* | Inspire Internet Relay Chat Daemon |
* +------------------------------------+
*
- * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
- * E-mail:
- * <brain@chatspike.net>
- * <Craig@chatspike.net>
- *
- * 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.
*
* ---------------------------------------------------
*/
/*
dns.cpp - Nonblocking DNS functions.
-Very loosely based on the firedns library,
-Copyright (C) 2002 Ian Gulliver.
-
-There have been so many modifications to this file
-to make it fit into InspIRCd and make it object
-orientated that you should not take this code as
-being what firedns really looks like. It used to
-look very different to this! :-P
+Very very loosely based on the firedns library,
+Copyright (C) 2002 Ian Gulliver. This file is no
+longer anything like firedns, there are many major
+differences between this code and the original.
+Please do not assume that firedns works like this,
+looks like this, walks like this or tastes like this.
*/
-using namespace std;
-
-#include <string>
-#include <time.h>
#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"
#include "inspircd.h"
-#include "helperfuncs.h"
-#include "inspircd_config.h"
#include "socketengine.h"
#include "configreader.h"
+#include "socket.h"
-extern InspIRCd* ServerInstance;
-extern ServerConfig* Config;
-extern time_t TIME;
-extern userrec* fd_ref_table[MAX_DESCRIPTORS];
+using irc::sockets::insp_inaddr;
+using irc::sockets::insp_ntoa;
+using irc::sockets::insp_aton;
+using irc::sockets::OpenTCPSocket;
-enum QueryType
+/** Masks to mask off the responses we get from the DNSRequest methods
+ */
+enum QueryInfo
{
- DNS_QRY_A = 1,
- DNS_QRY_PTR = 12
+ ERROR_MASK = 0x10000 /* Result is an error */
};
+/** Flags which can be ORed into a request or reply for different meanings
+ */
enum QueryFlags
{
- FLAGS_MASK_RD = 0x01,
+ FLAGS_MASK_RD = 0x01, /* Recursive */
FLAGS_MASK_TC = 0x02,
- FLAGS_MASK_AA = 0x04,
+ FLAGS_MASK_AA = 0x04, /* Authoritative */
FLAGS_MASK_OPCODE = 0x78,
FLAGS_MASK_QR = 0x80,
- FLAGS_MASK_RCODE = 0x0F,
+ FLAGS_MASK_RCODE = 0x0F, /* Request */
FLAGS_MASK_Z = 0x70,
FLAGS_MASK_RA = 0x80
};
-class dns_connection;
-typedef std::map<int,dns_connection*> connlist;
-typedef connlist::iterator connlist_iter;
-
-DNS* Res = NULL;
-
-connlist connections;
-int master_socket = -1;
-Resolver* dns_classes[65536];
-insp_inaddr myserver;
-class dns_rr_middle
+/** Represents a dns resource record (rr)
+ */
+struct ResourceRecord
{
- public:
- QueryType type;
- unsigned int rr_class;
- unsigned long ttl;
- unsigned int rdlength;
+ QueryType type; /* Record type */
+ unsigned int rr_class; /* Record class */
+ unsigned long ttl; /* Time to live */
+ unsigned int rdlength; /* Record length */
};
-class dns_header
+/** Represents a dns request/reply header, and its payload as opaque data.
