text: 
  /*
   * Copyright (C) Igor Sysoev
   * Copyright (C) Nginx, Inc.
   * Copyright (C) Manlio Perillo (manlio.perillo@gmail.com)
   */
  
  
  #include <ngx_config.h>
  #include <ngx_core.h>
  #include <ngx_http.h>
  
  
  typedef struct {
      ngx_array_t                caches;  /* ngx_http_file_cache_t * */
  } ngx_http_scgi_main_conf_t;
  
  
  typedef struct {
      ngx_array_t               *flushes;
      ngx_array_t               *lengths;
      ngx_array_t               *values;
      ngx_uint_t                 number;
      ngx_hash_t                 hash;
  } ngx_http_scgi_params_t;
  
  
  typedef struct {
      ngx_http_upstream_conf_t   upstream;
  
      ngx_http_scgi_params_t     params;
  #if (NGX_HTTP_CACHE)
      ngx_http_scgi_params_t     params_cache;
  #endif
      ngx_array_t               *params_source;
  
      ngx_array_t               *scgi_lengths;
      ngx_array_t               *scgi_values;
  
  #if (NGX_HTTP_CACHE)
      ngx_http_complex_value_t   cache_key;
  #endif
  } ngx_http_scgi_loc_conf_t;
  
  
  static ngx_int_t ngx_http_scgi_eval(ngx_http_request_t *r,
      ngx_http_scgi_loc_conf_t *scf);
  static ngx_int_t ngx_http_scgi_create_request(ngx_http_request_t *r);
  static ngx_int_t ngx_http_scgi_reinit_request(ngx_http_request_t *r);
  static ngx_int_t ngx_http_scgi_process_status_line(ngx_http_request_t *r);
  static ngx_int_t ngx_http_scgi_process_header(ngx_http_request_t *r);
  static void ngx_http_scgi_abort_request(ngx_http_request_t *r);
  static void ngx_http_scgi_finalize_request(ngx_http_request_t *r, ngx_int_t rc);
  
  static void *ngx_http_scgi_create_main_conf(ngx_conf_t *cf);
  static void *ngx_http_scgi_create_loc_conf(ngx_conf_t *cf);
  static char *ngx_http_scgi_merge_loc_conf(ngx_conf_t *cf, void *parent,
      void *child);
  static ngx_int_t ngx_http_scgi_init_params(ngx_conf_t *cf,
      ngx_http_scgi_loc_conf_t *conf, ngx_http_scgi_params_t *params,
      ngx_keyval_t *default_params);
  
  static char *ngx_http_scgi_pass(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
  static char *ngx_http_scgi_store(ngx_conf_t *cf, ngx_command_t *cmd,
      void *conf);
  
  #if (NGX_HTTP_CACHE)
  static ngx_int_t ngx_http_scgi_create_key(ngx_http_request_t *r);
  static char *ngx_http_scgi_cache(ngx_conf_t *cf, ngx_command_t *cmd,
      void *conf);
  static char *ngx_http_scgi_cache_key(ngx_conf_t *cf, ngx_command_t *cmd,
      void *conf);
  #endif
  
  
  static ngx_conf_bitmask_t ngx_http_scgi_next_upstream_masks[] = {
      { ngx_string("error"), NGX_HTTP_UPSTREAM_FT_ERROR },
      { ngx_string("timeout"), NGX_HTTP_UPSTREAM_FT_TIMEOUT },
      { ngx_string("invalid_header"), NGX_HTTP_UPSTREAM_FT_INVALID_HEADER },
      { ngx_string("non_idempotent"), NGX_HTTP_UPSTREAM_FT_NON_IDEMPOTENT },
      { ngx_string("http_500"), NGX_HTTP_UPSTREAM_FT_HTTP_500 },
      { ngx_string("http_503"), NGX_HTTP_UPSTREAM_FT_HTTP_503 },
      { ngx_string("http_403"), NGX_HTTP_UPSTREAM_FT_HTTP_403 },
      { ngx_string("http_404"), NGX_HTTP_UPSTREAM_FT_HTTP_404 },
      { ngx_string("http_429"), NGX_HTTP_UPSTREAM_FT_HTTP_429 },
      { ngx_string("updating"), NGX_HTTP_UPSTREAM_FT_UPDATING },
      { ngx_string("off"), NGX_HTTP_UPSTREAM_FT_OFF },
      { ngx_null_string, 0 }
  };
  
  
  ngx_module_t  ngx_http_scgi_module;
  
  
  static ngx_command_t ngx_http_scgi_commands[] = {
  
      { ngx_string("scgi_pass"),
        NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF|NGX_CONF_TAKE1,
        ngx_http_scgi_pass,
        NGX_HTTP_LOC_CONF_OFFSET,
        0,
        NULL },
  
      { ngx_string("scgi_store"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_http_scgi_store,
        NGX_HTTP_LOC_CONF_OFFSET,
        0,
        NULL },
  
      { ngx_string("scgi_store_access"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE123,
        ngx_conf_set_access_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.store_access),
        NULL },
  
      { ngx_string("scgi_buffering"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.buffering),
        NULL },
  
      { ngx_string("scgi_request_buffering"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.request_buffering),
        NULL },
  
      { ngx_string("scgi_ignore_client_abort"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.ignore_client_abort),
        NULL },
  
      { ngx_string("scgi_bind"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE12,
        ngx_http_upstream_bind_set_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.local),
        NULL },
  
      { ngx_string("scgi_connect_timeout"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_msec_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.connect_timeout),
        NULL },
  
      { ngx_string("scgi_send_timeout"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_msec_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.send_timeout),
        NULL },
  
      { ngx_string("scgi_buffer_size"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_size_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.buffer_size),
        NULL },
  
      { ngx_string("scgi_pass_request_headers"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.pass_request_headers),
        NULL },
  
      { ngx_string("scgi_pass_request_body"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.pass_request_body),
        NULL },
  
      { ngx_string("scgi_intercept_errors"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.intercept_errors),
        NULL },
  
      { ngx_string("scgi_read_timeout"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_msec_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.read_timeout),
        NULL },
  
      { ngx_string("scgi_buffers"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2,
        ngx_conf_set_bufs_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.bufs),
        NULL },
  
      { ngx_string("scgi_busy_buffers_size"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_size_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.busy_buffers_size_conf),
        NULL },
  
      { ngx_string("scgi_force_ranges"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.force_ranges),
        NULL },
  
      { ngx_string("scgi_limit_rate"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_size_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.limit_rate),
        NULL },
  
  #if (NGX_HTTP_CACHE)
  
      { ngx_string("scgi_cache"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_http_scgi_cache,
        NGX_HTTP_LOC_CONF_OFFSET,
        0,
        NULL },
  
      { ngx_string("scgi_cache_key"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_http_scgi_cache_key,
        NGX_HTTP_LOC_CONF_OFFSET,
        0,
        NULL },
  
      { ngx_string("scgi_cache_path"),
        NGX_HTTP_MAIN_CONF|NGX_CONF_2MORE,
        ngx_http_file_cache_set_slot,
        NGX_HTTP_MAIN_CONF_OFFSET,
        offsetof(ngx_http_scgi_main_conf_t, caches),
        &ngx_http_scgi_module },
  
      { ngx_string("scgi_cache_bypass"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
        ngx_http_set_predicate_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_bypass),
        NULL },
  
      { ngx_string("scgi_no_cache"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
        ngx_http_set_predicate_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.no_cache),
        NULL },
  
