options.c

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

    slprintf(path, pl, "%s%s", _PATH_TTYOPT, dev);
    /* Turn slashes into dots, for Solaris case (e.g. /dev/term/a) */
    for (p = path + strlen(_PATH_TTYOPT); *p != 0; ++p)
	if (*p == '/')
	    *p = '.';
    ret = options_from_file(path, 0, 0, 1);
    free(path);
    return ret;
}

/*
 * options_from_list - process a string of options in a wordlist.
 */
int
options_from_list(w, priv)
    struct wordlist *w;
    int priv;
{
    char *argv[MAXARGS];
    option_t *opt;
    int i, ret = 0;

    privileged_option = priv;
    option_source = "secrets file";

    while (w != NULL) {
	/*
	 * First see if it's a command.
	 */
	opt = find_option(w->word);
	if (opt != NULL) {
	    int n = n_arguments(opt);
	    struct wordlist *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;
	    }
	    current_option = w0->word;
	    if (!process_option(opt, argv))
		goto err;
            w = w->next;
	    continue;
	}

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

err:
    return ret;
}

/*
 * 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)
    char *name;
{
    option_t *opt;
    struct option_list *list;
    int i;

    for (list = extra_options; list != NULL; list = list->next)
	for (opt = list->options; opt->name != NULL; ++opt)
	    if (strcmp(name, opt->name) == 0)
		return opt;
    for (opt = general_options; opt->name != NULL; ++opt)
	if (strcmp(name, opt->name) == 0)
	    return opt;
    for (opt = auth_options; opt->name != NULL; ++opt)
	if (strcmp(name, opt->name) == 0)
	    return opt;
    for (i = 0; protocols[i] != NULL; ++i)
	if ((opt = protocols[i]->options) != NULL)
	    for (; opt->name != NULL; ++opt)
		if (strcmp(name, opt->name) == 0)
		    return opt;
    return NULL;
}

/*
 * process_option - process one new-style option.
 */
static int
process_option(opt, argv)
    option_t *opt;
    char **argv;
{
    u_int32_t v;
    int iv, a;
    char *sv;
    int (*parser) __P((char **));

    if ((opt->flags & OPT_PREPASS) == 0 && prepass)
	return 1;
    if ((opt->flags & OPT_INITONLY) && pppd_phase != PHASE_INITIALIZE) {
	option_error("it's too late to use the %s option", opt->name);
	return 0;
    }
    if ((opt->flags & OPT_PRIV) && !privileged_option) {
	option_error("using the %s option requires root privilege", opt->name);
	return 0;
    }
    if ((opt->flags & OPT_ENABLE) && *(bool *)(opt->addr2) == 0) {
	option_error("%s option is disabled", opt->name);
	return 0;
    }
    if ((opt->flags & OPT_PRIVFIX) && !privileged_option) {
	struct option_info *ip = (struct option_info *) opt->addr2;
	if (ip && ip->priv) {
	    option_error("%s option cannot be overridden", opt->name);
	    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;
	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, 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;
	} 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");
            if ( *(char **)(opt->addr) != NULL ) {
                free((void *)*(char **)(opt->addr));
                *(char **)(opt->addr) = NULL;
            }
	    *(char **)(opt->addr) = sv;
	}
	break;

    case o_special_noarg:
    case o_special:
	parser = (int (*) __P((char **))) opt->addr;
	if (!(*parser)(argv))
	    return 0;
	break;
    }

    if (opt->addr2) {
	if (opt->flags & OPT_A2INFO) {
	    struct option_info *ip = (struct option_info *) opt->addr2;
	    ip->priv = privileged_option;
	    ip->source = option_source;
	} else if ((opt->flags & (OPT_A2COPY|OPT_ENABLE)) == 0)
	    *(bool *)(opt->addr2) = 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;
}

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

/*
 * option_error - print a message about an error in an option.
 * The message is logged, and also sent to
 * stderr if pppd_phase == PHASE_INITIALIZE.
 */
void
option_error __V((char *fmt, ...))
{
    va_list args;
    char buf[256];

