IPv4 header

The macro IP_HDR builds an IPv4 header, as defined in [RFC791]. The macro IP_PCK is synonymous to IP_HDR, except that it also sets the protocol to ETH_P_IP with ``default'' priority.

$$\begin{tabular}{\vert cccccccccccccccccccccccccccccccc\vert}... ...{\vert c\vert}{{\bf global} 10.0.0.2} \\ \hline \end{tabular}$$

Note that $ip_src and $ip_dst are of type ``IPv4 address''.

The following flags are used for handling IP fragments:

$$\begin{tabular}{\vert c\vert c\vert c\vert} \multicolumn{1}... ...p\_DF} & {\tt\$ip\_MF} \\ 0 & 0 & 0 \\ \hline \end{tabular}$$

Example:

$ip_dst = 1.2.3.4

send IP_PCK($ip_tos=0xe0 $ip_proto=46)
  /* pretend this is RSVP */