git.r.bdr.sh - rbdr/ngx_http_office_hours_filter_module/blob - ngx_http_office_hours_filter_module.c

   1 /*
   2  * Copyright 2018 Rubén Beltrán del Río
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the
   5  * License. You may obtain a copy of the License at
   6  *
   7  * http://www.apache.org/licenses/LICENSE-2.0
   8  *
   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
  14
  15 #include <ngx_config.h>
  16 #include <ngx_core.h>
  17 #include <ngx_http.h>
  18
  19 /*
  20  * Declarations
  21  */
  22
  23 /* Main Configuration Structure */
  24
  25 typedef struct {
  26     ngx_array_t *office_hours;
  27 } ngx_http_office_hours_conf_t;
  28
  29 /* Lifecycle Functions For Module Context */
  30
  31 static void *ngx_http_office_hours_create_conf(ngx_conf_t * cf);
  32 static char *ngx_http_office_hours_merge_conf(ngx_conf_t * cf,
  33         void *parent, void *child);
  34 static ngx_int_t ngx_http_office_hours_init(ngx_conf_t * cf);
  35
  36 /* Configuration Handler */
  37
  38 static char *ngx_http_office_hours(ngx_conf_t * cf, ngx_command_t * cmd,
  39                                    void *conf);
  40
  41 /* Body Filter Storage */
  42
  43 static ngx_http_output_body_filter_pt ngx_http_next_body_filter;
  44
  45 /*
  46  * Module Definitions
  47  */
  48
  49 /* Module Directives */
  50
  51 static ngx_command_t ngx_http_office_hours_commands[] = {
  52     {
  53         ngx_string("office_hours"),
  54         NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_CONF_1MORE,
  55         ngx_http_office_hours,
  56         NGX_HTTP_LOC_CONF_OFFSET,
  57         offsetof(ngx_http_office_hours_conf_t, office_hours),
  58         NULL
  59     },
  60
  61     ngx_null_command
  62 };
  63
  64
  65 /* Module Context */
  66
  67 static ngx_http_module_t ngx_http_office_hours_filter_module_ctx = {
  68     NULL,                       /* Preconfiguration */
  69     ngx_http_office_hours_init, /* Postconfiguration */
  70
  71     NULL,                       /* Create main configuration */
  72     NULL,                       /* Initialize main configuration */
  73
  74     NULL,                       /* Create server configuration */
  75     NULL,                       /* Merge server configuration */
  76
  77     ngx_http_office_hours_create_conf,  /* Create location configuration */
  78     ngx_http_office_hours_merge_conf    /* Merge location configuration */
  79 };
  80
  81
  82 /* Module Definition */
  83
  84 ngx_module_t ngx_http_office_hours_filter_module = {
  85     NGX_MODULE_V1,              //Module Version
  86     &ngx_http_office_hours_filter_module_ctx,   //Module context
  87     ngx_http_office_hours_commands,     //Module commands
  88     NGX_HTTP_MODULE,            //Module Type
  89     NULL,                       //Initialize Master
  90     NULL,                       //Initialize Module
  91     NULL,                       //Initialize Process
  92     NULL,                       //Initialize Thread
  93     NULL,                       //Exit Thread
  94     NULL,                       //Exit Process
  95     NULL,                       //Exit Master
  96     NGX_MODULE_V1_PADDING
  97 };
  98
  99
 100 /*
 101  * Main Body Filter
 102  * If the current time is within office hours, it goes to the next
 103  * handler. Otherwise it returns 403 and the office hour listing.
 104  */
 105
 106 static ngx_int_t
 107 ngx_http_office_hours_body_filter(ngx_http_request_t * r, ngx_chain_t * in)
 108 {
 109
 110     ngx_http_office_hours_conf_t *conf;
 111     ngx_uint_t i;
 112     ngx_str_t *hours;
 113
 114     conf =
 115         ngx_http_get_module_loc_conf(r,
 116                                      ngx_http_office_hours_filter_module);
 117
 118     if (conf->office_hours == NULL) {
 119         ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
 120                       "Within office hours");
 121         return ngx_http_next_body_filter(r, in);
 122     }
 123
 124     ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
 125                   "Outside office hours");
 126
 127     hours = conf->office_hours->elts;
 128
 129     for (i = 0; i < conf->office_hours->nelts; ++i) {
 130         ngx_log_error(NGX_LOG_DEBUG, r->connection->log, 0,
 131                       (const char *) hours[i].data);
 132     }
 133
 134     r->keepalive = 0;
 135     return NGX_HTTP_FORBIDDEN;
 136 }
 137
 138 /*
 139  * Callback for `office_hours ` directive
 140  * Reads the configuration loaded from the config file(cf)
 141  * And writes it to the right place in the module configuration(conf)
 142  */
 143
 144 static char *ngx_http_office_hours(ngx_conf_t * cf, ngx_command_t * cmd,
 145                                    void *conf)
 146 {
 147
 148     char *conf_structure = conf;
 149
 150     ngx_array_t **office_hours;
 151     ngx_str_t *hours;
 152     ngx_str_t *value;
 153     ngx_uint_t i;
 154
 155     /* Gets the array from the config structure using the defined
 156      * offset, and if the pointer is unset it creates a new one.
 157      * (The first element is the directive itself, so we should be
 158      * offset by 1)
 159      */
 160     office_hours = (ngx_array_t **) (conf_structure + cmd->offset);
 161
 162     if (*office_hours == NGX_CONF_UNSET_PTR) {
 163         *office_hours = ngx_array_create(cf->pool, cf->args->nelts - 1,
 164                                          sizeof(ngx_str_t));
 165
 166         if (*office_hours == NULL) {
 167             return NGX_CONF_ERROR;
 168         }
 169     }
 170     value = cf->args->elts;
 171
 172     for (i = 1; i < cf->args->nelts; ++i) {
 173         hours = ngx_array_push(*office_hours);
 174         if (hours == NULL) {
 175             return NGX_CONF_ERROR;
 176         }
 177         *hours = value[i];
 178     }
 179
 180     return NGX_CONF_OK;
 181 }
 182
 183
 184 /*
 185  * Config Creator
 186  * Initializes the configuration structure
 187  */
 188
 189 static void *ngx_http_office_hours_create_conf(ngx_conf_t * cf)
 190 {
 191
 192     ngx_http_office_hours_conf_t *conf;
 193
 194     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_office_hours_conf_t));
 195
 196     if (conf == NULL) {
 197         return NULL;
 198     }
 199     conf->office_hours = NGX_CONF_UNSET_PTR;
 200
 201     return conf;
 202 }
 203
 204 /*
 205  * Merge Config Values
 206  * Sets the defaults for the configuration and merges
 207  * with other configurations
 208  */
 209
 210 static char *ngx_http_office_hours_merge_conf(ngx_conf_t * cf,
 211         void *parent, void *child)
 212 {
 213
 214     ngx_http_office_hours_conf_t *prev = parent;
 215     ngx_http_office_hours_conf_t *conf = child;
 216
 217     ngx_conf_merge_ptr_value(conf->office_hours, prev->office_hours, NULL);
 218
 219     return NGX_CONF_OK;
 220 }
 221
 222 /*
 223  * Postconfig Initialization Handler
 224  * Sets the request filter at the top of the chain
 225  */
 226
 227 static ngx_int_t ngx_http_office_hours_init(ngx_conf_t * cf)
 228 {
 229
 230     ngx_http_next_body_filter = ngx_http_top_body_filter;
 231     ngx_http_top_body_filter = ngx_http_office_hours_body_filter;
 232
 233     return NGX_OK;
 234 }