1/* 	$NetBSD: tcpdrop.c,v 1.2 2007/06/25 23:58:42 christos Exp $	 */
2
3/*
4 * Copyright (c) 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Herb Hasler and Rick Macklem at The University of Guelph.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35/* $OpenBSD: tcpdrop.c,v 1.5 2006/01/03 01:46:27 stevesk Exp $ */
36
37/*
38 * Copyright (c) 2004 Markus Friedl <markus@openbsd.org>
39 *
40 * Permission to use, copy, modify, and distribute this software for any
41 * purpose with or without fee is hereby granted, provided that the above
42 * copyright notice and this permission notice appear in all copies.
43 *
44 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
45 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
46 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
47 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
48 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
49 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
50 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
51 */
52
53#include <sys/param.h>
54#include <sys/socket.h>
55#include <sys/sysctl.h>
56
57#include <netinet/in.h>
58#include <netinet/tcp.h>
59#include <netinet/ip_var.h>
60#include <netinet/tcp_timer.h>
61#include <netinet/tcp_var.h>
62
63#include <assert.h>
64#include <err.h>
65#include <stdio.h>
66#include <string.h>
67#include <stdlib.h>
68#include <netdb.h>
69
70struct hpinfo {
71	char host[NI_MAXHOST];
72	char serv[NI_MAXSERV];
73};
74
75static struct addrinfo *
76egetaddrinfo(const char *host, const char *serv)
77{
78	static const struct addrinfo hints = {
79		.ai_family = AF_UNSPEC,
80		.ai_socktype = SOCK_STREAM,
81	};
82	struct addrinfo *ai;
83	int gaierr;
84
85	if ((gaierr = getaddrinfo(host, serv, &hints, &ai)) != 0)
86		errx(1, "%s port %s: %s", host, serv, gai_strerror(gaierr));
87	return ai;
88}
89
90static void
91egetnameinfo(const struct addrinfo *ai, struct hpinfo *hp)
92{
93	int gaierr;
94
95	if ((gaierr = getnameinfo(ai->ai_addr, ai->ai_addrlen,
96	    hp->host, sizeof(hp->host), hp->serv, sizeof(hp->serv),
97	    NI_NUMERICHOST | NI_NUMERICSERV)) != 0)
98		errx(1, "getnameinfo: %s", gai_strerror(gaierr));
99}
100
101/*
102 * Drop a tcp connection.
103 */
104int
105main(int argc, char **argv)
106{
107	int mib[] = { CTL_NET, 0, IPPROTO_TCP, TCPCTL_DROP };
108	struct addrinfo *ail, *aif, *laddr, *faddr;
109	struct sockaddr_storage sa[2];
110	struct hpinfo fhp, lhp;
111	int rval = 0;
112
113	setprogname(argv[0]);
114
115	if (argc != 5) {
116		(void)fprintf(stderr, "Usage: %s laddr lport faddr fport\n",
117		    getprogname());
118		return 1;
119	}
120
121	laddr = egetaddrinfo(argv[1], argv[2]);
122	faddr = egetaddrinfo(argv[3], argv[4]);
123
124	for (ail = laddr; ail; ail = ail->ai_next) {
125		for (aif = faddr; aif; aif = aif->ai_next) {
126
127			if (ail->ai_family != aif->ai_family)
128				continue;
129
130			egetnameinfo(ail, &lhp);
131			egetnameinfo(aif, &fhp);
132
133			(void)memset(sa, 0, sizeof(sa));
134
135			assert(aif->ai_addrlen <= sizeof(*sa));
136			assert(ail->ai_addrlen <= sizeof(*sa));
137
138			(void)memcpy(&sa[0], aif->ai_addr, aif->ai_addrlen);
139			(void)memcpy(&sa[1], ail->ai_addr, ail->ai_addrlen);
140
141			switch (ail->ai_family) {
142			case AF_INET:
143				mib[1] = PF_INET;
144				break;
145			case AF_INET6:
146				mib[1] = PF_INET6;
147				break;
148			default:
149				warnx("Unsupported socket address family %d",
150				    ail->ai_family);
151				continue;
152			}
153
154			if (sysctl(mib, sizeof(mib) / sizeof(int), NULL,
155			    NULL, sa, sizeof(sa)) == -1) {
156				rval = 1;
157				warn("%s:%s, %s:%s",
158				    lhp.host, lhp.serv, fhp.host, fhp.serv);
159			} else
160				(void)printf("%s:%s %s:%s dropped\n",
161				    lhp.host, lhp.serv, fhp.host, fhp.serv);
162
163		}
164	}
165	freeaddrinfo(laddr);
166	freeaddrinfo(faddr);
167	return rval;
168}
169