1 /* $OpenBSD: netcat.c,v 1.130 2015/07/26 19:12:28 chl Exp $ */
2 /*
3 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org>
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31 /*
32 * Re-written nc(1) for OpenBSD. Original implementation by
33 * *Hobbit* <hobbit@avian.org>.
34 */
35
36 #include <errno.h>
37 #include <stdio.h>
38 #include <sys/arb.h>
39 #include <sys/limits.h>
40 #include <sys/types.h>
41 #include <sys/sbuf.h>
42 #include <sys/socket.h>
43 #include <sys/sysctl.h>
44 #include <sys/qmath.h>
45 #include <sys/stats.h>
46 #include <sys/time.h>
47 #include <sys/uio.h>
48 #include <sys/un.h>
49
50 #include <netinet/in.h>
51 #ifdef IPSEC
52 #include <netipsec/ipsec.h>
53 #endif
54 #include <netinet/tcp.h>
55 #include <netinet/ip.h>
56 #include <arpa/telnet.h>
57
58 #include <err.h>
59 #include <getopt.h>
60 #include <fcntl.h>
61 #include <limits.h>
62 #include <netdb.h>
63 #include <poll.h>
64 #include <signal.h>
65 #include <stdarg.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <unistd.h>
69 #include "atomicio.h"
70
71 #ifndef SUN_LEN
72 #define SUN_LEN(su) \
73 (sizeof(*(su)) - sizeof((su)->sun_path) + strlen((su)->sun_path))
74 #endif
75
76 #define PORT_MAX 65535
77 #define PORT_MAX_LEN 6
78 #define UNIX_DG_TMP_SOCKET_SIZE 19
79
80 #define POLL_STDIN 0
81 #define POLL_NETOUT 1
82 #define POLL_NETIN 2
83 #define POLL_STDOUT 3
84 #define BUFSIZE 16384
85
86 /* Command Line Options */
87 int dflag; /* detached, no stdin */
88 int Fflag; /* fdpass sock to stdout */
89 unsigned int iflag; /* Interval Flag */
90 int kflag; /* More than one connect */
91 int lflag; /* Bind to local port */
92 int FreeBSD_Mflag; /* Measure using stats(3) */
93 int Nflag; /* shutdown() network socket */
94 int nflag; /* Don't do name look up */
95 int FreeBSD_Oflag; /* Do not use TCP options */
96 int FreeBSD_sctp; /* Use SCTP */
97 int FreeBSD_crlf; /* Convert LF to CRLF */
98 char *Pflag; /* Proxy username */
99 char *pflag; /* Localport flag */
100 int rflag; /* Random ports flag */
101 char *sflag; /* Source Address */
102 int tflag; /* Telnet Emulation */
103 int uflag; /* UDP - Default to TCP */
104 int vflag; /* Verbosity */
105 int xflag; /* Socks proxy */
106 int zflag; /* Port Scan Flag */
107 int Dflag; /* sodebug */
108 int Iflag; /* TCP receive buffer size */
109 int Oflag; /* TCP send buffer size */
110 int Sflag; /* TCP MD5 signature option */
111 int Tflag = -1; /* IP Type of Service */
112 int rtableid = -1;
113
114 int timeout = -1;
115 int family = AF_UNSPEC;
116 int tun_fd = -1;
117 char *portlist[PORT_MAX+1];
118 char *unix_dg_tmp_socket;
119
120 void atelnet(int, unsigned char *, unsigned int);
121 void build_ports(char *);
122 void help(void);
123 int local_listen(char *, char *, struct addrinfo);
124 void readwrite(int);
125 void fdpass(int nfd) __attribute__((noreturn));
126 int remote_connect(const char *, const char *, struct addrinfo);
127 int timeout_connect(int, const struct sockaddr *, socklen_t);
128 int socks_connect(const char *, const char *, struct addrinfo,
129 const char *, const char *, struct addrinfo, int, const char *);
130 int udptest(int);
131 int unix_bind(char *);
132 int unix_connect(char *);
133 int unix_listen(char *);
134 void FreeBSD_stats_setup(int);
135 void FreeBSD_stats_print(int);
136 void set_common_sockopts(int, int);
137 int map_tos(char *, int *);
138 void report_connect(const struct sockaddr *, socklen_t);
139 void usage(int);
140 ssize_t write_wrapper(int, const void *, size_t);
141 ssize_t drainbuf(int, unsigned char *, size_t *, int);
142 ssize_t fillbuf(int, unsigned char *, size_t *);
143
144 #ifdef IPSEC
145 void add_ipsec_policy(int, int, char *);
146
147 char *ipsec_policy[2];
148 #endif
149
150 enum {
151 FREEBSD_TUN = CHAR_MAX, /* avoid collision with return values from getopt */
152 };
153
154 int
main(int argc,char * argv[])155 main(int argc, char *argv[])
156 {
157 int ch, s, ret, socksv, ipsec_count;
158 int numfibs;
159 size_t intsize = sizeof(int);
160 char *host, *uport;
161 struct addrinfo hints;
162 struct servent *sv;
163 socklen_t len;
164 struct sockaddr_storage cliaddr;
165 char *proxy;
166 const char *errstr, *proxyhost = "", *proxyport = NULL, *tundev = NULL;
167 struct addrinfo proxyhints;
168 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE];
169 struct option longopts[] = {
170 { "crlf", no_argument, &FreeBSD_crlf, 1 },
171 { "no-tcpopt", no_argument, &FreeBSD_Oflag, 1 },
172 { "sctp", no_argument, &FreeBSD_sctp, 1 },
173 { "tun", required_argument, NULL, FREEBSD_TUN },
174 { NULL, 0, NULL, 0 }
175 };
176
177 ret = 1;
178 ipsec_count = 0;
179 s = 0;
180 socksv = 5;
181 host = NULL;
182 uport = NULL;
183 sv = NULL;
184
185 signal(SIGPIPE, SIG_IGN);
186
187 while ((ch = getopt_long(argc, argv,
188 "46DdEe:FhI:i:klMNnoO:P:p:rSs:tT:UuV:vw:X:x:z",
189 longopts, NULL)) != -1) {
190 switch (ch) {
191 case '4':
192 family = AF_INET;
193 break;
194 case '6':
195 family = AF_INET6;
196 break;
197 case 'U':
198 family = AF_UNIX;
199 break;
200 case 'X':
201 if (strcasecmp(optarg, "connect") == 0)
202 socksv = -1; /* HTTP proxy CONNECT */
203 else if (strcmp(optarg, "4") == 0)
204 socksv = 4; /* SOCKS v.4 */
205 else if (strcmp(optarg, "5") == 0)
206 socksv = 5; /* SOCKS v.5 */
207 else
208 errx(1, "unsupported proxy protocol");
209 break;
210 case 'd':
211 dflag = 1;
212 break;
213 case 'e':
214 #ifdef IPSEC
215 ipsec_policy[ipsec_count++ % 2] = optarg;
216 #else
217 errx(1, "IPsec support unavailable.");
218 #endif
219 break;
220 case 'E':
221 #ifdef IPSEC
222 ipsec_policy[0] = "in ipsec esp/transport//require";
