xref: /openbsd-src/usr.bin/ssh/scp.c (revision c0dd97bfcad3dab6c31ec12b9de1274fd2d2f993) 
1 /* $OpenBSD: scp.c,v 1.193 2017/10/21 23:06:24 millert 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 <sys/types.h>
75 #include <sys/poll.h>
76 #include <sys/wait.h>
77 #include <sys/stat.h>
78 #include <sys/time.h>
79 #include <sys/uio.h>
80 
81 #include <ctype.h>
82 #include <dirent.h>
83 #include <errno.h>
84 #include <fcntl.h>
85 #include <locale.h>
86 #include <pwd.h>
87 #include <signal.h>
88 #include <stdarg.h>
89 #include <stdint.h>
90 #include <stdio.h>
91 #include <stdlib.h>
92 #include <string.h>
93 #include <time.h>
94 #include <unistd.h>
95 #include <limits.h>
96 #include <vis.h>
97 
98 #include "xmalloc.h"
99 #include "ssh.h"
100 #include "atomicio.h"
101 #include "pathnames.h"
102 #include "log.h"
103 #include "misc.h"
104 #include "progressmeter.h"
105 #include "utf8.h"
106 
107 #define COPY_BUFLEN	16384
108 
109 int do_cmd(char *host, char *remuser, int port, char *cmd, int *fdin, int *fdout);
110 int do_cmd2(char *host, char *remuser, int port, char *cmd, int fdin, int fdout);
111 
112 /* Struct for addargs */
113 arglist args;
114 arglist remote_remote_args;
115 
116 /* Bandwidth limit */
117 long long limit_kbps = 0;
118 struct bwlimit bwlimit;
119 
120 /* Name of current file being transferred. */
121 char *curfile;
122 
123 /* This is set to non-zero to enable verbose mode. */
124 int verbose_mode = 0;
125 
126 /* This is set to zero if the progressmeter is not desired. */
127 int showprogress = 1;
128 
129 /*
130  * This is set to non-zero if remote-remote copy should be piped
131  * through this process.
132  */
133 int throughlocal = 0;
134 
135 /* Non-standard port to use for the ssh connection or -1. */
136 int sshport = -1;
137 
138 /* This is the program to execute for the secured connection. ("ssh" or -S) */
139 char *ssh_program = _PATH_SSH_PROGRAM;
140 
141 /* This is used to store the pid of ssh_program */
142 pid_t do_cmd_pid = -1;
143 
144 static void
145 killchild(int signo)
146 {
147 	if (do_cmd_pid > 1) {
148 		kill(do_cmd_pid, signo ? signo : SIGTERM);
149 		waitpid(do_cmd_pid, NULL, 0);
150 	}
151 
152 	if (signo)
153 		_exit(1);
154 	exit(1);
155 }
156 
157 static void
158 suspchild(int signo)
159 {
160 	int status;
161 
162 	if (do_cmd_pid > 1) {
163 		kill(do_cmd_pid, signo);
164 		while (waitpid(do_cmd_pid, &status, WUNTRACED) == -1 &&
165 		    errno == EINTR)
166 			;
167 		kill(getpid(), SIGSTOP);
168 	}
169 }
170 
171 static int
172 do_local_cmd(arglist *a)
173 {
174 	u_int i;
175 	int status;
176 	pid_t pid;
177 
178 	if (a->num == 0)
179 		fatal("do_local_cmd: no arguments");
180 
181 	if (verbose_mode) {
182 		fprintf(stderr, "Executing:");
183 		for (i = 0; i < a->num; i++)
184 			fmprintf(stderr, " %s", a->list[i]);
185 		fprintf(stderr, "\n");
186 	}
187 	if ((pid = fork()) == -1)
188 		fatal("do_local_cmd: fork: %s", strerror(errno));
189 
190 	if (pid == 0) {
191 		execvp(a->list[0], a->list);
192 		perror(a->list[0]);
193 		exit(1);
194 	}
195 
196 	do_cmd_pid = pid;
197 	signal(SIGTERM, killchild);
198 	signal(SIGINT, killchild);
199 	signal(SIGHUP, killchild);
200 
201 	while (waitpid(pid, &status, 0) == -1)
202 		if (errno != EINTR)
203 			fatal("do_local_cmd: waitpid: %s", strerror(errno));
204 
205 	do_cmd_pid = -1;
206 
207 	if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
208 		return (-1);
209 
210 	return (0);
211 }
212 
213 /*
214  * This function executes the given command as the specified user on the
215  * given host.  This returns < 0 if execution fails, and >= 0 otherwise. This
216  * assigns the input and output file descriptors on success.
217  */
218 
219 int
220 do_cmd(char *host, char *remuser, int port, char *cmd, int *fdin, int *fdout)
221 {
222 	int pin[2], pout[2], reserved[2];
223 
224 	if (verbose_mode)
225 		fmprintf(stderr,
226 		    "Executing: program %s host %s, user %s, command %s\n",
227 		    ssh_program, host,
228 		    remuser ? remuser : "(unspecified)", cmd);
229 
230 	if (port == -1)
231 		port = sshport;
232 
233 	/*
234 	 * Reserve two descriptors so that the real pipes won't get
235 	 * descriptors 0 and 1 because that will screw up dup2 below.
