diff options
Diffstat (limited to 'src/commands/cmd_dns.cpp')
| -rw-r--r-- | src/commands/cmd_dns.cpp | 842 |
1 files changed, 842 insertions, 0 deletions
diff --git a/src/commands/cmd_dns.cpp b/src/commands/cmd_dns.cpp new file mode 100644 index 000000000..2b7114128 --- /dev/null +++ b/src/commands/cmd_dns.cpp @@ -0,0 +1,842 @@ +/* + * InspIRCd -- Internet Relay Chat Daemon + * + * Copyright (C) 2013 Adam <Adam@anope.org> + * Copyright (C) 2003-2013 Anope Team <team@anope.org> + * + * This file is part of InspIRCd. InspIRCd is free software: you can + * redistribute it and/or modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more + * details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include "inspircd.h" +#include "modules/dns.h" +#include <iostream> +#include <fstream> + +#ifdef _WIN32 +#include <Iphlpapi.h> +#pragma comment(lib, "Iphlpapi.lib") +#endif + +using namespace DNS; + +/** A full packet sent or recieved to/from the nameserver + */ +class Packet : public Query +{ + void PackName(unsigned char* output, unsigned short output_size, unsigned short& pos, const std::string& name) + { + if (pos + name.length() + 2 > output_size) + throw Exception("Unable to pack name"); + + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: Packing name " + name); + + irc::sepstream sep(name, '.'); + std::string token; + + while (sep.GetToken(token)) + { + output[pos++] = token.length(); + memcpy(&output[pos], token.data(), token.length()); + pos += token.length(); + } + + output[pos++] = 0; + } + + std::string UnpackName(const unsigned char* input, unsigned short input_size, unsigned short& pos) + { + std::string name; + unsigned short pos_ptr = pos, lowest_ptr = input_size; + bool compressed = false; + + if (pos_ptr >= input_size) + throw Exception("Unable to unpack name - no input"); + + while (input[pos_ptr] > 0) + { + unsigned short offset = input[pos_ptr]; + + if (offset & POINTER) + { + if ((offset & POINTER) != POINTER) + throw Exception("Unable to unpack name - bogus compression header"); + if (pos_ptr + 1 >= input_size) + throw Exception("Unable to unpack name - bogus compression header"); + + /* Place pos at the second byte of the first (farthest) compression pointer */ + if (compressed == false) + { + ++pos; + compressed = true; + } + + pos_ptr = (offset & LABEL) << 8 | input[pos_ptr + 1]; + + /* Pointers can only go back */ + if (pos_ptr >= lowest_ptr) + throw Exception("Unable to unpack name - bogus compression pointer"); + lowest_ptr = pos_ptr; + } + else + { + if (pos_ptr + offset + 1 >= input_size) + throw Exception("Unable to unpack name - offset too large"); + if (!name.empty()) + name += "."; + for (unsigned i = 1; i <= offset; ++i) + name += input[pos_ptr + i]; + + pos_ptr += offset + 1; + if (compressed == false) + /* Move up pos */ + pos = pos_ptr; + } + } + + /* +1 pos either to one byte after the compression pointer or one byte after the ending \0 */ + ++pos; + + if (name.empty()) + throw Exception("Unable to unpack name - no name"); + + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: Unpack name " + name); + + return name; + } + + Question UnpackQuestion(const unsigned char* input, unsigned short input_size, unsigned short& pos) + { + Question question; + + question.name = this->UnpackName(input, input_size, pos); + + if (pos + 4 > input_size) + throw Exception("Unable to unpack question"); + + question.type = static_cast<QueryType>(input[pos] << 8 | input[pos + 1]); + pos += 2; + + question.qclass = input[pos] << 8 | input[pos + 1]; + pos += 2; + + return