103100a63Svk199839 /* $OpenBSD: netcat.c,v 1.89 2007/02/20 14:11:17 jmc Exp $ */ 203100a63Svk199839 /* 303100a63Svk199839 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org> 403100a63Svk199839 * 503100a63Svk199839 * Redistribution and use in source and binary forms, with or without 603100a63Svk199839 * modification, are permitted provided that the following conditions 703100a63Svk199839 * are met: 803100a63Svk199839 * 903100a63Svk199839 * 1. Redistributions of source code must retain the above copyright 1003100a63Svk199839 * notice, this list of conditions and the following disclaimer. 1103100a63Svk199839 * 2. Redistributions in binary form must reproduce the above copyright 1203100a63Svk199839 * notice, this list of conditions and the following disclaimer in the 1303100a63Svk199839 * documentation and/or other materials provided with the distribution. 1403100a63Svk199839 * 3. The name of the author may not be used to endorse or promote products 1503100a63Svk199839 * derived from this software without specific prior written permission. 1603100a63Svk199839 * 1703100a63Svk199839 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1803100a63Svk199839 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1903100a63Svk199839 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 2003100a63Svk199839 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 2103100a63Svk199839 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 2203100a63Svk199839 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2303100a63Svk199839 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2403100a63Svk199839 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2503100a63Svk199839 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2603100a63Svk199839 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2703100a63Svk199839 */ 2803100a63Svk199839 2903100a63Svk199839 /* 3003100a63Svk199839 * Re-written nc(1) for OpenBSD. Original implementation by 3103100a63Svk199839 * *Hobbit* <hobbit@avian.org>. 3203100a63Svk199839 */ 3303100a63Svk199839 34f8c3982aSvk199839 /* 35f8c3982aSvk199839 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 36f8c3982aSvk199839 * Use is subject to license terms. 37f8c3982aSvk199839 */ 38f8c3982aSvk199839 392eef1f2bSErik Trauschke /* 402eef1f2bSErik Trauschke * Portions Copyright 2008 Erik Trauschke 412eef1f2bSErik Trauschke */ 4203100a63Svk199839 4303100a63Svk199839 #include <sys/types.h> 4403100a63Svk199839 #include <sys/socket.h> 4503100a63Svk199839 #include <sys/time.h> 4603100a63Svk199839 #include <sys/un.h> 4703100a63Svk199839 4803100a63Svk199839 #include <netinet/in.h> 4903100a63Svk199839 #include <netinet/in_systm.h> 5003100a63Svk199839 #include <netinet/tcp.h> 5103100a63Svk199839 #include <netinet/ip.h> 5203100a63Svk199839 #include <arpa/telnet.h> 5303100a63Svk199839 5403100a63Svk199839 #include <err.h> 5503100a63Svk199839 #include <errno.h> 5603100a63Svk199839 #include <netdb.h> 5703100a63Svk199839 #include <poll.h> 5803100a63Svk199839 #include <stdarg.h> 5903100a63Svk199839 #include <stdio.h> 6003100a63Svk199839 #include <stdlib.h> 6103100a63Svk199839 #include <string.h> 6203100a63Svk199839 #include <unistd.h> 6303100a63Svk199839 #include <fcntl.h> 6403100a63Svk199839 #include <limits.h> 6503100a63Svk199839 #include <signal.h> 6603100a63Svk199839 6703100a63Svk199839 #include "atomicio.h" 6803100a63Svk199839 6903100a63Svk199839 #ifndef SUN_LEN 7003100a63Svk199839 #define SUN_LEN(su) \ 7103100a63Svk199839 (sizeof (*(su)) - sizeof ((su)->sun_path) + strlen((su)->sun_path)) 7203100a63Svk199839 #endif 7303100a63Svk199839 7403100a63Svk199839 #define PORT_MIN 1 7503100a63Svk199839 #define PORT_MAX 65535 7603100a63Svk199839 #define PORT_MAX_LEN 6 772eef1f2bSErik Trauschke #define PLIST_SZ 32 /* initial capacity of the portlist */ 7803100a63Svk199839 7903100a63Svk199839 /* Command Line Options */ 8003100a63Svk199839 int dflag; /* detached, no stdin */ 8103100a63Svk199839 unsigned int iflag; /* Interval Flag */ 8203100a63Svk199839 int kflag; /* More than one connect */ 8303100a63Svk199839 int lflag; /* Bind to local port */ 8403100a63Svk199839 int nflag; /* Don't do name lookup */ 8503100a63Svk199839 char *Pflag; /* Proxy username */ 8603100a63Svk199839 char *pflag; /* Localport flag */ 8703100a63Svk199839 int rflag; /* Random ports flag */ 8803100a63Svk199839 char *sflag; /* Source Address */ 8903100a63Svk199839 int tflag; /* Telnet Emulation */ 9003100a63Svk199839 int uflag; /* UDP - Default to TCP */ 9103100a63Svk199839 int vflag; /* Verbosity */ 9203100a63Svk199839 int xflag; /* Socks proxy */ 9303100a63Svk199839 int Xflag; /* indicator of Socks version set */ 9403100a63Svk199839 int zflag; /* Port Scan Flag */ 9503100a63Svk199839 int Dflag; /* sodebug */ 9603100a63Svk199839 int Tflag = -1; /* IP Type of Service */ 9703100a63Svk199839 9803100a63Svk199839 int timeout = -1; 9903100a63Svk199839 int family = AF_UNSPEC; 1002eef1f2bSErik Trauschke 1012eef1f2bSErik Trauschke /* 1022eef1f2bSErik Trauschke * portlist structure 1032eef1f2bSErik Trauschke * Used to store a list of ports given by the user and maintaining 1042eef1f2bSErik Trauschke * information about the number of ports stored. 