-/*
-dns.cpp - based on the firedns library Copyright (C) 2002 Ian Gulliver
-
-This program is free software; you can redistribute it and/or modify
-it under the terms of version 2 of the GNU General Public License as
-published by the Free Software Foundation.
+/* +------------------------------------+
+ * | Inspire Internet Relay Chat Daemon |
+ * +------------------------------------+
+ *
+ * InspIRCd: (C) 2002-2008 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.
+ *
+ * ---------------------------------------------------
+ */
-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.
+/* $Core: libIRCDasyncdns */
-You should have received a copy of the GNU General Public License
-along with this program; if not, write to the Free Software
-Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+/*
+dns.cpp - Nonblocking DNS functions.
+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.
*/
-#define _DNS_C
-
-using namespace std;
-
-#include <string>
-#include <stdlib.h>
-#include <time.h>
+#ifndef WIN32
#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>
+#else
+#include "inspircd_win32wrapper.h"
+#include "inspircd_se_config.h"
+#endif
+
#include "dns.h"
-#include "helperfuncs.h"
-
-extern int statsAccept,statsRefused,statsUnknown,statsCollisions,statsDns,statsDnsGood,statsDnsBad,statsConnects,statsSent,statsRecv;
-
-#define max(a,b) (a > b ? a : b)
-#define DNS_MAX 8 /* max number of nameservers used */
-#define DNS_CONFIG_FBCK "/etc/resolv.conf" /* fallback config file */
-#define DNS_PORT 53 /* DNS well known port */
-#define DNS_QRY_A 1 /* name to IP address */
-#define DNS_QRY_AAAA 28 /* name to IP6 address */
-#define DNS_QRY_PTR 12 /* IP address to name */
-#define DNS_QRY_MX 15 /* name to MX */
-#define DNS_QRY_TXT 16 /* name to TXT */
-#define DNS_QRY_CNAME 5
-
-#define DNS_ALIGN (sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long))
-#define DNS_TRIES 3
-#define RESULTSIZE 1024
-#define min(a,b) (a < b ? a : b)
-
-static struct in_addr servers4[DNS_MAX]; /* up to DNS_MAX nameservers; populated by dns_init() */
-static int i4; /* actual count of nameservers; set by dns_init() */
-
-static int initdone = 0; /* to ensure dns_init() only runs once (on the first call) */
-static int wantclose = 0;
-static int lastcreate = -1;
-
-struct s_connection { /* open DNS query */
- struct s_connection *next; /* next in list */
- unsigned char id[2];
- unsigned int _class;
- unsigned int type;
- int want_list;
- int fd; /* file descriptor returned from sockets */
+#include "inspircd.h"
+#include "socketengine.h"
+#include "configreader.h"
+#include "socket.h"
+
+using irc::sockets::insp_inaddr;
+using irc::sockets::insp_ntoa;
+using irc::sockets::insp_aton;
+using irc::sockets::OpenTCPSocket;
+
+/** Masks to mask off the responses we get from the DNSRequest methods
+ */
+enum QueryInfo
+{
+ ERROR_MASK = 0x10000 /* Result is an error */
};
-struct s_rr_middle {
- unsigned int type;
- unsigned int _class;
- unsigned long ttl;
- unsigned int rdlength;
+/** 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
};
-#define DNS_POINTER_VALUE 0xc000
-
-static s_connection *connection_head = NULL; /* linked list of open DNS queries; populated by dns_add_query(), decimated by dns_getresult_s() */
-
-struct s_header { /* DNS query header */
- unsigned char id[2];
- unsigned int flags1;
-#define FLAGS1_MASK_QR 0x80
-#define FLAGS1_MASK_OPCODE 0x78 /* bitshift right 3 */
-#define FLAGS1_MASK_AA 0x04
-#define FLAGS1_MASK_TC 0x02
-#define FLAGS1_MASK_RD 0x01
- unsigned int flags2;
-#define FLAGS2_MASK_RA 0x80
-#define FLAGS2_MASK_Z 0x70
-#define FLAGS2_MASK_RCODE 0x0f
- unsigned int qdcount;
- unsigned int ancount;
- unsigned int nscount;
- unsigned int arcount;
- unsigned char payload[512]; /* DNS question, populated by dns_build_query_payload() */
+
+/** Represents a dns resource record (rr)
+ */
+struct ResourceRecord
+{
+ QueryType type; /* Record type */
+ unsigned int rr_class; /* Record class */
+ unsigned long ttl; /* Time to live */
+ unsigned int rdlength; /* Record length */
};
-extern time_t TIME;
+/** Represents a dns request/reply header, and its payload as opaque data.
