xref: /freebsd/crypto/openssh/scp.c (revision 8657387683946d0c03e09fe77029edfe309eeb20)
1 /* $OpenBSD: scp.c,v 1.187 2016/09/12 01:22:38 deraadt Exp $ */
2 /*
3  * scp - secure remote copy.  This is basically patched BSD rcp which
4  * uses ssh to do the data transfer (instead of using rcmd).
5  *
6  * NOTE: This version should NOT be suid root.  (This uses ssh to
7  * do the transfer and ssh has the necessary privileges.)
8  *
9  * 1995 Timo Rinne <tri@iki.fi>, Tatu Ylonen <ylo@cs.hut.fi>
10  *
11  * As far as I am concerned, the code I have written for this software
12  * can be used freely for any purpose.  Any derived versions of this
13  * software must be clearly marked as such, and if the derived work is
14  * incompatible with the protocol description in the RFC file, it must be
15  * called by a name other than "ssh" or "Secure Shell".
16  */
17 /*
18  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
19  * Copyright (c) 1999 Aaron Campbell.  All rights reserved.
20  *
21  * Redistribution and use in source and binary forms, with or without
22  * modification, are permitted provided that the following conditions
23  * are met:
24  * 1. Redistributions of source code must retain the above copyright
25  *    notice, this list of conditions and the following disclaimer.
26  * 2. Redistributions in binary form must reproduce the above copyright
27  *    notice, this list of conditions and the following disclaimer in the
28  *    documentation and/or other materials provided with the distribution.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40  */
41 
42 /*
43  * Parts from:
44  *
45  * Copyright (c) 1983, 1990, 1992, 1993, 1995
46  *	The Regents of the University of California.  All rights reserved.
47  *
48  * Redistribution and use in source and binary forms, with or without
49  * modification, are permitted provided that the following conditions
50  * are met:
51  * 1. Redistributions of source code must retain the above copyright
52  *    notice, this list of conditions and the following disclaimer.
53  * 2. Redistributions in binary form must reproduce the above copyright
54  *    notice, this list of conditions and the following disclaimer in the
55  *    documentation and/or other materials provided with the distribution.
56  * 3. Neither the name of the University nor the names of its contributors
57  *    may be used to endorse or promote products derived from this software
58  *    without specific prior written permission.
59  *
60  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
61  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
62  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
63  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
64  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
65  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
66  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
67  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
68  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
69  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
70  * SUCH DAMAGE.
71  *
72  */
73 
74 #include "includes.h"
75 
76 #include <sys/types.h>
77 #ifdef HAVE_SYS_STAT_H
78 # include <sys/stat.h>
79 #endif
80 #ifdef HAVE_POLL_H
81 #include <poll.h>
82 #else
83 # ifdef HAVE_SYS_POLL_H
84 #  include <sys/poll.h>
85 # endif
86 #endif
87 #ifdef HAVE_SYS_TIME_H
88 # include <sys/time.h>
89 #endif
90 #include <sys/wait.h>
91 #include <sys/uio.h>
92 
93 #include <ctype.h>
94 #include <dirent.h>
95 #include <errno.h>
96 #include <fcntl.h>
97 #include <limits.h>
98 #include <locale.h>
99 #include <pwd.h>
100 #include <signal.h>
101 #include <stdarg.h>
102 #include <stdio.h>
103 #include <stdlib.h>
104 #include <string.h>
105 #include <time.h>
106 #include <unistd.h>
107 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
108 #include <vis.h>
109 #endif
110 
111 #include "xmalloc.h"
112 #include "atomicio.h"
113 #include "pathnames.h"
114 #include "log.h"
115 #include "misc.h"
116 #include "progressmeter.h"
117 #include "utf8.h"
118 
119 extern char *__progname;
120 
121 #define COPY_BUFLEN	16384
122 
123 int do_cmd(char *host, char *remuser, char *cmd, int *fdin, int *fdout);
124 int do_cmd2(char *host, char *remuser, char *cmd, int fdin, int fdout);
125 
126 /* Struct for addargs */
127 arglist args;
128 arglist remote_remote_args;
129 
130 /* Bandwidth limit */
131 long long limit_kbps = 0;
132 struct bwlimit bwlimit;
133 
134 /* Name of current file being transferred. */
135 char *curfile;
136 
137 /* This is set to non-zero to enable verbose mode. */
138 int verbose_mode = 0;
139 
140 /* This is set to zero if the progressmeter is not desired. */
141 int showprogress = 1;
142 
143 /*
144  * This is set to non-zero if remote-remote copy should be piped
145  * through this process.
146  */
147 int throughlocal = 0;
148 
149 /* This is the program to execute for the secured connection. ("ssh" or -S) */
150 char *ssh_program = _PATH_SSH_PROGRAM;
151 
152 /* This is used to store the pid of ssh_program */
153 pid_t do_cmd_pid = -1;
154 
155 static void
156 killchild(int signo)
157 {
158 	if (do_cmd_pid > 1) {
159 		kill(do_cmd_pid, signo ? signo : SIGTERM);
160 		waitpid(do_cmd_pid, NULL, 0);
161 	}
162 
163 	if (signo)
164 		_exit(1);
165 	exit(1);
166 }
167 
168 static void
169 suspchild(int signo)
170 {
171 	int status;
172 
173 	if (do_cmd_pid > 1) {
174 		kill(do_cmd_pid, signo);
175 		while (waitpid(do_cmd_pid, &status, WUNTRACED) == -1 &&
176 		    errno == EINTR)
177 			;
178 		kill(getpid(), SIGSTOP);
179 	}
180 }
181 
182 static int
183 do_local_cmd(arglist *a)
184 {
185 	u_int i;
186 	int status;
187 	pid_t pid;
188 
189 	if (a->num == 0)
190 		fatal("do_local_cmd: no arguments");
191 
192 	if (verbose_mode) {
193 		fprintf(stderr, "Executing:");
194 		for (i = 0; i < a->num; i++)
195 			fmprintf(stderr, " %s", a->list[i]);
196 		fprintf(stderr, "\n");
197 	}
198 	if ((pid = fork()) == -1)
199 		fatal("do_local_cmd: fork: %s", strerror(errno));
200 
201 	if (pid == 0) {
202 		execvp(a->list[0], a->list);
203 		perror(a->list[0]);
204 		exit(1);
205 	}
206 
207 	do_cmd_pid = pid;
208 	signal(SIGTERM, killchild);
209 	signal(SIGINT, killchild);
210 	signal(SIGHUP, killchild);
211 
212 	while (waitpid(pid, &status, 0) == -1)
213 		if (errno != EINTR)
214 			fatal("do_local_cmd: waitpid: %s", strerror(errno));
215 
216 	do_cmd_pid = -1;
217 
218 	if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
219 		return (-1);
220 
221 	return (0);
222 }
223 
224 /*
225  * This function executes the given command as the specified user on the
226  * given host.  This returns < 0 if execution fails, and >= 0 otherwise. This
227  * assigns the input and output file descriptors on success.
