Linux Cross Reference
Nginx/http/modules/ngx_http_addition_filter_module.c

   
   /*
    * Copyright (C) Igor Sysoev
    */
   
   
   #include <ngx_config.h>
   #include <ngx_core.h>
   #include <ngx_http.h>
  
  
  typedef struct {
      ngx_str_t     before_body;
      ngx_str_t     after_body;
  
      ngx_hash_t    types;
      ngx_array_t  *types_keys;
  } ngx_http_addition_conf_t;
  
  
  typedef struct {
      ngx_uint_t    before_body_sent;
  } ngx_http_addition_ctx_t;
  
  
  static void *ngx_http_addition_create_conf(ngx_conf_t *cf);
  static char *ngx_http_addition_merge_conf(ngx_conf_t *cf, void *parent,
      void *child);
  static ngx_int_t ngx_http_addition_filter_init(ngx_conf_t *cf);
  
  
  static ngx_command_t  ngx_http_addition_commands[] = {
  
      { ngx_string("add_before_body"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_str_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_addition_conf_t, before_body),
        NULL },
  
      { ngx_string("add_after_body"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_str_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_addition_conf_t, after_body),
        NULL },
  
      { ngx_string("addition_types"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
        ngx_http_types_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_addition_conf_t, types_keys),
        &ngx_http_html_default_types[0] },
  
        ngx_null_command
  };
  
  
  static ngx_http_module_t  ngx_http_addition_filter_module_ctx = {
      NULL,                                  /* preconfiguration */
      ngx_http_addition_filter_init,         /* postconfiguration */
  
      NULL,                                  /* create main configuration */
      NULL,                                  /* init main configuration */
  
      NULL,                                  /* create server configuration */
      NULL,                                  /* merge server configuration */
  
      ngx_http_addition_create_conf,         /* create location configuration */
      ngx_http_addition_merge_conf           /* merge location configuration */
  };
  
  
  ngx_module_t  ngx_http_addition_filter_module = {
      NGX_MODULE_V1,
      &ngx_http_addition_filter_module_ctx,  /* module context */
      ngx_http_addition_commands,            /* module directives */
      NGX_HTTP_MODULE,                       /* module type */
      NULL,                                  /* init master */
      NULL,                                  /* init module */
      NULL,                                  /* init process */
      NULL,                                  /* init thread */
      NULL,                                  /* exit thread */
      NULL,                                  /* exit process */
      NULL,                                  /* exit master */
      NGX_MODULE_V1_PADDING
  };
  
  
  static ngx_http_output_header_filter_pt  ngx_http_next_header_filter;
  static ngx_http_output_body_filter_pt    ngx_http_next_body_filter;
  
  
  static ngx_int_t
  ngx_http_addition_header_filter(ngx_http_request_t *r)
  {
      ngx_http_addition_ctx_t   *ctx;
      ngx_http_addition_conf_t  *conf;
  
     if (r->headers_out.status != NGX_HTTP_OK || r != r->main) {
         return ngx_http_next_header_filter(r);
     }
 
     conf = ngx_http_get_module_loc_conf(r, ngx_http_addition_filter_module);
 
     if (conf->before_body.len == 0 && conf->after_body.len == 0) {
         return ngx_http_next_header_filter(r);
     }
 
     if (ngx_http_test_content_type(r, &conf->types) == NULL) {
         return ngx_http_next_header_filter(r);
     }
 
     ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_addition_ctx_t));
     if (ctx == NULL) {
         return NGX_ERROR;
     }
 
     ngx_http_set_ctx(r, ctx, ngx_http_addition_filter_module);
 
     ngx_http_clear_content_length(r);
     ngx_http_clear_accept_ranges(r);
 
     return ngx_http_next_header_filter(r);
 }
 
 
 static ngx_int_t
 ngx_http_addition_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
 {
     ngx_int_t                  rc;
     ngx_uint_t                 last;
     ngx_chain_t               *cl;
     ngx_http_request_t        *sr;
     ngx_http_addition_ctx_t   *ctx;
     ngx_http_addition_conf_t  *conf;
 
     if (in == NULL || r->header_only) {
         return ngx_http_next_body_filter(r, in);
     }
 
     ctx = ngx_http_get_module_ctx(r, ngx_http_addition_filter_module);
 
     if (ctx == NULL) {
         return ngx_http_next_body_filter(r, in);
     }
 
     conf = ngx_http_get_module_loc_conf(r, ngx_http_addition_filter_module);
 
     if (!ctx->before_body_sent) {
         ctx->before_body_sent = 1;
 
         if (conf->before_body.len) {
             if (ngx_http_subrequest(r, &conf->before_body, NULL, &sr, NULL, 0)
                 != NGX_OK)
             {
                 return NGX_ERROR;
             }
         }
     }
 
     if (conf->after_body.len == 0) {
         ngx_http_set_ctx(r, NULL, ngx_http_addition_filter_module);
         return ngx_http_next_body_filter(r, in);
     }
 
     last = 0;
 
     for (cl = in; cl; cl = cl->next) {
         if (cl->buf->last_buf) {
             cl->buf->last_buf = 0;
             cl->buf->sync = 1;
             last = 1;
         }
     }
 
     rc = ngx_http_next_body_filter(r, in);
 
     if (rc == NGX_ERROR || !last || conf->after_body.len == 0) {
         return rc;
     }
 
     if (ngx_http_subrequest(r, &conf->after_body, NULL, &sr, NULL, 0)
         != NGX_OK)
     {
         return NGX_ERROR;
     }
 
     ngx_http_set_ctx(r, NULL, ngx_http_addition_filter_module);
 
     return ngx_http_send_special(r, NGX_HTTP_LAST);
 }
 
 
 static ngx_int_t
 ngx_http_addition_filter_init(ngx_conf_t *cf)
 {
     ngx_http_next_header_filter = ngx_http_top_header_filter;
     ngx_http_top_header_filter = ngx_http_addition_header_filter;
 
     ngx_http_next_body_filter = ngx_http_top_body_filter;
     ngx_http_top_body_filter = ngx_http_addition_body_filter;
 
     return NGX_OK;
 }
 
 
 static void *
 ngx_http_addition_create_conf(ngx_conf_t *cf)
 {
     ngx_http_addition_conf_t  *conf;
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_addition_conf_t));
     if (conf == NULL) {
         return NULL;
     }
 
     /*
      * set by ngx_pcalloc():
      *
      *     conf->before_body = { 0, NULL };
      *     conf->after_body = { 0, NULL };
      *     conf->types = { NULL };
      *     conf->types_keys = NULL;
      */
 
     return conf;
 }
 
 
 static char *
 ngx_http_addition_merge_conf(ngx_conf_t *cf, void *parent, void *child)
 {
     ngx_http_addition_conf_t *prev = parent;
     ngx_http_addition_conf_t *conf = child;
 
     ngx_conf_merge_str_value(conf->before_body, prev->before_body, "");
     ngx_conf_merge_str_value(conf->after_body, prev->after_body, "");
 
     if (ngx_http_merge_types(cf, conf->types_keys, &conf->types,
                              prev->types_keys, &prev->types,
                              ngx_http_html_default_types)
         != NGX_OK)
     {
         return NGX_CONF_ERROR;
     }
 
     return NGX_CONF_OK;
 }