+ */
+class DNSHeader
+{
+ public:
+ 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 */
+};
-void *dns_align(void *inp) {
- char *p = (char*)inp;
- int offby = ((char *)p - (char *)0) % DNS_ALIGN;
- if (offby != 0)
- return p + (DNS_ALIGN - offby);
- else
- return p;
+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 */
+ InspIRCd* ServerInstance;
+
+ DNSRequest(InspIRCd* Instance, DNS* dns, int id, const std::string &original);
+ ~DNSRequest();
+ DNSInfo ResultIsReady(DNSHeader &h, int length, int result_we_want);
+ int SendRequests(const DNSHeader *header, const int length, QueryType qt);
+};
+
+class CacheTimer : public Timer
+{
+ private:
+ InspIRCd* ServerInstance;
+ DNS* dns;
+ public:
+ CacheTimer(InspIRCd* Instance, DNS* thisdns)
+ : Timer(3600, Instance->Time(), true), ServerInstance(Instance), dns(thisdns) { }
+
+ virtual void Tick(time_t)
+ {
+ dns->PruneCache();
+ }
+};
+
+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)
+ {
+ }
+
+ void Tick(time_t)
+ {
+ if (ServerInstance->Res->requests[watchid] == watch)
+ {
+ /* Still exists, whack it */
+ if (ServerInstance->Res->Classes[watchid])
+ {
+ ServerInstance->Res->Classes[watchid]->OnError(RESOLVER_TIMEOUT, "Request timed out");
+ delete ServerInstance->Res->Classes[watchid];
+ ServerInstance->Res->Classes[watchid] = NULL;
+ }
+ ServerInstance->Res->requests[watchid] = NULL;
+ delete watch;
+ return;
+ }
+ }
+};
+
+/* Allocate the processing buffer */
+DNSRequest::DNSRequest(InspIRCd* Instance, DNS* dns, int rid, const std::string &original) : dnsobj(dns), ServerInstance(Instance)
+{
+ res = new unsigned char[512];
+ *res = 0;
+ orig = original;
+ RequestTimeout* RT = new RequestTimeout(Instance->Config->dns_timeout ? Instance->Config->dns_timeout : 5, Instance, this, rid);
+ Instance->Timers->AddTimer(RT); /* The timer manager frees this */
}
-/*
- * These little hacks are here to avoid alignment and type sizing issues completely by doing manual copies
- */
-void dns_fill_rr(s_rr_middle* rr, const unsigned char *input) {
- rr->type = input[0] * 256 + input[1];
- rr->_class = input[2] * 256 + input[3];
- rr->ttl = input[4] * 16777216 + input[5] * 65536 + input[6] * 256 + input[7];
- rr->rdlength = input[8] * 256 + input[9];
+/* 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->ttl = (input[4] << 24) + (input[5] << 16) + (input[6] << 8) + input[7];
+ rr->rdlength = (input[8] << 8) + input[9];
}
-void dns_fill_header(s_header *header, const unsigned char *input, const int l) {
+/** 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];
header->flags1 = input[2];
header->flags2 = input[3];
- header->qdcount = input[4] * 256 + input[5];
- header->ancount = input[6] * 256 + input[7];
- header->nscount = input[8] * 256 + input[9];
- header->arcount = input[10] * 256 + input[11];
- memcpy(header->payload,&input[12],l);
+ 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_empty_header(unsigned char *output, const s_header *header, const int l) {
+/** 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];
output[2] = header->flags1;
output[3] = header->flags2;
- output[4] = header->qdcount / 256;
- output[5] = header->qdcount % 256;
- output[6] = header->ancount / 256;
- output[7] = header->ancount % 256;
- output[8] = header->nscount / 256;
- output[9] = header->nscount % 256;
- output[10] = header->arcount / 256;
- output[11] = header->arcount % 256;
- memcpy(&output[12],header->payload,l);
-}
-
-void dns_close(int fd) { /* close query */
- if (fd == lastcreate) {
- wantclose = 1;
- return;
- }
- close(fd);
- return;
+ 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);
}
-void DNS::dns_init() { /* on first call only: populates servers4 struct with up to DNS_MAX nameserver IP addresses from /etc/resolv.conf */
- FILE *f;
- int i;
- in_addr addr4;
- char buf[1024];
