1 /* +------------------------------------+
2 * | Inspire Internet Relay Chat Daemon |
3 * +------------------------------------+
5 * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
7 * <brain@chatspike.net>
8 * <Craig@chatspike.net>
10 * Written by Craig Edwards, Craig McLure, and others.
11 * This program is free but copyrighted software; see
12 * the file COPYING for details.
14 * ---------------------------------------------------
18 dns.cpp - Nonblocking DNS functions.
19 Very very loosely based on the firedns library,
20 Copyright (C) 2002 Ian Gulliver. This file is no
21 longer anything like firedns, there are many major
22 differences between this code and the original.
23 Please do not assume that firedns works like this,
24 looks like this, walks like this or tastes like this.
29 #include <sys/types.h>
30 #include <sys/socket.h>
32 #include <netinet/in.h>
33 #include <arpa/inet.h>
36 #include "socketengine.h"
37 #include "configreader.h"
41 using irc::sockets::insp_sockaddr;
42 using irc::sockets::insp_inaddr;
43 using irc::sockets::insp_ntoa;
44 using irc::sockets::insp_aton;
46 /** Masks to mask off the responses we get from the DNSRequest methods
50 ERROR_MASK = 0x10000 /* Result is an error */
53 /** Flags which can be ORed into a request or reply for different meanings
57 FLAGS_MASK_RD = 0x01, /* Recursive */
59 FLAGS_MASK_AA = 0x04, /* Authoritative */
60 FLAGS_MASK_OPCODE = 0x78,
62 FLAGS_MASK_RCODE = 0x0F, /* Request */
68 /** Represents a dns resource record (rr)
73 QueryType type; /* Record type */
74 unsigned int rr_class; /* Record class */
75 unsigned long ttl; /* Time to live */
76 unsigned int rdlength; /* Record length */
79 /** Represents a dns request/reply header, and its payload as opaque data.
84 unsigned char id[2]; /* Request id */
85 unsigned int flags1; /* Flags */
86 unsigned int flags2; /* Flags */
88 unsigned int ancount; /* Answer count */
89 unsigned int nscount; /* Nameserver count */
91 unsigned char payload[512]; /* Packet payload */
97 unsigned char id[2]; /* Request id */
98 unsigned char* res; /* Result processing buffer */
99 unsigned int rr_class; /* Request class */
100 QueryType type; /* Request type */
101 insp_inaddr myserver; /* DNS server address*/
102 DNS* dnsobj; /* DNS caller (where we get our FD from) */
104 DNSRequest(InspIRCd* Instance, DNS* dns, insp_inaddr server, int id, requestlist &requests);
106 DNSInfo ResultIsReady(DNSHeader &h, int length);
107 int SendRequests(const DNSHeader *header, const int length, QueryType qt);
110 class RequestTimeout : public InspTimer
112 InspIRCd* ServerInstance;
117 RequestTimeout(InspIRCd* SI, DNSRequest* watching, int id, requestlist &requests) : InspTimer(2, time(NULL)), ServerInstance(SI), watch(watching), watchid(id), rl(requests)
119 ServerInstance->Log(DEBUG, "New DNS timeout set on %08x", watching);
122 void Tick(time_t TIME)
124 if (rl.find(watchid) != rl.end())
126 /* Still exists, whack it */
127 if (rl.find(watchid)->second == watch)
129 if (ServerInstance->Res->Classes[watchid])
131 ServerInstance->Res->Classes[watchid]->OnError(RESOLVER_TIMEOUT, "Request timed out");
132 delete ServerInstance->Res->Classes[watchid];
133 ServerInstance->Res->Classes[watchid] = NULL;
135 rl.erase(rl.find(watchid));
137 ServerInstance->Log(DEBUG, "DNS timeout on %08x squished pointer", watch);
141 ServerInstance->Log(DEBUG, "DNS timeout on %08x: result already received!", watch);
145 /* Allocate the processing buffer */
146 DNSRequest::DNSRequest(InspIRCd* Instance, DNS* dns, insp_inaddr server, int id, requestlist &requests) : dnsobj(dns)
148 res = new unsigned char[512];
150 memcpy(&myserver, &server, sizeof(insp_inaddr));
151 RequestTimeout* RT = new RequestTimeout(Instance, this, id, requests);
152 Instance->Timers->AddTimer(RT); /* The timer manager frees this */
155 /* Deallocate the processing buffer */
156 DNSRequest::~DNSRequest()
161 /** Fill a ResourceRecord class based on raw data input */
