* +------------------------------------+
*
* InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
- * E-mail:
- * <brain@chatspike.net>
- * <Craig@chatspike.net>
+ * 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.
+ * 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 <stdlib.h>
-#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
-#include <sys/time.h>
-#include <string.h>
-#include <unistd.h>
-#include <stdio.h>
#include <errno.h>
-#include <fcntl.h>
-#include <poll.h>
-#include <sys/types.h>
-#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
-#include <map>
-#include <algorithm>
#include "dns.h"
#include "inspircd.h"
-#include "helperfuncs.h"
-#include "inspircd_config.h"
#include "socketengine.h"
#include "configreader.h"
+#include "socket.h"
-#ifdef THREADED_DNS
-pthread_mutex_t connmap_lock = PTHREAD_MUTEX_INITIALIZER;
-#endif
-
-extern InspIRCd* ServerInstance;
-extern ServerConfig* Config;
-extern time_t TIME;
-extern userrec* fd_ref_table[MAX_DESCRIPTORS];
-
-enum QueryType { DNS_QRY_A = 1, DNS_QRY_PTR = 12 };
-enum QueryFlags1 { FLAGS1_MASK_RD = 0x01, FLAGS1_MASK_TC = 0x02, FLAGS1_MASK_AA = 0x04, FLAGS1_MASK_OPCODE = 0x78, FLAGS1_MASK_QR = 0x80 };
-enum QueryFlags2 { FLAGS2_MASK_RCODE = 0x0F, FLAGS2_MASK_Z = 0x70, FLAGS2_MASK_RA = 0x80 };
-
-class s_connection;
+using namespace std;
+using irc::sockets::insp_sockaddr;
+using irc::sockets::insp_inaddr;
+using irc::sockets::insp_ntoa;
+using irc::sockets::insp_aton;
-typedef std::map<int,s_connection*> connlist;
-typedef connlist::iterator connlist_iter;
-connlist connections;
+/** Masks to mask off the responses we get from the DNSRequest methods
+ */
+enum QueryInfo
+{
+ ERROR_MASK = 0x10000 /* Result is an error */
+};
-Resolver* dns_classes[MAX_DESCRIPTORS];
+/** Flags which can be ORed into a request or reply for different meanings
+ */
+enum QueryFlags
+{
+ FLAGS_MASK_RD = 0x01, /* Recursive */
+ FLAGS_MASK_TC = 0x02,
+ FLAGS_MASK_AA = 0x04, /* Authoritative */
+ FLAGS_MASK_OPCODE = 0x78,
+ FLAGS_MASK_QR = 0x80,
+ FLAGS_MASK_RCODE = 0x0F, /* Request */
+ FLAGS_MASK_Z = 0x70,
+ FLAGS_MASK_RA = 0x80
+};
-insp_inaddr servers[8];
-int i4;
-int initdone = 0;
-int lastcreate = -1;
-class s_connection
+/** Represents a dns resource record (rr)
+ */
+class ResourceRecord
{
public:
- unsigned char id[2];
- unsigned int _class;
- QueryType type;
- int want_list;
- int fd;
+ QueryType type; /* Record type */
+ unsigned int rr_class; /* Record class */
+ unsigned long ttl; /* Time to live */
+ unsigned int rdlength; /* Record length */
};
-class s_rr_middle
+/** Represents a dns request/reply header, and its payload as opaque data.
+ */
+class DNSHeader
{
public:
- QueryType type;
- unsigned int _class;
- unsigned long ttl;
- unsigned int rdlength;
+ unsigned char id[2]; /* Request id */
+ unsigned int flags1; /* Flags */
+ unsigned int flags2; /* Flags */
+ unsigned int qdcount;
+ unsigned int ancount; /* Answer count */
+ unsigned int nscount; /* Nameserver count */
+ unsigned int arcount;
+ unsigned char payload[512]; /* Packet payload */
};
-class s_header
+class DNSRequest
{
public:
- unsigned char id[2];
- unsigned int flags1;
- unsigned int flags2;
- unsigned int qdcount;
- unsigned int ancount;
- unsigned int nscount;
- unsigned int arcount;
- unsigned char payload[512];
+ unsigned char id[2]; /* Request id */
+ 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) */
+
+ DNSRequest(InspIRCd* Instance, DNS* dns, insp_inaddr server, int id, requestlist &requests);
+ ~DNSRequest();
+ DNSInfo ResultIsReady(DNSHeader &h, int length);
+ int SendRequests(const DNSHeader *header, const int length, QueryType qt);
};
-
-void *dns_align(void *inp)
-{
- char *p = (char*)inp;
- int offby = ((char *)p - (char *)0) % (sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long));
- if (offby != 0)
- return p + ((sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long)) - offby);
- else
- return p;
-}
-
-/*
- * 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.
