[U-Boot] TFTP - check for len == 0 before storing

[U-Boot] TFTP - check for len == 0 before storing

[David Andrey]

Hello,

I had a problem with an old TFTP Server which is sending a second "last"
data block with "len == 0" at end. It's clearly not RFC conform, but I
still made a additional check in u-boot/tftp to avoid a wrong "filesize"
value. This wrong filesize value caused some trouble by NAND operations.


Regards
David



Date: Wed, 20 Apr 2011 10:12:10 +0200
Subject: [PATCH] Check for for data block len == 0

---
 net/tftp.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/tftp.c b/net/tftp.c
index ed559b7..40d81b5 100644
--- a/net/tftp.c
+++ b/net/tftp.c
@@ -135,8 +135,14 @@ mcast_cleanup(void)
 static __inline__ void
 store_block (unsigned block, uchar * src, unsigned len)
 {
-       ulong offset = block * TftpBlkSize + TftpBlockWrapOffset;
-       ulong newsize = offset + len;
+       ulong offset = 0;
+       ulong newsize = 0;
+
+       if (len == 0)
+               return;
+
+       offset = block * TftpBlkSize + TftpBlockWrapOffset;
+       newsize = offset + len;
 #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
        int i, rc = 0;

[U-Boot] TFTP - check for len == 0 before storing

[Detlev Zundel]

Hi David,

> I had a problem with an old TFTP Server which is sending a second "last"
> data block with "len == 0" at end. It's clearly not RFC conform, but I
> still made a additional check in u-boot/tftp to avoid a wrong "filesize"
> value. This wrong filesize value caused some trouble by NAND operations.

Please look at our patch guidelines[1] on how to submit patches.
Especially a signed-off-by is missing on this patch.

Moreover, please put the explanation into the commit log so that one can
learn the rationale for the change when studying the source with git.

Thanks
  Detlev

[1] http://www.denx.de/wiki/U-Boot/Patches

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