X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fdns.cpp;h=53224ba864cefecab007ca0744d1cab4244aaa93;hb=12b9855339a3bbd05cc0636588ea68bf8db390f5;hp=648e8f4a440a8e17cc63ad65dcc051153e3e9979;hpb=bcc3c8566cc5fcff6c39c94ac823941ad1e60b83;p=user%2Fhenk%2Fcode%2Finspircd.git diff --git a/src/dns.cpp b/src/dns.cpp index 648e8f4a4..53224ba86 100644 --- a/src/dns.cpp +++ b/src/dns.cpp @@ -2,18 +2,17 @@ * | Inspire Internet Relay Chat Daemon | * +------------------------------------+ * - * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev. - * E-mail: - * - * - * - * Written by Craig Edwards, Craig McLure, and others. + * InspIRCd: (C) 2002-2007 InspIRCd Development Team + * See: http://www.inspircd.org/wiki/index.php/Credits + * * This program is free but copyrighted software; see - * the file COPYING for details. + * the file COPYING for details. * * --------------------------------------------------- */ +/* $Core: libIRCDasyncdns */ + /* dns.cpp - Nonblocking DNS functions. Very very loosely based on the firedns library, @@ -24,39 +23,37 @@ Please do not assume that firedns works like this, looks like this, walks like this or tastes like this. */ -using namespace std; - -#include -#include +#ifndef WIN32 #include #include #include -#include -#include #include #include -#include +#else +#include "inspircd_win32wrapper.h" +#include "inspircd_se_config.h" +#endif + #include "dns.h" #include "inspircd.h" -#include "helperfuncs.h" -#include "inspircd_config.h" #include "socketengine.h" #include "configreader.h" +#include "socket.h" -/* We need these */ -extern InspIRCd* ServerInstance; -extern ServerConfig* Config; - -/* Master file descriptor */ -int DNS::MasterSocket; +using irc::sockets::insp_inaddr; +using irc::sockets::insp_ntoa; +using irc::sockets::insp_aton; +using irc::sockets::OpenTCPSocket; -/* Masks to mask off the responses we get from the DNSRequest methods */ +/** Masks to mask off the responses we get from the DNSRequest methods + */ enum QueryInfo { ERROR_MASK = 0x10000 /* Result is an error */ }; -/* Flags which can be ORed into a request or reply for different meanings */ +/** Flags which can be ORed into a request or reply for different meanings + */ enum QueryFlags { FLAGS_MASK_RD = 0x01, /* Recursive */ @@ -70,17 +67,17 @@ enum QueryFlags }; -/* Represents a dns resource record (rr) */ -class ResourceRecord +/** Represents a dns resource record (rr) + */ +struct ResourceRecord { - public: QueryType type; /* Record type */ unsigned int rr_class; /* Record class */ unsigned long ttl; /* Time to live */ unsigned int rdlength; /* Record length */ }; -/* Represents a dns request/reply header, and its payload as opaque data. +/** Represents a dns request/reply header, and its payload as opaque data. */ class DNSHeader { @@ -95,40 +92,84 @@ class DNSHeader unsigned char payload[512]; /* Packet payload */ }; -/* Represents a request 'on the wire' with routing information relating to - * where to call when we get a result - */ class DNSRequest { public: unsigned char id[2]; /* Request id */ - unsigned char* res; /* Result processing buffer */ - unsigned int rr_class; /* Request class */ + unsigned char* res; /* Result processing buffer */ + unsigned int rr_class; /* Request class */ QueryType type; /* Request type */ - insp_inaddr myserver; /* DNS server address*/ + DNS* dnsobj; /* DNS caller (where we get our FD from) */ + unsigned long ttl; /* Time to live */ + std::string orig; /* Original requested name/ip */ + InspIRCd* ServerInstance; + + DNSRequest(InspIRCd* Instance, DNS* dns, int id, const std::string &original); + ~DNSRequest(); + DNSInfo ResultIsReady(DNSHeader &h, int length, int result_we_want); + int SendRequests(const DNSHeader *header, const