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freebsd-src/contrib/ipfilter/natparse.c
Darren Reed d564cc784f Import IPFilter 3.4.25
2002-03-19 11:45:20 +00:00

759 lines
16 KiB
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/*
* Copyright (C) 1993-2002 by Darren Reed.
*
* See the IPFILTER.LICENCE file for details on licencing.
*/
#ifdef __sgi
# include <sys/ptimers.h>
#endif
#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_nat.h"
#include "netinet/ip_state.h"
#include "netinet/ip_proxy.h"
#include "ipf.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 1.17.2.23 2002/02/22 15:32:55 darrenr Exp $";
#endif
#if SOLARIS
#define bzero(a,b) memset(a,0,b)
#endif
extern void printnat __P((ipnat_t *, int));
extern int countbits __P((u_32_t));
extern char *proto;
ipnat_t *natparse __P((char *, int));
void natparsefile __P((int, char *, int));
void nat_setgroupmap __P((struct ipnat *));
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;
}
}
/*
* Parse a line of input from the ipnat configuration file
*/
ipnat_t *natparse(line, linenum)
char *line;
int linenum;
{
static ipnat_t ipn;
struct protoent *pr;
char *dnetm = NULL, *dport = NULL;
char *s, *t, *cps[31], **cpp;
int i, cnt;
char *port1a = NULL, *port1b = NULL, *port2a = NULL;
proto = NULL;
/*
* Search for end of line and comment marker, advance of leading spaces
*/
if ((s = strchr(line, '\n')))
*s = '\0';
if ((s = strchr(line, '#')))
*s = '\0';
while (*line && isspace(*line))
line++;
if (!*line)
return NULL;
bzero((char *)&ipn, sizeof(ipn));
cnt = 0;
/*
* split line upto into segments.
*/
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;
/*
* Check first word is a recognised keyword and then is the interface
*/
if (!strcasecmp(*cpp, "map"))
ipn.in_redir = NAT_MAP;
else if (!strcasecmp(*cpp, "map-block"))
ipn.in_redir = NAT_MAPBLK;
else if (!strcasecmp(*cpp, "rdr"))
ipn.in_redir = NAT_REDIRECT;
else if (!strcasecmp(*cpp, "bimap"))
ipn.in_redir = NAT_BIMAP;
else {
fprintf(stderr, "%d: unknown mapping: \"%s\"\n",
linenum, *cpp);
return NULL;
}
cpp++;
strncpy(ipn.in_ifname, *cpp, sizeof(ipn.in_ifname) - 1);
ipn.in_ifname[sizeof(ipn.in_ifname) - 1] = '\0';
cpp++;
/*
* If the first word after the interface is "from" or is a ! then
* the expanded syntax is being used so parse it differently.
*/
if (!strcasecmp(*cpp, "from") || (**cpp == '!')) {
if (!strcmp(*cpp, "!")) {
cpp++;
if (strcasecmp(*cpp, "from")) {
fprintf(stderr, "Missing from after !\n");
return NULL;
}
ipn.in_flags |= IPN_NOTSRC;
} else if (**cpp == '!') {
if (strcasecmp(*cpp + 1, "from")) {
fprintf(stderr, "Missing from after !\n");
return NULL;
}
ipn.in_flags |= IPN_NOTSRC;
}
if ((ipn.in_flags & IPN_NOTSRC) &&
(ipn.in_redir & (NAT_MAP|NAT_MAPBLK))) {
fprintf(stderr, "Cannot use '! from' with map\n");
return NULL;
}
ipn.in_flags |= IPN_FILTER;
cpp++;
if (ipn.in_redir == NAT_REDIRECT) {
if (hostmask(&cpp, (u_32_t *)&ipn.in_srcip,
(u_32_t *)&ipn.in_srcmsk, &ipn.in_sport,
&ipn.in_scmp, &ipn.in_stop, linenum)) {
return NULL;
}
} else {
if (hostmask(&cpp, (u_32_t *)&ipn.in_inip,
(u_32_t *)&ipn.in_inmsk, &ipn.in_sport,
&ipn.in_scmp, &ipn.in_stop, linenum)) {
return NULL;
}
}
if (!strcmp(*cpp, "!")) {
cpp++;
ipn.in_flags |= IPN_NOTDST;
} else if (**cpp == '!') {
(*cpp)++;
ipn.in_flags |= IPN_NOTDST;
}
if (strcasecmp(*cpp, "to")) {
fprintf(stderr, "%d: unexpected keyword (%s) - to\n",
linenum, *cpp);
return NULL;
}
if ((ipn.in_flags & IPN_NOTDST) &&
(ipn.in_redir & (NAT_REDIRECT))) {
fprintf(stderr, "Cannot use '! to' with rdr\n");
return NULL;
}
if (!*++cpp) {
fprintf(stderr, "%d: missing host after to\n", linenum);
return NULL;
}
if (ipn.in_redir == NAT_REDIRECT) {
if (hostmask(&cpp, (u_32_t *)&ipn.in_outip,
(u_32_t *)&ipn.in_outmsk, &ipn.in_dport,
&ipn.in_dcmp, &ipn.in_dtop, linenum)) {
return NULL;
}
ipn.in_pmin = htons(ipn.in_dport);
} else {
if (hostmask(&cpp, (u_32_t *)&ipn.in_srcip,
(u_32_t *)&ipn.in_srcmsk, &ipn.in_dport,
&ipn.in_dcmp, &ipn.in_dtop, linenum)) {
return NULL;
}
}
} else {
s = *cpp;
if (!s) {
fprintf(stderr, "%d: short line\n", linenum);
return NULL;
}
t = strchr(s, '/');
if (!t) {
fprintf(stderr, "%d: no netmask on LHS\n", linenum);
return NULL;
}
*t++ = '\0';
if (ipn.in_redir == NAT_REDIRECT) {
if (hostnum((u_32_t *)&ipn.in_outip, s, linenum) == -1)
return NULL;
if (genmask(t, (u_32_t *)&ipn.in_outmsk) == -1) {
return NULL;
}
} else {
if (hostnum((u_32_t *)&ipn.in_inip, s, linenum) == -1)
return NULL;
if (genmask(t, (u_32_t *)&ipn.in_inmsk) == -1) {
return NULL;
}
}
cpp++;
if (!*cpp) {
fprintf(stderr, "%d: short line\n", linenum);
return NULL;
}
}
/*
* If it is a standard redirect then we expect it to have a port
* match after the hostmask.
*/
if ((ipn.in_redir == NAT_REDIRECT) && !(ipn.in_flags & IPN_FILTER)) {
if (strcasecmp(*cpp, "port")) {
fprintf(stderr, "%d: missing fields - 1st port\n",
linenum);
return NULL;
}
cpp++;
if (!*cpp) {
fprintf(stderr,
"%d: missing fields (destination port)\n",
linenum);
return NULL;
}
if (isdigit(**cpp) && (s = strchr(*cpp, '-')))
*s++ = '\0';
else
s = NULL;
port1a = *cpp++;
if (!strcmp(*cpp, "-")) {
cpp++;
s = *cpp++;
}
if (s)
port1b = s;
else
ipn.in_pmax = ipn.in_pmin;
}
/*
* In the middle of the NAT rule syntax is -> to indicate the
* direction of translation.
*/
if (!*cpp) {
fprintf(stderr, "%d: missing fields (->)\n", linenum);
return NULL;
}
if (strcmp(*cpp, "->")) {
fprintf(stderr, "%d: missing ->\n", linenum);
return NULL;
}
cpp++;
if (!*cpp) {
fprintf(stderr, "%d: missing fields (%s)\n",
linenum, ipn.in_redir ? "destination" : "target");
return NULL;
}
if (ipn.in_redir == NAT_MAP) {
if (!strcasecmp(*cpp, "range")) {
cpp++;
ipn.in_flags |= IPN_IPRANGE;
if (!*cpp) {
fprintf(stderr, "%d: missing fields (%s)\n",
linenum,
ipn.in_redir ? "destination":"target");
return NULL;
}
}
}
if (ipn.in_flags & IPN_IPRANGE) {
dnetm = strrchr(*cpp, '-');
if (dnetm == NULL) {
cpp++;
if (*cpp && !strcmp(*cpp, "-") && *(cpp + 1))
dnetm = *(cpp + 1);
} else
*dnetm++ = '\0';
if (dnetm == NULL || *dnetm == '\0') {
fprintf(stderr,
"%d: desination range not specified\n",
linenum);
return NULL;
}
} else if (ipn.in_redir != NAT_REDIRECT) {
dnetm = strrchr(*cpp, '/');
if (dnetm == NULL) {
cpp++;
if (*cpp && !strcasecmp(*cpp, "netmask"))
dnetm = *++cpp;
}
if (dnetm == NULL) {
fprintf(stderr,
"%d: missing fields (dest netmask)\n",
linenum);
return NULL;
}
if (*dnetm == '/')
*dnetm++ = '\0';
}
if (ipn.in_redir == NAT_REDIRECT) {
dnetm = strchr(*cpp, ',');
if (dnetm != NULL) {
ipn.in_flags |= IPN_SPLIT;