- if (initdone == 1)
- return;
- i4 = 0;
+/** Send requests we have previously built down the UDP socket */
+int DNSRequest::SendRequests(const DNSHeader *header, const int length, QueryType qt)
+{
+ ServerInstance->Logs->Log("RESOLVER", DEBUG,"DNSRequest::SendRequests");
- initdone = 1;
- srand((unsigned int) TIME);
- memset(servers4,'\0',sizeof(in_addr) * DNS_MAX);
- f = fopen(DNS_CONFIG_FBCK,"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 < DNS_MAX) {
- if (dns_aton4_s(&buf[i],&addr4) != NULL)
- memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
- }
- }
+ unsigned char payload[sizeof(DNSHeader)];
+
+ 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;
}
- fclose(f);
+ 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;
+ }
+
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"Sent OK");
+ return 0;
}
-void DNS::dns_init_2(const char* dnsserver)
+/** Add a query with a predefined header, and allocate an ID for it. */
+DNSRequest* DNS::AddQuery(DNSHeader *header, int &id, const char* original)
{
- in_addr addr4;
- i4 = 0;
- srand((unsigned int) TIME);
- memset(servers4,'\0',sizeof(in_addr) * DNS_MAX);
- if (dns_aton4_s(dnsserver,&addr4) != NULL)
- memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
+ /* Is the DNS connection down? */
+ if (this->GetFd() == -1)
+ return NULL;
+
+ /* Create an id */
+ id = this->PRNG() & DNS::MAX_REQUEST_ID;
+
+ /* 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->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;
}
+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;
+}
-static int dns_send_requests(const s_header *h, const s_connection *s, const int l)
+int DNS::PruneCache()
{
- int i;
- sockaddr_in addr4;
- unsigned char payload[sizeof(s_header)];
+ 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;
+}
- dns_empty_header(payload,h,l);
+void DNS::Rehash()
+{
+ ip6munge = false;
+ int portpass = 0;
+ if (this->GetFd() > -1)
+ {
+ if (ServerInstance && ServerInstance->SE)
+ ServerInstance->SE->DelFd(this);
+ ServerInstance->SE->Shutdown(this, 2);
+ ServerInstance->SE->Close(this);
+ this->SetFd(-1);
+
+ /* Rehash the cache */
+ this->PruneCache();
+ }
+ else
+ {
+ /* Create initial dns cache */
+ this->cache = new dnscache();
+ }
- i = 0;
+ 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;
+ }
- /* otherwise send via standard ipv4 boringness */
- memset(&addr4,0,sizeof(addr4));
- memcpy(&addr4.sin_addr,&servers4[i],sizeof(addr4.sin_addr));
- addr4.sin_family = AF_INET;
- addr4.sin_port = htons(DNS_PORT);
- if (sendto(s->fd, payload, l + 12, 0, (sockaddr *) &addr4, sizeof(addr4)) == -1)
+ this->socketfamily = AF_INET;
+#ifdef IPV6
+ if (strchr(ServerInstance->Config->DNSServer,':'))
{
- return -1;
+ 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
- return 0;
+ /* Initialize mastersocket */
+ int s = OpenTCPSocket(ServerInstance->Config->DNSServer, SOCK_DGRAM);
+ this->SetFd(s);
+ ServerInstance->SE->NonBlocking(this->GetFd());
+
+ /* Have we got a socket and is it nonblocking? */
+ if (this->GetFd() != -1)
+ {
+ /* Bind the port - port 0 INADDR_ANY */
+ if (!ServerInstance->BindSocket(this->GetFd(), portpass, "", false))
+ {
+ /* Failed to bind */
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"Error binding dns socket");
+ ServerInstance->SE->Shutdown(this, 2);
+ ServerInstance->SE->Close(this);
+ this->SetFd(-1);
+ }
+
+ if (this->GetFd() >= 0)
+ {
+ /* 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);
+ }
+ }
+ }
+ }
+ else
+ {
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"Error creating dns socket");
+ }
}
-static s_connection *dns_add_query(s_header *h) { /* build DNS query, add to list */
- s_connection * s;
+/** Initialise the DNS UDP socket so that we can send requests */
+DNS::DNS(InspIRCd* Instance) : ServerInstance(Instance)
