sys-linux.c

unix and linux net driver

 *
 * clean_check - Fetch the flags for the device and generate
 * appropriate error messages.
 */
void clean_check(void)
{
    int x;
    char *s;

    if (still_ppp()) {
	if (ioctl(ppp_fd, PPPIOCGFLAGS, (caddr_t) &x) == 0) {
	    s = NULL;
	    switch (~x & (SC_RCV_B7_0|SC_RCV_B7_1|SC_RCV_EVNP|SC_RCV_ODDP)) {
	    case SC_RCV_B7_0:
		s = "all had bit 7 set to 1";
		break;
		
	    case SC_RCV_B7_1:
		s = "all had bit 7 set to 0";
		break;
		
	    case SC_RCV_EVNP:
		s = "all had odd parity";
		break;
		
	    case SC_RCV_ODDP:
		s = "all had even parity";
		break;
	    }
	    
	    if (s != NULL) {
		warn("Receive serial link is not 8-bit clean:");
		warn("Problem: %s", s);
	    }
	}
    }
}
	

/*
 * List of valid speeds.
 */

struct speed {
    int speed_int, speed_val;
} speeds[] = {
#ifdef B50
    { 50, B50 },
#endif
#ifdef B75
    { 75, B75 },
#endif
#ifdef B110
    { 110, B110 },
#endif
#ifdef B134
    { 134, B134 },
#endif
#ifdef B150
    { 150, B150 },
#endif
#ifdef B200
    { 200, B200 },
#endif
#ifdef B300
    { 300, B300 },
#endif
#ifdef B600
    { 600, B600 },
#endif
#ifdef B1200
    { 1200, B1200 },
#endif
#ifdef B1800
    { 1800, B1800 },
#endif
#ifdef B2000
    { 2000, B2000 },
#endif
#ifdef B2400
    { 2400, B2400 },
#endif
#ifdef B3600
    { 3600, B3600 },
#endif
#ifdef B4800
    { 4800, B4800 },
#endif
#ifdef B7200
    { 7200, B7200 },
#endif
#ifdef B9600
    { 9600, B9600 },
#endif
#ifdef B19200
    { 19200, B19200 },
#endif
#ifdef B38400
    { 38400, B38400 },
#endif
#ifdef B57600
    { 57600, B57600 },
#endif
#ifdef B115200
    { 115200, B115200 },
#endif
#ifdef EXTA
    { 19200, EXTA },
#endif
#ifdef EXTB
    { 38400, EXTB },
#endif
#ifdef B230400
    { 230400, B230400 },
#endif
#ifdef B460800
    { 460800, B460800 },
#endif
    { 0, 0 }
};

/********************************************************************
 *
 * Translate from bits/second to a speed_t.
 */

static int translate_speed (int bps)
{
    struct speed *speedp;

    if (bps != 0) {
	for (speedp = speeds; speedp->speed_int; speedp++) {
	    if (bps == speedp->speed_int)
		return speedp->speed_val;
	}
	warn("speed %d not supported", bps);
    }
    return 0;
}

/********************************************************************
 *
 * Translate from a speed_t to bits/second.
 */

static int baud_rate_of (int speed)
{
    struct speed *speedp;
    
    if (speed != 0) {
	for (speedp = speeds; speedp->speed_int; speedp++) {
	    if (speed == speedp->speed_val)
		return speedp->speed_int;
	}
    }
    return 0;
}

/********************************************************************
 *
 * set_up_tty: Set up the serial port on `fd' for 8 bits, no parity,
 * at the requested speed, etc.  If `local' is true, set CLOCAL
 * regardless of whether the modem option was specified.
 */

void set_up_tty(int tty_fd, int local)
{
    int speed;
    struct termios tios;

    setdtr(tty_fd, 1);
    if (tcgetattr(tty_fd, &tios) < 0) {
	if (!ok_error(errno))
	    fatal("tcgetattr: %m(%d)", errno);
	return;
    }
    
    if (!restore_term)
	inittermios = tios;
    
    tios.c_cflag     &= ~(CSIZE | CSTOPB | PARENB | CLOCAL);
    tios.c_cflag     |= CS8 | CREAD | HUPCL;

    tios.c_iflag      = IGNBRK | IGNPAR;
    tios.c_oflag      = 0;
    tios.c_lflag      = 0;
    tios.c_cc[VMIN]   = 1;
    tios.c_cc[VTIME]  = 0;
    
    if (local || !modem)
	tios.c_cflag ^= (CLOCAL | HUPCL);

    switch (crtscts) {
    case 1:
	tios.c_cflag |= CRTSCTS;
	break;

