src/blacklist.c

   1 /*
   2  *  charybdis: A slightly useful ircd.
   3  *  blacklist.c: Manages DNS blacklist entries and lookups
   4  *
   5  *  Copyright (C) 2006 charybdis development team
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
  20  *  USA
  21  */
  22
  23 #include "stdinc.h"
  24 #include "client.h"
  25 #include "res.h"
  26 #include "tools.h"
  27 #include "memory.h"
  28 #include "numeric.h"
  29 #include "reject.h"
  30 #include "s_conf.h"
  31 #include "s_user.h"
  32 #include "blacklist.h"
  33
  34 dlink_list blacklist_list = { NULL, NULL, 0 };
  35
  36 /* private interfaces */
  37 static struct Blacklist *find_blacklist(char *name)
  38 {
  39         dlink_node *nptr;
  40
  41         DLINK_FOREACH(nptr, blacklist_list.head)
  42         {
  43                 struct Blacklist *blptr = (struct Blacklist *) nptr->data;
  44
  45                 if (!irccmp(blptr->host, name))
  46                         return blptr;
  47         }
  48
  49         return NULL;
  50 }
  51
  52 static void blacklist_dns_callback(void *vptr, struct DNSReply *reply)
  53 {
  54         struct BlacklistClient *blcptr = (struct BlacklistClient *) vptr;
  55
  56         if (blcptr == NULL || blcptr->client_p == NULL)
  57                 return;
  58
  59         if (blcptr->client_p->preClient == NULL)
  60         {
  61                 sendto_realops_snomask(SNO_GENERAL, L_ALL,
  62                                 "blacklist_dns_callback(): blcptr->client_p->preClient (%s) is NULL", get_client_name(blcptr->client_p, HIDE_IP));
  63                 MyFree(blcptr);
  64                 return;
  65         }
  66
  67         /* they have a blacklist entry for this client */
  68         if (reply != NULL && blcptr->client_p->preClient->dnsbl_listed == NULL)
  69         {
  70                 blcptr->client_p->preClient->dnsbl_listed = blcptr->blacklist;
  71                 /* reference to blacklist moves from blcptr to client_p->preClient... */
  72         }
  73         else
  74                 unref_blacklist(blcptr->blacklist);
  75
  76         dlinkDelete(&blcptr->node, &blcptr->client_p->preClient->dnsbl_queries);
  77
  78         /* yes, it can probably happen... */
  79         if (dlink_list_length(&blcptr->client_p->preClient->dnsbl_queries) == 0 && blcptr->client_p->flags & FLAGS_SENTUSER && !EmptyString(blcptr->client_p->name))
  80         {
  81                 char buf[USERLEN];
  82                 strlcpy(buf, blcptr->client_p->username, USERLEN);
  83                 register_local_user(blcptr->client_p, blcptr->client_p, buf);
  84         }
  85
  86         MyFree(blcptr);
  87 }
  88
  89 /* XXX: no IPv6 implementation, not to concerned right now though. */
  90 static void initiate_blacklist_dnsquery(struct Blacklist *blptr, struct Client *client_p)
  91 {
  92         struct BlacklistClient *blcptr = MyMalloc(sizeof(struct BlacklistClient));
  93         char buf[IRCD_BUFSIZE];
  94         int ip[4];
  95
  96         blcptr->blacklist = blptr;
  97         blcptr->client_p = client_p;
  98
  99         blcptr->dns_query.ptr = blcptr;
 100         blcptr->dns_query.callback = blacklist_dns_callback;
 101
 102         /* XXX: yes I know this is bad, I don't really care right now */
 103         sscanf(client_p->sockhost, "%d.%d.%d.%d", &ip[3], &ip[2], &ip[1], &ip[0]);
 104
 105         /* becomes 2.0.0.127.torbl.ahbl.org or whatever */
 106         ircsnprintf(buf, IRCD_BUFSIZE, "%d.%d.%d.%d.%s", ip[0], ip[1], ip[2], ip[3], blptr->host);
 107
 108         gethost_byname_type(buf, &blcptr->dns_query, T_A);
 109
 110         dlinkAdd(blcptr, &blcptr->node, &client_p->preClient->dnsbl_queries);
 111         blptr->refcount++;
 112 }
 113
 114 /* public interfaces */
 115 struct Blacklist *new_blacklist(char *name, char *reject_reason)
 116 {
 117         struct Blacklist *blptr;
 118
 119         if (name == NULL || reject_reason == NULL)
 120                 return NULL;
 121
 122         blptr = find_blacklist(name);
 123         if (blptr == NULL)
 124         {
 125                 blptr = MyMalloc(sizeof(struct Blacklist));
 126                 dlinkAddAlloc(blptr, &blacklist_list);
 127         }
 128         else
 129                 blptr->status &= ~CONF_ILLEGAL;
 130         strlcpy(blptr->host, name, HOSTLEN);
 131         strlcpy(blptr->reject_reason, reject_reason, IRCD_BUFSIZE);
 132
 133         return blptr;
 134 }
 135
 136 void unref_blacklist(struct Blacklist *blptr)
 137 {
 138         blptr->refcount--;
 139         if (blptr->status & CONF_ILLEGAL && blptr->refcount <= 0)
 140         {
 141                 dlinkFindDestroy(blptr, &blacklist_list);
 142                 MyFree(blptr);
 143         }
 144 }
 145
 146 void lookup_blacklists(struct Client *client_p)
 147 {
 148         dlink_node *nptr;
 149
 150         /* We don't do IPv6 right now, sorry! */
 151         if (client_p->localClient->ip.ss_family == AF_INET6)
 152                 return;
 153
 154         DLINK_FOREACH(nptr, blacklist_list.head)
 155         {
 156                 struct Blacklist *blptr = (struct Blacklist *) nptr->data;
 157
 158                 if (!(blptr->status & CONF_ILLEGAL))
 159                         initiate_blacklist_dnsquery(blptr, client_p);
 160         }
 161 }
 162
 163 void abort_blacklist_queries(struct Client *client_p)
 164 {
 165         dlink_node *ptr, *next_ptr;
 166         struct BlacklistClient *blcptr;
 167
 168         if (client_p->preClient == NULL)
 169                 return;
 170         DLINK_FOREACH_SAFE(ptr, next_ptr, client_p->preClient->dnsbl_queries.head)
 171         {
 172                 blcptr = ptr->data;
 173                 dlinkDelete(&blcptr->node, &client_p->preClient->dnsbl_queries);
 174                 unref_blacklist(blcptr->blacklist);
 175                 delete_resolver_queries(&blcptr->dns_query);
 176                 MyFree(blcptr);
 177         }
 178 }
 179
 180 void destroy_blacklists(void)
 181 {
 182         dlink_node *ptr, *next_ptr;
 183         struct Blacklist *blptr;
 184
 185         DLINK_FOREACH_SAFE(ptr, next_ptr, blacklist_list.head)
 186         {
 187                 blptr = ptr->data;
 188                 blptr->hits = 0; /* keep it simple and consistent */
 189                 if (blptr->refcount > 0)
 190                         blptr->status |= CONF_ILLEGAL;
 191                 else
 192                 {
 193                         MyFree(ptr->data);
 194                         dlinkDestroy(ptr, &blacklist_list);
 195                 }
 196         }
 197 }