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).

/*
 * Copyright (C) Roman Arutyunyan
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_HTTP_V3_UNI_H_INCLUDED_
#define _NGX_HTTP_V3_UNI_H_INCLUDED_


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


void ngx_http_v3_init_uni_stream(ngx_connection_t *c);
ngx_int_t ngx_http_v3_register_uni_stream(ngx_connection_t *c, uint64_t type);

ngx_int_t ngx_http_v3_cancel_stream(ngx_connection_t *c, ngx_uint_t stream_id);

ngx_int_t ngx_http_v3_send_settings(ngx_connection_t *c);
ngx_int_t ngx_http_v3_send_goaway(ngx_connection_t *c, uint64_t id);
ngx_int_t ngx_http_v3_send_ack_section(ngx_connection_t *c,
    ngx_uint_t stream_id);
ngx_int_t ngx_http_v3_send_cancel_stream(ngx_connection_t *c,
    ngx_uint_t stream_id);
ngx_int_t ngx_http_v3_send_inc_insert_count(ngx_connection_t *c,
    ngx_uint_t inc);


#endif /* _NGX_HTTP_V3_UNI_H_INCLUDED_ */