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

On Fri, 8 Nov 2024 at 15:39, 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

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