[rbdr/ngx_http_office_hours_filter_module] / ngx_http_office_hours_filter_module.c

/*
 * Copyright 2018 Rubén Beltrán del Río
 *
 * 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.
 */

#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>

/*
 * Declarations
 */

/* Constants */

const ngx_uint_t WEEK_LENGTH = 7;
const char * CLOSED_TOKEN = "closed";
const ngx_str_t TIME_REGEX = ngx_string("([0-9]{1,2})(?:\\:([0-9]{2}))?\\-([0-9]{1,2})(?:\\:([0-9]{2}))?");
const ngx_str_t HEAD_HTML = ngx_string("<!doctype html><html><head><title>This website is currently closed!</title></head><body><h1>This website is currently closed!</h1><p>This website has closed for the day, please check our office hours below</p><ul>");
const ngx_str_t MIDDLE_HTML = ngx_string("</ul><p><em>Current Server Time is: ");
const ngx_str_t FOOT_HTML = ngx_string("</em></p></body></html>");
const char * DAY_NAMES[7] = {
    "Monday",
    "Tuesday",
    "Wednesday",
    "Thursday",
    "Friday",
    "Saturday",
    "Sunday"
};

/* Main Configuration Structure */

typedef struct {
    ngx_array_t *office_hours;
} ngx_http_office_hours_conf_t;

/* Lifecycle Functions For Module Context */

static void *ngx_http_office_hours_create_conf(ngx_conf_t * cf);
static char *ngx_http_office_hours_merge_conf(ngx_conf_t * cf,
    void *parent, void *child);
static ngx_int_t ngx_http_office_hours_init(ngx_conf_t * cf);

/* Configuration Handler */

static char *ngx_http_office_hours(ngx_conf_t * cf, ngx_command_t * cmd,
                                   void *conf);

/* Filter Storage */

static ngx_http_output_header_filter_pt ngx_http_next_header_filter;
static ngx_http_output_body_filter_pt ngx_http_next_body_filter;

/* Utility Functions */
static ngx_uint_t ** parse_office_hours(ngx_array_t * office_hours);
static ngx_uint_t * parse_office_hours_string(ngx_str_t office_hours);
static ngx_flag_t within_office_hours(ngx_uint_t ** office_hours);
static ngx_uint_t get_day_of_week(time_t time);
static ngx_uint_t get_seconds_of_day(time_t time);
static ngx_uint_t parse_number(ngx_str_t string, ngx_uint_t start, ngx_uint_t end);
static ngx_str_t create_output_html(ngx_http_office_hours_conf_t * conf);
static char * format_hours(ngx_uint_t * seconds, char * day);
static char * format_seconds(ngx_uint_t seconds);
static char * left_pad(unsigned int number);

/* Globals */
ngx_regex_compile_t rc;
ngx_str_t OUTPUT_HTML;

/*
 * Module Definitions
 */

/* Module Directives */

static ngx_command_t ngx_http_office_hours_commands[] = {
    {
        ngx_string("office_hours"),
        NGX_HTTP_MAIN_CONF | NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1 | NGX_CONF_TAKE2 | NGX_CONF_TAKE3 | NGX_CONF_TAKE4 | NGX_CONF_TAKE5 | NGX_CONF_TAKE6 | NGX_CONF_TAKE7,
        ngx_http_office_hours,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_office_hours_conf_t, office_hours),
        NULL
    },

    ngx_null_command
};

/* Module Context */

static ngx_http_module_t ngx_http_office_hours_filter_module_ctx = {
    NULL,			/* Preconfiguration */
    ngx_http_office_hours_init,	/* Postconfiguration */

    NULL,			/* Create main configuration */
    NULL,			/* Initialize main configuration */

    NULL,			/* Create server configuration */
    NULL,			/* Merge server configuration */

    ngx_http_office_hours_create_conf,	/* Create location configuration */
    ngx_http_office_hours_merge_conf	/* Merge location configuration */
};

/* Module Definition */

ngx_module_t ngx_http_office_hours_filter_module = {
    NGX_MODULE_V1,		//Module Version
    &ngx_http_office_hours_filter_module_ctx,	//Module context
    ngx_http_office_hours_commands,	//Module commands
    NGX_HTTP_MODULE,		//Module Type
    NULL,			//Initialize Master
    NULL,			//Initialize Module
    NULL,			//Initialize Process
    NULL,			//Initialize Thread
    NULL,			//Exit Thread
    NULL,			//Exit Process
    NULL,			//Exit Master
    NGX_MODULE_V1_PADDING
};

/*
 * Main Header Filter
 * If the current time is within office hours, it goes to the next
 * handler. Otherwise it sets the headers to 403
 */

static ngx_int_t
ngx_http_office_hours_header_filter(ngx_http_request_t * r)
{

    ngx_uint_t ** parsed_office_hours;
    ngx_http_office_hours_conf_t *conf;

    conf =
        ngx_http_get_module_loc_conf(r,
                                     ngx_http_office_hours_filter_module);

    if (conf->office_hours == NULL) {
        ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
                      "Office hours disabled");
        return ngx_http_next_header_filter(r);
    }

    parsed_office_hours = parse_office_hours(conf->office_hours);

    if (within_office_hours(parsed_office_hours)) {
        ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
                      "Within office hours");
        return ngx_http_next_header_filter(r);
    }

    ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
                  "Outside office hours");

    if (OUTPUT_HTML.data == NULL) {
        OUTPUT_HTML = create_output_html(conf);
    }

    r->headers_out.status = NGX_HTTP_FORBIDDEN;
    r->headers_out.content_length_n = OUTPUT_HTML.len;

    return ngx_http_next_header_filter(r);
}

/*
 * Main Body Filter
 * If the current time is within office hours, it goes to the next
 * handler. Otherwise it replaces the body with the office hours.
 */

static ngx_int_t
ngx_http_office_hours_body_filter(ngx_http_request_t * r, ngx_chain_t *in)
{

    ngx_buf_t    *b;
    ngx_uint_t ** parsed_office_hours;
    ngx_chain_t   out;
    ngx_http_office_hours_conf_t *conf;

    conf =
        ngx_http_get_module_loc_conf(r,
                                     ngx_http_office_hours_filter_module);

    if (conf->office_hours == NULL) {
        ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
                      "Office hours disabled");
        return ngx_http_next_body_filter(r, in);
    }

    parsed_office_hours = parse_office_hours(conf->office_hours);

    if (within_office_hours(parsed_office_hours)) {
        ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
                      "Within office hours");
        return ngx_http_next_body_filter(r, in);
    }

    ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
                  "Outside office hours");

    if (OUTPUT_HTML.data == NULL) {
        OUTPUT_HTML = create_output_html(conf);
    }

    b = ngx_pcalloc(r->pool, sizeof(ngx_buf_t));
    if (b == NULL) {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "Failed to allocate response buffer.");
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    out.buf = b;
    out.next = NULL;

    b->start = OUTPUT_HTML.data;
    b->pos = b->start;
    b->end = OUTPUT_HTML.data + OUTPUT_HTML.len;
    b->last = b->end;

    b->memory = 1;
    b->last_buf = 1;

    return ngx_http_next_body_filter(r, &out);
}

/*
 * Callback for `office_hours ` directive
 * Reads the configuration loaded from the config file(cf)
 * And writes it to the right place in the module configuration(conf)
 */

static char *ngx_http_office_hours(ngx_conf_t * cf, ngx_command_t * cmd,
                                   void *conf)
{

    char *conf_structure = conf;

    ngx_str_t *hours, *value;
    ngx_array_t **office_hours;
    ngx_uint_t i;

    /* Gets the array from the config structure using the defined
     * offset, and if the pointer is unset it creates a new one.
     * (The first element is the directive itself, so we should be
     * offset by 1)
     */
    office_hours = (ngx_array_t **) (conf_structure + cmd->offset);

    if (*office_hours == NGX_CONF_UNSET_PTR) {
        *office_hours = ngx_array_create(cf->pool, cf->args->nelts - 1,
                                         sizeof(ngx_str_t));

        if (*office_hours == NULL) {
            return NGX_CONF_ERROR;
        }
    }
    value = cf->args->elts;

    for (i = 1; i < cf->args->nelts; ++i) {
        hours = ngx_array_push(*office_hours);
        if (hours == NULL) {
            return NGX_CONF_ERROR;
        }
        *hours = value[i];
    }

    return NGX_CONF_OK;
}

/*
 * Config Creator
 * Initializes the configuration structure
 */

static void *ngx_http_office_hours_create_conf(ngx_conf_t * cf)
{

    ngx_http_office_hours_conf_t *conf;

    conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_office_hours_conf_t));

    if (conf == NULL) {
        return NULL;
    }
    conf->office_hours = NGX_CONF_UNSET_PTR;

    return conf;
}

/*
 * Merge Config Values
 * Sets the defaults for the configuration and merges
 * with other configurations
 */

static char *ngx_http_office_hours_merge_conf(ngx_conf_t * cf,
    void *parent, void *child)
{

    ngx_http_office_hours_conf_t *prev = parent;
    ngx_http_office_hours_conf_t *conf = child;

    ngx_conf_merge_ptr_value(conf->office_hours, prev->office_hours, NULL);

    return NGX_CONF_OK;
}

/*
 * Parse the office hour strings in the configuration file
 * to fill out the hours array (in seconds)
 */

static ngx_uint_t ** parse_office_hours(ngx_array_t * office_hours)
{

    ngx_str_t *hours;
    ngx_uint_t ** parsed_office_hours;
    ngx_uint_t i, j;

    parsed_office_hours = malloc(7 * sizeof(ngx_uint_t *));

    hours = office_hours->elts;