228  */
229 
230 int
231 do_cmd(char *host, char *remuser, char *cmd, int *fdin, int *fdout)
232 {
233 	int pin[2], pout[2], reserved[2];
234 
235 	if (verbose_mode)
236 		fmprintf(stderr,
237 		    "Executing: program %s host %s, user %s, command %s\n",
238 		    ssh_program, host,
239 		    remuser ? remuser : "(unspecified)", cmd);
240 
241 	/*
242 	 * Reserve two descriptors so that the real pipes won't get
243 	 * descriptors 0 and 1 because that will screw up dup2 below.
244 	 */
245 	if (pipe(reserved) < 0)
246 		fatal("pipe: %s", strerror(errno));
247 
248 	/* Create a socket pair for communicating with ssh. */
249 	if (pipe(pin) < 0)
250 		fatal("pipe: %s", strerror(errno));
251 	if (pipe(pout) < 0)
252 		fatal("pipe: %s", strerror(errno));
253 
254 	/* Free the reserved descriptors. */
255 	close(reserved[0]);
256 	close(reserved[1]);
257 
258 	signal(SIGTSTP, suspchild);
259 	signal(SIGTTIN, suspchild);
260 	signal(SIGTTOU, suspchild);
261 
262 	/* Fork a child to execute the command on the remote host using ssh. */
263 	do_cmd_pid = fork();
264 	if (do_cmd_pid == 0) {
265 		/* Child. */
266 		close(pin[1]);
267 		close(pout[0]);
268 		dup2(pin[0], 0);
269 		dup2(pout[1], 1);
270 		close(pin[0]);
271 		close(pout[1]);
272 
273 		replacearg(&args, 0, "%s", ssh_program);
274 		if (remuser != NULL) {
275 			addargs(&args, "-l");
276 			addargs(&args, "%s", remuser);
277 		}
278 		addargs(&args, "--");
279 		addargs(&args, "%s", host);
280 		addargs(&args, "%s", cmd);
281 
282 		execvp(ssh_program, args.list);
283 		perror(ssh_program);
284 		exit(1);
285 	} else if (do_cmd_pid == -1) {
286 		fatal("fork: %s", strerror(errno));
287 	}
288 	/* Parent.  Close the other side, and return the local side. */
289 	close(pin[0]);
290 	*fdout = pin[1];
291 	close(pout[1]);
292 	*fdin = pout[0];
293 	signal(SIGTERM, killchild);
294 	signal(SIGINT, killchild);
295 	signal(SIGHUP, killchild);
296 	return 0;
297 }
298 
299 /*
300  * This functions executes a command simlar to do_cmd(), but expects the
301  * input and output descriptors to be setup by a previous call to do_cmd().
302  * This way the input and output of two commands can be connected.
303  */
304 int
305 do_cmd2(char *host, char *remuser, char *cmd, int fdin, int fdout)
306 {
307 	pid_t pid;
308 	int status;
309 
310 	if (verbose_mode)
311 		fmprintf(stderr,
312 		    "Executing: 2nd program %s host %s, user %s, command %s\n",
313 		    ssh_program, host,
314 		    remuser ? remuser : "(unspecified)", cmd);
315 
316 	/* Fork a child to execute the command on the remote host using ssh. */
317 	pid = fork();
318 	if (pid == 0) {
319 		dup2(fdin, 0);
320 		dup2(fdout, 1);
321 
322 		replacearg(&args, 0, "%s", ssh_program);
323 		if (remuser != NULL) {
324 			addargs(&args, "-l");
325 			addargs(&args, "%s", remuser);
326 		}
327 		addargs(&args, "--");
328 		addargs(&args, "%s", host);
329 		addargs(&args, "%s", cmd);
330 
331 		execvp(ssh_program, args.list);
332 		perror(ssh_program);
333 		exit(1);
334 	} else if (pid == -1) {
335 		fatal("fork: %s", strerror(errno));
336 	}
337 	while (waitpid(pid, &status, 0) == -1)
338 		if (errno != EINTR)
339 			fatal("do_cmd2: waitpid: %s", strerror(errno));
340 	return 0;
341 }
342 
343 typedef struct {
344 	size_t cnt;
345 	char *buf;
346 } BUF;
347 
348 BUF *allocbuf(BUF *, int, int);
349 void lostconn(int);
350 int okname(char *);
351 void run_err(const char *,...);
352 void verifydir(char *);
353 
354 struct passwd *pwd;
355 uid_t userid;
356 int errs, remin, remout;
357 int pflag, iamremote, iamrecursive, targetshouldbedirectory;
358 
359 #define	CMDNEEDS	64
360 char cmd[CMDNEEDS];		/* must hold "rcp -r -p -d\0" */
361 
362 int response(void);
363 void rsource(char *, struct stat *);
364 void sink(int, char *[]);
365 void source(int, char *[]);
366 void tolocal(int, char *[]);
367 void toremote(char *, int, char *[]);
368 void usage(void);
369 
370 int
371 main(int argc, char **argv)
372 {
373 	int ch, fflag, tflag, status, n;
374 	char *targ, **newargv;
375 	const char *errstr;
376 	extern char *optarg;
377 	extern int optind;
378 
379 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
380 	sanitise_stdfd();
381 
382 	msetlocale();
383 
384 	/* Copy argv, because we modify it */
385 	newargv = xcalloc(MAXIMUM(argc + 1, 1), sizeof(*newargv));
386 	for (n = 0; n < argc; n++)
387 		newargv[n] = xstrdup(argv[n]);
388 	argv = newargv;
389 
390 	__progname = ssh_get_progname(argv[0]);
391 
392 	memset(&args, '\0', sizeof(args));
393 	memset(&remote_remote_args, '\0', sizeof(remote_remote_args));