223 ipsec_policy[1] = "out ipsec esp/transport//require";
224 #else
225 errx(1, "IPsec support unavailable.");
226 #endif
227 break;
228 case 'F':
229 Fflag = 1;
230 break;
231 case 'h':
232 help();
233 break;
234 case 'i':
235 iflag = strtonum(optarg, 0, UINT_MAX, &errstr);
236 if (errstr)
237 errx(1, "interval %s: %s", errstr, optarg);
238 break;
239 case 'k':
240 kflag = 1;
241 break;
242 case 'l':
243 lflag = 1;
244 break;
245 case 'M':
246 #ifndef WITH_STATS
247 errx(1, "-M requires stats(3) support");
248 #else
249 FreeBSD_Mflag = 1;
250 #endif
251 break;
252 case 'N':
253 Nflag = 1;
254 break;
255 case 'n':
256 nflag = 1;
257 break;
258 case 'o':
259 fprintf(stderr, "option -o is deprecated.\n");
260 break;
261 case 'P':
262 Pflag = optarg;
263 break;
264 case 'p':
265 pflag = optarg;
266 break;
267 case 'r':
268 rflag = 1;
269 break;
270 case 's':
271 sflag = optarg;
272 break;
273 case 't':
274 tflag = 1;
275 break;
276 case 'u':
277 uflag = 1;
278 break;
279 case 'V':
280 if (sysctlbyname("net.fibs", &numfibs, &intsize, NULL, 0) == -1)
281 errx(1, "Multiple FIBS not supported");
282 rtableid = (int)strtonum(optarg, 0,
283 numfibs - 1, &errstr);
284 if (errstr)
285 errx(1, "rtable %s: %s", errstr, optarg);
286 break;
287 case 'v':
288 vflag = 1;
289 break;
290 case 'w':
291 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr);
292 if (errstr)
293 errx(1, "timeout %s: %s", errstr, optarg);
294 timeout *= 1000;
295 break;
296 case 'x':
297 xflag = 1;
298 if ((proxy = strdup(optarg)) == NULL)
299 err(1, NULL);
300 break;
301 case 'z':
302 zflag = 1;
303 break;
304 case 'D':
305 Dflag = 1;
306 break;
307 case 'I':
308 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr);
309 if (errstr != NULL)
310 errx(1, "TCP receive window %s: %s",
311 errstr, optarg);
312 break;
313 case 'O':
314 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr);
315 if (errstr != NULL) {
316 if (strcmp(errstr, "invalid") != 0)
317 errx(1, "TCP send window %s: %s",
318 errstr, optarg);
319 }
320 break;
321 case 'S':
322 Sflag = 1;
323 break;
324 case 'T':
325 errstr = NULL;
326 errno = 0;
327 if (map_tos(optarg, &Tflag))
328 break;
329 if (strlen(optarg) > 1 && optarg[0] == '0' &&
330 optarg[1] == 'x')
331 Tflag = (int)strtol(optarg, NULL, 16);
332 else
333 Tflag = (int)strtonum(optarg, 0, 255,
334 &errstr);
335 if (Tflag < 0 || Tflag > 255 || errstr || errno)
336 errx(1, "illegal tos value %s", optarg);
337 break;
338 case FREEBSD_TUN:
339 tundev = optarg;
340 break;
341 case 0:
342 /* Long option. */
343 break;
344 default:
345 usage(1);
346 }
347 }
348 argc -= optind;
349 argv += optind;
350
351 /* Cruft to make sure options are clean, and used properly. */
352 if (argv[0] && !argv[1] && family == AF_UNIX) {
353 host = argv[0];
354 uport = NULL;
355 } else if (argv[0] && !argv[1]) {
356 if (!lflag)
357 usage(1);
358 uport = argv[0];
359 host = NULL;
360 } else if (argv[0] && argv[1]) {
361 host = argv[0];
362 uport = argv[1];
363 } else
364 usage(1);
365
366 if (lflag && sflag)
367 errx(1, "cannot use -s and -l");
368 if (lflag && pflag)
369 errx(1, "cannot use -p and -l");
370 if (lflag && zflag)
371 errx(1, "cannot use -z and -l");
372 if (!lflag && kflag)
373 errx(1, "must use -l with -k");
374 if (FreeBSD_sctp) {
375 if (uflag)
376 errx(1, "cannot use -u and --sctp");
377 if (family == AF_UNIX)
378 errx(1, "cannot use -U and --sctp");
379 }
380 if (tundev != NULL) {
381 if (!uflag)
382 errx(1, "must use --tun with -u");
383 tun_fd = open(tundev, O_RDWR);
384 if (tun_fd == -1)
385 errx(1, "unable to open tun device %s", tundev);
386 }
387
388 /* Get name of temporary socket for unix datagram client */
389 if ((family == AF_UNIX) && uflag && !lflag) {
390 if (sflag) {
391 unix_dg_tmp_socket = sflag;
392 } else {
393 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX",
394 UNIX_DG_TMP_SOCKET_SIZE);
395 if (mktemp(unix_dg_tmp_socket_buf) == NULL)
396 err(1, "mktemp");
397 unix_dg_tmp_socket = unix_dg_tmp_socket_buf;
398 }
399 }
400
401 /* Initialize addrinfo structure. */
402 if (family != AF_UNIX) {
403 memset(&hints, 0, sizeof(struct addrinfo));
404 hints.ai_family = family;
405 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM;
406 hints.ai_protocol = uflag ? IPPROTO_UDP :
407 FreeBSD_sctp ? IPPROTO_SCTP : IPPROTO_TCP;
408 if (nflag)
409 hints.ai_flags |= AI_NUMERICHOST;
410 }
411
412 if (xflag) {
413 if (uflag)
414 errx(1, "no proxy support for UDP mode");
415
416 if (FreeBSD_sctp)
417 errx(1, "no proxy support for SCTP mode");
418
419 if (lflag)
420 errx(1, "no proxy support for listen");
421
422 if (family == AF_UNIX)
423 errx(1, "no proxy support for unix sockets");
424
425 /* XXX IPv6 transport to proxy would probably work */
426 if (family == AF_INET6)
427 errx(1, "no proxy support for IPv6");
428
429 if (sflag)
430 errx(1, "no proxy support for local source address");
431
432 proxyhost = strsep(&proxy, ":");
433 proxyport = proxy;
434
435 memset(&proxyhints, 0, sizeof(struct addrinfo));
436 proxyhints.ai_family = family;
437 proxyhints.ai_socktype = SOCK_STREAM;
438 proxyhints.ai_protocol = IPPROTO_TCP;
439 if (nflag)
440 proxyhints.ai_flags |= AI_NUMERICHOST;
441 }
442
443 if (lflag) {
444 int connfd;
445 ret = 0;
446
447 if (family == AF_UNIX) {
448 if (uflag)
449 s = unix_bind(host);
450 else
451 s = unix_listen(host);
452 }
453
454 /* Allow only one connection at a time, but stay alive. */
455 for (;;) {
456 if (family != AF_UNIX)
457 s = local_listen(host, uport, hints);
458 if (s < 0)
459 err(1, NULL);
460 /*
461 * For UDP and -k, don't connect the socket, let it
462 * receive datagrams from multiple socket pairs.
