]> git.netwichtig.de Git - user/henk/code/inspircd.git/blobdiff - src/dns.cpp
2.0.1 release
[user/henk/code/inspircd.git] / src / dns.cpp
index 718a1698f0bb000d552d37043d5b4e1e0c5cb628..945e1fb15c296577fce48a7c017fba18c0624f9d 100644 (file)
@@ -2,7 +2,7 @@
  *       | Inspire Internet Relay Chat Daemon |
  *       +------------------------------------+
  *
- *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
+ *  InspIRCd: (C) 2002-2010 InspIRCd Development Team
  * See: http://wiki.inspircd.org/Credits
  *
  * This program is free but copyrighted software; see
@@ -147,6 +147,17 @@ class RequestTimeout : public Timer
        }
 };
 
+CachedQuery::CachedQuery(const std::string &res, unsigned int ttl) : data(res)
+{
+       expires = ServerInstance->Time() + ttl;
+}
+
+int CachedQuery::CalcTTLRemaining()
+{
+       int n = expires - ServerInstance->Time();
+       return (n < 0 ? 0 : n);
+}
+
 /* Allocate the processing buffer */
 DNSRequest::DNSRequest(DNS* dns, int rid, const std::string &original) : dnsobj(dns)
 {
@@ -216,26 +227,8 @@ int DNSRequest::SendRequests(const DNSHeader *header, const int length, QueryTyp
 
        DNS::EmptyHeader(payload,header,length);
 
-       if (this->dnsobj->socketfamily == AF_INET6)
-       {
-               sockaddr_in6 addr;
-               memset(&addr,0,sizeof(addr));
-               memcpy(&addr.sin6_addr,&dnsobj->myserver6,sizeof(addr.sin6_addr));
-               addr.sin6_family = AF_INET6;
-               addr.sin6_port = htons(DNS::QUERY_PORT);
-               if (ServerInstance->SE->SendTo(dnsobj, payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) != length+12)
-                       return -1;
-       }
-       else
-       {
-               sockaddr_in addr;
-               memset(&addr,0,sizeof(addr));
-               memcpy(&addr.sin_addr.s_addr,&dnsobj->myserver4,sizeof(addr.sin_addr));
-               addr.sin_family = AF_INET;
-               addr.sin_port = htons(DNS::QUERY_PORT);
-               if (ServerInstance->SE->SendTo(dnsobj, (const char*)payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) != length+12)
-                       return -1;
-       }
+       if (ServerInstance->SE->SendTo(dnsobj, payload, length + 12, 0, &(dnsobj->myserver.sa), sa_size(dnsobj->myserver)) != length+12)
+               return -1;
 
        ServerInstance->Logs->Log("RESOLVER",DEBUG,"Sent OK");
        return 0;
@@ -249,11 +242,9 @@ DNSRequest* DNS::AddQuery(DNSHeader *header, int &id, const char* original)
                return NULL;
 
        /* Create an id */
-       id = this->PRNG() & DNS::MAX_REQUEST_ID;
-
-       /* If this id is already 'in flight', pick another. */
-       while (requests[id])
-               id = this->PRNG() & DNS::MAX_REQUEST_ID;
+       do {
+               id = ServerInstance->GenRandomInt(DNS::MAX_REQUEST_ID);
+       } while (requests[id]);
 
        DNSRequest* req = new DNSRequest(this, id, original);
 
@@ -302,13 +293,9 @@ int DNS::PruneCache()
 
 void DNS::Rehash()
 {
-       ip6munge = false;
-       int portpass = 0;
-
        if (this->GetFd() > -1)
        {
-               if (ServerInstance && ServerInstance->SE)
-                       ServerInstance->SE->DelFd(this);
+               ServerInstance->SE->DelFd(this);
                ServerInstance->SE->Shutdown(this, 2);
                ServerInstance->SE->Close(this);
                this->SetFd(-1);
@@ -322,62 +309,39 @@ void DNS::Rehash()
                this->cache = new dnscache();
        }
 
