netdev - Re: [PATCH bpf-next] libbpf: make sure bpf headers are c++ include-able

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 20 Nov 2018 13:00:57 -0800
From:   Y Song <ys114321@...il.com>
To:     Stanislav Fomichev <sdf@...gle.com>
Cc:     netdev <netdev@...r.kernel.org>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>
Subject: Re: [PATCH bpf-next] libbpf: make sure bpf headers are c++ include-able

On Tue, Nov 20, 2018 at 10:19 AM Stanislav Fomichev <sdf@...gle.com> wrote:
>
> Wrap headers in extern "C", to turn off C++ mangling.
> This simplifies including libbpf in c++ and linking against it.
>
> Signed-off-by: Stanislav Fomichev <sdf@...gle.com>
> ---
>  tools/lib/bpf/bpf.h    | 9 +++++++++
>  tools/lib/bpf/libbpf.h | 9 +++++++++

Do you want to add tools/lib/bpf/btf.h as well? it has some functions
which could be used outside libbpf as well.

>  2 files changed, 18 insertions(+)
>
> diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
> index 26a51538213c..9ea3aec82d8a 100644
> --- a/tools/lib/bpf/bpf.h
> +++ b/tools/lib/bpf/bpf.h
> @@ -27,6 +27,10 @@
>  #include <stdbool.h>
>  #include <stddef.h>
>
> +#ifdef __cplusplus
> +extern "C" {
> +#endif

Some (but not all) __cplusplus extern wrappers wraps standard include as well
like "#include <stdbool.h>", "#include <stddef.h>". probably does not
matter here
since they may not have function prototype. But just want to point it out so you
are aware of this and may double check.

> +
>  #ifndef LIBBPF_API
>  #define LIBBPF_API __attribute__((visibility("default")))
>  #endif
> @@ -128,4 +132,9 @@ LIBBPF_API int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf,
>  LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf,
>                                  __u32 *buf_len, __u32 *prog_id, __u32 *fd_type,
>                                  __u64 *probe_offset, __u64 *probe_addr);
> +
> +#ifdef __cplusplus
> +} /* extern "C" */
> +#endif
> +
>  #endif /* __LIBBPF_BPF_H */
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index b1686a787102..74e57e041705 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -16,6 +16,10 @@
>  #include <sys/types.h>  // for size_t
>  #include <linux/bpf.h>
>
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
>  #ifndef LIBBPF_API
>  #define LIBBPF_API __attribute__((visibility("default")))
>  #endif
> @@ -335,4 +339,9 @@ int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
>                         libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie);
>  int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
>                          libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
> +
> +#ifdef __cplusplus
> +} /* extern "C" */
> +#endif
> +
>  #endif /* __LIBBPF_LIBBPF_H */
> --
> 2.19.1.1215.g8438c0b245-goog
>