src/http/ngx_http_special_response.c - nginx - Git at Google


 /*
  * Copyright (C) Igor Sysoev
  */


 #include <ngx_config.h>
 #include <ngx_core.h>
 #include <ngx_http.h>
 #include <nginx.h>


 static u_char error_tail[] =
 "<hr><center>" NGINX_VER "</center>" CRLF
 "</body>" CRLF
 "</html>" CRLF
 ;


 static u_char ngx_http_msie_stub[] =
 "<!-- The padding to disable MSIE's friendly error page -->" CRLF
 "<!-- The padding to disable MSIE's friendly error page -->" CRLF
 "<!-- The padding to disable MSIE's friendly error page -->" CRLF
 "<!-- The padding to disable MSIE's friendly error page -->" CRLF
 "<!-- The padding to disable MSIE's friendly error page -->" CRLF
 "<!-- The padding to disable MSIE's friendly error page -->" CRLF
 ;


 static char error_301_page[] =
 "<html>" CRLF
 "<head><title>301 Moved Permanently</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>301 Moved Permanently</h1></center>" CRLF
 ;


 static char error_302_page[] =
 "<html>" CRLF
 "<head><title>302 Found</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>302 Found</h1></center>" CRLF
 ;


 static char error_400_page[] =
 "<html>" CRLF
 "<head><title>400 Bad Request</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>400 Bad Request</h1></center>" CRLF
 ;


 static char error_401_page[] =
 "<html>" CRLF
 "<head><title>401 Authorization Required</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>401 Authorization Required</h1></center>" CRLF
 ;


 static char error_402_page[] =
 "<html>" CRLF
 "<head><title>402 Payment Required</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>402 Payment Required</h1></center>" CRLF
 ;


 static char error_403_page[] =
 "<html>" CRLF
 "<head><title>403 Forbidden</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>403 Forbidden</h1></center>" CRLF
 ;


 static char error_404_page[] =
 "<html>" CRLF
 "<head><title>404 Not Found</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>404 Not Found</h1></center>" CRLF
 ;


 static char error_405_page[] =
 "<html>" CRLF
 "<head><title>405 Not Allowed</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>405 Not Allowed</h1></center>" CRLF
 ;


 static char error_406_page[] =
 "<html>" CRLF
 "<head><title>406 Not Acceptable</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>406 Not Acceptable</h1></center>" CRLF
 ;


 static char error_408_page[] =
 "<html>" CRLF
 "<head><title>408 Request Time-out</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>408 Request Time-out</h1></center>" CRLF
 ;


 static char error_410_page[] =
 "<html>" CRLF
 "<head><title>410 Gone</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>410 Gone</h1></center>" CRLF
 ;


 static char error_413_page[] =
 "<html>" CRLF
 "<head><title>413 Request Entity Too Large</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>413 Request Entity Too Large</h1></center>" CRLF
 ;


 static char error_414_page[] =
 "<html>" CRLF
 "<head><title>414 Request-URI Too Large</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>414 Request-URI Too Large</h1></center>" CRLF
 ;


 static char error_416_page[] =
 "<html>" CRLF
 "<head><title>416 Requested Range Not Satisfiable</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>416 Requested Range Not Satisfiable</h1></center>" CRLF
 ;


 static char error_497_page[] =
 "<html>" CRLF
 "<head><title>400 The plain HTTP request was sent to HTTPS port</title></head>"
 CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>400 Bad Request</h1></center>" CRLF
 "<center>The plain HTTP request was sent to HTTPS port</center>" CRLF
 ;


 static char error_500_page[] =
 "<html>" CRLF
 "<head><title>500 Internal Server Error</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>500 Internal Server Error</h1></center>" CRLF
 ;


 static char error_501_page[] =
 "<html>" CRLF
 "<head><title>501 Method Not Implemented</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>500 Method Not Implemented</h1></center>" CRLF
 ;


 static char error_502_page[] =
 "<html>" CRLF
 "<head><title>502 Bad Gateway</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>502 Bad Gateway</h1></center>" CRLF
 ;


 static char error_503_page[] =
 "<html>" CRLF
 "<head><title>503 Service Temporarily Unavailable</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>503 Service Temporarily Unavailable</h1></center>" CRLF
 ;


 static char error_504_page[] =
 "<html>" CRLF
 "<head><title>504 Gateway Time-out</title></head>" CRLF
 "<body bgcolor=\"white\">" CRLF
 "<center><h1>504 Gateway Time-out</h1></center>" CRLF
 ;


 static ngx_str_t error_pages[] = {

     ngx_null_string,             /* 204 */

 #define NGX_HTTP_LEVEL_200  1

     /* ngx_null_string, */       /* 300 */
     ngx_string(error_301_page),
     ngx_string(error_302_page),
     ngx_null_string,             /* 303 */

