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freebsd-dev/contrib/ipfilter/ipnat.c
Darren Reed 0eab801c99 Import version 3.2alpha7
1997-05-25 15:45:04 +00:00

801 lines
17 KiB
C
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/*
* (C)opyright 1993,1994,1995 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.
*
* Added redirect stuff and a variety of bug fixes. (mcn@EnGarde.com)
*
* Broken still:
* Displaying the nat with redirect entries is way confusing
*
* Example redirection line:
* rdr le1 0.0.0.0/0 port 79 -> 199.165.219.129 port 9901
*
* Will redirect all incoming packets on le1 to any machine, port 79 to
* host 199.165.219.129, port 9901
*/
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#if !defined(__SVR4) && !defined(__svr4__)
#include <strings.h>
#else
#include <sys/byteorder.h>
#endif
#include <sys/types.h>
#include <sys/time.h>
#include <sys/param.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#if defined(sun) && (defined(__svr4__) || defined(__SVR4))
# include <sys/ioccom.h>
# include <sys/sysmacros.h>
#endif
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <net/if.h>
#include <netdb.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <resolv.h>
#include <ctype.h>
#include "ip_compat.h"
#include "ip_fil.h"
#include "ip_proxy.h"
#include "ip_nat.h"
#include "kmem.h"
#if !defined(lint) && defined(LIBC_SCCS)
static char sccsid[] ="@(#)ipnat.c 1.9 6/5/96 (C) 1993 Darren Reed";
static char rcsid[] = "$Id: ipnat.c,v 2.0.2.9 1997/05/05 14:03:55 darrenr Exp $";
#endif
#if SOLARIS
#define bzero(a,b) memset(a,0,b)
#endif
extern char *optarg;
ipnat_t *parse __P((char *));
u_long hostnum __P((char *, int *));
u_long hostmask __P((char *));
u_short portnum __P((char *, char *));
void dostats __P((int, int)), flushtable __P((int, int));
void printnat __P((ipnat_t *, int, void *));
void parsefile __P((int, char *, int));
void usage __P((char *));
int countbits __P((u_long));
char *getnattype __P((ipnat_t *));
int main __P((int, char*[]));
#define OPT_REM 1
#define OPT_NODO 2
#define OPT_STAT 4
#define OPT_LIST 8
#define OPT_VERBOSE 16
#define OPT_FLUSH 32
#define OPT_CLEAR 64
void usage(name)
char *name;
{
fprintf(stderr, "%s: [-CFlnrsv] [-f filename]\n", name);
exit(1);
}
int main(argc, argv)
int argc;
char *argv[];
{
char *file = NULL, c;
int fd, opts = 1;
while ((c = getopt(argc, argv, "CFf:lnrsv")) != -1)
switch (c)
{
case 'C' :
opts |= OPT_CLEAR;
break;
case 'f' :
file = optarg;
break;
case 'F' :
opts |= OPT_FLUSH;
break;
case 'l' :
opts |= OPT_LIST;
break;
case 'n' :
opts |= OPT_NODO;
break;
case 'r' :
opts &= ~OPT_REM;
break;
case 's' :
opts |= OPT_STAT;
break;
case 'v' :
opts |= OPT_VERBOSE;
break;
default :
usage(argv[0]);
}
if (!(opts & OPT_NODO) && ((fd = open(IPL_NAT, O_RDWR)) == -1) &&
((fd = open(IPL_NAT, O_RDONLY)) == -1)) {
perror("open");
exit(-1);
}
if (opts & (OPT_FLUSH|OPT_CLEAR))
flushtable(fd, opts);
if (file)
parsefile(fd, file, opts);
if (opts & (OPT_LIST|OPT_STAT))
dostats(fd, opts);
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_long ip;
{
u_long 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;
}
void printnat(np, verbose, ptr)
