main.c

unix and linux net driver

    { 0x8043,	"Ascom Timeplex" },
    { 0x8045,	"Fujitsu LBLB Control Protocol" },
    { 0x8047,	"DCA Remote Lan Network Control Protocol (RLNCP)" },
    { 0x8049,	"Serial Data Control Protocol (PPP-SDCP)" },
    { 0x804b,	"SNA over 802.2 Control Protocol" },
    { 0x804d,	"SNA Control Protocol" },
    { 0x804f,	"IP6 Header Compression Control Protocol" },
    { 0x006f,	"Stampede Bridging Control Protocol" },
    { 0x80fb,	"Single Link Compression Control Protocol" },
    { 0x80fd,	"Compression Control Protocol" },
    { 0xc021,	"Link Control Protocol" },
    { 0xc023,	"Password Authentication Protocol" },
    { 0xc025,	"Link Quality Report" },
    { 0xc027,	"Shiva Password Authentication Protocol" },
    { 0xc029,	"CallBack Control Protocol (CBCP)" },
    { 0xc081,	"Container Control Protocol" },
    { 0xc223,	"Challenge Handshake Authentication Protocol" },
    { 0xc281,	"Proprietary Authentication Protocol" },
    { 0,	NULL },
};

/*
 * protocol_name - find a name for a PPP protocol.
 */
const char *
protocol_name(proto)
    int proto;
{
    struct protocol_list *lp;

    for (lp = protocol_list; lp->proto != 0; ++lp)
	if (proto == lp->proto)
	    return lp->name;
    return NULL;
}

/*
 * get_input - called when incoming data is available.
 */
static void
get_input()
{
    int len, i;
    u_char *p;
    u_short protocol;
    struct protent *protp;

    p = inpacket_buf;	/* point to beginning of packet buffer */

    len = read_packet(inpacket_buf);
    if (len < 0)
	return;

    if (len == 0) {
	notice("Modem hangup");
	hungup = 1;
	status = EXIT_HANGUP;
	lcp_lowerdown(0);	/* serial link is no longer available */
	link_terminated(0);
	return;
    }

    if (debug /*&& (debugflags & DBG_INPACKET)*/)
	dbglog("rcvd %P", p, len);

    if (len < PPP_HDRLEN) {
	MAINDEBUG(("io(): Received short packet."));
	return;
    }

    p += 2;				/* Skip address and control */
    GETSHORT(protocol, p);
    len -= PPP_HDRLEN;

    /*
     * Toss all non-LCP packets unless LCP is OPEN.
     */
    if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
	MAINDEBUG(("get_input: Received non-LCP packet when LCP not open."));
	return;
    }

    /*
     * Until we get past the authentication phase, toss all packets
     * except LCP, LQR and authentication packets.
     */
    if (phase <= PHASE_AUTHENTICATE
	&& !(protocol == PPP_LCP || protocol == PPP_LQR
	     || protocol == PPP_PAP || protocol == PPP_CHAP)) {
	MAINDEBUG(("get_input: discarding proto 0x%x in phase %d",
		   protocol, phase));
	return;
    }

    /*
     * Upcall the proper protocol input routine.
     */
    for (i = 0; (protp = protocols[i]) != NULL; ++i) {
	if (protp->protocol == protocol && protp->enabled_flag) {
	    (*protp->input)(0, p, len);
	    return;
	}
        if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
	    && protp->datainput != NULL) {
	    (*protp->datainput)(0, p, len);
	    return;
	}
    }

    if (debug) {
	const char *pname = protocol_name(protocol);
	if (pname != NULL)
	    warn("Unsupported protocol '%s' (0x%x) received", pname, protocol);
	else
	    warn("Unsupported protocol 0x%x received", protocol);
    }
    lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
}

/*
 * new_phase - signal the start of a new phase of pppd's operation.
 */
void
new_phase(p)
    int p;
{
    phase = p;
    if (new_phase_hook)
	(*new_phase_hook)(p);
}

/*
 * die - clean up state and exit with the specified status.
 */
void
die(status)
    int status;
{
    cleanup();
    syslog(LOG_INFO, "Exit.");
    exit(status);
}