int length, QueryType qt); +}; - /* Allocate the processing buffer */ - DNSRequest(insp_inaddr server) +class CacheTimer : public Timer +{ + private: + InspIRCd* ServerInstance; + DNS* dns; + public: + CacheTimer(InspIRCd* Instance, DNS* thisdns) + : Timer(3600, Instance->Time(), true), ServerInstance(Instance), dns(thisdns) { } + + virtual void Tick(time_t) { - res = new unsigned char[512]; - *res = 0; - memcpy(&myserver, &server, sizeof(insp_inaddr)); + dns->PruneCache(); } +}; - /* Deallocate the processing buffer */ - ~DNSRequest() +class RequestTimeout : public Timer +{ + InspIRCd* ServerInstance; + DNSRequest* watch; + int watchid; + public: + RequestTimeout(unsigned long n, InspIRCd* SI, DNSRequest* watching, int id) : Timer(n, time(NULL)), ServerInstance(SI), watch(watching), watchid(id) { - delete[] res; } - /* Called when a result is ready to be processed which matches this id */ - DNSInfo ResultIsReady(DNSHeader &h, int length); - - /* Called when there are requests to be sent out */ - int SendRequests(const DNSHeader *header, const int length, QueryType qt); + 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; + return; + } + } }; -/* Fill a ResourceRecord class based on raw data input */ +/* Allocate the processing buffer */ +DNSRequest::DNSRequest(InspIRCd* Instance, DNS* dns, int id, const std::string &original) : dnsobj(dns), ServerInstance(Instance) +{ + res = new unsigned char[512]; + *res = 0; + orig = original; + RequestTimeout* RT = new RequestTimeout(Instance->Config->dns_timeout ? Instance->Config->dns_timeout : 5, Instance, this, id); + Instance->Timers->AddTimer(RT); /* The timer manager frees this */ +} + +/* Deallocate the processing buffer */ +DNSRequest::~DNSRequest() +{ + delete[] res; +} + +/** 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]); @@ -137,7 +178,7 @@ inline void DNS::FillResourceRecord(ResourceRecord* rr, const unsigned char *inp rr->rdlength = (input[8] << 8) + input[9]; } -/* Fill a DNSHeader class based on raw data input of a given length */ +/** 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]; @@ -151,7 +192,7 @@ inline void DNS::FillHeader(DNSHeader *header, const unsigned char *input, const memcpy(header->payload,&input[12],length); } -/* Empty a DNSHeader class out into raw data, ready for transmission */ +/** 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]; @@ -169,10 +210,9 @@ inline void DNS::EmptyHeader(unsigned char *output, const DNSHeader *header, con memcpy(&output[12],header->payload,length); } -/* Send requests we have previously built down the UDP socket */ +/** Send requests we have previously built down the UDP socket */ int DNSRequest::SendRequests(const DNSHeader *header, const int length, QueryType qt) { - insp_sockaddr addr; unsigned char payload[sizeof(DNSHeader)]; this->rr_class = 1; @@ -180,37 +220,46 @@ int DNSRequest::SendRequests(const DNSHeader *header, const int length, QueryTyp DNS::EmptyHeader(payload,header,length); - memset(&addr,0,sizeof(addr)); #ifdef IPV6 - memcpy(&addr.sin6_addr,&myserver,sizeof(addr.sin6_addr)); - addr.sin6_family = AF_FAMILY; - addr.sin6_port = htons(53); -#else - memcpy(&addr.sin_addr.s_addr,&myserver,sizeof(addr.sin_addr)); - addr.sin_family = AF_FAMILY; - addr.sin_port = htons(53); + if (this->dnsobj->socketfamily == AF_INET6) + { + sockaddr_in6 addr; + memset(&addr,0,sizeof(addr)); + memcpy(&addr.sin6_addr,&dnsobj->myserver6,sizeof(addr.sin6_addr)); + addr.sin6_family = AF_INET6; + addr.sin6_port = htons(DNS::QUERY_PORT); + if (ServerInstance->SE->SendTo(dnsobj, payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) != length+12) + return -1; + } + else #endif - if (sendto(DNS::GetMasterSocket(), payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) == -1) { - log(DEBUG,"Error