+ */
+class DNSHeader
{
public:
- unsigned char id[2];
- unsigned int flags1;
- unsigned int flags2;
+ unsigned char id[2]; /* Request id */
+ unsigned int flags1; /* Flags */
+ unsigned int flags2; /* Flags */
unsigned int qdcount;
- unsigned int ancount;
- unsigned int nscount;
+ unsigned int ancount; /* Answer count */
+ unsigned int nscount; /* Nameserver count */
unsigned int arcount;
- unsigned char payload[512];
+ unsigned char payload[512]; /* Packet payload */
+};
+
+class DNSRequest
+{
+ public:
+ unsigned char id[2]; /* Request id */
+ unsigned char* res; /* Result processing buffer */
+ unsigned int rr_class; /* Request class */
+ QueryType type; /* Request type */
+ DNS* dnsobj; /* DNS caller (where we get our FD from) */
+ unsigned long ttl; /* Time to live */
+ std::string orig; /* Original requested name/ip */
+
+ DNSRequest(InspIRCd* Instance, DNS* dns, int id, const std::string &original);
+ ~DNSRequest();
+ DNSInfo ResultIsReady(DNSHeader &h, int length);
+ int SendRequests(const DNSHeader *header, const int length, QueryType qt);
};
-class dns_connection
+class CacheTimer : public InspTimer
{
+ private:
+ InspIRCd* ServerInstance;
+ DNS* dns;
public:
- unsigned char id[2];
- unsigned char* res;
- unsigned int rr_class;
- QueryType type;
+ CacheTimer(InspIRCd* Instance, DNS* thisdns)
+ : InspTimer(3600, Instance->Time(), true), ServerInstance(Instance), dns(thisdns) { }
- dns_connection()
+ virtual void Tick(time_t TIME)
{
- res = new unsigned char[512];
- *res = 0;
+ dns->PruneCache();
}
+};
- ~dns_connection()
+class RequestTimeout : public InspTimer
+{
+ InspIRCd* ServerInstance;
+ DNSRequest* watch;
+ int watchid;
+ public:
+ RequestTimeout(unsigned long n, InspIRCd* SI, DNSRequest* watching, int id) : InspTimer(n, time(NULL)), ServerInstance(SI), watch(watching), watchid(id)
{
- delete[] res;
}
- unsigned char* result_ready(dns_header &h, int length);
- int send_requests(const dns_header *header, const int length, QueryType qt);
+ void Tick(time_t TIME)
+ {
+ 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;
+ }
+ }
};
-/*
- * Optimized by brain, these were using integer division and modulus.
- * We can use logic shifts and logic AND to replace these even divisions
- * and multiplications, it should be a bit faster (probably not noticably,
- * but of course, more impressive). Also made these inline.
- */
+/* Allocate the processing buffer */
+DNSRequest::DNSRequest(InspIRCd* Instance, DNS* dns, int id, const std::string &original) : dnsobj(dns)
+{
+ 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 */
+}
-inline void dns_fill_rr(dns_rr_middle* rr, const unsigned char *input)
+/* 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->rr_class = (input[2] << 8) + input[3];
rr->rdlength = (input[8] << 8) + input[9];
}
-inline void dns_fill_header(dns_header *header, const unsigned char *input, const int 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];
header->id[1] = input[1];
memcpy(header->payload,&input[12],length);
}
-inline void dns_empty_header(unsigned char *output, const dns_header *header, const int length)
+/** Empty a DNSHeader class out into raw data, ready for transmission */
+inline void DNS::EmptyHeader(unsigned char *output, const DNSHeader *header, const int length)
{
output[0] = header->id[0];
output[1] = header->id[1];
memcpy(&output[12],header->payload,length);
}
-
-int dns_connection::send_requests(const dns_header *header, const int length, QueryType qt)
+/** 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(dns_header)];
+ unsigned char payload[sizeof(DNSHeader)];
this->rr_class = 1;
this->type = qt;
- dns_empty_header(payload,header,length);
+ 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);
-#endif
- if (sendto(master_socket, payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) == -1)
+ if (this->dnsobj->socketfamily == AF_INET6)
{
- log(DEBUG,"Error in sendto!");
- return -1;
+ 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 (sendto(dnsobj->GetFd(), payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) != length+12)
+ return -1;
}
+ else
+ {
+ 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 (sendto(dnsobj->GetFd(), payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) != length+12)
+ return -1;
+ }
+#else
