solanum-vs-hackint-and-char.../ircd/blacklist.c

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/*
* charybdis: A slightly useful ircd.
* blacklist.c: Manages DNS blacklist entries and lookups
*
* Copyright (C) 2006-2011 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.
*/
#include "stdinc.h"
#include "client.h"
#include "dns.h"
#include "numeric.h"
#include "reject.h"
#include "s_conf.h"
#include "s_user.h"
#include "blacklist.h"
#include "send.h"
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rb_dlink_list blacklist_list = { NULL, NULL, 0 };
/* private interfaces */
static struct Blacklist *find_blacklist(char *name)
{
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rb_dlink_node *nptr;
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RB_DLINK_FOREACH(nptr, blacklist_list.head)
{
struct Blacklist *blptr = (struct Blacklist *) nptr->data;
if (!irccmp(blptr->host, name))
return blptr;
}
return NULL;
}
static inline int blacklist_check_reply(struct BlacklistClient *blcptr, const char *ipaddr)
{
struct Blacklist *blptr = blcptr->blacklist;
const char *lastoctet;
rb_dlink_node *ptr;
/* No filters and entry found - thus positive match */
if (!rb_dlink_list_length(&blptr->filters))
return 1;
/* Below will prolly have to change too if the above changes */
if ((lastoctet = strrchr(ipaddr, '.')) == NULL || *(++lastoctet) == '\0')
goto blwarn;
RB_DLINK_FOREACH(ptr, blcptr->blacklist->filters.head)
{
struct BlacklistFilter *filter = ptr->data;
const char *cmpstr;
if (filter->type == BLACKLIST_FILTER_ALL)
cmpstr = ipaddr;
else if (filter->type == BLACKLIST_FILTER_LAST)
cmpstr = lastoctet;
else
{
sendto_realops_snomask(SNO_GENERAL, L_ALL,
"blacklist_check_reply(): Unknown filtertype (BUG!)");
continue;
}
if (strcmp(cmpstr, filter->filterstr) == 0)
/* Match! */
return 1;
}
return 0;
blwarn:
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();
}
return 0;
}
static void blacklist_dns_callback(const char *result, int status, int aftype, void *vptr)
{
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 (result != NULL && status)
{
if (blacklist_check_reply(blcptr, result))
listed = TRUE;
}
/* 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);
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rb_dlinkDelete(&blcptr->node, &blcptr->client_p->preClient->dnsbl_queries);
/* yes, it can probably happen... */
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if (rb_dlink_list_length(&blcptr->client_p->preClient->dnsbl_queries) == 0 && blcptr->client_p->flags & FLAGS_SENTUSER && !EmptyString(blcptr->client_p->name))
register_local_user(blcptr->client_p, blcptr->client_p);
rb_free(blcptr);
}
static void initiate_blacklist_dnsquery(struct Blacklist *blptr, struct Client *client_p)
{
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struct BlacklistClient *blcptr = rb_malloc(sizeof(struct BlacklistClient));
char buf[IRCD_RES_HOSTLEN + 1];
uint8_t *ip;
blcptr->blacklist = blptr;
blcptr->client_p = client_p;
if ((client_p->localClient->ip.ss_family == AF_INET) && blptr->ipv4)
{
ip = (uint8_t *)&((struct sockaddr_in *)&client_p->localClient->ip)->sin_addr.s_addr;
/* becomes 2.0.0.127.torbl.ahbl.org or whatever */
snprintf(buf, sizeof buf, "%d.%d.%d.%d.%s",
(unsigned int) ip[3],
(unsigned int) ip[2],
(unsigned int) ip[1],
(unsigned int) ip[0],
blptr->host);
}
/* IPv6 is supported now. --Elizabeth */
else if ((client_p->localClient->ip.ss_family == AF_INET6) && blptr->ipv6)
{
/* Breaks it into ip[0] = 0x00, ip[1] = 0x00... ip[16] = 0x01 for localhost
* I wish there was a uint4_t for C, this would make the below cleaner, but... */
ip = (uint8_t *)&((struct sockaddr_in6 *)&client_p->localClient->ip)->sin6_addr.s6_addr;
char *bufptr = buf;
int i;
/* The below will give us something like
* 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.foobl.invalid
*/
/* Going backwards */
for (i = 15; i >= 0; i--)
{
/* Get upper and lower nibbles (yes this works fine on
* both big and little endian) */
uint8_t hi = (ip[i] >> 4) & 0x0F;
uint8_t lo = ip[i] & 0x0F;
/* One part... (why 5? rb_snprintf adds \0) */
snprintf(bufptr, 5, "%1x.%1x.",
(unsigned int) lo, /* Remember, backwards */
(unsigned int) hi);
/* Lurch forward to next position */
bufptr += 4;
}
/* Tack host on */
strcpy(bufptr, blptr->host);
}
/* This shouldn't happen... */
else
return;
blcptr->dns_id = lookup_hostname(buf, AF_INET, blacklist_dns_callback, blcptr);
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rb_dlinkAdd(blcptr, &blcptr->node, &client_p->preClient->dnsbl_queries);
blptr->refcount++;
}
/* public interfaces */
struct Blacklist *new_blacklist(char *name, char *reject_reason, int ipv4, int ipv6, rb_dlink_list *filters)
{
struct Blacklist *blptr;
if (name == NULL || reject_reason == NULL)
return NULL;
blptr = find_blacklist(name);
if (blptr == NULL)
{
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blptr = rb_malloc(sizeof(struct Blacklist));
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rb_dlinkAddAlloc(blptr, &blacklist_list);
}
else
blptr->status &= ~CONF_ILLEGAL;
rb_strlcpy(blptr->host, name, IRCD_RES_HOSTLEN + 1);
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rb_strlcpy(blptr->reject_reason, reject_reason, IRCD_BUFSIZE);
blptr->ipv4 = ipv4;
blptr->ipv6 = ipv6;
rb_dlinkMoveList(filters, &blptr->filters);
blptr->lastwarning = 0;
return blptr;
}
void unref_blacklist(struct Blacklist *blptr)
{
rb_dlink_node *ptr, *next_ptr;
blptr->refcount--;
if (blptr->status & CONF_ILLEGAL && blptr->refcount <= 0)
{
RB_DLINK_FOREACH_SAFE(ptr, next_ptr, blptr->filters.head)
{
rb_dlinkDelete(ptr, &blptr->filters);
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rb_free(ptr);
}
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rb_dlinkFindDestroy(blptr, &blacklist_list);
rb_free(blptr);
}
}
void lookup_blacklists(struct Client *client_p)
{
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rb_dlink_node *nptr;
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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;
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rb_dlinkDelete(&blcptr->node, &client_p->preClient->dnsbl_queries);
unref_blacklist(blcptr->blacklist);
cancel_lookup(blcptr->dns_id);
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);
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rb_dlinkDestroy(ptr, &blacklist_list);
}
}
}