463 */
464 if (uflag && kflag)
465 readwrite(s);
466 /*
467 * For UDP and not -k, we will use recvfrom() initially
468 * to wait for a caller, then use the regular functions
469 * to talk to the caller.
470 */
471 else if (uflag && !kflag) {
472 int rv, plen;
473 char buf[16384];
474 struct sockaddr_storage z;
475
476 len = sizeof(z);
477 plen = 2048;
478 rv = recvfrom(s, buf, plen, MSG_PEEK,
479 (struct sockaddr *)&z, &len);
480 if (rv < 0)
481 err(1, "recvfrom");
482
483 rv = connect(s, (struct sockaddr *)&z, len);
484 if (rv < 0)
485 err(1, "connect");
486
487 if (vflag)
488 report_connect((struct sockaddr *)&z, len);
489
490 readwrite(s);
491 } else {
492 len = sizeof(cliaddr);
493 connfd = accept(s, (struct sockaddr *)&cliaddr,
494 &len);
495 if (connfd == -1) {
496 /* For now, all errnos are fatal */
497 err(1, "accept");
498 }
499 if (vflag)
500 report_connect((struct sockaddr *)&cliaddr, len);
501
502 if (FreeBSD_Mflag)
503 FreeBSD_stats_setup(connfd);
504 readwrite(connfd);
505 close(connfd);
506 }
507
508 if (family != AF_UNIX)
509 close(s);
510 else if (uflag) {
511 if (connect(s, NULL, 0) < 0)
512 err(1, "connect");
513 }
514
515 if (!kflag)
516 break;
517 }
518 } else if (family == AF_UNIX) {
519 ret = 0;
520
521 if ((s = unix_connect(host)) > 0 && !zflag) {
522 readwrite(s);
523 close(s);
524 } else
525 ret = 1;
526
527 if (uflag)
528 unlink(unix_dg_tmp_socket);
529 exit(ret);
530
531 } else {
532 int i = 0;
533
534 /* Construct the portlist[] array. */
535 build_ports(uport);
536
537 /* Cycle through portlist, connecting to each port. */
538 for (i = 0; portlist[i] != NULL; i++) {
539 if (s)
540 close(s);
541
542 if (xflag)
543 s = socks_connect(host, portlist[i], hints,
544 proxyhost, proxyport, proxyhints, socksv,
545 Pflag);
546 else
547 s = remote_connect(host, portlist[i], hints);
548
549 if (s < 0)
550 continue;
551
552 ret = 0;
553 if (vflag || zflag) {
554 /* For UDP, make sure we are connected. */
555 if (uflag) {
556 if (udptest(s) == -1) {
557 ret = 1;
558 continue;
559 }
560 }
561
562 /* Don't look up port if -n. */
563 if (nflag)
564 sv = NULL;
565 else {
566 sv = getservbyport(
567 ntohs(atoi(portlist[i])),
568 uflag ? "udp" : "tcp");
569 }
570
571 fprintf(stderr,
572 "Connection to %s %s port [%s/%s] "
573 "succeeded!\n", host, portlist[i],
574 uflag ? "udp" : "tcp",
575 sv ? sv->s_name : "*");
576 }
577 if (Fflag)
578 fdpass(s);
579 else if (!zflag)
580 readwrite(s);
581 }
582 }
583
584 if (s)
585 close(s);
586 if (tun_fd != -1)
587 close(tun_fd);
588
589 exit(ret);
590 }
591
592 /*
593 * unix_bind()
594 * Returns a unix socket bound to the given path
595 */
596 int
unix_bind(char * path)597 unix_bind(char *path)
598 {
599 struct sockaddr_un sun;
600 int s;
601
602 /* Create unix domain socket. */
603 if ((s = socket(AF_UNIX, uflag ? SOCK_DGRAM : SOCK_STREAM,
604 0)) < 0)
605 return (-1);
606
607 memset(&sun, 0, sizeof(struct sockaddr_un));
608 sun.sun_family = AF_UNIX;
609
610 if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >=
611 sizeof(sun.sun_path)) {
612 close(s);
613 errno = ENAMETOOLONG;
614 return (-1);
615 }
616
617 if (bind(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) {
618 close(s);
619 return (-1);
620 }
621 return (s);
622 }
623
624 /*
625 * unix_connect()
626 * Returns a socket connected to a local unix socket. Returns -1 on failure.
627 */
628 int
unix_connect(char * path)629 unix_connect(char *path)
630 {
631 struct sockaddr_un sun;
632 int s;
633
634 if (uflag) {
635 if ((s = unix_bind(unix_dg_tmp_socket)) < 0)
636 return (-1);
637 } else {
638 if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
639 return (-1);
640 }
641 (void)fcntl(s, F_SETFD, FD_CLOEXEC);
642
643 memset(&sun, 0, sizeof(struct sockaddr_un));
644 sun.sun_family = AF_UNIX;
645
646 if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >=
647 sizeof(sun.sun_path)) {
648 close(s);
649 errno = ENAMETOOLONG;
650 return (-1);
651 }
652 if (connect(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) {
653 close(s);
654 return (-1);
655 }
656 return (s);
657
658 }
659
660 /*
661 * unix_listen()
662 * Create a unix domain socket, and listen on it.
