view src/event/ngx_event_pipe.h @ 9204:631ee3c6d38c

Upstream: fixed usage of closed sockets with filter finalization. When filter finalization is triggered when working with an upstream server, and error_page redirects request processing to some simple handler, ngx_http_request_finalize() triggers request termination when the response is sent. In particular, via the upstream cleanup handler, nginx will close the upstream connection and the corresponding socket. Still, this can happen to be with ngx_event_pipe() on stack. While the code will set p->downstream_error due to NGX_ERROR returned from the output filter chain by filter finalization, otherwise the error will be ignored till control returns to ngx_http_upstream_process_request(). And event pipe might try reading from the (already closed) socket, resulting in "readv() failed (9: Bad file descriptor) while reading upstream" errors (or even segfaults with SSL). Such errors were seen with the following configuration: location /t2 { proxy_pass http://127.0.0.1:8080/big; image_filter_buffer 10m; image_filter resize 150 100; error_page 415 = /empty; } location /empty { return 204; } location /big { # big enough static file } Fix is to clear p->upstream in ngx_http_upstream_finalize_request(), and ensure that p->upstream is checked in ngx_event_pipe_read_upstream() and when handling events at ngx_event_pipe() exit.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 30 Jan 2024 03:20:10 +0300
parents adc2414856b1
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_EVENT_PIPE_H_INCLUDED_
#define _NGX_EVENT_PIPE_H_INCLUDED_


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


typedef struct ngx_event_pipe_s  ngx_event_pipe_t;

typedef ngx_int_t (*ngx_event_pipe_input_filter_pt)(ngx_event_pipe_t *p,
                                                    ngx_buf_t *buf);
typedef ngx_int_t (*ngx_event_pipe_output_filter_pt)(void *data,
                                                     ngx_chain_t *chain);


struct ngx_event_pipe_s {
    ngx_connection_t  *upstream;
    ngx_connection_t  *downstream;

    ngx_chain_t       *free_raw_bufs;
    ngx_chain_t       *in;
    ngx_chain_t      **last_in;

    ngx_chain_t       *writing;

    ngx_chain_t       *out;
    ngx_chain_t       *free;
    ngx_chain_t       *busy;

    /*
     * the input filter i.e. that moves HTTP/1.1 chunks
     * from the raw bufs to an incoming chain
     */

    ngx_event_pipe_input_filter_pt    input_filter;
    void                             *input_ctx;

    ngx_event_pipe_output_filter_pt   output_filter;
    void                             *output_ctx;

#if (NGX_THREADS || NGX_COMPAT)
    ngx_int_t                       (*thread_handler)(ngx_thread_task_t *task,
                                                      ngx_file_t *file);
    void                             *thread_ctx;
    ngx_thread_task_t                *thread_task;
#endif

    unsigned           read:1;
    unsigned           cacheable:1;
    unsigned           single_buf:1;
    unsigned           free_bufs:1;
    unsigned           upstream_done:1;
    unsigned           upstream_error:1;
    unsigned           upstream_eof:1;
    unsigned           upstream_blocked:1;
    unsigned           downstream_done:1;
    unsigned           downstream_error:1;
    unsigned           cyclic_temp_file:1;
    unsigned           aio:1;

    ngx_int_t          allocated;
    ngx_bufs_t         bufs;
    ngx_buf_tag_t      tag;

    ssize_t            busy_size;

    off_t              read_length;
    off_t              length;

    off_t              max_temp_file_size;
    ssize_t            temp_file_write_size;

    ngx_msec_t         read_timeout;
    ngx_msec_t         send_timeout;
    ssize_t            send_lowat;

    ngx_pool_t        *pool;
    ngx_log_t         *log;

    ngx_chain_t       *preread_bufs;
    size_t             preread_size;
    ngx_buf_t         *buf_to_file;

    size_t             limit_rate;
    time_t             start_sec;

    ngx_temp_file_t   *temp_file;

    /* STUB */ int     num;
};


ngx_int_t ngx_event_pipe(ngx_event_pipe_t *p, ngx_int_t do_write);
ngx_int_t ngx_event_pipe_copy_input_filter(ngx_event_pipe_t *p, ngx_buf_t *buf);
ngx_int_t ngx_event_pipe_add_free_buf(ngx_event_pipe_t *p, ngx_buf_t *b);


#endif /* _NGX_EVENT_PIPE_H_INCLUDED_ */