Re: [PATCH v3 04/15] efi_loader: device_path: add efi_dp_from_ipv4

Ilias Apalodimas
2024-11-13T10:19:37Z

On Mon, 11 Nov 2024 at 23:10, Adriano Cordova <adrianox@gmail.com> wrote:
>
> Add efi_dp_from_ipv4 to form a device path from an ipv4 address.
>
> Signed-off-by: Adriano Cordova <adrianox@gmail.com>
> ---
>
> Changes in v3:
> - Removed some unnecessary void* casts.
> - Changed sizeof(struct efi_device_path_ipv4) to sizeof(*ipv4dp)
> in efi_dp_from_ipv4.
>
> 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 ee387e1dfd..82a45da1fa 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(*ipv4dp);
> + 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;
> + if (ip)
> + memcpy(&ipv4dp->local_ip_address, (void *)&ip, 4);
> + if (mask)
> + memcpy(&ipv4dp->subnet_mask, (void *)&mask, 4);
> + if (srv)
> + memcpy(&ipv4dp->subnet_mask, (void *)&srv, 4);

The copies above seem wrong.
Isn't that supposed to be memcpy(&ipv4dp->local_ip_address, ip,
sizeof(*ip)); etc...

> + pos = (void *)((uintptr_t)ipv4dp + ipv4dp_len);
pos = (void *)(uintptr_t)ipv4dp+...

> + 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