diff options
Diffstat (limited to 'src/dns.cpp')
-rw-r--r-- | src/dns.cpp | 1422 |
1 files changed, 548 insertions, 874 deletions
diff --git a/src/dns.cpp b/src/dns.cpp index eee1e0234..a8268aafc 100644 --- a/src/dns.cpp +++ b/src/dns.cpp @@ -3,13 +3,13 @@ * +------------------------------------+ * * 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. * * --------------------------------------------------- */ @@ -53,10 +53,6 @@ using namespace std; #include "socketengine.h" #include "configreader.h" -#ifdef THREADED_DNS -pthread_mutex_t connmap_lock = PTHREAD_MUTEX_INITIALIZER; -#endif - extern InspIRCd* ServerInstance; extern ServerConfig* Config; extern time_t TIME; @@ -70,56 +66,70 @@ class s_connection; typedef std::map<int,s_connection*> connlist; typedef connlist::iterator connlist_iter; + +DNS* Res = NULL; + +/* As lookups are completed, they are pushed into this result_list */ +std::map<int, std::string> result_list; connlist connections; -Resolver* dns_classes[MAX_DESCRIPTORS]; +int master_socket = -1; + +Resolver* dns_classes[65536]; insp_inaddr servers[8]; int i4; -int initdone = 0; -int lastcreate = -1; -class s_connection +class s_rr_middle { public: - unsigned char id[2]; - unsigned int _class; - QueryType type; - int want_list; - int fd; + QueryType type; + unsigned int _class; + unsigned long ttl; + unsigned int rdlength; }; -class s_rr_middle +class s_header { public: - QueryType type; - unsigned int _class; - unsigned long ttl; - unsigned int rdlength; + 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]; }; -class s_header +class s_connection { 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]; + unsigned char res[512]; + unsigned int _class; + QueryType type; + int want_list; + + s_connection() + { + *res = 0; + } + + unsigned char* result_ready(s_header &h, int length); + int send_requests(const s_header *h, const int l); }; + 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; + 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; } /* @@ -131,352 +141,266 @@ void *dns_align(void *inp) 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]; + 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) { - 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); + 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); } 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 >> 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); + 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); } -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); - shutdown(fd,2); - close(fd); - return; -} -void DNS::dns_init() +int s_connection::send_requests(const s_header *h, const int l) { - 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) - { - log(DEBUG,"Add server %d, %s",i4,&buf[i]); - memcpy(&servers[i4++],&addr,sizeof(insp_inaddr)); - } - } - } - } - fclose(f); -} + insp_sockaddr addr; + unsigned char payload[sizeof(s_header)]; -void DNS::dns_init_2(const char* dnsserver) -{ - log(DEBUG,"*************** DNS INIT 2 **************"); - insp_inaddr addr; - i4 = 0; - srand((unsigned int) TIME); - memset(servers,'\0',sizeof(insp_inaddr) * 8); - log(DEBUG,"ADD DNS: %s",dnsserver); - if (insp_aton(dnsserver,&addr) > 0) + dns_empty_header(payload,h,l); + + /* otherwise send via standard ipv4 boringness */ + memset(&addr,0,sizeof(addr)); +#ifdef IPV6 + memcpy(&addr.sin6_addr,&servers[0],sizeof(addr.sin6_addr)); + addr.sin6_family = AF_FAMILY; + addr.sin6_port = htons(53); +#else + memcpy(&addr.sin_addr.s_addr,&servers[0],sizeof(addr.sin_addr)); + addr.sin_family = AF_FAMILY; + addr.sin_port = htons(53); +#endif + if (sendto(master_socket, payload, l + 12, 0, (sockaddr *) &addr, sizeof(addr)) == -1) { - unsigned char* n = (unsigned char*)&addr; - log(DEBUG,"***** Add server %d, %s: %d, %d, %d, %d",i4,dnsserver,n[0],n[1],n[2],n[3]); - memcpy(&servers[i4++],&addr,sizeof(insp_inaddr)); + log(DEBUG,"Error in sendto!"); + return -1; } -} + return 0; +} -int dns_send_requests(const s_header *h, const s_connection *s, const int l) +s_connection* dns_add_query(s_header *h, int &id) { - int i; - insp_sockaddr addr; - unsigned char payload[sizeof(s_header)]; - dns_empty_header(payload,h,l); + id = rand() % 65536; + s_connection * s = new s_connection(); - - i = 0; - - /* otherwise send via standard ipv4 boringness */ - 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); -#else - memcpy(&addr.sin_addr.s_addr,&servers[i],sizeof(addr.sin_addr)); - addr.sin_family = AF_FAMILY; - addr.sin_port = htons(53); -#endif - if (sendto(s->fd, payload, l + 12, 0, (sockaddr *) &addr, sizeof(addr)) == -1) - { - log(DEBUG,"Error in sendto!"); - return -1; - } - - return 0; + /* set header flags */ + h->id[0] = s->id[0] = id >> 8; + 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; + if (connections.find(id) == connections.end()) + connections[id] = s; + return s; } -s_connection *dns_add_query(s_header *h) +void create_socket() { + log(DEBUG,"---- BEGIN DNS INITIALIZATION, SERVER=%s ---",Config->DNSServer); + insp_inaddr addr; + i4 = 