summaryrefslogtreecommitdiffstats
path: root/extensions/libipt_time.c
blob: 1ad5058a308c4940a18ef8c8ef613ad6e0f72768 (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
/* Shared library add-on to iptables to add TIME matching support. */
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>

#include <iptables.h>
#include <linux/netfilter_ipv4/ipt_time.h>
#include <time.h>

static int globaldays;

/* Function which prints out usage message. */
static void
help(void)
{
	printf(
"TIME v%s options:\n"
" --timestart value --timestop value --days listofdays\n"
"          timestart value : HH:MM\n"
"          timestop  value : HH:MM\n"
"          listofdays value: a list of days to apply -> ie. Mon,Tue,Wed,Thu,Fri. Case sensitive\n",
NETFILTER_VERSION);
}

static struct option opts[] = {
	{ "timestart", 1, 0, '1' },
	{ "timestop", 1, 0, '2' },
	{ "days", 1, 0, '3'},
	{0}
};

/* Initialize the match. */
static void
init(struct ipt_entry_match *m, unsigned int *nfcache)
{
	/* caching not yet implemented */
        *nfcache |= NFC_UNKNOWN;
	globaldays = 0;
}

/**
 * param: part1, a pointer on a string 2 chars maximum long string, that will contain the hours.
 * param: part2, a pointer on a string 2 chars maximum long string, that will contain the minutes.
 * param: str_2_parse, the string to parse.
 * return: 1 if ok, 0 if error.
 */
static int
split_time(char **part1, char **part2, const char *str_2_parse)
{
	unsigned short int i,j=0;
	char *rpart1 = *part1;
	char *rpart2 = *part2;
	unsigned char found_column = 0;

	/* Check the length of the string */
	if (strlen(str_2_parse) > 5)
		return 0;
	/* parse the first part until the ':' */
	for (i=0; i<2; i++)
	{
		if (str_2_parse[i] == ':')
			found_column = 1;
		else
			rpart1[i] = str_2_parse[i];
	}
	if (!found_column)
		i++;
	j=i;
	/* parse the second part */
	for (; i<strlen(str_2_parse); i++)
	{
		rpart2[i-j] = str_2_parse[i];
	}
	/* if we are here, format should be ok. */
	return 1;
}

static void
parse_time_string(unsigned int *hour, unsigned int *minute, const char *time)
{
	char *hours;
	char *minutes;

	hours = (char *)malloc(3);
	minutes = (char *)malloc(3);
	bzero((void *)hours, 3);
	bzero((void *)minutes, 3);

	if (split_time(&hours, &minutes, time) == 1)
	{
                /* if the number starts with 0, replace it with a space else
                   this string_to_number will interpret it as octal !! */
                if ((hours[0] == '0') && (hours[1] != '\0'))
			hours[0] = ' ';
		if ((minutes[0] == '0') && (minutes[1] != '\0'))
			minutes[0] = ' ';

		if((string_to_number(hours, 0, 23, hour) == -1) ||
			(string_to_number(minutes, 0, 59, minute) == -1)) {
			*hour = *minute = (-1);
		}
	}
	if ((*hour != (-1)) && (*minute != (-1))) {
		free(hours);
		free(minutes);
		return;
	}

	/* If we are here, there was a problem ..*/
	exit_error(PARAMETER_PROBLEM,
		   "invalid time `%s' specified, should be HH:MM format", time);
}

/* return 1->ok, return 0->error */
static int
parse_day(int *days, int from, int to, const char *string)
{
	char *dayread;
	char *days_str[7] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
	unsigned short int days_of_week[7] = {64, 32, 16, 8, 4, 2, 1};
	unsigned int i;

	dayread = (char *)malloc(4);
	bzero(dayread, 4);
	if ((to-from) != 3) {
		free(dayread);
		return 0;
	}
	for (i=from; i<to; i++)
		dayread[i-from] = string[i];
	for (i=0; i<7; i++)
		if (strcmp(dayread, days_str[i]) == 0)
		{
			*days |= days_of_week[i];
			free(dayread);
			return 1;
		}
	/* if we are here, we didn't read a valid day */
	free(dayread);
	return 0;
}

static void
parse_days_string(int *days, const char *daystring)
{
	int len;
	int i=0;
	char *err = "invalid days `%s' specified, should be Sun,Mon,Tue... format";

	len = strlen(daystring);
	if (len < 3)
		exit_error(PARAMETER_PROBLEM, err, daystring);	
	while(i<len)
	{
		if (parse_day(days, i, i+3, daystring) == 0)
			exit_error(PARAMETER_PROBLEM, err, daystring);
		i += 4;
	}
}

