From 2514fb3dbf40faaccdd95cce0d4e772a1ad27056 Mon Sep 17 00:00:00 2001
From: Vladimir Dubrovin <3proxy@3proxy.ru>
Date: Thu, 22 Oct 2026 12:05:02 +0300
Subject: [PATCH] TLS: a part of a record read ahead is not pending data

SSL_has_pending() is true when only a part of a record has been read
ahead, which is no data yet. ssl_poll() took it for data: poll()
returned at once, over and over and without its timeout, until the rest
came, so a peer sending half a record kept a thread spinning and its
connection from timing out. ssl_pending() is now true only when
decrypted data waits, or when what was read ahead makes a whole record
(an SSL_peek() of one byte, the sockets not blocking); otherwise the
socket is polled for the rest.

splice() over kernel TLS still needs to know of any byte OpenSSL holds,
a part of a record too: ssl_buffered() tells it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/ssl.c    |  2 +-
 src/ssl.h    |  3 +++
 src/ssllib.c | 24 ++++++++++++++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/ssl.c b/src/ssl.c
index 4ff98f6..b64ceeb 100644
--- a/src/ssl.c
+++ b/src/ssl.c
@@ -429,7 +429,7 @@ static int ssl_splicetls(struct clientparam *param, SOCKET s){
  struct SSLsock *sslq = searchSSL(param->sostate, s);
 
  if(!sslq) return 0;
- return ssl_pending(sslq->conn)? SPLICE_TLSPENDING : SPLICE_TLS;
+ return ssl_buffered(sslq->conn)? SPLICE_TLSPENDING : SPLICE_TLS;
 }
 #endif
 
diff --git a/src/ssl.h b/src/ssl.h
index 4df3679..32cd19c 100644
--- a/src/ssl.h
+++ b/src/ssl.h
@@ -78,6 +78,9 @@ SSL_CONN ssl_handshake_to_server(SOCKET s, char * hostname, SSL_CONFIG *config,
 int ssl_read(SSL_CONN connection, void * buf, int bufsize);
 int ssl_write(SSL_CONN connection, void * buf, int bufsize);
 int ssl_pending(SSL_CONN connection);
+/* any data read from the socket and not handed out, a part of a record
+   too */
+int ssl_buffered(SSL_CONN connection);
 
 /* TLS records are read ahead, a buffer at a time rather than two reads for
    each record, where what is read ahead and not yet decrypted shows as
diff --git a/src/ssllib.c b/src/ssllib.c
index a6be34e..e8e1bae 100644
--- a/src/ssllib.c
+++ b/src/ssllib.c
@@ -259,6 +259,30 @@ int ssl_write(SSL_CONN connection, void * buf, int bufsize)
 	return SSL_write(conn->ssl, buf, bufsize);
 }
 int ssl_pending(SSL_CONN connection)
+{
+	ssl_conn *conn = (ssl_conn *) connection;
+#if SSL_READAHEAD
+	char c;
+	int res;
+
+	if(SSL_pending(conn->ssl) > 0) return 1;
+	if(!SSL_has_pending(conn->ssl)) return 0;
+	/* Read ahead and not decrypted: a record, or only a part of one. A
+	   part is no data, and saying so would have poll() return at once,
+	   again and again, without its timeout, until the rest came: it is
+	   pending only once the record is whole (or the connection ended),
+	   the socket polled for the rest otherwise. The sockets are not
+	   blocking, so this does not wait. */
+	res = SSL_peek(conn->ssl, &c, 1);
+	if(res > 0) return 1;
+	res = SSL_get_error(conn->ssl, res);
+	return res != SSL_ERROR_WANT_READ && res != SSL_ERROR_WANT_WRITE;
+#else
+	return SSL_pending(conn->ssl);
+#endif
+}
+
+int ssl_buffered(SSL_CONN connection)
 {
 	ssl_conn *conn = (ssl_conn *) connection;