dnsdist: Add `setUDPTimeout(n)`

diff --git a/pdns/README-dnsdist.md b/pdns/README-dnsdist.md
index 12f28841830664a3968538bad637d40bdbbe4db4..ca3cc993aef277465148ad7aa21f4f29ffc4008f 100644 (file)
--- a/pdns/README-dnsdist.md
+++ b/pdns/README-dnsdist.md
@@ -1485,13 +1485,14 @@ instantiate a server with additional parameters
         * member `check(DNSName)`: returns true if DNSName is matched by this group
         * member `add(DNSName)`: add this DNSName to the node
  * Tuning related:
-    * `setTCPRecvTimeout(n)`: set the read timeout on TCP connections from the client, in seconds
-    * `setTCPSendTimeout(n)`: set the write timeout on TCP connections from the client, in seconds
     * `setMaxTCPClientThreads(n)`: set the maximum of TCP client threads, handling TCP connections
     * `setMaxTCPQueuedConnections(n)`: set the maximum number of TCP connections queued (waiting to be picked up by a client thread), defaults to 1000. 0 means unlimited
     * `setMaxUDPOutstanding(n)`: set the maximum number of outstanding UDP queries to a given backend server. This can only be set at configuration time and defaults to 10240
     * `setCacheCleaningDelay(n)`: set the interval in seconds between two runs of the cache cleaning algorithm, removing expired entries
     * `setStaleCacheEntriesTTL(n)`: allows using cache entries expired for at most `n` seconds when no backend available to answer for a query
+    * `setTCPRecvTimeout(n)`: set the read timeout on TCP connections from the client, in seconds
+    * `setTCPSendTimeout(n)`: set the write timeout on TCP connections from the client, in seconds
+    * `setUDPTimeout(n)`: set the maximum time dnsdist will wait for a response from a backend over UDP, in seconds. Defaults to 2
  * DNSCrypt related:
     * `addDNSCryptBind("127.0.0.1:8443", "provider name", "/path/to/resolver.cert", "/path/to/resolver.key", [false], [TCP Fast Open queue size]):` listen to incoming DNSCrypt queries on 127.0.0.1 port 8443, with a provider name of "provider name", using a resolver certificate and associated key stored respectively in the `resolver.cert` and `resolver.key` files. The fifth optional parameter sets SO_REUSEPORT when available. The last parameter sets the TCP Fast Open queue size, enabling TCP Fast Open when available and the value is larger than 0.
     * `generateDNSCryptProviderKeys("/path/to/providerPublic.key", "/path/to/providerPrivate.key"):` generate a new provider keypair

diff --git a/pdns/dnsdist-console.cc b/pdns/dnsdist-console.cc
index 437c4b552587ddf35c0c360866431854c4ef7e6f..686d50de1297979522c78cb36872cd224aeb809e 100644 (file)
--- a/pdns/dnsdist-console.cc
+++ b/pdns/dnsdist-console.cc
@@ -341,6 +341,7 @@ const std::vector<ConsoleKeyword> g_consoleKeywords{
   { "setServerPolicyLua", true, "name, function", "set server selection policy to one named 'name' and provided by 'function'" },
   { "setTCPRecvTimeout", true, "n", "set the read timeout on TCP connections from the client, in seconds" },
   { "setTCPSendTimeout", true, "n", "set the write timeout on TCP connections from the client, in seconds" },
+  { "setUDPTimeout", true, "n", "set the maximum time dnsdist will wait for a response from a backend over UDP, in seconds" },
   { "setVerboseHealthChecks", true, "bool", "set whether health check errors will be logged" },
   { "show", true, "string", "outputs `string`" },
   { "showACL", true, "", "show our ACL set" },

diff --git a/pdns/dnsdist-lua.cc b/pdns/dnsdist-lua.cc
index ecfc53e8003bfcd083e5d5c51b97c401f5f8f22a..0edfb21deb90f017efaeb6909d7edd0b26269323 100644 (file)
--- a/pdns/dnsdist-lua.cc
+++ b/pdns/dnsdist-lua.cc
@@ -1458,6 +1458,8 @@ vector<std::function<void(void)>> setupLua(bool client, const std::string& confi
 
   g_lua.writeFunction("setTCPSendTimeout", [](int timeout) { g_tcpSendTimeout=timeout; });
 
+  g_lua.writeFunction("setUDPTimeout", [](int timeout) { g_udpTimeout=timeout; });
+
   g_lua.writeFunction("setMaxUDPOutstanding", [](uint16_t max) {
       if (!g_configurationDone) {
         g_maxOutstanding = max;

diff --git a/pdns/dnsdist.cc b/pdns/dnsdist.cc
index 4a281515de67d4f500d825137449cec13abc00a3..3aa2cac8580aa6d695060f177906308e9c763e7c 100644 (file)
--- a/pdns/dnsdist.cc
+++ b/pdns/dnsdist.cc
@@ -133,6 +133,7 @@ GlobalStateHolder<SuffixMatchTree<DynBlock>> g_dynblockSMT;
 DNSAction::Action g_dynBlockAction = DNSAction::Action::Drop;
 int g_tcpRecvTimeout{2};
 int g_tcpSendTimeout{2};
+int g_udpTimeout{2};
 
 bool g_truncateTC{1};
 bool g_fixupCase{0};
@@ -1362,7 +1363,7 @@ void* healthChecksThread()
       dss->prev.reuseds.store(dss->reuseds.load());
       
       for(IDState& ids  : dss->idStates) { // timeouts
-        if(ids.origFD >=0 && ids.age++ > 2) {
+        if(ids.origFD >=0 && ids.age++ > g_udpTimeout) {
           /* We set origFD to -1 as soon as possible
              to limit the risk of racing with the
              responder thread.

diff --git a/pdns/dnsdist.hh b/pdns/dnsdist.hh
index 4ada81837cd86151f1c7a2fe3225077b77d72079..bb19c82ab0fcdaa437c58b0d98fce05da6097a98 100644 (file)
--- a/pdns/dnsdist.hh
+++ b/pdns/dnsdist.hh
@@ -683,6 +683,7 @@ extern bool g_truncateTC;
 extern bool g_fixupCase;
 extern int g_tcpRecvTimeout;
 extern int g_tcpSendTimeout;
+extern int g_udpTimeout;
 extern uint16_t g_maxOutstanding;
 extern std::atomic<bool> g_configurationDone;
 extern uint64_t g_maxTCPClientThreads;