534 lines
13 KiB
C
534 lines
13 KiB
C
/*
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* PPP Filter command Interface
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*
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* Written by Toshiharu OHNO (tony-o@iij.ad.jp)
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*
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* Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the Internet Initiative Japan. The name of the
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* IIJ may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*
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* $Id: filter.c,v 1.22.2.19 1998/05/01 19:24:28 brian Exp $
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*
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* TODO: Shoud send ICMP error message when we discard packets.
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*/
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#include <sys/types.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <netdb.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <sys/un.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <strings.h>
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#include <termios.h>
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#include "command.h"
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#include "mbuf.h"
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#include "log.h"
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#include "defs.h"
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#include "iplist.h"
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#include "timer.h"
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#include "throughput.h"
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#include "lqr.h"
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#include "hdlc.h"
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#include "fsm.h"
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#include "lcp.h"
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#include "ccp.h"
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#include "link.h"
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#include "slcompress.h"
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#include "ipcp.h"
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#include "filter.h"
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#include "descriptor.h"
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#include "prompt.h"
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#include "mp.h"
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#include "bundle.h"
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static int filter_Nam2Proto(int, char const *const *);
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static int filter_Nam2Op(const char *);
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static const u_long netmasks[33] = {
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0x00000000,
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0x80000000, 0xC0000000, 0xE0000000, 0xF0000000,
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0xF8000000, 0xFC000000, 0xFE000000, 0xFF000000,
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0xFF800000, 0xFFC00000, 0xFFE00000, 0xFFF00000,
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0xFFF80000, 0xFFFC0000, 0xFFFE0000, 0xFFFF0000,
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0xFFFF8000, 0xFFFFC000, 0xFFFFE000, 0xFFFFF000,
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0xFFFFF800, 0xFFFFFC00, 0xFFFFFE00, 0xFFFFFF00,
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0xFFFFFF80, 0xFFFFFFC0, 0xFFFFFFE0, 0xFFFFFFF0,
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0xFFFFFFF8, 0xFFFFFFFC, 0xFFFFFFFE, 0xFFFFFFFF,
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};
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int
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ParseAddr(struct ipcp *ipcp, int argc, char const *const *argv,
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struct in_addr *paddr, struct in_addr *pmask, int *pwidth)
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{
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int bits, len;
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char *wp;
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const char *cp;
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if (argc < 1) {
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log_Printf(LogWARN, "ParseAddr: address/mask is expected.\n");
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return (0);
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}
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if (pmask)
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pmask->s_addr = INADDR_BROADCAST; /* Assume 255.255.255.255 as default */
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cp = pmask || pwidth ? strchr(*argv, '/') : NULL;
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len = cp ? cp - *argv : strlen(*argv);
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if (strncasecmp(*argv, "HISADDR", len) == 0)
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*paddr = ipcp->peer_ip;
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else if (strncasecmp(*argv, "MYADDR", len) == 0)
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*paddr = ipcp->my_ip;
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else if (len > 15)
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log_Printf(LogWARN, "ParseAddr: %s: Bad address\n", *argv);
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else {
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char s[16];
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strncpy(s, *argv, len);
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s[len] = '\0';
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if (inet_aton(s, paddr) == 0) {
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log_Printf(LogWARN, "ParseAddr: %s: Bad address\n", s);
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return (0);
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}
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}
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if (cp && *++cp) {
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bits = strtol(cp, &wp, 0);
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if (cp == wp || bits < 0 || bits > 32) {
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log_Printf(LogWARN, "ParseAddr: bad mask width.\n");
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return (0);
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}
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} else if (paddr->s_addr == INADDR_ANY)
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/* An IP of 0.0.0.0 without a width is anything */
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bits = 0;
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else
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/* If a valid IP is given without a width, assume 32 bits */
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bits = 32;
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if (pwidth)
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*pwidth = bits;
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if (pmask)
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pmask->s_addr = htonl(netmasks[bits]);
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return (1);
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}
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static int
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ParsePort(const char *service, int proto)
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{
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const char *protocol_name;
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char *cp;
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struct servent *servent;
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int port;
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switch (proto) {
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case P_UDP:
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protocol_name = "udp";
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break;
