view src/core/ngx_open_file_cache.h @ 6957:83bae3d354ab

HTTP/2: fixed connection finalization. All streams in connection must be finalized before the connection itself can be finalized and all related memory is freed. That's not always possible on the current event loop iteration. Thus when the last stream is finalized, it sets the special read event handler ngx_http_v2_handle_connection_handler() and posts the event. Previously, this handler didn't check the connection state and could call the regular event handler on a connection that was already in finalization stage. In the worst case that could lead to a segmentation fault, since some data structures aren't supposed to be used during connection finalization. Particularly, the waiting queue can contain already freed streams, so the WINDOW_UPDATE frame received by that moment could trigger accessing to these freed streams. Now, the connection error flag is explicitly checked in ngx_http_v2_handle_connection_handler().
author Valentin Bartenev <vbart@nginx.com>
date Wed, 29 Mar 2017 20:21:01 +0300
parents 47ece8818978
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


#ifndef _NGX_OPEN_FILE_CACHE_H_INCLUDED_
#define _NGX_OPEN_FILE_CACHE_H_INCLUDED_


#define NGX_OPEN_FILE_DIRECTIO_OFF  NGX_MAX_OFF_T_VALUE


typedef struct {
    ngx_fd_t                 fd;
    ngx_file_uniq_t          uniq;
    time_t                   mtime;
    off_t                    size;
    off_t                    fs_size;
    off_t                    directio;
    size_t                   read_ahead;

    ngx_err_t                err;
    char                    *failed;

    time_t                   valid;

    ngx_uint_t               min_uses;

#if (NGX_HAVE_OPENAT)
    size_t                   disable_symlinks_from;
    unsigned                 disable_symlinks:2;
#endif

    unsigned                 test_dir:1;
    unsigned                 test_only:1;
    unsigned                 log:1;
    unsigned                 errors:1;
    unsigned                 events:1;

    unsigned                 is_dir:1;
    unsigned                 is_file:1;
    unsigned                 is_link:1;
    unsigned                 is_exec:1;
    unsigned                 is_directio:1;
} ngx_open_file_info_t;


typedef struct ngx_cached_open_file_s  ngx_cached_open_file_t;

struct ngx_cached_open_file_s {
    ngx_rbtree_node_t        node;
    ngx_queue_t              queue;

    u_char                  *name;
    time_t                   created;
    time_t                   accessed;

    ngx_fd_t                 fd;
    ngx_file_uniq_t          uniq;
    time_t                   mtime;
    off_t                    size;
    ngx_err_t                err;

    uint32_t                 uses;

#if (NGX_HAVE_OPENAT)
    size_t                   disable_symlinks_from;
    unsigned                 disable_symlinks:2;
#endif

    unsigned                 count:24;
    unsigned                 close:1;
    unsigned                 use_event:1;

    unsigned                 is_dir:1;
    unsigned                 is_file:1;
    unsigned                 is_link:1;
    unsigned                 is_exec:1;
    unsigned                 is_directio:1;

    ngx_event_t             *event;
};


typedef struct {
    ngx_rbtree_t             rbtree;
    ngx_rbtree_node_t        sentinel;
    ngx_queue_t              expire_queue;

    ngx_uint_t               current;
    ngx_uint_t               max;
    time_t                   inactive;
} ngx_open_file_cache_t;


typedef struct {
    ngx_open_file_cache_t   *cache;
    ngx_cached_open_file_t  *file;
    ngx_uint_t               min_uses;
    ngx_log_t               *log;
} ngx_open_file_cache_cleanup_t;


typedef struct {

    /* ngx_connection_t stub to allow use c->fd as event ident */
    void                    *data;
    ngx_event_t             *read;
    ngx_event_t             *write;
    ngx_fd_t                 fd;

    ngx_cached_open_file_t  *file;
    ngx_open_file_cache_t   *cache;
} ngx_open_file_cache_event_t;


ngx_open_file_cache_t *ngx_open_file_cache_init(ngx_pool_t *pool,
    ngx_uint_t max, time_t inactive);
ngx_int_t ngx_open_cached_file(ngx_open_file_cache_t *cache, ngx_str_t *name,
    ngx_open_file_info_t *of, ngx_pool_t *pool);


#endif /* _NGX_OPEN_FILE_CACHE_H_INCLUDED_ */