ipnat_t *np;
int verbose;
void *ptr;
{
int bits;
switch (np->in_redir)
{
case NAT_REDIRECT :
printf("redir ");
break;
case NAT_MAP :
printf("map ");
break;
case NAT_BIMAP :
printf("bimap ");
break;
default :
fprintf(stderr, "unknown value for in_redir: %#x\n",
np->in_redir);
break;
}
if (np->in_redir == NAT_REDIRECT) {
printf("%s %s", np->in_ifname, inet_ntoa(np->in_out[0]));
bits = countbits(np->in_out[1].s_addr);
if (bits != -1)
printf("/%d ", bits);
else
printf("/%s ", inet_ntoa(np->in_out[1]));
if (np->in_pmin)
printf("port %d ", ntohs(np->in_pmin));
printf("-> %s", inet_ntoa(np->in_in[0]));
if (np->in_pnext)
printf(" port %d", ntohs(np->in_pnext));
if (np->in_flags & IPN_TCPUDP)
printf(" tcp/udp");
else if (np->in_flags & IPN_TCP)
printf(" tcp");
else if (np->in_flags & IPN_UDP)
printf(" udp");
printf("\n");
if (verbose)
printf("\t%p %u %x %u %p %d\n", np->in_ifp,
np->in_space, np->in_flags, np->in_pnext, np,
np->in_use);
} else {
np->in_nextip.s_addr = htonl(np->in_nextip.s_addr);
printf("%s %s/", np->in_ifname, inet_ntoa(np->in_in[0]));
bits = countbits(np->in_in[1].s_addr);
if (bits != -1)
printf("%d ", bits);
else
printf("%s", inet_ntoa(np->in_in[1]));
printf(" -> %s/", inet_ntoa(np->in_out[0]));
bits = countbits(ntohl(np->in_out[1].s_addr));
if (bits != -1)
printf("%d ", bits);
else
printf("%s", inet_ntoa(np->in_out[1]));
if (*np->in_plabel) {
printf(" proxy");
if (np->in_dport)
printf(" %hu", ntohs(np->in_dport));
printf(" %.*s/%d", sizeof(np->in_plabel),
np->in_plabel, np->in_p);
} else if (np->in_pmin || np->in_pmax) {
printf(" portmap");
if ((np->in_flags & IPN_TCPUDP) == IPN_TCPUDP)
printf(" tcp/udp");
else if (np->in_flags & IPN_TCP)
printf(" tcp");
else if (np->in_flags & IPN_UDP)
printf(" udp");
printf(" %d:%d", ntohs(np->in_pmin),
ntohs(np->in_pmax));
}
printf("\n");
if (verbose)
printf("\t%p %u %s %d %x\n", np->in_ifp,
np->in_space, inet_ntoa(np->in_nextip),
np->in_pnext, np->in_flags);
}
}
/*
* Get a nat filter type given its kernel address.
*/
char *getnattype(ipnat)
ipnat_t *ipnat;
{
char *which;
ipnat_t ipnatbuff;
if (ipnat && kmemcpy((char *)&ipnatbuff, (long)ipnat,
sizeof(ipnatbuff)))
return "???";
switch (ipnatbuff.in_redir)
{
case NAT_MAP :
which = "MAP";
break;
case NAT_REDIRECT :
which = "RDR";
break;
case NAT_BIMAP :
which = "BIMAP";
break;
default :
which = "unknown";
break;
}
return which;
}
void dostats(fd, opts)
int fd, opts;
{
natstat_t ns;
ipnat_t ipn;
nat_t **nt[2], *np, nat;
int i = 0;
bzero((char *)&ns, sizeof(ns));
if (!(opts & OPT_NODO) && ioctl(fd, SIOCGNATS, &ns) == -1) {
perror("ioctl(SIOCGNATS)");
return;
}
if (opts & OPT_STAT) {
printf("mapped\tin\t%lu\tout\t%lu\n",
ns.ns_mapped[0], ns.ns_mapped[1]);
printf("added\t%lu\texpired\t%lu\n",
ns.ns_added, ns.ns_expire);
printf("inuse\t%lu\nrules\t%lu\n", ns.ns_inuse, ns.ns_rules);
if (opts & OPT_VERBOSE)
printf("table %p list %p\n", ns.ns_table, ns.ns_list);
}
if (opts & OPT_LIST) {
printf("List of active MAP/Redirect filters:\n");
while (ns.ns_list) {
if (kmemcpy((char *)&ipn, (long)ns.ns_list,
sizeof(ipn))) {
perror("kmemcpy");
break;
}
printnat(&ipn, opts & OPT_VERBOSE, (void *)ns.ns_list);