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case P_TCP:
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protocol_name = "tcp";
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break;
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default:
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protocol_name = 0;
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}
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servent = getservbyname(service, protocol_name);
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if (servent != 0)
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return (ntohs(servent->s_port));
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port = strtol(service, &cp, 0);
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if (cp == service) {
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log_Printf(LogWARN, "ParsePort: %s is not a port name or number.\n",
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service);
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return (0);
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}
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return (port);
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}
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/*
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* ICMP Syntax: src eq icmp_message_type
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*/
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static int
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ParseIcmp(int argc, char const *const *argv, struct filterent *tgt)
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{
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int type;
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char *cp;
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switch (argc) {
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case 0:
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/* permit/deny all ICMP types */
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tgt->opt.srcop = OP_NONE;
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break;
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case 3:
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if (!strcmp(*argv, "src") && !strcmp(argv[1], "eq")) {
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type = strtol(argv[2], &cp, 0);
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if (cp == argv[2]) {
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log_Printf(LogWARN, "ParseIcmp: type is expected.\n");
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return (0);
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}
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tgt->opt.srcop = OP_EQ;
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tgt->opt.srcport = type;
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}
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break;
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default:
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log_Printf(LogWARN, "ParseIcmp: bad icmp syntax.\n");
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return (0);
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}
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return (1);
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}
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/*
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* UDP Syntax: [src op port] [dst op port]
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*/
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static int
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ParseUdpOrTcp(int argc, char const *const *argv, int proto,
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struct filterent *tgt)
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{
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tgt->opt.srcop = tgt->opt.dstop = OP_NONE;
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tgt->opt.estab = tgt->opt.syn = tgt->opt.finrst = 0;
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if (argc >= 3 && !strcmp(*argv, "src")) {
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tgt->opt.srcop = filter_Nam2Op(argv[1]);
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if (tgt->opt.srcop == OP_NONE) {
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log_Printf(LogWARN, "ParseUdpOrTcp: bad operation\n");
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return (0);
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}
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tgt->opt.srcport = ParsePort(argv[2], proto);
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if (tgt->opt.srcport == 0)
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return (0);
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argc -= 3;
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argv += 3;
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}
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if (argc >= 3 && !strcmp(argv[0], "dst")) {
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tgt->opt.dstop = filter_Nam2Op(argv[1]);
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if (tgt->opt.dstop == OP_NONE) {
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log_Printf(LogWARN, "ParseUdpOrTcp: bad operation\n");
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return (0);
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}
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tgt->opt.dstport = ParsePort(argv[2], proto);
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if (tgt->opt.dstport == 0)
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return (0);
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argc -= 3;
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argv += 3;
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}
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if (proto == P_TCP) {
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for (; argc > 0; argc--, argv++)
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if (!strcmp(*argv, "estab"))
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tgt->opt.estab = 1;
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else if (!strcmp(*argv, "syn"))
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tgt->opt.syn = 1;
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else if (!strcmp(*argv, "finrst"))
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tgt->opt.finrst = 1;
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else
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break;
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}
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if (argc > 0) {
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log_Printf(LogWARN, "ParseUdpOrTcp: bad src/dst port syntax: %s\n", *argv);
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return 0;
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}
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return 1;
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}
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static int
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Parse(struct ipcp *ipcp, int argc, char const *const *argv,
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struct filterent *ofp)
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{
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int action, proto;
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int val;
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char *wp;
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struct filterent filterdata;
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val = strtol(*argv, &wp, 0);
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if (*argv == wp || val > MAXFILTERS) {
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log_Printf(LogWARN, "Parse: invalid filter number.\n");
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return (0);
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}
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if (val < 0) {
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for (val = 0; val < MAXFILTERS; val++) {
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ofp->action = A_NONE;
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ofp++;