 #define NGX_HTTP_LEVEL_300  3

     ngx_string(error_400_page),
     ngx_string(error_401_page),
     ngx_string(error_402_page),
     ngx_string(error_403_page),
     ngx_string(error_404_page),
     ngx_string(error_405_page),
     ngx_string(error_406_page),
     ngx_null_string,             /* 407 */
     ngx_string(error_408_page),
     ngx_null_string,             /* 409 */
     ngx_string(error_410_page),
     ngx_null_string,             /* 411 */
     ngx_null_string,             /* 412 */
     ngx_string(error_413_page),
     ngx_string(error_414_page),
     ngx_null_string,             /* 415 */
     ngx_string(error_416_page),

 #define NGX_HTTP_LEVEL_400  17

     ngx_string(error_497_page),  /* 497, http to https */
     ngx_string(error_404_page),  /* 498, invalid host name */
     ngx_null_string,             /* 499, client had closed connection */

     ngx_string(error_500_page),
     ngx_string(error_501_page),
     ngx_string(error_502_page),
     ngx_string(error_503_page),
     ngx_string(error_504_page)
 };


 ngx_int_t
 ngx_http_special_response_handler(ngx_http_request_t *r, ngx_int_t error)
 {
     ngx_int_t                  rc;
     ngx_uint_t                 i, err, msie_padding;
     ngx_buf_t                 *b;
     ngx_chain_t               *out, *cl;
     ngx_http_err_page_t       *err_page;
     ngx_http_core_loc_conf_t  *clcf;

     rc = ngx_http_discard_body(r);

     if (rc == NGX_HTTP_INTERNAL_SERVER_ERROR) {
         error = NGX_HTTP_INTERNAL_SERVER_ERROR;
     }

     r->headers_out.status = error;

     if (r->keepalive != 0) {
         switch (error) {
             case NGX_HTTP_BAD_REQUEST:
             case NGX_HTTP_REQUEST_ENTITY_TOO_LARGE:
             case NGX_HTTP_REQUEST_URI_TOO_LARGE:
             case NGX_HTTP_TO_HTTPS:
             case NGX_HTTP_INTERNAL_SERVER_ERROR:
                 r->keepalive = 0;
         }
     }

     if (r->lingering_close == 1) {
         switch (error) {
             case NGX_HTTP_BAD_REQUEST:
             case NGX_HTTP_TO_HTTPS:
                 r->lingering_close = 0;
         }
     }

     clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

     if (r->err_ctx == NULL && clcf->error_pages) {

         err_page = clcf->error_pages->elts;

         for (i = 0; i < clcf->error_pages->nelts; i++) {

             if (err_page[i].status == error) {

                 if (err_page[i].overwrite) {
                     r->err_status = err_page[i].overwrite;
                 } else {
                     r->err_status = error;
                 }

                 r->err_ctx = r->ctx;

                 return ngx_http_internal_redirect(r, &err_page[i].uri, NULL);
             }
         }
     }

     if (error == NGX_HTTP_NO_CONTENT) {
         /* 204 */
         err = 0;

     } else if (error < NGX_HTTP_BAD_REQUEST) {
         /* 3XX */
         err = error - NGX_HTTP_MOVED_PERMANENTLY + NGX_HTTP_LEVEL_200;

     } else if (error < NGX_HTTP_NGX_CODES) {
         /* 4XX */
         err = error - NGX_HTTP_BAD_REQUEST + NGX_HTTP_LEVEL_200
                                            + NGX_HTTP_LEVEL_300;

     } else {
         /* 49X, 5XX */
         err = error - NGX_HTTP_NGX_CODES + NGX_HTTP_LEVEL_200
                                          + NGX_HTTP_LEVEL_300
                                          + NGX_HTTP_LEVEL_400;
         switch (error) {
             case NGX_HTTP_TO_HTTPS:
                 r->headers_out.status = NGX_HTTP_BAD_REQUEST;
                 error = NGX_HTTP_BAD_REQUEST;
                 break;

             case NGX_HTTP_INVALID_HOST:
                 r->headers_out.status = NGX_HTTP_NOT_FOUND;
                 error = NGX_HTTP_NOT_FOUND;
                 break;
         }
     }

     msie_padding = 0;

     if (error_pages[err].len) {
         r->headers_out.content_length_n = error_pages[err].len
                                           + sizeof(error_tail) - 1;

         if (clcf->msie_padding
             && r->headers_in.msie
             && r->http_version >= NGX_HTTP_VERSION_10
             && error >= NGX_HTTP_BAD_REQUEST
             && error != NGX_HTTP_REQUEST_URI_TOO_LARGE)
         {
             r->headers_out.content_length_n += sizeof(ngx_http_msie_stub) - 1;
             msie_padding = 1;
         }

         r->headers_out.content_type.len = sizeof("text/html") - 1;
         r->headers_out.content_type.data = (u_char *) "text/html";

