NetBSD/dist/ipf/natparse.c

797 lines
18 KiB
C
Raw Normal View History

/* $NetBSD: natparse.c,v 1.1.1.1 1999/12/11 22:23:59 veego Exp $ */
/*
* 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 <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/types.h>
#if !defined(__SVR4) && !defined(__svr4__)
#include <strings.h>
#else
#include <sys/byteorder.h>
#endif
#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>
#if __FreeBSD_version >= 300000
# include <net/if_var.h>
#endif
#include <netdb.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <resolv.h>
#include <ctype.h>
#include "netinet/ip_compat.h"
#include "netinet/ip_fil.h"
#include "netinet/ip_proxy.h"
#include "netinet/ip_nat.h"
#if defined(sun) && !SOLARIS2
# define STRERROR(x) sys_errlist[x]
extern char *sys_errlist[];
#else
# define STRERROR(x) strerror(x)
#endif
#if !defined(lint)
static const char sccsid[] ="@(#)ipnat.c 1.9 6/5/96 (C) 1993 Darren Reed";
static const char rcsid[] = "@(#)Id: natparse.c,v 1.2.2.1 1999/11/20 22:50:30 darrenr Exp";
#endif
#if SOLARIS
#define bzero(a,b) memset(a,0,b)
#endif
extern int countbits __P((u_32_t));
extern u_32_t hostnum __P((char *, int *, int));
ipnat_t *natparse __P((char *, int));
void printnat __P((ipnat_t *, int, void *));
void natparsefile __P((int, char *, int));
u_32_t n_hostmask __P((char *));
u_short n_portnum __P((char *, char *, int));
void nat_setgroupmap __P((struct ipnat *));
#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 printnat(np, verbose, ptr)
ipnat_t *np;
int verbose;
void *ptr;
{
struct protoent *pr;
struct servent *sv;
int bits;
switch (np->in_redir)
{
case NAT_REDIRECT :
printf("rdr ");
break;
case NAT_MAP :
printf("map ");
break;
case NAT_MAPBLK :
printf("map-block ");
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 ", np->in_ifname);
if (np->in_src[0].s_addr || np->in_src[1].s_addr) {
printf("from %s",inet_ntoa(np->in_src[0]));
bits = countbits(np->in_src[1].s_addr);
if (bits != -1)
printf("/%d ", bits);
else
printf("/%s ", inet_ntoa(np->in_src[1]));
}
printf("%s",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) == IPN_TCPUDP)
printf(" tcp/udp");
else if ((np->in_flags & IPN_TCP) == IPN_TCP)
printf(" tcp");
else if ((np->in_flags & IPN_UDP) == IPN_UDP)
printf(" udp");
printf("\n");
if (verbose)
printf("\t%p %lu %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(" -> ");
if (np->in_flags & IPN_RANGE) {
printf("range %s-", inet_ntoa(np->in_out[0]));
printf("%s", inet_ntoa(np->in_out[1]));
} else {
printf("%s/", 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_plabel) {
pr = getprotobynumber(np->in_p);
printf(" proxy port");
if (np->in_dport != 0) {
if (pr != NULL)
sv = getservbyport(np->in_dport,
pr->p_name);
else
sv = getservbyport(np->in_dport, NULL);
if (sv != NULL)
printf(" %s", sv->s_name);
else
printf(" %hu", ntohs(np->in_dport));
}
printf(" %.*s/", (int)sizeof(np->in_plabel),
np->in_plabel);
if (pr != NULL)
fputs(pr->p_name, stdout);
else
printf("%d", np->in_p);
} else if (np->in_redir == NAT_MAPBLK) {
printf(" ports %d", np->in_pmin);
if (verbose)
printf("\n\tip modulous %d", np->in_pmax);
} else if (np->in_pmin || np->in_pmax) {
printf(" portmap");
if (np->in_flags & IPN_AUTOPORTMAP) {
printf(" auto");
if (verbose)
printf(" [%d:%d %d %d]",
ntohs(np->in_pmin),
ntohs(np->in_pmax),
np->in_ippip, np->in_ppip);