394 	args.list = remote_remote_args.list = NULL;
395 	addargs(&args, "%s", ssh_program);
396 	addargs(&args, "-x");
397 	addargs(&args, "-oForwardAgent=no");
398 	addargs(&args, "-oPermitLocalCommand=no");
399 	addargs(&args, "-oClearAllForwardings=yes");
400 
401 	fflag = tflag = 0;
402 	while ((ch = getopt(argc, argv, "dfl:prtvBCc:i:P:q12346S:o:F:")) != -1)
403 		switch (ch) {
404 		/* User-visible flags. */
405 		case '1':
406 		case '2':
407 		case '4':
408 		case '6':
409 		case 'C':
410 			addargs(&args, "-%c", ch);
411 			addargs(&remote_remote_args, "-%c", ch);
412 			break;
413 		case '3':
414 			throughlocal = 1;
415 			break;
416 		case 'o':
417 		case 'c':
418 		case 'i':
419 		case 'F':
420 			addargs(&remote_remote_args, "-%c", ch);
421 			addargs(&remote_remote_args, "%s", optarg);
422 			addargs(&args, "-%c", ch);
423 			addargs(&args, "%s", optarg);
424 			break;
425 		case 'P':
426 			addargs(&remote_remote_args, "-p");
427 			addargs(&remote_remote_args, "%s", optarg);
428 			addargs(&args, "-p");
429 			addargs(&args, "%s", optarg);
430 			break;
431 		case 'B':
432 			addargs(&remote_remote_args, "-oBatchmode=yes");
433 			addargs(&args, "-oBatchmode=yes");
434 			break;
435 		case 'l':
436 			limit_kbps = strtonum(optarg, 1, 100 * 1024 * 1024,
437 			    &errstr);
438 			if (errstr != NULL)
439 				usage();
440 			limit_kbps *= 1024; /* kbps */
441 			bandwidth_limit_init(&bwlimit, limit_kbps, COPY_BUFLEN);
442 			break;
443 		case 'p':
444 			pflag = 1;
445 			break;
446 		case 'r':
447 			iamrecursive = 1;
448 			break;
449 		case 'S':
450 			ssh_program = xstrdup(optarg);
451 			break;
452 		case 'v':
453 			addargs(&args, "-v");
454 			addargs(&remote_remote_args, "-v");
455 			verbose_mode = 1;
456 			break;
457 		case 'q':
458 			addargs(&args, "-q");
459 			addargs(&remote_remote_args, "-q");
460 			showprogress = 0;
461 			break;
462 
463 		/* Server options. */
464 		case 'd':
465 			targetshouldbedirectory = 1;
466 			break;
467 		case 'f':	/* "from" */
468 			iamremote = 1;
469 			fflag = 1;
470 			break;
471 		case 't':	/* "to" */
472 			iamremote = 1;
473 			tflag = 1;
474 #ifdef HAVE_CYGWIN
475 			setmode(0, O_BINARY);
476 #endif
477 			break;
478 		default:
479 			usage();
480 		}
481 	argc -= optind;
482 	argv += optind;
483 
484 	if ((pwd = getpwuid(userid = getuid())) == NULL)
485 		fatal("unknown user %u", (u_int) userid);
486 
487 	if (!isatty(STDOUT_FILENO))
488 		showprogress = 0;
489 
490 	if (pflag) {
491 		/* Cannot pledge: -p allows setuid/setgid files... */
492 	} else {
493 		if (pledge("stdio rpath wpath cpath fattr tty proc exec",
494 		    NULL) == -1) {
495 			perror("pledge");
496 			exit(1);
497 		}
498 	}
499 
500 	remin = STDIN_FILENO;
501 	remout = STDOUT_FILENO;
502 
503 	if (fflag) {
504 		/* Follow "protocol", send data. */
505 		(void) response();
506 		source(argc, argv);
507 		exit(errs != 0);
508 	}
509 	if (tflag) {
510 		/* Receive data. */
511 		sink(argc, argv);
512 		exit(errs != 0);
513 	}
514 	if (argc < 2)
515 		usage();
516 	if (argc > 2)
517 		targetshouldbedirectory = 1;
518 
519 	remin = remout = -1;
520 	do_cmd_pid = -1;
521 	/* Command to be executed on remote system using "ssh". */
522 	(void) snprintf(cmd, sizeof cmd, "scp%s%s%s%s",
523 	    verbose_mode ? " -v" : "",
524 	    iamrecursive ? " -r" : "", pflag ? " -p" : "",
525 	    targetshouldbedirectory ? " -d" : "");
526 
527 	(void) signal(SIGPIPE, lostconn);
528 
529 	if ((targ = colon(argv[argc - 1])))	/* Dest is remote host. */
530 		toremote(targ, argc, argv);
531 	else {
532 		if (targetshouldbedirectory)
533 			verifydir(argv[argc - 1]);
534 		tolocal(argc, argv);	/* Dest is local host. */
535 	}
536 	/*
537 	 * Finally check the exit status of the ssh process, if one was forked
538 	 * and no error has occurred yet
539 	 */
540 	if (do_cmd_pid != -1 && errs == 0) {
541 		if (remin != -1)
542 		    (void) close(remin);
543 		if (remout != -1)
544 		    (void) close(remout);
545 		if (waitpid(do_cmd_pid, &status, 0) == -1)
546 			errs = 1;
547 		else {
548 			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
549 				errs = 1;
550 		}
551 	}
552 	exit(errs != 0);
553 }
554 
555 /* Callback from atomicio6 to update progress meter and limit bandwidth */
556 static int
557 scpio(void *_cnt, size_t s)
558 {
559 	off_t *cnt = (off_t *)_cnt;
560 
561 	*cnt += s;
562 	if (limit_kbps > 0)
563 		bandwidth_limit(&bwlimit, s);
564 	return 0;
565 }
566 
567 static int
568 do_times(int fd, int verb, const struct stat *sb)
569 {
570 	/* strlen(2^64) == 20; strlen(10^6) == 7 */
571 	char buf[(20 + 7 + 2) * 2 + 2];
572 
573 	(void)snprintf(buf, sizeof(buf), "T%llu 0 %llu 0\n",
574 	    (unsigned long long) (sb->st_mtime < 0 ? 0 : sb->st_mtime),
575 	    (unsigned long long) (sb->st_atime < 0 ? 0 : sb->st_atime));
576 	if (verb) {
577 		fprintf(stderr, "File mtime %lld atime %lld\n",
578 		    (long long)sb->st_mtime, (long long)sb->st_atime);
579 		fprintf(stderr, "Sending file timestamps: %s", buf);
580 	}
581 	(void) atomicio(vwrite, fd, buf, strlen(buf));
582 	return (response());
583 }
584 
585 void
586 toremote(char *targ, int argc, char **argv)
587 {
588 	char *bp, *host, *src, *suser, *thost, *tuser, *arg;
589 	arglist alist;
590 	int i;
591 	u_int j;
592 
593 	memset(&alist, '\0', sizeof(alist));
594 	alist.list = NULL;
595 
596 	*targ++ = 0;
597 	if (*targ == 0)
598 		targ = ".";
599 
600 	arg = xstrdup(argv[argc - 1]);
601 	if ((thost = strrchr(arg, '@'))) {
602 		/* user@host */
603 		*thost++ = 0;
604 		tuser = arg;
605 		if (*tuser == '\0')
606 			tuser = NULL;
607 	} else {
608 		thost = arg;
609 		tuser = NULL;
610 	}
611 
612 	if (tuser != NULL && !okname(tuser)) {
613 		free(arg);
614 		return;
615 	}
616 
617 	for (i = 0; i < argc - 1; i++) {
618 		src = colon(argv[i]);
619 		if (src && throughlocal) {	/* extended remote to remote */
620 			*src++ = 0;
621 			if (*src == 0)
622 				src = ".";
623 			host = strrchr(argv[i], '@');
624 			if (host) {
625 				*host++ = 0;
626 				host = cleanhostname(host);
627 				suser = argv[i];
628 				if (*suser == '\0')
629 					suser = pwd->pw_name;
630 				else if (!okname(suser))
631 					continue;
632 			} else {
633 				host = cleanhostname(argv[i]);
634 				suser = NULL;
635 			}
636 			xasprintf(&bp, "%s -f %s%s", cmd,
637 			    *src == '-' ? "-- " : "", src);
638 			if (do_cmd(host, suser, bp, &remin, &remout) < 0)
639 				exit(1);
640 			free(bp);
641 			host = cleanhostname(thost);
642 			xasprintf(&bp, "%s -t %s%s", cmd,
643 			    *targ == '-' ? "-- " : "", targ);
644 			if (do_cmd2(host, tuser, bp, remin, remout) < 0)
645 				exit(1);
646 			free(bp);
647 			(void) close(remin);
648 			(void) close(remout);
649 			remin = remout = -1;
650 		} else if (src) {	/* standard remote to remote */
651 			freeargs(&alist);
652 			addargs(&alist, "%s", ssh_program);
653 			addargs(&alist, "-x");
654 			addargs(&alist, "-oClearAllForwardings=yes");
655 			addargs(&alist, "-n");
656 			for (j = 0; j < remote_remote_args.num; j++) {
657 				addargs(&alist, "%s",
658 				    remote_remote_args.list[j]);
659 			}
660 			*src++ = 0;
661 			if (*src == 0)
662 				src = ".";
663 			host = strrchr(argv[i], '@');
664 
665 			if (host) {
666 				*host++ = 0;
667 				host = cleanhostname(host);
668 				suser = argv[i];
669 				if (*suser == '\0')
670 					suser = pwd->pw_name;
671 				else if (!okname(suser))
672 					continue;
673 				addargs(&alist, "-l");
674 				addargs(&alist, "%s", suser);
675 			} else {
676 				host = cleanhostname(argv[i]);
677 			}
678 			addargs(&alist, "--");
679 			addargs(&alist, "%s", host);
680 			addargs(&alist, "%s", cmd);
681 			addargs(&alist, "%s", src);
682 			addargs(&alist, "%s%s%s:%s",
683 			    tuser ? tuser : "", tuser ? "@" : "",
684 			    thost, targ);
685 			if (do_local_cmd(&alist) != 0)
686 				errs = 1;
687 		} else {	/* local to remote */
688 			if (remin == -1) {
689 				xasprintf(&bp, "%s -t %s%s", cmd,
690 				    *targ == '-' ? "-- " : "", targ);
691 				host = cleanhostname(thost);
692 				if (do_cmd(host, tuser, bp, &remin,
693 				    &remout) < 0)
694 					exit(1);
695 				if (response() < 0)
696 					exit(1);
697 				free(bp);
698 			}
699 			source(1, argv + i);
700 		}
701 	}
702 	free(arg);
703 }
704 
705 void
706 tolocal(int argc, char **argv)
707 {
708 	char *bp, *host, *src, *suser;
709 	arglist alist;
710 	int i;
711 
712 	memset(&alist, '\0', sizeof(alist));
713 	alist.list = NULL;
714 
715 	for (i = 0; i < argc - 1; i++) {
716 		if (!(src = colon(argv[i]))) {	/* Local to local. */
717 			freeargs(&alist);
718 			addargs(&alist, "%s", _PATH_CP);
719 			if (iamrecursive)
720 				addargs(&alist, "-r");
721 			if (pflag)
722 				addargs(&alist, "-p");
723 			addargs(&alist, "--");
724 			addargs(&alist, "%s", argv[i]);
725 			addargs(&alist, "%s", argv[argc-1]);
726 			if (do_local_cmd(&alist))
727 				++errs;
728 			continue;
729 		}
730 		*src++ = 0;
731 		if (*src == 0)
732 			src = ".";
733 		if ((host = strrchr(argv[i], '@')) == NULL) {
734 			host = argv[i];
