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freebsd-skq/contrib/ipfilter/parse.c
guido 1fa4f6782a Import of ipfilter 3.3.8 
Approved by: jkh
2000-02-09 20:46:45 +00:00

1607 lines
35 KiB
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/*
* Copyright (C) 1993-1998 by Darren Reed.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and due credit is given
* to the original author and the contributors.
*/
#include <sys/types.h>
#if !defined(__SVR4) && !defined(__svr4__)
#include <strings.h>
#else
#include <sys/byteorder.h>
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <net/if.h>
#if __FreeBSD_version >= 300000
# include <net/if_var.h>
#endif
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <netdb.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <resolv.h>
#include <ctype.h>
#include <syslog.h>
#include "ip_compat.h"
#include "ip_fil.h"
#include "ipf.h"
#include "facpri.h"
#if !defined(lint)
static const char sccsid[] = "@(#)parse.c 1.44 6/5/96 (C) 1993-1996 Darren Reed";
static const char rcsid[] = "@(#)$Id: parse.c,v 2.1.2.8 2000/01/27 08:49:42 darrenr Exp $";
#endif
extern struct ipopt_names ionames[], secclass[];
extern int opts;
int portnum __P((char *, u_short *, int));
u_char tcp_flags __P((char *, u_char *, int));
int addicmp __P((char ***, struct frentry *, int));
int extras __P((char ***, struct frentry *, int));
char ***seg;
u_long *sa, *msk;
u_short *pp, *tp;
u_char *cp;
int hostmask __P((char ***, u_32_t *, u_32_t *, u_short *, u_char *,
u_short *, int));
int ports __P((char ***, u_short *, u_char *, u_short *, int));
int icmpcode __P((char *)), addkeep __P((char ***, struct frentry *, int));
int to_interface __P((frdest_t *, char *, int));
void print_toif __P((char *, frdest_t *));
void optprint __P((u_short *, u_long, u_long));
int countbits __P((u_32_t));
char *portname __P((int, int));
int ratoi __P((char *, int *, int, int));
char *proto = NULL;
char flagset[] = "FSRPAU";
u_char flags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH, TH_ACK, TH_URG };
static char thishost[MAXHOSTNAMELEN];
void initparse()
{
gethostname(thishost, sizeof(thishost));
thishost[sizeof(thishost) - 1] = '\0';
}
/* parse()
*
* parse a line read from the input filter rule file
*/
struct frentry *parse(line, linenum)
char *line;
int linenum;
{
static struct frentry fil;
struct protoent *p = NULL;
char *cps[31], **cpp, *endptr;
u_char ch;
int i, cnt = 1, j;
while (*line && isspace(*line))
line++;
if (!*line)
return NULL;
bzero((char *)&fil, sizeof(fil));
fil.fr_mip.fi_v = 0xf;
fil.fr_ip.fi_v = 4;
fil.fr_loglevel = 0xffff;
/*
* break line up into max of 20 segments
*/
if (opts & OPT_DEBUG)
fprintf(stderr, "parse [%s]\n", line);
for (i = 0, *cps = strtok(line, " \b\t\r\n"); cps[i] && i < 30; cnt++)
cps[++i] = strtok(NULL, " \b\t\r\n");
cps[i] = NULL;
if (cnt < 3) {
fprintf(stderr, "%d: not enough segments in line\n", linenum);
return NULL;
}
cpp = cps;
if (**cpp == '@')
fil.fr_hits = (U_QUAD_T)atoi(*cpp++ + 1) + 1;
if (!strcasecmp("block", *cpp)) {
fil.fr_flags |= FR_BLOCK;
if (!strncasecmp(*(cpp+1), "return-icmp-as-dest", 19) &&
(i = 19))
fil.fr_flags |= FR_FAKEICMP;
else if (!strncasecmp(*(cpp+1), "return-icmp", 11) && (i = 11))
fil.fr_flags |= FR_RETICMP;
if (fil.fr_flags & FR_RETICMP) {
cpp++;
if (strlen(*cpp) == i) {
if (*(cpp + 1) && **(cpp +1) == '(') {
cpp++;
i = 0;
} else
i = -1;
}
/*
* The ICMP code is not required to follow in ()'s
*/
if ((i >= 0) && (*(*cpp + i) == '(')) {
i++;
j = icmpcode(*cpp + i);
if (j == -1) {
fprintf(stderr,
"%d: unrecognised icmp code %s\n",
linenum, *cpp + 20);
return NULL;
}
fil.fr_icode = j;
}
} else if (!strncasecmp(*(cpp+1), "return-rst", 10)) {
fil.fr_flags |= FR_RETRST;
cpp++;
}
} else if (!strcasecmp("count", *cpp)) {
fil.fr_flags |= FR_ACCOUNT;
} else if (!strcasecmp("pass", *cpp)) {
fil.fr_flags |= FR_PASS;
} else if (!strcasecmp("auth", *cpp)) {
fil.fr_flags |= FR_AUTH;
} else if (!strcasecmp("preauth", *cpp)) {
fil.fr_flags |= FR_PREAUTH;
} else if (!strcasecmp("skip", *cpp)) {
cpp++;
if (ratoi(*cpp, &i, 0, USHRT_MAX))
fil.fr_skip = i;
else {
fprintf(stderr, "%d: integer must follow skip\n",
linenum);
return NULL;
}
} else if (!strcasecmp("log", *cpp)) {