question; + } + + ResourceRecord UnpackResourceRecord(const unsigned char* input, unsigned short input_size, unsigned short& pos) + { + ResourceRecord record = static_cast<ResourceRecord>(this->UnpackQuestion(input, input_size, pos)); + + if (pos + 6 > input_size) + throw Exception("Unable to unpack resource record"); + + record.ttl = (input[pos] << 24) | (input[pos + 1] << 16) | (input[pos + 2] << 8) | input[pos + 3]; + pos += 4; + + //record.rdlength = input[pos] << 8 | input[pos + 1]; + pos += 2; + + switch (record.type) + { + case QUERY_A: + { + if (pos + 4 > input_size) + throw Exception("Unable to unpack resource record"); + + irc::sockets::sockaddrs addrs; + memset(&addrs, 0, sizeof(addrs)); + + addrs.in4.sin_family = AF_INET; + addrs.in4.sin_addr.s_addr = input[pos] | (input[pos + 1] << 8) | (input[pos + 2] << 16) | (input[pos + 3] << 24); + pos += 4; + + record.rdata = addrs.addr(); + break; + } + case QUERY_AAAA: + { + if (pos + 16 > input_size) + throw Exception("Unable to unpack resource record"); + + irc::sockets::sockaddrs addrs; + memset(&addrs, 0, sizeof(addrs)); + + addrs.in6.sin6_family = AF_INET6; + for (int j = 0; j < 16; ++j) + addrs.in6.sin6_addr.s6_addr[j] = input[pos + j]; + pos += 16; + + record.rdata = addrs.addr(); + + break; + } + case QUERY_CNAME: + case QUERY_PTR: + { + record.rdata = this->UnpackName(input, input_size, pos); + break; + } + default: + break; + } + + if (!record.name.empty() && !record.rdata.empty()) + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: " + record.name + " -> " + record.rdata); + + return record; + } + + public: + static const int POINTER = 0xC0; + static const int LABEL = 0x3F; + static const int HEADER_LENGTH = 12; + + /* ID for this packet */ + unsigned short id; + /* Flags on the packet */ + unsigned short flags; + + Packet() : id(0), flags(0) + { + } + + void Fill(const unsigned char* input, const unsigned short len) + { + if (len < HEADER_LENGTH) + throw Exception("Unable to fill packet"); + + unsigned short packet_pos = 0; + + this->id = (input[packet_pos] << 8) | input[packet_pos + 1]; + packet_pos += 2; + + if (this->id >= MAX_REQUEST_ID) + throw Exception("Query ID too large?"); + + this->flags = (input[packet_pos] << 8) | input[packet_pos + 1]; + packet_pos += 2; + + unsigned short qdcount = (input[packet_pos] << 8) | input[packet_pos + 1]; + packet_pos += 2; + + unsigned short ancount = (input[packet_pos] << 8) | input[packet_pos + 1]; + packet_pos += 2; + + unsigned short nscount = (input[packet_pos] << 8) | input[packet_pos + 1]; + packet_pos += 2; + + unsigned short arcount = (input[packet_pos] << 8) | input[packet_pos + 1]; + packet_pos += 2; + + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: qdcount: " + ConvToStr(qdcount) + " ancount: " + ConvToStr(ancount) + " nscount: " + ConvToStr(nscount) + " arcount: " + ConvToStr(arcount)); + + for (unsigned i = 0; i < qdcount; ++i) + this->questions.push_back(this->UnpackQuestion(input, len, packet_pos)); + + for (unsigned i = 0; i < ancount; ++i) + this->answers.push_back(this->UnpackResourceRecord(input, len, packet_pos)); + } + + unsigned short Pack(unsigned char* output, unsigned short output_size) + { + if (output_size < HEADER_LENGTH) + throw Exception("Unable to pack packet"); + + unsigned short pos = 0; + + output[pos++] = this->id >> 8; + output[pos++] = this->id & 0xFF; + output[pos++] = this->flags >> 8; + output[pos++] = this->flags & 0xFF; + output[pos++] = this->questions.size() >> 8; + output[pos++] = this->questions.size() & 