From 4b571f2a242b6e5468633b5879d5ec9858c7fa0c Mon Sep 17 00:00:00 2001
From: Torsten Dreyer <torsten@t3r.de>
Date: Tue, 8 Nov 2016 17:08:38 +0100
Subject: [PATCH] Implement SRV and TXT DNS records

---
 simgear/io/DNSClient.cxx | 70 +++++++++++++++++++++++++++++++++++++++-
 simgear/io/DNSClient.hxx | 30 +++++++++++++++--
 2 files changed, 97 insertions(+), 3 deletions(-)

diff --git a/simgear/io/DNSClient.cxx b/simgear/io/DNSClient.cxx
index 8681e900..9c129eae 100644
--- a/simgear/io/DNSClient.cxx
+++ b/simgear/io/DNSClient.cxx
@@ -69,6 +69,75 @@ NAPTRRequest::NAPTRRequest( const std::string & dn ) :
     _type = DNS_T_NAPTR;
 }
 
+SRVRequest::SRVRequest( const std::string & dn ) :
+        Request(dn)
+{
+    _type = DNS_T_SRV;
+}
+
+static void dnscbSRV(struct dns_ctx *ctx, struct dns_rr_srv *result, void *data)
+{
+    SRVRequest * r = static_cast<SRVRequest*>(data);
+    if (result) {
+        r->cname = result->dnssrv_cname;
+        r->qname = result->dnssrv_qname;
+        r->ttl = result->dnssrv_ttl;
+        for (int i = 0; i < result->dnssrv_nrr; i++) {
+            SRVRequest::SRV_ptr srv(new SRVRequest::SRV);
+            r->entries.push_back(srv);
+            srv->priority = result->dnssrv_srv[i].priority;
+            srv->weight = result->dnssrv_srv[i].weight;
+            srv->port = result->dnssrv_srv[i].port;
+            srv->target = result->dnssrv_srv[i].name;
+        }
+//        std::sort( r->entries.begin(), r->entries.end(), sortNAPTR );
+        free(result);
+    }
+    r->setComplete();
+}
+void SRVRequest::submit()
+{
+    // protocol and service an already encoded in DN so pass in NULL for both
+    if (!dns_submit_srv(NULL, getDn().c_str(), NULL, NULL, 0, dnscbSRV, this )) {
+        SG_LOG(SG_IO, SG_ALERT, "Can't submit dns request for " << getDn());
+        return;
+    }
+    _start = time(NULL);
+}
+
+TXTRequest::TXTRequest( const std::string & dn ) :
+        Request(dn)
+{
+    _type = DNS_T_TXT;
+}
+
+static void dnscbTXT(struct dns_ctx *ctx, struct dns_rr_txt *result, void *data)
+{
+    TXTRequest * r = static_cast<TXTRequest*>(data);
+    if (result) {
+        r->cname = result->dnstxt_cname;
+        r->qname = result->dnstxt_qname;
+        r->ttl = result->dnstxt_ttl;
+        for (int i = 0; i < result->dnstxt_nrr; i++) {
+          //TODO: interprete the .len field of dnstxt_txt?
+          r->entries.push_back(string((char*)result->dnstxt_txt[i].txt));
+        }
+        free(result);
+    }
+    r->setComplete();
+}
+
+void TXTRequest::submit()
+{
+    // protocol and service an already encoded in DN so pass in NULL for both
+    if (!dns_submit_txt(NULL, getDn().c_str(), 0, 0, dnscbTXT, this )) {
+        SG_LOG(SG_IO, SG_ALERT, "Can't submit dns request for " << getDn());
+        return;
+    }
+    _start = time(NULL);
+}
+
+
 static bool sortNAPTR( const NAPTRRequest::NAPTR_ptr a, const NAPTRRequest::NAPTR_ptr b )
 {
     if( a->order > b->order ) return false;
@@ -130,7 +199,6 @@ void Client::makeRequest(const Request_ptr& r)
     r->submit();
 }
 
-
 void Client::update(int waitTimeout)
 {
     time_t now = time(NULL);
diff --git a/simgear/io/DNSClient.hxx b/simgear/io/DNSClient.hxx
index 7cabd41c..41fa6a17 100644
--- a/simgear/io/DNSClient.hxx
+++ b/simgear/io/DNSClient.hxx
@@ -31,6 +31,7 @@
 
 #include <simgear/structure/SGReferenced.hxx>
 #include <simgear/structure/SGSharedPtr.hxx>
+#include <simgear/structure/event_mgr.hxx>
 
 namespace simgear
 {
@@ -61,6 +62,7 @@ protected:
     time_t _timeout_secs;
     time_t _start;
 };
+typedef SGSharedPtr<Request> Request_ptr;
 
 class NAPTRRequest : public Request
 {
@@ -84,7 +86,32 @@ public:
     std::string qservice;
 };
 
-typedef SGSharedPtr<Request> Request_ptr;
+class SRVRequest : public Request
+{
+public:
+    SRVRequest( const std::string & dn );
+    virtual void submit();
+
+    struct SRV : SGReferenced {
+      int priority;
+      int weight;
+      int port;
+      std::string target;
+    };
+    typedef SGSharedPtr<SRV> SRV_ptr;
+    typedef std::vector<SRV_ptr> SRV_list;
+    SRV_list entries;
+};
+
+class TXTRequest : public Request
+{
+public:
+    TXTRequest( const std::string & dn );
+    virtual void submit();
+
+    typedef std::vector<string> TXT_list;
+    TXT_list entries;
+};
 
 class Client
 {
@@ -99,7 +126,6 @@ public:
 //    void cancelRequest(const Request_ptr& r, std::string reason = std::string());
 
 private:
-
     class ClientPrivate;
     std::auto_ptr<ClientPrivate> d;
 };