+ 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 (sendto(dnsobj->GetFd(), payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) != length+12)
+ return -1;
+#endif
return 0;
}
-dns_connection* dns_add_query(dns_header *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)
{
+ /* Is the DNS connection down? */
+ if (this->GetFd() == -1)
+ return NULL;
+
+ /* Create an id */
+ id = this->PRNG() & DNS::MAX_REQUEST_ID;
- id = rand() % 65536;
- dns_connection* req = new dns_connection();
+ /* If this id is already 'in flight', pick another. */
+ while (requests[id])
+ id = this->PRNG() & DNS::MAX_REQUEST_ID;
+
+ DNSRequest* req = new DNSRequest(ServerInstance, this, id, original);
header->id[0] = req->id[0] = id >> 8;
header->id[1] = req->id[1] = id & 0xFF;
header->nscount = 0;
header->arcount = 0;
- if (connections.find(id) == connections.end())
- connections[id] = req;
+ /* At this point we already know the id doesnt exist,
+ * so there needs to be no second check for the ::end()
+ */
+ requests[id] = req;
/* According to the C++ spec, new never returns NULL. */
return req;
}
-void create_socket()
+int DNS::ClearCache()
+{
+ /* This ensures the buckets are reset to sane levels */
+ int rv = this->cache->size();
+ delete this->cache;
+ this->cache = new dnscache();
+ return rv;
+}
+
+int DNS::PruneCache()
+{
+ int n = 0;
+ dnscache* newcache = new dnscache();
+ for (dnscache::iterator i = this->cache->begin(); i != this->cache->end(); i++)
+ /* Dont include expired items (theres no point) */
+ if (i->second.CalcTTLRemaining())
+ newcache->insert(*i);
+ else
+ n++;
+
+ delete this->cache;
+ this->cache = newcache;
+ return n;
+}
+
+void DNS::Rehash()
{
- log(DEBUG,"---- BEGIN DNS INITIALIZATION, SERVER=%s ---",Config->DNSServer);
- insp_inaddr addr;
- srand((unsigned int) TIME);
- memset(&myserver,0,sizeof(insp_inaddr));
- if (insp_aton(Config->DNSServer,&addr) > 0)
- memcpy(&myserver,&addr,sizeof(insp_inaddr));
+ ip6munge = false;
+ int portpass = 0;
- master_socket = socket(PF_PROTOCOL, SOCK_DGRAM, 0);
- if (master_socket != -1)
+ if (this->GetFd() > -1)
{
- log(DEBUG,"Set query socket nonblock");
- if (fcntl(master_socket, F_SETFL, O_NONBLOCK) != 0)
- {
- shutdown(master_socket,2);
- close(master_socket);
- master_socket = -1;
- }
+ if (ServerInstance && ServerInstance->SE)
+ ServerInstance->SE->DelFd(this);
+ shutdown(this->GetFd(), 2);
+ close(this->GetFd());
+ this->SetFd(-1);
+
+ /* Rehash the cache */
+ this->PruneCache();
+ }
+ else
+ {
+ /* Create initial dns cache */
+ this->cache = new dnscache();
}
- if (master_socket != -1)
+
+ 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;
+ }
+
+ this->socketfamily = AF_INET;
#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));
+ 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
- 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
- log(DEBUG,"Binding query port");
- if (bind(master_socket,(sockaddr *)&addr,sizeof(addr)) != 0)
+
+ /* Initialize mastersocket */
+ int s = OpenTCPSocket(ServerInstance->Config->DNSServer, SOCK_DGRAM);
+ this->SetFd(s);
+
+ /* 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))
{
- log(DEBUG,"Cant bind with source port = 0");
- shutdown(master_socket,2);
- close(master_socket);
- master_socket = -1;
+ /* Failed to bind */
+ shutdown(this->GetFd(),2);
+ close(this->GetFd());
+ this->SetFd(-1);
}
- if (master_socket >= 0)
+ if (this->GetFd() >= 0)
{
- log(DEBUG,"Attach query port to socket engine");
+ /* Hook the descriptor into the socket engine */
if (ServerInstance && ServerInstance->SE)
- ServerInstance->SE->AddFd(master_socket,true,X_ESTAB_DNS);
+ {
+ if (!ServerInstance->SE->AddFd(this))
+ {
+ ServerInstance->Log(DEFAULT,"Internal error starting DNS - hostnames will NOT resolve.");
+ shutdown(this->GetFd(),2);
+ close(this->GetFd());
+ this->SetFd(-1);
+ }
+ }
}
}
}
-int dns_build_query_payload(const char * const name, const unsigned short rr, const unsigned short rr_class, unsigned char * const payload)
+/** Initialise the DNS UDP socket so that we can send requests */
+DNS::DNS(InspIRCd* Instance) : ServerInstance(Instance)
{
- short payloadpos;
- const char * tempchr, * tempchr2;
- unsigned short l;
+ /* 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;
- payloadpos = 0;
- tempchr2 = name;
+ /* 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;
