conflex.c

DHCP服务器源码

/* conflex.c

   Lexical scanner for dhcpd config file... */

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1995-2003 by Internet Software Consortium
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 *   Internet Systems Consortium, Inc.
 *   950 Charter Street
 *   Redwood City, CA 94063
 *   <[e-mail]>
 *   http://www.isc.org/
 *
 * This software has been written for Internet Systems Consortium
 * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
 * To learn more about Internet Systems Consortium, see
 * ``http://www.isc.org/''.  To learn more about Vixie Enterprises,
 * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
 * ``http://www.nominum.com''.
 */

#ifndef lint
static char copyright[] =
"$Id: conflex.c,v 1.92.2.7 2004/06/10 17:59:14 dhankins Exp $ Copyright (c) 2004 Internet Systems Consortium.  All rights reserved.\n";
#endif /* not lint */

#include "dhcpd.h"
#include <ctype.h>

static int get_char PROTO ((struct parse *));
static enum dhcp_token get_token PROTO ((struct parse *));
static void skip_to_eol PROTO ((struct parse *));
static enum dhcp_token read_string PROTO ((struct parse *));
static enum dhcp_token read_number PROTO ((int, struct parse *));
static enum dhcp_token read_num_or_name PROTO ((int, struct parse *));
static enum dhcp_token intern PROTO ((char *, enum dhcp_token));

isc_result_t new_parse (cfile, file, inbuf, buflen, name, eolp)
	struct parse **cfile;
	int file;
	char *inbuf;
	unsigned buflen;
	const char *name;
	int eolp;
{
	struct parse *tmp;

	tmp = dmalloc (sizeof (struct parse), MDL);
	if (!tmp)
		return ISC_R_NOMEMORY;
	memset (tmp, 0, sizeof *tmp);

	tmp -> token = 0;
	tmp -> tlname = name;
	tmp -> lpos = tmp -> line = 1;
	tmp -> cur_line = tmp -> line1;
	tmp -> prev_line = tmp -> line2;
	tmp -> token_line = tmp -> cur_line;
	tmp -> cur_line [0] = tmp -> prev_line [0] = 0;
	tmp -> warnings_occurred = 0;
	tmp -> file = file;
	tmp -> eol_token = eolp;

	tmp -> bufix = 0;
	tmp -> buflen = buflen;
	if (inbuf) {
		tmp -> bufsiz = 0;
		tmp -> inbuf = inbuf;
	} else {
		tmp -> inbuf = dmalloc (8192, MDL);
		if (!tmp -> inbuf) {
			dfree (tmp, MDL);
			return ISC_R_NOMEMORY;
		}
		tmp -> bufsiz = 8192;
	}

	*cfile = tmp;
	return ISC_R_SUCCESS;
}

isc_result_t end_parse (cfile)
	struct parse **cfile;
{
	if ((*cfile) -> bufsiz)
		dfree ((*cfile) -> inbuf, MDL);
	dfree (*cfile, MDL);
	*cfile = (struct parse *)0;
	return ISC_R_SUCCESS;
}

static int get_char (cfile)
	struct parse *cfile;
{
	/* My kingdom for WITH... */
	int c;

	if (cfile -> bufix == cfile -> buflen) {
		if (cfile -> file != -1) {
			cfile -> buflen =
				read (cfile -> file,
				      cfile -> inbuf, cfile -> bufsiz);
			if (cfile -> buflen == 0) {
				c = EOF;
				cfile -> bufix = 0;
			} else if (cfile -> buflen < 0) {
				c = EOF;
				cfile -> bufix = cfile -> buflen = 0;
			} else {
				c = cfile -> inbuf [0];
				cfile -> bufix = 1;
			}
		} else
			c = EOF;
	} else {
		c = cfile -> inbuf [cfile -> bufix];
		cfile -> bufix++;
	}

