X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fdns.cpp;h=3b8f8cc95426a7cf23febdb329b3aa384b5d9505;hb=59b1a8955142935b02af6446005ab47fc7c3fc8c;hp=025f4979c5ebba985abe56cda34797d1436117d7;hpb=4936887931ace82526cf6dc77fd07666120f49cc;p=user%2Fhenk%2Fcode%2Finspircd.git diff --git a/src/dns.cpp b/src/dns.cpp index 025f4979c..3b8f8cc95 100644 --- a/src/dns.cpp +++ b/src/dns.cpp @@ -1,22 +1,31 @@ -/* -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. - -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: + * + * + * + * 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 @@ -36,6 +45,7 @@ using namespace std; #include #include #include +#include #include "dns.h" #include "inspircd.h" #include "helperfuncs.h" @@ -43,67 +53,63 @@ using namespace std; extern InspIRCd* ServerInstance; extern ServerConfig* Config; +extern time_t TIME; -#define max(a,b) (a > b ? a : b) -#define min(a,b) (a < b ? a : b) - -enum QueryTypes { DNS_QRY_A = 1, DNS_QRY_PTR = 12}; +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 }; -#define DNS_ALIGN (sizeof(void *) > sizeof(long) ? sizeof(void *) : sizeof(long)) -#define RESULTSIZE 1024 +class s_connection; -static struct in_addr servers4[8]; /* up to 8 nameservers; populated by dns_init() */ -static int i4; /* actual count of nameservers; set by dns_init() */ +typedef std::map connlist; +typedef connlist::iterator connlist_iter; +connlist connections; -static int initdone = 0; /* to ensure dns_init() only runs once (on the first call) */ -static int wantclose = 0; -static int lastcreate = -1; +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; - unsigned int type; - int want_list; - int fd; /* file descriptor returned from sockets */ + unsigned char id[2]; + unsigned int _class; + QueryType type; + int want_list; + int fd; }; class s_rr_middle { public: - unsigned int type; - unsigned int _class; - unsigned long ttl; - unsigned int rdlength; + QueryType type; + unsigned int _class; + unsigned long ttl; + unsigned int rdlength; }; -typedef std::map connlist; -typedef connlist::iterator connlist_iter; -connlist connections; - 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]; /* DNS question, populated by dns_build_query_payload() */ + 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; } @@ -115,14 +121,16 @@ void *dns_align(void *inp) { * but of course, more impressive). Also made these inline. */ -inline void dns_fill_rr(s_rr_middle* rr, const unsigned char *input) { - rr->type = (input[0] << 8) + input[1]; +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]; } -inline 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]; @@ -134,7 +142,8 @@ inline void dns_fill_header(s_header *header, const unsigned char *input, const memcpy(header->payload,&input[12],l); } -inline 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; @@ -150,12 +159,14 @@ inline void dns_empty_header(unsigned char *output, const s_header *header, cons memcpy(&output[12],header->payload,l); } -void dns_close(int fd) { /* close query */ +void dns_close(int fd) +{ #ifndef THREADED_DNS ServerInstance->SE->DelFd(fd); #endif log(DEBUG,"DNS: dns_close on fd %d",fd); - if (fd == lastcreate) { + if (fd == lastcreate) + { wantclose = 1; return; } @@ -164,7 +175,8 @@ void dns_close(int fd) { /* close query */ return; } -void DNS::dns_init() { +void DNS::dns_init() +{ FILE *f; int i; in_addr addr4; @@ -180,11 +192,13 @@ void DNS::dns_init() { 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 < 8) { + if (i4 < 8) + { if (dns_aton4_s(&buf[i],&addr4) != NULL) memcpy(&servers4[i4++],&addr4,sizeof(in_addr)); } @@ -204,7 +218,7 @@ void DNS::dns_init_2(const char* dnsserver) } -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; @@ -228,7 +242,8 @@ static int dns_send_requests(const s_header *h, const s_connection *s, const int return 0; } -static s_connection *dns_add_query(s_header *h) { /* build DNS query, add to list */ +s_connection *dns_add_query(s_header *h) +{ s_connection * s = new s_connection; int id = rand() % 65536; @@ -242,40 +257,42 @@ static s_connection *dns_add_query(s_header *h) { /* build DNS query, add