if_ppp.c

基于组件方式开发操作系统的OSKIT源代码

ppp_btom(sc)
    struct ppp_softc *sc;
{
    register struct mbuf *m, **mp;
    struct mbuf *top = sc->sc_m;

    /*
     * First check current mbuf.  If we have more than a small mbuf,
     * return the whole cluster and set beginning of buffer to the
     * next mbuf.
     * Else, copy the current bytes into a small mbuf, attach the new
     * mbuf to the end of the chain and set beginning of buffer to the
     * current mbuf.
     */

    if (sc->sc_mc->m_len > MHLEN) {
	sc->sc_m = sc->sc_mc->m_next;
	sc->sc_mc->m_next = NULL;
    }
    else {
	/* rather than waste a whole cluster on <= MHLEN bytes,
	   alloc a small mbuf and copy to it */
	MGETHDR(m, M_DONTWAIT, MT_DATA);
	if (m == NULL)
	    return (NULL);

	bcopy(mtod(sc->sc_mc, caddr_t), mtod(m, caddr_t), sc->sc_mc->m_len);
	m->m_len = sc->sc_mc->m_len;
	for (mp = &top; *mp != sc->sc_mc; mp = &(*mp)->m_next)
	    ;
	*mp = m;
	sc->sc_m = sc->sc_mc;
    }

    /*
     * Try to allocate enough extra mbufs to handle the next packet.
     */
    if (pppgetm(sc) == 0) {
	m_freem(top);
	if (pppgetm(sc) == 0)
	{
	    sc->sc_if.if_flags &= ~IFF_UP;
	    microtime(&sc->sc_if.if_lastchange);
	}
	return (NULL);
    }

    return (top);
}

/*
 * PPP packet input routine.
 * The caller has checked and removed the FCS.
 * The return value is 1 if the packet was put on sc->sc_inq,
 * 0 otherwise.
 */
#define COMPTYPE(proto)	((proto) == PPP_VJC_COMP? TYPE_COMPRESSED_TCP: \
			 TYPE_UNCOMPRESSED_TCP)

int
ppppktin(sc, m, ilen)
    struct ppp_softc *sc;
    struct mbuf *m;
    int ilen;
{
    struct ifqueue *inq;
    int s, xlen, proto, rv;
    struct ppp_header hdr;

    sc->sc_if.if_ipackets++;
    rv = 0;

    hdr = *mtod(m, struct ppp_header *);
    proto = ntohs(hdr.ph_protocol);

#ifdef VJC
    /*
     * See if we have a VJ-compressed packet to uncompress.
     */
    if (proto == PPP_VJC_COMP || proto == PPP_VJC_UNCOMP) {
	char *pkttype = proto == PPP_VJC_COMP? "": "un";

	if (sc->sc_flags & SC_REJ_COMP_TCP) {
	    if (sc->sc_flags & SC_DEBUG)
		printf("ppp%d: %scomp pkt w/o compression; flags 0x%x\n",
			sc->sc_if.if_unit, pkttype, sc->sc_flags);
	    sc->sc_if.if_ierrors++;
	    return 0;
	}

	m->m_data += PPP_HDRLEN;
	m->m_len -= PPP_HDRLEN;
	ilen -= PPP_HDRLEN;
	xlen = sl_uncompress_tcp_part((u_char **)(&m->m_data),
					m->m_len, ilen,
					COMPTYPE(proto), &sc->sc_comp);

	if (xlen == 0) {
	    if (sc->sc_flags & SC_DEBUG)
		printf("ppp%d: sl_uncompress failed on type %scomp\n",
			sc->sc_if.if_unit, pkttype);
	    sc->sc_if.if_ierrors++;
	    return 0;
	}

	/* adjust the first mbuf by the decompressed amt */
	xlen += PPP_HDRLEN;
	m->m_len += xlen - ilen;
	ilen = xlen;
	m->m_data -= PPP_HDRLEN;
	proto = PPP_IP;

	/* put the ppp header back in place */
	hdr.ph_protocol = htons(PPP_IP);
	*mtod(m, struct ppp_header *) = hdr;
    }
#endif /* VJC */

    /* get this packet as an mbuf chain */
    if ((m = ppp_btom(sc)) == NULL) {
	sc->sc_if.if_ierrors++;
	return 0;
    }
    m->m_pkthdr.len = ilen;
    m->m_pkthdr.rcvif = &sc->sc_if;