+{
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS::DNS");
+ /* Clear the Resolver class table */
+ memset(Classes,0,sizeof(Classes));
- s = new s_connection;
+ /* Clear the requests class table */
+ memset(requests,0,sizeof(requests));
- /* set header flags */
- h->id[0] = s->id[0] = rand() % 255; /* verified by dns_getresult_s() */
- h->id[1] = s->id[1] = rand() % 255;
- h->flags1 = 0 | FLAGS1_MASK_RD;
- h->flags2 = 0;
- h->qdcount = 1;
- h->ancount = 0;
- h->nscount = 0;
- h->arcount = 0;
+ /* Set the id of the next request to 0
+ */
+ currid = 0;
- /* turn off want_list by default */
- s->want_list = 0;
+ /* DNS::Rehash() sets this to a valid ptr
+ */
+ this->cache = NULL;
+
+ /* Again, DNS::Rehash() sets this to a
+ * valid value
+ */
+ this->SetFd(-1);
- /* try to create ipv6 or ipv4 socket */
- s->fd = socket(PF_INET, SOCK_DGRAM, 0);
- if (s->fd != -1) {
- if (fcntl(s->fd, F_SETFL, O_NONBLOCK) != 0) {
- close(s->fd);
- s->fd = -1;
- }
- }
- if (s->fd != -1) {
- sockaddr_in addr;
- memset(&addr,0,sizeof(addr));
- addr.sin_family = AF_INET;
- addr.sin_port = 0;
- addr.sin_addr.s_addr = INADDR_ANY;
- if (bind(s->fd,(sockaddr *)&addr,sizeof(addr)) != 0) {
- close(s->fd);
- s->fd = -1;
- }
- }
- if (s->fd == -1) {
- delete s;
- return NULL;
- }
- /* create new connection object, add to linked list */
- s->next = connection_head;
- connection_head = s;
+ /* Actually read the settings
+ */
+ this->Rehash();
- if (wantclose == 1) {
- close(lastcreate);
- wantclose = 0;
- }
- lastcreate = s->fd;
- return s;
+ this->PruneTimer = new CacheTimer(ServerInstance, this);
+
+ ServerInstance->Timers->AddTimer(this->PruneTimer);
}
-static int dns_build_query_payload(const char * const name, const unsigned short rr, const unsigned short _class, unsigned char * const payload) {
- short payloadpos;
- const char * tempchr, * tempchr2;
- unsigned short l;
-
- payloadpos = 0;
- tempchr2 = name;
+/** 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)
+ while ((tempchr = strchr(tempchr2,'.')) != NULL)
+ {
+ 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) {
- if (payloadpos + l + 2 > 507)
+ length = strlen(tempchr2);
+ if (length)
+ {
+ 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(_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;
}
-in_addr* DNS::dns_aton4(const char * const ipstring) { /* ascii to numeric: convert string to static 4part IP addr struct */
- static in_addr ip;
- return dns_aton4_s(ipstring,&ip);
-}
+/** 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;
-in_addr* DNS::dns_aton4_r(const char *ipstring) { /* ascii to numeric (reentrant): convert string to new 4part IP addr struct */
- in_addr* ip;
- ip = new in_addr;
- if(dns_aton4_s(ipstring,ip) == NULL) {
- delete ip;
- return NULL;
- }
- return ip;
-}
+ DNSRequest* req = this->AddQuery(&h, id, name);
-in_addr* DNS::dns_aton4_s(const char *ipstring, in_addr *ip) { /* ascii to numeric (buffered): convert string to given 4part IP addr struct */
- inet_aton(ipstring,ip);
- return ip;
-}
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_A) == -1))
+ return -1;
-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;
+ return id;
+}
- dns_init();
-
+/** Start lookup of an hostname to an IPv6 address */
+int DNS::GetIP6(const char *name)
+{
+ DNSHeader h;
+ int id;
+ int length;
- 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)
+ if ((length = this->MakePayload(name, DNS_QUERY_AAAA, 1, (unsigned char*)&h.payload)) == -1)
return -1;
- s->_class = 1;
- s->type = DNS_QRY_A;
- if (dns_send_requests(&h,s,l) == -1)
+
+ DNSRequest* req = this->AddQuery(&h, id, name);
+
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_AAAA) == -1))
return -1;
- return s->fd;
+ return id;
}
-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();
-
+/** Start lookup of a cname to another name */