/*
 * cleanup - restore anything which needs to be restored before we exit
 */
/* ARGSUSED */
static void
cleanup()
{
    sys_cleanup();

    if (fd_ppp >= 0)
	disestablish_ppp(ttyfd);
    if (real_ttyfd >= 0)
	close_tty();

    if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT) 
	warn("unable to delete pid file %s: %m", pidfilename);
    pidfilename[0] = 0;
    if (linkpidfile[0] != 0 && unlink(linkpidfile) < 0 && errno != ENOENT) 
	warn("unable to delete pid file %s: %m", linkpidfile);
    linkpidfile[0] = 0;

    if (locked)
	unlock();
}

/*
 * close_tty - restore the terminal device and close it.
 */
static void
close_tty()
{
    /* drop dtr to hang up */
    if (!default_device && modem) {
	setdtr(real_ttyfd, 0);
	/*
	 * This sleep is in case the serial port has CLOCAL set by default,
	 * and consequently will reassert DTR when we close the device.
	 */
	sleep(1);
    }

    restore_tty(real_ttyfd);

    if (tty_mode != (mode_t) -1) {
	if (fchmod(real_ttyfd, tty_mode) != 0) {
	    /* XXX if devnam is a symlink, this will change the link */
	    chmod(devnam, tty_mode);
	}
    }

    close(real_ttyfd);
    real_ttyfd = -1;
}

/*
 * update_link_stats - get stats at link termination.
 */
void
update_link_stats(u)
    int u;
{
    struct timeval now;
    char numbuf[32];

    if (!get_ppp_stats(u, &link_stats)
	|| gettimeofday(&now, NULL) < 0)
	return;
    link_connect_time = now.tv_sec - start_time.tv_sec;
    link_stats_valid = 1;

    slprintf(numbuf, sizeof(numbuf), "%d", link_connect_time);
    script_setenv("CONNECT_TIME", numbuf);
    slprintf(numbuf, sizeof(numbuf), "%d", link_stats.bytes_out);
    script_setenv("BYTES_SENT", numbuf);
    slprintf(numbuf, sizeof(numbuf), "%d", link_stats.bytes_in);
    script_setenv("BYTES_RCVD", numbuf);
}


struct	callout {
    struct timeval	c_time;		/* time at which to call routine */
    void		*c_arg;		/* argument to routine */
    void		(*c_func) __P((void *)); /* routine */
    struct		callout *c_next;
};

static struct callout *callout = NULL;	/* Callout list */
static struct timeval timenow;		/* Current time */

/*
 * timeout - Schedule a timeout.
 *
 * Note that this timeout takes the number of seconds, NOT hz (as in
 * the kernel).
 */
void
timeout(func, arg, time)
    void (*func) __P((void *));
    void *arg;
    int time;
{
    struct callout *newp, *p, **pp;
  
    MAINDEBUG(("Timeout %p:%p in %d seconds.", func, arg, time));
  
    /*
     * Allocate timeout.
     */
    if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
	fatal("Out of memory in timeout()!");
    newp->c_arg = arg;
    newp->c_func = func;
    gettimeofday(&timenow, NULL);
    newp->c_time.tv_sec = timenow.tv_sec + time;
    newp->c_time.tv_usec = timenow.tv_usec;
  
    /*
     * Find correct place and link it in.
     */
    for (pp = &callout; (p = *pp); pp = &p->c_next)
	if (newp->c_time.tv_sec < p->c_time.tv_sec
	    || (newp->c_time.tv_sec == p->c_time.tv_sec
		&& newp->c_time.tv_usec < p->c_time.tv_usec))
	    break;
    newp->c_next = p;
    *pp = newp;
}


/*
 * untimeout - Unschedule a timeout.
 */
void
untimeout(func, arg)
    void (*func) __P((void *));
    void *arg;
{
    struct callout **copp, *freep;
  
    MAINDEBUG(("Untimeout %p:%p.", func, arg));
  
    /*
     * Find first matching timeout and remove it from the list.
     */
    for (copp = &callout; (freep = *copp); copp = &freep->c_next)
	if (freep->c_func == func && freep->c_arg == arg) {
	    *copp = freep->c_next;
	    free((char *) freep);
	    break;
	}
}


/*
 * calltimeout - Call any timeout routines which are now due.
 */
static void
calltimeout()
{
    struct callout *p;

    while (callout != NULL) {
	p = callout;

	if (gettimeofday(&timenow, NULL) < 0)
	    fatal("Failed to get time of day: %m");
	if (!(p->c_time.tv_sec < timenow.tv_sec
	      || (p->c_time.tv_sec == timenow.tv_sec
		  && p->c_time.tv_usec <= timenow.tv_usec)))
	    break;		/* no, it's not time yet */

	callout = p->c_next;
	(*p->c_func)(p->c_arg);

	free((char *) p);
    }
}


/*
 * timeleft - return the length of time until the next timeout is due.
 */
static struct timeval *
timeleft(tvp)
    struct timeval *tvp;
{
    if (callout == NULL)
	return NULL;

    gettimeofday(&timenow, NULL);
    tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
    tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
    if (tvp->tv_usec < 0) {
	tvp->tv_usec += 1000000;
	tvp->tv_sec -= 1;
    }
    if (tvp->tv_sec < 0)
	tvp->tv_sec = tvp->tv_usec = 0;

    return tvp;
}


/*
 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
 */
static void
kill_my_pg(sig)
    int sig;
{
    struct sigaction act, oldact;

    act.sa_handler = SIG_IGN;
    act.sa_flags = 0;
    kill(0, sig);
    sigaction(sig, &act, &oldact);
    sigaction(sig, &oldact, NULL);
}