162 inline void DNS::FillResourceRecord(ResourceRecord* rr, const unsigned char *input)
164 rr->type = (QueryType)((input[0] << 8) + input[1]);
165 rr->rr_class = (input[2] << 8) + input[3];
166 rr->ttl = (input[4] << 24) + (input[5] << 16) + (input[6] << 8) + input[7];
167 rr->rdlength = (input[8] << 8) + input[9];
170 /** Fill a DNSHeader class based on raw data input of a given length */
171 inline void DNS::FillHeader(DNSHeader *header, const unsigned char *input, const int length)
173 header->id[0] = input[0];
174 header->id[1] = input[1];
175 header->flags1 = input[2];
176 header->flags2 = input[3];
177 header->qdcount = (input[4] << 8) + input[5];
178 header->ancount = (input[6] << 8) + input[7];
179 header->nscount = (input[8] << 8) + input[9];
180 header->arcount = (input[10] << 8) + input[11];
181 memcpy(header->payload,&input[12],length);
184 /** Empty a DNSHeader class out into raw data, ready for transmission */
185 inline void DNS::EmptyHeader(unsigned char *output, const DNSHeader *header, const int length)
187 output[0] = header->id[0];
188 output[1] = header->id[1];
189 output[2] = header->flags1;
190 output[3] = header->flags2;
191 output[4] = header->qdcount >> 8;
192 output[5] = header->qdcount & 0xFF;
193 output[6] = header->ancount >> 8;
194 output[7] = header->ancount & 0xFF;
195 output[8] = header->nscount >> 8;
196 output[9] = header->nscount & 0xFF;
197 output[10] = header->arcount >> 8;
198 output[11] = header->arcount & 0xFF;
199 memcpy(&output[12],header->payload,length);
202 /** Send requests we have previously built down the UDP socket */
203 int DNSRequest::SendRequests(const DNSHeader *header, const int length, QueryType qt)
206 unsigned char payload[sizeof(DNSHeader)];
211 DNS::EmptyHeader(payload,header,length);
213 memset(&addr,0,sizeof(addr));
215 memcpy(&addr.sin6_addr,&myserver,sizeof(addr.sin6_addr));
216 addr.sin6_family = AF_FAMILY;
217 addr.sin6_port = htons(DNS::QUERY_PORT);
219 memcpy(&addr.sin_addr.s_addr,&myserver,sizeof(addr.sin_addr));
220 addr.sin_family = AF_FAMILY;
221 addr.sin_port = htons(DNS::QUERY_PORT);
223 if (sendto(dnsobj->GetFd(), payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) == -1)
229 /** Add a query with a predefined header, and allocate an ID for it. */
230 DNSRequest* DNS::AddQuery(DNSHeader *header, int &id)
232 /* Is the DNS connection down? */
233 if (this->GetFd() == -1)
236 /* Are there already the max number of requests on the go? */
237 if (requests.size() == DNS::MAX_REQUEST_ID + 1)
241 id = this->PRNG() & DNS::MAX_REQUEST_ID;
243 /* If this id is already 'in flight', pick another. */
244 while (requests.find(id) != requests.end())
245 id = this->PRNG() & DNS::MAX_REQUEST_ID;
247 DNSRequest* req = new DNSRequest(ServerInstance, this, this->myserver, id, requests);
249 header->id[0] = req->id[0] = id >> 8;
250 header->id[1] = req->id[1] = id & 0xFF;
251 header->flags1 = FLAGS_MASK_RD;
258 /* At this point we already know the id doesnt exist,
259 * so there needs to be no second check for the ::end()
263 /* According to the C++ spec, new never returns NULL. */
267 /** Initialise the DNS UDP socket so that we can send requests */
268 DNS::DNS(InspIRCd* Instance) : ServerInstance(Instance)
270 ServerInstance->Log(DEBUG,"DNS::DNS: Instance = %08x",Instance);
274 /* Clear the Resolver class table */
275 memset(Classes,0,sizeof(Classes));
277 /* Set the id of the next request to 0
281 /* By default we're not munging ip's
285 /* Clear the namesever address */
286 memset(&myserver,0,sizeof(insp_inaddr));
288 /* Convert the nameserver address into an insp_inaddr */
289 if (insp_aton(ServerInstance->Config->DNSServer,&addr) > 0)
291 memcpy(&myserver,&addr,sizeof(insp_inaddr));
292 if ((strstr(ServerInstance->Config->DNSServer,"::ffff:") == (char*)&ServerInstance->Config->DNSServer) || (strstr(ServerInstance->Config->DNSServer,"::FFFF:") == (char*)&ServerInstance->Config->DNSServer))
294 /* These dont come back looking like they did when they went in.
