-/* +------------------------------------+
- * | Inspire Internet Relay Chat Daemon |
- * +------------------------------------+
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ * Copyright (C) 2012 William Pitcock <nenolod@dereferenced.org>
+ * Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
+ * Copyright (C) 2006, 2009 Robin Burchell <robin+git@viroteck.net>
+ * Copyright (C) 2007, 2009 Dennis Friis <peavey@inspircd.org>
+ * Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
+ * Copyright (C) 2005-2007 Craig Edwards <craigedwards@brainbox.cc>
*
- * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
- * E-mail:
- * <brain@chatspike.net>
- * <Craig@chatspike.net>
- *
- * Written by Craig Edwards, Craig McLure, and others.
- * This program is free but copyrighted software; see
- * the file COPYING for details.
+ * 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/>.
*/
+
+/* $Core */
+
/*
dns.cpp - Nonblocking DNS functions.
Very very loosely based on the firedns library,
looks like this, walks like this or tastes like this.
*/
-using namespace std;
-
-#include <string>
-#include <time.h>
+#ifndef _WIN32
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
-#include <map>
-#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"
-/* We need these */
-extern InspIRCd* ServerInstance;
-extern ServerConfig* Config;
-
-/* Master file descriptor */
-int DNS::MasterSocket;
+#define DN_COMP_BITMASK 0xC000 /* highest 6 bits in a DN label header */
-/* 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 */
};
-/* 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
{
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 */
+
+ 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 CacheTimer : public Timer
+{
+ private:
+ DNS* dns;
+ public:
+ CacheTimer(DNS* thisdns)
+ : Timer(5*60, ServerInstance->Time(), true), dns(thisdns) { }
- /* Allocate the processing buffer */
- DNSRequest(insp_inaddr server)
+ 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
+{
+ DNSRequest* watch;
+ int watchid;
+ public:
+ RequestTimeout(unsigned long n, DNSRequest* watching, int id) : Timer(n, ServerInstance->Time()), watch(watching), watchid(id)
{
- delete[] res;
+ }
+ ~RequestTimeout()
+ {
+ if (ServerInstance->Res)
+ Tick(0);
}
- /* 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;
+ }
+ }
};
-/* Fill a ResourceRecord class based on raw data input */
+CachedQuery::CachedQuery(const std::string &res, QueryType qt, unsigned int ttl) : data(res), type(qt)
+{
+ if (ttl > 5*60)
+ ttl = 5*60;
+ expires = ServerInstance->Time() + ttl;
+}
+
+int CachedQuery::CalcTTLRemaining()
+{
+ int n = expires - ServerInstance->Time();
+ return (n < 0 ? 0 : n);
+}
+
+/* Allocate the processing buffer */
+DNSRequest::DNSRequest(DNS* dns, int rid, const std::string &original) : dnsobj(dns)
+{
+ /* 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;
+}
+
+/** 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->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];
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];
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;
+ ServerInstance->Logs->Log("RESOLVER", DEBUG,"DNSRequest::SendRequests");
+
unsigned char payload[sizeof(DNSHeader)];
this->rr_class = 1;
this->type = qt;
-
+
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(DNS::QUERY_PORT);
-#else
- memcpy(&addr.sin_addr.s_addr,&myserver,sizeof(addr.sin_addr));
- addr.sin_family = AF_FAMILY;
- addr.sin_port = htons(DNS::QUERY_PORT);
-#endif
- if (sendto(DNS::GetMasterSocket(), payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) == -1)
- {
- log(DEBUG,"Error in sendto!");
+ 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)
+/** Add a query with a predefined header, and allocate an ID for it. */
+DNSRequest* DNS::AddQuery(DNSHeader *header, int &id, const char* original)
{
- /* Are there already the max number of requests on the go? */
- if (requests.size() == DNS::MAX_REQUEST_ID + 1)
+ /* Is the DNS connection down? */
+ if (this->GetFd() == -1)
return NULL;
-
+
/* Create an id */
- id = this->PRNG() & DNS::MAX_REQUEST_ID;
+ unsigned int tries = 0;
+ do {
+ 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
+ id = -1;
+ for (int i = 0; i < DNS::MAX_REQUEST_ID; i++)
+ {
+ if (!requests[i])
+ {
+ id = i;
+ break;
+ }
+ }
- /* If this id is already 'in flight', pick another. */
- while (requests.find(id) != requests.end())
- id = this->PRNG() & DNS::MAX_REQUEST_ID;
+ if (id == -1)
+ throw ModuleException("DNS: All ids are in use");
- DNSRequest* req = new DNSRequest(this->myserver);
+ break;
+ }
+ } 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;
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()
+{
+ if (this->GetFd() > -1)
+ {
+ ServerInstance->SE->DelFd(this);
+ ServerInstance->SE->Shutdown(this, 2);
+ ServerInstance->SE->Close(this);
+ this->SetFd(-1);
- /* Clear the namesever address */
- memset(&myserver,0,sizeof(insp_inaddr));
+ /* 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));