+int DNS::GetCName(const char *alias)
+{
+ DNSHeader h;
+ int id;
+ int length;
- 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)
+ if ((length = this->MakePayload(alias, DNS_QUERY_CNAME, 1, (unsigned char*)&h.payload)) == -1)
return -1;
- return s->fd;
-}
+ DNSRequest* req = this->AddQuery(&h, id, alias);
-int DNS::dns_getname4(const in_addr *ip) { /* build, add and send PTR query; retrieve result with dns_getresult() */
- char query[512];
- s_header h;
- s_connection * s;
- unsigned char *c;
- int l;
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_CNAME) == -1))
+ return -1;
- c = (unsigned char *)&ip->s_addr;
+ 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
- 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)
+ if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1)
return -1;
- s->_class = 1;
- s->type = DNS_QRY_PTR;
- if (dns_send_requests(&h,s,l) == -1)
+
+ DNSRequest* req = this->AddQuery(&h, id, insp_ntoa(*ip));
+
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
return -1;
- return s->fd;
+ return id;
}
-char* DNS::dns_ntoa4(const in_addr * const ip) { /* numeric to ascii: convert 4part IP addr struct to static string */
- static char r[256];
- return dns_ntoa4_s(ip,r);
-}
+/** 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;
+ }
-char* DNS::dns_ntoa4_r(const in_addr *ip) { /* numeric to ascii (reentrant): convert 4part IP addr struct to new string */
- char *r;
- r = new char[256];
- return dns_ntoa4_s(ip,r);
-}
+ if ((length = this->MakePayload(query, DNS_QUERY_PTR, 1, (unsigned char*)&h.payload)) == -1)
+ return -1;
-char* DNS::dns_ntoa4_s(const in_addr *ip, char *r) { /* numeric to ascii (buffered): convert 4part IP addr struct to given string */
- unsigned char *m;
- m = (unsigned char *)&ip->s_addr;
- sprintf(r,"%d.%d.%d.%d",m[0],m[1],m[2],m[3]);
- return r;
-}
+ DNSRequest* req = this->AddQuery(&h, id, ip);
+
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_PTR) == -1))
+ return -1;
-char* DNS::dns_getresult(const int cfd) { /* retrieve result of DNS query */
- static char r[RESULTSIZE];
- return dns_getresult_s(cfd,r);
+ return id;
}
-char* DNS::dns_getresult_r(const int cfd) { /* retrieve result of DNS query (reentrant) */
- char *r;
- r = new char[RESULTSIZE];
- if(dns_getresult_s(cfd,r) == NULL) {
- delete r;
- return NULL;
+/** Build an ipv6 reverse domain from an in6_addr
+ */
+void DNS::MakeIP6Int(char* query, const in6_addr *ip)
+{
+#ifdef SUPPORT_IP6LINKS
+ const char* hex = "0123456789abcdef";
+ for (int index = 31; index >= 0; index--) /* for() loop steps twice per byte */
+ {
+ if (index % 2)
+ /* low nibble */
+ *query++ = hex[ip->s6_addr[index / 2] & 0x0F];
+ else
+ /* high nibble */
+ *query++ = hex[(ip->s6_addr[index / 2] & 0xF0) >> 4];
+ *query++ = '.'; /* Seperator */
}
- return r;
+ strcpy(query,"ip6.arpa"); /* Suffix the string */
+#else
+ *query = 0;
+#endif
}
-char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS query (buffered) */
- s_header h;
- s_connection *c, *prev;
- int l,i,q,curanswer,o;
- s_rr_middle rr;
- unsigned char buffer[sizeof(s_header)];
- unsigned short p;
-
- if (res)
+/** Return the next id which is ready, and the result attached to it */
+DNSResult DNS::GetResult(int resultnum)
+{
+ /* Fetch dns query response and decide where it belongs */
+ DNSHeader header;
+ DNSRequest *req;
+ unsigned char buffer[sizeof(DNSHeader)];
+ sockaddr* from = new sockaddr[2];
+#ifdef IPV6
+ socklen_t x = this->socketfamily == AF_INET ? sizeof(sockaddr_in) : sizeof(sockaddr_in6);
+#else
+ socklen_t x = sizeof(sockaddr_in);
+#endif
+ const char* ipaddr_from;
+ unsigned short int port_from = 0;
+
+ int length = ServerInstance->SE->RecvFrom(this, (char*)buffer, sizeof(DNSHeader), 0, from, &x);
+
+ /* Did we get the whole header? */
+ if (length < 12)
