X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fdns.cpp;h=14305ccab2f49a2a4e94f94ee67dc543c34e92c2;hb=68211809ee3111bdc9609fbd46dc3c875fbb5ea6;hp=aaa6bf89ec36feedd6d6cc8f2240b5871814cf36;hpb=cd146649029d2d6d2a5edd804d2e6a31e13593bc;p=user%2Fhenk%2Fcode%2Finspircd.git diff --git a/src/dns.cpp b/src/dns.cpp index aaa6bf89e..14305ccab 100644 --- a/src/dns.cpp +++ b/src/dns.cpp @@ -1,138 +1,206 @@ -/* +------------------------------------+ - * | Inspire Internet Relay Chat Daemon | - * +------------------------------------+ +/* + * InspIRCd -- Internet Relay Chat Daemon + * + * Copyright (C) 2012 William Pitcock + * Copyright (C) 2009-2010 Daniel De Graaf + * Copyright (C) 2006, 2009 Robin Burchell + * Copyright (C) 2007, 2009 Dennis Friis + * Copyright (C) 2008 Thomas Stagner + * Copyright (C) 2005-2007 Craig Edwards + * + * 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. * - * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev. - * E-mail: - * - * - * - * Written by Craig Edwards, Craig McLure, and others. - * This program is free but copyrighted software; see - * the file COPYING for details. + * 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 . */ + +/* $Core */ + /* dns.cpp - Nonblocking DNS functions. -Very loosely based on the firedns library, -Copyright (C) 2002 Ian Gulliver. - -There have been so many modifications to this file -to make it fit into InspIRCd and make it object -orientated that you should not take this code as -being what firedns really looks like. It used to -look very different to this! :-P +Very very loosely based on the firedns library, +Copyright (C) 2002 Ian Gulliver. This file is no +longer anything like firedns, there are many major +differences between this code and the original. +Please do not assume that firedns works like this, +looks like this, walks like this or tastes like this. */ -using namespace std; - -#include -#include -#include +#ifndef _WIN32 #include #include -#include -#include -#include -#include #include -#include -#include -#include -#include #include #include -#include -#include -#include "dns.h" +#else +#include "inspircd_win32wrapper.h" +#endif + #include "inspircd.h" -#include "helperfuncs.h" -#include "inspircd_config.h" #include "socketengine.h" #include "configreader.h" +#include "socket.h" -extern InspIRCd* ServerInstance; -extern ServerConfig* Config; -extern time_t TIME; +#define DN_COMP_BITMASK 0xC000 /* highest 6 bits in a DN label header */ -enum QueryType { DNS_QRY_A = 1, DNS_QRY_PTR = 12 }; -enum QueryFlags1 { FLAGS1_MASK_RD = 0x01, FLAGS1_MASK_TC = 0x02, FLAGS1_MASK_AA = 0x04, FLAGS1_MASK_OPCODE = 0x78, FLAGS1_MASK_QR = 0x80 }; -enum QueryFlags2 { FLAGS2_MASK_RCODE = 0x0F, FLAGS2_MASK_Z = 0x70, FLAGS2_MASK_RA = 0x80 }; +/** Masks to mask off the responses we get from the DNSRequest methods + */ +enum QueryInfo +{ + ERROR_MASK = 0x10000 /* Result is an error */ +}; -class s_connection; +/** Flags which can be ORed into a request or reply for different meanings + */ +enum QueryFlags +{ + FLAGS_MASK_RD = 0x01, /* Recursive */ + FLAGS_MASK_TC = 0x02, + FLAGS_MASK_AA = 0x04, /* Authoritative */ + FLAGS_MASK_OPCODE = 0x78, + FLAGS_MASK_QR = 0x80, + FLAGS_MASK_RCODE = 0x0F, /* Request */ + FLAGS_MASK_Z = 0x70, + FLAGS_MASK_RA = 0x80 +}; -typedef std::map connlist; -typedef connlist::iterator connlist_iter; -connlist connections; -Resolver* dns_classes[MAX_DESCRIPTORS]; +/** Represents a dns resource record (rr) + */ +struct ResourceRecord +{ + QueryType type; /* Record type */ + unsigned int rr_class; /* Record class */ + unsigned long ttl; /* Time to live */ + unsigned int rdlength; /* Record length */ +}; -struct in_addr servers4[8]; -int i4; -int initdone = 0; -int lastcreate = -1; +/** Represents a dns request/reply header, and its payload as opaque data. + */ +class DNSHeader +{ + public: + unsigned char id[2]; /* Request id */ + unsigned int flags1; /* Flags */ + unsigned int flags2; /* Flags */ + unsigned int qdcount; + unsigned int ancount; /* Answer count */ + unsigned int nscount; /* Nameserver count */ + unsigned int arcount; + unsigned char payload[512]; /* Packet payload */ +}; -class s_connection +class DNSRequest { public: - unsigned char id[2]; - unsigned int _class; - QueryType type; - int want_list; - int fd; + unsigned char id[2]; /* Request id */ + unsigned char* res; /* Result processing buffer */ + unsigned int rr_class; /* Request class */ + QueryType type; /* Request type */ + DNS* dnsobj; /* DNS caller (where we get our FD from) */ + unsigned long ttl; /* Time to live */ + std::string orig; /* Original requested name/ip */ + + DNSRequest(DNS* dns, int id, const std::string &original); + ~DNSRequest(); + DNSInfo ResultIsReady(DNSHeader &h, unsigned length); + int SendRequests(const DNSHeader *header, const int length, QueryType qt); }; -class s_rr_middle +class CacheTimer : public Timer { + private: + DNS* dns; public: - QueryType type; - unsigned int _class; - unsigned long ttl; - unsigned int rdlength; + CacheTimer(DNS* thisdns) + : Timer(3600, ServerInstance->Time(), true), dns(thisdns) { } + + virtual void Tick(time_t) + { + dns->PruneCache(); + } }; -class s_header +class RequestTimeout : public Timer { + DNSRequest* watch; + int watchid; public: - unsigned char id[2]; - unsigned int flags1; - unsigned int flags2; - unsigned int qdcount; - unsigned int ancount; - unsigned int nscount; - unsigned int arcount; - unsigned char payload[512]; + RequestTimeout(unsigned long n, DNSRequest* watching, int id) : Timer(n, ServerInstance->Time()), watch(watching), watchid(id) + { + } + ~RequestTimeout() + { + if (ServerInstance->Res) + Tick(0); + } + + void Tick(time_t) + { + if (ServerInstance->Res->requests[watchid] == watch) + { + /* Still exists, whack it */ + if (ServerInstance->Res->Classes[watchid]) + { + ServerInstance->Res->Classes[watchid]->OnError(RESOLVER_TIMEOUT, "Request timed out"); + delete ServerInstance->Res->Classes[watchid]; + ServerInstance->Res->Classes[watchid] = NULL; + } + ServerInstance->Res->requests[watchid] = NULL; + delete watch; + } + } }; +CachedQuery::CachedQuery(const std::string &res, QueryType qt, unsigned int ttl) : data(res), type(qt) +{ + expires = ServerInstance->Time() + ttl; +} -void *dns_align(void *inp) +int CachedQuery::CalcTTLRemaining() { - char *p = (char*)inp; - int offby = ((char *)p - (char *)0) % (sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long)); - if (offby != 0) - return p + ((sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long)) - offby); - else - return p; + int n = expires - ServerInstance->Time(); + return (n < 0 ? 