view src/core/ngx_palloc.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 d620f497c50f
children ef935cd7ed8d
line wrap: on
line source


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


#ifndef _NGX_PALLOC_H_INCLUDED_
#define _NGX_PALLOC_H_INCLUDED_


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


/*
 * NGX_MAX_ALLOC_FROM_POOL should be (ngx_pagesize - 1), i.e. 4095 on x86.
 * On Windows NT it decreases a number of locked pages in a kernel.
 */
#define NGX_MAX_ALLOC_FROM_POOL  (ngx_pagesize - 1)

#define NGX_DEFAULT_POOL_SIZE    (16 * 1024)

#define NGX_POOL_ALIGNMENT       16
#define NGX_MIN_POOL_SIZE                                                     \
    ngx_align((sizeof(ngx_pool_t) + 2 * sizeof(ngx_pool_large_t)),            \
              NGX_POOL_ALIGNMENT)


typedef void (*ngx_pool_cleanup_pt)(void *data);

typedef struct ngx_pool_cleanup_s  ngx_pool_cleanup_t;

struct ngx_pool_cleanup_s {
    ngx_pool_cleanup_pt   handler;
    void                 *data;
    ngx_pool_cleanup_t   *next;
};


typedef struct ngx_pool_large_s  ngx_pool_large_t;

struct ngx_pool_large_s {
    ngx_pool_large_t     *next;
    void                 *alloc;
};


typedef struct {
    u_char               *last;
    u_char               *end;
    ngx_pool_t           *next;
    ngx_uint_t            failed;
} ngx_pool_data_t;


struct ngx_pool_s {
    ngx_pool_data_t       d;
    size_t                max;
    ngx_pool_t           *current;
    ngx_chain_t          *chain;
    ngx_pool_large_t     *large;
    ngx_pool_cleanup_t   *cleanup;
    ngx_log_t            *log;
};


typedef struct {
    ngx_fd_t              fd;
    u_char               *name;
    ngx_log_t            *log;
} ngx_pool_cleanup_file_t;


void *ngx_alloc(size_t size, ngx_log_t *log);
void *ngx_calloc(size_t size, ngx_log_t *log);

ngx_pool_t *ngx_create_pool(size_t size, ngx_log_t *log);
void ngx_destroy_pool(ngx_pool_t *pool);
void ngx_reset_pool(ngx_pool_t *pool);

void *ngx_palloc(ngx_pool_t *pool, size_t size);
void *ngx_pnalloc(ngx_pool_t *pool, size_t size);
void *ngx_pcalloc(ngx_pool_t *pool, size_t size);
void *ngx_pmemalign(ngx_pool_t *pool, size_t size, size_t alignment);
ngx_int_t ngx_pfree(ngx_pool_t *pool, void *p);


ngx_pool_cleanup_t *ngx_pool_cleanup_add(ngx_pool_t *p, size_t size);
void ngx_pool_run_cleanup_file(ngx_pool_t *p, ngx_fd_t fd);
void ngx_pool_cleanup_file(void *data);
void ngx_pool_delete_file(void *data);


#endif /* _NGX_PALLOC_H_INCLUDED_ */