1052eef1f2bSErik Trauschke */ 1062eef1f2bSErik Trauschke struct { 1072eef1f2bSErik Trauschke uint16_t *list; /* list containing the ports */ 1082eef1f2bSErik Trauschke uint_t listsize; /* capacity of the list (number of entries) */ 1092eef1f2bSErik Trauschke uint_t numports; /* number of ports in the list */ 1102eef1f2bSErik Trauschke } ports; 11103100a63Svk199839 11203100a63Svk199839 void atelnet(int, unsigned char *, unsigned int); 11303100a63Svk199839 void build_ports(char *); 11403100a63Svk199839 void help(void); 11503100a63Svk199839 int local_listen(char *, char *, struct addrinfo); 11603100a63Svk199839 void readwrite(int); 11703100a63Svk199839 int remote_connect(const char *, const char *, struct addrinfo); 11803100a63Svk199839 int socks_connect(const char *, const char *, 11903100a63Svk199839 const char *, const char *, struct addrinfo, int, const char *); 12003100a63Svk199839 int udptest(int); 12103100a63Svk199839 int unix_connect(char *); 12203100a63Svk199839 int unix_listen(char *); 12303100a63Svk199839 void set_common_sockopts(int); 12403100a63Svk199839 int parse_iptos(char *); 12503100a63Svk199839 void usage(int); 126f8c3982aSvk199839 char *print_addr(char *, size_t, struct sockaddr *, int, int); 12703100a63Svk199839 12803100a63Svk199839 int 12903100a63Svk199839 main(int argc, char *argv[]) 13003100a63Svk199839 { 13103100a63Svk199839 int ch, s, ret, socksv; 13203100a63Svk199839 char *host, *uport, *proxy; 13303100a63Svk199839 struct addrinfo hints; 13403100a63Svk199839 struct servent *sv; 13503100a63Svk199839 socklen_t len; 13603100a63Svk199839 struct sockaddr_storage cliaddr; 13703100a63Svk199839 const char *errstr, *proxyhost = "", *proxyport = NULL; 13803100a63Svk199839 struct addrinfo proxyhints; 1392eef1f2bSErik Trauschke char port[PORT_MAX_LEN]; 14003100a63Svk199839 14103100a63Svk199839 ret = 1; 1422eef1f2bSErik Trauschke s = -1; 14303100a63Svk199839 socksv = 5; 14403100a63Svk199839 host = NULL; 14503100a63Svk199839 uport = NULL; 14603100a63Svk199839 sv = NULL; 14703100a63Svk199839 14803100a63Svk199839 while ((ch = getopt(argc, argv, 14903100a63Svk199839 "46Ddhi:klnP:p:rs:T:tUuvw:X:x:z")) != -1) { 15003100a63Svk199839 switch (ch) { 15103100a63Svk199839 case '4': 15203100a63Svk199839 family = AF_INET; 15303100a63Svk199839 break; 15403100a63Svk199839 case '6': 15503100a63Svk199839 family = AF_INET6; 15603100a63Svk199839 break; 15703100a63Svk199839 case 'U': 15803100a63Svk199839 family = AF_UNIX; 15903100a63Svk199839 break; 16003100a63Svk199839 case 'X': 16103100a63Svk199839 Xflag = 1; 16203100a63Svk199839 if (strcasecmp(optarg, "connect") == 0) 16303100a63Svk199839 socksv = -1; /* HTTP proxy CONNECT */ 16403100a63Svk199839 else if (strcmp(optarg, "4") == 0) 16503100a63Svk199839 socksv = 4; /* SOCKS v.4 */ 16603100a63Svk199839 else if (strcmp(optarg, "5") == 0) 16703100a63Svk199839 socksv = 5; /* SOCKS v.5 */ 16803100a63Svk199839 else 16903100a63Svk199839 errx(1, "unsupported proxy protocol"); 17003100a63Svk199839 break; 17103100a63Svk199839 case 'd': 17203100a63Svk199839 dflag = 1; 17303100a63Svk199839 break; 17403100a63Svk199839 case 'h': 17503100a63Svk199839 help(); 17603100a63Svk199839 break; 17703100a63Svk199839 case 'i': 17803100a63Svk199839 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 17903100a63Svk199839 if (errstr) 18003100a63Svk199839 errx(1, "interval %s: %s", errstr, optarg); 18103100a63Svk199839 break; 18203100a63Svk199839 case 'k': 18303100a63Svk199839 kflag = 1; 18403100a63Svk199839 break; 18503100a63Svk199839 case 'l': 18603100a63Svk199839 lflag = 1; 18703100a63Svk199839 break; 18803100a63Svk199839 case 'n': 18903100a63Svk199839 nflag = 1; 19003100a63Svk199839 break; 19103100a63Svk199839 case 'P': 19203100a63Svk199839 Pflag = optarg; 19303100a63Svk199839 break; 19403100a63Svk199839 case 'p': 19503100a63Svk199839 pflag = optarg; 19603100a63Svk199839 break; 19703100a63Svk199839 case 'r': 19803100a63Svk199839 rflag = 1; 19903100a63Svk199839 break; 20003100a63Svk199839 case 's': 20103100a63Svk199839 sflag = optarg; 20203100a63Svk199839 break; 20303100a63Svk199839 case 't': 20403100a63Svk199839 tflag = 1; 20503100a63Svk199839 break; 20603100a63Svk199839 case 'u': 20703100a63Svk199839 uflag = 1; 20803100a63Svk199839 break; 20903100a63Svk199839 case 'v': 21003100a63Svk199839 vflag = 1; 21103100a63Svk199839 break; 21203100a63Svk199839 case 'w': 21303100a63Svk199839 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 21403100a63Svk199839 if (errstr) 21503100a63Svk199839 errx(1, "timeout %s: %s", errstr, optarg); 21603100a63Svk199839 timeout *= 1000; 21703100a63Svk199839 break; 21803100a63Svk199839 case 'x': 21903100a63Svk199839 xflag = 1; 22003100a63Svk199839 if ((proxy = strdup(optarg)) == NULL) 22103100a63Svk199839 err(1, NULL); 22203100a63Svk199839 break; 22303100a63Svk199839 case 'z': 22403100a63Svk199839 zflag = 1; 