main.c

自己精简过的PPPD代码。在嵌入中应用可以更好的发挥。比原先的小了很多

	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 ||
		protocol == PPP_EAP)) {
	dbglog("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);
}

/*
 * ppp_send_config - configure the transmit-side characteristics of
 * the ppp interface.  Returns -1, indicating an error, if the channel
 * send_config procedure called error() (or incremented error_count
 * itself), otherwise 0.
 */
int
ppp_send_config(unit, mtu, accm, pcomp, accomp)
    int unit, mtu;
    u_int32_t accm;
    int pcomp, accomp;
{
	int errs;

	if (the_channel->send_config == NULL)
		return 0;
	errs = error_count;
	(*the_channel->send_config)(mtu, accm, pcomp, accomp);
	return (error_count != errs)? -1: 0;
}

/*
 * ppp_recv_config - configure the receive-side characteristics of
 * the ppp interface.  Returns -1, indicating an error, if the channel
 * recv_config procedure called error() (or incremented error_count
 * itself), otherwise 0.
 */
int
ppp_recv_config(unit, mru, accm, pcomp, accomp)
    int unit, mru;
    u_int32_t accm;
    int pcomp, accomp;
{
	int errs;

	if (the_channel->recv_config == NULL)
		return 0;
	errs = error_count;
	(*the_channel->recv_config)(mru, accm, pcomp, accomp);
	return (error_count != errs)? -1: 0;
}

/*
 * 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);
    notify(phasechange, p);
}

/*
 * die - clean up state and exit with the specified status.
 */
void
die(status)
    int status;
{
    if (!doing_multilink || multilink_master)
	print_link_stats();
    cleanup();
    notify(exitnotify, status);
    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)
	the_channel->disestablish_ppp(devfd);
    if (the_channel->cleanup)
	(*the_channel->cleanup)();
    remove_pidfiles();

#ifdef USE_TDB
    if (pppdb != NULL)
	cleanup_db();
#endif

}

void
print_link_stats()
{
    /*
     * Print connect time and statistics.
     */
    if (link_stats_valid) {
       int t = (link_connect_time + 5) / 6;    /* 1/10ths of minutes */
       info("Connect time %d.%d minutes.", t/10, t%10);
       info("Sent %u bytes, received %u bytes.",
	    link_stats.bytes_out, link_stats.bytes_in);
       link_stats_valid = 0;
    }
}

/*
 * reset_link_stats - "reset" stats when link goes up.
 */
void
reset_link_stats(u)
    int u;
{
    if (!get_ppp_stats(u, &old_link_stats))
	return;
    gettimeofday(&start_time, NULL);
}

/*
 * 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;

    link_stats.bytes_in  -= old_link_stats.bytes_in;
    link_stats.bytes_out -= old_link_stats.bytes_out;
    link_stats.pkts_in   -= old_link_stats.pkts_in;
    link_stats.pkts_out  -= old_link_stats.pkts_out;

    slprintf(numbuf, sizeof(numbuf), "%u", link_connect_time);
    script_setenv("CONNECT_TIME", numbuf, 0);
    slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_out);
    script_setenv("BYTES_SENT", numbuf, 0);
    slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_in);
    script_setenv("BYTES_RCVD", numbuf, 0);
}


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.
 */
void
timeout(func, arg, secs, usecs)
    void (*func) __P((void *));
    void *arg;
    int secs, usecs;
{
    struct callout *newp, *p, **pp;

    /*
     * 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 + secs;
    newp->c_time.tv_usec = timenow.tv_usec + usecs;
    if (newp->c_time.tv_usec >= 1000000) {
	newp->c_time.tv_sec += newp->c_time.tv_usec / 1000000;
	newp->c_time.tv_usec %= 1000000;
    }

    /*
     * 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;

    /*
     * 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.
 * We assume that sig is currently blocked.
 */
static void
kill_my_pg(sig)
    int sig;
{
    struct sigaction act, oldact;

    sigemptyset(&act.sa_mask);		/* unnecessary in fact */
    act.sa_handler = SIG_IGN;
    act.sa_flags = 0;
    kill(0, sig);
    /*
     * The kill() above made the signal pending for us, as well as
     * the rest of our process group, but we don't want it delivered
     * to us.  It is blocked at the moment.  Setting it to be ignored
     * will cause the pending signal to be discarded.  If we did the
     * kill() after setting the signal to be ignored, it is unspecified
     * (by POSIX) whether the signal is immediately discarded or left
     * pending, and in fact Linux would leave it pending, and so it
     * would be delivered after the current signal handler exits,
     * leading to an infinite loop.
     */
    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;
{
    /* can't log a message here, it can deadlock */
    got_sighup = 1;
    if (conn_running)
	/* Send the signal to the [dis]connector process(es) also */
	kill_my_pg(sig);
    notify(sigreceived, 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;
{
    /* can't log a message here, it can deadlock */
    got_sigterm = sig;
    if (conn_running)
	/* Send the signal to the [dis]connector process(es) also */
	kill_my_pg(sig);
    notify(sigreceived, 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;
{
    got_sigusr2 = 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);
    notify(sigreceived, sig);
    die(127);
}

/*
 * safe_fork - Create a child process.  The child closes all the
 * file descriptors that we don't want to leak to a script.
 * The parent waits for the child to do this before returning.
 * This also arranges for the specified fds to be dup'd to
 * fds 0, 1, 2 in the child.
 */
pid_t
safe_fork(int infd, int outfd, int errfd)
{
	pid_t pid;
	int fd, pipefd[2];
	char buf[1];

	/* make sure fds 0, 1, 2 are occupied (probably not necessary) */
	while ((fd = dup(fd_devnull)) >= 0) {
		if (fd > 2) {
			close(fd);
			break;
		}
	}

	if (pipe(pipefd) == -1)
		pipefd[0] = pipefd[1] = -1;
	pid = fork();
	if (pid < 0) {
		error("fork failed: %m");
		return -1;
	}
	if (pid > 0) {
		/* parent */
		close(pipefd[1]);
		/* this read() blocks until the close(pipefd[1]) below */
		complete_read(pipefd[0], buf, 1);
		close(pipefd[0]);
		return pid;
	}

	/* Executing in the child */
	sys_close();
#ifdef USE_TDB
	tdb_close(pppdb);
#endif

	/* make sure infd, outfd and errfd won't get tromped on below */
	if (infd == 1 || infd == 2)
		infd = dup(infd);
	if (outfd == 0 || outfd == 2)
		outfd = dup(outfd);
	if (errfd == 0 || errfd == 1)
		errfd = dup(errfd);

	/* dup the in, out, err fds to 0, 1, 2 */
	if (infd != 0)
		dup2(infd, 0);
	if (outfd != 1)
		dup2(outfd, 1);
	if (errfd != 2)
		dup2(errfd, 2);

	closelog();
	if (log_to_fd > 2)
		close(log_to_fd);
	if (the_channel->close)
		(*the_channel->close)();
	else
		close(devfd);	/* some plugins don't have a close function */
	close(fd_ppp);
	close(fd_devnull);
	if (infd != 0)
		close(infd);
	if (outfd != 1)
		close(outfd);
	if (errfd != 2)
		close(errfd);

	notify(fork_notifier, 0);
	close(pipefd[0]);
	/* this close unblocks the read() call above in the parent */
	close(pipefd[1]);

	return 0;
}