fil.fr_flags |= FR_LOG;
if (!strcasecmp(*(cpp+1), "body")) {
fil.fr_flags |= FR_LOGBODY;
cpp++;
}
if (!strcasecmp(*(cpp+1), "first")) {
fil.fr_flags |= FR_LOGFIRST;
}
if (!strcasecmp(*(cpp+1), "level")) {
int fac, pri;
char *s;
fac = 0;
pri = 0;
if (!*++cpp) {
fprintf(stderr, "%d: %s\n", linenum,
"missing identifier after level");
return NULL;
}
s = index(*cpp, '.');
if (s) {
*s++ = '\0';
fac = fac_findname(*cpp);
if (fac == -1) {
fprintf(stderr, "%d: %s %s\n", linenum,
"Unknown facility", *cpp);
return NULL;
}
pri = pri_findname(s);
if (pri == -1) {
fprintf(stderr, "%d: %s %s\n", linenum,
"Unknown priority", s);
return NULL;
}
} else {
pri = pri_findname(*cpp);
if (pri == -1) {
fprintf(stderr, "%d: %s %s\n", linenum,
"Unknown priority", *cpp);
return NULL;
}
}
fil.fr_loglevel = fac|pri;
cpp++;
}
} else {
/*
* Doesn't start with one of the action words
*/
fprintf(stderr, "%d: unknown keyword (%s)\n", linenum, *cpp);
return NULL;
}
if (!*++cpp) {
fprintf(stderr, "%d: missing 'in'/'out' keyword\n", linenum);
return NULL;
}
if (!strcasecmp("in", *cpp))
fil.fr_flags |= FR_INQUE;
else if (!strcasecmp("out", *cpp)) {
fil.fr_flags |= FR_OUTQUE;
if (fil.fr_flags & FR_RETICMP) {
fprintf(stderr,
"%d: Can only use return-icmp with 'in'\n",
linenum);
return NULL;
} else if (fil.fr_flags & FR_RETRST) {
fprintf(stderr,
"%d: Can only use return-rst with 'in'\n",
linenum);
return NULL;
}
}
if (!*++cpp) {
fprintf(stderr, "%d: missing source specification\n", linenum);
return NULL;
}
if (!strcasecmp("log", *cpp)) {
if (!*++cpp) {
fprintf(stderr, "%d: missing source specification\n",
linenum);
return NULL;
}
if (fil.fr_flags & FR_PASS)
fil.fr_flags |= FR_LOGP;
else if (fil.fr_flags & FR_BLOCK)
fil.fr_flags |= FR_LOGB;
if (*cpp && !strcasecmp(*cpp, "body")) {
fil.fr_flags |= FR_LOGBODY;
cpp++;
}
if (*cpp && !strcasecmp(*cpp, "first")) {
fil.fr_flags |= FR_LOGFIRST;
cpp++;
}
if (*cpp && !strcasecmp(*cpp, "or-block")) {
if (!(fil.fr_flags & FR_PASS)) {
fprintf(stderr,
"%d: or-block must be used with pass\n",
linenum);
return NULL;
}
fil.fr_flags |= FR_LOGORBLOCK;
cpp++;
}
if (*cpp && !strcasecmp(*cpp, "level")) {
int fac, pri;
char *s;
fac = 0;
pri = 0;
if (!*++cpp) {
fprintf(stderr, "%d: %s\n", linenum,
"missing identifier after level");
return NULL;
}
s = index(*cpp, '.');
if (s) {
*s++ = '\0';
fac = fac_findname(*cpp);
if (fac == -1) {
fprintf(stderr, "%d: %s %s\n", linenum,
"Unknown facility", *cpp);
return NULL;
}
pri = pri_findname(s);
if (pri == -1) {
fprintf(stderr, "%d: %s %s\n", linenum,
"Unknown priority", s);
return NULL;
}
} else {
pri = pri_findname(*cpp);
if (pri == -1) {
fprintf(stderr, "%d: %s %s\n", linenum,
"Unknown priority", *cpp);
return NULL;
}
}
fil.fr_loglevel = fac|pri;
cpp++;
}
}
if (*cpp && !strcasecmp("quick", *cpp)) {
cpp++;
fil.fr_flags |= FR_QUICK;
}
*fil.fr_ifname = '\0';
if (*cpp && !strcasecmp(*cpp, "on")) {
if (!*++cpp) {
fprintf(stderr, "%d: interface name missing\n",
linenum);
return NULL;
}
(void)strncpy(fil.fr_ifname, *cpp, IFNAMSIZ-1);
fil.fr_ifname[IFNAMSIZ-1] = '\0';
cpp++;
if (!*cpp) {
if ((fil.fr_flags & FR_RETMASK) == FR_RETRST) {
fprintf(stderr,
"%d: %s can only be used with TCP\n",
linenum, "return-rst");
return NULL;
}
return &fil;
}
if (*cpp) {
if (!strcasecmp(*cpp, "dup-to") && *(cpp + 1)) {
cpp++;
if (to_interface(&fil.fr_dif, *cpp, linenum))
return NULL;
cpp++;
}
if (*cpp && !strcasecmp(*cpp, "to") && *(cpp + 1)) {
cpp++;
if (to_interface(&fil.fr_tif, *cpp, linenum))
return NULL;
cpp++;
} else if (*cpp && !strcasecmp(*cpp, "fastroute")) {
if (!(fil.fr_flags & FR_INQUE)) {
fprintf(stderr,
"can only use %s with 'in'\n",
"fastroute");
return NULL;
}
fil.fr_flags |= FR_FASTROUTE;
cpp++;
}
}
}
if (*cpp && !strcasecmp(*cpp, "tos")) {
if (!*++cpp) {
fprintf(stderr, "%d: tos missing value\n", linenum);
return NULL;
}
fil.fr_tos = strtol(*cpp, NULL, 0);
fil.fr_mip.fi_tos = 0xff;
cpp++;
}
if (*cpp && !strcasecmp(*cpp, "ttl")) {
if (!*++cpp) {
fprintf(stderr, "%d: ttl missing hopcount value\n",
linenum);
return NULL;
}
if (ratoi(*cpp, &i, 0, 255))
fil.fr_ttl = i;
else {
fprintf(stderr, "%d: invalid ttl (%s)\n",
linenum, *cpp);
return NULL;
}
fil.fr_mip.fi_ttl = 0xff;