    /*
     * On the configuration file, the leftmost element
     * always applies to all remaining days, all others
     * are read from right to left. So first we will apply
     * the initial override, and then iterate based on the
     * number of overrides
     */

    for (i = 0; i < WEEK_LENGTH + 1 - office_hours->nelts; ++i) {
        parsed_office_hours[i] = parse_office_hours_string(hours[0]);
    }

    for (i = 1; i < office_hours->nelts; ++i) {
        j = WEEK_LENGTH - office_hours->nelts + i;
        parsed_office_hours[j] = parse_office_hours_string(hours[i]);
    }

    return parsed_office_hours;
}

/*
 * Given a time string or the closed token, return a tuple
 * of numbers representing opening and closing hours
 */

static ngx_uint_t * parse_office_hours_string(ngx_str_t office_hours)
{

    int captures[(1 + 4) * 3];
    ngx_int_t n;
    ngx_uint_t * parsed_hours;

    parsed_hours = malloc(2 * sizeof(ngx_uint_t));

    if(ngx_strcmp(office_hours.data, CLOSED_TOKEN) == 0) {
        parsed_hours[0] = 0;
        parsed_hours[1] = 0;
        return parsed_hours;
    }

    n = ngx_regex_exec(rc.regex, &office_hours, captures, (1 + 4) * 3);

    if (n >= 0) {
        /* Opening Hours */

        parsed_hours[0] = 60 * 60 * parse_number(office_hours, captures[2], captures[3]);
        parsed_hours[0] = parsed_hours[0] + 60 * parse_number(office_hours, captures[4], captures[5]);

        parsed_hours[1] = 60 * 60 * parse_number(office_hours, captures[6], captures[7]);
        parsed_hours[1] = parsed_hours[1] + 60 * parse_number(office_hours, captures[8], captures[9]);

        return parsed_hours;
    }

    /* Non-matching strings count as open */

    parsed_hours[0] = 0;
    parsed_hours[1] = 86400;
    return parsed_hours;
}

/*
 * Given an office hours array, it returns whether or not
 * it is currently within office hours.
 */

static ngx_flag_t within_office_hours(ngx_uint_t ** office_hours)
{

    time_t now;
    ngx_uint_t day_of_week, seconds_of_day;
    ngx_uint_t * current_hours;

    ngx_time_update();
    now = ngx_time();
    day_of_week = get_day_of_week(now);
    seconds_of_day = get_seconds_of_day(now);
    current_hours = office_hours[day_of_week];

    return seconds_of_day >= current_hours[0] && seconds_of_day <= current_hours[1];
}

/*
 * Calculate the day of the week given a timestamp
 */

static ngx_uint_t get_day_of_week(time_t time)
{

    /* Epoch was thursday, so add 3 so we start on monday */
    return (time / 86400 + 3) % 7;
}

/*
 * Calculate the number of seconds elapsed today
 */

static ngx_uint_t get_seconds_of_day(time_t time)
{

    return time - (time / 86400) * 86400;
}

/*
 * Parses a string, returns 0 if match was not found
 */

static ngx_uint_t parse_number(ngx_str_t string, ngx_uint_t start, ngx_uint_t end)
{

    if (end - start == 0) {
        return 0;
    }

    return ngx_atoi(&string.data[start], end - start);
}

/*
 * Given the current office hours configuration it creates the custom
 * HTML
 */

static ngx_str_t create_output_html(ngx_http_office_hours_conf_t * conf)
{

    char * output_buffer;
    time_t now;
    ngx_str_t output_html;
    ngx_uint_t i, seconds_of_day;
    ngx_uint_t ** parsed_office_hours;

    output_buffer = malloc(1024 * sizeof(char));
    parsed_office_hours = parse_office_hours(conf->office_hours);
    now = ngx_time();
    seconds_of_day = get_seconds_of_day(now);

    sprintf(output_buffer, "%s", (char *) HEAD_HTML.data);

    for (i = 0; i < 7; ++i) {
        sprintf(output_buffer + strlen(output_buffer), "%s", format_hours(parsed_office_hours[i], (char *) DAY_NAMES[i]));
    }

    sprintf(output_buffer + strlen(output_buffer), "%s", (char *) MIDDLE_HTML.data);
    sprintf(output_buffer + strlen(output_buffer), "%s", format_seconds(seconds_of_day));
    sprintf(output_buffer + strlen(output_buffer), "%s", (char *) FOOT_HTML.data);

    output_html.data = (unsigned char *) output_buffer;
    output_html.len = strlen(output_buffer);

    return output_html;
}

/*
 * Given a tuple of seconds and a day name, outputs an HTML
 * string containing the formatted data as a list item
 */

static char * format_hours(ngx_uint_t * hours, char * day)
{

    char * output_html;

    output_html = malloc(64 * sizeof(char));
    if (hours[0] == hours[1]) {
        sprintf(output_html, "<li><strong>%s</strong>: CLOSED</li>",
                day
               );
        return output_html;
    }

    sprintf(output_html, "<li><strong>%s</strong>: %s - %s</li>",
            day,
            (char *) format_seconds(hours[0]),
            (char *) format_seconds(hours[1])
           );