+ irc::sockets::aptosa(ServerInstance->Config->DNSServer, DNS::QUERY_PORT, myserver);
/* Initialize mastersocket */
- MasterSocket = socket(PF_PROTOCOL, SOCK_DGRAM, 0);
- if (MasterSocket != -1)
- {
- /* Did it succeed? */
- if (fcntl(MasterSocket, F_SETFL, O_NONBLOCK) != 0)
- {
- /* Couldn't make the socket nonblocking */
- shutdown(MasterSocket,2);
- close(MasterSocket);
- MasterSocket = -1;
- }
- }
+ int s = socket(myserver.sa.sa_family, SOCK_DGRAM, 0);
+ this->SetFd(s);
+
/* Have we got a socket and is it nonblocking? */
- if (MasterSocket != -1)
- {
-#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));
-#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;
-#endif
- /* Bind the port */
- if (bind(MasterSocket,(sockaddr *)&addr,sizeof(addr)) != 0)
+ 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 */
- log(DEBUG,"Cant bind DNS::MasterSocket");
- shutdown(MasterSocket,2);
- close(MasterSocket);
- MasterSocket = -1;
+ 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 (MasterSocket >= 0)
+ else if (!ServerInstance->SE->AddFd(this, FD_WANT_POLL_READ | FD_WANT_NO_WRITE))
{
- /* Hook the descriptor into the socket engine */
- if (ServerInstance && ServerInstance->SE)
- ServerInstance->SE->AddFd(MasterSocket,true,X_ESTAB_DNS);
+ ServerInstance->Logs->Log("RESOLVER",SPARSE,"Internal error starting DNS - hostnames will NOT resolve.");
+ ServerInstance->SE->Shutdown(this, 2);
+ ServerInstance->SE->Close(this);
+ this->SetFd(-1);
}
}
+ else
+ {
+ ServerInstance->Logs->Log("RESOLVER",SPARSE,"Error creating DNS socket - hostnames will NOT resolve");
+ }
+}
+
+/** Initialise the DNS UDP socket so that we can send requests */
+DNS::DNS()
+{
+ 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;
+
+ /* 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 */
+/** 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;
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;
int id;
int length;
-
+
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 */
+/** Start lookup of an hostname to an IPv6 address */
int DNS::GetIP6(const char *name)
{
DNSHeader h;
if ((length = this->MakePayload(name, DNS_QUERY_AAAA, 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_AAAA) == -1))
return -1;
return id;
}
-/* Start lookup of a cname to another name */
+/** Start lookup of a cname to another name */
int DNS::GetCName(const char *alias)
{
DNSHeader h;
if ((length = this->MakePayload(alias, DNS_QUERY_CNAME, 1, (unsigned char*)&h.payload)) == -1)
return -1;
- DNSRequest* req = this->AddQuery(&h, id);
+ 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)
-{
- char query[128];
- DNSHeader h;
- int id;
- int length;
-
-#ifdef IPV6
- 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);
-
- if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
- return -1;
-
- return id;
-}
-
-/* Start lookup of an IP address to a hostname */
+/** Start lookup of an IP address to a hostname */
int DNS::GetNameForce(const char *ip, ForceProtocol fp)
{
char query[128];
DNS::MakeIP6Int(query, &i);
}
else
+ {
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce IPv6 bad format for '%s'", ip);
/* Invalid IP address */
return -1;
+ }
}
else
{
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;
+ }
}
- log(DEBUG,"DNS::GetNameForce: %s %d",query, fp);
-
- if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1)
+ length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload);
+ if (length == -1)
+ {
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce can't query '%s' using '%s' because it's too long", ip, query);
return -1;
+ }
- DNSRequest* req = this->AddQuery(&h, id);
+ DNSRequest* req = this->AddQuery(&h, id, ip);
- if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
+ if (!req)
+ {
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce can't add query (resolver down?)");
return -1;
+ }
+
+ if (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1)
+ {
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce can't send (firewall?)");
+ return -1;
+ }
return id;
}
+/** Build an ipv6 reverse domain from an in6_addr
+ */
void DNS::MakeIP6Int(char* query, const in6_addr *ip)
{
const char* hex = "0123456789abcdef";
strcpy(query,"ip6.arpa"); /* Suffix the string */
}
-/* Return the next id which is ready, and the result attached to it */
+/** 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)];
- sockaddr from;
+ irc::sockets::sockaddrs from;
+ memset(&from, 0, sizeof(from));
socklen_t x = sizeof(from);
- const char* ipaddr_from = "";
- unsigned short int port_from = 0;
- int length = recvfrom(MasterSocket,buffer,sizeof(DNSHeader),0,&from,&x);
+ int length = ServerInstance->SE->RecvFrom(this, (char*)buffer, sizeof(DNSHeader), 0, &from.sa, &x);
/* Did we get the whole header? */
if (length < 12)
+ {
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"GetResult didn't get a full packet (len=%d)", length);
/* Nope - something screwed up. */
- return std::make_pair(-1,"");
+ 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.