    case -2:
	tios.c_iflag     |= IXON | IXOFF;
	tios.c_cc[VSTOP]  = 0x13;	/* DC3 = XOFF = ^S */
	tios.c_cc[VSTART] = 0x11;	/* DC1 = XON  = ^Q */
	break;

    case -1:
	tios.c_cflag &= ~CRTSCTS;
	break;

    default:
	break;
    }
    
    speed = translate_speed(inspeed);
    if (speed) {
	cfsetospeed (&tios, speed);
	cfsetispeed (&tios, speed);
    }
/*
 * We can't proceed if the serial port speed is B0,
 * since that implies that the serial port is disabled.
 */
    else {
	speed = cfgetospeed(&tios);
	if (speed == B0)
	    fatal("Baud rate for %s is 0; need explicit baud rate", devnam);
    }

    if (tcsetattr(tty_fd, TCSAFLUSH, &tios) < 0)
	if (!ok_error(errno))
	    fatal("tcsetattr: %m");
    
    baud_rate    = baud_rate_of(speed);
    restore_term = 1;
}

/********************************************************************
 *
 * setdtr - control the DTR line on the serial port.
 * This is called from die(), so it shouldn't call die().
 */

void setdtr (int tty_fd, int on)
{
    int modembits = TIOCM_DTR;

    ioctl(tty_fd, (on ? TIOCMBIS : TIOCMBIC), &modembits);
}

/********************************************************************
 *
 * restore_tty - restore the terminal to the saved settings.
 */

void restore_tty (int tty_fd)
{
    if (restore_term) {
	restore_term = 0;
/*
 * Turn off echoing, because otherwise we can get into
 * a loop with the tty and the modem echoing to each other.
 * We presume we are the sole user of this tty device, so
 * when we close it, it will revert to its defaults anyway.
 */
	if (!default_device)
	    inittermios.c_lflag &= ~(ECHO | ECHONL);
	
	if (tcsetattr(tty_fd, TCSAFLUSH, &inittermios) < 0) {
	    if (! ok_error (errno))
		warn("tcsetattr: %m");
	}
    }
}

/********************************************************************
 *
 * output - Output PPP packet.
 */

void output (int unit, unsigned char *p, int len)
{
    if (debug)
	dbglog("sent %P", p, len);

    if (len < PPP_HDRLEN)
	return;
    if (new_style_driver) {
	p += 2;
	len -= 2;
    }
    if (write(ppp_dev_fd, p, len) < 0) {
	if (errno == EWOULDBLOCK || errno == ENOBUFS
	    || errno == ENXIO || errno == EIO || errno == EINTR)
	    warn("write: warning: %m (%d)", errno);
	else
	    error("write: %m (%d)", errno);
    }
}

/********************************************************************
 *
 * wait_input - wait until there is data available,
 * for the length of time specified by *timo (indefinite
 * if timo is NULL).
 */

void wait_input(struct timeval *timo)
{
    fd_set ready;
    int n;

    ready = in_fds;
    n = select(max_in_fd + 1, &ready, NULL, &ready, timo);
    if (n < 0 && errno != EINTR)
	fatal("select: %m(%d)", errno);
}

/*
 * add_fd - add an fd to the set that wait_input waits for.
 */
void add_fd(int fd)
{
    FD_SET(fd, &in_fds);
    if (fd > max_in_fd)
	max_in_fd = fd;
}

/*
 * remove_fd - remove an fd from the set that wait_input waits for.
 */
void remove_fd(int fd)
{
    FD_CLR(fd, &in_fds);
}


/********************************************************************
 *
 * read_packet - get a PPP packet from the serial device.
 */

int read_packet (unsigned char *buf)
{
    int len, nr;

    len = PPP_MRU + PPP_HDRLEN;
    if (new_style_driver) {
	*buf++ = PPP_ALLSTATIONS;
	*buf++ = PPP_UI;
	len -= 2;
    }
    nr = read(ppp_fd, buf, len);
    if (new_style_driver && nr < 0 && (errno == EWOULDBLOCK || errno == EIO))
	nr = read(ppp_dev_fd, buf, len);
    if (nr < 0) {
	if (errno == EWOULDBLOCK || errno == EIO)
	    return -1;
	fatal("read: %m(%d)", errno);
    }
    return (new_style_driver && nr > 0)? nr+2: nr;
}

