Re: [PATCH net-next v9 5/6] selftest: tun: Add tests for virtio-net hashing

[Jason Wang <jasowang@redhat.com>]

On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> The added tests confirm tun can perform RSS and hash reporting, and
> reject invalid configurations for them.

Let's be more verbose here. E.g what's the network topology used here.

>
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> Tested-by: Lei Yang <leiyang@redhat.com>
> ---
>  tools/testing/selftests/net/Makefile |   2 +-
>  tools/testing/selftests/net/tun.c    | 584 ++++++++++++++++++++++++++++++++++-
>  2 files changed, 576 insertions(+), 10 deletions(-)
>
> diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
> index 73ee88d6b043004be23b444de667a1d99a6045de..9772f691a9a011d99212df32463cdb930cf0a1a0 100644
> --- a/tools/testing/selftests/net/Makefile
> +++ b/tools/testing/selftests/net/Makefile
> @@ -123,6 +123,6 @@ $(OUTPUT)/reuseport_bpf_numa: LDLIBS += -lnuma
>  $(OUTPUT)/tcp_mmap: LDLIBS += -lpthread -lcrypto
>  $(OUTPUT)/tcp_inq: LDLIBS += -lpthread
>  $(OUTPUT)/bind_bhash: LDLIBS += -lpthread
> -$(OUTPUT)/io_uring_zerocopy_tx: CFLAGS += -I../../../include/
> +$(OUTPUT)/io_uring_zerocopy_tx $(OUTPUT)/tun: CFLAGS += -I../../../include/
>
>  include bpf.mk
> diff --git a/tools/testing/selftests/net/tun.c b/tools/testing/selftests/net/tun.c
> index 463dd98f2b80b1bdcb398cee43c834e7dc5cf784..acadeea7194eaea9416a605b47f99f7a5f1f80cd 100644
> --- a/tools/testing/selftests/net/tun.c
> +++ b/tools/testing/selftests/net/tun.c
> @@ -2,21 +2,38 @@
>
>  #define _GNU_SOURCE
>
> +#include <endian.h>
>  #include <errno.h>
>  #include <fcntl.h>
> +#include <sched.h>

Is this needed?

> +#include <stddef.h>
>  #include <stdio.h>
>  #include <stdlib.h>
>  #include <string.h>
>  #include <unistd.h>
> -#include <linux/if.h>
> +#include <net/if.h>
> +#include <netinet/ip.h>
> +#include <sys/ioctl.h>
> +#include <sys/socket.h>
> +#include <linux/compiler.h>
> +#include <linux/icmp.h>
> +#include <linux/if_arp.h>
>  #include <linux/if_tun.h>
> +#include <linux/ipv6.h>
>  #include <linux/netlink.h>
>  #include <linux/rtnetlink.h>
> -#include <sys/ioctl.h>
> -#include <sys/socket.h>
> +#include <linux/sockios.h>
> +#include <linux/tcp.h>
> +#include <linux/udp.h>
> +#include <linux/virtio_net.h>
>
>  #include "../kselftest_harness.h"
>
> +#define TUN_HWADDR_SOURCE { 0x02, 0x00, 0x00, 0x00, 0x00, 0x00 }
> +#define TUN_HWADDR_DEST { 0x02, 0x00, 0x00, 0x00, 0x00, 0x01 }
> +#define TUN_IPADDR_SOURCE htonl((172 << 24) | (17 << 16) | 0)
> +#define TUN_IPADDR_DEST htonl((172 << 24) | (17 << 16) | 1)
> +
>  static int tun_attach(int fd, char *dev)
>  {
>         struct ifreq ifr;
> @@ -39,7 +56,7 @@ static int tun_detach(int fd, char *dev)
>         return ioctl(fd, TUNSETQUEUE, (void *) &ifr);
>  }
>
> -static int tun_alloc(char *dev)
> +static int tun_alloc(char *dev, short flags)
>  {
>         struct ifreq ifr;
>         int fd, err;
> @@ -52,7 +69,8 @@ static int tun_alloc(char *dev)
>
>         memset(&ifr, 0, sizeof(ifr));
>         strcpy(ifr.ifr_name, dev);
> -       ifr.ifr_flags = IFF_TAP | IFF_NAPI | IFF_MULTI_QUEUE;
> +       ifr.ifr_flags = flags | IFF_TAP | IFF_NAPI | IFF_NO_PI |
> +                       IFF_MULTI_QUEUE;
>
>         err = ioctl(fd, TUNSETIFF, (void *) &ifr);
>         if (err < 0) {
> @@ -64,6 +82,40 @@ static int tun_alloc(char *dev)
>         return fd;
>  }
>
> +static bool tun_add_to_bridge(int local_fd, const char *name)
> +{

I wonder if a packet socket is more convenient here.

Thanks