    return output_html;
}

/*
 * Given seconds of the day, it returns a string showing
 * HH:MM in 24 hour format
 */

static char * format_seconds(ngx_uint_t seconds)
{

    char * output_html;
    unsigned int hours, minutes;

    output_html = malloc(6 * sizeof(char));

    hours = seconds / 60 / 60;
    minutes = (seconds / 60) % 60;

    sprintf(output_html, "%s:%s",
            left_pad(hours),
            left_pad(minutes)
           );

    return output_html;
}

/*
 * Returns a number as a string adding 0 if < 10
 */

static char * left_pad(unsigned int number)
{

    char * output_string;
    char * padding;

    padding = "";
    output_string = malloc(4 * sizeof(char));

    if (number < 10) {
        padding = "0";
    }

    snprintf(output_string, 4, "%s%u", padding, number);

    return output_string;
}

/*
 * Postconfig Initialization Handler
 * Sets the request filter at the top of the chain
 */

static ngx_int_t ngx_http_office_hours_init(ngx_conf_t * cf)
{

    ngx_http_next_header_filter = ngx_http_top_header_filter;
    ngx_http_top_header_filter = ngx_http_office_hours_header_filter;

    ngx_http_next_body_filter = ngx_http_top_body_filter;
    ngx_http_top_body_filter = ngx_http_office_hours_body_filter;

    rc.pattern = TIME_REGEX;
    rc.pool = cf->pool;
    if (ngx_regex_compile(&rc) != NGX_OK) {
        return NGX_ERROR;
    }

