611 lines
12 KiB
C
611 lines
12 KiB
C
/*
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* Copyright (C) 1993-2001 by Darren Reed.
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*
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* See the IPFILTER.LICENCE file for details on licencing.
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*/
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#if defined(__sgi) && (IRIX > 602)
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# include <sys/ptimers.h>
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#endif
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#include <sys/types.h>
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#if !defined(__SVR4) && !defined(__svr4__)
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#include <strings.h>
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#else
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#include <sys/byteorder.h>
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#endif
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#include <sys/param.h>
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#include <sys/time.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/tcp.h>
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#include <net/if.h>
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#if __FreeBSD_version >= 300000
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# include <net/if_var.h>
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#endif
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#include <stdio.h>
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#include <string.h>
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#include <limits.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <stddef.h>
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#include <netdb.h>
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#include <arpa/nameser.h>
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#include <arpa/inet.h>
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#include <resolv.h>
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#include <ctype.h>
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#include <syslog.h>
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#include "ip_compat.h"
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#include "ip_fil.h"
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#include "ipf.h"
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#include "facpri.h"
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#if !defined(lint)
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static const char sccsid[] = "@(#)parse.c 1.44 6/5/96 (C) 1993-2000 Darren Reed";
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static const char rcsid[] = "@(#)$IPFilter: parse.c,v 2.8 1999/12/28 10:49:46 darrenr Exp $";
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#endif
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extern struct ipopt_names ionames[], secclass[];
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extern int opts;
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extern int use_inet6;
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char *proto = NULL;
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char flagset[] = "FSRPAUEC";
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u_char flags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH, TH_ACK, TH_URG,
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TH_ECN, TH_CWR };
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void fill6bits __P((int, u_32_t *));
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int count6bits __P((u_32_t *));
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static char thishost[MAXHOSTNAMELEN];
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void initparse()
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{
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gethostname(thishost, sizeof(thishost));
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thishost[sizeof(thishost) - 1] = '\0';
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}
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int genmask(msk, mskp)
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char *msk;
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u_32_t *mskp;
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{
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char *endptr = NULL;
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#ifdef USE_INET6
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u_32_t addr;
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#endif
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int bits;
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if (index(msk, '.') || index(msk, 'x') || index(msk, ':')) {
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/* possibly of the form xxx.xxx.xxx.xxx
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* or 0xYYYYYYYY */
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#ifdef USE_INET6
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if (use_inet6) {
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if (inet_pton(AF_INET6, msk, &addr) != 1)
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return -1;
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} else
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#endif
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if (inet_aton(msk, (struct in_addr *)mskp) == 0)
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return -1;
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} else {
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/*
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* set x most significant bits
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*/
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bits = (int)strtol(msk, &endptr, 0);
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if ((*endptr != '\0') ||
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((bits > 32) && !use_inet6) || (bits < 0) ||
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((bits > 128) && use_inet6))
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return -1;
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if (use_inet6)
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fill6bits(bits, mskp);
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else {
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if (bits == 0)
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*mskp = 0;
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else
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*mskp = htonl(0xffffffff << (32 - bits));
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}
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}
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return 0;
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}
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void fill6bits(bits, msk)
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int bits;
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u_32_t *msk;
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{
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int i;
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for (i = 0; bits >= 32 && i < 4 ; ++i, bits -= 32)
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msk[i] = 0xffffffff;
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if (bits > 0 && i < 4)
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msk[i++] = htonl(0xffffffff << (32 - bits));
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while (i < 4)
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msk[i++] = 0;
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}
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/*
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* returns -1 if neither "hostmask/num" or "hostmask mask addr" are
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* found in the line segments, there is an error processing this information,
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* or there is an error processing ports information.
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*/
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int hostmask(seg, sa, msk, pp, cp, tp, linenum)
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char ***seg;
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u_32_t *sa, *msk;
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u_short *pp, *tp;
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int *cp;
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int linenum;
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{
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struct in_addr maskaddr;
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char *s;
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/*
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* is it possibly hostname/num ?
