Re: [PATCH] efinet: filter multicast traffic based on addresses

[Andrei Borzenkov]

17.11.2015 21:35, Josef Bacik пишет:
> We have some hardware that claims to support PROMISCUOUS_MULTICAST but doesn't
> actually work.  Instead utilize the multicast filters and specifically enable
> the multicast traffic we care about.  In reality we only care about ipv6
> multicast traffic but enable ipv4 multicast as well just in case.  Whenever we
> add a new address to the card we calculate the solicited node multicast address
> to the multicast filter.  With this patch my broken hardware is still broken but
> functional.  Thanks,
>
> Signed-off-by: Josef Bacik <address@hidden>
> ---
>   grub-core/net/drivers/efi/efinet.c | 84 ++++++++++++++++++++++++++++++++++----
>   grub-core/net/net.c                |  2 +
>   include/grub/net.h                 | 54 ++++++++++++------------
>   3 files changed, 105 insertions(+), 35 deletions(-)
>
> diff --git a/grub-core/net/drivers/efi/efinet.c 
> b/grub-core/net/drivers/efi/efinet.c
> index c8f80a1..bbbadd2 100644
> --- a/grub-core/net/drivers/efi/efinet.c
> +++ b/grub-core/net/drivers/efi/efinet.c
> @@ -23,6 +23,7 @@
>   #include <grub/efi/api.h>
>   #include <grub/efi/efi.h>
>   #include <grub/i18n.h>
> +#include <grub/net/ip.h>
>
>   GRUB_MOD_LICENSE ("GPLv3+");
>
> @@ -183,8 +184,9 @@ open_card (struct grub_net_card *dev)
>          We need unicast and broadcast and additionaly all nodes and
>          solicited multicast for IPv6. Solicited multicast is per-IPv6
>          address and we currently do not have API to do it so simply
> -        try to enable receive of all multicast packets or evertyhing in
> -        the worst case (i386 PXE driver always enables promiscuous too).
> +        enable the all node addresses and the link local address.  We do this
> +        because some firmware has been found to not do promiscuous multicast
> +        mode properly.
>
>          This does trust firmware to do what it claims to do.
>          */
> @@ -192,14 +194,25 @@ open_card (struct grub_net_card *dev)
>         {
>           grub_uint32_t filters = GRUB_EFI_SIMPLE_NETWORK_RECEIVE_UNICAST   |
>                                   GRUB_EFI_SIMPLE_NETWORK_RECEIVE_BROADCAST |
> -                                 
> GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST;
> +                                 GRUB_EFI_SIMPLE_NETWORK_RECEIVE_MULTICAST;
> +         grub_efi_status_t st;
> +         grub_efi_mac_address_t mac_filter[2] = {
> +                 { 0x1, 0, 0x5e, 0, 0, 1, },
> +                 { 0x33, 0x33, 0, 0, 0, 1, },};
>
>           filters &= net->mode->receive_filter_mask;
> -         if (!(filters & 
> GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST))
> -           filters |= (net->mode->receive_filter_mask &
> -                       GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS);
> -


could you do a favor and test whether enabling lone 
GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS (without any additional 
filters flags) works for you? I.e. just do

  efi_call_6 (net->receive_filters, net, 
GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS, 0, 0, 0, NULL);

It is possible that attempt to set promiscuous together with other 
filters does not work.

I still believe it is better workaround in general to avoid increasing 
complexity.