view src/http/ngx_http_cache.h @ 6874:7cc2d3a96ea3

Fixed trailer construction with limit on FreeBSD and macOS. The ngx_chain_coalesce_file() function may produce more bytes to send then requested in the limit passed, as it aligns the last file position to send to memory page boundary. As a result, (limit - send) may become negative. This resulted in big positive number when converted to size_t while calling ngx_output_chain_to_iovec(). Another part of the problem is in ngx_chain_coalesce_file(): it changes cl to the next chain link even if the current buffer is only partially sent due to limit. Therefore, if a file buffer was not expected to be fully sent due to limit, and was followed by a memory buffer, nginx called sendfile() with a part of the file buffer, and the memory buffer in trailer. If there were enough room in the socket buffer, this resulted in a part of the file buffer being skipped, and corresponding part of the memory buffer sent instead. The bug was introduced in 8e903522c17a (1.7.8). Configurations affected are ones using limits, that is, limit_rate and/or sendfile_max_chunk, and memory buffers after file ones (may happen when using subrequests or with proxying with disk buffering). Fix is to explicitly check if (send < limit) before constructing trailer with ngx_output_chain_to_iovec(). Additionally, ngx_chain_coalesce_file() was modified to preserve unfinished file buffers in cl.
author Maxim Dounin <mdounin@mdounin.ru>
date Fri, 20 Jan 2017 21:12:48 +0300
parents 1a917932db96
children 9a9e13686869
line wrap: on
line source


/*
 * 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      42
#define NGX_HTTP_CACHE_VARY_LEN      42

#define NGX_HTTP_CACHE_VERSION       3


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                           last_modified;
    time_t                           date;

    ngx_str_t                        etag;
    ngx_str_t                        vary;
    u_char                           variant[NGX_HTTP_CACHE_KEY_LEN];

    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;
};


typedef struct {
    ngx_uint_t                       version;
    time_t                           valid_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                            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_ */