} else {
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("\tifp %p space %lu nextip %s pnext %d",
np->in_ifp, np->in_space,
inet_ntoa(np->in_nextip), np->in_pnext);
printf(" flags %x use %u\n",
np->in_flags, np->in_use);
}
}
}
void nat_setgroupmap(n)
ipnat_t *n;
{
if (n->in_outmsk == n->in_inmsk)
n->in_ippip = 1;
else if (n->in_flags & IPN_AUTOPORTMAP) {
n->in_ippip = ~ntohl(n->in_inmsk);
if (n->in_outmsk != 0xffffffff)
n->in_ippip /= (~ntohl(n->in_outmsk) + 1);
n->in_ippip++;
if (n->in_ippip == 0)
n->in_ippip = 1;
n->in_ppip = USABLE_PORTS / n->in_ippip;
} else {
n->in_space = USABLE_PORTS * ~ntohl(n->in_outmsk);
n->in_nip = 0;
if (!(n->in_ppip = n->in_pmin))
n->in_ppip = 1;
n->in_ippip = USABLE_PORTS / n->in_ppip;
}
}
ipnat_t *natparse(line, linenum)
char *line;
int linenum;
{
struct protoent *pr;
static ipnat_t ipn;
char *s, *t;
char *shost, *snetm, *dhost, *proto, *srchost, *srcnetm;
char *dnetm = NULL, *dport = NULL, *tport = NULL;
int resolved;
srchost = NULL;
srcnetm = NULL;
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, "map-block"))
ipn.in_redir = NAT_MAPBLK;
else if (!strcasecmp(s, "rdr"))
ipn.in_redir = NAT_REDIRECT;
else if (!strcasecmp(s, "bimap"))
ipn.in_redir = NAT_BIMAP;
else {
fprintf(stderr, "%d: unknown mapping: \"%s\"\n",
linenum, s);
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "%d: missing fields (interface)\n",
linenum);
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, "%d: missing fields (%s)\n", linenum,
ipn.in_redir ? "from source | destination" : "source");
return NULL;
}
if ((ipn.in_redir == NAT_REDIRECT) && !strcasecmp(s, "from")) {
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing fields (source address)\n",
linenum);
return NULL;
}
srchost = s;
srcnetm = strrchr(srchost, '/');
if (srcnetm == NULL) {
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing fields (source netmask)\n",
linenum);
return NULL;
}
if (strcasecmp(s, "netmask")) {
fprintf(stderr,
"%d: missing fields (netmask)\n",
linenum);
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing fields (source netmask)\n",
linenum);
return NULL;
}
srcnetm = s;
}
if (*srcnetm == '/')
*srcnetm++ = '\0';
/* re read the next word -- destination */
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing fields (destination)\n", linenum);
return NULL;
}
}
shost = s;
if (ipn.in_redir == NAT_REDIRECT) {
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing fields (destination port)\n",
linenum);
return NULL;
}
if (strcasecmp(s, "port")) {
fprintf(stderr, "%d: missing fields (port)\n", linenum);
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing fields (destination port)\n",
linenum);
return NULL;
}
dport = s;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "%d: missing fields (->)\n", linenum);
return NULL;
}
if (!strcmp(s, "->")) {
snetm = strrchr(shost, '/');
if (!snetm) {
fprintf(stderr,
"%d: missing fields (%s netmask)\n", linenum,
ipn.in_redir ? "destination" : "source");
return NULL;
}
} else {
if (strcasecmp(s, "netmask")) {
fprintf(stderr, "%d: missing fields (netmask)\n",
linenum);
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing fields (%s netmask)\n", linenum,
ipn.in_redir ? "destination" : "source");
return NULL;
}
snetm = s;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "%d: missing fields (%s)\n",