    return NGX_OK;
}
Commit	Line	Data
e4db4a20 BB	1	/*
e4db4a20 BB	2	* Copyright 2018 Rubén Beltrán del Río
af4b488f	3	*
e4db4a20 BB	4	* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the
e4db4a20 BB	5	* License. You may obtain a copy of the License at
af4b488f	6	*
e4db4a20	7	* http://www.apache.org/licenses/LICENSE-2.0
af4b488f	8	*
e4db4a20 BB	9	* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
	10	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
	11	* specific language governing permissions and limitations under the License.
	12	*/
	13
e4db4a20 BB	14	#include <ngx_config.h>
	15	#include <ngx_core.h>
	16	#include <ngx_http.h>
	17
fa2b280d BB	18	/*
	19	* Declarations
	20	*/
	21
fbdf81df BB	22	/* Constants */
	23
	24	const ngx_uint_t WEEK_LENGTH = 7;
	25	const char * CLOSED_TOKEN = "closed";
80c4c3cc	26	const ngx_str_t TIME_REGEX = ngx_string("([0-9]{1,2})(?:\\:([0-9]{2}))?\\-([0-9]{1,2})(?:\\:([0-9]{2}))?");
61fca89b BB	27	const ngx_str_t HEAD_HTML = ngx_string("<!doctype html><html><head><title>This website is currently closed!</title></head><body><h1>This website is currently closed!</h1><p>This website has closed for the day, please check our office hours below</p><ul>");
	28	const ngx_str_t MIDDLE_HTML = ngx_string("</ul><p><em>Current Server Time is: ");
	29	const ngx_str_t FOOT_HTML = ngx_string("</em></p></body></html>");
	30	const char * DAY_NAMES[7] = {
	31	"Monday",
	32	"Tuesday",
	33	"Wednesday",
	34	"Thursday",
	35	"Friday",
	36	"Saturday",
	37	"Sunday"
	38	};
fbdf81df	39
fa2b280d	40	/* Main Configuration Structure */
e4db4a20 BB	41
e4db4a20 BB	42	typedef struct {
af4b488f BB	43	ngx_array_t *office_hours;
af4b488f BB	44	} ngx_http_office_hours_conf_t;
e4db4a20	45
fa2b280d BB	46	/* Lifecycle Functions For Module Context */
fa2b280d BB	47
af4b488f	48	static void ngx_http_office_hours_create_conf(ngx_conf_t cf);
fa2b280d	49	static char ngx_http_office_hours_merge_conf(ngx_conf_t cf,
f34685bb	50	void parent, void child);
e4db4a20 BB	51	static ngx_int_t ngx_http_office_hours_init(ngx_conf_t * cf);
e4db4a20 BB	52
fa2b280d BB	53	/* Configuration Handler */
	54
	55	static char ngx_http_office_hours(ngx_conf_t cf, ngx_command_t * cmd,
	56	void *conf);
	57
67206816	58	/* Filter Storage */
fa2b280d	59
67206816	60	static ngx_http_output_header_filter_pt ngx_http_next_header_filter;
fa2b280d BB	61	static ngx_http_output_body_filter_pt ngx_http_next_body_filter;
fa2b280d BB	62
fbdf81df BB	63	/* Utility Functions */
	64	static ngx_uint_t ** parse_office_hours(ngx_array_t * office_hours);
	65	static ngx_uint_t * parse_office_hours_string(ngx_str_t office_hours);
	66	static ngx_flag_t within_office_hours(ngx_uint_t ** office_hours);
	67	static ngx_uint_t get_day_of_week(time_t time);
	68	static ngx_uint_t get_seconds_of_day(time_t time);
bbe15175	69	static ngx_uint_t parse_number(ngx_str_t string, ngx_uint_t start, ngx_uint_t end);
61fca89b BB	70	static ngx_str_t create_output_html(ngx_http_office_hours_conf_t * conf);
	71	static char * format_hours(ngx_uint_t * seconds, char * day);
	72	static char * format_seconds(ngx_uint_t seconds);
	73	static char * left_pad(unsigned int number);
fbdf81df	74
61fca89b	75	/* Globals */
80c4c3cc	76	ngx_regex_compile_t rc;
61fca89b	77	ngx_str_t OUTPUT_HTML;
80c4c3cc	78
fa2b280d BB	79	/*
	80	* Module Definitions
	81	*/
e4db4a20	82
fa2b280d	83	/* Module Directives */
e4db4a20 BB	84
	85	static ngx_command_t ngx_http_office_hours_commands[] = {
	86	{
fa2b280d	87	ngx_string("office_hours"),
fbdf81df	88	NGX_HTTP_MAIN_CONF \| NGX_HTTP_SRV_CONF \| NGX_HTTP_LOC_CONF \| NGX_CONF_TAKE1 \| NGX_CONF_TAKE2 \| NGX_CONF_TAKE3 \| NGX_CONF_TAKE4 \| NGX_CONF_TAKE5 \| NGX_CONF_TAKE6 \| NGX_CONF_TAKE7,
fa2b280d BB	89	ngx_http_office_hours,
	90	NGX_HTTP_LOC_CONF_OFFSET,
	91	offsetof(ngx_http_office_hours_conf_t, office_hours),
	92	NULL
e4db4a20 BB	93	},
	94
	95	ngx_null_command
	96	};
	97
fa2b280d	98	/* Module Context */
e4db4a20 BB	99
e4db4a20 BB	100	static ngx_http_module_t ngx_http_office_hours_filter_module_ctx = {
fa2b280d BB	101	NULL, /* Preconfiguration */
fa2b280d BB	102	ngx_http_office_hours_init, /* Postconfiguration */
e4db4a20	103
fa2b280d BB	104	NULL, /* Create main configuration */
fa2b280d BB	105	NULL, /* Initialize main configuration */
e4db4a20	106
fa2b280d BB	107	NULL, /* Create server configuration */
	108	NULL, /* Merge server configuration */
	109
	110	ngx_http_office_hours_create_conf, /* Create location configuration */
	111	ngx_http_office_hours_merge_conf /* Merge location configuration */
e4db4a20 BB	112	};
e4db4a20 BB	113
