main.c

unix and linux net driver

		    kill_link = 0;
		}
		if (get_loop_output())
		    break;
		if (got_sigchld)
		    reap_kids(0);
	    }
	    remove_fd(fd_loop);
	    if (kill_link && !persist)
		break;

	    /*
	     * Now we want to bring up the link.
	     */
	    demand_block();
	    info("Starting link");
	}

	new_phase(PHASE_SERIALCONN);

	/*
	 * Get a pty master/slave pair if the pty, notty, or record
	 * options were specified.
	 */
	strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
	pty_master = -1;
	pty_slave = -1;
	if (ptycommand != NULL || notty || record_file != NULL) {
	    if (!get_pty(&pty_master, &pty_slave, ppp_devnam, uid)) {
		error("Couldn't allocate pseudo-tty");
		status = EXIT_FATAL_ERROR;
		goto fail;
	    }
	    set_up_tty(pty_slave, 1);
	}

	/*
	 * Lock the device if we've been asked to.
	 */
	status = EXIT_LOCK_FAILED;
	if (lockflag && !privopen) {
	    if (lock(devnam) < 0)
		goto fail;
	    locked = 1;
	}

	/*
	 * Open the serial device and set it up to be the ppp interface.
	 * First we open it in non-blocking mode so we can set the
	 * various termios flags appropriately.  If we aren't dialling
	 * out and we want to use the modem lines, we reopen it later
	 * in order to wait for the carrier detect signal from the modem.
	 */
	hungup = 0;
	kill_link = 0;
	connector = doing_callback? callback_script: connect_script;
	if (devnam[0] != 0) {
	    for (;;) {
		/* If the user specified the device name, become the
		   user before opening it. */
		int err;
		if (!devnam_info.priv && !privopen)
		    seteuid(uid);
		ttyfd = open(devnam, O_NONBLOCK | O_RDWR, 0);
		err = errno;
		if (!devnam_info.priv && !privopen)
		    seteuid(0);
		if (ttyfd >= 0)
		    break;
		errno = err;
		if (err != EINTR) {
		    error("Failed to open %s: %m", devnam);
		    status = EXIT_OPEN_FAILED;
		}
		if (!persist || err != EINTR)
		    goto fail;
	    }
	    if ((fdflags = fcntl(ttyfd, F_GETFL)) == -1
		|| fcntl(ttyfd, F_SETFL, fdflags & ~O_NONBLOCK) < 0)
		warn("Couldn't reset non-blocking mode on device: %m");

	    /*
	     * Do the equivalent of `mesg n' to stop broadcast messages.
	     */
	    if (fstat(ttyfd, &statbuf) < 0
		|| fchmod(ttyfd, statbuf.st_mode & ~(S_IWGRP | S_IWOTH)) < 0) {
		warn("Couldn't restrict write permissions to %s: %m", devnam);
	    } else
		tty_mode = statbuf.st_mode;

	    /*
	     * Set line speed, flow control, etc.
	     * If we have a non-null connection or initializer script,
	     * on most systems we set CLOCAL for now so that we can talk
	     * to the modem before carrier comes up.  But this has the
	     * side effect that we might miss it if CD drops before we
	     * get to clear CLOCAL below.  On systems where we can talk
	     * successfully to the modem with CLOCAL clear and CD down,
	     * we could clear CLOCAL at this point.
	     */
	    set_up_tty(ttyfd, ((connector != NULL && connector[0] != 0)
			       || initializer != NULL));
	    real_ttyfd = ttyfd;
	}

	/*
	 * If the notty and/or record option was specified,
	 * start up the character shunt now.
	 */
	status = EXIT_PTYCMD_FAILED;
	if (ptycommand != NULL) {
	    if (record_file != NULL) {
		int ipipe[2], opipe[2], ok;

		if (pipe(ipipe) < 0 || pipe(opipe) < 0)
		    fatal("Couldn't create pipes for record option: %m");
		ok = device_script(ptycommand, opipe[0], ipipe[1], 1) == 0
		    && start_charshunt(ipipe[0], opipe[1]);
		close(ipipe[0]);
		close(ipipe[1]);
		close(opipe[0]);
		close(opipe[1]);
		if (!ok)
		    goto fail;
	    } else {
		if (device_script(ptycommand, pty_master, pty_master, 1) < 0)
		    goto fail;
		ttyfd = pty_slave;
		close(pty_master);
		pty_master = -1;
	    }
	} else if (notty) {
	    if (!start_charshunt(0, 1))
		goto fail;
	} else if (record_file != NULL) {
	    if (!start_charshunt(ttyfd, ttyfd))
		goto fail;
	}

