elemental-ircd/src/blacklist.c

226 lines
6.5 KiB
C

/*
* charybdis: A slightly useful ircd.
* blacklist.c: Manages DNS blacklist entries and lookups
*
* Copyright (C) 2006-2008 charybdis development team
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* $Id: blacklist.c 2743 2006-11-10 15:15:00Z jilles $
*/
#include "stdinc.h"
#include "client.h"
#include "res.h"
#include "numeric.h"
#include "reject.h"
#include "s_conf.h"
#include "s_user.h"
#include "blacklist.h"
rb_dlink_list blacklist_list = { NULL, NULL, 0 };
/* private interfaces */
static struct Blacklist *find_blacklist(char *name)
{
rb_dlink_node *nptr;
RB_DLINK_FOREACH(nptr, blacklist_list.head)
{
struct Blacklist *blptr = (struct Blacklist *) nptr->data;
if (!irccmp(blptr->host, name))
return blptr;
}
return NULL;
}
static void blacklist_dns_callback(void *vptr, struct DNSReply *reply)
{
struct BlacklistClient *blcptr = (struct BlacklistClient *) vptr;
int listed = 0;
if (blcptr == NULL || blcptr->client_p == NULL)
return;
if (blcptr->client_p->preClient == NULL)
{
sendto_realops_snomask(SNO_GENERAL, L_ALL,
"blacklist_dns_callback(): blcptr->client_p->preClient (%s) is NULL", get_client_name(blcptr->client_p, HIDE_IP));
rb_free(blcptr);
return;
}
if (reply != NULL)
{
/* only accept 127.x.y.z as a listing */
if (reply->addr.ss_family == AF_INET &&
!memcmp(&((struct sockaddr_in *)&reply->addr)->sin_addr, "\177", 1))
listed = TRUE;
else if (blcptr->blacklist->lastwarning + 3600 < rb_current_time())
{
sendto_realops_snomask(SNO_GENERAL, L_ALL,
"Garbage reply from blacklist %s",
blcptr->blacklist->host);
blcptr->blacklist->lastwarning = rb_current_time();
}
}
/* they have a blacklist entry for this client */
if (listed && blcptr->client_p->preClient->dnsbl_listed == NULL)
{
blcptr->client_p->preClient->dnsbl_listed = blcptr->blacklist;
/* reference to blacklist moves from blcptr to client_p->preClient... */
}
else
unref_blacklist(blcptr->blacklist);
rb_dlinkDelete(&blcptr->node, &blcptr->client_p->preClient->dnsbl_queries);
/* yes, it can probably happen... */
if (rb_dlink_list_length(&blcptr->client_p->preClient->dnsbl_queries) == 0 && blcptr->client_p->flags & FLAGS_SENTUSER && !EmptyString(blcptr->client_p->name))
{
char buf[USERLEN + 1];
rb_strlcpy(buf, blcptr->client_p->username, sizeof buf);
register_local_user(blcptr->client_p, blcptr->client_p, buf);
}
rb_free(blcptr);
}
/* XXX: no IPv6 implementation, not to concerned right now though. */
static void initiate_blacklist_dnsquery(struct Blacklist *blptr, struct Client *client_p)
{
struct BlacklistClient *blcptr = rb_malloc(sizeof(struct BlacklistClient));
char buf[IRCD_RES_HOSTLEN + 1];
int ip[4];
blcptr->blacklist = blptr;
blcptr->client_p = client_p;
blcptr->dns_query.ptr = blcptr;
blcptr->dns_query.callback = blacklist_dns_callback;
/* XXX: yes I know this is bad, I don't really care right now */
sscanf(client_p->sockhost, "%d.%d.%d.%d", &ip[3], &ip[2], &ip[1], &ip[0]);
/* becomes 2.0.0.127.torbl.ahbl.org or whatever */
rb_snprintf(buf, sizeof buf, "%d.%d.%d.%d.%s", ip[0], ip[1], ip[2], ip[3], blptr->host);
gethost_byname_type(buf, &blcptr->dns_query, T_A);
rb_dlinkAdd(blcptr, &blcptr->node, &client_p->preClient->dnsbl_queries);
blptr->refcount++;
}
/* public interfaces */
struct Blacklist *new_blacklist(char *name, char *reject_reason)
{
struct Blacklist *blptr;
if (name == NULL || reject_reason == NULL)
return NULL;
blptr = find_blacklist(name);
if (blptr == NULL)
{
blptr = rb_malloc(sizeof(struct Blacklist));
rb_dlinkAddAlloc(blptr, &blacklist_list);
}
else
blptr->status &= ~CONF_ILLEGAL;
rb_strlcpy(blptr->host, name, IRCD_RES_HOSTLEN + 1);
rb_strlcpy(blptr->reject_reason, reject_reason, IRCD_BUFSIZE);
blptr->lastwarning = 0;
return blptr;
}
void unref_blacklist(struct Blacklist *blptr)
{
blptr->refcount--;
if (blptr->status & CONF_ILLEGAL && blptr->refcount <= 0)
{
rb_dlinkFindDestroy(blptr, &blacklist_list);
rb_free(blptr);
}
}
void lookup_blacklists(struct Client *client_p)
{
rb_dlink_node *nptr;
/* We don't do IPv6 right now, sorry! */
if (client_p->localClient->ip.ss_family == AF_INET6)
return;
RB_DLINK_FOREACH(nptr, blacklist_list.head)
{
struct Blacklist *blptr = (struct Blacklist *) nptr->data;
if (!(blptr->status & CONF_ILLEGAL))
initiate_blacklist_dnsquery(blptr, client_p);
}
}
void abort_blacklist_queries(struct Client *client_p)
{
rb_dlink_node *ptr, *next_ptr;
struct BlacklistClient *blcptr;
if (client_p->preClient == NULL)
return;
RB_DLINK_FOREACH_SAFE(ptr, next_ptr, client_p->preClient->dnsbl_queries.head)
{
blcptr = ptr->data;
rb_dlinkDelete(&blcptr->node, &client_p->preClient->dnsbl_queries);
unref_blacklist(blcptr->blacklist);
delete_resolver_queries(&blcptr->dns_query);
rb_free(blcptr);
}
}
void destroy_blacklists(void)
{
rb_dlink_node *ptr, *next_ptr;
struct Blacklist *blptr;
RB_DLINK_FOREACH_SAFE(ptr, next_ptr, blacklist_list.head)
{
blptr = ptr->data;
blptr->hits = 0; /* keep it simple and consistent */
if (blptr->refcount > 0)
blptr->status |= CONF_ILLEGAL;
else
{
rb_free(ptr->data);
rb_dlinkDestroy(ptr, &blacklist_list);
}
}
}