236 	 */
237 	if (pipe(reserved) < 0)
238 		fatal("pipe: %s", strerror(errno));
239 
240 	/* Create a socket pair for communicating with ssh. */
241 	if (pipe(pin) < 0)
242 		fatal("pipe: %s", strerror(errno));
243 	if (pipe(pout) < 0)
244 		fatal("pipe: %s", strerror(errno));
245 
246 	/* Free the reserved descriptors. */
247 	close(reserved[0]);
248 	close(reserved[1]);
249 
250 	signal(SIGTSTP, suspchild);
251 	signal(SIGTTIN, suspchild);
252 	signal(SIGTTOU, suspchild);
253 
254 	/* Fork a child to execute the command on the remote host using ssh. */
255 	do_cmd_pid = fork();
256 	if (do_cmd_pid == 0) {
257 		/* Child. */
258 		close(pin[1]);
259 		close(pout[0]);
260 		dup2(pin[0], 0);
261 		dup2(pout[1], 1);
262 		close(pin[0]);
263 		close(pout[1]);
264 
265 		replacearg(&args, 0, "%s", ssh_program);
266 		if (port != -1) {
267 			addargs(&args, "-p");
268 			addargs(&args, "%d", port);
269 		}
270 		if (remuser != NULL) {
271 			addargs(&args, "-l");
272 			addargs(&args, "%s", remuser);
273 		}
274 		addargs(&args, "--");
275 		addargs(&args, "%s", host);
276 		addargs(&args, "%s", cmd);
277 
278 		execvp(ssh_program, args.list);
279 		perror(ssh_program);
280 		exit(1);
281 	} else if (do_cmd_pid == -1) {
282 		fatal("fork: %s", strerror(errno));
283 	}
284 	/* Parent.  Close the other side, and return the local side. */
285 	close(pin[0]);
286 	*fdout = pin[1];
287 	close(pout[1]);
288 	*fdin = pout[0];
289 	signal(SIGTERM, killchild);
290 	signal(SIGINT, killchild);
291 	signal(SIGHUP, killchild);
292 	return 0;
293 }
294 
295 /*
296  * This functions executes a command simlar to do_cmd(), but expects the
297  * input and output descriptors to be setup by a previous call to do_cmd().
298  * This way the input and output of two commands can be connected.
299  */
300 int
301 do_cmd2(char *host, char *remuser, int port, char *cmd, int fdin, int fdout)
302 {
303 	pid_t pid;
304 	int status;
305 
306 	if (verbose_mode)
307 		fmprintf(stderr,
308 		    "Executing: 2nd program %s host %s, user %s, command %s\n",
309 		    ssh_program, host,
310 		    remuser ? remuser : "(unspecified)", cmd);
311 
312 	if (port == -1)
313 		port = sshport;
314 
315 	/* Fork a child to execute the command on the remote host using ssh. */
316 	pid = fork();
317 	if (pid == 0) {
318 		dup2(fdin, 0);
319 		dup2(fdout, 1);
320 
321 		replacearg(&args, 0, "%s", ssh_program);
322 		if (port != -1) {
323 			addargs(&args, "-p");
324 			addargs(&args, "%d", port);
325 		}
326 		if (remuser != NULL) {
327 			addargs(&args, "-l");
328 			addargs(&args, "%s", remuser);
329 		}
330 		addargs(&args, "--");
331 		addargs(&args, "%s", host);
332 		addargs(&args, "%s", cmd);
333 
334 		execvp(ssh_program, args.list);
335 		perror(ssh_program);
336 		exit(1);
337 	} else if (pid == -1) {
338 		fatal("fork: %s", strerror(errno));
339 	}
340 	while (waitpid(pid, &status, 0) == -1)
341 		if (errno != EINTR)
342 			fatal("do_cmd2: waitpid: %s", strerror(errno));
343 	return 0;
344 }
345 
346 typedef struct {
347 	size_t cnt;
348 	char *buf;
349 } BUF;
350 
351 BUF *allocbuf(BUF *, int, int);
352 void lostconn(int);
353 int okname(char *);
354 void run_err(const char *,...);
355 void verifydir(char *);
356 
357 struct passwd *pwd;
358 uid_t userid;
359 int errs, remin, remout;
360 int pflag, iamremote, iamrecursive, targetshouldbedirectory;
361 
362 #define	CMDNEEDS	64
363 char cmd[CMDNEEDS];		/* must hold "rcp -r -p -d\0" */
364 
365 int response(void);
366 void rsource(char *, struct stat *);
367 void sink(int, char *[]);
368 void source(int, char *[]);
369 void tolocal(int, char *[]);
370 void toremote(int, char *[]);
371 void usage(void);
372 
373 int
374 main(int argc, char **argv)
375 {
376 	int ch, fflag, tflag, status, n;
377 	char **newargv;
378 	const char *errstr;
379 	extern char *optarg;
380 	extern int optind;