0xFF; + output[pos++] = this->answers.size() >> 8; + output[pos++] = this->answers.size() & 0xFF; + output[pos++] = 0; + output[pos++] = 0; + output[pos++] = 0; + output[pos++] = 0; + + for (unsigned i = 0; i < this->questions.size(); ++i) + { + Question& q = this->questions[i]; + + if (q.type == QUERY_PTR) + { + irc::sockets::sockaddrs ip; + irc::sockets::aptosa(q.name, 0, ip); + + if (q.name.find(':') != std::string::npos) + { + static const char* const hex = "0123456789abcdef"; + char reverse_ip[128]; + unsigned reverse_ip_count = 0; + for (int j = 15; j >= 0; --j) + { + reverse_ip[reverse_ip_count++] = hex[ip.in6.sin6_addr.s6_addr[j] & 0xF]; + reverse_ip[reverse_ip_count++] = '.'; + reverse_ip[reverse_ip_count++] = hex[ip.in6.sin6_addr.s6_addr[j] >> 4]; + reverse_ip[reverse_ip_count++] = '.'; + } + reverse_ip[reverse_ip_count++] = 0; + + q.name = reverse_ip; + q.name += "ip6.arpa"; + } + else + { + unsigned long forward = ip.in4.sin_addr.s_addr; + ip.in4.sin_addr.s_addr = forward << 24 | (forward & 0xFF00) << 8 | (forward & 0xFF0000) >> 8 | forward >> 24; + + q.name = ip.addr() + ".in-addr.arpa"; + } + } + + this->PackName(output, output_size, pos, q.name); + + if (pos + 4 >= output_size) + throw Exception("Unable to pack packet"); + + short s = htons(q.type); + memcpy(&output[pos], &s, 2); + pos += 2; + + s = htons(q.qclass); + memcpy(&output[pos], &s, 2); + pos += 2; + } + + for (unsigned int i = 0; i < answers.size(); i++) + { + ResourceRecord& rr = answers[i]; + + this->PackName(output, output_size, pos, rr.name); + + if (pos + 8 >= output_size) + throw Exception("Unable to pack packet"); + + short s = htons(rr.type); + memcpy(&output[pos], &s, 2); + pos += 2; + + s = htons(rr.qclass); + memcpy(&output[pos], &s, 2); + pos += 2; + + long l = htonl(rr.ttl); + memcpy(&output[pos], &l, 4); + pos += 4; + + switch (rr.type) + { + case QUERY_A: + { + if (pos + 6 > output_size) + throw Exception("Unable to pack packet"); + + irc::sockets::sockaddrs a; + irc::sockets::aptosa(rr.rdata, 0, a); + + s = htons(4); + memcpy(&output[pos], &s, 2); + pos += 2; + + memcpy(&output[pos], &a.in4.sin_addr, 4); + pos += 4; + break; + } + case QUERY_AAAA: + { + if (pos + 18 > output_size) + throw Exception("Unable to pack packet"); + + irc::sockets::sockaddrs a; + irc::sockets::aptosa(rr.rdata, 0, a); + + s = htons(16); + memcpy(&output[pos], &s, 2); + pos += 2; + + memcpy(&output[pos], &a.in6.sin6_addr, 16); + pos += 16; + break; + } + case QUERY_CNAME: + case QUERY_PTR: + { + if (pos + 2 >= output_size) + throw Exception("Unable to pack packet"); + + unsigned short packet_pos_save = pos; + pos += 2; + + this->PackName(output, output_size, pos, rr.rdata); + + s = htons(pos - packet_pos_save - 2); + memcpy(&output[packet_pos_save], &s, 2); + break; + } + default: + break; + } + } + + return pos; + } +}; + +class MyManager : public Manager, public Timer, public EventHandler +{ + typedef TR1NS::unordered_map<Question, Query, Question::hash> cache_map; + cache_map cache; + + irc::sockets::sockaddrs myserver; + + static bool IsExpired(const Query& record, time_t now = ServerInstance->Time()) + { + const ResourceRecord& req = record.answers[0]; + return (req.created + static_cast<time_t>(req.ttl) < now); + } + + /** Check the DNS cache to see if request can be handled by a cached result + * @return true if a cached result was found. + */ + bool CheckCache(DNS::Request* req, const DNS::Question& question) + { + ServerInstance->Logs->Log("RESOLVER", LOG_SPARSE, "Resolver: cache: Checking cache for " + question.name); + + cache_map::iterator