[PATCH v2 04/15] efi_loader: device_path: add efi_dp_from_ipv4

[Ilias Apalodimas]

On Fri, 8 Nov 2024 at 15:39, Adriano Cordova <adrianox at gmail.com> wrote:
>
> Add efi_dp_from_ipv4 to form a device path from an ipv4 address.
>
> Signed-off-by: Adriano Cordova <adrianox at gmail.com>
> ---
>  lib/efi_loader/efi_device_path.c | 38 ++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
>
> diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
> index d7444588aa..3e02341224 100644
> --- a/lib/efi_loader/efi_device_path.c
> +++ b/lib/efi_loader/efi_device_path.c
> @@ -974,6 +974,44 @@ struct efi_device_path __maybe_unused *efi_dp_from_eth(void)
>         return start;
>  }
>
> +struct efi_device_path *efi_dp_from_ipv4(struct efi_ipv4_address *ip,
> +                                        struct efi_ipv4_address *mask,
> +                                        struct efi_ipv4_address *srv)
> +{
> +       struct efi_device_path *dp1, *dp2;
> +       efi_uintn_t ipv4dp_len;
> +       struct efi_device_path_ipv4 *ipv4dp;
> +       char *pos;
> +
> +       ipv4dp_len = sizeof(struct efi_device_path_ipv4);

sizeof(*ipv4dp) is usually preferred here

> +       ipv4dp = efi_alloc(ipv4dp_len + sizeof(END));
> +       if (!ipv4dp) {
> +               log_err("Out of memory\n");
> +               return NULL;
> +       }
> +
> +       ipv4dp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
> +       ipv4dp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_IPV4;
> +       ipv4dp->dp.length = ipv4dp_len;
> +       ipv4dp->protocol = 6;

is this 4 or 6?

> +       if (ip)
> +               memcpy((void *)&ipv4dp->local_ip_address, (void *)&ip, 4);
> +       if (mask)
> +               memcpy((void *)&ipv4dp->subnet_mask, (void *)&mask, 4);
> +       if (srv)
> +               memcpy((void *)&ipv4dp->subnet_mask, (void *)&srv, 4);

You can skip the void casts

> +       pos = (char *)ipv4dp + ipv4dp_len;

That's ok, but we tend to do (void *)((uintptr_t) casts nowadays

> +       memcpy(pos, &END, sizeof(END));
> +
> +       dp1 = efi_dp_from_eth();
> +       dp2 = efi_dp_concat(dp1, (const struct efi_device_path *)ipv4dp, 0);
> +
> +       efi_free_pool(ipv4dp);
> +       efi_free_pool(dp1);
> +
> +       return dp2;
> +}
> +
>  /* Construct a device-path for memory-mapped image */
>  struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
>                                         uint64_t start_address,
> --
> 2.43.0
>

Thanks
/Ilias