381 
382 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
383 	sanitise_stdfd();
384 
385 	setlocale(LC_CTYPE, "");
386 
387 	/* Copy argv, because we modify it */
388 	newargv = xcalloc(MAXIMUM(argc + 1, 1), sizeof(*newargv));
389 	for (n = 0; n < argc; n++)
390 		newargv[n] = xstrdup(argv[n]);
391 	argv = newargv;
392 
393 	memset(&args, '\0', sizeof(args));
394 	memset(&remote_remote_args, '\0', sizeof(remote_remote_args));
395 	args.list = remote_remote_args.list = NULL;
396 	addargs(&args, "%s", ssh_program);
397 	addargs(&args, "-x");
398 	addargs(&args, "-oForwardAgent=no");
399 	addargs(&args, "-oPermitLocalCommand=no");
400 	addargs(&args, "-oClearAllForwardings=yes");
401 
402 	fflag = tflag = 0;
403 	while ((ch = getopt(argc, argv, "dfl:prtvBCc:i:P:q12346S:o:F:")) != -1)
404 		switch (ch) {
405 		/* User-visible flags. */
406 		case '1':
407 			fatal("SSH protocol v.1 is no longer supported");
408 			break;
409 		case '2':
410 			/* Ignored */
411 			break;
412 		case '4':
413 		case '6':
414 		case 'C':
415 			addargs(&args, "-%c", ch);
416 			addargs(&remote_remote_args, "-%c", ch);
417 			break;
418 		case '3':
419 			throughlocal = 1;
420 			break;
421 		case 'o':
422 		case 'c':
423 		case 'i':
424 		case 'F':
425 			addargs(&remote_remote_args, "-%c", ch);
426 			addargs(&remote_remote_args, "%s", optarg);
427 			addargs(&args, "-%c", ch);
428 			addargs(&args, "%s", optarg);
429 			break;
430 		case 'P':
431 			sshport = a2port(optarg);
432 			if (sshport <= 0)
433 				fatal("bad port \"%s\"\n", optarg);
434 			break;
435 		case 'B':
436 			addargs(&remote_remote_args, "-oBatchmode=yes");
437 			addargs(&args, "-oBatchmode=yes");
438 			break;
439 		case 'l':
440 			limit_kbps = strtonum(optarg, 1, 100 * 1024 * 1024,
441 			    &errstr);
442 			if (errstr != NULL)
443 				usage();
444 			limit_kbps *= 1024; /* kbps */
445 			bandwidth_limit_init(&bwlimit, limit_kbps, COPY_BUFLEN);
446 			break;
447 		case 'p':
448 			pflag = 1;
449 			break;
450 		case 'r':
451 			iamrecursive = 1;
452 			break;
453 		case 'S':
454 			ssh_program = xstrdup(optarg);
455 			break;
456 		case 'v':
457 			addargs(&args, "-v");
458 			addargs(&remote_remote_args, "-v");
459 			verbose_mode = 1;
460 			break;
461 		case 'q':
462 			addargs(&args, "-q");
463 			addargs(&remote_remote_args, "-q");
464 			showprogress = 0;
465 			break;
466 
467 		/* Server options. */
468 		case 'd':
469 			targetshouldbedirectory = 1;
470 			break;
471 		case 'f':	/* "from" */
472 			iamremote = 1;
473 			fflag = 1;
474 			break;
475 		case 't':	/* "to" */
476 			iamremote = 1;
477 			tflag = 1;
478 			break;
479 		default:
480 			usage();
481 		}
482 	argc -= optind;
483 	argv += optind;
484 
485 	if ((pwd = getpwuid(userid = getuid())) == NULL)
486 		fatal("unknown user %u", (u_int) userid);
487 
488 	if (!isatty(STDOUT_FILENO))
489 		showprogress = 0;
490 
491 	if (pflag) {
492 		/* Cannot pledge: -p allows setuid/setgid files... */
493 	} else {
494 		if (pledge("stdio rpath wpath cpath fattr tty proc exec",
495 		    NULL) == -1) {
496 			perror("pledge");
497 			exit(1);
498 		}
499 	}
500 
501 	remin = STDIN_FILENO;
502 	remout = STDOUT_FILENO;
503 
504 	if (fflag) {
505 		/* Follow "protocol", send data. */
506 		(void) response();
507 		source(argc, argv);
508 		exit(errs != 0);
509 	}
510 	if (tflag) {
511 		/* Receive data. */
512 		sink(argc, argv);
513 		exit(errs != 0);
514 	}
515 	if (argc < 2)
516 		usage();
517 	if (argc > 2)
518 		targetshouldbedirectory = 1;
519 
520 	remin = remout = -1;
521 	do_cmd_pid = -1;
522 	/* Command to be executed on remote system using "ssh". */
523 	(void) snprintf(cmd, sizeof cmd, "scp%s%s%s%s",
524 	    verbose_mode ? " -v" : "",
525 	    iamrecursive ? " -r" : "", pflag ? " -p" : "",
526 	    targetshouldbedirectory ? " -d" : "");
527 
528 	(void) signal(SIGPIPE, lostconn);
