view src/event/ngx_event_posted.h @ 6957:83bae3d354ab

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().
author Valentin Bartenev <vbart@nginx.com>
date Wed, 29 Mar 2017 20:21:01 +0300
parents 3d4730eada9c
children 9d2ad2fb4423
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_EVENT_POSTED_H_INCLUDED_
#define _NGX_EVENT_POSTED_H_INCLUDED_


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


#define ngx_post_event(ev, q)                                                 \
                                                                              \
    if (!(ev)->posted) {                                                      \
        (ev)->posted = 1;                                                     \
        ngx_queue_insert_tail(q, &(ev)->queue);                               \
                                                                              \
        ngx_log_debug1(NGX_LOG_DEBUG_CORE, (ev)->log, 0, "post event %p", ev);\
                                                                              \
    } else  {                                                                 \
        ngx_log_debug1(NGX_LOG_DEBUG_CORE, (ev)->log, 0,                      \
                       "update posted event %p", ev);                         \
    }


#define ngx_delete_posted_event(ev)                                           \
                                                                              \
    (ev)->posted = 0;                                                         \
    ngx_queue_remove(&(ev)->queue);                                           \
                                                                              \
    ngx_log_debug1(NGX_LOG_DEBUG_CORE, (ev)->log, 0,                          \
                   "delete posted event %p", ev);



void ngx_event_process_posted(ngx_cycle_t *cycle, ngx_queue_t *posted);


extern ngx_queue_t  ngx_posted_accept_events;
extern ngx_queue_t  ngx_posted_events;


#endif /* _NGX_EVENT_POSTED_H_INCLUDED_ */