xref: /netbsd/usr.sbin/tcpdrop/tcpdrop.c (revision 9bba0412)
1 /* 	$NetBSD: tcpdrop.c,v 1.3 2007/06/28 18:47:17 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 
70 struct hpinfo {
71 	char host[NI_MAXHOST];
72 	char serv[NI_MAXSERV];
73 };
74 
75 static struct addrinfo *
egetaddrinfo(const char * host,const char * serv)76 egetaddrinfo(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 
90 static void
egetnameinfo(const struct addrinfo * ai,struct hpinfo * hp)91 egetnameinfo(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  */
104 int
main(int argc,char ** argv)105 main(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