uefi: SNP transmit: demystify parameters

Author: phip1611

uefi/src/proto/network/snp.rs

@@ -213,13 +213,30 @@ impl SimpleNetwork {
         status.to_result_with_val(|| NonNull::new(tx_buf.cast()))
     }
 
-    /// Place a packet in the transmit queue of a network interface.
+    /// Place a packet in the transmit queue of the network interface.
+    ///
+    /// This depends on the type of network interface. Typically, this takes
+    /// ethernet frames and send them over the ethernet network interface.
+    ///
+    /// The header of the packet is filled by the function with the given
+    /// parameters, but the buffer must contain the space for this header.
+    ///
+    /// # Arguments
+    /// - `header_size`: The size in bytes of the media header to be filled by
+    ///   the transmit() function.
+    /// - `buffer`: The buffer containing the whole network packet with all
+    ///   its payload including the header for the medium.
+    /// - `src_addr`: The optional source address.
+    /// - `dst_addr`: The optional destination address.
+    /// - `protocol`: Ether Type as of RFC 3232. See
+    ///   https://www.iana.org/assignments/ieee-802-numbers/ieee-802-numbers.xhtml#ieee-802-numbers-1
+    ///   for examples. Typically, this is `0x0800` (IPv4).
     pub fn transmit(
         &self,
         header_size: usize,
         buffer: &[u8],
         src_addr: Option<MacAddress>,
-        dest_addr: Option<MacAddress>,
+        dst_addr: Option<MacAddress>,
         protocol: Option<u16>,
     ) -> Result {
         (self.transmit)(
@@ -228,7 +245,7 @@ impl SimpleNetwork {
             buffer.len(),
             buffer.as_ptr().cast(),
             src_addr.as_ref(),
-            dest_addr.as_ref(),
+            dst_addr.as_ref(),
             protocol.as_ref(),
         )
         .to_result()