cpp++;
}
/*
* check for "proto <protoname>" only decode udp/tcp/icmp as protoname
*/
proto = NULL;
if (*cpp && !strcasecmp(*cpp, "proto")) {
if (!*++cpp) {
fprintf(stderr, "%d: protocol name missing\n", linenum);
return NULL;
}
proto = *cpp++;
if (!strcasecmp(proto, "tcp/udp")) {
fil.fr_ip.fi_fl |= FI_TCPUDP;
fil.fr_mip.fi_fl |= FI_TCPUDP;
} else {
if (!(p = getprotobyname(proto)) && !isdigit(*proto)) {
fprintf(stderr,
"%d: unknown protocol (%s)\n",
linenum, proto);
return NULL;
}
if (p)
fil.fr_proto = p->p_proto;
else if (isdigit(*proto)) {
i = (int)strtol(proto, &endptr, 0);
if (*endptr != '\0' || i < 0 || i > 255) {
fprintf(stderr,
"%d: unknown protocol (%s)\n",
linenum, proto);
return NULL;
}
fil.fr_proto = i;
}
fil.fr_mip.fi_p = 0xff;
}
}
if ((fil.fr_proto != IPPROTO_TCP) &&
((fil.fr_flags & FR_RETMASK) == FR_RETRST)) {
fprintf(stderr, "%d: %s can only be used with TCP\n",
linenum, "return-rst");
return NULL;
}
/*
* get the from host and bit mask to use against packets
*/
if (!*cpp) {
fprintf(stderr, "%d: missing source specification\n", linenum);
return NULL;
}
if (!strcasecmp(*cpp, "all")) {
cpp++;
if (!*cpp)
return &fil;
} else {
if (strcasecmp(*cpp, "from")) {
fprintf(stderr, "%d: unexpected keyword (%s) - from\n",
linenum, *cpp);
return NULL;
}
if (!*++cpp) {
fprintf(stderr, "%d: missing host after from\n",
linenum);
return NULL;
}
ch = 0;
if (**cpp == '!') {
fil.fr_flags |= FR_NOTSRCIP;
(*cpp)++;
}
if (hostmask(&cpp, (u_32_t *)&fil.fr_src,
(u_32_t *)&fil.fr_smsk, &fil.fr_sport, &ch,
&fil.fr_stop, linenum)) {
return NULL;
}
fil.fr_scmp = ch;
if (!*cpp) {
fprintf(stderr, "%d: missing to fields\n", linenum);
return NULL;
}
/*
* do the same for the to field (destination host)
*/
if (strcasecmp(*cpp, "to")) {
fprintf(stderr, "%d: unexpected keyword (%s) - to\n",
linenum, *cpp);
return NULL;
}
if (!*++cpp) {
fprintf(stderr, "%d: missing host after to\n", linenum);
return NULL;
}
ch = 0;
if (**cpp == '!') {
fil.fr_flags |= FR_NOTDSTIP;
(*cpp)++;
}
if (hostmask(&cpp, (u_32_t *)&fil.fr_dst,
(u_32_t *)&fil.fr_dmsk, &fil.fr_dport, &ch,
&fil.fr_dtop, linenum)) {
return NULL;
}
fil.fr_dcmp = ch;
}
/*
* check some sanity, make sure we don't have icmp checks with tcp
* or udp or visa versa.
*/
if (fil.fr_proto && (fil.fr_dcmp || fil.fr_scmp) &&
fil.fr_proto != IPPROTO_TCP && fil.fr_proto != IPPROTO_UDP) {
fprintf(stderr, "%d: port operation on non tcp/udp\n", linenum);
return NULL;
}
if (fil.fr_icmp && fil.fr_proto != IPPROTO_ICMP) {
fprintf(stderr, "%d: icmp comparisons on wrong protocol\n",
linenum);
return NULL;
}
if (!*cpp)
return &fil;
if (*cpp && !strcasecmp(*cpp, "flags")) {
if (!*++cpp) {
fprintf(stderr, "%d: no flags present\n", linenum);
return NULL;
}
fil.fr_tcpf = tcp_flags(*cpp, &fil.fr_tcpfm, linenum);
cpp++;
}
/*
* extras...
*/
if (*cpp && (!strcasecmp(*cpp, "with") || !strcasecmp(*cpp, "and")))
if (extras(&cpp, &fil, linenum))
return NULL;
/*
* icmp types for use with the icmp protocol
*/
if (*cpp && !strcasecmp(*cpp, "icmp-type")) {
if (fil.fr_proto != IPPROTO_ICMP) {
fprintf(stderr,
"%d: icmp with wrong protocol (%d)\n",
linenum, fil.fr_proto);
return NULL;
}
if (addicmp(&cpp, &fil, linenum))
return NULL;
fil.fr_icmp = htons(fil.fr_icmp);
fil.fr_icmpm = htons(fil.fr_icmpm);
}
/*
* Keep something...
*/
while (*cpp && !strcasecmp(*cpp, "keep"))
if (addkeep(&cpp, &fil, linenum))
return NULL;
/*
* head of a new group ?
*/
if (*cpp && !strcasecmp(*cpp, "head")) {
if (!*++cpp) {
fprintf(stderr, "%d: head without group #\n", linenum);
return NULL;
}
if (ratoi(*cpp, &i, 0, USHRT_MAX))
fil.fr_grhead = i;
else {
fprintf(stderr, "%d: invalid group (%s)\n",
linenum, *cpp);
return NULL;
}
cpp++;
}
/*
* head of a new group ?
*/
if (*cpp && !strcasecmp(*cpp, "group")) {
if (!*++cpp) {
fprintf(stderr, "%d: group without group #\n",
linenum);
return NULL;
}
if (ratoi(*cpp, &i, 0, USHRT_MAX))
fil.fr_group = i;
else {
fprintf(stderr, "%d: invalid group (%s)\n",
linenum, *cpp);
return NULL;
}
cpp++;
}
/*
* leftovers...yuck
*/
if (*cpp && **cpp) {
fprintf(stderr, "%d: unknown words at end: [", linenum);
for (; *cpp; cpp++)
fprintf(stderr, "%s ", *cpp);
fprintf(stderr, "]\n");
return NULL;
}
/*
* lazy users...
