-/* +------------------------------------+
- * | 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: (C) 2002-2008 InspIRCd Development Team
- * See: http://www.inspircd.org/wiki/index.php/Credits
+ * 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 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 <http://www.gnu.org/licenses/>.
*/
+
/* $Core */
/*
looks like this, walks like this or tastes like this.
*/
-#ifndef WIN32
+#ifndef _WIN32
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <arpa/inet.h>
#else
#include "inspircd_win32wrapper.h"
-#include "inspircd_se_config.h"
#endif
-#include "dns.h"
#include "inspircd.h"
#include "socketengine.h"
#include "configreader.h"
#include "socket.h"
+#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
*/
enum QueryInfo
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(DNS* dns, int id, const std::string &original);
~DNSRequest();
- DNSInfo ResultIsReady(DNSHeader &h, int length, int result_we_want);
+ DNSInfo ResultIsReady(DNSHeader &h, unsigned length);
int SendRequests(const DNSHeader *header, const int length, QueryType qt);
};
class CacheTimer : public Timer
{
private:
- InspIRCd* ServerInstance;
DNS* dns;
public:
- CacheTimer(InspIRCd* Instance, DNS* thisdns)
- : Timer(3600, Instance->Time(), true), ServerInstance(Instance), dns(thisdns) { }
+ CacheTimer(DNS* thisdns)
+ : Timer(5*60, ServerInstance->Time(), true), dns(thisdns) { }
virtual void Tick(time_t)
{
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)
+ 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)
}
ServerInstance->Res->requests[watchid] = NULL;
delete watch;
- return;
}
}
};
+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(InspIRCd* Instance, DNS* dns, int rid, const std::string &original) : dnsobj(dns), ServerInstance(Instance)
+DNSRequest::DNSRequest(DNS* dns, int rid, const std::string &original) : dnsobj(dns)
{
- res = new unsigned char[512];
+ /* 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(Instance->Config->dns_timeout ? Instance->Config->dns_timeout : 5, Instance, this, rid);
- Instance->Timers->AddTimer(RT); /* The timer manager frees this */
+ 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 */
this->rr_class = 1;
this->type = qt;
-
+
DNS::EmptyHeader(payload,header,length);
-#ifdef IPV6
- 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
- {
- 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;
- }
+ 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;
/* 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[id])
- id = this->PRNG() & DNS::MAX_REQUEST_ID;
+ if (id == -1)
+ throw ModuleException("DNS: All ids are in use");
- DNSRequest* req = new DNSRequest(ServerInstance, this, id, original);
+ 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;
void DNS::Rehash()
{
- ip6munge = false;
- int portpass = 0;
-
if (this->GetFd() > -1)
{
- if (ServerInstance && ServerInstance->SE)
- ServerInstance->SE->DelFd(this);
+ ServerInstance->SE->DelFd(this);
ServerInstance->SE->Shutdown(this, 2);
ServerInstance->SE->Close(this);
this->SetFd(-1);
this->cache = new dnscache();
}
- if ((strstr(ServerInstance->Config->DNSServer,"::ffff:") == (char*)&ServerInstance->Config->DNSServer) || (strstr(ServerInstance->Config->DNSServer,"::FFFF:") == (char*)&ServerInstance->Config->DNSServer))
- {
- ServerInstance->Logs->Log("RESOLVER",DEFAULT,"WARNING: Using IPv4 addresses over IPv6 forces some DNS checks to be disabled.");
- ServerInstance->Logs->Log("RESOLVER",DEFAULT," This should not cause a problem, however it is recommended you migrate");
- ServerInstance->Logs->Log("RESOLVER",DEFAULT," to a true IPv6 environment.");
- this->ip6munge = true;
- }
-
- this->socketfamily = AF_INET;
-#ifdef IPV6
- if (strchr(ServerInstance->Config->DNSServer,':'))
- {
- this->socketfamily = AF_INET6;
- inet_pton(AF_INET6, ServerInstance->Config->DNSServer, &this->myserver6);
- }
- else
- {
- inet_aton(ServerInstance->Config->DNSServer, &this->myserver4);
- portpass = -1;
- }
-#else
- inet_aton(ServerInstance->Config->DNSServer, &this->myserver4);
-#endif
+ irc::sockets::aptosa(ServerInstance->Config->DNSServer, DNS::QUERY_PORT, myserver);
/* Initialize mastersocket */
- int s = irc::sockets::OpenTCPSocket(ServerInstance->Config->DNSServer, SOCK_DGRAM);
+ int s = socket(myserver.sa.sa_family, SOCK_DGRAM, 0);
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))
+ ServerInstance->SE->SetReuse(s);
+ ServerInstance->SE->NonBlocking(s);
+ irc::sockets::sockaddrs bindto;
+ memset(&bindto, 0, sizeof(bindto));
+ bindto.sa.sa_family = myserver.sa.sa_family;
+ if (ServerInstance->SE->Bind(this->GetFd(), bindto) < 0)
{
/* Failed to bind */
- ServerInstance->Logs->Log("RESOLVER",DEBUG,"Error binding dns socket");
+ 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 (this->GetFd() >= 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)
- {
- if (!ServerInstance->SE->AddFd(this))
- {
- ServerInstance->Logs->Log("RESOLVER",DEFAULT,"Internal error starting DNS - hostnames will NOT resolve.");
- ServerInstance->SE->Shutdown(this, 2);
- ServerInstance->SE->Close(this);
- this->SetFd(-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);
}
}
else
{
- ServerInstance->Logs->Log("RESOLVER",DEBUG,"Error creating dns socket");
+ 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(InspIRCd* Instance) : ServerInstance(Instance)
+DNS::DNS()
{
ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::DNS");
/* Clear the Resolver class table */
/* 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->Rehash();
- this->PruneTimer = new CacheTimer(ServerInstance, this);
+ this->PruneTimer = new CacheTimer(this);
ServerInstance->Timers->AddTimer(this->PruneTimer);
}
DNSHeader h;
int id;
int length;
-
+
if ((length = this->MakePayload(name, DNS_QUERY_A, 1, (unsigned char*)&h.payload)) == -1)
return -1;
return id;
}
-/** Start lookup of an IP address to a hostname */
-int DNS::GetName(const irc::sockets::insp_inaddr *ip)
-{
- 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, irc::sockets::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)
{
DNSHeader h;
int id;
int length;
-#ifdef SUPPORT_IP6LINKS
+
if (fp == PROTOCOL_IPV6)
{
in6_addr i;
DNS::MakeIP6Int(query, &i);
}
else
+ {
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::GetNameForce IPv6 bad format for '%s'", ip);
/* Invalid IP address */
return -1;
+ }
}
else
-#endif
{
in_addr i;
if (inet_aton(ip, &i))
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;
+ }
}
- 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, 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;
}
*/
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 */
{
*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(int resultnum)
+DNSResult DNS::GetResult()
{
/* 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;
+ 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, &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. */
- delete[] from;
return DNSResult(-1,"",0,"");
}
* 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
- 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
+ if (from != myserver)
{
- 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,"");
- }
+ 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 */
if (!requests[this_id])
{
/* 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,"");
}
else
* 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, resultnum);
+ DNSInfo data = req->ResultIsReady(header, length);
std::string resultstr;
/* Check if we got a result, if we didnt, its an error */
case DNS_QUERY_AAAA:
{
- inet_ntop(AF_INET6, data.first, formatted, sizeof(formatted));
- 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
/* 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 DNSResult(this_id,resultstr,ttl,ro);
+ return result;
}
}
/** A result is ready, process it */
-DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length, int result_we_want)
+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;
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 */
- if (curanswer == result_we_want)
- DNS::FillResourceRecord(&rr,&header.payload[i]);
-
+ 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 more answers (" + ConvToStr(header.ancount) + " answers, wanted #" + ConvToStr(result_we_want) + ")");
+ 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");
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");
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)
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);
+ OnLookupComplete(CQ->data, time_left, true);
}
/** 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)
+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;
{
ServerInstance->Res->DelCache(source);
}
- else
+ else if (CQ->type == qt)
{
cached = true;
return;
}
+ CQ = NULL;
}
- irc::sockets::insp_inaddr binip;
-
switch (querytype)
{
case DNS_QUERY_A:
this->myid = ServerInstance->Res->GetIP(source.c_str());
break;
- case DNS_QUERY_PTR:
- if (irc::sockets::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)
{
- 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
{
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->Logs->Log("RESOLVER",DEBUG,"Handle DNS event");
- res = this->GetResult(resultnum);
+ res = this->GetResult();
+
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"Result id %d", res.id);
- ServerInstance->Logs->Log("RESOLVER",DEBUG,"Result %d id %d", resultnum, res.id);
-
/* Is there a usable request id? */
if (res.id != -1)
{
{
if (ServerInstance && ServerInstance->stats)
ServerInstance->stats->statsDnsGood++;
-
+
if (!this->GetCache(res.original.c_str()))
- this->cache->insert(std::make_pair(res.original.c_str(), CachedQuery(res.result, res.ttl)));
+ {
+ 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)));
+ }
- Classes[res.id]->OnLookupComplete(res.result, res.ttl, false, resultnum);
+ Classes[res.id]->OnLookupComplete(res.result, res.ttl, false);
delete Classes[res.id];
Classes[res.id] = NULL;
}
}
-
+
if (ServerInstance && ServerInstance->stats)
ServerInstance->stats->statsDns++;
}
-
- resultnum++;
}
-
+
/** Add a derived Resolver to the working set */
bool DNS::AddResolverClass(Resolver* r)
{
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;
}
void DNS::CleanResolvers(Module* module)
{
if (Classes[i]->GetCreator() == module)
{
- Classes[i]->OnError(RESLOVER_FORCEUNLOAD, "Parent module is unloading");
+ Classes[i]->OnError(RESOLVER_FORCEUNLOAD, "Parent module is unloading");
delete Classes[i];
Classes[i] = NULL;
}
}
}
}
-
-/** Generate pseudo-random number */
-unsigned long DNS::PRNG()
-{
- 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) - ServerInstance->Config->ports.size();
- return val;
-}
-
-
projects / user / henk / code / inspircd.git / blobdiff