view src/stream/ngx_stream_script.h @ 7629:f47f7d3d1bfa

Mp4: fixed possible chunk offset overflow. In "co64" atom chunk start offset is a 64-bit unsigned integer. When trimming the "mdat" atom, chunk offsets are casted to off_t values which are typically 64-bit signed integers. A specially crafted mp4 file with huge chunk offsets may lead to off_t overflow and result in negative trim boundaries. The consequences of the overflow are: - Incorrect Content-Length header value in the response. - Negative left boundary of the response file buffer holding the trimmed "mdat". This leads to pread()/sendfile() errors followed by closing the client connection. On rare systems where off_t is a 32-bit integer, this scenario is also feasible with the "stco" atom. The fix is to add checks which make sure data chunks referenced by each track are within the mp4 file boundaries. Additionally a few more checks are added to ensure mp4 file consistency and log errors.
author Roman Arutyunyan <arut@nginx.com>
date Wed, 26 Feb 2020 15:10:46 +0300
parents b82162b8496a
children 3ab8e1e2f0f7
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;

    union {
        size_t                    size;
    } u;
} 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);
size_t ngx_stream_complex_value_size(ngx_stream_session_t *s,
    ngx_stream_complex_value_t *val, size_t default_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);
char *ngx_stream_set_complex_value_size_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_ */