	/* run connection script */
	if ((connector && connector[0]) || initializer) {
	    if (real_ttyfd != -1) {
		/* XXX do this if doing_callback == CALLBACK_DIALIN? */
		if (!default_device && modem) {
		    setdtr(real_ttyfd, 0);	/* in case modem is off hook */
		    sleep(1);
		    setdtr(real_ttyfd, 1);
		}
	    }

	    if (initializer && initializer[0]) {
		if (device_script(initializer, ttyfd, ttyfd, 0) < 0) {
		    error("Initializer script failed");
		    status = EXIT_INIT_FAILED;
		    goto fail;
		}
		if (kill_link)
		    goto disconnect;

		info("Serial port initialized.");
	    }

	    if (connector && connector[0]) {
		if (device_script(connector, ttyfd, ttyfd, 0) < 0) {
		    error("Connect script failed");
		    status = EXIT_CONNECT_FAILED;
		    goto fail;
		}
		if (kill_link)
		    goto disconnect;

		info("Serial connection established.");
	    }

	    /* set line speed, flow control, etc.;
	       clear CLOCAL if modem option */
	    if (real_ttyfd != -1)
		set_up_tty(real_ttyfd, 0);

	    if (doing_callback == CALLBACK_DIALIN)
		connector = NULL;
	}

	/* reopen tty if necessary to wait for carrier */
	if (connector == NULL && modem && devnam[0] != 0) {
	    for (;;) {
		if ((i = open(devnam, O_RDWR)) >= 0)
		    break;
		if (errno != EINTR) {
		    error("Failed to reopen %s: %m", devnam);
		    status = EXIT_OPEN_FAILED;
		}
		if (!persist || errno != EINTR || hungup || kill_link)
		    goto fail;
	    }
	    close(i);
	}

	slprintf(numbuf, sizeof(numbuf), "%d", baud_rate);
	script_setenv("SPEED", numbuf);

	/* run welcome script, if any */
	if (welcomer && welcomer[0]) {
	    if (device_script(welcomer, ttyfd, ttyfd, 0) < 0)
		warn("Welcome script failed");
	}

	/* set up the serial device as a ppp interface */
	fd_ppp = establish_ppp(ttyfd);
	if (fd_ppp < 0) {
	    status = EXIT_FATAL_ERROR;
	    goto disconnect;
	}

	if (!demand) {
	    
	    info("Using interface ppp%d", ifunit);
	    slprintf(ifname, sizeof(ifname), "ppp%d", ifunit);
	    script_setenv("IFNAME", ifname);

	    create_pidfile();	/* write pid to file */
	}

	/*
	 * Start opening the connection and wait for
	 * incoming events (reply, timeout, etc.).
	 */
	notice("Connect: %s <--> %s", ifname, ppp_devnam);
	gettimeofday(&start_time, NULL);
	link_stats_valid = 0;
	script_unsetenv("CONNECT_TIME");
	script_unsetenv("BYTES_SENT");
	script_unsetenv("BYTES_RCVD");
	lcp_lowerup(0);

	/*
	 * If we are initiating this connection, wait for a short
	 * time for something from the peer.  This can avoid bouncing
	 * our packets off his tty before he has it set up.
	 */
	add_fd(fd_ppp);
	if (connect_delay != 0 && (connector != NULL || ptycommand != NULL)) {
	    struct timeval t;
	    t.tv_sec = connect_delay / 1000;
	    t.tv_usec = connect_delay % 1000;
	    wait_input(&t);
	}

	lcp_open(0);		/* Start protocol */
	open_ccp_flag = 0;
	status = EXIT_NEGOTIATION_FAILED;
	new_phase(PHASE_ESTABLISH);
	while (phase != PHASE_DEAD) {
	    if (sigsetjmp(sigjmp, 1) == 0) {
		sigprocmask(SIG_BLOCK, &mask, NULL);
		if (kill_link || open_ccp_flag || got_sigchld) {
		    sigprocmask(SIG_UNBLOCK, &mask, NULL);
		} else {
		    waiting = 1;
		    sigprocmask(SIG_UNBLOCK, &mask, NULL);
		    wait_input(timeleft(&timo));
		}
	    }
	    waiting = 0;
	    calltimeout();
	    get_input();
	    if (kill_link) {
		lcp_close(0, "User request");
		kill_link = 0;
	    }
	    if (open_ccp_flag) {
		if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
		    ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
		    (*ccp_protent.open)(0);
		}
		open_ccp_flag = 0;
	    }
	    if (got_sigchld)
		reap_kids(0);	/* Don't leave dead kids lying around */
	}

