-/*
-dns.cpp - based on the dns 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.
-
-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.
+/* +------------------------------------+
+ * | Inspire Internet Relay Chat Daemon |
+ * +------------------------------------+
+ *
+ * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
+ * E-mail:
+ * <brain@chatspike.net>
+ * <Craig@chatspike.net>
+ *
+ * Written by Craig Edwards, Craig McLure, and others.
+ * This program is free but copyrighted software; see
+ * the file COPYING for details.
+ *
+ * ---------------------------------------------------
+ */
-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 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
*/
-#define _DNS_C
+using namespace std;
#include <string>
#include <stdlib.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 "socketengine.h"
+
+extern InspIRCd* ServerInstance;
+extern ServerConfig* Config;
+extern time_t TIME;
+
+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 };
-static const char tagstring[] = "$Id$";
-
-#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 */
+class s_connection;
+
+typedef std::map<int,s_connection*> connlist;
+typedef connlist::iterator connlist_iter;
+connlist connections;
+
+struct in_addr servers4[8];
+int i4;
+int initdone = 0;
+int wantclose = 0;
+int lastcreate = -1;
+
+class s_connection
+{
+ public:
+ unsigned char id[2];
+ unsigned int _class;
+ QueryType type;
+ int want_list;
+ int fd;
};
-struct s_rr_middle {
- unsigned int type;
- unsigned int _class;
- unsigned long ttl;
- unsigned int rdlength;
+class s_rr_middle
+{
+ public:
+ QueryType type;
+ unsigned int _class;
+ unsigned long ttl;
+ unsigned int rdlength;
};
-#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() */
+class s_header
+{
+ 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];
};
-extern time_t TIME;
-void *dns_align(void *inp) {
+void *dns_align(void *inp)
+{
char *p = (char*)inp;
- int offby = ((char *)p - (char *)0) % DNS_ALIGN;
+ int offby = ((char *)p - (char *)0) % (sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long));
if (offby != 0)
- return p + (DNS_ALIGN - offby);
+ return p + ((sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long)) - offby);
else
return p;
}
/*
- * These little hacks are here to avoid alignment and type sizing issues completely by doing manual copies
+ * 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.
*/
-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];
+
+inline void dns_fill_rr(s_rr_middle* rr, const unsigned char *input)
+{
+ 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];
}
-void dns_fill_header(s_header *header, const unsigned char *input, const int l) {
+inline void dns_fill_header(s_header *header, const unsigned char *input, const int l)
+{
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];
+ 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);
}
-void dns_empty_header(unsigned char *output, const s_header *header, const int l) {
+inline void dns_empty_header(unsigned char *output, const s_header *header, const int l)
+{
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;
+ 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);
}
-void dns_close(int fd) { /* close query */
- if (fd == lastcreate) {
+void dns_close(int fd)
+{
+#ifndef THREADED_DNS
+ if (ServerInstance && ServerInstance->SE)
+ ServerInstance->SE->DelFd(fd);
+#endif
+ log(DEBUG,"DNS: dns_close on fd %d",fd);
+ if (fd == lastcreate)
+ {
wantclose = 1;
return;
}
+ shutdown(fd,2);
close(fd);
return;
}
-void DNS::dns_init() { /* on first call only: populates servers4 struct with up to DNS_MAX nameserver IP addresses from /etc/resolv.conf */
+void DNS::dns_init()
+{
FILE *f;
int i;
in_addr addr4;
initdone = 1;
srand((unsigned int) TIME);
- memset(servers4,'\0',sizeof(in_addr) * DNS_MAX);
- f = fopen(DNS_CONFIG_FBCK,"r");
+ memset(servers4,'\0',sizeof(in_addr) * 8);
+ f = fopen("/etc/resolv.conf","r");
if (f == NULL)
return;
while (fgets(buf,1024,f) != NULL) {
- if (strncmp(buf,"nameserver",10) == 0) {