+ const char* tempchr, *tempchr2 = name;
+ unsigned short length;
/* split name up into labels, create query */
while ((tempchr = strchr(tempchr2,'.')) != NULL)
{
- l = tempchr - tempchr2;
- if (payloadpos + l + 1 > 507)
+ length = tempchr - tempchr2;
+ if (payloadpos + length + 1 > 507)
return -1;
- payload[payloadpos++] = l;
- memcpy(&payload[payloadpos],tempchr2,l);
- payloadpos += l;
+ payload[payloadpos++] = length;
+ memcpy(&payload[payloadpos],tempchr2,length);
+ payloadpos += length;
tempchr2 = &tempchr[1];
}
- l = strlen(tempchr2);
- if (l)
+ length = strlen(tempchr2);
+ if (length)
{
- if (payloadpos + l + 2 > 507)
+ if (payloadpos + length + 2 > 507)
return -1;
- payload[payloadpos++] = l;
- memcpy(&payload[payloadpos],tempchr2,l);
- payloadpos += l;
- payload[payloadpos++] = '\0';
+ payload[payloadpos++] = length;
+ memcpy(&payload[payloadpos],tempchr2,length);
+ payloadpos += length;
+ payload[payloadpos++] = 0;
}
if (payloadpos > 508)
return -1;
- l = htons(rr);
- memcpy(&payload[payloadpos],&l,2);
- l = htons(rr_class);
- memcpy(&payload[payloadpos + 2],&l,2);
+ length = htons(rr);
+ memcpy(&payload[payloadpos],&length,2);
+ length = htons(rr_class);
+ memcpy(&payload[payloadpos + 2],&length,2);
return payloadpos + 4;
}
-int DNS::dns_getip4(const char *name)
+/** Start lookup of an hostname to an IP address */
+int DNS::GetIP(const char *name)
{
- dns_header h;
+ DNSHeader h;
int id;
int length;
- dns_connection* req;
- if ((length = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char*)&h.payload)) == -1)
+ if ((length = this->MakePayload(name, DNS_QUERY_A, 1, (unsigned char*)&h.payload)) == -1)
return -1;
- req = dns_add_query(&h, id);
+ DNSRequest* req = this->AddQuery(&h, id, name);
- if (req->send_requests(&h,length,DNS_QRY_A) == -1)
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_A) == -1))
return -1;
return id;
}
-int DNS::dns_getname4(const insp_inaddr *ip)
+/** Start lookup of an hostname to an IPv6 address */
+int DNS::GetIP6(const char *name)
{
-#ifdef IPV6
- return -1;
-#else
- char query[29];
- dns_header h;
+ DNSHeader h;
int id;
int length;
- dns_connection* req;
- unsigned char* c = (unsigned char*)&ip->s_addr;
+ if ((length = this->MakePayload(name, DNS_QUERY_AAAA, 1, (unsigned char*)&h.payload)) == -1)
+ return -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 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)
+{
+ 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 = dns_build_query_payload(query,DNS_QRY_PTR,1,(unsigned char*)&h.payload)) == -1)
+ if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1)
return -1;
- req = dns_add_query(&h, id);
+ DNSRequest* req = this->AddQuery(&h, id, insp_ntoa(*ip));
- if (req->send_requests(&h,length,DNS_QRY_PTR) == -1)
+ 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, ip);
+
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
+ return -1;
+
+ return id;
}
-/* Return the next id which is ready, and the result attached to it
+/** Build an ipv6 reverse domain from an in6_addr
*/
-DNSResult DNS::dns_getresult()
+void DNS::MakeIP6Int(char* query, const in6_addr *ip)
{
- /* retrieve result of DNS query (buffered) */
- dns_header header;
- dns_connection *req;
- int length;
- unsigned char buffer[sizeof(dns_header)];
+#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
+}
- length = recv(master_socket,buffer,sizeof(dns_header),0);
+/** 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 = 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;
+ int length = recvfrom(this->GetFd(),buffer,sizeof(DNSHeader),0,from,&x);
+
+ /* Did we get the whole header? */
if (length < 12)
- return std::make_pair(-1,"");
+ {
+ /* Nope - something screwed up. */
+ 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
+ {
+ ipaddr_from = inet_ntoa(((sockaddr_in*)from)->sin_addr);
+ port_from = ntohs(((sockaddr_in*)from)->sin_port);
+ }
+#else
+ ipaddr_from = inet_ntoa(((sockaddr_in*)from)->sin_addr);
+ port_from = ntohs(((sockaddr_in*)from)->sin_port);
+#endif
+
+ 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,"");
+ }
+ }
- dns_fill_header(&header,buffer,length - 12);
+ /* Put the read header info into a header class */
+ DNS::FillHeader(&header,buffer,length - 12);
- // Get the id of this request
+ /* Get the id of this request.
