operation between two literal strings, if
 105  *    one of them is a (full) star globbing pattern, the binary
 106  *    operation is either == or !=.
 107  */
 108 LTTNG_HIDDEN
 109 int filter_visitor_ir_validate_globbing(struct filter_parser_ctx *ctx)
 110 {
 111         return validate_globbing(ctx->ir_root);
 112 }