Re: [RFC PATCH 1/6] net: Added SetSteeringEBPF method for NetClientState.

[Jason Wang <jasowang@redhat.com>]

On 2020/11/3 上午2:51, Andrew Melnychenko wrote:
> From: Andrew <andrew@daynix.com>
>
> For now, that method supported only by Linux TAP.
> Linux TAP uses TUNSETSTEERINGEBPF ioctl.
> TUNSETSTEERINGBPF was added 3 years ago.
> Qemu checks if it was defined before using.
>
> Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
> ---
>   include/net/net.h |  2 ++
>   net/tap-bsd.c     |  5 +++++
>   net/tap-linux.c   | 19 +++++++++++++++++++
>   net/tap-solaris.c |  5 +++++
>   net/tap-stub.c    |  5 +++++
>   net/tap.c         |  9 +++++++++
>   net/tap_int.h     |  1 +
>   7 files changed, 46 insertions(+)
>
> diff --git a/include/net/net.h b/include/net/net.h
> index 897b2d7595..d8a41fb010 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -60,6 +60,7 @@ typedef int (SetVnetBE)(NetClientState *, bool);
>   typedef struct SocketReadState SocketReadState;
>   typedef void (SocketReadStateFinalize)(SocketReadState *rs);
>   typedef void (NetAnnounce)(NetClientState *);
> +typedef bool (SetSteeringEBPF)(NetClientState *, int);
>   
>   typedef struct NetClientInfo {
>       NetClientDriver type;
> @@ -81,6 +82,7 @@ typedef struct NetClientInfo {
>       SetVnetLE *set_vnet_le;
>       SetVnetBE *set_vnet_be;
>       NetAnnounce *announce;
> +    SetSteeringEBPF *set_steering_ebpf;
>   } NetClientInfo;
>   
>   struct NetClientState {
> diff --git a/net/tap-bsd.c b/net/tap-bsd.c
> index 77aaf674b1..4f64f31e98 100644
> --- a/net/tap-bsd.c
> +++ b/net/tap-bsd.c
> @@ -259,3 +259,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
>   {
>       return -1;
>   }
> +
> +int tap_fd_set_steering_ebpf(int fd, int prog_fd)
> +{
> +    return -1;
> +}
> diff --git a/net/tap-linux.c b/net/tap-linux.c
> index b0635e9e32..196373019f 100644
> --- a/net/tap-linux.c
> +++ b/net/tap-linux.c
> @@ -31,6 +31,7 @@
>   
>   #include <net/if.h>
>   #include <sys/ioctl.h>
> +#include <linux/if_tun.h> /* TUNSETSTEERINGEBPF */
>   
>   #include "qapi/error.h"
>   #include "qemu/error-report.h"
> @@ -316,3 +317,21 @@ int tap_fd_get_ifname(int fd, char *ifname)
>       pstrcpy(ifname, sizeof(ifr.ifr_name), ifr.ifr_name);
>       return 0;
>   }
> +
> +int tap_fd_set_steering_ebpf(int fd, int prog_fd)
> +{
> +#ifdef TUNSETSTEERINGEBPF


I'm not sure how much this can help.

But looking at tap-linux.h, I wonder do we need to pull TUN/TAP uapi 
headers.

Thanks


> +    if (ioctl(fd, TUNSETSTEERINGEBPF, (void *) &prog_fd) != 0) {
> +        error_report("Issue while setting TUNSETSTEERINGEBPF:"
> +                    " %s with fd: %d, prog_fd: %d",
> +                    strerror(errno), fd, prog_fd);
> +
> +       return -1;
> +    }
> +
> +    return 0;
> +#else
> +    error_report("TUNSETSTEERINGEBPF is not supported");
> +    return -1;
> +#endif
> +}
> diff --git a/net/tap-solaris.c b/net/tap-solaris.c
> index 0475a58207..d85224242b 100644
> --- a/net/tap-solaris.c
> +++ b/net/tap-solaris.c
> @@ -255,3 +255,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
>   {
>       return -1;
>   }
> +
> +int tap_fd_set_steering_ebpf(int fd, int prog_fd)
> +{
> +    return -1;
> +}
> diff --git a/net/tap-stub.c b/net/tap-stub.c
> index de525a2e69..a0fa25804b 100644
> --- a/net/tap-stub.c
> +++ b/net/tap-stub.c
> @@ -85,3 +85,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
>   {
>       return -1;
>   }
> +
> +int tap_fd_set_steering_ebpf(int fd, int prog_fd)
> +{
> +    return -1;
> +}
> diff --git a/net/tap.c b/net/tap.c
> index c46ff66184..81f50017bd 100644
> --- a/net/tap.c
> +++ b/net/tap.c
> @@ -337,6 +337,14 @@ static void tap_poll(NetClientState *nc, bool enable)
>       tap_write_poll(s, enable);
>   }
>   
> +static bool tap_set_steering_ebpf(NetClientState *nc, int prog_fd)
> +{
> +    TAPState *s = DO_UPCAST(TAPState, nc, nc);
> +    assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
> +
> +    return tap_fd_set_steering_ebpf(s->fd, prog_fd) == 0;
> +}
> +
>   int tap_get_fd(NetClientState *nc)
>   {
>       TAPState *s = DO_UPCAST(TAPState, nc, nc);
> @@ -362,6 +370,7 @@ static NetClientInfo net_tap_info = {
>       .set_vnet_hdr_len = tap_set_vnet_hdr_len,
>       .set_vnet_le = tap_set_vnet_le,
>       .set_vnet_be = tap_set_vnet_be,
> +    .set_steering_ebpf = tap_set_steering_ebpf,
>   };
>   
>   static TAPState *net_tap_fd_init(NetClientState *peer,
> diff --git a/net/tap_int.h b/net/tap_int.h
> index 225a49ea48..547f8a5a28 100644
> --- a/net/tap_int.h
> +++ b/net/tap_int.h
> @@ -44,5 +44,6 @@ int tap_fd_set_vnet_be(int fd, int vnet_is_be);
>   int tap_fd_enable(int fd);
>   int tap_fd_disable(int fd);
>   int tap_fd_get_ifname(int fd, char *ifname);
> +int tap_fd_set_steering_ebpf(int fd, int prog_fd);
>   
>   #endif /* NET_TAP_INT_H */