freebsd-dev/usr.sbin/ppp/filter.c
1997-02-22 16:15:28 +00:00

497 lines
9.6 KiB
C

/*
* PPP Filter command Interface
*
* Written by Toshiharu OHNO (tony-o@iij.ad.jp)
*
* Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the Internet Initiative Japan. The name of the
* IIJ may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Id$
*
* TODO: Shoud send ICMP error message when we discard packets.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include "command.h"
#include "filter.h"
static struct filterent filterdata;
static u_long netmasks[33] = {
0x00000000,
0x80000000, 0xC0000000, 0xE0000000, 0xF0000000,
0xF8000000, 0xFC000000, 0xFE000000, 0xFF000000,
0xFF800000, 0xFFC00000, 0xFFE00000, 0xFFF00000,
0xFFF80000, 0xFFFC0000, 0xFFFE0000, 0xFFFF0000,
0xFFFF8000, 0xFFFFC000, 0xFFFFE000, 0xFFFFF000,
0xFFFFF800, 0xFFFFFC00, 0xFFFFFE00, 0xFFFFFF00,
0xFFFFFF80, 0xFFFFFFC0, 0xFFFFFFE0, 0xFFFFFFF0,
0xFFFFFFF8, 0xFFFFFFFC, 0xFFFFFFFE, 0xFFFFFFFF,
};
int
ParseAddr(argc, argv, paddr, pmask, pwidth)
int argc;
char **argv;
struct in_addr *paddr;
struct in_addr *pmask;
int *pwidth;
{
u_long addr;
int bits;
char *cp, *wp;
if (argc < 1) {
#ifdef notdef
printf("address/mask is expected.\n");
#endif
return(0);
}
pmask->s_addr = -1; /* Assume 255.255.255.255 as default */
cp = index(*argv, '/');
if (cp) *cp++ = '\0';
addr = inet_addr(*argv);
paddr->s_addr = addr;
if (cp && *cp) {
bits = strtol(cp, &wp, 0);
if (cp == wp || bits < 0 || bits > 32) {
printf("bad mask width.\n");
return(0);
}
} else {
/* if width is not given, assume whole 32 bits are meaningfull */
bits = 32;
}
*pwidth = bits;
pmask->s_addr = htonl(netmasks[bits]);
return(1);
}
static int
ParseProto(argc, argv)
int argc;
char **argv;
{
int proto;
if (argc < 1)
return(P_NONE);
if (STREQ(*argv, "tcp"))
proto = P_TCP;
else if (STREQ(*argv, "udp"))
proto = P_UDP;
else if (STREQ(*argv, "icmp"))
proto = P_ICMP;
else
proto = P_NONE;
return(proto);
}
static int
ParsePort(service, proto)
char *service;
int proto;
{
char *protocol_name, *cp;
struct servent *servent;
int port;
switch (proto) {
case P_UDP:
protocol_name = "udp";
break;
case P_TCP:
protocol_name = "tcp";
break;
default:
protocol_name = 0;
}
servent = getservbyname (service, protocol_name);
if (servent != 0)
return(ntohs(servent->s_port));
port = strtol(service, &cp, 0);
if (cp == service) {
printf("%s is not a port name or number.\n", service);
return(0);
}
return(port);
}
/*
* ICMP Syntax: src eq icmp_message_type
*/
static int
ParseIcmp(argc, argv)
int argc;
char **argv;
{
int type;
char *cp;
switch (argc) {
case 0:
/* permit/deny all ICMP types */
filterdata.opt.srcop = OP_NONE;
break;
default:
printf("bad icmp syntax.\n");
return(0);
case 3:
if (STREQ(*argv, "src") && STREQ(argv[1], "eq")) {
type = strtol(argv[2], &cp, 0);
if (cp == argv[2]) {
printf("type is expected.\n");
return(0);
}
filterdata.opt.srcop = OP_EQ;
filterdata.opt.srcport = type;
}
break;
}
return(1);
}
static int
ParseOp(cp)
char *cp;
{
int op = OP_NONE;
if (STREQ(cp, "eq"))
op = OP_EQ;
else if (STREQ(cp, "gt"))
op = OP_GT;
else if (STREQ(cp, "lt"))
op = OP_LT;
return(op);
}
/*
* UDP Syntax: [src op port] [dst op port]
*/
static int
ParseUdpOrTcp(argc, argv, proto)
int argc;
char **argv;
int proto;
{
if (argc == 0) {
/* permit/deny all tcp traffic */
filterdata.opt.srcop = filterdata.opt.dstop = A_NONE;
return(1);
}
if (argc < 3) {
#ifdef notdef
printf("bad udp syntax.\n");
#endif
return(0);
}
if (argc >= 3 && STREQ(*argv, "src")) {
filterdata.opt.srcop = ParseOp(argv[1]);
if (filterdata.opt.srcop == OP_NONE) {
printf("bad operation\n");
return(0);
}
filterdata.opt.srcport = ParsePort(argv[2], proto);
if (filterdata.opt.srcport == 0)
return(0);
argc -= 3; argv += 3;
if (argc == 0)
return(1);
}
if (argc >= 3 && STREQ(argv[0], "dst")) {
filterdata.opt.dstop = ParseOp(argv[1]);
if (filterdata.opt.dstop == OP_NONE) {
printf("bad operation\n");
return(0);
}
filterdata.opt.dstport = ParsePort(argv[2], proto);
if (filterdata.opt.dstport == 0)
return(0);
argc -= 3; argv += 3;
if (argc == 0)
return(1);
}
if (argc == 1) {
if (STREQ(*argv, "estab")) {
