Add packet timestamp support by trondn · Pull Request #2 · couchbasedeps/libevent

trondn · 2026-06-04T16:11:06Z

FIx the test suite to work with OpenSSL 3.x and add support for the packet timestamp

jimwwalker

still looking over this - can copilot do anything as well to help?

trondn · 2026-06-08T17:47:51Z

I've done a code review with copilot, gemini and droid and looked at the results

Copilot

Pull request overview

This PR adds receive/packet timestamp plumbing to evbuffers and bufferevents (including OpenSSL bufferevents), and adjusts HTTP/SSL tests for OpenSSL 3.x shutdown behavior.

Changes:

Introduce evbuffer timestamp storage/retrieval APIs and timestamp-aware read path (evbuffer_read_with_timestamp, evbuffer_get_timestamp).
Add BEV_OPT_RECV_TIMESTAMPS and enable timestamp capture in socket and OpenSSL bufferevents.
Extend/adjust regression tests (buffer/bufferevent/SSL/HTTP) to exercise timestamp paths and tolerate OpenSSL 3.x shutdown semantics.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 11 comments.

Show a summary per file

File	Description
`test/regress_ssl.c`	Adds OpenSSL bufferevent timestamp tests (direct + filter).
`test/regress_http.c`	Adjusts HTTPS test bufferevent shutdown behavior and incomplete-request error handling for OpenSSL 3.x.
`test/regress_bufferevent.c`	Adds a socket bufferevent receive-timestamp regression test.
`test/regress_buffer.c`	Adds new evbuffer pullup regression and timestamp read/get regression.
`include/event2/bufferevent.h`	Adds `BEV_OPT_RECV_TIMESTAMPS` option and related documentation.
`include/event2/buffer.h`	Declares new timestamp-aware evbuffer APIs and documents timestamp semantics.
`event-config.h.cmake`	Adds CMake-configurable defines for SO_TIMESTAMP/SO_TIMESTAMPNS declarations.
`evbuffer-internal.h`	Extends `evbuffer_chain` with timestamp metadata fields.
`configure.ac`	Adds autoconf checks for SO_TIMESTAMP/SO_TIMESTAMPNS declarations.
`CMakeLists.txt`	Adds CMake checks for SO_TIMESTAMP/SO_TIMESTAMPNS declarations.
`bufferevent-internal.h`	Adds internal flag for timestamp enablement and declares `be_socket_enable_timestamps_()`.
`bufferevent_sock.c`	Enables SO_TIMESTAMP* and uses `evbuffer_read_with_timestamp()` when requested.
`bufferevent_openssl.c`	Adds recvmsg-capable BIO for OpenSSL socket bufferevents and propagates timestamps into decrypted input.
`buffer.c`	Implements timestamp-aware commit/read/get logic and propagates timestamps across chain operations.

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Under OpenSSL 3.0+, unexpected socket closures before a clean SSL/TLS shutdown alert is exchanged are classified as protocol errors rather than clean EOFs. This behavior change causes various regression tests to fail. To resolve these compatibility issues: 1. bufferevent_openssl.c: Identify the SSL_R_UNEXPECTED_EOF_WHILE_READING protocol error and treat it as a dirty shutdown (clean TCP closure) to ensure backward compatibility. 2. test/regress_http.c (https_bev): Enable 'allow_dirty_shutdown = 1' on server bufferevents inside the mock HTTPS server to cleanly handle abrupt client socket closures. 3. test/regress_http.c (http_incomplete_errorcb): Recognize SSL protocol errors arising from raw socket shutdowns on OpenSSL 3.0 as successful terminations during the incomplete HTTP request test.

Copilot

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 5 comments.

Copilot

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 6 comments.

Copilot

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 4 comments.

