view src/http/ngx_http_upstream_round_robin.h @ 4471:b19a651471d9

Core: protection from subrequest loops. Without the protection, subrequest loop results in r->count overflow and SIGSEGV. Protection was broken in 0.7.25. Note that this also limits number of parallel subrequests. This wasn't exactly the case before 0.7.25 as local subrequests were completed directly. See here for details: http://nginx.org/pipermail/nginx-ru/2010-February/032184.html
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 13 Feb 2012 15:33:08 +0000
parents d620f497c50f
children c90801720a0c
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_HTTP_UPSTREAM_ROUND_ROBIN_H_INCLUDED_
#define _NGX_HTTP_UPSTREAM_ROUND_ROBIN_H_INCLUDED_


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


typedef struct {
    struct sockaddr                *sockaddr;
    socklen_t                       socklen;
    ngx_str_t                       name;

    ngx_int_t                       current_weight;
    ngx_int_t                       weight;

    ngx_uint_t                      fails;
    time_t                          accessed;
    time_t                          checked;

    ngx_uint_t                      max_fails;
    time_t                          fail_timeout;

    ngx_uint_t                      down;          /* unsigned  down:1; */

#if (NGX_HTTP_SSL)
    ngx_ssl_session_t              *ssl_session;   /* local to a process */
#endif
} ngx_http_upstream_rr_peer_t;


typedef struct ngx_http_upstream_rr_peers_s  ngx_http_upstream_rr_peers_t;

struct ngx_http_upstream_rr_peers_s {
    ngx_uint_t                      single;        /* unsigned  single:1; */
    ngx_uint_t                      number;
    ngx_uint_t                      last_cached;

 /* ngx_mutex_t                    *mutex; */
    ngx_connection_t              **cached;

    ngx_str_t                      *name;

    ngx_http_upstream_rr_peers_t   *next;

    ngx_http_upstream_rr_peer_t     peer[1];
};


typedef struct {
    ngx_http_upstream_rr_peers_t   *peers;
    ngx_uint_t                      current;
    uintptr_t                      *tried;
    uintptr_t                       data;
} ngx_http_upstream_rr_peer_data_t;


ngx_int_t ngx_http_upstream_init_round_robin(ngx_conf_t *cf,
    ngx_http_upstream_srv_conf_t *us);
ngx_int_t ngx_http_upstream_init_round_robin_peer(ngx_http_request_t *r,
    ngx_http_upstream_srv_conf_t *us);
ngx_int_t ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r,
    ngx_http_upstream_resolved_t *ur);
ngx_int_t ngx_http_upstream_get_round_robin_peer(ngx_peer_connection_t *pc,
    void *data);
void ngx_http_upstream_free_round_robin_peer(ngx_peer_connection_t *pc,
    void *data, ngx_uint_t state);

#if (NGX_HTTP_SSL)
ngx_int_t
    ngx_http_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc,
    void *data);
void ngx_http_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc,
    void *data);
#endif


#endif /* _NGX_HTTP_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ */