FreeBSD-5.3/usr.sbin/ppp/filter.c
/*-
* Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
* based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
* Internet Initiative Japan, Inc (IIJ)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: src/usr.sbin/ppp/filter.c,v 1.51 2002/08/27 20:11:57 brian Exp $
*/
#include <sys/param.h>
#include <netinet/in.h>
#include <netdb.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include "layer.h"
#include "defs.h"
#include "command.h"
#include "mbuf.h"
#include "log.h"
#include "iplist.h"
#include "timer.h"
#include "throughput.h"
#include "lqr.h"
#include "hdlc.h"
#include "fsm.h"
#include "lcp.h"
#include "ccp.h"
#include "link.h"
#include "slcompress.h"
#include "ncpaddr.h"
#include "ipcp.h"
#include "filter.h"
#include "descriptor.h"
#include "prompt.h"
#include "mp.h"
#ifndef NORADIUS
#include "radius.h"
#endif
#include "ipv6cp.h"
#include "ncp.h"
#include "bundle.h"
static int filter_Nam2Op(const char *);
static int
ParsePort(const char *service, const char *proto)
{
struct servent *servent;
char *cp;
int port;
servent = getservbyname(service, proto);
if (servent != 0)
return ntohs(servent->s_port);
port = strtol(service, &cp, 0);
if (cp == service) {
log_Printf(LogWARN, "ParsePort: %s is not a port name or number.\n",
service);
return 0;
}
return port;
}
/*
* ICMP Syntax: src eq icmp_message_type
*/
static int
ParseIcmp(int argc, char const *const *argv, const struct protoent *pe,
struct filterent *tgt)
{
int type;
char *cp;
switch (argc) {
case 0:
/* permit/deny all ICMP types */
tgt->f_srcop = tgt->f_dstop = OP_NONE;
break;
case 3:
if (!strcmp(*argv, "src") && !strcmp(argv[1], "eq")) {
type = strtol(argv[2], &cp, 0);
if (cp == argv[2]) {
log_Printf(LogWARN, "ParseIcmp: type is expected.\n");
return 0;
}
tgt->f_srcop = OP_EQ;
tgt->f_srcport = type;
tgt->f_dstop = OP_NONE;
}
break;
default:
log_Printf(LogWARN, "ParseIcmp: bad icmp syntax.\n");
return 0;
}
return 1;
}
/*
* UDP Syntax: [src op port] [dst op port]
*/
static int
ParseUdpOrTcp(int argc, char const *const *argv, const struct protoent *pe,
struct filterent *tgt)
{
tgt->f_srcop = tgt->f_dstop = OP_NONE;
tgt->f_estab = tgt->f_syn = tgt->f_finrst = 0;
if (argc >= 3 && !strcmp(*argv, "src")) {
tgt->f_srcop = filter_Nam2Op(argv[1]);
if (tgt->f_srcop == OP_NONE) {
log_Printf(LogWARN, "ParseUdpOrTcp: bad operator\n");
return 0;
}
if (pe == NULL)
return 0;
tgt->f_srcport = ParsePort(argv[2], pe->p_name);
if (tgt->f_srcport == 0)
return 0;
argc -= 3;
argv += 3;
}
if (argc >= 3 && !strcmp(argv[0], "dst")) {
tgt->f_dstop = filter_Nam2Op(argv[1]);
if (tgt->f_dstop == OP_NONE) {
log_Printf(LogWARN, "ParseUdpOrTcp: bad operator\n");
return 0;
}
if (pe == NULL)
return 0;
tgt->f_dstport = ParsePort(argv[2], pe->p_name);
if (tgt->f_dstport == 0)
return 0;
argc -= 3;
argv += 3;
}
if (pe && pe->p_proto == IPPROTO_TCP) {
for (; argc > 0; argc--, argv++)
if (!strcmp(*argv, "estab"))
tgt->f_estab = 1;
else if (!strcmp(*argv, "syn"))
tgt->f_syn = 1;
else if (!strcmp(*argv, "finrst"))
tgt->f_finrst = 1;
else
break;
}
if (argc > 0) {
log_Printf(LogWARN, "ParseUdpOrTcp: bad src/dst port syntax: %s\n", *argv);
return 0;
}
return 1;
}
static int
ParseGeneric(int argc, char const * const *argv, const struct protoent *pe,
struct filterent *tgt)
{
/*
* Filter currently is a catch-all. Requests are either permitted or
* dropped.
