it deals with ip options (see rfc's 791 and 1122).
ip_options_build is called while putting together the headers, but
prior to checksumming from numerous places in net/ipv4/ip_output.c.
ip_options_fragment does special handling for options in fragmented
datagrams (again, ip_output.c).
ip_options_echo is used to setup the options used in a reply; see
net/ipv4/icmp.c et al.
ip_options_compile and ip_options_get both seem to be used to extract raw
options from an skb.
ip_options_forward handles setting up source-routed packets, while
ip_options_rcv_srr handles their receipt.
i am by not any mean at all an authority on these matters, so take this with
a grain of salt :).
-- nicholas black (dank@trellisinc.com) "c has types for a reason. c++ improved the type system for a reason. perl and php programs have run-time failures for a reason." - lkml - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/