- */
-
-inline void dns_fill_rr(s_rr_middle* rr, const unsigned char *input)
+class RequestTimeout : public InspTimer
{
- rr->type = (QueryType)((input[0] << 8) + input[1]);
- rr->_class = (input[2] << 8) + input[3];
- rr->ttl = (input[4] << 24) + (input[5] << 16) + (input[6] << 8) + input[7];
- rr->rdlength = (input[8] << 8) + input[9];
-}
+ InspIRCd* ServerInstance;
+ DNSRequest* watch;
+ int watchid;
+ requestlist &rl;
+ public:
+ RequestTimeout(unsigned long n, InspIRCd* SI, DNSRequest* watching, int id, requestlist &requests) : InspTimer(n, time(NULL)), ServerInstance(SI), watch(watching), watchid(id), rl(requests)
+ {
+ ServerInstance->Log(DEBUG, "New DNS timeout set on %08x", watching);
+ }
+
+ void Tick(time_t TIME)
+ {
+ if (rl.find(watchid) != rl.end())
+ {
+ /* Still exists, whack it */
+ if (rl.find(watchid)->second == watch)
+ {
+ 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;
+ }
+ rl.erase(rl.find(watchid));
+ delete watch;
+ ServerInstance->Log(DEBUG, "DNS timeout on %08x squished pointer", watch);
+ }
+ return;
+ }
+ ServerInstance->Log(DEBUG, "DNS timeout on %08x: result already received!", watch);
+ }
+};
-inline void dns_fill_header(s_header *header, const unsigned char *input, const int l)
+/* Allocate the processing buffer */
+DNSRequest::DNSRequest(InspIRCd* Instance, DNS* dns, insp_inaddr server, int id, requestlist &requests) : dnsobj(dns)
{
- header->id[0] = input[0];
- header->id[1] = input[1];
- header->flags1 = input[2];
- header->flags2 = input[3];
- header->qdcount = (input[4] << 8) + input[5];
- header->ancount = (input[6] << 8) + input[7];
- header->nscount = (input[8] << 8) + input[9];
- header->arcount = (input[10] << 8) + input[11];
- memcpy(header->payload,&input[12],l);
+ res = new unsigned char[512];
+ *res = 0;
+ memcpy(&myserver, &server, sizeof(insp_inaddr));
+ RequestTimeout* RT = new RequestTimeout(Instance->Config->dns_timeout ? Instance->Config->dns_timeout : 5, Instance, this, id, requests);
+ Instance->Timers->AddTimer(RT); /* The timer manager frees this */
}
-inline void dns_empty_header(unsigned char *output, const s_header *header, const int l)
+/* Deallocate the processing buffer */
+DNSRequest::~DNSRequest()
{
- output[0] = header->id[0];
- output[1] = header->id[1];
- output[2] = header->flags1;
- output[3] = header->flags2;
- output[4] = header->qdcount >> 8;
- output[5] = header->qdcount & 0xFF;
- output[6] = header->ancount >> 8;
- output[7] = header->ancount & 0xFF;
- output[8] = header->nscount >> 8;
- output[9] = header->nscount & 0xFF;
- output[10] = header->arcount >> 8;
- output[11] = header->arcount & 0xFF;
- memcpy(&output[12],header->payload,l);
+ delete[] res;
}
-void dns_close(int fd)
+/** Fill a ResourceRecord class based on raw data input */
+inline void DNS::FillResourceRecord(ResourceRecord* rr, const unsigned char *input)
{
-#ifndef THREADED_DNS
- if (ServerInstance && ServerInstance->SE)
- ServerInstance->SE->DelFd(fd);
-#endif
- log(DEBUG,"DNS: dns_close on fd %d",fd);
- shutdown(fd,2);
- close(fd);
- return;
+ rr->type = (QueryType)((input[0] << 8) + input[1]);
+ rr->rr_class = (input[2] << 8) + input[3];
+ rr->ttl = (input[4] << 24) + (input[5] << 16) + (input[6] << 8) + input[7];
+ rr->rdlength = (input[8] << 8) + input[9];
}
-void DNS::dns_init()
+/** 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)
{
- FILE *f;
- int i;
- insp_inaddr addr;
- char buf[1024];
- if (initdone == 1)
- return;
- i4 = 0;
-
- initdone = 1;
- srand((unsigned int) TIME);
- memset(servers,'\0',sizeof(insp_inaddr) * 8);
- f = fopen("/etc/resolv.conf","r");
- if (f == NULL)
- return;
- while (fgets(buf,1024,f) != NULL) {
- if (strncmp(buf,"nameserver",10) == 0)
- {
- i = 10;
- while (buf[i] == ' ' || buf[i] == '\t')
- i++;
- if (i4 < 8)
- {
- if (insp_aton(&buf[i],&addr) == 0)
- memcpy(&servers[i4++],&addr,sizeof(insp_inaddr));
- }
- }
- }
- fclose(f);
+ header->id[0] = input[0];
+ header->id[1] = input[1];
+ header->flags1 = input[2];
+ header->flags2 = input[3];
+ header->qdcount = (input[4] << 8) + input[5];
+ header->ancount = (input[6] << 8) + input[7];
+ header->nscount = (input[8] << 8) + input[9];
+ header->arcount = (input[10] << 8) + input[11];
+ memcpy(header->payload,&input[12],length);
}
-void DNS::dns_init_2(const char* dnsserver)
+/** Empty a DNSHeader class out into raw data, ready for transmission */
+inline void DNS::EmptyHeader(unsigned char *output, const DNSHeader *header, const int length)
{
- insp_inaddr addr;
- i4 = 0;
- srand((unsigned int) TIME);
- memset(servers,'\0',sizeof(insp_inaddr) * 8);
- if (insp_aton(dnsserver,&addr) == 0)
- memcpy(&servers[i4++],&addr,sizeof(insp_inaddr));
+ output[0] = header->id[0];
+ output[1] = header->id[1];
+ output[2] = header->flags1;
+ output[3] = header->flags2;
+ output[4] = header->qdcount >> 8;
+ output[5] = header->qdcount & 0xFF;
+ output[6] = header->ancount >> 8;
+ output[7] = header->ancount & 0xFF;
+ output[8] = header->nscount >> 8;
+ output[9] = header->nscount & 0xFF;
+ output[10] = header->arcount >> 8;
+ output[11] = header->arcount & 0xFF;