0; + srand((unsigned int) TIME); + memset(servers,'\0',sizeof(insp_inaddr) * 8); + if (insp_aton(Config->DNSServer,&addr) > 0) + memcpy(&servers[i4++],&addr,sizeof(insp_inaddr)); - 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) - { + master_socket = socket(PF_PROTOCOL, SOCK_DGRAM, 0); + if (master_socket != -1) + { + log(DEBUG,"Set query socket nonblock"); + if (fcntl(master_socket, F_SETFL, O_NONBLOCK) != 0) + { + shutdown(master_socket,2); + close(master_socket); + master_socket = -1; + } + } + if (master_socket != -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; + memset(&addr.sin6_addr,255,sizeof(in6_addr)); #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; - } + 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 - } - 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); -#endif - - return s; + log(DEBUG,"Binding query port"); + if (bind(master_socket,(sockaddr *)&addr,sizeof(addr)) != 0) + { + log(DEBUG,"Cant bind with source port = 0"); + shutdown(master_socket,2); + close(master_socket); + master_socket = -1; + } + + if (master_socket >= 0) + { + log(DEBUG,"Attach query port to socket engine"); + if (ServerInstance && ServerInstance->SE) + ServerInstance->SE->AddFd(master_socket,true,X_ESTAB_DNS); + } + } } 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) - { - 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; -} - -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; + short payloadpos; + const char * tempchr, * tempchr2; + unsigned short l; - dns_init(); - + payloadpos = 0; + tempchr2 = name; - 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; -} - -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; + /* 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; +} + +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; + int id; + + l = dns_build_query_payload(name,DNS_QRY_A,1,(unsigned char *)&h.payload); + if (l == -1) + return -1; + s = dns_add_query(&h, id); + if (s == NULL) + return -1; + s->_class = 1; + s->type = DNS_QRY_A; + if (s->send_requests(&h,l) == -1) + return -1; + + return id; } int DNS::dns_getname4(const insp_inaddr *ip) { /* build, add and send PTR query; retrieve result with dns_getresult() */ #ifdef IPV6 - return -1; + return -1; #else - log(DEBUG,"DNS::dns_getname4"); - char query[512]; - s_header h; - s_connection * s; - unsigned char *c; - int l; + log(DEBUG,"DNS::dns_getname4"); + char query[512]; + s_header h; + s_connection * s; + unsigned char *c; + int l; + int id; + + 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, id); + if (s == NULL) + return -1; + s->_class = 1; + s->type = DNS_QRY_PTR; + if (s->send_requests(&h,l) == -1) + return -1; + + return id; +#endif +} - c = (unsigned char *)&ip->s_addr; +/* Return the next id which is ready. + * result_list[id] will have been populated with the result string. + */ +int DNS::dns_getresult() +{ + /* retrieve result of DNS query (buffered) */ + s_header h; + s_connection *c; + int length; + unsigned char buffer[sizeof(s_header)]; - sprintf(query,"%d.%d.%d.%d.in-addr.arpa",c[3],c[2],c[1],c[0]); + length = recv(master_socket,buffer,sizeof(s_header),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; + if (length < 12) + return -1; - return s->fd; -#endif -} + dns_fill_header(&h,buffer,length - 12); -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); -} + // Get the id of this request + unsigned long this_id = h.id[1] + (h.id[0] << 8); -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); + // Do we have a pending request for it? + + connlist_iter n_iter = connections.find(this_id); if (n_iter == connections.end()) { - log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d",cfd); -#ifdef THREADED_DNS - pthread_mutex_unlock(&connmap_lock); -#endif - return NULL; + log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d queryid=%d",master_socket,this_id); + return -1; } else { @@ -485,543 +409,287 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS /* 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 + unsigned char* a = c->result_ready(h, 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; -} - -DNS::DNS() -{ - dns_init(); - log(DEBUG,"Create blank DNS"); -} - -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(const std::string &dnsserver) -{ - dns_init_2(dnsserver.c_str()); - log(DEBUG,"Set NS"); -} - -DNS::~DNS() -{ -} - -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) < 1) - { - 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; -} - -bool DNS::ForwardLookup(const std::string &host, bool ins) -{ - 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); - } -#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 (a == NULL) + { + result_list[this_id] = ""; + } + else + { + if (c->type == DNS_QRY_A) + { + char formatted[1024]; + snprintf(formatted,1024,"%u.%u.%u.