735 			suser = NULL;
736 		} else {
737 			*host++ = 0;
738 			suser = argv[i];
739 			if (*suser == '\0')
740 				suser = pwd->pw_name;
741 		}
742 		host = cleanhostname(host);
743 		xasprintf(&bp, "%s -f %s%s",
744 		    cmd, *src == '-' ? "-- " : "", src);
745 		if (do_cmd(host, suser, bp, &remin, &remout) < 0) {
746 			free(bp);
747 			++errs;
748 			continue;
749 		}
750 		free(bp);
751 		sink(1, argv + argc - 1);
752 		(void) close(remin);
753 		remin = remout = -1;
754 	}
755 }
756 
757 void
758 source(int argc, char **argv)
759 {
760 	struct stat stb;
761 	static BUF buffer;
762 	BUF *bp;
763 	off_t i, statbytes;
764 	size_t amt, nr;
765 	int fd = -1, haderr, indx;
766 	char *last, *name, buf[2048], encname[PATH_MAX];
767 	int len;
768 
769 	for (indx = 0; indx < argc; ++indx) {
770 		name = argv[indx];
771 		statbytes = 0;
772 		len = strlen(name);
773 		while (len > 1 && name[len-1] == '/')
774 			name[--len] = '\0';
775 		if ((fd = open(name, O_RDONLY|O_NONBLOCK, 0)) < 0)
776 			goto syserr;
777 		if (strchr(name, '\n') != NULL) {
778 			strnvis(encname, name, sizeof(encname), VIS_NL);
779 			name = encname;
780 		}
781 		if (fstat(fd, &stb) < 0) {
782 syserr:			run_err("%s: %s", name, strerror(errno));
783 			goto next;
784 		}
785 		if (stb.st_size < 0) {
786 			run_err("%s: %s", name, "Negative file size");
787 			goto next;
788 		}
789 		unset_nonblock(fd);
790 		switch (stb.st_mode & S_IFMT) {
791 		case S_IFREG:
792 			break;
793 		case S_IFDIR:
794 			if (iamrecursive) {
795 				rsource(name, &stb);
796 				goto next;
797 			}
798 			/* FALLTHROUGH */
799 		default:
800 			run_err("%s: not a regular file", name);
801 			goto next;
802 		}
803 		if ((last = strrchr(name, '/')) == NULL)
804 			last = name;
805 		else
806 			++last;
807 		curfile = last;
808 		if (pflag) {
809 			if (do_times(remout, verbose_mode, &stb) < 0)
810 				goto next;
811 		}
812 #define	FILEMODEMASK	(S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
813 		snprintf(buf, sizeof buf, "C%04o %lld %s\n",
814 		    (u_int) (stb.st_mode & FILEMODEMASK),
815 		    (long long)stb.st_size, last);
816 		if (verbose_mode)
817 			fmprintf(stderr, "Sending file modes: %s", buf);
818 		(void) atomicio(vwrite, remout, buf, strlen(buf));
819 		if (response() < 0)
820 			goto next;
821 		if ((bp = allocbuf(&buffer, fd, COPY_BUFLEN)) == NULL) {
822 next:			if (fd != -1) {
823 				(void) close(fd);
824 				fd = -1;
825 			}
826 			continue;
827 		}
828 		if (showprogress)
829 			start_progress_meter(curfile, stb.st_size, &statbytes);
830 		set_nonblock(remout);
831 		for (haderr = i = 0; i < stb.st_size; i += bp->cnt) {
832 			amt = bp->cnt;
833 			if (i + (off_t)amt > stb.st_size)
834 				amt = stb.st_size - i;
835 			if (!haderr) {
836 				if ((nr = atomicio(read, fd,
837 				    bp->buf, amt)) != amt) {
838 					haderr = errno;
839 					memset(bp->buf + nr, 0, amt - nr);
840 				}
841 			}
842 			/* Keep writing after error to retain sync */
843 			if (haderr) {
844 				(void)atomicio(vwrite, remout, bp->buf, amt);
845 				memset(bp->buf, 0, amt);
846 				continue;
847 			}
848 			if (atomicio6(vwrite, remout, bp->buf, amt, scpio,
849 			    &statbytes) != amt)
850 				haderr = errno;
851 		}
852 		unset_nonblock(remout);
853 
854 		if (fd != -1) {
855 			if (close(fd) < 0 && !haderr)
856 				haderr = errno;
857 			fd = -1;
858 		}
859 		if (!haderr)
860 			(void) atomicio(vwrite, remout, "", 1);
861 		else
862 			run_err("%s: %s", name, strerror(haderr));
863 		(void) response();
864 		if (showprogress)
865 			stop_progress_meter();
866 	}
867 }
868 
869 void
870 rsource(char *name, struct stat *statp)
871 {
872 	DIR *dirp;
873 	struct dirent *dp;
874 	char *last, *vect[1], path[PATH_MAX];
875 
876 	if (!(dirp = opendir(name))) {
877 		run_err("%s: %s", name, strerror(errno));
878 		return;
879 	}
880 	last = strrchr(name, '/');
881 	if (last == NULL)
882 		last = name;
883 	else
884 		last++;
885 	if (pflag) {
886 		if (do_times(remout, verbose_mode, statp) < 0) {
887 			closedir(dirp);
888 			return;
889 		}
890 	}
891 	(void) snprintf(path, sizeof path, "D%04o %d %.1024s\n",
892 	    (u_int) (statp->st_mode & FILEMODEMASK), 0, last);
893 	if (verbose_mode)
894 		fmprintf(stderr, "Entering directory: %s", path);
895 	(void) atomicio(vwrite, remout, path, strlen(path));
896 	if (response() < 0) {
897 		closedir(dirp);
898 		return;
899 	}
900 	while ((dp = readdir(dirp)) != NULL) {
901 		if (dp->d_ino == 0)
902 			continue;
903 		if (!strcmp(dp->d_name, ".") || !strcmp(dp->d_name, ".."))
