248 lines
8.3 KiB
C
248 lines
8.3 KiB
C
/*
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* charybdis: A slightly useful ircd.
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* blacklist.c: Manages DNS blacklist entries and lookups
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*
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* Copyright (C) 2006-2011 charybdis development team
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include "stdinc.h"
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#include "client.h"
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#include "res.h"
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#include "numeric.h"
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#include "reject.h"
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#include "s_conf.h"
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#include "s_user.h"
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#include "blacklist.h"
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rb_dlink_list blacklist_list = { NULL, NULL, 0 };
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/* private interfaces */
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static struct Blacklist *find_blacklist(char *name)
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{
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rb_dlink_node *nptr;
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RB_DLINK_FOREACH(nptr, blacklist_list.head) {
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struct Blacklist *blptr = (struct Blacklist *) nptr->data;
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if (!irccmp(blptr->host, name))
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return blptr;
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}
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return NULL;
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}
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static void blacklist_dns_callback(void *vptr, struct DNSReply *reply)
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{
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struct BlacklistClient *blcptr = (struct BlacklistClient *) vptr;
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int listed = 0;
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if (blcptr == NULL || blcptr->client_p == NULL)
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return;
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if (blcptr->client_p->preClient == NULL) {
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sendto_realops_snomask(SNO_GENERAL, L_ALL,
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"blacklist_dns_callback(): blcptr->client_p->preClient (%s) is NULL", get_client_name(blcptr->client_p, HIDE_IP));
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rb_free(blcptr);
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return;
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}
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if (reply != NULL) {
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/* only accept 127.x.y.z as a listing */
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if (reply->addr.ss_family == AF_INET &&
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!memcmp(&((struct sockaddr_in *)&reply->addr)->sin_addr, "\177", 1))
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listed = TRUE;
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else if (blcptr->blacklist->lastwarning + 3600 < rb_current_time()) {
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sendto_realops_snomask(SNO_GENERAL, L_ALL,
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"Garbage reply from blacklist %s",
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blcptr->blacklist->host);
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blcptr->blacklist->lastwarning = rb_current_time();
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}
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}
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/* they have a blacklist entry for this client */
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if (listed && blcptr->client_p->preClient->dnsbl_listed == NULL) {
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blcptr->client_p->preClient->dnsbl_listed = blcptr->blacklist;
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/* reference to blacklist moves from blcptr to client_p->preClient... */
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} else
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unref_blacklist(blcptr->blacklist);
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rb_dlinkDelete(&blcptr->node, &blcptr->client_p->preClient->dnsbl_queries);
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/* 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)) {
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char buf[USERLEN + 1];
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rb_strlcpy(buf, blcptr->client_p->username, sizeof buf);
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register_local_user(blcptr->client_p, blcptr->client_p, buf);
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}
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rb_free(blcptr);
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}
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static void initiate_blacklist_dnsquery(struct Blacklist *blptr, struct Client *client_p)
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{
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struct BlacklistClient *blcptr = rb_malloc(sizeof(struct BlacklistClient));
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char buf[IRCD_RES_HOSTLEN + 1];
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uint8_t *ip;
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blcptr->blacklist = blptr;
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blcptr->client_p = client_p;
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blcptr->dns_query.ptr = blcptr;
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blcptr->dns_query.callback = blacklist_dns_callback;
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if ((client_p->localClient->ip.ss_family == AF_INET) && blptr->ipv4) {
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ip = (uint8_t *)&((struct sockaddr_in *)&client_p->localClient->ip)->sin_addr.s_addr;
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/* becomes 2.0.0.127.torbl.ahbl.org or whatever */
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snprintf(buf, sizeof buf, "%d.%d.%d.%d.%s",
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(unsigned int) ip[3],
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(unsigned int) ip[2],
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(unsigned int) ip[1],
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(unsigned int) ip[0],
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blptr->host);
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}
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/* IPv6 is supported now. --Elizabeth */
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else if ((client_p->localClient->ip.ss_family == AF_INET6) && blptr->ipv6) {
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/* Breaks it into ip[0] = 0x00, ip[1] = 0x00... ip[16] = 0x01 for localhost
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* I wish there was a uint4_t for C, this would make the below cleaner, but... */