663 */
664 int
unix_listen(char * path)665 unix_listen(char *path)
666 {
667 int s;
668 if ((s = unix_bind(path)) < 0)
669 return (-1);
670
671 if (listen(s, 5) < 0) {
672 close(s);
673 return (-1);
674 }
675 return (s);
676 }
677
678 /*
679 * remote_connect()
680 * Returns a socket connected to a remote host. Properly binds to a local
681 * port or source address if needed. Returns -1 on failure.
682 */
683 int
remote_connect(const char * host,const char * port,struct addrinfo hints)684 remote_connect(const char *host, const char *port, struct addrinfo hints)
685 {
686 struct addrinfo *res, *res0;
687 int s, error, on = 1;
688
689 if ((error = getaddrinfo(host, port, &hints, &res)))
690 errx(1, "getaddrinfo: %s", gai_strerror(error));
691
692 res0 = res;
693 do {
694 if ((s = socket(res0->ai_family, res0->ai_socktype,
695 res0->ai_protocol)) < 0)
696 continue;
697
698 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_SETFIB,
699 &rtableid, sizeof(rtableid)) == -1))
700 err(1, "setsockopt SO_SETFIB");
701
702 /* Bind to a local port or source address if specified. */
703 if (sflag || pflag) {
704 struct addrinfo ahints, *ares;
705
706 /* try IP_BINDANY, but don't insist */
707 setsockopt(s, IPPROTO_IP, IP_BINDANY, &on, sizeof(on));
708 memset(&ahints, 0, sizeof(struct addrinfo));
709 ahints.ai_family = res0->ai_family;
710 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM;
711 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP;
712 ahints.ai_flags = AI_PASSIVE;
713 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares)))
714 errx(1, "getaddrinfo: %s", gai_strerror(error));
715
716 if (bind(s, (struct sockaddr *)ares->ai_addr,
717 ares->ai_addrlen) < 0)
718 err(1, "bind failed");
719 freeaddrinfo(ares);
720 }
721
722 set_common_sockopts(s, res0->ai_family);
723
724 if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0)
725 break;
726 else if (vflag)
727 warn("connect to %s port %s (%s) failed", host, port,
728 uflag ? "udp" : "tcp");
729
730 close(s);
731 s = -1;
732 } while ((res0 = res0->ai_next) != NULL);
733
734 freeaddrinfo(res);
735
736 return (s);
737 }
738
739 int
timeout_connect(int s,const struct sockaddr * name,socklen_t namelen)740 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen)
741 {
742 struct pollfd pfd;
743 socklen_t optlen;
744 int flags, optval;
745 int ret;
746
747 if (timeout != -1) {
748 flags = fcntl(s, F_GETFL, 0);
749 if (fcntl(s, F_SETFL, flags | O_NONBLOCK) == -1)
750 err(1, "set non-blocking mode");
751 }
752
753 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) {
754 pfd.fd = s;
755 pfd.events = POLLOUT;
756 if ((ret = poll(&pfd, 1, timeout)) == 1) {
757 optlen = sizeof(optval);
758 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR,
759 &optval, &optlen)) == 0) {
760 errno = optval;
761 ret = optval == 0 ? 0 : -1;
762 }
763 } else if (ret == 0) {
764 errno = ETIMEDOUT;
765 ret = -1;
766 } else
767 err(1, "poll failed");
768 }
769
770 if (timeout != -1 && fcntl(s, F_SETFL, flags) == -1)
771 err(1, "restoring flags");
772
773 return (ret);
774 }
775
776 /*
777 * local_listen()
778 * Returns a socket listening on a local port, binds to specified source
779 * address. Returns -1 on failure.
780 */
781 int
local_listen(char * host,char * port,struct addrinfo hints)782 local_listen(char *host, char *port, struct addrinfo hints)
783 {
784 struct addrinfo *res, *res0;
785 int s, ret, x = 1;
786 int error;
787
788 /* Allow nodename to be null. */
789 hints.ai_flags |= AI_PASSIVE;
790
791 /*
792 * In the case of binding to a wildcard address
793 * default to binding to an ipv4 address.
794 */
795 if (host == NULL && hints.ai_family == AF_UNSPEC)
796 hints.ai_family = AF_INET;
797
798 if ((error = getaddrinfo(host, port, &hints, &res)))
799 errx(1, "getaddrinfo: %s", gai_strerror(error));
800
801 res0 = res;
802 do {
803 if ((s = socket(res0->ai_family, res0->ai_socktype,
804 res0->ai_protocol)) < 0)
805 continue;
806
807 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_SETFIB,
808 &rtableid, sizeof(rtableid)) == -1))
809 err(1, "setsockopt SO_SETFIB");
810
811 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x));
812 if (ret == -1)
813 err(1, NULL);
814
815 if (FreeBSD_Oflag) {
816 if (setsockopt(s, IPPROTO_TCP, TCP_NOOPT,
817 &FreeBSD_Oflag, sizeof(FreeBSD_Oflag)) == -1)
818 err(1, "disable TCP options");
819 }
820
821 set_common_sockopts(s, res0->ai_family);
822
823 if (bind(s, (struct sockaddr *)res0->ai_addr,
824 res0->ai_addrlen) == 0)
825 break;
826
827 close(s);
828 s = -1;
829 } while ((res0 = res0->ai_next) != NULL);
830
831 if (!uflag && s != -1) {
832 if (listen(s, 1) < 0)
833 err(1, "listen");
834 }
835
836 freeaddrinfo(res);
837
838 return (s);
839 }
840
841 /*
842 * readwrite()
843 * Loop that polls on the network file descriptor and stdin.
