Mercurial > hg > nginx
view src/http/ngx_http_special_response.c @ 9300:5be23505292b
SSI: fixed incorrect or duplicate stub output.
Following 3518:eb3aaf8bd2a9 (0.8.37), r->request_output is only set
if there are data in the first buffer sent in the subrequest. As a
result, following the change mentioned this flag cannot be used to
prevent duplicate ngx_http_ssi_stub_output() calls, since it is not
set if there was already some output, but the first buffer was empty.
Still, when there are multiple subrequests, even an empty subrequest
response might be delayed by the postpone filter, leading to a second
call of ngx_http_ssi_stub_output() during finalization from
ngx_http_writer() the subreqest buffers are released by the postpone
filter. Since r->request_output is not set after the first call, this
resulted in duplicate stub output.
Additionally, checking only the first buffer might be wrong in some
unusual cases. For example, the first buffer might be empty if
$r->flush() is called before printing any data in the embedded Perl
module.
Depending on the postpone_output value and corresponding sizes, this
issue can result in either duplicate or unexpected stub output, or
"zero size buf in writer" alerts.
Following 8124:f5515e727656 (1.23.4), it became slightly easier to
reproduce the issue, as empty static files and empty cache items now
result in a response with an empty buffer. Before the change, an empty
proxied response can be used to reproduce the issue.
Fix is check all buffers and set r->request_output if any non-empty
buffers are sent. This ensures that all unusual cases of non-empty
responses are covered, and also that r->request_output will be set
after the first stub output, preventing duplicate output.
Reported by Jan Gassen.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 04 Jul 2024 17:41:28 +0300 |
parents | afd36b161859 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #include <nginx.h> static ngx_int_t ngx_http_send_error_page(ngx_http_request_t *r, ngx_http_err_page_t *err_page); static ngx_int_t ngx_http_send_special_response(ngx_http_request_t *r, ngx_http_core_loc_conf_t *clcf, ngx_uint_t err); static ngx_int_t ngx_http_send_refresh(ngx_http_request_t *r); static u_char ngx_http_error_full_tail[] = "<hr><center>" NGINX_VER "</center>" CRLF "</body>" CRLF "</html>" CRLF ; static u_char ngx_http_error_build_tail[] = "<hr><center>" NGINX_VER_BUILD "</center>" CRLF "</body>" CRLF "</html>" CRLF ; static u_char ngx_http_error_tail[] = "<hr><center>" NGINX_NAME "</center>" CRLF "</body>" CRLF "</html>" CRLF ; static u_char ngx_http_msie_padding[] = "<!-- a padding to disable MSIE and Chrome friendly error page -->" CRLF "<!-- a padding to disable MSIE and Chrome friendly error page -->" CRLF "<!-- a padding to disable MSIE and Chrome friendly error page -->" CRLF "<!-- a padding to disable MSIE and Chrome friendly error page -->" CRLF "<!-- a padding to disable MSIE and Chrome friendly error page -->" CRLF "<!