529 
530 	if (colon(argv[argc - 1]))	/* Dest is remote host. */
531 		toremote(argc, argv);
532 	else {
533 		if (targetshouldbedirectory)
534 			verifydir(argv[argc - 1]);
535 		tolocal(argc, argv);	/* Dest is local host. */
536 	}
537 	/*
538 	 * Finally check the exit status of the ssh process, if one was forked
539 	 * and no error has occurred yet
540 	 */
541 	if (do_cmd_pid != -1 && errs == 0) {
542 		if (remin != -1)
543 		    (void) close(remin);
544 		if (remout != -1)
545 		    (void) close(remout);
546 		if (waitpid(do_cmd_pid, &status, 0) == -1)
547 			errs = 1;
548 		else {
549 			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
550 				errs = 1;
551 		}
552 	}
553 	exit(errs != 0);
554 }
555 
556 /* Callback from atomicio6 to update progress meter and limit bandwidth */
557 static int
558 scpio(void *_cnt, size_t s)
559 {
560 	off_t *cnt = (off_t *)_cnt;
561 
562 	*cnt += s;
563 	if (limit_kbps > 0)
564 		bandwidth_limit(&bwlimit, s);
565 	return 0;
566 }
567 
568 static int
569 do_times(int fd, int verb, const struct stat *sb)
570 {
571 	/* strlen(2^64) == 20; strlen(10^6) == 7 */
572 	char buf[(20 + 7 + 2) * 2 + 2];
573 
574 	(void)snprintf(buf, sizeof(buf), "T%llu 0 %llu 0\n",
575 	    (unsigned long long) (sb->st_mtime < 0 ? 0 : sb->st_mtime),
576 	    (unsigned long long) (sb->st_atime < 0 ? 0 : sb->st_atime));
577 	if (verb) {
578 		fprintf(stderr, "File mtime %lld atime %lld\n",
579 		    (long long)sb->st_mtime, (long long)sb->st_atime);
580 		fprintf(stderr, "Sending file timestamps: %s", buf);
581 	}
582 	(void) atomicio(vwrite, fd, buf, strlen(buf));
583 	return (response());
584 }
585 
586 void
587 toremote(int argc, char **argv)
588 {
589 	char *suser = NULL, *host = NULL, *src = NULL;
590 	char *bp, *tuser, *thost, *targ;
591 	int sport = -1, tport = -1;
592 	arglist alist;
593 	int i, r;
594 	u_int j;
595 
596 	memset(&alist, '\0', sizeof(alist));
597 	alist.list = NULL;
598 
599 	/* Parse target */
600 	r = parse_uri("scp", argv[argc - 1], &tuser, &thost, &tport, &targ);
601 	if (r == -1)
602 		goto out;	/* invalid URI */
603 	if (r != 0) {
604 		if (parse_user_host_path(argv[argc - 1], &tuser, &thost,
605 		    &targ) == -1)
606 			goto out;
607 	}
608 	if (tuser != NULL && !okname(tuser))
609 		goto out;
610 
611 	/* Parse source files */
612 	for (i = 0; i < argc - 1; i++) {
613 		free(suser);
614 		free(host);
615 		free(src);
616 		r = parse_uri("scp", argv[i], &suser, &host, &sport, &src);
617 		if (r == -1)
618 			continue;	/* invalid URI */
619 		if (r != 0)
620 			parse_user_host_path(argv[i], &suser, &host, &src);
621 		if (suser != NULL && !okname(suser)) {
622 			++errs;
623 			continue;
624 		}
625 		if (host && throughlocal) {	/* extended remote to remote */
626 			xasprintf(&bp, "%s -f %s%s", cmd,
627 			    *src == '-' ? "-- " : "", src);
628 			if (do_cmd(host, suser, sport, bp, &remin, &remout) < 0)
629 				exit(1);
630 			free(bp);
631 			xasprintf(&bp, "%s -t %s%s", cmd,
632 			    *targ == '-' ? "-- " : "", targ);
633 			if (do_cmd2(thost, tuser, tport, bp, remin, remout) < 0)
634 				exit(1);
635 			free(bp);
636 			(void) close(remin);
637 			(void) close(remout);
638 			remin = remout = -1;
639 		} else if (host) {	/* standard remote to remote */
640 			if (tport != -1 && tport != SSH_DEFAULT_PORT) {
641 				/* This would require the remote support URIs */
642 				fatal("target port not supported with two "
643 				    "remote hosts without the -3 option");
644 			}
645 
646 			freeargs(&alist);
647 			addargs(&alist, "%s", ssh_program);
648 			addargs(&alist, "-x");
649 			addargs(&alist, "-oClearAllForwardings=yes");
650 			addargs(&alist, "-n");
651 			for (j = 0; j < remote_remote_args.num; j++) {
652 				addargs(&alist, "%s",
653 				    remote_remote_args.list[j]);
654 			}
655 
656 			if (sport != -1) {
