From: Andre Noll <maan@tuebingen.mpg.de>
Date: Tue, 22 Dec 2015 23:52:18 +0000 (+0000)
Subject: udp_send.c: Send EOF packet only once.
X-Git-Tag: v0.5.6~42
X-Git-Url: http://git.tue.mpg.de/?a=commitdiff_plain;h=ab51fc9c72dc51e76ccabbc150413c8031751436;p=paraslash.git

udp_send.c: Send EOF packet only once.

Currently this can be sent many times, which is pointless and might
confuse clients. This patch adds a bool member to struct udp_target
to keep track whether the EOF packet has been sent.
---

diff --git a/udp_send.c b/udp_send.c
index bbc38f01..425118a1 100644
--- a/udp_send.c
+++ b/udp_send.c
@@ -46,6 +46,8 @@ struct udp_target {
 	struct fec_client *fc;
 	/** The FEC parameters for this target. */
 	struct fec_client_parms fcp;
+	/** Whether we already sent the FEC eof packet to this target. */
+	bool sent_fec_eof;
 };
 
 static struct list_head targets;
@@ -54,15 +56,16 @@ static int sender_status;
 static void udp_close_target(struct sender_client *sc)
 {
 	const char *buf;
-	size_t len = vss_get_fec_eof_packet(&buf);
-
-	/*
-	 * Ignore the return value of write() since we are closing the target
-	 * anyway. The sole purpose of the "do_nothing" statement is to silence
-	 * gcc.
-	 */
-	if (write(sc->fd, buf, len))
-		do_nothing;
+	size_t len;
+	struct udp_target *ut = sc->private_data;
+
+	if (ut->sent_fec_eof)
+		return;
+	PARA_NOTICE_LOG("sending FEC EOF\n");
+	len = vss_get_fec_eof_packet(&buf);
+	/* Ignore write() errors since we are closing the target anyway. */
+	if (write(sc->fd, buf, len) == len)
+		ut->sent_fec_eof = true;
 }
 
 static void udp_delete_target(struct sender_client *sc, const char *msg)
@@ -232,9 +235,11 @@ static int udp_com_delete(struct sender_command_data *scd)
 /** Initialize UDP session and set maximum payload size. */
 static int udp_init_fec(struct sender_client *sc)
 {
+	struct udp_target *ut = sc->private_data;
 	int mps;
 
 	PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
+	ut->sent_fec_eof = false;
 	mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
 	PARA_INFO_LOG("current MPS = %d bytes\n", mps);
 	return mps;