summaryrefslogtreecommitdiffstats
path: root/extensions/libxt_time.c
blob: a766f11007acf2cb944e99b0067ce61cb6d666b7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
/*
 *	libxt_time - iptables part for xt_time
 *	Copyright  Jan Engelhardt <jengelh@computergmbh.de>, 2007
 *
 *	libxt_time.c is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 or 3 of the License.
 *
 *	Based on libipt_time.c.
 */
#include <sys/types.h>
#include <getopt.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <time.h>
#include <linux/netfilter/xt_time.h>
#include <xtables.h>
#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*x))

enum { /* getopt "seen" bits */
	F_DATE_START = 1 << 0,
	F_DATE_STOP  = 1 << 1,
	F_TIME_START = 1 << 2,
	F_TIME_STOP  = 1 << 3,
	F_MONTHDAYS  = 1 << 4,
	F_WEEKDAYS   = 1 << 5,
	F_TIMEZONE   = 1 << 6,
};

static const char *const week_days[] = {
	NULL, "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun",
};

static const struct option time_opts[] = {
	{"datestart", true,  NULL, 'D'},
	{"datestop",  true,  NULL, 'E'},
	{"timestart", true,  NULL, 'X'},
	{"timestop",  true,  NULL, 'Y'},
	{"weekdays",  true,  NULL, 'w'},
	{"monthdays", true,  NULL, 'm'},
	{"localtz",   false, NULL, 'l'},
	{"utc",       false, NULL, 'u'},
	{NULL},
};

static void time_help(void)
{
	printf(
"TIME v%s options:\n"
"  --datestart time     Start and stop time, to be given in ISO 8601\n"
"  --datestop time      (YYYY[-MM[-DD[Thh[:mm[:ss]]]]])\n"
"  --timestart time     Start and stop daytime (hh:mm[:ss])\n"
"  --timestop time      (between 00:00:00 and 23:59:59)\n"
"  --monthdays value    List of days on which to match, separated by comma\n"
"                       (Possible days: 1 to 31; defaults to all)\n"
"  --weekdays value     List of weekdays on which to match, sep. by comma\n"
"                       (Possible days: Mon,Tue,Wed,Thu,Fri,Sat,Sun or 1 to 7\n"
"                       Defaults to all weekdays.)\n"
"  --localtz/--utc      Time is interpreted as UTC/local time\n",
IPTABLES_VERSION);
}

static void time_init(struct xt_entry_match *m)
{
	struct xt_time_info *info = (void *)m->data;

	/* By default, we match on every day, every daytime */
	info->monthdays_match = XT_TIME_ALL_MONTHDAYS;
	info->weekdays_match  = XT_TIME_ALL_WEEKDAYS;
	info->daytime_start   = XT_TIME_MIN_DAYTIME;
	info->daytime_stop    = XT_TIME_MAX_DAYTIME;

	/* ...and have no date-begin or date-end boundary */
	info->date_start = 0;
	info->date_stop  = LONG_MAX;

	/* local time is default */
	info->flags |= XT_TIME_LOCAL_TZ;
}

static time_t time_parse_date(const char *s, bool end)
{
	unsigned int month = 1, day = 1, hour = 0, minute = 0, second = 0;
	unsigned int year  = end ? 2038 : 1970;
	const char *os = s;
	struct tm tm;
	time_t ret;
	char *e;

	year = strtoul(s, &e, 10);
	if ((*e != '-' && *e != '\0') || year < 1970 || year > 2038)
		goto out;
	if (*e == '\0')
		goto eval;

	s = e + 1;
	month = strtoul(s, &e, 10);
	if ((*e != '-' && *e != '\0') || month > 12)
		goto out;
	if (*e == '\0')
		goto eval;

	s = e + 1;
	day = strtoul(s, &e, 10);
	if ((*e != 'T' && *e != '\0') || day > 31)
		goto out;
	if (*e == '\0')
		goto eval;

	s = e + 1;
	hour = strtoul(s, &e, 10);
	if ((*e != ':' && *e != '\0') || hour > 23)
		goto out;
	if (*e == '\0')
		goto eval;

