freebsd-dev/sbin/dhclient/conflex.c
Rob Norris 461ccb55d5 dhclient: add ability to ignore options in offers
A machine might exist on multiple networks, all of which offer, say, default
routes or name servers. There's no easy way to indicate in the config
that those options are only valid for a single interface.

Now, we can write:

    interface "lan0" {
      request routers;
      require routers;
    }
    interface "lan1" {
      ignore routers;
    }

And only take action on default routes offered on lan0.

Tested by:	Jose Luis Duran <jlduran at gmail dot com>
MFC after:	2 months
Reviewed by:	allanjude, imp
Sponsored by:	Zenith Electronics LLC
Sponsored by:	Klara, Inc.
Pull Request:	#693
2023-04-10 23:13:18 +00:00

539 lines
12 KiB
C

/* $OpenBSD: conflex.c,v 1.7 2004/09/15 19:02:38 deraadt Exp $ */
/* Lexical scanner for dhcpd config file... */
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1995, 1996, 1997 The Internet Software Consortium.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of The Internet Software Consortium nor the names
* of its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This software has been written for the Internet Software Consortium
* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
* Enterprises. To learn more about the Internet Software Consortium,
* see ``http://www.vix.com/isc''. To learn more about Vixie
* Enterprises, see ``http://www.vix.com''.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <ctype.h>
#include "dhcpd.h"
#include "dhctoken.h"
int lexline;
int lexchar;
char *token_line;
static char *prev_line;
static char *cur_line;
const char *tlname;
int eol_token;
static char line1[81];
static char line2[81];
static unsigned lpos;
static unsigned line;
static int tlpos;
static int tline;
static int token;
static int ugflag;
static char *tval;
static char tokbuf[1500];
static int get_char(FILE *);
static int get_token(FILE *);
static void skip_to_eol(FILE *);
static int read_string(FILE *);
static int read_number(int, FILE *);
static int read_num_or_name(int, FILE *);
static int intern(char *, int);
void
new_parse(const char *name)
{
tlname = name;
lpos = line = 1;
cur_line = line1;
prev_line = line2;
token_line = cur_line;
cur_line[0] = prev_line[0] = 0;
warnings_occurred = 0;
}
static int
get_char(FILE *cfile)
{
int c = getc(cfile);
if (!ugflag) {
if (c == '\n') {
if (cur_line == line1) {
cur_line = line2;
prev_line = line1;
} else {
cur_line = line1;
prev_line = line2;
}
line++;
lpos = 1;
cur_line[0] = 0;
} else if (c != EOF) {
if (lpos < sizeof(line1)) {
cur_line[lpos - 1] = c;
cur_line[lpos] = 0;
}
lpos++;
}
} else
ugflag = 0;
return (c);
}
static int
get_token(FILE *cfile)
{
int c, ttok;
static char tb[2];
int l, p;
do {
l = line;
p = lpos;
c = get_char(cfile);
if (!(c == '\n' && eol_token) && isascii(c) && isspace(c))
continue;
if (c == '#') {
skip_to_eol(cfile);
continue;
}
if (c == '"') {
lexline = l;
lexchar = p;
ttok = read_string(cfile);
break;
}
if ((isascii(c) && isdigit(c)) || c == '-') {
lexline = l;
lexchar = p;
ttok = read_number(c, cfile);
break;
} else if (isascii(c) && isalpha(c)) {
lexline = l;
lexchar = p;
ttok = read_num_or_name(c, cfile);
break;
} else {
lexline = l;
lexchar = p;
tb[0] = c;
tb[1] = 0;
tval = tb;
ttok = c;
break;
}
} while (1);
return (ttok);
}
int
next_token(char **rval, FILE *cfile)
{
int rv;
if (token) {
if (lexline != tline)
token_line = cur_line;
lexchar = tlpos;
lexline = tline;
rv = token;
token = 0;
} else {
rv = get_token(cfile);