fa2b280d	114	/* Module Definition */
e4db4a20 BB	115
e4db4a20 BB	116	ngx_module_t ngx_http_office_hours_filter_module = {
fa2b280d BB	117	NGX_MODULE_V1, //Module Version
	118	&ngx_http_office_hours_filter_module_ctx, //Module context
	119	ngx_http_office_hours_commands, //Module commands
	120	NGX_HTTP_MODULE, //Module Type
	121	NULL, //Initialize Master
	122	NULL, //Initialize Module
	123	NULL, //Initialize Process
	124	NULL, //Initialize Thread
	125	NULL, //Exit Thread
	126	NULL, //Exit Process
	127	NULL, //Exit Master
	128	NGX_MODULE_V1_PADDING
e4db4a20 BB	129	};
e4db4a20 BB	130
67206816 BB	131	/*
	132	* Main Header Filter
	133	* If the current time is within office hours, it goes to the next
	134	* handler. Otherwise it sets the headers to 403
	135	*/
	136
	137	static ngx_int_t
	138	ngx_http_office_hours_header_filter(ngx_http_request_t * r)
	139	{
	140
	141	ngx_uint_t ** parsed_office_hours;
	142	ngx_http_office_hours_conf_t *conf;
	143
	144	conf =
	145	ngx_http_get_module_loc_conf(r,
	146	ngx_http_office_hours_filter_module);
	147
67206816 BB	148	if (conf->office_hours == NULL) {
	149	ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
	150	"Office hours disabled");
	151	return ngx_http_next_header_filter(r);
	152	}
	153
	154	parsed_office_hours = parse_office_hours(conf->office_hours);
	155
	156	if (within_office_hours(parsed_office_hours)) {
	157	ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
	158	"Within office hours");
	159	return ngx_http_next_header_filter(r);
	160	}
	161
	162	ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
	163	"Outside office hours");
	164
61fca89b BB	165	if (OUTPUT_HTML.data == NULL) {
	166	OUTPUT_HTML = create_output_html(conf);
	167	}
	168
67206816 BB	169	r->headers_out.status = NGX_HTTP_FORBIDDEN;
	170	r->headers_out.content_length_n = OUTPUT_HTML.len;
	171
	172	return ngx_http_next_header_filter(r);
	173	}
	174
fa2b280d BB	175	/*
	176	* Main Body Filter
	177	* If the current time is within office hours, it goes to the next
67206816	178	* handler. Otherwise it replaces the body with the office hours.
fa2b280d	179	*/
e4db4a20	180
af4b488f	181	static ngx_int_t
67206816	182	ngx_http_office_hours_body_filter(ngx_http_request_t * r, ngx_chain_t *in)
af4b488f	183	{
e4db4a20	184
67206816	185	ngx_buf_t *b;
fbdf81df	186	ngx_uint_t ** parsed_office_hours;
67206816	187	ngx_chain_t out;
af4b488f	188	ngx_http_office_hours_conf_t *conf;
e4db4a20	189
fa2b280d BB	190	conf =
	191	ngx_http_get_module_loc_conf(r,
	192	ngx_http_office_hours_filter_module);
e4db4a20 BB	193
e4db4a20 BB	194	if (conf->office_hours == NULL) {
fa2b280d	195	ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
fbdf81df	196	"Office hours disabled");
fa2b280d	197	return ngx_http_next_body_filter(r, in);
e4db4a20	198	}
fa2b280d	199
fbdf81df	200	parsed_office_hours = parse_office_hours(conf->office_hours);
e4db4a20	201
fbdf81df	202	if (within_office_hours(parsed_office_hours)) {
fa2b280d	203	ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
fbdf81df BB	204	"Within office hours");
fbdf81df BB	205	return ngx_http_next_body_filter(r, in);
e4db4a20 BB	206	}
e4db4a20 BB	207
fbdf81df BB	208	ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
	209	"Outside office hours");
	210
61fca89b BB	211	if (OUTPUT_HTML.data == NULL) {
	212	OUTPUT_HTML = create_output_html(conf);
	213	}
	214
67206816 BB	215	b = ngx_pcalloc(r->pool, sizeof(ngx_buf_t));
	216	if (b == NULL) {
	217	ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "Failed to allocate response buffer.");
	218	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	219	}
	220
	221	out.buf = b;
	222	out.next = NULL;
	223
	224	b->start = OUTPUT_HTML.data;
	225	b->pos = b->start;
	226	b->end = OUTPUT_HTML.data + OUTPUT_HTML.len;
	227	b->last = b->end;
	228
	229	b->memory = 1;
	230	b->last_buf = 1;
	231
	232	return ngx_http_next_body_filter(r, &out);
e4db4a20 BB	233	}
e4db4a20 BB	234
fa2b280d BB	235	/*
	236	* Callback for `office_hours ` directive
	237	* Reads the configuration loaded from the config file(cf)
	238	* And writes it to the right place in the module configuration(conf)
	239	*/
e4db4a20	240
fa2b280d BB	241	static char ngx_http_office_hours(ngx_conf_t cf, ngx_command_t * cmd,
fa2b280d BB	242	void *conf)
af4b488f	243	{
e4db4a20	244
af4b488f	245	char *conf_structure = conf;
e4db4a20	246
fbdf81df	247	ngx_str_t hours, value;
af4b488f	248	ngx_array_t **office_hours;
af4b488f	249	ngx_uint_t i;
e4db4a20	250
fa2b280d BB	251	/* Gets the array from the config structure using the defined
	252	* offset, and if the pointer is unset it creates a new one.
