X-Git-Url: https://git.r.bdr.sh/rbdr/ngx_http_office_hours_filter_module/blobdiff_plain/956d445da3b512e802a57858afaedbd8cb3395c0..61fca89be791eb7479b036c0bf994090c9f5cd0f:/ngx_http_office_hours_filter_module.c?ds=sidebyside diff --git a/ngx_http_office_hours_filter_module.c b/ngx_http_office_hours_filter_module.c index f19b4e0..6f169b9 100644 --- a/ngx_http_office_hours_filter_module.c +++ b/ngx_http_office_hours_filter_module.c @@ -1,11 +1,11 @@ /* * 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. @@ -16,24 +16,77 @@ #include #include -// 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("This website is currently closed!

This website is currently closed!

This website has closed for the day, please check our office hours below

Current Server Time is: "); +const ngx_str_t FOOT_HTML = ngx_string("

"); +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; + 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 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); -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_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), @@ -43,109 +96,186 @@ static ngx_command_t ngx_http_office_hours_commands[] = { 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 main configuration - NULL, //Initialize main configuration - NULL, //Create server configuration - NULL, //Merge server 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 + 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) +{ -static ngx_int_t -ngx_http_office_hours_body_filter(ngx_http_request_t * r, ngx_chain_t * in) { + ngx_uint_t ** parsed_office_hours; + ngx_http_office_hours_conf_t *conf; -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_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); + } - ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0, "Within office hours"); + 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"); + ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0, + "Outside office hours"); - hours = conf->office_hours->elts; + if (OUTPUT_HTML.data == NULL) { + OUTPUT_HTML = create_output_html(conf); + } - for (i = 0; i < conf->office_hours->nelts; ++i) { - ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0, (const char *)hours[i].data); + 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); } -//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; + char *conf_structure = conf; -ngx_array_t **office_hours; -ngx_str_t *hours; -ngx_str_t *value; -ngx_uint_t i; + 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); + /* 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)); + 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]; } @@ -153,45 +283,305 @@ ngx_uint_t i; } -//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; + 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 +/* + * 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; -ngx_http_office_hours_conf_t *conf = 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; } -//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_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, "
  • %s: CLOSED
    • ", + day + ); + return output_html; + } + + sprintf(output_html, "
  • %s: %s - %s
    • ", + 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; -static ngx_int_t -ngx_http_office_hours_init(ngx_conf_t * cf) { + 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; }