22503100a63Svk199839 break; 22603100a63Svk199839 case 'D': 22703100a63Svk199839 Dflag = 1; 22803100a63Svk199839 break; 22903100a63Svk199839 case 'T': 23003100a63Svk199839 Tflag = parse_iptos(optarg); 23103100a63Svk199839 break; 23203100a63Svk199839 default: 23303100a63Svk199839 usage(1); 23403100a63Svk199839 } 23503100a63Svk199839 } 23603100a63Svk199839 argc -= optind; 23703100a63Svk199839 argv += optind; 23803100a63Svk199839 23903100a63Svk199839 /* Cruft to make sure options are clean, and used properly. */ 24003100a63Svk199839 if (argv[0] && !argv[1] && family == AF_UNIX) { 24103100a63Svk199839 if (uflag) 24203100a63Svk199839 errx(1, "cannot use -u and -U"); 24303100a63Svk199839 host = argv[0]; 24403100a63Svk199839 uport = NULL; 24503100a63Svk199839 } else if (argv[0] && !argv[1]) { 24603100a63Svk199839 if (!lflag) 24703100a63Svk199839 usage(1); 24803100a63Svk199839 uport = argv[0]; 24903100a63Svk199839 host = NULL; 25003100a63Svk199839 } else if (argv[0] && argv[1]) { 25103100a63Svk199839 if (family == AF_UNIX) 25203100a63Svk199839 usage(1); 25303100a63Svk199839 host = argv[0]; 25403100a63Svk199839 uport = argv[1]; 25503100a63Svk199839 } else { 25603100a63Svk199839 if (!(lflag && pflag)) 25703100a63Svk199839 usage(1); 25803100a63Svk199839 } 25903100a63Svk199839 26063c99f93Svk199839 if (argc > 2) 26163c99f93Svk199839 usage(1); 26263c99f93Svk199839 26303100a63Svk199839 if (lflag && sflag) 26403100a63Svk199839 errx(1, "cannot use -s and -l"); 26503100a63Svk199839 if (lflag && rflag) 26603100a63Svk199839 errx(1, "cannot use -r and -l"); 26763c99f93Svk199839 if (lflag && (timeout >= 0)) 26863c99f93Svk199839 warnx("-w has no effect with -l"); 26903100a63Svk199839 if (lflag && pflag) { 27003100a63Svk199839 if (uport) 27103100a63Svk199839 usage(1); 27203100a63Svk199839 uport = pflag; 27303100a63Svk199839 } 27403100a63Svk199839 if (lflag && zflag) 27503100a63Svk199839 errx(1, "cannot use -z and -l"); 27603100a63Svk199839 if (!lflag && kflag) 27703100a63Svk199839 errx(1, "must use -l with -k"); 27803100a63Svk199839 if (lflag && (Pflag || xflag || Xflag)) 27903100a63Svk199839 errx(1, "cannot use -l with -P, -X or -x"); 28003100a63Svk199839 28103100a63Svk199839 /* Initialize addrinfo structure. */ 28203100a63Svk199839 if (family != AF_UNIX) { 28303100a63Svk199839 (void) memset(&hints, 0, sizeof (struct addrinfo)); 28403100a63Svk199839 hints.ai_family = family; 28503100a63Svk199839 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 28603100a63Svk199839 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 28703100a63Svk199839 if (nflag) 28803100a63Svk199839 hints.ai_flags |= AI_NUMERICHOST; 28903100a63Svk199839 } 29003100a63Svk199839 29103100a63Svk199839 if (xflag) { 29203100a63Svk199839 if (uflag) 29303100a63Svk199839 errx(1, "no proxy support for UDP mode"); 29403100a63Svk199839 29503100a63Svk199839 if (lflag) 29603100a63Svk199839 errx(1, "no proxy support for listen"); 29703100a63Svk199839 29803100a63Svk199839 if (family == AF_UNIX) 29903100a63Svk199839 errx(1, "no proxy support for unix sockets"); 30003100a63Svk199839 30103100a63Svk199839 if (family == AF_INET6) 30203100a63Svk199839 errx(1, "no proxy support for IPv6"); 30303100a63Svk199839 30403100a63Svk199839 if (sflag) 30503100a63Svk199839 errx(1, "no proxy support for local source address"); 30603100a63Svk199839 30703100a63Svk199839 if ((proxyhost = strtok(proxy, ":")) == NULL) 30803100a63Svk199839 errx(1, "missing port specification"); 30903100a63Svk199839 proxyport = strtok(NULL, ":"); 31003100a63Svk199839 31103100a63Svk199839 (void) memset(&proxyhints, 0, sizeof (struct addrinfo)); 31203100a63Svk199839 proxyhints.ai_family = family; 31303100a63Svk199839 proxyhints.ai_socktype = SOCK_STREAM; 31403100a63Svk199839 proxyhints.ai_protocol = IPPROTO_TCP; 31503100a63Svk199839 if (nflag) 31603100a63Svk199839 proxyhints.ai_flags |= AI_NUMERICHOST; 31703100a63Svk199839 } 31803100a63Svk199839 31903100a63Svk199839 if (lflag) { 32003100a63Svk199839 int connfd; 32103100a63Svk199839 ret = 0; 32203100a63Svk199839 3232eef1f2bSErik Trauschke if (family == AF_UNIX) { 3242eef1f2bSErik Trauschke if (host == NULL) 3252eef1f2bSErik Trauschke usage(1); 32603100a63Svk199839 s = unix_listen(host); 3272eef1f2bSErik Trauschke } 32803100a63Svk199839 32903100a63Svk199839 /* Allow only one connection at a time, but stay alive. */ 33003100a63Svk199839 for (;;) { 3312eef1f2bSErik Trauschke if (family != AF_UNIX) { 3322eef1f2bSErik Trauschke /* check if uport is valid */ 3332eef1f2bSErik Trauschke if (strtonum(uport, PORT_MIN, PORT_MAX, 3342eef1f2bSErik Trauschke &errstr) == 0) 3352eef1f2bSErik Trauschke errx(1, "port number %s: %s", 3362eef1f2bSErik Trauschke uport, errstr); 33703100a63Svk199839 s = local_listen(host, uport, hints); 3382eef1f2bSErik Trauschke } 33903100a63Svk199839 if (s < 0) 34003100a63Svk199839 err(1, NULL); 34103100a63Svk199839 /* 34203100a63Svk199839 * For UDP, we will use recvfrom() initially 34303100a63Svk199839 * to wait for a caller, then use the regular 34403100a63Svk199839 * functions to talk to the caller. 