+ * Its a 16 bit value stored in two char's,
+ * so we use logic shifts to create the value.
+ */
unsigned long this_id = header.id[1] + (header.id[0] << 8);
- // Do we have a pending request for it?
-
- connlist_iter n_iter = connections.find(this_id);
- if (n_iter == connections.end())
- {
- log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d queryid=%d",master_socket,this_id);
- return std::make_pair(-1,"");
- }
- else
- {
- /* Remove the query from the list */
- req = (dns_connection*)n_iter->second;
- /* We don't delete c here, because its done later when needed */
- connections.erase(n_iter);
- }
- unsigned char* data = req->result_ready(header, length);
+ /* Do we have a pending request matching this id? */
+ if (!requests[this_id])
+ {
+ /* Somehow we got a DNS response for a request we never made... */
+ return DNSResult(-1,"",0,"");
+ }
+ else
+ {
+ /* Remove the query from the list of pending queries */
+ 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);
std::string resultstr;
- if (data == NULL)
+ /* Check if we got a result, if we didnt, its an error */
+ if (data.first == NULL)
{
- resultstr = "";
+ /* An error.
+ * Mask the ID with the value of ERROR_MASK, so that
+ * the dns_deal_with_classes() function knows that its
+ * an error response and needs to be treated uniquely.
+ * Put the error message in the second field.
+ */
+ std::string ro = req->orig;
+ delete req;
+ return DNSResult(this_id | ERROR_MASK, data.second, 0, ro);
}
else
{
- if (req->type == DNS_QRY_A)
- {
- char formatted[16];
- snprintf(formatted,16,"%u.%u.%u.%u",data[0],data[1],data[2],data[3]);
- resultstr = formatted;
- }
- else
+ unsigned long ttl = req->ttl;
+ char formatted[128];
+
+ /* Forward lookups come back as binary data. We must format them into ascii */
+ switch (req->type)
{
- resultstr = std::string((const char*)data);
+ 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:
+ {
+ 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)
+ {
+ 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 = "0" + resultstr;
+ }
+ 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;
+
}
- }
- delete req;
- return std::make_pair(this_id,resultstr);
+ /* Build the reply with the id and hostname/ip in it */
+ std::string ro = req->orig;
+ delete req;
+ return DNSResult(this_id,resultstr,ttl,ro);
+ }
}
-/** A result is ready, process it
- */
-unsigned char* dns_connection::result_ready(dns_header &header, int length)
+/** A result is ready, process it */
+DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
{
int i = 0;
int q = 0;
int curanswer, o;
- dns_rr_middle rr;
- unsigned short p;
-
+ 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))
- {
- log(DEBUG,"DNS: didnt get a query result");
- return NULL;
- }
+ return std::make_pair((unsigned char*)NULL,"Not a query result");
+
if (header.flags1 & FLAGS_MASK_OPCODE)
- {
- log(DEBUG,"DNS: got an OPCODE and didnt want one");
- return NULL;
- }
+ return std::make_pair((unsigned char*)NULL,"Unexpected value in DNS reply packet");
+
if (header.flags2 & FLAGS_MASK_RCODE)
- {
- log(DEBUG,"DNS lookup failed due to SERVFAIL");
- return NULL;
- }
+ return std::make_pair((unsigned char*)NULL,"Domain name not found");
+
if (header.ancount < 1)
- {
- log(DEBUG,"DNS: no answers!");
