src/dnsqueue.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
   6  *                       E-mail:
   7  *                <brain@chatspike.net>
   8  *                <Craig@chatspike.net>
   9  *
  10  * Written by Craig Edwards, Craig McLure, and others.
  11  * This program is free but copyrighted software; see
  12  *            the file COPYING for details.
  13  *
  14  * ---------------------------------------------------
  15  */
  16
  17 using namespace std;
  18
  19 #include "inspircd_config.h"
  20 #include "inspircd.h"
  21 #include "inspircd_io.h"
  22 #include <unistd.h>
  23 #include <sys/errno.h>
  24 #include <sys/ioctl.h>
  25 #include <sys/utsname.h>
  26 #include <cstdio>
  27 #include <time.h>
  28 #include <string>
  29 #ifdef GCC3
  30 #include <ext/hash_map>
  31 #else
  32 #include <hash_map>
  33 #endif
  34 #include <map>
  35 #include <sstream>
  36 #include <vector>
  37 #include <deque>
  38 #include "users.h"
  39 #include "globals.h"
  40 #include "inspstring.h"
  41 #include "dnsqueue.h"
  42 #include <time.h>
  43 #include <sys/types.h>
  44 #include <sys/socket.h>
  45 #include <sys/time.h>
  46 #include <netinet/in.h>
  47 #include <string.h>
  48 #include "dns.h"
  49 #include "helperfuncs.h"
  50 #include "hashcomp.h"
  51 #include "socketengine.h"
  52
  53 extern ServerConfig* Config;
  54 extern InspIRCd* ServerInstance;
  55
  56 address_cache addrcache;
  57
  58 class Lookup;
  59
  60 Lookup* dnslist[MAX_DESCRIPTORS];
  61
  62 //enum LookupState { reverse, forward };
  63
  64 class Lookup {
  65 private:
  66         DNS resolver1;
  67         DNS resolver2;
  68         char u[NICKMAX];
  69         std::string hostname;
  70 public:
  71         Lookup()
  72         {
  73                 *u = 0;
  74         }
  75
  76         void Reset()
  77         {
  78                 *u = 0;
  79         }
  80
  81         ~Lookup()
  82         {
  83         }
  84
  85         bool DoLookup(std::string nick)
  86         {
  87                 hostname = "";
  88                 userrec* usr = Find(nick);
  89                 if (usr)
  90                 {
  91                         resolver1.SetNS(std::string(Config->DNSServer));
  92                         if (!resolver1.ReverseLookup(std::string(usr->host)))
  93                         {
  94                                 return false;
  95                         }
  96                         strlcpy(u,nick.c_str(),NICKMAX);
  97
  98                         /* ASSOCIATE WITH DNS LOOKUP LIST */
  99                         if (resolver1.GetFD() != -1)
 100                         {
 101                                 dnslist[resolver1.GetFD()] = this;
 102                                 return true;
 103                         }
 104                 }
 105                 return false;
 106         }
 107
 108         bool Done(int fdcheck)
 109         {
 110                 if (hostname != "")
 111                 {
 112                         // doing forward lookup
 113                         userrec* usr = NULL;
 114                         if (resolver2.HasResult(fdcheck))
 115                         {
 116                                 if (resolver2.GetFD() != -1)
 117                                 {
 118                                         dnslist[resolver2.GetFD()] = NULL;
 119                                         std::string ip = resolver2.GetResultIP();
 120                                         usr = Find(u);
 121                                         if (usr)
 122                                         {
 123                                                 if (usr->registered > 3)
 124                                                 {
 125                                                         usr->dns_done = true;
 126                                                         return true;
 127                                                 }
 128                                                 if ((hostname != "") && (usr->registered != 7))
 129                                                 {
 130                                                         if (std::string((char*)inet_ntoa(usr->ip4)) == ip)
 131                                                         {
 132                                                                 strlcpy(usr->host,hostname.c_str(),MAXBUF);
 133                                                                 strlcpy(usr->dhost,hostname.c_str(),MAXBUF);
 134                                                                 address_hash::iterator address = addrcache.find(usr->ip4);
 135                                                                 if (address == addrcache.end())
 136                                                                 {
 137                                                                         log(DEBUG,"Caching hostname %s -> %s",(char*)inet_ntoa(usr->ip4),hostname.c_str());
 138                                                                         addrcache[usr->ip4] = new std::string(hostname);
 139                                                                 }
 140                                                         }
 141                                                         usr->dns_done = true;
 142                                                         return true;
 143                                                 }
 144                                         }
 145                                 }
 146                                 else
 147                                 {
 148                                         usr = Find(u);
 149                                         if (usr)
 150                                         {
 151                                                 usr->dns_done = true;
 152                                         }
 153                                         return true;
 154                                 }
 155                         }
 156                         return false;
 157                 }