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*/
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if ((s = index(**seg, '/')) ||
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((s = index(**seg, ':')) && !index(s + 1, ':'))) {
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*s++ = '\0';
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if (genmask(s, msk) == -1) {
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fprintf(stderr, "%d: bad mask (%s)\n", linenum, s);
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return -1;
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}
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if (hostnum(sa, **seg, linenum) == -1) {
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fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg);
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return -1;
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}
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*sa &= *msk;
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(*seg)++;
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return ports(seg, pp, cp, tp, linenum);
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}
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/*
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* look for extra segments if "mask" found in right spot
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*/
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if (*(*seg+1) && *(*seg+2) && !strcasecmp(*(*seg+1), "mask")) {
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if (hostnum(sa, **seg, linenum) == -1) {
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fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg);
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return -1;
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}
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(*seg)++;
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(*seg)++;
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if (inet_aton(**seg, &maskaddr) == 0) {
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fprintf(stderr, "%d: bad mask (%s)\n", linenum, **seg);
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return -1;
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}
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*msk = maskaddr.s_addr;
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(*seg)++;
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*sa &= *msk;
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return ports(seg, pp, cp, tp, linenum);
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}
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if (**seg) {
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if (hostnum(sa, **seg, linenum) == -1) {
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fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg);
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return -1;
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}
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(*seg)++;
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if (use_inet6) {
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u_32_t k = 0;
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if (sa[0] || sa[1] || sa[2] || sa[3])
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k = 0xffffffff;
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msk[0] = msk[1] = msk[2] = msk[3] = k;
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}
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else
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*msk = *sa ? 0xffffffff : 0;
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return ports(seg, pp, cp, tp, linenum);
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}
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fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg);
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return -1;
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}
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/*
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* returns an ip address as a long var as a result of either a DNS lookup or
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* straight inet_addr() call
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*/
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int hostnum(ipa, host, linenum)
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u_32_t *ipa;
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char *host;
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int linenum;
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{
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struct hostent *hp;
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struct netent *np;
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struct in_addr ip;
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if (!strcasecmp("any", host))
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return 0;
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#ifdef USE_INET6
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if (use_inet6) {
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if (inet_pton(AF_INET6, host, ipa) == 1)
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return 0;
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else
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return -1;
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}
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#endif
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if (isdigit(*host) && inet_aton(host, &ip)) {
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*ipa = ip.s_addr;
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return 0;
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}
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if (!strcasecmp("<thishost>", host))
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host = thishost;
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if (!(hp = gethostbyname(host))) {
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if (!(np = getnetbyname(host))) {
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fprintf(stderr, "%d: can't resolve hostname: %s\n",
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linenum, host);
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return -1;
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}
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*ipa = htonl(np->n_net);
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return 0;
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}
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*ipa = *(u_32_t *)hp->h_addr;
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return 0;
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}
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/*
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* check for possible presence of the port fields in the line
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*/
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int ports(seg, pp, cp, tp, linenum)
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char ***seg;
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u_short *pp, *tp;
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int *cp;
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int linenum;
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{
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int comp = -1;
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if (!*seg || !**seg || !***seg)
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return 0;
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if (!strcasecmp(**seg, "port") && *(*seg + 1) && *(*seg + 2)) {
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(*seg)++;
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if (!strcmp(**seg, "=") || !strcasecmp(**seg, "eq"))
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comp = FR_EQUAL;
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else if (!strcmp(**seg, "!=") || !strcasecmp(**seg, "ne"))
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comp = FR_NEQUAL;
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else if (!strcmp(**seg, "<") || !strcasecmp(**seg, "lt"))
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comp = FR_LESST;
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else if (!strcmp(**seg, ">") || !strcasecmp(**seg, "gt"))
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comp = FR_GREATERT;
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else if (!strcmp(**seg, "<=") || !strcasecmp(**seg, "le"))
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comp = FR_LESSTE;
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else if (!strcmp(**seg, ">=") || !strcasecmp(**seg, "ge"))
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comp = FR_GREATERTE;
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else if (isalnum(***seg) && *(*seg + 2)) {
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if (portnum(**seg, pp, linenum) == 0)
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return -1;
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(*seg)++;
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if (!strcmp(**seg, "<>"))
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comp = FR_OUTRANGE;
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else if (!strcmp(**seg, "><"))
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comp = FR_INRANGE;
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else {
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fprintf(stderr,
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"%d: unknown range operator (%s)\n",
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linenum, **seg);
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return -1;
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}
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(*seg)++;
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if (**seg == NULL) {
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fprintf(stderr, "%d: missing 2nd port value\n",
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linenum);
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return -1;
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}
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if (portnum(**seg, tp, linenum) == 0)
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return -1;
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} else {
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fprintf(stderr, "%d: unknown comparator (%s)\n",
