From: Oguzhan Ozmen <oozmen@bloomberg.net>
Date: Fri, 13 Feb 2026 01:33:24 +0000 (+0000)
Subject: rgw: handle plain-text object tags in RGWObjTags::decode()
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=b2d9dbb81e9e6aa3cbb184488ccae16253586257;p=ceph.git

rgw: handle plain-text object tags in RGWObjTags::decode()

Objects created via multipart upload have had their tags stored as
plain URL-encoded strings (e.g. "ttl_tag=23") since the tagging
feature was introduced in 2017, because RGWInitMultipart::execute()
never called encode_obj_tags_attr() (tracker #53016).

While #53016 fixes the write path going forward, existing objects on
disk still carry plain-text tags. RGWObjTags::decode() throws
buffer::error on these, causing lifecycle tag matching to fail with
-EIO and GetObjectTagging to return empty results.

Fall back to set_from_string() when binary decoding fails, so both
formats are handled transparently.

Fixes: https://tracker.ceph.com/issues/74917
Signed-off-by: Oguzhan Ozmen <oozmen@bloomberg.net>
---

diff --git a/src/rgw/rgw_tag.h b/src/rgw/rgw_tag.h
index 51e2620bd42..4a1b47d3221 100644
--- a/src/rgw/rgw_tag.h
+++ b/src/rgw/rgw_tag.h
@@ -34,9 +34,35 @@ protected:
   }
 
   void decode(bufferlist::const_iterator &bl) {
-    DECODE_START_LEGACY_COMPAT_LEN(1, 1, 1, bl);
-    decode(tag_map,bl);
-    DECODE_FINISH(bl);
+    // Some older objects may have stored tags as a plain URL-encoded
+    // string (e.g. "key=value") rather than binary ENCODE_START format.
+    // Try binary decode first, fall back to set_from_string() on failure.
+    auto start_pos = bl;
+    try {
+      DECODE_START_LEGACY_COMPAT_LEN(1, 1, 1, bl);
+      decode(tag_map, bl);
+      DECODE_FINISH(bl);
+    } catch (buffer::error& e) {
+      // Failed binary decode. Try plain-text URL-encoded tag string.
+      tag_map.clear();
+      bl = start_pos;
+      std::string raw;
+      try {
+        auto remaining = bl.get_remaining();
+        if (remaining > 0) {
+          bl.copy(remaining, raw);
+          // strip trailing null bytes
+          while (!raw.empty() && raw.back() == '\0') {
+            raw.pop_back();
+          }
+        }
+      } catch (buffer::error&) {
+        throw e;
+      }
+      if (raw.empty() || set_from_string(raw) < 0) {
+        throw e;
+      }
+    }
   }
 