*/
if ((fil.fr_tcpf || fil.fr_tcpfm) && fil.fr_proto != IPPROTO_TCP) {
fprintf(stderr, "%d: TCP protocol not specified\n", linenum);
return NULL;
}
if (!(fil.fr_ip.fi_fl & FI_TCPUDP) && (fil.fr_proto != IPPROTO_TCP) &&
(fil.fr_proto != IPPROTO_UDP) && (fil.fr_dcmp || fil.fr_scmp)) {
if (!fil.fr_proto) {
fil.fr_ip.fi_fl |= FI_TCPUDP;
fil.fr_mip.fi_fl |= FI_TCPUDP;
} else {
fprintf(stderr,
"%d: port comparisons for non-TCP/UDP\n",
linenum);
return NULL;
}
}
/*
if ((fil.fr_flags & FR_KEEPFRAG) &&
(!(fil.fr_ip.fi_fl & FI_FRAG) || !(fil.fr_ip.fi_fl & FI_FRAG))) {
fprintf(stderr,
"%d: must use 'with frags' with 'keep frags'\n",
linenum);
return NULL;
}
*/
return &fil;
}
int to_interface(fdp, to, linenum)
frdest_t *fdp;
char *to;
int linenum;
{
int r = 0;
char *s;
s = index(to, ':');
fdp->fd_ifp = NULL;
if (s) {
*s++ = '\0';
fdp->fd_ip.s_addr = hostnum(s, &r, linenum);
if (r == -1)
return -1;
}
(void) strncpy(fdp->fd_ifname, to, sizeof(fdp->fd_ifname) - 1);
fdp->fd_ifname[sizeof(fdp->fd_ifname) - 1] = '\0';
return 0;
}
void print_toif(tag, fdp)
char *tag;
frdest_t *fdp;
{
printf("%s %s%s", tag, fdp->fd_ifname,
(fdp->fd_ifp || (long)fdp->fd_ifp == -1) ? "" : "(!)");
if (fdp->fd_ip.s_addr)
printf(":%s", inet_ntoa(fdp->fd_ip));
putchar(' ');
}
/*
* returns -1 if neither "hostmask/num" or "hostmask mask addr" are
* found in the line segments, there is an error processing this information,
* or there is an error processing ports information.
*/
int hostmask(seg, sa, msk, pp, cp, tp, linenum)
char ***seg;
u_32_t *sa, *msk;
u_short *pp, *tp;
u_char *cp;
int linenum;
{
char *s, *endptr;
int bits = -1, resolved;
struct in_addr maskaddr;
/*
* is it possibly hostname/num ?
*/
if ((s = index(**seg, '/')) || (s = index(**seg, ':'))) {
*s++ = '\0';
if (index(s, '.') || index(s, 'x')) {
/* possibly of the form xxx.xxx.xxx.xxx
* or 0xYYYYYYYY */
if (inet_aton(s, &maskaddr) == 0) {
fprintf(stderr, "%d: bad mask (%s)\n",
linenum, s);
return -1;
}
*msk = maskaddr.s_addr;
} else {
/*
* set x most significant bits
*/
bits = (int)strtol(s, &endptr, 0);
if (*endptr != '\0' || bits > 32 || bits < 0) {
fprintf(stderr, "%d: bad mask (/%s)\n",
linenum, s);
return -1;
}
if (bits == 0)
*msk = 0;
else
*msk = htonl(0xffffffff << (32 - bits));
}
*sa = hostnum(**seg, &resolved, linenum) & *msk;
if (resolved == -1) {
fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg);
return -1;
}
(*seg)++;
return ports(seg, pp, cp, tp, linenum);
}
/*
* look for extra segments if "mask" found in right spot
*/
if (*(*seg+1) && *(*seg+2) && !strcasecmp(*(*seg+1), "mask")) {
*sa = hostnum(**seg, &resolved, linenum);
if (resolved == -1) {
fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg);
return -1;
}
(*seg)++;
(*seg)++;
if (inet_aton(**seg, &maskaddr) == 0) {
fprintf(stderr, "%d: bad mask (%s)\n", linenum, **seg);
return -1;
}
*msk = maskaddr.s_addr;
(*seg)++;
*sa &= *msk;
return ports(seg, pp, cp, tp, linenum);
}
if (**seg) {
*sa = hostnum(**seg, &resolved, linenum);
if (resolved == -1) {
fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg);
return -1;
}
(*seg)++;
*msk = (*sa ? inet_addr("255.255.255.255") : 0L);
*sa &= *msk;
return ports(seg, pp, cp, tp, linenum);
}
fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg);
return -1;
}
/*
* returns an ip address as a long var as a result of either a DNS lookup or
* straight inet_addr() call
*/
u_32_t hostnum(host, resolved, linenum)
char *host;
int *resolved;
int linenum;
{
struct hostent *hp;
struct netent *np;
struct in_addr ip;
*resolved = 0;
if (!strcasecmp("any", host))
return 0;
if (isdigit(*host) && inet_aton(host, &ip))
return ip.s_addr;
if (!strcasecmp("<thishost>", host))
host = thishost;
if (!(hp = gethostbyname(host))) {
if (!(np = getnetbyname(host))) {
*resolved = -1;
fprintf(stderr, "%d: can't resolve hostname: %s\n",
linenum, host);
return 0;
}
return htonl(np->n_net);
}
return *(u_32_t *)hp->h_addr;
}
/*
* check for possible presence of the port fields in the line
*/
int ports(seg, pp, cp, tp, linenum)
char ***seg;
u_short *pp, *tp;
u_char *cp;
int linenum;
{
int comp = -1;
if (!*seg || !**seg || !***seg)
return 0;
if (!strcasecmp(**seg, "port") && *(*seg + 1) && *(*seg + 2)) {
