options.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

    while (w != NULL) {
	opt = find_option(w->word);
	if (opt == NULL) {
	    option_error("In secrets file: unrecognized option '%s'",
			 w->word);
	    goto err;
	}
	n = n_arguments(opt);
	w0 = w;
	for (i = 0; i < n; ++i) {
	    w = w->next;
	    if (w == NULL) {
		option_error(
			"In secrets file: too few parameters for option '%s'",
			w0->word);
		goto err;
	    }
	    argv[i] = w->word;
	}
	if (!process_option(opt, w0->word, argv))
	    goto err;
	w = w->next;
    }
    ret = 1;

err:
    return ret;
}

/*
 * match_option - see if this option matches an option_t structure.
 */
static int
match_option(name, opt, dowild)
    char *name;
    option_t *opt;
    int dowild;
{
	int (*match) __P((char *, char **, int));

	if (dowild != (opt->type == o_wild))
		return 0;
	if (!dowild)
		return strcmp(name, opt->name) == 0;
	match = (int (*) __P((char *, char **, int))) opt->addr;
	return (*match)(name, NULL, 0);
}

/*
 * find_option - scan the option lists for the various protocols
 * looking for an entry with the given name.
 * This could be optimized by using a hash table.
 */
static option_t *
find_option(name)
    const char *name;
{
	option_t *opt;
	struct option_list *list;
	int i, dowild;

	for (dowild = 0; dowild <= 1; ++dowild) {
		for (opt = general_options; opt->name != NULL; ++opt)
			if (match_option(name, opt, dowild))
				return opt;
		for (opt = auth_options; opt->name != NULL; ++opt)
			if (match_option(name, opt, dowild))
				return opt;
		for (list = extra_options; list != NULL; list = list->next)
			for (opt = list->options; opt->name != NULL; ++opt)
				if (match_option(name, opt, dowild))
					return opt;
		for (opt = the_channel->options; opt->name != NULL; ++opt)
			if (match_option(name, opt, dowild))
				return opt;
		for (i = 0; protocols[i] != NULL; ++i)
			if ((opt = protocols[i]->options) != NULL)
				for (; opt->name != NULL; ++opt)
					if (match_option(name, opt, dowild))
						return opt;
	}
	return NULL;
}

/*
 * process_option - process one new-style option.
 */
static int
process_option(opt, cmd, argv)
    option_t *opt;
    char *cmd;
    char **argv;
{
    u_int32_t v;
    int iv, a;
    char *sv;
    int (*parser) __P((char **));
    int (*wildp) __P((char *, char **, int));
    char *optopt = (opt->type == o_wild)? "": " option";
    int prio = option_priority;
    option_t *mainopt = opt;

    current_option = opt->name;
    if ((opt->flags & OPT_PRIVFIX) && privileged_option)
	prio += OPRIO_ROOT;
    while (mainopt->flags & OPT_PRIOSUB)
	--mainopt;
    if (mainopt->flags & OPT_PRIO) {
	if (prio < mainopt->priority) {
	    /* new value doesn't override old */
	    if (prio == OPRIO_CMDLINE && mainopt->priority > OPRIO_ROOT) {
		option_error("%s%s set in %s cannot be overridden\n",
			     opt->name, optopt, mainopt->source);
		return 0;
	    }
	    return 1;
	}
	if (prio > OPRIO_ROOT && mainopt->priority == OPRIO_CMDLINE)
	    warn("%s%s from %s overrides command line",
		 opt->name, optopt, option_source);
    }

    if ((opt->flags & OPT_INITONLY) && phase != PHASE_INITIALIZE) {
	option_error("%s%s cannot be changed after initialization",
		     opt->name, optopt);
	return 0;
    }
    if ((opt->flags & OPT_PRIV) && !privileged_option) {
	option_error("using the %s%s requires root privilege",
		     opt->name, optopt);
	return 0;
    }
    if ((opt->flags & OPT_ENABLE) && *(bool *)(opt->addr2) == 0) {
	option_error("%s%s is disabled", opt->name, optopt);
	return 0;
    }
    if ((opt->flags & OPT_DEVEQUIV) && devnam_fixed) {
	option_error("the %s%s may not be changed in %s",
		     opt->name, optopt, option_source);
	return 0;
    }