-- a padding to disable MSIE and Chrome friendly error page -->" CRLF ; static u_char ngx_http_msie_refresh_head[] = "<html><head><meta http-equiv=\"Refresh\" content=\"0; URL="; static u_char ngx_http_msie_refresh_tail[] = "\"></head><body></body></html>" CRLF; static char ngx_http_error_301_page[] = "<html>" CRLF "<head><title>301 Moved Permanently</title></head>" CRLF "<body>" CRLF "<center><h1>301 Moved Permanently</h1></center>" CRLF ; static char ngx_http_error_302_page[] = "<html>" CRLF "<head><title>302 Found</title></head>" CRLF "<body>" CRLF "<center><h1>302 Found</h1></center>" CRLF ; static char ngx_http_error_303_page[] = "<html>" CRLF "<head><title>303 See Other</title></head>" CRLF "<body>" CRLF "<center><h1>303 See Other</h1></center>" CRLF ; static char ngx_http_error_307_page[] = "<html>" CRLF "<head><title>307 Temporary Redirect</title></head>" CRLF "<body>" CRLF "<center><h1>307 Temporary Redirect</h1></center>" CRLF ; static char ngx_http_error_308_page[] = "<html>" CRLF "<head><title>308 Permanent Redirect</title></head>" CRLF "<body>" CRLF "<center><h1>308 Permanent Redirect</h1></center>" CRLF ; static char ngx_http_error_400_page[] = "<html>" CRLF "<head><title>400 Bad Request</title></head>" CRLF "<body>" CRLF "<center><h1>400 Bad Request</h1></center>" CRLF ; static char ngx_http_error_401_page[] = "<html>" CRLF "<head><title>401 Unauthorized</title></head>" CRLF "<body>" CRLF "<center><h1>401 Unauthorized</h1></center>" CRLF ; static char ngx_http_error_402_page[] = "<html>" CRLF "<head><title>402 Payment Required</title></head>" CRLF "<body>" CRLF "<center><h1>402 Payment Required</h1></center>" CRLF ; static char ngx_http_error_403_page[] = "<html>" CRLF "<head><title>403 Forbidden</title></head>" CRLF "<body>" CRLF "<center><h1>403 Forbidden</h1></center>" CRLF ; static char ngx_http_error_404_page[] = "<html>" CRLF "<head><title>404 Not Found</title></head>" CRLF "<body>" CRLF "<center><h1>404 Not Found</h1></center>" CRLF ; static char ngx_http_error_405_page[] = "<html>" CRLF "<head><title>405 Method Not Allowed</title></head>" CRLF "<body>" CRLF "<center><h1>405 Method Not Allowed</h1></center>" CRLF ; static char ngx_http_error_406_page[] = "<html>" CRLF "<head><title>406 Not Acceptable</title></head>" CRLF "<body>" CRLF "<center><h1>406 Not Acceptable</h1></center>" CRLF ; static char ngx_http_error_408_page[] = "<html>" CRLF "<head><title>408 Request Timeout</title></head>" CRLF "<body>" CRLF "<center><h1>408 Request Timeout</h1></center>" CRLF ; static char ngx_http_error_409_page[] = "<html>" CRLF "<head><title>409 Conflict</title></head>" CRLF "<body>" CRLF "<center><h1>409 Conflict</h1></center>" CRLF ; static char ngx_http_error_410_page[] = "<html>" CRLF "<head><title>410 Gone</title></head>" CRLF "<body>" CRLF "<center><h1>410 Gone</h1></center>" CRLF ; static char ngx_http_error_411_page[] = "<html>" CRLF "<head><title>411 Length Required</title></head>" CRLF "<body>" CRLF "<center><h1>411 Length Required</h1></center>" CRLF ; static char ngx_http_error_412_page[] = "<html>" CRLF "<head><title>412 Precondition Failed</title></head>" CRLF "<body>" CRLF "<center><h1>412 Precondition Failed</h1></center>" CRLF ; static char ngx_http_error_413_page[] = "<html>" CRLF "<head><title>413 Request Entity Too Large</title></head>" CRLF "<body>" CRLF "<center><h1>413 Request Entity Too Large</h1></center>" CRLF ; static char ngx_http_error_414_page[] = "<html>" CRLF "<head><title>414 URI Too Long</title></head>" CRLF "<body>" CRLF "<center><h1>414 URI Too Long</h1></center>" CRLF ; static char ngx_http_error_415_page[] = "<html>" CRLF "<head><title>415 Unsupported Media Type</title></head>" CRLF "<body>" CRLF "<center><h1>415 Unsupported Media Type</h1></center>" CRLF ; static char ngx_http_error_416_page[] = "<html>" CRLF "<head><title>416 Range Not Satisfiable</title></head>" CRLF "<body>" CRLF "<center><h1>416 Range Not Satisfiable</h1></center>" CRLF ; static char ngx_http_error_421_page[] = "<html>" CRLF "<head><title>421 Misdirected Request</title></head>" CRLF "<body>" CRLF "<center><h1>421 Misdirected Request</h1></center>" CRLF ; static char ngx_http_error_429_page[] = "<html>" CRLF "<head><title>429 Too Many Requests</title></head>" CRLF "<body>" CRLF "<center><h1>429 Too Many Requests</h1></center>" CRLF ; static char ngx_http_error_494_page[] = "<html>" CRLF "<head><title>400 Request Header Or Cookie Too Large</title></head>" CRLF "<body>" CRLF "<center><h1>400 Bad Request</h1></center>" CRLF "<center>Request Header Or Cookie Too Large</center>" CRLF ; static char ngx_http_error_495_page[] = "<html>" CRLF "<head><title>400 The SSL certificate error</title></head>" CRLF "<body>" CRLF "<center><h1>400 Bad Request</h1></center>" CRLF "<center>The SSL certificate error</center>" CRLF ; static char ngx_http_error_496_page[] = "<html>" CRLF "<head><title>400 No required SSL certificate was sent</title></head>" CRLF "<body>" CRLF "<center><h1>400 Bad Request</h1></center>" CRLF "<center>No required SSL certificate was sent</center>" CRLF ; static char ngx_http_error_497_page[] = "<html>" CRLF "<head><title>400 The plain HTTP request was sent to HTTPS port</title></head>" CRLF "<body>" CRLF "<center><h1>400 Bad Request</h1></center>" CRLF "<center>The plain HTTP request was sent to HTTPS port</center>" CRLF ; static char ngx_http_error_500_page[] = "<html>" CRLF "<head><title>500 Internal Server Error</title></head>" CRLF "<body>" CRLF "<center><h1>500 Internal Server Error</h1></center>" CRLF ; static char ngx_http_error_501_page[] = "<html>" CRLF "<head><title>501 Not Implemented</title></head>" CRLF "<body>" CRLF "<center><h1>501 Not Implemented</h1></center>" CRLF ; static char ngx_http_error_502_page[] = "<html>" CRLF "<head><title>502 Bad Gateway</title></head>" CRLF "<body>" CRLF "<center><h1>502 Bad Gateway</h1></center>" CRLF ; static char ngx_http_error_503_page[] = "<html>" CRLF "<head><title>503 Service Unavailable</title></head>" CRLF "<body>" CRLF "<center><h1>503 Service Unavailable</h1></center>" CRLF ; static char ngx_http_error_504_page[] = "<html>" CRLF "<head><title>504 Gateway Timeout</title></head>" CRLF "<body>" CRLF "<center><h1>504 Gateway Timeout</h1></center>" CRLF ; static char ngx_http_error_505_page[] = "<html>" CRLF "<head><title>505 HTTP Version Not Supported</title></head>" CRLF "<body>" CRLF "<center><h1>505 HTTP Version Not Supported</h1></center>" CRLF ; static char ngx_http_error_507_page[] = "<html>" CRLF "<head><title>507 Insufficient Storage</title></head>" CRLF "<body>" CRLF "<center><h1>507 Insufficient Storage</h1></center>" CRLF ; static ngx_str_t ngx_http_error_pages[] = { ngx_null_string, /* 201, 204 */ #define NGX_HTTP_LAST_2XX 202 #define NGX_HTTP_OFF_3XX (NGX_HTTP_LAST_2XX - 201) /* ngx_null_string, */ /* 300 */ ngx_string(ngx_http_error_301_page), ngx_string(ngx_http_error_302_page), ngx_string(ngx_http_error_303_page), ngx_null_string, /* 304 */ ngx_null_string, /* 305 */ ngx_null_string, /* 306 */ ngx_string(ngx_http_error_307_page), ngx_string(ngx_http_error_308_page), #define NGX_HTTP_LAST_3XX 309 #define NGX_HTTP_OFF_4XX (NGX_HTTP_LAST_3XX - 301 + NGX_HTTP_OFF_3XX) ngx_string(ngx_http_error_400_page), ngx_string(ngx_http_error_401_page), ngx_string(ngx_http_error_402_page), ngx_string(ngx_http_error_403_page), ngx_string(ngx_http_error_404_page), ngx_string(ngx_http_error_405_page), ngx_string(ngx_http_error_406_page), ngx_null_string, /* 