#if NBPFILTER > 0
    /* See if bpf wants to look at the packet. */
    if (sc->sc_bpf)
	bpf_mtap(sc->sc_bpf, m);
#endif

    switch (proto) {
#ifdef INET
    case PPP_IP:
	/*
	 * IP packet - take off the ppp header and pass it up to IP.
	 */
	if ((sc->sc_if.if_flags & IFF_UP) == 0
	    || (sc->sc_flags & SC_ENABLE_IP) == 0) {
	    /* interface is down - drop the packet. */
	    m_freem(m);
	    return 0;
	}
	m->m_pkthdr.len -= PPP_HDRLEN;
	m->m_data += PPP_HDRLEN;
	m->m_len -= PPP_HDRLEN;
	schednetisr(NETISR_IP);
	inq = &ipintrq;
	break;
#endif

    default:
	/*
	 * Some other protocol - place on input queue for read().
	 */
	inq = &sc->sc_inq;
	rv = 1;
	break;
    }

    /*
     * Put the packet on the appropriate input queue.
     */
    s = splimp();
    if (IF_QFULL(inq)) {
	IF_DROP(inq);
	if (sc->sc_flags & SC_DEBUG)
	    printf("ppp%d: queue full\n", sc->sc_if.if_unit);
	sc->sc_if.if_ierrors++;
	sc->sc_if.if_iqdrops++;
	m_freem(m);
	rv = 0;
    } else
	IF_ENQUEUE(inq, m);

    splx(s);
    return rv;
}

/*
 * tty interface receiver interrupt.
 */
static unsigned paritytab[8] = {
    0x96696996, 0x69969669, 0x69969669, 0x96696996,
    0x69969669, 0x96696996, 0x96696996, 0x69969669
};

int
pppinput(c, tp)
    int c;
    register struct tty *tp;
{
    register struct ppp_softc *sc;
    struct mbuf *m;
    int ilen;

    tk_nin++;
    sc = (struct ppp_softc *) tp->t_sc;
    if (sc == NULL || tp != (struct tty *) sc->sc_devp)
	return 0;

    ++sc->sc_bytesrcvd;

    if ((tp->t_state & TS_CONNECTED) == 0) {
	if (sc->sc_flags & SC_DEBUG)
	    printf("ppp%d: no carrier\n", sc->sc_if.if_unit);
	goto flush;
    }
    if (c & TTY_ERRORMASK) {
	if (sc->sc_flags & SC_DEBUG)
	    printf("ppp%d: line error %x\n", sc->sc_if.if_unit, c & TTY_ERRORMASK);
	goto flush;
    }

    c &= TTY_CHARMASK;

    if (c & 0x80)
	sc->sc_flags |= SC_RCV_B7_1;
    else
	sc->sc_flags |= SC_RCV_B7_0;
    if (paritytab[c >> 5] & (1 << (c & 0x1F)))
	sc->sc_flags |= SC_RCV_ODDP;
    else
	sc->sc_flags |= SC_RCV_EVNP;

    if (sc->sc_flags & SC_LOG_RAWIN)
	ppplogchar(sc, c);

    if (c == PPP_FLAG) {
	ilen = sc->sc_ilen;
	sc->sc_ilen = 0;
	sc->sc_if.if_ibytes = sc->sc_bytesrcvd;

	if (sc->sc_rawin_count > 0)
	    ppplogchar(sc, -1);

	/*
	 * If SC_ESCAPED is set, then we've seen the packet
	 * abort sequence "}~".
	 */
	if (sc->sc_flags & (SC_FLUSH | SC_ESCAPED)
	    || ilen > 0 && sc->sc_fcs != PPP_GOODFCS) {
#ifdef VJC
	    /*
	     * If we've missed a packet, we must toss subsequent compressed
	     * packets which don't have an explicit connection ID.
	     */
	    sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &sc->sc_comp);
#endif
	    if ((sc->sc_flags & (SC_FLUSH | SC_ESCAPED)) == 0){
		if (sc->sc_flags & SC_DEBUG)
		    printf("ppp%d: bad fcs\n", sc->sc_if.if_unit);
		sc->sc_if.if_ierrors++;
	    } else
		sc->sc_flags &= ~(SC_FLUSH | SC_ESCAPED);
	    return 0;
	}

	if (ilen < PPP_HDRLEN + PPP_FCSLEN) {
	    if (ilen) {
		if (sc->sc_flags & SC_DEBUG)
		    printf("ppp%d: too short (%d)\n", sc->sc_if.if_unit, ilen);
		sc->sc_if.if_ierrors++;
	    }
	    return 0;
	}

