milliken@bbn.com (Walter Milliken) (09/22/90)
I've been attempting to do some work with IP messages under Mach 2.5, and run into a problem. While it is possible to receive a more-or-less reasonable IP header using read on a SOCK_RAW socket, there doesn't appear to be a way to hand the kernel a corresponding IP header via write. Note that what I want is to supply the header myself, not to have the kernel supply it for me (as it does with sendto on a SOCK_RAW socket). It appears that SunOS release 4.1 allows IP headers to be supplied by the user by using a protocol number of 0 when creating a raw IP socket. As far as I can tell, this feature doesn't exist in Mach. When I looked at the Mach 3.0 sources, all the raw IP output packets appear to be passed through rip_output, which insists on adding a header to the packet. The question is, am I overlooking something? (No, I already know about DLI, which doesn't work on the Sun ie device I'm using, anyway.) If not, it would be nice if the Sun raw socket extension could be added to the socket code in Mach 3.0 -- it doesn't seem like it ought to be hard to do. ---Walter