	if (!cfile -> ugflag) {
		if (c == EOL) {
			if (cfile -> cur_line == cfile -> line1) {	
				cfile -> cur_line = cfile -> line2;
				cfile -> prev_line = cfile -> line1;
			} else {
				cfile -> cur_line = cfile -> line1;
				cfile -> prev_line = cfile -> line2;
			}
			cfile -> line++;
			cfile -> lpos = 1;
			cfile -> cur_line [0] = 0;
		} else if (c != EOF) {
			if (cfile -> lpos <= 80) {
				cfile -> cur_line [cfile -> lpos - 1] = c;
				cfile -> cur_line [cfile -> lpos] = 0;
			}
			cfile -> lpos++;
		}
	} else
		cfile -> ugflag = 0;
	return c;		
}

static enum dhcp_token get_token (cfile)
	struct parse *cfile;
{
	int c;
	enum dhcp_token ttok;
	static char tb [2];
	int l, p, u;

	do {
		l = cfile -> line;
		p = cfile -> lpos;
		u = cfile -> ugflag;

		c = get_char (cfile);
#ifdef OLD_LEXER
		if (c == '\n' && p == 1 && !u
		    && cfile -> comment_index < sizeof cfile -> comments)
			cfile -> comments [cfile -> comment_index++] = '\n';
#endif

		if (!(c == '\n' && cfile -> eol_token)
		    && isascii (c) && isspace (c))
			continue;
		if (c == '#') {
#ifdef OLD_LEXER
			if (cfile -> comment_index < sizeof cfile -> comments)
			    cfile -> comments [cfile -> comment_index++] = '#';
#endif
			skip_to_eol (cfile);
			continue;
		}
		if (c == '"') {
			cfile -> lexline = l;
			cfile -> lexchar = p;
			ttok = read_string (cfile);
			break;
		}
		if ((isascii (c) && isdigit (c)) || c == '-') {
			cfile -> lexline = l;
			cfile -> lexchar = p;
			ttok = read_number (c, cfile);
			break;
		} else if (isascii (c) && isalpha (c)) {
			cfile -> lexline = l;
			cfile -> lexchar = p;
			ttok = read_num_or_name (c, cfile);
			break;
		} else if (c == EOF) {
			ttok = END_OF_FILE;
			cfile -> tlen = 0;
			break;
		} else {
			cfile -> lexline = l;
			cfile -> lexchar = p;
			tb [0] = c;
			tb [1] = 0;
			cfile -> tval = tb;
			cfile -> tlen = 1;
			ttok = c;
			break;
		}
	} while (1);
	return ttok;
}

enum dhcp_token next_token (rval, rlen, cfile)
	const char **rval;
	unsigned *rlen;
	struct parse *cfile;
{
	int rv;

	if (cfile -> token) {
		if (cfile -> lexline != cfile -> tline)
			cfile -> token_line = cfile -> cur_line;
		cfile -> lexchar = cfile -> tlpos;
		cfile -> lexline = cfile -> tline;
		rv = cfile -> token;
		cfile -> token = 0;
	} else {
		rv = get_token (cfile);
		cfile -> token_line = cfile -> cur_line;
	}
	if (rval)
		*rval = cfile -> tval;
	if (rlen)
		*rlen = cfile -> tlen;
#ifdef DEBUG_TOKENS
	fprintf (stderr, "%s:%d ", cfile -> tval, rv);
#endif
	return rv;
}

enum dhcp_token peek_token (rval, rlen, cfile)
	const char **rval;
	unsigned int *rlen;
	struct parse *cfile;
{
	int x;

	if (!cfile -> token) {
		cfile -> tlpos = cfile -> lexchar;
		cfile -> tline = cfile -> lexline;
		cfile -> token = get_token (cfile);
		if (cfile -> lexline != cfile -> tline)
			cfile -> token_line = cfile -> prev_line;

		x = cfile -> lexchar;
		cfile -> lexchar = cfile -> tlpos;
		cfile -> tlpos = x;