    switch (opt->type) {
    case o_bool:
	v = opt->flags & OPT_VALUE;
	*(bool *)(opt->addr) = v;
	if (opt->addr2 && (opt->flags & OPT_A2COPY))
	    *(bool *)(opt->addr2) = v;
	else if (opt->addr2 && (opt->flags & OPT_A2CLR))
	    *(bool *)(opt->addr2) = 0;
	else if (opt->addr2 && (opt->flags & OPT_A2CLRB))
	    *(u_char *)(opt->addr2) &= ~v;
	else if (opt->addr2 && (opt->flags & OPT_A2OR))
	    *(u_char *)(opt->addr2) |= v;
	break;

    case o_int:
	iv = 0;
	if ((opt->flags & OPT_NOARG) == 0) {
	    if (!int_option(*argv, &iv))
		return 0;
	    if ((((opt->flags & OPT_LLIMIT) && iv < opt->lower_limit)
		 || ((opt->flags & OPT_ULIMIT) && iv > opt->upper_limit))
		&& !((opt->flags & OPT_ZEROOK && iv == 0))) {
		char *zok = (opt->flags & OPT_ZEROOK)? " zero or": "";
		switch (opt->flags & OPT_LIMITS) {
		case OPT_LLIMIT:
		    option_error("%s value must be%s >= %d",
				 opt->name, zok, opt->lower_limit);
		    break;
		case OPT_ULIMIT:
		    option_error("%s value must be%s <= %d",
				 opt->name, zok, opt->upper_limit);
		    break;
		case OPT_LIMITS:
		    option_error("%s value must be%s between %d and %d",
				opt->name, zok, opt->lower_limit, opt->upper_limit);
		    break;
		}
		return 0;
	    }
	}
	a = opt->flags & OPT_VALUE;
	if (a >= 128)
	    a -= 256;		/* sign extend */
	iv += a;
	if (opt->flags & OPT_INC)
	    iv += *(int *)(opt->addr);
	if ((opt->flags & OPT_NOINCR) && !privileged_option) {
	    int oldv = *(int *)(opt->addr);
	    if ((opt->flags & OPT_ZEROINF) ?
		(oldv != 0 && (iv == 0 || iv > oldv)) : (iv > oldv)) {
		option_error("%s value cannot be increased", opt->name);
		return 0;
	    }
	}
	*(int *)(opt->addr) = iv;
	if (opt->addr2 && (opt->flags & OPT_A2COPY))
	    *(int *)(opt->addr2) = iv;
	break;

    case o_uint32:
	if (opt->flags & OPT_NOARG) {
	    v = opt->flags & OPT_VALUE;
	    if (v & 0x80)
		    v |= 0xffffff00U;
	} else if (!number_option(*argv, &v, 16))
	    return 0;
	if (opt->flags & OPT_OR)
	    v |= *(u_int32_t *)(opt->addr);
	*(u_int32_t *)(opt->addr) = v;
	if (opt->addr2 && (opt->flags & OPT_A2COPY))
	    *(u_int32_t *)(opt->addr2) = v;
	break;

    case o_string:
	if (opt->flags & OPT_STATIC) {
	    strlcpy((char *)(opt->addr), *argv, opt->upper_limit);
	} else {
	    sv = strdup(*argv);
	    if (sv == NULL)
		novm("option argument");
	    *(char **)(opt->addr) = sv;
	}
	break;

    case o_special_noarg:
    case o_special:
	parser = (int (*) __P((char **))) opt->addr;
	if (!(*parser)(argv))
	    return 0;
	if (opt->flags & OPT_A2LIST) {
	    struct option_value *ovp, **pp;