in sendto!"); - return -1; + sockaddr_in addr; + memset(&addr,0,sizeof(addr)); + memcpy(&addr.sin_addr.s_addr,&dnsobj->myserver4,sizeof(addr.sin_addr)); + addr.sin_family = AF_INET; + addr.sin_port = htons(DNS::QUERY_PORT); + if (ServerInstance->SE->SendTo(dnsobj, (const char*)payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) != length+12) + return -1; } - return 0; } -/* Add a query with a predefined header, and allocate an ID for it. */ -DNSRequest* DNS::AddQuery(DNSHeader *header, int &id) +/** Add a query with a predefined header, and allocate an ID for it. */ +DNSRequest* DNS::AddQuery(DNSHeader *header, int &id, const char* original) { - id = this->PRNG() & 0xFFFF; + /* Is the DNS connection down? */ + if (this->GetFd() == -1) + return NULL; + + /* Create an id */ + id = this->PRNG() & DNS::MAX_REQUEST_ID; - /* This id is already 'in flight', pick another. - * -- Thanks jilles - */ - while (requests.find(id) != requests.end()) - id = this->PRNG() & 0xFFFF; + /* If this id is already 'in flight', pick another. */ + while (requests[id]) + id = this->PRNG() & DNS::MAX_REQUEST_ID; - DNSRequest* req = new DNSRequest(this->myserver); + DNSRequest* req = new DNSRequest(ServerInstance, this, id, original); header->id[0] = req->id[0] = id >> 8; header->id[1] = req->id[1] = id & 0xFF; @@ -230,79 +279,143 @@ DNSRequest* DNS::AddQuery(DNSHeader *header, int &id) return req; } -int DNS::GetMasterSocket() +int DNS::ClearCache() { - return MasterSocket; + /* This ensures the buckets are reset to sane levels */ + int rv = this->cache->size(); + delete this->cache; + this->cache = new dnscache(); + return rv; } -/* Initialise the DNS UDP socket so that we can send requests */ -DNS::DNS() +int DNS::PruneCache() { - insp_inaddr addr; + 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++; - /* Clear the Resolver class table */ - memset(Classes,0,sizeof(Classes)); + delete this->cache; + this->cache = newcache; + return n; +} - /* Set the id of the next request to 0 - */ - currid = 0; +void DNS::Rehash() +{ + ip6munge = false; + int portpass = 0; - /* Clear the namesever address */ - memset(&myserver,0,sizeof(insp_inaddr)); + if (this->GetFd() > -1) + { + if (ServerInstance && ServerInstance->SE) + ServerInstance->SE->DelFd(this); + ServerInstance->SE->Shutdown(this, 2); + ServerInstance->SE->Close(this); + this->SetFd(-1); + + /* Rehash the cache */ + this->PruneCache(); + } + else + { + /* Create initial dns cache */ + this->cache = new dnscache(); + } - /* Convert the nameserver address into an insp_inaddr */ - if (insp_aton(Config->DNSServer,&addr) > 0) - memcpy(&myserver,&addr,sizeof(insp_inaddr)); + if ((strstr(ServerInstance->Config->DNSServer,"::ffff:") == (char*)&ServerInstance->Config->DNSServer) || (strstr(ServerInstance->Config->DNSServer,"::FFFF:") == (char*)&ServerInstance->Config->DNSServer)) + { + ServerInstance->Log(DEFAULT,"WARNING: Using IPv4 addresses over IPv6 forces some DNS checks to be disabled."); + ServerInstance->Log(DEFAULT," This should not cause a problem, however it is recommended you migrate"); + ServerInstance->Log(DEFAULT," to a true IPv6 environment."); + this->ip6munge = true; + } - /* Initialize mastersocket */ - MasterSocket = socket(PF_PROTOCOL, SOCK_DGRAM, 0); - if (MasterSocket != -1) + this->socketfamily = AF_INET; +#ifdef IPV6 + if (strchr(ServerInstance->Config->DNSServer,':')) { - /* Did it succeed? */ - if (fcntl(MasterSocket, F_SETFL, O_NONBLOCK) != 0) - { - /* Couldn't make the socket nonblocking */ - shutdown(MasterSocket,2); - close(MasterSocket); - MasterSocket = -1; - } + this->socketfamily = AF_INET6; + inet_pton(AF_INET6, ServerInstance->Config->DNSServer, &this->myserver6); } - /* Have