[2/6] kunit: add a convenience allocation wrapper for SKBs

From: Benjamin Berg <benjamin.berg@intel.com>

Add a simple convenience helper to allocate and zero fill an SKB for the
use by a kunit test. Also provide a way to free it again in case that
may be desirable.

This simply mirrors the kunit_kmalloc API.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
---
 include/kunit/skbuff.h | 56 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 include/kunit/skbuff.h

On Wed, 20 Dec 2023 at 23:20, <benjamin@sipsolutions.net> wrote:
>
> From: Benjamin Berg <benjamin.berg@intel.com>
>
> Add a simple convenience helper to allocate and zero fill an SKB for the
> use by a kunit test. Also provide a way to free it again in case that
> may be desirable.
>
> This simply mirrors the kunit_kmalloc API.
>
> Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
> ---

I'm happy with this as-is, but do think there's a discussion to be had
about where subsystem-specific KUnit helpers should live. I think,
because this is just a header (and it mirrors the normal
linux/skbuff.h), that having it in include/kunit works well.

If it needed a source file, I'm not 100% sure whether it should be in
net/core/ or lib/kunit.

Regardless, this looks good to me, modulo the small nitpick below.

Reviewed-by: David Gow <davidgow@google.com>

>  include/kunit/skbuff.h | 56 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 56 insertions(+)
>  create mode 100644 include/kunit/skbuff.h
>
> diff --git a/include/kunit/skbuff.h b/include/kunit/skbuff.h
> new file mode 100644
> index 000000000000..2144d01e556f
> --- /dev/null
> +++ b/include/kunit/skbuff.h
> @@ -0,0 +1,56 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Base unit test (KUnit) API.

This probably needs a better description which mentions skbuff, and
that it's for resource management.


> + *
> + * Copyright (C) 2023 Intel Corporation
> + */
> +
> +#ifndef _KUNIT_SKBUFF_H
> +#define _KUNIT_SKBUFF_H
> +
> +#include <kunit/resource.h>
> +#include <linux/skbuff.h>
> +
> +static void kunit_action_kfree_skb(void *p)
> +{
> +       kfree_skb((struct sk_buff *)p);
> +}
> +
> +/**
> + * kunit_zalloc_skb() - Allocate and initialize a resource managed skb.
> + * @test: The test case to which the skb belongs
> + * @len: size to allocate
> + *
> + * Allocate a new struct sk_buff with GFP_KERNEL, zero fill the give length
> + * and add it as a resource to the kunit test for automatic cleanup.
> + *
> + * Returns: newly allocated SKB, or %NULL on error
> + */
> +static inline struct sk_buff *kunit_zalloc_skb(struct kunit *test, int len,
> +                                              gfp_t gfp)
> +{
> +       struct sk_buff *res = alloc_skb(len, GFP_KERNEL);
> +
> +       if (!res || skb_pad(res, len))
> +               return NULL;
> +
> +       if (kunit_add_action_or_reset(test, kunit_action_kfree_skb, res))
> +               return NULL;
> +
> +       return res;
> +}
> +
> +/**
> + * kunit_kfree_skb() - Like kfree_skb except for allocations managed by KUnit.
> + * @test: The test case to which the resource belongs.
> + * @skb: The SKB to free.
> + */
> +static inline void kunit_kfree_skb(struct kunit *test, struct sk_buff *skb)
> +{
> +       if (!skb)
> +               return;
> +
> +       kunit_release_action(test, kunit_action_kfree_skb, (void *)skb);
> +}
> +
> +#endif /* _KUNIT_SKBUFF_H */
> --
> 2.43.0
>
> --
> You received this message because you are subscribed to the Google Groups "KUnit Development" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to kunit-dev+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/kunit-dev/20231220151952.415232-3-benjamin%40sipsolutions.net.