[PATCH v4 03/14] efi_loader: device_path: add efi_dp_from_ipv4

[Adriano Cordova]

Add efi_dp_from_ipv4 to form a device path from an ipv4 address.

Signed-off-by: Adriano Cordova <adrianox at gmail.com>
---

Changes in v4:
- Fixed memcpy mistake

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..cdeea4791f 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, ip, sizeof(*ip));
+	if (mask)
+		memcpy(&ipv4dp->subnet_mask, mask, sizeof(*mask));
+	if (srv)
+		memcpy(&ipv4dp->remote_ip_address, srv, sizeof(*srv));
+	pos = (void *)(uintptr_t)ipv4dp + ipv4dp_len;
+	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