From: Stephan Bosch <stephan.bosch@open-xchange.com>
Date: Wed, 23 Sep 2020 20:02:41 +0000 (+0200)
Subject: lib-ssl-iostream: iostream-openssl - Use o_stream_uncork_flush() to uncork the plain... 
X-Git-Tag: 2.3.18~278
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b4d477a50bb58aefa6f57b4e1fe055fec4422bf3;p=thirdparty%2Fdovecot%2Fcore.git

lib-ssl-iostream: iostream-openssl - Use o_stream_uncork_flush() to uncork the plain output.

This flushes the stream after uncorking it, fixing I/O hang with nested SSL
layers.
---

diff --git a/src/lib-ssl-iostream/iostream-openssl.c b/src/lib-ssl-iostream/iostream-openssl.c
index 156cb7e401..e1a8d31b6f 100644
--- a/src/lib-ssl-iostream/iostream-openssl.c
+++ b/src/lib-ssl-iostream/iostream-openssl.c
@@ -391,7 +391,7 @@ static void openssl_iostream_destroy(struct ssl_iostream *ssl_io)
 
 static int openssl_iostream_bio_output_real(struct ssl_iostream *ssl_io)
 {
-	size_t bytes, max_bytes;
+	size_t bytes, max_bytes = 0;
 	ssize_t sent;
 	unsigned char buffer[IO_BLOCK_SIZE];
 	int result = 0;
@@ -405,8 +405,6 @@ static int openssl_iostream_bio_output_real(struct ssl_iostream *ssl_io)
 		if (bytes > max_bytes) {
 			if (max_bytes == 0) {
 				/* wait until output buffer clears */
-				o_stream_set_flush_pending(ssl_io->plain_output,
-							   TRUE);
 				break;
 			}
 			bytes = max_bytes;
@@ -430,7 +428,13 @@ static int openssl_iostream_bio_output_real(struct ssl_iostream *ssl_io)
 		i_assert(sent == (ssize_t)bytes);
 		result = 1;
 	}
-	o_stream_uncork(ssl_io->plain_output);
+
+	ret = o_stream_uncork_flush(ssl_io->plain_output);
+	if (ret < 0)
+		return -1;
+	if (ret == 0 || (bytes > 0 && max_bytes == 0))
+		o_stream_set_flush_pending(ssl_io->plain_output, TRUE);
+
 	return result;
 }