*/
if (argc != 0) {
log_Printf(LogWARN, "ParseGeneric: Too many parameters\n");
return 0;
} else
tgt->f_srcop = tgt->f_dstop = OP_NONE;
return 1;
}
static unsigned
addrtype(const char *addr)
{
if (!strncasecmp(addr, "MYADDR", 6) && (addr[6] == '\0' || addr[6] == '/'))
return T_MYADDR;
if (!strncasecmp(addr, "MYADDR6", 7) && (addr[7] == '\0' || addr[7] == '/'))
return T_MYADDR6;
if (!strncasecmp(addr, "HISADDR", 7) && (addr[7] == '\0' || addr[7] == '/'))
return T_HISADDR;
if (!strncasecmp(addr, "HISADDR6", 8) && (addr[8] == '\0' || addr[8] == '/'))
return T_HISADDR6;
if (!strncasecmp(addr, "DNS0", 4) && (addr[4] == '\0' || addr[4] == '/'))
return T_DNS0;
if (!strncasecmp(addr, "DNS1", 4) && (addr[4] == '\0' || addr[4] == '/'))
return T_DNS1;
return T_ADDR;
}
static const char *
addrstr(struct ncprange *addr, unsigned type)
{
switch (type) {
case T_MYADDR:
return "MYADDR";
case T_HISADDR:
return "HISADDR";
case T_DNS0:
return "DNS0";
case T_DNS1:
return "DNS1";
}
return ncprange_ntoa(addr);
}
static int
filter_Parse(struct ncp *ncp, int argc, char const *const *argv,
struct filterent *ofp)
{
struct filterent fe;
struct protoent *pe;
char *wp;
int action, family, ruleno, val, width;
ruleno = strtol(*argv, &wp, 0);
if (*argv == wp || ruleno >= MAXFILTERS) {
log_Printf(LogWARN, "Parse: invalid filter number.\n");
return 0;
}
if (ruleno < 0) {
for (ruleno = 0; ruleno < MAXFILTERS; ruleno++) {
ofp->f_action = A_NONE;
ofp++;
}
log_Printf(LogWARN, "Parse: filter cleared.\n");
return 1;
}
ofp += ruleno;
if (--argc == 0) {
log_Printf(LogWARN, "Parse: missing action.\n");
return 0;
}
argv++;
memset(&fe, '\0', sizeof fe);
val = strtol(*argv, &wp, 0);
if (!*wp && val >= 0 && val < MAXFILTERS) {
if (val <= ruleno) {
log_Printf(LogWARN, "Parse: Can only jump forward from rule %d\n",
ruleno);
return 0;
}
action = val;
} else if (!strcmp(*argv, "permit")) {
action = A_PERMIT;
} else if (!strcmp(*argv, "deny")) {
action = A_DENY;
} else if (!strcmp(*argv, "clear")) {
ofp->f_action = A_NONE;
return 1;
} else {
log_Printf(LogWARN, "Parse: %s: bad action\n", *argv);
return 0;
}
fe.f_action = action;
argc--;
argv++;
if (argc && argv[0][0] == '!' && !argv[0][1]) {
fe.f_invert = 1;
argc--;
argv++;
}
ncprange_init(&fe.f_src);
ncprange_init(&fe.f_dst);
if (argc == 0)
pe = NULL;
else if ((pe = getprotobyname(*argv)) == NULL && strcmp(*argv, "all") != 0) {
if (argc < 2) {
log_Printf(LogWARN, "Parse: Protocol or address pair expected\n");
return 0;
} else if (strcasecmp(*argv, "any") == 0 ||
ncprange_aton(&fe.f_src, ncp, *argv)) {
family = ncprange_family(&fe.f_src);
if (!ncprange_getwidth(&fe.f_src, &width))
width = 0;
if (width == 0)
ncprange_init(&fe.f_src);
fe.f_srctype = addrtype(*argv);
argc--;
argv++;
if (strcasecmp(*argv, "any") == 0 ||
ncprange_aton(&fe.f_dst, ncp, *argv)) {
if (ncprange_family(&fe.f_dst) != AF_UNSPEC &&
ncprange_family(&fe.f_src) != AF_UNSPEC &&
family != ncprange_family(&fe.f_dst)) {
log_Printf(LogWARN, "Parse: src and dst address families differ\n");
return 0;
}
if (!ncprange_getwidth(&fe.f_dst, &width))
width = 0;
if (width == 0)
ncprange_init(&fe.f_dst);
fe.f_dsttype = addrtype(*argv);
argc--;
argv++;
} else {