657 				addargs(&alist, "-p");
658 				addargs(&alist, "%d", sport);
659 			}
660 			if (suser) {
661 				addargs(&alist, "-l");
662 				addargs(&alist, "%s", suser);
663 			}
664 			addargs(&alist, "--");
665 			addargs(&alist, "%s", host);
666 			addargs(&alist, "%s", cmd);
667 			addargs(&alist, "%s", src);
668 			addargs(&alist, "%s%s%s:%s",
669 			    tuser ? tuser : "", tuser ? "@" : "",
670 			    thost, targ);
671 			if (do_local_cmd(&alist) != 0)
672 				errs = 1;
673 		} else {	/* local to remote */
674 			if (remin == -1) {
675 				xasprintf(&bp, "%s -t %s%s", cmd,
676 				    *targ == '-' ? "-- " : "", targ);
677 				if (do_cmd(thost, tuser, tport, bp, &remin,
678 				    &remout) < 0)
679 					exit(1);
680 				if (response() < 0)
681 					exit(1);
682 				free(bp);
683 			}
684 			source(1, argv + i);
685 		}
686 	}
687 out:
688 	free(tuser);
689 	free(thost);
690 	free(targ);
691 	free(suser);
692 	free(host);
693 	free(src);
694 }
695 
696 void
697 tolocal(int argc, char **argv)
698 {
699 	char *bp, *host = NULL, *src = NULL, *suser = NULL;
700 	arglist alist;
701 	int i, r, sport = -1;
702 
703 	memset(&alist, '\0', sizeof(alist));
704 	alist.list = NULL;
705 
706 	for (i = 0; i < argc - 1; i++) {
707 		free(suser);
708 		free(host);
709 		free(src);
710 		r = parse_uri("scp", argv[i], &suser, &host, &sport, &src);
711 		if (r == -1) {
712 			++errs;
713 			continue;
714 		}
715 		if (r != 0)
716 			parse_user_host_path(argv[i], &suser, &host, &src);
717 		if (suser != NULL && !okname(suser)) {
718 			++errs;
719 			continue;
720 		}
721 		if (!host) {	/* Local to local. */
722 			freeargs(&alist);
723 			addargs(&alist, "%s", _PATH_CP);
724 			if (iamrecursive)
725 				addargs(&alist, "-r");
726 			if (pflag)
727 				addargs(&alist, "-p");
728 			addargs(&alist, "--");
729 			addargs(&alist, "%s", argv[i]);
730 			addargs(&alist, "%s", argv[argc-1]);
731 			if (do_local_cmd(&alist))
732 				++errs;
733 			continue;
734 		}
735 		/* Remote to local. */
736 		xasprintf(&bp, "%s -f %s%s",
737 		    cmd, *src == '-' ? "-- " : "", src);
738 		if (do_cmd(host, suser, sport, bp, &remin, &remout) < 0) {
739 			free(bp);
740 			++errs;
741 			continue;
742 		}
743 		free(bp);
744 		sink(1, argv + argc - 1);
745 		(void) close(remin);
746 		remin = remout = -1;
747 	}
748 	free(suser);
749 	free(host);
750 	free(src);
751 }
752 
753 void
754 source(int argc, char **argv)
755 {
756 	struct stat stb;
757 	static BUF buffer;
758 	BUF *bp;
759 	off_t i, statbytes;
760 	size_t amt, nr;
761 	int fd = -1, haderr, indx;
762 	char *last, *name, buf[2048], encname[PATH_MAX];
763 	int len;
764 
765 	for (indx = 0; indx < argc; ++indx) {
766 		name = argv[indx];
767 		statbytes = 0;
768 		len = strlen(name);
769 		while (len > 1 && name[len-1] == '/')
770 			name[--len] = '\0';
771 		if ((fd = open(name, O_RDONLY|O_NONBLOCK, 0)) < 0)
772 			goto syserr;
773 		if (strchr(name, '\n') != NULL) {
774 			strnvis(encname, name, sizeof(encname), VIS_NL);
775 			name = encname;
776 		}
777 		if (fstat(fd, &stb) < 0) {
778 syserr:			run_err("%s: %s", name, strerror(errno));
779 			goto next;
780 		}
781 		if (stb.st_size < 0) {
782 			run_err("%s: %s", name, "Negative file size");
783 			goto next;
784 		}
785 		unset_nonblock(fd);
786 		switch (stb.st_mode & S_IFMT) {
787 		case S_IFREG:
788 			break;
789 		case S_IFDIR:
790 			if (iamrecursive) {
791 				rsource(name, &stb);
792 				goto next;
793 			}
794 			/* FALLTHROUGH */
795 		default:
796 			run_err("%s: not a regular file", name);
797 			goto next;
798 		}
799 		if ((last = strrchr(name, '/')) == NULL)
800 			last = name;
801 		else
802 			++last;
803 		curfile = last;
804 		if (pflag) {
805 			if (do_times(remout, verbose_mode, &stb) < 0)
806 				goto next;
807 		}
808 #define	FILEMODEMASK	(S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
