Re: [PATCH] net: ethernet: use ip_hdrlen() instead of bit shift

On Fri, Aug 02, 2024 at 03:15:34PM +0100, Simon Horman wrote:

On Fri, Aug 02, 2024 at 02:44:21PM +0900, Moon Yeounsu wrote:

quoted

`ip_hdr(skb)->ihl << 2` are the same as `ip_hdrlen(skb)`
Therefore, we should use a well-defined function not a bit shift
to find the header length.

It also compress two lines at a single line.

Signed-off-by: Moon Yeounsu <redacted>

Firstly, I think this clean-up is both correct and safe.  Safe because
ip_hdrlen() only relies on ip_hdr(), which is already used in the same code
path. And correct because ip_hdrlen multiplies ihl by 4, which is clearly
equivalent to a left shift of 2 bits.

However, I do wonder about the value of clean-ups for what appears to be a
very old driver, which hasn't received a new feature for quite sometime

And further, I wonder if we should update this driver from "Maintained" to
"Odd Fixes" as the maintainer, "Guo-Fu Tseng" [off-list ref],
doesn't seem to have been seen by lore since early 2020.

https://lore.kernel.org/netdev/20200219034801.M31679@cooldavid.org/ (local)

By "Odd Fixes" I meant "Orphan"

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