it = this->cache.find(question); + if (it == this->cache.end()) + return false; + + Query& record = it->second; + if (IsExpired(record)) + { + this->cache.erase(it); + return false; + } + + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: cache: Using cached result for " + question.name); + record.cached = true; + req->OnLookupComplete(&record); + return true; + } + + /** Add a record to the dns cache + * @param r The record + */ + void AddCache(Query& r) + { + const ResourceRecord& rr = r.answers[0]; + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: cache: added cache for " + rr.name + " -> " + rr.rdata + " ttl: " + ConvToStr(rr.ttl)); + this->cache[r.questions[0]] = r; + } + + public: + DNS::Request* requests[MAX_REQUEST_ID]; + + MyManager(Module* c) : Manager(c), Timer(3600, ServerInstance->Time(), true) + { + for (int i = 0; i < MAX_REQUEST_ID; ++i) + requests[i] = NULL; + ServerInstance->Timers->AddTimer(this); + } + + ~MyManager() + { + for (int i = 0; i < MAX_REQUEST_ID; ++i) + { + DNS::Request* request = requests[i]; + if (!request) + continue; + + Query rr(*request); + rr.error = ERROR_UNKNOWN; + request->OnError(&rr); + + delete request; + } + } + + void Process(DNS::Request* req) + { + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: Processing request to lookup " + req->name + " of type " + ConvToStr(req->type) + " to " + this->myserver.addr()); + + /* Create an id */ + unsigned int tries = 0; + do + { + req->id = ServerInstance->GenRandomInt(DNS::MAX_REQUEST_ID); + + if (++tries == DNS::MAX_REQUEST_ID*5) + { + // If we couldn't find an empty slot this many times, do a sequential scan as a last + // resort. If an empty slot is found that way, go on, otherwise throw an exception + req->id = 0; + for (int i = 1; i < DNS::MAX_REQUEST_ID; i++) + { + if (!this->requests[i]) + { + req->id = i; + break; + } + } + + if (req->id == 0) + throw Exception("DNS: All ids are in use"); + + break; + } + } + while (!req->id || this->requests[req->id]); + + this->requests[req->id] = req; + + Packet p; + p.flags = QUERYFLAGS_RD; + p.id = req->id; + p.questions.push_back(*req); + + unsigned char buffer[524]; + unsigned short len = p.Pack(buffer, sizeof(buffer)); + + /* Note that calling Pack() above can actually change the contents of p.questions[0].name, if the query is a PTR, + * to contain the value that would be in the DNS cache, which is why this is here. + */ + if (req->use_cache && this->CheckCache(req, p.questions[0])) + { + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: Using cached result"); + delete req; + return; + } + + if (ServerInstance->SE->SendTo(this, buffer, len, 0, &this->myserver.sa, this->myserver.sa_size()) != len) + throw Exception("DNS: Unable to send query"); + } + + void RemoveRequest(DNS::Request* req) + { + this->requests[req->id] = NULL; + } + + std::string GetErrorStr(Error e) + { + switch (e) + { + case ERROR_UNLOADED: + return "Module is unloading"; + case ERROR_TIMEDOUT: + return "Request timed out"; + case ERROR_NOT_AN_ANSWER: + case ERROR_NONSTANDARD_QUERY: + case ERROR_FORMAT_ERROR: + return "Malformed answer"; + case ERROR_SERVER_FAILURE: + case ERROR_NOT_IMPLEMENTED: + case ERROR_REFUSED: + case ERROR_INVALIDTYPE: + return "Nameserver failure"; + case ERROR_DOMAIN_NOT_FOUND: + case ERROR_NO_RECORDS: + return "Domain not found"; + case ERROR_NONE: + case ERROR_UNKNOWN: + default: + return "Unknown error"; + } + } + + void HandleEvent(EventType et, int) + { + if (et == EVENT_ERROR) + { + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: UDP socket got an error event"); + return; + } + + unsigned char buffer[524]; + irc::sockets::sockaddrs from; + socklen_t x = sizeof(from); + + int length = ServerInstance->SE->RecvFrom(this, buffer, sizeof(buffer), 0, &from.sa, &x); + + if (length < Packet::HEADER_LENGTH) + return; + + Packet recv_packet; + + try + { + recv_packet.Fill(buffer, length); + } + catch (Exception& ex) + { + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, std::string(ex.GetReason())); + return; + } + + if (myserver != from) + { + std::string server1 = from.str(); + std::string server2 = myserver.str(); + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: Got a result from the wrong server! Bad NAT or DNS forging attempt? '%s' != '%s'", + server1.c_str(), server2.c_str()); + return; + } + + DNS::Request* request = this->requests[recv_packet.id]; + if (request == NULL) + { + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: Received an answer for something we didn't request"); + return; + } + + if (recv_packet.flags & QUERYFLAGS_OPCODE) + { + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: Received a nonstandard query"); + ServerInstance->stats->statsDnsBad++; + recv_packet.error = ERROR_NONSTANDARD_QUERY; + request->OnError(&recv_packet); + } + else if (recv_packet.flags & QUERYFLAGS_RCODE) + { + Error error = ERROR_UNKNOWN; + + switch (recv_packet.flags & QUERYFLAGS_RCODE) + { + case 1: + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: format error"); + error = ERROR_FORMAT_ERROR; + break; + case 2: + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: server error"); + error = ERROR_SERVER_FAILURE; + break; + case 3: + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: domain not found"); + error = ERROR_DOMAIN_NOT_FOUND; + break; + case 4: + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: not implemented"); + error = ERROR_NOT_IMPLEMENTED; + break; + case 5: + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: refused"); + error = ERROR_REFUSED; + break; + default: + break; + } + + ServerInstance->stats->statsDnsBad++; + recv_packet.error = error; + request->OnError(&recv_packet); + } + else if (recv_packet.questions.empty() || recv_packet.answers.empty()) + { + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: No resource records returned"); + ServerInstance->stats->statsDnsBad++; + recv_packet.error = ERROR_NO_RECORDS; + request->OnError(&recv_packet); + } + else + { + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: Lookup complete for " + request->name); + ServerInstance->stats->statsDnsGood++; + request->OnLookupComplete(&recv_packet); + this->AddCache(recv_packet); + } + + ServerInstance->stats->statsDns++; + + /* Request's destructor removes it from the request map */ + delete request; + } + + bool Tick(time_t now) + { + ServerInstance->Logs->Log("RESOLVER", LOG_DEBUG, "Resolver: cache: purging DNS cache"); + + for (cache_map::iterator it = this->cache.begin(); it != this->cache.end(); ) + { + const Query& query = it->second; + if (IsExpired(query, now)) + this->cache.erase(it++); + else + ++it; + } + return true; + } + + void Rehash(const std::string& dnsserver) + { + if (this->GetFd() > -1) + { + ServerInstance->SE->DelFd(this); + ServerInstance->SE->Shutdown(this, 2); + ServerInstance->SE->Close(this); + this->SetFd(-1); + + /* Remove expired entries from the cache */ + this->Tick(ServerInstance->Time()); + } + + irc::sockets::aptosa(dnsserver, DNS::PORT, myserver); + + /* Initialize mastersocket */ + int s = socket(myserver.sa.sa_family, SOCK_DGRAM, 