[PATCH v2 2/2] tftp: ignore trailing garbage in the request

[Aaro Koskinen]

Hi,

On Wed, Sep 03, 2014 at 06:36:36PM +0200, Denys Vlasenko wrote:
> On Mon, Sep 1, 2014 at 10:24 PM, Aaro Koskinen <aaro.koskinen at iki.fi> wrote:
> > The firmware in some HP PA-RISC boxes is always sending fixed
> > 512-byte requests, and sometimes there is some garbage at the end
> > which makes busybox to reject the request. Ignore any characters after
> > the last NUL.
> 
> How about this?

As you pointed out, I missed the short read possibility, and by
ignoring them that also made me to screw up my testing & analysis
(should have checked with tcpdump) - the box is actually sending
*516-byte* requests. :-(

So following is still needed to current git to work with some PA-RISC:

diff --git a/networking/tftp.c b/networking/tftp.c
index 8e3b0a2..d9295c9 100644
--- a/networking/tftp.c
+++ b/networking/tftp.c
@@ -118,7 +118,7 @@ struct globals {
 	uint8_t error_pkt[4 + 32];
 	struct passwd *pw;
 	/* used in tftpd_main(), a bit big for stack: */
-	char block_buf[TFTP_BLKSIZE_DEFAULT];
+	char block_buf[TFTP_BLKSIZE_DEFAULT + 4];
 	char block_buf_tail[1];
 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
 	off_t pos;
@@ -811,7 +811,7 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
 	) {
 		goto err;
 	}
-	/* Some HP PA-RISC firmware always sends fixed 512-byte requests,
+	/* Some HP PA-RISC firmware always sends fixed 516-byte requests,
 	 * with trailing garbage.
 	 * Support that by not requiring NUL to be the last byte (see above).
 	 * To make strXYZ() ops safe, force NUL termination:

Very sorry not realizing this earlier,

A.