Merge pull request #8918 from rgacogne/rec-edns-padding-plus-tests

rec: Implement EDNS0 padding (rfc7830) for outgoing responses

diff --cc .circleci/config.yml
Simple merge

diff --cc pdns/dnswriter.hh
Simple merge

diff --cc pdns/lua-recursor4.cc
Simple merge

diff --cc pdns/lua-recursor4.hh
Simple merge

diff --cc pdns/pdns_recursor.cc
index d4e27295e1a44106f3ce457c3248b2267cd73af3,33e7c607e0ff87778814bdf89cc8767c12d2f784..d293c73d307128aab38b6c24a5c7dcad52aefe92
--- 1/pdns/pdns_recursor.cc
--- 2/pdns/pdns_recursor.cc
+++ b/pdns/pdns_recursor.cc
@@@ -5529,8 -5600,12 +5601,12 @@@ int main(int argc, char **argv
  
      ::arg().setSwitch("extended-resolution-errors", "If set, send an EDNS Extended Error extension on resolution failures, like DNSSEC validation errors")="no";
  
 -    ::arg().setSwitch("aggressive-nsec-cache-size", "The number of records to cache in the aggressive cache. If set to a value greater than 0, and DNSSEC validation is enabled, the recursor will cache NSEC and NSEC3 records to generate negative answers, as defined in rfc8198")="100000";
 +    ::arg().setSwitch("aggressive-nsec-cache-size", "The number of records to cache in the aggressive cache. If set to a value greater than 0, and DNSSEC processing or validation is enabled, the recursor will cache NSEC and NSEC3 records to generate negative answers, as defined in rfc8198")="100000";
  
+     ::arg().set("edns-padding-from", "List of netmasks (proxy IP in case of XPF or proxy-protocol presence, client IP otherwise) for which EDNS padding will be enabled in responses, provided that 'edns-padding-mode' applies")="";
+     ::arg().set("edns-padding-mode", "Whether to add EDNS padding to all responses ('always') or only to responses for queries containing the EDNS padding option ('padded-queries-only', the default). In both modes, padding will only be added to responses for queries coming from `edns-padding-from`_ sources")="padded-queries-only";
+     ::arg().set("edns-padding-tag", "Packetcache tag associated to responses sent with EDNS padding, to prevent sending these to non-whitelisted clients.")="7830";
+ 
      ::arg().setCmd("help","Provide a helpful message");
      ::arg().setCmd("version","Print version string");
      ::arg().setCmd("config","Output blank configuration");

diff --cc pdns/recursordist/docs/settings.rst
Simple merge