if_ppp.c

unix and linux net driver

	    if (!suser())
		return EPERM;
	    if (npi->mode != sc->sc_npmode[npx]) {
		s = splnet();
		sc->sc_npmode[npx] = npi->mode;
		if (npi->mode != NPMODE_QUEUE) {
		    ppp_requeue(sc);
		    (*sc->sc_start)(sc);
		}
		splx(s);
	    }
	}
	break;

    case PPPIOCGIDLE:
	s = splnet();
	t = time.tv_sec;
	((struct ppp_idle *)data)->xmit_idle = t - sc->sc_last_sent;
	((struct ppp_idle *)data)->recv_idle = t - sc->sc_last_recv;
	splx(s);
	break;

    default:
	return (-1);
    }
    return (0);
}

/*
 * Process an ioctl request to the ppp network interface.
 */
int
pppsioctl(ifp, cmd, data)
    register struct ifnet *ifp;
    int cmd;
    caddr_t data;
{
    struct proc *p = u.u_procp;
    register struct ppp_softc *sc = &ppp_softc[ifp->if_unit];
    register struct ifaddr *ifa = (struct ifaddr *)data;
    register struct ifreq *ifr = (struct ifreq *)data;
    struct ppp_stats *psp;
#ifdef	PPP_COMPRESS
    struct ppp_comp_stats *pcp;
#endif
    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;

/*
 * Ioctls other than the above don't get through until the
 * interface has its IP addresses set :-(
 */

#if 0
    case SIOCSIFMTU:
	if (!suser())
	    return EPERM;
	sc->sc_if.if_mtu = ifr->ifr_mtu;
	break;

    case SIOCGIFMTU:
	ifr->ifr_mtu = sc->sc_if.if_mtu;
	break;
#endif

    case SIOCGPPPSTATS:
	psp = &((struct ifpppstatsreq *) data)->stats;
	bzero(psp, sizeof(*psp));
	psp->p = sc->sc_stats;
#if defined(VJC) && !defined(SL_NO_STATS)
	if (sc->sc_comp) {
	    psp->vj.vjs_packets = sc->sc_comp->sls_packets;
	    psp->vj.vjs_compressed = sc->sc_comp->sls_compressed;
	    psp->vj.vjs_searches = sc->sc_comp->sls_searches;
	    psp->vj.vjs_misses = sc->sc_comp->sls_misses;
	    psp->vj.vjs_uncompressedin = sc->sc_comp->sls_uncompressedin;
	    psp->vj.vjs_compressedin = sc->sc_comp->sls_compressedin;
	    psp->vj.vjs_errorin = sc->sc_comp->sls_errorin;
	    psp->vj.vjs_tossed = sc->sc_comp->sls_tossed;
	}
#endif /* VJC */
	break;

#ifdef PPP_COMPRESS
    case SIOCGPPPCSTATS:
	pcp = &((struct ifpppcstatsreq *) data)->stats;
	bzero(pcp, sizeof(*pcp));
	if (sc->sc_xc_state != NULL)
	    (*sc->sc_xcomp->comp_stat)(sc->sc_xc_state, &pcp->c);
	if (sc->sc_rc_state != NULL)
	    (*sc->sc_rcomp->decomp_stat)(sc->sc_rc_state, &pcp->d);
	break;
#endif /* PPP_COMPRESS */

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

/*
 * Queue a packet.  Start transmission if not active.
 * Packet is placed in Information field of PPP frame.
 */
int
pppoutput(ifp, m0, dst)
    struct ifnet *ifp;
    struct mbuf *m0;
    struct sockaddr *dst;
{
    register struct ppp_softc *sc = &ppp_softc[ifp->if_unit];
    int protocol, address, control;
    u_char *cp;
    int s, error;
    struct ip *ip;
    struct ifqueue *ifq;
    enum NPmode mode;
    int len;
    struct mbuf *m;

    if (sc->sc_devp == NULL || (ifp->if_flags & IFF_RUNNING) == 0
	|| ((ifp->if_flags & IFF_UP) == 0 && dst->sa_family != AF_UNSPEC)) {
	error = ENETDOWN;	/* sort of */
	goto bad;
    }

    /*
     * Compute PPP header.
     * We use the m_context field of the mbuf to indicate whether
     * the packet should go on the fast queue.
     */
    m0->m_context = 0;
    switch (dst->sa_family) {
#ifdef INET
    case AF_INET:
	address = PPP_ALLSTATIONS;
	control = PPP_UI;
	protocol = PPP_IP;
	mode = sc->sc_npmode[NP_IP];