/*
 * hup - Catch SIGHUP signal.
 *
 * Indicates that the physical layer has been disconnected.
 * We don't rely on this indication; if the user has sent this
 * signal, we just take the link down.
 */
static void
hup(sig)
    int sig;
{
    info("Hangup (SIGHUP)");
    kill_link = 1;
    if (status != EXIT_HANGUP)
	status = EXIT_USER_REQUEST;
    if (conn_running)
	/* Send the signal to the [dis]connector process(es) also */
	kill_my_pg(sig);
    if (charshunt_pid)
	kill(charshunt_pid, sig);
    if (waiting)
	siglongjmp(sigjmp, 1);
}


/*
 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
 *
 * Indicates that we should initiate a graceful disconnect and exit.
 */
/*ARGSUSED*/
static void
term(sig)
    int sig;
{
    info("Terminating on signal %d.", sig);
    persist = 0;		/* don't try to restart */
    kill_link = 1;
    status = EXIT_USER_REQUEST;
    if (conn_running)
	/* Send the signal to the [dis]connector process(es) also */
	kill_my_pg(sig);
    if (charshunt_pid)
	kill(charshunt_pid, sig);
    if (waiting)
	siglongjmp(sigjmp, 1);
}


/*
 * chld - Catch SIGCHLD signal.
 * Sets a flag so we will call reap_kids in the mainline.
 */
static void
chld(sig)
    int sig;
{
    got_sigchld = 1;
    if (waiting)
	siglongjmp(sigjmp, 1);
}


/*
 * toggle_debug - Catch SIGUSR1 signal.
 *
 * Toggle debug flag.
 */
/*ARGSUSED*/
static void
toggle_debug(sig)
    int sig;
{
    debug = !debug;
    if (debug) {
	setlogmask(LOG_UPTO(LOG_DEBUG));
    } else {
	setlogmask(LOG_UPTO(LOG_WARNING));
    }
}


/*
 * open_ccp - Catch SIGUSR2 signal.
 *
 * Try to (re)negotiate compression.
 */
/*ARGSUSED*/
static void
open_ccp(sig)
    int sig;
{
    open_ccp_flag = 1;
    if (waiting)
	siglongjmp(sigjmp, 1);
}


/*
 * bad_signal - We've caught a fatal signal.  Clean up state and exit.
 */
static void
bad_signal(sig)
    int sig;
{
    static int crashed = 0;

    if (crashed)
	_exit(127);
    crashed = 1;
    error("Fatal signal %d", sig);
    if (conn_running)
	kill_my_pg(SIGTERM);
    if (charshunt_pid)
	kill(charshunt_pid, SIGTERM);
    die(127);
}


/*
 * device_script - run a program to talk to the serial device
 * (e.g. to run the connector or disconnector script).
 */
static int
device_script(program, in, out, dont_wait)
    char *program;
    int in, out;
    int dont_wait;
{
    int pid;
    int status = -1;
    int errfd;

    ++conn_running;
    pid = fork();

    if (pid < 0) {
	--conn_running;
	error("Failed to create child process: %m");
	return -1;
    }

    if (pid == 0) {
	sys_close();
	closelog();
	if (in == 2) {
	    /* aargh!!! */
	    int newin = dup(in);
	    if (in == out)
		out = newin;
	    in = newin;
	} else if (out == 2) {
	    out = dup(out);
	}
	if (log_to_fd >= 0) {
	    if (log_to_fd != 2)
		dup2(log_to_fd, 2);
	} else {
	    close(2);
	    errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
	    if (errfd >= 0 && errfd != 2) {
		dup2(errfd, 2);
		close(errfd);
	    }
	}
	if (in != 0) {
	    if (out == 0)
		out = dup(out);
	    dup2(in, 0);
	}
	if (out != 1) {
	    dup2(out, 1);
	}
	if (real_ttyfd > 2)
	    close(real_ttyfd);
	if (pty_master > 2)
	    close(pty_master);
	if (pty_slave > 2)
	    close(pty_slave);
	setuid(uid);
	if (getuid() != uid) {
	    error("setuid failed");
	    exit(1);
	}
	setgid(getgid());
	execl("/bin/sh", "sh", "-c", program, (char *)0);
	error("could not exec /bin/sh: %m");
	exit(99);
	/* NOTREACHED */
    }

    if (dont_wait) {
	record_child(pid, program, NULL, NULL);
	status = 0;