+ memcpy(&output[12],header->payload,length);
}
-
-int dns_send_requests(const s_header *h, const s_connection *s, const int l)
+/** Send requests we have previously built down the UDP socket */
+int DNSRequest::SendRequests(const DNSHeader *header, const int length, QueryType qt)
{
- int i;
- insp_sockaddr addr;
- unsigned char payload[sizeof(s_header)];
+ insp_sockaddr addr;
+ unsigned char payload[sizeof(DNSHeader)];
- dns_empty_header(payload,h,l);
+ this->rr_class = 1;
+ this->type = qt;
+
+ DNS::EmptyHeader(payload,header,length);
-
- i = 0;
-
- /* otherwise send via standard ipv4 boringness */
- memset(&addr,0,sizeof(addr));
+ memset(&addr,0,sizeof(addr));
#ifdef IPV6
- memcpy(&addr.sin6_addr,&servers[i],sizeof(addr.sin6_addr));
- addr.sin6_family = AF_FAMILY;
- addr.sin6_port = htons(53);
+ 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,&servers[i],sizeof(addr.sin_addr));
- addr.sin_family = AF_FAMILY;
- addr.sin_port = htons(53);
+ 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(s->fd, payload, l + 12, 0, (sockaddr *) &addr, sizeof(addr)) == -1)
- {
- log(DEBUG,"Error in sendto!");
- return -1;
- }
+ if (sendto(dnsobj->GetFd(), payload, length + 12, 0, (sockaddr *) &addr, sizeof(addr)) == -1)
+ return -1;
- return 0;
+ return 0;
}
-s_connection *dns_add_query(s_header *h)
+/** Add a query with a predefined header, and allocate an ID for it. */
+DNSRequest* DNS::AddQuery(DNSHeader *header, int &id)
{
+ /* Is the DNS connection down? */
+ if (this->GetFd() == -1)
+ return NULL;
+
+ /* Are there already the max number of requests on the go? */
+ if (requests.size() == DNS::MAX_REQUEST_ID + 1)
+ return NULL;
+
+ /* Create an id */
+ id = this->PRNG() & DNS::MAX_REQUEST_ID;
+
+ /* If this id is already 'in flight', pick another. */
+ while (requests.find(id) != requests.end())
+ id = this->PRNG() & DNS::MAX_REQUEST_ID;
+
+ DNSRequest* req = new DNSRequest(ServerInstance, this, this->myserver, id, requests);
+
+ header->id[0] = req->id[0] = id >> 8;
+ header->id[1] = req->id[1] = id & 0xFF;
+ header->flags1 = FLAGS_MASK_RD;
+ header->flags2 = 0;
+ header->qdcount = 1;
+ header->ancount = 0;
+ header->nscount = 0;
+ header->arcount = 0;
+
+ /* At this point we already know the id doesnt exist,
+ * so there needs to be no second check for the ::end()
+ */
+ requests[id] = req;
+
+ /* According to the C++ spec, new never returns NULL. */
+ return req;
+}
- s_connection * s = new s_connection;
- int id = rand() % 65536;
-
- /* set header flags */
- h->id[0] = s->id[0] = id >> 8; /* verified by dns_getresult_s() */
- h->id[1] = s->id[1] = id & 0xFF;
- h->flags1 = 0 | FLAGS1_MASK_RD;
- h->flags2 = 0;
- h->qdcount = 1;
- h->ancount = 0;
- h->nscount = 0;
- h->arcount = 0;
- s->want_list = 0;
- s->fd = socket(PF_PROTOCOL, SOCK_DGRAM, 0);
- if (s->fd != -1)
- {
- log(DEBUG,"Set query socket nonblock");
- if (fcntl(s->fd, F_SETFL, O_NONBLOCK) != 0)
- {
- shutdown(s->fd,2);
- close(s->fd);
- s->fd = -1;
- }
- }
- if (s->fd != -1)
- {
+/** Initialise the DNS UDP socket so that we can send requests */
+DNS::DNS(InspIRCd* Instance) : ServerInstance(Instance)
+{
+ ServerInstance->Log(DEBUG,"DNS::DNS: Instance = %08x",Instance);
+
+ insp_inaddr addr;
+
+ /* Clear the Resolver class table */
+ memset(Classes,0,sizeof(Classes));
+
+ /* Set the id of the next request to 0
+ */
+ currid = 0;
+
+ /* By default we're not munging ip's
+ */
+ ip6munge = false;
+
+ /* Clear the namesever address */
+ memset(&myserver,0,sizeof(insp_inaddr));
+
+ /* Convert the nameserver address into an insp_inaddr */
+ if (insp_aton(ServerInstance->Config->DNSServer,&addr) > 0)
+ {
+ memcpy(&myserver,&addr,sizeof(insp_inaddr));
+ if ((strstr(ServerInstance->Config->DNSServer,"::ffff:") == (char*)&ServerInstance->Config->DNSServer) || (strstr(ServerInstance->Config->DNSServer,"::FFFF:") == (char*)&ServerInstance->Config->DNSServer))
+ {
+ /* These dont come back looking like they did when they went in.
+ * We're forced to turn some checks off.
+ * If anyone knows how to fix this, let me know. --Brain
+ */
+ 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;
+ }
+ ServerInstance->Log(DEBUG,"Added nameserver '%s'",ServerInstance->Config->DNSServer);
+ }
+ else
+ {
+ ServerInstance->Log(DEBUG,"GACK! insp_aton says the nameserver '%s' is invalid!",ServerInstance->Config->DNSServer);
+ }
+
+ /* Initialize mastersocket */
+ this->SetFd(socket(PF_PROTOCOL, SOCK_DGRAM, 0));
+ if (this->GetFd() != -1)
+ {
+ /* Did it succeed? */
+ if (fcntl(this->GetFd(), F_SETFL, O_NONBLOCK) != 0)
+ {
+ /* Couldn't make the socket nonblocking */
+ shutdown(this->GetFd(),2);
+ close(this->GetFd());
+ this->SetFd(-1);
+ }
+ }
+ else
+ {
+ ServerInstance->Log(DEBUG,"I cant socket() this socket! (%s)",strerror(errno));
+ }
+ /* Have we got a socket and is it nonblocking? */
+ if (this->GetFd() != -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));
+ insp_sockaddr addr;
+ memset(&addr,0,sizeof(addr));
+ addr.sin6_family = AF_FAMILY;
+ addr.sin6_port = 0;
+ addr.sin6_addr = in6addr_any;
#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;
