Mercurial > hg > nginx
view src/http/ngx_http_cache.h @ 9300:5be23505292b default tip
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 | 3781de64e747 |
| children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_HTTP_CACHE_H_INCLUDED_ #define _NGX_HTTP_CACHE_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #define NGX_HTTP_CACHE_MISS 1 #define NGX_HTTP_CACHE_BYPASS 2 #define NGX_HTTP_CACHE_EXPIRED 3 #define NGX_HTTP_CACHE_STALE 4 #define NGX_HTTP_CACHE_UPDATING 5 #define NGX_HTTP_CACHE_REVALIDATED 6 #define NGX_HTTP_CACHE_HIT 7 #define NGX_HTTP_CACHE_SCARCE 8 #define NGX_HTTP_CACHE_KEY_LEN 16 #define NGX_HTTP_CACHE_ETAG_LEN 128 #define NGX_HTTP_CACHE_VARY_LEN 128 #define NGX_HTTP_CACHE_VERSION 5 typedef struct { ngx_uint_t status; time_t valid; } ngx_http_cache_valid_t; typedef struct { ngx_rbtree_node_t node; ngx_queue_t queue; u_char key[NGX_HTTP_CACHE_KEY_LEN - sizeof(ngx_rbtree_key_t)]; unsigned count:20; unsigned uses:10; unsigned valid_msec:10; unsigned error:10; unsigned exists:1; unsigned updating:1; unsigned deleting:1; unsigned purged:1; /* 10 unused bits */ ngx_file_uniq_t uniq; time_t expire; time_t valid_sec; size_t body_start; off_t fs_size; ngx_msec_t lock_time; } ngx_http_file_cache_node_t; struct ngx_http_cache_s { ngx_file_t file; ngx_array_t keys; uint32_t crc32; u_char key[NGX_HTTP_CACHE_KEY_LEN]; u_char main[NGX_HTTP_CACHE_KEY_LEN]; ngx_file_uniq_t uniq; time_t valid_sec; time_t updating_sec; time_t error_sec; time_t last_modified; time_t date; ngx_str_t etag; ngx_str_t vary; u_char variant[NGX_HTTP_CACHE_KEY_LEN]; size_t buffer_size; size_t header_start; size_t body_start; off_t length; off_t fs_size; ngx_uint_t min_uses; ngx_uint_t error; ngx_uint_t valid_msec; ngx_uint_t vary_tag; ngx_buf_t *buf; ngx_http_file_cache_t *file_cache; ngx_http_file_cache_node_t *node; #if (NGX_THREADS || NGX_COMPAT) ngx_thread_task_t *thread_task; #endif ngx_msec_t lock_timeout; ngx_msec_t lock_age; ngx_msec_t lock_time; ngx_msec_t wait_time; ngx_event_t wait_event; unsigned lock:1; unsigned waiting:1; unsigned updated:1; unsigned updating:1; unsigned exists:1; unsigned temp_file:1; unsigned purged:1; unsigned reading:1; unsigned secondary:1; unsigned update_variant:1; unsigned background:1; unsigned stale_updating:1; unsigned stale_error:1; }; typedef struct { ngx_uint_t version; time_t valid_sec; time_t updating_sec; time_t error_sec; time_t last_modified; time_t date; uint32_t crc32; u_short valid_msec; u_short header_start; u_short body_start; u_char etag_len; u_char etag[NGX_HTTP_CACHE_ETAG_LEN]; u_char vary_len; u_char vary[NGX_HTTP_CACHE_VARY_LEN]; u_char variant[NGX_HTTP_CACHE_KEY_LEN]; } ngx_http_file_cache_header_t; typedef struct { ngx_rbtree_t rbtree; ngx_rbtree_node_t sentinel; ngx_queue_t queue; ngx_atomic_t cold; ngx_atomic_t loading; off_t size; ngx_uint_t count; ngx_uint_t watermark; } ngx_http_file_cache_sh_t; struct ngx_http_file_cache_s { ngx_http_file_cache_sh_t *sh; ngx_slab_pool_t *shpool; ngx_path_t *path; off_t min_free; off_t max_size; size_t bsize; time_t inactive; time_t fail_time; ngx_uint_t files; ngx_uint_t loader_files; ngx_msec_t last; ngx_msec_t loader_sleep; ngx_msec_t loader_threshold; ngx_uint_t manager_files; ngx_msec_t manager_sleep; ngx_msec_t manager_threshold; ngx_shm_zone_t *shm_zone; ngx_uint_t use_temp_path; /* unsigned use_temp_path:1 */ }; ngx_int_t ngx_http_file_cache_new(ngx_http_request_t *r); ngx_int_t ngx_http_file_cache_create(ngx_http_request_t *r); void ngx_http_file_cache_create_key(ngx_http_request_t *r); ngx_int_t ngx_http_file_cache_open(ngx_http_request_t *r); ngx_int_t ngx_http_file_cache_set_header(ngx_http_request_t *r, u_char *buf); void ngx_http_file_cache_update(ngx_http_request_t *r, ngx_temp_file_t *tf); void ngx_http_file_cache_update_header(ngx_http_request_t *r); ngx_int_t ngx_http_cache_send(ngx_http_request_t *); void ngx_http_file_cache_free(ngx_http_cache_t *c, ngx_temp_file_t *tf); time_t ngx_http_file_cache_valid(ngx_array_t *cache_valid, ngx_uint_t status); char *ngx_http_file_cache_set_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); char *ngx_http_file_cache_valid_set_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); extern ngx_str_t ngx_http_cache_status[]; #endif /* _NGX_HTTP_CACHE_H_INCLUDED_ */