Minor corrections

src/net/ipv4.c

 	pshdr.dest = iphdr->dest;
 	pshdr.zero_padding = 0x00;
 	pshdr.protocol = iphdr->protocol;
+	/* This is only valid when IPv4 does not have options */
 	pshdr.len = htons ( pkb_len ( pkb ) - sizeof ( *iphdr ) );
 
 	/* Update the checksum value */

src/net/tcp.c

 	tcphdr->win = htons ( conn->rcv_win );
 	/* Set urgent pointer to 0 */
 	tcphdr->urg = 0;
-	/* Calculate and store partial checksum, in network byte order */
+	/* Calculate and store partial checksum, in host byte order */
 	tcphdr->csum = 0;
 	tcphdr->csum = tcpip_chksum ( pkb->data, pkb_len ( pkb ) );