	s = e + 1;
	minute = strtoul(s, &e, 10);
	if ((*e != ':' && *e != '\0') || minute > 59)
		goto out;
	if (*e == '\0')
		goto eval;

	s = e + 1;
	second = strtoul(s, &e, 10);
	if (*e != '\0' || second > 59)
		goto out;

 eval:
	tm.tm_year = year - 1900;
	tm.tm_mon  = month - 1;
	tm.tm_mday = day;
	tm.tm_hour = hour;
	tm.tm_min  = minute;
	tm.tm_sec  = second;
	ret = mktime(&tm);
	if (ret >= 0)
		return ret;
	perror("mktime");
	exit_error(OTHER_PROBLEM, "mktime returned an error");

 out:
	exit_error(PARAMETER_PROBLEM, "Invalid date \"%s\" specified. Should "
	           "be YYYY[-MM[-DD[Thh[:mm[:ss]]]]]", os);
	return -1;
}

static unsigned int time_parse_minutes(const char *s)
{
	unsigned int hour, minute, second = 0;
	char *e;

	hour = strtoul(s, &e, 10);
	if (*e != ':' || hour > 23)
		goto out;

	s = e + 1;
	minute = strtoul(s, &e, 10);
	if ((*e != ':' && *e != '\0') || minute > 59)
		goto out;
	if (*e == '\0')
		goto eval;

	s = e + 1;
	second = strtoul(s, &e, 10);
	if (*e != '\0' || second > 59)
		goto out;

 eval:
	return 60 * 60 * hour + 60 * minute + second;

 out:
	exit_error(PARAMETER_PROBLEM, "invalid time \"%s\" specified, "
	           "should be hh:mm[:ss] format and within the boundaries", s);
	return -1;
}

static const char *my_strseg(char *buf, unsigned int buflen,
    const char **arg, char delim)
{
	const char *sep;

	if (*arg == NULL || **arg == '\0')
		return NULL;
	sep = strchr(*arg, delim);
	if (sep == NULL) {
		snprintf(buf, buflen, "%s", *arg);
		*arg = NULL;
		return buf;
	}
	snprintf(buf, buflen, "%.*s", (unsigned int)(sep - *arg), *arg);
	*arg = sep + 1;
	return buf;
}

static uint32_t time_parse_monthdays(const char *arg)
{
	char day[3], *err = NULL;
	uint32_t ret = 0;
	unsigned int i;

	while (my_strseg(day, sizeof(day), &arg, ',') != NULL) {
		i = strtoul(day, &err, 0);
		if ((*err != ',' && *err != '\0') || i > 31)
			exit_error(PARAMETER_PROBLEM,
			           "%s is not a valid day for --monthdays", day);
		ret |= 1 << i;
	}

	return ret;
}

static unsigned int time_parse_weekdays(const char *arg)
{
	char day[4], *err = NULL;
	unsigned int i, ret = 0;
	bool valid;

	while (my_strseg(day, sizeof(day), &arg, ',') != NULL) {
		i = strtoul(day, &err, 0);
		if (*err == '\0') {
			if (i == 0)
				exit_error(PARAMETER_PROBLEM,
				           "No, the week does NOT begin with Sunday.");
			ret |= 1 << i;
			continue;
		}

		valid = false;
		for (i = 1; i < ARRAY_SIZE(week_days); ++i)
			if (strncmp(day, week_days[i], 2) == 0) {
				ret |= 1 << i;
				valid = true;
			}

		if (!valid)
			exit_error(PARAMETER_PROBLEM,
			           "%s is not a valid day specifier", day);
	}

	return ret;
}

static int time_parse(int c, char **argv, int invert, unsigned int *flags,
                      const void *entry, struct xt_entry_match **match)
{
	struct xt_time_info *info = (void *)(*match)->data;

