1 /* $OpenBSD: tcpdrop.c,v 1.3 2004/05/09 03:22:39 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/param.h> 20 #include <sys/socket.h> 21 #include <sys/sysctl.h> 22 23 #include <netinet/in.h> 24 #include <netinet/tcp.h> 25 #include <netinet/ip_var.h> 26 #include <netinet/tcp_timer.h> 27 #include <netinet/tcp_var.h> 28 29 #include <err.h> 30 #include <stdio.h> 31 #include <string.h> 32 #include <netdb.h> 33 34 extern char *__progname; 35 36 /* 37 * Drop a tcp connection. 38 */ 39 int 40 main(int argc, char **argv) 41 { 42 int mib[] = { CTL_NET, PF_INET, IPPROTO_TCP, TCPCTL_DROP }; 43 struct addrinfo hints, *ail, *aif, *laddr, *faddr; 44 char fhbuf[NI_MAXHOST], fsbuf[NI_MAXSERV]; 45 char lhbuf[NI_MAXHOST], lsbuf[NI_MAXSERV]; 46 struct tcp_ident_mapping tir; 47 int gaierr, rval = 0; 48 49 if (argc != 5) { 50 fprintf(stderr, "usage: %s laddr lport faddr fport\n", 51 __progname); 52 exit(1); 53 } 54 55 memset(&hints, 0, sizeof(hints)); 56 hints.ai_family = AF_UNSPEC; 57 hints.ai_socktype = SOCK_STREAM; 58 59 if ((gaierr = getaddrinfo(argv[1], argv[2], &hints, &laddr)) != 0) 60 errx(1, "%s port %s: %s", argv[1], argv[2], 61 gai_strerror(gaierr)); 62 63 if ((gaierr = getaddrinfo(argv[3], argv[4], &hints, &faddr)) != 0) { 64 freeaddrinfo(laddr); 65 errx(1, "%s port %s: %s", argv[3], argv[4], 66 gai_strerror(gaierr)); 67 } 68 69 for (ail = laddr; ail; ail = ail->ai_next) { 70 for (aif = faddr; aif; aif = aif->ai_next) { 71 if (ail->ai_family != aif->ai_family) 72 continue; 73 memcpy(&tir.faddr, aif->ai_addr, aif->ai_addrlen); 74 memcpy(&tir.laddr, ail->ai_addr, ail->ai_addrlen); 75 76 if (getnameinfo(aif->ai_addr, aif->ai_addrlen, 77 fhbuf, sizeof(fhbuf), 78 fsbuf, sizeof(fsbuf), 79 NI_NUMERICHOST | NI_NUMERICSERV) == -1) 80 err(1, "getnameinfo"); 81 if (getnameinfo(ail->ai_addr, ail->ai_addrlen, 82 lhbuf, sizeof(lhbuf), 83 lsbuf, sizeof(lsbuf), 84 NI_NUMERICHOST | NI_NUMERICSERV) == -1) 85 err(1, "getnameinfo"); 86 87 if (sysctl(mib, sizeof (mib) / sizeof (int), NULL, 88 NULL, &tir, sizeof(tir)) == -1) { 89 rval = 1; 90 warn("%s %s %s %s", lhbuf, lsbuf, fhbuf, fsbuf); 91 } else 92 printf("%s %s %s %s: dropped\n", 93 lhbuf, lsbuf, fhbuf, fsbuf); 94 95 } 96 } 97 freeaddrinfo(laddr); 98 freeaddrinfo(faddr); 99 exit(rval); 100 } 101