Initial commit of m_dnsbl, v2.0 - based on satmd's 1.0 m_dnsbl, modified to work with 1.1 (and hopefully work a bit faster. Removed tag option, as it doesn't broadcast to multiple servers, leaks memory, and is largely useless.

git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@5944 e03df62e-2008-0410-955e-edbf42e46eb7

1 files changed, 347 insertions, 0 deletions

diff --git a/src/modules/m_dnsbl.cpp b/src/modules/m_dnsbl.cpp
new file mode 100644
index 000000000..4c217fc3e
--- /dev/null
+++ b/src/modules/m_dnsbl.cpp
@@ -0,0 +1,347 @@
+/*
+ * Formerly written and maintained by satmd.
+ * This version written and maintained by w00t.
+ */
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <stdint.h>
+#include "inspircd.h"
+#include "dns.h"
+#include "users.h"
+#include "channels.h"
+#include "modules.h"
+
+/* $ModDesc: Provides handling of DNS blacklists */
+
+/* Class holding data for a single entry */
+class DNSBLConfEntry
+{
+	public:
+		enum EnumBanaction { I_UNKNOWN, I_KILL, I_ZLINE, I_KLINE, I_GLINE };
+		std::string name, domain, reason;
+		EnumBanaction banaction;
+		long duration;
+		int bitmask;
+		DNSBLConfEntry(): duration(86400),bitmask(0) {}
+};
+
+
+/** Resolver for CGI:IRC hostnames encoded in ident/GECOS
+ */
+class DNSBLResolver : public Resolver
+{
+	int theirfd;
+	userrec* them;
+	DNSBLConfEntry *ConfEntry;
+
+    public:
+	DNSBLResolver(Module *me, InspIRCd *ServerInstance, const std::string &hostname, userrec* u, int userfd, DNSBLConfEntry *conf)
+		: Resolver(ServerInstance, hostname, DNS_QUERY_A, me)
+	{
+		theirfd = userfd;
+		them = u;
+		ConfEntry = conf;
+	}
+
+	virtual void OnLookupComplete(const std::string &result)
+	{
+		/* Check the user still exists */
+		if ((them) && (them == ServerInstance->SE->GetRef(theirfd)))
+		{
+			ServerInstance->Log(DEBUG, "m_dnsbl:  %s got a result from dnsbl %s", them->nick, ConfEntry->name.c_str());
+
+			// Now we calculate the bitmask: 256*(256*(256*a+b)+c)+d
+			if(result.length())
+			{
+				unsigned int bitmask=0;
+				unsigned int octetpos=0;
+				std::string tmp = result;
+
+				while(tmp.length()>0)
+				{
+					std::string octet;
+					unsigned int lastdot = tmp.rfind(".");
+
+					if (lastdot == std::string::npos)
+					{
+						octet=tmp;
+						tmp.clear();
+					}
+					else
+					{
+						octet=tmp.substr(lastdot+1,tmp.length()-lastdot+1);
+						tmp.resize(lastdot);
+					}
+
+					bitmask += (256 ^ octetpos) * atoi(octet.c_str());
+					octetpos += 1;
+				}
+
+				bitmask &= ConfEntry->bitmask;
+
+				if (bitmask != 0)
+				{
+					std::string reason = ConfEntry->reason;
+
+					while (int pos = reason.find("%ip%") != std::string::npos)
+					{
+						reason.replace(pos, 4, them->GetIPString());
+					}
+
+					ServerInstance->WriteOpers("*** Connecting user %s detected as being on a DNS blacklist (%s) with result %d", them->GetFullRealHost(), ConfEntry->name.c_str(), bitmask);
+
+					switch (ConfEntry->banaction)
+					{
+						case DNSBLConfEntry::I_KILL:
+						{
+							them->QuitUser(ServerInstance, them, std::string("Killed (") + reason + ")");