      { ngx_string("scgi_cache_valid"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
        ngx_http_file_cache_valid_set_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_valid),
        NULL },
  
      { ngx_string("scgi_cache_min_uses"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_num_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_min_uses),
        NULL },
  
      { ngx_string("scgi_cache_max_range_offset"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_off_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_max_range_offset),
        NULL },
  
      { ngx_string("scgi_cache_use_stale"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
        ngx_conf_set_bitmask_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_use_stale),
        &ngx_http_scgi_next_upstream_masks },
  
      { ngx_string("scgi_cache_methods"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
        ngx_conf_set_bitmask_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_methods),
        &ngx_http_upstream_cache_method_mask },
  
      { ngx_string("scgi_cache_lock"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_lock),
        NULL },
  
      { ngx_string("scgi_cache_lock_timeout"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_msec_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_lock_timeout),
        NULL },
  
      { ngx_string("scgi_cache_lock_age"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_msec_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_lock_age),
        NULL },
  
      { ngx_string("scgi_cache_revalidate"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_revalidate),
        NULL },
  
      { ngx_string("scgi_cache_background_update"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.cache_background_update),
        NULL },
  
  #endif
  
      { ngx_string("scgi_temp_path"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1234,
        ngx_conf_set_path_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.temp_path),
        NULL },
  
      { ngx_string("scgi_max_temp_file_size"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_size_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.max_temp_file_size_conf),
        NULL },
  
      { ngx_string("scgi_temp_file_write_size"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_size_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.temp_file_write_size_conf),
        NULL },
  
      { ngx_string("scgi_next_upstream"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
        ngx_conf_set_bitmask_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.next_upstream),
        &ngx_http_scgi_next_upstream_masks },
  
      { ngx_string("scgi_next_upstream_tries"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_num_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.next_upstream_tries),
        NULL },
  
      { ngx_string("scgi_next_upstream_timeout"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_msec_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.next_upstream_timeout),
        NULL },
  
      { ngx_string("scgi_param"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE23,
        ngx_http_upstream_param_set_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, params_source),
        NULL },
  
      { ngx_string("scgi_pass_header"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_str_array_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.pass_headers),
        NULL },
  
      { ngx_string("scgi_hide_header"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_str_array_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.hide_headers),
        NULL },
  
      { ngx_string("scgi_ignore_headers"),
        NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
        ngx_conf_set_bitmask_slot,
        NGX_HTTP_LOC_CONF_OFFSET,
        offsetof(ngx_http_scgi_loc_conf_t, upstream.ignore_headers),
        &ngx_http_upstream_ignore_headers_masks },
  
        ngx_null_command
  };
  
  
  static ngx_http_module_t ngx_http_scgi_module_ctx = {
      NULL,                                  /* preconfiguration */
      NULL,                                  /* postconfiguration */
  
      ngx_http_scgi_create_main_conf,        /* create main configuration */
      NULL,                                  /* init main configuration */
  
      NULL,                                  /* create server configuration */
      NULL,                                  /* merge server configuration */
  
      ngx_http_scgi_create_loc_conf,         /* create location configuration */
      ngx_http_scgi_merge_loc_conf           /* merge location configuration */
  };
  
  
  ngx_module_t ngx_http_scgi_module = {
      NGX_MODULE_V1,
      &ngx_http_scgi_module_ctx,             /* module context */
      ngx_http_scgi_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_str_t ngx_http_scgi_hide_headers[] = {
      ngx_string("Status"),
      ngx_string("X-Accel-Expires"),
      ngx_string("X-Accel-Redirect"),
      ngx_string("X-Accel-Limit-Rate"),
      ngx_string("X-Accel-Buffering"),
      ngx_string("X-Accel-Charset"),
      ngx_null_string
  };
  
  
  #if (NGX_HTTP_CACHE)
  
  static ngx_keyval_t  ngx_http_scgi_cache_headers[] = {
      { ngx_string("HTTP_IF_MODIFIED_SINCE"),
        ngx_string("$upstream_cache_last_modified") },
      { ngx_string("HTTP_IF_UNMODIFIED_SINCE"), ngx_string("") },
      { ngx_string("HTTP_IF_NONE_MATCH"), ngx_string("$upstream_cache_etag") },
      { ngx_string("HTTP_IF_MATCH"), ngx_string("") },
      { ngx_string("HTTP_RANGE"), ngx_string("") },
      { ngx_string("HTTP_IF_RANGE"), ngx_string("") },
      { ngx_null_string, ngx_null_string }
  };
  
  #endif
  
  
  static ngx_path_init_t ngx_http_scgi_temp_path = {
      ngx_string(NGX_HTTP_SCGI_TEMP_PATH), { 1, 2, 0 }
  };
  
  
  static ngx_int_t
  ngx_http_scgi_handler(ngx_http_request_t *r)
  {
      ngx_int_t                   rc;
      ngx_http_status_t          *status;
      ngx_http_upstream_t        *u;
      ngx_http_scgi_loc_conf_t   *scf;
  #if (NGX_HTTP_CACHE)
      ngx_http_scgi_main_conf_t  *smcf;
  #endif
  
      if (ngx_http_upstream_create(r) != NGX_OK) {
          return NGX_HTTP_INTERNAL_SERVER_ERROR;
      }
  
      status = ngx_pcalloc(r->pool, sizeof(ngx_http_status_t));
      if (status == NULL) {
          return NGX_HTTP_INTERNAL_SERVER_ERROR;
      }
  
      ngx_http_set_ctx(r, status, ngx_http_scgi_module);
  
      scf = ngx_http_get_module_loc_conf(r, ngx_http_scgi_module);
  
      if (scf->scgi_lengths) {
          if (ngx_http_scgi_eval(r, scf) != NGX_OK) {
              return NGX_HTTP_INTERNAL_SERVER_ERROR;
          }
      }
  
      u = r->upstream;
  
      ngx_str_set(&u->schema, "scgi://");
      u->output.tag = (ngx_buf_tag_t) &ngx_http_scgi_module;
  
      u->conf = &scf->upstream;
  
  #if (NGX_HTTP_CACHE)
      smcf = ngx_http_get_module_main_conf(r, ngx_http_scgi_module);
  
      u->caches = &smcf->caches;
      u->create_key = ngx_http_scgi_create_key;
  #endif
  
      u->create_request = ngx_http_scgi_create_request;
      u->reinit_request = ngx_http_scgi_reinit_request;
      u->process_header = ngx_http_scgi_process_status_line;
      u->abort_request = ngx_http_scgi_abort_request;
      u->finalize_request = ngx_http_scgi_finalize_request;
      r->state = 0;
  
      u->buffering = scf->upstream.buffering;
  
      u->pipe = ngx_pcalloc(r->pool, sizeof(ngx_event_pipe_t));
      if (u->pipe == NULL) {
          return NGX_HTTP_INTERNAL_SERVER_ERROR;
      }
  
      u->pipe->input_filter = ngx_event_pipe_copy_input_filter;
      u->pipe->input_ctx = r;
  
      if (!scf->upstream.request_buffering
          && scf->upstream.pass_request_body
          && !r->headers_in.chunked)
      {
          r->request_body_no_buffering = 1;
      }
  
      rc = ngx_http_read_client_request_body(r, ngx_http_upstream_init);
  
      if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
          return rc;
      }
  