34503100a63Svk199839 */ 34603100a63Svk199839 if (uflag) { 34703100a63Svk199839 int rv, plen; 34803100a63Svk199839 char buf[8192]; 34903100a63Svk199839 struct sockaddr_storage z; 35003100a63Svk199839 35103100a63Svk199839 len = sizeof (z); 35203100a63Svk199839 plen = 1024; 35303100a63Svk199839 rv = recvfrom(s, buf, plen, MSG_PEEK, 35403100a63Svk199839 (struct sockaddr *)&z, &len); 35503100a63Svk199839 if (rv < 0) 35603100a63Svk199839 err(1, "recvfrom"); 35703100a63Svk199839 35803100a63Svk199839 rv = connect(s, (struct sockaddr *)&z, len); 35903100a63Svk199839 if (rv < 0) 36003100a63Svk199839 err(1, "connect"); 36103100a63Svk199839 36203100a63Svk199839 connfd = s; 36303100a63Svk199839 } else { 36403100a63Svk199839 len = sizeof (cliaddr); 36503100a63Svk199839 connfd = accept(s, (struct sockaddr *)&cliaddr, 36603100a63Svk199839 &len); 367f8c3982aSvk199839 if ((connfd != -1) && vflag) { 368f8c3982aSvk199839 char ntop[NI_MAXHOST + NI_MAXSERV]; 369f8c3982aSvk199839 (void) fprintf(stderr, 370f8c3982aSvk199839 "Received connection from %s\n", 371f8c3982aSvk199839 print_addr(ntop, sizeof (ntop), 372f8c3982aSvk199839 (struct sockaddr *)&cliaddr, len, 373f8c3982aSvk199839 nflag ? NI_NUMERICHOST : 0)); 374f8c3982aSvk199839 } 37503100a63Svk199839 } 37603100a63Svk199839 37703100a63Svk199839 readwrite(connfd); 37803100a63Svk199839 (void) close(connfd); 37903100a63Svk199839 if (family != AF_UNIX) 38003100a63Svk199839 (void) close(s); 38103100a63Svk199839 38203100a63Svk199839 if (!kflag) 38303100a63Svk199839 break; 38403100a63Svk199839 } 38503100a63Svk199839 } else if (family == AF_UNIX) { 38603100a63Svk199839 ret = 0; 38703100a63Svk199839 38803100a63Svk199839 if ((s = unix_connect(host)) > 0 && !zflag) { 38903100a63Svk199839 readwrite(s); 39003100a63Svk199839 (void) close(s); 39103100a63Svk199839 } else 39203100a63Svk199839 ret = 1; 39303100a63Svk199839 39403100a63Svk199839 exit(ret); 39503100a63Svk199839 39603100a63Svk199839 } else { /* AF_INET or AF_INET6 */ 3972eef1f2bSErik Trauschke int i; 39803100a63Svk199839 3992eef1f2bSErik Trauschke /* Construct the portlist. */ 40003100a63Svk199839 build_ports(uport); 40103100a63Svk199839 40203100a63Svk199839 /* Cycle through portlist, connecting to each port. */ 4032eef1f2bSErik Trauschke for (i = 0; i < ports.numports; i++) { 4042eef1f2bSErik Trauschke (void) snprintf(port, sizeof (port), "%u", 4052eef1f2bSErik Trauschke ports.list[i]); 4062eef1f2bSErik Trauschke 4072eef1f2bSErik Trauschke if (s != -1) 40803100a63Svk199839 (void) close(s); 40903100a63Svk199839 41003100a63Svk199839 if (xflag) 4112eef1f2bSErik Trauschke s = socks_connect(host, port, 41203100a63Svk199839 proxyhost, proxyport, proxyhints, socksv, 41303100a63Svk199839 Pflag); 41403100a63Svk199839 else 4152eef1f2bSErik Trauschke s = remote_connect(host, port, hints); 41603100a63Svk199839 41703100a63Svk199839 if (s < 0) 41803100a63Svk199839 continue; 41903100a63Svk199839 42003100a63Svk199839 ret = 0; 42103100a63Svk199839 if (vflag || zflag) { 42203100a63Svk199839 /* For UDP, make sure we are connected. */ 42303100a63Svk199839 if (uflag) { 42403100a63Svk199839 if (udptest(s) == -1) { 42503100a63Svk199839 ret = 1; 42603100a63Svk199839 continue; 42703100a63Svk199839 } 42803100a63Svk199839 } 42903100a63Svk199839 43003100a63Svk199839 /* Don't look up port if -n. */ 43103100a63Svk199839 if (nflag) 43203100a63Svk199839 sv = NULL; 43303100a63Svk199839 else { 43403100a63Svk199839 sv = getservbyport( 4352eef1f2bSErik Trauschke ntohs(ports.list[i]), 43603100a63Svk199839 uflag ? "udp" : "tcp"); 43703100a63Svk199839 } 43803100a63Svk199839 439f8c3982aSvk199839 (void) fprintf(stderr, "Connection to %s %s " 44003100a63Svk199839 "port [%s/%s] succeeded!\n", 4412eef1f2bSErik Trauschke host, port, uflag ? "udp" : "tcp", 44203100a63Svk199839 sv ? sv->s_name : "*"); 44303100a63Svk199839 } 44403100a63Svk199839 if (!zflag) 44503100a63Svk199839 readwrite(s); 44603100a63Svk199839 } 4472eef1f2bSErik Trauschke free(ports.list); 44803100a63Svk199839 } 44903100a63Svk199839 4502eef1f2bSErik Trauschke if (s != -1) 45103100a63Svk199839 (void) close(s); 45203100a63Svk199839 45303100a63Svk199839 return (ret); 45403100a63Svk199839 } 45503100a63Svk199839 45603100a63Svk199839 /* 457f8c3982aSvk199839 * print IP address and (optionally) a port 458f8c3982aSvk199839 */ 459f8c3982aSvk199839 char * 460f8c3982aSvk199839 print_addr(char *ntop, size_t ntlen, struct sockaddr *addr, int len, int flags) 461f8c3982aSvk199839 { 462f8c3982aSvk199839 char port[NI_MAXSERV]; 463f8c3982aSvk199839 int e; 464f8c3982aSvk199839 465f8c3982aSvk199839 /* print port always as number */ 466f8c3982aSvk199839 if ((e = getnameinfo(addr, len, ntop, ntlen, 467f8c3982aSvk199839 port, sizeof (port), flags|NI_NUMERICSERV)) != 0) { 468f8c3982aSvk199839 return ((char *)gai_strerror(e)); 469f8c3982aSvk199839 } 470f8c3982aSvk199839 471*afa82053SToomas Soome (void) strlcat(ntop, " port ", ntlen); 472*afa82053SToomas Soome (void) strlcat(ntop, port, ntlen); 473f8c3982aSvk199839 474f8c3982aSvk199839 return (ntop); 475f8c3982aSvk199839 } 476f8c3982aSvk199839 477f8c3982aSvk199839 /* 47803100a63Svk199839 * unix_connect() 47903100a63Svk199839 * Returns a socket connected to a local unix socket. Returns -1 on failure. 