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 extended) 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 currently consists 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), hp300/intro(4), rbootd(8) An Introductory 4.4BSD Interprocess Communication Tutorial, Stuart Sechrest. (see /usr/share/doc/reference/ref3/sockets) Advanced 4.4BSD IPC Tutorial, Samuel J. Leffler, Robert S. Fabry, William N. Joy, Phil Lapsley, Steve Miller, Chris Torek. (see /usr/share/doc/reference/ref3/sockets-advanced)

HISTORY
The rmp protocol interface

BUGS

•   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.

•   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 mechanism for doing so should be provided.

•   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.

•   There is no support for bind(2)'ing an address in the RMP domain. Something like an RMPADDR_ANY should be provided to prevent more than one rbootd(8) server from running at the same time.