0 : n); } -/* - * Optimized by brain, these were using integer division and modulus. - * We can use logic shifts and logic AND to replace these even divisions - * and multiplications, it should be a bit faster (probably not noticably, - * but of course, more impressive). Also made these inline. - */ +/* Allocate the processing buffer */ +DNSRequest::DNSRequest(DNS* dns, int rid, const std::string &original) : dnsobj(dns) +{ + /* hardening against overflow here: make our work buffer twice the theoretical + * maximum size so that hostile input doesn't screw us over. + */ + res = new unsigned char[sizeof(DNSHeader) * 2]; + *res = 0; + orig = original; + RequestTimeout* RT = new RequestTimeout(ServerInstance->Config->dns_timeout ? ServerInstance->Config->dns_timeout : 5, this, rid); + ServerInstance->Timers->AddTimer(RT); /* The timer manager frees this */ +} + +/* Deallocate the processing buffer */ +DNSRequest::~DNSRequest() +{ + delete[] res; +} -inline void dns_fill_rr(s_rr_middle* rr, const unsigned char *input) +/** Fill a ResourceRecord class based on raw data input */ +inline void DNS::FillResourceRecord(ResourceRecord* rr, const unsigned char *input) { rr->type = (QueryType)((input[0] << 8) + input[1]); - rr->_class = (input[2] << 8) + input[3]; + rr->rr_class = (input[2] << 8) + input[3]; rr->ttl = (input[4] << 24) + (input[5] << 16) + (input[6] << 8) + input[7]; rr->rdlength = (input[8] << 8) + input[9]; } -inline void dns_fill_header(s_header *header, const unsigned char *input, const int l) +/** Fill a DNSHeader class based on raw data input of a given length */ +inline void DNS::FillHeader(DNSHeader *header, const unsigned char *input, const int length) { header->id[0] = input[0]; header->id[1] = input[1]; @@ -142,10 +210,11 @@ inline void dns_fill_header(s_header *header, const unsigned char *input, const header->ancount = (input[6] << 8) + input[7]; header->nscount = (input[8] << 8) + input[9]; header->arcount = (input[10] << 8) + input[11]; - memcpy(header->payload,&input[12],l); + memcpy(header->payload,&input[12],length); } -inline void dns_empty_header(unsigned char *output, const s_header *header, const int l) +/** Empty a DNSHeader class out into raw data, ready for transmission */ +inline void DNS::EmptyHeader(unsigned char *output, const DNSHeader *header, const int length) { output[0] = header->id[0]; output[1] = header->id[1]; @@ -159,407 +228,585 @@ inline void dns_empty_header(unsigned char *output, const s_header *header, cons output[9] = header->nscount & 0xFF; output[10] = header->arcount >> 8; output[11] = header->arcount & 0xFF; - memcpy(&output[12],header->payload,l); + memcpy(&output[12],header->payload,length); } -void dns_close(int fd) +/** Send requests we have previously built down the UDP socket */ +int DNSRequest::SendRequests(const DNSHeader *header, const int length, QueryType qt) { -#ifndef THREADED_DNS - if (ServerInstance && ServerInstance->SE) - ServerInstance->SE->DelFd(fd); -#endif - log(DEBUG,"DNS: dns_close on fd %d",fd); - shutdown(fd,2); - close(fd); - return; -} - -void DNS::dns_init() -{ - FILE *f; - int i; - in_addr addr4; - char buf[1024]; - if (initdone == 1) - return; - i4 = 0; - - initdone = 1; - srand((unsigned int) TIME); - memset(servers4,'\0',sizeof(in_addr) * 8); - f = fopen("/etc/resolv.conf","r"); - if (f == NULL) - return; - while (fgets(buf,1024,f) != NULL) { - if (strncmp(buf,"nameserver",10) == 0) + ServerInstance->Logs->Log("RESOLVER", DEBUG,"DNSRequest::SendRequests"); + + unsigned char payload[sizeof(DNSHeader)]; + + this->rr_class = 1; + this->type = qt; + + DNS::EmptyHeader(payload,header,length); + + 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; +} + +/** Add a query with a predefined header, and allocate an ID for it. */ +DNSRequest* DNS::AddQuery(DNSHeader *header, int &id, const char* original) +{ + /* Is the DNS connection down? */ + if (this->GetFd() == -1) + return NULL; + + /* Create an id */ + unsigned int tries = 0; + do { + id = ServerInstance->GenRandomInt(DNS::MAX_REQUEST_ID); + if (++tries == DNS::MAX_REQUEST_ID*5) { - i = 10; - while (buf[i] == ' ' || buf[i] == '\t') - i++; - if (i4 < 8) + // 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 + id = -1; + for (int i = 0; i < DNS::MAX_REQUEST_ID; i++) { - if (dns_aton4_s(&buf[i],&addr4) != NULL) - memcpy(&servers4[i4++],&addr4,sizeof(in_addr)); + if (!requests[i]) + { + id = i; + break; + } } + + if (id == -1) + throw ModuleException("DNS: All ids are in use"); + + break; } - } - fclose(f); + } while (requests[id]); + + DNSRequest* req = new DNSRequest(this, id, original); + + header->id[0] = req->id[0] = id >> 8; + header->id[1] = req->id[1] = id & 0xFF; + header->flags1 = FLAGS_MASK_RD; + header->flags2 = 0; + header->qdcount = 1; + header->ancount = 0; + header->nscount = 0; + header->arcount = 0; + + /* At this point we already know the id doesnt