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}
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log_Printf(LogWARN, "Parse: filter cleared.\n");
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return (1);
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}
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ofp += val;
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if (--argc == 0) {
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log_Printf(LogWARN, "Parse: missing action.\n");
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return (0);
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}
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argv++;
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proto = P_NONE;
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memset(&filterdata, '\0', sizeof filterdata);
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if (!strcmp(*argv, "permit")) {
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action = A_PERMIT;
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} else if (!strcmp(*argv, "deny")) {
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action = A_DENY;
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} else if (!strcmp(*argv, "clear")) {
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ofp->action = A_NONE;
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return (1);
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} else {
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log_Printf(LogWARN, "Parse: bad action: %s\n", *argv);
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return (0);
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}
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filterdata.action = action;
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argc--;
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argv++;
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if (filterdata.action == A_DENY) {
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if (!strcmp(*argv, "host")) {
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filterdata.action |= A_UHOST;
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argc--;
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argv++;
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} else if (!strcmp(*argv, "port")) {
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filterdata.action |= A_UPORT;
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argc--;
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argv++;
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}
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}
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proto = filter_Nam2Proto(argc, argv);
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if (proto == P_NONE) {
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if (ParseAddr(ipcp, argc, argv, &filterdata.saddr, &filterdata.smask,
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&filterdata.swidth)) {
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argc--;
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argv++;
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proto = filter_Nam2Proto(argc, argv);
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if (proto == P_NONE) {
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if (ParseAddr(ipcp, argc, argv, &filterdata.daddr, &filterdata.dmask,
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&filterdata.dwidth)) {
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argc--;
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argv++;
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}
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proto = filter_Nam2Proto(argc, argv);
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if (proto != P_NONE) {
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argc--;
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argv++;
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}
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} else {
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argc--;
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argv++;
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}
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} else {
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log_Printf(LogWARN, "Parse: Address/protocol expected.\n");
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return (0);
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}
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} else {
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argc--;
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argv++;
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}
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val = 1;
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filterdata.proto = proto;
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switch (proto) {
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case P_TCP:
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val = ParseUdpOrTcp(argc, argv, P_TCP, &filterdata);
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break;
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case P_UDP:
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val = ParseUdpOrTcp(argc, argv, P_UDP, &filterdata);
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break;
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case P_ICMP:
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val = ParseIcmp(argc, argv, &filterdata);
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break;
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}
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log_Printf(LogDEBUG, "Parse: Src: %s\n", inet_ntoa(filterdata.saddr));
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log_Printf(LogDEBUG, "Parse: Src mask: %s\n", inet_ntoa(filterdata.smask));
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log_Printf(LogDEBUG, "Parse: Dst: %s\n", inet_ntoa(filterdata.daddr));
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log_Printf(LogDEBUG, "Parse: Dst mask: %s\n", inet_ntoa(filterdata.dmask));
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log_Printf(LogDEBUG, "Parse: Proto = %d\n", proto);
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log_Printf(LogDEBUG, "Parse: src: %s (%d)\n",
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filter_Op2Nam(filterdata.opt.srcop), filterdata.opt.srcport);
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log_Printf(LogDEBUG, "Parse: dst: %s (%d)\n",
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filter_Op2Nam(filterdata.opt.dstop), filterdata.opt.dstport);
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log_Printf(LogDEBUG, "Parse: estab: %u\n", filterdata.opt.estab);
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log_Printf(LogDEBUG, "Parse: syn: %u\n", filterdata.opt.syn);
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log_Printf(LogDEBUG, "Parse: finrst: %u\n", filterdata.opt.finrst);
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if (val)
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*ofp = filterdata;
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return (val);
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}
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int
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filter_Set(struct cmdargs const *arg)
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{
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struct filter *filter;
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if (arg->argc < arg->argn+2)
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return -1;
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if (!strcmp(arg->argv[arg->argn], "in"))
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filter = &arg->bundle->filter.in;
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else if (!strcmp(arg->argv[arg->argn], "out"))
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filter = &arg->bundle->filter.out;
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else if (!strcmp(arg->argv[arg->argn], "dial"))
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filter = &arg->bundle->filter.dial;
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else if (!strcmp(arg->argv[arg->argn], "alive"))
