1 /* $OpenBSD: tcpdrop.c,v 1.4 2004/05/22 23:55:22 deraadt Exp $ */ 2 3 /*- 4 * Copyright (c) 2004 Markus Friedl <markus@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/cdefs.h> 20 __FBSDID("$FreeBSD$"); 21 22 #include <sys/types.h> 23 #include <sys/socket.h> 24 #include <sys/sysctl.h> 25 #include <netinet/in.h> 26 #include <netinet/tcp_var.h> 27 28 #include <err.h> 29 #include <netdb.h> 30 #include <stdio.h> 31 #include <stdlib.h> 32 #include <string.h> 33 34 /* 35 * Drop a tcp connection. 36 */ 37 int 38 main(int argc, char *argv[]) 39 { 40 struct addrinfo hints, *ail, *aif, *laddr, *faddr; 41 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 42 struct sockaddr_storage addrs[2]; 43 int mib[] = { CTL_NET, PF_INET, IPPROTO_TCP, TCPCTL_DROP }; 44 int gaierr, rval = 0; 45 char fhbuf[NI_MAXHOST], fsbuf[NI_MAXSERV], lhbuf[NI_MAXHOST], 46 lsbuf[NI_MAXSERV]; 47 48 if (argc != 5) { 49 fprintf(stderr, "usage: tcpdrop laddr lport faddr fport\n"); 50 exit(1); 51 } 52 memset(&hints, 0, sizeof(hints)); 53 hints.ai_family = AF_UNSPEC; 54 hints.ai_socktype = SOCK_STREAM; 55 if ((gaierr = getaddrinfo(argv[1], argv[2], &hints, &laddr)) != 0) 56 errx(1, "%s port %s: %s", argv[1], argv[2], 57 gai_strerror(gaierr)); 58 if ((gaierr = getaddrinfo(argv[3], argv[4], &hints, &faddr)) != 0) { 59 freeaddrinfo(laddr); 60 errx(1, "%s port %s: %s", argv[3], argv[4], 61 gai_strerror(gaierr)); 62 } 63 for (ail = laddr; ail; ail = ail->ai_next) { 64 for (aif = faddr; aif; aif = aif->ai_next) { 65 if (ail->ai_family != aif->ai_family) 66 continue; 67 memcpy(&addrs[0], aif->ai_addr, aif->ai_addrlen); 68 memcpy(&addrs[1], ail->ai_addr, ail->ai_addrlen); 69 if (getnameinfo(aif->ai_addr, aif->ai_addrlen, 70 fhbuf, sizeof(fhbuf), 71 fsbuf, sizeof(fsbuf), 72 NI_NUMERICHOST | NI_NUMERICSERV) == -1) 73 err(1, "getnameinfo"); 74 if (getnameinfo(ail->ai_addr, ail->ai_addrlen, 75 lhbuf, sizeof(lhbuf), 76 lsbuf, sizeof(lsbuf), 77 NI_NUMERICHOST | NI_NUMERICSERV) == -1) 78 err(1, "getnameinfo"); 79 if (sysctl(mib, sizeof (mib) / sizeof (int), NULL, 80 NULL, &addrs, sizeof(addrs)) == -1) { 81 rval = 1; 82 warn("%s %s %s %s", lhbuf, lsbuf, fhbuf, fsbuf); 83 } else 84 printf("%s %s %s %s: dropped\n", 85 lhbuf, lsbuf, fhbuf, fsbuf); 86 } 87 } 88 freeaddrinfo(laddr); 89 freeaddrinfo(faddr); 90 exit(rval); 91 } 92