+ if (strncmp(buf,"nameserver",10) == 0)
+ {
i = 10;
while (buf[i] == ' ' || buf[i] == '\t')
i++;
- if (i4 < DNS_MAX) {
+ if (i4 < 8)
+ {
if (dns_aton4_s(&buf[i],&addr4) != NULL)
memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
}
in_addr addr4;
i4 = 0;
srand((unsigned int) TIME);
- memset(servers4,'\0',sizeof(in_addr) * DNS_MAX);
+ memset(servers4,'\0',sizeof(in_addr) * 8);
if (dns_aton4_s(dnsserver,&addr4) != NULL)
memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
}
-static int dns_send_requests(const s_header *h, const s_connection *s, const int l)
+int dns_send_requests(const s_header *h, const s_connection *s, const int l)
{
int i;
sockaddr_in addr4;
dns_empty_header(payload,h,l);
- for (i = 0; i < i4; i++) {
- /* 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)
- {
- return -1;
- }
+ i = 0;
+
+ /* 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(53);
+ if (sendto(s->fd, payload, l + 12, 0, (sockaddr *) &addr4, sizeof(addr4)) == -1)
+ {
+ return -1;
}
return 0;
}
-static s_connection *dns_add_query(s_header *h) { /* build DNS query, add to list */
- s_connection * s;
+s_connection *dns_add_query(s_header *h)
+{
- s = new s_connection;
+ s_connection * s = new s_connection;
+ int id = rand() % 65536;
/* 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->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;
-
- /* turn off want_list by default */
s->want_list = 0;
-
- /* 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;
- }
+ s->fd = socket(PF_INET, SOCK_DGRAM, 0);
+ if (s->fd != -1)
+ {
+ if (fcntl(s->fd, F_SETFL, O_NONBLOCK) != 0)
+ {
+ shutdown(s->fd,2);
+ close(s->fd);
+ s->fd = -1;
}
- if (s->fd == -1) {
- delete s;
- return NULL;
+ }
+ 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)
+ {
+ shutdown(s->fd,2);
+ 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;
+ if (connections.find(s->fd) == connections.end())
+ connections[s->fd] = s;
- if (wantclose == 1) {
+ if (wantclose == 1)
+ {
+ shutdown(lastcreate,2);
close(lastcreate);
wantclose = 0;
}
return s;
}
-static int dns_build_query_payload(const char * const name, const unsigned short rr, const unsigned short _class, unsigned char * const payload) {
+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;
/* split name up into labels, create query */
- while ((tempchr = strchr(tempchr2,'.')) != NULL) {
+ while ((tempchr = strchr(tempchr2,'.')) != NULL)
+ {
l = tempchr - tempchr2;
if (payloadpos + l + 1 > 507)
return -1;
tempchr2 = &tempchr[1];
}
l = strlen(tempchr2);
- if (l) {
+ if (l)
+ {
if (payloadpos + l + 2 > 507)
return -1;
payload[payloadpos++] = l;
return payloadpos + 4;
}
-in_addr* DNS::dns_aton4(const char * const ipstring) { /* ascii to numeric: convert string to static 4part IP addr struct */
- in_addr ip;
+in_addr* DNS::dns_aton4(const char * const ipstring)
+{
+ static in_addr ip;
return dns_aton4_s(ipstring,&ip);
}
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) {
+ if(dns_aton4_s(ipstring,ip) == NULL)
+ {
delete ip;
return NULL;
}
}
in_addr* DNS::dns_aton4_s(const char *ipstring, in_addr *ip) { /* ascii to numeric (buffered): convert string to given 4part IP addr struct */
- unsigned char *myip;
- int i,part = 0;
- myip = (unsigned char *)ip;
-
- memset(myip,'\0',4);
- for (i = 0; i < 16; i++) {
- switch (ipstring[i]) {
- case '\0':
- if (part != 3)
- return NULL;
- return ip;
- break;
- case '0':
- case '1':
- case '2':
- case '3':
- case '4':
- case '5':
- case '6':
- case '7':
- case '8':
- case '9':
- if (myip[part] > 25)
- return NULL;
- myip[part] *= 10;
- if (myip[part] == 250 && ipstring[i] - '0' > 6)
- return NULL;
- myip[part] += ipstring[i] - '0';
- break;
- case '.':
- if (part == 3)
- return ip;
- else
- part++;
- break;
- default:
- if (part == 3)
- return ip;
- else
- return NULL;
- break;
- }
- }
- if (part == 3)
- return ip;
- else
- return NULL;
+ inet_aton(ipstring,ip);
+ return ip;
}
int DNS::dns_getip4(const char *name) { /* build, add and send A query; retrieve result with dns_getresult() */
dns_init();
-
l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload);
