Breno Leitao <leitao@xxxxxxxxxx> writes:
> Add BPF hook support for getsockopts io_uring command. So, BPF cgroups
> programs can run when SOCKET_URING_OP_GETSOCKOPT command is executed
> through io_uring.
>
> This implementation follows a similar approach to what
> __sys_getsockopt() does, but, using USER_SOCKPTR() for optval instead of
> kernel pointer.
>
> Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
> ---
> io_uring/uring_cmd.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
> index a567dd32df00..9e08a14760c3 100644
> --- a/io_uring/uring_cmd.c
> +++ b/io_uring/uring_cmd.c
> @@ -5,6 +5,8 @@
> #include <linux/io_uring.h>
> #include <linux/security.h>
> #include <linux/nospec.h>
> +#include <linux/compat.h>
> +#include <linux/bpf-cgroup.h>
>
> #include <uapi/linux/io_uring.h>
> #include <uapi/asm-generic/ioctls.h>
> @@ -184,17 +186,23 @@ static inline int io_uring_cmd_getsockopt(struct socket *sock,
> if (err)
> return err;
>
> - if (level == SOL_SOCKET) {
> + err = -EOPNOTSUPP;
> + if (level == SOL_SOCKET)
> err = sk_getsockopt(sock->sk, level, optname,
> USER_SOCKPTR(optval),
> KERNEL_SOCKPTR(&optlen));
> - if (err)
> - return err;
>
> + if (!(issue_flags & IO_URING_F_COMPAT))
> + err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level,
> + optname,
> + USER_SOCKPTR(optval),
> + KERNEL_SOCKPTR(&optlen),
> + optlen, err);
> +
> + if (!err)
> return optlen;
> - }
Shouldn't you call sock->ops->getsockopt for level!=SOL_SOCKET prior to
running the hook? Before this patch, it would bail out with EOPNOTSUPP,
but now the bpf hook gets called even for level!=SOL_SOCKET, which
doesn't fit __sys_getsockopt. Am I misreading the code?
--
Gabriel Krisman Bertazi
