view src/core/ngx_list.h @ 7401:a7ff19afbb14

Negative size buffers detection. In the past, there were several security issues which resulted in worker process memory disclosure due to buffers with negative size. It looks reasonable to check for such buffers in various places, much like we already check for zero size buffers. While here, removed "#if 1 / #endif" around zero size buffer checks. It looks highly unlikely that we'll disable these checks anytime soon.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 26 Nov 2018 18:29:56 +0300
parents d620f497c50f
children
line wrap: on
line source


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


#ifndef _NGX_LIST_H_INCLUDED_
#define _NGX_LIST_H_INCLUDED_


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


typedef struct ngx_list_part_s  ngx_list_part_t;

struct ngx_list_part_s {
    void             *elts;
    ngx_uint_t        nelts;
    ngx_list_part_t  *next;
};


typedef struct {
    ngx_list_part_t  *last;
    ngx_list_part_t   part;
    size_t            size;
    ngx_uint_t        nalloc;
    ngx_pool_t       *pool;
} ngx_list_t;


ngx_list_t *ngx_list_create(ngx_pool_t *pool, ngx_uint_t n, size_t size);

static ngx_inline ngx_int_t
ngx_list_init(ngx_list_t *list, ngx_pool_t *pool, ngx_uint_t n, size_t size)
{
    list->part.elts = ngx_palloc(pool, n * size);
    if (list->part.elts == NULL) {
        return NGX_ERROR;
    }

    list->part.nelts = 0;
    list->part.next = NULL;
    list->last = &list->part;
    list->size = size;
    list->nalloc = n;
    list->pool = pool;

    return NGX_OK;
}


/*
 *
 *  the iteration through the list:
 *
 *  part = &list.part;
 *  data = part->elts;
 *
 *  for (i = 0 ;; i++) {
 *
 *      if (i >= part->nelts) {
 *          if (part->next == NULL) {
 *              break;
 *          }
 *
 *          part = part->next;
 *          data = part->elts;
 *          i = 0;
 *      }
 *
 *      ...  data[i] ...
 *
 *  }
 */


void *ngx_list_push(ngx_list_t *list);


#endif /* _NGX_LIST_H_INCLUDED_ */