	switch (c) {
	case 'D': /* --datestart */
		if (*flags & F_DATE_START)
			exit_error(PARAMETER_PROBLEM,
			           "Cannot specify --datestart twice");
		if (invert)
			exit_error(PARAMETER_PROBLEM,
			           "Unexpected \"!\" with --datestart");
		info->date_start = time_parse_date(optarg, false);
		*flags |= F_DATE_START;
		return 1;
	case 'E': /* --datestop */
		if (*flags & F_DATE_STOP)
			exit_error(PARAMETER_PROBLEM,
			           "Cannot specify --datestop more than once");
		if (invert)
			exit_error(PARAMETER_PROBLEM,
			           "unexpected \"!\" with --datestop");
		info->date_stop = time_parse_date(optarg, true);
		*flags |= F_DATE_STOP;
		return 1;
	case 'X': /* --timestart */
		if (*flags & F_TIME_START)
			exit_error(PARAMETER_PROBLEM,
			           "Cannot specify --timestart more than once");
		if (invert)
			exit_error(PARAMETER_PROBLEM,
			           "Unexpected \"!\" with --timestart");
		info->daytime_start = time_parse_minutes(optarg);
		*flags |= F_TIME_START;
		return 1;
	case 'Y': /* --timestop */
		if (*flags & F_TIME_STOP)
			exit_error(PARAMETER_PROBLEM,
			           "Cannot specify --timestop more than once");
		if (invert)
			exit_error(PARAMETER_PROBLEM,
			           "Unexpected \"!\" with --timestop");
		info->daytime_stop = time_parse_minutes(optarg);
		*flags |= F_TIME_STOP;
		return 1;
	case 'l': /* --localtz */
		if (*flags & F_TIMEZONE)
			exit_error(PARAMETER_PROBLEM,
			           "Can only specify exactly one of --localtz or --utc");
		info->flags |= XT_TIME_LOCAL_TZ;
		*flags |= F_TIMEZONE;
		return 1;
	case 'm': /* --monthdays */
		if (*flags & F_MONTHDAYS)
			exit_error(PARAMETER_PROBLEM,
			           "Cannot specify --monthdays more than once");
		info->monthdays_match = time_parse_monthdays(optarg);
		if (invert)
			info->monthdays_match ^= XT_TIME_ALL_MONTHDAYS;
		*flags |= F_MONTHDAYS;
		return 1;
	case 'w': /* --weekdays */
		if (*flags & F_WEEKDAYS)
			exit_error(PARAMETER_PROBLEM,
			           "Cannot specify --weekdays more than once");
		info->weekdays_match = time_parse_weekdays(optarg);
		if (invert)
			info->weekdays_match ^= XT_TIME_ALL_WEEKDAYS;
		*flags |= F_WEEKDAYS;
		return 1;
	case 'u': /* --utc */
		if (*flags & F_TIMEZONE)
			exit_error(PARAMETER_PROBLEM,
			           "Can only specify exactly one of --localtz or --utc");
		info->flags &= ~XT_TIME_LOCAL_TZ;
		*flags |= F_TIMEZONE;
		return 1;
	}
	return 0;
}

static void time_print_date(time_t date, const char *command)
{
	struct tm *t;

	/* If it is the default value, do not print it. */
	if (date == 0 || date == LONG_MAX)
		return;

	t = localtime(&date);
	if (command != NULL)
		/*
		 * Need a contiguous string (no whitespaces), hence using
		 * the ISO 8601 "T" variant.
		 */
		printf("%s %04u-%02u-%02uT%02u:%02u:%02u ",
		       command, t->tm_year + 1900, t->tm_mon + 1,
		       t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec);
	else
		printf("%04u-%02u-%02u %02u:%02u:%02u ",
		       t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
		       t->tm_hour, t->tm_min, t->tm_sec);
}

static void time_print_monthdays(uint32_t mask, bool human_readable)
{
	unsigned int i, nbdays = 0;

	for (i = 1; i <= 31; ++i)
		if (mask & (1 << i)) {
			if (nbdays++ > 0)
				printf(",");
			printf("%u", i);
			if (human_readable)
				switch (i % 10) {
					case 1:
						printf("st");
						break;
					case 2:
						printf("nd");
						break;
					case 3:
						printf("rd");
						break;
					default:
						printf("th");
						break;
				}
		}
	printf(" ");
}

