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/*-
* tirc -- client for the Internet Relay Chat
*
* Copyright (c) 1996, 1997, 1998
* Matthias Buelow. All rights reserved.
*
* See the file ``COPYRIGHT'' for the usage and distribution
* license and warranty disclaimer.
*/
#ifndef lint
static char rcsid[] = "$Id: flood.c,v 1.11 1998/02/02 03:41:29 mkb Exp $";
#endif
#include "tirc.h"
#ifdef HAVE_STRING_H
#include <string.h>
#elif defined(HAVE_MEMORY_H)
#include <memory.h>
#endif
#include "compat.h"
#include "colour.h"
static struct f_cache *flnextentry __P((void));
extern char ppre[], nick[];
static struct f_cache {
int fc_used;
long fc_loginhash;
long fc_machinehash;
long fc_contentshash;
long fc_time;
char *fc_source;
} msgring[FLRINGSIZE];
static int flptr;
/*
* Initialize the flood protection.
*/
void
flinit()
{
int i;
for (i = 0; i < FLRINGSIZE; i++) {
if (msgring[i].fc_used && msgring[i].fc_source != NULL)
free(msgring[i].fc_source);
msgring[i].fc_used = 0;
msgring[i].fc_source = NULL;
}
flptr = 0;
}
/*
* Register a message to the buffer ring of last recently received
* messages. Don't register messages that come from the server
* directly, only those from users. You must specify which server
* message parameter counts as the contents of the message.
* After that, calculate statistics about the messages gathered so
* far and act if flooding has been detected.
* flregister returns 1 if the message should be ignored.
*/
int
flregister(sm, contents, type)
struct servmsg *sm;
int contents, type;
{
struct f_cache *fc;
char *excl, *at;
int i, strict = 0;
int acnt = 0, tcnt = 0, ccnt = 0;
register long x, y;
struct timeval tv;
char nname[NICKSZ+1], imask[MSGSZ];
char ftype[32];
static long saved_time;
long now;
if (!check_conf(CONF_FLOODP))
return 0;
gettimeofday(&tv, NULL);
now = tv.tv_sec;
/*
* If for longer than 15 seconds we have received nothing, clear the
* message ring.
*/
if (now-saved_time > 15)
flinit();
saved_time = now;
from_nick(sm, nname);
if (!irc_strcmp(nname, nick))
return 0;
if (sm->sm_prefix == NULL ||
(excl = strchr(sm->sm_prefix, '!')) == NULL ||
(at = strchr(sm->sm_prefix, '@')) == NULL)
return 0;
fc = flnextentry();
fc->fc_source = chkmem(Strdup(sm->sm_prefix));
fc->fc_loginhash = elf_hash(excl+1);
fc->fc_machinehash = elf_hash(at+1);
fc->fc_contentshash = elf_hash(sm->sm_par[contents]);
fc->fc_time = now;
fc->fc_used = 1;
/*
* Now iterate through the ring and accumulate statistics.
*/
if (check_conf(CONF_FLSTRICT)) {
strict = 1;
y = fc->fc_machinehash;
}
else
y = fc->fc_loginhash;
for (i = 0; i < FLRINGSIZE; i++) {
if (msgring[i].fc_used) {
x = (strict) ? msgring[i].fc_machinehash
: msgring[i].fc_loginhash;
if (x == y) {
acnt++;
/* More than one line / 2 sec? */
if (labs(msgring[i].fc_time - fc->fc_time) <=
FLRINGSIZE)
tcnt++;
if (msgring[i].fc_contentshash ==
fc->fc_contentshash)
ccnt++;
}
}
}
if (acnt >= FLRINGSIZE/2) {
/*
* Flooding detcted.
*/
if (tcnt >= FLRINGSIZE/2 || ccnt >= FLRINGSIZE/2) {
switch (type) {
case FL_PUBLIC:
strcpy(ftype, "Public");
break;
case FL_MSG:
strcpy(ftype, "Msg");
break;
case FL_NOTICE:
strcpy(ftype, "Notice");
break;
case FL_INVITE:
strcpy(ftype, "Invite");
break;
default:
ftype[0] = 0;
break;
}
iw_printf(COLI_WARN, "%s%s flooding detected from %s\n",
ppre, ftype, fc->fc_source);
/*
* Remove the abuser's occurence from the ring
* to avoid constant warnings.
*/
x = (strict) ? fc->fc_machinehash : fc->fc_loginhash;
for (i = 0; i < FLRINGSIZE; i++) {
x = (strict) ? msgring[i].fc_machinehash
: msgring[i].fc_loginhash;
if (msgring[i].fc_used && x == y) {
msgring[i].fc_used = 0;
if (msgring[i].fc_source != NULL)
free(msgring[i].fc_source);
}
}
/* Ignore offending source when configured. */
if (check_conf(CONF_FLIGNORE)) {
if (strict)
sprintf(imask, "*!*%s", at);
else
sprintf(imask, "*%s", excl);
add_ignore(imask, 3);
return 1;
}
}
}
return 0;
}
static struct f_cache *
flnextentry()
{
flptr = (flptr+1) % FLRINGSIZE;
if (msgring[flptr].fc_used && msgring[flptr].fc_source != NULL) {
free(msgring[flptr].fc_source);
msgring[flptr].fc_source = NULL;
}
msgring[flptr].fc_used = 0;
return &msgring[flptr];
}
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