- return NULL;
- }
+ return std::make_pair((unsigned char*)NULL,"No resource records returned");
+
+ /* Subtract the length of the header from the length of the packet */
length -= 12;
+
while ((unsigned int)q < header.qdcount && i < length)
{
if (header.payload[i] > 63)
}
}
if (length - i < 10)
- {
- return NULL;
- }
- dns_fill_rr(&rr,&header.payload[i]);
+ return std::make_pair((unsigned char*)NULL,"Incorrectly sized DNS reply");
+
+ /* XXX: We actually initialise 'rr' here including its ttl field */
+ DNS::FillResourceRecord(&rr,&header.payload[i]);
i += 10;
if (rr.type != this->type)
{
break;
}
if ((unsigned int)curanswer == header.ancount)
- return NULL;
+ return std::make_pair((unsigned char*)NULL,"No valid answers");
+
if (i + rr.rdlength > (unsigned int)length)
- return NULL;
+ return std::make_pair((unsigned char*)NULL,"Resource record larger than stated");
+
if (rr.rdlength > 1023)
- return NULL;
+ return std::make_pair((unsigned char*)NULL,"Resource record too large");
+
+ this->ttl = rr.ttl;
switch (rr.type)
{
- case DNS_QRY_PTR:
- log(DEBUG,"DNS: got a result of type DNS_QRY_PTR");
+ case DNS_QUERY_CNAME:
+ /* CNAME and PTR have the same processing code */
+ case DNS_QUERY_PTR:
o = 0;
q = 0;
while (q == 0 && i < length && o + 256 < 1023)
{
if (header.payload[i] > 63)
{
- log(DEBUG,"DNS: h.payload[i] > 63");
- memcpy(&p,&header.payload[i],2);
- i = ntohs(p) - 0xC000 - 12;
+ memcpy(&ptr,&header.payload[i],2);
+ i = ntohs(ptr) - 0xC000 - 12;
}
else
{
}
else
{
- res[o] = '\0';
+ res[o] = 0;
if (o != 0)
res[o++] = '.';
memcpy(&res[o],&header.payload[i + 1],header.payload[i]);
}
}
}
- res[o] = '\0';
+ res[o] = 0;
break;
- case DNS_QRY_A:
- log(DEBUG,"DNS: got a result of type DNS_QRY_A");
+ case DNS_QUERY_AAAA:
memcpy(res,&header.payload[i],rr.rdlength);
- res[rr.rdlength] = '\0';
- break;
+ res[rr.rdlength] = 0;
+ break;
+ case DNS_QUERY_A:
+ memcpy(res,&header.payload[i],rr.rdlength);
+ res[rr.rdlength] = 0;
+ break;
default:
memcpy(res,&header.payload[i],rr.rdlength);
- res[rr.rdlength] = '\0';
- break;
+ res[rr.rdlength] = 0;
+ break;
}
- return res;
+ return std::make_pair(res,"No error");;
}
-DNS::DNS()
+/** Close the master socket */
+DNS::~DNS()
{
+ shutdown(this->GetFd(), 2);
+ close(this->GetFd());
+ ServerInstance->Timers->DelTimer(this->PruneTimer);
+ delete this->PruneTimer;
}
-DNS::~DNS()
+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());
}
-Resolver::Resolver(const std::string &source, bool forward) : input(source), fwd(forward)
+void Resolver::TriggerCachedResult()
{
- if (forward)
- {
- log(DEBUG,"Resolver: Forward lookup on %s",source.c_str());
- this->myid = Res->dns_getip4(source.c_str());
- }
- else
+ if (CQ)
+ 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)
+{
+ 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)
+ {
+ ServerInstance->Res->DelCache(source);
+ }
+ else
{
- /* Valid ip address */
- this->myid = Res->dns_getname4(&binip);
+ 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);
+ 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::OnLookupComplete(const std::string &result)
-{
-}
-
-void Resolver::OnError(ResolverError e)
+/** Called when an error occurs */
+void Resolver::OnError(ResolverError e, const std::string &errormessage)
{