we got a socket and is it nonblocking? */ - if (MasterSocket != -1) + else { -#ifdef IPV6 - insp_sockaddr addr; - memset(&addr,0,sizeof(addr)); - addr.sin6_family = AF_FAMILY; - addr.sin6_port = 0; - memset(&addr.sin6_addr,255,sizeof(in6_addr)); + inet_aton(ServerInstance->Config->DNSServer, &this->myserver4); + portpass = -1; + } #else - insp_sockaddr addr; - memset(&addr,0,sizeof(addr)); - addr.sin_family = AF_FAMILY; - addr.sin_port = 0; - addr.sin_addr.s_addr = INADDR_ANY; + inet_aton(ServerInstance->Config->DNSServer, &this->myserver4); #endif - /* Bind the port */ - if (bind(MasterSocket,(sockaddr *)&addr,sizeof(addr)) != 0) + + /* Initialize mastersocket */ + int s = OpenTCPSocket(ServerInstance->Config->DNSServer, SOCK_DGRAM); + this->SetFd(s); + ServerInstance->SE->NonBlocking(this->GetFd()); + + /* Have we got a socket and is it nonblocking? */ + if (this->GetFd() != -1) + { + /* Bind the port - port 0 INADDR_ANY */ + if (!ServerInstance->BindSocket(this->GetFd(), portpass, "", false)) { /* Failed to bind */ - log(DEBUG,"Cant bind DNS::MasterSocket"); - shutdown(MasterSocket,2); - close(MasterSocket); - MasterSocket = -1; + ServerInstance->SE->Shutdown(this, 2); + ServerInstance->SE->Close(this); + this->SetFd(-1); } - if (MasterSocket >= 0) + if (this->GetFd() >= 0) { /* Hook the descriptor into the socket engine */ if (ServerInstance && ServerInstance->SE) - ServerInstance->SE->AddFd(MasterSocket,true,X_ESTAB_DNS); + { + if (!ServerInstance->SE->AddFd(this)) + { + ServerInstance->Log(DEFAULT,"Internal error starting DNS - hostnames will NOT resolve."); + ServerInstance->SE->Shutdown(this, 2); + ServerInstance->SE->Close(this); + this->SetFd(-1); + } + } } } } -/* Build a payload to be placed after the header, based upon input data, a resource type, a class and a pointer to a buffer */ +/** Initialise the DNS UDP socket so that we can send requests */ +DNS::DNS(InspIRCd* Instance) : ServerInstance(Instance) +{ + /* Clear the Resolver class table */ + memset(Classes,0,sizeof(Classes)); + + /* Clear the requests class table */ + memset(requests,0,sizeof(requests)); + + /* Set the id of the next request to 0 + */ + currid = 0; + + /* DNS::Rehash() sets this to a valid ptr + */ + this->cache = NULL; + + /* Again, DNS::Rehash() sets this to a + * valid value + */ + this->SetFd(-1); + + /* Actually read the settings + */ + this->Rehash(); + + this->PruneTimer = new CacheTimer(ServerInstance, 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; @@ -339,7 +452,7 @@ int DNS::MakePayload(const char * const name, const QueryType rr, const unsigned return payloadpos + 4; } -/* Start lookup of an hostname to an IP address */ +/** Start lookup of an hostname to an IP address */ int DNS::GetIP(const char *name) { DNSHeader h; @@ -349,56 +462,209 @@ int DNS::GetIP(const char *name) if ((length = this->MakePayload(name, DNS_QUERY_A, 1, (unsigned char*)&h.payload)) == -1) return -1; - DNSRequest* req = this->AddQuery(&h, id); + DNSRequest* req = this->AddQuery(&h, id, name); + + if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_A) == -1)) + return -1; + + return id; +} + +/** Start lookup of an hostname to an IPv6 address */ +int DNS::GetIP6(const char *name) +{ + DNSHeader h; + int id; + int length; + + if ((length = this->MakePayload(name, DNS_QUERY_AAAA, 1, (unsigned char*)&h.payload)) == -1) + return -1; - if (req->SendRequests(&h, length, DNS_QUERY_A) == -1) + DNSRequest* req = this->AddQuery(&h, id, name); + + if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_AAAA) == -1)) return -1; return id; } -/* Start lookup of an IP address to a hostname */ +/** Start lookup of a cname to another name */ +int DNS::GetCName(const char *alias) +{ + DNSHeader