- if (bind(s->fd,(sockaddr *)&addr,sizeof(addr)) != 0)
- {
- log(DEBUG,"Cant bind with source port = 0");
- shutdown(s->fd,2);
- close(s->fd);
- s->fd = -1;
- }
-#endif
- }
- if (s->fd == -1)
- {
- DELETE(s);
- return NULL;
- }
- /* create new connection object, add to linked list */
-#ifdef THREADED_DNS
- pthread_mutex_lock(&connmap_lock);
-#endif
- if (connections.find(s->fd) == connections.end())
- connections[s->fd] = s;
-#ifdef THREADED_DNS
- pthread_mutex_unlock(&connmap_lock);
+ 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
-
- return s;
+ /* Bind the port */
+ if (bind(this->GetFd(),(sockaddr *)&addr,sizeof(addr)) != 0)
+ {
+ /* Failed to bind */
+ ServerInstance->Log(DEBUG,"Cant bind DNS fd");
+ shutdown(this->GetFd(),2);
+ close(this->GetFd());
+ this->SetFd(-1);
+ }
+
+ if (this->GetFd() >= 0)
+ {
+ ServerInstance->Log(DEBUG,"Add master socket %d",this->GetFd());
+ /* Hook the descriptor into the socket engine */
+ if (ServerInstance && ServerInstance->SE)
+ {
+ 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 _class, unsigned char * const payload)
+/** 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;
- const char * tempchr, * tempchr2;
- unsigned short l;
-
- payloadpos = 0;
- tempchr2 = name;
-
- /* split name up into labels, create query */
- while ((tempchr = strchr(tempchr2,'.')) != NULL)
- {
- l = tempchr - tempchr2;
- if (payloadpos + l + 1 > 507)
- return -1;
- payload[payloadpos++] = l;
- memcpy(&payload[payloadpos],tempchr2,l);
- payloadpos += l;
- tempchr2 = &tempchr[1];
- }
- l = strlen(tempchr2);
- if (l)
- {
- if (payloadpos + l + 2 > 507)
- return -1;
- payload[payloadpos++] = l;
- memcpy(&payload[payloadpos],tempchr2,l);
- payloadpos += l;
- payload[payloadpos++] = '\0';
- }
- if (payloadpos > 508)
- return -1;
- l = htons(rr);
- memcpy(&payload[payloadpos],&l,2);
- l = htons(_class);
- memcpy(&payload[payloadpos + 2],&l,2);
- return payloadpos + 4;
+ short payloadpos = 0;
+ const char* tempchr, *tempchr2 = name;
+ unsigned short length;
+
+ /* split name up into labels, create query */
+ while ((tempchr = strchr(tempchr2,'.')) != NULL)
+ {
+ length = tempchr - tempchr2;
+ if (payloadpos + length + 1 > 507)
+ return -1;
+ payload[payloadpos++] = length;
+ memcpy(&payload[payloadpos],tempchr2,length);
+ payloadpos += length;
+ tempchr2 = &tempchr[1];
+ }
+ length = strlen(tempchr2);
+ if (length)
+ {
+ if (payloadpos + length + 2 > 507)
+ return -1;
+ payload[payloadpos++] = length;
+ memcpy(&payload[payloadpos],tempchr2,length);
+ payloadpos += length;
+ payload[payloadpos++] = 0;
+ }
+ if (payloadpos > 508)
+ return -1;
+ 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) { /* build, add and send A query; retrieve result with dns_getresult() */
- s_header h;
- s_connection *s;
- int l;
-
- dns_init();
-
-
- l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload);
- if (l == -1)
- return -1;
- s = dns_add_query(&h);
- if (s == NULL)
- return -1;
- s->_class = 1;
- s->type = DNS_QRY_A;
- if (dns_send_requests(&h,s,l) == -1)
- return -1;
-
- return s->fd;
-}
+/** 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;
-int DNS::dns_getip4list(const char *name) { /* build, add and send A query; retrieve result with dns_getresult() */
- s_header h;
- s_connection *s;
- int l;
-
- dns_init();
-
- l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload);
- if (l == -1)
- return -1;
- s = dns_add_query(&h);
- if (s == NULL)
- return -1;
- s->_class = 1;
- s->type = DNS_QRY_A;
- s->want_list = 1;
- if (dns_send_requests(&h,s,l) == -1)
- return -1;
-
- return s->fd;
-}
+ DNSRequest* req = this->AddQuery(&h, id);
-int DNS::dns_getname4(const insp_inaddr *ip)
-{ /* build, add and send PTR query; retrieve result with dns_getresult() */
-#ifdef IPV6
- return -1;
-#else
- log(DEBUG,"DNS::dns_getname4");
- char query[512];
- s_header h;
- s_connection * s;
- unsigned char *c;
- int l;
-
- c = (unsigned char *)&ip->s_addr;
-
- sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]);
-
- l = dns_build_query_payload(query,DNS_QRY_PTR,1,(unsigned char *)&h.payload);
- if (l == -1)
- return -1;
- s = dns_add_query(&h);
- if (s == NULL)
- return -1;
- s->_class = 1;
- s->type = DNS_QRY_PTR;
- if (dns_send_requests(&h,s,l) == -1)
- return -1;
-
- return s->fd;
-#endif
-}
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_A) == -1))
+ return -1;
-char* DNS::dns_getresult(const int cfd) { /* retrieve result of DNS query */
- log(DEBUG,"DNS: dns_getresult with cfd=%d",cfd);
- return dns_getresult_s(cfd,this->localbuf);
+ return id;
}
-char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS query (buffered) */
- s_header h;
- s_connection *c;
- int l, i, q, curanswer, o;
- s_rr_middle rr;
- unsigned char buffer[sizeof(s_header)];
- unsigned short p;
-
- if (res)
- *res = 0;
-
- /* FireDNS used a linked list for this. How ugly (and slow). */
-
-#ifdef THREADED_DNS
- /* XXX: STL really does NOT like being poked and prodded in more than
- * one orifice by threaded apps. Make sure we remain nice to it, and
- * lock a mutex around any access to the std::map.
