view src/stream/ngx_stream_variables.h @ 9112:d59277dd3d8c

QUIC: fixed post-close use-after-free. Previously, ngx_quic_close_connection() could be called in a way that QUIC connection was accessed after the call. In most cases the connection is not closed right away, but close timeout is scheduled. However, it's not always the case. Also, if the close process started earlier for a different reason, calling ngx_quic_close_connection() may actually close the connection. The connection object should not be accessed after that. Now, when possible, return statement is added to eliminate post-close connection object access. In other places ngx_quic_close_connection() is substituted with posting close event. Also, the new way of closing connection in ngx_quic_stream_cleanup_handler() fixes another problem in this function. Previously it passed stream connection instead of QUIC connection to ngx_quic_close_connection(). This could result in incomplete connection shutdown. One consequence of that could be that QUIC streams were freed without shutting down their application contexts. This could result in another use-after-free. Found by Coverity (CID 1530402).
author Roman Arutyunyan <arut@nginx.com>
date Mon, 22 May 2023 15:59:42 +0400
parents 2a288909abc6
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_STREAM_VARIABLES_H_INCLUDED_
#define _NGX_STREAM_VARIABLES_H_INCLUDED_


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


typedef ngx_variable_value_t  ngx_stream_variable_value_t;

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

typedef struct ngx_stream_variable_s  ngx_stream_variable_t;

typedef void (*ngx_stream_set_variable_pt) (ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
typedef ngx_int_t (*ngx_stream_get_variable_pt) (ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);


#define NGX_STREAM_VAR_CHANGEABLE   1
#define NGX_STREAM_VAR_NOCACHEABLE  2
#define NGX_STREAM_VAR_INDEXED      4
#define NGX_STREAM_VAR_NOHASH       8
#define NGX_STREAM_VAR_WEAK         16
#define NGX_STREAM_VAR_PREFIX       32


struct ngx_stream_variable_s {
    ngx_str_t                     name;   /* must be first to build the hash */
    ngx_stream_set_variable_pt    set_handler;
    ngx_stream_get_variable_pt    get_handler;
    uintptr_t                     data;
    ngx_uint_t                    flags;
    ngx_uint_t                    index;
};

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


ngx_stream_variable_t *ngx_stream_add_variable(ngx_conf_t *cf, ngx_str_t *name,
    ngx_uint_t flags);
ngx_int_t ngx_stream_get_variable_index(ngx_conf_t *cf, ngx_str_t *name);
ngx_stream_variable_value_t *ngx_stream_get_indexed_variable(
    ngx_stream_session_t *s, ngx_uint_t index);
ngx_stream_variable_value_t *ngx_stream_get_flushed_variable(
    ngx_stream_session_t *s, ngx_uint_t index);

ngx_stream_variable_value_t *ngx_stream_get_variable(ngx_stream_session_t *s,
    ngx_str_t *name, ngx_uint_t key);


#if (NGX_PCRE)

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


typedef struct {
    ngx_regex_t                  *regex;
    ngx_uint_t                    ncaptures;
    ngx_stream_regex_variable_t  *variables;
    ngx_uint_t                    nvariables;
    ngx_str_t                     name;
} ngx_stream_regex_t;


typedef struct {
    ngx_stream_regex_t           *regex;
    void                         *value;
} ngx_stream_map_regex_t;


ngx_stream_regex_t *ngx_stream_regex_compile(ngx_conf_t *cf,
    ngx_regex_compile_t *rc);
ngx_int_t ngx_stream_regex_exec(ngx_stream_session_t *s, ngx_stream_regex_t *re,
    ngx_str_t *str);

#endif


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


void *ngx_stream_map_find(ngx_stream_session_t *s, ngx_stream_map_t *map,
    ngx_str_t *match);


ngx_int_t ngx_stream_variables_add_core_vars(ngx_conf_t *cf);
ngx_int_t ngx_stream_variables_init_vars(ngx_conf_t *cf);


extern ngx_stream_variable_value_t  ngx_stream_variable_null_value;
extern ngx_stream_variable_value_t  ngx_stream_variable_true_value;


#endif /* _NGX_STREAM_VARIABLES_H_INCLUDED_ */