1 files changed, 176 insertions, 0 deletions
diff --git a/Swiften/Network/DomainNameResolver.cpp b/Swiften/Network/DomainNameResolver.cpp
new file mode 100644
index 0000000..d2bbf0d
--- /dev/null
+++ b/Swiften/Network/DomainNameResolver.cpp
@@ -0,0 +1,176 @@
+#include "Swiften/Network/DomainNameResolver.h"
+#include "Swiften/Base/Platform.h"
+
+#include <stdlib.h>
+#include <boost/asio.hpp>
+#include <idna.h>
+#ifdef SWIFTEN_PLATFORM_WINDOWS
+#undef UNICODE
+#include <windows.h>
+#include <windns.h>
+#ifndef DNS_TYPE_SRV
+#define DNS_TYPE_SRV 33
+#endif
+#else
+#include <arpa/nameser.h>
+#include <arpa/nameser_compat.h>
+#include <resolv.h>
+#endif
+
+#include "Swiften/Network/DomainNameResolveException.h"
+#include "Swiften/Base/String.h"
+#include "Swiften/Base/ByteArray.h"
+
+namespace Swift {
+
+DomainNameResolver::DomainNameResolver() {
+}
+
+DomainNameResolver::~DomainNameResolver() {
+}
+
+HostAddressPort DomainNameResolver::resolve(const String& domain) {
+  char* output;
+  if (idna_to_ascii_8z(domain.getUTF8Data(), &output, 0) == IDNA_SUCCESS) {
+    std::string outputString(output);
+    free(output);
+    return resolveDomain(outputString);
+  }
+  else {
+    return resolveDomain(domain.getUTF8String());
+  }
+}
+
+HostAddressPort DomainNameResolver::resolveDomain(const std::string& domain) {
+	try {
+		return resolveXMPPService(domain);
+	}
+	catch (const DomainNameResolveException&) {
+	}
+	return HostAddressPort(resolveHostName(domain), 5222);
+}
+
+HostAddressPort DomainNameResolver::resolveXMPPService(const std::string& domain) {
+  std::string srvQuery = "_xmpp-client._tcp." + domain;
+
+#if defined(SWIFTEN_PLATFORM_WINDOWS)
+	DNS_RECORD* responses;
+	// FIXME: This conversion doesn't work if unicode is deffed above
+  	if (DnsQuery(srvQuery.c_str(), DNS_TYPE_SRV, DNS_QUERY_STANDARD, NULL, &responses, NULL) != ERROR_SUCCESS) {
+		throw DomainNameResolveException();
+  	}
+
+	DNS_RECORD* currentEntry = responses;
+	while (currentEntry) {
+		if (currentEntry->wType == DNS_TYPE_SRV) {
+			int port = currentEntry->Data.SRV.wPort;
+			try {
+				// The pNameTarget is actually a PCWSTR, so I would have expected this 
+				// conversion to not work at all, but it does.
+				// Actually, it doesn't. Fix this and remove explicit cast
+				// Remove unicode undef above as well
+				std::string hostname((const char*) currentEntry->Data.SRV.pNameTarget);
+				HostAddress address = resolveHostName(hostname);
+				DnsRecordListFree(responses, DnsFreeRecordList);
+				return HostAddressPort(address, port);
+			}
+			catch (const DomainNameResolveException&) {
+			}
+		}
+		currentEntry = currentEntry->pNext;
+	}
+	DnsRecordListFree(responses, DnsFreeRecordList);
+
+#else
+
+  ByteArray response;
+  response.resize(NS_PACKETSZ);
+  int responseLength = res_query(const_cast<char*>(srvQuery.c_str()), ns_c_in, ns_t_srv, reinterpret_cast<u_char*>(response.getData()), response.getSize());
+  if (responseLength == -1) {
+		throw DomainNameResolveException();
+	}
+
+	// Parse header
+	HEADER* header = reinterpret_cast<HEADER*>(response.getData());
+	unsigned char* messageStart = reinterpret_cast<unsigned char*>(response.getData());
+	unsigned char* messageEnd = messageStart + responseLength;
+	unsigned char* currentEntry = messageStart + NS_HFIXEDSZ;
+
+	// Skip over the queries
+	int queriesCount = ntohs(header->qdcount);
+	while (queriesCount > 0) {
+		int entryLength = dn_skipname(currentEntry, messageEnd);
+		if (entryLength < 0) {
+			throw DomainNameResolveException();
+		}
+		currentEntry += entryLength + NS_QFIXEDSZ;
+		queriesCount--;
+	}
+
+	// Process the SRV answers
+	int answersCount = ntohs(header->ancount);
+	while (answersCount > 0) {
+		int entryLength = dn_skipname(currentEntry, messageEnd);
+		currentEntry += entryLength;
+		currentEntry += NS_RRFIXEDSZ;
+
+		// Uninteresting information
+		currentEntry += 2; // PRIORITY
+		currentEntry += 2; // WEIGHT
+
+		// Port
+		if (currentEntry >= messageEnd) {
+			throw DomainNameResolveException();
+		}
+		int port = ns_get16(currentEntry);
+		currentEntry += 2; 
+
+		// Hostname
+		if (currentEntry >= messageEnd) {
+			throw DomainNameResolveException();
+		}
+		ByteArray entry;
+		entry.resize(NS_MAXDNAME);
+		entryLength = dn_expand(messageStart, messageEnd, currentEntry, entry.getData(), entry.getSize());
+		if (entryLength < 0) {
+			throw DomainNameResolveException();
+		}
+		try {
+			// Resolve the hostname
+			std::string hostname(entry.getData(), entryLength);
+			HostAddress address = resolveHostName(hostname);
+			return HostAddressPort(address, port);
+		}
+		catch (const DomainNameResolveException&) {
+		}
+		currentEntry += entryLength;
+		answersCount--;
+	}
+#endif
+
+	throw DomainNameResolveException();
+}
+
+HostAddress DomainNameResolver::resolveHostName(const std::string& hostname) {
+	boost::asio::io_service ioService;
+	boost::asio::ip::tcp::resolver resolver(ioService);
+	boost::asio::ip::tcp::resolver::query query(hostname, "5222");
+	try {
+		boost::asio::ip::tcp::resolver::iterator endpointIterator = resolver.resolve(query);
+		if (endpointIterator == boost::asio::ip::tcp::resolver::iterator()) {
+			throw DomainNameResolveException();
+		}
+		boost::asio::ip::address address = (*endpointIterator).endpoint().address();
+		if (address.is_v4()) {
+			return HostAddress(&address.to_v4().to_bytes()[0], 4);
+		}
+		else {
+			return HostAddress(&address.to_v6().to_bytes()[0], 16);
+		}
+	}
+	catch (...) {
+		throw DomainNameResolveException();
+	}
+}
+
+}