295 * We're forced to turn some checks off.
296 * If anyone knows how to fix this, let me know. --Brain
298 ServerInstance->Log(DEFAULT,"WARNING: Using IPv4 addresses over IPv6 forces some DNS checks to be disabled.");
299 ServerInstance->Log(DEFAULT," This should not cause a problem, however it is recommended you migrate");
300 ServerInstance->Log(DEFAULT," to a true IPv6 environment.");
301 this->ip6munge = true;
303 ServerInstance->Log(DEBUG,"Added nameserver '%s'",ServerInstance->Config->DNSServer);
307 ServerInstance->Log(DEBUG,"GACK! insp_aton says the nameserver '%s' is invalid!",ServerInstance->Config->DNSServer);
310 /* Initialize mastersocket */
311 this->SetFd(socket(PF_PROTOCOL, SOCK_DGRAM, 0));
312 if (this->GetFd() != -1)
314 /* Did it succeed? */
315 if (fcntl(this->GetFd(), F_SETFL, O_NONBLOCK) != 0)
317 /* Couldn't make the socket nonblocking */
318 shutdown(this->GetFd(),2);
319 close(this->GetFd());
325 ServerInstance->Log(DEBUG,"I cant socket() this socket! (%s)",strerror(errno));
327 /* Have we got a socket and is it nonblocking? */
328 if (this->GetFd() != -1)
332 memset(&addr,0,sizeof(addr));
333 addr.sin6_family = AF_FAMILY;
335 addr.sin6_addr = in6addr_any;
338 memset(&addr,0,sizeof(addr));
339 addr.sin_family = AF_FAMILY;
341 addr.sin_addr.s_addr = INADDR_ANY;
344 if (bind(this->GetFd(),(sockaddr *)&addr,sizeof(addr)) != 0)
347 ServerInstance->Log(DEBUG,"Cant bind DNS fd");
348 shutdown(this->GetFd(),2);
349 close(this->GetFd());
353 if (this->GetFd() >= 0)
355 ServerInstance->Log(DEBUG,"Add master socket %d",this->GetFd());
356 /* Hook the descriptor into the socket engine */
357 if (ServerInstance && ServerInstance->SE)
359 if (!ServerInstance->SE->AddFd(this))
361 ServerInstance->Log(DEFAULT,"Internal error starting DNS - hostnames will NOT resolve.");
362 shutdown(this->GetFd(),2);
363 close(this->GetFd());
371 /** Build a payload to be placed after the header, based upon input data, a resource type, a class and a pointer to a buffer */
372 int DNS::MakePayload(const char * const name, const QueryType rr, const unsigned short rr_class, unsigned char * const payload)
374 short payloadpos = 0;
375 const char* tempchr, *tempchr2 = name;
376 unsigned short length;
378 /* split name up into labels, create query */
379 while ((tempchr = strchr(tempchr2,'.')) != NULL)
381 length = tempchr - tempchr2;
382 if (payloadpos + length + 1 > 507)
384 payload[payloadpos++] = length;
385 memcpy(&payload[payloadpos],tempchr2,length);
386 payloadpos += length;
387 tempchr2 = &tempchr[1];
389 length = strlen(tempchr2);
392 if (payloadpos + length + 2 > 507)
394 payload[payloadpos++] = length;
395 memcpy(&payload[payloadpos],tempchr2,length);
396 payloadpos += length;
397 payload[payloadpos++] = 0;
399 if (payloadpos > 508)
402 memcpy(&payload[payloadpos],&length,2);
403 length = htons(rr_class);
404 memcpy(&payload[payloadpos + 2],&length,2);
405 return payloadpos + 4;
408 /** Start lookup of an hostname to an IP address */
409 int DNS::GetIP(const char *name)
415 if ((length = this->MakePayload(name, DNS_QUERY_A, 1, (unsigned char*)&h.payload)) == -1)
418 DNSRequest* req = this->AddQuery(&h, id);
