options.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 * options.c - handles option processing for PPP.
 *
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#define RCSID	"$Id: options.c,v 1.4.4.1 2003/04/10 13:09:09 joel Exp $"

#include <ctype.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <termios.h>
#include <string.h>
#include <netdb.h>
#include <pwd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#ifdef PLUGIN
#include <dlfcn.h>
#endif
#ifdef PPP_FILTER
#include <pcap.h>
#include <pcap-int.h>	/* XXX: To get struct pcap */
#endif

#include "pppd.h"
#include "pathnames.h"
#include "patchlevel.h"
#include "fsm.h"
#include "lcp.h"
#include "ipcp.h"
#include "upap.h"
#include "chap.h"
#include "ccp.h"

#include <net/ppp-comp.h>

#if defined(ultrix) || defined(NeXT)
char *strdup __P((char *));
#endif

static const char rcsid[] = RCSID;

/*
 * Option variables and default values.
 */
#ifdef PPP_FILTER
int	dflag = 0;		/* Tell libpcap we want debugging */
#endif
int	debug = 0;		/* Debug flag */
int	kdebugflag = 0;		/* Tell kernel to print debug messages */
int	default_device = 1;	/* Using /dev/tty or equivalent */
char	devnam[MAXPATHLEN];	/* Device name */
int	crtscts = 0;		/* Use hardware flow control */
bool	modem = 1;		/* Use modem control lines */
int	inspeed = 0;		/* Input/Output speed requested */
u_int32_t netmask = 0;		/* IP netmask to set on interface */
bool	lockflag = 0;		/* Create lock file to lock the serial dev */
bool	nodetach = 0;		/* Don't detach from controlling tty */
bool	updetach = 0;		/* Detach once link is up */
char	*initializer = NULL;	/* Script to initialize physical link */
char	*connect_script = NULL;	/* Script to establish physical link */
char	*disconnect_script = NULL; /* Script to disestablish physical link */
char	*welcomer = NULL;	/* Script to run after phys link estab. */
char	*ptycommand = NULL;	/* Command to run on other side of pty */
int	maxconnect = 0;		/* Maximum connect time */
char	user[MAXNAMELEN];	/* Username for PAP */
char	passwd[MAXSECRETLEN];	/* Password for PAP */
bool	persist = 0;		/* Reopen link after it goes down */
char	our_name[MAXNAMELEN];	/* Our name for authentication purposes */
bool	demand = 0;		/* do dial-on-demand */
char	*ipparam = NULL;	/* Extra parameter for ip up/down scripts */
int	idle_time_limit = 0;	/* Disconnect if idle for this many seconds */
int	holdoff = 30;		/* # seconds to pause before reconnecting */
bool	holdoff_specified;	/* true if a holdoff value has been given */
bool	notty = 0;		/* Stdin/out is not a tty */
char	*record_file = NULL;	/* File to record chars sent/received */
int	using_pty = 0;
bool	sync_serial = 0;	/* Device is synchronous serial device */
int	log_to_fd = 1;		/* send log messages to this fd too */
int	maxfail = 10;		/* max # of unsuccessful connection attempts */
char	linkname[MAXPATHLEN];	/* logical name for link */
bool	tune_kernel;		/* may alter kernel settings */
int	connect_delay = 1000;	/* wait this many ms after connect script */

extern option_t auth_options[];
extern struct stat devstat;
extern int prepass;		/* Doing pre-pass to find device name */

struct option_info initializer_info;
struct option_info connect_script_info;
struct option_info disconnect_script_info;
struct option_info welcomer_info;
struct option_info devnam_info;
struct option_info ptycommand_info;

#ifdef PPP_FILTER
struct	bpf_program pass_filter;/* Filter program for packets to pass */
struct	bpf_program active_filter; /* Filter program for link-active pkts */
pcap_t  pc;			/* Fake struct pcap so we can compile expr */
#endif

char *current_option;		/* the name of the option being parsed */
int  privileged_option;		/* set iff the current option came from root */
char *option_source;		/* string saying where the option came from */
bool log_to_file;		/* log_to_fd is a file opened by us */

