add QXmppServiceInfo for DNS SRV lookups

1 files changed, 171 insertions, 0 deletions

diff --git a/src/QXmppServiceInfo.cpp b/src/QXmppServiceInfo.cpp
new file mode 100644
index 00000000..3125709b
--- /dev/null
+++ b/src/QXmppServiceInfo.cpp
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2008-2010 The QXmpp developers
+ *
+ * Author:
+ *  Jeremy Lainé
+ *
+ * Source:
+ *  http://code.google.com/p/qxmpp
+ *
+ * This file is a part of QXmpp library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ */
+
+#include <QDebug>
+
+#include "QXmppServiceInfo.h"
+
+#ifdef Q_OS_WIN
+#include <windows.h>
+#include <windns.h>
+#else
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <arpa/nameser.h>
+#include <arpa/nameser_compat.h>
+#include <resolv.h>
+#endif
+
+QString QXmppServiceInfo::hostName() const
+{
+    return host_name;
+}
+
+quint16 QXmppServiceInfo::port() const
+{
+    return host_port;
+}
+
+void QXmppServiceInfo::setHostName(const QString &hostName)
+{
+    host_name = hostName;
+}
+
+void QXmppServiceInfo::setPort(quint16 port)
+{
+    host_port = port;
+}
+
+/// Perform a DNS lookup for an SRV entry.
+///
+/// Returns true if the lookup was succesful, false if it failed.
+///
+/// \param dname
+/// \param results
+
+bool QXmppServiceInfo::lookupService(const QString &dname, QList<QXmppServiceInfo> &results)
+{
+#ifdef Q_OS_WIN
+    PDNS_RECORD records, ptr;
+
+    /* perform DNS query */
+    if (DnsQuery_UTF8(dname.toAscii(), DNS_TYPE_SRV, DNS_QUERY_STANDARD, NULL, &records, NULL) != ERROR_SUCCESS)
+    {
+        qWarning() << "SRV lookup for" << dname << "failed";
+        return false;
+    }
+
+    /* extract results */
+    for (ptr = records; ptr != NULL; ptr = ptr->pNext)
+    {
+        if ((ptr->wType == DNS_TYPE_SRV) && !strcmp(ptr->pName, dname.toAscii()))
+        {
+            QXmppServiceInfo info;
+            info.setHostName(ptr->Data.Srv.pNameTarget);
+            info.setPort(ptr->Data.Srv.wPort);
+            results.append(info);
+        }
+    }
+
+    DnsRecordListFree(records, DnsFreeRecordList);
+#else
+    unsigned char response[PACKETSZ];
+    int responseLength, answerCount, answerIndex;
+
+    /* explicitly call res_init in case config changed */
+    res_init();
+
+    /* perform DNS query */
+    memset(response, 0, sizeof(response));
+    responseLength = res_query(dname.toAscii(), C_IN, T_SRV, response, sizeof(response));
+    if (responseLength < int(sizeof(HEADER)))
+    {
+        qWarning() << "SRV lookup for" << dname << "failed";
+        herror("SRV lookup error");
+        return false;
+    }
+
+    /* check the response header */
+    HEADER *header = (HEADER*)response;
+    if (header->rcode != NOERROR || !(answerCount = ntohs(header->ancount)))
+    {
+        qWarning() << "SRV lookup for" << dname << "returned an error";
+        return false;
+    }
+
+    /* skip the query */
+    char host[PACKETSZ], answer[PACKETSZ];
+    unsigned char *p = response + sizeof(HEADER);
+    int status = dn_expand(response, response + responseLength, p, host, sizeof(host));
+    if (status < 0)
+    {
+        qWarning("dn_expand failed");
+        return false;
+    }
+    p += status + 4;
+
+    /* parse answers */
+    answerIndex = 0;
+    while ((p < response + responseLength) && (answerIndex < answerCount))
+    {
+        int type, klass, ttl, size;
+        status = dn_expand(response, response + responseLength, p, host, sizeof(host));
+        if (status < 0)
+        {
+            qWarning("dn_expand failed");
+            return false;
+        }
+
+        p += status;
+        type = (p[0] << 8) | p[1];
+        p += 2;
+        klass = (p[0] << 8) | p[1];
+        p += 2;
+        ttl = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
+        p += 4;
+        size = (p[0] << 8) | p[1];
+        p += 2;
+
+        if (type == T_SRV)
+        {
+            quint16 port = (p[4] << 8) | p[5];
+            status = dn_expand(response, response + responseLength, p + 6, answer, sizeof(answer));
+            if (status < 0)
+            {
+                qWarning("dn_expand failed");
+                return false;
+            }
+            QXmppServiceInfo info;
+            info.setHostName(answer);
+            info.setPort(port);
+            results.append(info);
+        } else {
+            qWarning("Unexpected DNS answer type");
+        }
+        p += size;
+        answerIndex++;
+    }
+#endif
+    return !results.isEmpty();
+}