exist, + * so there needs to be no second check for the ::end() + */ + requests[id] = req; + + /* According to the C++ spec, new never returns NULL. */ + return req; } -void DNS::dns_init_2(const char* dnsserver) +int DNS::ClearCache() { - in_addr addr4; - i4 = 0; - srand((unsigned int) TIME); - memset(servers4,'\0',sizeof(in_addr) * 8); - if (dns_aton4_s(dnsserver,&addr4) != NULL) - memcpy(&servers4[i4++],&addr4,sizeof(in_addr)); + /* This ensures the buckets are reset to sane levels */ + int rv = this->cache->size(); + delete this->cache; + this->cache = new dnscache(); + return rv; } - -int dns_send_requests(const s_header *h, const s_connection *s, const int l) +int DNS::PruneCache() { - int i; - sockaddr_in addr4; - unsigned char payload[sizeof(s_header)]; - - dns_empty_header(payload,h,l); + int n = 0; + dnscache* newcache = new dnscache(); + for (dnscache::iterator i = this->cache->begin(); i != this->cache->end(); i++) + /* Dont include expired items (theres no point) */ + if (i->second.CalcTTLRemaining()) + newcache->insert(*i); + else + n++; + delete this->cache; + this->cache = newcache; + return n; +} - i = 0; +void DNS::Rehash() +{ + if (this->GetFd() > -1) + { + ServerInstance->SE->DelFd(this); + ServerInstance->SE->Shutdown(this, 2); + ServerInstance->SE->Close(this); + this->SetFd(-1); - /* otherwise send via standard ipv4 boringness */ - memset(&addr4,0,sizeof(addr4)); - memcpy(&addr4.sin_addr,&servers4[i],sizeof(addr4.sin_addr)); - addr4.sin_family = AF_INET; - addr4.sin_port = htons(53); - if (sendto(s->fd, payload, l + 12, 0, (sockaddr *) &addr4, sizeof(addr4)) == -1) + /* Rehash the cache */ + this->PruneCache(); + } + else { - return -1; + /* Create initial dns cache */ + this->cache = new dnscache(); } - return 0; -} - -s_connection *dns_add_query(s_header *h) -{ + irc::sockets::aptosa(ServerInstance->Config->DNSServer, DNS::QUERY_PORT, myserver); - s_connection * s = new s_connection; - int id = rand() % 65536; + /* Initialize mastersocket */ + int s = socket(myserver.sa.sa_family, SOCK_DGRAM, 0); + this->SetFd(s); - /* set header flags */ - h->id[0] = s->id[0] = id >> 8; /* verified by dns_getresult_s() */ - h->id[1] = s->id[1] = id & 0xFF; - h->flags1 = 0 | FLAGS1_MASK_RD; - h->flags2 = 0; - h->qdcount = 1; - h->ancount = 0; - h->nscount = 0; - h->arcount = 0; - s->want_list = 0; - s->fd = socket(PF_INET, SOCK_DGRAM, 0); - if (s->fd != -1) + /* Have we got a socket and is it nonblocking? */ + if (this->GetFd() != -1) { - if (fcntl(s->fd, F_SETFL, O_NONBLOCK) != 0) + 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) { - shutdown(s->fd,2); - close(s->fd); - s->fd = -1; + /* Failed to bind */ + 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 (s->fd != -1) - { - sockaddr_in addr; - memset(&addr,0,sizeof(addr)); - addr.sin_family = AF_INET; - addr.sin_port = 0; - addr.sin_addr.s_addr = INADDR_ANY; - if (bind(s->fd,(sockaddr *)&addr,sizeof(addr)) != 0) + else if (!ServerInstance->SE->AddFd(this, FD_WANT_POLL_READ | FD_WANT_NO_WRITE)) { - shutdown(s->fd,2); - close(s->fd); - s->fd = -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); } } - if (s->fd == -1) + else { - DELETE(s); - return NULL; + ServerInstance->Logs->Log("RESOLVER",SPARSE,"Error creating DNS socket - hostnames will NOT resolve"); } - /* create new connection object, add to linked list */ - if (connections.find(s->fd) == connections.end()) - connections[s->fd] = s; - - lastcreate = s->fd; - return s; } -int dns_build_query_payload(const char * const name, const unsigned short rr, const unsigned short _class, unsigned char * const payload) +/** Initialise the DNS UDP socket so that we can send requests */ +DNS::DNS() { - short payloadpos; - const char * tempchr, * tempchr2; - unsigned short l; + ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::DNS"); + /* Clear the Resolver class table */ + memset(Classes,0,sizeof(Classes)); + + /* Clear the requests class table */ + memset(requests,0,sizeof(requests)); + + /* DNS::Rehash() sets this to a valid ptr + */ + this->cache = NULL; - payloadpos = 0; - tempchr2 = name; + /* Again, DNS::Rehash() sets this to a + * valid value + */ + this->SetFd(-1); + + /* Actually read the settings + */ + this->Rehash(); + + this->PruneTimer = new CacheTimer(this); + + ServerInstance->Timers->AddTimer(this->PruneTimer); +} + +/** Build a payload to be placed after the header, based upon input data, a resource type, a class and a pointer to a buffer */ +int DNS::MakePayload(const char * const name, const QueryType rr, const unsigned short rr_class, unsigned char * const payload) +{ + short payloadpos = 0; + const char* tempchr, *tempchr2 = name; + unsigned short length; /* split name up into labels, create query */ while ((tempchr = strchr(tempchr2,'.')) != NULL) { - l = tempchr - tempchr2; - if (payloadpos + l + 1 > 507) + length = tempchr - tempchr2; + if (payloadpos + length + 1 > 507) return -1; - payload[payloadpos++] = l; - memcpy(&payload[payloadpos],tempchr2,l); - payloadpos += l; + payload[payloadpos++] = length; + memcpy(&payload[payloadpos],tempchr2,length); + payloadpos += length; tempchr2 = &tempchr[1]; } - l = strlen(tempchr2); - if (l) + length = strlen(tempchr2); + if (length) { - if (payloadpos + l + 2 > 507) + if (payloadpos + length + 2 > 507) return -1; - payload[payloadpos++] = l; - memcpy(&payload[payloadpos],tempchr2,l); - payloadpos += l; - payload[payloadpos++] = '\0'; + payload[payloadpos++] = length; + memcpy(&payload[payloadpos],tempchr2,length); + payloadpos += length; + payload[payloadpos++] = 0; } if (payloadpos > 508) return -1; - l = htons(rr); - memcpy(&payload[payloadpos],&l,2); - l = htons(_class); - memcpy(&payload[payloadpos + 2],&l,2); + length = htons(rr); + memcpy(&payload[payloadpos],&length,2); + length = htons(rr_class); + memcpy(&payload[payloadpos + 2],&length,2); return payloadpos + 4; } -in_addr* DNS::dns_aton4(const char * const ipstring) +/** Start lookup of an hostname to an IP address */ +int DNS::GetIP(const char *name) { - static in_addr ip; - return dns_aton4_s(ipstring,&ip); -} - -in_addr* DNS::dns_aton4_r(const char *ipstring) { /* ascii to numeric (reentrant): convert string to new 4part IP addr struct */ - in_addr* ip; - ip = new in_addr; - if(dns_aton4_s(ipstring,ip) == NULL) - { - DELETE(ip); - return NULL; - } - return ip; -} + DNSHeader h; + int id; + int length; -in_addr* DNS::dns_aton4_s(const char *ipstring, in_addr *ip) { /* ascii to numeric (buffered): convert string to given 4part IP addr struct */ - inet_aton(ipstring,ip); - return ip; -} - -int DNS::dns_getip4(const char *name) { /* build, add and send A query; retrieve result with dns_getresult() */ - s_header h; - s_connection *s; - int l; + if ((length = this->MakePayload(name, DNS_QUERY_A, 1, (unsigned char*)&h.payload)) == -1) + return -1; - dns_init(); - + DNSRequest* req = this->AddQuery(&h, id, name); - l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload); - if (l == -1) - return -1; - s = dns_add_query(&h); - if (s == NULL) - return -1; - s->_class = 1; - s->type = DNS_QRY_A; - if (dns_send_requests(&h,s,l) == -1) + if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_A) == -1)) return -1; - return s->fd; + return id; } -int DNS::dns_getip4list(const char *name) { /* build, add and send A query; retrieve result with dns_getresult() */ - s_header h; - s_connection *s; - int l; +/** Start lookup of an hostname to an IPv6 address */ +int DNS::GetIP6(const char *name) +{ + DNSHeader h; + int id; + int length; - dns_init(); - - l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload); - if (l == -1) + if ((length = this->MakePayload(name, DNS_QUERY_AAAA, 1, (unsigned char*)&h.payload)) == -1) return -1; - s = dns_add_query(&h); - if (s == NULL) - return -1; - s->_class = 1; - s->type = DNS_QRY_A; - s->want_list = 1; - if (dns_send_requests(&h,s,l) == -1) + + DNSRequest* req = this->AddQuery(&h, id, name); + + if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_AAAA) == -1)) return -1; - return s->fd; + return id; } -int DNS::dns_getname4(const in_addr *ip) { /* build, add and send PTR query; retrieve result with dns_getresult() */ - char query[512]; - s_header h; - s_connection * s; - unsigned char *c; - int l; +/** Start lookup of a cname to another name */ +int DNS::GetCName(const char *alias) +{ + DNSHeader h; + int id; + int length; - c = (unsigned char *)&ip->s_addr; + if ((length = this->MakePayload(alias, DNS_QUERY_CNAME, 1, (unsigned char*)&h.payload)) == -1) + return -1; - sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]); + DNSRequest* req = this->AddQuery(&h, id, alias); - l = dns_build_query_payload(query,DNS_QRY_PTR,1,(unsigned char *)&h.payload); - if (l == -1) - return -1; - s = dns_add_query(&h); - if (s == NULL) - return -1; - s->_class = 1; - s->type = DNS_QRY_PTR; - if (dns_send_requests(&h,s,l) == -1) + if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_CNAME) == -1)) return -1; - return s->fd; + return id; } -char* DNS::dns_ntoa4(const in_addr * const ip) { /* numeric to ascii: convert 4part IP addr struct to static string */ - static char r[256]; - return dns_ntoa4_s(ip,r); -} +/** Start lookup of an IP address to a hostname */ +int DNS::GetNameForce(const char *ip, ForceProtocol fp) +{ + char query[128]; + DNSHeader h; + int id; + int length; -char* DNS::dns_ntoa4_s(const in_addr *ip, char *r) { /* numeric to ascii (buffered): convert 4part IP addr struct to given string */ - unsigned char *m; - m = (unsigned char *)&ip->s_addr; - sprintf(r,"%d.%d.%d.%d",m[0],m[1],m[2],m[3]); - return r; -} + if (fp == PROTOCOL_IPV6) + { + in6_addr i; + if (inet_pton(AF_INET6, ip, &i) > 0) + { + DNS::MakeIP6Int(query, &i); + } + else + { + ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce IPv6 bad format for '%s'", ip); + /* Invalid IP address */ + return -1; + } + } + else + { + in_addr i; + if (inet_aton(ip, &i)) + { + unsigned char* c = (unsigned char*)&i.s_addr; + 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; + } + } -char* DNS::dns_getresult(const int cfd) { /* retrieve result of DNS query */ - log(DEBUG,"DNS: dns_getresult with cfd=%d",cfd); - return dns_getresult_s(cfd,this->localbuf); -} + 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; + } -char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS query (buffered) */ - s_header h; - s_connection *c; - int l, i, q, curanswer, o; - s_rr_middle rr; - unsigned char buffer[sizeof(s_header)]; - unsigned short p; + DNSRequest* req = this->AddQuery(&h, id, ip); - if (res) - *res = 0; + if (!req) + { + ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce can't add query (resolver down?)"); + return -1; + } - /* FireDNS used a linked list for this. How ugly (and slow). */ - connlist_iter n_iter = connections.find(cfd); - if (n_iter == connections.end()) + if (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1) { - log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d",cfd); - return NULL; + ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce can't send (firewall?)"); + return -1; } - else + + return id; +} + +/** Build an ipv6 reverse domain from an in6_addr + */ +void DNS::MakeIP6Int(char* query, const in6_addr *ip) +{ + const char* hex = "0123456789abcdef"; + for (int index = 31; index >= 0; index--) /* for() loop steps twice per byte */ { - /* Remove the query from the list */ - c = (s_connection*)n_iter->second; - /* We don't delete c here, because its done later when needed */ - connections.erase(n_iter); + if (index % 2) + /* low nibble */ + *query++ = hex[ip->s6_addr[index / 2] & 0x0F]; + else + /* high nibble */ + *query++ = hex[(ip->s6_addr[index / 2] & 0xF0) >> 4]; + *query++ = '.'; /* Seperator */ } + strcpy(query,"ip6.arpa"); /* Suffix the string */ +} - l = recv(c->fd,buffer,sizeof(s_header),0); - dns_close(c->fd); - if (l < 12) +/** Return the next id which is ready, and the result attached to it */ +DNSResult DNS::GetResult() +{ + /* Fetch dns query response and decide where it belongs */ + DNSHeader header; + DNSRequest *req; + unsigned char buffer[sizeof(DNSHeader)]; + irc::sockets::sockaddrs from; + 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) { - DELETE(c); - return NULL; + ServerInstance->Logs->Log("RESOLVER",DEBUG,"GetResult didn't get a full packet (len=%d)", length); + /* Nope - something screwed up. */ + return DNSResult(-1,"",0,""); } - dns_fill_header(&h,buffer,l - 12); - if (c->id[0] != h.id[0] || c->id[1] != h.id[1]) + + /* Check wether the reply came from a different DNS + * server to the one we sent it to, or the source-port + * is not 53. + * A user could in theory still spoof dns packets anyway + * but this is less trivial than just sending garbage + * to the server, which is possible without this check. + * + * -- Thanks jilles for pointing this one out. + */ + if (from != myserver) { - log(DEBUG,"DNS: id mismatch on query"); - DELETE(c); - return NULL; /* ID mismatch */ + std::string server1 = from.str(); + std::string server2 = myserver.str(); + ServerInstance->Logs->Log("RESOLVER",DEBUG,"Got a result from the wrong server! Bad NAT or DNS forging attempt? '%s' != '%s'", + server1.c_str(), server2.c_str()); + return DNSResult(-1,"",0,""); } - if ((h.flags1 & FLAGS1_MASK_QR) == 0) + + /* Put the read header info into a header class */ + DNS::FillHeader(&header,buffer,length - 12); + + /* Get the id of this request. + * Its a 16 bit value stored in two char's, + * so we use logic shifts to create the value. + */ + unsigned long this_id = header.id[1] + (header.id[0] << 8); + + /* Do we have a pending request matching this id? */ + if (!requests[this_id]) { - log(DEBUG,"DNS: didnt get a query result"); - DELETE(c); - return NULL; + /* 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,""); } - if ((h.flags1 & FLAGS1_MASK_OPCODE) != 0) + else { - log(DEBUG,"DNS: got an OPCODE and didnt want one"); - DELETE(c); - return NULL; + /* Remove the query from the list of pending queries */ + req = requests[this_id]; + requests[this_id] = NULL; } - if ((h.flags2 & FLAGS2_MASK_RCODE) != 0) + + /* Inform the DNSRequest class that it has a result to be read. + * When its finished it will return a DNSInfo which is a pair of + * unsigned char* resource record data, and an error message. + */ + DNSInfo data = req->ResultIsReady(header, length); + std::string resultstr; + + /* Check if we got a result, if we didnt, its an error */ + if (data.first == NULL) { - log(DEBUG,"DNS lookup failed due to SERVFAIL"); - DELETE(c); - return NULL; + /* An error. + * Mask the ID with the value of ERROR_MASK, so that + * the dns_deal_with_classes() function knows that its + * an error response and needs to be treated uniquely. + * Put the error message in the second field. + */ + std::string ro = req->orig; + delete req; + return DNSResult(this_id | ERROR_MASK, data.second, 0, ro); } - if (h.ancount < 1) + else { - log(DEBUG,"DNS: no answers!"); - DELETE(c); - return NULL; + unsigned long ttl = req->ttl; + char formatted[128]; + + /* Forward lookups come back as binary data. We must format them into ascii */ + switch (req->type) + { + case DNS_QUERY_A: + snprintf(formatted,16,"%u.%u.%u.%u",data.first[0],data.first[1],data.first[2],data.first[3]); + resultstr = formatted; + break; + + case DNS_QUERY_AAAA: + { + if (!inet_ntop(AF_INET6, data.first, formatted, sizeof(formatted))) + { + std::string ro = req->orig; + delete req; + return DNSResult(this_id | ERROR_MASK, "inet_ntop() failed", 0, ro); + } + + resultstr = formatted; + + /* Special case. Sending ::1 around between servers + * and to clients is dangerous, because the : on the + * start makes the client or server interpret the IP + * as the last parameter on the line with a value ":1". + */ + if (*formatted == ':') + resultstr.insert(0, "0"); + } + break; + + case DNS_QUERY_CNAME: + /* Identical handling to PTR */ + + case DNS_QUERY_PTR: + { + /* Reverse lookups just come back as char* */ + resultstr = std::string((const char*)data.first); + if (resultstr.find_first_not_of("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-") != std::string::npos) + { + std::string ro = req->orig; + delete req; + return DNSResult(this_id | ERROR_MASK, "Invalid char(s) in reply", 0, ro); + } + } + break; + + default: + break; + } + + /* Build the reply with the id and hostname/ip in it */ + std::string ro = req->orig; + DNSResult result = DNSResult(this_id,resultstr,ttl,ro,req->type); + delete req; + return result; } - i = 0; - q = 0; - l -= 12; - while ((unsigned)q < h.qdcount && i < l) +} + +/** A result is ready, process it */ +DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, unsigned length) +{ + unsigned i = 0, o; + int q = 0; + int curanswer; + ResourceRecord rr; + unsigned short ptr; + + /* This is just to keep _FORTIFY_SOURCE happy */ + rr.type = DNS_QUERY_NONE; + rr.rdlength = 0; + rr.ttl = 1; /* GCC is a whiney bastard -- see the XXX below. */ + rr.rr_class = 0; /* Same for VC++ */ + + if (!