Re: [PATCH v3] net: remove an assert call in eth_get_gso_type

[Jason Wang]

On 2020/10/21 下午2:05, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
>
> eth_get_gso_type() routine returns segmentation offload type based on
> L3 protocol type. It calls g_assert_not_reached if L3 protocol is
> unknown, making the following return statement unreachable. Remove the
> g_assert call, it maybe triggered by a guest user.
>
> Reported-by: Gaoning Pan <pgn@zju.edu.cn>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
>   net/eth.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
>
> Update v3: use LOG_GUEST_ERROR mask and %0x04PRIx16 conversion.
>    -> https://lists.nongnu.org/archive/html/qemu-devel/2020-10/msg05759.html
>    -> https://lists.nongnu.org/archive/html/qemu-devel/2020-10/msg05752.html
>
> diff --git a/net/eth.c b/net/eth.c
> index 0c1d413ee2..eee77071f9 100644
> --- a/net/eth.c
> +++ b/net/eth.c
> @@ -16,6 +16,7 @@
>    */
>
>   #include "qemu/osdep.h"
> +#include "qemu/log.h"
>   #include "net/eth.h"
>   #include "net/checksum.h"
>   #include "net/tap.h"
> @@ -71,9 +72,8 @@ eth_get_gso_type(uint16_t l3_proto, uint8_t *l3_hdr, uint8_t 
> l4proto)
>               return VIRTIO_NET_HDR_GSO_TCPV6 | ecn_state;
>           }
>       }
> -
> -    /* Unsupported offload */
> -    g_assert_not_reached();
> +    qemu_log_mask(LOG_GUEST_ERROR, "%s: probably not GSO frame, "
> +        "unknown L3 protocol: 0x%04"PRIx16"\n", __func__, l3_proto);
>
>       return VIRTIO_NET_HDR_GSO_NONE | ecn_state;
>   }
> --
> 2.26.2


Hi Prasad:

If I understand the code correctly. It should not be a guest error, 
since guest is allowed to send a packet other than IPV4(6).

Thanks


>