filterdata.opt.estab = 1;
return(1);
}
printf("estab is expected: %s\n", *argv);
return(0);
}
if (argc > 0)
printf("bad src/dst port syntax: %s\n", *argv);
return(0);
}
char *opname[] = { "none", "eq", "gt", "lt" };
static int
Parse(argc, argv, ofp)
int argc;
char **argv;
struct filterent *ofp;
{
int action, proto;
int val;
char *wp;
struct filterent *fp = &filterdata;
val = strtol(*argv, &wp, 0);
if (*argv == wp || val > MAXFILTERS) {
printf("invalid filter number.\n");
return(0);
}
if (val < 0) {
for (val = 0; val < MAXFILTERS; val++) {
ofp->action = A_NONE;
ofp++;
}
printf("filter cleard.\n");
return(1);
}
ofp += val;
if (--argc == 0) {
printf("missing action.\n");
return(0);
}
argv++;
proto = P_NONE;
bzero(&filterdata, sizeof(filterdata));
if (STREQ(*argv, "permit")) {
action = A_PERMIT;
} else if (STREQ(*argv, "deny")) {
action = A_DENY;
} else if (STREQ(*argv, "clear")) {
ofp->action = A_NONE;
return(1);
} else {
printf("bad action: %s\n", *argv);
return(0);
}
fp->action = action;
argc--; argv++;
if (ofp->action == A_DENY) {
if (STREQ(*argv, "host")) {
fp->action |= A_UHOST;
argc--; argv++;
} else if (STREQ(*argv, "port")) {
fp->action |= A_UPORT;
argc--; argv++;
}
}
proto = ParseProto(argc, argv);
if (proto == P_NONE) {
if (ParseAddr(argc, argv, &fp->saddr, &fp->smask, &fp->swidth)) {
argc--; argv++;
proto = ParseProto(argc, argv);
if (proto == P_NONE) {
if (ParseAddr(argc, argv, &fp->daddr, &fp->dmask, &fp->dwidth)) {
argc--; argv++;
}
proto = ParseProto(argc, argv);
if (proto) {
argc--; argv++;
}
}
} else {
printf("Address/protocol expected.\n");
return(0);
}
} else {
argc--; argv++;
}
val = 1;
fp->proto = proto;
switch (proto) {
case P_TCP:
val = ParseUdpOrTcp(argc, argv, P_TCP);
break;
case P_UDP:
val = ParseUdpOrTcp(argc, argv, P_UDP);
break;
case P_ICMP:
val = ParseIcmp(argc, argv);
break;
}
#ifdef DEBUG
printf("src: %s/", inet_ntoa(fp->saddr));
printf("%s ", inet_ntoa(fp->smask));
printf("dst: %s/", inet_ntoa(fp->daddr));
printf("%s proto = %d\n", inet_ntoa(fp->dmask), proto);
printf("src: %s (%d)\n", opname[fp->opt.srcop], fp->opt.srcport);
printf("dst: %s (%d)\n", opname[fp->opt.dstop], fp->opt.dstport);
printf("estab: %d\n", fp->opt.estab);
#endif
if (val)
*ofp = *fp;
return(val);
}
int
SetIfilter(list, argc, argv)
struct cmdtab *list;
int argc;
char **argv;
{
if (argc > 0)
(void) Parse(argc, argv, ifilters);
else
printf("syntax error.\n");
return(1);
}
int
SetOfilter(list, argc, argv)
struct cmdtab *list;
int argc;
char **argv;
{
if (argc > 0)
(void) Parse(argc, argv, ofilters);
else
printf("syntax error.\n");
return(1);
}
int
SetDfilter(list, argc, argv)
struct cmdtab *list;
int argc;
char **argv;
{
if (argc > 0)
(void) Parse(argc, argv, dfilters);
else
printf("syntax error.\n");
return(1);
}
int
SetAfilter(list, argc, argv)
struct cmdtab *list;
int argc;
char **argv;
{
if (argc > 0)
(void) Parse(argc, argv, afilters);
else
printf("syntax error.\n");
return(1);
}
static char *protoname[] = {
"none", "tcp", "udp", "icmp",
};
static char *actname[] = {
"none ", "permit ", "deny ",
};
static void
ShowFilter(fp)
struct filterent *fp;
{
int n;
for (n = 0; n < MAXFILTERS; n++, fp++) {
if (fp->action != A_NONE) {
printf("%2d %s", n, actname[fp->action]);
printf("%s/%d ", inet_ntoa(fp->saddr), fp->swidth);
printf("%s/%d ", inet_ntoa(fp->daddr), fp->dwidth);
if (fp->proto) {
printf("%s", protoname[fp->proto]);
if (fp->opt.srcop)
printf(" src %s %d", opname[fp->opt.srcop], fp->opt.srcport);
if (fp->opt.dstop)
printf(" dst %s %d", opname[fp->opt.dstop], fp->opt.dstport);
if (fp->opt.estab)
printf(" estab");
}
printf("\n");
}
}
}
int
ShowIfilter(list, argc, argv)
struct cmdtab *list;
int argc;
char **argv;
{
ShowFilter(ifilters);
return(1);
}
int
ShowOfilter(list, argc, argv)
struct cmdtab *list;
int argc;
char **argv;
{
ShowFilter(ofilters);
return(1);
}
int
ShowDfilter(list, argc, argv)
struct cmdtab *list;
int argc;
char **argv;
{
ShowFilter(dfilters);
return(1);
}
int
ShowAfilter(list, argc, argv)
struct cmdtab *list;
int argc;
char **argv;
{
ShowFilter(afilters);
return(1);
}