release/src/router/iptables/extensions/libipt_time.c

   1 /* Shared library add-on to iptables to add TIME matching support. */
   2 #include <stdio.h>
   3 #include <netdb.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <stddef.h> /* for 'offsetof' */
   7 #include <getopt.h>
   8
   9 #include <iptables.h>
  10 #include <linux/netfilter_ipv4/ipt_time.h>
  11 #include <time.h>
  12
  13 static int globaldays;
  14
  15 /* Function which prints out usage message. */
  16 static void
  17 help(void)
  18 {
  19         printf(
  20 "TIME v%s options:\n"
  21 " [ --timestart value ] [ --timestop value] [ --days listofdays ] [ --datestart value ] [ --datestop value ]\n"
  22 "          timestart value : HH:MM (default 00:00)\n"
  23 "          timestop  value : HH:MM (default 23:59)\n"
  24 "                            Note: daylight savings time changes are not tracked\n"
  25 "          listofdays value: a list of days to apply\n"
  26 "                            from Mon,Tue,Wed,Thu,Fri,Sat,Sun\n"
  27 "                            Coma speparated, no space, case sensitive.\n"
  28 "                            Defaults to all days.\n"
  29 "          datestart value : YYYY[:MM[:DD[:hh[:mm[:ss]]]]]\n"
  30 "                            If any of month, day, hour, minute or second is\n"
  31 "                            not specified, then defaults to their smallest\n"
  32 "                            1900 <= YYYY < 2037\n"
  33 "                               1 <= MM <= 12\n"
  34 "                               1 <= DD <= 31\n"
  35 "                               0 <= hh <= 23\n"
  36 "                               0 <= mm <= 59\n"
  37 "                               0 <= ss <= 59\n"
  38 "          datestop  value : YYYY[:MM[:DD[:hh[:mm[:ss]]]]]\n"
  39 "                            If the whole option is ommited, default to never stop\n"
  40 "                            If any of month, day, hour, minute or second is\n"
  41 "                            not specified, then default to their smallest\n",
  42 IPTABLES_VERSION);
  43 }
  44
  45 static struct option opts[] = {
  46         { "timestart", 1, 0, '1' },
  47         { "timestop", 1, 0, '2' },
  48         { "days", 1, 0, '3'},
  49         { "datestart", 1, 0, '4' },
  50         { "datestop", 1, 0, '5' },
  51         {0}
  52 };
  53
  54 /* Initialize the match. */
  55 static void
  56 init(struct ipt_entry_match *m, unsigned int *nfcache)
  57 {
  58         struct ipt_time_info *info = (struct ipt_time_info *)m->data;
  59         globaldays = 0;
  60         /* By default, we match on everyday */
  61         info->days_match = 127;
  62         /* By default, we match on every hour:min of the day */
  63         info->time_start = 0;
  64         info->time_stop  = 1439;  /* (23*60+59 = 1439 */
  65         /* By default, we don't have any date-begin or date-end boundaries */
  66         info->date_start = 0;
  67         info->date_stop  = LONG_MAX;
  68 }
  69
  70 /**
  71  * param: part1, a pointer on a string 2 chars maximum long string, that will contain the hours.
  72  * param: part2, a pointer on a string 2 chars maximum long string, that will contain the minutes.
  73  * param: str_2_parse, the string to parse.
  74  * return: 1 if ok, 0 if error.
