usr.sbin/tcpdrop/tcpdrop.c

   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
  70 struct hpinfo {
  71         char host[NI_MAXHOST];
  72         char serv[NI_MAXSERV];
  73 };
  74
  75 static struct addrinfo *
  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
  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
 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 }