(header.flags1 & FLAGS_MASK_QR)) + return std::make_pair((unsigned char*)NULL,"Not a query result"); + + if (header.flags1 & FLAGS_MASK_OPCODE) + return std::make_pair((unsigned char*)NULL,"Unexpected value in DNS reply packet"); + + if (header.flags2 & FLAGS_MASK_RCODE) + return std::make_pair((unsigned char*)NULL,"Domain name not found"); + + if (header.ancount < 1) + return std::make_pair((unsigned char*)NULL,"No resource records returned"); + + /* Subtract the length of the header from the length of the packet */ + length -= 12; + + while ((unsigned int)q < header.qdcount && i < length) { - if (h.payload[i] > 63) + if (header.payload[i] > 63) { i += 6; q++; } else { - if (h.payload[i] == 0) + if (header.payload[i] == 0) { q++; i += 5; } - else i += h.payload[i] + 1; + else i += header.payload[i] + 1; } } curanswer = 0; - while ((unsigned)curanswer < h.ancount) + while ((unsigned)curanswer < header.ancount) { q = 0; - while (q == 0 && i < l) + while (q == 0 && i < length) { - if (h.payload[i] > 63) + if (header.payload[i] > 63) { i += 2; q = 1; } else { - if (h.payload[i] == 0) + if (header.payload[i] == 0) { i++; q = 1; } - else i += h.payload[i] + 1; /* skip length and label */ + else i += header.payload[i] + 1; /* skip length and label */ } } - if (l - i < 10) - { - DELETE(c); - return NULL; - } - dns_fill_rr(&rr,&h.payload[i]); + if (static_cast(length - i) < 10) + return std::make_pair((unsigned char*)NULL,"Incorrectly sized DNS reply"); + + /* XXX: We actually initialise 'rr' here including its ttl field */ + DNS::FillResourceRecord(&rr,&header.payload[i]); + i += 10; - if (rr.type != c->type) + ServerInstance->Logs->Log("RESOLVER",DEBUG,"Resolver: rr.type is %d and this.type is %d rr.class %d this.class %d", rr.type, this->type, rr.rr_class, this->rr_class); + if (rr.type != this->type) { curanswer++; i += rr.rdlength; continue; } - if (rr._class != c->_class) + if (rr.rr_class != this->rr_class) { curanswer++; i += rr.rdlength; @@ -567,446 +814,301 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS } break; } - if ((unsigned)curanswer == h.ancount) - return NULL; - if ((unsigned)i + rr.rdlength > (unsigned)l) - return NULL; + if ((unsigned int)curanswer == header.ancount) + return std::make_pair((unsigned char*)NULL,"No A, AAAA or PTR type answers (" + ConvToStr(header.ancount) + " answers)"); + + if (i + rr.rdlength > (unsigned int)length) + return std::make_pair((unsigned char*)NULL,"Resource record larger than stated"); + if (rr.rdlength > 1023) - return NULL; + return std::make_pair((unsigned char*)NULL,"Resource record too large"); + + this->ttl = rr.ttl; switch (rr.type) { - case DNS_QRY_PTR: - log(DEBUG,"DNS: got a result of type DNS_QRY_PTR"); + /* + * CNAME and PTR are compressed. We need to decompress them. + */ + case DNS_QUERY_CNAME: + case DNS_QUERY_PTR: + { + unsigned short lowest_pos = length; o = 0; q = 0; - while (q == 0 && i < l && o + 256 < 1023) + while (q == 0 && i < length && o + 256 < 1023) { - if (h.payload[i] > 63) + /* DN label found (byte over 63) */ + if (header.payload[i] > 63) { - log(DEBUG,"DNS: h.payload[i] > 63"); - memcpy(&p,&h.payload[i],2); - i = ntohs(p) - 0xC000 - 12; + memcpy(&ptr,&header.payload[i],2); + + i = ntohs(ptr); + + /* check that highest two bits are set. if not, we've been had */ + if ((i & DN_COMP_BITMASK) != DN_COMP_BITMASK) + return std::make_pair((unsigned char *) NULL, "DN label decompression header is bogus"); + + /* mask away the two highest bits. */ + i &= ~DN_COMP_BITMASK; + + /* and decrease length by 12 bytes. */ + i -= 12; + + if (i >= lowest_pos) + return std::make_pair((unsigned char *) NULL, "Invalid decompression pointer"); + lowest_pos = i; } else { - if (h.payload[i] == 0) + if (header.payload[i] == 0) { q = 1; } else { - res[o] = '\0'; + res[o] = 0; if (o != 0) res[o++] = '.'; - memcpy(&res[o],&h.payload[i + 1],h.payload[i]); - o += h.payload[i]; - i += h.payload[i] + 1; + + if (o + header.payload[i] > sizeof(DNSHeader)) + return std::make_pair((unsigned char *) NULL, "DN label decompression is impossible -- malformed/hostile packet?"); + + memcpy(&res[o], &header.payload[i + 1], header.payload[i]); + o += header.payload[i]; + i += header.payload[i] + 1; } } } - res[o] = '\0'; + res[o] = 0; + } + break; + case DNS_QUERY_AAAA: + if (rr.rdlength != sizeof(struct in6_addr)) + return std::make_pair((unsigned char *) NULL, "rr.rdlength is larger than 16 bytes for an ipv6 entry -- malformed/hostile packet?"); + + memcpy(res,&header.payload[i],rr.rdlength); + res[rr.rdlength] = 0; + break; + case DNS_QUERY_A: + if (rr.rdlength != sizeof(struct in_addr)) + return std::make_pair((unsigned char *) NULL, "rr.rdlength is larger than 4 bytes for an ipv4 entry -- malformed/hostile packet?"); + + memcpy(res,&header.payload[i],rr.rdlength); + res[rr.rdlength] = 0; break; - case DNS_QRY_A: - log(DEBUG,"DNS: got a result of type DNS_QRY_A"); - if (c->want_list) - { - dns_ip4list *alist = (dns_ip4list *) res; /* we have to trust that this is aligned */ - while ((char *)alist - (char *)res < 700) - { - if (rr.type != DNS_QRY_A) - break; - if (rr._class != 1) - break; - if (rr.rdlength != 4) - { - DELETE(c); - return NULL; - } - memcpy(&alist->ip,&h.payload[i],4); - if ((unsigned)++curanswer >= h.ancount) - break; - i += rr.rdlength; - q = 0; - while (q == 0 && i < l) - { - if (h.payload[i] > 63) - { - i += 2; - q = 1; - } - else - { - if (h.payload[i] == 0) - { - i++; - q = 1; - } - else i += h.payload[i] + 1; - } - } - if (l - i < 10) - { - DELETE(c); - return NULL; - } - dns_fill_rr(&rr,&h.payload[i]); - i += 10; - alist->next = (dns_ip4list *) dns_align(((char *) alist) + sizeof(dns_ip4list)); - alist = alist->next; - alist->next = NULL; - } - alist->next = NULL; - break; - } - memcpy(res,&h.payload[i],rr.rdlength); - res[rr.rdlength] = '\0'; - break; default: - memcpy(res,&h.payload[i],rr.rdlength); - res[rr.rdlength] = '\0'; - break; + return std::make_pair((unsigned char *) NULL, "don't know how to handle undefined type (" + ConvToStr(rr.type) + ") -- rejecting"); + break; } - DELETE(c); - return res; + return std::make_pair(res,"No error"); } -DNS::DNS() +/** Close the master socket */ +DNS::~DNS() { - dns_init(); - log(DEBUG,"Create blank DNS"); + ServerInstance->SE->Shutdown(this, 2); + ServerInstance->SE->Close(this); + ServerInstance->Timers->DelTimer(this->PruneTimer); + if (cache) + delete cache; } -DNS::DNS(const std::string &dnsserver) +CachedQuery* DNS::GetCache(const std::string &source) { - dns_init_2(dnsserver.c_str()); - log(DEBUG,"Create DNS with server '%s'",dnsserver.c_str()); + dnscache::iterator x = cache->find(source.c_str()); + if (x != cache->end()) + return &(x->second); + else + return NULL; } -void DNS::SetNS(const std::string &dnsserver) +void DNS::DelCache(const std::string &source) { - dns_init_2(dnsserver.c_str()); - log(DEBUG,"Set NS"); + cache->erase(source.c_str()); } -DNS::~DNS() +void Resolver::TriggerCachedResult() { + if (CQ) + OnLookupComplete(CQ->data, time_left, true); } -bool DNS::ReverseLookup(const std::string &ip, bool ins) +/** High level abstraction of dns used by application at large */ +Resolver::Resolver(const std::string &source, QueryType qt, bool &cached, Module* creator) : Creator(creator), input(source), querytype(qt) { - if (ServerInstance && ServerInstance->stats) - ServerInstance->stats->statsDns++; - binip = dns_aton4(ip.c_str()); - if (binip == NULL) - { - return false; - } + ServerInstance->Logs->Log("RESOLVER",DEBUG,"Resolver::Resolver"); + cached = false; - this->myfd = dns_getname4(binip); - if (this->myfd == -1) + CQ = ServerInstance->Res->GetCache(source); + if (CQ) { - return false; - } - log(DEBUG,"DNS: ReverseLookup, fd=%d",this->myfd); -#ifndef THREADED_DNS - if (ins) - { - if (ServerInstance && ServerInstance->SE) - ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS); + time_left = CQ->CalcTTLRemaining(); + if (!time_left) + { + ServerInstance->Res->DelCache(source); + } + else if (CQ->type == qt) + { + cached = true; + return; + } + CQ = NULL; } -#endif - return true; -} -bool DNS::ForwardLookup(const std::string &host, bool ins) -{ - if (ServerInstance && ServerInstance->stats) - ServerInstance->stats->statsDns++; - this->myfd = dns_getip4(host.c_str()); - if (this->myfd == -1) + switch (querytype) { - return false; + case DNS_QUERY_A: + this->myid = ServerInstance->Res->GetIP(source.c_str()); + break; + + case DNS_QUERY_PTR4: + querytype = DNS_QUERY_PTR; + this->myid = ServerInstance->Res->GetNameForce(source.c_str(), PROTOCOL_IPV4); + break; + + case DNS_QUERY_PTR6: + querytype = DNS_QUERY_PTR; + this->myid = ServerInstance->Res->GetNameForce(source.c_str(), PROTOCOL_IPV6); + break; + + case DNS_QUERY_AAAA: + this->myid = ServerInstance->Res->GetIP6(source.c_str()); + break; + + case DNS_QUERY_CNAME: + this->myid = ServerInstance->Res->GetCName(source.c_str()); + break; + + default: + ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS request with unknown query type %d", querytype); + this->myid = -1; + break; } - log(DEBUG,"DNS: ForwardLookup, fd=%d",this->myfd); -#ifndef THREADED_DNS - if (ins) + if (this->myid == -1) { - if (ServerInstance && ServerInstance->SE) - ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS); + throw ModuleException("Resolver: Couldn't get an id to make a request"); } -#endif - return true; -} - -bool DNS::ForwardLookupWithFD(const std::string &host, int &fd) -{ - if (ServerInstance && ServerInstance->stats) - ServerInstance->stats->statsDns++; - this->myfd = dns_getip4(host.c_str()); - fd = this->myfd; - if (this->myfd == -1) + else { - return false; + ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS request id %d", this->myid); } - log(DEBUG,"DNS: ForwardLookupWithFD, fd=%d",this->myfd); - if (ServerInstance && ServerInstance->SE) - ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_MODULE); - return true; } -bool DNS::HasResult(int fd) +/** Called when an error occurs */ +void Resolver::OnError(ResolverError, const std::string&) { - return (fd == this->myfd); + /* Nothing in here */ } -/* Only the multithreaded dns uses this poll() based - * check now. As its in another thread we dont have - * to worry about its performance that much. - */ -bool DNS::HasResult() +/** Destroy a resolver */ +Resolver::~Resolver() { - log(DEBUG,"DNS: HasResult, fd=%d",this->myfd); - pollfd polls; - polls.fd = this->myfd; - polls.events = POLLIN; - int ret = poll(&polls,1,1); - log(DEBUG,"DNS: Hasresult returning %d",ret); - return (ret > 0); + /* Nothing here (yet) either */ } -int DNS::GetFD() +/** Get the request id associated with this class */ +int Resolver::GetId() { - return this->myfd; + return this->myid; } -std::string DNS::GetResult() +Module* Resolver::GetCreator() { - log(DEBUG,"DNS: GetResult()"); - result = dns_getresult(this->myfd); - if (result) - { - if (ServerInstance && ServerInstance->stats) - ServerInstance->stats->statsDnsGood++; - dns_close(this->myfd); - this->myfd = -1; - return result; - } - else - { - if (ServerInstance && ServerInstance->stats) - ServerInstance->stats->statsDnsBad++; - if (this->myfd != -1) - { - dns_close(this->myfd); - this->myfd = -1; - } - return ""; - } + return this->Creator; } -std::string DNS::GetResultIP() +/** Process a socket read event */ +void DNS::HandleEvent(EventType, int) { - char r[1024]; - log(DEBUG,"DNS: GetResultIP()"); - result = dns_getresult(this->myfd); - if (this->myfd != -1) - { - dns_close(this->myfd); - this->myfd = -1; - } - if (result) - { - if (ServerInstance && ServerInstance->stats) - ServerInstance->stats->statsDnsGood++; - unsigned char a = (unsigned)result[0]; - unsigned char b = (unsigned)result[1]; - unsigned char c = (unsigned)result[2]; - unsigned char d = (unsigned)result[3]; - snprintf(r,1024,"%u.%u.%u.