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linenum, **seg);
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return -1;
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}
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if (comp != FR_OUTRANGE && comp != FR_INRANGE) {
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(*seg)++;
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if (portnum(**seg, pp, linenum) == 0)
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return -1;
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}
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*cp = comp;
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(*seg)++;
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}
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return 0;
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}
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/*
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* find the port number given by the name, either from getservbyname() or
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* straight atoi(). Return 1 on success, 0 on failure
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*/
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int portnum(name, port, linenum)
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char *name;
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u_short *port;
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int linenum;
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{
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struct servent *sp, *sp2;
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u_short p1 = 0;
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int i;
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if (isdigit(*name)) {
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if (ratoi(name, &i, 0, USHRT_MAX)) {
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*port = (u_short)i;
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return 1;
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}
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fprintf(stderr, "%d: unknown port \"%s\"\n", linenum, name);
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return 0;
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}
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if (proto != NULL && strcasecmp(proto, "tcp/udp") != 0) {
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sp = getservbyname(name, proto);
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if (sp) {
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*port = ntohs(sp->s_port);
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return 1;
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}
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fprintf(stderr, "%d: unknown service \"%s\".\n", linenum, name);
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return 0;
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}
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sp = getservbyname(name, "tcp");
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if (sp)
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p1 = sp->s_port;
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sp2 = getservbyname(name, "udp");
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if (!sp || !sp2) {
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fprintf(stderr, "%d: unknown tcp/udp service \"%s\".\n",
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linenum, name);
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return 0;
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}
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if (p1 != sp2->s_port) {
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fprintf(stderr, "%d: %s %d/tcp is a different port to ",
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linenum, name, p1);
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fprintf(stderr, "%d: %s %d/udp\n", linenum, name, sp->s_port);
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return 0;
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}
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*port = ntohs(p1);
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return 1;
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}
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u_char tcp_flags(flgs, mask, linenum)
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char *flgs;
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u_char *mask;
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int linenum;
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{
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u_char tcpf = 0, tcpfm = 0, *fp = &tcpf;
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char *s, *t;
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if (*flgs == '0') {
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s = strchr(flgs, '/');
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if (s)
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*s++ = '\0';
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tcpf = strtol(flgs, NULL, 0);
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fp = &tcpfm;
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} else
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s = flgs;
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for (; *s; s++) {
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if (*s == '/' && fp == &tcpf) {
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fp = &tcpfm;
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if (*(s + 1) == '0')
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break;
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continue;
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}
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if (!(t = index(flagset, *s))) {
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fprintf(stderr, "%d: unknown flag (%c)\n", linenum, *s);
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return 0;
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}
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*fp |= flags[t - flagset];
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}
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if (s && *s == '0')
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tcpfm = strtol(s, NULL, 0);
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if (!tcpfm) {
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if (tcpf == TH_SYN)
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tcpfm = 0xff & ~(TH_ECN|TH_CWR);
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else
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tcpfm = 0xff & ~(TH_ECN);
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}
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*mask = tcpfm;
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return tcpf;
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}
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/*
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* count consecutive 1's in bit mask. If the mask generated by counting
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* consecutive 1's is different to that passed, return -1, else return #
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* of bits.
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*/
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int countbits(ip)
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u_32_t ip;
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{
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u_32_t ipn;
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int cnt = 0, i, j;
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ip = ipn = ntohl(ip);
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for (i = 32; i; i--, ipn *= 2)
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if (ipn & 0x80000000)
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cnt++;
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else
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break;
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ipn = 0;
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for (i = 32, j = cnt; i; i--, j--) {
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ipn *= 2;
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if (j > 0)
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ipn++;
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}
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if (ipn == ip)
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return cnt;
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return -1;
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}
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int count6bits(msk)
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u_32_t *msk;
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{
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int i = 0, k;
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u_32_t j;
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for (k = 3; k >= 0; k--)
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if (msk[k] == 0xffffffff)
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i += 32;
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else {
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for (j = msk[k]; j; j <<= 1)
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if (j & 0x80000000)
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i++;
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}
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return i;
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}
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char *portname(pr, port)
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int pr, port;
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{
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static char buf[32];
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struct protoent *p = NULL;
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struct servent *sv = NULL, *sv1 = NULL;
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if (pr == -1) {
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if ((sv = getservbyport(htons(port), "tcp"))) {
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strncpy(buf, sv->s_name, sizeof(buf)-1);
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buf[sizeof(buf)-1] = '\0';
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sv1 = getservbyport(htons(port), "udp");
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sv = strncasecmp(buf, sv->s_name, strlen(buf)) ?