{
- res[0] = 0;
+ /* Nope - something screwed up. */
+ delete[] from;
+ return DNSResult(-1,"",0,"");
}
- prev = NULL;
- c = connection_head;
- while (c != NULL) { /* find query in list of open queries */
- if (c->fd == cfd)
- break;
- prev = c;
- c = c->next;
- }
- if (c == NULL) {
- return NULL; /* query not found */
+ /* 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);
}
- /* query found-- pull from list: */
- if (prev != NULL)
- prev->next = c->next;
else
- connection_head = c->next;
-
- l = recv(c->fd,buffer,sizeof(s_header),0);
- dns_close(c->fd);
- if (l < 12) {
- delete c;
- return NULL;
+#endif
+ {
+ ipaddr_from = inet_ntoa(((sockaddr_in*)from)->sin_addr);
+ port_from = ntohs(((sockaddr_in*)from)->sin_port);
}
- dns_fill_header(&h,buffer,l - 12);
- if (c->id[0] != h.id[0] || c->id[1] != h.id[1]) {
- delete c;
- return NULL; /* ID mismatch */
+
+ 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,"");
+ }
}
- if ((h.flags1 & FLAGS1_MASK_QR) == 0) {
- delete c;
- return NULL;
+
+ /* 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? */
+ if (!requests[this_id])
+ {
+ /* Somehow we got a DNS response for a request we never made... */
+ return DNSResult(-1,"",0,"");
}
- if ((h.flags1 & FLAGS1_MASK_OPCODE) != 0) {
- delete c;
- return NULL;
+ else
+ {
+ /* Remove the query from the list of pending queries */
+ req = requests[this_id];
+ requests[this_id] = NULL;
}
- if ((h.flags2 & FLAGS2_MASK_RCODE) != 0) {
- delete c;
- return 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, resultnum);
+ 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.
+ */
+ std::string ro = req->orig;
+ delete req;
+ return DNSResult(this_id | ERROR_MASK, data.second, 0, ro);
}
- if (h.ancount < 1) { /* no sense going on if we don't have any answers */
- delete c;
- return NULL;
+ 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)
+ {
+ case DNS_QUERY_A:
+ snprintf(formatted,16,"%u.%u.%u.%u",data.first[0],data.first[1],data.first[2],data.first[3]);
+ resultstr = formatted;
+ break;
+
+ case DNS_QUERY_AAAA:
+ {
+ inet_ntop(AF_INET6, data.first, formatted, sizeof(formatted));
+ char* c = strstr(formatted,":0:");
+ if (c != NULL)
+ {
+ memmove(c+1,c+2,strlen(c+2) + 1);
+ c += 2;
+ while (memcmp(c,"0:",2) == 0)
+ memmove(c,c+2,strlen(c+2) + 1);
+ if (memcmp(c,"0",2) == 0)
+ *c = 0;
+ if (memcmp(formatted,"0::",3) == 0)
+ memmove(formatted,formatted + 1, strlen(formatted + 1) + 1);
+ }
+ resultstr = formatted;
+
+ /* Special case. Sending ::1 around between servers
+ * and to clients is dangerous, because the : on the
+ * start makes the client or server interpret the IP
+ * as the last parameter on the line with a value ":1".
+ */
+ if (*formatted == ':')
+ resultstr.insert(0, "0");
+ }
+ break;
+
+ case DNS_QUERY_CNAME:
+ /* Identical handling to PTR */
+
+ case DNS_QUERY_PTR:
+ /* Reverse lookups just come back as char* */
+ resultstr = std::string((const char*)data.first);
+ break;
+
+ default:
+ break;
+
+ }
+
+ /* Build the reply with the id and hostname/ip in it */
+ std::string ro = req->orig;
+ delete req;
+ return DNSResult(this_id,resultstr,ttl,ro);
}
- /* skip queries */
- i = 0;
- q = 0;
- l -= 12;
- while ((unsigned)q < h.qdcount && i < l) {
- if (h.payload[i] > 63) { /* pointer */
- i += 6; /* skip pointer, _class and type */
+}
+
+/** A result is ready, process it */
+DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length, int result_we_want)
+{
+ int i = 0;
+ int q = 0;
+ int curanswer, o;
+ ResourceRecord rr;
+ unsigned short ptr;
+
+ /* This is just to keep _FORTIFY_SOURCE happy */
+ rr.type = DNS_QUERY_NONE;
+ rr.rdlength = 0;
+ rr.ttl = 1; /* GCC is a whiney bastard -- see the XXX below. */
+ rr.rr_class = 0; /* Same for VC++ */
+
+ 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 { /* label */