48003100a63Svk199839 */ 48103100a63Svk199839 int 48203100a63Svk199839 unix_connect(char *path) 48303100a63Svk199839 { 48403100a63Svk199839 struct sockaddr_un sunaddr; 48503100a63Svk199839 int s; 48603100a63Svk199839 48703100a63Svk199839 if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) 48803100a63Svk199839 return (-1); 48903100a63Svk199839 49003100a63Svk199839 (void) memset(&sunaddr, 0, sizeof (struct sockaddr_un)); 49103100a63Svk199839 sunaddr.sun_family = AF_UNIX; 49203100a63Svk199839 49303100a63Svk199839 if (strlcpy(sunaddr.sun_path, path, sizeof (sunaddr.sun_path)) >= 49403100a63Svk199839 sizeof (sunaddr.sun_path)) { 49503100a63Svk199839 (void) close(s); 49603100a63Svk199839 errno = ENAMETOOLONG; 49703100a63Svk199839 return (-1); 49803100a63Svk199839 } 49903100a63Svk199839 if (connect(s, (struct sockaddr *)&sunaddr, SUN_LEN(&sunaddr)) < 0) { 50003100a63Svk199839 (void) close(s); 50103100a63Svk199839 return (-1); 50203100a63Svk199839 } 50303100a63Svk199839 return (s); 50403100a63Svk199839 } 50503100a63Svk199839 50603100a63Svk199839 /* 50703100a63Svk199839 * unix_listen() 50803100a63Svk199839 * Create a unix domain socket, and listen on it. 50903100a63Svk199839 */ 51003100a63Svk199839 int 51103100a63Svk199839 unix_listen(char *path) 51203100a63Svk199839 { 51303100a63Svk199839 struct sockaddr_un sunaddr; 51403100a63Svk199839 int s; 51503100a63Svk199839 51603100a63Svk199839 /* Create unix domain socket. */ 51703100a63Svk199839 if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) 51803100a63Svk199839 return (-1); 51903100a63Svk199839 52003100a63Svk199839 (void) memset(&sunaddr, 0, sizeof (struct sockaddr_un)); 52103100a63Svk199839 sunaddr.sun_family = AF_UNIX; 52203100a63Svk199839 52303100a63Svk199839 if (strlcpy(sunaddr.sun_path, path, sizeof (sunaddr.sun_path)) >= 52403100a63Svk199839 sizeof (sunaddr.sun_path)) { 52503100a63Svk199839 (void) close(s); 52603100a63Svk199839 errno = ENAMETOOLONG; 52703100a63Svk199839 return (-1); 52803100a63Svk199839 } 52903100a63Svk199839 53003100a63Svk199839 if (bind(s, (struct sockaddr *)&sunaddr, SUN_LEN(&sunaddr)) < 0) { 53103100a63Svk199839 (void) close(s); 53203100a63Svk199839 return (-1); 53303100a63Svk199839 } 53403100a63Svk199839 53503100a63Svk199839 if (listen(s, 5) < 0) { 53603100a63Svk199839 (void) close(s); 53703100a63Svk199839 return (-1); 53803100a63Svk199839 } 53903100a63Svk199839 return (s); 54003100a63Svk199839 } 54103100a63Svk199839 54203100a63Svk199839 /* 54303100a63Svk199839 * remote_connect() 54403100a63Svk199839 * Returns a socket connected to a remote host. Properly binds to a local 54503100a63Svk199839 * port or source address if needed. Returns -1 on failure. 54603100a63Svk199839 */ 54703100a63Svk199839 int 54803100a63Svk199839 remote_connect(const char *host, const char *port, struct addrinfo hints) 54903100a63Svk199839 { 55003100a63Svk199839 struct addrinfo *res, *res0; 55103100a63Svk199839 int s, error; 55203100a63Svk199839 55303100a63Svk199839 if ((error = getaddrinfo(host, port, &hints, &res))) 55403100a63Svk199839 errx(1, "getaddrinfo: %s", gai_strerror(error)); 55503100a63Svk199839 55603100a63Svk199839 res0 = res; 55703100a63Svk199839 do { 55803100a63Svk199839 if ((s = socket(res0->ai_family, res0->ai_socktype, 55903100a63Svk199839 res0->ai_protocol)) < 0) { 56003100a63Svk199839 warn("failed to create socket"); 56103100a63Svk199839 continue; 56203100a63Svk199839 } 56303100a63Svk199839 56403100a63Svk199839 /* Bind to a local port or source address if specified. */ 56503100a63Svk199839 if (sflag || pflag) { 56603100a63Svk199839 struct addrinfo ahints, *ares; 56703100a63Svk199839 56803100a63Svk199839 (void) memset(&ahints, 0, sizeof (struct addrinfo)); 56903100a63Svk199839 ahints.ai_family = res0->ai_family; 57003100a63Svk199839 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 57103100a63Svk199839 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 57203100a63Svk199839 ahints.ai_flags = AI_PASSIVE; 57303100a63Svk199839 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 57403100a63Svk199839 errx(1, "getaddrinfo: %s", gai_strerror(error)); 57503100a63Svk199839 57603100a63Svk199839 if (bind(s, (struct sockaddr *)ares->ai_addr, 57703100a63Svk199839 ares->ai_addrlen) < 0) 57803100a63Svk199839 errx(1, "bind failed: %s", strerror(errno)); 57903100a63Svk199839 freeaddrinfo(ares); 580f8c3982aSvk199839 581f8c3982aSvk199839 if (vflag && !lflag) { 582f8c3982aSvk199839 if (sflag != NULL) 583f8c3982aSvk199839 (void) fprintf(stderr, 584f8c3982aSvk199839 "Using source address: %s\n", 585f8c3982aSvk199839 sflag); 586f8c3982aSvk199839 if (pflag != NULL) 587f8c3982aSvk199839 (void) fprintf(stderr, 588f8c3982aSvk199839 "Using source port: %s\n", pflag); 589f8c3982aSvk199839 } 59003100a63Svk199839 } 59103100a63Svk199839 59203100a63Svk199839 