   void dump(Formatter *f) const;
diff --git a/src/test/rgw/CMakeLists.txt b/src/test/rgw/CMakeLists.txt
index 9b5ca191932..acc3ab36292 100644
--- a/src/test/rgw/CMakeLists.txt
+++ b/src/test/rgw/CMakeLists.txt
@@ -427,3 +427,7 @@ add_catch2_test_rgw(rgw_hex)
 add_executable(unittest_rgw_async_utils test_rgw_async_utils.cc)
 add_ceph_unittest(unittest_rgw_async_utils)
 target_link_libraries(unittest_rgw_async_utils ${rgw_libs} ${UNITTEST_LIBS})
+
+add_executable(unittest_rgw_tag test_rgw_tag.cc)
+add_ceph_unittest(unittest_rgw_tag)
+target_link_libraries(unittest_rgw_tag ${rgw_libs} ${UNITTEST_LIBS})
diff --git a/src/test/rgw/test_rgw_tag.cc b/src/test/rgw/test_rgw_tag.cc
new file mode 100644
index 00000000000..dec9866bb7d
--- /dev/null
+++ b/src/test/rgw/test_rgw_tag.cc
@@ -0,0 +1,217 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "gtest/gtest.h"
+#include "rgw_tag.h"
+
+using namespace std;
+
+// Helper: binary-encode an RGWObjTags into a bufferlist (the normal path)
+static bufferlist encode_tags(const RGWObjTags& tags) {
+  bufferlist bl;
+  tags.encode(bl);
+  return bl;
+}
+
+// Helper: store a raw plain-text string into a bufferlist the way
+// rgw_get_request_metadata() does: bl.append(str.c_str(), str.size() + 1)
+// (includes trailing null byte)
+static bufferlist plain_text_bl(const string& s) {
+  bufferlist bl;
+  bl.append(s.c_str(), s.size() + 1);
+  return bl;
+}
+
+// ---------- Binary-encoded tags (the normal path) ----------
+
+TEST(RGWObjTagsDecode, BinaryEncodedSingleTag)
+{
+  RGWObjTags src;
+  src.add_tag("ttl_tag", "23");
+
+  bufferlist bl = encode_tags(src);
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  dst.decode(iter);
+
+  ASSERT_EQ(dst.count(), 1u);
+  auto& m = dst.get_tags();
+  auto it = m.find("ttl_tag");
+  ASSERT_NE(it, m.end());
+  EXPECT_EQ(it->second, "23");
+}
+
+TEST(RGWObjTagsDecode, BinaryEncodedMultipleTags)
+{
+  RGWObjTags src;
+  src.add_tag("env", "production");
+  src.add_tag("team", "storage");
+  src.add_tag("ttl", "86400");
+
+  bufferlist bl = encode_tags(src);
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  dst.decode(iter);
+
+  ASSERT_EQ(dst.count(), 3u);
+  auto& m = dst.get_tags();
+  EXPECT_EQ(m.find("env")->second, "production");
+  EXPECT_EQ(m.find("team")->second, "storage");
+  EXPECT_EQ(m.find("ttl")->second, "86400");
+}
+
+// ---------- Plain-text tags (before the fix for tracker #53016 used) -----
+
+TEST(RGWObjTagsDecode, PlainTextSingleTag)
+{
+  // This is what rgw_get_request_metadata() stored for multipart uploads:
+  // the raw HTTP header value "key=value" plus a trailing null byte.
+  bufferlist bl = plain_text_bl("ttl_tag=23");
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  dst.decode(iter);
+
+  ASSERT_EQ(dst.count(), 1u);
+  auto& m = dst.get_tags();
+  auto it = m.find("ttl_tag");
+  ASSERT_NE(it, m.end());
+  EXPECT_EQ(it->second, "23");
+}
+
+TEST(RGWObjTagsDecode, PlainTextMultipleTags)
+{
+  // Multiple tags are &-separated, URL-encoded
+  bufferlist bl = plain_text_bl("env=production&team=storage&ttl=86400");
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  dst.decode(iter);
+
+  ASSERT_EQ(dst.count(), 3u);
+  auto& m = dst.get_tags();
+  EXPECT_EQ(m.find("env")->second, "production");
+  EXPECT_EQ(m.find("team")->second, "storage");
+  EXPECT_EQ(m.find("ttl")->second, "86400");
+}
+
+TEST(RGWObjTagsDecode, PlainTextUrlEncodedTag)
+{
+  // Keys/values with special characters get URL-encoded
+  bufferlist bl = plain_text_bl("my%20key=my%20value");
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  dst.decode(iter);
+
+  ASSERT_EQ(dst.count(), 1u);
+  auto& m = dst.get_tags();
+  auto it = m.find("my key");
+  ASSERT_NE(it, m.end());
+  EXPECT_EQ(it->second, "my value");
+}
+
+TEST(RGWObjTagsDecode, PlainTextNoValue)
+{
+  // Tag with key only, no '='
+  bufferlist bl = plain_text_bl("orphan_key");
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  dst.decode(iter);
+
+  ASSERT_EQ(dst.count(), 1u);
+  auto& m = dst.get_tags();
+  auto it = m.find("orphan_key");
+  ASSERT_NE(it, m.end());
+  EXPECT_EQ(it->second, "");
+}
+
+// ---------- Edge cases ----------
+
+TEST(RGWObjTagsDecode, PlainTextNoTrailingNull)
+{
+  // Plain text without trailing null (just raw bytes)
+  string s = "key1=val1&key2=val2";
+  bufferlist bl;
+  bl.append(s.data(), s.size()); // no trailing '\0'
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  dst.decode(iter);
+
+  ASSERT_EQ(dst.count(), 2u);
+  auto& m = dst.get_tags();
+  EXPECT_EQ(m.find("key1")->second, "val1");
+  EXPECT_EQ(m.find("key2")->second, "val2");
+}
+
+TEST(RGWObjTagsDecode, BinaryRoundTrip)
+{
+  // Encode -> decode -> re-encode should produce identical bufferlist
+  RGWObjTags src;
+  src.add_tag("alpha", "1");
+  src.add_tag("beta", "2");
+
+  bufferlist bl1 = encode_tags(src);
+
+  RGWObjTags dst;
+  auto iter = bl1.cbegin();
+  dst.decode(iter);
+
+  bufferlist bl2 = encode_tags(dst);
+
+  EXPECT_TRUE(bl1.contents_equal(bl2));
+}
+
+// ---------- Exception handling tests ----------
+
+TEST(RGWObjTagsDecode, TagKeyTooLongThrowsOriginalException)
+{
+  // Create plain-text tag with key longer than max_tag_key_size (128)
+  // set_from_string() will return -ERR_INVALID_TAG
+  string long_key(200, 'k');  // 200 chars, exceeds 128 limit
+  string tag_string = long_key + "=value";
+  bufferlist bl = plain_text_bl(tag_string);
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  EXPECT_THROW(dst.decode(iter), buffer::error);
+}
+
+TEST(RGWObjTagsDecode, EmptyTagKeyThrowsOriginalException)
+{
+  // Plain-text with empty key: "=value" - empty key is invalid
+  // set_from_string() returns -ERR_INVALID_TAG for empty key
+  bufferlist bl = plain_text_bl("=value");
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  EXPECT_THROW(dst.decode(iter), buffer::error);
+}
+
+TEST(RGWObjTagsDecode, EmptyAfterNullStrippingThrowsOriginalException)
+{
+  // Buffer containing only null bytes: fails binary decode, then after
+  // stripping trailing nulls we have empty raw string -> throws original exception
+  bufferlist bl;
+  bl.append("\0\0\0", 3);  // just null bytes
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+  EXPECT_THROW(dst.decode(iter), buffer::error);
+}
+
+TEST(RGWObjTagsDecode, EmptyBufferlist)
+{
+  // Empty bufferlist should produce no tags and also raise exception
+  bufferlist bl;
+
+  RGWObjTags dst;
+  auto iter = bl.cbegin();
+
+  EXPECT_THROW(dst.decode(iter), buffer::error);
+  EXPECT_EQ(dst.count(), 0u);
+}