      return NGX_DONE;
  }
  
  
  static ngx_int_t
  ngx_http_scgi_eval(ngx_http_request_t *r, ngx_http_scgi_loc_conf_t * scf)
  {
      ngx_url_t             url;
      ngx_http_upstream_t  *u;
  
      ngx_memzero(&url, sizeof(ngx_url_t));
  
      if (ngx_http_script_run(r, &url.url, scf->scgi_lengths->elts, 0,
                              scf->scgi_values->elts)
          == NULL)
      {
          return NGX_ERROR;
      }
  
      url.no_resolve = 1;
  
      if (ngx_parse_url(r->pool, &url) != NGX_OK) {
          if (url.err) {
              ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                            "%s in upstream \"%V\"", url.err, &url.url);
          }
  
          return NGX_ERROR;
      }
  
      u = r->upstream;
  
      u->resolved = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_resolved_t));
      if (u->resolved == NULL) {
          return NGX_ERROR;
      }
  
      if (url.addrs) {
          u->resolved->sockaddr = url.addrs[0].sockaddr;
          u->resolved->socklen = url.addrs[0].socklen;
          u->resolved->name = url.addrs[0].name;
          u->resolved->naddrs = 1;
      }
  
      u->resolved->host = url.host;
      u->resolved->port = url.port;
      u->resolved->no_port = url.no_port;
  
      return NGX_OK;
  }
  
  
  #if (NGX_HTTP_CACHE)
  
  static ngx_int_t
  ngx_http_scgi_create_key(ngx_http_request_t *r)
  {
      ngx_str_t                 *key;
      ngx_http_scgi_loc_conf_t  *scf;
  
      key = ngx_array_push(&r->cache->keys);
      if (key == NULL) {
          return NGX_ERROR;
      }
  
      scf = ngx_http_get_module_loc_conf(r, ngx_http_scgi_module);
  
      if (ngx_http_complex_value(r, &scf->cache_key, key) != NGX_OK) {
          return NGX_ERROR;
      }
  
      return NGX_OK;
  }
  
  #endif
  
  
  static ngx_int_t
  ngx_http_scgi_create_request(ngx_http_request_t *r)
  {
      off_t                         content_length_n;
      u_char                        ch, *key, *val, *lowcase_key;
      size_t                        len, key_len, val_len, allocated;
      ngx_buf_t                    *b;
      ngx_str_t                     content_length;
      ngx_uint_t                    i, n, hash, skip_empty, header_params;
      ngx_chain_t                  *cl, *body;
      ngx_list_part_t              *part;
      ngx_table_elt_t              *header, **ignored;
      ngx_http_scgi_params_t       *params;
      ngx_http_script_code_pt       code;
      ngx_http_script_engine_t      e, le;
      ngx_http_scgi_loc_conf_t     *scf;
      ngx_http_script_len_code_pt   lcode;
      u_char                        buffer[NGX_OFF_T_LEN];
  
      content_length_n = 0;
      body = r->upstream->request_bufs;
  
      while (body) {
          content_length_n += ngx_buf_size(body->buf);
          body = body->next;
      }
  
      content_length.data = buffer;
      content_length.len = ngx_sprintf(buffer, "%O", content_length_n) - buffer;
  
      len = sizeof("CONTENT_LENGTH") + content_length.len + 1;
  
      header_params = 0;
      ignored = NULL;
  
      scf = ngx_http_get_module_loc_conf(r, ngx_http_scgi_module);
  
  #if (NGX_HTTP_CACHE)
      params = r->upstream->cacheable ? &scf->params_cache : &scf->params;
  #else
      params = &scf->params;
  #endif
  
      if (params->lengths) {
          ngx_memzero(&le, sizeof(ngx_http_script_engine_t));
  
          ngx_http_script_flush_no_cacheable_variables(r, params->flushes);
          le.flushed = 1;
  
          le.ip = params->lengths->elts;
          le.request = r;
  
          while (*(uintptr_t *) le.ip) {
  
              lcode = *(ngx_http_script_len_code_pt *) le.ip;
              key_len = lcode(&le);
  
              lcode = *(ngx_http_script_len_code_pt *) le.ip;
              skip_empty = lcode(&le);
  
              for (val_len = 0; *(uintptr_t *) le.ip; val_len += lcode(&le)) {
                  lcode = *(ngx_http_script_len_code_pt *) le.ip;
              }
              le.ip += sizeof(uintptr_t);
  
              if (skip_empty && val_len == 0) {
                  continue;
              }
  
              len += key_len + val_len + 1;
          }
      }
  
      if (scf->upstream.pass_request_headers) {
  
          allocated = 0;
          lowcase_key = NULL;
  
          if (params->number) {
              n = 0;
              part = &r->headers_in.headers.part;
  
              while (part) {
                  n += part->nelts;
                  part = part->next;
              }
  
              ignored = ngx_palloc(r->pool, n * sizeof(void *));
              if (ignored == NULL) {
                  return NGX_ERROR;
              }
          }
  
          part = &r->headers_in.headers.part;
          header = part->elts;
  
          for (i = 0; /* void */; i++) {
  
              if (i >= part->nelts) {
                  if (part->next == NULL) {
                      break;
                  }
  
                  part = part->next;
                  header = part->elts;
                  i = 0;
              }
  
              if (params->number) {
                  if (allocated < header[i].key.len) {
                      allocated = header[i].key.len + 16;
                      lowcase_key = ngx_pnalloc(r->pool, allocated);
                      if (lowcase_key == NULL) {
                          return NGX_ERROR;
                      }
                  }
  
                  hash = 0;
  
                  for (n = 0; n < header[i].key.len; n++) {
                      ch = header[i].key.data[n];
  
                      if (ch >= 'A' && ch <= 'Z') {
                          ch |= 0x20;
  
                      } else if (ch == '-') {
                          ch = '_';
                      }
  
                      hash = ngx_hash(hash, ch);
                      lowcase_key[n] = ch;
                  }
  
                  if (ngx_hash_find(&params->hash, hash, lowcase_key, n)) {
                      ignored[header_params++] = &header[i];
                      continue;
                  }
              }
  
              len += sizeof("HTTP_") - 1 + header[i].key.len + 1
                  + header[i].value.len + 1;
          }
      }
  
      /* netstring: "length:" + packet + "," */
  
      b = ngx_create_temp_buf(r->pool, NGX_SIZE_T_LEN + 1 + len + 1);
      if (b == NULL) {
          return NGX_ERROR;
      }
  
      cl = ngx_alloc_chain_link(r->pool);
      if (cl == NULL) {
          return NGX_ERROR;
      }
  
      cl->buf = b;
  
      b->last = ngx_sprintf(b->last, "%ui:CONTENT_LENGTH%Z%V%Z",
                            len, &content_length);
  
      if (params->lengths) {
          ngx_memzero(&e, sizeof(ngx_http_script_engine_t));
  
          e.ip = params->values->elts;
          e.pos = b->last;
          e.request = r;
          e.flushed = 1;
  
          le.ip = params->lengths->elts;
  
          while (*(uintptr_t *) le.ip) {
  
              lcode = *(ngx_http_script_len_code_pt *) le.ip;
              lcode(&le); /* key length */
  
              lcode = *(ngx_http_script_len_code_pt *) le.ip;
              skip_empty = lcode(&le);
  
              for (val_len = 0; *(uintptr_t *) le.ip; val_len += lcode(&le)) {
                  lcode = *(ngx_http_script_len_code_pt *) le.ip;
              }
              le.ip += sizeof(uintptr_t);
  
              if (skip_empty && val_len == 0) {
                  e.skip = 1;
  
                  while (*(uintptr_t *) e.ip) {
                      code = *(ngx_http_script_code_pt *) e.ip;
                      code((ngx_http_script_engine_t *) &e);
                  }
                  e.ip += sizeof(uintptr_t);
  
                  e.skip = 0;
  
                  continue;
              }
  
  #if (NGX_DEBUG)
              key = e.pos;
  #endif
              code = *(ngx_http_script_code_pt *) e.ip;
              code((ngx_http_script_engine_t *) & e);
  