     } else {
         r->headers_out.content_length_n = -1;
     }

     if (r->headers_out.content_length) {
         r->headers_out.content_length->hash = 0;
         r->headers_out.content_length = NULL;
     }

     rc = ngx_http_send_header(r);

     if (rc == NGX_ERROR || r->header_only) {
         return rc;
     }

     if (error_pages[err].len == 0) {
         return NGX_OK;
     }


     b = ngx_calloc_buf(r->pool);
     if (b == NULL) {
         return NGX_ERROR;
     }

     b->memory = 1;
     b->pos = error_pages[err].data;
     b->last = error_pages[err].data + error_pages[err].len;

     cl = ngx_alloc_chain_link(r->pool);
     if (cl == NULL) {
         return NGX_ERROR;
     }

     cl->buf = b;
     out = cl;


     b = ngx_calloc_buf(r->pool);
     if (b == NULL) {
         return NGX_ERROR;
     }

     b->memory = 1;
     b->pos = error_tail;
     b->last = error_tail + sizeof(error_tail) - 1;

     cl->next = ngx_alloc_chain_link(r->pool);
     if (cl->next == NULL) {
         return NGX_ERROR;
     }

     cl = cl->next;
     cl->buf = b;

     if (msie_padding) {
         b = ngx_calloc_buf(r->pool);
         if (b == NULL) {
             return NGX_ERROR;
         }

         b->memory = 1;
         b->pos = ngx_http_msie_stub;
         b->last = ngx_http_msie_stub + sizeof(ngx_http_msie_stub) - 1;

         cl->next = ngx_alloc_chain_link(r->pool);
         if (cl->next == NULL) {
             return NGX_ERROR;
         }

         cl = cl->next;
         cl->buf = b;
     }

     if (r->main == NULL) {
         b->last_buf = 1;
     }

     b->last_in_chain = 1;

     cl->next = NULL;

     return ngx_http_output_filter(r, out);
 }

	/*
	* Copyright (C) Igor Sysoev
	*/


	#include <ngx_config.h>
	#include <ngx_core.h>
	#include <ngx_http.h>
	#include <nginx.h>


	static u_char error_tail[] =
	"<hr><center>" NGINX_VER "</center>" CRLF
	"</body>" CRLF
	"</html>" CRLF
	;


	static u_char ngx_http_msie_stub[] =
	"<!-- The padding to disable MSIE's friendly error page -->" CRLF
	"<!-- The padding to disable MSIE's friendly error page -->" CRLF
	"<!-- The padding to disable MSIE's friendly error page -->" CRLF
	"<!-- The padding to disable MSIE's friendly error page -->" CRLF
	"<!-- The padding to disable MSIE's friendly error page -->" CRLF
	"<!-- The padding to disable MSIE's friendly error page -->" CRLF
	;


	static char error_301_page[] =
	"<html>" CRLF
	"<head><title>301 Moved Permanently</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>301 Moved Permanently</h1></center>" CRLF
	;


	static char error_302_page[] =
	"<html>" CRLF
	"<head><title>302 Found</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>302 Found</h1></center>" CRLF
	;


	static char error_400_page[] =
	"<html>" CRLF
	"<head><title>400 Bad Request</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>400 Bad Request</h1></center>" CRLF
	;


	static char error_401_page[] =
	"<html>" CRLF
	"<head><title>401 Authorization Required</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>401 Authorization Required</h1></center>" CRLF
	;


	static char error_402_page[] =
	"<html>" CRLF
	"<head><title>402 Payment Required</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>402 Payment Required</h1></center>" CRLF
	;


	static char error_403_page[] =
	"<html>" CRLF
	"<head><title>403 Forbidden</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>403 Forbidden</h1></center>" CRLF
	;


	static char error_404_page[] =
	"<html>" CRLF
	"<head><title>404 Not Found</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>404 Not Found</h1></center>" CRLF
	;


	static char error_405_page[] =
	"<html>" CRLF
	"<head><title>405 Not Allowed</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>405 Not Allowed</h1></center>" CRLF
	;


