RMP(4)                OpenBSD Programmer's Manual (HP300)               RMP(4)

NAME
     rmp - HP Remote Maintenance Protocol Family

SYNOPSIS
     options RMP
     #include <sys/types.h>
     #include <sys/socket.h>
     #include <netrmp/rmp.h>
     #include <netrmp/rmp_var.h>

     int
     socket(AF_RMP, SOCK_RAW, proto);

DESCRIPTION
     Hewlett-Packard's Remote Maintenance Protocol family is a collection of
     protocols layered atop IEEE 802.3. The current implementation of the RMP
     family provides protocol support only for the SOCK_RAW socket type.  As a
     result, sendto(2) and recvfrom(2) must be used to send and receive RMP
     packets.

     The format of an RMP packet is defined in the include file
     <netrmp/rmp_var.h>. The RMP packet arrives encapsulated in an (HP extend-
     ed) IEEE 802.2 packet.  The IEEE 802.2 packet is preceded by the kernel
     address of an ifnet struct which is used to `route' a packet out the same
     interface it arrived on.  Outgoing packets are encapsulated in a standard
     IEEE 802.3 packet, while incoming packets have this information stripped
     away.

ADDRESSING
     RMP (IEEE 802.3) addresses are 6 octets in length (48 bytes).  Sockets in
     the Remote Maintenance Protocol family use the following addressing
     structure:

           struct sockaddr_rmp {
                   short           srmp_family;
                   u_char          srmp_dhost[6];
           };

PROTOCOLS
     The RMP protocol family supported by the operating system is currently
     comprised of the Boot Protocol (proto=RMPPROTO_BOOT). Unfortunately, we
     have no documentation on the Remote Maintenance Protocol and only sketchy
     information about the Boot Protocol.

SEE ALSO
     bind(2), recvfrom(2), sendto(2), socket(2), intro(4), rbootd(8)

     An Advanced 4.3 BSD Interprocess Communication Tutorial.

HISTORY
     The rmp protocol interface currently under development.

BUGS
     o   The HP ROM uses IEEE 802.3 (as opposed to Ethernet) packets.  While
         the kernel heuristically recognizes these packets, a more general
         mechanism for doing so should be provided.

     o   The HP ROM uses a multicast address when first trying to locate boot
         servers.  While the Ethernet [sic] board is programmed to recognize
         this particular multicast address (9:0:9:0:0:4), a more general mech-
         anism for doing so should be provided.

     o   The kernel supports only RAW sockets for the RMP protocol.  This is
         either a bug or a feature, since the kernel is smaller at the price
         of greater complexity in the server.

     o   There is no support for bind'ing an address in the RMP domain.  Some-
         thing like an RMPADDR_ANY should be provided to prevent more than one
         rbootd server from running at the same time.

OpenBSD 2.8                     March 27, 1991                               2