809 		snprintf(buf, sizeof buf, "C%04o %lld %s\n",
810 		    (u_int) (stb.st_mode & FILEMODEMASK),
811 		    (long long)stb.st_size, last);
812 		if (verbose_mode)
813 			fmprintf(stderr, "Sending file modes: %s", buf);
814 		(void) atomicio(vwrite, remout, buf, strlen(buf));
815 		if (response() < 0)
816 			goto next;
817 		if ((bp = allocbuf(&buffer, fd, COPY_BUFLEN)) == NULL) {
818 next:			if (fd != -1) {
819 				(void) close(fd);
820 				fd = -1;
821 			}
822 			continue;
823 		}
824 		if (showprogress)
825 			start_progress_meter(curfile, stb.st_size, &statbytes);
826 		set_nonblock(remout);
827 		for (haderr = i = 0; i < stb.st_size; i += bp->cnt) {
828 			amt = bp->cnt;
829 			if (i + (off_t)amt > stb.st_size)
830 				amt = stb.st_size - i;
831 			if (!haderr) {
832 				if ((nr = atomicio(read, fd,
833 				    bp->buf, amt)) != amt) {
834 					haderr = errno;
835 					memset(bp->buf + nr, 0, amt - nr);
836 				}
837 			}
838 			/* Keep writing after error to retain sync */
839 			if (haderr) {
840 				(void)atomicio(vwrite, remout, bp->buf, amt);
841 				memset(bp->buf, 0, amt);
842 				continue;
843 			}
844 			if (atomicio6(vwrite, remout, bp->buf, amt, scpio,
845 			    &statbytes) != amt)
846 				haderr = errno;
847 		}
848 		unset_nonblock(remout);
849 
850 		if (fd != -1) {
851 			if (close(fd) < 0 && !haderr)
852 				haderr = errno;
853 			fd = -1;
854 		}
855 		if (!haderr)
856 			(void) atomicio(vwrite, remout, "", 1);
857 		else
858 			run_err("%s: %s", name, strerror(haderr));
859 		(void) response();
860 		if (showprogress)
861 			stop_progress_meter();
862 	}
863 }
864 
865 void
866 rsource(char *name, struct stat *statp)
867 {
868 	DIR *dirp;
869 	struct dirent *dp;
870 	char *last, *vect[1], path[PATH_MAX];
871 
872 	if (!(dirp = opendir(name))) {
873 		run_err("%s: %s", name, strerror(errno));
874 		return;
875 	}
876 	last = strrchr(name, '/');
877 	if (last == NULL)
878 		last = name;
879 	else
880 		last++;
881 	if (pflag) {
882 		if (do_times(remout, verbose_mode, statp) < 0) {
883 			closedir(dirp);
884 			return;
885 		}
886 	}
887 	(void) snprintf(path, sizeof path, "D%04o %d %.1024s\n",
888 	    (u_int) (statp->st_mode & FILEMODEMASK), 0, last);
889 	if (verbose_mode)
890 		fmprintf(stderr, "Entering directory: %s", path);
891 	(void) atomicio(vwrite, remout, path, strlen(path));
892 	if (response() < 0) {
893 		closedir(dirp);
894 		return;
895 	}
896 	while ((dp = readdir(dirp)) != NULL) {
897 		if (dp->d_ino == 0)
898 			continue;
899 		if (!strcmp(dp->d_name, ".") || !strcmp(dp->d_name, ".."))
900 			continue;
901 		if (strlen(name) + 1 + strlen(dp->d_name) >= sizeof(path) - 1) {
902 			run_err("%s/%s: name too long", name, dp->d_name);
903 			continue;
904 		}
905 		(void) snprintf(path, sizeof path, "%s/%s", name, dp->d_name);
906 		vect[0] = path;
907 		source(1, vect);
908 	}
909 	(void) closedir(dirp);
910 	(void) atomicio(vwrite, remout, "E\n", 2);
911 	(void) response();
912 }
913 
914 #define TYPE_OVERFLOW(type, val) \
915 	((sizeof(type) == 4 && (val) > INT32_MAX) || \
916 	 (sizeof(type) == 8 && (val) > INT64_MAX) || \
917 	 (sizeof(type) != 4 && sizeof(type) != 8))
918 
919 void
920 sink(int argc, char **argv)
921 {
922 	static BUF buffer;
923 	struct stat stb;
924 	enum {
925 		YES, NO, DISPLAYED
926 	} wrerr;
927 	BUF *bp;
928 	off_t i;
929 	size_t j, count;
930 	int amt, exists, first, ofd;
931 	mode_t mode, omode, mask;
932 	off_t size, statbytes;
933 	unsigned long long ull;
934 	int setimes, targisdir, wrerrno = 0;
935 	char ch, *cp, *np, *targ, *why, *vect[1], buf[2048], visbuf[2048];
936 	struct timeval tv[2];
937 
938 #define	atime	tv[0]
939 #define	mtime	tv[1]
940 #define	SCREWUP(str)	{ why = str; goto screwup; }
941 
942 	if (TYPE_OVERFLOW(time_t, 0) || TYPE_OVERFLOW(off_t, 0))
943 		SCREWUP("Unexpected off_t/time_t size");
944 
945 	setimes = targisdir = 0;