set_common_sockopts(s); 59303100a63Svk199839 59403100a63Svk199839 if (connect(s, res0->ai_addr, res0->ai_addrlen) == 0) 59503100a63Svk199839 break; 596f8c3982aSvk199839 else if (vflag) { 597f8c3982aSvk199839 char ntop[NI_MAXHOST + NI_MAXSERV]; 598f8c3982aSvk199839 warn("connect to %s [host %s] (%s) failed", 599f8c3982aSvk199839 print_addr(ntop, sizeof (ntop), 600f8c3982aSvk199839 res0->ai_addr, res0->ai_addrlen, NI_NUMERICHOST), 601f8c3982aSvk199839 host, uflag ? "udp" : "tcp"); 602f8c3982aSvk199839 } 60303100a63Svk199839 60403100a63Svk199839 (void) close(s); 60503100a63Svk199839 s = -1; 60603100a63Svk199839 } while ((res0 = res0->ai_next) != NULL); 60703100a63Svk199839 60803100a63Svk199839 freeaddrinfo(res); 60903100a63Svk199839 61003100a63Svk199839 return (s); 61103100a63Svk199839 } 61203100a63Svk199839 61303100a63Svk199839 /* 61403100a63Svk199839 * local_listen() 61503100a63Svk199839 * Returns a socket listening on a local port, binds to specified source 61603100a63Svk199839 * address. Returns -1 on failure. 61703100a63Svk199839 */ 61803100a63Svk199839 int 61903100a63Svk199839 local_listen(char *host, char *port, struct addrinfo hints) 62003100a63Svk199839 { 62103100a63Svk199839 struct addrinfo *res, *res0; 62203100a63Svk199839 int s, ret, x = 1; 62303100a63Svk199839 int error; 62403100a63Svk199839 62503100a63Svk199839 /* Allow nodename to be null. */ 62603100a63Svk199839 hints.ai_flags |= AI_PASSIVE; 62703100a63Svk199839 62803100a63Svk199839 if ((error = getaddrinfo(host, port, &hints, &res))) 62903100a63Svk199839 errx(1, "getaddrinfo: %s", gai_strerror(error)); 63003100a63Svk199839 63103100a63Svk199839 res0 = res; 63203100a63Svk199839 do { 63303100a63Svk199839 if ((s = socket(res0->ai_family, res0->ai_socktype, 63403100a63Svk199839 res0->ai_protocol)) < 0) { 63503100a63Svk199839 warn("failed to create socket"); 63603100a63Svk199839 continue; 63703100a63Svk199839 } 63803100a63Svk199839 63903100a63Svk199839 ret = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &x, sizeof (x)); 64003100a63Svk199839 if (ret == -1) 64103100a63Svk199839 err(1, NULL); 64203100a63Svk199839 64303100a63Svk199839 set_common_sockopts(s); 64403100a63Svk199839 64503100a63Svk199839 if (bind(s, (struct sockaddr *)res0->ai_addr, 64603100a63Svk199839 res0->ai_addrlen) == 0) 64703100a63Svk199839 break; 64803100a63Svk199839 64903100a63Svk199839 (void) close(s); 65003100a63Svk199839 s = -1; 65103100a63Svk199839 } while ((res0 = res0->ai_next) != NULL); 65203100a63Svk199839 65303100a63Svk199839 if (!uflag && s != -1) { 65403100a63Svk199839 if (listen(s, 1) < 0) 65503100a63Svk199839 err(1, "listen"); 65603100a63Svk199839 } 65703100a63Svk199839 65803100a63Svk199839 freeaddrinfo(res); 65903100a63Svk199839 66003100a63Svk199839 return (s); 66103100a63Svk199839 } 66203100a63Svk199839 66303100a63Svk199839 /* 66403100a63Svk199839 * readwrite() 66503100a63Svk199839 * Loop that polls on the network file descriptor and stdin. 66603100a63Svk199839 */ 66703100a63Svk199839 void 66803100a63Svk199839 readwrite(int nfd) 66903100a63Svk199839 { 67003100a63Svk199839 struct pollfd pfd[2]; 67103100a63Svk199839 unsigned char buf[8192]; 67203100a63Svk199839 int n, wfd = fileno(stdin); 67303100a63Svk199839 int lfd = fileno(stdout); 67403100a63Svk199839 int plen; 67503100a63Svk199839 67603100a63Svk199839 plen = 1024; 67703100a63Svk199839 67803100a63Svk199839 /* Setup Network FD */ 67903100a63Svk199839 pfd[0].fd = nfd; 68003100a63Svk199839 pfd[0].events = POLLIN; 68103100a63Svk199839 68203100a63Svk199839 /* Set up STDIN FD. */ 68303100a63Svk199839 pfd[1].fd = wfd; 68403100a63Svk199839 pfd[1].events = POLLIN; 68503100a63Svk199839 68603100a63Svk199839 while (pfd[0].fd != -1) { 68703100a63Svk199839 if (iflag) 68803100a63Svk199839 (void) sleep(iflag); 68903100a63Svk199839 69003100a63Svk199839 if ((n = poll(pfd, 2 - dflag, timeout)) < 0) { 69103100a63Svk199839 (void) close(nfd); 69203100a63Svk199839 err(1, "Polling Error"); 69303100a63Svk199839 } 69403100a63Svk199839 69503100a63Svk199839 if (n == 0) 69603100a63Svk199839 return; 69703100a63Svk199839 69803100a63Svk199839 if (pfd[0].revents & (POLLIN|POLLHUP)) { 69903100a63Svk199839 if ((n = read(nfd, buf, plen)) < 0) 70003100a63Svk199839 return; 70103100a63Svk199839 else if (n == 0) { 70203100a63Svk199839 (void) shutdown(nfd, SHUT_RD); 70303100a63Svk199839 pfd[0].fd = -1; 70403100a63Svk199839 pfd[0].events = 0; 70503100a63Svk199839 } else { 70603100a63Svk199839 if (tflag) 70703100a63Svk199839 atelnet(nfd, buf, n); 70803100a63Svk199839 if (atomicio(vwrite, lfd, buf, n) != n) 70903100a63Svk199839 return; 71003100a63Svk199839 } 71103100a63Svk199839 } 71203100a63Svk199839 71303100a63Svk199839 /* 71403100a63Svk199839 * handle the case of disconnected pipe: after pipe 71503100a63Svk199839 * is closed (indicated by POLLHUP) there may still 71603100a63Svk199839 * be some data lingering (POLLIN). After we read 71703100a63Svk199839 * the data, only POLLHUP remains, read() returns 0 71803100a63Svk199839 * and we are finished. 