	static char error_406_page[] =
	"<html>" CRLF
	"<head><title>406 Not Acceptable</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>406 Not Acceptable</h1></center>" CRLF
	;


	static char error_408_page[] =
	"<html>" CRLF
	"<head><title>408 Request Time-out</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>408 Request Time-out</h1></center>" CRLF
	;


	static char error_410_page[] =
	"<html>" CRLF
	"<head><title>410 Gone</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>410 Gone</h1></center>" CRLF
	;


	static char error_413_page[] =
	"<html>" CRLF
	"<head><title>413 Request Entity Too Large</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>413 Request Entity Too Large</h1></center>" CRLF
	;


	static char error_414_page[] =
	"<html>" CRLF
	"<head><title>414 Request-URI Too Large</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>414 Request-URI Too Large</h1></center>" CRLF
	;


	static char error_416_page[] =
	"<html>" CRLF
	"<head><title>416 Requested Range Not Satisfiable</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>416 Requested Range Not Satisfiable</h1></center>" CRLF
	;


	static char error_497_page[] =
	"<html>" CRLF
	"<head><title>400 The plain HTTP request was sent to HTTPS port</title></head>"
	CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>400 Bad Request</h1></center>" CRLF
	"<center>The plain HTTP request was sent to HTTPS port</center>" CRLF
	;


	static char error_500_page[] =
	"<html>" CRLF
	"<head><title>500 Internal Server Error</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>500 Internal Server Error</h1></center>" CRLF
	;


	static char error_501_page[] =
	"<html>" CRLF
	"<head><title>501 Method Not Implemented</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>500 Method Not Implemented</h1></center>" CRLF
	;


	static char error_502_page[] =
	"<html>" CRLF
	"<head><title>502 Bad Gateway</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>502 Bad Gateway</h1></center>" CRLF
	;


	static char error_503_page[] =
	"<html>" CRLF
	"<head><title>503 Service Temporarily Unavailable</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>503 Service Temporarily Unavailable</h1></center>" CRLF
	;


	static char error_504_page[] =
	"<html>" CRLF
	"<head><title>504 Gateway Time-out</title></head>" CRLF
	"<body bgcolor=\"white\">" CRLF
	"<center><h1>504 Gateway Time-out</h1></center>" CRLF
	;


	static ngx_str_t error_pages[] = {

	ngx_null_string, /* 204 */

	#define NGX_HTTP_LEVEL_200 1

	/* ngx_null_string, / / 300 */
	ngx_string(error_301_page),
	ngx_string(error_302_page),
	ngx_null_string, /* 303 */

	#define NGX_HTTP_LEVEL_300 3

	ngx_string(error_400_page),
	ngx_string(error_401_page),
	ngx_string(error_402_page),
	ngx_string(error_403_page),
	ngx_string(error_404_page),
	ngx_string(error_405_page),
	ngx_string(error_406_page),
	ngx_null_string, /* 407 */
	ngx_string(error_408_page),
	ngx_null_string, /* 409 */
	ngx_string(error_410_page),
	ngx_null_string, /* 411 */
	ngx_null_string, /* 412 */
	ngx_string(error_413_page),
	ngx_string(error_414_page),
	ngx_null_string, /* 415 */
	ngx_string(error_416_page),

	#define NGX_HTTP_LEVEL_400 17

	ngx_string(error_497_page), /* 497, http to https */
	ngx_string(error_404_page), /* 498, invalid host name */
	ngx_null_string, /* 499, client had closed connection */

	ngx_string(error_500_page),
	ngx_string(error_501_page),
	ngx_string(error_502_page),
	ngx_string(error_503_page),
	ngx_string(error_504_page)
	};


	ngx_int_t
	ngx_http_special_response_handler(ngx_http_request_t *r, ngx_int_t error)
	{
	ngx_int_t rc;
	ngx_uint_t i, err, msie_padding;
	ngx_buf_t *b;
	ngx_chain_t out, cl;
	ngx_http_err_page_t *err_page;
	ngx_http_core_loc_conf_t *clcf;

	rc = ngx_http_discard_body(r);

	if (rc == NGX_HTTP_INTERNAL_SERVER_ERROR) {
	error = NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	r->headers_out.status = error;

	if (r->keepalive != 0) {
	switch (error) {
	case NGX_HTTP_BAD_REQUEST:
	case NGX_HTTP_REQUEST_ENTITY_TOO_LARGE:
	case NGX_HTTP_REQUEST_URI_TOO_LARGE:
	case NGX_HTTP_TO_HTTPS:
	case NGX_HTTP_INTERNAL_SERVER_ERROR:
	r->keepalive = 0;
	}
	}