	253	* (The first element is the directive itself, so we should be
	254	* offset by 1)
	255	*/
	256	office_hours = (ngx_array_t **) (conf_structure + cmd->offset);
e4db4a20 BB	257
e4db4a20 BB	258	if (*office_hours == NGX_CONF_UNSET_PTR) {
fa2b280d BB	259	*office_hours = ngx_array_create(cf->pool, cf->args->nelts - 1,
fa2b280d BB	260	sizeof(ngx_str_t));
e4db4a20	261
fa2b280d BB	262	if (*office_hours == NULL) {
	263	return NGX_CONF_ERROR;
	264	}
e4db4a20	265	}
e4db4a20 BB	266	value = cf->args->elts;
	267
	268	for (i = 1; i < cf->args->nelts; ++i) {
fa2b280d BB	269	hours = ngx_array_push(*office_hours);
	270	if (hours == NULL) {
	271	return NGX_CONF_ERROR;
	272	}
	273	*hours = value[i];
e4db4a20 BB	274	}
	275
	276	return NGX_CONF_OK;
	277	}
	278
fa2b280d BB	279	/*
	280	* Config Creator
	281	* Initializes the configuration structure
	282	*/
e4db4a20	283
fa2b280d	284	static void ngx_http_office_hours_create_conf(ngx_conf_t cf)
af4b488f	285	{
e4db4a20	286
af4b488f	287	ngx_http_office_hours_conf_t *conf;
e4db4a20 BB	288
	289	conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_office_hours_conf_t));
	290
	291	if (conf == NULL) {
fa2b280d	292	return NULL;
e4db4a20	293	}
e4db4a20 BB	294	conf->office_hours = NGX_CONF_UNSET_PTR;
	295
	296	return conf;
	297	}
	298
fa2b280d BB	299	/*
	300	* Merge Config Values
	301	* Sets the defaults for the configuration and merges
	302	* with other configurations
	303	*/
e4db4a20	304
fa2b280d	305	static char ngx_http_office_hours_merge_conf(ngx_conf_t cf,
f34685bb	306	void parent, void child)
af4b488f	307	{
e4db4a20	308
af4b488f BB	309	ngx_http_office_hours_conf_t *prev = parent;
af4b488f BB	310	ngx_http_office_hours_conf_t *conf = child;
e4db4a20 BB	311
	312	ngx_conf_merge_ptr_value(conf->office_hours, prev->office_hours, NULL);
	313
	314	return NGX_CONF_OK;
	315	}
	316
fbdf81df BB	317	/*
	318	* Parse the office hour strings in the configuration file
	319	* to fill out the hours array (in seconds)
	320	*/
	321
	322	static ngx_uint_t ** parse_office_hours(ngx_array_t * office_hours)
	323	{
	324
	325	ngx_str_t *hours;
	326	ngx_uint_t ** parsed_office_hours;
	327	ngx_uint_t i, j;
	328
	329	parsed_office_hours = malloc(7 * sizeof(ngx_uint_t *));
	330
	331	hours = office_hours->elts;
	332
	333	/*
	334	* On the configuration file, the leftmost element
	335	* always applies to all remaining days, all others
	336	* are read from right to left. So first we will apply
	337	* the initial override, and then iterate based on the
	338	* number of overrides
	339	*/
	340
	341	for (i = 0; i < WEEK_LENGTH + 1 - office_hours->nelts; ++i) {
	342	parsed_office_hours[i] = parse_office_hours_string(hours[0]);
	343	}
	344
	345	for (i = 1; i < office_hours->nelts; ++i) {
	346	j = WEEK_LENGTH - office_hours->nelts + i;
	347	parsed_office_hours[j] = parse_office_hours_string(hours[i]);
	348	}
	349
	350	return parsed_office_hours;
	351	}
	352
	353	/*
	354	* Given a time string or the closed token, return a tuple
	355	* of numbers representing opening and closing hours
	356	*/
	357
	358	static ngx_uint_t * parse_office_hours_string(ngx_str_t office_hours)
	359	{
	360
80c4c3cc BB	361	int captures[(1 + 4) * 3];
80c4c3cc BB	362	ngx_int_t n;
fbdf81df BB	363	ngx_uint_t * parsed_hours;
	364
	365	parsed_hours = malloc(2 * sizeof(ngx_uint_t));
	366
	367	if(ngx_strcmp(office_hours.data, CLOSED_TOKEN) == 0) {
	368	parsed_hours[0] = 0;
	369	parsed_hours[1] = 0;
	370	return parsed_hours;
	371	}
	372
80c4c3cc BB	373	n = ngx_regex_exec(rc.regex, &office_hours, captures, (1 + 4) * 3);
	374
	375	if (n >= 0) {
	376	/* Opening Hours */
	377
bbe15175 BB	378	parsed_hours[0] = 60 * 60 * parse_number(office_hours, captures[2], captures[3]);
bbe15175 BB	379	parsed_hours[0] = parsed_hours[0] + 60 * parse_number(office_hours, captures[4], captures[5]);
80c4c3cc	380
bbe15175 BB	381	parsed_hours[1] = 60 * 60 * parse_number(office_hours, captures[6], captures[7]);
bbe15175 BB	382	parsed_hours[1] = parsed_hours[1] + 60 * parse_number(office_hours, captures[8], captures[9]);
80c4c3cc BB	383
	384	return parsed_hours;
	385	}
	386
	387	/* Non-matching strings count as open */
	388
fbdf81df BB	389	parsed_hours[0] = 0;
	390	parsed_hours[1] = 86400;
	391	return parsed_hours;
	392	}
	393
	394	/*
	395	* Given an office hours array, it returns whether or not
	396	* it is currently within office hours.
	397	*/
	398
	399	static ngx_flag_t within_office_hours(ngx_uint_t ** office_hours)
	400	{
	401
	402	time_t now;
	403	ngx_uint_t day_of_week, seconds_of_day;
	404	ngx_uint_t * current_hours;