h; + int id; + int length; + + if ((length = this->MakePayload(alias, DNS_QUERY_CNAME, 1, (unsigned char*)&h.payload)) == -1) + return -1; + + DNSRequest* req = this->AddQuery(&h, id, alias); + + if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_CNAME) == -1)) + return -1; + + return id; +} + +/** Start lookup of an IP address to a hostname */ int DNS::GetName(const insp_inaddr *ip) { -#ifdef IPV6 - return -1; -#else - char query[29]; + char query[128]; DNSHeader h; int id; int length; +#ifdef IPV6 + unsigned char* c = (unsigned char*)&ip->s6_addr; + if (c[0] == 0 && c[1] == 0 && c[2] == 0 && c[3] == 0 && + c[4] == 0 && c[5] == 0 && c[6] == 0 && c[7] == 0 && + c[8] == 0 && c[9] == 0 && c[10] == 0xFF && c[11] == 0xFF) + sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[15],c[14],c[13],c[12]); + else + DNS::MakeIP6Int(query, (in6_addr*)ip); +#else unsigned char* c = (unsigned char*)&ip->s_addr; - sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]); +#endif + + if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1) + return -1; + + DNSRequest* req = this->AddQuery(&h, id, insp_ntoa(*ip)); + + if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1)) + return -1; + + return id; +} + +/** 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; +#ifdef SUPPORT_IP6LINKS + if (fp == PROTOCOL_IPV6) + { + in6_addr i; + if (inet_pton(AF_INET6, ip, &i) > 0) + { + DNS::MakeIP6Int(query, &i); + } + else + /* Invalid IP address */ + return -1; + } + else +#endif + { + 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 + /* Invalid IP address */ + return -1; + } if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1) return -1; - DNSRequest* req = this->AddQuery(&h, id); + DNSRequest* req = this->AddQuery(&h, id, ip); - if (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1) + if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1)) return -1; return id; +} + +/** Build an ipv6 reverse domain from an in6_addr + */ +void DNS::MakeIP6Int(char* query, const in6_addr *ip) +{ +#ifdef SUPPORT_IP6LINKS + const char* hex = "0123456789abcdef"; + for (int index = 31; index >= 0; index--) /* for() loop steps twice per byte */ + { + 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 */ +#else + *query = 0; #endif } -/* Return the next id which is ready, and the result attached to it */ -DNSResult DNS::GetResult() +/** Return the next id which is ready, and the result attached to it */ +DNSResult DNS::GetResult(int resultnum) { /* Fetch dns query response and decide where it belongs */ DNSHeader header; DNSRequest *req; unsigned char buffer[sizeof(DNSHeader)]; + sockaddr* from = new sockaddr[2]; +#ifdef IPV6 + socklen_t x = this->socketfamily == AF_INET ? sizeof(sockaddr_in) : sizeof(sockaddr_in6); +#else + socklen_t x = sizeof(sockaddr_in); +#endif + const char* ipaddr_from; + unsigned short int port_from = 0; - /* Attempt to read a header */ - int length = recv(MasterSocket,buffer,sizeof(DNSHeader),0); + int length = ServerInstance->SE->RecvFrom(this, (char*)buffer, sizeof(DNSHeader), 0, from, &x); /* Did we get the whole header? */ if (length < 12) + { /* Nope - something screwed up. */ - return std::make_pair(-1,""); + delete[] from; + return DNSResult(-1,"",0,""); + } + + /* 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 client, which is possible without this check. + * + * -- Thanks jilles for pointing this one out. + */ +#ifdef IPV6 + char nbuf[MAXBUF]; + if (this->socketfamily == AF_INET6) + { + ipaddr_from = inet_ntop(AF_INET6, &((sockaddr_in6*)from)->sin6_addr, nbuf, sizeof(nbuf)); + port_from = ntohs(((sockaddr_in6*)from)->sin6_port); + } + else +#endif + { + ipaddr_from = inet_ntoa(((sockaddr_in*)from)->sin_addr); + port_from = ntohs(((sockaddr_in*)from)->sin_port); + } + + delete[] from; + + /* We cant perform this security check if you're using 4in6. + * Tough luck to you, choose one or't other! + */ + if (!ip6munge) + { + if ((port_from != DNS::QUERY_PORT) || (strcasecmp(ipaddr_from, ServerInstance->Config->DNSServer))) + { + return DNSResult(-1,"",0,""); + } + } /* Put the read header info into a header class */ DNS::FillHeader(&header,buffer,length - 12); @@ -410,25 +676,23 @@ DNSResult DNS::GetResult() unsigned long this_id = header.id[1] + (header.id[0] << 8); /* Do we have a pending request matching this id? */ - requestlist_iter n_iter = requests.find(this_id); - if (n_iter == requests.end()) + if (!requests[this_id]) { /* Somehow we got a DNS response for a request we never made... */ - log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d queryid=%d",MasterSocket,this_id); - return std::make_pair(-1,""); + return DNSResult(-1,"",0,""); } else { /* Remove the query from the list of pending queries */ - req = (DNSRequest*)n_iter->second; - requests.erase(n_iter); + req = requests[this_id]; + requests[this_id] = NULL; } /* 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); + DNSInfo data = req->ResultIsReady(header, length, resultnum); std::string resultstr; /* Check if we got a result, if we didnt, its an error */ @@ -440,39 +704,84 @@ DNSResult DNS::GetResult() * 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 std::make_pair(this_id | ERROR_MASK, data.second); + return DNSResult(this_id | ERROR_MASK, data.second, 0, ro); } else { + unsigned long ttl = req->ttl; + char formatted[128]; + /* Forward lookups come back as binary data. We must format them into ascii */ - if (req->type == DNS_QUERY_A) + switch (req->type) { - char formatted[16]; - snprintf(formatted,16,"%u.%u.%u.%u",data.first[0],data.first[1],data.first[2],data.first[3]); - resultstr = formatted; - } - else - { - /* Reverse lookups just come back as char* */ - resultstr = std::string((const char*)data.first); + 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: + { + inet_ntop(AF_INET6, data.first, formatted, sizeof(formatted)); + char* c = strstr(formatted,":0:"); + if (c != NULL) + { + memmove(c+1,c+2,strlen(c+2) + 1); + c += 2; + while (memcmp(c,"0:",2) == 0) + memmove(c,c+2,strlen(c+2) + 1); + if (memcmp(c,"0",2) == 0) + *c = 0; + if (memcmp(formatted,"0::",3) == 0) + memmove(formatted,formatted + 1, strlen(formatted + 1) + 1); + } + 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); + break; + + default: + break; + } /* Build the reply with the id and hostname/ip in it */ + std::string ro = req->orig; delete req; - return std::make_pair(this_id,resultstr); + return DNSResult(this_id,resultstr,ttl,ro); } } -/* A result is ready, process it */ -DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length) +/** A result is ready, process it */ +DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length, int result_we_want) { int i = 0; int q = 0; int curanswer, o; 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. */ + if (!(header.flags1 & FLAGS_MASK_QR)) return std::make_pair((unsigned char*)NULL,"Not a query result"); @@ -529,7 +838,10 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length) if (length - i < 10) return std::make_pair((unsigned char*)NULL,"Incorrectly sized DNS reply"); - DNS::FillResourceRecord(&rr,&header.payload[i]); + /* XXX: We actually initialise 'rr' here including its ttl field */ + if (curanswer == result_we_want) + DNS::FillResourceRecord(&rr,&header.payload[i]); + i += 10; if (rr.type != this->type) { @@ -546,7 +858,7 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length) break; } if ((unsigned int)curanswer == header.ancount) - return std::make_pair((unsigned