*dnetm++ = '\0';
}
if (hostnum((u_32_t *)&ipn.in_inip, *cpp, linenum) == -1)
return NULL;
} else {
if (!strcmp(*cpp, ipn.in_ifname))
*cpp = "0";
if (hostnum((u_32_t *)&ipn.in_outip, *cpp, linenum) == -1)
return NULL;
}
cpp++;
if (ipn.in_redir & NAT_MAPBLK) {
if (*cpp && strcasecmp(*cpp, "ports")) {
fprintf(stderr,
"%d: expected \"ports\" - got \"%s\"\n",
linenum, *cpp);
return NULL;
}
cpp++;
if (*cpp) {
ipn.in_pmin = atoi(*cpp);
cpp++;
} else
ipn.in_pmin = 0;
} else if ((ipn.in_redir & NAT_BIMAP) == NAT_REDIRECT) {
if (*cpp && (strrchr(*cpp, '/') != NULL)) {
fprintf(stderr, "%d: No netmask supported in %s\n",
linenum, "destination host for redirect");
return NULL;
}
if (!*cpp) {
fprintf(stderr, "%d: Missing destination port %s\n",
linenum, "in redirect");
return NULL;
}
/* If it's a in_redir, expect target port */
if (strcasecmp(*cpp, "port")) {
fprintf(stderr, "%d: missing fields - 2nd port (%s)\n",
linenum, *cpp);
return NULL;
}
cpp++;
if (!*cpp) {
fprintf(stderr,
"%d: missing fields (destination port)\n",
linenum);
return NULL;
}
port2a = *cpp++;
}
if (dnetm && *dnetm == '/')
*dnetm++ = '\0';
if (ipn.in_redir & (NAT_MAP|NAT_MAPBLK)) {
if (ipn.in_flags & IPN_IPRANGE) {
if (hostnum((u_32_t *)&ipn.in_outmsk, dnetm,
linenum) == -1)
return NULL;
} else if (genmask(dnetm, (u_32_t *)&ipn.in_outmsk))
return NULL;
} else {
if (ipn.in_flags & IPN_SPLIT) {
if (hostnum((u_32_t *)&ipn.in_inmsk, dnetm,
linenum) == -1)
return NULL;
} else if (genmask("255.255.255.255", (u_32_t *)&ipn.in_inmsk))
return NULL;
if (!*cpp) {
ipn.in_flags |= IPN_TCP; /* XXX- TCP only by default */
proto = "tcp";
} else {
proto = *cpp++;
if (!strcasecmp(proto, "tcp"))
ipn.in_flags |= IPN_TCP;
else if (!strcasecmp(proto, "udp"))
ipn.in_flags |= IPN_UDP;
else if (!strcasecmp(proto, "tcp/udp"))
ipn.in_flags |= IPN_TCPUDP;
else if (!strcasecmp(proto, "tcpudp")) {
ipn.in_flags |= IPN_TCPUDP;
proto = "tcp/udp";
} else if (!strcasecmp(proto, "ip"))
ipn.in_flags |= IPN_ANY;
else {
ipn.in_flags |= IPN_ANY;
if ((pr = getprotobyname(proto)))
ipn.in_p = pr->p_proto;
else {
if (!isdigit(*proto)) {
fprintf(stderr,
"%d: Unknown protocol %s\n",
linenum, proto);
return NULL;
} else
ipn.in_p = atoi(proto);
}
}
if (*cpp && !strcasecmp(*cpp, "round-robin")) {
cpp++;
ipn.in_flags |= IPN_ROUNDR;
}
if (*cpp && !strcasecmp(*cpp, "frag")) {
cpp++;
ipn.in_flags |= IPN_FRAG;
}
if (*cpp && !strcasecmp(*cpp, "age")) {
cpp++;
if (!*cpp) {
fprintf(stderr,
"%d: age with no parameters\n",
linenum);
return NULL;
}
ipn.in_age[0] = atoi(*cpp);
s = index(*cpp, '/');
if (s != NULL)
ipn.in_age[1] = atoi(s + 1);
else
ipn.in_age[1] = ipn.in_age[0];
cpp++;
}
if (*cpp) {
fprintf(stderr,
"%d: extra junk at the end of the line: %s\n",
linenum, *cpp);
return NULL;
}
}
}
if ((ipn.in_redir == NAT_REDIRECT) && !(ipn.in_flags & IPN_FILTER)) {
if (!portnum(port1a, &ipn.in_pmin, linenum))
return NULL;
ipn.in_pmin = htons(ipn.in_pmin);
if (port1b != NULL) {
if (!portnum(port1b, &ipn.in_pmax, linenum))
return NULL;
ipn.in_pmax = htons(ipn.in_pmax);
} else
ipn.in_pmax = ipn.in_pmin;
}
if ((ipn.in_redir & NAT_BIMAP) == NAT_REDIRECT) {
if (!portnum(port2a, &ipn.in_pnext, linenum))
return NULL;
ipn.in_pnext = htons(ipn.in_pnext);
}
if (!(ipn.in_flags & IPN_SPLIT))