	/*
	 * Remove FCS trailer.  Somewhat painful...
	 */
	ilen -= 2;
	if (--sc->sc_mc->m_len == 0) {
	    for (m = sc->sc_m; m->m_next != sc->sc_mc; m = m->m_next)
		;
	    sc->sc_mc = m;
	}
	sc->sc_mc->m_len--;

	m = sc->sc_m;

	if (sc->sc_flags & SC_LOG_INPKT) {
	    printf("ppp%d: got %d bytes\n", sc->sc_if.if_unit, ilen);
	    pppdumpm(m, ilen);
	}

	if (ppppktin(sc, m, ilen)) {
	    /* Put a placeholder byte in canq for ttselect()/ttnread(). */
	    putc(0, &tp->t_canq);
	    ttwakeup(tp);
	}
	return 0;
    }

    if (sc->sc_flags & SC_FLUSH) {
	if (sc->sc_flags & SC_LOG_FLUSH)
	    ppplogchar(sc, c);
	return 0;
    }

    if (c < 0x20 && (sc->sc_rasyncmap & (1 << c)))
	return 0;

    if (sc->sc_flags & SC_ESCAPED) {
	sc->sc_flags &= ~SC_ESCAPED;
	c ^= PPP_TRANS;
    } else if (c == PPP_ESCAPE) {
	sc->sc_flags |= SC_ESCAPED;
	return 0;
    }

    /*
     * Initialize buffer on first octet received.
     * First octet could be address or protocol (when compressing
     * address/control).
     * Second octet is control.
     * Third octet is first or second (when compressing protocol)
     * octet of protocol.
     * Fourth octet is second octet of protocol.
     */
    if (sc->sc_ilen == 0) {
	/* reset the first input mbuf */
	m = sc->sc_m;
	m->m_len = 0;
	m->m_data = M_DATASTART(sc->sc_m) + HDROFF;
	sc->sc_mc = m;
	sc->sc_mp = mtod(m, char *);
	sc->sc_fcs = PPP_INITFCS;
	if (c != PPP_ALLSTATIONS) {
	    if (sc->sc_flags & SC_REJ_COMP_AC) {
		if (sc->sc_flags & SC_DEBUG)
		    printf("ppp%d: garbage received: 0x%x (need 0xFF)\n",
			   sc->sc_if.if_unit, c);
		goto flush;
	    }
	    *sc->sc_mp++ = PPP_ALLSTATIONS;
	    *sc->sc_mp++ = PPP_UI;
	    sc->sc_ilen += 2;
	    m->m_len += 2;
	}
    }
    if (sc->sc_ilen == 1 && c != PPP_UI) {
	if (sc->sc_flags & SC_DEBUG)
	    printf("ppp%d: missing UI (0x3), got 0x%x\n",
		   sc->sc_if.if_unit, c);
	goto flush;
    }
    if (sc->sc_ilen == 2 && (c & 1) == 1) {
	/* a compressed protocol */
	*sc->sc_mp++ = 0;
	sc->sc_ilen++;
	sc->sc_mc->m_len++;
    }
    if (sc->sc_ilen == 3 && (c & 1) == 0) {
	if (sc->sc_flags & SC_DEBUG)
	    printf("ppp%d: bad protocol %x\n", sc->sc_if.if_unit,
		   (sc->sc_mp[-1] << 8) + c);
	goto flush;
    }

    /* packet beyond configured mru? */
    if (++sc->sc_ilen > sc->sc_mru + PPP_HDRLEN + PPP_FCSLEN) {
	if (sc->sc_flags & SC_DEBUG)
	    printf("ppp%d: packet too big\n", sc->sc_if.if_unit);
	goto flush;
    }

    /* is this mbuf full? */
    m = sc->sc_mc;
    if (M_TRAILINGSPACE(m) <= 0) {
	sc->sc_mc = m = m->m_next;
	if (m == NULL) {
	    printf("ppp%d: too few input mbufs!\n", sc->sc_if.if_unit);
	    goto flush;
	}
	m->m_len = 0;
	m->m_data = M_DATASTART(m);
	sc->sc_mp = mtod(m, char *);
    }

    ++m->m_len;
    *sc->sc_mp++ = c;
    sc->sc_fcs = PPP_FCS(sc->sc_fcs, c);
    return 0;

 flush:
    if (!(sc->sc_flags & SC_FLUSH)) {
	sc->sc_if.if_ierrors++;
	sc->sc_flags |= SC_FLUSH;
	if (sc->sc_flags & SC_LOG_FLUSH)
	    ppplogchar(sc, c);
    }
    return 0;
}