  #if (NGX_DEBUG)
              val = e.pos;
  #endif
              while (*(uintptr_t *) e.ip) {
                  code = *(ngx_http_script_code_pt *) e.ip;
                  code((ngx_http_script_engine_t *) &e);
              }
              *e.pos++ = '\0';
              e.ip += sizeof(uintptr_t);
  
              ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                             "scgi param: \"%s: %s\"", key, val);
          }
  
          b->last = e.pos;
      }
  
      if (scf->upstream.pass_request_headers) {
  
          part = &r->headers_in.headers.part;
          header = part->elts;
  
          for (i = 0; /* void */; i++) {
  
              if (i >= part->nelts) {
                  if (part->next == NULL) {
                      break;
                  }
  
                  part = part->next;
                  header = part->elts;
                  i = 0;
              }
  
              for (n = 0; n < header_params; n++) {
                  if (&header[i] == ignored[n]) {
                      goto next;
                  }
              }
  
              key = b->last;
              b->last = ngx_cpymem(key, "HTTP_", sizeof("HTTP_") - 1);
  
              for (n = 0; n < header[i].key.len; n++) {
                  ch = header[i].key.data[n];
  
                  if (ch >= 'a' && ch <= 'z') {
                      ch &= ~0x20;
  
                  } else if (ch == '-') {
                      ch = '_';
                  }
  
                  *b->last++ = ch;
              }
  
              *b->last++ = (u_char) 0;
  
              val = b->last;
              b->last = ngx_copy(val, header[i].value.data, header[i].value.len);
              *b->last++ = (u_char) 0;
  
              ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                             "scgi param: \"%s: %s\"", key, val);
  
          next:
  
              continue;
          }
      }
  
      *b->last++ = (u_char) ',';
  
      if (r->request_body_no_buffering) {
          r->upstream->request_bufs = cl;
  
      } else if (scf->upstream.pass_request_body) {
          body = r->upstream->request_bufs;
          r->upstream->request_bufs = cl;
  
          while (body) {
              b = ngx_alloc_buf(r->pool);
              if (b == NULL) {
                  return NGX_ERROR;
              }
  
              ngx_memcpy(b, body->buf, sizeof(ngx_buf_t));
  
              cl->next = ngx_alloc_chain_link(r->pool);
              if (cl->next == NULL) {
                  return NGX_ERROR;
              }
  
              cl = cl->next;
              cl->buf = b;
  
              body = body->next;
          }
  
      } else {
          r->upstream->request_bufs = cl;
      }
  
      cl->next = NULL;
  
      return NGX_OK;
  }
  
  
  static ngx_int_t
  ngx_http_scgi_reinit_request(ngx_http_request_t *r)
  {
      ngx_http_status_t  *status;
  
      status = ngx_http_get_module_ctx(r, ngx_http_scgi_module);
  
      if (status == NULL) {
          return NGX_OK;
      }
  
      status->code = 0;
      status->count = 0;
      status->start = NULL;
      status->end = NULL;
  
      r->upstream->process_header = ngx_http_scgi_process_status_line;
      r->state = 0;
  
      return NGX_OK;
  }
  
  
  static ngx_int_t
  ngx_http_scgi_process_status_line(ngx_http_request_t *r)
  {
      size_t                len;
      ngx_int_t             rc;
      ngx_http_status_t    *status;
      ngx_http_upstream_t  *u;
  
      status = ngx_http_get_module_ctx(r, ngx_http_scgi_module);
  
      if (status == NULL) {
          return NGX_ERROR;
      }
  
      u = r->upstream;
  
      rc = ngx_http_parse_status_line(r, &u->buffer, status);
  
      if (rc == NGX_AGAIN) {
          return rc;
      }
  
      if (rc == NGX_ERROR) {
          u->process_header = ngx_http_scgi_process_header;
          return ngx_http_scgi_process_header(r);
      }
  
      if (u->state && u->state->status == 0) {
          u->state->status = status->code;
      }
  
      u->headers_in.status_n = status->code;
  
      len = status->end - status->start;
      u->headers_in.status_line.len = len;
  
      u->headers_in.status_line.data = ngx_pnalloc(r->pool, len);
      if (u->headers_in.status_line.data == NULL) {
          return NGX_ERROR;
      }
  
      ngx_memcpy(u->headers_in.status_line.data, status->start, len);
  
      ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                     "http scgi status %ui \"%V\"",
                     u->headers_in.status_n, &u->headers_in.status_line);
  
      u->process_header = ngx_http_scgi_process_header;
  
      return ngx_http_scgi_process_header(r);
  }
  
  
  static ngx_int_t
  ngx_http_scgi_process_header(ngx_http_request_t *r)
  {
      ngx_str_t                      *status_line;
      ngx_int_t                       rc, status;
      ngx_table_elt_t                *h;
      ngx_http_upstream_t            *u;
      ngx_http_upstream_header_t     *hh;
      ngx_http_upstream_main_conf_t  *umcf;
  
      umcf = ngx_http_get_module_main_conf(r, ngx_http_upstream_module);
  
      for ( ;; ) {
  
          rc = ngx_http_parse_header_line(r, &r->upstream->buffer, 1);
  
          if (rc == NGX_OK) {
  
              /* a header line has been parsed successfully */
  
              h = ngx_list_push(&r->upstream->headers_in.headers);
              if (h == NULL) {
                  return NGX_ERROR;
              }
  
              h->hash = r->header_hash;
  
              h->key.len = r->header_name_end - r->header_name_start;
              h->value.len = r->header_end - r->header_start;
  
              h->key.data = ngx_pnalloc(r->pool,
                                        h->key.len + 1 + h->value.len + 1
                                        + h->key.len);
              if (h->key.data == NULL) {
                  return NGX_ERROR;
              }
  
              h->value.data = h->key.data + h->key.len + 1;
              h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
  
              ngx_memcpy(h->key.data, r->header_name_start, h->key.len);
              h->key.data[h->key.len] = '\0';
              ngx_memcpy(h->value.data, r->header_start, h->value.len);
              h->value.data[h->value.len] = '\0';
  
              if (h->key.len == r->lowcase_index) {
                  ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
  
              } else {
                  ngx_strlow(h->lowcase_key, h->key.data, h->key.len);
              }
  
              hh = ngx_hash_find(&umcf->headers_in_hash, h->hash,
                                 h->lowcase_key, h->key.len);
  
              if (hh && hh->handler(r, h, hh->offset) != NGX_OK) {
                  return NGX_ERROR;
              }
  
              ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                             "http scgi header: \"%V: %V\"", &h->key, &h->value);
  
              continue;
          }
  
          if (rc == NGX_HTTP_PARSE_HEADER_DONE) {
  
              /* a whole header has been parsed successfully */
  
              ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                             "http scgi header done");
  
              u = r->upstream;
  
              if (u->headers_in.status_n) {
                  goto done;
              }
  
              if (u->headers_in.status) {
                  status_line = &u->headers_in.status->value;
  
                  status = ngx_atoi(status_line->data, 3);
                  if (status == NGX_ERROR) {
                      ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                                    "upstream sent invalid status \"%V\"",
                                    status_line);
                      return NGX_HTTP_UPSTREAM_INVALID_HEADER;
                  }
  
                  u->headers_in.status_n = status;
                  u->headers_in.status_line = *status_line;
  
              } else if (u->headers_in.location) {
                  u->headers_in.status_n = 302;
                  ngx_str_set(&u->headers_in.status_line,
                              "302 Moved Temporarily");
  
              } else {
                  u->headers_in.status_n = 200;
                  ngx_str_set(&u->headers_in.status_line, "200 OK");
              }
  
              if (u->state && u->state->status == 0) {
                  u->state->status = u->headers_in.status_n;
              }
  
          done:
  
              if (u->headers_in.status_n == NGX_HTTP_SWITCHING_PROTOCOLS
                  && r->headers_in.upgrade)
              {
                  u->upgrade = 1;
              }
  
              return NGX_OK;
          }
  
          if (rc == NGX_AGAIN) {
              return NGX_AGAIN;
          }
  
          /* there was error while a header line parsing */
  
          ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                        "upstream sent invalid header");
  
          return NGX_HTTP_UPSTREAM_INVALID_HEADER;
      }
  }
  
  
  static void
  ngx_http_scgi_abort_request(ngx_http_request_t *r)
  {
      ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                     "abort http scgi request");
  
      return;
  }
  
  
  static void
  ngx_http_scgi_finalize_request(ngx_http_request_t *r, ngx_int_t rc)
  {
      ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                     "finalize http scgi request");
  
      return;
  }
  
  
  static void *
  ngx_http_scgi_create_main_conf(ngx_conf_t *cf)
  {
      ngx_http_scgi_main_conf_t  *conf;
  
      conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_scgi_main_conf_t));
      if (conf == NULL) {
          return NULL;
      }
  
  #if (NGX_HTTP_CACHE)
      if (ngx_array_init(&conf->caches, cf->pool, 4,
                         sizeof(ngx_http_file_cache_t *))
          != NGX_OK)
      {
          return NULL;
      }
  #endif
  
      return conf;
  }
  
  
  static void *
  ngx_http_scgi_create_loc_conf(ngx_conf_t *cf)
  {
      ngx_http_scgi_loc_conf_t  *conf;
  
      conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_scgi_loc_conf_t));
      if (conf == NULL) {
          return NULL;
      }
  
      conf->upstream.store = NGX_CONF_UNSET;
      conf->upstream.store_access = NGX_CONF_UNSET_UINT;
      conf->upstream.next_upstream_tries = NGX_CONF_UNSET_UINT;
      conf->upstream.buffering = NGX_CONF_UNSET;
      conf->upstream.request_buffering = NGX_CONF_UNSET;
      conf->upstream.ignore_client_abort = NGX_CONF_UNSET;
      conf->upstream.force_ranges = NGX_CONF_UNSET;
  
      conf->upstream.local = NGX_CONF_UNSET_PTR;
  
      conf->upstream.connect_timeout = NGX_CONF_UNSET_MSEC;
      conf->upstream.send_timeout = NGX_CONF_UNSET_MSEC;
      conf->upstream.read_timeout = NGX_CONF_UNSET_MSEC;
      conf->upstream.next_upstream_timeout = NGX_CONF_UNSET_MSEC;
  
      conf->upstream.send_lowat = NGX_CONF_UNSET_SIZE;
      conf->upstream.buffer_size = NGX_CONF_UNSET_SIZE;
      conf->upstream.limit_rate = NGX_CONF_UNSET_SIZE;
  
      conf->upstream.busy_buffers_size_conf = NGX_CONF_UNSET_SIZE;
      conf->upstream.max_temp_file_size_conf = NGX_CONF_UNSET_SIZE;
      conf->upstream.temp_file_write_size_conf = NGX_CONF_UNSET_SIZE;
  
      conf->upstream.pass_request_headers = NGX_CONF_UNSET;
      conf->upstream.pass_request_body = NGX_CONF_UNSET;
  
  #if (NGX_HTTP_CACHE)
      conf->upstream.cache = NGX_CONF_UNSET;
      conf->upstream.cache_min_uses = NGX_CONF_UNSET_UINT;
      conf->upstream.cache_max_range_offset = NGX_CONF_UNSET;
      conf->upstream.cache_bypass = NGX_CONF_UNSET_PTR;
      conf->upstream.no_cache = NGX_CONF_UNSET_PTR;
      conf->upstream.cache_valid = NGX_CONF_UNSET_PTR;
      conf->upstream.cache_lock = NGX_CONF_UNSET;
      conf->upstream.cache_lock_timeout = NGX_CONF_UNSET_MSEC;
      conf->upstream.cache_lock_age = NGX_CONF_UNSET_MSEC;
      conf->upstream.cache_revalidate = NGX_CONF_UNSET;
      conf->upstream.cache_background_update = NGX_CONF_UNSET;
  #endif
  
      conf->upstream.hide_headers = NGX_CONF_UNSET_PTR;
      conf->upstream.pass_headers = NGX_CONF_UNSET_PTR;
  
      conf->upstream.intercept_errors = NGX_CONF_UNSET;
  
      /* "scgi_cyclic_temp_file" is disabled */
      conf->upstream.cyclic_temp_file = 0;
  
      conf->upstream.change_buffering = 1;
  
      ngx_str_set(&conf->upstream.module, "scgi");
  
      return conf;
  }
  
  
  static char *
  ngx_http_scgi_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
  {
      ngx_http_scgi_loc_conf_t *prev = parent;
      ngx_http_scgi_loc_conf_t *conf = child;
  
      size_t                        size;
      ngx_int_t                     rc;
      ngx_hash_init_t               hash;
      ngx_http_core_loc_conf_t     *clcf;
  
  #if (NGX_HTTP_CACHE)
  
      if (conf->upstream.store > 0) {
          conf->upstream.cache = 0;
      }
  
      if (conf->upstream.cache > 0) {
          conf->upstream.store = 0;
      }
  
  #endif
  
      if (conf->upstream.store == NGX_CONF_UNSET) {
          ngx_conf_merge_value(conf->upstream.store, prev->upstream.store, 0);
  
          conf->upstream.store_lengths = prev->upstream.store_lengths;
          conf->upstream.store_values = prev->upstream.store_values;
      }
  
      ngx_conf_merge_uint_value(conf->upstream.store_access,
                                prev->upstream.store_access, 0600);
  
      ngx_conf_merge_uint_value(conf->upstream.next_upstream_tries,
                                prev->upstream.next_upstream_tries, 0);
  
      ngx_conf_merge_value(conf->upstream.buffering,
                                prev->upstream.buffering, 1);
  
      ngx_conf_merge_value(conf->upstream.request_buffering,
                                prev->upstream.request_buffering, 1);
  
      ngx_conf_merge_value(conf->upstream.ignore_client_abort,
                                prev->upstream.ignore_client_abort, 0);
  
      ngx_conf_merge_value(conf->upstream.force_ranges,
                                prev->upstream.force_ranges, 0);
  
      ngx_conf_merge_ptr_value(conf->upstream.local,
                                prev->upstream.local, NULL);
  
      ngx_conf_merge_msec_value(conf->upstream.connect_timeout,
                                prev->upstream.connect_timeout, 60000);
  