ns.ns_list = ipn.in_next;
}
nt[0] = (nat_t **)malloc(sizeof(*nt) * NAT_SIZE);
if (kmemcpy((char *)nt[0], (long)ns.ns_table[0],
sizeof(**nt) * NAT_SIZE)) {
perror("kmemcpy");
return;
}
printf("\nList of active sessions:\n");
for (i = 0; i < NAT_SIZE; i++)
for (np = nt[0][i]; np; np = nat.nat_hnext[0]) {
if (kmemcpy((char *)&nat, (long)np,
sizeof(nat)))
break;
printf("%s %-15s %-5hu <- ->",
getnattype(nat.nat_ptr),
inet_ntoa(nat.nat_inip),
ntohs(nat.nat_inport));
printf(" %-15s %-5hu",
inet_ntoa(nat.nat_outip),
ntohs(nat.nat_outport));
printf(" [%s %hu]", inet_ntoa(nat.nat_oip),
ntohs(nat.nat_oport));
printf(" %ld %hu %lx", nat.nat_age,
nat.nat_use, nat.nat_sumd);
#if SOLARIS
printf(" %lx", nat.nat_ipsumd);
#endif
putchar('\n');
}
free(nt[0]);
}
}
u_short portnum(name, proto)
char *name, *proto;
{
struct servent *sp, *sp2;
u_short p1 = 0;
if (isdigit(*name))
return htons((u_short)atoi(name));
if (!proto)
proto = "tcp/udp";
if (strcasecmp(proto, "tcp/udp")) {
sp = getservbyname(name, proto);
if (sp)
return sp->s_port;
(void) fprintf(stderr, "unknown service \"%s\".\n", name);
return 0;
}
sp = getservbyname(name, "tcp");
if (sp)
p1 = sp->s_port;
sp2 = getservbyname(name, "udp");
if (!sp || !sp2) {
(void) fprintf(stderr, "unknown tcp/udp service \"%s\".\n",
name);
return 0;
}
if (p1 != sp2->s_port) {
(void) fprintf(stderr, "%s %d/tcp is a different port to ",
name, p1);
(void) fprintf(stderr, "%s %d/udp\n", name, sp->s_port);
return 0;
}
return p1;
}
u_long hostmask(msk)
char *msk;
{
int bits = -1;
u_long mask;
if (!isdigit(*msk))
return (u_long)-1;
if (strchr(msk, '.'))
return inet_addr(msk);
if (strchr(msk, 'x'))
return (u_long)strtol(msk, NULL, 0);
/*
* set x most significant bits
*/
for (mask = 0, bits = atoi(msk); bits; bits--) {
mask /= 2;
mask |= ntohl(inet_addr("128.0.0.0"));
}
mask = htonl(mask);
return mask;
}
/*
* returns an ip address as a long var as a result of either a DNS lookup or
* straight inet_addr() call
*/
u_long hostnum(host, resolved)
char *host;
int *resolved;
{
struct hostent *hp;
struct netent *np;
*resolved = 0;
if (!strcasecmp("any", host))
return 0L;
if (isdigit(*host))
return inet_addr(host);
if (!(hp = gethostbyname(host))) {
if (!(np = getnetbyname(host))) {
*resolved = -1;
fprintf(stderr, "can't resolve hostname: %s\n", host);
return 0;
}
return np->n_net;
}
return *(u_long *)hp->h_addr;
}
ipnat_t *parse(line)
char *line;
{
struct protoent *pr;
static ipnat_t ipn;
char *s, *t;
char *shost, *snetm, *dhost, *proto;
char *dnetm = NULL, *dport = NULL, *tport = NULL;
int resolved;
bzero((char *)&ipn, sizeof(ipn));
if ((s = strchr(line, '\n')))
*s = '\0';
if ((s = strchr(line, '#')))
*s = '\0';
if (!*line)
return NULL;
if (!(s = strtok(line, " \t")))
return NULL;
if (!strcasecmp(s, "map"))
ipn.in_redir = NAT_MAP;
else if (!strcasecmp(s, "rdr"))
ipn.in_redir = NAT_REDIRECT;
else if (!strcasecmp(s, "bimap"))
ipn.in_redir = NAT_BIMAP;
else {
(void)fprintf(stderr,
"expected map/rdr/bimap, got \"%s\"\n", s);
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing fields (interface)\n");
return NULL;
}
strncpy(ipn.in_ifname, s, sizeof(ipn.in_ifname) - 1);