	/*
	 * 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 %d bytes, received %d bytes.",
		 link_stats.bytes_out, link_stats.bytes_in);
	}

	/*
	 * Delete pid file before disestablishing ppp.  Otherwise it
	 * can happen that another pppd gets the same unit and then
	 * we delete its pid file.
	 */
	if (!demand) {
	    if (pidfilename[0] != 0
		&& unlink(pidfilename) < 0 && errno != ENOENT) 
		warn("unable to delete pid file %s: %m", pidfilename);
	    pidfilename[0] = 0;
	}

	/*
	 * If we may want to bring the link up again, transfer
	 * the ppp unit back to the loopback.  Set the
	 * real serial device back to its normal mode of operation.
	 */
	remove_fd(fd_ppp);
	clean_check();
	if (demand)
	    restore_loop();
	disestablish_ppp(ttyfd);
	fd_ppp = -1;
	if (!hungup)
	    lcp_lowerdown(0);

	/*
	 * Run disconnector script, if requested.
	 * XXX we may not be able to do this if the line has hung up!
	 */
    disconnect:
	if (disconnect_script && !hungup) {
	    new_phase(PHASE_DISCONNECT);
	    if (real_ttyfd >= 0)
		set_up_tty(real_ttyfd, 1);
	    if (device_script(disconnect_script, ttyfd, ttyfd, 0) < 0) {
		warn("disconnect script failed");
	    } else {
		info("Serial link disconnected.");
	    }
	}

    fail:
	if (pty_master >= 0)
	    close(pty_master);
	if (pty_slave >= 0)
	    close(pty_slave);
	if (real_ttyfd >= 0)
	    close_tty();
	if (locked) {
	    unlock();
	    locked = 0;
	}

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

	if (!persist || (maxfail > 0 && unsuccess >= maxfail))
	    break;

	kill_link = 0;
	if (demand)
	    demand_discard();
	t = need_holdoff? holdoff: 0;
	if (holdoff_hook)
	    t = (*holdoff_hook)();
	if (t > 0) {
	    new_phase(PHASE_HOLDOFF);
	    TIMEOUT(holdoff_end, NULL, t);
	    do {
		if (sigsetjmp(sigjmp, 1) == 0) {
		    sigprocmask(SIG_BLOCK, &mask, NULL);
		    if (kill_link || got_sigchld) {
			sigprocmask(SIG_UNBLOCK, &mask, NULL);
		    } else {
			waiting = 1;
			sigprocmask(SIG_UNBLOCK, &mask, NULL);
			wait_input(timeleft(&timo));
		    }
		}
		waiting = 0;
		calltimeout();
		if (kill_link) {
		    kill_link = 0;
		    new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
		}
		if (got_sigchld)
		    reap_kids(0);
	    } while (phase == PHASE_HOLDOFF);
	    if (!persist)
		break;
	}
    }

    /* Wait for scripts to finish */
    /* XXX should have a timeout here */
    while (n_children > 0) {
	if (debug) {
	    struct subprocess *chp;
	    dbglog("Waiting for %d child processes...", n_children);
	    for (chp = children; chp != NULL; chp = chp->next)
		dbglog("  script %s, pid %d", chp->prog, chp->pid);
	}
	if (reap_kids(1) < 0)
	    break;
    }

    die(status);
    return 0;
}

/*
 * detach - detach us from the controlling terminal.
 */
void
detach()
{
    int pid;

    if (detached)
	return;
    if ((pid = fork()) < 0) {
	error("Couldn't detach (fork failed: %m)");
	die(1);			/* or just return? */
    }
    if (pid != 0) {
	/* parent */
	if (locked)
	    relock(pid);
	exit(0);		/* parent dies */
    }
    setsid();
    chdir("/");
    close(0);
    close(1);
    close(2);
    detached = 1;
    log_to_fd = -1;
    /* update pid files if they have been written already */
    if (pidfilename[0])
	create_pidfile();
    if (linkpidfile[0])
	create_linkpidfile();
}