	/*
	 * If this is a TCP packet to or from an "interactive" port,
	 * put the packet on the fastq instead.
	 */
	if ((ip = mtod(m0, struct ip *))->ip_p == IPPROTO_TCP) {
	    register int p = ntohl(((int *)ip)[ip->ip_hl]);
	    if (INTERACTIVE(p & 0xffff) || INTERACTIVE(p >> 16))
		m0->m_context = 1;
	}
	break;
#endif
    case AF_UNSPEC:
	address = PPP_ADDRESS(dst->sa_data);
	control = PPP_CONTROL(dst->sa_data);
	protocol = PPP_PROTOCOL(dst->sa_data);
	mode = NPMODE_PASS;
	break;
    default:
	printf("ppp%d: af%d not supported\n", ifp->if_unit, dst->sa_family);
	error = EAFNOSUPPORT;
	goto bad;
    }

    /*
     * Drop this packet, or return an error, if necessary.
     */
    if (mode == NPMODE_ERROR) {
	error = ENETDOWN;
	goto bad;
    }
    if (mode == NPMODE_DROP) {
	error = 0;
	goto bad;
    }

    /*
     * Add PPP header.  If no space in first mbuf, allocate another.
     */
    if (M_IS_CLUSTER(m0) || m0->m_off < MMINOFF + PPP_HDRLEN) {
	struct mbuf *m;

	MGET(m, M_DONTWAIT, MT_DATA);
	if (m == NULL) {
	    m_freem(m0);
	    return (ENOBUFS);
	}
	m->m_len = 0;
	m->m_next = m0;
	m0 = m;
    } else
	m0->m_off -= PPP_HDRLEN;

    cp = mtod(m0, u_char *);
    *cp++ = address;
    *cp++ = control;
    *cp++ = protocol >> 8;
    *cp++ = protocol & 0xff;
    m0->m_len += PPP_HDRLEN;

    len = 0;
    for (m = m0; m != 0; m = m->m_next)
	len += m->m_len;

    if (sc->sc_flags & SC_LOG_OUTPKT) {
	printf("ppp%d output: ", ifp->if_unit);
	pppdumpm(m0);
    }

    if ((protocol & 0x8000) == 0) {
	/*
	 * Update the time we sent the most recent data packet.
	 */
	sc->sc_last_sent = time.tv_sec;
    }

#if NBPFILTER > 0
    /*
     * See if bpf wants to look at the packet.
     */
    if (sc->sc_bpf)
	bpf_mtap(sc->sc_bpf, m0);
#endif

    /*
     * Put the packet on the appropriate queue.
     */
    s = splnet();
    if (mode == NPMODE_QUEUE) {
	/* XXX we should limit the number of packets on this queue */
	*sc->sc_npqtail = m0;
	m0->m_act = NULL;
	sc->sc_npqtail = &m0->m_act;
    } else {
	ifq = m0->m_context? &sc->sc_fastq: &ifp->if_snd;
	if (IF_QFULL(ifq) && dst->sa_family != AF_UNSPEC) {
	    IF_DROP(ifq);
	    splx(s);
	    sc->sc_if.if_oerrors++;
	    sc->sc_stats.ppp_oerrors++;
	    error = ENOBUFS;
	    goto bad;
	}
	IF_ENQUEUE(ifq, m0);
	(*sc->sc_start)(sc);
    }
    ifp->if_opackets++;

    splx(s);
    return (0);

bad:
    m_freem(m0);
    return (error);
}

/*
 * After a change in the NPmode for some NP, move packets from the
 * npqueue to the send queue or the fast queue as appropriate.
 * Should be called at splnet.
 */
static void
ppp_requeue(sc)
    struct ppp_softc *sc;
{
    struct mbuf *m, **mpp;
    struct ifqueue *ifq;
    enum NPmode mode;

    for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
	switch (PPP_PROTOCOL(mtod(m, u_char *))) {
	case PPP_IP:
	    mode = sc->sc_npmode[NP_IP];
	    break;
	default:
	    mode = NPMODE_PASS;
	}

	switch (mode) {
	case NPMODE_PASS:
	    /*
	     * This packet can now go on one of the queues to be sent.
	     */
	    *mpp = m->m_act;
	    m->m_act = NULL;
	    ifq = m->m_context? &sc->sc_fastq: &sc->sc_if.if_snd;
	    if (IF_QFULL(ifq)) {
		IF_DROP(ifq);
		sc->sc_if.if_oerrors++;
		sc->sc_stats.ppp_oerrors++;
	    } else
		IF_ENQUEUE(ifq, m);
	    break;

	case NPMODE_DROP:
	case NPMODE_ERROR:
	    *mpp = m->m_act;
	    m_freem(m);
	    break;

	case NPMODE_QUEUE:
	    mpp = &m->m_act;
	    break;
	}
    }
    sc->sc_npqtail = mpp;
}