#define IPT_TIME_START 0x01
#define IPT_TIME_STOP  0x02
#define IPT_TIME_DAYS  0x04


/* Function which parses command options; returns true if it
   ate an option */
static int
parse(int c, char **argv, int invert, unsigned int *flags,
      const struct ipt_entry *entry,
      unsigned int *nfcache,
      struct ipt_entry_match **match)
{
	struct ipt_time_info *timeinfo = (struct ipt_time_info *)(*match)->data;
	int hours, minutes;

	switch (c)
	{
		/* timestart */
	case '1':
		if (invert)
			exit_error(PARAMETER_PROBLEM,
                                   "unexpected '!' with --timestart");
		if (*flags & IPT_TIME_START)
                        exit_error(PARAMETER_PROBLEM,
                                   "Can't specify --timestart twice");
		parse_time_string(&hours, &minutes, optarg);
		timeinfo->time_start = (hours * 60) + minutes;
		*flags |= IPT_TIME_START;
		break;
		/* timestop */
	case '2':
		if (invert)
			exit_error(PARAMETER_PROBLEM,
                                   "unexpected '!' with --timestop");
		if (*flags & IPT_TIME_STOP)
                        exit_error(PARAMETER_PROBLEM,
                                   "Can't specify --timestop twice");
		parse_time_string(&hours, &minutes, optarg);
		timeinfo->time_stop = (hours * 60) + minutes;
		*flags |= IPT_TIME_STOP;
		break;

		/* days */
	case '3':
		if (invert)
			exit_error(PARAMETER_PROBLEM,
                                   "unexpected '!' with --days");
		if (*flags & IPT_TIME_DAYS)
                        exit_error(PARAMETER_PROBLEM,
                                   "Can't specify --days twice");
		parse_days_string(&globaldays, optarg);
		timeinfo->days_match = globaldays;
		*flags |= IPT_TIME_DAYS;
		break;
	default:
		return 0;
	}
	return 1;
}

/* Final check; must have specified --timestart --timestop --days. */
static void
final_check(unsigned int flags)
{
	if (flags != (IPT_TIME_START | IPT_TIME_STOP | IPT_TIME_DAYS))
		exit_error(PARAMETER_PROBLEM,
			   "TIME match: You must specify `--timestart --timestop and --days'");
}


static void
print_days(int daynum)
{
	char *days[7] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
	unsigned short int days_of_week[7] = {64, 32, 16, 8, 4, 2, 1};
	unsigned short int i, nbdays=0;

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

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

/* Prints out the matchinfo. */
static void
print(const struct ipt_ip *ip,
      const struct ipt_entry_match *match,
      int numeric)
{
	struct ipt_time_info *time = ((struct ipt_time_info *)match->data);
	int hour_start, hour_stop, minute_start, minute_stop;

	divide_time(time->time_start, &hour_start, &minute_start);
	divide_time(time->time_stop, &hour_stop, &minute_stop);
	printf(" TIME from %d:%d to %d:%d on ",
	       hour_start, minute_start,
	       hour_stop, minute_stop);
	print_days(time->days_match);
	printf(" ");
}

/* Saves the data in parsable form to stdout. */
static void
save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
{
	struct ipt_time_info *time = ((struct ipt_time_info *)match->data);
	int hour_start, hour_stop, minute_start, minute_stop;

	divide_time(time->time_start, &hour_start, &minute_start);
	divide_time(time->time_stop, &hour_stop, &minute_stop);
	printf(" --timestart %.2d:%.2d --timestop %.2d:%.2d --days ",
	       hour_start, minute_start,
	       hour_stop, minute_stop);
	print_days(time->days_match);
	printf(" ");
}

static
struct iptables_match timestruct
= { NULL,
    "time",
    NETFILTER_VERSION,
    IPT_ALIGN(sizeof(struct ipt_time_info)),
    IPT_ALIGN(sizeof(struct ipt_time_info)),
    &help,
    &init,
    &parse,
    &final_check,
    &print,
    &save,
    opts
};

void _init(void)
{
	register_match(&timestruct);
}