71903100a63Svk199839 */ 72003100a63Svk199839 if (!dflag && (pfd[1].revents & (POLLIN|POLLHUP))) { 72103100a63Svk199839 if ((n = read(wfd, buf, plen)) < 0) 72203100a63Svk199839 return; 72303100a63Svk199839 else if (n == 0) { 72403100a63Svk199839 (void) shutdown(nfd, SHUT_WR); 72503100a63Svk199839 pfd[1].fd = -1; 72603100a63Svk199839 pfd[1].events = 0; 72703100a63Svk199839 } else { 72803100a63Svk199839 if (atomicio(vwrite, nfd, buf, n) != n) 72903100a63Svk199839 return; 73003100a63Svk199839 } 73103100a63Svk199839 } 73203100a63Svk199839 } 73303100a63Svk199839 } 73403100a63Svk199839 73503100a63Svk199839 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 73603100a63Svk199839 void 73703100a63Svk199839 atelnet(int nfd, unsigned char *buf, unsigned int size) 73803100a63Svk199839 { 73903100a63Svk199839 unsigned char *p, *end; 74003100a63Svk199839 unsigned char obuf[4]; 74103100a63Svk199839 74203100a63Svk199839 end = buf + size; 74303100a63Svk199839 obuf[0] = '\0'; 74403100a63Svk199839 74503100a63Svk199839 for (p = buf; p < end; p++) { 74603100a63Svk199839 if (*p != IAC) 74703100a63Svk199839 break; 74803100a63Svk199839 74903100a63Svk199839 obuf[0] = IAC; 75003100a63Svk199839 obuf[1] = 0; 75103100a63Svk199839 p++; 75203100a63Svk199839 /* refuse all options */ 75303100a63Svk199839 if ((*p == WILL) || (*p == WONT)) 75403100a63Svk199839 obuf[1] = DONT; 75503100a63Svk199839 if ((*p == DO) || (*p == DONT)) 75603100a63Svk199839 obuf[1] = WONT; 75703100a63Svk199839 if (obuf[1]) { 75803100a63Svk199839 p++; 75903100a63Svk199839 obuf[2] = *p; 76003100a63Svk199839 obuf[3] = '\0'; 76103100a63Svk199839 if (atomicio(vwrite, nfd, obuf, 3) != 3) 76203100a63Svk199839 warn("Write Error!"); 76303100a63Svk199839 obuf[0] = '\0'; 76403100a63Svk199839 } 76503100a63Svk199839 } 76603100a63Svk199839 } 76703100a63Svk199839 76803100a63Svk199839 /* 76903100a63Svk199839 * build_ports() 7702eef1f2bSErik Trauschke * Build an array of ports in ports.list[], listing each port 77103100a63Svk199839 * that we should try to connect to. 77203100a63Svk199839 */ 77303100a63Svk199839 void 77403100a63Svk199839 build_ports(char *p) 77503100a63Svk199839 { 77603100a63Svk199839 const char *errstr; 7772eef1f2bSErik Trauschke const char *token; 77803100a63Svk199839 char *n; 7792eef1f2bSErik Trauschke int lo, hi, cp; 7802eef1f2bSErik Trauschke int i; 78103100a63Svk199839 7822eef1f2bSErik Trauschke /* Set up initial portlist. */ 7832eef1f2bSErik Trauschke ports.list = malloc(PLIST_SZ * sizeof (uint16_t)); 7842eef1f2bSErik Trauschke if (ports.list == NULL) 7852eef1f2bSErik Trauschke err(1, NULL); 7862eef1f2bSErik Trauschke ports.listsize = PLIST_SZ; 7872eef1f2bSErik Trauschke ports.numports = 0; 78803100a63Svk199839 7892eef1f2bSErik Trauschke /* Cycle through list of given ports sep. by "," */ 7902eef1f2bSErik Trauschke while ((token = strsep(&p, ",")) != NULL) { 7912eef1f2bSErik Trauschke if (*token == '\0') 7922eef1f2bSErik Trauschke errx(1, "Invalid port/portlist format: " 7932eef1f2bSErik Trauschke "zero length port"); 79403100a63Svk199839 7952eef1f2bSErik Trauschke /* check if it is a range */ 7962eef1f2bSErik Trauschke if ((n = strchr(token, '-')) != NULL) 7972eef1f2bSErik Trauschke *n++ = '\0'; 7982eef1f2bSErik Trauschke 7992eef1f2bSErik Trauschke lo = strtonum(token, PORT_MIN, PORT_MAX, &errstr); 8002eef1f2bSErik Trauschke if (errstr) 8012eef1f2bSErik Trauschke errx(1, "port number %s: %s", errstr, token); 8022eef1f2bSErik Trauschke 8032eef1f2bSErik Trauschke if (n == NULL) { 8042eef1f2bSErik Trauschke hi = lo; 8052eef1f2bSErik Trauschke } else { 80603100a63Svk199839 hi = strtonum(n, PORT_MIN, PORT_MAX, &errstr); 80703100a63Svk199839 if (errstr) 80803100a63Svk199839 errx(1, "port number %s: %s", errstr, n); 80903100a63Svk199839 if (lo > hi) { 81003100a63Svk199839 cp = hi; 81103100a63Svk199839 hi = lo; 81203100a63Svk199839 lo = cp; 81303100a63Svk199839 } 8142eef1f2bSErik Trauschke } 8152eef1f2bSErik Trauschke 8162eef1f2bSErik Trauschke /* 8172eef1f2bSErik Trauschke * Grow the portlist if needed. 8182eef1f2bSErik Trauschke * We double the size and add size of current range 8192eef1f2bSErik Trauschke * to make sure we don't have to resize that often. 8202eef1f2bSErik Trauschke */ 8212eef1f2bSErik Trauschke if (hi - lo + ports.numports + 1 >= ports.listsize) { 8222eef1f2bSErik Trauschke ports.listsize = ports.listsize * 2 + hi - lo; 8232eef1f2bSErik Trauschke ports.list = realloc(ports.list, 8242eef1f2bSErik Trauschke ports.listsize * sizeof (uint16_t)); 8252eef1f2bSErik Trauschke if (ports.list == NULL) 8262eef1f2bSErik Trauschke err(1, NULL); 8272eef1f2bSErik Trauschke } 82803100a63Svk199839 82903100a63Svk199839 /* Load ports sequentially. */ 8302eef1f2bSErik Trauschke for (i = lo; i <= hi; i++) 8312eef1f2bSErik Trauschke ports.list[ports.numports++] = i; 83203100a63Svk199839 } 83303100a63Svk199839 83403100a63Svk199839 /* Randomly swap ports. */ 83503100a63Svk199839 if (rflag) { 83603100a63Svk199839 int y; 8372eef1f2bSErik Trauschke uint16_t u; 83803100a63Svk199839 8392eef1f2bSErik Trauschke if (ports.numports < 2) { 8402eef1f2bSErik Trauschke warnx("can not swap %d port randomly", 8412eef1f2bSErik Trauschke ports.numports); 8422eef1f2bSErik Trauschke return; 84303100a63Svk199839 } 8442eef1f2bSErik Trauschke srandom(time(NULL)); 8452eef1f2bSErik Trauschke for (i = 0; i < ports.numports; i++) { 8462eef1f2bSErik Trauschke y = random() % (ports.numports - 1); 8472eef1f2bSErik Trauschke u = ports.list[i]; 8482eef1f2bSErik Trauschke ports.list[i] = ports.list[y]; 8492eef1f2bSErik Trauschke ports.list[y] = u; 85003100a63Svk199839 } 85103100a63Svk199839 } 85203100a63Svk199839 } 85303100a63Svk199839 85403100a63Svk199839 /* 85503100a63Svk199839 * udptest() 85603100a63Svk199839 * Do a few writes to see if the UDP port is there. 