X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fdns.cpp;h=63bde0eccb46e5819b213d33f71df21f8d4cf32a;hb=21f7e4a8cdad2f29fda2768215c3a5352a9fa632;hp=2e1c751c4c496b635b4598c959d390f3edb0bc0a;hpb=fe7dbd2c104c37f6f3af7d9f1646a3c332aea4a4;p=user%2Fhenk%2Fcode%2Finspircd.git

diff --git a/src/dns.cpp b/src/dns.cpp
index 2e1c751c4..63bde0ecc 100644
--- a/src/dns.cpp
+++ b/src/dns.cpp
@@ -1,16 +1,27 @@
-/*       +------------------------------------+
- *       | Inspire Internet Relay Chat Daemon |
- *       +------------------------------------+
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2012 William Pitcock <nenolod@dereferenced.org>
+ *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
+ *   Copyright (C) 2006, 2009 Robin Burchell <robin+git@viroteck.net>
+ *   Copyright (C) 2007, 2009 Dennis Friis <peavey@inspircd.org>
+ *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
+ *   Copyright (C) 2005-2007 Craig Edwards <craigedwards@brainbox.cc>
  *
- *  InspIRCd: (C) 2002-2010 InspIRCd Development Team
- * See: http://wiki.inspircd.org/Credits
+ * This file is part of InspIRCd.  InspIRCd is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
  *
- * This program is free but copyrighted software; see
- *            the file COPYING for details.
+ * 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.
  *
- * ---------------------------------------------------
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+
 /* $Core */
 
 /*
@@ -23,7 +34,7 @@ Please do not assume that firedns works like this,
 looks like this, walks like this or tastes like this.
 */
 
-#ifndef WIN32
+#ifndef _WIN32
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <errno.h>
@@ -247,8 +258,28 @@ DNSRequest* DNS::AddQuery(DNSHeader *header, int &id, const char* original)
 		return NULL;
 
 	/* Create an id */
+	unsigned int tries = 0;
 	do {
 		id = ServerInstance->GenRandomInt(DNS::MAX_REQUEST_ID);
+		if (++tries == DNS::MAX_REQUEST_ID*5)
+		{
+			// If we couldn't find an empty slot this many times, do a sequential scan as a last
+			// resort. If an empty slot is found that way, go on, otherwise throw an exception
+			id = -1;
+			for (int i = 0; i < DNS::MAX_REQUEST_ID; i++)
+			{
+				if (!requests[i])
+				{
+					id = i;
+					break;
+				}
+			}
+
+			if (id == -1)
+				throw ModuleException("DNS: All ids are in use");
+
+			break;
+		}
 	} while (requests[id]);
 
 	DNSRequest* req = new DNSRequest(this, id, original);
@@ -360,10 +391,6 @@ DNS::DNS()
 	/* Clear the requests class table */
 	memset(requests,0,sizeof(requests));
 
-	/* Set the id of the next request to 0
-	 */
-	currid = 0;
-
 	/* DNS::Rehash() sets this to a valid ptr
 	 */
 	this->cache = NULL;
@@ -585,8 +612,10 @@ DNSResult DNS::GetResult()
 	 */
 	if (from != myserver)
 	{
+		std::string server1 = from.str();
+		std::string server2 = myserver.str();
 		ServerInstance->Logs->Log("RESOLVER",DEBUG,"Got a result from the wrong server! Bad NAT or DNS forging attempt? '%s' != '%s'",
-			from.str().c_str(), myserver.str().c_str());
+			server1.c_str(), server2.c_str());
 		return DNSResult(-1,"",0,"");
 	}
 
@@ -760,7 +789,7 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, unsigned length)
 				else i += header.payload[i] + 1; /* skip length and label */
 			}
 		}
-		if (length - i < 10)
+		if (static_cast<int>(length - i) < 10)
 			return std::make_pair((unsigned char*)NULL,"Incorrectly sized DNS reply");
 
 		/* XXX: We actually initialise 'rr' here including its ttl field */
@@ -800,6 +829,8 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, unsigned length)
 		 */
 		case DNS_QUERY_CNAME:
 		case DNS_QUERY_PTR:
+		{
+			unsigned short lowest_pos = length;
 			o = 0;
 			q = 0;
 			while (q == 0 && i < length && o + 256 < 1023)
@@ -812,14 +843,18 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, unsigned length)
 					i = ntohs(ptr);
 
 					/* check that highest two bits are set. if not, we've been had */
-					if (!(i & DN_COMP_BITMASK))
+					if ((i & DN_COMP_BITMASK) != DN_COMP_BITMASK)
 						return std::make_pair((unsigned char *) NULL, "DN label decompression header is bogus");
 
 					/* mask away the two highest bits. */
 					i &= ~DN_COMP_BITMASK;
 
 					/* and decrease length by 12 bytes. */
-					i =- 12;
+					i -= 12;
+
+					if (i >= lowest_pos)
+						return std::make_pair((unsigned char *) NULL, "Invalid decompression pointer");
+					lowest_pos = i;
 				}
 				else
 				{
@@ -843,6 +878,7 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, unsigned length)
 				}
 			}
 			res[o] = 0;
+		}
 		break;
 		case DNS_QUERY_AAAA:
 			if (rr.rdlength != sizeof(struct in6_addr))
@@ -1048,20 +1084,13 @@ bool DNS::AddResolverClass(Resolver* r)
 			Classes[r->GetId()] = r;
 			return true;
 		}
-		else
-			/* Duplicate id */
-			return false;
 	}
-	else
-	{
-		/* Pointer or id not valid.
-		 * Free the item and return
-		 */
-		if (r)
-			delete r;
 
-		return false;
-	}
+	/* Pointer or id not valid, or duplicate id.
+	 * Free the item and return
+	 */
+	delete r;
+	return false;
 }
 
 void DNS::CleanResolvers(Module* module)