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ip = (uint8_t *)&((struct sockaddr_in6 *)&client_p->localClient->ip)->sin6_addr.s6_addr;
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char *bufptr = buf;
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int i;
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/* The below will give us something like
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* 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
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*/
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/* Going backwards */
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for (i = 15; i >= 0; i--) {
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/* Get upper and lower nibbles (yes this works fine on
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* both big and little endian) */
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uint8_t hi = (ip[i] >> 4) & 0x0F;
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uint8_t lo = ip[i] & 0x0F;
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/* One part... (why 5? snprintf adds \0) */
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snprintf(bufptr, 5, "%1x.%1x.",
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(unsigned int) lo, /* Remember, backwards */
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(unsigned int) hi);
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/* Lurch forward to next position */
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bufptr += 4;
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}
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/* Tack host on */
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strcpy(bufptr, blptr->host);
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}
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/* This shouldn't happen... */
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else
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return;
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gethost_byname_type(buf, &blcptr->dns_query, T_A);
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rb_dlinkAdd(blcptr, &blcptr->node, &client_p->preClient->dnsbl_queries);
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blptr->refcount++;
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}
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/* public interfaces */
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struct Blacklist *new_blacklist(char *name, char *reject_reason, int ipv4, int ipv6)
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{
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struct Blacklist *blptr;
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if (name == NULL || reject_reason == NULL)
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return NULL;
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blptr = find_blacklist(name);
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if (blptr == NULL) {
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blptr = rb_malloc(sizeof(struct Blacklist));
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rb_dlinkAddAlloc(blptr, &blacklist_list);
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} else
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blptr->status &= ~CONF_ILLEGAL;
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rb_strlcpy(blptr->host, name, IRCD_RES_HOSTLEN + 1);
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rb_strlcpy(blptr->reject_reason, reject_reason, IRCD_BUFSIZE);
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blptr->ipv4 = ipv4;
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blptr->ipv6 = ipv6;
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blptr->lastwarning = 0;
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return blptr;
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}
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void unref_blacklist(struct Blacklist *blptr)
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{
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blptr->refcount--;
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if (blptr->status & CONF_ILLEGAL && blptr->refcount <= 0) {
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rb_dlinkFindDestroy(blptr, &blacklist_list);
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rb_free(blptr);
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}
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}
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void lookup_blacklists(struct Client *client_p)
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{
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rb_dlink_node *nptr;
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RB_DLINK_FOREACH(nptr, blacklist_list.head) {
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struct Blacklist *blptr = (struct Blacklist *) nptr->data;
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if (!(blptr->status & CONF_ILLEGAL))
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initiate_blacklist_dnsquery(blptr, client_p);
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}
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}
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void abort_blacklist_queries(struct Client *client_p)
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{
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rb_dlink_node *ptr, *next_ptr;
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struct BlacklistClient *blcptr;
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if (client_p->preClient == NULL)
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return;
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RB_DLINK_FOREACH_SAFE(ptr, next_ptr, client_p->preClient->dnsbl_queries.head) {
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blcptr = ptr->data;
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rb_dlinkDelete(&blcptr->node, &client_p->preClient->dnsbl_queries);
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unref_blacklist(blcptr->blacklist);
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delete_resolver_queries(&blcptr->dns_query);
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rb_free(blcptr);
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}
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}
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void destroy_blacklists(void)
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{
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rb_dlink_node *ptr, *next_ptr;
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struct Blacklist *blptr;
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RB_DLINK_FOREACH_SAFE(ptr, next_ptr, blacklist_list.head) {
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blptr = ptr->data;
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blptr->hits = 0; /* keep it simple and consistent */
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if (blptr->refcount > 0)
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blptr->status |= CONF_ILLEGAL;
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else {
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rb_free(ptr->data);
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rb_dlinkDestroy(ptr, &blacklist_list);
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}
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}
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}
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