Implement kernel-measured socket receive timestamps with nanosecond precision on supported platforms via the recvmsg() syscall. Timestamps are stored per-chain in the evbuffer. Infrastructure changes: - evbuffer-internal.h: Add timestamp storage and validity flag to evbuffer_chain structure. - evbuffer_read_with_timestamp(): New internal function for reading data via recvmsg(), parsing control messages for timestamps, and safeguarding against MSG_CTRUNC truncation. - bufferevent-internal.h: Add recv_timestamps_enabled flag to the bufferevent_private structure. - bufferevent_sock.c: Enable receive timestamps and swap standard reads with evbuffer_read_with_timestamp() when requested. - bufferevent_openssl.c: Add a custom socket BIO to extract kernel timestamps during direct socket reads, and propagate timestamps from underlying bufferevents in filtered TLS mode. - Build system: Add CMake and Autotools socket timestamp checks for SO_TIMESTAMP and SO_TIMESTAMPNS option availability. Public API additions: - BEV_OPT_RECV_TIMESTAMPS option flag for socket bufferevents. - evbuffer_get_timestamp() to fetch the receipt timestamp of the oldest data currently in the buffer. - evbuffer_commit_space_with_timespec() to commit reserved space and manually attach a timestamp to the committed chains. Platform support: - Linux 2.6.22+: Nanosecond (SO_TIMESTAMPNS) and microsecond (SO_TIMESTAMP) precision. - macOS 10.12+: Microsecond (SO_TIMESTAMP) precision. Testing: - Added unit tests for evbuffer receive timestamping. - Added direct socket and filtered OpenSSL bufferevent timestamp regress tests. - Verified all 344 unit tests pass successfully.

Copilot

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 6 comments.

 		buf->last->off += vec[0].iov_len;
 		added = vec[0].iov_len;
+		if (ts && added && buf->last->timestamp.valid == 0) {
+			buf->last->timestamp.ts = *ts;
+			buf->last->timestamp.valid = 1;
+		}


 	for (i=0; i<n_vecs; ++i) {
 		(*chainp)->off += vec[i].iov_len;
 		added += vec[i].iov_len;
+		if (ts && vec[i].iov_len && (*chainp)->timestamp.valid == 0) {
+			(*chainp)->timestamp.ts = *ts;
+			(*chainp)->timestamp.valid = 1;
+		}


 		if ((ev_ssize_t)space < remaining) {
 			(*chainp)->off += space;
 			remaining -= (int)space;
+			if (ts_found && (*chainp)->timestamp.valid == 0) {
+				(*chainp)->timestamp.ts = ts;
+				(*chainp)->timestamp.valid = 1;
+			}
 		} else {
 			(*chainp)->off += remaining;
+			if (ts_found && (*chainp)->timestamp.valid == 0) {
+				(*chainp)->timestamp.ts = ts;
+				(*chainp)->timestamp.valid = 1;
+			}
 			buf->last_with_datap = chainp;
 			break;
 		}


+	data = BIO_get_data(b);
+	if (data) {
+		if (BIO_get_shutdown(b)) {
+#ifdef _WIN32
+			closesocket(data->fd);
+#else
+			close(data->fd);
+#endif
+		}
+		mm_free(data);
+		BIO_set_data(b, NULL);
+	}


+	/* 10. Drain remaining 4 bytes of packet A.
+	 * The buffer now contains only packet B's bytes. The timestamp should shift to packet B's. */
+	tt_int_op(evbuffer_drain(buf, 4), ==, 0);
+	tt_int_op(evbuffer_get_timestamp(buf, &ts2), ==, 0);
+	/* Timestamps for B should be valid and greater than or equal to A */
+	tt_assert(ts2.tv_sec >= ts.tv_sec);
+	if (ts2.tv_sec == ts.tv_sec) {
+		tt_assert(ts2.tv_nsec >= ts.tv_nsec);
+	}
+	TT_BLATHER(("Captured timestamp B: %lld.%09ld", (long long)ts2.tv_sec, (long)ts2.tv_nsec));


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