(*seg)++;
if (isdigit(***seg) && *(*seg + 2)) {
if (portnum(**seg, pp, linenum) == 0)
return -1;
(*seg)++;
if (!strcmp(**seg, "<>"))
comp = FR_OUTRANGE;
else if (!strcmp(**seg, "><"))
comp = FR_INRANGE;
else {
fprintf(stderr,
"%d: unknown range operator (%s)\n",
linenum, **seg);
return -1;
}
(*seg)++;
if (**seg == NULL) {
fprintf(stderr, "%d: missing 2nd port value\n",
linenum);
return -1;
}
if (portnum(**seg, tp, linenum) == 0)
return -1;
} else if (!strcmp(**seg, "=") || !strcasecmp(**seg, "eq"))
comp = FR_EQUAL;
else if (!strcmp(**seg, "!=") || !strcasecmp(**seg, "ne"))
comp = FR_NEQUAL;
else if (!strcmp(**seg, "<") || !strcasecmp(**seg, "lt"))
comp = FR_LESST;
else if (!strcmp(**seg, ">") || !strcasecmp(**seg, "gt"))
comp = FR_GREATERT;
else if (!strcmp(**seg, "<=") || !strcasecmp(**seg, "le"))
comp = FR_LESSTE;
else if (!strcmp(**seg, ">=") || !strcasecmp(**seg, "ge"))
comp = FR_GREATERTE;
else {
fprintf(stderr, "%d: unknown comparator (%s)\n",
linenum, **seg);
return -1;
}
if (comp != FR_OUTRANGE && comp != FR_INRANGE) {
(*seg)++;
if (portnum(**seg, pp, linenum) == 0)
return -1;
}
*cp = comp;
(*seg)++;
}
return 0;
}
/*
* find the port number given by the name, either from getservbyname() or
* straight atoi(). Return 1 on success, 0 on failure
*/
int portnum(name, port, linenum)
char *name;
u_short *port;
int linenum;
{
struct servent *sp, *sp2;
u_short p1 = 0;
int i;
if (isdigit(*name)) {
if (ratoi(name, &i, 0, USHRT_MAX)) {
*port = (u_short)i;
return 1;
}
fprintf(stderr, "%d: unknown port \"%s\"\n", linenum, name);
return 0;
}
if (proto != NULL && strcasecmp(proto, "tcp/udp") != 0) {
sp = getservbyname(name, proto);
if (sp) {
*port = ntohs(sp->s_port);
return 1;
}
fprintf(stderr, "%d: unknown service \"%s\".\n", linenum, name);
return 0;
}
sp = getservbyname(name, "tcp");
if (sp)
p1 = sp->s_port;
sp2 = getservbyname(name, "udp");
if (!sp || !sp2) {
fprintf(stderr, "%d: unknown tcp/udp service \"%s\".\n",
linenum, name);
return 0;
}
if (p1 != sp2->s_port) {
fprintf(stderr, "%d: %s %d/tcp is a different port to ",
linenum, name, p1);
fprintf(stderr, "%d: %s %d/udp\n", linenum, name, sp->s_port);
return 0;
}
*port = ntohs(p1);
return 1;
}
u_char tcp_flags(flgs, mask, linenum)
char *flgs;
u_char *mask;
int linenum;
{
u_char tcpf = 0, tcpfm = 0, *fp = &tcpf;
char *s, *t;
for (s = flgs; *s; s++) {
if (*s == '/' && fp == &tcpf) {
fp = &tcpfm;
continue;
}
if (!(t = index(flagset, *s))) {
fprintf(stderr, "%d: unknown flag (%c)\n", linenum, *s);
return 0;
}
*fp |= flags[t - flagset];
}
if (!tcpfm)
tcpfm = 0xff;
*mask = tcpfm;
return tcpf;
}
/*
* deal with extra bits on end of the line
*/
int extras(cp, fr, linenum)
char ***cp;
struct frentry *fr;
int linenum;
{
u_short secmsk;
u_long opts;
int notopt;
char oflags;
opts = 0;
secmsk = 0;
notopt = 0;
(*cp)++;
if (!**cp)
return -1;
while (**cp && (!strncasecmp(**cp, "ipopt", 5) ||
!strncasecmp(**cp, "not", 3) || !strncasecmp(**cp, "opt", 4) ||
!strncasecmp(**cp, "frag", 3) || !strncasecmp(**cp, "no", 2) ||
!strncasecmp(**cp, "short", 5))) {
if (***cp == 'n' || ***cp == 'N') {
notopt = 1;
(*cp)++;
continue;
} else if (***cp == 'i' || ***cp == 'I') {
if (!notopt)
fr->fr_ip.fi_fl |= FI_OPTIONS;
fr->fr_mip.fi_fl |= FI_OPTIONS;
goto nextopt;
} else if (***cp == 'f' || ***cp == 'F') {
if (!notopt)
fr->fr_ip.fi_fl |= FI_FRAG;
fr->fr_mip.fi_fl |= FI_FRAG;
goto nextopt;
} else if (***cp == 'o' || ***cp == 'O') {
if (!*(*cp + 1)) {
fprintf(stderr,
"%d: opt missing arguements\n",
linenum);
return -1;
}
(*cp)++;
if (!(opts = optname(cp, &secmsk, linenum)))
return -1;
oflags = FI_OPTIONS;
} else if (***cp == 's' || ***cp == 'S') {
if (fr->fr_tcpf) {
fprintf(stderr,
"%d: short cannot be used with TCP flags\n",
linenum);
return -1;
}
if (!notopt)
fr->fr_ip.fi_fl |= FI_SHORT;
fr->fr_mip.fi_fl |= FI_SHORT;
goto nextopt;
} else
return -1;
if (!notopt || !opts)
fr->fr_mip.fi_fl |= oflags;
if (notopt) {
if (!secmsk) {
fr->fr_mip.fi_optmsk |= opts;
} else {
fr->fr_mip.fi_optmsk |= (opts & ~0x0100);
}
} else {
fr->fr_mip.fi_optmsk |= opts;
}
fr->fr_mip.fi_secmsk |= secmsk;
if (notopt) {
fr->fr_ip.fi_fl &= (~oflags & 0xf);
fr->fr_ip.fi_optmsk &= ~opts;
fr->fr_ip.fi_secmsk &= ~secmsk;
} else {