/*
 * reopen_log - (re)open our connection to syslog.
 */
void
reopen_log()
{
#ifdef ULTRIX
    openlog("pppd", LOG_PID);
#else
    openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
    setlogmask(LOG_UPTO(LOG_INFO));
#endif
}

/*
 * Create a file containing our process ID.
 */
static void
create_pidfile()
{
    FILE *pidfile;
    char numbuf[16];

    slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
	     _PATH_VARRUN, ifname);
    if ((pidfile = fopen(pidfilename, "w")) != NULL) {
	fprintf(pidfile, "%d\n", getpid());
	(void) fclose(pidfile);
    } else {
	error("Failed to create pid file %s: %m", pidfilename);
	pidfilename[0] = 0;
    }
    slprintf(numbuf, sizeof(numbuf), "%d", getpid());
    script_setenv("PPPD_PID", numbuf);
    if (linkpidfile[0])
	create_linkpidfile();
}

static void
create_linkpidfile()
{
    FILE *pidfile;

    if (linkname[0] == 0)
	return;
    slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
	     _PATH_VARRUN, linkname);
    if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
	fprintf(pidfile, "%d\n", getpid());
	if (pidfilename[0])
	    fprintf(pidfile, "%s\n", ifname);
	(void) fclose(pidfile);
    } else {
	error("Failed to create pid file %s: %m", linkpidfile);
	linkpidfile[0] = 0;
    }
    script_setenv("LINKNAME", linkname);
}

/*
 * holdoff_end - called via a timeout when the holdoff period ends.
 */
static void
holdoff_end(arg)
    void *arg;
{
    new_phase(PHASE_DORMANT);
}

/* List of protocol names, to make our messages a little more informative. */
struct protocol_list {
    u_short	proto;
    const char	*name;
} protocol_list[] = {
    { 0x21,	"IP" },
    { 0x23,	"OSI Network Layer" },
    { 0x25,	"Xerox NS IDP" },
    { 0x27,	"DECnet Phase IV" },
    { 0x29,	"Appletalk" },
    { 0x2b,	"Novell IPX" },
    { 0x2d,	"VJ compressed TCP/IP" },
    { 0x2f,	"VJ uncompressed TCP/IP" },
    { 0x31,	"Bridging PDU" },
    { 0x33,	"Stream Protocol ST-II" },
    { 0x35,	"Banyan Vines" },
    { 0x39,	"AppleTalk EDDP" },
    { 0x3b,	"AppleTalk SmartBuffered" },
    { 0x3d,	"Multi-Link" },
    { 0x3f,	"NETBIOS Framing" },
    { 0x41,	"Cisco Systems" },
    { 0x43,	"Ascom Timeplex" },
    { 0x45,	"Fujitsu Link Backup and Load Balancing (LBLB)" },
    { 0x47,	"DCA Remote Lan" },
    { 0x49,	"Serial Data Transport Protocol (PPP-SDTP)" },
    { 0x4b,	"SNA over 802.2" },
    { 0x4d,	"SNA" },
    { 0x4f,	"IP6 Header Compression" },
    { 0x6f,	"Stampede Bridging" },
    { 0xfb,	"single-link compression" },
    { 0xfd,	"1st choice compression" },
    { 0x0201,	"802.1d Hello Packets" },
    { 0x0203,	"IBM Source Routing BPDU" },
    { 0x0205,	"DEC LANBridge100 Spanning Tree" },
    { 0x0231,	"Luxcom" },
    { 0x0233,	"Sigma Network Systems" },
    { 0x8021,	"Internet Protocol Control Protocol" },
    { 0x8023,	"OSI Network Layer Control Protocol" },
    { 0x8025,	"Xerox NS IDP Control Protocol" },
    { 0x8027,	"DECnet Phase IV Control Protocol" },
    { 0x8029,	"Appletalk Control Protocol" },
    { 0x802b,	"Novell IPX Control Protocol" },
    { 0x8031,	"Bridging NCP" },
    { 0x8033,	"Stream Protocol Control Protocol" },
    { 0x8035,	"Banyan Vines Control Protocol" },
    { 0x803d,	"Multi-Link Control Protocol" },
    { 0x803f,	"NETBIOS Framing Control Protocol" },
    { 0x8041,	"Cisco Systems Control Protocol" },