		x = cfile -> lexline;
		cfile -> lexline = cfile -> tline;
		cfile -> tline = x;
	}
	if (rval)
		*rval = cfile -> tval;
	if (rlen)
		*rlen = cfile -> tlen;
#ifdef DEBUG_TOKENS
	fprintf (stderr, "(%s:%d) ", cfile -> tval, cfile -> token);
#endif
	return cfile -> token;
}

static void skip_to_eol (cfile)
	struct parse *cfile;
{
	int c;
	do {
		c = get_char (cfile);
		if (c == EOF)
			return;
#ifdef OLD_LEXER
		if (cfile -> comment_index < sizeof (cfile -> comments))
			comments [cfile -> comment_index++] = c;
#endif
		if (c == EOL) {
			return;
		}
	} while (1);
}

static enum dhcp_token read_string (cfile)
	struct parse *cfile;
{
	int i;
	int bs = 0;
	int c;
	int value;
	int hex;

	for (i = 0; i < sizeof cfile -> tokbuf; i++) {
	      again:
		c = get_char (cfile);
		if (c == EOF) {
			parse_warn (cfile, "eof in string constant");
			break;
		}
		if (bs == 1) {
			switch (c) {
			      case 't':
				cfile -> tokbuf [i] = '\t';
				break;
			      case 'r':
				cfile -> tokbuf [i] = '\r';
				break;
			      case 'n':
				cfile -> tokbuf [i] = '\n';
				break;
			      case 'b':
				cfile -> tokbuf [i] = '\b';
				break;
			      case '0':
			      case '1':
			      case '2':
			      case '3':
				hex = 0;
				value = c - '0';
				++bs;
				goto again;
			      case 'x':
				hex = 1;
				value = 0;
				++bs;
				goto again;
			      default:
				cfile -> tokbuf [i] = c;
				bs = 0;
				break;
			}
			bs = 0;
		} else if (bs > 1) {
			if (hex) {
				if (c >= '0' && c <= '9') {
					value = value * 16 + (c - '0');
				} else if (c >= 'a' && c <= 'f') {
					value = value * 16 + (c - 'a' + 10);
				} else if (c >= 'A' && c <= 'F') {
					value = value * 16 + (c - 'A' + 10);
				} else {
					parse_warn (cfile,
						    "invalid hex digit: %x",
						    c);
					bs = 0;
					continue;
				}
				if (++bs == 4) {
					cfile -> tokbuf [i] = value;
					bs = 0;
				} else
					goto again;
			} else {
				if (c >= '0' && c <= '9') {
					value = value * 8 + (c - '0');
				} else {
				    if (value != 0) {
					parse_warn (cfile,
						    "invalid octal digit %x",
						    c);
					continue;
				    } else
					cfile -> tokbuf [i] = 0;
				    bs = 0;
				}
				if (++bs == 4) {
					cfile -> tokbuf [i] = value;
					bs = 0;
				} else
					goto again;
			}
		} else if (c == '\\') {
			bs = 1;
			goto again;
		} else if (c == '"')
			break;
		else
			cfile -> tokbuf [i] = c;
	}
	/* Normally, I'd feel guilty about this, but we're talking about
	   strings that'll fit in a DHCP packet here... */
	if (i == sizeof cfile -> tokbuf) {
		parse_warn (cfile,
			    "string constant larger than internal buffer");
		--i;
	}
	cfile -> tokbuf [i] = 0;
	cfile -> tlen = i;
	cfile -> tval = cfile -> tokbuf;
	return STRING;
}

static enum dhcp_token read_number (c, cfile)
	int c;
	struct parse *cfile;
{
	int seenx = 0;
	int i = 0;
	int token = NUMBER;