+ * to the server, which is possible without this check.
*
* -- Thanks jilles for pointing this one out.
*/
-#ifdef IPV6
- ipaddr_from = insp_ntoa(((sockaddr_in6*)&from)->sin6_addr);
- port_from = ntohs(((sockaddr_in6*)&from)->sin6_port);
-#else
- ipaddr_from = insp_ntoa(((sockaddr_in*)&from)->sin_addr);
- port_from = ntohs(((sockaddr_in*)&from)->sin_port);
-#endif
-
- if ((port_from != DNS::QUERY_PORT) || (strcasecmp(ipaddr_from, Config->DNSServer)))
- return std::make_pair(-1,"");
+ if (from != myserver)
+ {
+ 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,"");
+ }
/* Put the read header info into a header class */
DNS::FillHeader(&header,buffer,length - 12);
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,"");
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"Hmm, got a result that we didn't ask for (id=%lx). Ignoring.", this_id);
+ return DNSResult(-1,"",0,"");
}
else
{
/* 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.
* 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 */
case DNS_QUERY_AAAA:
{
- snprintf(formatted,40,"%x:%x:%x:%x:%x:%x:%x:%x",
- (ntohs(data.first[0]) + ntohs(data.first[1] << 8)),
- (ntohs(data.first[2]) + ntohs(data.first[3] << 8)),
- (ntohs(data.first[4]) + ntohs(data.first[5] << 8)),
- (ntohs(data.first[6]) + ntohs(data.first[7] << 8)),
- (ntohs(data.first[8]) + ntohs(data.first[9] << 8)),
- (ntohs(data.first[10]) + ntohs(data.first[11] << 8)),
- (ntohs(data.first[12]) + ntohs(data.first[13] << 8)),
- (ntohs(data.first[14]) + ntohs(data.first[15] << 8)));
- char* c = strstr(formatted,":0:");
- if (c != NULL)
+ if (!inet_ntop(AF_INET6, data.first, formatted, sizeof(formatted)))
{
- 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);
+ 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;
/* 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:
- log(DEBUG,"WARNING: Somehow we made a request for a DNS_QUERY_PTR4 or DNS_QUERY_PTR6, but these arent real rr types!");
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 std::make_pair(this_id,resultstr);
+ return result;
}
}
-/* A result is ready, process it */
-DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
+/** A result is ready, process it */
+DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, unsigned length)
{
- int i = 0;
+ unsigned i = 0, o;
int q = 0;
- int curanswer, o;
+ 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");
else i += header.payload[i] + 1; /* skip length and label */
}
}
- if (length - i < 10)
+ if (static_cast<int>(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;
+ 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++;
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 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 std::make_pair((unsigned char*)NULL,"Resource record too large");
+ this->ttl = rr.ttl;
+
switch (rr.type)
{
+ /*
+ * CNAME and PTR are compressed. We need to decompress them.
