if_imp.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)if_imp.c	4.1.1.1	(ULTRIX)	1/15/88";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1985 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/************************************************************************
 *			Modification History				*
 *									*
 *	Larry Cohen  -	09/16/85					*
 * 		Add 43bsd alpha tape changes for subnet routing		*
 *									*
 ************************************************************************/

/*
 * Copyright (c) 1982 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	@(#)if_imp.c	6.6 (Berkeley) 6/8/85
 */

#include "imp.h"
#if NIMP > 0
/*
 * ARPANET IMP interface driver.
 *
 * The IMP-host protocol is handled here, leaving
 * hardware specifics to the lower level interface driver.
 */
#include "../machine/pte.h"

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/mbuf.h"
#include "../h/buf.h"
#include "../h/protosw.h"
#include "../h/socket.h"
#include "../h/vmmac.h"
#include "../h/time.h"
#include "../h/kernel.h"
#include "../h/errno.h"
#include "../h/ioctl.h"

#include "../machine/cpu.h"
#ifdef vax
#include "../machine/mtpr.h"
#include "../io/uba/ubareg.h"
#include "../io/uba/ubavar.h"
#endif vax

#include "../net/if.h"
#include "../net/route.h"

#include "../net/netisr.h"
#include "../netinet/in.h"
#include "../netinet/in_systm.h"
#include "../netinet/in_var.h"
#include "../netinet/ip.h"
#include "../netinet/ip_var.h"
/* define IMPLEADERS here to get leader printing code */
#include "../netimp/if_imp.h"
#include "../netimp/if_imphost.h"

/*
 * IMP software status per interface.
 * (partially shared with the hardware specific module)
 *
 * Each interface is referenced by a network interface structure,
 * imp_if, which the routing code uses to locate the interface.
 * This structure contains the output queue for the interface, its
 * address, ...  IMP specific structures used in connecting the
 * IMP software modules to the hardware specific interface routines
 * are stored here.  The common structures are made visible to the
 * interface driver by passing a pointer to the hardware routine
 * at "attach" time.
 *
 * NOTE: imp_if and imp_cb are assumed adjacent in hardware code.
 */
struct imp_softc {
	struct	ifnet imp_if;		/* network visible interface */
	struct	impcb imp_cb;		/* hooks to hardware module */
	u_char	imp_state;		/* current state of IMP */
	char	imp_dropcnt;		/* used during initialization */
} imp_softc[NIMP];

/*
 * Messages from IMP regarding why
 * it's going down.
 */
static char *impmessage[] = {
	"in 30 seconds",
	"for hardware PM",
	"to reload software",
	"for emergency reset"
};

#define HOSTDEADTIMER	10		/* How long to wait when down */

int	impdown(), impinit(), impioctl(), impoutput();

/*
 * IMP attach routine.  Called from hardware device attach routine
 * at configuration time with a pointer to the UNIBUS device structure.
 * Sets up local state and returns pointer to base of ifnet+impcb
 * structures.  This is then used by the device's attach routine
 * set up its back pointers. 
 */
impattach(ui, reset)
	struct uba_device *ui;
	int (*reset)();
{
	struct imp_softc *sc = &imp_softc[ui->ui_unit];
	register struct ifnet *ifp = &sc->imp_if;

	/* UNIT COULD BE AMBIGUOUS */
	ifp->if_unit = ui->ui_unit;
	ifp->if_name = "imp";
	ifp->if_mtu = IMPMTU - sizeof(struct imp_leader);
	ifp->if_reset = reset;
	ifp->if_init = impinit;
	ifp->if_ioctl = impioctl;
	ifp->if_output = impoutput;
	/* reset is handled at the hardware level */
	if_attach(ifp);
	return ((int)&sc->imp_if);
}

/*
 * IMP initialization routine: call hardware module to
 * setup UNIBUS resources, init state and get ready for
 * NOOPs the IMP should send us, and that we want to drop.
 */
impinit(unit)
	int unit;
{
	int s = splimp();
	register struct imp_softc *sc = &imp_softc[unit];

	if (sc->imp_if.if_addrlist == 0)
		return;
	if ((*sc->imp_cb.ic_init)(unit) == 0) {
		sc->imp_state = IMPS_DOWN;
		sc->imp_if.if_flags &= ~IFF_UP;
		splx(s);
		return;
	}
	sc->imp_state = IMPS_INIT;
	impnoops(sc);
	splx(s);
}

struct sockproto impproto = { PF_IMPLINK };
struct sockaddr_in impdst = { AF_IMPLINK };
struct sockaddr_in impsrc = { AF_IMPLINK };
#ifdef IMPLEADERS
int	impprintfs = 0;
#endif

/*
 * ARPAnet 1822 input routine.
 * Called from hardware input interrupt routine to handle 1822
 * IMP-host messages.  Type 0 messages (non-control) are
 * passed to higher level protocol processors on the basis
 * of link number.  Other type messages (control) are handled here.
 */
impinput(unit, m)
	int unit;
	register struct mbuf *m;
{
	register struct imp_leader *ip;
	register struct imp_softc *sc = &imp_softc[unit];
	register struct host *hp;
	register struct ifqueue *inq;
	struct control_leader *cp;
	struct in_addr addr;
	struct mbuf *next;
	struct sockaddr_in *sin;

	/* verify leader length. */
	if (m->m_len < sizeof(struct control_leader) &&
	    (m = m_pullup(m, sizeof(struct control_leader))) == 0)
		return;
	cp = mtod(m, struct control_leader *);
	if (cp->dl_mtype == IMPTYPE_DATA)
		if (m->m_len < sizeof(struct imp_leader) &&
		    (m = m_pullup(m, sizeof(struct imp_leader))) == 0)
			return;
	ip = mtod(m, struct imp_leader *);
#ifdef IMPLEADERS
	if (impprintfs)
		printleader("impinput", ip);
#endif