log_Printf(LogWARN, "Parse: Protocol or address pair expected\n");
return 0;
}
if (argc) {
if ((pe = getprotobyname(*argv)) == NULL && strcmp(*argv, "all") != 0) {
log_Printf(LogWARN, "Parse: %s: Protocol expected\n", *argv);
return 0;
} else {
argc--;
argv++;
}
}
} else {
log_Printf(LogWARN, "Parse: Protocol or address pair expected\n");
return 0;
}
} else {
argc--;
argv++;
}
if (argc >= 2 && strcmp(*argv, "timeout") == 0) {
fe.timeout = strtoul(argv[1], NULL, 10);
argc -= 2;
argv += 2;
}
val = 1;
fe.f_proto = (pe == NULL) ? 0 : pe->p_proto;
switch (fe.f_proto) {
case IPPROTO_TCP:
case IPPROTO_UDP:
case IPPROTO_IPIP:
#ifndef NOINET6
case IPPROTO_IPV6:
#endif
val = ParseUdpOrTcp(argc, argv, pe, &fe);
break;
case IPPROTO_ICMP:
#ifndef NOINET6
case IPPROTO_ICMPV6:
#endif
val = ParseIcmp(argc, argv, pe, &fe);
break;
default:
val = ParseGeneric(argc, argv, pe, &fe);
break;
}
log_Printf(LogDEBUG, "Parse: Src: %s\n", ncprange_ntoa(&fe.f_src));
log_Printf(LogDEBUG, "Parse: Dst: %s\n", ncprange_ntoa(&fe.f_dst));
log_Printf(LogDEBUG, "Parse: Proto: %d\n", fe.f_proto);
log_Printf(LogDEBUG, "Parse: src: %s (%d)\n",
filter_Op2Nam(fe.f_srcop), fe.f_srcport);
log_Printf(LogDEBUG, "Parse: dst: %s (%d)\n",
filter_Op2Nam(fe.f_dstop), fe.f_dstport);
log_Printf(LogDEBUG, "Parse: estab: %u\n", fe.f_estab);
log_Printf(LogDEBUG, "Parse: syn: %u\n", fe.f_syn);
log_Printf(LogDEBUG, "Parse: finrst: %u\n", fe.f_finrst);
if (val)
*ofp = fe;
return val;
}
int
filter_Set(struct cmdargs const *arg)
{
struct filter *filter;
if (arg->argc < arg->argn+2)
return -1;
if (!strcmp(arg->argv[arg->argn], "in"))
filter = &arg->bundle->filter.in;
else if (!strcmp(arg->argv[arg->argn], "out"))
filter = &arg->bundle->filter.out;
else if (!strcmp(arg->argv[arg->argn], "dial"))
filter = &arg->bundle->filter.dial;
else if (!strcmp(arg->argv[arg->argn], "alive"))
filter = &arg->bundle->filter.alive;
else {
log_Printf(LogWARN, "filter_Set: %s: Invalid filter name.\n",
arg->argv[arg->argn]);
return -1;
}
filter_Parse(&arg->bundle->ncp, arg->argc - arg->argn - 1,
arg->argv + arg->argn + 1, filter->rule);
return 0;
}
const char *
filter_Action2Nam(int act)
{
static const char * const actname[] = { " none ", "permit ", " deny " };
static char buf[8];
if (act >= 0 && act < MAXFILTERS) {
snprintf(buf, sizeof buf, "%6d ", act);
return buf;
} else if (act >= A_NONE && act < A_NONE + sizeof(actname)/sizeof(char *))
return actname[act - A_NONE];
else
return "?????? ";
}
static void
doShowFilter(struct filterent *fp, struct prompt *prompt)
{
struct protoent *pe;
int n;
for (n = 0; n < MAXFILTERS; n++, fp++) {
if (fp->f_action != A_NONE) {
prompt_Printf(prompt, " %2d %s", n, filter_Action2Nam(fp->f_action));
prompt_Printf(prompt, "%c ", fp->f_invert ? '!' : ' ');
if (ncprange_isset(&fp->f_src))
prompt_Printf(prompt, "%s ", addrstr(&fp->f_src, fp->f_srctype));
else
prompt_Printf(prompt, "any ");
if (ncprange_isset(&fp->f_dst))
prompt_Printf(prompt, "%s ", addrstr(&fp->f_dst, fp->f_dsttype));
else
prompt_Printf(prompt, "any ");
if (fp->f_proto) {
if ((pe = getprotobynumber(fp->f_proto)) == NULL)
prompt_Printf(prompt, "P:%d", fp->f_proto);
else
prompt_Printf(prompt, "%s", pe->p_name);
if (fp->f_srcop)
