/* * 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 "tools.h" #include "memory.h" #include "numeric.h" #include "reject.h" #include "s_conf.h" #include "s_user.h" #include "blacklist.h" dlink_list blacklist_list = { NULL, NULL, 0 }; /* private interfaces */ static struct Blacklist *find_blacklist(char *name) { dlink_node *nptr; 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)); MyFree(blcptr); return; } if (reply != NULL) { /* only accept 127.0.0.x as a listing */ if (reply->addr.ss_family == AF_INET && !memcmp(&((struct sockaddr_in *)&reply->addr)->sin_addr, "\177\0\0", 3)) listed = TRUE; else if (blcptr->blacklist->lastwarning + 3600 < CurrentTime) { sendto_realops_snomask(SNO_GENERAL, L_ALL, "Garbage reply from blacklist %s", blcptr->blacklist->host); blcptr->blacklist->lastwarning = CurrentTime; } } /* 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); dlinkDelete(&blcptr->node, &blcptr->client_p->preClient->dnsbl_queries); /* yes, it can probably happen... */ if (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]; strlcpy(buf, blcptr->client_p->username, sizeof buf); register_local_user(blcptr->client_p, blcptr->client_p, buf); } MyFree(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 = MyMalloc(sizeof(struct BlacklistClient)); char buf[IRCD_BUFSIZE]; 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 */ ircsnprintf(buf, IRCD_BUFSIZE, "%d.%d.%d.%d.%s", ip[0], ip[1], ip[2], ip[3], blptr->host); gethost_byname_type(buf, &blcptr->dns_query, T_A); 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 = MyMalloc(sizeof(struct Blacklist)); dlinkAddAlloc(blptr, &blacklist_list); } else blptr->status &= ~CONF_ILLEGAL; strlcpy(blptr->host, name, HOSTLEN); 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) { dlinkFindDestroy(blptr, &blacklist_list); MyFree(blptr); } } void lookup_blacklists(struct Client *client_p) { dlink_node *nptr; /* We don't do IPv6 right now, sorry! */ if (client_p->localClient->ip.ss_family == AF_INET6) return; 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) { dlink_node *ptr, *next_ptr; struct BlacklistClient *blcptr; if (client_p->preClient == NULL) return; DLINK_FOREACH_SAFE(ptr, next_ptr, client_p->preClient->dnsbl_queries.head) { blcptr = ptr->data; dlinkDelete(&blcptr->node, &client_p->preClient->dnsbl_queries); unref_blacklist(blcptr->blacklist); delete_resolver_queries(&blcptr->dns_query); MyFree(blcptr); } } void destroy_blacklists(void) { dlink_node *ptr, *next_ptr; struct Blacklist *blptr; 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 { MyFree(ptr->data); dlinkDestroy(ptr, &blacklist_list); } } }