- */
- pthread_mutex_lock(&connmap_lock);
-#endif
- connlist_iter n_iter = connections.find(cfd);
- if (n_iter == connections.end())
- {
- log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d",cfd);
-#ifdef THREADED_DNS
- pthread_mutex_unlock(&connmap_lock);
-#endif
- return NULL;
- }
- else
- {
- /* Remove the query from the list */
- c = (s_connection*)n_iter->second;
- /* We don't delete c here, because its done later when needed */
- connections.erase(n_iter);
- }
-#ifdef THREADED_DNS
- pthread_mutex_unlock(&connmap_lock);
-#endif
+/** Start lookup of an hostname to an IPv6 address */
+int DNS::GetIP6(const char *name)
+{
+ DNSHeader h;
+ int id;
+ int length;
- l = recv(c->fd,buffer,sizeof(s_header),0);
- dns_close(c->fd);
- if (l < 12)
- {
- DELETE(c);
- return NULL;
- }
- dns_fill_header(&h,buffer,l - 12);
- if (c->id[0] != h.id[0] || c->id[1] != h.id[1])
- {
- log(DEBUG,"DNS: id mismatch on query");
- DELETE(c);
- return NULL; /* ID mismatch */
- }
- if ((h.flags1 & FLAGS1_MASK_QR) == 0)
- {
- log(DEBUG,"DNS: didnt get a query result");
- DELETE(c);
- return NULL;
- }
- if ((h.flags1 & FLAGS1_MASK_OPCODE) != 0)
- {
- log(DEBUG,"DNS: got an OPCODE and didnt want one");
- DELETE(c);
- return NULL;
- }
- if ((h.flags2 & FLAGS2_MASK_RCODE) != 0)
- {
- log(DEBUG,"DNS lookup failed due to SERVFAIL");
- DELETE(c);
- return NULL;
- }
- if (h.ancount < 1)
- {
- log(DEBUG,"DNS: no answers!");
- DELETE(c);
- return NULL;
- }
- i = 0;
- q = 0;
- l -= 12;
- while ((unsigned)q < h.qdcount && i < l)
- {
- if (h.payload[i] > 63)
- {
- i += 6;
- q++;
- }
- else
- {
- if (h.payload[i] == 0)
- {
- q++;
- i += 5;
- }
- else i += h.payload[i] + 1;
- }
- }
- curanswer = 0;
- while ((unsigned)curanswer < h.ancount)
- {
- q = 0;
- while (q == 0 && i < l)
- {
- if (h.payload[i] > 63)
- {
- i += 2;
- q = 1;
- }
- else
- {
- if (h.payload[i] == 0)
- {
- i++;
- q = 1;
- }
- else i += h.payload[i] + 1; /* skip length and label */
- }
- }
- if (l - i < 10)
- {
- DELETE(c);
- return NULL;
- }
- dns_fill_rr(&rr,&h.payload[i]);
- i += 10;
- if (rr.type != c->type)
- {
- curanswer++;
- i += rr.rdlength;
- continue;
- }
- if (rr._class != c->_class)
- {
- curanswer++;
- i += rr.rdlength;
- continue;
- }
- break;
- }
- if ((unsigned)curanswer == h.ancount)
- return NULL;
- if ((unsigned)i + rr.rdlength > (unsigned)l)
- return NULL;
- if (rr.rdlength > 1023)
- return NULL;
-
- switch (rr.type)
- {
- case DNS_QRY_PTR:
- log(DEBUG,"DNS: got a result of type DNS_QRY_PTR");
- o = 0;
- q = 0;
- while (q == 0 && i < l && o + 256 < 1023)
- {
- if (h.payload[i] > 63)
- {
- log(DEBUG,"DNS: h.payload[i] > 63");
- memcpy(&p,&h.payload[i],2);
- i = ntohs(p) - 0xC000 - 12;
- }
- else
- {
- if (h.payload[i] == 0)
- {
- q = 1;
- }
- else
- {
- res[o] = '\0';
- if (o != 0)
- res[o++] = '.';
- memcpy(&res[o],&h.payload[i + 1],h.payload[i]);
- o += h.payload[i];
- i += h.payload[i] + 1;
- }
- }
- }
- res[o] = '\0';
- break;
- case DNS_QRY_A:
- log(DEBUG,"DNS: got a result of type DNS_QRY_A");
- if (c->want_list)
- {
- dns_ip4list *alist = (dns_ip4list *) res; /* we have to trust that this is aligned */
- while ((char *)alist - (char *)res < 700)
- {
- if (rr.type != DNS_QRY_A)
- break;
- if (rr._class != 1)
- break;
- if (rr.rdlength != 4)
- {
- DELETE(c);
- return NULL;
- }
- memcpy(&alist->ip,&h.payload[i],4);
- if ((unsigned)++curanswer >= h.ancount)
- break;
- i += rr.rdlength;
- q = 0;
- while (q == 0 && i < l)
- {
- if (h.payload[i] > 63)
- {
- i += 2;
- q = 1;
- }
- else
- {
- if (h.payload[i] == 0)
- {
- i++;
- q = 1;
- }
- else i += h.payload[i] + 1;
- }
- }
- if (l - i < 10)
- {
- DELETE(c);
- return NULL;
- }
- dns_fill_rr(&rr,&h.payload[i]);
- i += 10;
- alist->next = (dns_ip4list *) dns_align(((char *) alist) + sizeof(dns_ip4list));
- alist = alist->next;
- alist->next = NULL;
- }
- alist->next = NULL;
- break;
- }
- memcpy(res,&h.payload[i],rr.rdlength);
- res[rr.rdlength] = '\0';
- break;
- default:
- memcpy(res,&h.payload[i],rr.rdlength);
- res[rr.rdlength] = '\0';
- break;
- }
- DELETE(c);
- return res;
-}
+ if ((length = this->MakePayload(name, DNS_QUERY_AAAA, 1, (unsigned char*)&h.payload)) == -1)
+ return -1;
-DNS::DNS()
-{
- dns_init();
- log(DEBUG,"Create blank DNS");
-}
+ DNSRequest* req = this->AddQuery(&h, id);
-DNS::DNS(const std::string &dnsserver)
-{
- dns_init_2(dnsserver.c_str());
- log(DEBUG,"Create DNS with server '%s'",dnsserver.c_str());
-}
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_AAAA) == -1))
+ return -1;
-void DNS::SetNS(const std::string &dnsserver)
-{
- dns_init_2(dnsserver.c_str());
- log(DEBUG,"Set NS");
+ return id;
}
-DNS::~DNS()
+/** Start lookup of a cname to another name */
+int DNS::GetCName(const char *alias)
{
-}
+ DNSHeader h;
+ int id;
+ int length;
-bool DNS::ReverseLookup(const std::string &ip, bool ins)
-{
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDns++;
- insp_inaddr binip;
- if (insp_aton(ip.c_str(), &binip) < 0)
- {
- return false;
- }
-
- this->myfd = dns_getname4(&binip);
- if (this->myfd == -1)
- {
- return false;
- }
- log(DEBUG,"DNS: ReverseLookup, fd=%d",this->myfd);
-#ifndef THREADED_DNS
- if (ins)
- {
- if (ServerInstance && ServerInstance->SE)
- ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS);
- }
-#endif
- return true;
+ if ((length = this->MakePayload(alias, DNS_QUERY_CNAME, 1, (unsigned char*)&h.payload)) == -1)
+ return -1;
+
+ DNSRequest* req = this->AddQuery(&h, id);
+
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_CNAME) == -1))
+ return -1;
+
+ return id;
}
-bool DNS::ForwardLookup(const std::string &host, bool ins)
+/** Start lookup of an IP address to a hostname */
+int DNS::GetName(const insp_inaddr *ip)
{
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDns++;
- this->myfd = dns_getip4(host.c_str());
- if (this->myfd == -1)
- {
- return false;
- }
- log(DEBUG,"DNS: ForwardLookup, fd=%d",this->myfd);
-#ifndef THREADED_DNS
- if (ins)
- {
- if (ServerInstance && ServerInstance->SE)
- ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS);
- }
+ 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
- return true;
-}
-bool DNS::ForwardLookupWithFD(const std::string &host, int &fd)
-{
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDns++;
- this->myfd = dns_getip4(host.c_str());
- fd = this->myfd;
- if (this->myfd == -1)
- {
- return false;
- }
- log(DEBUG,"DNS: ForwardLookupWithFD, fd=%d",this->myfd);
- if (ServerInstance && ServerInstance->SE)
- ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_MODULE);
- return true;
-}
+ if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1)
+ return -1;
-bool DNS::HasResult(int fd)
-{
- return (fd == this->myfd);
-}
+ DNSRequest* req = this->AddQuery(&h, id);
-/* Only the multithreaded dns uses this poll() based
- * check now. As its in another thread we dont have
- * to worry about its performance that much.