407 */ ngx_string(ngx_http_error_408_page), ngx_string(ngx_http_error_409_page), ngx_string(ngx_http_error_410_page), ngx_string(ngx_http_error_411_page), ngx_string(ngx_http_error_412_page), ngx_string(ngx_http_error_413_page), ngx_string(ngx_http_error_414_page), ngx_string(ngx_http_error_415_page), ngx_string(ngx_http_error_416_page), ngx_null_string, /* 417 */ ngx_null_string, /* 418 */ ngx_null_string, /* 419 */ ngx_null_string, /* 420 */ ngx_string(ngx_http_error_421_page), ngx_null_string, /* 422 */ ngx_null_string, /* 423 */ ngx_null_string, /* 424 */ ngx_null_string, /* 425 */ ngx_null_string, /* 426 */ ngx_null_string, /* 427 */ ngx_null_string, /* 428 */ ngx_string(ngx_http_error_429_page), #define NGX_HTTP_LAST_4XX 430 #define NGX_HTTP_OFF_5XX (NGX_HTTP_LAST_4XX - 400 + NGX_HTTP_OFF_4XX) ngx_string(ngx_http_error_494_page), /* 494, request header too large */ ngx_string(ngx_http_error_495_page), /* 495, https certificate error */ ngx_string(ngx_http_error_496_page), /* 496, https no certificate */ ngx_string(ngx_http_error_497_page), /* 497, http to https */ ngx_string(ngx_http_error_404_page), /* 498, canceled */ ngx_null_string, /* 499, client has closed connection */ ngx_string(ngx_http_error_500_page), ngx_string(ngx_http_error_501_page), ngx_string(ngx_http_error_502_page), ngx_string(ngx_http_error_503_page), ngx_string(ngx_http_error_504_page), ngx_string(ngx_http_error_505_page), ngx_null_string, /* 506 */ ngx_string(ngx_http_error_507_page) #define NGX_HTTP_LAST_5XX 508 }; ngx_int_t ngx_http_special_response_handler(ngx_http_request_t *r, ngx_int_t error) { ngx_uint_t i, err; ngx_http_err_page_t *err_page; ngx_http_core_loc_conf_t *clcf; ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http special response: %i, \"%V?%V\"", error, &r->uri, &r->args); r->err_status = error; if (r->keepalive) { 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_HTTPS_CERT_ERROR: case NGX_HTTPS_NO_CERT: case NGX_HTTP_INTERNAL_SERVER_ERROR: case NGX_HTTP_NOT_IMPLEMENTED: r->keepalive = 0; } } if (r->lingering_close) { switch (error) { case NGX_HTTP_BAD_REQUEST: case NGX_HTTP_TO_HTTPS: case NGX_HTTPS_CERT_ERROR: case NGX_HTTPS_NO_CERT: r->lingering_close = 0; } } r->headers_out.content_type.len = 0; clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (!r->error_page && clcf->error_pages && r->uri_changes != 0) { if (clcf->recursive_error_pages == 0) { r->error_page = 1; } err_page = clcf->error_pages->elts; for (i = 0; i < clcf->error_pages->nelts; i++) { if (err_page[i].status == error) { return ngx_http_send_error_page(r, &err_page[i]); } } } r->expect_tested = 1; if (ngx_http_discard_request_body(r) != NGX_OK) { r->keepalive = 0; } if (clcf->msie_refresh && r->headers_in.msie && (error == NGX_HTTP_MOVED_PERMANENTLY || error == NGX_HTTP_MOVED_TEMPORARILY)) { return ngx_http_send_refresh(r); } if (error == NGX_HTTP_CREATED) { /* 201 */ err = 0; } else if (error == NGX_HTTP_NO_CONTENT) { /* 204 */ err = 0; } else if (error >= NGX_HTTP_MOVED_PERMANENTLY && error < NGX_HTTP_LAST_3XX) { /* 3XX */ err = error - NGX_HTTP_MOVED_PERMANENTLY + NGX_HTTP_OFF_3XX; } else if (error >= NGX_HTTP_BAD_REQUEST && error < NGX_HTTP_LAST_4XX) { /* 4XX */ err = error - NGX_HTTP_BAD_REQUEST + NGX_HTTP_OFF_4XX; } else if (error >= NGX_HTTP_NGINX_CODES && error < NGX_HTTP_LAST_5XX) { /* 49X, 5XX */ err = error - NGX_HTTP_NGINX_CODES + NGX_HTTP_OFF_5XX; switch (error) { case NGX_HTTP_TO_HTTPS: case NGX_HTTPS_CERT_ERROR: case NGX_HTTPS_NO_CERT: case NGX_HTTP_REQUEST_HEADER_TOO_LARGE: r->err_status = NGX_HTTP_BAD_REQUEST; } } else { /* unknown code, zero body */ err = 0; } return ngx_http_send_special_response(r, clcf, err); } ngx_int_t ngx_http_filter_finalize_request(ngx_http_request_t *r, ngx_module_t *m, ngx_int_t error) { void *ctx; ngx_int_t rc; ngx_http_clean_header(r); ctx = NULL; if (m) { ctx = r->ctx[m->ctx_index]; } /* clear the modules contexts */ ngx_memzero(r->ctx, sizeof(void *) * ngx_http_max_module); if (m) { r->ctx[m->ctx_index] = ctx; } r->filter_finalize = 1; rc = ngx_http_special_response_handler(r, error); /* NGX_ERROR resets any pending data */ switch (rc) { case NGX_OK: case NGX_DONE: return NGX_ERROR; default: return rc; } } void ngx_http_clean_header(ngx_http_request_t *r) { ngx_memzero(&r->headers_out.status, sizeof(ngx_http_headers_out_t) - offsetof(ngx_http_headers_out_t, status)); r->headers_out.headers.part.nelts = 0; r->headers_out.headers.part.next = NULL; r->headers_out.headers.last = &r->headers_out.headers.part; r->headers_out.trailers.part.nelts = 0; r->headers_out.trailers.part.next = NULL; r->headers_out.trailers.last = &r->headers_out.trailers.part; r->headers_out.content_length_n = -1; r->headers_out.last_modified_time = -1; } static ngx_int_t ngx_http_send_error_page(ngx_http_request_t *r, ngx_http_err_page_t *err_page) { ngx_int_t overwrite; ngx_str_t uri, args; ngx_table_elt_t *location; ngx_http_core_loc_conf_t *clcf; overwrite = err_page->overwrite; if (overwrite && overwrite != NGX_HTTP_OK) { r->expect_tested = 1; } if (overwrite >= 0) { r->err_status = overwrite; } if (ngx_http_complex_value(r, &err_page->value, &uri) != NGX_OK) { return NGX_ERROR; } if (uri.len && uri.data[0] == '/') { if (err_page->value.lengths) { ngx_http_split_args(r, &uri, &args); } else { args = err_page->args; } if (r->method != NGX_HTTP_HEAD) { r->method = NGX_HTTP_GET; r->method_name = ngx_http_core_get_method; } return ngx_http_internal_redirect(r, &uri, &args); } if (uri.len && uri.data[0] == '@') { return ngx_http_named_location(r, &uri); } r->expect_tested = 1; if (ngx_http_discard_request_body(r) != NGX_OK) { r->keepalive = 0; } location = ngx_list_push(&r->headers_out.headers); if (location == NULL) { return NGX_ERROR; } if (overwrite != NGX_HTTP_MOVED_PERMANENTLY && overwrite != NGX_HTTP_MOVED_TEMPORARILY && overwrite != NGX_HTTP_SEE_OTHER && overwrite != NGX_HTTP_TEMPORARY_REDIRECT && overwrite != NGX_HTTP_PERMANENT_REDIRECT) { r->err_status = NGX_HTTP_MOVED_TEMPORARILY; } location->hash = 1; location->next = NULL; ngx_str_set(&location->key, "Location"); location->value = uri; ngx_http_clear_location(r); r->headers_out.location = location; clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (clcf->msie_refresh && r->headers_in.msie) { return ngx_http_send_refresh(r); } return ngx_http_send_special_response(r, clcf, r->err_status - NGX_HTTP_MOVED_PERMANENTLY + NGX_HTTP_OFF_3XX); } static ngx_int_t ngx_http_send_special_response(ngx_http_request_t *r, ngx_http_core_loc_conf_t *clcf, ngx_uint_t err) { u_char *tail; size_t len; ngx_int_t rc; ngx_buf_t *b; ngx_uint_t msie_padding; ngx_chain_t out[3]; if (clcf->server_tokens == NGX_HTTP_SERVER_TOKENS_ON) { len = sizeof(ngx_http_error_full_tail) - 1; tail = ngx_http_error_full_tail; } else