1 files changed, 163 insertions, 0 deletions
diff --git a/protozero.cc b/protozero.cc
new file mode 100644
index 0000000..6f6fcf3
--- /dev/null
+++ b/protozero.cc
@@ -0,0 +1,163 @@
+/*
+ * This file is part of PowerDNS or dnsdist.
+ * Copyright -- PowerDNS.COM B.V. and its contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * In addition, for the avoidance of any doubt, permission is granted to
+ * link this program with OpenSSL and to (re)distribute the binaries
+ * produced as the result of such linking.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "protozero.hh"
+
+#ifndef DISABLE_PROTOBUF
+#include "dnsparser.hh"
+
+void pdns::ProtoZero::Message::encodeComboAddress(const protozero::pbf_tag_type type, const ComboAddress& ca)
+{
+  if (ca.sin4.sin_family == AF_INET) {
+    d_message.add_bytes(type, reinterpret_cast<const char*>(&ca.sin4.sin_addr.s_addr), sizeof(ca.sin4.sin_addr.s_addr));
+  }
+  else if (ca.sin4.sin_family == AF_INET6) {
+    d_message.add_bytes(type, reinterpret_cast<const char*>(&ca.sin6.sin6_addr.s6_addr), sizeof(ca.sin6.sin6_addr.s6_addr));
+  }
+}
+
+void pdns::ProtoZero::Message::encodeNetmask(const protozero::pbf_tag_type type, const Netmask& subnet, uint8_t mask)
+{
+  if (!subnet.empty()) {
+    ComboAddress ca(subnet.getNetwork());
+    ca.truncate(mask);
+    if (ca.sin4.sin_family == AF_INET) {
+      d_message.add_bytes(type, reinterpret_cast<const char*>(&ca.sin4.sin_addr.s_addr), sizeof(ca.sin4.sin_addr.s_addr));
+    }
+    else if (ca.sin4.sin_family == AF_INET6) {
+      d_message.add_bytes(type, reinterpret_cast<const char*>(&ca.sin6.sin6_addr.s6_addr), sizeof(ca.sin6.sin6_addr.s6_addr));
+    }
+  }
+}
+
+void pdns::ProtoZero::Message::encodeDNSName(protozero::pbf_writer& pbf, std::string& buffer, const protozero::pbf_tag_type type, const DNSName& name)
+{
+  // this will append the tag, mark the current position then reserve enough place to write the size
+  protozero::pbf_writer pbf_name{pbf, type};
+  // we append the name to the buffer
+  name.toString(buffer);
+  // leaving the block will cause the sub writer to compute how much was written based on the new size and update the size accordingly
+}
+
+void pdns::ProtoZero::Message::setRequest(const boost::uuids::uuid& uniqueId, const ComboAddress& requestor, const ComboAddress& local, const DNSName& qname, uint16_t qtype, uint16_t qclass, uint16_t id, pdns::ProtoZero::Message::TransportProtocol proto, size_t len)
+{
+  setMessageIdentity(uniqueId);
+  setSocketFamily(requestor.sin4.sin_family);
+  setSocketProtocol(proto);
+  setFrom(requestor);
+  setTo(local);
+  setInBytes(len);
+  setTime();
+  setId(id);
+  setQuestion(qname, qtype, qclass);
+  setFromPort(requestor.getPort());
+  setToPort(local.getPort());
+}
+
+void pdns::ProtoZero::Message::setResponse(const DNSName& qname, uint16_t qtype, uint16_t qclass)
+{
+  setType(pdns::ProtoZero::Message::MessageType::DNSResponseType);
+  setQuestion(qname, qtype, qclass);
+}
+
+void pdns::ProtoZero::Message::addRRsFromPacket(const char* packet, const size_t len, bool includeCNAME)
+{
+  if (len < sizeof(struct dnsheader)) {
+    return;
+  }
+
+  const struct dnsheader* dh = reinterpret_cast<const struct dnsheader*>(packet);
+
+  if (ntohs(dh->ancount) == 0) {
+    return;
+  }
+
+  if (ntohs(dh->qdcount) == 0) {
+    return;
+  }
+
+  PacketReader pr(std::string_view(packet, len));
+
+  size_t idx = 0;
+  DNSName rrname;
+  uint16_t qdcount = ntohs(dh->qdcount);
+  uint16_t ancount = ntohs(dh->ancount);
+  uint16_t rrtype;
+  uint16_t rrclass;
+  string blob;
+  struct dnsrecordheader ah;
+
+  rrname = pr.getName();
+  rrtype = pr.get16BitInt();
+  rrclass = pr.get16BitInt();
+  (void) rrtype;
+  (void) rrclass;
+
+  /* consume remaining qd if any */
+  if (qdcount > 1) {
+    for(idx = 1; idx < qdcount; idx++) {
+      rrname = pr.getName();
+      rrtype = pr.get16BitInt();
+      rrclass = pr.get16BitInt();
+      (void) rrtype;
+      (void) rrclass;
+    }
+  }
+
+  /* parse AN */
+  for (idx = 0; idx < ancount; idx++) {
+    rrname = pr.getName();
+    pr.getDnsrecordheader(ah);
+
+    if (ah.d_type == QType::A || ah.d_type == QType::AAAA) {
+      pr.xfrBlob(blob);
+
+      addRR(rrname, ah.d_type, ah.d_class, ah.d_ttl, blob);
+
+    } else if (ah.d_type == QType::CNAME && includeCNAME) {
+      protozero::pbf_writer pbf_rr{d_response, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::ResponseField::rrs)};
+
+      encodeDNSName(pbf_rr, d_buffer, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::name), rrname);
+      pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::type), ah.d_type);
+      pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::class_), ah.d_class);
+      pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::ttl), ah.d_ttl);
+      DNSName target;
+      pr.xfrName(target, true);
+      encodeDNSName(pbf_rr, d_buffer, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::rdata), target);
+    }
+    else {
+      pr.xfrBlob(blob);
+    }
+  }
+}
+
+void pdns::ProtoZero::Message::addRR(const DNSName& name, uint16_t uType, uint16_t uClass, uint32_t uTTL, const std::string& blob)
+{
+  protozero::pbf_writer pbf_rr{d_response, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::ResponseField::rrs)};
+  encodeDNSName(pbf_rr, d_buffer, static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::name), name);
+  pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::type), uType);
+  pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::class_), uClass);
+  pbf_rr.add_uint32(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::ttl), uTTL);
+  pbf_rr.add_string(static_cast<protozero::pbf_tag_type>(pdns::ProtoZero::Message::RRField::rdata), blob);
+}
+
+#endif /* DISABLE_PROTOBUF */