  75  */
  76 static int
  77 split_time(char **part1, char **part2, const char *str_2_parse)
  78 {
  79         unsigned short int i,j=0;
  80         char *rpart1 = *part1;
  81         char *rpart2 = *part2;
  82         unsigned char found_column = 0;
  83
  84         /* Check the length of the string */
  85         if (strlen(str_2_parse) > 5)
  86                 return 0;
  87         /* parse the first part until the ':' */
  88         for (i=0; i<2; i++)
  89         {
  90                 if (str_2_parse[i] == ':')
  91                         found_column = 1;
  92                 else
  93                         rpart1[i] = str_2_parse[i];
  94         }
  95         if (!found_column)
  96                 i++;
  97         j=i;
  98         /* parse the second part */
  99         for (; i<strlen(str_2_parse); i++)
 100         {
 101                 rpart2[i-j] = str_2_parse[i];
 102         }
 103         /* if we are here, format should be ok. */
 104         return 1;
 105 }
 106
 107 static int
 108 parse_number(char *str, int num_min, int num_max, int *number)
 109 {
 110         /* if the number starts with 0, replace it with a space else
 111         string_to_number() will interpret it as octal !! */
 112         if (strlen(str) == 0)
 113                 return 0;
 114
 115         if ((str[0] == '0') && (str[1] != '\0'))
 116                 str[0] = ' ';
 117
 118         return string_to_number(str, num_min, num_max, number);
 119 }
 120
 121 static void
 122 parse_time_string(int *hour, int *minute, const char *time)
 123 {
 124         char *hours;
 125         char *minutes;
 126         hours = (char *)malloc(3);
 127         minutes = (char *)malloc(3);
 128         memset(hours, 0, 3);
 129         memset(minutes, 0, 3);
 130
 131         if (split_time((char **)&hours, (char **)&minutes, time) == 1)
 132         {
 133                 *hour = 0;
 134                 *minute = 0;
 135                 if ((parse_number((char *)hours, 0, 23, hour) != -1) &&
 136                     (parse_number((char *)minutes, 0, 59, minute) != -1))
 137                 {
 138                         free(hours);
 139                         free(minutes);
 140                         return;
 141                 }
 142         }
 143
 144         free(hours);
 145         free(minutes);
 146
 147         /* If we are here, there was a problem ..*/
 148         exit_error(PARAMETER_PROBLEM,
 149                    "invalid time `%s' specified, should be HH:MM format", time);
 150 }
 151
 152 /* return 1->ok, return 0->error */
 153 static int
 154 parse_day(int *days, int from, int to, const char *string)
 155 {
 156         char *dayread;
 157         char *days_str[7] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
 158         unsigned short int days_of_week[7] = {64, 32, 16, 8, 4, 2, 1};
 159         unsigned int i;
 160
 161         dayread = (char *)malloc(4);
 162         bzero(dayread, 4);
 163         if ((to-from) != 3) {
 164                 free(dayread);
 165                 return 0;
 166         }
 167         for (i=from; i<to; i++)
 168                 dayread[i-from] = string[i];
 169         for (i=0; i<7; i++)
 170                 if (strcmp(dayread, days_str[i]) == 0)
 171                 {
 172                         *days |= days_of_week[i];
 173                         free(dayread);
 174                         return 1;
 175                 }
 176         /* if we are here, we didn't read a valid day */
 177         free(dayread);
 178         return 0;
 179 }
 180
 181 static void
 182 parse_days_string(int *days, const char *daystring)
 183 {
 184         int len;
 185         int i=0;
 186         char *err = "invalid days `%s' specified, should be Sun,Mon,Tue... format";
 187
 188         len = strlen(daystring);
 189         if (len < 3)
 190                 exit_error(PARAMETER_PROBLEM, err, daystring);
 191         while(i<len)
 192         {
 193                 if (parse_day(days, i, i+3, daystring) == 0)
 194                         exit_error(PARAMETER_PROBLEM, err, daystring);
 195                 i += 4;
 196         }
 197 }
 198
 199 static int
 200 parse_date_field(const char *str_to_parse, int str_to_parse_s, int start_pos,
 201                  char *dest, int *next_pos)
 202 {
 203         unsigned char found_value = 0;
