From: Timo Sirainen <timo.sirainen@dovecot.fi>
Date: Fri, 27 Oct 2017 23:02:13 +0000 (+0300)
Subject: lib: o_stream_flush() - check for send overflows and reset error handling
X-Git-Tag: 2.3.0.rc1~709
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=34d5077c37dc6224a2d430a72ae51a3f38e9e4f6;p=thirdparty%2Fdovecot%2Fcore.git

lib: o_stream_flush() - check for send overflows and reset error handling

This begins the removal of o_stream_nfinish().
---

diff --git a/src/lib/ostream.c b/src/lib/ostream.c
index 4ea970c58c..9b27293ff9 100644
--- a/src/lib/ostream.c
+++ b/src/lib/ostream.c
@@ -173,11 +173,21 @@ int o_stream_flush(struct ostream *stream)
 	struct ostream_private *_stream = stream->real_stream;
 	int ret = 1;
 
+	o_stream_ignore_last_errors(stream);
+
 	if (unlikely(stream->closed || stream->stream_errno != 0)) {
 		errno = stream->stream_errno;
 		return -1;
 	}
 
+	if (unlikely(_stream->noverflow)) {
+		io_stream_set_error(&_stream->iostream,
+			"Output stream buffer was full (%"PRIuSIZE_T" bytes)",
+			o_stream_get_max_buffer_size(stream));
+		errno = stream->stream_errno = ENOBUFS;
+		return -1;
+	}
+
 	if (unlikely((ret = _stream->flush(_stream)) < 0)) {
 		i_assert(stream->stream_errno != 0);
 		errno = stream->stream_errno;
@@ -315,19 +325,6 @@ void o_stream_nsend_str(struct ostream *stream, const char *str)
 	o_stream_nsend(stream, str, strlen(str));
 }
 
-int o_stream_nfinish(struct ostream *stream)
-{
-	(void)o_stream_flush(stream);
-	o_stream_ignore_last_errors(stream);
-	if (stream->stream_errno == 0 && stream->real_stream->noverflow) {
-		io_stream_set_error(&stream->real_stream->iostream,
-			"Output stream buffer was full (%"PRIuSIZE_T" bytes)",
-			o_stream_get_max_buffer_size(stream));
-		stream->stream_errno = ENOBUFS;
-	}
-	return stream->stream_errno != 0 ? -1 : 0;
-}
-
 void o_stream_ignore_last_errors(struct ostream *stream)
 {
 	while (stream != NULL) {
diff --git a/src/lib/ostream.h b/src/lib/ostream.h
index e0f4c50e9f..586747f373 100644
--- a/src/lib/ostream.h
+++ b/src/lib/ostream.h
@@ -122,12 +122,13 @@ size_t o_stream_get_max_buffer_size(struct ostream *stream);
    TCP_CORK on if supported. */
 void o_stream_cork(struct ostream *stream);
 /* Try to flush the buffer by calling o_stream_flush() and remove TCP_CORK.
-   Note that after this o_stream_nfinish() must be called, unless the stream
+   Note that after this o_stream_flush() must be called, unless the stream
    ignores errors. */
 void o_stream_uncork(struct ostream *stream);
 bool o_stream_is_corked(struct ostream *stream);
-/* Try to flush the output stream. Returns 1 if all sent, 0 if not,
-   -1 if error. */
+/* Try to flush the output stream. If o_stream_nsend*() had been used and
+   the stream had overflown, return error. Returns 1 if all data is sent,
+   0 there's still buffered data, -1 if error. */
 int o_stream_flush(struct ostream *stream);
 /* Set "flush pending" state of stream. If set, the flush callback is called
    when more data is allowed to be sent, even if the buffer itself is empty. */
@@ -145,19 +146,19 @@ ssize_t o_stream_send(struct ostream *stream, const void *data, size_t size);
 ssize_t o_stream_sendv(struct ostream *stream, const struct const_iovec *iov,
 		       unsigned int iov_count);
 ssize_t o_stream_send_str(struct ostream *stream, const char *str);
-/* Send with delayed error handling. o_stream_nfinish() or
+/* Send with delayed error handling. o_stream_flush() or
    o_stream_ignore_last_errors() must be called after these functions before
    the stream is destroyed. If any of the data can't be sent due to stream's
-   buffer getting full, all further nsends are ignores and o_stream_nfinish()
+   buffer getting full, all further nsends are ignores and o_stream_flush()
    will fail. */
 void o_stream_nsend(struct ostream *stream, const void *data, size_t size);
 void o_stream_nsendv(struct ostream *stream, const struct const_iovec *iov,
 		     unsigned int iov_count);
 void o_stream_nsend_str(struct ostream *stream, const char *str);
-/* Marks the stream's error handling as completed. Flushes the stream and
-   returns -1 if stream->stream_errno is non-zero. Returns failure if any of
-   the o_stream_nsend*() didn't write all data. */
-int o_stream_nfinish(struct ostream *stream);
+static inline int o_stream_nfinish(struct ostream *stream)
+{
+	return o_stream_flush(stream) < 0 ? -1 : 0;
+}
 /* Marks the stream's error handling as completed to avoid i_panic() on
    destroy. */
 void o_stream_ignore_last_errors(struct ostream *stream);
@@ -178,7 +179,7 @@ void o_stream_set_no_error_handling(struct ostream *stream, bool set);
 enum ostream_send_istream_result
 o_stream_send_istream(struct ostream *outstream, struct istream *instream);
 /* Same as o_stream_send_istream(), but assume that reads and writes will
-   succeed. If not, o_stream_nfinish() will fail with the correct error
+   succeed. If not, o_stream_flush() will fail with the correct error
    message (even istream's). */
 void o_stream_nsend_istream(struct ostream *outstream, struct istream *instream);