ipn.in_ifname[sizeof(ipn.in_ifname) - 1] = '\0';
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing fields (%s)\n",
ipn.in_redir ? "destination": "source");
return NULL;
}
shost = s;
if (ipn.in_redir == NAT_REDIRECT) {
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing fields (destination port)\n");
return NULL;
}
if (strcasecmp(s, "port")) {
fprintf(stderr, "missing fields (port)\n");
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing fields (destination port)\n");
return NULL;
}
dport = s;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing fields (->)\n");
return NULL;
}
if (!strcmp(s, "->")) {
snetm = strrchr(shost, '/');
if (!snetm) {
fprintf(stderr, "missing fields (%s netmask)\n",
ipn.in_redir ? "destination":"source");
return NULL;
}
} else {
if (strcasecmp(s, "netmask")) {
fprintf(stderr, "missing fields (netmask)\n");
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing fields (%s netmask)\n",
ipn.in_redir ? "destination":"source");
return NULL;
}
snetm = s;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing fields (%s)\n",
ipn.in_redir ? "destination":"target");
return NULL;
}
dhost = s;
if (ipn.in_redir & NAT_MAP) {
if (!(s = strtok(NULL, " \t"))) {
dnetm = strrchr(dhost, '/');
if (!dnetm) {
fprintf(stderr,
"missing fields (dest netmask)\n");
return NULL;
}
}
if (!s || !strcasecmp(s, "portmap") ||
!strcasecmp(s, "proxy")) {
dnetm = strrchr(dhost, '/');
if (!dnetm) {
fprintf(stderr,
"missing fields (dest netmask)\n");
return NULL;
}
} else {
if (strcasecmp(s, "netmask")) {
fprintf(stderr,
"missing fields (dest netmask)\n");
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"missing fields (dest netmask)\n");
return NULL;
}
dnetm = s;
}
if (*dnetm == '/')
*dnetm++ = '\0';
} else {
/* If it's a in_redir, expect target port */
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing fields (destination port)\n");
return NULL;
}
if (strcasecmp(s, "port")) {
fprintf(stderr, "missing fields (port)\n");
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing fields (destination port)\n");
return NULL;
}
tport = s;
}
if (*snetm == '/')
*snetm++ = '\0';
if (ipn.in_redir & NAT_MAP) {
ipn.in_inip = hostnum(shost, &resolved);
if (resolved == -1)
return NULL;
ipn.in_inmsk = hostmask(snetm);
ipn.in_outip = hostnum(dhost, &resolved);
if (resolved == -1)
return NULL;
ipn.in_outmsk = hostmask(dnetm);
} else {
ipn.in_inip = hostnum(dhost, &resolved); /* Inside is target */
if (resolved == -1)
return NULL;
ipn.in_inmsk = hostmask("255.255.255.255");
ipn.in_outip = hostnum(shost, &resolved);
if (resolved == -1)
return NULL;
ipn.in_outmsk = hostmask(snetm);
if (!(s = strtok(NULL, " \t"))) {
ipn.in_flags = IPN_TCP; /* XXX- TCP only by default */
proto = "tcp";
} else {
if (!strcasecmp(s, "tcp"))
ipn.in_flags = IPN_TCP;
else if (!strcasecmp(s, "udp"))
ipn.in_flags = IPN_UDP;
else if (!strcasecmp(s, "tcp/udp"))
ipn.in_flags = IPN_TCPUDP;
else if (!strcasecmp(s, "tcpudp"))
ipn.in_flags = IPN_TCPUDP;
else {
fprintf(stderr,
"expected protocol - got \"%s\"\n", s);
return NULL;
}
proto = s;
if ((s = strtok(NULL, " \t"))) {
fprintf(stderr,