+ */
case DNS_QUERY_CNAME:
- /* CNAME and PTR have the same processing code */
case DNS_QUERY_PTR:
+ {
+ unsigned short lowest_pos = length;
o = 0;
q = 0;
while (q == 0 && i < length && o + 256 < 1023)
{
+ /* DN label found (byte over 63) */
if (header.payload[i] > 63)
{
memcpy(&ptr,&header.payload[i],2);
- i = ntohs(ptr) - 0xC000 - 12;
+
+ 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
{
res[o] = 0;
if (o != 0)
res[o++] = '.';
- memcpy(&res[o],&header.payload[i + 1],header.payload[i]);
+
+ 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;
+ }
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;
default:
- memcpy(res,&header.payload[i],rr.rdlength);
- res[rr.rdlength] = 0;
+ return std::make_pair((unsigned char *) NULL, "don't know how to handle undefined type (" + ConvToStr(rr.type) + ") -- rejecting");
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);
+ if (cache)
+ delete cache;
+}
+
+CachedQuery* DNS::GetCache(const std::string &source)
+{
+ 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());
}
-/* High level abstraction of dns used by application at large */
-Resolver::Resolver(const std::string &source, QueryType qt) : input(source), querytype(qt)
+void Resolver::TriggerCachedResult()
{
- insp_inaddr binip;
+ if (CQ)
+ OnLookupComplete(CQ->data, time_left, true);
+}
+
+/** 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)
+{
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"Resolver::Resolver");
+ cached = false;
+
+ CQ = ServerInstance->Res->GetCache(source);
+ if (CQ)
+ {
+ time_left = CQ->CalcTTLRemaining();
+ if (!time_left)
+ {
+ ServerInstance->Res->DelCache(source);
+ }
+ else if (CQ->type == qt)
+ {
+ cached = true;
+ return;
+ }
+ CQ = NULL;
+ }
switch (querytype)
{
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;
default:
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS request with unknown query type %d", querytype);
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;
+ throw ModuleException("Resolver: Couldn't get an id to make a request");
+ }
+ else
+ {
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS request id %d", this->myid);
}
-
- 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()
+{
+ return this->Creator;
+}
+
+/** Process a socket read event */
+void DNS::HandleEvent(EventType, int)
{
- /* We are only intrested in our single fd */
- if (fd == GetMasterSocket())
+ /* 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);
+
+ /* Is there a usable request id? */
+ if (res.id != -1)
{
- /* Fetch the id and result of the next available packet */
- DNSResult res = this->GetResult();
- /* Is there a usable request id? */
- if (res.first != -1)
+ /* Its an error reply */
+ if (res.id & ERROR_MASK)
{
- /* Its an error reply */
- if (res.first & ERROR_MASK)
+ /* Mask off the error bit */
+ res.id -= ERROR_MASK;
+ /* Marshall the error to the correct class */
+ if (Classes[res.id])
{
- /* Mask off the error bit */
- res.first -= ERROR_MASK;
-
- /* Marshall the error to the correct class */
- log(DEBUG,"Error available, id=%d",res.first);
- if (Classes[res.first])
- {
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDnsBad++;
- Classes[res.first]->OnError(RESOLVER_NXDOMAIN, res.second);
- delete Classes[res.first];
- Classes[res.first] = NULL;
- }
+ if (ServerInstance && ServerInstance->stats)
+ ServerInstance->stats->statsDnsBad++;
+ Classes[res.id]->OnError(RESOLVER_NXDOMAIN, res.result);
+ delete Classes[res.id];
+ Classes[res.id] = NULL;
}
- else
+ return;
+ }
+ else
+ {
+ /* It is a non-error result, marshall the result to the correct class */
+ if (Classes[res.id])
{
- /* 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])
+ if (ServerInstance && ServerInstance->stats)
+ ServerInstance->stats->statsDnsGood++;
+
+ if (!this->GetCache(res.original.c_str()))
{
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDnsGood++;
- Classes[res.first]->OnLookupComplete(res.second);
- delete Classes[res.first];
- Classes[res.first] = NULL;
+ if (cache->size() >= MAX_CACHE_SIZE)
+ cache->clear();
+ this->cache->insert(std::make_pair(res.original.c_str(), CachedQuery(res.result, res.type, res.ttl)));
}
- }
-
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDns++;
+ Classes[res.id]->OnLookupComplete(res.result, res.ttl, false);
+ delete Classes[res.id];
+ Classes[res.id] = NULL;
+ }
}
+
+ if (ServerInstance && ServerInstance->stats)
+ ServerInstance->stats->statsDns++;
}
}
-/* Add a derived Resolver to the working set */
+/** Add a derived Resolver to the working set */
bool DNS::AddResolverClass(Resolver* r)
{
+ 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))
{
Classes[r->GetId()] = r;
return true;
}
- else
- /* Duplicate id */
- return false;
}
- else
- {
- /* Pointer or id not valid.
- * Free the item and return
- */
- if (r)
- delete r;
- return false;
- }
+ /* Pointer or id not valid, or duplicate id.
+ * Free the item and return
+ */
+ delete r;
+ return false;
}
-unsigned long DNS::PRNG()
+void DNS::CleanResolvers(Module* module)
{
- unsigned long val = 0;
- timeval n;
- serverstats* s = ServerInstance->stats;
- gettimeofday(&n,NULL);
- val = (n.tv_usec ^ getpid() ^ geteuid() ^ (this->currid++)) ^ s->statsAccept + n.tv_sec;
- val = val + s->statsCollisions ^ s->statsDnsGood - s->statsDnsBad;
- val += (s->statsConnects ^ (unsigned long)s->statsSent ^ (unsigned long)s->statsRecv) - s->BoundPortCount;
- return val;
+ for (int i = 0; i < MAX_REQUEST_ID; i++)
+ {
+ if (Classes[i])
+ {
+ if (Classes[i]->GetCreator() == module)
+ {
+ Classes[i]->OnError(RESOLVER_FORCEUNLOAD, "Parent module is unloading");
+ delete Classes[i];
+ Classes[i] = NULL;
+ }
+ }
+ }
}
-
projects / user / henk / code / inspircd.git / blobdiff