view src/stream/ngx_stream_script.h @ 7054:e02555553d0b

Range filter: protect from total size overflows. The overflow can be used to circumvent the restriction on total size of ranges introduced in c2a91088b0c0 (1.1.2). Additionally, overflow allows producing ranges with negative start (such ranges can be created by using a suffix, "bytes=-100"; normally this results in 200 due to the total size check). These can result in the following errors in logs: [crit] ... pread() ... failed (22: Invalid argument) [alert] ... sendfile() failed (22: Invalid argument) When using cache, it can be also used to reveal cache file header. It is believed that there are no other negative effects, at least with standard nginx modules. In theory, this can also result in memory disclosure and/or segmentation faults if multiple ranges are allowed, and the response is returned in a single in-memory buffer. This never happens with standard nginx modules though, as well as known 3rd party modules. Fix is to properly protect from possible overflow when incrementing size.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 11 Jul 2017 16:06:23 +0300
parents 0125b151c9a5
children b82162b8496a
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_STREAM_SCRIPT_H_INCLUDED_
#define _NGX_STREAM_SCRIPT_H_INCLUDED_


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


typedef struct {
    u_char                       *ip;
    u_char                       *pos;
    ngx_stream_variable_value_t  *sp;

    ngx_str_t                     buf;
    ngx_str_t                     line;

    unsigned                      flushed:1;
    unsigned                      skip:1;

    ngx_stream_session_t         *session;
} ngx_stream_script_engine_t;


typedef struct {
    ngx_conf_t                   *cf;
    ngx_str_t                    *source;

    ngx_array_t                 **flushes;
    ngx_array_t                 **lengths;
    ngx_array_t                 **values;

    ngx_uint_t                    variables;
    ngx_uint_t                    ncaptures;
    ngx_uint_t                    size;

    void                         *main;

    unsigned                      complete_lengths:1;
    unsigned                      complete_values:1;
    unsigned                      zero:1;
    unsigned                      conf_prefix:1;
    unsigned                      root_prefix:1;
} ngx_stream_script_compile_t;


typedef struct {
    ngx_str_t                     value;
    ngx_uint_t                   *flushes;
    void                         *lengths;
    void                         *values;
} ngx_stream_complex_value_t;


typedef struct {
    ngx_conf_t                   *cf;
    ngx_str_t                    *value;
    ngx_stream_complex_value_t   *complex_value;

    unsigned                      zero:1;
    unsigned                      conf_prefix:1;
    unsigned                      root_prefix:1;
} ngx_stream_compile_complex_value_t;


typedef void (*ngx_stream_script_code_pt) (ngx_stream_script_engine_t *e);
typedef size_t (*ngx_stream_script_len_code_pt) (ngx_stream_script_engine_t *e);


typedef struct {
    ngx_stream_script_code_pt     code;
    uintptr_t                     len;
} ngx_stream_script_copy_code_t;


typedef struct {
    ngx_stream_script_code_pt     code;
    uintptr_t                     index;
} ngx_stream_script_var_code_t;


typedef struct {
    ngx_stream_script_code_pt     code;
    uintptr_t                     n;
} ngx_stream_script_copy_capture_code_t;


typedef struct {
    ngx_stream_script_code_pt     code;
    uintptr_t                     conf_prefix;
} ngx_stream_script_full_name_code_t;


void ngx_stream_script_flush_complex_value(ngx_stream_session_t *s,
    ngx_stream_complex_value_t *val);
ngx_int_t ngx_stream_complex_value(ngx_stream_session_t *s,
    ngx_stream_complex_value_t *val, ngx_str_t *value);
ngx_int_t ngx_stream_compile_complex_value(
    ngx_stream_compile_complex_value_t *ccv);
char *ngx_stream_set_complex_value_slot(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


ngx_uint_t ngx_stream_script_variables_count(ngx_str_t *value);
ngx_int_t ngx_stream_script_compile(ngx_stream_script_compile_t *sc);
u_char *ngx_stream_script_run(ngx_stream_session_t *s, ngx_str_t *value,
    void *code_lengths, size_t reserved, void *code_values);
void ngx_stream_script_flush_no_cacheable_variables(ngx_stream_session_t *s,
    ngx_array_t *indices);

void *ngx_stream_script_add_code(ngx_array_t *codes, size_t size, void *code);

size_t ngx_stream_script_copy_len_code(ngx_stream_script_engine_t *e);
void ngx_stream_script_copy_code(ngx_stream_script_engine_t *e);
size_t ngx_stream_script_copy_var_len_code(ngx_stream_script_engine_t *e);
void ngx_stream_script_copy_var_code(ngx_stream_script_engine_t *e);
size_t ngx_stream_script_copy_capture_len_code(ngx_stream_script_engine_t *e);
void ngx_stream_script_copy_capture_code(ngx_stream_script_engine_t *e);

#endif /* _NGX_STREAM_SCRIPT_H_INCLUDED_ */