shout: clear buffer before calling the encoder

Always assume the buffer is empty before calling the encoder.  Always
flush the buffer immediately after there has been added something.
This reduces the risk of buffer overruns, because there will never be
a "rest" in the current buffer.

NEWS

@@ -50,6 +50,7 @@ ver 0.14.2 (2009/??/??)
   - shout: switch to blocking mode
   - shout: use libshout's synchronization
   - shout: don't postpone metadata
+  - shout: clear buffer before calling the encoder
 * mapper: remove trailing slashes from music_directory
 * player: set player error when output device fails
 

src/output/shout_mp3.c

@@ -43,8 +43,8 @@ static int shout_mp3_encoder_clear_encoder(struct shout_data *sd)
 	struct shout_buffer *buf = &sd->buf;
 	int ret;
 
-	if ((ret = lame_encode_flush(ld->gfp, buf->data + buf->len,
-				     buf->len)) < 0)
+	ret = lame_encode_flush(ld->gfp, buf->data, sizeof(buf->data));
+	if (ret < 0)
 		g_warning("error flushing lame buffers\n");
 
 	lame_close(ld->gfp);
@@ -164,7 +164,7 @@ static int shout_mp3_encoder_encode(struct shout_data *sd,
 
 	bytes_out = lame_encode_buffer_float(ld->gfp, left, right,
 					     samples, buf->data,
-					     sizeof(buf->data) - buf->len);
+					     sizeof(buf->data));
 
 	g_free(left);
 	if (right != left)

src/output/shout_ogg.c

@@ -75,23 +75,14 @@ static void copy_tag_to_vorbis_comment(struct shout_data *sd)
 static int copy_ogg_buffer_to_shout_buffer(ogg_page *og,
 					   struct shout_buffer *buf)
 {
-	if (sizeof(buf->data) - buf->len >= (size_t)og->header_len) {
-		memcpy(buf->data + buf->len,
-		       og->header, og->header_len);
-		buf->len += og->header_len;
-	} else {
+	if ((size_t)og->header_len + (size_t)og->body_len > sizeof(buf->data)) {
 		g_warning("%s: not enough buffer space!\n", __func__);
 		return -1;
 	}
 
-	if (sizeof(buf->data) - buf->len >= (size_t)og->body_len) {
-		memcpy(buf->data + buf->len,
-		       og->body, og->body_len);
-		buf->len += og->body_len;
-	} else {
-		g_warning("%s: not enough buffer space!\n", __func__);
-		return -1;
-	}
+	memcpy(buf->data, og->header, og->header_len);
+	memcpy(buf->data + og->header_len, og->body, og->body_len);
+	buf->len = og->header_len + og->body_len;
 
 	return 0;
 }

src/output/shout_plugin.c

@@ -58,7 +58,6 @@ static struct shout_data *new_shout_data(void)
 	ret->bitrate = -1;
 	ret->quality = -2.0;
 	ret->timeout = DEFAULT_CONN_TIMEOUT;
-	ret->buf.len = 0;
 
 	return ret;
 }
@@ -287,13 +286,14 @@ static int write_page(struct shout_data *sd)
 	err = shout_send(sd->shout_conn, sd->buf.data, sd->buf.len);
 	if (handle_shout_error(sd, err) < 0)
 		return -1;
-	sd->buf.len = 0;
 
 	return 0;
 }
 
 static void close_shout_conn(struct shout_data * sd)
 {
+	sd->buf.len = 0;
+
 	if (sd->encoder->clear_encoder_func(sd))
 		write_page(sd);
 
@@ -359,6 +359,8 @@ static int open_shout_conn(void *data)
 	if (status != 0)
 		return status;
 
+	sd->buf.len = 0;
+
 	if (sd->encoder->init_encoder_func(sd) < 0) {
 		shout_close(sd->shout_conn);
 		return -1;
@@ -386,6 +388,8 @@ my_shout_play(void *data, const char *chunk, size_t size)
 {
 	struct shout_data *sd = (struct shout_data *)data;
 
+	sd->buf.len = 0;
+
 	if (sd->encoder->encode_func(sd, chunk, size))
 		return false;
 
@@ -410,6 +414,7 @@ static void my_shout_set_tag(void *data,
 	char song[1024];
 	bool ret;
 
+	sd->buf.len = 0;
 	sd->tag = tag;
 	ret = sd->encoder->send_metadata_func(sd, song, sizeof(song));
 	if (ret) {