904 			continue;
905 		if (strlen(name) + 1 + strlen(dp->d_name) >= sizeof(path) - 1) {
906 			run_err("%s/%s: name too long", name, dp->d_name);
907 			continue;
908 		}
909 		(void) snprintf(path, sizeof path, "%s/%s", name, dp->d_name);
910 		vect[0] = path;
911 		source(1, vect);
912 	}
913 	(void) closedir(dirp);
914 	(void) atomicio(vwrite, remout, "E\n", 2);
915 	(void) response();
916 }
917 
918 void
919 sink(int argc, char **argv)
920 {
921 	static BUF buffer;
922 	struct stat stb;
923 	enum {
924 		YES, NO, DISPLAYED
925 	} wrerr;
926 	BUF *bp;
927 	off_t i;
928 	size_t j, count;
929 	int amt, exists, first, ofd;
930 	mode_t mode, omode, mask;
931 	off_t size, statbytes;
932 	unsigned long long ull;
933 	int setimes, targisdir, wrerrno = 0;
934 	char ch, *cp, *np, *targ, *why, *vect[1], buf[2048], visbuf[2048];
935 	struct timeval tv[2];
936 
937 #define	atime	tv[0]
938 #define	mtime	tv[1]
939 #define	SCREWUP(str)	{ why = str; goto screwup; }
940 
941 	setimes = targisdir = 0;
942 	mask = umask(0);
943 	if (!pflag)
944 		(void) umask(mask);
945 	if (argc != 1) {
946 		run_err("ambiguous target");
947 		exit(1);
948 	}
949 	targ = *argv;
950 	if (targetshouldbedirectory)
951 		verifydir(targ);
952 
953 	(void) atomicio(vwrite, remout, "", 1);
954 	if (stat(targ, &stb) == 0 && S_ISDIR(stb.st_mode))
955 		targisdir = 1;
956 	for (first = 1;; first = 0) {
957 		cp = buf;
958 		if (atomicio(read, remin, cp, 1) != 1)
959 			return;
960 		if (*cp++ == '\n')
961 			SCREWUP("unexpected <newline>");
962 		do {
963 			if (atomicio(read, remin, &ch, sizeof(ch)) != sizeof(ch))
964 				SCREWUP("lost connection");
965 			*cp++ = ch;
966 		} while (cp < &buf[sizeof(buf) - 1] && ch != '\n');
967 		*cp = 0;
968 		if (verbose_mode)
969 			fmprintf(stderr, "Sink: %s", buf);
970 
971 		if (buf[0] == '\01' || buf[0] == '\02') {
972 			if (iamremote == 0) {
973 				(void) snmprintf(visbuf, sizeof(visbuf),
974 				    NULL, "%s", buf + 1);
975 				(void) atomicio(vwrite, STDERR_FILENO,
976 				    visbuf, strlen(visbuf));
977 			}
978 			if (buf[0] == '\02')
979 				exit(1);
980 			++errs;
981 			continue;
982 		}
983 		if (buf[0] == 'E') {
984 			(void) atomicio(vwrite, remout, "", 1);
985 			return;
986 		}
987 		if (ch == '\n')
988 			*--cp = 0;
989 
990 		cp = buf;
991 		if (*cp == 'T') {
992 			setimes++;
993 			cp++;
994 			if (!isdigit((unsigned char)*cp))
995 				SCREWUP("mtime.sec not present");
996 			ull = strtoull(cp, &cp, 10);
997 			if (!cp || *cp++ != ' ')
998 				SCREWUP("mtime.sec not delimited");
999 			if ((time_t)ull < 0 ||
1000 			    (unsigned long long)(time_t)ull != ull)
1001 				setimes = 0;	/* out of range */
1002 			mtime.tv_sec = ull;
1003 			mtime.tv_usec = strtol(cp, &cp, 10);
1004 			if (!cp || *cp++ != ' ' || mtime.tv_usec < 0 ||
1005 			    mtime.tv_usec > 999999)
1006 				SCREWUP("mtime.usec not delimited");
1007 			if (!isdigit((unsigned char)*cp))
1008 				SCREWUP("atime.sec not present");
1009 			ull = strtoull(cp, &cp, 10);
1010 			if (!cp || *cp++ != ' ')
1011 				SCREWUP("atime.sec not delimited");
1012 			if ((time_t)ull < 0 ||
1013 			    (unsigned long long)(time_t)ull != ull)
1014 				setimes = 0;	/* out of range */
1015 			atime.tv_sec = ull;
1016 			atime.tv_usec = strtol(cp, &cp, 10);
1017 			if (!cp || *cp++ != '\0' || atime.tv_usec < 0 ||
1018 			    atime.tv_usec > 999999)
1019 				SCREWUP("atime.usec not delimited");
1020 			(void) atomicio(vwrite, remout, "", 1);
1021 			continue;
1022 		}
1023 		if (*cp != 'C' && *cp != 'D') {
1024 			/*
1025 			 * Check for the case "rcp remote:foo\* local:bar".
1026 			 * In this case, the line "No match." can be returned
1027 			 * by the shell before the rcp command on the remote is
1028 			 * executed so the ^Aerror_message convention isn't
1029 			 * followed.