844 */
845 void
readwrite(int net_fd)846 readwrite(int net_fd)
847 {
848 struct pollfd pfd[4];
849 int stdin_fd = STDIN_FILENO;
850 int stdout_fd = STDOUT_FILENO;
851 unsigned char netinbuf[BUFSIZE];
852 size_t netinbufpos = 0;
853 unsigned char stdinbuf[BUFSIZE];
854 size_t stdinbufpos = 0;
855 int n, num_fds;
856 int stats_printed = 0;
857 ssize_t ret;
858
859 /* don't read from stdin if requested */
860 if (dflag)
861 stdin_fd = -1;
862
863 /* stdin */
864 pfd[POLL_STDIN].fd = (tun_fd != -1) ? tun_fd : stdin_fd;
865 pfd[POLL_STDIN].events = POLLIN;
866
867 /* network out */
868 pfd[POLL_NETOUT].fd = net_fd;
869 pfd[POLL_NETOUT].events = 0;
870
871 /* network in */
872 pfd[POLL_NETIN].fd = net_fd;
873 pfd[POLL_NETIN].events = POLLIN;
874
875 /* stdout */
876 pfd[POLL_STDOUT].fd = (tun_fd != -1) ? tun_fd : stdout_fd;
877 pfd[POLL_STDOUT].events = 0;
878
879 while (1) {
880 /* both inputs are gone, buffers are empty, we are done */
881 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1
882 && stdinbufpos == 0 && netinbufpos == 0) {
883 if (FreeBSD_Mflag && !stats_printed)
884 FreeBSD_stats_print(net_fd);
885 close(net_fd);
886 return;
887 }
888 /* both outputs are gone, we can't continue */
889 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) {
890 if (FreeBSD_Mflag && !stats_printed)
891 FreeBSD_stats_print(net_fd);
892 close(net_fd);
893 return;
894 }
895 /* listen and net in gone, queues empty, done */
896 if (lflag && pfd[POLL_NETIN].fd == -1
897 && stdinbufpos == 0 && netinbufpos == 0) {
898 if (FreeBSD_Mflag && !stats_printed)
899 FreeBSD_stats_print(net_fd);
900 close(net_fd);
901 return;
902 }
903
904 /* help says -i is for "wait between lines sent". We read and
905 * write arbitrary amounts of data, and we don't want to start
906 * scanning for newlines, so this is as good as it gets */
907 if (iflag)
908 sleep(iflag);
909
910 /* poll */
911 num_fds = poll(pfd, 4, timeout);
912
913 /* treat poll errors */
914 if (num_fds == -1) {
915 close(net_fd);
916 err(1, "polling error");
917 }
918
919 /* timeout happened */
920 if (num_fds == 0) {
921 if (FreeBSD_Mflag)
922 FreeBSD_stats_print(net_fd);
923 return;
924 }
925
926 /* treat socket error conditions */
927 for (n = 0; n < 4; n++) {
928 if (pfd[n].revents & (POLLERR|POLLNVAL)) {
929 pfd[n].fd = -1;
930 }
931 }
932 /* reading is possible after HUP */
933 if (pfd[POLL_STDIN].events & POLLIN &&
934 pfd[POLL_STDIN].revents & POLLHUP &&
935 ! (pfd[POLL_STDIN].revents & POLLIN))
936 pfd[POLL_STDIN].fd = -1;
937
938 if (pfd[POLL_NETIN].events & POLLIN &&
939 pfd[POLL_NETIN].revents & POLLHUP &&
940 ! (pfd[POLL_NETIN].revents & POLLIN))
941 pfd[POLL_NETIN].fd = -1;
942
943 if (pfd[POLL_NETOUT].revents & POLLHUP) {
944 if (Nflag)
945 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR);
946 pfd[POLL_NETOUT].fd = -1;
947 }
948 /* if HUP, stop watching stdout */
949 if (pfd[POLL_STDOUT].revents & POLLHUP)
950 pfd[POLL_STDOUT].fd = -1;
951 /* if no net out, stop watching stdin */
952 if (pfd[POLL_NETOUT].fd == -1)
953 pfd[POLL_STDIN].fd = -1;
954 /* if no stdout, stop watching net in */
955 if (pfd[POLL_STDOUT].fd == -1) {
956 if (pfd[POLL_NETIN].fd != -1)
957 shutdown(pfd[POLL_NETIN].fd, SHUT_RD);
958 pfd[POLL_NETIN].fd = -1;
959 }
960
961 /* try to read from stdin */
962 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) {
963 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf,
964 &stdinbufpos);
965 /* error or eof on stdin - remove from pfd */
966 if (ret == 0 || ret == -1)
967 pfd[POLL_STDIN].fd = -1;
968 /* read something - poll net out */
969 if (stdinbufpos > 0)
970 pfd[POLL_NETOUT].events = POLLOUT;
971 /* filled buffer - remove self from polling */
972 if (stdinbufpos == BUFSIZE)
973 pfd[POLL_STDIN].events = 0;
974 }
975 /* try to write to network */
976 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) {
977 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf,
978 &stdinbufpos, FreeBSD_crlf);
979 if (ret == -1)
980 pfd[POLL_NETOUT].fd = -1;
981 /* buffer empty - remove self from polling */
982 if (stdinbufpos == 0)
983 pfd[POLL_NETOUT].events = 0;
984 /* buffer no longer full - poll stdin again */
985 if (stdinbufpos < BUFSIZE)
986 pfd[POLL_STDIN].events = POLLIN;
987 }
988 /* try to read from network */
989 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) {
990 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf,
991 &netinbufpos);
992 if (ret == -1)
993 pfd[POLL_NETIN].fd = -1;
994 /* eof on net in - remove from pfd */
995 if (ret == 0) {
996 shutdown(pfd[POLL_NETIN].fd, SHUT_RD);
997 pfd[POLL_NETIN].fd = -1;
998 }
999 /* read something - poll stdout */
1000 if (netinbufpos > 0)
1001 pfd[POLL_STDOUT].events = POLLOUT;
1002 /* filled buffer - remove self from polling */
1003 if (netinbufpos == BUFSIZE)
1004 pfd[POLL_NETIN].events = 0;
1005 /* handle telnet */
1006 if (tflag)
1007 atelnet(pfd[POLL_NETIN].fd, netinbuf,
1008 netinbufpos);
1009 }
1010 /* try to write to stdout */
1011 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) {
1012 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf,
1013 &netinbufpos, 0);
1014 if (ret == -1)
1015 pfd[POLL_STDOUT].fd = -1;
1016 /* buffer empty - remove self from polling */
1017 if (netinbufpos == 0)
1018 pfd[POLL_STDOUT].events = 0;
1019 /* buffer no longer full - poll net in again */
1020 if (netinbufpos < BUFSIZE)
1021 pfd[POLL_NETIN].events = POLLIN;
1022 }
1023
1024 /* stdin gone and queue empty? */
1025 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) {
1026 if (pfd[POLL_NETOUT].fd != -1 && Nflag) {
