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

Commit Message

Peter Seiderer Feb. 5, 2025, 1:11 p.m. UTC

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 <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
---
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(-)

Patch

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);