1030 			 */
1031 			if (first) {
1032 				run_err("%s", cp);
1033 				exit(1);
1034 			}
1035 			SCREWUP("expected control record");
1036 		}
1037 		mode = 0;
1038 		for (++cp; cp < buf + 5; cp++) {
1039 			if (*cp < '0' || *cp > '7')
1040 				SCREWUP("bad mode");
1041 			mode = (mode << 3) | (*cp - '0');
1042 		}
1043 		if (*cp++ != ' ')
1044 			SCREWUP("mode not delimited");
1045 
1046 		for (size = 0; isdigit((unsigned char)*cp);)
1047 			size = size * 10 + (*cp++ - '0');
1048 		if (*cp++ != ' ')
1049 			SCREWUP("size not delimited");
1050 		if ((strchr(cp, '/') != NULL) || (strcmp(cp, "..") == 0)) {
1051 			run_err("error: unexpected filename: %s", cp);
1052 			exit(1);
1053 		}
1054 		if (targisdir) {
1055 			static char *namebuf;
1056 			static size_t cursize;
1057 			size_t need;
1058 
1059 			need = strlen(targ) + strlen(cp) + 250;
1060 			if (need > cursize) {
1061 				free(namebuf);
1062 				namebuf = xmalloc(need);
1063 				cursize = need;
1064 			}
1065 			(void) snprintf(namebuf, need, "%s%s%s", targ,
1066 			    strcmp(targ, "/") ? "/" : "", cp);
1067 			np = namebuf;
1068 		} else
1069 			np = targ;
1070 		curfile = cp;
1071 		exists = stat(np, &stb) == 0;
1072 		if (buf[0] == 'D') {
1073 			int mod_flag = pflag;
1074 			if (!iamrecursive)
1075 				SCREWUP("received directory without -r");
1076 			if (exists) {
1077 				if (!S_ISDIR(stb.st_mode)) {
1078 					errno = ENOTDIR;
1079 					goto bad;
1080 				}
1081 				if (pflag)
1082 					(void) chmod(np, mode);
1083 			} else {
1084 				/* Handle copying from a read-only
1085 				   directory */
1086 				mod_flag = 1;
1087 				if (mkdir(np, mode | S_IRWXU) < 0)
1088 					goto bad;
1089 			}
1090 			vect[0] = xstrdup(np);
1091 			sink(1, vect);
1092 			if (setimes) {
1093 				setimes = 0;
1094 				if (utimes(vect[0], tv) < 0)
1095 					run_err("%s: set times: %s",
1096 					    vect[0], strerror(errno));
1097 			}
1098 			if (mod_flag)
1099 				(void) chmod(vect[0], mode);
1100 			free(vect[0]);
1101 			continue;
1102 		}
1103 		omode = mode;
1104 		mode |= S_IWUSR;
1105 		if ((ofd = open(np, O_WRONLY|O_CREAT, mode)) < 0) {
1106 bad:			run_err("%s: %s", np, strerror(errno));
1107 			continue;
1108 		}
1109 		(void) atomicio(vwrite, remout, "", 1);
1110 		if ((bp = allocbuf(&buffer, ofd, COPY_BUFLEN)) == NULL) {
1111 			(void) close(ofd);
1112 			continue;
1113 		}
1114 		cp = bp->buf;
1115 		wrerr = NO;
1116 
1117 		statbytes = 0;
1118 		if (showprogress)
1119 			start_progress_meter(curfile, size, &statbytes);
1120 		set_nonblock(remin);
1121 		for (count = i = 0; i < size; i += bp->cnt) {
1122 			amt = bp->cnt;
1123 			if (i + amt > size)
1124 				amt = size - i;
1125 			count += amt;
1126 			do {
1127 				j = atomicio6(read, remin, cp, amt,
1128 				    scpio, &statbytes);
1129 				if (j == 0) {
1130 					run_err("%s", j != EPIPE ?
1131 					    strerror(errno) :
1132 					    "dropped connection");
1133 					exit(1);
1134 				}
1135 				amt -= j;
1136 				cp += j;
1137 			} while (amt > 0);
1138 
1139 			if (count == bp->cnt) {
1140 				/* Keep reading so we stay sync'd up. */
1141 				if (wrerr == NO) {
1142 					if (atomicio(vwrite, ofd, bp->buf,
1143 					    count) != count) {
1144 						wrerr = YES;
1145 						wrerrno = errno;
1146 					}
1147 				}
1148 				count = 0;
1149 				cp = bp->buf;
1150 			}
1151 		}
1152 		unset_nonblock(remin);
1153 		if (count != 0 && wrerr == NO &&
1154 		    atomicio(vwrite, ofd, bp->buf, count) != count) {
1155 			wrerr = YES;
1156 			wrerrno = errno;
1157 		}
1158 		if (wrerr == NO && (!exists || S_ISREG(stb.st_mode)) &&
1159 		    ftruncate(ofd, size) != 0) {
1160 			run_err("%s: truncate: %s", np, strerror(errno));
1161 			wrerr = DISPLAYED;
1162 		}
1163 		if (pflag) {
1164 			if (exists || omode != mode)
1165 #ifdef HAVE_FCHMOD
1166 				if (fchmod(ofd, omode)) {
1167 #else /* HAVE_FCHMOD */
1168 				if (chmod(np, omode)) {
1169 #endif /* HAVE_FCHMOD */
1170 					run_err("%s: set mode: %s",
1171 					    np, strerror(errno));
1172 					wrerr = DISPLAYED;
1173 				}
1174 		} else {
1175 			if (!exists && omode != mode)
1176 #ifdef HAVE_FCHMOD
1177 				if (fchmod(ofd, omode & ~mask)) {
1178 #else /* HAVE_FCHMOD */
1179 				if (chmod(np, omode & ~mask)) {
1180 #endif /* HAVE_FCHMOD */
1181 					run_err("%s: set mode: %s",
1182 					    np, strerror(errno));
