pktgen and tos

pktgen and tos

[Ben Greear]

Here's a half-arsed bug report, in case someone is bored.

At least in my hacked up pktgen, you cannot set a one-digit tos,
because the parser fails if length is not 2 digits.

echo tos 4 > /proc/net/pktgen/rddVR2 && cat /proc/net/pktgen/rddVR2

...
Result: ERROR: tos must be 00-ff

If you use '04' instead, it works.  In my case, it will be easier to hack user-space
to deal with this than fix pktgen, but I thought someone might want to fix it proper.

Also, could be that upstream code doesn't have this limitation...

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com

Re: pktgen and tos

[Cong Wang]

On Wed, Aug 20, 2014 at 2:52 PM, Ben Greear <greearb@candelatech.com> wrote:
> Here's a half-arsed bug report, in case someone is bored.
>
> At least in my hacked up pktgen, you cannot set a one-digit tos,
> because the parser fails if length is not 2 digits.
>
> echo tos 4 > /proc/net/pktgen/rddVR2 && cat /proc/net/pktgen/rddVR2
>
> ...
> Result: ERROR: tos must be 00-ff
>
> If you use '04' instead, it works.  In my case, it will be easier to hack
> user-space
> to deal with this than fix pktgen, but I thought someone might want to fix
> it proper.
>
> Also, could be that upstream code doesn't have this limitation...

We need something like this:

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 8b849dd..f8cb428 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -1674,7 +1674,7 @@ static ssize_t pktgen_if_write(struct file *file,
  return len;

  i += len;
- if (len == 2) {
+ if (len <= 2) {
  pkt_dev->tos = tmp_value;
  sprintf(pg_result, "OK: tos=0x%02x", pkt_dev->tos);
  } else {