char*)NULL,"No valid answers"); + return std::make_pair((unsigned char*)NULL,"No more records"); if (i + rr.rdlength > (unsigned int)length) return std::make_pair((unsigned char*)NULL,"Resource record larger than stated"); @@ -554,8 +866,12 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length) if (rr.rdlength > 1023) return std::make_pair((unsigned char*)NULL,"Resource record too large"); + this->ttl = rr.ttl; + switch (rr.type) { + case DNS_QUERY_CNAME: + /* CNAME and PTR have the same processing code */ case DNS_QUERY_PTR: o = 0; q = 0; @@ -585,128 +901,206 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length) } res[o] = 0; break; + case DNS_QUERY_AAAA: + memcpy(res,&header.payload[i],rr.rdlength); + res[rr.rdlength] = 0; + break; case DNS_QUERY_A: memcpy(res,&header.payload[i],rr.rdlength); res[rr.rdlength] = 0; - break; + break; default: memcpy(res,&header.payload[i],rr.rdlength); res[rr.rdlength] = 0; - break; + break; } - return std::make_pair(res,"No error");; + return std::make_pair(res,"No error"); } -/* Close the master socket */ +/** Close the master socket */ DNS::~DNS() { - shutdown(MasterSocket, 2); - close(MasterSocket); + ServerInstance->SE->Shutdown(this, 2); + ServerInstance->SE->Close(this); + ServerInstance->Timers->DelTimer(this->PruneTimer); + delete this->PruneTimer; } -/* High level abstraction of dns used by application at large */ -Resolver::Resolver(const std::string &source, bool forward) : input(source), fwd(forward) +CachedQuery* DNS::GetCache(const std::string &source) { - if (forward) - { - log(DEBUG,"Resolver: Forward lookup on %s",source.c_str()); - this->myid = ServerInstance->Res->GetIP(source.c_str()); - } + dnscache::iterator x = cache->find(source.c_str()); + if (x != cache->end()) + return &(x->second); else + return NULL; +} + +void DNS::DelCache(const std::string &source) +{ + cache->erase(source.c_str()); +} + +void Resolver::TriggerCachedResult() +{ + if (CQ) + OnLookupComplete(CQ->data, time_left, true, 0); +} + +/** High level abstraction of dns used by application at large */ +Resolver::Resolver(InspIRCd* Instance, const std::string &source, QueryType qt, bool &cached, Module* creator) : ServerInstance(Instance), Creator(creator), input(source), querytype(qt) +{ + cached = false; + + CQ = ServerInstance->Res->GetCache(source); + if (CQ) { - log(DEBUG,"Resolver: Reverse lookup on %s",source.c_str()); - insp_inaddr binip; - if (insp_aton(source.c_str(), &binip) > 0) + time_left = CQ->CalcTTLRemaining(); + if (!time_left) { - /* Valid ip address */ - this->myid = ServerInstance->Res->GetName(&binip); + ServerInstance->Res->DelCache(source); } else { - this->OnError(RESOLVER_BADIP, "Bad IP address for reverse lookup"); - throw ModuleException("Resolver: Bad IP address"); + cached = true; return; } } + + insp_inaddr binip; + + switch (querytype) + { + case DNS_QUERY_A: + this->myid = ServerInstance->Res->GetIP(source.c_str()); + break; + + case DNS_QUERY_PTR: + if (insp_aton(source.c_str(), &binip) > 0) + { + /* Valid ip address */ + this->myid = ServerInstance->Res->GetName(&binip); + } + else + { + this->OnError(RESOLVER_BADIP, "Bad IP address for reverse lookup"); + throw ModuleException("Resolver: Bad IP address"); + return; + } + 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: + this->myid = -1; + break; + } if (this->myid == -1) { - log(DEBUG,"Resolver::Resolver: Could not get an id!"); this->OnError(RESOLVER_NSDOWN, "Nameserver is down"); throw ModuleException("Resolver: Couldnt get an id to make a request"); /* We shouldnt get here really */ return; } - - log(DEBUG,"Resolver::Resolver: this->myid=%d",this->myid); } -void Resolver::OnError(ResolverError e, const std::string &errormessage) +/** Called when