 204         unsigned char found_column = 0;
 205         int i;
 206
 207         for (i=0; i<2; i++)
 208         {
 209                 if ((i+start_pos) >= str_to_parse_s) /* don't exit boundaries of the string..  */
 210                         break;
 211                 if (str_to_parse[i+start_pos] == ':')
 212                         found_column = 1;
 213                 else
 214                 {
 215                         found_value = 1;
 216                         dest[i] = str_to_parse[i+start_pos];
 217                 }
 218         }
 219         if (found_value == 0)
 220                 return 0;
 221         *next_pos = i + start_pos;
 222         if (found_column == 0)
 223                 ++(*next_pos);
 224         return 1;
 225 }
 226
 227 static int
 228 split_date(char *year, char *month,  char *day,
 229            char *hour, char *minute, char *second,
 230            const char *str_to_parse)
 231 {
 232         int i;
 233         unsigned char found_column = 0;
 234         int str_to_parse_s = strlen(str_to_parse);
 235
 236         /* Check the length of the string */
 237         if ((str_to_parse_s > 19) ||  /* YYYY:MM:DD:HH:MM:SS */
 238             (str_to_parse_s < 4))     /* YYYY*/
 239                 return 0;
 240
 241         /* Clear the buffers */
 242         memset(year, 0, 4);
 243         memset(month, 0, 2);
 244         memset(day, 0, 2);
 245         memset(hour, 0, 2);
 246         memset(minute, 0, 2);
 247         memset(second, 0, 2);
 248
 249         /* parse the year YYYY */
 250         found_column = 0;
 251         for (i=0; i<5; i++)
 252         {
 253                 if (i >= str_to_parse_s)
 254                         break;
 255                 if (str_to_parse[i] == ':')
 256                 {
 257                         found_column = 1;
 258                         break;
 259                 }
 260                 else
 261                         year[i] = str_to_parse[i];
 262         }
 263         if (found_column == 1)
 264                 ++i;
 265
 266         /* parse the month if it exists */
 267         if (! parse_date_field(str_to_parse, str_to_parse_s, i, month, &i))
 268                 return 1;
 269
 270         if (! parse_date_field(str_to_parse, str_to_parse_s, i, day, &i))
 271                 return 1;
 272
 273         if (! parse_date_field(str_to_parse, str_to_parse_s, i, hour, &i))
 274                 return 1;
 275
 276         if (! parse_date_field(str_to_parse, str_to_parse_s, i, minute, &i))
 277                 return 1;
 278
 279         parse_date_field(str_to_parse, str_to_parse_s, i, second, &i);
 280
 281         /* if we are here, format should be ok. */
 282         return 1;
 283 }
 284
 285 static time_t
 286 parse_date_string(const char *str_to_parse)
 287 {
 288         char year[5];
 289         char month[3];
 290         char day[3];
 291         char hour[3];
 292         char minute[3];
 293         char second[3];
 294         struct tm t;
 295         time_t temp_time;
 296
 297         memset(year, 0, 5);
 298         memset(month, 0, 3);
 299         memset(day, 0, 3);
 300         memset(hour, 0, 3);
 301         memset(minute, 0, 3);
 302         memset(second, 0, 3);
 303
 304         if (split_date(year, month, day, hour, minute, second, str_to_parse) == 1)
 305         {
 306                 memset((void *)&t, 0, sizeof(struct tm));
 307                 t.tm_isdst = -1;
 308                 t.tm_mday = 1;
 309                 if (!((parse_number(year, 1900, 2037, &(t.tm_year)) == -1) ||
 310                       (parse_number(month, 1, 12, &(t.tm_mon)) == -1) ||
 311                       (parse_number(day, 1, 31, &(t.tm_mday)) == -1) ||
 312                       (parse_number(hour, 0, 9999, &(t.tm_hour)) == -1) ||
 313                       (parse_number(minute, 0, 59, &(t.tm_min)) == -1) ||
 314                       (parse_number(second, 0, 59, &(t.tm_sec)) == -1)))
 315                 {
 316                         t.tm_year -= 1900;
 317                         --(t.tm_mon);
 318                         temp_time = mktime(&t);
 319                         if (temp_time != -1)
 320                                 return temp_time;
 321                 }
 322         }
 323         exit_error(PARAMETER_PROBLEM,
 324                    "invalid date `%s' specified, should be YYYY[:MM[:DD[:hh[:mm[:ss]]]]] format", str_to_parse);