0); + this->SetFd(s); + + /* Have we got a socket? */ + if (this->GetFd() != -1) + { + 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", LOG_SPARSE, "Resolver: Error binding dns socket - hostnames will NOT resolve"); + ServerInstance->SE->Close(this); + this->SetFd(-1); + } + else if (!ServerInstance->SE->AddFd(this, FD_WANT_POLL_READ | FD_WANT_NO_WRITE)) + { + ServerInstance->Logs->Log("RESOLVER", LOG_SPARSE, "Resolver: Internal error starting DNS - hostnames will NOT resolve."); + ServerInstance->SE->Close(this); + this->SetFd(-1); + } + } + else + { + ServerInstance->Logs->Log("RESOLVER", LOG_SPARSE, "Resolver: Error creating DNS socket - hostnames will NOT resolve"); + } + } +}; + +class ModuleDNS : public Module +{ + MyManager manager; + std::string DNSServer; + + void FindDNSServer() + { +#ifdef _WIN32 + // attempt to look up their nameserver from the system + ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "WARNING: <dns:server> not defined, attempting to find a working server in the system settings..."); + + PFIXED_INFO pFixedInfo; + DWORD dwBufferSize = sizeof(FIXED_INFO); + pFixedInfo = (PFIXED_INFO) HeapAlloc(GetProcessHeap(), 0, sizeof(FIXED_INFO)); + + if (pFixedInfo) + { + if (GetNetworkParams(pFixedInfo, &dwBufferSize) == ERROR_BUFFER_OVERFLOW) + { + HeapFree(GetProcessHeap(), 0, pFixedInfo); + pFixedInfo = (PFIXED_INFO) HeapAlloc(GetProcessHeap(), 0, dwBufferSize); + } + + if (pFixedInfo) + { + if (GetNetworkParams(pFixedInfo, &dwBufferSize) == NO_ERROR) + DNSServer = pFixedInfo->DnsServerList.IpAddress.String; + + HeapFree(GetProcessHeap(), 0, pFixedInfo); + } + + if (!DNSServer.empty()) + { + ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "<dns:server> set to '%s' as first active resolver in the system settings.", DNSServer.c_str()); + return; + } + } + + ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "No viable nameserver found! Defaulting to nameserver '127.0.0.1'!"); +#else + // attempt to look up their nameserver from /etc/resolv.conf + ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "WARNING: <dns:server> not defined, attempting to find working server in /etc/resolv.conf..."); + + std::ifstream resolv("/etc/resolv.conf"); + + while (resolv >> DNSServer) + { + if (DNSServer == "nameserver") + { + resolv >> DNSServer; + if (DNSServer.find_first_not_of("0123456789.") == std::string::npos) + { + ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "<dns:server> set to '%s' as first resolver in /etc/resolv.conf.",DNSServer.c_str()); + return; + } + } + } + + ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "/etc/resolv.conf contains no viable nameserver entries! Defaulting to nameserver '127.0.0.1'!"); +#endif + DNSServer = "127.0.0.1"; + } + + public: + ModuleDNS() : manager(this) + { + } + + void init() + { + ServerInstance->Modules->AddService(this->manager); + + this->OnRehash(NULL); + } + + void OnRehash(User* user) + { + std::string oldserver = DNSServer; + DNSServer = ServerInstance->Config->ConfValue("dns")->getString("server"); + if (DNSServer.empty()) + FindDNSServer(); + + if (oldserver != DNSServer) + this->manager.Rehash(DNSServer); + } + + void OnUnloadModule(Module* mod) + { + for (int i = 0; i < MAX_REQUEST_ID; ++i) + { + DNS::Request* req = this->manager.requests[i]; + if (!req) + continue; + + if (req->creator == mod) + { + Query rr(*req); + rr.error = ERROR_UNLOADED; + req->OnError(&rr); + + delete req; + } + } + } + + Version GetVersion() + { + return Version("DNS support", VF_CORE|VF_VENDOR); + } +}; + +MODULE_INIT(ModuleDNS) + |