1027 if (FreeBSD_Mflag) {
1028 FreeBSD_stats_print(net_fd);
1029 stats_printed = 1;
1030 }
1031 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR);
1032 }
1033 pfd[POLL_NETOUT].fd = -1;
1034 }
1035 /* net in gone and queue empty? */
1036 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) {
1037 pfd[POLL_STDOUT].fd = -1;
1038 }
1039 }
1040 }
1041
1042 ssize_t
write_wrapper(int fd,const void * buf,size_t buflen)1043 write_wrapper(int fd, const void *buf, size_t buflen)
1044 {
1045 ssize_t n = write(fd, buf, buflen);
1046 /* don't treat EAGAIN, EINTR as error */
1047 return (n == -1 && (errno == EAGAIN || errno == EINTR)) ? -2 : n;
1048 }
1049
1050 ssize_t
drainbuf(int fd,unsigned char * buf,size_t * bufpos,int crlf)1051 drainbuf(int fd, unsigned char *buf, size_t *bufpos, int crlf)
1052 {
1053 ssize_t n = *bufpos, n2 = 0;
1054 ssize_t adjust;
1055 unsigned char *lf = NULL;
1056
1057 if (crlf) {
1058 lf = memchr(buf, '\n', *bufpos);
1059 if (lf && (lf == buf || *(lf - 1) != '\r'))
1060 n = lf - buf;
1061 else
1062 lf = NULL;
1063 }
1064
1065 if (n != 0) {
1066 n = write_wrapper(fd, buf, n);
1067 if (n <= 0)
1068 return n;
1069 }
1070
1071 if (lf) {
1072 n2 = write_wrapper(fd, "\r\n", 2);
1073 if (n2 <= 0)
1074 return n2;
1075 n += 1;
1076 }
1077
1078 /* adjust buffer */
1079 adjust = *bufpos - n;
1080 if (adjust > 0)
1081 memmove(buf, buf + n, adjust);
1082 *bufpos -= n;
1083 return n;
1084 }
1085
1086
1087 ssize_t
fillbuf(int fd,unsigned char * buf,size_t * bufpos)1088 fillbuf(int fd, unsigned char *buf, size_t *bufpos)
1089 {
1090 size_t num = BUFSIZE - *bufpos;
1091 ssize_t n;
1092
1093 n = read(fd, buf + *bufpos, num);
1094 /* don't treat EAGAIN, EINTR as error */
1095 if (n == -1 && (errno == EAGAIN || errno == EINTR))
1096 n = -2;
1097 if (n <= 0)
1098 return n;
1099 *bufpos += n;
1100 return n;
1101 }
1102
1103 /*
1104 * fdpass()
1105 * Pass the connected file descriptor to stdout and exit.
1106 */
1107 void
fdpass(int nfd)1108 fdpass(int nfd)
1109 {
1110 struct msghdr mh;
1111 union {
1112 struct cmsghdr hdr;
1113 char buf[CMSG_SPACE(sizeof(int))];
1114 } cmsgbuf;
1115 struct cmsghdr *cmsg;
1116 struct iovec iov;
1117 char c = '\0';
1118 ssize_t r;
1119 struct pollfd pfd;
1120
1121 /* Avoid obvious stupidity */
1122 if (isatty(STDOUT_FILENO))
1123 errx(1, "Cannot pass file descriptor to tty");
1124
1125 bzero(&mh, sizeof(mh));
1126 bzero(&cmsgbuf, sizeof(cmsgbuf));
1127 bzero(&iov, sizeof(iov));
1128
1129 mh.msg_control = (caddr_t)&cmsgbuf.buf;
1130 mh.msg_controllen = sizeof(cmsgbuf.buf);
1131 cmsg = CMSG_FIRSTHDR(&mh);
1132 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
1133 cmsg->cmsg_level = SOL_SOCKET;
1134 cmsg->cmsg_type = SCM_RIGHTS;
1135 *(int *)CMSG_DATA(cmsg) = nfd;
1136
1137 iov.iov_base = &c;
1138 iov.iov_len = 1;
1139 mh.msg_iov = &iov;
1140 mh.msg_iovlen = 1;
1141
1142 bzero(&pfd, sizeof(pfd));
1143 pfd.fd = STDOUT_FILENO;
1144 pfd.events = POLLOUT;
1145 for (;;) {
1146 r = sendmsg(STDOUT_FILENO, &mh, 0);
1147 if (r == -1) {
1148 if (errno == EAGAIN || errno == EINTR) {
1149 if (poll(&pfd, 1, -1) == -1)
1150 err(1, "poll");
1151 continue;
1152 }
1153 err(1, "sendmsg");
1154 } else if (r != 1)
1155 errx(1, "sendmsg: unexpected return value %zd", r);
1156 else
1157 break;
1158 }
1159 exit(0);
1160 }
1161
1162 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */
1163 void
atelnet(int nfd,unsigned char * buf,unsigned int size)1164 atelnet(int nfd, unsigned char *buf, unsigned int size)
1165 {
1166 unsigned char *p, *end;
1167 unsigned char obuf[4];
1168
1169 if (size < 3)
1170 return;
1171 end = buf + size - 2;
1172
1173 for (p = buf; p < end; p++) {
1174 if (*p != IAC)
1175 continue;
1176
1177 obuf[0] = IAC;
1178 p++;
1179 if ((*p == WILL) || (*p == WONT))
1180 obuf[1] = DONT;
1181 else if ((*p == DO) || (*p == DONT))
1182 obuf[1] = WONT;
1183 else
1184 continue;
1185
1186 p++;
1187 obuf[2] = *p;
1188 if (atomicio(vwrite, nfd, obuf, 3) != 3)
1189 warn("Write Error!");
1190 }
1191 }
1192
1193 /*
1194 * build_ports()
1195 * Build an array of ports in portlist[], listing each port
1196 * that we should try to connect to.
1197 */
1198 void
build_ports(char * p)1199 build_ports(char *p)
1200 {
1201 const char *errstr;
1202 char *n;
1203 int hi, lo, cp;
1204 int x = 0;
1205
1206 if ((n = strchr(p, '-')) != NULL) {
1207 *n = '\0';
1208 n++;
1209
1210 /* Make sure the ports are in order: lowest->highest. */
1211 hi = strtonum(n, 1, PORT_MAX, &errstr);
1212 if (errstr)
1213 errx(1, "port number %s: %s", errstr, n);
1214 lo = strtonum(p, 1, PORT_MAX, &errstr);
1215 if (errstr)
1216 errx(1, "port number %s: %s", errstr, p);
1217
1218 if (lo > hi) {
1219 cp = hi;
1220 hi = lo;
1221 lo = cp;
1222 }
1223
1224 /* Load ports sequentially. */
1225 for (cp = lo; cp <= hi; cp++) {
1226 portlist[x] = calloc(1, PORT_MAX_LEN);
1227 if (portlist[x] == NULL)
1228 err(1, NULL);
1229 snprintf(portlist[x], PORT_MAX_LEN, "%d", cp);
1230 x++;
1231 }
1232
1233 /* Randomly swap ports. */
1234 if (rflag) {
1235 int y;
1236 char *c;
1237
1238 for (x = 0; x <= (hi - lo); x++) {
1239 y = (arc4random() & 0xFFFF) % (hi - lo);
1240 c = portlist[x];
1241 portlist[x] = portlist[y];
1242 portlist[y] = c;
1243 }
1244 }
1245 } else {
1246 hi = strtonum(p, 1, PORT_MAX, &errstr);
1247 if (errstr)
1248 errx(1, "port number %s: %s", errstr, p);
1249 portlist[0] = strdup(p);
1250 if (portlist[0] == NULL)
1251 err(1, NULL);
1252 }
1253 }
1254
1255 /*
1256 * udptest()
1257 * Do a few writes to see if the UDP port is there.