%u",a,b,c,d); - return r; - } - else - { - if (ServerInstance && ServerInstance->stats) - ServerInstance->stats->statsDnsBad++; - log(DEBUG,"DANGER WILL ROBINSON! NXDOMAIN for forward lookup, but we got a reverse lookup!"); - return ""; - } -} + /* Fetch the id and result of the next available packet */ + DNSResult res(0,"",0,""); + res.id = 0; + ServerInstance->Logs->Log("RESOLVER",DEBUG,"Handle DNS event"); + res = this->GetResult(); + ServerInstance->Logs->Log("RESOLVER",DEBUG,"Result id %d", res.id); -#ifdef THREADED_DNS -void* dns_task(void* arg) -{ - userrec* u = (userrec*)arg; - int thisfd = u->fd; - - log(DEBUG,"DNS thread for user %s",u->nick); - DNS dns1; - DNS dns2; - std::string host; - std::string ip; - if (dns1.ReverseLookup((char*)inet_ntoa(u->ip4))) + /* Is there a usable request id? */ + if (res.id != -1) { - while (!dns1.HasResult()) + /* Its an error reply */ + if (res.id & ERROR_MASK) { - usleep(100); - } - host = dns1.GetResult(); - if (host != "") - { - if (dns2.ForwardLookup(host), false) + /* Mask off the error bit */ + res.id -= ERROR_MASK; + /* Marshall the error to the correct class */ + if (Classes[res.id]) { - while (!dns2.HasResult()) - { - usleep(100); - } - ip = dns2.GetResultIP(); - if (ip == std::string(inet_ntoa(u->ip4))) - { - if (host.length() < 160) - { - if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd])) - strcpy(u->host,host.c_str()); - if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd])) - strcpy(u->dhost,host.c_str()); - } - } + if (ServerInstance && ServerInstance->stats) + ServerInstance->stats->statsDnsBad++; + Classes[res.id]->OnError(RESOLVER_NXDOMAIN, res.result); + delete Classes[res.id]; + Classes[res.id] = NULL; } + return; } - } - if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd])) - u->dns_done = true; - return NULL; -} -#endif + else + { + /* It is a non-error result, marshall the result to the correct class */ + if (Classes[res.id]) + { + if (ServerInstance && ServerInstance->stats) + ServerInstance->stats->statsDnsGood++; -Resolver::Resolver(const std::string &source, bool forward, const std::string &dnsserver = "") : input(source), fwd(forward), server(dnsserver) -{ - if (this->server != "") - Query.SetNS(this->server); - else - Query.SetNS(Config->DNSServer); + if (!this->GetCache(res.original.c_str())) + this->cache->insert(std::make_pair(res.original.c_str(), CachedQuery(res.result, res.type, res.ttl))); - if (forward) - { - Query.ForwardLookup(input.c_str(), false); - this->fd = Query.GetFD(); - } - else - { - Query.ReverseLookup(input.c_str(), false); - this->fd = Query.GetFD(); - } - if (fd < 0) - { - log(DEBUG,"Resolver::Resolver: RESOLVER_NSDOWN"); - this->OnError(RESOLVER_NSDOWN); - ModuleException e("Resolver: Nameserver is down"); - throw e; - /* We shouldnt get here really */ - return; - } + Classes[res.id]->OnLookupComplete(res.result, res.ttl, false); + delete Classes[res.id]; + Classes[res.id] = NULL; + } + } - if (ServerInstance && ServerInstance->SE) - { - log(DEBUG,"Resolver::Resolver: this->fd=%d",this->fd); - ServerInstance->SE->AddFd(this->fd,true,X_ESTAB_CLASSDNS); - } - else - { - log(DEBUG,"Resolver::Resolver: RESOLVER_NOTREADY"); - this->OnError(RESOLVER_NOTREADY); - ModuleException e("Resolver: Core not initialized yet"); - throw e; - /* We shouldnt get here really */ - return; + if (ServerInstance && ServerInstance->stats) + ServerInstance->stats->statsDns++; } } -Resolver::~Resolver() -{ - log(DEBUG,"Resolver::~Resolver"); - if (ServerInstance && ServerInstance->SE) - ServerInstance->SE->DelFd(this->fd); -} - -int Resolver::GetFd() +/** Add a derived Resolver to the working set */ +bool DNS::AddResolverClass(Resolver* r) { - return this->fd; -} - -bool Resolver::ProcessResult() -{ - log(DEBUG,"Resolver::ProcessResult"); - if (this->fwd) - result = Query.GetResultIP(); - else - result = Query.GetResult(); - - if (result != "") + ServerInstance->Logs->Log("RESOLVER",DEBUG,"AddResolverClass 0x%08lx", (unsigned long)r); + /* Check the pointers validity and the id's validity */ + if ((r) && (r->GetId() > -1)) { - log(DEBUG,"Resolver::OnLookupComplete(%s)",result.c_str()); - this->OnLookupComplete(result); - return true; - } - else - { - log(DEBUG,"Resolver::OnError(RESOLVER_NXDOMAIN)"); - this->OnError(RESOLVER_NXDOMAIN); - return false; + /* Check the slot isnt already occupied - + * This should NEVER happen unless we have + * a severely broken DNS server somewhere + */ + if (!Classes[r->GetId()]) + { + /* Set up the pointer to the class */ + Classes[r->GetId()] = r; + return true; + } } -} -void Resolver::OnLookupComplete(const std::string &result) -{ -} - -void Resolver::OnError(ResolverError e) -{ + /* Pointer or id not valid, or duplicate id. + * Free the item and return + */ + delete r; + return false; } -void dns_deal_with_classes(int fd) +void DNS::CleanResolvers(Module* module) { - log(DEBUG,"dns_deal_with_classes(%d)",fd); - if ((fd > -1) && (dns_classes[fd])) + for (int i = 0; i < MAX_REQUEST_ID; i++) { - log(DEBUG,"Valid fd %d",fd); - dns_classes[fd]->ProcessResult(); - delete dns_classes[fd]; - dns_classes[fd] = NULL; - } -} - -bool dns_add_class(Resolver* r) -{ - log(DEBUG,"dns_add_class"); - if ((r) && (r->GetFd() > -1)) - { - if (!dns_classes[r->GetFd()]) - { - log(DEBUG,"dns_add_class: added class"); - dns_classes[r->GetFd()] = r; - return true; - } - else + if (Classes[i]) { - log(DEBUG,"Space occupied!"); - return false; + if (Classes[i]->GetCreator() == module) + { + Classes[i]->OnError(RESOLVER_FORCEUNLOAD, "Parent module is unloading"); + delete Classes[i]; + Classes[i] = NULL; + } } } - else - { - log(DEBUG,"Bad class"); - delete r; - return true; - } } - -void init_dns() -{ - memset(dns_classes,0,sizeof(dns_classes)); -} -