TimeFilter.c

/*
Copyright (C) <2010-2011> Karl Hiramoto <karl@hiramoto.org>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

#define _GNU_SOURCE
#include <string.h>
#include <stdlib.h>

#ifdef HAVE_CONFIG_H
#include "nfq-web-filter-config.h"
#endif

#include <time.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include "Filter.h"
#include "FilterType.h"
#include "HttpReq.h"
#include "nfq_wf_private.h"
#include "HttpConn.h"
#define DAYS_IN_WEEK 7
/**
* @ingroup FilterObject
* @defgroup TimeFilter Time Filter Object
* @{
*/

struct TimeFilter
{
	FILTER_OBJECT_COMMON
	bool dow[DAYS_IN_WEEK]; /* Days of week */
	uint8_t from_min; /* 0 to 23 */
	uint8_t from_hour; /* 0 to 59 */
	uint8_t to_min; /* 0 to 23 */
	uint8_t to_hour; /* 0 to 59 */
};
#define HOST_STR "host"

static int TimeFilter_load_from_xml(struct Filter *fobj, xmlNode *node)
{
	struct TimeFilter *filt = (struct TimeFilter *) fobj; /* filter object */
	xmlChar *prop = NULL;
	const char *days[] = { "sun", "mon", "tue", "wed", "thu", "fri", "sat", "" };
	int i;
	int ret;
	DBG(5, "Loading XML config\n");

	for (i = 0; i < DAYS_IN_WEEK; i++) {
		prop = xmlGetProp(node, BAD_CAST days[i]);
		if (prop) {
			filt->dow[i] = atoi((const char *)prop);
			xmlFree(prop);
		} else {
			filt->dow[i] = false;
		}
	}

	prop = xmlGetProp(node, BAD_CAST "from");
	if (prop) {
		ret = sscanf((const char*) prop, "%hhd:%hhd", &filt->from_hour, &filt->from_min);
		if (ret != 2) {
			ERROR("parsing time 'from'\n");
			filt->from_hour = 0;
			filt->from_min = 0;
		}
		xmlFree(prop);
	} else {
		filt->from_hour = 0;
		filt->from_min = 0;
	}

	prop = xmlGetProp(node, BAD_CAST "to");
	if (prop) {
		ret = sscanf((const char*) prop, "%hhd:%hhd", &filt->to_hour, &filt->to_min);
		if (ret != 2) {
			ERROR("parsing time 'to'\n");
			filt->to_hour = 23;
			filt->to_min = 59;
		}
		xmlFree(prop);
	} else {
		filt->to_hour = 23;
		filt->to_min = 59;
	}

	DBG(2, "Loaded TimeFilter object ID=%d "
		"su=%d mo=%d tu=%d we=%d th=%d fr=%d sa=%d from=%02d:%02d to=%02d:%02d\n",
		Filter_getFilterId(fobj), filt->dow[0], filt->dow[1], filt->dow[2],
		filt->dow[3], filt->dow[4], filt->dow[5], filt->dow[6],
		filt->from_hour, filt->from_min, filt->to_hour, filt->to_min);

	return 0;
}

static int time_filter_matches(struct TimeFilter *filt, struct HttpReq *req)
{
	struct HttpConn *con = req->con;
	struct tm tm;

	if (!localtime_r(&con->last_pkt, &tm)) {
		ERROR(" calling localtime\n");
	}

	if(filt->dow[tm.tm_wday]) {
		// day of week matches
		if (tm.tm_hour >= filt->from_hour && tm.tm_hour <= filt->to_hour &&
			tm.tm_min >= filt->from_min && tm.tm_min <= filt->to_min) {
			// time matches
			return 1;
		}
	}
	return 0;
}

//Note saving to the private con data may be faster, when
// there are multiple requests per connection and the private data lookup
// NOTE if private connection data is used, then we only check the time at the
// start of the connection, not at the start of each request,
// A long lived connection may bypass the checks
// #define PRIV_CON_DATA 1

#ifdef PRIV_CON_DATA
static int TimeFilter_start_req(struct Filter *fobj, struct HttpReq *req)
{
	struct TimeFilter *filt = (struct TimeFilter *) fobj; /* Host filter object */
	struct HttpConn *con = req->con;
	void *data;

	if (con->cur_request > 1) {
		DBG(7, "multiple requests to same host filter_id=%d\n", Filter_getObjId(fobj));
		return 0;
	}
	data = HttpConn_newPrivData(con, Filter_getObjId(fobj), sizeof(int));
	if (!data) {
		ERROR_FATAL("Missing private data id=%d\n", Filter_getObjId(fobj));
		return -1;
	}

	(*(int *)data) = time_filter_matches(filt, req);

	return 0; // OK
}
#endif
static int TimeFilter_matches_req(struct Filter *fobj, struct HttpReq *req)
{
	#ifdef PRIV_CON_DATA
	struct HttpConn *con = req->con;
	void *data;

	// every request in the same connection will be to the same host so use saved value.
	data = HttpConn_getPrivData(con, Filter_getObjId(fobj));
	if (!data) {
		ERROR_FATAL("Missing private data with id=%d\n", Filter_getObjId(fobj));
	}
	// return saved match
	return (*(int *)data);
	#else
	struct TimeFilter *filt = (struct TimeFilter *) fobj; /* Host filter object */

	return time_filter_matches(filt, req);
	#endif
}
static struct Object_ops obj_ops = {
	.obj_type           = "filter/time",
	.obj_size           = sizeof(struct TimeFilter),
};

static struct Filter_ops TimeFilter_obj_ops = {
	.ops                = &obj_ops,
#if 0
	.foo_destructor     = TimeFilter_destructor,
	.foo_constructor	= TimeFilter_constructor,
#endif
	.foo_load_from_xml  = TimeFilter_load_from_xml,
#if PRIV_CON_DATA
	.foo_request_start  = TimeFilter_start_req,
#endif
	.foo_matches_req    = TimeFilter_matches_req,
};


/**
* Initialization function to register this filter type.
*/
static void __init TimeFilter_init(void)
{
	DBG(5, "init Time filter\n");
	FilterType_register(&TimeFilter_obj_ops);
}

/** @} */