#include "dns.h"
#include "inspircd.h"
#include "helperfuncs.h"
+#include "inspircd_config.h"
#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;
+extern userrec* fd_ref_table[MAX_DESCRIPTORS];
enum QueryType { DNS_QRY_A = 1, DNS_QRY_PTR = 12 };
enum QueryFlags1 { FLAGS1_MASK_RD = 0x01, FLAGS1_MASK_TC = 0x02, FLAGS1_MASK_AA = 0x04, FLAGS1_MASK_OPCODE = 0x78, FLAGS1_MASK_QR = 0x80 };
Resolver* dns_classes[MAX_DESCRIPTORS];
-struct in_addr servers4[8];
+insp_inaddr servers4[8];
int i4;
int initdone = 0;
-int wantclose = 0;
int lastcreate = -1;
class s_connection
ServerInstance->SE->DelFd(fd);
#endif
log(DEBUG,"DNS: dns_close on fd %d",fd);
- if (fd == lastcreate)
- {
- wantclose = 1;
- }
shutdown(fd,2);
close(fd);
return;
{
FILE *f;
int i;
- in_addr addr4;
+ insp_inaddr addr4;
char buf[1024];
if (initdone == 1)
return;
initdone = 1;
srand((unsigned int) TIME);
- memset(servers4,'\0',sizeof(in_addr) * 8);
+ memset(servers4,'\0',sizeof(insp_inaddr) * 8);
f = fopen("/etc/resolv.conf","r");
if (f == NULL)
return;
if (i4 < 8)
{
if (dns_aton4_s(&buf[i],&addr4) != NULL)
- memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
+ memcpy(&servers4[i4++],&addr4,sizeof(insp_inaddr));
}
}
}
void DNS::dns_init_2(const char* dnsserver)
{
- in_addr addr4;
+ insp_inaddr addr4;
i4 = 0;
srand((unsigned int) TIME);
- memset(servers4,'\0',sizeof(in_addr) * 8);
+ memset(servers4,'\0',sizeof(insp_inaddr) * 8);
if (dns_aton4_s(dnsserver,&addr4) != NULL)
- memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
+ memcpy(&servers4[i4++],&addr4,sizeof(insp_inaddr));
}
int dns_send_requests(const s_header *h, const s_connection *s, const int l)
{
int i;
- sockaddr_in addr4;
+ insp_sockaddr addr4;
unsigned char payload[sizeof(s_header)];
dns_empty_header(payload,h,l);
}
if (s->fd != -1)
{
- sockaddr_in addr;
+ insp_sockaddr addr;
memset(&addr,0,sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = 0;
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
- if (wantclose == 1)
- {
- shutdown(lastcreate,2);
- close(lastcreate);
- wantclose = 0;
- }
- lastcreate = s->fd;
return s;
}
return payloadpos + 4;
}
-in_addr* DNS::dns_aton4(const char * const ipstring)
+insp_inaddr* DNS::dns_aton4(const char * const ipstring)
{
- static in_addr ip;
+ static insp_inaddr 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;
+insp_inaddr* DNS::dns_aton4_r(const char *ipstring) { /* ascii to numeric (reentrant): convert string to new 4part IP addr struct */
+ insp_inaddr* ip;
+ ip = new insp_inaddr;
if(dns_aton4_s(ipstring,ip) == NULL)
{
DELETE(ip);
return ip;
}
-in_addr* DNS::dns_aton4_s(const char *ipstring, in_addr *ip) { /* ascii to numeric (buffered): convert string to given 4part IP addr struct */
+insp_inaddr* DNS::dns_aton4_s(const char *ipstring, insp_inaddr *ip) { /* ascii to numeric (buffered): convert string to given 4part IP addr struct */
inet_aton(ipstring,ip);
return ip;
}
return s->fd;
}
-int DNS::dns_getname4(const in_addr *ip) { /* build, add and send PTR query; retrieve result with dns_getresult() */
+int DNS::dns_getname4(const insp_inaddr *ip) { /* build, add and send PTR query; retrieve result with dns_getresult() */
char query[512];
s_header h;
s_connection * s;
return s->fd;
}
-char* DNS::dns_ntoa4(const in_addr * const ip) { /* numeric to ascii: convert 4part IP addr struct to static string */
+char* DNS::dns_ntoa4(const insp_inaddr * const ip) { /* numeric to ascii: convert 4part IP addr struct to static string */
static char r[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 */
+char* DNS::dns_ntoa4_s(const insp_inaddr *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]);
*res = 0;
/* FireDNS used a linked list for this. How ugly (and slow). */
+
+#ifdef THREADED_DNS
+ /* XXX: STL really does NOT like being poked and prodded in more than
+ * one orifice by threaded apps. Make sure we remain nice to it, and
+ * lock a mutex around any access to the std::map.
+ */
+ pthread_mutex_lock(&connmap_lock);
+#endif
connlist_iter n_iter = connections.find(cfd);
if (n_iter == connections.end())
{
log(DEBUG,"DNS: got a response for a query we didnt send with fd=%d",cfd);
+#ifdef THREADED_DNS
+ pthread_mutex_unlock(&connmap_lock);
+#endif
return NULL;
}
else
/* 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
l = recv(c->fd,buffer,sizeof(s_header),0);
dns_close(c->fd);
#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)
{
userrec* u = (userrec*)arg;
int thisfd = u->fd;
log(DEBUG,"DNS thread for user %s",u->nick);
- DNS dns1;
- DNS dns2;
+ DNS dns1(Config->DNSServer);
+ DNS dns2(Config->DNSServer);
std::string host;
std::string ip;
- if (dns1.ReverseLookup((char*)inet_ntoa(u->ip4)))
+ int iterations = 0;
+
+ if (dns1.ReverseLookup(inet_ntoa(u->ip4),false))
{
- while (!dns1.HasResult())
- {
+ /* FIX: Dont make these infinite! */
+ while ((!dns1.HasResult()) && (++iterations < 20))
usleep(100);
- }
- host = dns1.GetResult();
- if (host != "")
+
+ if (iterations < 20)
{
- if (dns2.ForwardLookup(host), false)
+ if (dns1.GetFD() != -1)
{
- while (!dns2.HasResult())
- {
- usleep(100);
- }
- ip = dns2.GetResultIP();
- if (ip == std::string(inet_ntoa(u->ip4)))
+ host = dns1.GetResult();
+ if (host != "")
{
- if (host.length() < 160)
+ if (dns2.ForwardLookup(host, false))
{
- if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
+ iterations = 0;
+ while ((!dns2.HasResult()) && (++iterations < 20))
+ usleep(100);
+
+ if (iterations < 20)
{
- strcpy(u->host,host.c_str());
- strcpy(u->dhost,host.c_str());
+ if (dns2.GetFD() != -1)
+ {
+ ip = dns2.GetResultIP();
+ if (ip == std::string(inet_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
projects / user / henk / code / inspircd.git / blobdiff