Re: [PATCH] selftests/bpf: fix compile errors with older glibc

[Yonghong Song <yhs@fb.com>]

On 4/17/19 10:48 AM, Wang YanQing wrote:
> The older glibc (for example, 2.23) doesn't handle __UAPI_DEF_*
> in libc-compat.h properly, and it bring below compile errors:

I have an even old glibc 2.17 and it still works. Not sure
why it failed here. Could you explain more?

But I applied the change, it still works with 2.17 glibc and gcc 4.8.5.
So change probably safe.

> "
> In file included from test_tcpnotify_kern.c:12:
> /usr/include/netinet/in.h:101:5: error: expected identifier
>      IPPROTO_HOPOPTS = 0,   /* IPv6 Hop-by-Hop options.  */
>      ^
> /usr/include/linux/in6.h:131:26: note: expanded from macro 'IPPROTO_HOPOPTS'
>                                  ^
> In file included from test_tcpnotify_kern.c:12:
> /usr/include/netinet/in.h:103:5: error: expected identifier
>      IPPROTO_ROUTING = 43,  /* IPv6 routing header.  */
>      ^
> /usr/include/linux/in6.h:132:26: note: expanded from macro 'IPPROTO_ROUTING'
>                                  ^
> In file included from test_tcpnotify_kern.c:12:
> /usr/include/netinet/in.h:105:5: error: expected identifier
>      IPPROTO_FRAGMENT = 44, /* IPv6 fragmentation header.  */
>      ^
> /usr/include/linux/in6.h:133:26: note: expanded from macro 'IPPROTO_FRAGMENT'
> "
> The same compile errors are reported for test_tcpbpf_kern.c too.
> 
> This patch fixes the compile errors by moving <netinet/in.h> to before the
> <linux/*.h>.
> 
> Signed-off-by: Wang YanQing <udknight@gmail.com>
> ---
>   tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c    | 2 +-
>   tools/testing/selftests/bpf/progs/test_tcpnotify_kern.c | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c b/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c
> index 74f73b3..c7c3240 100644
> --- a/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c
> +++ b/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c
> @@ -1,6 +1,7 @@
>   // SPDX-License-Identifier: GPL-2.0
>   #include <stddef.h>
>   #include <string.h>
> +#include <netinet/in.h>
>   #include <linux/bpf.h>
>   #include <linux/if_ether.h>
>   #include <linux/if_packet.h>
> @@ -9,7 +10,6 @@
>   #include <linux/types.h>
>   #include <linux/socket.h>
>   #include <linux/tcp.h>
> -#include <netinet/in.h>
>   #include "bpf_helpers.h"
>   #include "bpf_endian.h"
>   #include "test_tcpbpf.h"
> diff --git a/tools/testing/selftests/bpf/progs/test_tcpnotify_kern.c b/tools/testing/selftests/bpf/progs/test_tcpnotify_kern.c
> index edbca20..ec6db6e 100644
> --- a/tools/testing/selftests/bpf/progs/test_tcpnotify_kern.c
> +++ b/tools/testing/selftests/bpf/progs/test_tcpnotify_kern.c
> @@ -1,6 +1,7 @@
>   // SPDX-License-Identifier: GPL-2.0
>   #include <stddef.h>
>   #include <string.h>
> +#include <netinet/in.h>
>   #include <linux/bpf.h>
>   #include <linux/if_ether.h>
>   #include <linux/if_packet.h>
> @@ -9,7 +10,6 @@
>   #include <linux/types.h>
>   #include <linux/socket.h>
>   #include <linux/tcp.h>
> -#include <netinet/in.h>
>   #include "bpf_helpers.h"
>   #include "bpf_endian.h"
>   #include "test_tcpnotify.h"
>