token_line = cur_line;
}
if (rval)
*rval = tval;
return (rv);
}
int
peek_token(char **rval, FILE *cfile)
{
int x;
if (!token) {
tlpos = lexchar;
tline = lexline;
token = get_token(cfile);
if (lexline != tline)
token_line = prev_line;
x = lexchar;
lexchar = tlpos;
tlpos = x;
x = lexline;
lexline = tline;
tline = x;
}
if (rval)
*rval = tval;
return (token);
}
static void
skip_to_eol(FILE *cfile)
{
int c;
do {
c = get_char(cfile);
if (c == EOF)
return;
if (c == '\n')
return;
} while (1);
}
static int
read_string(FILE *cfile)
{
int c, bs = 0;
unsigned i;
for (i = 0; i < sizeof(tokbuf); i++) {
c = get_char(cfile);
if (c == EOF) {
parse_warn("eof in string constant");
break;
}
if (bs) {
bs = 0;
i--;
tokbuf[i] = c;
} else if (c == '\\')
bs = 1;
else if (c == '"')
break;
else
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(tokbuf)) {
parse_warn("string constant larger than internal buffer");
i--;
}
tokbuf[i] = 0;
tval = tokbuf;
return (STRING);
}
static int
read_number(int c, FILE *cfile)
{
int seenx = 0, _token = NUMBER;
unsigned i = 0;
tokbuf[i++] = c;
for (; i < sizeof(tokbuf); i++) {
c = get_char(cfile);
if (!seenx && c == 'x')
seenx = 1;
else if (!isascii(c) || !isxdigit(c)) {
ungetc(c, cfile);
ugflag = 1;
break;
}
tokbuf[i] = c;
}
if (i == sizeof(tokbuf)) {
parse_warn("numeric token larger than internal buffer");
i--;
}
tokbuf[i] = 0;
tval = tokbuf;
return (_token);
}
static int
read_num_or_name(int c, FILE *cfile)
{
unsigned i = 0;
int rv = NUMBER_OR_NAME;
tokbuf[i++] = c;
for (; i < sizeof(tokbuf); i++) {
c = get_char(cfile);
if (!isascii(c) || (c != '-' && c != '_' && !isalnum(c))) {
ungetc(c, cfile);
ugflag = 1;
break;
}
if (!isxdigit(c))
rv = NAME;
tokbuf[i] = c;
}
if (i == sizeof(tokbuf)) {
parse_warn("token larger than internal buffer");
i--;
}
tokbuf[i] = 0;
tval = tokbuf;
return (intern(tval, rv));
}
static int
intern(char *atom, int dfv)
{
if (!isascii(atom[0]))
return (dfv);
switch (tolower(atom[0])) {
case 'a':
if (!strcasecmp(atom + 1, "lways-reply-rfc1048"))
return (ALWAYS_REPLY_RFC1048);
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, "bandoned"))
return (ABANDONED);
if (!strcasecmp(atom + 1, "uthoritative"))
return (AUTHORITATIVE);
break;
case 'b':
if (!strcasecmp(atom + 1, "ackoff-cutoff"))
return (BACKOFF_CUTOFF);
if (!strcasecmp(atom + 1, "ootp"))
return (BOOTP);
if (!strcasecmp(atom + 1, "ooting"))
return (BOOTING);
if (!strcasecmp(atom + 1, "oot-unknown-clients"))
return (BOOT_UNKNOWN_CLIENTS);
break;
case 'c':
if (!strcasecmp(atom + 1, "lass"))
return (CLASS);
if (!strcasecmp(atom + 1, "iaddr"))
return (CIADDR);
if (!strcasecmp(atom + 1, "lient-identifier"))
return (CLIENT_IDENTIFIER);
if (!strcasecmp(atom + 1, "lient-hostname"))
return (CLIENT_HOSTNAME);
break;
case 'd':
if (!strcasecmp(atom + 1, "omain"))
return (DOMAIN);
if (!strcasecmp(atom + 1, "eny"))
return (DENY);
if (!strncasecmp(atom + 1, "efault", 6)) {
if (!atom[7])
return (DEFAULT);
if (!strcasecmp(atom + 7, "-lease-time"))
return (DEFAULT_LEASE_TIME);
break;
}
if (!strncasecmp(atom + 1, "ynamic-bootp", 12)) {
if (!atom[13])
return (DYNAMIC_BOOTP);
if (!strcasecmp(atom + 13, "-lease-cutoff"))
return (DYNAMIC_BOOTP_LEASE_CUTOFF);
if (!strcasecmp(atom + 13, "-lease-length"))
return (DYNAMIC_BOOTP_LEASE_LENGTH);
break;
}
break;
case 'e':
if (!strcasecmp(atom + 1, "thernet"))
return (ETHERNET);
if (!strcasecmp(atom + 1, "nds"))
return (ENDS);
if (!strcasecmp(atom + 1, "xpire"))
return (EXPIRE);
break;
case 'f':
if (!strcasecmp(atom + 1, "ilename"))