 325 }
 326
 327 #define IPT_TIME_START 0x01
 328 #define IPT_TIME_STOP  0x02
 329 #define IPT_TIME_DAYS  0x04
 330 #define IPT_DATE_START 0x08
 331 #define IPT_DATE_STOP  0x10
 332
 333 /* Function which parses command options; returns true if it
 334    ate an option */
 335 static int
 336 parse(int c, char **argv, int invert, unsigned int *flags,
 337       const struct ipt_entry *entry,
 338       unsigned int *nfcache,
 339       struct ipt_entry_match **match)
 340 {
 341         struct ipt_time_info *timeinfo = (struct ipt_time_info *)(*match)->data;
 342         int hours, minutes;
 343         time_t temp_date;
 344
 345         switch (c)
 346         {
 347                 /* timestart */
 348         case '1':
 349                 if (invert)
 350                         exit_error(PARAMETER_PROBLEM,
 351                                    "unexpected '!' with --timestart");
 352                 if (*flags & IPT_TIME_START)
 353                         exit_error(PARAMETER_PROBLEM,
 354                                    "Can't specify --timestart twice");
 355                 parse_time_string(&hours, &minutes, optarg);
 356                 timeinfo->time_start = (hours * 60) + minutes;
 357                 *flags |= IPT_TIME_START;
 358                 break;
 359                 /* timestop */
 360         case '2':
 361                 if (invert)
 362                         exit_error(PARAMETER_PROBLEM,
 363                                    "unexpected '!' with --timestop");
 364                 if (*flags & IPT_TIME_STOP)
 365                         exit_error(PARAMETER_PROBLEM,
 366                                    "Can't specify --timestop twice");
 367                 parse_time_string(&hours, &minutes, optarg);
 368                 timeinfo->time_stop = (hours * 60) + minutes;
 369                 *flags |= IPT_TIME_STOP;
 370                 break;
 371
 372                 /* days */
 373         case '3':
 374                 if (invert)
 375                         exit_error(PARAMETER_PROBLEM,
 376                                    "unexpected '!' with --days");
 377                 if (*flags & IPT_TIME_DAYS)
 378                         exit_error(PARAMETER_PROBLEM,
 379                                    "Can't specify --days twice");
 380                 parse_days_string(&globaldays, optarg);
 381                 timeinfo->days_match = globaldays;
 382                 *flags |= IPT_TIME_DAYS;
 383                 break;
 384
 385                 /* datestart */
 386         case '4':
 387                 if (invert)
 388                         exit_error(PARAMETER_PROBLEM,
 389                                    "unexpected '!' with --datestart");
 390                 if (*flags & IPT_DATE_START)
 391                         exit_error(PARAMETER_PROBLEM,
 392                                    "Can't specify --datestart twice");
 393                 temp_date = parse_date_string(optarg);
 394                 timeinfo->date_start = temp_date;
 395                 *flags |= IPT_DATE_START;
 396                 break;
 397
 398                 /* datestop*/
 399         case '5':
 400                 if (invert)
 401                         exit_error(PARAMETER_PROBLEM,
 402                                    "unexpected '!' with --datestop");
 403                 if (*flags & IPT_DATE_STOP)
 404                         exit_error(PARAMETER_PROBLEM,
 405                                    "Can't specify --datestop twice");
 406                 temp_date = parse_date_string(optarg);
 407                 timeinfo->date_stop = temp_date;
 408                 *flags |= IPT_DATE_STOP;
 409                 break;
 410         default:
 411                 return 0;
 412         }
 413         return 1;
 414 }
 415
 416 /* Final check */
 417 static void
 418 final_check(unsigned int flags)
 419 {
 420         /* Nothing to do */
 421 }
 422
 423
 424 static void
 425 print_days(int daynum)
 426 {
 427         char *days[7] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
 428         unsigned short int days_of_week[7] = {64, 32, 16, 8, 4, 2, 1};
 429         unsigned short int i, nbdays=0;
 430
 431         for (i=0; i<7; i++) {
 432                 if ((days_of_week[i] & daynum) == days_of_week[i])
 433                 {