- */
-bool DNS::HasResult()
-{
- log(DEBUG,"DNS: HasResult, fd=%d",this->myfd);
- pollfd polls;
- polls.fd = this->myfd;
- polls.events = POLLIN;
- int ret = poll(&polls,1,1);
- log(DEBUG,"DNS: Hasresult returning %d",ret);
- return (ret > 0);
-}
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
+ return -1;
-int DNS::GetFD()
-{
- return this->myfd;
+ return id;
}
-std::string DNS::GetResult()
+/** Start lookup of an IP address to a hostname */
+int DNS::GetNameForce(const char *ip, ForceProtocol fp)
{
- log(DEBUG,"DNS: GetResult()");
- result = dns_getresult(this->myfd);
- if (result)
- {
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDnsGood++;
- dns_close(this->myfd);
- this->myfd = -1;
- return result;
- }
- else
- {
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDnsBad++;
- if (this->myfd != -1)
- {
- dns_close(this->myfd);
- this->myfd = -1;
- }
- return "";
- }
-}
+ 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;
+ }
-std::string DNS::GetResultIP()
-{
- char r[1024];
- log(DEBUG,"DNS: GetResultIP()");
- result = dns_getresult(this->myfd);
- if (this->myfd != -1)
- {
- dns_close(this->myfd);
- this->myfd = -1;
- }
- if (result)
- {
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDnsGood++;
- unsigned char a = (unsigned)result[0];
- unsigned char b = (unsigned)result[1];
- unsigned char c = (unsigned)result[2];
- unsigned char d = (unsigned)result[3];
- snprintf(r,1024,"%u.%u.%u.%u",a,b,c,d);
- return r;
- }
- else
- {
- if (ServerInstance && ServerInstance->stats)
- ServerInstance->stats->statsDnsBad++;
- log(DEBUG,"DANGER WILL ROBINSON! NXDOMAIN for forward lookup, but we got a reverse lookup!");
- return "";
- }
-}
+ ServerInstance->Log(DEBUG,"DNS::GetNameForce: %s %d",query, fp);
+ if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1)
+ return -1;
+ DNSRequest* req = this->AddQuery(&h, id);
-#ifdef THREADED_DNS
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
+ return -1;
-/* This function is a thread function which can be thought of as a lightweight process
- * to all you non-threaded people. In actuality its so much more, and pretty damn cool.
- * With threaded dns enabled, each user which connects gets a thread attached to their
- * user record when their DNS lookup starts. This function starts in parallel, and
- * commences a blocking dns lookup. Because its a seperate thread, this occurs without
- * actually blocking the main application. Once the dns lookup is completed, the thread
- * checks if the user is still around by checking their fd against the reference table,
- * and if they are, writes the hostname into the struct and terminates, after setting
- * userrec::dns_done to true. Because this is multi-threaded it can make proper use of
- * SMP setups (like the one i have here *grin*).
- * This is in comparison to the non-threaded dns, which must monitor the thread sockets
- * in a nonblocking fashion, consuming more resources to do so.
- *
- * NB: Yes this does scale, thank you. Even with large numbers of connecting clients
- * in any one timeframe, they wont all connect *at the same time* therefore any argument
- * of "but there will be thousands of threads it'll blow up" is moot, ive tested this and
- * there will only ever be somewhere around the listen backlog in number of pending
- * lookups at any one time. This is significant on any modern SMP system.
+ return id;
+}
+
+/** Build an ipv6 reverse domain from an in6_addr
*/
-void* dns_task(void* arg)
+void DNS::MakeIP6Int(char* query, const in6_addr *ip)
{
- userrec* u = (userrec*)arg;
- int thisfd = u->fd;
-
- log(DEBUG,"DNS thread for user %s on ip %s",u->nick,insp_ntoa(u->ip4));
- DNS dns1(Config->DNSServer);
- DNS dns2(Config->DNSServer);
- std::string host;
- std::string ip;
- int iterations = 0;
-
- if (dns1.ReverseLookup(insp_ntoa(u->ip4),false))
- {
- /* FIX: Dont make these infinite! */
- while ((!dns1.HasResult()) && (++iterations < 20))
- usleep(100);
-
- if (iterations < 20)
- {
- if (dns1.GetFD() != -1)
- {
- host = dns1.GetResult();
- if (host != "")
- {
- if (dns2.ForwardLookup(host, false))
- {
- iterations = 0;
- while ((!dns2.HasResult()) && (++iterations < 20))
- usleep(100);
-
- if (iterations < 20)
- {
- if (dns2.GetFD() != -1)
- {
- ip = dns2.GetResultIP();
- if (ip == std::string(insp_ntoa(u->ip4)))
- {
- if (host.length() < 65)
- {
- if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
- {
- if (!u->dns_done)
- {
- strcpy(u->host,host.c_str());
- if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
- {
- strcpy(u->dhost,host.c_str());
- }
- }
- }
- }
- }
- }
- }
- }
- }
- }
- }
- }
- if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
- u->dns_done = true;
- log(DEBUG,"THREAD EXIT");
- return NULL;
+#ifdef SUPPORT_IP6LINKS
+ const char* hex = "0123456789abcdef";
+ for (int index = 31; index >= 0; index--) /* for() loop steps twice per byte */
+ {
+ if (index % 2)
+ /* low nibble */
+ *query++ = hex[ip->s6_addr[index / 2] & 0x0F];
+ else
+ /* high nibble */
+ *query++ = hex[(ip->s6_addr[index / 2] & 0xF0) >> 4];
+ *query++ = '.'; /* Seperator */
+ }
+ strcpy(query,"ip6.arpa"); /* Suffix the string */
+#else
+ *query = 0;
+#endif
}
+
+/** Return the next id which is ready, and the result attached to it */
+DNSResult DNS::GetResult()
+{
+ /* Fetch dns query response and decide where it belongs */
+ DNSHeader header;
+ DNSRequest *req;
+ unsigned char buffer[sizeof(DNSHeader)];
+ sockaddr from;
+ socklen_t x = sizeof(from);
+ const char* ipaddr_from = "";
+ unsigned short int port_from = 0;
+
+ int length = recvfrom(this->GetFd(),buffer,sizeof(DNSHeader),0,&from,&x);
+
+ if (length < 0)
+ ServerInstance->Log(DEBUG,"Error in recvfrom()! (%s)",strerror(errno));
+
+ /* Did we get the whole header? */
+ if (length < 12)
+ {
+ /* Nope - something screwed up. */
+ ServerInstance->Log(DEBUG,"Whole header not read!");
+ return std::make_pair(-1,"");
+ }
+
+ /* Check wether the reply came from a different DNS
+ * server to the one we sent it to, or the source-port
+ * is not 53.