/*
 * Prototypes
 */
static int setdevname __P((char *));
static int setipaddr __P((char *));
static int setspeed __P((char *));
static int noopt __P((char **));
static int setdomain __P((char **));
static int setnetmask __P((char **));
static int setxonxoff __P((char **));
static int readfile __P((char **));
static int callfile __P((char **));
static void usage __P((void));
static int setlogfile __P((char **));
#ifdef PLUGIN
static int loadplugin __P((char **));
#endif

#ifdef PPP_FILTER
static int setpassfilter __P((char **));
static int setactivefilter __P((char **));
#endif

static option_t *find_option __P((char *name));
static int process_option __P((option_t *, char **));
static int n_arguments __P((option_t *));
static int number_option __P((char *, u_int32_t *, int));

/*
 * Structure to store extra lists of options.
 */
struct option_list {
    option_t *options;
    struct option_list *next;
};

static struct option_list *extra_options = NULL;

/*
 * Valid arguments.
 */
option_t general_options[] = {
    { "debug", o_int, &debug,
      "Increase debugging level", OPT_INC|OPT_NOARG|1 },
    { "-d", o_int, &debug,
      "Increase debugging level", OPT_INC|OPT_NOARG|1 },
    { "kdebug", o_int, &kdebugflag,
      "Set kernel driver debug level" },
    { "nodetach", o_bool, &nodetach,
      "Don't detach from controlling tty", 1 },
    { "-detach", o_bool, &nodetach,
      "Don't detach from controlling tty", 1 },
    { "updetach", o_bool, &updetach,
      "Detach from controlling tty once link is up", 1 },
    { "holdoff", o_int, &holdoff,
      "Set time in seconds before retrying connection" },
    { "idle", o_int, &idle_time_limit,
      "Set time in seconds before disconnecting idle link" },
    { "lock", o_bool, &lockflag,
      "Lock serial device with UUCP-style lock file", 1 },
    { "-all", o_special_noarg, noopt,
      "Don't request/allow any LCP or IPCP options (useless)" },
    { "init", o_string, &initializer,
      "A program to initialize the device",
      OPT_A2INFO | OPT_PRIVFIX, &initializer_info },
    { "connect", o_string, &connect_script,
      "A program to set up a connection",
      OPT_A2INFO | OPT_PRIVFIX, &connect_script_info },
    { "disconnect", o_string, &disconnect_script,
      "Program to disconnect serial device",
      OPT_A2INFO | OPT_PRIVFIX, &disconnect_script_info },
    { "welcome", o_string, &welcomer,
      "Script to welcome client",
      OPT_A2INFO | OPT_PRIVFIX, &welcomer_info },
    { "pty", o_string, &ptycommand,
      "Script to run on pseudo-tty master side",
      OPT_A2INFO | OPT_PRIVFIX | OPT_DEVNAM, &ptycommand_info },
    { "notty", o_bool, &notty,
      "Input/output is not a tty", OPT_DEVNAM | 1 },
    { "record", o_string, &record_file,
      "Record characters sent/received to file" },
    { "maxconnect", o_int, &maxconnect,
      "Set connection time limit", OPT_LLIMIT|OPT_NOINCR|OPT_ZEROINF },
    { "crtscts", o_int, &crtscts,
      "Set hardware (RTS/CTS) flow control", OPT_NOARG|OPT_VAL(1) },
    { "nocrtscts", o_int, &crtscts,
      "Disable hardware flow control", OPT_NOARG|OPT_VAL(-1) },
    { "-crtscts", o_int, &crtscts,
      "Disable hardware flow control", OPT_NOARG|OPT_VAL(-1) },
    { "cdtrcts", o_int, &crtscts,
      "Set alternate hardware (DTR/CTS) flow control", OPT_NOARG|OPT_VAL(2) },
    { "nocdtrcts", o_int, &crtscts,
      "Disable hardware flow control", OPT_NOARG|OPT_VAL(-1) },
    { "xonxoff", o_special_noarg, setxonxoff,
      "Set software (XON/XOFF) flow control" },
    { "domain", o_special, setdomain,
      "Add given domain name to hostname" },
    { "mtu", o_int, &lcp_allowoptions[0].mru,
      "Set our MTU", OPT_LIMITS, NULL, MAXMRU, MINMRU },
    { "netmask", o_special, setnetmask,
      "set netmask" },
    { "modem", o_bool, &modem,
      "Use modem control lines", 1 },
    { "local", o_bool, &modem,
      "Don't use modem control lines" },
    { "file", o_special, readfile,
      "Take options from a file", OPT_PREPASS },
    { "call", o_special, callfile,
      "Take options from a privileged file", OPT_PREPASS },
    { "persist", o_bool, &persist,
      "Keep on reopening connection after close", 1 },
    { "nopersist", o_bool, &persist,
      "Turn off persist option" },
    { "demand", o_bool, &demand,
      "Dial on demand", OPT_INITONLY | 1, &persist },
    { "sync", o_bool, &sync_serial,
      "Use synchronous HDLC serial encoding", 1 },
    { "logfd", o_int, &log_to_fd,
      "Send log messages to this file descriptor" },
    { "logfile", o_special, setlogfile,
      "Append log messages to this file" },
    { "nolog", o_int, &log_to_fd,
      "Don't send log messages to any file",
      OPT_NOARG | OPT_VAL(-1) },
    { "nologfd", o_int, &log_to_fd,
      "Don't send log messages to any file descriptor",
      OPT_NOARG | OPT_VAL(-1) },
    { "linkname", o_string, linkname,
      "Set logical name for link",
      OPT_PRIV|OPT_STATIC, NULL, MAXPATHLEN },
    { "maxfail", o_int, &maxfail,
      "Maximum number of unsuccessful connection attempts to allow" },
    { "ktune", o_bool, &tune_kernel,
      "Alter kernel settings as necessary", 1 },
    { "noktune", o_bool, &tune_kernel,
      "Don't alter kernel settings", 0 },
    { "connect-delay", o_int, &connect_delay,
      "Maximum time (in ms) to wait after connect script finishes" },
#ifdef PLUGIN
    { "plugin", o_special, loadplugin,
      "Load a plug-in module into pppd", OPT_PRIV },
#endif