linenum, ipn.in_redir ? "destination":"target");
return NULL;
}
if (ipn.in_redir == NAT_MAP) {
if (!strcasecmp(s, "range")) {
ipn.in_flags |= IPN_RANGE;
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "%d: missing fields (%s)\n",
linenum,
ipn.in_redir ? "destination":"target");
return NULL;
}
}
}
dhost = s;
if (ipn.in_redir & (NAT_MAP|NAT_MAPBLK)) {
if (ipn.in_flags & IPN_RANGE) {
dnetm = strrchr(dhost, '-');
if (dnetm == NULL) {
if (!(s = strtok(NULL, " \t")))
dnetm = NULL;
else {
if (strcmp(s, "-"))
s = NULL;
else if ((s = strtok(NULL, " \t"))) {
dnetm = s;
}
}
} else
*dnetm++ = '\0';
if (dnetm == NULL || *dnetm == '\0') {
fprintf(stderr,
"%d: desination range not specified\n",
linenum);
return NULL;
}
} else {
dnetm = strrchr(dhost, '/');
if (dnetm == NULL) {
if (!(s = strtok(NULL, " \t")))
dnetm = NULL;
else if (!strcasecmp(s, "netmask"))
if ((s = strtok(NULL, " \t")) != NULL)
dnetm = s;
}
if (dnetm == NULL) {
fprintf(stderr,
"%d: missing fields (dest netmask)\n",
linenum);
return NULL;
}
if (*dnetm == '/')
*dnetm++ = '\0';
}
s = strtok(NULL, " \t");
}
if (ipn.in_redir & NAT_MAPBLK) {
if (s && strcasecmp(s, "ports")) {
fprintf(stderr,
"%d: expected \"ports\" - got \"%s\"\n",
linenum, s);
return NULL;
}
if (s != NULL) {
if ((s = strtok(NULL, " \t")) == NULL)
return NULL;
ipn.in_pmin = atoi(s);
s = strtok(NULL, " \t");
} else
ipn.in_pmin = 0;
} else if ((ipn.in_redir & NAT_BIMAP) == NAT_REDIRECT) {
if (strrchr(dhost, '/') != NULL) {
fprintf(stderr, "%d: No netmask supported in %s\n",
linenum, "destination host for redirect");
return NULL;
}
/* If it's a in_redir, expect target port */
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing fields (destination port)\n",
linenum);
return NULL;
}
if (strcasecmp(s, "port")) {
fprintf(stderr, "%d: missing fields (port)\n",
linenum);
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing fields (destination port)\n",
linenum);
return NULL;
}
tport = s;
}
if (dnetm && *dnetm == '/')
*dnetm++ = '\0';
if (snetm && *snetm == '/')
*snetm++ = '\0';
if (ipn.in_redir & (NAT_MAP|NAT_MAPBLK)) {
ipn.in_inip = hostnum(shost, &resolved, linenum);
if (resolved == -1)
return NULL;
ipn.in_inmsk = n_hostmask(snetm);
ipn.in_outip = hostnum(dhost, &resolved, linenum);
if (resolved == -1)
return NULL;
if (ipn.in_flags & IPN_RANGE) {
ipn.in_outmsk = hostnum(dnetm, &resolved, linenum);
if (resolved == -1)
return NULL;
} else
ipn.in_outmsk = n_hostmask(dnetm);
if (srchost) {
ipn.in_srcip = hostnum(srchost, &resolved, linenum);
if (resolved == -1)
return NULL;
}
if (srcnetm)
ipn.in_srcmsk = n_hostmask(srcnetm);
} else {
if (srchost) {
ipn.in_srcip = hostnum(srchost, &resolved, linenum);
if (resolved == -1)
return NULL;
}
if (srcnetm)
ipn.in_srcmsk = n_hostmask(srcnetm);
ipn.in_inip = hostnum(dhost, &resolved, linenum);
if (resolved == -1)
return NULL;
ipn.in_inmsk = n_hostmask("255.255.255.255");
ipn.in_outip = hostnum(shost, &resolved, linenum);
if (resolved == -1)
return NULL;
ipn.in_outmsk = n_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 if (!strcasecmp(s, "ip"))
ipn.in_flags = IPN_ANY;
else {
ipn.in_flags = IPN_ANY;
if ((pr = getprotobyname(s)))
ipn.in_p = pr->p_proto;
else
ipn.in_p = atoi(s);
}
proto = s;
if ((s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: extra junk at the end of rdr: %s\n",
linenum, s);
