1 /* $OpenBSD: tcpdrop.c,v 1.17 2015/01/16 06:40:21 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/socket.h> 20 #include <sys/sysctl.h> 21 #include <sys/queue.h> 22 #include <sys/timeout.h> 23 24 #include <netinet/in.h> 25 #include <netinet/tcp.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 __dead void usage(void); 36 37 __dead void 38 usage(void) 39 { 40 extern char *__progname; 41 42 fprintf(stderr, 43 "usage: %s local-addr local-port remote-addr remote-port\n", 44 __progname); 45 fprintf(stderr, 46 " %s local-addr:local-port remote-addr:remote-port\n", 47 __progname); 48 exit(1); 49 } 50 51 /* 52 * Drop a tcp connection. 53 */ 54 int 55 main(int argc, char **argv) 56 { 57 int mib[] = { CTL_NET, PF_INET, IPPROTO_TCP, TCPCTL_DROP }; 58 struct addrinfo hints, *ail, *aif, *laddr, *faddr; 59 char fhbuf[NI_MAXHOST], fsbuf[NI_MAXSERV]; 60 char lhbuf[NI_MAXHOST], lsbuf[NI_MAXSERV]; 61 char *laddr1, *addr1, *port1, *faddr2, *addr2, *port2; 62 struct tcp_ident_mapping tir; 63 int gaierr, rval = 0; 64 65 memset(&hints, 0, sizeof(hints)); 66 hints.ai_family = AF_UNSPEC; 67 hints.ai_socktype = SOCK_STREAM; 68 69 if (argc == 3) { 70 laddr1 = addr1 = strdup(argv[1]); 71 if (!addr1) 72 err(1, "strdup"); 73 port1 = strrchr(addr1, ':'); 74 if (port1) 75 *port1++ = '\0'; 76 else 77 usage(); 78 79 faddr2 = addr2 = strdup(argv[2]); 80 if (!addr2) 81 err(1, "strdup"); 82 port2 = strrchr(addr2, ':'); 83 if (port2) 84 *port2++ = '\0'; 85 else 86 usage(); 87 } else if (argc == 5) { 88 laddr1 = addr1 = argv[1]; 89 port1 = argv[2]; 90 faddr2 = addr2 = argv[3]; 91 port2 = argv[4]; 92 } else 93 usage(); 94 95 if (addr1[0] == '[' && addr1[strlen(addr1) - 1] == ']') { 96 laddr1 = strdup(addr1); 97 if (!laddr1) 98 err(1, "strdup"); 99 laddr1[strlen(laddr1) - 1] = '\0'; 100 laddr1++; 101 } 102 if (addr2[0] == '[' && addr2[strlen(addr2) - 1] == ']') { 103 faddr2 = strdup(addr2); 104 if (!faddr2) 105 err(1, "strdup"); 106 faddr2[strlen(faddr2) - 1] = '\0'; 107 faddr2++; 108 } 109 110 if ((gaierr = getaddrinfo(laddr1, port1, &hints, &laddr)) != 0) 111 errx(1, "%s port %s: %s", addr1, port1, 112 gai_strerror(gaierr)); 113 114 if ((gaierr = getaddrinfo(faddr2, port2, &hints, &faddr)) != 0) 115 errx(1, "%s port %s: %s", addr2, port2, 116 gai_strerror(gaierr)); 117 118 rval = 1; 119 for (ail = laddr; ail; ail = ail->ai_next) { 120 for (aif = faddr; aif; aif = aif->ai_next) { 121 if (ail->ai_family != aif->ai_family) 122 continue; 123 rval = 0; 124 memset(&tir, 0, sizeof(tir)); 125 memcpy(&tir.faddr, aif->ai_addr, aif->ai_addrlen); 126 memcpy(&tir.laddr, ail->ai_addr, ail->ai_addrlen); 127 128 if ((gaierr = getnameinfo(aif->ai_addr, aif->ai_addrlen, 129 fhbuf, sizeof(fhbuf), fsbuf, sizeof(fsbuf), 130 NI_NUMERICHOST | NI_NUMERICSERV)) != 0) 131 errx(1, "getnameinfo: %s", gai_strerror(gaierr)); 132 if ((gaierr = getnameinfo(ail->ai_addr, ail->ai_addrlen, 133 lhbuf, sizeof(lhbuf), lsbuf, sizeof(lsbuf), 134 NI_NUMERICHOST | NI_NUMERICSERV)) != 0) 135 errx(1, "getnameinfo: %s", gai_strerror(gaierr)); 136 137 if (sysctl(mib, sizeof (mib) / sizeof (int), NULL, 138 NULL, &tir, sizeof(tir)) == -1) { 139 rval = 1; 140 warn("%s %s %s %s", lhbuf, lsbuf, fhbuf, fsbuf); 141 } else { 142 if (aif->ai_family == PF_INET6) 143 printf("[%s]:%s [%s]:%s dropped\n", 144 lhbuf, lsbuf, fhbuf, fsbuf); 145 else 146 printf("%s:%s %s:%s dropped\n", 147 lhbuf, lsbuf, fhbuf, fsbuf); 148 } 149 } 150 } 151 freeaddrinfo(laddr); 152 freeaddrinfo(faddr); 153 exit(rval); 154 } 155