#ifdef PPP_FILTER
    { "pdebug", o_int, &dflag,
      "libpcap debugging" },
    { "pass-filter", 1, setpassfilter,
      "set filter for packets to pass" },
    { "active-filter", 1, setactivefilter,
      "set filter for active pkts" },
#endif

    { NULL }
};

#ifndef IMPLEMENTATION
#define IMPLEMENTATION ""
#endif

static char *usage_string = "\
pppd version %s.%d%s\n\
Usage: %s [ options ], where options are:\n\
	<device>	Communicate over the named device\n\
	<speed>		Set the baud rate to <speed>\n\
	<loc>:<rem>	Set the local and/or remote interface IP\n\
			addresses.  Either one may be omitted.\n\
	asyncmap <n>	Set the desired async map to hex <n>\n\
	auth		Require authentication from peer\n\
        connect <p>     Invoke shell command <p> to set up the serial line\n\
	crtscts		Use hardware RTS/CTS flow control\n\
	defaultroute	Add default route through interface\n\
	file <f>	Take options from file <f>\n\
	modem		Use modem control lines\n\
	mru <n>		Set MRU value to <n> for negotiation\n\
See pppd(8) for more options.\n\
";

/*
 * parse_args - parse a string of arguments from the command line.
 * If prepass is true, we are scanning for the device name and only
 * processing a few options, so error messages are suppressed.
 */
int
parse_args(argc, argv)
    int argc;
    char **argv;
{
    char *arg;
    option_t *opt;
    int ret;

    privileged_option = privileged;
    option_source = "command line";
    while (argc > 0) {
	arg = *argv++;
	--argc;

	/*
	 * First see if it's an option in the new option list.
	 */
	opt = find_option(arg);
	if (opt != NULL) {
	    int n = n_arguments(opt);
	    if (argc < n) {
		option_error("too few parameters for option %s", arg);
		return 0;
	    }
	    current_option = arg;
	    if (!process_option(opt, argv))
		return 0;
	    argc -= n;
	    argv += n;
	    continue;
	}

