view src/core/ngx_open_file_cache.h @ 4487:a786c85e8268

Disable symlinks: don't allow creating or truncating a file via a symlink in the last path component if "if_not_owner" parameter is used. To prevent race condition we have to open a file before checking its owner and there's no way to change access flags for already opened file descriptor, so we disable symlinks for the last path component at all if flags allow creating or truncating the file.
author Valentin Bartenev <vbart@nginx.com>
date Tue, 21 Feb 2012 15:04:41 +0000
parents 7033faf6dc3c
children 47ece8818978
line wrap: on
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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)
    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)
    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_ */