420 if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_A) == -1))
426 /** Start lookup of an hostname to an IPv6 address */
427 int DNS::GetIP6(const char *name)
433 if ((length = this->MakePayload(name, DNS_QUERY_AAAA, 1, (unsigned char*)&h.payload)) == -1)
436 DNSRequest* req = this->AddQuery(&h, id);
438 if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_AAAA) == -1))
444 /** Start lookup of a cname to another name */
445 int DNS::GetCName(const char *alias)
451 if ((length = this->MakePayload(alias, DNS_QUERY_CNAME, 1, (unsigned char*)&h.payload)) == -1)
454 DNSRequest* req = this->AddQuery(&h, id);
456 if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_CNAME) == -1))
462 /** Start lookup of an IP address to a hostname */
463 int DNS::GetName(const insp_inaddr *ip)
471 DNS::MakeIP6Int(query, (in6_addr*)ip);
473 unsigned char* c = (unsigned char*)&ip->s_addr;
475 sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]);
478 if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1)
481 DNSRequest* req = this->AddQuery(&h, id);
483 if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
489 /** Start lookup of an IP address to a hostname */
490 int DNS::GetNameForce(const char *ip, ForceProtocol fp)
496 #ifdef SUPPORT_IP6LINKS
497 if (fp == PROTOCOL_IPV6)
500 if (inet_pton(AF_INET6, ip, &i) > 0)
502 DNS::MakeIP6Int(query, &i);
505 /* Invalid IP address */
512 if (inet_aton(ip, &i))
514 unsigned char* c = (unsigned char*)&i.s_addr;
515 sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]);
518 /* Invalid IP address */
522 ServerInstance->Log(DEBUG,"DNS::GetNameForce: %s %d",query, fp);
524 if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1)
527 DNSRequest* req = this->AddQuery(&h, id);
529 if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
535 /** Build an ipv6 reverse domain from an in6_addr
537 void DNS::MakeIP6Int(char* query, const in6_addr *ip)
539 #ifdef SUPPORT_IP6LINKS
540 const char* hex = "0123456789abcdef";
541 for (int index = 31; index >= 0; index--) /* for() loop steps twice per byte */
545 *query++ = hex[ip->s6_addr[index / 2] & 0x0F];
548 *query++ = hex[(ip->s6_addr[index / 2] & 0xF0) >> 4];
549 *query++ = '.'; /* Seperator */
551 strcpy(query,"ip6.arpa"); /* Suffix the string */
557 /** Return the next id which is ready, and the result attached to it */
558 DNSResult DNS::GetResult()
560 /* Fetch dns query response and decide where it belongs */
563 unsigned char buffer[sizeof(DNSHeader)];
565 socklen_t x = sizeof(from);
566 const char* ipaddr_from = "";
567 unsigned short int port_from = 0;
569 int length = recvfrom(this->GetFd(),buffer,sizeof(DNSHeader),0,&from,&x);
572 ServerInstance->Log(DEBUG,"Error in recvfrom()! (%s)",strerror(errno));
574 /* Did we get the whole header? */
577 /* Nope - something screwed up. */
578 ServerInstance->Log(DEBUG,"Whole header not read!");
579 return std::make_pair(-1,"");
582 /* Check wether the reply came from a different DNS
583 * server to the one we sent it to, or the source-port
585 * A user could in theory still spoof dns packets anyway
586 * but this is less trivial than just sending garbage
587 * to the client, which is possible without this check.