"extra junk at the end of rdr: %s\n",
s);
return NULL;
}
}
ipn.in_pmin = portnum(dport, proto); /* dest port */
ipn.in_pmax = ipn.in_pmin; /* NECESSARY of removing nats */
ipn.in_pnext = portnum(tport, proto); /* target port */
s = NULL; /* That's all she wrote! */
}
if (!s)
return &ipn;
if (ipn.in_redir == NAT_BIMAP) {
fprintf(stderr, "extra words at the end of bimap line: %s\n",
s);
return NULL;
}
if (!strcasecmp(s, "proxy")) {
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "missing parameter for \"proxy\"\n");
return NULL;
}
dport = NULL;
if (!strcasecmp(s, "port")) {
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"missing parameter for \"port\"\n");
return NULL;
}
dport = s;
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"missing parameter for \"proxy\"\n");
return NULL;
}
}
if ((proto = index(s, '/'))) {
*proto++ = '\0';
if ((pr = getprotobyname(proto)))
ipn.in_p = pr->p_proto;
else
ipn.in_p = atoi(proto);
if (dport)
ipn.in_dport = portnum(dport, proto);
} else {
ipn.in_p = 0;
if (dport)
ipn.in_dport = portnum(dport, NULL);
}
(void) strncpy(ipn.in_plabel, s, sizeof(ipn.in_plabel));
if ((s = strtok(NULL, " \t"))) {
fprintf(stderr, "too many parameters for \"proxy\"\n");
return NULL;
}
return &ipn;
}
if (strcasecmp(s, "portmap")) {
fprintf(stderr, "expected \"portmap\" - got \"%s\"\n", s);
return NULL;
}
if (!(s = strtok(NULL, " \t")))
return NULL;
if (!strcasecmp(s, "tcp"))
ipn.in_flags = IPN_TCP;
else if (!strcasecmp(s, "udp"))
ipn.in_flags = IPN_UDP;
else if (!strcasecmp(s, "tcpudp"))
ipn.in_flags = IPN_TCPUDP;
else if (!strcasecmp(s, "tcp/udp"))
ipn.in_flags = IPN_TCPUDP;
else {
fprintf(stderr, "expected protocol name - got \"%s\"\n", s);
return NULL;
}
proto = s;
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "no port range found\n");
return NULL;
}
if (!(t = strchr(s, ':'))) {
fprintf(stderr, "no port range in \"%s\"\n", s);
return NULL;
}
*t++ = '\0';
ipn.in_pmin = portnum(s, proto);
ipn.in_pmax = portnum(t, proto);
return &ipn;
}
void parsefile(fd, file, opts)
int fd;
char *file;
int opts;
{
char line[512], *s;
ipnat_t *np;
FILE *fp;
int linenum = 1;
if (strcmp(file, "-"))
fp = fopen(file, "r");
else
fp = stdin;
while (fgets(line, sizeof(line) - 1, fp)) {
line[sizeof(line) - 1] = '\0';
if ((s = strchr(line, '\n')))
*s = '\0';
if (!(np = parse(line))) {
if (*line)
fprintf(stderr, "%d: syntax error in \"%s\"\n",
linenum, line);
} else if (!(opts & OPT_NODO)) {
if ((opts & OPT_VERBOSE) && np)
printnat(np, opts & OPT_VERBOSE, NULL);
if (opts & OPT_REM) {
if (ioctl(fd, SIOCADNAT, np) == -1)
perror("ioctl(SIOCADNAT)");
} else if (ioctl(fd, SIOCRMNAT, np) == -1)
perror("ioctl(SIOCRMNAT)");
}
linenum++;
}
fclose(stdin);
}
void flushtable(fd, opts)
int fd, opts;
{
int n = 0;
if (opts & OPT_FLUSH) {
n = 0;
if (!(opts & OPT_NODO) && ioctl(fd, SIOCFLNAT, &n) == -1)
perror("ioctl(SIOCFLNAT)");
else
printf("%d entries flushed from NAT table\n", n);
}
if (opts & OPT_CLEAR) {
n = 0;
if (!(opts & OPT_NODO) && ioctl(fd, SIOCCNATL, &n) == -1)
perror("ioctl(SIOCCNATL)");
else
printf("%d entries flushed from NAT list\n", n);
}
}
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