 158                 else
 159                 {
 160                         // doing reverse lookup
 161                         userrec* usr = NULL;
 162                         if (resolver1.HasResult(fdcheck))
 163                         {
 164                                 usr = Find(u);
 165                                 if ((usr) && (usr->dns_done))
 166                                 {
 167                                         if (resolver1.GetFD() != -1)
 168                                                 dnslist[resolver1.GetFD()] = NULL;
 169                                         return true;
 170                                 }
 171                                 if (resolver1.GetFD() != -1)
 172                                 {
 173                                         dnslist[resolver1.GetFD()] = NULL;
 174                                         hostname = resolver1.GetResult();
 175                                         if (usr)
 176                                         {
 177                                                 if ((usr->registered > 3) || (hostname == ""))
 178                                                 {
 179                                                         usr->dns_done = true;
 180                                                         return true;
 181                                                 }
 182                                         }
 183                                         if (hostname != "")
 184                                         {
 185                                                 resolver2.ForwardLookup(hostname);
 186                                                 if (resolver2.GetFD() != -1)
 187                                                         dnslist[resolver2.GetFD()] = this;
 188                                         }
 189                                 }
 190                         }
 191                 }
 192                 return false;
 193         }
 194
 195         int GetFD()
 196         {
 197                 userrec* usr = Find(u);
 198                 if (!usr)
 199                         return 0;
 200                 if (usr->dns_done)
 201                         return 0;
 202                 return usr->fd;
 203         }
 204 };
 205
 206 bool lookup_dns(std::string nick)
 207 {
 208         /* First attempt to find the nickname */
 209         userrec* u = Find(nick);
 210         if (u)
 211         {
 212                 /* Check the cache */
 213                 address_hash::iterator address = addrcache.find(u->ip4);
 214                 if (address != addrcache.end())
 215                 {
 216                         /* Theyre in the cache, dont waste a lookup */
 217                         WriteServ(u->fd,"NOTICE Auth :*** Found your hostname (cached)");
 218                         log(DEBUG,"Found cached host");
 219                         strlcpy(u->host,address->second->c_str(),MAXBUF);
 220                         strlcpy(u->dhost,address->second->c_str(),MAXBUF);
 221                         u->dns_done = true;
 222                         return true;
 223                 }
 224                 /* If the user exists, create a new
 225                  * lookup object, and associate it
 226                  * with the user. The lookup object
 227                  * will maintain the reference table
 228                  * which we use for quickly finding
 229                  * dns results. Please note that we
 230                  * do not associate a lookup with a
 231                  * userrec* pointer and we use the
 232                  * nickname instead because, by the
 233                  * time the DNS lookup has completed,
 234                  * the nickname could have quit and
 235                  * if we then try and access the
 236                  * pointer we get a nice segfault.
 237                  */
 238                 Lookup* L = new Lookup();
 239                 L->DoLookup(nick);
 240                 return true;
 241         }
 242         return false;
 243 }
 244
 245 void dns_poll(int fdcheck)
 246 {
 247         /* Check the given file descriptor is in valid range */
 248         if ((fdcheck < 0) || (fdcheck > MAX_DESCRIPTORS))
 249                 return;
 250
 251         /* Try and find the file descriptor in our list of
 252          * active DNS lookups
 253          */
 254         Lookup *x = dnslist[fdcheck];
 255         if (x)
 256         {
 257                 /* If it exists check if its a valid fd still */
 258                 if (x->GetFD() != -1)
 259                 {
 260                         /* Check if its done, if it is delete it */
 261                         if (x->Done(fdcheck))
 262                         {
 263                                 /* We don't need to delete the file descriptor
 264                                  * from the socket engine, as dns.cpp tracks it
 265                                  * for us if we are in single-threaded country.
 266                                  */
 267                                 delete x;
 268                         }
 269                 }
 270                 else
 271                 {
 272                         /* its fd is dodgy, the dns code probably
 273                          * bashed it due to error. Free the class.
 274                          */
 275                         delete x;
 276                 }
 277                 /* If we got down here, the dns lookup was valid, BUT,
 278                  * its still in progress. Be patient, and wait for
 279                  * more socketengine events to complete the lookups.
 280                  */
 281                 return;
 282         }
 283         /* This FD doesnt belong here, lets be rid of it,
 284          * just to be safe so we dont get any more events
 285          * about it.
 286          */
 287         if (ServerInstance && ServerInstance->SE)
 288                 ServerInstance->SE->DelFd(fdcheck);
 289 }
 290