#if defined(__STDC__)
    va_start(args, fmt);
#else
    char *fmt;
    va_start(args);
    fmt = va_arg(args, char *);
#endif
    if (prepass) {
	va_end(args);
	return;
    }
    vslprintf(buf, sizeof(buf), fmt, args);
    va_end(args);

    fprintf(stderr, "pppd: %s\n", buf);
}

/*
 * Read a word from a file.
 * Words are delimited by white-space or by quotes (" or ').
 * Quotes, white-space and \ may be escaped with \.
 * \<newline> is ignored.
 */
int
getword(f, word, newlinep, filename)
    FILE *f;
    char *word;
    int *newlinep;
    char *filename;
{
    int c, len, escape;
    int quoted, comment;
    int value, digit, got, n;

#define isoctal(c) ((c) >= '0' && (c) < '8')

    *newlinep = 0;
    len = 0;
    escape = 0;
    comment = 0;

    /*
     * First skip white-space and comments.
     */
    for (;;) {
	c = getc(f);
	if (c == EOF)
	    break;

	/*
	 * A newline means the end of a comment; backslash-newline
	 * is ignored.  Note that we cannot have escape && comment.
	 */
	if (c == '\n') {
	    if (!escape) {
		*newlinep = 1;
		comment = 0;
	    } else
		escape = 0;
	    continue;
	}

	/*
	 * Ignore characters other than newline in a comment.
	 */
	if (comment)
	    continue;

	/*
	 * If this character is escaped, we have a word start.
	 */
	if (escape)
	    break;

	/*
	 * If this is the escape character, look at the next character.
	 */
	if (c == '\\') {
	    escape = 1;
	    continue;
	}

	/*
	 * If this is the start of a comment, ignore the rest of the line.
	 */
	if (c == '#') {
	    comment = 1;
	    continue;
	}

	/*
	 * A non-whitespace character is the start of a word.
	 */
	if (!isspace(c))
	    break;
    }

    /*
     * Save the delimiter for quoted strings.
     */
    if (!escape && (c == '"' || c == '\'')) {
        quoted = c;
	c = getc(f);
    } else
        quoted = 0;

    /*
     * Process characters until the end of the word.
     */
    while (c != EOF) {
	if (escape) {
	    /*
	     * This character is escaped: backslash-newline is ignored,
	     * various other characters indicate particular values
	     * as for C backslash-escapes.
	     */
	    escape = 0;
	    if (c == '\n') {
	        c = getc(f);
		continue;
	    }

	    got = 0;
	    switch (c) {
	    case 'a':
		value = '\a';
		break;
	    case 'b':
		value = '\b';
		break;
	    case 'f':
		value = '\f';
		break;
	    case 'n':
		value = '\n';
		break;
	    case 'r':
		value = '\r';
		break;
	    case 's':
		value = ' ';
		break;
	    case 't':
		value = '\t';
		break;

	    default:
		if (isoctal(c)) {
		    /*
		     * \ddd octal sequence
		     */
		    value = 0;
		    for (n = 0; n < 3 && isoctal(c); ++n) {
			value = (value << 3) + (c & 07);
			c = getc(f);
		    }
		    got = 1;
		    break;
		}

		if (c == 'x') {
		    /*
		     * \x<hex_string> sequence
		     */
		    value = 0;
		    c = getc(f);
		    for (n = 0; n < 2 && isxdigit(c); ++n) {
			digit = toupper(c) - '0';
			if (digit > 10)
			    digit += '0' + 10 - 'A';
			value = (value << 4) + digit;
			c = getc (f);
		    }
		    got = 1;
		    break;
		}

		/*
		 * Otherwise the character stands for itself.
		 */
		value = c;
		break;
	    }

	    /*
	     * Store the resulting character for the escape sequence.
	     */
	    if (len < MAXWORDLEN-1)
		word[len] = value;
	    ++len;

	    if (!got)
		c = getc(f);
	    continue;

	}

	/*
	 * Not escaped: see if we've reached the end of the word.
	 */
	if (quoted) {
	    if (c == quoted)
		break;
	} else {
	    if (isspace(c) || c == '#') {
		ungetc (c, f);
		break;
	    }
	}

	/*
	 * Backslash starts an escape sequence.
	 */
	if (c == '\\') {
	    escape = 1;
	    c = getc(f);
	    continue;
	}

	/*
	 * An ordinary character: store it in the word and get another.
	 */
	if (len < MAXWORDLEN-1)