fr->fr_ip.fi_fl |= oflags;
fr->fr_ip.fi_optmsk |= opts;
fr->fr_ip.fi_secmsk |= secmsk;
}
nextopt:
notopt = 0;
opts = 0;
oflags = 0;
secmsk = 0;
(*cp)++;
}
return 0;
}
u_32_t optname(cp, sp, linenum)
char ***cp;
u_short *sp;
int linenum;
{
struct ipopt_names *io, *so;
u_long msk = 0;
u_short smsk = 0;
char *s;
int sec = 0;
for (s = strtok(**cp, ","); s; s = strtok(NULL, ",")) {
for (io = ionames; io->on_name; io++)
if (!strcasecmp(s, io->on_name)) {
msk |= io->on_bit;
break;
}
if (!io->on_name) {
fprintf(stderr, "%d: unknown IP option name %s\n",
linenum, s);
return 0;
}
if (!strcasecmp(s, "sec-class"))
sec = 1;
}
if (sec && !*(*cp + 1)) {
fprintf(stderr, "%d: missing security level after sec-class\n",
linenum);
return 0;
}
if (sec) {
(*cp)++;
for (s = strtok(**cp, ","); s; s = strtok(NULL, ",")) {
for (so = secclass; so->on_name; so++)
if (!strcasecmp(s, so->on_name)) {
smsk |= so->on_bit;
break;
}
if (!so->on_name) {
fprintf(stderr,
"%d: no such security level: %s\n",
linenum, s);
return 0;
}
}
if (smsk)
*sp = smsk;
}
return msk;
}
#ifdef __STDC__
void optprint(u_short *sec, u_long optmsk, u_long optbits)
#else
void optprint(sec, optmsk, optbits)
u_short *sec;
u_long optmsk, optbits;
#endif
{
u_short secmsk = sec[0], secbits = sec[1];
struct ipopt_names *io, *so;
char *s;
int secflag = 0;
s = " opt ";
for (io = ionames; io->on_name; io++)
if ((io->on_bit & optmsk) &&
((io->on_bit & optmsk) == (io->on_bit & optbits))) {
if ((io->on_value != IPOPT_SECURITY) ||
(!secmsk && !secbits)) {
printf("%s%s", s, io->on_name);
if (io->on_value == IPOPT_SECURITY)
io++;
s = ",";
} else
secflag = 1;
}
if (secmsk & secbits) {
printf("%ssec-class", s);
s = " ";
for (so = secclass; so->on_name; so++)
if ((secmsk & so->on_bit) &&
((so->on_bit & secmsk) == (so->on_bit & secbits))) {
printf("%s%s", s, so->on_name);
s = ",";
}
}
if ((optmsk && (optmsk != optbits)) ||
(secmsk && (secmsk != secbits))) {
s = " ";
printf(" not opt");
if (optmsk != optbits) {
for (io = ionames; io->on_name; io++)
if ((io->on_bit & optmsk) &&
((io->on_bit & optmsk) !=
(io->on_bit & optbits))) {
if ((io->on_value != IPOPT_SECURITY) ||
(!secmsk && !secbits)) {
printf("%s%s", s, io->on_name);
s = ",";
if (io->on_value ==
IPOPT_SECURITY)
io++;
} else
io++;
}
}
if (secmsk != secbits) {
printf("%ssec-class", s);
s = " ";
for (so = secclass; so->on_name; so++)
if ((so->on_bit & secmsk) &&
((so->on_bit & secmsk) !=
(so->on_bit & secbits))) {
printf("%s%s", s, so->on_name);
s = ",";
}
}
}
}
char *icmptypes[] = {
"echorep", (char *)NULL, (char *)NULL, "unreach", "squench",
"redir", (char *)NULL, (char *)NULL, "echo", "routerad",
"routersol", "timex", "paramprob", "timest", "timestrep",
"inforeq", "inforep", "maskreq", "maskrep", "END"
};
/*
* set the icmp field to the correct type if "icmp" word is found
*/
int addicmp(cp, fp, linenum)
char ***cp;
struct frentry *fp;
int linenum;
{
char **t;
int i;
(*cp)++;
if (!**cp)
return -1;
if (!fp->fr_proto) /* to catch lusers */
fp->fr_proto = IPPROTO_ICMP;
if (isdigit(***cp)) {
if (!ratoi(**cp, &i, 0, 255)) {
fprintf(stderr,
"%d: Invalid icmp-type (%s) specified\n",
linenum, **cp);
return -1;
}
} else {
for (t = icmptypes, i = 0; ; t++, i++) {
if (!*t)
continue;
if (!strcasecmp("END", *t)) {
i = -1;
break;
}
if (!strcasecmp(*t, **cp))
break;
}
if (i == -1) {
fprintf(stderr,
"%d: Invalid icmp-type (%s) specified\n",
linenum, **cp);
return -1;
}
}
fp->fr_icmp = (u_short)(i << 8);
fp->fr_icmpm = (u_short)0xff00;
(*cp)++;
if (!**cp)
return 0;
if (**cp && strcasecmp("code", **cp))
return 0;
(*cp)++;
if (isdigit(***cp)) {
if (!ratoi(**cp, &i, 0, 255)) {
fprintf(stderr,
"%d: Invalid icmp code (%s) specified\n",
linenum, **cp);
return -1;
}
fp->fr_icmp |= (u_short)i;
fp->fr_icmpm = (u_short)0xffff;
(*cp)++;
return 0;
}
fprintf(stderr, "%d: Invalid icmp code (%s) specified\n",
linenum, **cp);
return -1;
}
#define MAX_ICMPCODE 15
char *icmpcodes[] = {
"net-unr", "host-unr", "proto-unr", "port-unr", "needfrag", "srcfail",
"net-unk", "host-unk", "isolate", "net-prohib", "host-prohib",
"net-tos", "host-tos", "filter-prohib", "host-preced", "preced-cutoff",
NULL };
/*
* Return the number for the associated ICMP unreachable code.