589 * -- Thanks jilles for pointing this one out.
592 ipaddr_from = insp_ntoa(((sockaddr_in6*)&from)->sin6_addr);
593 port_from = ntohs(((sockaddr_in6*)&from)->sin6_port);
595 ipaddr_from = insp_ntoa(((sockaddr_in*)&from)->sin_addr);
596 port_from = ntohs(((sockaddr_in*)&from)->sin_port);
599 /* We cant perform this security check if you're using 4in6.
600 * Tough luck to you, choose one or't other!
604 if ((port_from != DNS::QUERY_PORT) || (strcasecmp(ipaddr_from, ServerInstance->Config->DNSServer)))
606 ServerInstance->Log(DEBUG,"port %d is not 53, or %s is not %s",port_from, ipaddr_from, ServerInstance->Config->DNSServer);
607 return std::make_pair(-1,"");
611 /* Put the read header info into a header class */
612 DNS::FillHeader(&header,buffer,length - 12);
614 /* Get the id of this request.
615 * Its a 16 bit value stored in two char's,
616 * so we use logic shifts to create the value.
618 unsigned long this_id = header.id[1] + (header.id[0] << 8);
620 /* Do we have a pending request matching this id? */
621 requestlist_iter n_iter = requests.find(this_id);
622 if (n_iter == requests.end())
624 /* Somehow we got a DNS response for a request we never made... */
625 ServerInstance->Log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d queryid=%d",this->GetFd(),this_id);
626 return std::make_pair(-1,"");
630 /* Remove the query from the list of pending queries */
631 req = (DNSRequest*)n_iter->second;
632 requests.erase(n_iter);
635 /* Inform the DNSRequest class that it has a result to be read.
636 * When its finished it will return a DNSInfo which is a pair of
637 * unsigned char* resource record data, and an error message.
639 DNSInfo data = req->ResultIsReady(header, length);
640 std::string resultstr;
642 /* Check if we got a result, if we didnt, its an error */
643 if (data.first == NULL)
646 * Mask the ID with the value of ERROR_MASK, so that
647 * the dns_deal_with_classes() function knows that its
648 * an error response and needs to be treated uniquely.
649 * Put the error message in the second field.
652 return std::make_pair(this_id | ERROR_MASK, data.second);
658 /* Forward lookups come back as binary data. We must format them into ascii */
662 snprintf(formatted,16,"%u.%u.%u.%u",data.first[0],data.first[1],data.first[2],data.first[3]);
663 resultstr = formatted;
668 snprintf(formatted,40,"%x:%x:%x:%x:%x:%x:%x:%x",
669 (ntohs(data.first[0]) + ntohs(data.first[1] << 8)),
670 (ntohs(data.first[2]) + ntohs(data.first[3] << 8)),
671 (ntohs(data.first[4]) + ntohs(data.first[5] << 8)),
672 (ntohs(data.first[6]) + ntohs(data.first[7] << 8)),
673 (ntohs(data.first[8]) + ntohs(data.first[9] << 8)),
674 (ntohs(data.first[10]) + ntohs(data.first[11] << 8)),
675 (ntohs(data.first[12]) + ntohs(data.first[13] << 8)),
676 (ntohs(data.first[14]) + ntohs(data.first[15] << 8)));
677 char* c = strstr(formatted,":0:");
680 memmove(c+1,c+2,strlen(c+2) + 1);
682 while (memcmp(c,"0:",2) == 0)
683 memmove(c,c+2,strlen(c+2) + 1);
684 if (memcmp(c,"0",2) == 0)
686 if (memcmp(formatted,"0::",3) == 0)
687 memmove(formatted,formatted + 1, strlen(formatted + 1) + 1);
689 resultstr = formatted;
691 /* Special case. Sending ::1 around between servers
692 * and to clients is dangerous, because the : on the
693 * start makes the client or server interpret the IP
694 * as the last parameter on the line with a value ":1".