+ /* Nothing in here */
}
+/** Destroy a resolver */
Resolver::~Resolver()
{
- log(DEBUG,"Resolver::~Resolver");
+ /* Nothing here (yet) either */
}
+/** Get the request id associated with this class */
int Resolver::GetId()
{
return this->myid;
}
-bool Resolver::ProcessResult(const std::string &result)
+Module* Resolver::GetCreator()
{
- log(DEBUG,"Resolver::ProcessResult");
-
- if (!result.length())
- {
- log(DEBUG,"Resolver::OnError(RESOLVER_NXDOMAIN)");
- this->OnError(RESOLVER_NXDOMAIN);
- return false;
- }
- else
- {
-
- log(DEBUG,"Resolver::OnLookupComplete(%s)",result.c_str());
- this->OnLookupComplete(result);
- return true;
- }
+ return this->Creator;
}
-void dns_deal_with_classes(int fd)
+/** Process a socket read event */
+void DNS::HandleEvent(EventType et, int errornum)
{
- log(DEBUG,"dns_deal_with_classes(%d)",fd);
- if (fd == master_socket)
+ /* Fetch the id and result of the next available packet */
+ DNSResult res = this->GetResult();
+ /* Is there a usable request id? */
+ if (res.id != -1)
{
- DNSResult res = Res->dns_getresult();
- if (res.first != -1)
+ /* Its an error reply */
+ if (res.id & ERROR_MASK)
+ {
+ /* Mask off the error bit */
+ res.id -= ERROR_MASK;
+ /* Marshall the error to the correct class */
+ if (Classes[res.id])
+ {
+ if (ServerInstance && ServerInstance->stats)
+ ServerInstance->stats->statsDnsBad++;
+ Classes[res.id]->OnError(RESOLVER_NXDOMAIN, res.result);
+ delete Classes[res.id];
+ Classes[res.id] = NULL;
+ }
+ }
+ else
{
- log(DEBUG,"Result available, id=%d",res.first);
- if (dns_classes[res.first])
+ /* It is a non-error result, marshall the result to the correct class */
+ if (Classes[res.id])
{
- dns_classes[res.first]->ProcessResult(res.second);
- delete dns_classes[res.first];
- dns_classes[res.first] = NULL;
+ 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)));
+
+ Classes[res.id]->OnLookupComplete(res.result, res.ttl, false);
+ delete Classes[res.id];
+ Classes[res.id] = NULL;
}
}
+
+ if (ServerInstance && ServerInstance->stats)
+ ServerInstance->stats->statsDns++;
}
}
-bool dns_add_class(Resolver* r)
+/** Add a derived Resolver to the working set */
+bool DNS::AddResolverClass(Resolver* r)
{
- log(DEBUG,"dns_add_class");
+ /* Check the pointers validity and the id's validity */
if ((r) && (r->GetId() > -1))
{
- if (!dns_classes[r->GetId()])
+ /* Check the slot isnt already occupied -
+ * This should NEVER happen unless we have
+ * a severely broken DNS server somewhere
+ */
+ if (!Classes[r->GetId()])
{
- log(DEBUG,"dns_add_class: added class");
- dns_classes[r->GetId()] = r;
+ /* Set up the pointer to the class */
+ Classes[r->GetId()] = r;
return true;
}
else
- {
- log(DEBUG,"Space occupied!");
+ /* Duplicate id */
return false;
- }
}
else
{
- log(DEBUG,"Bad class");
- delete r;
- return true;
+ /* Pointer or id not valid.
+ * Free the item and return
+ */
+ if (r)
+ delete r;
+
+ return false;
+ }
+}
+
+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;
+ }
+ }
}
}
-void init_dns()
+/** Generate pseudo-random number */
+unsigned long DNS::PRNG()
{
- Res = new DNS();
- memset(dns_classes,0,sizeof(dns_classes));
- create_socket();
+ 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;
}
projects / user / henk / code / inspircd.git / blobdiff