From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Thu, 12 Mar 2020 10:58:11 +0000 (+0200)
Subject: lib: ostream-file - Fix using sendfile() when input stream is ends unexpectedly early
X-Git-Tag: 2.3.11.2~508
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ca5bd71af269d64f961e389985d7f51d84ac642;p=thirdparty%2Fdovecot%2Fcore.git

lib: ostream-file - Fix using sendfile() when input stream is ends unexpectedly early

Handle this the same as if writing was done without sendfile(), i.e. ignore
the problem and just return EOF in input stream early.
---

diff --git a/src/lib/ostream-file.c b/src/lib/ostream-file.c
index 869a670ddc..b1f3f9f592 100644
--- a/src/lib/ostream-file.c
+++ b/src/lib/ostream-file.c
@@ -777,8 +777,13 @@ io_stream_sendfile(struct ostream_private *outstream,
 		ret = safe_sendfile(foutstream->fd, in_fd, &offset,
 				    MAX_SSIZE_T(send_size));
 		if (ret <= 0) {
-			if (ret == 0)
-				break;
+			if (ret == 0) {
+				/* Unexpectedly early EOF at input */
+				i_stream_seek(instream, v_offset);
+				instream->eof = TRUE;
+				*res_r = OSTREAM_SEND_ISTREAM_RESULT_FINISHED;
+				return TRUE;
+			}
 			if (foutstream->file) {
 				if (errno == EINTR) {
 					/* automatically retry */
diff --git a/src/lib/test-ostream-file.c b/src/lib/test-ostream-file.c
index d61c5a819c..d4a9eff88e 100644
--- a/src/lib/test-ostream-file.c
+++ b/src/lib/test-ostream-file.c
@@ -164,8 +164,16 @@ static void test_ostream_file_send_istream_sendfile(void)
 	test_assert(read(sock_fd[1], buf, sizeof(buf)) == 4 &&
 		    memcmp(buf, "defg", 4) == 0);
 	i_stream_unref(&input2);
-	i_stream_unref(&input);
 
+	/* test reading past EOF */
+	i_stream_seek(input, 0);
+	input2 = i_stream_create_limit(input, 20);
+	test_assert(o_stream_send_istream(output, input2) == OSTREAM_SEND_ISTREAM_RESULT_FINISHED);
+	test_assert(input2->v_offset == 10);
+	test_assert(output->offset == 14);
+	i_stream_unref(&input2);
+
+	i_stream_unref(&input);
 	o_stream_destroy(&output);
 	i_close_fd(&sock_fd[1]);