Mercurial > hg > nginx
view src/http/ngx_http.h @ 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 | f3df785649ae |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_HTTP_H_INCLUDED_ #define _NGX_HTTP_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef struct ngx_http_request_s ngx_http_request_t; typedef struct ngx_http_upstream_s ngx_http_upstream_t; typedef struct ngx_http_cache_s ngx_http_cache_t; typedef struct ngx_http_file_cache_s ngx_http_file_cache_t; typedef struct ngx_http_log_ctx_s ngx_http_log_ctx_t; typedef struct ngx_http_chunked_s ngx_http_chunked_t; typedef struct ngx_http_v2_stream_s ngx_http_v2_stream_t; typedef struct ngx_http_v3_parse_s ngx_http_v3_parse_t; typedef struct ngx_http_v3_session_s ngx_http_v3_session_t; typedef ngx_int_t (*ngx_http_header_handler_pt)(ngx_http_request_t *r, ngx_table_elt_t *h, ngx_uint_t offset); typedef u_char *(*ngx_http_log_handler_pt)(ngx_http_request_t *r, ngx_http_request_t *sr, u_char *buf, size_t len); #include <ngx_http_variables.h> #include <ngx_http_config.h> #include <ngx_http_request.h> #include <ngx_http_script.h> #include <ngx_http_upstream.h> #include <ngx_http_upstream_round_robin.h> #include <ngx_http_core_module.h> #if (NGX_HTTP_V2) #include <ngx_http_v2.h> #endif #if (NGX_HTTP_V3) #include <ngx_http_v3.h> #endif #if (NGX_HTTP_CACHE) #include <ngx_http_cache.h> #endif #if (NGX_HTTP_SSI) #include <ngx_http_ssi_filter_module.h> #endif #if (NGX_HTTP_SSL) #include <ngx_http_ssl_module.h> #endif struct ngx_http_log_ctx_s { ngx_connection_t *connection; ngx_http_request_t *request; ngx_http_request_t *current_request; }; struct ngx_http_chunked_s { ngx_uint_t state; off_t size; off_t length; off_t skipped; }; typedef struct { ngx_uint_t http_version; ngx_uint_t code; ngx_uint_t count; u_char *start; u_char *end; } ngx_http_status_t; #define ngx_http_get_module_ctx(r, module) (r)->ctx[module.ctx_index] #define ngx_http_set_ctx(r, c, module) r->ctx[module.ctx_index] = c; ngx_int_t ngx_http_add_location(ngx_conf_t *cf, ngx_queue_t **locations, ngx_http_core_loc_conf_t *clcf); ngx_int_t ngx_http_add_listen(ngx_conf_t *cf, ngx_http_core_srv_conf_t *cscf, ngx_http_listen_opt_t *lsopt); void ngx_http_init_connection(ngx_connection_t *c); void ngx_http_close_connection(ngx_connection_t *c); #if (NGX_HTTP_SSL && defined SSL_CTRL_SET_TLSEXT_HOSTNAME) int ngx_http_ssl_servername(ngx_ssl_conn_t *ssl_conn, int *ad, void *arg); #endif #if (NGX_HTTP_SSL && defined SSL_R_CERT_CB_ERROR) int ngx_http_ssl_certificate(ngx_ssl_conn_t *ssl_conn, void *arg); #endif ngx_int_t ngx_http_parse_request_line(ngx_http_request_t *r, ngx_buf_t *b); ngx_int_t ngx_http_parse_uri(ngx_http_request_t *r); ngx_int_t ngx_http_parse_complex_uri(ngx_http_request_t *r, ngx_uint_t merge_slashes); ngx_int_t ngx_http_parse_status_line(ngx_http_request_t *r, ngx_buf_t *b, ngx_http_status_t *status); ngx_int_t ngx_http_parse_unsafe_uri(ngx_http_request_t *r, ngx_str_t *uri, ngx_str_t *args, ngx_uint_t *flags); ngx_int_t ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b, ngx_uint_t allow_underscores); ngx_table_elt_t *ngx_http_parse_multi_header_lines(ngx_http_request_t *r, ngx_table_elt_t *headers, ngx_str_t *name, ngx_str_t *value); ngx_table_elt_t *ngx_http_parse_set_cookie_lines(ngx_http_request_t *r, ngx_table_elt_t *headers, ngx_str_t *name, ngx_str_t *value); ngx_int_t ngx_http_arg(ngx_http_request_t *r, u_char *name, size_t len, ngx_str_t *value); void ngx_http_split_args(ngx_http_request_t *r, ngx_str_t *uri, ngx_str_t *args); ngx_int_t ngx_http_parse_chunked(ngx_http_request_t *r, ngx_buf_t *b, ngx_http_chunked_t *ctx); ngx_http_request_t *ngx_http_create_request(ngx_connection_t *c); ngx_int_t ngx_http_process_request_uri(ngx_http_request_t *r); ngx_int_t ngx_http_process_request_header(ngx_http_request_t *r); void ngx_http_process_request(ngx_http_request_t *r); void ngx_http_update_location_config(ngx_http_request_t *r); void ngx_http_handler(ngx_http_request_t *r); void ngx_http_run_posted_requests(ngx_connection_t *c); ngx_int_t ngx_http_post_request(ngx_http_request_t *r, ngx_http_posted_request_t *pr); ngx_int_t ngx_http_set_virtual_server(ngx_http_request_t *r, ngx_str_t *host); ngx_int_t ngx_http_validate_host(ngx_str_t *host, ngx_pool_t *pool, ngx_uint_t alloc); void ngx_http_close_request(ngx_http_request_t *r, ngx_int_t rc); void ngx_http_finalize_request(ngx_http_request_t *r, ngx_int_t rc); void ngx_http_free_request(ngx_http_request_t *r, ngx_int_t rc); void ngx_http_empty_handler(ngx_event_t *wev); void ngx_http_request_empty_handler(ngx_http_request_t *r); #define NGX_HTTP_LAST 1 #define NGX_HTTP_FLUSH 2 ngx_int_t ngx_http_send_special(ngx_http_request_t *r, ngx_uint_t flags); ngx_int_t ngx_http_read_client_request_body(ngx_http_request_t *r, ngx_http_client_body_handler_pt post_handler); ngx_int_t ngx_http_read_unbuffered_request_body(ngx_http_request_t *r); ngx_int_t ngx_http_send_header(ngx_http_request_t *r); ngx_int_t ngx_http_special_response_handler(ngx_http_request_t *r, ngx_int_t error); ngx_int_t ngx_http_filter_finalize_request(ngx_http_request_t *r, ngx_module_t *m, ngx_int_t error); void ngx_http_clean_header(ngx_http_request_t *r); ngx_int_t ngx_http_discard_request_body(ngx_http_request_t *r); void ngx_http_discarded_request_body_handler(ngx_http_request_t *r); void ngx_http_block_reading(ngx_http_request_t *r); void ngx_http_test_reading(ngx_http_request_t *r); char *ngx_http_types_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); char *ngx_http_merge_types(ngx_conf_t *cf, ngx_array_t **keys, ngx_hash_t *types_hash, ngx_array_t **prev_keys, ngx_hash_t *prev_types_hash, ngx_str_t *default_types); ngx_int_t ngx_http_set_default_types(ngx_conf_t *cf, ngx_array_t **types, ngx_str_t *default_type); #if (NGX_HTTP_DEGRADATION) ngx_uint_t ngx_http_degraded(ngx_http_request_t *); #endif #if (NGX_HTTP_V2 || NGX_HTTP_V3) ngx_int_t ngx_http_huff_decode(u_char *state, u_char *src, size_t len, u_char **dst, ngx_uint_t last, ngx_log_t *log); size_t ngx_http_huff_encode(u_char *src, size_t len, u_char *dst, ngx_uint_t lower); #endif extern ngx_module_t ngx_http_module; extern ngx_str_t ngx_http_html_default_types[]; extern ngx_http_output_header_filter_pt ngx_http_top_header_filter; extern ngx_http_output_body_filter_pt ngx_http_top_body_filter; extern ngx_http_request_body_filter_pt ngx_http_top_request_body_filter; #endif /* _NGX_HTTP_H_INCLUDED_ */