+							break;
+						}
+						case DNSBLConfEntry::I_KLINE:
+						{
+							ServerInstance->AddKLine(ConfEntry->duration, ServerInstance->Config->ServerName, reason, std::string("*@") + them->GetIPString());
+							break;
+						}
+						case DNSBLConfEntry::I_GLINE:
+						{
+							ServerInstance->AddGLine(ConfEntry->duration, ServerInstance->Config->ServerName, reason, std::string("*@") + them->GetIPString());
+							break;
+						}
+						case DNSBLConfEntry::I_ZLINE:
+						{
+							ServerInstance->AddZLine(ConfEntry->duration, ServerInstance->Config->ServerName, reason, them->GetIPString());
+							break;
+						}
+						case DNSBLConfEntry::I_UNKNOWN:
+						{
+							break;
+						}
+						break;
+					}
+				}
+			}
+		}
+	}
+
+	virtual void OnError(ResolverError e, const std::string &errormessage)
+	{
+		/*
+		this just means they don't appear in the respective dnsbl
+		if ((them) && (them == ServerInstance->SE->GetRef(theirfd)))
+		{
+		}
+		*/
+		/* Check the user still exists */
+		if ((them) && (them == ServerInstance->SE->GetRef(theirfd)))
+		{
+			ServerInstance->Log(DEBUG, "m_dnsbl:  %s got an error while resolving for dnsbl %s", them->nick, ConfEntry->name.c_str());
+		}
+	}
+ 
+	virtual ~DNSBLResolver()
+	{
+	}
+};
+
+class ModuleDNSBL : public Module
+{
+ private:
+	std::vector<DNSBLConfEntry *> DNSBLConfEntries;
+	
+	/*
+	 *	Convert a string to EnumBanaction
+	 */
+	DNSBLConfEntry::EnumBanaction str2banaction(const std::string &action)
+	{
+		if(action.compare("KILL")==0)
+			return DNSBLConfEntry::I_KILL;
+		if(action.compare("KLINE")==0)
+			return DNSBLConfEntry::I_KLINE;
+		if(action.compare("ZLINE")==0)
+			return DNSBLConfEntry::I_ZLINE;
+		if(action.compare("GLINE")==0)
+			return DNSBLConfEntry::I_GLINE;
+	
+		return DNSBLConfEntry::I_UNKNOWN;
+	}
+ public:
+	ModuleDNSBL(InspIRCd *Me) : Module::Module(Me)
+	{
+		ReadConf();
+	}
+	
+	virtual ~ModuleDNSBL()
+	{
+	}
+	
+	virtual Version GetVersion()
+	{
+		return Version(2, 0, 0, 0, 0, API_VERSION);
+	}
+
+	void Implements(char* List)
+	{
+		List[I_OnRehash] = List[I_OnUserRegister] = 1;
+	}
+
+	/*
+	 * Fill our conf vector with data
+	 */	
+	virtual void ReadConf()
+	{
+		ConfigReader *MyConf = new ConfigReader(ServerInstance);
+		DNSBLConfEntries.clear();
+
+		for (int i=0; i< MyConf->Enumerate("dnsbl"); i++)
+		{
+			DNSBLConfEntry *e = new DNSBLConfEntry();
+
+			e->name = MyConf->ReadValue("dnsbl", "name", i);
+			e->reason = MyConf->ReadValue("dnsbl", "reason", i);
+			e->domain = MyConf->ReadValue("dnsbl", "domain", i);
+			e->banaction = str2banaction(MyConf->ReadValue("dnsbl", "action", i));
+			e->duration = ServerInstance->Duration(MyConf->ReadValue("dnsbl", "duration", i).c_str());
+			e->bitmask = MyConf->ReadInteger("dnsbl", "bitmask", i, false);
+
+			/* yeah, logic here is a little messy */
+			if (e->bitmask <= 0)
+			{
+				ServerInstance->WriteOpers("*** DNSBL(#%d): invalid bitmask",i);
+			}
+			else if (e->name == "")
+			{
+				ServerInstance->WriteOpers("*** DNSBL(#%d): Invalid name",i);
+			}