	405
	406	ngx_time_update();
	407	now = ngx_time();
	408	day_of_week = get_day_of_week(now);
	409	seconds_of_day = get_seconds_of_day(now);
	410	current_hours = office_hours[day_of_week];
	411
	412	return seconds_of_day >= current_hours[0] && seconds_of_day <= current_hours[1];
	413	}
	414
	415	/*
	416	* Calculate the day of the week given a timestamp
	417	*/
61fca89b	418
fbdf81df BB	419	static ngx_uint_t get_day_of_week(time_t time)
	420	{
	421
	422	/* Epoch was thursday, so add 3 so we start on monday */
	423	return (time / 86400 + 3) % 7;
	424	}
	425
	426	/*
	427	* Calculate the number of seconds elapsed today
	428	*/
61fca89b	429
fbdf81df BB	430	static ngx_uint_t get_seconds_of_day(time_t time)
	431	{
	432
	433	return time - (time / 86400) * 86400;
	434	}
bbe15175 BB	435
	436	/*
	437	* Parses a string, returns 0 if match was not found
	438	*/
61fca89b	439
bbe15175 BB	440	static ngx_uint_t parse_number(ngx_str_t string, ngx_uint_t start, ngx_uint_t end)
	441	{
	442
	443	if (end - start == 0) {
	444	return 0;
	445	}
	446
	447	return ngx_atoi(&string.data[start], end - start);
	448	}
	449
61fca89b BB	450	/*
	451	* Given the current office hours configuration it creates the custom
	452	* HTML
	453	*/
	454
	455	static ngx_str_t create_output_html(ngx_http_office_hours_conf_t * conf)
	456	{
	457
	458	char * output_buffer;
	459	time_t now;
	460	ngx_str_t output_html;
	461	ngx_uint_t i, seconds_of_day;
	462	ngx_uint_t ** parsed_office_hours;
	463
61fca89b BB	464	output_buffer = malloc(1024 * sizeof(char));
	465	parsed_office_hours = parse_office_hours(conf->office_hours);
	466	now = ngx_time();
	467	seconds_of_day = get_seconds_of_day(now);
	468
	469	sprintf(output_buffer, "%s", (char *) HEAD_HTML.data);
	470
	471	for (i = 0; i < 7; ++i) {
	472	sprintf(output_buffer + strlen(output_buffer), "%s", format_hours(parsed_office_hours[i], (char *) DAY_NAMES[i]));
	473	}
	474
	475	sprintf(output_buffer + strlen(output_buffer), "%s", (char *) MIDDLE_HTML.data);
	476	sprintf(output_buffer + strlen(output_buffer), "%s", format_seconds(seconds_of_day));
	477	sprintf(output_buffer + strlen(output_buffer), "%s", (char *) FOOT_HTML.data);
	478
	479	output_html.data = (unsigned char *) output_buffer;
	480	output_html.len = strlen(output_buffer);
	481
	482	return output_html;
	483	}
	484
	485	/*
	486	* Given a tuple of seconds and a day name, outputs an HTML
	487	* string containing the formatted data as a list item
	488	*/
	489
	490	static char * format_hours(ngx_uint_t * hours, char * day)
	491	{
	492
	493	char * output_html;
	494
	495	output_html = malloc(64 * sizeof(char));
	496	if (hours[0] == hours[1]) {
	497	sprintf(output_html, "<li><strong>%s</strong>: CLOSED</li>",
	498	day
	499	);
	500	return output_html;
	501	}
	502
	503	sprintf(output_html, "<li><strong>%s</strong>: %s - %s</li>",
	504	day,
	505	(char *) format_seconds(hours[0]),
	506	(char *) format_seconds(hours[1])
	507	);
	508
	509	return output_html;
	510	}
	511
	512	/*
	513	* Given seconds of the day, it returns a string showing
	514	* HH:MM in 24 hour format
	515	*/
	516
	517	static char * format_seconds(ngx_uint_t seconds)
	518	{
	519
	520	char * output_html;
	521	unsigned int hours, minutes;
	522
	523	output_html = malloc(6 * sizeof(char));
	524
	525	hours = seconds / 60 / 60;
	526	minutes = (seconds / 60) % 60;
	527
528	sprintf(output_html, "%s:%s",
529	left_pad(hours),
530	left_pad(minutes)
531	);
532
533	return output_html;
534	}
535
536	/*
537	* Returns a number as a string adding 0 if < 10
538	*/
539
540	static char * left_pad(unsigned int number)
541	{
542
543	char * output_string;
544	char * padding;
545
546	padding = "";
f34685bb	547	output_string = malloc(4 * sizeof(char));
61fca89b BB	548
	549	if (number < 10) {
	550	padding = "0";
	551	}
	552
f34685bb	553	snprintf(output_string, 4, "%s%u", padding, number);
61fca89b BB	554
	555	return output_string;
	556	}
	557
bbe15175 BB	558	/*
	559	* Postconfig Initialization Handler
	560	* Sets the request filter at the top of the chain
	561	*/
	562
	563	static ngx_int_t ngx_http_office_hours_init(ngx_conf_t * cf)
	564	{
	565
67206816 BB	566	ngx_http_next_header_filter = ngx_http_top_header_filter;
	567	ngx_http_top_header_filter = ngx_http_office_hours_header_filter;
	568
bbe15175 BB	569	ngx_http_next_body_filter = ngx_http_top_body_filter;
	570	ngx_http_top_body_filter = ngx_http_office_hours_body_filter;
	571
	572	rc.pattern = TIME_REGEX;
	573	rc.pool = cf->pool;
	574	if (ngx_regex_compile(&rc) != NGX_OK) {
	575	return NGX_ERROR;
	576	}
	577
	578	return NGX_OK;
	579	}