696 if (*formatted == ':')
697 resultstr = "0" + resultstr;
701 case DNS_QUERY_CNAME:
702 /* Identical handling to PTR */
705 /* Reverse lookups just come back as char* */
706 resultstr = std::string((const char*)data.first);
710 ServerInstance->Log(DEBUG,"WARNING: Somehow we made a request for a DNS_QUERY_PTR4 or DNS_QUERY_PTR6, but these arent real rr types!");
715 /* Build the reply with the id and hostname/ip in it */
717 return std::make_pair(this_id,resultstr);
721 /** A result is ready, process it */
722 DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
730 if (!(header.flags1 & FLAGS_MASK_QR))
731 return std::make_pair((unsigned char*)NULL,"Not a query result");
733 if (header.flags1 & FLAGS_MASK_OPCODE)
734 return std::make_pair((unsigned char*)NULL,"Unexpected value in DNS reply packet");
736 if (header.flags2 & FLAGS_MASK_RCODE)
737 return std::make_pair((unsigned char*)NULL,"Domain name not found");
739 if (header.ancount < 1)
740 return std::make_pair((unsigned char*)NULL,"No resource records returned");
742 /* Subtract the length of the header from the length of the packet */
745 while ((unsigned int)q < header.qdcount && i < length)
747 if (header.payload[i] > 63)
754 if (header.payload[i] == 0)
759 else i += header.payload[i] + 1;
763 while ((unsigned)curanswer < header.ancount)
766 while (q == 0 && i < length)
768 if (header.payload[i] > 63)
775 if (header.payload[i] == 0)
780 else i += header.payload[i] + 1; /* skip length and label */
784 return std::make_pair((unsigned char*)NULL,"Incorrectly sized DNS reply");
786 DNS::FillResourceRecord(&rr,&header.payload[i]);
788 if (rr.type != this->type)
794 if (rr.rr_class != this->rr_class)
802 if ((unsigned int)curanswer == header.ancount)
803 return std::make_pair((unsigned char*)NULL,"No valid answers");
805 if (i + rr.rdlength > (unsigned int)length)
806 return std::make_pair((unsigned char*)NULL,"Resource record larger than stated");
808 if (rr.rdlength > 1023)
809 return std::make_pair((unsigned char*)NULL,"Resource record too large");
813 case DNS_QUERY_CNAME:
814 /* CNAME and PTR have the same processing code */
818 while (q == 0 && i < length && o + 256 < 1023)
820 if (header.payload[i] > 63)
822 memcpy(&ptr,&header.payload[i],2);
823 i = ntohs(ptr) - 0xC000 - 12;
827 if (header.payload[i] == 0)
836 memcpy(&res[o],&header.payload[i + 1],header.payload[i]);
837 o += header.payload[i];
838 i += header.payload[i] + 1;
845 memcpy(res,&header.payload[i],rr.rdlength);
846 res[rr.rdlength] = 0;
849 memcpy(res,&header.payload[i],rr.rdlength);
850 res[rr.rdlength] = 0;
853 memcpy(res,&header.payload[i],rr.rdlength);
854 res[rr.rdlength] = 0;
857 return std::make_pair(res,"No error");;
860 /** Close the master socket */
863 shutdown(this->GetFd(), 2);
864 close(this->GetFd());
867 /** High level abstraction of dns used by application at large */
868 Resolver::Resolver(InspIRCd* Instance, const std::string &source, QueryType qt) : ServerInstance(Instance), input(source), querytype(qt)
870 ServerInstance->Log(DEBUG,"Instance: %08x %08x",Instance, ServerInstance);
877 this->myid = ServerInstance->Res->GetIP(source.c_str());
881 if (insp_aton(source.c_str(), &binip) > 0)
883 /* Valid ip address */
884 this->myid = ServerInstance->Res->GetName(&binip);
888 this->OnError(RESOLVER_BADIP, "Bad IP address for reverse lookup");