 434                         if (nbdays>0)
 435                                 printf(",%s", days[i]);
 436                         else
 437                                 printf("%s", days[i]);
 438                         ++nbdays;
 439                 }
 440         }
 441         printf(" ");
 442 }
 443
 444 static void
 445 divide_time(int fulltime, int *hours, int *minutes)
 446 {
 447         *hours = fulltime / 60;
 448         *minutes = fulltime % 60;
 449 }
 450
 451 static void
 452 print_date(time_t date, char *command)
 453 {
 454         struct tm *t;
 455
 456         /* If it's default value, don't print..*/
 457         if (((date == 0) || (date == LONG_MAX)) && (command != NULL))
 458                 return;
 459         t = localtime(&date);
 460         if (command != NULL)
 461                 printf("%s %d:%d:%d:%d:%d:%d ", command, (t->tm_year + 1900), (t->tm_mon + 1),
 462                         t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec);
 463         else
 464                 printf("%d-%d-%d %d:%d:%d ", (t->tm_year + 1900), (t->tm_mon + 1),
 465                         t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec);
 466 }
 467
 468 /* Prints out the matchinfo. */
 469 static void
 470 print(const struct ipt_ip *ip,
 471       const struct ipt_entry_match *match,
 472       int numeric)
 473 {
 474         struct ipt_time_info *time = ((struct ipt_time_info *)match->data);
 475         int hour_start, hour_stop, minute_start, minute_stop;
 476
 477         divide_time(time->time_start, &hour_start, &minute_start);
 478         divide_time(time->time_stop, &hour_stop, &minute_stop);
 479         printf("TIME ");
 480         if (time->time_start != 0)
 481                 printf("from %d:%d ", hour_start, minute_start);
 482         if (time->time_stop != 1439) /* 23*60+59 = 1439 */
 483                 printf("to %d:%d ", hour_stop, minute_stop);
 484         printf("on ");
 485         if (time->days_match == 127)
 486                 printf("all days ");
 487         else
 488                 print_days(time->days_match);
 489         if (time->date_start != 0)
 490         {
 491                 printf("starting from ");
 492                 print_date(time->date_start, NULL);
 493         }
 494         if (time->date_stop != LONG_MAX)
 495         {
 496                 printf("until date ");
 497                 print_date(time->date_stop, NULL);
 498         }
 499 }
 500
 501 /* Saves the data in parsable form to stdout. */
 502 static void
 503 save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
 504 {
 505         struct ipt_time_info *time = ((struct ipt_time_info *)match->data);
 506         int hour_start, hour_stop, minute_start, minute_stop;
 507
 508         divide_time(time->time_start, &hour_start, &minute_start);
 509         divide_time(time->time_stop, &hour_stop, &minute_stop);
 510         if (time->time_start != 0)
 511                 printf("--timestart %.2d:%.2d ",
 512                         hour_start, minute_start);
 513
 514         if (time->time_stop != 1439) /* 23*60+59 = 1439 */
 515                 printf("--timestop %.2d:%.2d ",
 516                         hour_stop, minute_stop);
 517
 518         if (time->days_match != 127)
 519         {
 520                 printf("--days ");
 521                 print_days(time->days_match);
 522                 printf(" ");
 523         }
 524         print_date(time->date_start, "--datestart");
 525         print_date(time->date_stop, "--datestop");
 526 }
 527
 528 /* have to use offsetof() instead of IPT_ALIGN(), since kerneltime must not
 529  * be compared when user deletes rule with '-D' */
 530 static
 531 struct iptables_match timestruct = {
 532         .next           = NULL,
 533         .name           = "time",
 534         .version        = IPTABLES_VERSION,
 535         .size           = IPT_ALIGN(sizeof(struct ipt_time_info)),
 536         .userspacesize  = offsetof(struct ipt_time_info, kerneltime),
 537         .help           = &help,
 538         .init           = &init,
 539         .parse          = &parse,
 540         .final_check    = &final_check,
 541         .print          = &print,
 542         .save           = &save,
 543         .extra_opts     = opts
 544 };
 545
 546 void _init(void)
 547 {
 548         register_match(&timestruct);
 549 }