1258 * Fails once PF state table is full.
1259 */
1260 int
udptest(int s)1261 udptest(int s)
1262 {
1263 int i, ret;
1264
1265 for (i = 0; i <= 3; i++) {
1266 if (write(s, "X", 1) == 1)
1267 ret = 1;
1268 else
1269 ret = -1;
1270 }
1271 return (ret);
1272 }
1273
1274 void
FreeBSD_stats_setup(int s)1275 FreeBSD_stats_setup(int s)
1276 {
1277
1278 if (setsockopt(s, IPPROTO_TCP, TCP_STATS,
1279 &FreeBSD_Mflag, sizeof(FreeBSD_Mflag)) == -1) {
1280 if (errno == EOPNOTSUPP) {
1281 warnx("getsockopt(TCP_STATS) failed; "
1282 "kernel built without \"options STATS\"?");
1283 }
1284 err(1, "enable TCP_STATS gathering");
1285 }
1286 }
1287
1288 void
FreeBSD_stats_print(int s)1289 FreeBSD_stats_print(int s)
1290 {
1291 #ifdef WITH_STATS
1292 struct statsblob *statsb;
1293 struct sbuf *sb;
1294 socklen_t sockoptlen;
1295 int error;
1296
1297 /*
1298 * This usleep is a workaround for TCP_STATS reporting
1299 * incorrect values for TXPB.
1300 */
1301 usleep(100000);
1302
1303 sockoptlen = 2048;
1304 statsb = malloc(sockoptlen);
1305 if (statsb == NULL)
1306 err(1, "malloc");
1307 error = getsockopt(s, IPPROTO_TCP, TCP_STATS, statsb, &sockoptlen);
1308 if (error != 0) {
1309 if (errno == EOVERFLOW && statsb->cursz > sockoptlen) {
1310 /* Retry with a larger size. */
1311 sockoptlen = statsb->cursz;
1312 statsb = realloc(statsb, sockoptlen);
1313 if (statsb == NULL)
1314 err(1, "realloc");
1315 error = getsockopt(s, IPPROTO_TCP, TCP_STATS,
1316 statsb, &sockoptlen);
1317 }
1318 if (error != 0)
1319 err(1, "getsockopt");
1320 }
1321
1322 sb = sbuf_new_auto();
1323 error = stats_blob_tostr(statsb, sb, SB_STRFMT_JSON, SB_TOSTR_META);
1324 if (error != 0)
1325 errc(1, error, "stats_blob_tostr");
1326
1327 error = sbuf_finish(sb);
1328 if (error != 0)
1329 err(1, "sbuf_finish");
1330
1331 fprintf(stderr, "%s\n", sbuf_data(sb));
1332 #endif
1333 }
1334
1335 void
set_common_sockopts(int s,int af)1336 set_common_sockopts(int s, int af)
1337 {
1338 int x = 1;
1339
1340 if (Sflag) {
1341 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG,
1342 &x, sizeof(x)) == -1)
1343 err(1, NULL);
1344 }
1345 if (Dflag) {
1346 if (setsockopt(s, SOL_SOCKET, SO_DEBUG,
1347 &x, sizeof(x)) == -1)
1348 err(1, NULL);
1349 }
1350 if (Tflag != -1) {
1351 int proto, option;
1352
1353 if (af == AF_INET6) {
1354 proto = IPPROTO_IPV6;
1355 option = IPV6_TCLASS;
1356 } else {
1357 proto = IPPROTO_IP;
1358 option = IP_TOS;
1359 }
1360
1361 if (setsockopt(s, proto, option, &Tflag, sizeof(Tflag)) == -1)
1362 err(1, "set IP ToS");
1363 }
1364 if (Iflag) {
1365 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF,
1366 &Iflag, sizeof(Iflag)) == -1)
1367 err(1, "set TCP receive buffer size");
1368 }
1369 if (Oflag) {
1370 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF,
1371 &Oflag, sizeof(Oflag)) == -1)
1372 err(1, "set TCP send buffer size");
1373 }
1374 if (FreeBSD_Oflag) {
1375 if (setsockopt(s, IPPROTO_TCP, TCP_NOOPT,
1376 &FreeBSD_Oflag, sizeof(FreeBSD_Oflag)) == -1)
1377 err(1, "disable TCP options");
1378 }
1379 if (FreeBSD_Mflag)
1380 FreeBSD_stats_setup(s);
1381 #ifdef IPSEC
1382 if (ipsec_policy[0] != NULL)
1383 add_ipsec_policy(s, af, ipsec_policy[0]);
1384 if (ipsec_policy[1] != NULL)
1385 add_ipsec_policy(s, af, ipsec_policy[1]);
1386 #endif
1387 }
1388
1389 int
map_tos(char * s,int * val)1390 map_tos(char *s, int *val)
1391 {
1392 /* DiffServ Codepoints and other TOS mappings */
1393 const struct toskeywords {
1394 const char *keyword;
1395 int val;
1396 } *t, toskeywords[] = {
1397 { "af11", IPTOS_DSCP_AF11 },
1398 { "af12", IPTOS_DSCP_AF12 },
1399 { "af13", IPTOS_DSCP_AF13 },
1400 { "af21", IPTOS_DSCP_AF21 },
1401 { "af22", IPTOS_DSCP_AF22 },
1402 { "af23", IPTOS_DSCP_AF23 },
1403 { "af31", IPTOS_DSCP_AF31 },
1404 { "af32", IPTOS_DSCP_AF32 },
1405 { "af33", IPTOS_DSCP_AF33 },
1406 { "af41", IPTOS_DSCP_AF41 },
1407 { "af42", IPTOS_DSCP_AF42 },
1408 { "af43", IPTOS_DSCP_AF43 },
1409 { "critical", IPTOS_PREC_CRITIC_ECP },
1410 { "cs0", IPTOS_DSCP_CS0 },
1411 { "cs1", IPTOS_DSCP_CS1 },
1412 { "cs2", IPTOS_DSCP_CS2 },
1413 { "cs3", IPTOS_DSCP_CS3 },
1414 { "cs4", IPTOS_DSCP_CS4 },
1415 { "cs5", IPTOS_DSCP_CS5 },
1416 { "cs6", IPTOS_DSCP_CS6 },
1417 { "cs7", IPTOS_DSCP_CS7 },
1418 { "ef", IPTOS_DSCP_EF },
1419 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL },
1420 { "lowdelay", IPTOS_LOWDELAY },
1421 { "netcontrol", IPTOS_PREC_NETCONTROL },
1422 { "reliability", IPTOS_RELIABILITY },
1423 { "throughput", IPTOS_THROUGHPUT },
1424 { NULL, -1 },
1425 };
1426
1427 for (t = toskeywords; t->keyword != NULL; t++) {
1428 if (strcmp(s, t->keyword) == 0) {
1429 *val = t->val;
1430 return (1);
1431 }
1432 }
1433
1434 return (0);
1435 }
1436
1437 void
report_connect(const struct sockaddr * sa,socklen_t salen)1438 report_connect(const struct sockaddr *sa, socklen_t salen)
1439 {
1440 char remote_host[NI_MAXHOST];
1441 char remote_port[NI_MAXSERV];
1442 int herr;
1443 int flags = NI_NUMERICSERV;
1444
1445 if (nflag)
1446 flags |= NI_NUMERICHOST;
1447
1448 if ((herr = getnameinfo(sa, salen,
1449 remote_host, sizeof(remote_host),
1450 remote_port, sizeof(remote_port),
1451 flags)) != 0) {
1452 if (herr == EAI_SYSTEM)
1453 err(1, "getnameinfo");
1454 else
1455 errx(1, "getnameinfo: %s", gai_strerror(herr));
1456 }
1457
1458 fprintf(stderr,
1459 "Connection from %s %s "
1460 "received!\n", remote_host, remote_port);
1461 }
1462
1463 void
help(void)1464 help(void)
1465 {
1466 usage(0);
1467 fprintf(stderr, "\tCommand Summary:\n\
1468 \t-4 Use IPv4\n\
1469 \t-6 Use IPv6\n\
1470 \t--crlf Convert LF into CRLF when sending data over the network\n\
1471 \t-D Enable the debug socket option\n\
1472 \t-d Detach from stdin\n");
1473 #ifdef IPSEC
1474 fprintf(stderr, "\
1475 \t-E Use IPsec ESP\n\
1476 \t-e policy Use specified IPsec policy\n");
1477 #endif
1478 fprintf(stderr, "\
1479 \t-F Pass socket fd\n\
1480 \t-h This help text\n\
1481 \t-I length TCP receive buffer length\n\
1482 \t-i secs\t Delay interval for lines sent, ports scanned\n\
1483 \t-k Keep inbound sockets open for multiple connects\n\
1484 \t-l Listen mode, for inbound connects\n\
1485 \t-N Shutdown the network socket after EOF on stdin\n\
1486 \t-n Suppress name/port resolutions\n\
1487 \t--no-tcpopt Disable TCP options\n\
1488 \t--sctp\t SCTP mode\n\
1489 \t--tun tundev Use tun device rather than stdio\n\
1490 \t-O length TCP send buffer length\n\
1491 \t-P proxyuser\tUsername for proxy authentication\n\
1492 \t-p port\t Specify local port for remote connects\n\
1493 \t-r Randomize remote ports\n\
1494 \t-S Enable the TCP MD5 signature option\n\
1495 \t-s addr\t Local source address\n\
1496 \t-T toskeyword\tSet IP Type of Service\n\
1497 \t-t Answer TELNET negotiation\n\
1498 \t-U Use UNIX domain socket\n\
1499 \t-u UDP mode\n\
1500 \t-V rtable Specify alternate routing table\n\
1501 \t-v Verbose\n\
1502 \t-w secs\t Timeout for connects and final net reads\n\
1503 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\
1504 \t-x addr[:port]\tSpecify proxy address and port\n\
1505 \t-z Zero-I/O mode [used for scanning]\n\
1506 Port numbers can be individual or ranges: lo-hi [inclusive]\n");
1507 #ifdef IPSEC
1508 fprintf(stderr, "\tSee ipsec_set_policy(3) for -e argument format\n");
1509 #endif
1510 exit(1);
1511 }
1512
1513 #ifdef IPSEC
1514 void
add_ipsec_policy(int s,int af,char * policy)1515 add_ipsec_policy(int s, int af, char *policy)
1516 {
1517 char *raw;
1518 int e;
1519
1520 raw = ipsec_set_policy(policy, strlen(policy));
1521 if (raw == NULL)
1522 errx(1, "ipsec_set_policy `%s': %s", policy,
1523 ipsec_strerror());
1524 if (af == AF_INET)
1525 e = setsockopt(s, IPPROTO_IP, IP_IPSEC_POLICY, raw,
1526 ipsec_get_policylen(raw));
1527 if (af == AF_INET6)
1528 e = setsockopt(s, IPPROTO_IPV6, IPV6_IPSEC_POLICY, raw,
1529 ipsec_get_policylen(raw));
1530 if (e < 0)
1531 err(1, "ipsec policy cannot be configured");
1532 free(raw);
1533 if (vflag)
1534 fprintf(stderr, "ipsec policy configured: `%s'\n", policy);
1535 return;
1536 }
1537 #endif /* IPSEC */
1538
1539 void
usage(int ret)1540 usage(int ret)
1541 {
1542 fprintf(stderr,
1543 #ifdef IPSEC
1544 "usage: nc [-46DdEFhklNnrStUuvz] [-e policy] [-I length] [-i interval] [-O length]\n"
1545 #else
1546 "usage: nc [-46DdFhklNnrStUuvz] [-I length] [-i interval] [-O length]\n"
1547 #endif
1548 "\t [--no-tcpopt] [--sctp]\n"
1549 "\t [-P proxy_username] [-p source_port] [-s source] [-T ToS]\n"
1550 "\t [--tun tundev] [-V rtable] [-w timeout] [-X proxy_protocol]\n"
1551 "\t [-x proxy_address[:port]] [destination] [port]\n");
1552 if (ret)
1553 exit(1);
1554 }
1555