      ngx_conf_merge_msec_value(conf->upstream.send_timeout,
                                prev->upstream.send_timeout, 60000);
  
      ngx_conf_merge_msec_value(conf->upstream.read_timeout,
                                prev->upstream.read_timeout, 60000);
  
      ngx_conf_merge_msec_value(conf->upstream.next_upstream_timeout,
                                prev->upstream.next_upstream_timeout, 0);
  
      ngx_conf_merge_size_value(conf->upstream.send_lowat,
                                prev->upstream.send_lowat, 0);
  
      ngx_conf_merge_size_value(conf->upstream.buffer_size,
                                prev->upstream.buffer_size,
                                (size_t) ngx_pagesize);
  
      ngx_conf_merge_size_value(conf->upstream.limit_rate,
                                prev->upstream.limit_rate, 0);
  
  
      ngx_conf_merge_bufs_value(conf->upstream.bufs, prev->upstream.bufs,
                                8, ngx_pagesize);
  
      if (conf->upstream.bufs.num < 2) {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                             "there must be at least 2 \"scgi_buffers\"");
          return NGX_CONF_ERROR;
      }
  
  
      size = conf->upstream.buffer_size;
      if (size < conf->upstream.bufs.size) {
          size = conf->upstream.bufs.size;
      }
  
  
      ngx_conf_merge_size_value(conf->upstream.busy_buffers_size_conf,
                                prev->upstream.busy_buffers_size_conf,
                                NGX_CONF_UNSET_SIZE);
  
      if (conf->upstream.busy_buffers_size_conf == NGX_CONF_UNSET_SIZE) {
          conf->upstream.busy_buffers_size = 2 * size;
      } else {
          conf->upstream.busy_buffers_size =
              conf->upstream.busy_buffers_size_conf;
      }
  
      if (conf->upstream.busy_buffers_size < size) {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
              "\"scgi_busy_buffers_size\" must be equal to or greater "
              "than the maximum of the value of \"scgi_buffer_size\" and "
              "one of the \"scgi_buffers\"");
  
          return NGX_CONF_ERROR;
      }
  
      if (conf->upstream.busy_buffers_size
          > (conf->upstream.bufs.num - 1) * conf->upstream.bufs.size)
      {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
              "\"scgi_busy_buffers_size\" must be less than "
              "the size of all \"scgi_buffers\" minus one buffer");
  
          return NGX_CONF_ERROR;
      }
  
  
      ngx_conf_merge_size_value(conf->upstream.temp_file_write_size_conf,
                                prev->upstream.temp_file_write_size_conf,
                                NGX_CONF_UNSET_SIZE);
  
      if (conf->upstream.temp_file_write_size_conf == NGX_CONF_UNSET_SIZE) {
          conf->upstream.temp_file_write_size = 2 * size;
      } else {
          conf->upstream.temp_file_write_size =
              conf->upstream.temp_file_write_size_conf;
      }
  
      if (conf->upstream.temp_file_write_size < size) {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
              "\"scgi_temp_file_write_size\" must be equal to or greater than "
              "the maximum of the value of \"scgi_buffer_size\" and "
              "one of the \"scgi_buffers\"");
  
          return NGX_CONF_ERROR;
      }
  
  
      ngx_conf_merge_size_value(conf->upstream.max_temp_file_size_conf,
                                prev->upstream.max_temp_file_size_conf,
                                NGX_CONF_UNSET_SIZE);
  
      if (conf->upstream.max_temp_file_size_conf == NGX_CONF_UNSET_SIZE) {
          conf->upstream.max_temp_file_size = 1024 * 1024 * 1024;
      } else {
          conf->upstream.max_temp_file_size =
              conf->upstream.max_temp_file_size_conf;
      }
  
      if (conf->upstream.max_temp_file_size != 0
          && conf->upstream.max_temp_file_size < size)
      {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
              "\"scgi_max_temp_file_size\" must be equal to zero to disable "
              "temporary files usage or must be equal to or greater than "
              "the maximum of the value of \"scgi_buffer_size\" and "
              "one of the \"scgi_buffers\"");
  
          return NGX_CONF_ERROR;
      }
  
  
      ngx_conf_merge_bitmask_value(conf->upstream.ignore_headers,
                                   prev->upstream.ignore_headers,
                                   NGX_CONF_BITMASK_SET);
  
  
      ngx_conf_merge_bitmask_value(conf->upstream.next_upstream,
                                   prev->upstream.next_upstream,
                                   (NGX_CONF_BITMASK_SET
                                    |NGX_HTTP_UPSTREAM_FT_ERROR
                                    |NGX_HTTP_UPSTREAM_FT_TIMEOUT));
  
      if (conf->upstream.next_upstream & NGX_HTTP_UPSTREAM_FT_OFF) {
          conf->upstream.next_upstream = NGX_CONF_BITMASK_SET
                                         |NGX_HTTP_UPSTREAM_FT_OFF;
      }
  
      if (ngx_conf_merge_path_value(cf, &conf->upstream.temp_path,
                                    prev->upstream.temp_path,
                                    &ngx_http_scgi_temp_path)
          != NGX_OK)
      {
          return NGX_CONF_ERROR;
      }
  
  #if (NGX_HTTP_CACHE)
  
      if (conf->upstream.cache == NGX_CONF_UNSET) {
          ngx_conf_merge_value(conf->upstream.cache,
                                prev->upstream.cache, 0);
  
          conf->upstream.cache_zone = prev->upstream.cache_zone;
          conf->upstream.cache_value = prev->upstream.cache_value;
      }
  
      if (conf->upstream.cache_zone && conf->upstream.cache_zone->data == NULL) {
          ngx_shm_zone_t  *shm_zone;
  
          shm_zone = conf->upstream.cache_zone;
  
          ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                             "\"scgi_cache\" zone \"%V\" is unknown",
                             &shm_zone->shm.name);
  
          return NGX_CONF_ERROR;
      }
  
      ngx_conf_merge_uint_value(conf->upstream.cache_min_uses,
                                prev->upstream.cache_min_uses, 1);
  
      ngx_conf_merge_off_value(conf->upstream.cache_max_range_offset,
                                prev->upstream.cache_max_range_offset,
                                NGX_MAX_OFF_T_VALUE);
  
      ngx_conf_merge_bitmask_value(conf->upstream.cache_use_stale,
                                prev->upstream.cache_use_stale,
                                (NGX_CONF_BITMASK_SET
                                 |NGX_HTTP_UPSTREAM_FT_OFF));
  
      if (conf->upstream.cache_use_stale & NGX_HTTP_UPSTREAM_FT_OFF) {
          conf->upstream.cache_use_stale = NGX_CONF_BITMASK_SET
                                           |NGX_HTTP_UPSTREAM_FT_OFF;
      }
  
      if (conf->upstream.cache_use_stale & NGX_HTTP_UPSTREAM_FT_ERROR) {
          conf->upstream.cache_use_stale |= NGX_HTTP_UPSTREAM_FT_NOLIVE;
      }
  
      if (conf->upstream.cache_methods == 0) {
          conf->upstream.cache_methods = prev->upstream.cache_methods;
      }
  
      conf->upstream.cache_methods |= NGX_HTTP_GET|NGX_HTTP_HEAD;
  
      ngx_conf_merge_ptr_value(conf->upstream.cache_bypass,
                               prev->upstream.cache_bypass, NULL);
  