static void time_print_weekdays(unsigned int mask)
{
	unsigned int i, nbdays = 0;

	for (i = 1; i <= 7; ++i)
		if (mask & (1 << i)) {
			if (nbdays > 0)
				printf(",%s", week_days[i]);
			else
				printf("%s", week_days[i]);
			++nbdays;
		}
	printf(" ");
}

static inline void divide_time(unsigned int fulltime, unsigned int *hours,
    unsigned int *minutes, unsigned int *seconds)
{
	*seconds  = fulltime % 60;
	fulltime /= 60;
	*minutes  = fulltime % 60;
	*hours    = fulltime / 60;
}

static void time_print(const void *ip, const struct xt_entry_match *match,
                       int numeric)
{
	struct xt_time_info *info = (void *)match->data;
	unsigned int h, m, s;

	printf("TIME ");

	if (info->daytime_start != XT_TIME_MIN_DAYTIME ||
	    info->daytime_stop != XT_TIME_MAX_DAYTIME) {
		divide_time(info->daytime_start, &h, &m, &s);
		printf("from %02u:%02u:%02u ", h, m, s);
		divide_time(info->daytime_stop, &h, &m, &s);
		printf("to %02u:%02u:%02u ", h, m, s);
	}
	if (info->weekdays_match != XT_TIME_ALL_WEEKDAYS) {
		printf("on ");
		time_print_weekdays(info->weekdays_match);
	}
	if (info->monthdays_match != XT_TIME_ALL_MONTHDAYS) {
		printf("on ");
		time_print_monthdays(info->monthdays_match, true);
	}
	if (info->date_start != 0) {
		printf("starting from ");
		time_print_date(info->date_start, NULL);
	}
	if (info->date_stop != LONG_MAX) {
		printf("until date ");
		time_print_date(info->date_stop, NULL);
	}
	if (!(info->flags & XT_TIME_LOCAL_TZ))
		printf("UTC ");
}

static void time_save(const void *ip, const struct xt_entry_match *match)
{
	const struct xt_time_info *info = (const void *)match->data;
	unsigned int h, m, s;

	if (info->daytime_start != XT_TIME_MIN_DAYTIME ||
	    info->daytime_stop != XT_TIME_MAX_DAYTIME) {
		divide_time(info->daytime_start, &h, &m, &s);
		printf("--timestart %02u:%02u:%02u ", h, m, s);
		divide_time(info->daytime_stop, &h, &m, &s);
		printf("--timestop %02u:%02u:%02u ", h, m, s);
	}
	if (info->monthdays_match != XT_TIME_ALL_MONTHDAYS) {
		printf("--monthdays ");
		time_print_monthdays(info->monthdays_match, false);
	}
	if (info->weekdays_match != XT_TIME_ALL_WEEKDAYS) {
		printf("--weekdays ");
		time_print_weekdays(info->weekdays_match);
		printf(" ");
	}
	time_print_date(info->date_start, "--datestart");
	time_print_date(info->date_stop, "--datestop");
	if (!(info->flags & XT_TIME_LOCAL_TZ))
		printf("--utc ");
}

static struct xtables_match time_reg = {
	.name          = "time",
	.family        = AF_INET,
	.version       = IPTABLES_VERSION,
	.size          = XT_ALIGN(sizeof(struct xt_time_info)),
	.userspacesize = XT_ALIGN(sizeof(struct xt_time_info)),
	.help          = time_help,
	.init          = time_init,
	.parse         = time_parse,
	.print         = time_print,
	.save          = time_save,
	.extra_opts    = time_opts,
};

static struct xtables_match time6_reg = {
	.name          = "time",
	.family        = AF_INET6,
	.version       = IPTABLES_VERSION,
	.size          = XT_ALIGN(sizeof(struct xt_time_info)),
	.userspacesize = XT_ALIGN(sizeof(struct xt_time_info)),
	.help          = time_help,
	.init          = time_init,
	.parse         = time_parse,
	.print         = time_print,
	.save          = time_save,
	.extra_opts    = time_opts,
};

void _init(void)
{
	xtables_register_match(&time_reg);
	xtables_register_match(&time6_reg);
}