	/*
	 * Maybe a tty name, speed or IP address?
	 */
	if ((ret = setdevname(arg)) == 0
	    && (ret = setspeed(arg)) == 0
	    && (ret = setipaddr(arg)) == 0
	    && !prepass) {
	    option_error("unrecognized option '%s'", arg);
	    usage();
	    return 0;
	}
	if (ret < 0)	/* error */
	    return 0;
    }
    return 1;
}

#if 0
/*
 * scan_args - scan the command line arguments to get the tty name,
 * if specified.  Also checks whether the notty or pty option was given.
 */
void
scan_args(argc, argv)
    int argc;
    char **argv;
{
    char *arg;
    option_t *opt;

    privileged_option = privileged;
    while (argc > 0) {
	arg = *argv++;
	--argc;

	if (strcmp(arg, "notty") == 0 || strcmp(arg, "pty") == 0)
	    using_pty = 1;

	/* Skip options and their arguments */
	opt = find_option(arg);
	if (opt != NULL) {
	    int n = n_arguments(opt);
	    argc -= n;
	    argv += n;
	    continue;
	}

	/* Check if it's a tty name and copy it if so */
	(void) setdevname(arg, 1);
    }
}
#endif

/*
 * options_from_file - Read a string of options from a file,
 * and interpret them.
 */
int
options_from_file(filename, must_exist, check_prot, priv)
    char *filename;
    int must_exist;
    int check_prot;
    int priv;
{
    FILE *f;
    int i, newline, ret, err;
    option_t *opt;
    int oldpriv;
    char *oldsource;
    char *argv[MAXARGS];
    char args[MAXARGS][MAXWORDLEN];
    char cmd[MAXWORDLEN];

    f = fopen(filename, "r");
    err = errno;
    if (f == NULL) {
	if (!must_exist && err == ENOENT)
	    return 1;
	errno = err;
	option_error("Can't open options file %s: %m", filename);
	return 0;
    }

    oldpriv = privileged_option;
    privileged_option = priv;
    oldsource = option_source;
    option_source = strdup(filename);
    if (option_source == NULL)
	option_source = "file";
    ret = 0;
    while (getword(f, cmd, &newline, filename)) {
	/*
	 * First see if it's a command.
	 */
	opt = find_option(cmd);
	if (opt != NULL) {
	    int n = n_arguments(opt);
	    for (i = 0; i < n; ++i) {
		if (!getword(f, args[i], &newline, filename)) {
		    option_error(
			"In file %s: too few parameters for option '%s'",
			filename, cmd);
		    goto err;
		}
		argv[i] = args[i];
	    }
	    current_option = cmd;
	    if ((opt->flags & OPT_DEVEQUIV) && devnam_fixed) {
		option_error("the %s option may not be used in the %s file",
			     cmd, filename);
		goto err;
	    }
	    if (!process_option(opt, argv))
		goto err;
	    continue;
	}

	/*
	 * Maybe a tty name, speed or IP address?
	 */
	if ((i = setdevname(cmd)) == 0
	    && (i = setspeed(cmd)) == 0
	    && (i = setipaddr(cmd)) == 0) {
	    option_error("In file %s: unrecognized option '%s'",
			 filename, cmd);
	    goto err;
	}
	if (i < 0)		/* error */
	    goto err;
    }
    ret = 1;

err:
    fclose(f);
    privileged_option = oldpriv;
    option_source = oldsource;
    return ret;
}

/*
 * options_from_user - See if the use has a ~/.ppprc file,
 * and if so, interpret options from it.
 */
int
options_from_user()
{
    return 0;
}

/*
 * options_for_tty - See if an options file exists for the serial
 * device, and if so, interpret options from it.
 */
int
options_for_tty()
{
    char *dev, *path, *p;
    int ret;
    size_t pl;

    dev = devnam;
    if (strncmp(dev, "/dev/", 5) == 0)
	dev += 5;
    if (dev[0] == 0 || strcmp(dev, "tty") == 0)
	return 1;		/* don't look for /etc/ppp/options.tty */
    pl = strlen(_PATH_TTYOPT) + strlen(dev) + 1;
    path = malloc(pl);
    if (path == NULL)
	novm("tty init file name");