      ngx_conf_merge_ptr_value(conf->upstream.no_cache,
                               prev->upstream.no_cache, NULL);
  
      ngx_conf_merge_ptr_value(conf->upstream.cache_valid,
                               prev->upstream.cache_valid, NULL);
  
      if (conf->cache_key.value.data == NULL) {
          conf->cache_key = prev->cache_key;
      }
  
      if (conf->upstream.cache && conf->cache_key.value.data == NULL) {
          ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                             "no \"scgi_cache_key\" for \"scgi_cache\"");
      }
  
      ngx_conf_merge_value(conf->upstream.cache_lock,
                                prev->upstream.cache_lock, 0);
  
      ngx_conf_merge_msec_value(conf->upstream.cache_lock_timeout,
                                prev->upstream.cache_lock_timeout, 5000);
  
      ngx_conf_merge_msec_value(conf->upstream.cache_lock_age,
                                prev->upstream.cache_lock_age, 5000);
  
      ngx_conf_merge_value(conf->upstream.cache_revalidate,
                                prev->upstream.cache_revalidate, 0);
  
      ngx_conf_merge_value(conf->upstream.cache_background_update,
                                prev->upstream.cache_background_update, 0);
  
  #endif
  
      ngx_conf_merge_value(conf->upstream.pass_request_headers,
                           prev->upstream.pass_request_headers, 1);
      ngx_conf_merge_value(conf->upstream.pass_request_body,
                           prev->upstream.pass_request_body, 1);
  
      ngx_conf_merge_value(conf->upstream.intercept_errors,
                           prev->upstream.intercept_errors, 0);
  
      hash.max_size = 512;
      hash.bucket_size = ngx_align(64, ngx_cacheline_size);
      hash.name = "scgi_hide_headers_hash";
  
      if (ngx_http_upstream_hide_headers_hash(cf, &conf->upstream,
              &prev->upstream, ngx_http_scgi_hide_headers, &hash)
          != NGX_OK)
      {
          return NGX_CONF_ERROR;
      }
  
      clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
  
      if (clcf->noname
          && conf->upstream.upstream == NULL && conf->scgi_lengths == NULL)
      {
          conf->upstream.upstream = prev->upstream.upstream;
          conf->scgi_lengths = prev->scgi_lengths;
          conf->scgi_values = prev->scgi_values;
      }
  
      if (clcf->lmt_excpt && clcf->handler == NULL
          && (conf->upstream.upstream || conf->scgi_lengths))
      {
          clcf->handler = ngx_http_scgi_handler;
      }
  
      if (conf->params_source == NULL) {
          conf->params = prev->params;
  #if (NGX_HTTP_CACHE)
          conf->params_cache = prev->params_cache;
  #endif
          conf->params_source = prev->params_source;
      }
  
      rc = ngx_http_scgi_init_params(cf, conf, &conf->params, NULL);
      if (rc != NGX_OK) {
          return NGX_CONF_ERROR;
      }
  
  #if (NGX_HTTP_CACHE)
  
      if (conf->upstream.cache) {
          rc = ngx_http_scgi_init_params(cf, conf, &conf->params_cache,
                                         ngx_http_scgi_cache_headers);
          if (rc != NGX_OK) {
              return NGX_CONF_ERROR;
          }
      }
  
  #endif
  
      /*
       * special handling to preserve conf->params in the "http" section
       * to inherit it to all servers
       */
  
      if (prev->params.hash.buckets == NULL
          && conf->params_source == prev->params_source)
      {
          prev->params = conf->params;
  #if (NGX_HTTP_CACHE)
          prev->params_cache = conf->params_cache;
  #endif
      }
  
      return NGX_CONF_OK;
  }
  
  
  static ngx_int_t
  ngx_http_scgi_init_params(ngx_conf_t *cf, ngx_http_scgi_loc_conf_t *conf,
      ngx_http_scgi_params_t *params, ngx_keyval_t *default_params)
  {
      u_char                       *p;
      size_t                        size;
      uintptr_t                    *code;
      ngx_uint_t                    i, nsrc;
      ngx_array_t                   headers_names, params_merged;
      ngx_keyval_t                 *h;
      ngx_hash_key_t               *hk;
      ngx_hash_init_t               hash;
      ngx_http_upstream_param_t    *src, *s;
      ngx_http_script_compile_t     sc;
      ngx_http_script_copy_code_t  *copy;
  
      if (params->hash.buckets) {
          return NGX_OK;
      }
  
      if (conf->params_source == NULL && default_params == NULL) {
          params->hash.buckets = (void *) 1;
          return NGX_OK;
      }
  
      params->lengths = ngx_array_create(cf->pool, 64, 1);
      if (params->lengths == NULL) {
          return NGX_ERROR;
      }
  
      params->values = ngx_array_create(cf->pool, 512, 1);
      if (params->values == NULL) {
          return NGX_ERROR;
      }
  
      if (ngx_array_init(&headers_names, cf->temp_pool, 4, sizeof(ngx_hash_key_t))
          != NGX_OK)
      {
          return NGX_ERROR;
      }
  
      if (conf->params_source) {
          src = conf->params_source->elts;
          nsrc = conf->params_source->nelts;
  
      } else {
          src = NULL;
          nsrc = 0;
      }
  
      if (default_params) {
          if (ngx_array_init(&params_merged, cf->temp_pool, 4,
                             sizeof(ngx_http_upstream_param_t))
              != NGX_OK)
          {
              return NGX_ERROR;
          }
  
          for (i = 0; i < nsrc; i++) {
  
              s = ngx_array_push(&params_merged);
              if (s == NULL) {
                  return NGX_ERROR;
              }
  
              *s = src[i];
          }
  
          h = default_params;
  
          while (h->key.len) {
  
              src = params_merged.elts;
              nsrc = params_merged.nelts;
  
              for (i = 0; i < nsrc; i++) {
                  if (ngx_strcasecmp(h->key.data, src[i].key.data) == 0) {
                      goto next;
                  }
              }
  
              s = ngx_array_push(&params_merged);
              if (s == NULL) {
                  return NGX_ERROR;
              }
  
              s->key = h->key;
              s->value = h->value;
              s->skip_empty = 1;
  
          next:
  
              h++;
          }
  
          src = params_merged.elts;
          nsrc = params_merged.nelts;
      }
  
      for (i = 0; i < nsrc; i++) {
  
          if (src[i].key.len > sizeof("HTTP_") - 1
              && ngx_strncmp(src[i].key.data, "HTTP_", sizeof("HTTP_") - 1) == 0)
          {
              hk = ngx_array_push(&headers_names);
              if (hk == NULL) {
                  return NGX_ERROR;
              }
  
              hk->key.len = src[i].key.len - 5;
              hk->key.data = src[i].key.data + 5;
              hk->key_hash = ngx_hash_key_lc(hk->key.data, hk->key.len);
              hk->value = (void *) 1;
  
              if (src[i].value.len == 0) {
                  continue;
              }
          }
  
          copy = ngx_array_push_n(params->lengths,
                                  sizeof(ngx_http_script_copy_code_t));
          if (copy == NULL) {
              return NGX_ERROR;
          }
  
          copy->code = (ngx_http_script_code_pt) ngx_http_script_copy_len_code;
          copy->len = src[i].key.len + 1;
  
          copy = ngx_array_push_n(params->lengths,
                                  sizeof(ngx_http_script_copy_code_t));
          if (copy == NULL) {
              return NGX_ERROR;
          }
  