to lis 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) { - shutdown(s->fd,2); - 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) { - shutdown(s->fd,2); - 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 */ if (connections.find(s->fd) == connections.end()) connections[s->fd] = s; - if (wantclose == 1) { + if (wantclose == 1) + { shutdown(lastcreate,2); close(lastcreate); wantclose = 0; @@ -284,7 +301,8 @@ static s_connection *dns_add_query(s_header *h) { /* build DNS query, add to lis 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; @@ -293,7 +311,8 @@ static int dns_build_query_payload(const char * const name, const unsigned short 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; @@ -303,7 +322,8 @@ static int dns_build_query_payload(const char * const name, const unsigned short tempchr2 = &tempchr[1]; } l = strlen(tempchr2); - if (l) { + if (l) + { if (payloadpos + l + 2 > 507) return -1; payload[payloadpos++] = l; @@ -320,7 +340,8 @@ static int dns_build_query_payload(const char * const name, const unsigned short 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* DNS::dns_aton4(const char * const ipstring) +{ static in_addr ip; return dns_aton4_s(ipstring,&ip); } @@ -328,7 +349,8 @@ in_addr* DNS::dns_aton4(const char * const ipstring) { /* ascii to numeric: conv 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; } @@ -369,7 +391,6 @@ int DNS::dns_getip4list(const char *name) { /* build, add and send A query; retr dns_init(); - l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload); if (l == -1) return -1; @@ -455,80 +476,98 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS 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 ((unsigned)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 ((unsigned)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; @@ -542,19 +581,27 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS 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) - 0xC000 - 12; - } else { /* label */ + } + else + { if (h.payload[i] == 0) + { q = 1; - else { + } + else + { res[o] = '\0'; if (o != 0) res[o++] = '.'; @@ -565,17 +612,20 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS } } res[o] = '\0'; - break; + break; case DNS_QRY_A: log(DEBUG,"DNS: got a result of type DNS_QRY_A"); - if (c->want_list) { + 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; } @@ -583,23 +633,26 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS 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; } @@ -612,11 +665,10 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS alist->next = NULL; break; } - goto defaultcase; + memcpy(res,&h.payload[i],rr.rdlength); + res[rr.rdlength] = '\0'; break; default: - defaultcase: - log(DEBUG,"DNS: doing something with result 'default'"); memcpy(res,&h.payload[i],rr.rdlength); res[rr.rdlength] = '\0'; break; @@ -651,7 +703,8 @@ bool DNS::ReverseLookup(std::string ip) { ServerInstance->stats->statsDns++; binip = dns_aton4(ip.c_str()); - if (binip == NULL) { + if (binip == NULL) + { return false; } @@ -682,6 +735,20 @@ bool DNS::ForwardLookup(std::string host) return true; } +bool DNS::ForwardLookupWithFD(std::string host, int &fd) +{ + 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); + ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_MODULE); + return true; +} + bool DNS::HasResult(int fd) { return (fd == this->myfd); @@ -711,11 +778,14 @@ std::string DNS::GetResult() { log(DEBUG,"DNS: GetResult()"); result = dns_getresult(this->myfd); - if (result) { + if (result) + { ServerInstance->stats->statsDnsGood++; dns_close(this->myfd); return result; - } else { + } + else + { ServerInstance->stats->statsDnsBad++; if (this->myfd != -1) { @@ -763,7 +833,7 @@ void* dns_task(void* arg) DNS dns2; std::string host; std::string ip; - if (dns1.ReverseLookup(u->ip)) + if (dns1.ReverseLookup((char*)inet_ntoa(u->ip4))) { while (!dns1.HasResult()) { @@ -779,7 +849,7 @@ void* dns_task(void* arg) usleep(100); } ip = dns2.GetResultIP(); - if (ip == std::string(u->ip)) + if (ip == std::string((char*)inet_ntoa(u->ip4))) { if (host.length() < 160) {