if (clcf->server_tokens == NGX_HTTP_SERVER_TOKENS_BUILD) { len = sizeof(ngx_http_error_build_tail) - 1; tail = ngx_http_error_build_tail; } else { len = sizeof(ngx_http_error_tail) - 1; tail = ngx_http_error_tail; } msie_padding = 0; if (ngx_http_error_pages[err].len) { r->headers_out.content_length_n = ngx_http_error_pages[err].len + len; if (clcf->msie_padding && (r->headers_in.msie || r->headers_in.chrome) && r->http_version >= NGX_HTTP_VERSION_10 && err >= NGX_HTTP_OFF_4XX) { r->headers_out.content_length_n += sizeof(ngx_http_msie_padding) - 1; msie_padding = 1; } r->headers_out.content_type_len = sizeof("text/html") - 1; ngx_str_set(&r->headers_out.content_type, "text/html"); r->headers_out.content_type_lowcase = NULL; } else { r->headers_out.content_length_n = 0; } if (r->headers_out.content_length) { r->headers_out.content_length->hash = 0; r->headers_out.content_length = NULL; } ngx_http_clear_accept_ranges(r); ngx_http_clear_last_modified(r); ngx_http_clear_etag(r); rc = ngx_http_send_header(r); if (rc == NGX_ERROR || r->header_only) { return rc; } if (ngx_http_error_pages[err].len == 0) { return ngx_http_send_special(r, NGX_HTTP_LAST); } b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->memory = 1; b->pos = ngx_http_error_pages[err].data; b->last = ngx_http_error_pages[err].data + ngx_http_error_pages[err].len; out[0].buf = b; out[0].next = &out[1]; b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->memory = 1; b->pos = tail; b->last = tail + len; out[1].buf = b; out[1].next = NULL; if (msie_padding) { b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->memory = 1; b->pos = ngx_http_msie_padding; b->last = ngx_http_msie_padding + sizeof(ngx_http_msie_padding) - 1; out[1].next = &out[2]; out[2].buf = b; out[2].next = NULL; } if (r == r->main) { b->last_buf = 1; } b->last_in_chain = 1; return ngx_http_output_filter(r, &out[0]); } static ngx_int_t ngx_http_send_refresh(ngx_http_request_t *r) { u_char *p, *location; size_t len, size; uintptr_t escape; ngx_int_t rc; ngx_buf_t *b; ngx_chain_t out; len = r->headers_out.location->value.len; location = r->headers_out.location->value.data; escape = 2 * ngx_escape_uri(NULL, location, len, NGX_ESCAPE_REFRESH); size = sizeof(ngx_http_msie_refresh_head) - 1 + escape + len + sizeof(ngx_http_msie_refresh_tail) - 1; r->err_status = NGX_HTTP_OK; r->headers_out.content_type_len = sizeof("text/html") - 1; ngx_str_set(&r->headers_out.content_type, "text/html"); r->headers_out.content_type_lowcase = NULL; r->headers_out.location->hash = 0; r->headers_out.location = NULL; r->headers_out.content_length_n = size; if (r->headers_out.content_length) { r->headers_out.content_length->hash = 0; r->headers_out.content_length = NULL; } ngx_http_clear_accept_ranges(r); ngx_http_clear_last_modified(r); ngx_http_clear_etag(r); rc = ngx_http_send_header(r); if (rc == NGX_ERROR || r->header_only) { return rc; } b = ngx_create_temp_buf(r->pool, size); if (b == NULL) { return NGX_ERROR; } p = ngx_cpymem(b->pos, ngx_http_msie_refresh_head, sizeof(ngx_http_msie_refresh_head) - 1); if (escape == 0) { p = ngx_cpymem(p, location, len); } else { p = (u_char *) ngx_escape_uri(p, location, len, NGX_ESCAPE_REFRESH); } b->last = ngx_cpymem(p, ngx_http_msie_refresh_tail, sizeof(ngx_http_msie_refresh_tail) - 1); b->last_buf = (r == r->main) ? 1 : 0; b->last_in_chain = 1; out.buf = b; out.next = NULL; return ngx_http_output_filter(r, &out); }