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

   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 "filter-ast.hpp"
  13 #include "filter-ir.hpp"
  14 #include "filter-parser.hpp"
  15
  16 #include <common/compat/errno.hpp>
  17 #include <common/macros.hpp>
  18
  19 #include <inttypes.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24
  25 static int validate_globbing(struct ir_op *node)
  26 {
  27         int ret;
  28
  29         switch (node->op) {
  30         case IR_OP_UNKNOWN:
  31         default:
  32                 fprintf(stderr, "[error] %s: unknown op type\n", __func__);
  33                 return -EINVAL;
  34
  35         case IR_OP_ROOT:
  36                 return validate_globbing(node->u.root.child);
  37         case IR_OP_LOAD:
  38                 return 0;
  39         case IR_OP_UNARY:
  40                 return validate_globbing(node->u.unary.child);
  41         case IR_OP_BINARY:
  42         {
  43                 struct ir_op *left = node->u.binary.left;
  44                 struct ir_op *right = node->u.binary.right;
  45
  46                 if (left->op == IR_OP_LOAD && right->op == IR_OP_LOAD &&
  47                     left->data_type == IR_DATA_STRING && right->data_type == IR_DATA_STRING) {
  48                         /* Test 1. */
  49                         if (left->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR &&
  50                             right->u.load.u.string.type != IR_LOAD_STRING_TYPE_PLAIN) {
  51                                 fprintf(stderr, "[error] Cannot compare two globbing patterns\n");
  52                                 return -1;
  53                         }
  54
  55                         if (right->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR &&
  56                             left->u.load.u.string.type != IR_LOAD_STRING_TYPE_PLAIN) {
  57                                 fprintf(stderr, "[error] Cannot compare two globbing patterns\n");
  58                                 return -1;
  59                         }
  60                 }
  61
  62                 if ((left->op == IR_OP_LOAD && left->data_type == IR_DATA_STRING) ||
  63                     (right->op == IR_OP_LOAD && right->data_type == IR_DATA_STRING)) {
  64                         if ((left->op == IR_OP_LOAD &&
  65                              left->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR) ||
  66                             (right->op == IR_OP_LOAD &&
  67                              right->u.load.u.string.type == IR_LOAD_STRING_TYPE_GLOB_STAR)) {
  68                                 /* Test 2. */
  69                                 if (node->u.binary.type != AST_OP_EQ &&
  70                                     node->u.binary.type != AST_OP_NE) {
  71                                         fprintf(stderr,
  72                                                 "[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 int filter_visitor_ir_validate_globbing(struct filter_parser_ctx *ctx)
 109 {
 110         return validate_globbing(ctx->ir_root);
 111 }