From c96f86eefc215b67dd222694ce2b6f60e6a42b0b Mon Sep 17 00:00:00 2001 From: Wolfgang Denk Date: Sun, 17 Jan 2010 23:55:53 +0100 Subject: [PATCH] TFTP: allow for adjustable retransmission timout So far, TFTP negotiated a fixed retransmission timeout of 5 seconds. In some cases (busy networks, slow TFTP servers) this caused very slow transfers. A new environment variable "tftptimeout" allows to set this timeout. Lowering this value may make downloads succeed faster in networks with high packet loss rates or with unreliable TFTP servers. Signed-off-by: Wolfgang Denk Cc: Ben Warren Signed-off-by: Ben Warren --- README | 19 ++++++++++++++++--- net/tftp.c | 23 ++++++++++++++++++----- 2 files changed, 34 insertions(+), 8 deletions(-) diff --git a/README b/README index 1158e24de..940b50794 100644 --- a/README +++ b/README @@ -3005,7 +3005,9 @@ environment. As long as you don't save the environment you are working with an in-memory copy. In case the Flash area containing the environment is erased by accident, a default environment is provided. -Some configuration options can be set using Environment Variables: +Some configuration options can be set using Environment Variables. + +List of environment variables (most likely not complete): baudrate - see CONFIG_BAUDRATE @@ -3117,7 +3119,7 @@ Some configuration options can be set using Environment Variables: available network interfaces. It just stays at the currently selected interface. - netretry - When set to "no" each network operation will + netretry - When set to "no" each network operation will either succeed or fail without retrying. When set to "once" the network operation will fail when all the available network interfaces @@ -3133,7 +3135,18 @@ Some configuration options can be set using Environment Variables: tftpdstport - If this is set, the value is used for TFTP's UDP destination port instead of the Well Know Port 69. - vlan - When set to a value < 4095 the traffic over + tftpblocksize - Block size to use for TFTP transfers; if not set, + we use the TFTP server's default block size + + tftptimeout - Retransmission timeout for TFTP packets (in milli- + seconds, minimum value is 1000 = 1 second). Defines + when a packet is considered to be lost so it has to + be retransmitted. The default is 5000 = 5 seconds. + Lowering this value may make downloads succeed + faster in networks with high packet loss rates or + with unreliable TFTP servers. + + vlan - When set to a value < 4095 the traffic over Ethernet is encapsulated/received over 802.1q VLAN tagged frames. diff --git a/net/tftp.c b/net/tftp.c index a02463b00..ed559b71d 100644 --- a/net/tftp.c +++ b/net/tftp.c @@ -211,7 +211,7 @@ TftpSend (void) pkt += 5 /*strlen("octet")*/ + 1; strcpy ((char *)pkt, "timeout"); pkt += 7 /*strlen("timeout")*/ + 1; - sprintf((char *)pkt, "%lu", TIMEOUT / 1000); + sprintf((char *)pkt, "%lu", TftpTimeoutMSecs / 1000); debug("send option \"timeout %s\"\n", (char *)pkt); pkt += strlen((char *)pkt) + 1; #ifdef CONFIG_TFTP_TSIZE @@ -413,7 +413,6 @@ TftpHandler (uchar * pkt, unsigned dest, unsigned src, unsigned len) } TftpLastBlock = TftpBlock; - TftpTimeoutMSecs = TIMEOUT; TftpTimeoutCountMax = TIMEOUT_COUNT; NetSetTimeout (TftpTimeoutMSecs, TftpTimeout); @@ -528,10 +527,25 @@ TftpStart (void) { char *ep; /* Environment pointer */ - /* Allow the user to choose tftpblocksize */ + /* + * Allow the user to choose TFTP blocksize and timeout. + * TFTP protocol has a minimal timeout of 1 second. + */ if ((ep = getenv("tftpblocksize")) != NULL) TftpBlkSizeOption = simple_strtol(ep, NULL, 10); - debug("tftp block size is %i\n", TftpBlkSizeOption); + + if ((ep = getenv("tftptimeout")) != NULL) + TftpTimeoutMSecs = simple_strtol(ep, NULL, 10); + + if (TftpTimeoutMSecs < 1000) { + printf("TFTP timeout (%ld ms) too low, " + "set minimum = 1000 ms\n", + TftpTimeoutMSecs); + TftpTimeoutMSecs = 1000; + } + + debug("TFTP blocksize = %i, timeout = %ld ms\n", + TftpBlkSizeOption, TftpTimeoutMSecs); TftpServerIP = NetServerIP; if (BootFile[0] == '\0') { @@ -588,7 +602,6 @@ TftpStart (void) puts ("Loading: *\b"); - TftpTimeoutMSecs = TftpRRQTimeoutMSecs; TftpTimeoutCountMax = TftpRRQTimeoutCountMax; NetSetTimeout (TftpTimeoutMSecs, TftpTimeout);