946 	mask = umask(0);
947 	if (!pflag)
948 		(void) umask(mask);
949 	if (argc != 1) {
950 		run_err("ambiguous target");
951 		exit(1);
952 	}
953 	targ = *argv;
954 	if (targetshouldbedirectory)
955 		verifydir(targ);
956 
957 	(void) atomicio(vwrite, remout, "", 1);
958 	if (stat(targ, &stb) == 0 && S_ISDIR(stb.st_mode))
959 		targisdir = 1;
960 	for (first = 1;; first = 0) {
961 		cp = buf;
962 		if (atomicio(read, remin, cp, 1) != 1)
963 			return;
964 		if (*cp++ == '\n')
965 			SCREWUP("unexpected <newline>");
966 		do {
967 			if (atomicio(read, remin, &ch, sizeof(ch)) != sizeof(ch))
968 				SCREWUP("lost connection");
969 			*cp++ = ch;
970 		} while (cp < &buf[sizeof(buf) - 1] && ch != '\n');
971 		*cp = 0;
972 		if (verbose_mode)
973 			fmprintf(stderr, "Sink: %s", buf);
974 
975 		if (buf[0] == '\01' || buf[0] == '\02') {
976 			if (iamremote == 0) {
977 				(void) snmprintf(visbuf, sizeof(visbuf),
978 				    NULL, "%s", buf + 1);
979 				(void) atomicio(vwrite, STDERR_FILENO,
980 				    visbuf, strlen(visbuf));
981 			}
982 			if (buf[0] == '\02')
983 				exit(1);
984 			++errs;
985 			continue;
986 		}
987 		if (buf[0] == 'E') {
988 			(void) atomicio(vwrite, remout, "", 1);
989 			return;
990 		}
991 		if (ch == '\n')
992 			*--cp = 0;
993 
994 		cp = buf;
995 		if (*cp == 'T') {
996 			setimes++;
997 			cp++;
998 			if (!isdigit((unsigned char)*cp))
999 				SCREWUP("mtime.sec not present");
1000 			ull = strtoull(cp, &cp, 10);
1001 			if (!cp || *cp++ != ' ')
1002 				SCREWUP("mtime.sec not delimited");
1003 			if (TYPE_OVERFLOW(time_t, ull))
1004 				setimes = 0;	/* out of range */
1005 			mtime.tv_sec = ull;
1006 			mtime.tv_usec = strtol(cp, &cp, 10);
1007 			if (!cp || *cp++ != ' ' || mtime.tv_usec < 0 ||
1008 			    mtime.tv_usec > 999999)
1009 				SCREWUP("mtime.usec not delimited");
1010 			if (!isdigit((unsigned char)*cp))
1011 				SCREWUP("atime.sec not present");
1012 			ull = strtoull(cp, &cp, 10);
1013 			if (!cp || *cp++ != ' ')
1014 				SCREWUP("atime.sec not delimited");
1015 			if (TYPE_OVERFLOW(time_t, ull))
1016 				setimes = 0;	/* out of range */
1017 			atime.tv_sec = ull;
1018 			atime.tv_usec = strtol(cp, &cp, 10);
1019 			if (!cp || *cp++ != '\0' || atime.tv_usec < 0 ||
1020 			    atime.tv_usec > 999999)
1021 				SCREWUP("atime.usec not delimited");
1022 			(void) atomicio(vwrite, remout, "", 1);
1023 			continue;
1024 		}
1025 		if (*cp != 'C' && *cp != 'D') {
1026 			/*
1027 			 * Check for the case "rcp remote:foo\* local:bar".
1028 			 * In this case, the line "No match." can be returned
1029 			 * by the shell before the rcp command on the remote is
1030 			 * executed so the ^Aerror_message convention isn't
1031 			 * followed.
1032 			 */
1033 			if (first) {
1034 				run_err("%s", cp);
1035 				exit(1);
1036 			}
1037 			SCREWUP("expected control record");
1038 		}
1039 		mode = 0;
1040 		for (++cp; cp < buf + 5; cp++) {
1041 			if (*cp < '0' || *cp > '7')
1042 				SCREWUP("bad mode");
1043 			mode = (mode << 3) | (*cp - '0');
1044 		}
1045 		if (*cp++ != ' ')
1046 			SCREWUP("mode not delimited");
1047 
1048 		if (!isdigit((unsigned char)*cp))
1049 			SCREWUP("size not present");
1050 		ull = strtoull(cp, &cp, 10);
1051 		if (!cp || *cp++ != ' ')
1052 			SCREWUP("size not delimited");
1053 		if (TYPE_OVERFLOW(off_t, ull))
1054 			SCREWUP("size out of range");
1055 		size = (off_t)ull;
1056 
1057 		if ((strchr(cp, '/') != NULL) || (strcmp(cp, "..") == 0)) {
1058 			run_err("error: unexpected filename: %s", cp);
1059 			exit(1);
1060 		}
1061 		if (targisdir) {
1062 			static char *namebuf;
1063 			static size_t cursize;
1064 			size_t need;
1065 
1066 			need = strlen(targ) + strlen(cp) + 250;
1067 			if (need > cursize) {
1068 				free(namebuf);
1069 				namebuf = xmalloc(need);
1070 				cursize = need;
1071 			}