85703100a63Svk199839 * XXX - Better way of doing this? Doesn't work for IPv6. 85803100a63Svk199839 * Also fails after around 100 ports checked. 85903100a63Svk199839 */ 86003100a63Svk199839 int 86103100a63Svk199839 udptest(int s) 86203100a63Svk199839 { 86303100a63Svk199839 int i, ret; 86403100a63Svk199839 86503100a63Svk199839 for (i = 0; i <= 3; i++) { 86603100a63Svk199839 if (write(s, "X", 1) == 1) 86703100a63Svk199839 ret = 1; 86803100a63Svk199839 else 86903100a63Svk199839 ret = -1; 87003100a63Svk199839 } 87103100a63Svk199839 return (ret); 87203100a63Svk199839 } 87303100a63Svk199839 87403100a63Svk199839 void 87503100a63Svk199839 set_common_sockopts(int s) 87603100a63Svk199839 { 87703100a63Svk199839 int x = 1; 87803100a63Svk199839 87903100a63Svk199839 if (Dflag) { 88003100a63Svk199839 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, &x, sizeof (x)) == -1) 88103100a63Svk199839 err(1, NULL); 88203100a63Svk199839 } 88303100a63Svk199839 if (Tflag != -1) { 88403100a63Svk199839 if (setsockopt(s, IPPROTO_IP, IP_TOS, &Tflag, 88503100a63Svk199839 sizeof (Tflag)) == -1) 88603100a63Svk199839 err(1, "set IP ToS"); 88703100a63Svk199839 } 88803100a63Svk199839 } 88903100a63Svk199839 89003100a63Svk199839 int 89103100a63Svk199839 parse_iptos(char *s) 89203100a63Svk199839 { 89303100a63Svk199839 int tos = -1; 89403100a63Svk199839 89503100a63Svk199839 if (strcmp(s, "lowdelay") == 0) 89603100a63Svk199839 return (IPTOS_LOWDELAY); 89703100a63Svk199839 if (strcmp(s, "throughput") == 0) 89803100a63Svk199839 return (IPTOS_THROUGHPUT); 89903100a63Svk199839 if (strcmp(s, "reliability") == 0) 90003100a63Svk199839 return (IPTOS_RELIABILITY); 90103100a63Svk199839 90203100a63Svk199839 if (sscanf(s, "0x%x", (unsigned int *) &tos) != 1 || 90303100a63Svk199839 tos < 0 || tos > 0xff) 90403100a63Svk199839 errx(1, "invalid IP Type of Service"); 90503100a63Svk199839 return (tos); 90603100a63Svk199839 } 90703100a63Svk199839 90803100a63Svk199839 void 90903100a63Svk199839 help(void) 91003100a63Svk199839 { 91103100a63Svk199839 usage(0); 91203100a63Svk199839 (void) fprintf(stderr, "\tCommand Summary:\n\ 91303100a63Svk199839 \t-4 Use IPv4\n\ 91403100a63Svk199839 \t-6 Use IPv6\n\ 91503100a63Svk199839 \t-D Enable the debug socket option\n\ 91603100a63Svk199839 \t-d Detach from stdin\n\ 91703100a63Svk199839 \t-h This help text\n\ 91803100a63Svk199839 \t-i secs\t Delay interval for lines sent, ports scanned\n\ 91903100a63Svk199839 \t-k Keep inbound sockets open for multiple connects\n\ 92003100a63Svk199839 \t-l Listen mode, for inbound connects\n\ 92103100a63Svk199839 \t-n Suppress name/port resolutions\n\ 92203100a63Svk199839 \t-P proxyuser\tUsername for proxy authentication\n\ 92303100a63Svk199839 \t-p port\t Specify local port or listen port\n\ 92403100a63Svk199839 \t-r Randomize remote ports\n\ 92503100a63Svk199839 \t-s addr\t Local source address\n\ 92603100a63Svk199839 \t-T ToS\t Set IP Type of Service\n\ 92703100a63Svk199839 \t-t Answer TELNET negotiation\n\ 92803100a63Svk199839 \t-U Use UNIX domain socket\n\ 92903100a63Svk199839 \t-u UDP mode\n\ 93003100a63Svk199839 \t-v Verbose\n\ 93103100a63Svk199839 \t-w secs\t Timeout for connects and final net reads\n\ 93203100a63Svk199839 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 93303100a63Svk199839 \t-x addr[:port]\tSpecify proxy address and port\n\ 93403100a63Svk199839 \t-z Zero-I/O mode [used for scanning]\n\ 9352eef1f2bSErik Trauschke Port numbers can be individuals, ranges (lo-hi; inclusive) and\n\ 9362eef1f2bSErik Trauschke combinations of both separated by comma (e.g. 10,22-25,80)\n"); 93703100a63Svk199839 exit(1); 93803100a63Svk199839 } 93903100a63Svk199839 94003100a63Svk199839 void 94103100a63Svk199839 usage(int ret) 94203100a63Svk199839 { 94303100a63Svk199839 (void) fprintf(stderr, 94403100a63Svk199839 "usage: nc [-46DdhklnrtUuvz] [-i interval] [-P proxy_username]" 94503100a63Svk199839 " [-p port]\n"); 94603100a63Svk199839 (void) fprintf(stderr, 94703100a63Svk199839 "\t [-s source_ip_address] [-T ToS] [-w timeout]" 94803100a63Svk199839 " [-X proxy_protocol]\n"); 94903100a63Svk199839 (void) fprintf(stderr, 95003100a63Svk199839 "\t [-x proxy_address[:port]] [hostname]" 95103100a63Svk199839 " [port[s]]\n"); 95203100a63Svk199839 if (ret) 95303100a63Svk199839 exit(1); 95403100a63Svk199839 } 955