1183 					wrerr = DISPLAYED;
1184 				}
1185 		}
1186 		if (close(ofd) == -1) {
1187 			wrerr = YES;
1188 			wrerrno = errno;
1189 		}
1190 		(void) response();
1191 		if (showprogress)
1192 			stop_progress_meter();
1193 		if (setimes && wrerr == NO) {
1194 			setimes = 0;
1195 			if (utimes(np, tv) < 0) {
1196 				run_err("%s: set times: %s",
1197 				    np, strerror(errno));
1198 				wrerr = DISPLAYED;
1199 			}
1200 		}
1201 		switch (wrerr) {
1202 		case YES:
1203 			run_err("%s: %s", np, strerror(wrerrno));
1204 			break;
1205 		case NO:
1206 			(void) atomicio(vwrite, remout, "", 1);
1207 			break;
1208 		case DISPLAYED:
1209 			break;
1210 		}
1211 	}
1212 screwup:
1213 	run_err("protocol error: %s", why);
1214 	exit(1);
1215 }
1216 
1217 int
1218 response(void)
1219 {
1220 	char ch, *cp, resp, rbuf[2048], visbuf[2048];
1221 
1222 	if (atomicio(read, remin, &resp, sizeof(resp)) != sizeof(resp))
1223 		lostconn(0);
1224 
1225 	cp = rbuf;
1226 	switch (resp) {
1227 	case 0:		/* ok */
1228 		return (0);
1229 	default:
1230 		*cp++ = resp;
1231 		/* FALLTHROUGH */
1232 	case 1:		/* error, followed by error msg */
1233 	case 2:		/* fatal error, "" */
1234 		do {
1235 			if (atomicio(read, remin, &ch, sizeof(ch)) != sizeof(ch))
1236 				lostconn(0);
1237 			*cp++ = ch;
1238 		} while (cp < &rbuf[sizeof(rbuf) - 1] && ch != '\n');
1239 
1240 		if (!iamremote) {
1241 			cp[-1] = '\0';
1242 			(void) snmprintf(visbuf, sizeof(visbuf),
1243 			    NULL, "%s\n", rbuf);
1244 			(void) atomicio(vwrite, STDERR_FILENO,
1245 			    visbuf, strlen(visbuf));
1246 		}
1247 		++errs;
1248 		if (resp == 1)
1249 			return (-1);
1250 		exit(1);
1251 	}
1252 	/* NOTREACHED */
1253 }
1254 
1255 void
1256 usage(void)
1257 {
1258 	(void) fprintf(stderr,
1259 	    "usage: scp [-12346BCpqrv] [-c cipher] [-F ssh_config] [-i identity_file]\n"
1260 	    "           [-l limit] [-o ssh_option] [-P port] [-S program]\n"
1261 	    "           [[user@]host1:]file1 ... [[user@]host2:]file2\n");
1262 	exit(1);
1263 }
1264 
1265 void
1266 run_err(const char *fmt,...)
1267 {
1268 	static FILE *fp;
1269 	va_list ap;
1270 
1271 	++errs;
1272 	if (fp != NULL || (remout != -1 && (fp = fdopen(remout, "w")))) {
1273 		(void) fprintf(fp, "%c", 0x01);
1274 		(void) fprintf(fp, "scp: ");
1275 		va_start(ap, fmt);
1276 		(void) vfprintf(fp, fmt, ap);
1277 		va_end(ap);
1278 		(void) fprintf(fp, "\n");
1279 		(void) fflush(fp);
1280 	}
1281 
1282 	if (!iamremote) {
1283 		va_start(ap, fmt);
1284 		vfmprintf(stderr, fmt, ap);
1285 		va_end(ap);
1286 		fprintf(stderr, "\n");
1287 	}
1288 }
1289 
1290 void
1291 verifydir(char *cp)
1292 {
1293 	struct stat stb;
1294 
1295 	if (!stat(cp, &stb)) {
1296 		if (S_ISDIR(stb.st_mode))
1297 			return;
1298 		errno = ENOTDIR;
1299 	}
1300 	run_err("%s: %s", cp, strerror(errno));
1301 	killchild(0);
1302 }
1303 
1304 int
1305 okname(char *cp0)
1306 {
1307 	int c;
1308 	char *cp;
1309 
1310 	cp = cp0;
1311 	do {
1312 		c = (int)*cp;
1313 		if (c & 0200)
1314 			goto bad;
1315 		if (!isalpha(c) && !isdigit((unsigned char)c)) {
1316 			switch (c) {
1317 			case '\'':
1318 			case '"':
1319 			case '`':
1320 			case ' ':
1321 			case '#':
1322 				goto bad;
1323 			default:
1324 				break;
1325 			}
1326 		}
1327 	} while (*++cp);
1328 	return (1);
1329 
1330 bad:	fmprintf(stderr, "%s: invalid user name\n", cp0);
1331 	return (0);
1332 }
1333 
1334 BUF *
1335 allocbuf(BUF *bp, int fd, int blksize)
1336 {
1337 	size_t size;
1338 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
1339 	struct stat stb;
1340 
1341 	if (fstat(fd, &stb) < 0) {
1342 		run_err("fstat: %s", strerror(errno));
1343 		return (0);
1344 	}
1345 	size = ROUNDUP(stb.st_blksize, blksize);
1346 	if (size == 0)
1347 		size = blksize;
1348 #else /* HAVE_STRUCT_STAT_ST_BLKSIZE */
1349 	size = blksize;
1350 #endif /* HAVE_STRUCT_STAT_ST_BLKSIZE */
1351 	if (bp->cnt >= size)
1352 		return (bp);
1353 	if (bp->buf == NULL)
1354 		bp->buf = xmalloc(size);
1355 	else
1356 		bp->buf = xreallocarray(bp->buf, 1, size);
1357 	memset(bp->buf, 0, size);
1358 	bp->cnt = size;
1359 	return (bp);
1360 }
1361 
1362 void
1363 lostconn(int signo)
1364 {
1365 	if (!iamremote)
1366 		(void)write(STDERR_FILENO, "lost connection\n", 16);
1367 	if (signo)
1368 		_exit(1);
1369 	else
1370 		exit(1);
1371 }
1372