view src/http/ngx_http_variables.h @ 7507:ea05113adbdb

Range filter: fixed loss of incoming chain links. Filters are not allowed to change incoming chain links, and should allocate their own links if any modifications are needed. Nevertheless ngx_http_range_singlepart_body() modified incoming chain links in some cases, notably at the end of the requested range. No problems caused by this are currently known, mostly because of limited number of possible modifications and the position of the range body filter in the filter chain. Though this behaviour is clearly incorrect and tests demonstrate that it can at least cause some proxy buffers being lost when using proxy_force_ranges, leading to less effective handling of responses. Fix is to always allocate new chain links in ngx_http_range_singlepart_body(). Links are explicitly freed to ensure constant memory usage with long-lived requests.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 13 May 2019 22:44:02 +0300
parents 2a288909abc6
children 08b3ea81ff5f
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_HTTP_VARIABLES_H_INCLUDED_
#define _NGX_HTTP_VARIABLES_H_INCLUDED_


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


typedef ngx_variable_value_t  ngx_http_variable_value_t;

#define ngx_http_variable(v)     { sizeof(v) - 1, 1, 0, 0, 0, (u_char *) v }

typedef struct ngx_http_variable_s  ngx_http_variable_t;

typedef void (*ngx_http_set_variable_pt) (ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
typedef ngx_int_t (*ngx_http_get_variable_pt) (ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);


#define NGX_HTTP_VAR_CHANGEABLE   1
#define NGX_HTTP_VAR_NOCACHEABLE  2
#define NGX_HTTP_VAR_INDEXED      4
#define NGX_HTTP_VAR_NOHASH       8
#define NGX_HTTP_VAR_WEAK         16
#define NGX_HTTP_VAR_PREFIX       32


struct ngx_http_variable_s {
    ngx_str_t                     name;   /* must be first to build the hash */
    ngx_http_set_variable_pt      set_handler;
    ngx_http_get_variable_pt      get_handler;
    uintptr_t                     data;
    ngx_uint_t                    flags;
    ngx_uint_t                    index;
};

#define ngx_http_null_variable  { ngx_null_string, NULL, NULL, 0, 0, 0 }


ngx_http_variable_t *ngx_http_add_variable(ngx_conf_t *cf, ngx_str_t *name,
    ngx_uint_t flags);
ngx_int_t ngx_http_get_variable_index(ngx_conf_t *cf, ngx_str_t *name);
ngx_http_variable_value_t *ngx_http_get_indexed_variable(ngx_http_request_t *r,
    ngx_uint_t index);
ngx_http_variable_value_t *ngx_http_get_flushed_variable(ngx_http_request_t *r,
    ngx_uint_t index);

ngx_http_variable_value_t *ngx_http_get_variable(ngx_http_request_t *r,
    ngx_str_t *name, ngx_uint_t key);

ngx_int_t ngx_http_variable_unknown_header(ngx_http_variable_value_t *v,
    ngx_str_t *var, ngx_list_part_t *part, size_t prefix);


#if (NGX_PCRE)

typedef struct {
    ngx_uint_t                    capture;
    ngx_int_t                     index;
} ngx_http_regex_variable_t;


typedef struct {
    ngx_regex_t                  *regex;
    ngx_uint_t                    ncaptures;
    ngx_http_regex_variable_t    *variables;
    ngx_uint_t                    nvariables;
    ngx_str_t                     name;
} ngx_http_regex_t;


typedef struct {
    ngx_http_regex_t             *regex;
    void                         *value;
} ngx_http_map_regex_t;


ngx_http_regex_t *ngx_http_regex_compile(ngx_conf_t *cf,
    ngx_regex_compile_t *rc);
ngx_int_t ngx_http_regex_exec(ngx_http_request_t *r, ngx_http_regex_t *re,
    ngx_str_t *s);

#endif


typedef struct {
    ngx_hash_combined_t           hash;
#if (NGX_PCRE)
    ngx_http_map_regex_t         *regex;
    ngx_uint_t                    nregex;
#endif
} ngx_http_map_t;


void *ngx_http_map_find(ngx_http_request_t *r, ngx_http_map_t *map,
    ngx_str_t *match);


ngx_int_t ngx_http_variables_add_core_vars(ngx_conf_t *cf);
ngx_int_t ngx_http_variables_init_vars(ngx_conf_t *cf);


extern ngx_http_variable_value_t  ngx_http_variable_null_value;
extern ngx_http_variable_value_t  ngx_http_variable_true_value;


#endif /* _NGX_HTTP_VARIABLES_H_INCLUDED_ */