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NULL : sv1;
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}
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if (sv)
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return buf;
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} else if (pr && (p = getprotobynumber(pr))) {
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if ((sv = getservbyport(htons(port), p->p_name))) {
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strncpy(buf, sv->s_name, sizeof(buf)-1);
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buf[sizeof(buf)-1] = '\0';
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return buf;
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}
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}
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(void) sprintf(buf, "%d", port);
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return buf;
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}
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int ratoi(ps, pi, min, max)
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char *ps;
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int *pi, min, max;
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{
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int i;
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char *pe;
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i = (int)strtol(ps, &pe, 0);
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if (*pe != '\0' || i < min || i > max)
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return 0;
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*pi = i;
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return 1;
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}
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int ratoui(ps, pi, min, max)
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char *ps;
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u_int *pi, min, max;
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{
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u_int i;
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char *pe;
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i = (u_int)strtol(ps, &pe, 0);
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if (*pe != '\0' || i < min || i > max)
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return 0;
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*pi = i;
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return 1;
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}
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void printhostmask(v, addr, mask)
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int v;
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u_32_t *addr, *mask;
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{
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struct in_addr ipa;
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int ones;
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#ifdef USE_INET6
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if (v == 6) {
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ones = count6bits(mask);
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if (ones == 0 && !addr[0] && !addr[1] && !addr[2] && !addr[3])
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printf("any");
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else {
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char ipbuf[64];
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printf("%s/%d",
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inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf)),
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ones);
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}
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}
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else
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#endif
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if (!*addr && !*mask)
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printf("any");
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else {
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ipa.s_addr = *addr;
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printf("%s", inet_ntoa(ipa));
|
|
if ((ones = countbits(*mask)) == -1) {
|
|
ipa.s_addr = *mask;
|
|
printf("/%s", inet_ntoa(ipa));
|
|
} else
|
|
printf("/%d", ones);
|
|
}
|
|
}
|
|
|
|
|
|
void printportcmp(pr, frp)
|
|
int pr;
|
|
frpcmp_t *frp;
|
|
{
|
|
static char *pcmp1[] = { "*", "=", "!=", "<", ">", "<=", ">=",
|
|
"<>", "><"};
|
|
|
|
if (frp->frp_cmp == FR_INRANGE || frp->frp_cmp == FR_OUTRANGE)
|
|
printf(" port %d %s %d", frp->frp_port,
|
|
pcmp1[frp->frp_cmp], frp->frp_top);
|
|
else
|
|
printf(" port %s %s", pcmp1[frp->frp_cmp],
|
|
portname(pr, frp->frp_port));
|
|
}
|
|
|
|
|
|
void printbuf(buf, len, zend)
|
|
char *buf;
|
|
int len, zend;
|
|
{
|
|
char *s, c;
|
|
int i;
|
|
|
|
for (s = buf, i = len; i; i--) {
|
|
c = *s++;
|
|
if (isprint(c))
|
|
putchar(c);
|
|
else
|
|
printf("\\%03o", c);
|
|
if ((c == '\0') && zend)
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
char *hostname(v, ip)
|
|
int v;
|
|
void *ip;
|
|
{
|
|
#ifdef USE_INET6
|
|
static char hostbuf[MAXHOSTNAMELEN+1];
|
|
#endif
|
|
struct in_addr ipa;
|
|
|
|
if (v == 4) {
|
|
ipa.s_addr = *(u_32_t *)ip;
|
|
return inet_ntoa(ipa);
|
|
}
|
|
#ifdef USE_INET6
|
|
(void) inet_ntop(AF_INET6, ip, hostbuf, sizeof(hostbuf) - 1);
|
|
hostbuf[MAXHOSTNAMELEN] = '\0';
|
|
return hostbuf;
|
|
#else
|
|
return "IPv6";
|
|
#endif
|
|
}
|