[U-Boot] [PATCH 1/3] net: Make TFTP server timeout configurable

[Bartlomiej Sieka]

There are two aspects of a TFTP transfer involving timeouts:
1. timeout waiting for initial server reply after sending RRQ
2. timeouts while transferring actual data from the server

Since the upcoming auto-update feature attempts a TFTP download during each
boot, it is undesirable to have a long delay when the TFTP server is not
available. Thus, this commit makes the server timeout (1.) configurable by two
global variables:

TftpRRQTimeoutSecs
TftpRRQTimeoutCountMax

TftpRRQTimeoutSecs overrides default timeout when trying to connect to a TFTP
server, TftpRRQTimeoutCountMax overrides default number of connection retries.
The total delay when trying to download a file from a non-existing TFTP server
is TftpRRQTimeoutSecs x TftpRRQTimeoutCountMax seconds.

Timeouts during file transfers (2.) are unaffected.

Signed-off-by: Rafal Czubak <rcz at semihalf.com>
Signed-off-by: Bartlomiej Sieka <tur at semihalf.com>
---
 net/tftp.c |   30 +++++++++++++++++++++++++-----
 1 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/net/tftp.c b/net/tftp.c
index 9aeecb8..fe6a204 100644
--- a/net/tftp.c
+++ b/net/tftp.c
@@ -34,6 +34,21 @@
 #define TFTP_ERROR	5
 #define TFTP_OACK	6
 
+static ulong TftpTimeoutSecs = TIMEOUT;
+static int TftpTimeoutCountMax = TIMEOUT_COUNT;
+
+/*
+ * These globals govern the timeout behavior when attempting a connection to a
+ * TFTP server. TftpRRQTimeoutSecs specifies the number of seconds to wait for
+ * the server to respond to initial connection, and TftpRRQTimeoutCountMax
+ * gives the number of such connection retries. TftpRRQTimeoutCountMax must be
+ * non-negative and TftpRRQTimeoutSecs must be positive. The globals are meant
+ * to be set (and restored) by code needing non-standard timeout behavior when
+ * initiating a TFTP transfer.
+ */
+ulong TftpRRQTimeoutSecs = TIMEOUT;
+int TftpRRQTimeoutCountMax = TIMEOUT_COUNT;
+
 static IPaddr_t TftpServerIP;
 static int	TftpServerPort;		/* The UDP port at their end		*/
 static int	TftpOurPort;		/* The UDP port at our end		*/
@@ -180,7 +195,7 @@ TftpSend (void)
 		pkt += 5 /*strlen("octet")*/ + 1;
 		strcpy ((char *)pkt, "timeout");
 		pkt += 7 /*strlen("timeout")*/ + 1;
-		sprintf((char *)pkt, "%lu", TIMEOUT);
+		sprintf((char *)pkt, "%lu", TftpTimeoutSecs);
 #ifdef ET_DEBUG
 		printf("send option \"timeout %s\"\n", (char *)pkt);
 #endif
@@ -370,7 +385,9 @@ TftpHandler (uchar * pkt, unsigned dest, unsigned src, unsigned len)
 		}
 
 		TftpLastBlock = TftpBlock;
-		NetSetTimeout (TIMEOUT * CFG_HZ, TftpTimeout);
+		TftpTimeoutSecs = TIMEOUT;
+		TftpTimeoutCountMax = TIMEOUT_COUNT;
+		NetSetTimeout (TftpTimeoutSecs * CFG_HZ, TftpTimeout);
 
 		store_block (TftpBlock - 1, pkt + 2, len);
 
@@ -441,7 +458,7 @@ TftpHandler (uchar * pkt, unsigned dest, unsigned src, unsigned len)
 static void
 TftpTimeout (void)
 {
-	if (++TftpTimeoutCount > TIMEOUT_COUNT) {
+	if (++TftpTimeoutCount > TftpTimeoutCountMax) {
 		puts ("\nRetry count exceeded; starting again\n");
 #ifdef CONFIG_MCAST_TFTP
 		mcast_cleanup();
@@ -449,7 +466,7 @@ TftpTimeout (void)
 		NetStartAgain ();
 	} else {
 		puts ("T ");
-		NetSetTimeout (TIMEOUT * CFG_HZ, TftpTimeout);
+		NetSetTimeout (TftpTimeoutSecs * CFG_HZ, TftpTimeout);
 		TftpSend ();
 	}
 }
@@ -520,7 +537,10 @@ TftpStart (void)
 
 	puts ("Loading: *\b");
 
-	NetSetTimeout (TIMEOUT * CFG_HZ, TftpTimeout);
+	TftpTimeoutSecs = TftpRRQTimeoutSecs;
+	TftpTimeoutCountMax = TftpRRQTimeoutCountMax;
+
+	NetSetTimeout (TftpTimeoutSecs * CFG_HZ, TftpTimeout);
 	NetSetHandler (TftpHandler);
 
 	TftpServerPort = WELL_KNOWN_PORT;
-- 
1.5.3.4