[PATCH net-next v4 04/17] net: pktgen: fix 'rate 0' error handling (return -EINVAL)

Peter Seiderer
2025-02-05T13:12:03Z

Given an invalid 'rate' command e.g. 'rate 0' the return value is '1',
leading to the following misleading output:

- the good case

$ echo "rate 100" > /proc/net/pktgen/lo\@0
$ grep "Result:" /proc/net/pktgen/lo\@0
Result: OK: rate=100

- the bad case (before the patch)

$ echo "rate 0" > /proc/net/pktgen/lo\@0"
-bash: echo: write error: Invalid argument
$ grep "Result:" /proc/net/pktgen/lo\@0
Result: No such parameter "ate"

- with patch applied

$ echo "rate 0" > /proc/net/pktgen/lo\@0
-bash: echo: write error: Invalid argument
$ grep "Result:" /proc/net/pktgen/lo\@0
Result: Idle

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Reviewed-by: Simon Horman <horms@kernel.org>
---
Changes v3 -> v4
- add rev-by Simon Horman

Changes v2 -> v3:
- no changes

Changes v1 -> v2:
- new patch
---
net/core/pktgen.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 28dbbf70e142..75c7511bf492 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -1115,7 +1115,7 @@ static ssize_t pktgen_if_write(struct file *file,

i += len;
if (!value)
- return len;
+ return -EINVAL;
pkt_dev->delay = pkt_dev->min_pkt_size*8*NSEC_PER_USEC/value;
if (debug)
pr_info("Delay set at: %llu ns\n", pkt_dev->delay);
--
2.48.1