/*
 * Transmitter has finished outputting some stuff;
 * remember to call sc->sc_start later at splnet.
 */
void
ppp_restart(sc)
    struct ppp_softc *sc;
{
    int s = splimp();

    sc->sc_flags &= ~SC_TBUSY;
    schednetisr(NETISR_PPP);
    splx(s);
}

/*
 * Get a packet to send.  This procedure is intended to be called at
 * splnet, since it may involve time-consuming operations such as
 * applying VJ compression, packet compression, address/control and/or
 * protocol field compression to the packet.
 */
struct mbuf *
ppp_dequeue(sc)
    struct ppp_softc *sc;
{
    struct mbuf *m, *mp;
    u_char *cp;
    int address, control, protocol;
    int s;

    /*
     * Grab a packet to send: first try the fast queue, then the
     * normal queue.
     */
    IF_DEQUEUE(&sc->sc_fastq, m);
    if (m == NULL)
	IF_DEQUEUE(&sc->sc_if.if_snd, m);
    if (m == NULL)
	return NULL;

    ++sc->sc_stats.ppp_opackets;

    /*
     * Extract the ppp header of the new packet.
     * The ppp header will be in one mbuf.
     */
    cp = mtod(m, u_char *);
    address = PPP_ADDRESS(cp);
    control = PPP_CONTROL(cp);
    protocol = PPP_PROTOCOL(cp);

    switch (protocol) {
    case PPP_IP:
#ifdef VJC
	/*
	 * If the packet is a TCP/IP packet, see if we can compress it.
	 */
	if ((sc->sc_flags & SC_COMP_TCP) && sc->sc_comp != NULL) {
	    struct ip *ip;
	    int type;

	    mp = m;
	    ip = (struct ip *) (cp + PPP_HDRLEN);
	    if (mp->m_len <= PPP_HDRLEN) {
		mp = mp->m_next;
		if (mp == NULL)
		    break;
		ip = mtod(mp, struct ip *);
	    }
	    /* this code assumes the IP/TCP header is in one non-shared mbuf */
	    if (ip->ip_p == IPPROTO_TCP) {
		type = sl_compress_tcp(mp, ip, sc->sc_comp,
				       !(sc->sc_flags & SC_NO_TCP_CCID));
		switch (type) {
		case TYPE_UNCOMPRESSED_TCP:
		    protocol = PPP_VJC_UNCOMP;
		    break;
		case TYPE_COMPRESSED_TCP:
		    protocol = PPP_VJC_COMP;
		    cp = mtod(m, u_char *);
		    cp[0] = address;	/* header has moved */
		    cp[1] = control;
		    cp[2] = 0;
		    break;
		}
		cp[3] = protocol;	/* update protocol in PPP header */
	    }
	}
#endif	/* VJC */
	break;

#ifdef PPP_COMPRESS
    case PPP_CCP:
	ppp_ccp(sc, m, 0);
	break;
#endif	/* PPP_COMPRESS */
    }

#ifdef PPP_COMPRESS
    if (protocol != PPP_LCP && protocol != PPP_CCP
	&& sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN)) {
	struct mbuf *mcomp = NULL;
	int slen, clen;

	slen = 0;
	for (mp = m; mp != NULL; mp = mp->m_next)
	    slen += mp->m_len;
	clen = (*sc->sc_xcomp->compress)
	    (sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
	if (mcomp != NULL) {
	    if (sc->sc_flags & SC_CCP_UP) {
		/* Send the compressed packet instead of the original. */
		m_freem(m);
		m = mcomp;
		cp = mtod(m, u_char *);
		protocol = cp[3];
	    } else {
		/* Can't transmit compressed packets until CCP is up. */
		m_freem(mcomp);
	    }
	}
    }
#endif	/* PPP_COMPRESS */

    /*
     * Compress the address/control and protocol, if possible.
     */
    if (sc->sc_flags & SC_COMP_AC && address == PPP_ALLSTATIONS &&
	control == PPP_UI && protocol != PPP_ALLSTATIONS &&
	protocol != PPP_LCP) {
	/* can compress address/control */
	m->m_off += 2;
	m->m_len -= 2;
    }
    if (sc->sc_flags & SC_COMP_PROT && protocol < 0xFF) {
	/* can compress protocol */
	if (mtod(m, u_char *) == cp) {
	    cp[2] = cp[1];	/* move address/control up */
	    cp[1] = cp[0];
	}
	++m->m_off;
	--m->m_len;
    }

    return m;
}

/*
 * Software interrupt routine, called at splnet.