Add User::WriteRemoteNumeric() and switch code using SendText() to send numerics...

[user/henk/code/inspircd.git] / src / coremods / core_dns.cpp

diff --git a/src/coremods/core_dns.cpp b/src/coremods/core_dns.cpp
index 829351f04dceec1cc07ee37786ced76aaf1b9a85..1e8bb753389272725e5aa5bd80c4c0dd615beca9 100644 (file)
--- a/src/coremods/core_dns.cpp
+++ b/src/coremods/core_dns.cpp
@@ -27,6 +27,13 @@
 #pragma comment(lib, "Iphlpapi.lib")
 #endif
 
+namespace DNS
+{
+       /** Maximum value of a dns request id, 16 bits wide, 0xFFFF.
+        */
+       const unsigned int MAX_REQUEST_ID = 0xFFFF;
+}
+
 using namespace DNS;
 
 /** A full packet sent or recieved to/from the nameserver
@@ -332,6 +339,10 @@ class MyManager : public Manager, public Timer, public EventHandler
 
        irc::sockets::sockaddrs myserver;
 
+       /** Maximum number of entries in cache
+        */
+       static const unsigned int MAX_CACHE_SIZE = 1000;
+
        static bool IsExpired(const Query& record, time_t now = ServerInstance->Time())
        {
                const ResourceRecord& req = record.answers[0];
@@ -367,7 +378,22 @@ class MyManager : public Manager, public Timer, public EventHandler
         */
        void AddCache(Query& r)
        {
-               const ResourceRecord& rr = r.answers[0];
+               if (cache.size() >= MAX_CACHE_SIZE)
+                       cache.clear();
+
+               // Determine the lowest TTL value and use that as the TTL of the cache entry
+               unsigned int cachettl = UINT_MAX;
+               for (std::vector<ResourceRecord>::const_iterator i = r.answers.begin(); i != r.answers.end(); ++i)
+               {
+                       const ResourceRecord& rr = *i;
+                       if (rr.ttl < cachettl)
+                               cachettl = rr.ttl;
+               }
+
+               cachettl = std::min(cachettl, (unsigned int)5*60);
+               ResourceRecord& rr = r.answers.front();
+               // Set TTL to what we've determined to be the lowest
+               rr.ttl = cachettl;
                ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "cache: added cache for " + rr.name + " -> " + rr.rdata + " ttl: " + ConvToStr(rr.ttl));
                this->cache[r.question] = r;
        }
@@ -375,7 +401,7 @@ class MyManager : public Manager, public Timer, public EventHandler
  public:
        DNS::Request* requests[MAX_REQUEST_ID+1];
 
-       MyManager(Module* c) : Manager(c), Timer(3600, true)
+       MyManager(Module* c) : Manager(c), Timer(5*60, true)
        {
                for (unsigned int i = 0; i <= MAX_REQUEST_ID; ++i)
                        requests[i] = NULL;
@@ -457,11 +483,15 @@ class MyManager : public Manager, public Timer, public EventHandler
 
                if (SocketEngine::SendTo(this, buffer, len, 0, &this->myserver.sa, this->myserver.sa_size()) != len)
                        throw Exception("DNS: Unable to send query");
+
+               // Add timer for timeout
+               ServerInstance->Timers.AddTimer(req);
        }
 
        void RemoveRequest(DNS::Request* req)
        {
-               this->requests[req->id] = NULL;
+               if (requests[req->id] == req)
+                       requests[req->id] = NULL;
        }
 
        std::string GetErrorStr(Error e)
@@ -475,6 +505,7 @@ class MyManager : public Manager, public Timer, public EventHandler
                        case ERROR_NOT_AN_ANSWER:
                        case ERROR_NONSTANDARD_QUERY:
                        case ERROR_FORMAT_ERROR:
+                       case ERROR_MALFORMED:
                                return "Malformed answer";
                        case ERROR_SERVER_FAILURE:
                        case ERROR_NOT_IMPLEMENTED:
@@ -517,17 +548,19 @@ class MyManager : public Manager, public Timer, public EventHandler
                }
 
                Packet recv_packet;
+               bool valid = false;
 
                try
                {
                        recv_packet.Fill(buffer, length);
+                       valid = true;
                }
                catch (Exception& ex)
                {
                        ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, ex.GetReason());
-                       return;
                }
 
+               // recv_packet.id must be filled in here
                DNS::Request* request = this->requests[recv_packet.id];
                if (request == NULL)
                {
@@ -542,14 +575,20 @@ class MyManager : public Manager, public Timer, public EventHandler
                        return;
                }
 
-               if (recv_packet.flags & QUERYFLAGS_OPCODE)
+               if (!valid)
+               {
+                       ServerInstance->stats.DnsBad++;
+                       recv_packet.error = ERROR_MALFORMED;
+                       request->OnError(&recv_packet);
+               }
+               else if (recv_packet.flags & QUERYFLAGS_OPCODE)
                {
                        ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Received a nonstandard query");
                        ServerInstance->stats.DnsBad++;
                        recv_packet.error = ERROR_NONSTANDARD_QUERY;
                        request->OnError(&recv_packet);
                }
-               else if (recv_packet.flags & QUERYFLAGS_RCODE)
+               else if (!(recv_packet.flags & QUERYFLAGS_QR) || (recv_packet.flags & QUERYFLAGS_RCODE))
                {
                        Error error = ERROR_UNKNOWN;
 
@@ -717,7 +756,7 @@ class ModuleDNS : public Module
                        if (DNSServer == "nameserver")
                        {
                                resolv >> DNSServer;
-                               if (DNSServer.find_first_not_of("0123456789.") == std::string::npos)
+                               if (DNSServer.find_first_not_of("0123456789.") == std::string::npos || DNSServer.find_first_not_of("0123456789ABCDEFabcdef:") == std::string::npos)
                                {
                                        ServerInstance->Logs->Log("CONFIG", LOG_DEFAULT, "<dns:server> set to '%s' as first resolver in /etc/resolv.conf.",DNSServer.c_str());
                                        return;