	cfile -> tokbuf [i++] = c;
	for (; i < sizeof cfile -> tokbuf; i++) {
		c = get_char (cfile);
		if (!seenx && c == 'x') {
			seenx = 1;
#ifndef OLD_LEXER
		} else if (isascii (c) && !isxdigit (c) &&
			   (c == '-' || c == '_' || isalpha (c))) {
			token = NAME;
		} else if (isascii (c) && !isdigit (c) && isxdigit (c)) {
			token = NUMBER_OR_NAME;
#endif
		} else if (!isascii (c) || !isxdigit (c)) {
			if (c != EOF) {
				cfile -> bufix--;
				cfile -> ugflag = 1;
			}
			break;
		}
		cfile -> tokbuf [i] = c;
	}
	if (i == sizeof cfile -> tokbuf) {
		parse_warn (cfile,
			    "numeric token larger than internal buffer");
		--i;
	}
	cfile -> tokbuf [i] = 0;
	cfile -> tlen = i;
	cfile -> tval = cfile -> tokbuf;
	return token;
}

static enum dhcp_token read_num_or_name (c, cfile)
	int c;
	struct parse *cfile;
{
	int i = 0;
	enum dhcp_token rv = NUMBER_OR_NAME;
	cfile -> tokbuf [i++] = c;
	for (; i < sizeof cfile -> tokbuf; i++) {
		c = get_char (cfile);
		if (!isascii (c) ||
		    (c != '-' && c != '_' && !isalnum (c))) {
			if (c != EOF) {
				cfile -> bufix--;
				cfile -> ugflag = 1;
			}
			break;
		}
		if (!isxdigit (c))
			rv = NAME;
		cfile -> tokbuf [i] = c;
	}
	if (i == sizeof cfile -> tokbuf) {
		parse_warn (cfile, "token larger than internal buffer");
		--i;
	}
	cfile -> tokbuf [i] = 0;
	cfile -> tlen = i;
	cfile -> tval = cfile -> tokbuf;
	return intern (cfile -> tval, rv);
}

static enum dhcp_token intern (atom, dfv)
	char *atom;
	enum dhcp_token dfv;
{
	if (!isascii (atom [0]))
		return dfv;

	switch (tolower (atom [0])) {
	      case '-':
		if (atom [1] == 0)
			return MINUS;
		break;

	      case 'a':
		if (!strncasecmp (atom + 1, "uth", 3)) {
			if (!strncasecmp (atom + 3, "uthenticat", 10)) {
				if (!strcasecmp (atom + 13, "ed"))
					return AUTHENTICATED;
				if (!strcasecmp (atom + 13, "ion"))
					return AUTHENTICATION;
				break;
			}
			if (!strcasecmp (atom + 1, "uthoritative"))
				return AUTHORITATIVE;
			break;
		}
		if (!strcasecmp (atom + 1, "nd"))
			return AND;
		if (!strcasecmp (atom + 1, "ppend"))
			return APPEND;
		if (!strcasecmp (atom + 1, "llow"))
			return ALLOW;
		if (!strcasecmp (atom + 1, "lias"))
			return ALIAS;
		if (!strcasecmp (atom + 1, "lgorithm"))
			return ALGORITHM;
		if (!strcasecmp (atom + 1, "bandoned"))
			return TOKEN_ABANDONED;
		if (!strcasecmp (atom + 1, "dd"))
			return TOKEN_ADD;
		if (!strcasecmp (atom + 1, "ll"))
			return ALL;
		if (!strcasecmp (atom + 1, "t"))
			return AT;
		if (!strcasecmp (atom + 1, "rray"))
			return ARRAY;
		if (!strcasecmp (atom + 1, "ddress"))
			return ADDRESS;
		if (!strcasecmp (atom + 1, "ctive"))
			return TOKEN_ACTIVE;
		break;
	      case 'b':
		if (!strcasecmp (atom + 1, "ackup"))
			return TOKEN_BACKUP;
		if (!strcasecmp (atom + 1, "ootp"))
			return TOKEN_BOOTP;
		if (!strcasecmp (atom + 1, "inding"))
			return BINDING;