From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Mon, 7 Nov 2022 16:54:52 +0000 (+0100)
Subject: dnsdist: Add a helper to hash arbitrary data from Lua FFI
X-Git-Tag: dnsdist-1.9.0-alpha4~8^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=859690487ba7055450db74728bd996b9d764dbf6;p=thirdparty%2Fpdns.git

dnsdist: Add a helper to hash arbitrary data from Lua FFI
---

diff --git a/pdns/dnsdistdist/dnsdist-lua-ffi-interface.h b/pdns/dnsdistdist/dnsdist-lua-ffi-interface.h
index 41647bf38b..20d3f6ccb4 100644
--- a/pdns/dnsdistdist/dnsdist-lua-ffi-interface.h
+++ b/pdns/dnsdistdist/dnsdist-lua-ffi-interface.h
@@ -282,3 +282,5 @@ size_t dnsdist_ffi_dynamic_blocks_get_entries(dnsdist_ffi_dynamic_blocks_list_t*
 size_t dnsdist_ffi_dynamic_blocks_smt_get_entries(dnsdist_ffi_dynamic_blocks_list_t** out) __attribute__ ((visibility ("default")));
 const dnsdist_ffi_dynamic_block_entry_t* dnsdist_ffi_dynamic_blocks_list_get(const dnsdist_ffi_dynamic_blocks_list_t* list, size_t idx) __attribute__ ((visibility ("default")));
 void dnsdist_ffi_dynamic_blocks_list_free(dnsdist_ffi_dynamic_blocks_list_t*) __attribute__ ((visibility ("default")));
+
+uint32_t dnsdist_ffi_hash(uint32_t seed, const unsigned char* data, size_t dataSize, bool caseInsensitive) __attribute__ ((visibility ("default")));
diff --git a/pdns/dnsdistdist/dnsdist-lua-ffi.cc b/pdns/dnsdistdist/dnsdist-lua-ffi.cc
index 65db270ac7..7cf99bb93d 100644
--- a/pdns/dnsdistdist/dnsdist-lua-ffi.cc
+++ b/pdns/dnsdistdist/dnsdist-lua-ffi.cc
@@ -2003,3 +2003,16 @@ void dnsdist_ffi_dynamic_blocks_list_free(dnsdist_ffi_dynamic_blocks_list_t* lis
 }
 
 #endif /* DISABLE_DYNBLOCKS */
+
+uint32_t dnsdist_ffi_hash(uint32_t seed, const unsigned char* data, size_t dataSize, bool caseInsensitive)
+{
+  if (data == nullptr || dataSize == 0) {
+    return seed;
+  }
+
+  if (caseInsensitive) {
+    return burtleCI(data, dataSize, seed);
+  }
+
+  return burtle(data, dataSize, seed);
+}
diff --git a/pdns/dnsdistdist/test-dnsdist-lua-ffi.cc b/pdns/dnsdistdist/test-dnsdist-lua-ffi.cc
index cce308eb87..79c9ef9677 100644
--- a/pdns/dnsdistdist/test-dnsdist-lua-ffi.cc
+++ b/pdns/dnsdistdist/test-dnsdist-lua-ffi.cc
@@ -816,4 +816,31 @@ BOOST_AUTO_TEST_CASE(test_NetworkEndpoint)
   }
 }
 
+BOOST_AUTO_TEST_CASE(test_hash)
+{
+  const uint32_t seed = 0x42;
+  const std::array<unsigned char, 10> data{{'0', 'x', 'd', 'e', 'a', 'd', 'b', 'E', 'e', 'F'}};
+  const std::array<unsigned char, 10> capitalizedData{{'0', 'X', 'D', 'E', 'A', 'D', 'B', 'E', 'E', 'F'}};
+
+  {
+    /* invalid */
+    BOOST_CHECK_EQUAL(dnsdist_ffi_hash(0, nullptr, 0, false), 0U);
+    BOOST_CHECK_EQUAL(dnsdist_ffi_hash(seed, nullptr, 0, false), seed);
+  }
+  {
+    /* case sensitive */
+    auto hash = dnsdist_ffi_hash(seed, data.data(), data.size(), false);
+    BOOST_CHECK_EQUAL(hash, burtle(data.data(), data.size(), seed));
+    BOOST_CHECK_NE(hash, burtle(capitalizedData.data(), capitalizedData.size(), seed));
+    BOOST_CHECK_NE(hash, burtleCI(capitalizedData.data(), capitalizedData.size(), seed));
+  }
+  {
+    /* case insensitive */
+    auto hash = dnsdist_ffi_hash(seed, data.data(), data.size(), true);
+    BOOST_CHECK_EQUAL(hash, burtleCI(data.data(), data.size(), seed));
+    BOOST_CHECK_NE(hash, burtle(capitalizedData.data(), capitalizedData.size(), seed));
+    BOOST_CHECK_EQUAL(hash, burtleCI(capitalizedData.data(), capitalizedData.size(), seed));
+  }
+}
+
 BOOST_AUTO_TEST_SUITE_END();