if (l == -1)
return -1;
unsigned char *c;
int l;
- dns_init();
-
c = (unsigned char *)&ip->s_addr;
sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]);
return dns_ntoa4_s(ip,r);
}
-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);
-}
-
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;
}
char* DNS::dns_getresult(const int cfd) { /* retrieve result of DNS query */
- static char r[RESULTSIZE];
- return dns_getresult_s(cfd,r);
-}
-
-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;
- }
- return r;
+ log(DEBUG,"DNS: dns_getresult with cfd=%d",cfd);
+ return dns_getresult_s(cfd,this->localbuf);
}
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_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] = 0;
- }
+ *res = 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 */
+ /* FireDNS used a linked list for this. How ugly (and slow). */
+ 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);
+ return NULL;
}
- /* query found-- pull from list: */
- if (prev != NULL)
- prev->next = c->next;
else
- connection_head = c->next;
+ {
+ /* 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);
+ }
l = recv(c->fd,buffer,sizeof(s_header),0);
dns_close(c->fd);
- if (l < 12) {
+ 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]) {
+ 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) {
+ 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) {
+ 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) {
+ if ((h.flags2 & FLAGS2_MASK_RCODE) != 0)
+ {
+ log(DEBUG,"DNS lookup failed due to SERVFAIL");
delete c;
return NULL;
}
- if (h.ancount < 1) { /* no sense going on if we don't have any answers */
+ if (h.ancount < 1)
+ {
+ log(DEBUG,"DNS: no answers!");
delete c;
return NULL;
}
- /* skip queries */
i = 0;
q = 0;
l -= 12;
- while (q < h.qdcount && i < l) {
- if (h.payload[i] > 63) { /* pointer */
- i += 6; /* skip pointer, _class and type */
+ while ((unsigned)q < h.qdcount && i < l)
+ {
+ if (h.payload[i] > 63)
+ {
+ i += 6;
q++;
- } else { /* label */
- if (h.payload[i] == 0) {
+ }
+ else
+ {
+ if (h.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 += h.payload[i] + 1;
}
}
- /* &h.payload[i] should now be the start of the first response */
curanswer = 0;
- while (curanswer < h.ancount) {
+ while ((unsigned)curanswer < h.ancount)
+ {
q = 0;
- while (q == 0 && i < l) {
- if (h.payload[i] > 63) { /* pointer */
- i += 2; /* skip pointer */
+ while (q == 0 && i < l)
+ {
+ if (h.payload[i] > 63)
+ {
+ i += 2;
q = 1;
- } else { /* label */
- if (h.payload[i] == 0) {
+ }
+ else
+ {
+ if (h.payload[i] == 0)
+ {
i++;
q = 1;
- } else
- i += h.payload[i] + 1; /* skip length and label */
+ }
+ else i += h.payload[i] + 1; /* skip length and label */
}
}
- if (l - i < 10) {
+ if (l - i < 10)
+ {
delete c;
return NULL;
}
dns_fill_rr(&rr,&h.payload[i]);
i += 10;
- if (rr.type != c->type) {
+ if (rr.type != c->type)
+ {
curanswer++;
i += rr.rdlength;
continue;
}
- if (rr._class != c->_class) {
+ if (rr._class != c->_class)
+ {
curanswer++;
i += rr.rdlength;
continue;
}
break;
}
- if (curanswer == h.ancount)
+ if ((unsigned)curanswer == h.ancount)
return NULL;
- if (i + rr.rdlength > l)
+ if ((unsigned)i + rr.rdlength > (unsigned)l)
return NULL;
if (rr.rdlength > 1023)
return NULL;
- switch (rr.type) {
+ 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) { /* pointer */
+ while (q == 0 && i < l && o + 256 < 1023)
+ {
+ if (h.payload[i] > 63)
+ {
memcpy(&p,&h.payload[i],2);
- i = ntohs(p) - DNS_POINTER_VALUE - 12;
- } else { /* label */
+ i = ntohs(p) - 0xC000 - 12;
+ }
+ else
+ {
if (h.payload[i] == 0)
+ {
q = 1;
- else {
+ }
+ else
+ {
res[o] = '\0';
if (o != 0)
res[o++] = '.';
}
}
res[o] = '\0';
- break;
+ break;
case DNS_QRY_A:
- if (c->want_list) {
+ 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) {
+ while ((char *)alist - (char *)res < 700)
+ {
if (rr.type != DNS_QRY_A)
break;
if (rr._class != 1)
break;
- if (rr.rdlength != 4) {
+ if (rr.rdlength != 4)
+ {
delete c;
return NULL;
}
memcpy(&alist->ip,&h.payload[i],4);
- if (++curanswer >= h.ancount)
+ if ((unsigned)++curanswer >= h.ancount)
break;
i += rr.rdlength;
+ q = 0;
+ while (q == 0 && i < l)
{
- /* skip next name */
- q = 0;
- while (q == 0 && i < l) {
- if (h.payload[i] > 63) { /* pointer */
- i += 2; /* skip pointer */
+ if (h.payload[i] > 63)
+ {
+ i += 2;
+ q = 1;
+ }
+ else
+ {
+ if (h.payload[i] == 0)
+ {
+ i++;
q = 1;
- } else { /* label */
- if (h.payload[i] == 0) {
- i++;
- q = 1;
- } else
- i += h.payload[i] + 1; /* skip length and label */
}
+ else i += h.payload[i] + 1;
}
}
- if (l - i < 10) {
+ if (l - i < 10)
+ {
delete c;
return NULL;
}
alist->next = NULL;
break;
}
- goto defaultcase;
+ memcpy(res,&h.payload[i],rr.rdlength);
+ res[rr.rdlength] = '\0';
break;
default:
- defaultcase:
memcpy(res,&h.payload[i],rr.rdlength);
res[rr.rdlength] = '\0';
break;
DNS::DNS()
{
dns_init();
+ log(DEBUG,"Create blank DNS");
}
-DNS::DNS(std::string dnsserver)
+DNS::DNS(const std::string &dnsserver)
{
dns_init_2(dnsserver.c_str());
+ log(DEBUG,"Create DNS with server '%s'",dnsserver.c_str());
}
-void DNS::SetNS(std::string dnsserver)
+void DNS::SetNS(const std::string &dnsserver)
{
dns_init_2(dnsserver.c_str());
+ log(DEBUG,"Set NS");
}
DNS::~DNS()
{
}
-bool DNS::ReverseLookup(std::string ip)
+bool DNS::ReverseLookup(const std::string &ip)
{
+ if (ServerInstance && ServerInstance->stats)
+ ServerInstance->stats->statsDns++;
binip = dns_aton4(ip.c_str());
- if (binip == NULL) {
+ if (binip == NULL)
+ {
return false;
}
- this->fd = dns_getname4(binip);
- if (this->fd == -1)
+
+ this->myfd = dns_getname4(binip);
+ if (this->myfd == -1)
+ {
+ return false;
+ }
+ log(DEBUG,"DNS: ReverseLookup, fd=%d",this->myfd);
+#ifndef THREADED_DNS
+ if (ServerInstance && ServerInstance->SE)
+ ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS);
+#endif
+ return true;
+}
+
+bool DNS::ForwardLookup(const std::string &host)
+{
+ 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 (ServerInstance && ServerInstance->SE)
+ ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS);
+#endif
return true;
}
-bool DNS::ForwardLookup(std::string host)
+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)
+ {
+
+ }
+ log(DEBUG,"DNS: ForwardLookupWithFD, fd=%d",this->myfd);
+ if (ServerInstance && ServerInstance->SE)
+ ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_MODULE);
+ return true;
+}
+
+bool DNS::HasResult(int fd)
+{
+ return (fd == this->myfd);
}
+/* 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->fd;
+ polls.fd = this->myfd;
polls.events = POLLIN;
int ret = poll(&polls,1,1);
+ log(DEBUG,"DNS: Hasresult returning %d",ret);
return (ret > 0);
}
int DNS::GetFD()
{
- return this->fd;
+ return this->myfd;
}
std::string DNS::GetResult()
{
- result = dns_getresult(this->fd);
- if (result) {
- dns_close(this->fd);
+ log(DEBUG,"DNS: GetResult()");
+ result = dns_getresult(this->myfd);
+ if (result)
+ {
+ if (ServerInstance && ServerInstance->stats)
+ ServerInstance->stats->statsDnsGood++;
+ dns_close(this->myfd);
return result;
- } else {
+ }
+ else
+ {
+ if (ServerInstance && ServerInstance->stats)
+ ServerInstance->stats->statsDnsBad++;
+ if (this->myfd != -1)
+ {
+ dns_close(this->myfd);
+ }
+ return "";
+ }
+}
+
+std::string DNS::GetResultIP()
+{
+ char r[1024];
+ log(DEBUG,"DNS: GetResultIP()");
+ result = dns_getresult(this->myfd);
+ if (this->myfd != -1)
+ {
+ dns_close(this->myfd);
+ }
+ 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 "";
}
}
+
+
+
+#ifdef THREADED_DNS
+void* dns_task(void* arg)
+{
+ userrec* u = (userrec*)arg;
+ log(DEBUG,"DNS thread for user %s",u->nick);
+ DNS dns1;
+ DNS dns2;
+ std::string host;
+ std::string ip;
+ if (dns1.ReverseLookup((char*)inet_ntoa(u->ip4)))
+ {
+ while (!dns1.HasResult())
+ {
+ usleep(100);
+ }
+ host = dns1.GetResult();
+ if (host != "")
+ {
+ if (dns2.ForwardLookup(host))
+ {
+ while (!dns2.HasResult())
+ {
+ usleep(100);
+ }
+ ip = dns2.GetResultIP();
+ if (ip == std::string((char*)inet_ntoa(u->ip4)))
+ {
+ if (host.length() < 160)
+ {
+ strcpy(u->host,host.c_str());
+ strcpy(u->dhost,host.c_str());
+ }
+ }
+ }
+ }
+ }
+ u->dns_done = true;
+ return NULL;
+}
+#endif