	    ovp = malloc(sizeof(*ovp) + strlen(*argv));
	    if (ovp != 0) {
		strcpy(ovp->value, *argv);
		ovp->source = option_source;
		ovp->next = NULL;
		pp = (struct option_value **) &opt->addr2;
		while (*pp != 0)
		    pp = &(*pp)->next;
		*pp = ovp;
	    }
	}
	break;

    case o_wild:
	wildp = (int (*) __P((char *, char **, int))) opt->addr;
	if (!(*wildp)(cmd, argv, 1))
	    return 0;
	break;
    }

    if (opt->addr2 && (opt->flags & (OPT_A2COPY|OPT_ENABLE
		|OPT_A2PRINTER|OPT_A2STRVAL|OPT_A2LIST|OPT_A2OR)) == 0)
	*(bool *)(opt->addr2) = !(opt->flags & OPT_A2CLR);

    mainopt->source = option_source;
    mainopt->priority = prio;
    mainopt->winner = opt - mainopt;

    return 1;
}

/*
 * override_value - if the option priorities would permit us to
 * override the value of option, return 1 and update the priority
 * and source of the option value.  Otherwise returns 0.
 */
int
override_value(option, priority, source)
    const char *option;
    int priority;
    const char *source;
{
	option_t *opt;

	opt = find_option(option);
	if (opt == NULL)
		return 0;
	while (opt->flags & OPT_PRIOSUB)
		--opt;
	if ((opt->flags & OPT_PRIO) && priority < opt->priority)
		return 0;
	opt->priority = priority;
	opt->source = source;
	opt->winner = -1;
	return 1;
}

/*
 * n_arguments - tell how many arguments an option takes
 */
static int
n_arguments(opt)
    option_t *opt;
{
	return (opt->type == o_bool || opt->type == o_special_noarg
		|| (opt->flags & OPT_NOARG))? 0: 1;
}

/*
 * add_options - add a list of options to the set we grok.
 */
void
add_options(opt)
    option_t *opt;
{
    struct option_list *list;

    list = malloc(sizeof(*list));
    if (list == 0)
	novm("option list entry");
    list->options = opt;
    list->next = extra_options;
    extra_options = list;
}

/*
 * check_options - check that options are valid and consistent.
 */
void
check_options()
{
	if (logfile_fd >= 0 && logfile_fd != log_to_fd)
		close(logfile_fd);
}

/*
 * print_option - print out an option and its value
 */
static void
print_option(opt, mainopt, printer, arg)
    option_t *opt, *mainopt;
    void (*printer) __P((void *, char *, ...));
    void *arg;
{
	int i, v;
	char *p;

	if (opt->flags & OPT_NOPRINT)
		return;
	switch (opt->type) {
	case o_bool:
		v = opt->flags & OPT_VALUE;
		if (*(bool *)opt->addr != v)
			/* this can happen legitimately, e.g. lock
			   option turned off for default device */
			break;
		printer(arg, "%s", opt->name);
		break;
	case o_int:
		v = opt->flags & OPT_VALUE;
		if (v >= 128)
			v -= 256;
		i = *(int *)opt->addr;
		if (opt->flags & OPT_NOARG) {
			printer(arg, "%s", opt->name);
			if (i != v) {
				if (opt->flags & OPT_INC) {
					for (; i > v; i -= v)
						printer(arg, " %s", opt->name);
				} else
					printer(arg, " # oops: %d not %d\n",
						i, v);
			}
		} else {
			printer(arg, "%s %d", opt->name, i);
		}
		break;
	case o_uint32:
		printer(arg, "%s", opt->name);
		if ((opt->flags & OPT_NOARG) == 0)
			printer(arg, " %x", *(u_int32_t *)opt->addr);
		break;

	case o_string:
		if (opt->flags & OPT_HIDE) {
			p = "??????";
		} else {
			p = (char *) opt->addr;
			if ((opt->flags & OPT_STATIC) == 0)
				p = *(char **)p;
		}
		printer(arg, "%s %q", opt->name, p);
		break;