/********************************************************************
 *
 * get_loop_output - get outgoing packets from the ppp device,
 * and detect when we want to bring the real link up.
 * Return value is 1 if we need to bring up the link, 0 otherwise.
 */
int
get_loop_output(void)
{
    int rv = 0;
    int n;

    if (new_style_driver) {
	while ((n = read_packet(inpacket_buf)) > 0)
	    if (loop_frame(inpacket_buf, n))
		rv = 1;
	return rv;
    }

    while ((n = read(master_fd, inbuf, sizeof(inbuf))) > 0)
	if (loop_chars(inbuf, n))
	    rv = 1;

    if (n == 0)
	fatal("eof on loopback");

    if (errno != EWOULDBLOCK)
	fatal("read from loopback: %m(%d)", errno);

    return rv;
}

/********************************************************************
 *
 * ppp_send_config - configure the transmit characteristics of
 * the ppp interface.
 */

void ppp_send_config (int unit,int mtu,u_int32_t asyncmap,int pcomp,int accomp)
{
    u_int x;
    struct ifreq ifr;
  
    SYSDEBUG ((LOG_DEBUG, "send_config: mtu = %d\n", mtu));
/*
 * Set the MTU and other parameters for the ppp device
 */
    memset (&ifr, '\0', sizeof (ifr));
    strlcpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
    ifr.ifr_mtu = mtu;
	
    if (ioctl(sock_fd, SIOCSIFMTU, (caddr_t) &ifr) < 0)
	fatal("ioctl(SIOCSIFMTU): %m(%d)", errno);
	
    if (!still_ppp())
	return;
    SYSDEBUG ((LOG_DEBUG, "send_config: asyncmap = %lx\n", asyncmap));
    if (ioctl(ppp_fd, PPPIOCSASYNCMAP, (caddr_t) &asyncmap) < 0) {
	if (!ok_error(errno))
	    fatal("ioctl(PPPIOCSASYNCMAP): %m(%d)", errno);
	return;
    }
    
    x = get_flags(ppp_fd);
    x = pcomp  ? x | SC_COMP_PROT : x & ~SC_COMP_PROT;
    x = accomp ? x | SC_COMP_AC   : x & ~SC_COMP_AC;
    x = sync_serial ? x | SC_SYNC : x & ~SC_SYNC;
    set_flags(ppp_fd, x);
}

/********************************************************************
 *
 * ppp_set_xaccm - set the extended transmit ACCM for the interface.
 */

void ppp_set_xaccm (int unit, ext_accm accm)
{
    SYSDEBUG ((LOG_DEBUG, "set_xaccm: %08lx %08lx %08lx %08lx\n",
		accm[0], accm[1], accm[2], accm[3]));

    if (!still_ppp())
	return;
    if (ioctl(ppp_fd, PPPIOCSXASYNCMAP, accm) < 0 && errno != ENOTTY) {
	if ( ! ok_error (errno))
	    warn("ioctl(set extended ACCM): %m(%d)", errno);
    }
}

/********************************************************************
 *
 * ppp_recv_config - configure the receive-side characteristics of
 * the ppp interface.
 */

void ppp_recv_config (int unit,int mru,u_int32_t asyncmap,int pcomp,int accomp)
{
    SYSDEBUG ((LOG_DEBUG, "recv_config: mru = %d\n", mru));
/*
 * If we were called because the link has gone down then there is nothing
 * which may be done. Just return without incident.
 */
    if (!still_ppp())
	return;
/*
 * Set the receiver parameters
 */
    if (ioctl(ppp_fd, PPPIOCSMRU, (caddr_t) &mru) < 0) {
	if ( ! ok_error (errno))
	    error("ioctl(PPPIOCSMRU): %m(%d)", errno);
    }
    if (new_style_driver && ioctl(ppp_dev_fd, PPPIOCSMRU, (caddr_t) &mru) < 0)
	error("Couldn't set MRU in generic PPP layer: %m");

    SYSDEBUG ((LOG_DEBUG, "recv_config: asyncmap = %lx\n", asyncmap));
    if (ioctl(ppp_fd, PPPIOCSRASYNCMAP, (caddr_t) &asyncmap) < 0) {
	if (!ok_error(errno))
	    error("ioctl(PPPIOCSRASYNCMAP): %m(%d)", errno);
    }
}

/********************************************************************
 *
 * ccp_test - ask kernel whether a given compression method
 * is acceptable for use.
 */

int ccp_test (int unit, u_char *opt_ptr, int opt_len, int for_transmit)
{
    struct ppp_option_data data;

    memset (&data, '\0', sizeof (data));
    data.ptr      = opt_ptr;
    data.length   = opt_len;
    data.transmit = for_transmit;

    if (ioctl(ppp_dev_fd, PPPIOCSCOMPRESS, (caddr_t) &data) >= 0)
	return 1;

    return (errno == ENOBUFS)? 0: -1;
}

/********************************************************************
 *
 * ccp_flags_set - inform kernel about the current state of CCP.