return NULL;
}
}
ipn.in_pmin = n_portnum(dport, proto, linenum);
ipn.in_pmax = ipn.in_pmin;
ipn.in_pnext = n_portnum(tport, proto, linenum);
s = NULL;
}
ipn.in_inip &= ipn.in_inmsk;
if ((ipn.in_flags & IPN_RANGE) == 0)
ipn.in_outip &= ipn.in_outmsk;
ipn.in_srcip &= ipn.in_srcmsk;
if ((ipn.in_redir & NAT_MAPBLK) != 0)
nat_setgroupmap(&ipn);
if (!s)
return &ipn;
if (ipn.in_redir == NAT_BIMAP) {
fprintf(stderr,
"%d: extra words at the end of bimap line: %s\n",
linenum, s);
return NULL;
}
if (!strcasecmp(s, "proxy")) {
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing parameter for \"proxy\"\n",
linenum);
return NULL;
}
dport = NULL;
if (!strcasecmp(s, "port")) {
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing parameter for \"port\"\n",
linenum);
return NULL;
}
dport = s;
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: missing parameter for \"proxy\"\n",
linenum);
return NULL;
}
} else {
fprintf(stderr,
"%d: missing keyword \"port\"\n", linenum);
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 = n_portnum(dport, proto, linenum);
} else {
ipn.in_p = 0;
if (dport)
ipn.in_dport = n_portnum(dport, NULL, linenum);
}
(void) strncpy(ipn.in_plabel, s, sizeof(ipn.in_plabel));
if ((s = strtok(NULL, " \t"))) {
fprintf(stderr,
"%d: too many parameters for \"proxy\"\n",
linenum);
return NULL;
}
return &ipn;
}
if (strcasecmp(s, "portmap")) {
fprintf(stderr,
"%d: expected \"portmap\" - got \"%s\"\n", linenum, 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,
"%d: expected protocol name - got \"%s\"\n",
linenum, s);
return NULL;
}
if (!(s = strtok(NULL, " \t"))) {
fprintf(stderr, "%d: no port range found\n", linenum);
return NULL;
}
if (!strcasecmp(s, "auto")) {
ipn.in_flags |= IPN_AUTOPORTMAP;
ipn.in_pmin = htons(1024);
ipn.in_pmax = htons(65535);
nat_setgroupmap(&ipn);
return &ipn;
}
proto = s;
if (!(t = strchr(s, ':'))) {
fprintf(stderr, "%d: no port range in \"%s\"\n", linenum, s);
return NULL;
}
*t++ = '\0';
ipn.in_pmin = n_portnum(s, proto, linenum);
ipn.in_pmax = n_portnum(t, proto, linenum);
return &ipn;
}
void natparsefile(fd, file, opts)
int fd;
char *file;
int opts;
{
char line[512], *s;
ipnat_t *np;
FILE *fp;
int linenum = 0;
if (strcmp(file, "-")) {
if (!(fp = fopen(file, "r"))) {
fprintf(stderr, "%s: open: %s\n", file,
STRERROR(errno));
exit(1);
}
} else
fp = stdin;
while (fgets(line, sizeof(line) - 1, fp)) {
linenum++;
line[sizeof(line) - 1] = '\0';
if ((s = strchr(line, '\n')))
*s = '\0';
if (!(np = natparse(line, linenum))) {
if (*line)
fprintf(stderr, "%d: syntax error in \"%s\"\n",
linenum, line);
} else {
if ((opts & OPT_VERBOSE) && np)
printnat(np, opts & OPT_VERBOSE, NULL);
if (!(opts & OPT_NODO)) {
if (!(opts & OPT_REM)) {
if (ioctl(fd, SIOCADNAT, np) == -1)
perror("ioctl(SIOCADNAT)");
} else if (ioctl(fd, SIOCRMNAT, np) == -1)
perror("ioctl(SIOCRMNAT)");
}
}
}
if (fp != stdin)
fclose(fp);
}
u_32_t n_hostmask(msk)
char *msk;
{
int bits = -1;
u_32_t mask;
if (!isdigit(*msk))
return (u_32_t)-1;
if (strchr(msk, '.'))
return inet_addr(msk);
if (strchr(msk, 'x'))
return (u_32_t)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;
}
u_short n_portnum(name, proto, linenum)
char *name, *proto;
int linenum;
{
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;
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;
}
return p1;
}