-       if ((strstr(ServerInstance->Config->DNSServer,"::ffff:") == (char*)&ServerInstance->Config->DNSServer) ||  (strstr(ServerInstance->Config->DNSServer,"::FFFF:") == (char*)&ServerInstance->Config->DNSServer))
-       {
-               ServerInstance->Logs->Log("RESOLVER",DEFAULT,"WARNING: Using IPv4 addresses over IPv6 forces some DNS checks to be disabled.");
-               ServerInstance->Logs->Log("RESOLVER",DEFAULT,"         This should not cause a problem, however it is recommended you migrate");
-               ServerInstance->Logs->Log("RESOLVER",DEFAULT,"         to a true IPv6 environment.");
-               this->ip6munge = true;
-       }
-
-       this->socketfamily = AF_INET;
-       if (strchr(ServerInstance->Config->DNSServer,':'))
-       {
-               this->socketfamily = AF_INET6;
-               inet_pton(AF_INET6, ServerInstance->Config->DNSServer, &this->myserver6);
-       }
-       else
-       {
-               inet_aton(ServerInstance->Config->DNSServer, &this->myserver4);
-               portpass = -1;
-       }
+       irc::sockets::aptosa(ServerInstance->Config->DNSServer, DNS::QUERY_PORT, myserver);
 
        /* Initialize mastersocket */
-       int s = irc::sockets::OpenTCPSocket(ServerInstance->Config->DNSServer, SOCK_DGRAM);
+       int s = socket(myserver.sa.sa_family, SOCK_DGRAM, 0);
        this->SetFd(s);
-       ServerInstance->SE->NonBlocking(this->GetFd());
 
        /* Have we got a socket and is it nonblocking? */
        if (this->GetFd() != -1)
        {
-               /* Bind the port - port 0 INADDR_ANY */
-               if (!ServerInstance->BindSocket(this->GetFd(), portpass, "", false))
+               ServerInstance->SE->SetReuse(s);
+               ServerInstance->SE->NonBlocking(s);
+               irc::sockets::sockaddrs bindto;
+               memset(&bindto, 0, sizeof(bindto));
+               bindto.sa.sa_family = myserver.sa.sa_family;
+               if (ServerInstance->SE->Bind(this->GetFd(), bindto) < 0)
                {
                        /* Failed to bind */
-                       ServerInstance->Logs->Log("RESOLVER",DEBUG,"Error binding dns socket");
+                       ServerInstance->Logs->Log("RESOLVER",SPARSE,"Error binding dns socket - hostnames will NOT resolve");
                        ServerInstance->SE->Shutdown(this, 2);
                        ServerInstance->SE->Close(this);
                        this->SetFd(-1);
                }
-
-               if (this->GetFd() >= 0)
+               else if (!ServerInstance->SE->AddFd(this, FD_WANT_POLL_READ | FD_WANT_NO_WRITE))
                {
-                       /* Hook the descriptor into the socket engine */
-                       if (ServerInstance && ServerInstance->SE)
-                       {
-                               if (!ServerInstance->SE->AddFd(this, FD_WANT_POLL_READ | FD_WANT_NO_WRITE))
-                               {
-                                       ServerInstance->Logs->Log("RESOLVER",DEFAULT,"Internal error starting DNS - hostnames will NOT resolve.");
-                                       ServerInstance->SE->Shutdown(this, 2);
-                                       ServerInstance->SE->Close(this);
-                                       this->SetFd(-1);
-                               }
-                       }
+                       ServerInstance->Logs->Log("RESOLVER",SPARSE,"Internal error starting DNS - hostnames will NOT resolve.");
+                       ServerInstance->SE->Shutdown(this, 2);
+                       ServerInstance->SE->Close(this);
+                       this->SetFd(-1);
                }
        }
        else
        {
-               ServerInstance->Logs->Log("RESOLVER",DEBUG,"Error creating dns socket");
+               ServerInstance->Logs->Log("RESOLVER",SPARSE,"Error creating DNS socket - hostnames will NOT resolve");
        }
 }
 
@@ -520,8 +484,11 @@ int DNS::GetNameForce(const char *ip, ForceProtocol fp)
                        DNS::MakeIP6Int(query, &i);
                }
                else
+               {
+                       ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce IPv6 bad format for '%s'", ip);
                        /* Invalid IP address */
                        return -1;
+               }
        }
        else
        {
@@ -532,17 +499,33 @@ int DNS::GetNameForce(const char *ip, ForceProtocol fp)
                        sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]);
                }
                else
+               {
+                       ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce IPv4 bad format for '%s'", ip);
                        /* Invalid IP address */
                        return -1;
+               }
        }
 
-       if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1)
+       length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload);
+       if (length == -1)
+       {
+               ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce can't query '%s' using '%s' because it's too long", ip, query);
                return -1;
+       }
 
        DNSRequest* req = this->AddQuery(&h, id, ip);
 