*/
int icmpcode(str)
char *str;
{
char *s;
int i, len;
if (!(s = strrchr(str, ')')))
return -1;
*s = '\0';
if (isdigit(*str)) {
if (!ratoi(str, &i, 0, 255))
return -1;
else
return i;
}
len = strlen(str);
for (i = 0; icmpcodes[i]; i++)
if (!strncasecmp(str, icmpcodes[i], MIN(len,
strlen(icmpcodes[i])) ))
return i;
return -1;
}
/*
* set the icmp field to the correct type if "icmp" word is found
*/
int addkeep(cp, fp, linenum)
char ***cp;
struct frentry *fp;
int linenum;
{
if (fp->fr_proto != IPPROTO_TCP && fp->fr_proto != IPPROTO_UDP &&
fp->fr_proto != IPPROTO_ICMP && !(fp->fr_ip.fi_fl & FI_TCPUDP)) {
fprintf(stderr, "%d: Can only use keep with UDP/ICMP/TCP\n",
linenum);
return -1;
}
(*cp)++;
if (**cp && strcasecmp(**cp, "state") && strcasecmp(**cp, "frags")) {
fprintf(stderr, "%d: Unrecognised state keyword \"%s\"\n",
linenum, **cp);
return -1;
}
if (***cp == 's' || ***cp == 'S')
fp->fr_flags |= FR_KEEPSTATE;
else if (***cp == 'f' || ***cp == 'F')
fp->fr_flags |= FR_KEEPFRAG;
(*cp)++;
return 0;
}
/*
* count consecutive 1's in bit mask. If the mask generated by counting
* consecutive 1's is different to that passed, return -1, else return #
* of bits.
*/
int countbits(ip)
u_32_t ip;
{
u_32_t ipn;
int cnt = 0, i, j;
ip = ipn = ntohl(ip);
for (i = 32; i; i--, ipn *= 2)
if (ipn & 0x80000000)
cnt++;
else
break;
ipn = 0;
for (i = 32, j = cnt; i; i--, j--) {
ipn *= 2;
if (j > 0)
ipn++;
}
if (ipn == ip)
return cnt;
return -1;
}
char *portname(pr, port)
int pr, port;
{
static char buf[32];
struct protoent *p = NULL;
struct servent *sv = NULL, *sv1 = NULL;
if (pr == -1) {
if ((sv = getservbyport(htons(port), "tcp"))) {
strncpy(buf, sv->s_name, sizeof(buf)-1);
buf[sizeof(buf)-1] = '\0';
sv1 = getservbyport(htons(port), "udp");
sv = strncasecmp(buf, sv->s_name, strlen(buf)) ?
NULL : sv1;
}
if (sv)
return buf;
} else if (pr && (p = getprotobynumber(pr))) {
if ((sv = getservbyport(htons(port), p->p_name))) {
strncpy(buf, sv->s_name, sizeof(buf)-1);
buf[sizeof(buf)-1] = '\0';
return buf;
}
}
(void) sprintf(buf, "%d", port);
return buf;
}
/*
* print the filter structure in a useful way
*/
void printfr(fp)
struct frentry *fp;
{
static char *pcmp1[] = { "*", "=", "!=", "<", ">", "<=", ">=",
"<>", "><"};
struct protoent *p;
int ones = 0, pr;
char *s, *u;
u_char *t;
u_short sec[2];
if (fp->fr_flags & FR_PASS)
printf("pass");
else if (fp->fr_flags & FR_BLOCK) {
printf("block");
if (fp->fr_flags & FR_RETICMP) {
if ((fp->fr_flags & FR_RETMASK) == FR_FAKEICMP)
printf(" return-icmp-as-dest");
else if ((fp->fr_flags & FR_RETMASK) == FR_RETICMP)
printf(" return-icmp");
if (fp->fr_icode) {
if (fp->fr_icode <= MAX_ICMPCODE)
printf("(%s)",
icmpcodes[(int)fp->fr_icode]);
else
printf("(%d)", fp->fr_icode);
}
} else if ((fp->fr_flags & FR_RETMASK) == FR_RETRST)
printf(" return-rst");
} else if ((fp->fr_flags & FR_LOGMASK) == FR_LOG) {
printf("log");
if (fp->fr_flags & FR_LOGBODY)
printf(" body");
if (fp->fr_flags & FR_LOGFIRST)
printf(" first");
} else if (fp->fr_flags & FR_ACCOUNT)
printf("count");
else if (fp->fr_flags & FR_AUTH)
printf("auth");
else if (fp->fr_flags & FR_PREAUTH)
printf("preauth");
else if (fp->fr_skip)
printf("skip %hu", fp->fr_skip);
if (fp->fr_flags & FR_OUTQUE)
printf(" out ");
else
printf(" in ");
if (((fp->fr_flags & FR_LOGB) == FR_LOGB) ||
((fp->fr_flags & FR_LOGP) == FR_LOGP)) {
printf("log ");
if (fp->fr_flags & FR_LOGBODY)
printf("body ");
if (fp->fr_flags & FR_LOGFIRST)
printf("first ");
if (fp->fr_flags & FR_LOGORBLOCK)
printf("or-block ");
if (fp->fr_loglevel != 0xffff) {
if (fp->fr_loglevel & LOG_FACMASK) {
s = fac_toname(fp->fr_loglevel);
if (s == NULL)
s = "!!!";
} else
s = "";
u = pri_toname(fp->fr_loglevel);
if (u == NULL)
u = "!!!";
if (*s)
printf("level %s.%s ", s, u);
else
