dnsdist: dump more packet cache

pdns/dnsdistdist/Makefile.am

@@ -538,8 +538,9 @@ bin_PROGRAMS += \
 	$(fuzz_targets_programs)
 
 fuzz_targets_libs = \
-	$(LIBCRYPTO_LIBS) \
 	$(ARC4RANDOM_LIBS) \
+	$(LIBCRYPTO_LIBS) \
+	$(LIBSODIUM_LIBS) \
 	$(LIB_FUZZING_ENGINE)
 
 fuzz_targets_ldflags = \
@@ -556,6 +557,7 @@ fuzz_target_dnsdistcache_SOURCES = \
 	dns.cc dns.hh \
 	dnsdist-cache.cc dnsdist-cache.hh \
 	dnsdist-configuration.cc dnsdist-configuration.hh \
+	dnsdist-crypto.cc dnsdist-crypto.hh \
 	dnsdist-dnsparser.cc dnsdist-dnsparser.hh \
 	dnsdist-dnsquestion.cc \
 	dnsdist-ecs.cc dnsdist-ecs.hh \

pdns/dnsdistdist/dnsdist-cache.cc

@@ -28,6 +28,7 @@
 #include "dnsdist-ecs.hh"
 #include "ednssubnet.hh"
 #include "packetcache.hh"
+#include "base64.hh"
 
 // NOLINTNEXTLINE(bugprone-easily-swappable-parameters): too cumbersome to change at this point
 DNSDistPacketCache::DNSDistPacketCache(size_t maxEntries, uint32_t maxTTL, uint32_t minTTL, uint32_t tempFailureTTL, uint32_t maxNegativeTTL, uint32_t staleTTL, bool dontAge, uint32_t shards, bool deferrableInsertLock, bool parseECS) :
@@ -481,7 +482,7 @@ uint64_t DNSDistPacketCache::getEntriesCount()
   return getSize();
 }
 
-uint64_t DNSDistPacketCache::dump(int fileDesc)
+uint64_t DNSDistPacketCache::dump(int fileDesc, bool rawResponse)
 {
   auto filePtr = pdns::UniqueFilePtr(fdopen(dup(fileDesc), "w"));
   if (filePtr == nullptr) {
@@ -507,7 +508,13 @@ uint64_t DNSDistPacketCache::dump(int fileDesc)
           rcode = dnsHeader.rcode;
         }
 
-        fprintf(filePtr.get(), "%s %" PRId64 " %s ; rcode %" PRIu8 ", key %" PRIu32 ", length %" PRIu16 ", received over UDP %d, added %" PRId64 "\n", value.qname.toString().c_str(), static_cast<int64_t>(value.validity - now), QType(value.qtype).toString().c_str(), rcode, entry.first, value.len, value.receivedOverUDP ? 1 : 0, static_cast<int64_t>(value.added));
+        fprintf(filePtr.get(), "%s %" PRId64 " %s %s ; ecs %s, rcode %" PRIu8 ", key %" PRIu32 ", length %" PRIu16 ", received over UDP %d, added %" PRId64 ", dnssecOK %d, raw query flags %" PRIu16, value.qname.toString().c_str(), static_cast<int64_t>(value.validity - now), QClass(value.qclass).toString().c_str(), QType(value.qtype).toString().c_str(), value.subnet ? value.subnet.get().toString().c_str() : "empty", rcode, entry.first, value.len, value.receivedOverUDP ? 1 : 0, static_cast<int64_t>(value.added), value.dnssecOK ? 1 : 0, value.queryFlags);
+
+        if (rawResponse) {
+          std::string rawDataResponse = Base64Encode(value.value);
+          fprintf(filePtr.get(), ", base64response %s", rawDataResponse.c_str());
+        }
+        fprintf(filePtr.get(), "\n");
       }
       catch (...) {
         fprintf(filePtr.get(), "; error printing '%s'\n", value.qname.empty() ? "EMPTY" : value.qname.toString().c_str());

pdns/dnsdistdist/dnsdist-cache.hh

@@ -55,7 +55,7 @@ public:
   uint64_t getTTLTooShorts() const { return d_ttlTooShorts.load(); }
   uint64_t getCleanupCount() const { return d_cleanupCount.load(); }
   uint64_t getEntriesCount();
-  uint64_t dump(int fileDesc);
+  uint64_t dump(int fileDesc, bool rawResponse = false);
 
   /* get the list of domains (qnames) that contains the given address in an A or AAAA record */
   std::set<DNSName> getDomainsContainingRecords(const ComboAddress& addr);

pdns/dnsdistdist/dnsdist-lua-bindings-packetcache.cc

@@ -202,7 +202,7 @@ void setupLuaBindingsPacketCache(LuaContext& luaCtx, bool client)
       return results;
     });
 
-  luaCtx.registerFunction<void(std::shared_ptr<DNSDistPacketCache>::*)(const std::string& fname)const>("dump", [](const std::shared_ptr<DNSDistPacketCache>& cache, const std::string& fname) {
+  luaCtx.registerFunction<void(std::shared_ptr<DNSDistPacketCache>::*)(const std::string& fname, boost::optional<bool> rawResponse)const>("dump", [](const std::shared_ptr<DNSDistPacketCache>& cache, const std::string& fname, boost::optional<bool> rawResponse) {
       if (cache) {
 
         int fd = open(fname.c_str(), O_CREAT | O_EXCL | O_WRONLY, 0660);
@@ -213,7 +213,7 @@ void setupLuaBindingsPacketCache(LuaContext& luaCtx, bool client)
 
         uint64_t records = 0;
         try {
-          records = cache->dump(fd);
+          records = cache->dump(fd, rawResponse? *rawResponse : false);
         }
         catch (const std::exception& e) {
           close(fd);

pdns/dnsdistdist/docs/reference/config.rst

@@ -1004,11 +1004,15 @@ See :doc:`../guides/cache` for a how to.
 
   Represents a cache that can be part of :class:`ServerPool`.
 
-  .. method:: PacketCache:dump(fname)
+  .. method:: PacketCache:dump(fname [, rawResponse=false])
 
-    Dump a summary of the cache entries to a file.
+    .. versionchanged:: 2.0.0
+      ``rawResponse`` added
+
+    Dump a summary of the cache entries to a file. The raw response packet can be decoded by passing it to ``sdig``: ``echo [base64 encoded packet] | openssl base64 -d | sdig stdin 0 . A``
 
     :param str fname: The path to a file where the cache summary should be dumped. Note that if the target file already exists, it will not be overwritten.
+    :param bool rawResponse: Dump the raw packet response encoded with base64.
 
   .. method:: PacketCache:expunge(n)