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Attempt to stop another DoS attack related to ping flooding.

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PR:		6649
Submitted by:	Jason Young <doogie@forbidden-donut.anet-stl.com>
This commit is contained in:
Steve Price 1998-05-25 03:50:51 +00:00
parent 7edcb9366e
commit a39f52db0f
1 changed files with 21 additions and 9 deletions
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30
sbin/ping/ping.c
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@ -45,7 +45,7 @@ static const char copyright[] =
static char sccsid[] = "@(#)ping.c 8.1 (Berkeley) 6/5/93";
*/
static const char rcsid[] =
"$Id: ping.c,v 1.33 1998/04/15 19:55:14 phk Exp $";
"$Id: ping.c,v 1.34 1998/05/16 00:19:27 jb Exp $";
#endif /* not lint */
/*
@ -161,6 +161,7 @@ double tsumsq = 0.0; /* sum of all times squared, for std. dev. */
volatile sig_atomic_t finish_up; /* nonzero if we've been told to finish up */
int reset_kerninfo;
volatile sig_atomic_t siginfo_p;
volatile time_t lasttime;
static void fill(char *, char *);
static u_short in_cksum(u_short *, int);
@ -212,6 +213,7 @@ main(argc, argv)
uid = getuid();
preload = 0;
lasttime = 0;
datap = &outpack[8 + PHDR_LEN];
while ((ch = getopt(argc, argv, "I:LQRT:c:adfi:l:np:qrs:v")) != -1) {
@ -521,19 +523,29 @@ catcher(int sig)
{
int waittime;
struct sigaction si_sa;
time_t timenow;
if (nreceived) {
waittime = 2 * tmax / 1000;
if (!waittime)
waittime = 1;
} else
waittime = MAXWAIT;
/*
* Die if SIGALRM is caught earlier than it should have been. This
* is usually the result of someone sending thousands of SIGALRMs
* in an attempt to simulate a ping -f (flood).
*/
if(time((time_t *)&timenow) < lasttime + waittime)
exit(0);
lasttime = timenow;
pinger();
if (!npackets || ntransmitted < npackets)
(void)alarm((u_int)interval);
else {
if (nreceived) {
waittime = 2 * tmax / 1000;
if (!waittime)
waittime = 1;
} else
waittime = MAXWAIT;
si_sa.sa_handler = stopit;
sigemptyset(&si_sa.sa_mask);
si_sa.sa_flags = 0;