- if (h.payload[i] == 0) {
+ }
+ else
+ {
+ if (header.payload[i] == 0)
+ {
q++;
- i += 5; /* skip nil, _class and type */
- } else
- i += h.payload[i] + 1; /* skip length and label */
+ i += 5;
+ }
+ else i += header.payload[i] + 1;
}
}
- /* &h.payload[i] should now be the start of the first response */
curanswer = 0;
- while ((unsigned)curanswer < h.ancount) {
+ while ((unsigned)curanswer < header.ancount)
+ {
q = 0;
- while (q == 0 && i < l) {
- if (h.payload[i] > 63) { /* pointer */
- i += 2; /* skip pointer */
+ while (q == 0 && i < length)
+ {
+ if (header.payload[i] > 63)
+ {
+ i += 2;
q = 1;
- } else { /* label */
- if (h.payload[i] == 0) {
+ }
+ else
+ {
+ if (header.payload[i] == 0)
+ {
i++;
q = 1;
- } else
- i += h.payload[i] + 1; /* skip length and label */
+ }
+ else i += header.payload[i] + 1; /* skip length and label */
}
}
- if (l - i < 10) {
- delete c;
- return NULL;
- }
- dns_fill_rr(&rr,&h.payload[i]);
+ if (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]);
+
i += 10;
- if (rr.type != c->type) {
+ if (rr.type != this->type)
+ {
curanswer++;
i += rr.rdlength;
continue;
}
- if (rr._class != c->_class) {
+ if (rr.rr_class != this->rr_class)
+ {
curanswer++;
i += rr.rdlength;
continue;
}
break;
}
- if ((unsigned)curanswer == h.ancount)
- return NULL;
- if ((unsigned)i + rr.rdlength > (unsigned)l)
- return NULL;
+ 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) + ")");
+
+ if (i + rr.rdlength > (unsigned int)length)
+ 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:
+ 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 < l && o + 256 < 1023) {
- if (h.payload[i] > 63) { /* pointer */
- memcpy(&p,&h.payload[i],2);
- i = ntohs(p) - DNS_POINTER_VALUE - 12;
- } else { /* label */
- 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;
- }
+ while (q == 0 && i < length && o + 256 < 1023)
+ {
+ if (header.payload[i] > 63)
+ {
+ memcpy(&ptr,&header.payload[i],2);
+ i = ntohs(ptr) - 0xC000 - 12;
}
- }
- res[o] = '\0';
- break;
- case 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;
+ else
+ {
+ if (header.payload[i] == 0)
{
- /* skip next name */
- q = 0;
- while (q == 0 && i < l) {
- if (h.payload[i] > 63) { /* pointer */
- i += 2; /* skip pointer */
- q = 1;
- } else { /* label */
- if (h.payload[i] == 0) {
- i++;
- q = 1;
- } else
- i += h.payload[i] + 1; /* skip length and label */
- }
- }
+ q = 1;
}
- if (l - i < 10) {
- delete c;
- return NULL;
+ 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;
}
- 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;
}
- goto defaultcase;
- break;
+ 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:
- defaultcase:
- memcpy(res,&h.payload[i],rr.rdlength);
- res[rr.rdlength] = '\0';
- break;
+ memcpy(res,&header.payload[i],rr.rdlength);
+ res[rr.rdlength] = 0;
+ break;
}
- delete c;
- return res;
+ return std::make_pair(res,"No error");
}
-DNS::DNS()
+/** Close the master socket */
+DNS::~DNS()
{
- dns_init();
+ ServerInstance->SE->Shutdown(this, 2);
+ ServerInstance->SE->Close(this);
+ ServerInstance->Timers->DelTimer(this->PruneTimer);
}
-DNS::DNS(std::string dnsserver)
+CachedQuery* DNS::GetCache(const std::string &source)
{
- dns_init_2(dnsserver.c_str());
+ dnscache::iterator x = cache->find(source.c_str());
+ if (x != cache->end())
+ return &(x->second);
+ else
+ return NULL;
}
-
-void DNS::SetNS(std::string dnsserver)
+
+void DNS::DelCache(const std::string &source)
{
- dns_init_2(dnsserver.c_str());
+ cache->erase(source.c_str());
}
-DNS::~DNS()
+void Resolver::TriggerCachedResult()
{
+ if (CQ)
+ OnLookupComplete(CQ->data, time_left, true, 0);
}
-bool DNS::ReverseLookup(std::string ip)
+/** 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)
{
- statsDns++;
- binip = dns_aton4(ip.c_str());
- if (binip == NULL) {
- return false;
- }