prompt_Printf(prompt, " src %s %d", filter_Op2Nam(fp->f_srcop),
fp->f_srcport);
if (fp->f_dstop)
prompt_Printf(prompt, " dst %s %d", filter_Op2Nam(fp->f_dstop),
fp->f_dstport);
if (fp->f_estab)
prompt_Printf(prompt, " estab");
if (fp->f_syn)
prompt_Printf(prompt, " syn");
if (fp->f_finrst)
prompt_Printf(prompt, " finrst");
} else
prompt_Printf(prompt, "all");
if (fp->timeout != 0)
prompt_Printf(prompt, " timeout %u", fp->timeout);
prompt_Printf(prompt, "\n");
}
}
}
int
filter_Show(struct cmdargs const *arg)
{
if (arg->argc > arg->argn+1)
return -1;
if (arg->argc == arg->argn+1) {
struct filter *filter;
if (!strcmp(arg->argv[arg->argn], "in"))
filter = &arg->bundle->filter.in;
else if (!strcmp(arg->argv[arg->argn], "out"))
filter = &arg->bundle->filter.out;
else if (!strcmp(arg->argv[arg->argn], "dial"))
filter = &arg->bundle->filter.dial;
else if (!strcmp(arg->argv[arg->argn], "alive"))
filter = &arg->bundle->filter.alive;
else
return -1;
doShowFilter(filter->rule, arg->prompt);
} else {
struct filter *filter[4];
int f;
filter[0] = &arg->bundle->filter.in;
filter[1] = &arg->bundle->filter.out;
filter[2] = &arg->bundle->filter.dial;
filter[3] = &arg->bundle->filter.alive;
for (f = 0; f < 4; f++) {
if (f)
prompt_Printf(arg->prompt, "\n");
prompt_Printf(arg->prompt, "%s:\n", filter[f]->name);
doShowFilter(filter[f]->rule, arg->prompt);
}
}
return 0;
}
static const char * const opname[] = {"none", "eq", "gt", "lt"};
const char *
filter_Op2Nam(int op)
{
if (op >= sizeof opname / sizeof opname[0])
return "unknown";
return opname[op];
}
static int
filter_Nam2Op(const char *cp)
{
int op;
for (op = sizeof opname / sizeof opname[0] - 1; op; op--)
if (!strcasecmp(cp, opname[op]))
break;
return op;
}
void
filter_AdjustAddr(struct filter *filter, struct ncpaddr *local,
struct ncpaddr *remote, struct in_addr *dns)
{
struct filterent *fp;
int n;
for (fp = filter->rule, n = 0; n < MAXFILTERS; fp++, n++)
if (fp->f_action != A_NONE) {
if (local) {
if (fp->f_srctype == T_MYADDR && ncpaddr_family(local) == AF_INET)
ncprange_sethost(&fp->f_src, local);
if (fp->f_dsttype == T_MYADDR && ncpaddr_family(local) == AF_INET)
ncprange_sethost(&fp->f_dst, local);
#ifndef NOINET6
if (fp->f_srctype == T_MYADDR6 && ncpaddr_family(local) == AF_INET6)
ncprange_sethost(&fp->f_src, local);
if (fp->f_dsttype == T_MYADDR6 && ncpaddr_family(local) == AF_INET6)
ncprange_sethost(&fp->f_dst, local);
#endif
}
if (remote) {
if (fp->f_srctype == T_HISADDR && ncpaddr_family(remote) == AF_INET)
ncprange_sethost(&fp->f_src, remote);
if (fp->f_dsttype == T_HISADDR && ncpaddr_family(remote) == AF_INET)
ncprange_sethost(&fp->f_dst, remote);
#ifndef NOINET6
if (fp->f_srctype == T_HISADDR6 && ncpaddr_family(remote) == AF_INET6)
ncprange_sethost(&fp->f_src, remote);
if (fp->f_dsttype == T_HISADDR6 && ncpaddr_family(remote) == AF_INET6)
ncprange_sethost(&fp->f_dst, remote);
#endif
}
if (dns) {
if (fp->f_srctype == T_DNS0)
ncprange_setip4host(&fp->f_src, dns[0]);
if (fp->f_dsttype == T_DNS0)
ncprange_setip4host(&fp->f_dst, dns[0]);
if (fp->f_srctype == T_DNS1)
ncprange_setip4host(&fp->f_src, dns[1]);
if (fp->f_dsttype == T_DNS1)
ncprange_setip4host(&fp->f_dst, dns[1]);
}
}
}