1 /* $OpenBSD: tcpdrop.c,v 1.7 2007/03/28 17:04:03 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 <stdlib.h> 33 #include <netdb.h> 34 35 extern char *__progname; 36 37 /* 38 * Drop a tcp connection. 39 */ 40 int 41 main(int argc, char **argv) 42 { 43 int mib[] = { CTL_NET, PF_INET, IPPROTO_TCP, TCPCTL_DROP }; 44 struct addrinfo hints, *ail, *aif, *laddr, *faddr; 45 char fhbuf[NI_MAXHOST], fsbuf[NI_MAXSERV]; 46 char lhbuf[NI_MAXHOST], lsbuf[NI_MAXSERV]; 47 char *laddr1, *addr1, *port1, *laddr2, *addr2, *port2; 48 struct tcp_ident_mapping tir; 49 int gaierr, rval = 0; 50 51 memset(&hints, 0, sizeof(hints)); 52 hints.ai_family = AF_UNSPEC; 53 hints.ai_socktype = SOCK_STREAM; 54 55 if (argc == 3) { 56 laddr1 = addr1 = strdup(argv[1]); 57 port1 = strrchr(addr1, ':'); 58 if (port1) 59 *port1++ = '\0'; 60 else 61 goto fail; 62 63 laddr2 = addr2 = strdup(argv[2]); 64 port2 = strrchr(addr2, ':'); 65 if (port2) 66 *port2++ = '\0'; 67 else 68 goto fail; 69 } else if (argc == 5) { 70 laddr1 = addr1 = argv[1]; 71 port1 = argv[2]; 72 laddr2 = addr2 = argv[3]; 73 port2 = argv[4]; 74 } else { 75 fail: 76 fprintf(stderr, 77 "usage: %s local-addr local-port remote-addr remote-port\n", 78 __progname); 79 fprintf(stderr, 80 " %s local-addr:local-port remote-addr:remote-port\n", 81 __progname); 82 exit(1); 83 } 84 85 if (addr1[0] == '[' && addr1[strlen(addr1) - 1] == ']') { 86 laddr1 = strdup(addr1); 87 laddr1[strlen(laddr1) - 1] = '\0'; 88 laddr1++; 89 } 90 if (addr2[0] == '[' && addr2[strlen(addr2) - 1] == ']') { 91 laddr2 = strdup(addr2); 92 laddr2[strlen(laddr2) - 1] = '\0'; 93 laddr2++; 94 } 95 96 if ((gaierr = getaddrinfo(laddr1, port1, &hints, &laddr)) != 0) 97 errx(1, "%s port %s: %s", addr1, port1, 98 gai_strerror(gaierr)); 99 100 if ((gaierr = getaddrinfo(laddr2, port2, &hints, &faddr)) != 0) { 101 freeaddrinfo(laddr); 102 errx(1, "%s port %s: %s", addr2, port2, 103 gai_strerror(gaierr)); 104 } 105 106 for (ail = laddr; ail; ail = ail->ai_next) { 107 for (aif = faddr; aif; aif = aif->ai_next) { 108 if (ail->ai_family != aif->ai_family) 109 continue; 110 memcpy(&tir.faddr, aif->ai_addr, aif->ai_addrlen); 111 memcpy(&tir.laddr, ail->ai_addr, ail->ai_addrlen); 112 113 if ((gaierr = getnameinfo(aif->ai_addr, aif->ai_addrlen, 114 fhbuf, sizeof(fhbuf), fsbuf, sizeof(fsbuf), 115 NI_NUMERICHOST | NI_NUMERICSERV)) != 0) 116 errx(1, "getnameinfo: %s", gai_strerror(gaierr)); 117 if ((gaierr = getnameinfo(ail->ai_addr, ail->ai_addrlen, 118 lhbuf, sizeof(lhbuf), lsbuf, sizeof(lsbuf), 119 NI_NUMERICHOST | NI_NUMERICSERV)) != 0) 120 errx(1, "getnameinfo: %s", gai_strerror(gaierr)); 121 122 if (sysctl(mib, sizeof (mib) / sizeof (int), NULL, 123 NULL, &tir, sizeof(tir)) == -1) { 124 rval = 1; 125 warn("%s %s %s %s", lhbuf, lsbuf, fhbuf, fsbuf); 126 } else { 127 if (aif->ai_family == PF_INET6) 128 printf("[%s]:%s [%s]:%s dropped\n", 129 lhbuf, lsbuf, fhbuf, fsbuf); 130 else 131 printf("%s:%s %s:%s dropped\n", 132 lhbuf, lsbuf, fhbuf, fsbuf); 133 } 134 } 135 } 136 freeaddrinfo(laddr); 137 freeaddrinfo(faddr); 138 exit(rval); 139 } 140