The definitions are in the file STRUCTS.FTH.
You will find the books TCP/IP Illustrated, Volumes 1 and 2 useful when exploring the PowerNet data structures.
These structures are used in almost all systems.
STRUCT ether_hdr \ -- size ; of ether_hdr structure
Ethernet header. The fields have the prefix "ETHER_".
STRUCT arp_hdr \ -- size ; of arp_hdr structure
ARP header. The fields have the prefix "AR_".
STRUCT arp_ip_data \ -- size ; of arp_ip_data structure
ARP data.
STRUCT icmp_hdr \ -- size ; of icmp header structure
ICMP header structure. The fields have the prefix "ICMP_".
STRUCT ip_hdr \ -- size
IP header structure. The fields have the prefix "IP_".
STRUCT udp_hdr \ -- size ; of udp header structure
UDP header structure. The fields have the prefix "UH_".
STRUCT (socket) \ -- size ; of (socket) structure
The main socket structure. The fields have the prefix "SO_".
STRUCT tcpcb \ -- size
TCP control block structure. Notes:
STRUCT port_struct \ -- size ; of structure
Port control data. The fields have the prefix "PORT_".
Unused by systems with only a single port.
STRUCT iproute_struct \ -- size ; of structure
Routing table entry. The fields have the prefix "IPROUTE_".
The entries are added to when a new IP address is received.
PSIZE ether_hdr - ip_hdr - udp_hdr - equ PDATA_MAX
The size of the largest data block.
STRUCT SOCKADDR_IN \ -- size
Used to hold socket family (always AF_INET), port
number and IP address. The fields have the prefix "SIN_".
STRUCT TAGLIST_ENTRY \ -- size
SNMP Tx/Rx taglist entry definition.
The fields have the prefix "SNMP_".