an error occurs */ +void Resolver::OnError(ResolverError, const std::string&) { /* Nothing in here */ } +/** Destroy a resolver */ Resolver::~Resolver() { /* Nothing here (yet) either */ } -/* Get the request id associated with this class */ +/** Get the request id associated with this class */ int Resolver::GetId() { return this->myid; } -/* Process a socket read event */ -void DNS::MarshallReads(int fd) +Module* Resolver::GetCreator() { - /* We are only intrested in our single fd */ - if (fd == GetMasterSocket()) + return this->Creator; +} + +/** Process a socket read event */ +void DNS::HandleEvent(EventType, int) +{ + /* Fetch the id and result of the next available packet */ + int resultnum = 0; + DNSResult res(0,"",0,""); + res.id = 0; + ServerInstance->Log(DEBUG,"Handle DNS event"); + while ((res.id & ERROR_MASK) == 0) { - /* Fetch the id and result of the next available packet */ - DNSResult res = this->GetResult(); + res = this->GetResult(resultnum); + + ServerInstance->Log(DEBUG,"Result %d id %d", resultnum, res.id); + /* Is there a usable request id? */ - if (res.first != -1) + if (res.id != -1) { /* Its an error reply */ - if (res.first & ERROR_MASK) + if (res.id & ERROR_MASK) { /* Mask off the error bit */ - res.first -= ERROR_MASK; - + res.id -= ERROR_MASK; /* Marshall the error to the correct class */ - log(DEBUG,"Error available, id=%d",res.first); - if (Classes[res.first]) + if (Classes[res.id]) { if (ServerInstance && ServerInstance->stats) ServerInstance->stats->statsDnsBad++; - Classes[res.first]->OnError(RESOLVER_NXDOMAIN, res.second); - delete Classes[res.first]; - Classes[res.first] = NULL; + Classes[res.id]->OnError(RESOLVER_NXDOMAIN, res.result); + delete Classes[res.id]; + Classes[res.id] = NULL; } + break; } else { - /* It is a non-error result */ - log(DEBUG,"Result available, id=%d",res.first); - /* Marshall the result to the correct class */ - if (Classes[res.first]) + /* It is a non-error result, marshall the result to the correct class */ + if (Classes[res.id]) { if (ServerInstance && ServerInstance->stats) ServerInstance->stats->statsDnsGood++; - Classes[res.first]->OnLookupComplete(res.second); - delete Classes[res.first]; - Classes[res.first] = NULL; + + if (!this->GetCache(res.original.c_str())) + this->cache->insert(std::make_pair(res.original.c_str(), CachedQuery(res.result, res.ttl))); + + Classes[res.id]->OnLookupComplete(res.result, res.ttl, false, resultnum); + delete Classes[res.id]; + Classes[res.id] = NULL; } } - + if (ServerInstance && ServerInstance->stats) ServerInstance->stats->statsDns++; - } + + resultnum++; } } - -/* Add a derived Resolver to the working set */ + +/** Add a derived Resolver to the working set */ bool DNS::AddResolverClass(Resolver* r) { /* Check the pointers validity and the id's validity */ @@ -738,6 +1132,23 @@ bool DNS::AddResolverClass(Resolver* r) } } +void DNS::CleanResolvers(Module* module) +{ + for (int i = 0; i < MAX_REQUEST_ID; i++) + { + if (Classes[i]) + { + if (Classes[i]->GetCreator() == module) + { + Classes[i]->OnError(RESLOVER_FORCEUNLOAD, "Parent module is unloading"); + delete Classes[i]; + Classes[i] = NULL; + } + } + } +} + +/** Generate pseudo-random number */ unsigned long DNS::PRNG() { unsigned long val = 0; @@ -746,7 +1157,7 @@ unsigned long DNS::PRNG() gettimeofday(&n,NULL); val = (n.tv_usec ^ getpid() ^ geteuid() ^ (this->currid++)) ^ s->statsAccept + n.tv_sec; val = val + s->statsCollisions ^ s->statsDnsGood - s->statsDnsBad; - val += (s->statsConnects ^ (unsigned long)s->statsSent ^ (unsigned long)s->statsRecv) - s->BoundPortCount; + val += (s->statsConnects ^ (unsigned long)s->statsSent ^ (unsigned long)s->statsRecv) - ServerInstance->Config->ports.size(); return val; }