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(res_nmkquery): Randomize request ID every time.

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This commit is contained in:
Ulrich Drepper 2004-09-18 18:00:50 +00:00
parent 9530eaf007
commit e33b89df22
1 changed files with 32 additions and 4 deletions
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36
resolv/res_mkquery.c
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@ -1,7 +1,7 @@
/*
* Copyright (c) 1985, 1993
* The Regents of the University of California. All rights reserved.
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
@ -13,7 +13,7 @@
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
@ -29,14 +29,14 @@
/*
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
*
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies, and that
* the name of Digital Equipment Corporation not be used in advertising or
* publicity pertaining to distribution of the document or software without
* specific, written prior permission.
*
*
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
@ -81,6 +81,13 @@ static const char rcsid[] = "$BINDId: res_mkquery.c,v 8.12 1999/10/13 16:39:40 v
/* Options. Leave them on. */
/* #define DEBUG */
#ifdef _LIBC
# include <hp-timing.h>
# if HP_TIMING_AVAIL
# define RANDOM_BITS(Var) { uint64_t v64; HP_TIMING_NOW (v64); Var = v64; }
# endif
#endif
extern const char *_res_opcodes[];
/*
@ -115,7 +122,28 @@ res_nmkquery(res_state statp,
return (-1);
memset(buf, 0, HFIXEDSZ);
hp = (HEADER *) buf;
/* We randomize the IDs every time. The old code just
incremented by one after the initial randomization which
still predictable if the application does multiple
requests. */
#if 0
hp->id = htons(++statp->id);
#else
hp->id = htons(statp->id);
int randombits;
do
{
#ifdef RANDOM_BITS
RANDOM_BITS (randombits);
#else
struct timeval tv;
__gettimeofday (&tv, NULL);
random_time_bits = (tv.tv_sec << 8) ^ tv.tv_usec;
#endif
}
while (randombits == 0);
statp->id = (statp->id + randombits) & 0xffff;
#endif
hp->opcode = op;
hp->rd = (statp->options & RES_RECURSE) != 0;
hp->rcode = NOERROR;