+			else if (e->domain == "")
+			{
+				ServerInstance->WriteOpers("*** DNSBL(#%d): Invalid domain",i);
+			}
+			else if (e->banaction == DNSBLConfEntry::I_UNKNOWN)
+			{
+				ServerInstance->WriteOpers("*** DNSBL(#%d): Invalid banaction", i);
+			}
+			else
+			{
+				if (e->reason == "")
+				{
+					ServerInstance->WriteOpers("*** DNSBL(#%d): empty reason, using defaults",i);
+					e->reason = "Your IP has been blacklisted.";
+				}
+
+				/* add it, all is ok */
+				DNSBLConfEntries.push_back(e);
+				delete MyConf;
+				return;
+			}
+
+			/* delete and drop it, error somewhere */
+			delete e;
+		}
+
+		delete MyConf;
+	}
+	
+	
+	virtual void OnRehash(const std::string &parameter)
+	{
+		ReadConf();
+	}
+
+	/*
+	 * We will check each user that connects *locally* (userrec::fd>0)
+	 */
+	virtual int OnUserRegister(userrec* user)
+	{
+		if (IS_LOCAL(user))
+		{
+			/* following code taken from bopm, reverses an IP address. */
+			struct in_addr in;
+			unsigned char a, b, c, d;
+			char reversedipbuf[128];
+			std::string reversedip;
+
+			if (!inet_aton(user->GetIPString(), &in))
+			{
+				ServerInstance->WriteOpers("Invalid IP address in m_dnsbl! Bailing check");
+				return 0;
+			}
+
+			d = (unsigned char) (in.s_addr >> 24) & 0xFF;
+			c = (unsigned char) (in.s_addr >> 16) & 0xFF;
+			b = (unsigned char) (in.s_addr >> 8) & 0xFF;
+			a = (unsigned char) in.s_addr & 0xFF;
+
+			snprintf(reversedipbuf, 128, "%d.%d.%d.%d", d, c, b, a);
+			reversedip = std::string(reversedipbuf);
+
+/*
+	this is satmd's old code
+			std::string reversedip;
+			std::string userip = user->GetIPString();
+			std::string tempip = userip;
+
+			// reversedip will created in there
+			while (tempip.length()>0)
+			{
+				unsigned int lastdot=tempip.rfind(".");
+				if (lastdot == std::string::npos)
+				{
+					reversedip+=tempip;
+					tempip.clear();
+				}
+				else
+				{
+					reversedip += tempip.substr(lastdot+1,tempip.length()-lastdot+1);
+					reversedip += ".";
+					tempip.resize(lastdot);
+				}
+			}
+*/
+		
+			// For each DNSBL, we will run through this lookup
+			for (std::vector<DNSBLConfEntry *>::iterator i = DNSBLConfEntries.begin(); i != DNSBLConfEntries.end(); i++)
+			{
+				// Fill hostname with a dnsbl style host (d.c.b.a.domain.tld)
+				std::string hostname=reversedip+"."+ (*i)->domain;
+
+				ServerInstance->Log(DEBUG, "m_dnsbl: sending %s for resolution", hostname.c_str());
+
+				/* now we'd need to fire off lookups for `hostname'. */
+				DNSBLResolver *r = new DNSBLResolver(this, ServerInstance, hostname, user, user->GetFd(), *i);
+				ServerInstance->AddResolver(r);
+			}
+		}
+
+		/* don't do anything with this hot potato */
+		return 0;
+	}
+};
+
+// stuff down here is the module-factory stuff.
+
+class ModuleDNSBLFactory : public ModuleFactory
+{
+ public:
+	ModuleDNSBLFactory()
+	{
+	}
+	
+	~ModuleDNSBLFactory()
+	{
+	}
+	
+	virtual Module *CreateModule(InspIRCd *Me)
+	{
+		return new ModuleDNSBL(Me);
+	}
+	
+};
+
+
+extern "C" void * init_module( void )
+{
+	return new ModuleDNSBLFactory;
+}
+