ipn.in_inip &= ipn.in_inmsk;
if ((ipn.in_flags & IPN_IPRANGE) == 0)
ipn.in_outip &= ipn.in_outmsk;
ipn.in_srcip &= ipn.in_srcmsk;
if ((ipn.in_redir & NAT_MAPBLK) != 0)
nat_setgroupmap(&ipn);
if (*cpp && !strcasecmp(*cpp, "frag")) {
cpp++;
ipn.in_flags |= IPN_FRAG;
}
if (!*cpp)
return &ipn;
if (ipn.in_redir == NAT_BIMAP) {
fprintf(stderr,
"%d: extra words at the end of bimap line: %s\n",
linenum, *cpp);
return NULL;
}
if (!strcasecmp(*cpp, "proxy")) {
if (ipn.in_redir == NAT_BIMAP) {
fprintf(stderr, "%d: cannot use proxy with bimap\n",
linenum);
return NULL;
}
cpp++;
if (!*cpp) {
fprintf(stderr,
"%d: missing parameter for \"proxy\"\n",
linenum);
return NULL;
}
dport = NULL;
if (!strcasecmp(*cpp, "port")) {
cpp++;
if (!*cpp) {
fprintf(stderr,
"%d: missing parameter for \"port\"\n",
linenum);
return NULL;
}
dport = *cpp;
cpp++;
if (!*cpp) {
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(*cpp, '/'))) {
*proto++ = '\0';
if ((pr = getprotobyname(proto)))
ipn.in_p = pr->p_proto;
else
ipn.in_p = atoi(proto);
} else
ipn.in_p = 0;
if (dport && !portnum(dport, &ipn.in_dport, linenum))
return NULL;
ipn.in_dport = htons(ipn.in_dport);
(void) strncpy(ipn.in_plabel, *cpp, sizeof(ipn.in_plabel));
cpp++;
if (*cpp) {
fprintf(stderr,
"%d: too many parameters for \"proxy\"\n",
linenum);
return NULL;
}
} else if (!strcasecmp(*cpp, "portmap")) {
if (ipn.in_redir == NAT_BIMAP) {
fprintf(stderr, "%d: cannot use portmap with bimap\n",
linenum);
return NULL;
}
cpp++;
if (!*cpp) {
fprintf(stderr,
"%d: missing expression following portmap\n",
linenum);
return NULL;
}
if (!strcasecmp(*cpp, "tcp"))
ipn.in_flags |= IPN_TCP;
else if (!strcasecmp(*cpp, "udp"))
ipn.in_flags |= IPN_UDP;
else if (!strcasecmp(*cpp, "tcpudp"))
ipn.in_flags |= IPN_TCPUDP;
else if (!strcasecmp(*cpp, "tcp/udp"))
ipn.in_flags |= IPN_TCPUDP;
else {
fprintf(stderr,
"%d: expected protocol name - got \"%s\"\n",
linenum, *cpp);
return NULL;
}
proto = *cpp;
cpp++;
if (!*cpp) {
fprintf(stderr, "%d: no port range found\n", linenum);
return NULL;
}
if (!strcasecmp(*cpp, "auto")) {
ipn.in_flags |= IPN_AUTOPORTMAP;
ipn.in_pmin = htons(1024);
ipn.in_pmax = htons(65535);
nat_setgroupmap(&ipn);
cpp++;
} else {
if (!(t = strchr(*cpp, ':'))) {
fprintf(stderr,
"%d: no port range in \"%s\"\n",
linenum, *cpp);
return NULL;
}
*t++ = '\0';
if (!portnum(*cpp, &ipn.in_pmin, linenum) ||
!portnum(t, &ipn.in_pmax, linenum))
return NULL;
ipn.in_pmin = htons(ipn.in_pmin);
ipn.in_pmax = htons(ipn.in_pmax);
cpp++;
}
}
if (*cpp && !strcasecmp(*cpp, "age")) {
cpp++;
if (!*cpp) {
fprintf(stderr, "%d: age with no parameters\n",
linenum);
return NULL;
}
s = index(*cpp, '/');
if (s != NULL)
ipn.in_age[1] = atoi(s + 1);
else
ipn.in_age[1] = ipn.in_age[0];
cpp++;
}
if (*cpp) {
fprintf(stderr, "%d: extra junk at the end of the line: %s\n",
linenum, *cpp);
return NULL;
}
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);
if (!(opts & OPT_NODO)) {
if (!(opts & OPT_REMOVE)) {
if (ioctl(fd, SIOCADNAT, &np) == -1) {
fprintf(stderr, "%d:",
linenum);
perror("ioctl(SIOCADNAT)");
}
} else if (ioctl(fd, SIOCRMNAT, &np) == -1) {
fprintf(stderr, "%d:", linenum);
perror("ioctl(SIOCRMNAT)");
}
}
}
}
if (fp != stdin)
fclose(fp);
}
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