%u",a[0],a[1],a[2],a[3]); + result_list[this_id] = std::string(formatted); + } + else + { + result_list[this_id] = std::string((const char*)a); + } + } -bool DNS::HasResult(int fd) -{ - return (fd == this->myfd); + delete c; + return this_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. +/** A result is ready, process it */ -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); -} - -int DNS::GetFD() +unsigned char* s_connection::result_ready(s_header &h, int length) { - return this->myfd; -} - -std::string DNS::GetResult() -{ - 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 ""; - } + int i, q, curanswer, o; + s_rr_middle rr; + unsigned short p; + + if ((h.flags1 & FLAGS1_MASK_QR) == 0) + { + log(DEBUG,"DNS: didnt get a query result"); + return NULL; + } + if ((h.flags1 & FLAGS1_MASK_OPCODE) != 0) + { + log(DEBUG,"DNS: got an OPCODE and didnt want one"); + return NULL; + } + if ((h.flags2 & FLAGS2_MASK_RCODE) != 0) + { + log(DEBUG,"DNS lookup failed due to SERVFAIL"); + return NULL; + } + if (h.ancount < 1) + { + log(DEBUG,"DNS: no answers!"); + return NULL; + } + i = 0; + q = 0; + length -= 12; + while ((unsigned)q < h.qdcount && i < length) + { + 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 < length) + { + 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 (length - i < 10) + { + return NULL; + } + dns_fill_rr(&rr,&h.payload[i]); + i += 10; + if (rr.type != this->type) + { + curanswer++; + i += rr.rdlength; + continue; + } + if (rr._class != this->_class) + { + curanswer++; + i += rr.rdlength; + continue; + } + break; + } + if ((unsigned int)curanswer == h.ancount) + return NULL; + if (i + rr.rdlength > (unsigned int)length) + 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 < length && 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 (this->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) + { + return NULL; + } + memcpy(&alist->ip,&h.payload[i],4); + if ((unsigned)++curanswer >= h.ancount) + break; + i += rr.rdlength; + q = 0; + while (q == 0 && i < length) + { + 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 (length - i < 10) + { + 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; + } + return res; } -std::string DNS::GetResultIP() +DNS::DNS() { - 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 ""; - } + log(DEBUG,"Create blank DNS"); } - - -#ifdef THREADED_DNS - -/* 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. - */ -void* dns_task(void* arg) +DNS::~DNS() { - 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; } -#endif Resolver::Resolver(const std::string &source, bool forward, const std::string &dnsserver = "") : input(source), fwd(forward), server(dnsserver) { - 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 (forward) + { + this->myid = Res->dns_getip4(source.c_str()); + } + else + { + insp_inaddr binip; + if (insp_aton(source.c_str(), &binip) > 0) + { + /* Valid ip address */ + this->myid = Res->dns_getname4(&binip); + } + } + if (this->myid == -1) + { + log(DEBUG,"Resolver::Resolver: Could not get an id!"); + this->OnError(RESOLVER_NSDOWN); + ModuleException e("Resolver: Couldnt get an id to make a request"); + 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; - } + log(DEBUG,"Resolver::Resolver: this->myid=%d",this->myid); } Resolver::~Resolver() { - log(DEBUG,"Resolver::~Resolver"); - if (ServerInstance && ServerInstance->SE) - ServerInstance->SE->DelFd(this->fd); + log(DEBUG,"Resolver::~Resolver"); } -int Resolver::GetFd() +int Resolver::GetId() { - return this->fd; + return this->myid; } bool Resolver::ProcessResult() { - log(DEBUG,"Resolver::ProcessResult"); - if (this->fwd) - result = Query.GetResultIP(); - else - result = Query.GetResult(); + log(DEBUG,"Resolver::ProcessResult"); - 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; - } + std::map<int, std::string>::iterator x = result_list.find(this->myid); + + if (x == result_list.end()) + { + log(DEBUG,"Resolver::OnError(RESOLVER_NXDOMAIN)"); + this->OnError(RESOLVER_NXDOMAIN); + return false; + } + else + { + + log(DEBUG,"Resolver::OnLookupComplete(%s)",x->second.c_str()); + this->OnLookupComplete(x->second); + result_list.erase(x); + return true; + } } void Resolver::OnLookupComplete(const std::string &result) @@ -1034,43 +702,49 @@ void Resolver::OnError(ResolverError e) void dns_deal_with_classes(int fd) { - 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; - } + log(DEBUG,"dns_deal_with_classes(%d)",fd); + if (fd == master_socket) + { + int id = Res->dns_getresult(); + if (id != -1) + { + log(DEBUG,"Result available, id=%d",id); + dns_classes[id]->ProcessResult(); + delete dns_classes[id]; + dns_classes[id] = NULL; + } + } } bool dns_add_class(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; - } + log(DEBUG,"dns_add_class"); + if ((r) && (r->GetId() > -1)) + { + if (!dns_classes[r->GetId()]) + { + log(DEBUG,"dns_add_class: added class"); + dns_classes[r->GetId()] = r; + return true; + } + else + { + log(DEBUG,"Space occupied!"); + return false; + } + } + else + { + log(DEBUG,"Bad class"); + delete r; + return true; + } } void init_dns() { - memset(dns_classes,0,sizeof(dns_classes)); + Res = new DNS(); + memset(dns_classes,0,sizeof(dns_classes)); + create_socket(); } |