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"Resolver::Resolver");
+ cached = false;
- this->fd = dns_getname4(binip);
- if (this->fd == -1)
+ CQ = ServerInstance->Res->GetCache(source);
+ if (CQ)
{
- return false;
+ time_left = CQ->CalcTTLRemaining();
+ if (!time_left)
+ {
+ ServerInstance->Res->DelCache(source);
+ }
+ else
+ {
+ cached = true;
+ return;
+ }
}
- return true;
-}
-bool DNS::ForwardLookup(std::string host)
-{
- statsDns++;
- this->fd = dns_getip4(host.c_str());
- if (this->fd == -1)
+ insp_inaddr binip;
+
+ switch (querytype)
{
- return false;
+ 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)
+ {
+ this->OnError(RESOLVER_NSDOWN, "Nameserver is down");
+ throw ModuleException("Resolver: Couldnt get an id to make a request");
+ /* We shouldnt get here really */
+ return;
}
- return true;
+ else
+ {
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"DNS request id %d", this->myid);
+ }
+}
+
+/** Called when an error occurs */
+void Resolver::OnError(ResolverError, const std::string&)
+{
+ /* Nothing in here */
}
-bool DNS::HasResult()
+/** Destroy a resolver */
+Resolver::~Resolver()
{
- pollfd polls;
- polls.fd = this->fd;
- polls.events = POLLIN;
- int ret = poll(&polls,1,1);
- return (ret > 0);
+ /* Nothing here (yet) either */
}
-int DNS::GetFD()
+/** Get the request id associated with this class */
+int Resolver::GetId()
{
- return this->fd;
+ return this->myid;
}
-std::string DNS::GetResult()
+Module* Resolver::GetCreator()
{
- result = dns_getresult(this->fd);
- if (result) {
- statsDnsGood++;
- dns_close(this->fd);
- return result;
- } else {
- statsDnsBad++;
- if (this->fd != -1)
+ return this->Creator;
+}
+
+/** Process a socket read event */
+void DNS::HandleEvent(EventType, int)
+{
+ /* Fetch the id and result of the next available packet */
+ int resultnum = 0;
+ DNSResult res(0,"",0,"");
+ res.id = 0;
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"Handle DNS event");
+
+ res = this->GetResult(resultnum);
+
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"Result %d id %d", resultnum, res.id);
+
+ /* Is there a usable request id? */
+ if (res.id != -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;
+ }
+ return;
+ }
+ else
{
- dns_close(this->fd);
+ /* It is a non-error result, marshall the result to the correct class */
+ if (Classes[res.id])
+ {
+ 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, resultnum);
+ delete Classes[res.id];
+ Classes[res.id] = NULL;
+ }
}
- return "";
+
+ if (ServerInstance && ServerInstance->stats)
+ ServerInstance->stats->statsDns++;
}
-}
-std::string DNS::GetResultIP()
+ resultnum++;
+}
+
+/** Add a derived Resolver to the working set */
+bool DNS::AddResolverClass(Resolver* r)
{
- char r[1024];
- result = dns_getresult(this->fd);
- if (this->fd != -1)
+ ServerInstance->Logs->Log("RESOLVER",DEBUG,"AddResolverClass 0x%08lx", (unsigned long)r);
+ /* Check the pointers validity and the id's validity */
+ if ((r) && (r->GetId() > -1))
{
- dns_close(this->fd);
+ /* 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;
}
- if (result)
+ else
{
- sprintf(r,"%u.%u.%u.%u",result[0],result[1],result[2],result[3]);
- return r;
+ /* Pointer or id not valid.
+ * Free the item and return
+ */
+ if (r)
+ delete r;
+
+ return false;
}
- else
+}
+
+void DNS::CleanResolvers(Module* module)
+{
+ for (int i = 0; i < MAX_REQUEST_ID; i++)
{
- log(DEBUG,"DANGER WILL ROBINSON! NXDOMAIN for forward lookup, but we got a reverse lookup!");
- return "";
+ if (Classes[i])
+ {
+ if (Classes[i]->GetCreator() == module)
+ {
+ Classes[i]->OnError(RESLOVER_FORCEUNLOAD, "Parent module is unloading");
+ delete Classes[i];
+ Classes[i] = NULL;
+ }
+ }
}
}
+
+/** Generate pseudo-random number */
+unsigned long DNS::PRNG()
+{
+ unsigned long val = 0;
+ 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;
+}
+
+