	if (r->lingering_close == 1) {
	switch (error) {
	case NGX_HTTP_BAD_REQUEST:
	case NGX_HTTP_TO_HTTPS:
	r->lingering_close = 0;
	}
	}

	clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

	if (r->err_ctx == NULL && clcf->error_pages) {

	err_page = clcf->error_pages->elts;

	for (i = 0; i < clcf->error_pages->nelts; i++) {

	if (err_page[i].status == error) {

	if (err_page[i].overwrite) {
	r->err_status = err_page[i].overwrite;
	} else {
	r->err_status = error;
	}

	r->err_ctx = r->ctx;

	return ngx_http_internal_redirect(r, &err_page[i].uri, NULL);
	}
	}
	}

	if (error == NGX_HTTP_NO_CONTENT) {
	/* 204 */
	err = 0;

	} else if (error < NGX_HTTP_BAD_REQUEST) {
	/* 3XX */
	err = error - NGX_HTTP_MOVED_PERMANENTLY + NGX_HTTP_LEVEL_200;

	} else if (error < NGX_HTTP_NGX_CODES) {
	/* 4XX */
	err = error - NGX_HTTP_BAD_REQUEST + NGX_HTTP_LEVEL_200
	+ NGX_HTTP_LEVEL_300;

	} else {
	/* 49X, 5XX */
	err = error - NGX_HTTP_NGX_CODES + NGX_HTTP_LEVEL_200
	+ NGX_HTTP_LEVEL_300
	+ NGX_HTTP_LEVEL_400;
	switch (error) {
	case NGX_HTTP_TO_HTTPS:
	r->headers_out.status = NGX_HTTP_BAD_REQUEST;
	error = NGX_HTTP_BAD_REQUEST;
	break;

	case NGX_HTTP_INVALID_HOST:
	r->headers_out.status = NGX_HTTP_NOT_FOUND;
	error = NGX_HTTP_NOT_FOUND;
	break;
	}
	}

	msie_padding = 0;

	if (error_pages[err].len) {
	r->headers_out.content_length_n = error_pages[err].len
	+ sizeof(error_tail) - 1;

	if (clcf->msie_padding
	&& r->headers_in.msie
	&& r->http_version >= NGX_HTTP_VERSION_10
	&& error >= NGX_HTTP_BAD_REQUEST
	&& error != NGX_HTTP_REQUEST_URI_TOO_LARGE)
	{
	r->headers_out.content_length_n += sizeof(ngx_http_msie_stub) - 1;
	msie_padding = 1;
	}

	r->headers_out.content_type.len = sizeof("text/html") - 1;
	r->headers_out.content_type.data = (u_char *) "text/html";

	} else {
	r->headers_out.content_length_n = -1;
	}

	if (r->headers_out.content_length) {
	r->headers_out.content_length->hash = 0;
	r->headers_out.content_length = NULL;
	}

	rc = ngx_http_send_header(r);

	if (rc == NGX_ERROR \|\| r->header_only) {
	return rc;
	}

	if (error_pages[err].len == 0) {
	return NGX_OK;
	}


	b = ngx_calloc_buf(r->pool);
	if (b == NULL) {
	return NGX_ERROR;
	}

	b->memory = 1;
	b->pos = error_pages[err].data;
	b->last = error_pages[err].data + error_pages[err].len;

	cl = ngx_alloc_chain_link(r->pool);
	if (cl == NULL) {
	return NGX_ERROR;
	}

	cl->buf = b;
	out = cl;


	b = ngx_calloc_buf(r->pool);
	if (b == NULL) {
	return NGX_ERROR;
	}

	b->memory = 1;
	b->pos = error_tail;
	b->last = error_tail + sizeof(error_tail) - 1;

	cl->next = ngx_alloc_chain_link(r->pool);
	if (cl->next == NULL) {
	return NGX_ERROR;
	}

	cl = cl->next;
	cl->buf = b;

	if (msie_padding) {
	b = ngx_calloc_buf(r->pool);
	if (b == NULL) {
	return NGX_ERROR;
	}

	b->memory = 1;
	b->pos = ngx_http_msie_stub;
	b->last = ngx_http_msie_stub + sizeof(ngx_http_msie_stub) - 1;

	cl->next = ngx_alloc_chain_link(r->pool);
	if (cl->next == NULL) {
	return NGX_ERROR;
	}

	cl = cl->next;
	cl->buf = b;
	}

	if (r->main == NULL) {
	b->last_buf = 1;
	}

	b->last_in_chain = 1;

	cl->next = NULL;

	return ngx_http_output_filter(r, out);
	}