Merge of r4654, r4672, r4684, r4685, r4692: resolver changes. *) Resolver: fixed format specification. Patch by Yichun Zhang (agentzh). *) Support for IPv6 literals and an optional port in resolver. *) Fixed crash in ngx_resolver_cleanup_tree(). If sending a DNS request fails with an error (e.g., when mistakenly trying to send it to a local IP broadcast), such a request is not deleted if there are clients waiting on it. However, it was still erroneously removed from the queue. Later ngx_resolver_cleanup_tree() attempted to remove it from the queue again that resulted in a NULL pointer dereference. *) When "resolver" is configured with a domain name, only the first resolved address was used. Now all addresses will be used. *) Fixed segfault with poll and resolver used. Poll event method needs ngx_cycle->files to work, and use of ngx_exit_cycle without files set caused null pointer dereference in resolver's cleanup on udp socket close.

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


#ifndef _NGX_CRC_H_INCLUDED_
#define _NGX_CRC_H_INCLUDED_


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


/* 32-bit crc16 */

static ngx_inline uint32_t
ngx_crc(u_char *data, size_t len)
{
    uint32_t  sum;

    for (sum = 0; len; len--) {

        /*
         * gcc 2.95.2 x86 and icc 7.1.006 compile
         * that operator into the single "rol" opcode,
         * msvc 6.0sp2 compiles it into four opcodes.
         */
        sum = sum >> 1 | sum << 31;

        sum += *data++;
    }

    return sum;
}


#endif /* _NGX_CRC_H_INCLUDED_ */