/*
 * Process an ioctl request to interface.
 */
int
pppioctl(ifp, cmd, data)
    register struct ifnet *ifp;
    int cmd;
    caddr_t data;
{
    struct proc *p = curproc;	/* XXX */
    register struct ppp_softc *sc = &ppp_softc[ifp->if_unit];
    register struct ifaddr *ifa = (struct ifaddr *)data;
    register struct ifreq *ifr = (struct ifreq *)data;
    int s = splimp(), error = 0;


    switch (cmd) {
    case SIOCSIFFLAGS:
	if ((ifp->if_flags & IFF_RUNNING) == 0)
	    ifp->if_flags &= ~IFF_UP;
	break;

    case SIOCSIFADDR:
	if (ifa->ifa_addr->sa_family != AF_INET)
	    error = EAFNOSUPPORT;
	break;

    case SIOCSIFDSTADDR:
	if (ifa->ifa_addr->sa_family != AF_INET)
	    error = EAFNOSUPPORT;
	break;

    case SIOCSIFMTU:
	if (error = suser(p->p_ucred, &p->p_acflag))
	    return (error);
	if (ifr->ifr_mtu > PPP_MAXMTU)
	    error = EINVAL;
	else {
	    struct tty *tp;

	    sc->sc_if.if_mtu = ifr->ifr_mtu;
	    tp = (struct tty *) sc->sc_devp;
	    if (tp != NULL)
		clist_alloc_cblocks(&tp->t_outq, sc->sc_if.if_mtu + PPP_HIWAT,
				    sc->sc_if.if_mtu + PPP_HIWAT);
	}
	break;

    case SIOCGIFMTU:
	ifr->ifr_mtu = sc->sc_if.if_mtu;
	break;
    case SIOCADDMULTI:
    case SIOCDELMULTI:
	switch(ifr->ifr_addr.sa_family) {
#ifdef INET
	case AF_INET:
		break;
#endif
	default:
		error = EAFNOSUPPORT;
		break;
	}
	break;

    default:
	error = EINVAL;
    }
    splx(s);
    return (error);
}

#define MAX_DUMP_BYTES	128

static void
pppdumpm(m0, pktlen)
    struct mbuf *m0;
    int pktlen;
{
    char buf[3*MAX_DUMP_BYTES+4];
    char *bp = buf;
    struct mbuf *m;
    static char digits[] = "0123456789abcdef";

    for (m = m0; m && pktlen; m = m->m_next) {
	int l = m->m_len;
	u_char *rptr = (u_char *)m->m_data;

	if (pktlen > 0) {
	    if (l > pktlen)
		l = pktlen;
	    pktlen -= l;
	}
	while (l--) {
	    if (bp > buf + sizeof(buf) - 4)
		goto done;
	    *bp++ = digits[*rptr >> 4]; /* convert byte to ascii hex */
	    *bp++ = digits[*rptr++ & 0xf];
	}

	if (m->m_next) {
	    if (bp > buf + sizeof(buf) - 3)
		goto done;
	    *bp++ = '|';
	} else
	    *bp++ = ' ';
    }
done:
    if (m && pktlen)
	*bp++ = '>';
    *bp = 0;
    printf("%s\n", buf);
}

static void
ppplogchar(sc, c)
    struct ppp_softc *sc;
    int c;
{
    if (c >= 0)
	sc->sc_rawin[sc->sc_rawin_count++] = c;
    if (sc->sc_rawin_count >= sizeof(sc->sc_rawin)
	|| c < 0 && sc->sc_rawin_count > 0) {
	printf("ppp%d input: ", sc->sc_if.if_unit);
	pppdumpb(sc->sc_rawin, sc->sc_rawin_count);
	sc->sc_rawin_count = 0;
    }
}

static void
pppdumpb(b, l)
    u_char *b;
    int l;
{
    char buf[3*MAX_DUMP_BYTES+4];
    char *bp = buf;
    static char digits[] = "0123456789abcdef";

    while (l--) {
	if (bp >= buf + sizeof(buf) - 3) {
	    *bp++ = '>';
	    break;
	}
	*bp++ = digits[*b >> 4]; /* convert byte to ascii hex */
	*bp++ = digits[*b++ & 0xf];
	*bp++ = ' ';
    }

    *bp = 0;
    printf("%s\n", buf);
}

PSEUDO_SET(pppattach, if_ppp);

#endif	/* NPPP > 0 */