	case o_special:
	case o_special_noarg:
	case o_wild:
		if (opt->type != o_wild) {
			printer(arg, "%s", opt->name);
			if (n_arguments(opt) == 0)
				break;
			printer(arg, " ");
		}
		if (opt->flags & OPT_A2PRINTER) {
			void (*oprt) __P((option_t *,
					  void ((*)__P((void *, char *, ...))),
					  void *));
			oprt = (void (*) __P((option_t *,
					 void ((*)__P((void *, char *, ...))),
					 void *)))opt->addr2;
			(*oprt)(opt, printer, arg);
		} else if (opt->flags & OPT_A2STRVAL) {
			p = (char *) opt->addr2;
			if ((opt->flags & OPT_STATIC) == 0)
				p = *(char **)p;
			printer("%q", p);
		} else if (opt->flags & OPT_A2LIST) {
			struct option_value *ovp;

			ovp = (struct option_value *) opt->addr2;
			for (;;) {
				printer(arg, "%q", ovp->value);
				if ((ovp = ovp->next) == NULL)
					break;
				printer(arg, "\t\t# (from %s)\n%s ",
					ovp->source, opt->name);
			}
		} else {
			printer(arg, "xxx # [don't know how to print value]");
		}
		break;

	default:
		printer(arg, "# %s value (type %d\?\?)", opt->name, opt->type);
		break;
	}
	printer(arg, "\t\t# (from %s)\n", mainopt->source);
}

/*
 * print_option_list - print out options in effect from an
 * array of options.
 */
static void
print_option_list(opt, printer, arg)
    option_t *opt;
    void (*printer) __P((void *, char *, ...));
    void *arg;
{
	while (opt->name != NULL) {
		if (opt->priority != OPRIO_DEFAULT
		    && opt->winner != (short int) -1)
			print_option(opt + opt->winner, opt, printer, arg);
		do {
			++opt;
		} while (opt->flags & OPT_PRIOSUB);
	}
}

/*
 * print_options - print out what options are in effect.
 */
void
print_options(printer, arg)
    void (*printer) __P((void *, char *, ...));
    void *arg;
{
	struct option_list *list;
	int i;

	printer(arg, "pppd options in effect:\n");
	print_option_list(general_options, printer, arg);
	print_option_list(auth_options, printer, arg);
	for (list = extra_options; list != NULL; list = list->next)
		print_option_list(list->options, printer, arg);
	print_option_list(the_channel->options, printer, arg);
	for (i = 0; protocols[i] != NULL; ++i)
		print_option_list(protocols[i]->options, printer, arg);
}

/*
 * usage - print out a message telling how to use the program.
 */
static void
usage()
{
    if (phase == PHASE_INITIALIZE)
	fprintf(stderr, usage_string, VERSION, progname);
}

/*
 * showhelp - print out usage message and exit.
 */
static int
showhelp(argv)
    char **argv;
{
    if (phase == PHASE_INITIALIZE) {
	usage();
	exit(0);
    }
    return 0;
}

/*
 * showversion - print out the version number and exit.
 */
static int
showversion(argv)
    char **argv;
{
    if (phase == PHASE_INITIALIZE) {
	fprintf(stderr, "pppd version %s\n", VERSION);
	exit(0);
    }
    return 0;
}

/*
 * option_error - print a message about an error in an option.
 * The message is logged, and also sent to
 * stderr if phase == PHASE_INITIALIZE.
 */
void
option_error __V((char *fmt, ...))
{
    va_list args;
    char buf[1024];

#if defined(__STDC__)
    va_start(args, fmt);
#else
    char *fmt;
    va_start(args);
    fmt = va_arg(args, char *);
#endif
    vslprintf(buf, sizeof(buf), fmt, args);
    va_end(args);
    if (phase == PHASE_INITIALIZE)
	fprintf(stderr, "%s: %s\n", progname, buf);
    syslog(LOG_ERR, "%s", buf);
}

#if 0
/*