-       if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
+       if (!req)
+       {
+               ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce can't add query (resolver down?)");
+               return -1;
+       }
+
+       if (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1)
+       {
+               ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce can't send (firewall?)");
                return -1;
+       }
 
        return id;
 }
@@ -573,15 +556,15 @@ DNSResult DNS::GetResult()
        DNSRequest *req;
        unsigned char buffer[sizeof(DNSHeader)];
        irc::sockets::sockaddrs from;
-       socklen_t x = this->socketfamily == AF_INET ? sizeof(sockaddr_in) : sizeof(sockaddr_in6);
-       const char* ipaddr_from;
-       unsigned short int port_from = 0;
+       memset(&from, 0, sizeof(from));
+       socklen_t x = sizeof(from);
 
        int length = ServerInstance->SE->RecvFrom(this, (char*)buffer, sizeof(DNSHeader), 0, &from.sa, &x);
 
        /* Did we get the whole header? */
        if (length < 12)
        {
+               ServerInstance->Logs->Log("RESOLVER",DEBUG,"GetResult didn't get a full packet (len=%d)", length);
                /* Nope - something screwed up. */
                return DNSResult(-1,"",0,"");
        }
@@ -591,31 +574,15 @@ DNSResult DNS::GetResult()
         * is not 53.
         * A user could in theory still spoof dns packets anyway
         * but this is less trivial than just sending garbage
-        * to the client, which is possible without this check.
+        * to the server, which is possible without this check.
         *
         * -- Thanks jilles for pointing this one out.
         */
-       char nbuf[MAXBUF];
-       if (this->socketfamily == AF_INET6)
-       {
-               ipaddr_from = inet_ntop(AF_INET6, &from.in6.sin6_addr, nbuf, sizeof(nbuf));
-               port_from = ntohs(from.in6.sin6_port);
-       }
-       else
-       {
-               ipaddr_from = inet_ntoa(from.in4.sin_addr);
-               port_from = ntohs(from.in4.sin_port);
-       }
-
-       /* We cant perform this security check if you're using 4in6.
-        * Tough luck to you, choose one or't other!
-        */
-       if (!ip6munge)
+       if (from != myserver)
        {
-               if ((port_from != DNS::QUERY_PORT) || (strcasecmp(ipaddr_from, ServerInstance->Config->DNSServer)))
-               {
-                       return DNSResult(-1,"",0,"");
-               }
+               ServerInstance->Logs->Log("RESOLVER",DEBUG,"Got a result from the wrong server! Bad NAT or DNS forging attempt? '%s' != '%s'",
+                       from.str().c_str(), myserver.str().c_str());
+               return DNSResult(-1,"",0,"");
        }
 
        /* Put the read header info into a header class */
@@ -631,6 +598,7 @@ DNSResult DNS::GetResult()
        if (!requests[this_id])
        {
                /* Somehow we got a DNS response for a request we never made... */
+               ServerInstance->Logs->Log("RESOLVER",DEBUG,"Hmm, got a result that we didn't ask for (id=%lx). Ignoring.", this_id);
                return DNSResult(-1,"",0,"");
        }
        else
@@ -945,15 +913,13 @@ Resolver::Resolver(const std::string &source, QueryType qt, bool &cached, Module
                break;
 
                default:
+                       ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS request with unknown query type %d", querytype);
                        this->myid = -1;
                break;
        }
        if (this->myid == -1)
        {
-               this->OnError(RESOLVER_NSDOWN, "Nameserver is down");
-               throw ModuleException("Resolver: Couldnt get an id to make a request");
-               /* We shouldnt get here really */
-               return;
+               throw ModuleException("Resolver: Couldn't get an id to make a request");
        }
        else
        {
@@ -1085,16 +1051,3 @@ void DNS::CleanResolvers(Module* module)
                }
        }
 }
-
-/** Generate pseudo-random number */
-unsigned long DNS::PRNG()
-{
-       unsigned long val = 0;
-       timeval n;
-       serverstats* s = ServerInstance->stats;
-       gettimeofday(&n,NULL);
-       val = (n.tv_usec ^ (getpid() ^ geteuid()) ^ ((this->currid++)) ^ s->statsAccept) + n.tv_sec;
-       val = val + (s->statsCollisions ^ s->statsDnsGood) - s->statsDnsBad;
-       val += (s->statsConnects ^ (unsigned long)s->statsSent ^ (unsigned long)s->statsRecv) - ServerInstance->ports.size();
-       return val;
-}