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* [PATCH bpf-next] libbpf: make bpf_endian co-exist with vmlinux.h
@ 2020-06-30  2:05 Andrii Nakryiko
  2020-06-30  3:09 ` Alexei Starovoitov
  0 siblings, 1 reply; 3+ messages in thread
From: Andrii Nakryiko @ 2020-06-30  2:05 UTC (permalink / raw)
  To: bpf, netdev, ast, daniel; +Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko

Copy over few #defines from UAPI swab.h header to make all the rest of
bpf_endian.h work and not rely on any extra headers. This way it can be used
both with linux header includes, as well with a vmlinux.h. This has been
a frequent complaint from users, that need this header.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
 tools/lib/bpf/bpf_endian.h | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/tools/lib/bpf/bpf_endian.h b/tools/lib/bpf/bpf_endian.h
index fbe28008450f..a4be8a70845c 100644
--- a/tools/lib/bpf/bpf_endian.h
+++ b/tools/lib/bpf/bpf_endian.h
@@ -2,8 +2,26 @@
 #ifndef __BPF_ENDIAN__
 #define __BPF_ENDIAN__
 
-#include <linux/stddef.h>
-#include <linux/swab.h>
+/* copied from include/uapi/linux/swab.h */
+#define ___constant_swab16(x) ((__u16)(				\
+	(((__u16)(x) & (__u16)0x00ffU) << 8) |			\
+	(((__u16)(x) & (__u16)0xff00U) >> 8)))
+
+#define ___constant_swab32(x) ((__u32)(				\
+	(((__u32)(x) & (__u32)0x000000ffUL) << 24) |		\
+	(((__u32)(x) & (__u32)0x0000ff00UL) <<  8) |		\
+	(((__u32)(x) & (__u32)0x00ff0000UL) >>  8) |		\
+	(((__u32)(x) & (__u32)0xff000000UL) >> 24)))
+
+#define ___constant_swab64(x) ((__u64)(				\
+	(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) |	\
+	(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) |	\
+	(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) |	\
+	(((__u64)(x) & (__u64)0x00000000ff000000ULL) <<  8) |	\
+	(((__u64)(x) & (__u64)0x000000ff00000000ULL) >>  8) |	\
+	(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) |	\
+	(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) |	\
+	(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56)))
 
 /* LLVM's BPF target selects the endianness of the CPU
  * it compiles on, or the user specifies (bpfel/bpfeb),
-- 
2.24.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH bpf-next] libbpf: make bpf_endian co-exist with vmlinux.h
  2020-06-30  2:05 [PATCH bpf-next] libbpf: make bpf_endian co-exist with vmlinux.h Andrii Nakryiko
@ 2020-06-30  3:09 ` Alexei Starovoitov
  2020-06-30  3:35   ` Andrii Nakryiko
  0 siblings, 1 reply; 3+ messages in thread
From: Alexei Starovoitov @ 2020-06-30  3:09 UTC (permalink / raw)
  To: Andrii Nakryiko; +Cc: bpf, netdev, ast, daniel, andrii.nakryiko, kernel-team

On Mon, Jun 29, 2020 at 07:05:38PM -0700, Andrii Nakryiko wrote:
> Copy over few #defines from UAPI swab.h header to make all the rest of
> bpf_endian.h work and not rely on any extra headers. This way it can be used
> both with linux header includes, as well with a vmlinux.h. This has been
> a frequent complaint from users, that need this header.
> 
> Signed-off-by: Andrii Nakryiko <andriin@fb.com>
> ---
>  tools/lib/bpf/bpf_endian.h | 22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/lib/bpf/bpf_endian.h b/tools/lib/bpf/bpf_endian.h
> index fbe28008450f..a4be8a70845c 100644
> --- a/tools/lib/bpf/bpf_endian.h
> +++ b/tools/lib/bpf/bpf_endian.h
> @@ -2,8 +2,26 @@
>  #ifndef __BPF_ENDIAN__
>  #define __BPF_ENDIAN__
>  
> -#include <linux/stddef.h>
> -#include <linux/swab.h>
> +/* copied from include/uapi/linux/swab.h */

You cannot just copy due to different licenses.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH bpf-next] libbpf: make bpf_endian co-exist with vmlinux.h
  2020-06-30  3:09 ` Alexei Starovoitov
@ 2020-06-30  3:35   ` Andrii Nakryiko
  0 siblings, 0 replies; 3+ messages in thread
From: Andrii Nakryiko @ 2020-06-30  3:35 UTC (permalink / raw)
  To: Alexei Starovoitov
  Cc: Andrii Nakryiko, bpf, Networking, Alexei Starovoitov,
	Daniel Borkmann, Kernel Team

On Mon, Jun 29, 2020 at 8:09 PM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Mon, Jun 29, 2020 at 07:05:38PM -0700, Andrii Nakryiko wrote:
> > Copy over few #defines from UAPI swab.h header to make all the rest of
> > bpf_endian.h work and not rely on any extra headers. This way it can be used
> > both with linux header includes, as well with a vmlinux.h. This has been
> > a frequent complaint from users, that need this header.
> >
> > Signed-off-by: Andrii Nakryiko <andriin@fb.com>
> > ---
> >  tools/lib/bpf/bpf_endian.h | 22 ++++++++++++++++++++--
> >  1 file changed, 20 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/lib/bpf/bpf_endian.h b/tools/lib/bpf/bpf_endian.h
> > index fbe28008450f..a4be8a70845c 100644
> > --- a/tools/lib/bpf/bpf_endian.h
> > +++ b/tools/lib/bpf/bpf_endian.h
> > @@ -2,8 +2,26 @@
> >  #ifndef __BPF_ENDIAN__
> >  #define __BPF_ENDIAN__
> >
> > -#include <linux/stddef.h>
> > -#include <linux/swab.h>
> > +/* copied from include/uapi/linux/swab.h */
>
> You cannot just copy due to different licenses.

Ah, I see. I was thinking that because it's from UAPI header it might
be ok. Alright, I'll try to re-implement it instead.

^ permalink raw reply	[flat|nested] 3+ messages in thread

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Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-06-30  2:05 [PATCH bpf-next] libbpf: make bpf_endian co-exist with vmlinux.h Andrii Nakryiko
2020-06-30  3:09 ` Alexei Starovoitov
2020-06-30  3:35   ` Andrii Nakryiko

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