#include <ngx_core.h>
#include <ngx_http.h>
-// Module Config Definitions
+/*
+ * 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 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);
-static char *ngx_http_office_hours(ngx_conf_t * cf, ngx_command_t * cmd, void *conf);
+/* Configuration Handler */
-//Module Directive Definitions
+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_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_CONF_1MORE,
- ngx_http_office_hours,
- NGX_HTTP_LOC_CONF_OFFSET,
- offsetof(ngx_http_office_hours_conf_t, office_hours),
- NULL
+ 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
};
-//Define the module context
+
+/* Module Context */
static ngx_http_module_t ngx_http_office_hours_filter_module_ctx = {
- NULL, //Preconfiguration
- ngx_http_office_hours_init, //Postconfiguration
+ NULL, /* Preconfiguration */
+ ngx_http_office_hours_init, /* Postconfiguration */
- NULL, //Create main configuration
- NULL, //Initialize main configuration
- NULL, //Create server configuration
- NULL, //Merge server configuration
+ NULL, /* Create main configuration */
+ NULL, /* Initialize main configuration */
- ngx_http_office_hours_create_conf, //Create location configuration
- ngx_http_office_hours_merge_conf // Merge location 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 */
};
-//Define the module
+
+/* 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
+ 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 Body Filter
+/*
+ * 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_http_output_body_filter_pt ngx_http_next_body_filter;
+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_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;
- ngx_uint_t i;
- ngx_str_t *hours;
- conf = ngx_http_get_module_loc_conf(r, ngx_http_office_hours_filter_module);
+ 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);
+ }
- ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0, "Within office hours");
+ parsed_office_hours = parse_office_hours(conf->office_hours);
- return ngx_http_next_body_filter(r, in);
+ 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");
- hours = conf->office_hours->elts;
+ ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
+ "Outside office hours");
- for (i = 0; i < conf->office_hours->nelts; ++i) {
- ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0, (const char *)hours[i].data);
+ if (OUTPUT_HTML.data == NULL) {
+ OUTPUT_HTML = create_output_html(conf);
}
- r->keepalive = 0;
- return NGX_HTTP_FORBIDDEN;
+ 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);
}
-//Read Arguments from config file
+/*
+ * 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)
+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_str_t *hours;
- ngx_str_t *value;
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);
+ /* 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));
+ *office_hours = ngx_array_create(cf->pool, cf->args->nelts - 1,
+ sizeof(ngx_str_t));
- if (*office_hours == NULL) {
- return NGX_CONF_ERROR;
- }
+ 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];
+ hours = ngx_array_push(*office_hours);
+ if (hours == NULL) {
+ return NGX_CONF_ERROR;
+ }
+ *hours = value[i];
}
return NGX_CONF_OK;
}
-//Initialize the Configuration Object
+/*
+ * Config Creator
+ * Initializes the configuration structure
+ */
-static void *
- ngx_http_office_hours_create_conf(ngx_conf_t * cf)
+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;
+ return NULL;
}
conf->office_hours = NGX_CONF_UNSET_PTR;
return conf;
}
-//Merge Config Values
+/*
+ * 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)
+static char *ngx_http_office_hours_merge_conf(ngx_conf_t * cf,
+ void *parent, void *child)
{
ngx_http_office_hours_conf_t *prev = parent;
return NGX_CONF_OK;
}
-//Postconfig Initialization Handler
-// Sets the request filter at the top of the chain
+/*
+ * Parse the office hour strings in the configuration file
+ * to fill out the hours array (in seconds)
+ */
-static ngx_int_t
- ngx_http_office_hours_init(ngx_conf_t * cf)
+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(3 * sizeof(char));
+
+ if (number < 10) {
+ padding = "0";
+ }
+
+ sprintf(output_string, "%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;
}