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filter = &arg->bundle->filter.alive;
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else {
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log_Printf(LogWARN, "filter_Set: %s: Invalid filter name.\n",
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arg->argv[arg->argn]);
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return -1;
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}
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Parse(&arg->bundle->ncp.ipcp, arg->argc - arg->argn - 1,
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arg->argv + arg->argn + 1, filter->rule);
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return 0;
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}
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const char *
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filter_Action2Nam(int act)
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{
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static const char *actname[] = { "none ", "permit ", "deny " };
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return actname[act & (A_PERMIT|A_DENY)];
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}
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static void
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doShowFilter(struct filterent *fp, struct prompt *prompt)
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{
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int n;
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for (n = 0; n < MAXFILTERS; n++, fp++) {
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if (fp->action != A_NONE) {
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prompt_Printf(prompt, " %2d %s", n, filter_Action2Nam(fp->action));
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if (fp->action & A_UHOST)
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prompt_Printf(prompt, "host ");
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else if (fp->action & A_UPORT)
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prompt_Printf(prompt, "port ");
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else
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prompt_Printf(prompt, " ");
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prompt_Printf(prompt, "%s/%d ", inet_ntoa(fp->saddr), fp->swidth);
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prompt_Printf(prompt, "%s/%d ", inet_ntoa(fp->daddr), fp->dwidth);
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if (fp->proto) {
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prompt_Printf(prompt, "%s", filter_Proto2Nam(fp->proto));
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if (fp->opt.srcop)
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prompt_Printf(prompt, " src %s %d", filter_Op2Nam(fp->opt.srcop),
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fp->opt.srcport);
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if (fp->opt.dstop)
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prompt_Printf(prompt, " dst %s %d", filter_Op2Nam(fp->opt.dstop),
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fp->opt.dstport);
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if (fp->opt.estab)
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prompt_Printf(prompt, " estab");
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if (fp->opt.syn)
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prompt_Printf(prompt, " syn");
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if (fp->opt.finrst)
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prompt_Printf(prompt, " finrst");
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}
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prompt_Printf(prompt, "\n");
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}
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}
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}
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int
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filter_Show(struct cmdargs const *arg)
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{
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if (arg->argc > arg->argn+1)
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return -1;
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if (arg->argc == arg->argn+1) {
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struct filter *filter;
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if (!strcmp(arg->argv[arg->argn], "in"))
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filter = &arg->bundle->filter.in;
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else if (!strcmp(arg->argv[arg->argn], "out"))
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filter = &arg->bundle->filter.out;
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else if (!strcmp(arg->argv[arg->argn], "dial"))
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filter = &arg->bundle->filter.dial;
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else if (!strcmp(arg->argv[arg->argn], "alive"))
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filter = &arg->bundle->filter.alive;
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else
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return -1;
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doShowFilter(filter->rule, arg->prompt);
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} else {
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struct filter *filter[4];
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int f;
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filter[0] = &arg->bundle->filter.in;
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filter[1] = &arg->bundle->filter.out;
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filter[2] = &arg->bundle->filter.dial;
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filter[3] = &arg->bundle->filter.alive;
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for (f = 0; f < 4; f++) {
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if (f)
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prompt_Printf(arg->prompt, "\n");
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prompt_Printf(arg->prompt, "%s:\n", filter[f]->name);
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doShowFilter(filter[f]->rule, arg->prompt);
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}
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}
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return 0;
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}
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static const char *protoname[] = { "none", "tcp", "udp", "icmp" };
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const char *
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filter_Proto2Nam(int proto)
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{
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if (proto >= sizeof protoname / sizeof protoname[0])
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return "unknown";
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return protoname[proto];
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}
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static int
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filter_Nam2Proto(int argc, char const *const *argv)
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{
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int proto;
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if (argc == 0)
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proto = 0;
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else
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for (proto = sizeof protoname / sizeof protoname[0] - 1; proto; proto--)
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if (!strcasecmp(*argv, protoname[proto]))
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break;
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return proto;
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}
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static const char *opname[] = {"none", "eq", "gt", "unknown", "lt"};
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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;
|
|
}
|