          copy->code = (ngx_http_script_code_pt) ngx_http_script_copy_len_code;
          copy->len = src[i].skip_empty;
  
  
          size = (sizeof(ngx_http_script_copy_code_t)
                  + src[i].key.len + 1 + sizeof(uintptr_t) - 1)
                 & ~(sizeof(uintptr_t) - 1);
  
          copy = ngx_array_push_n(params->values, size);
          if (copy == NULL) {
              return NGX_ERROR;
          }
  
          copy->code = ngx_http_script_copy_code;
          copy->len = src[i].key.len + 1;
  
          p = (u_char *) copy + sizeof(ngx_http_script_copy_code_t);
          (void) ngx_cpystrn(p, src[i].key.data, src[i].key.len + 1);
  
  
          ngx_memzero(&sc, sizeof(ngx_http_script_compile_t));
  
          sc.cf = cf;
          sc.source = &src[i].value;
          sc.flushes = &params->flushes;
          sc.lengths = &params->lengths;
          sc.values = &params->values;
  
          if (ngx_http_script_compile(&sc) != NGX_OK) {
              return NGX_ERROR;
          }
  
          code = ngx_array_push_n(params->lengths, sizeof(uintptr_t));
          if (code == NULL) {
              return NGX_ERROR;
          }
  
          *code = (uintptr_t) NULL;
  
  
          code = ngx_array_push_n(params->values, sizeof(uintptr_t));
          if (code == NULL) {
              return NGX_ERROR;
          }
  
          *code = (uintptr_t) NULL;
      }
  
      code = ngx_array_push_n(params->lengths, sizeof(uintptr_t));
      if (code == NULL) {
          return NGX_ERROR;
      }
  
      *code = (uintptr_t) NULL;
  
      params->number = headers_names.nelts;
  
      hash.hash = &params->hash;
      hash.key = ngx_hash_key_lc;
      hash.max_size = 512;
      hash.bucket_size = 64;
      hash.name = "scgi_params_hash";
      hash.pool = cf->pool;
      hash.temp_pool = NULL;
  
      return ngx_hash_init(&hash, headers_names.elts, headers_names.nelts);
  }
  
  
  static char *
  ngx_http_scgi_pass(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
  {
      ngx_http_scgi_loc_conf_t *scf = conf;
  
      ngx_url_t                   u;
      ngx_str_t                  *value, *url;
      ngx_uint_t                  n;
      ngx_http_core_loc_conf_t   *clcf;
      ngx_http_script_compile_t   sc;
  
      if (scf->upstream.upstream || scf->scgi_lengths) {
          return "is duplicate";
      }
  
      clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
      clcf->handler = ngx_http_scgi_handler;
  
      value = cf->args->elts;
  
      url = &value[1];
  
      n = ngx_http_script_variables_count(url);
  
      if (n) {
  
          ngx_memzero(&sc, sizeof(ngx_http_script_compile_t));
  
          sc.cf = cf;
          sc.source = url;
          sc.lengths = &scf->scgi_lengths;
          sc.values = &scf->scgi_values;
          sc.variables = n;
          sc.complete_lengths = 1;
          sc.complete_values = 1;
  
          if (ngx_http_script_compile(&sc) != NGX_OK) {
              return NGX_CONF_ERROR;
          }
  
          return NGX_CONF_OK;
      }
  
      ngx_memzero(&u, sizeof(ngx_url_t));
  
      u.url = value[1];
      u.no_resolve = 1;
  
      scf->upstream.upstream = ngx_http_upstream_add(cf, &u, 0);
      if (scf->upstream.upstream == NULL) {
          return NGX_CONF_ERROR;
      }
  
      if (clcf->name.data[clcf->name.len - 1] == '/') {
          clcf->auto_redirect = 1;
      }
  
      return NGX_CONF_OK;
  }
  
  
  static char *
  ngx_http_scgi_store(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
  {
      ngx_http_scgi_loc_conf_t *scf = conf;
  
      ngx_str_t                  *value;
      ngx_http_script_compile_t   sc;
  
      if (scf->upstream.store != NGX_CONF_UNSET) {
          return "is duplicate";
      }
  
      value = cf->args->elts;
  
      if (ngx_strcmp(value[1].data, "off") == 0) {
          scf->upstream.store = 0;
          return NGX_CONF_OK;
      }
  
  #if (NGX_HTTP_CACHE)
      if (scf->upstream.cache > 0) {
          return "is incompatible with \"scgi_cache\"";
      }
  #endif
  
      scf->upstream.store = 1;
  
      if (ngx_strcmp(value[1].data, "on") == 0) {
          return NGX_CONF_OK;
      }
  
      /* include the terminating '\0' into script */
      value[1].len++;
  
      ngx_memzero(&sc, sizeof(ngx_http_script_compile_t));
  
      sc.cf = cf;
      sc.source = &value[1];
      sc.lengths = &scf->upstream.store_lengths;
      sc.values = &scf->upstream.store_values;
      sc.variables = ngx_http_script_variables_count(&value[1]);
      sc.complete_lengths = 1;
      sc.complete_values = 1;
  
      if (ngx_http_script_compile(&sc) != NGX_OK) {
          return NGX_CONF_ERROR;
      }
  
      return NGX_CONF_OK;
  }
  
  
  #if (NGX_HTTP_CACHE)
  
  static char *
  ngx_http_scgi_cache(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
  {
      ngx_http_scgi_loc_conf_t *scf = conf;
  
      ngx_str_t                         *value;
      ngx_http_complex_value_t           cv;
      ngx_http_compile_complex_value_t   ccv;
  
      value = cf->args->elts;
  
      if (scf->upstream.cache != NGX_CONF_UNSET) {
          return "is duplicate";
      }
  
      if (ngx_strcmp(value[1].data, "off") == 0) {
          scf->upstream.cache = 0;
          return NGX_CONF_OK;
      }
  
      if (scf->upstream.store > 0) {
          return "is incompatible with \"scgi_store\"";
      }
  
      scf->upstream.cache = 1;
  
      ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));
  
      ccv.cf = cf;
      ccv.value = &value[1];
      ccv.complex_value = &cv;
  
      if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
          return NGX_CONF_ERROR;
      }
  
      if (cv.lengths != NULL) {
  
          scf->upstream.cache_value = ngx_palloc(cf->pool,
                                               sizeof(ngx_http_complex_value_t));
          if (scf->upstream.cache_value == NULL) {
              return NGX_CONF_ERROR;
          }
  
          *scf->upstream.cache_value = cv;
  
          return NGX_CONF_OK;
      }
  
      scf->upstream.cache_zone = ngx_shared_memory_add(cf, &value[1], 0,
                                                       &ngx_http_scgi_module);
      if (scf->upstream.cache_zone == NULL) {
          return NGX_CONF_ERROR;
      }
  
      return NGX_CONF_OK;
  }
  
  
  static char *
  ngx_http_scgi_cache_key(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
  {
      ngx_http_scgi_loc_conf_t *scf = conf;
  
      ngx_str_t                         *value;
      ngx_http_compile_complex_value_t   ccv;
  
      value = cf->args->elts;
  
      if (scf->cache_key.value.data) {
          return "is duplicate";
      }
  
      ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));
  
      ccv.cf = cf;
      ccv.value = &value[1];
      ccv.complex_value = &scf->cache_key;
  
      if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
          return NGX_CONF_ERROR;
      }
  
      return NGX_CONF_OK;
  }
  
  #endif
  