HTTP/2: fixed connection finalization. All streams in connection must be finalized before the connection itself can be finalized and all related memory is freed. That's not always possible on the current event loop iteration. Thus when the last stream is finalized, it sets the special read event handler ngx_http_v2_handle_connection_handler() and posts the event. Previously, this handler didn't check the connection state and could call the regular event handler on a connection that was already in finalization stage. In the worst case that could lead to a segmentation fault, since some data structures aren't supposed to be used during connection finalization. Particularly, the waiting queue can contain already freed streams, so the WINDOW_UPDATE frame received by that moment could trigger accessing to these freed streams. Now, the connection error flag is explicitly checked in ngx_http_v2_handle_connection_handler().

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


#ifndef _NGX_MAIL_IMAP_MODULE_H_INCLUDED_
#define _NGX_MAIL_IMAP_MODULE_H_INCLUDED_


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


typedef struct {
    size_t       client_buffer_size;

    ngx_str_t    capability;
    ngx_str_t    starttls_capability;
    ngx_str_t    starttls_only_capability;

    ngx_uint_t   auth_methods;

    ngx_array_t  capabilities;
} ngx_mail_imap_srv_conf_t;


void ngx_mail_imap_init_session(ngx_mail_session_t *s, ngx_connection_t *c);
void ngx_mail_imap_init_protocol(ngx_event_t *rev);
void ngx_mail_imap_auth_state(ngx_event_t *rev);
ngx_int_t ngx_mail_imap_parse_command(ngx_mail_session_t *s);


extern ngx_module_t  ngx_mail_imap_module;


#endif /* _NGX_MAIL_IMAP_MODULE_H_INCLUDED_ */