	/* check leader type */
	if (ip->il_format != IMP_NFF) {
		sc->imp_if.if_collisions++;	/* XXX */
		goto drop;
	}

	if (ip->il_mtype != IMPTYPE_DATA) {
		/* If not data packet, build IP addr from leader (BRL) */
		imp_leader_to_addr(&addr, ip, &sc->imp_if);
	}
	switch (ip->il_mtype) {

	case IMPTYPE_DATA:
		break;

	/*
	 * IMP leader error.  Reset the IMP and discard the packet.
	 */
	case IMPTYPE_BADLEADER:
		/*
		 * According to 1822 document, this message
		 * will be generated in response to the
		 * first noop sent to the IMP after
		 * the host resets the IMP interface.
		 */
		if (sc->imp_state != IMPS_INIT) {
			impmsg(sc, "leader error");
			hostreset(((struct in_ifaddr *)&sc->imp_if.if_addrlist)->ia_net);
			impnoops(sc);
		}
		goto drop;

	/*
	 * IMP going down.  Print message, and if not immediate,
	 * set off a timer to insure things will be reset at the
	 * appropriate time.
	 */
	case IMPTYPE_DOWN:
		if (sc->imp_state < IMPS_INIT)
			goto drop;
		if ((ip->il_link & IMP_DMASK) == 0) {
			sc->imp_state = IMPS_GOINGDOWN;
			timeout(impdown, (caddr_t)sc, 30 * hz);
		}
		impmsg(sc, "going down %s",
			(u_int)impmessage[ip->il_link&IMP_DMASK]);
		goto drop;

	/*
	 * A NOP usually seen during the initialization sequence.
	 * Compare the local address with that in the message.
	 * Reset the local address notion if it doesn't match.
	 */
	case IMPTYPE_NOOP:
		if (sc->imp_state == IMPS_DOWN) {
			sc->imp_state = IMPS_INIT;
			sc->imp_dropcnt = IMP_DROPCNT;
		}
		if (sc->imp_state == IMPS_INIT && --sc->imp_dropcnt > 0)
			goto drop;
		sin = (struct sockaddr_in *)&sc->imp_if.if_addrlist->ifa_addr;
		if (ip->il_imp != 0) {	/* BRL */
			struct in_addr leader_addr;
			imp_leader_to_addr(&leader_addr, ip, &sc->imp_if);
			if (sin->sin_addr.s_addr != leader_addr.s_addr) {
				impmsg(sc, "address reset to x%x (%d/%d)",
					htonl(leader_addr.s_addr),
					(u_int)ip->il_host,
					htons(ip->il_imp));
				sin->sin_addr.s_addr = leader_addr.s_addr;
			}
		}
		sc->imp_state = IMPS_UP;
		sc->imp_if.if_flags |= IFF_UP;
		goto drop;

	/*
	 * RFNM or INCOMPLETE message, send next
	 * message on the q.  We could pass incomplete's
	 * up to the next level, but this currently isn't
	 * needed.
	 */
	case IMPTYPE_RFNM:
	case IMPTYPE_INCOMPLETE:
		if (hp = hostlookup(addr)) {
			if (hp->h_rfnm == 0)
				hp->h_flags &= ~HF_INUSE;
			else if (next = hostdeque(hp))
				(void) impsnd(&sc->imp_if, next);
		}
		goto drop;

	/*
	 * Host or IMP can't be reached.  Flush any packets
	 * awaiting transmission and release the host structure.
	 */
	case IMPTYPE_HOSTDEAD:
	case IMPTYPE_HOSTUNREACH:
		impnotify((int)ip->il_mtype, (struct control_leader *)ip,
		    hostlookup(addr), &sc->imp_if);
		goto rawlinkin;

	/*
	 * Error in data.  Clear RFNM status for this host and send
	 * noops to the IMP to clear the interface.
	 */
	case IMPTYPE_BADDATA:
		impmsg(sc, "data error");
		if (hp = hostlookup(addr))
			hp->h_rfnm = 0;
		impnoops(sc);
		goto drop;

	/*
	 * Interface reset.
	 */
	case IMPTYPE_RESET:
		impmsg(sc, "interface reset");
		/* clear RFNM counts */
		hostreset(((struct in_ifaddr *)&sc->imp_if.if_addrlist)->ia_net);
		impnoops(sc);
		goto drop;

	default:
		sc->imp_if.if_collisions++;		/* XXX */
		goto drop;
	}

	/*
	 * Data for a protocol.  Dispatch to the appropriate
	 * protocol routine (running at software interrupt).
	 * If this isn't a raw interface, advance pointer
	 * into mbuf past leader.
	 */
	switch (ip->il_link) {

#ifdef INET
	case IMPLINK_IP:
		m->m_len -= sizeof(struct imp_leader);
		m->m_off += sizeof(struct imp_leader);
		schednetisr(NETISR_IP);
		inq = &ipintrq;
		break;
#endif

	default:
	rawlinkin:
		impproto.sp_protocol = ip->il_link;
		sin = (struct sockaddr_in *)&sc->imp_if.if_addrlist->ifa_addr;
		impdst.sin_addr = sin->sin_addr;
		imp_leader_to_addr(&impsrc.sin_addr, ip, &sc->imp_if);
		raw_input(m, &impproto, (struct sockaddr *)&impsrc,
		  (struct sockaddr *)&impdst);
		return;
	}
	if (IF_QFULL(inq)) {