return (FILENAME);
if (!strcasecmp(atom + 1, "ixed-address"))
return (FIXED_ADDR);
if (!strcasecmp(atom + 1, "ddi"))
return (FDDI);
break;
case 'g':
if (!strcasecmp(atom + 1, "iaddr"))
return (GIADDR);
if (!strcasecmp(atom + 1, "roup"))
return (GROUP);
if (!strcasecmp(atom + 1, "et-lease-hostnames"))
return (GET_LEASE_HOSTNAMES);
break;
case 'h':
if (!strcasecmp(atom + 1, "ost"))
return (HOST);
if (!strcasecmp(atom + 1, "ardware"))
return (HARDWARE);
if (!strcasecmp(atom + 1, "ostname"))
return (HOSTNAME);
break;
case 'i':
if (!strcasecmp(atom + 1, "gnore"))
return (IGNORE);
if (!strcasecmp(atom + 1, "nitial-interval"))
return (INITIAL_INTERVAL);
if (!strcasecmp(atom + 1, "nterface"))
return (INTERFACE);
break;
case 'l':
if (!strcasecmp(atom + 1, "ease"))
return (LEASE);
break;
case 'm':
if (!strcasecmp(atom + 1, "ax-lease-time"))
return (MAX_LEASE_TIME);
if (!strncasecmp(atom + 1, "edi", 3)) {
if (!strcasecmp(atom + 4, "a"))
return (MEDIA);
if (!strcasecmp(atom + 4, "um"))
return (MEDIUM);
break;
}
break;
case 'n':
if (!strcasecmp(atom + 1, "ameserver"))
return (NAMESERVER);
if (!strcasecmp(atom + 1, "etmask"))
return (NETMASK);
if (!strcasecmp(atom + 1, "ext-server"))
return (NEXT_SERVER);
if (!strcasecmp(atom + 1, "ot"))
return (TOKEN_NOT);
break;
case 'o':
if (!strcasecmp(atom + 1, "ption"))
return (OPTION);
if (!strcasecmp(atom + 1, "ne-lease-per-client"))
return (ONE_LEASE_PER_CLIENT);
break;
case 'p':
if (!strcasecmp(atom + 1, "repend"))
return (PREPEND);
if (!strcasecmp(atom + 1, "acket"))
return (PACKET);
break;
case 'r':
if (!strcasecmp(atom + 1, "ange"))
return (RANGE);
if (!strcasecmp(atom + 1, "equest"))
return (REQUEST);
if (!strcasecmp(atom + 1, "equire"))
return (REQUIRE);
if (!strcasecmp(atom + 1, "etry"))
return (RETRY);
if (!strcasecmp(atom + 1, "enew"))
return (RENEW);
if (!strcasecmp(atom + 1, "ebind"))
return (REBIND);
if (!strcasecmp(atom + 1, "eboot"))
return (REBOOT);
if (!strcasecmp(atom + 1, "eject"))
return (REJECT);
break;
case 's':
if (!strcasecmp(atom + 1, "earch"))
return (SEARCH);
if (!strcasecmp(atom + 1, "tarts"))
return (STARTS);
if (!strcasecmp(atom + 1, "iaddr"))
return (SIADDR);
if (!strcasecmp(atom + 1, "ubnet"))
return (SUBNET);
if (!strcasecmp(atom + 1, "hared-network"))
return (SHARED_NETWORK);
if (!strcasecmp(atom + 1, "erver-name"))
return (SERVER_NAME);
if (!strcasecmp(atom + 1, "erver-identifier"))
return (SERVER_IDENTIFIER);
if (!strcasecmp(atom + 1, "elect-timeout"))
return (SELECT_TIMEOUT);
if (!strcasecmp(atom + 1, "end"))
return (SEND);
if (!strcasecmp(atom + 1, "cript"))
return (SCRIPT);
if (!strcasecmp(atom + 1, "upersede"))
return (SUPERSEDE);
break;
case 't':
if (!strcasecmp(atom + 1, "imestamp"))
return (TIMESTAMP);
if (!strcasecmp(atom + 1, "imeout"))
return (TIMEOUT);
if (!strcasecmp(atom + 1, "oken-ring"))
return (TOKEN_RING);
break;
case 'u':
if (!strncasecmp(atom + 1, "se", 2)) {
if (!strcasecmp(atom + 3, "r-class"))
return (USER_CLASS);
if (!strcasecmp(atom + 3, "-host-decl-names"))
return (USE_HOST_DECL_NAMES);
if (!strcasecmp(atom + 3,
"-lease-addr-for-default-route"))
return (USE_LEASE_ADDR_FOR_DEFAULT_ROUTE);
break;
}
if (!strcasecmp(atom + 1, "id"))
return (UID);
if (!strcasecmp(atom + 1, "nknown-clients"))
return (UNKNOWN_CLIENTS);
break;
case 'v':
if (!strcasecmp(atom + 1, "endor-class"))
return (VENDOR_CLASS);
if (!strcasecmp(atom + 1, "lan-pcp"))
return (VLAN_PCP);
break;
case 'y':
if (!strcasecmp(atom + 1, "iaddr"))
return (YIADDR);
break;
}
return (dfv);
}