printf("level %s ", u);
}
}
if (fp->fr_flags & FR_QUICK)
printf("quick ");
if (*fp->fr_ifname) {
printf("on %s%s ", fp->fr_ifname,
(fp->fr_ifa || (long)fp->fr_ifa == -1) ? "" : "(!)");
if (*fp->fr_dif.fd_ifname)
print_toif("dup-to", &fp->fr_dif);
if (*fp->fr_tif.fd_ifname)
print_toif("to", &fp->fr_tif);
if (fp->fr_flags & FR_FASTROUTE)
printf("fastroute ");
}
if (fp->fr_mip.fi_tos)
printf("tos %#x ", fp->fr_tos);
if (fp->fr_mip.fi_ttl)
printf("ttl %d ", fp->fr_ttl);
if (fp->fr_ip.fi_fl & FI_TCPUDP) {
printf("proto tcp/udp ");
pr = -1;
} else if ((pr = fp->fr_mip.fi_p)) {
if ((p = getprotobynumber(fp->fr_proto)))
printf("proto %s ", p->p_name);
else
printf("proto %d ", fp->fr_proto);
}
printf("from %s", fp->fr_flags & FR_NOTSRCIP ? "!" : "");
if (!fp->fr_src.s_addr && !fp->fr_smsk.s_addr)
printf("any ");
else {
printf("%s", inet_ntoa(fp->fr_src));
if ((ones = countbits(fp->fr_smsk.s_addr)) == -1)
printf("/%s ", inet_ntoa(fp->fr_smsk));
else
printf("/%d ", ones);
}
if (fp->fr_scmp) {
if (fp->fr_scmp == FR_INRANGE || fp->fr_scmp == FR_OUTRANGE)
printf("port %d %s %d ", fp->fr_sport,
pcmp1[fp->fr_scmp], fp->fr_stop);
else
printf("port %s %s ", pcmp1[fp->fr_scmp],
portname(pr, fp->fr_sport));
}
printf("to %s", fp->fr_flags & FR_NOTDSTIP ? "!" : "");
if (!fp->fr_dst.s_addr && !fp->fr_dmsk.s_addr)
printf("any");
else {
printf("%s", inet_ntoa(fp->fr_dst));
if ((ones = countbits(fp->fr_dmsk.s_addr)) == -1)
printf("/%s", inet_ntoa(fp->fr_dmsk));
else
printf("/%d", ones);
}
if (fp->fr_dcmp) {
if (fp->fr_dcmp == FR_INRANGE || fp->fr_dcmp == FR_OUTRANGE)
printf(" port %d %s %d", fp->fr_dport,
pcmp1[fp->fr_dcmp], fp->fr_dtop);
else
printf(" port %s %s", pcmp1[fp->fr_dcmp],
portname(pr, fp->fr_dport));
}
if ((fp->fr_ip.fi_fl & ~FI_TCPUDP) ||
(fp->fr_mip.fi_fl & ~FI_TCPUDP) ||
fp->fr_ip.fi_optmsk || fp->fr_mip.fi_optmsk ||
fp->fr_ip.fi_secmsk || fp->fr_mip.fi_secmsk) {
printf(" with");
if (fp->fr_ip.fi_optmsk || fp->fr_mip.fi_optmsk ||
fp->fr_ip.fi_secmsk || fp->fr_mip.fi_secmsk) {
sec[0] = fp->fr_mip.fi_secmsk;
sec[1] = fp->fr_ip.fi_secmsk;
optprint(sec,
fp->fr_mip.fi_optmsk, fp->fr_ip.fi_optmsk);
} else if (fp->fr_mip.fi_fl & FI_OPTIONS) {
if (!(fp->fr_ip.fi_fl & FI_OPTIONS))
printf(" not");
printf(" ipopt");
}
if (fp->fr_mip.fi_fl & FI_SHORT) {
if (!(fp->fr_ip.fi_fl & FI_SHORT))
printf(" not");
printf(" short");
}
if (fp->fr_mip.fi_fl & FI_FRAG) {
if (!(fp->fr_ip.fi_fl & FI_FRAG))
printf(" not");
printf(" frag");
}
}
if (fp->fr_proto == IPPROTO_ICMP && fp->fr_icmpm) {
int type = fp->fr_icmp, code;
type = ntohs(fp->fr_icmp);
code = type & 0xff;
type /= 256;
if (type < (sizeof(icmptypes) / sizeof(char *)) &&
icmptypes[type])
printf(" icmp-type %s", icmptypes[type]);
else
printf(" icmp-type %d", type);
if (code)
printf(" code %d", code);
}
if (fp->fr_proto == IPPROTO_TCP && (fp->fr_tcpf || fp->fr_tcpfm)) {
printf(" flags ");
for (s = flagset, t = flags; *s; s++, t++)
if (fp->fr_tcpf & *t)
(void)putchar(*s);
if (fp->fr_tcpfm) {
(void)putchar('/');
for (s = flagset, t = flags; *s; s++, t++)
if (fp->fr_tcpfm & *t)
(void)putchar(*s);
}
}
if (fp->fr_flags & FR_KEEPSTATE)
printf(" keep state");
if (fp->fr_flags & FR_KEEPFRAG)
printf(" keep frags");
if (fp->fr_grhead)
printf(" head %d", fp->fr_grhead);
if (fp->fr_group)
printf(" group %d", fp->fr_group);
(void)putchar('\n');
}
void binprint(fp)
struct frentry *fp;
{
int i = sizeof(*fp), j = 0;
u_char *s;
for (s = (u_char *)fp; i; i--, s++) {
j++;
printf("%02x ", *s);
if (j == 16) {
printf("\n");
j = 0;
}
}
putchar('\n');
(void)fflush(stdout);
}
int ratoi(ps, pi, min, max)
char *ps;
int *pi, min, max;
{
int i;
char *pe;
i = (int)strtol(ps, &pe, 0);
if (*pe != '\0' || i < min || i > max)
return 0;
*pi = i;
return 1;
}
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