+ * A user could in theory still spoof dns packets anyway
+ * but this is less trivial than just sending garbage
+ * to the client, 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
-Resolver::Resolver(const std::string &source, bool forward, const std::string &dnsserver = "") : input(source), fwd(forward), server(dnsserver)
+ /* 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)))
+ {
+ ServerInstance->Log(DEBUG,"port %d is not 53, or %s is not %s",port_from, ipaddr_from, ServerInstance->Config->DNSServer);
+ return std::make_pair(-1,"");
+ }
+ }
+
+ /* Put the read header info into a header class */
+ DNS::FillHeader(&header,buffer,length - 12);
+
+ /* Get the id of this request.
+ * Its a 16 bit value stored in two char's,
+ * so we use logic shifts to create the value.
+ */
+ unsigned long this_id = header.id[1] + (header.id[0] << 8);
+
+ /* Do we have a pending request matching this id? */
+ requestlist_iter n_iter = requests.find(this_id);
+ if (n_iter == requests.end())
+ {
+ /* Somehow we got a DNS response for a request we never made... */
+ ServerInstance->Log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d queryid=%d",this->GetFd(),this_id);
+ return std::make_pair(-1,"");
+ }
+ else
+ {
+ /* Remove the query from the list of pending queries */
+ req = (DNSRequest*)n_iter->second;
+ requests.erase(n_iter);
+ }
+
+ /* Inform the DNSRequest class that it has a result to be read.
+ * When its finished it will return a DNSInfo which is a pair of
+ * unsigned char* resource record data, and an error message.
+ */
+ DNSInfo data = req->ResultIsReady(header, length);
+ std::string resultstr;
+
+ /* Check if we got a result, if we didnt, its an error */
+ if (data.first == NULL)
+ {
+ /* 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.
+ */
+ delete req;
+ return std::make_pair(this_id | ERROR_MASK, data.second);
+ }
+ else
+ {
+ char formatted[128];
+
+ /* Forward lookups come back as binary data. We must format them into ascii */
+ switch (req->type)
+ {
+ case DNS_QUERY_A:
+ snprintf(formatted,16,"%u.%u.%u.%u",data.first[0],data.first[1],data.first[2],data.first[3]);
+ resultstr = formatted;
+ break;
+
+ case DNS_QUERY_AAAA:
+ {
+ 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:
+ ServerInstance->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 */
+ delete req;
+ return std::make_pair(this_id,resultstr);
+ }
+}
+
+/** A result is ready, process it */
+DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
{
- if (this->server != "")
- Query.SetNS(this->server);
- else
- Query.SetNS(Config->DNSServer);
-
- if (forward)
- {
- Query.ForwardLookup(input.c_str(), false);
- this->fd = Query.GetFD();
- }
- else
- {
- Query.ReverseLookup(input.c_str(), false);
- this->fd = Query.GetFD();
- }
- if (fd < 0)
- {
- log(DEBUG,"Resolver::Resolver: RESOLVER_NSDOWN");
- this->OnError(RESOLVER_NSDOWN);
- ModuleException e("Resolver: Nameserver is down");
- throw e;
- /* We shouldnt get here really */
- return;
- }
-
- if (ServerInstance && ServerInstance->SE)
- {
- log(DEBUG,"Resolver::Resolver: this->fd=%d",this->fd);
- ServerInstance->SE->AddFd(this->fd,true,X_ESTAB_CLASSDNS);
- }
- else
- {
- log(DEBUG,"Resolver::Resolver: RESOLVER_NOTREADY");
- this->OnError(RESOLVER_NOTREADY);
- ModuleException e("Resolver: Core not initialized yet");
- throw e;
- /* We shouldnt get here really */
- return;
- }
+ int i = 0;
+ int q = 0;
+ int curanswer, o;
+ ResourceRecord rr;
+ unsigned short ptr;
+
+ if (!(header.flags1 & FLAGS_MASK_QR))
+ return std::make_pair((unsigned char*)NULL,"Not a query result");
+
+ if (header.flags1 & FLAGS_MASK_OPCODE)
+ return std::make_pair((unsigned char*)NULL,"Unexpected value in DNS reply packet");
+
+ if (header.flags2 & FLAGS_MASK_RCODE)
+ return std::make_pair((unsigned char*)NULL,"Domain name not found");
+
+ if (header.ancount < 1)
+ return std::make_pair((unsigned char*)NULL,"No resource records returned");
+
+ /* Subtract the length of the header from the length of the packet */
+ length -= 12;
+
+ while ((unsigned int)q < header.qdcount && i < length)
+ {
+ if (header.payload[i] > 63)
+ {
+ i += 6;
+ q++;
+ }
+ else
+ {
+ if (header.payload[i] == 0)
+ {
+ q++;
+ i += 5;
+ }
+ else i += header.payload[i] + 1;
+ }
+ }
+ curanswer = 0;
+ while ((unsigned)curanswer < header.ancount)
+ {
+ q = 0;
+ while (q == 0 && i < length)
+ {
+ if (header.payload[i] > 63)
+ {
+ i += 2;
+ q = 1;
+ }
+ else
+ {
+ if (header.payload[i] == 0)
+ {
+ i++;
+ q = 1;
+ }
+ else i += header.payload[i] + 1; /* skip length and label */
+ }
+ }
+ if (length - i < 10)
+ return std::make_pair((unsigned char*)NULL,"Incorrectly sized DNS reply");
+
+ DNS::FillResourceRecord(&rr,&header.payload[i]);
+ i += 10;
+ if (rr.type != this->type)
+ {
+ curanswer++;
+ i += rr.rdlength;
+ continue;
+ }
+ if (rr.rr_class != this->rr_class)
+ {
+ curanswer++;
+ i += rr.rdlength;
+ continue;
+ }
+ break;
+ }
+ if ((unsigned int)curanswer == header.ancount)
+ return std::make_pair((unsigned char*)NULL,"No valid 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");
+
+ switch (rr.type)
+ {
+ 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)
+ {
+ memcpy(&ptr,&header.payload[i],2);
+ i = ntohs(ptr) - 0xC000 - 12;
+ }
+ else
+ {
+ if (header.payload[i] == 0)
+ {
+ q = 1;
+ }
+ else
+ {
+ res[o] = 0;
+ if (o != 0)
+ res[o++] = '.';
+ 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:
+ memcpy(res,&header.payload[i],rr.rdlength);
+ res[rr.rdlength] = 0;
+ break;
+ case DNS_QUERY_A:
+ memcpy(res,&header.payload[i],rr.rdlength);
+ res[rr.rdlength] = 0;
+ break;
+ default:
+ memcpy(res,&header.payload[i],rr.rdlength);
+ res[rr.rdlength] = 0;
+ break;
+ }
+ return std::make_pair(res,"No error");;
}
-Resolver::~Resolver()
+/** Close the master socket */
+DNS::~DNS()
{
- log(DEBUG,"Resolver::~Resolver");
- if (ServerInstance && ServerInstance->SE)
- ServerInstance->SE->DelFd(this->fd);
+ shutdown(this->GetFd(), 2);
+ close(this->GetFd());
}
-int Resolver::GetFd()
+/** High level abstraction of dns used by application at large */
+Resolver::Resolver(InspIRCd* Instance, const std::string &source, QueryType qt) : ServerInstance(Instance), input(source), querytype(qt)
{
- return this->fd;
+ ServerInstance->Log(DEBUG,"Instance: %08x %08x",Instance, ServerInstance);
+
+ 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)
+ {
+ ServerInstance->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;
+ }
+
+ ServerInstance->Log(DEBUG,"Resolver::Resolver: this->myid=%d",this->myid);
}
-bool Resolver::ProcessResult()
+/** Called when an error occurs */
+void Resolver::OnError(ResolverError e, const std::string &errormessage)
{
- log(DEBUG,"Resolver::ProcessResult");
- if (this->fwd)
- result = Query.GetResultIP();
- else
- result = Query.GetResult();
-
- if (result != "")
- {
- log(DEBUG,"Resolver::OnLookupComplete(%s)",result.c_str());
- this->OnLookupComplete(result);
- return true;
- }
- else
- {
- log(DEBUG,"Resolver::OnError(RESOLVER_NXDOMAIN)");
- this->OnError(RESOLVER_NXDOMAIN);
- return false;
- }
+ /* Nothing in here */
}
-void Resolver::OnLookupComplete(const std::string &result)
+/** Destroy a resolver */
+Resolver::~Resolver()
{
+ /* Nothing here (yet) either */
}
-void Resolver::OnError(ResolverError e)
+/** Get the request id associated with this class */
+int Resolver::GetId()
{
+ return this->myid;
}
-void dns_deal_with_classes(int fd)
+/** Process a socket read event */
+void DNS::HandleEvent(EventType et)
{
- log(DEBUG,"dns_deal_with_classes(%d)",fd);
- if ((fd > -1) && (dns_classes[fd]))
- {
- log(DEBUG,"Valid fd %d",fd);
- dns_classes[fd]->ProcessResult();
- delete dns_classes[fd];
- dns_classes[fd] = NULL;
- }
+ ServerInstance->Log(DEBUG,"Marshall reads: %d",this->GetFd());
+ /* 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.first & ERROR_MASK)
+ {
+ /* Mask off the error bit */
+ res.first -= ERROR_MASK;
+ /* Marshall the error to the correct class */
+ ServerInstance->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;
+ }
+ }
+ else
+ {
+ /* It is a non-error result */
+ ServerInstance->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++;
+ Classes[res.first]->OnLookupComplete(res.second);
+ delete Classes[res.first];
+ Classes[res.first] = 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");
- if ((r) && (r->GetFd() > -1))
- {
- if (!dns_classes[r->GetFd()])
- {
- log(DEBUG,"dns_add_class: added class");
- dns_classes[r->GetFd()] = r;
- return true;
- }
- else
- {
- log(DEBUG,"Space occupied!");
- return false;
- }
- }
- else
- {
- log(DEBUG,"Bad class");
- delete r;
- return true;
- }
+ /* Check the pointers validity and the id's validity */
+ if ((r) && (r->GetId() > -1))
+ {
+ /* Check the slot isnt already occupied -
+ * This should NEVER happen unless we have
+ * a severely broken DNS server somewhere
+ */
+ if (!Classes[r->GetId()])
+ {
+ /* Set up the pointer to the class */
+ Classes[r->GetId()] = r;
+ return true;
+ }
+ else
+ /* Duplicate id */
+ return false;
+ }
+ else
+ {
+ /* Pointer or id not valid.
+ * Free the item and return
+ */
+ if (r)
+ delete r;
+
+ return false;
+ }
}
-void init_dns()
+/** Generate pseudo-random number */
+unsigned long DNS::PRNG()
{
- memset(dns_classes,0,sizeof(dns_classes));
+ 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