From: Otto Moerbeek <otto.moerbeek@open-xchange.com>
Date: Wed, 13 Nov 2019 09:11:58 +0000 (+0100)
Subject: ednsmap might be cleared while yielding; so reassign pointer.
X-Git-Tag: dnsdist-1.4.0^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=90e8ea71abacb8879482fe27a5521d1f4d0ef76d;p=thirdparty%2Fpdns.git

ednsmap might be cleared while yielding; so reassign pointer.

Switch away from a ref to a pointer because of above and use modern
init for EDNSStatus.
---

diff --git a/pdns/syncres.cc b/pdns/syncres.cc
index 2e3b03d1af..1eed0ea2aa 100644
--- a/pdns/syncres.cc
+++ b/pdns/syncres.cc
@@ -536,16 +536,15 @@ int SyncRes::asyncresolveWrapper(const ComboAddress& ip, bool ednsMANDATORY, con
      If '3', send bare queries
   */
 
-  SyncRes::EDNSStatus* ednsstatus;
-  ednsstatus = &t_sstorage.ednsstatus[ip]; // does this include port? YES
+  SyncRes::EDNSStatus* ednsstatus = &t_sstorage.ednsstatus[ip]; // does this include port? YES
 
-  if(ednsstatus->modeSetAt && ednsstatus->modeSetAt + 3600 < d_now.tv_sec) {
-    *ednsstatus=SyncRes::EDNSStatus();
+  if (ednsstatus->modeSetAt && ednsstatus->modeSetAt + 3600 < d_now.tv_sec) {
+    *ednsstatus = SyncRes::EDNSStatus();
     //    cerr<<"Resetting EDNS Status for "<<ip.toString()<<endl);
   }
 
-  SyncRes::EDNSStatus::EDNSMode& mode=ednsstatus->mode;
-  SyncRes::EDNSStatus::EDNSMode oldmode = mode;
+  SyncRes::EDNSStatus::EDNSMode *mode = &ednsstatus->mode;
+  SyncRes::EDNSStatus::EDNSMode oldmode = *mode;
   int EDNSLevel = 0;
   auto luaconfsLocal = g_luaconfs.getLocal();
   ResolveContext ctx;
@@ -560,11 +559,11 @@ int SyncRes::asyncresolveWrapper(const ComboAddress& ip, bool ednsMANDATORY, con
   for(int tries = 0; tries < 3; ++tries) {
     //    cerr<<"Remote '"<<ip.toString()<<"' currently in mode "<<mode<<endl;
     
-    if(mode==EDNSStatus::NOEDNS) {
+    if (*mode == EDNSStatus::NOEDNS) {
       g_stats.noEdnsOutQueries++;
       EDNSLevel = 0; // level != mode
     }
-    else if(ednsMANDATORY || mode==EDNSStatus::UNKNOWN || mode==EDNSStatus::EDNSOK || mode==EDNSStatus::EDNSIGNORANT)
+    else if (ednsMANDATORY || *mode == EDNSStatus::UNKNOWN || *mode == EDNSStatus::EDNSOK || *mode == EDNSStatus::EDNSIGNORANT)
       EDNSLevel = 1;
 
     DNSName sendQname(domain);
@@ -577,6 +576,9 @@ int SyncRes::asyncresolveWrapper(const ComboAddress& ip, bool ednsMANDATORY, con
     else {
       ret=asyncresolve(ip, sendQname, type, doTCP, sendRDQuery, EDNSLevel, now, srcmask, ctx, d_outgoingProtobufServers, d_frameStreamServers, luaconfsLocal->outgoingProtobufExportConfig.exportTypes, res, chained);
     }
+    // ednsstatus might be cleared, so do a new lookup
+    ednsstatus = &t_sstorage.ednsstatus[ip]; // does this include port? YES
+    mode = &ednsstatus->mode;
     if(ret < 0) {
       return ret; // transport error, nothing to learn here
     }
@@ -584,25 +586,25 @@ int SyncRes::asyncresolveWrapper(const ComboAddress& ip, bool ednsMANDATORY, con
     if(ret == 0) { // timeout, not doing anything with it now
       return ret;
     }
-    else if(mode==EDNSStatus::UNKNOWN || mode==EDNSStatus::EDNSOK || mode == EDNSStatus::EDNSIGNORANT ) {
+    else if (*mode == EDNSStatus::UNKNOWN || *mode == EDNSStatus::EDNSOK || *mode == EDNSStatus::EDNSIGNORANT ) {
       if(res->d_validpacket && !res->d_haveEDNS && res->d_rcode == RCode::FormErr)  {
 	//	cerr<<"Downgrading to NOEDNS because of "<<RCode::to_s(res->d_rcode)<<" for query to "<<ip.toString()<<" for '"<<domain<<"'"<<endl;
-        mode = EDNSStatus::NOEDNS;
+        *mode = EDNSStatus::NOEDNS;
         continue;
       }
       else if(!res->d_haveEDNS) {
-        if(mode != EDNSStatus::EDNSIGNORANT) {
-          mode = EDNSStatus::EDNSIGNORANT;
+        if (*mode != EDNSStatus::EDNSIGNORANT) {
+          *mode = EDNSStatus::EDNSIGNORANT;
 	  //	  cerr<<"We find that "<<ip.toString()<<" is an EDNS-ignorer for '"<<domain<<"', moving to mode 2"<<endl;
 	}
       }
       else {
-	mode = EDNSStatus::EDNSOK;
+	*mode = EDNSStatus::EDNSOK;
 	//	cerr<<"We find that "<<ip.toString()<<" is EDNS OK!"<<endl;
       }
       
     }
-    if(oldmode != mode || !ednsstatus->modeSetAt)
+    if (oldmode != *mode || !ednsstatus->modeSetAt)
       ednsstatus->modeSetAt=d_now.tv_sec;
     //    cerr<<"Result: ret="<<ret<<", EDNS-level: "<<EDNSLevel<<", haveEDNS: "<<res->d_haveEDNS<<", new mode: "<<mode<<endl;  
     return ret;
diff --git a/pdns/syncres.hh b/pdns/syncres.hh
index e420fba03e..1270452109 100644
--- a/pdns/syncres.hh
+++ b/pdns/syncres.hh
@@ -294,9 +294,8 @@ public:
 
   struct EDNSStatus
   {
-    EDNSStatus() : mode(UNKNOWN), modeSetAt(0) {}
-    enum EDNSMode { UNKNOWN=0, EDNSOK=1, EDNSIGNORANT=2, NOEDNS=3 } mode;
-    time_t modeSetAt;
+    time_t modeSetAt{0};
+    enum EDNSMode { UNKNOWN=0, EDNSOK=1, EDNSIGNORANT=2, NOEDNS=3 } mode{UNKNOWN};
   };
 
   enum class HardenNXD { No, DNSSEC, Yes };