* 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 OUTPUT_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></body></html>");
+
/* Main Configuration Structure */
typedef struct {
static char *ngx_http_office_hours(ngx_conf_t * cf, ngx_command_t * cmd,
void *conf);
-/* Body Filter Storage */
+/* 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);
+
+/* Compiled Regex */
+ngx_regex_compile_t rc;
+
/*
* Module Definitions
*/
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_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),
/*
- * Main Body Filter
+ * Main Header Filter
* If the current time is within office hours, it goes to the next
- * handler. Otherwise it returns 403 and the office hour listing.
+ * handler. Otherwise it sets the headers to 403
*/
static ngx_int_t
-ngx_http_office_hours_body_filter(ngx_http_request_t * r, ngx_chain_t * in)
+ngx_http_office_hours_header_filter(ngx_http_request_t * r)
{
+ ngx_uint_t ** parsed_office_hours;
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);
+
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_body_filter(r, in);
+ return ngx_http_next_header_filter(r);
}
ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
"Outside office hours");
- hours = conf->office_hours->elts;
+ 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);
- for (i = 0; i < conf->office_hours->nelts; ++i) {
+
+ 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,
- (const char *) hours[i].data);
+ "Within office hours");
+ return ngx_http_next_body_filter(r, in);
+ }
+
+ ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
+ "Outside office hours");
+
+ 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;
}
- r->keepalive = 0;
- return NGX_HTTP_FORBIDDEN;
+ 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);
}
/*
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
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);
+}
+
/*
* 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;
}