889 throw ModuleException("Resolver: Bad IP address");
895 querytype = DNS_QUERY_PTR;
896 this->myid = ServerInstance->Res->GetNameForce(source.c_str(), PROTOCOL_IPV4);
900 querytype = DNS_QUERY_PTR;
901 this->myid = ServerInstance->Res->GetNameForce(source.c_str(), PROTOCOL_IPV6);
905 this->myid = ServerInstance->Res->GetIP6(source.c_str());
908 case DNS_QUERY_CNAME:
909 this->myid = ServerInstance->Res->GetCName(source.c_str());
916 if (this->myid == -1)
918 ServerInstance->Log(DEBUG,"Resolver::Resolver: Could not get an id!");
919 this->OnError(RESOLVER_NSDOWN, "Nameserver is down");
920 throw ModuleException("Resolver: Couldnt get an id to make a request");
921 /* We shouldnt get here really */
925 ServerInstance->Log(DEBUG,"Resolver::Resolver: this->myid=%d",this->myid);
928 /** Called when an error occurs */
929 void Resolver::OnError(ResolverError e, const std::string &errormessage)
931 /* Nothing in here */
934 /** Destroy a resolver */
935 Resolver::~Resolver()
937 /* Nothing here (yet) either */
940 /** Get the request id associated with this class */
941 int Resolver::GetId()
946 /** Process a socket read event */
947 void DNS::HandleEvent(EventType et)
949 ServerInstance->Log(DEBUG,"Marshall reads: %d",this->GetFd());
950 /* Fetch the id and result of the next available packet */
951 DNSResult res = this->GetResult();
952 /* Is there a usable request id? */
955 /* Its an error reply */
956 if (res.first & ERROR_MASK)
958 /* Mask off the error bit */
959 res.first -= ERROR_MASK;
960 /* Marshall the error to the correct class */
961 ServerInstance->Log(DEBUG,"Error available, id=%d",res.first);
962 if (Classes[res.first])
964 if (ServerInstance && ServerInstance->stats)
965 ServerInstance->stats->statsDnsBad++;
966 Classes[res.first]->OnError(RESOLVER_NXDOMAIN, res.second);
967 delete Classes[res.first];
968 Classes[res.first] = NULL;
973 /* It is a non-error result */
974 ServerInstance->Log(DEBUG,"Result available, id=%d",res.first);
975 /* Marshall the result to the correct class */
976 if (Classes[res.first])
978 if (ServerInstance && ServerInstance->stats)
979 ServerInstance->stats->statsDnsGood++;
980 Classes[res.first]->OnLookupComplete(res.second);
981 delete Classes[res.first];
982 Classes[res.first] = NULL;
986 if (ServerInstance && ServerInstance->stats)
987 ServerInstance->stats->statsDns++;
991 /** Add a derived Resolver to the working set */
992 bool DNS::AddResolverClass(Resolver* r)
994 /* Check the pointers validity and the id's validity */
995 if ((r) && (r->GetId() > -1))
997 /* Check the slot isnt already occupied -
998 * This should NEVER happen unless we have
999 * a severely broken DNS server somewhere
1001 if (!Classes[r->GetId()])
1003 /* Set up the pointer to the class */
1004 Classes[r->GetId()] = r;
1013 /* Pointer or id not valid.
1014 * Free the item and return
1023 /** Generate pseudo-random number */
1024 unsigned long DNS::PRNG()
1026 unsigned long val = 0;
1028 serverstats* s = ServerInstance->stats;
1029 gettimeofday(&n,NULL);
1030 val = (n.tv_usec ^ getpid() ^ geteuid() ^ (this->currid++)) ^ s->statsAccept + n.tv_sec;
1031 val = val + s->statsCollisions ^ s->statsDnsGood - s->statsDnsBad;
1032 val += (s->statsConnects ^ (unsigned long)s->statsSent ^ (unsigned long)s->statsRecv) - s->BoundPortCount;