view src/stream/ngx_stream_upstream_round_robin.h @ 6874:7cc2d3a96ea3

Fixed trailer construction with limit on FreeBSD and macOS. The ngx_chain_coalesce_file() function may produce more bytes to send then requested in the limit passed, as it aligns the last file position to send to memory page boundary. As a result, (limit - send) may become negative. This resulted in big positive number when converted to size_t while calling ngx_output_chain_to_iovec(). Another part of the problem is in ngx_chain_coalesce_file(): it changes cl to the next chain link even if the current buffer is only partially sent due to limit. Therefore, if a file buffer was not expected to be fully sent due to limit, and was followed by a memory buffer, nginx called sendfile() with a part of the file buffer, and the memory buffer in trailer. If there were enough room in the socket buffer, this resulted in a part of the file buffer being skipped, and corresponding part of the memory buffer sent instead. The bug was introduced in 8e903522c17a (1.7.8). Configurations affected are ones using limits, that is, limit_rate and/or sendfile_max_chunk, and memory buffers after file ones (may happen when using subrequests or with proxying with disk buffering). Fix is to explicitly check if (send < limit) before constructing trailer with ngx_output_chain_to_iovec(). Additionally, ngx_chain_coalesce_file() was modified to preserve unfinished file buffers in cl.
author Maxim Dounin <mdounin@mdounin.ru>
date Fri, 20 Jan 2017 21:12:48 +0300
parents f41c2530dd17
children 90cc7194e993
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_STREAM_UPSTREAM_ROUND_ROBIN_H_INCLUDED_
#define _NGX_STREAM_UPSTREAM_ROUND_ROBIN_H_INCLUDED_


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


typedef struct ngx_stream_upstream_rr_peer_s   ngx_stream_upstream_rr_peer_t;

struct ngx_stream_upstream_rr_peer_s {
    struct sockaddr                 *sockaddr;
    socklen_t                        socklen;
    ngx_str_t                        name;
    ngx_str_t                        server;

    ngx_int_t                        current_weight;
    ngx_int_t                        effective_weight;
    ngx_int_t                        weight;

    ngx_uint_t                       conns;
    ngx_uint_t                       max_conns;

    ngx_uint_t                       fails;
    time_t                           accessed;
    time_t                           checked;

    ngx_uint_t                       max_fails;
    time_t                           fail_timeout;
    ngx_msec_t                       slow_start;
    ngx_msec_t                       start_time;

    ngx_uint_t                       down;

    void                            *ssl_session;
    int                              ssl_session_len;

#if (NGX_STREAM_UPSTREAM_ZONE)
    ngx_atomic_t                     lock;
#endif

    ngx_stream_upstream_rr_peer_t   *next;

    NGX_COMPAT_BEGIN(25)
    NGX_COMPAT_END
};


typedef struct ngx_stream_upstream_rr_peers_s  ngx_stream_upstream_rr_peers_t;

struct ngx_stream_upstream_rr_peers_s {
    ngx_uint_t                       number;

#if (NGX_STREAM_UPSTREAM_ZONE)
    ngx_slab_pool_t                 *shpool;
    ngx_atomic_t                     rwlock;
    ngx_stream_upstream_rr_peers_t  *zone_next;
#endif

    ngx_uint_t                       total_weight;

    unsigned                         single:1;
    unsigned                         weighted:1;

    ngx_str_t                       *name;

    ngx_stream_upstream_rr_peers_t  *next;

    ngx_stream_upstream_rr_peer_t   *peer;
};


#if (NGX_STREAM_UPSTREAM_ZONE)

#define ngx_stream_upstream_rr_peers_rlock(peers)                             \
                                                                              \
    if (peers->shpool) {                                                      \
        ngx_rwlock_rlock(&peers->rwlock);                                     \
    }

#define ngx_stream_upstream_rr_peers_wlock(peers)                             \
                                                                              \
    if (peers->shpool) {                                                      \
        ngx_rwlock_wlock(&peers->rwlock);                                     \
    }

#define ngx_stream_upstream_rr_peers_unlock(peers)                            \
                                                                              \
    if (peers->shpool) {                                                      \
        ngx_rwlock_unlock(&peers->rwlock);                                    \
    }


#define ngx_stream_upstream_rr_peer_lock(peers, peer)                         \
                                                                              \
    if (peers->shpool) {                                                      \
        ngx_rwlock_wlock(&peer->lock);                                        \
    }

#define ngx_stream_upstream_rr_peer_unlock(peers, peer)                       \
                                                                              \
    if (peers->shpool) {                                                      \
        ngx_rwlock_unlock(&peer->lock);                                       \
    }

#else

#define ngx_stream_upstream_rr_peers_rlock(peers)
#define ngx_stream_upstream_rr_peers_wlock(peers)
#define ngx_stream_upstream_rr_peers_unlock(peers)
#define ngx_stream_upstream_rr_peer_lock(peers, peer)
#define ngx_stream_upstream_rr_peer_unlock(peers, peer)

#endif


typedef struct {
    ngx_uint_t                       config;
    ngx_stream_upstream_rr_peers_t  *peers;
    ngx_stream_upstream_rr_peer_t   *current;
    uintptr_t                       *tried;
    uintptr_t                        data;
} ngx_stream_upstream_rr_peer_data_t;


ngx_int_t ngx_stream_upstream_init_round_robin(ngx_conf_t *cf,
    ngx_stream_upstream_srv_conf_t *us);
ngx_int_t ngx_stream_upstream_init_round_robin_peer(ngx_stream_session_t *s,
    ngx_stream_upstream_srv_conf_t *us);
ngx_int_t ngx_stream_upstream_create_round_robin_peer(ngx_stream_session_t *s,
    ngx_stream_upstream_resolved_t *ur);
ngx_int_t ngx_stream_upstream_get_round_robin_peer(ngx_peer_connection_t *pc,
    void *data);
void ngx_stream_upstream_free_round_robin_peer(ngx_peer_connection_t *pc,
    void *data, ngx_uint_t state);


#endif /* _NGX_STREAM_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ */