ppp_io.c

eCos/RedBoot for勤研ARM AnywhereII(4510) 含全部源代码

//==========================================================================
/*
 * Line specific (tty) write routine.
 * called at zero spl from the device driver in the response to user-level
 * writes on the tty file descriptor (ie: pppd).
 */

int
cyg_ppp_pppwrite(tp, uio, flag)
    register struct tty *tp;
    struct uio *uio;
    int flag;
{
    register struct ppp_softc *sc = (struct ppp_softc *)tp->t_sc;
    struct mbuf *m, *m0, **mp;
    struct sockaddr dst;
    int len, error, s;
    
    s = spltty();
    for (mp = &m0; uio->uio_resid; mp = &m->m_next) {
	MGET(m, M_WAIT, MT_DATA);
	if ((*mp = m) == NULL) {
	    m_freem(m0);
	    splx(s);
	    return (ENOBUFS);
	}
	m->m_len = 0;
	if (uio->uio_resid >= MCLBYTES / 2)
	    MCLGET(m, M_DONTWAIT);
	len = M_TRAILINGSPACE(m);
	if (len > uio->uio_resid)
	    len = uio->uio_resid;
	if ((error = uiomove(mtod(m, u_char *), len, uio)) != 0) {
	    m_freem(m0);
	    splx(s);
	    return (error);
	}
	m->m_len = len;
    }
    dst.sa_family = AF_UNSPEC;
    bcopy(mtod(m0, u_char *), dst.sa_data, PPP_HDRLEN);
    m0->m_data += PPP_HDRLEN;
    m0->m_len -= PPP_HDRLEN;

    /* call the upper layer to "transmit" it... */
    error = pppoutput(&sc->sc_if, m0, &dst, (struct rtentry *)0);
    splx(s);
    return (error);
}

//==========================================================================
/*
 * Line specific (tty) ioctl routine.
 * This discipline requires that tty device drivers call
 * the line specific l_ioctl routine from their ioctl routines.
 */
/* ARGSUSED */
int
cyg_ppp_ppptioctl(tp, cmd, data, flag)
    struct tty *tp;
    u_long cmd;
    caddr_t data;
    int flag;
//    struct proc *p;
{
    struct ppp_softc *sc = (struct ppp_softc *) tp->t_sc;
    int error, s;

    if (sc == NULL || tp != (struct tty *) sc->sc_devp)
	return (ENOIOCTL);

    error = 0;
    switch (cmd) {
    case PPPIOCSASYNCMAP:
	sc->sc_asyncmap[0] = *(u_int *)data;
	break;

    case PPPIOCGASYNCMAP:
	*(u_int *)data = sc->sc_asyncmap[0];
	break;

    case PPPIOCSRASYNCMAP:
	if ((error = suser(p)) != 0)
	    break;
	sc->sc_rasyncmap = *(u_int *)data;
	break;

    case PPPIOCGRASYNCMAP:
	*(u_int *)data = sc->sc_rasyncmap;
	break;

    case PPPIOCSXASYNCMAP:
	s = spltty();
	bcopy(data, sc->sc_asyncmap, sizeof(sc->sc_asyncmap));
	sc->sc_asyncmap[1] = 0;		    /* mustn't escape 0x20 - 0x3f */
	sc->sc_asyncmap[2] &= ~0x40000000;  /* mustn't escape 0x5e */
	sc->sc_asyncmap[3] |= 0x60000000;   /* must escape 0x7d, 0x7e */
	splx(s);
	break;

    case PPPIOCGXASYNCMAP:
	bcopy(sc->sc_asyncmap, data, sizeof(sc->sc_asyncmap));
	break;

    default:
	error = pppioctl(sc, cmd, data, flag, 0);
	if (error == 0 && cmd == PPPIOCSMRU)
	    pppgetm(sc);
    }

    return error;
}

//==========================================================================
/*
 * FCS lookup table as calculated by genfcstab.
 */
static u_short fcstab[256] = {
	0x0000,	0x1189,	0x2312,	0x329b,	0x4624,	0x57ad,	0x6536,	0x74bf,
	0x8c48,	0x9dc1,	0xaf5a,	0xbed3,	0xca6c,	0xdbe5,	0xe97e,	0xf8f7,
	0x1081,	0x0108,	0x3393,	0x221a,	0x56a5,	0x472c,	0x75b7,	0x643e,
	0x9cc9,	0x8d40,	0xbfdb,	0xae52,	0xdaed,	0xcb64,	0xf9ff,	0xe876,
	0x2102,	0x308b,	0x0210,	0x1399,	0x6726,	0x76af,	0x4434,	0x55bd,
	0xad4a,	0xbcc3,	0x8e58,	0x9fd1,	0xeb6e,	0xfae7,	0xc87c,	0xd9f5,
	0x3183,	0x200a,	0x1291,	0x0318,	0x77a7,	0x662e,	0x54b5,	0x453c,
	0xbdcb,	0xac42,	0x9ed9,	0x8f50,	0xfbef,	0xea66,	0xd8fd,	0xc974,
	0x4204,	0x538d,	0x6116,	0x709f,	0x0420,	0x15a9,	0x2732,	0x36bb,
	0xce4c,	0xdfc5,	0xed5e,	0xfcd7,	0x8868,	0x99e1,	0xab7a,	0xbaf3,
	0x5285,	0x430c,	0x7197,	0x601e,	0x14a1,	0x0528,	0x37b3,	0x263a,
	0xdecd,	0xcf44,	0xfddf,	0xec56,	0x98e9,	0x8960,	0xbbfb,	0xaa72,
	0x6306,	0x728f,	0x4014,	0x519d,	0x2522,	0x34ab,	0x0630,	0x17b9,
	0xef4e,	0xfec7,	0xcc5c,	0xddd5,	0xa96a,	0xb8e3,	0x8a78,	0x9bf1,
	0x7387,	0x620e,	0x5095,	0x411c,	0x35a3,	0x242a,	0x16b1,	0x0738,
	0xffcf,	0xee46,	0xdcdd,	0xcd54,	0xb9eb,	0xa862,	0x9af9,	0x8b70,
	0x8408,	0x9581,	0xa71a,	0xb693,	0xc22c,	0xd3a5,	0xe13e,	0xf0b7,
	0x0840,	0x19c9,	0x2b52,	0x3adb,	0x4e64,	0x5fed,	0x6d76,	0x7cff,
	0x9489,	0x8500,	0xb79b,	0xa612,	0xd2ad,	0xc324,	0xf1bf,	0xe036,
	0x18c1,	0x0948,	0x3bd3,	0x2a5a,	0x5ee5,	0x4f6c,	0x7df7,	0x6c7e,
	0xa50a,	0xb483,	0x8618,	0x9791,	0xe32e,	0xf2a7,	0xc03c,	0xd1b5,
	0x2942,	0x38cb,	0x0a50,	0x1bd9,	0x6f66,	0x7eef,	0x4c74,	0x5dfd,
	0xb58b,	0xa402,	0x9699,	0x8710,	0xf3af,	0xe226,	0xd0bd,	0xc134,
	0x39c3,	0x284a,	0x1ad1,	0x0b58,	0x7fe7,	0x6e6e,	0x5cf5,	0x4d7c,
	0xc60c,	0xd785,	0xe51e,	0xf497,	0x8028,	0x91a1,	0xa33a,	0xb2b3,
	0x4a44,	0x5bcd,	0x6956,	0x78df,	0x0c60,	0x1de9,	0x2f72,	0x3efb,
	0xd68d,	0xc704,	0xf59f,	0xe416,	0x90a9,	0x8120,	0xb3bb,	0xa232,
	0x5ac5,	0x4b4c,	0x79d7,	0x685e,	0x1ce1,	0x0d68,	0x3ff3,	0x2e7a,
	0xe70e,	0xf687,	0xc41c,	0xd595,	0xa12a,	0xb0a3,	0x8238,	0x93b1,
	0x6b46,	0x7acf,	0x4854,	0x59dd,	0x2d62,	0x3ceb,	0x0e70,	0x1ff9,
	0xf78f,	0xe606,	0xd49d,	0xc514,	0xb1ab,	0xa022,	0x92b9,	0x8330,
	0x7bc7,	0x6a4e,	0x58d5,	0x495c,	0x3de3,	0x2c6a,	0x1ef1,	0x0f78
};

//==========================================================================
/*
 * Calculate a new FCS given the current FCS and the new data.
 */
static u_short
pppfcs(u_short fcs, u_char *cp, int len)
{
    while (len--)
	fcs = PPP_FCS(fcs, *cp++);
    return (fcs);
}

//==========================================================================

#ifdef __ECOS

// Call pppasyncstart() to kick transmission into life. 
int cyg_ppp_pppstart( struct tty *tp )
{
    struct ppp_softc *sc = (struct ppp_softc *) tp->t_sc;

    while( sc->sc_outm != NULL )
    {
        // We wait for the output buffer to drain of all characters
        // before we call pppasyncstart(). That way we know there will
        // be room for some data. We would really like to just drain
        // down to some low water mark, but the drivers don't provide
        // that functionality. However, since most devices have
        // hardware FIFO's, we have a grace period to get more
        // characters into the device, so hopefully there won't be a
        // gap on the line.
        
        cyg_uint32 nb = 0;
        cyg_uint32 len = sizeof(nb);
        int s;

        cyg_io_get_config( tp->t_handle,
                           CYG_IO_GET_CONFIG_SERIAL_OUTPUT_DRAIN,
                           &nb, &len);

        s = splsoftnet();

        pppasyncstart( sc );

        splx(s);
    }
    
    return 0;
}

#endif


//==========================================================================
/*
 * This gets called at splsoftnet from if_ppp.c at various times
 * when there is data ready to be sent.
 */
static void
pppasyncstart(sc)
    register struct ppp_softc *sc;
{
    register struct tty *tp = (struct tty *) sc->sc_devp;
    register struct mbuf *m;
    register int len;
    register u_char *start, *stop, *cp;
    int n, ndone, done, idle;
    struct mbuf *m2;
    int s;

    idle = 0;

    while (1) {        
	/*
	 * See if we have an existing packet partly sent.
	 * If not, get a new packet and start sending it.
	 */
	m = sc->sc_outm;
	if (m == NULL) {
	    /*
	     * Get another packet to be sent.
	     */
	    m = ppp_dequeue(sc);
	    if (m == NULL) {
		idle = 1;
		break;
	    }

	    /* Calculate the FCS for the first mbuf's worth. */
	    sc->sc_outfcs = pppfcs(PPP_INITFCS, mtod(m, u_char *), m->m_len);
	    getmicrotime(&sc->sc_if.if_lastchange);
	}

	for (;;) {
	    start = mtod(m, u_char *);
	    len = m->m_len;
	    stop = start + len;
	    while (len > 0) {
		/*
		 * Find out how many bytes in the string we can
		 * handle without doing something special.
		 */
		for (cp = start; cp < stop; cp++)
		    if (ESCAPE_P(*cp))
			break;
		n = cp - start;
		if (n) {
#ifndef __ECOS        
		    /* NetBSD (0.9 or later), 4.3-Reno or similar. */
		    ndone = n - b_to_q(start, n, &tp->t_outq);
#else
                    ndone = 0;
//                    db_printf("send: data %d\n",ndone);
//                    db_dump_buf(start,ndone);
                    {
                        cyg_serial_buf_info_t info;
                        cyg_uint32 ilen = sizeof(info);
                        if( cyg_io_get_config( tp->t_handle, CYG_IO_GET_CONFIG_SERIAL_BUFFER_INFO, &info, &ilen ) == 0 )
                        {
                            ndone = info.tx_bufsize-info.tx_count;
                            if( ndone > n )
                                ndone = n;
                            cyg_io_write( tp->t_handle, start, &ndone);
                        }
                    }
#endif
		    len -= ndone;
		    start += ndone;
		    sc->sc_stats.ppp_obytes += ndone;

		    if (ndone < n)
			break;	/* packet doesn't fit */
		}
		/*
		 * If there are characters left in the mbuf,
		 * the first one must be special.
		 * Put it out in a different form.
		 */
		if (len) {
		    s = spltty();
#ifndef __ECOS        
		    if (putc(PPP_ESCAPE, &tp->t_outq)) {
			splx(s);
			break;
		    }
		    if (putc(*start ^ PPP_TRANS, &tp->t_outq)) {
			(void) unputc(&tp->t_outq);
			splx(s);
			break;
		    }
#else
                    {
                        cyg_serial_buf_info_t info;
                        cyg_uint32 ilen = sizeof(info);
                        if( cyg_io_get_config( tp->t_handle, CYG_IO_GET_CONFIG_SERIAL_BUFFER_INFO, &info, &ilen ) == 0 &&
                            info.tx_bufsize-info.tx_count >= 2 )
                        {
                            char buf[2];
                            int blen = 2;
                            buf[0] = PPP_ESCAPE;
                            buf[1] = *start ^ PPP_TRANS;
                            if( cyg_io_write( tp->t_handle, buf, &blen) != 0 ) {
                                splx(s);
                                break;
                            }
                        }
                        else
                        {
                            splx(s);
                            break;
                        }
                    }
#endif
		    splx(s);
		    sc->sc_stats.ppp_obytes += 2;
		    start++;
		    len--;
                } // if( len )
            } // while (len > 0)

	    /*
	     * If we didn't empty this mbuf, remember where we're up to.
	     * If we emptied the last mbuf, try to add the FCS and closing
	     * flag, and if we can't, leave sc_outm pointing to m, but with
	     * m->m_len == 0, to remind us to output the FCS and flag later.
	     */
	    done = len == 0;
	    if (done && m->m_next == NULL) {
		u_char *p, *q;
		int c;
		u_char endseq[8];

		/*
		 * We may have to escape the bytes in the FCS.
		 */
		p = endseq;
		c = ~sc->sc_outfcs & 0xFF;
		if (ESCAPE_P(c)) {
		    *p++ = PPP_ESCAPE;
		    *p++ = c ^ PPP_TRANS;
		} else
		    *p++ = c;
		c = (~sc->sc_outfcs >> 8) & 0xFF;
		if (ESCAPE_P(c)) {
		    *p++ = PPP_ESCAPE;
		    *p++ = c ^ PPP_TRANS;
		} else
		    *p++ = c;
		*p++ = PPP_FLAG;

		/*
		 * Try to output the FCS and flag.  If the bytes
		 * don't all fit, back out.
		 */
		s = spltty();
#ifndef __ECOS
		for (q = endseq; q < p; ++q)
		    if (putc(*q, &tp->t_outq)) {
			done = 0;
			for (; q > endseq; --q)
			    unputc(&tp->t_outq);
			break;
		    }
#else
                {
                    int elen = p-endseq;
                    cyg_serial_buf_info_t info;
                    cyg_uint32 ilen = sizeof(info);
                    q = p;