yarac.c

/*
Copyright (c) 2013. The YARA Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

#ifndef _WIN32

#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <time.h>

#else

#include <windows.h>
#include "getopt.h"

#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <yara.h>

#include "config.h"

#ifndef MAX_PATH
#define MAX_PATH 255
#endif


int show_warnings = TRUE;


void show_help()
{
  printf("usage:  yarac [OPTION]... [RULE_FILE]... OUTPUT_FILE\n");
  printf("options:\n");
  printf("  -d <identifier>=<value>   define external variable.\n");
  printf("  -w                        disable warnings.\n");
  printf("  -v                        show version information.\n");
  printf("\nReport bugs to: <%s>\n", PACKAGE_BUGREPORT);
}


int is_numeric(
    const char *str)
{
  while(*str)
  {
    if(!isdigit(*str++))
      return 0;
  }

  return 1;
}


int process_cmd_line(
    YR_COMPILER* compiler,
    int argc,
    char const* argv[])
{
  char* equal_sign;
  char* value;
  char c;
  opterr = 0;

  while ((c = getopt (argc, (char**) argv, "wvd:")) != -1)
  {
    switch (c)
    {
      case 'v':
        printf("%s\n", PACKAGE_STRING);
        return 0;

      case 'w':
        show_warnings = FALSE;
        break;

      case 'd':
        equal_sign = strchr(optarg, '=');

        if (equal_sign != NULL)
        {
          *equal_sign = '\0';
          value = equal_sign + 1;

          if (is_numeric(value))
          {
            yr_compiler_define_integer_variable(
                compiler,
                optarg,
                atol(value));
          }
          else if (strcmp(value, "true") == 0  || strcmp(value, "false") == 0)
          {
            yr_compiler_define_boolean_variable(
                compiler,
                optarg,
                strcmp(value, "true") == 0);
          }
          else
          {
            yr_compiler_define_string_variable(
                compiler,
                optarg,
                value);
          }
        }
        break;

      case '?':

        if (isprint(optopt))
        {
          fprintf(stderr, "Unknown option `-%c'.\n", optopt);
        }
        else
        {
          fprintf(stderr, "Unknown option character `\\x%x'.\n", optopt);
        }
        return 0;

      default:
        abort();
    }
  }

  return 1;
}


void report_error(
    int error_level,
    const char* file_name,
    int line_number,
    const char* message)
{
  if (error_level == YARA_ERROR_LEVEL_ERROR)
  {
    fprintf(stderr, "%s(%d): error: %s\n", file_name, line_number, message);
  }
  else
  {
    if (show_warnings)
      fprintf(stderr, "%s(%d): warning: %s\n", file_name, line_number, message);
  }
}


int main(
    int argc,
    char const* argv[])
{
  int i, result, errors;

  YR_COMPILER* compiler;
  YR_RULES* rules;
  FILE* rule_file;

  result = yr_initialize();

  if (result != ERROR_SUCCESS)
    return EXIT_FAILURE;

  if (yr_compiler_create(&compiler) != ERROR_SUCCESS)
  {
    yr_finalize();
    return EXIT_FAILURE;
  }

  if (!process_cmd_line(compiler, argc, argv))
  {
    yr_compiler_destroy(compiler);
    yr_finalize();
    return EXIT_FAILURE;
  }

  if (argc == 1 || optind == argc)
  {
    show_help();
    yr_compiler_destroy(compiler);
    yr_finalize();
    return EXIT_FAILURE;
  }

  yr_compiler_set_callback(compiler, report_error);

  for (i = optind; i < argc - 1; i++)
  {
    rule_file = fopen(argv[i], "r");

    if (rule_file != NULL)
    {
      errors = yr_compiler_add_file(compiler, rule_file, NULL, argv[i]);

      fclose(rule_file);

      if (errors) // errors during compilation
      {
        yr_compiler_destroy(compiler);
        yr_finalize();
        return EXIT_FAILURE;
      }
    }
    else
    {
      fprintf(stderr, "could not open file: %s\n", argv[i]);
    }
  }

  result = yr_compiler_get_rules(compiler, &rules);

  if (result != ERROR_SUCCESS)
  {
    fprintf(stderr, "error: %d\n", result);
    return EXIT_FAILURE;
  }

  result = yr_rules_save(rules, argv[argc - 1]);

  if (result != ERROR_SUCCESS)
  {
    fprintf(stderr, "error: %d\n", result);
    return EXIT_FAILURE;
  }

  yr_rules_destroy(rules);
  yr_compiler_destroy(compiler);

  yr_finalize();

  return EXIT_SUCCESS;
}