1072 			(void) snprintf(namebuf, need, "%s%s%s", targ,
1073 			    strcmp(targ, "/") ? "/" : "", cp);
1074 			np = namebuf;
1075 		} else
1076 			np = targ;
1077 		curfile = cp;
1078 		exists = stat(np, &stb) == 0;
1079 		if (buf[0] == 'D') {
1080 			int mod_flag = pflag;
1081 			if (!iamrecursive)
1082 				SCREWUP("received directory without -r");
1083 			if (exists) {
1084 				if (!S_ISDIR(stb.st_mode)) {
1085 					errno = ENOTDIR;
1086 					goto bad;
1087 				}
1088 				if (pflag)
1089 					(void) chmod(np, mode);
1090 			} else {
1091 				/* Handle copying from a read-only
1092 				   directory */
1093 				mod_flag = 1;
1094 				if (mkdir(np, mode | S_IRWXU) < 0)
1095 					goto bad;
1096 			}
1097 			vect[0] = xstrdup(np);
1098 			sink(1, vect);
1099 			if (setimes) {
1100 				setimes = 0;
1101 				if (utimes(vect[0], tv) < 0)
1102 					run_err("%s: set times: %s",
1103 					    vect[0], strerror(errno));
1104 			}
1105 			if (mod_flag)
1106 				(void) chmod(vect[0], mode);
1107 			free(vect[0]);
1108 			continue;
1109 		}
1110 		omode = mode;
1111 		mode |= S_IWUSR;
1112 		if ((ofd = open(np, O_WRONLY|O_CREAT, mode)) < 0) {
1113 bad:			run_err("%s: %s", np, strerror(errno));
1114 			continue;
1115 		}
1116 		(void) atomicio(vwrite, remout, "", 1);
1117 		if ((bp = allocbuf(&buffer, ofd, COPY_BUFLEN)) == NULL) {
1118 			(void) close(ofd);
1119 			continue;
1120 		}
1121 		cp = bp->buf;
1122 		wrerr = NO;
1123 
1124 		statbytes = 0;
1125 		if (showprogress)
1126 			start_progress_meter(curfile, size, &statbytes);
1127 		set_nonblock(remin);
1128 		for (count = i = 0; i < size; i += bp->cnt) {
1129 			amt = bp->cnt;
1130 			if (i + amt > size)
1131 				amt = size - i;
1132 			count += amt;
1133 			do {
1134 				j = atomicio6(read, remin, cp, amt,
1135 				    scpio, &statbytes);
1136 				if (j == 0) {
1137 					run_err("%s", j != EPIPE ?
1138 					    strerror(errno) :
1139 					    "dropped connection");
1140 					exit(1);
1141 				}
1142 				amt -= j;
1143 				cp += j;
1144 			} while (amt > 0);
1145 
1146 			if (count == bp->cnt) {
1147 				/* Keep reading so we stay sync'd up. */
1148 				if (wrerr == NO) {
1149 					if (atomicio(vwrite, ofd, bp->buf,
1150 					    count) != count) {
1151 						wrerr = YES;
1152 						wrerrno = errno;
1153 					}
1154 				}
1155 				count = 0;
1156 				cp = bp->buf;
1157 			}
1158 		}
1159 		unset_nonblock(remin);
1160 		if (count != 0 && wrerr == NO &&
1161 		    atomicio(vwrite, ofd, bp->buf, count) != count) {
1162 			wrerr = YES;
1163 			wrerrno = errno;
1164 		}
1165 		if (wrerr == NO && (!exists || S_ISREG(stb.st_mode)) &&
1166 		    ftruncate(ofd, size) != 0) {
1167 			run_err("%s: truncate: %s", np, strerror(errno));
1168 			wrerr = DISPLAYED;
1169 		}
1170 		if (pflag) {
1171 			if (exists || omode != mode)
1172 				if (fchmod(ofd, omode)) {
1173 					run_err("%s: set mode: %s",
1174 					    np, strerror(errno));
1175 					wrerr = DISPLAYED;
1176 				}
1177 		} else {
1178 			if (!exists && omode != mode)
1179 				if (fchmod(ofd, omode & ~mask)) {
1180 					run_err("%s: set mode: %s",
1181 					    np, strerror(errno));
1182 					wrerr = DISPLAYED;
1183 				}
1184 		}
1185 		if (close(ofd) == -1) {
1186 			wrerr = YES;
1187 			wrerrno = errno;
1188 		}
1189 		(void) response();
1190 		if (showprogress)
1191 			stop_progress_meter();
1192 		if (setimes && wrerr == NO) {
1193 			setimes = 0;
1194 			if (utimes(np, tv) < 0) {
1195 				run_err("%s: set times: %s",
1196 				    np, strerror(errno));
1197 				wrerr = DISPLAYED;
1198 			}
1199 		}
1200 		switch (wrerr) {
1201 		case YES:
1202 			run_err("%s: %s", np, strerror(wrerrno));
1203 			break;
1204 		case NO:
1205 			(void) atomicio(vwrite, remout, "", 1);
1206 			break;
1207 		case DISPLAYED:
1208 			break;
1209 		}
1210 	}
1211 screwup:
1212 	run_err("protocol error: %s", why);
1213 	exit(1);
1214 }
1215 
1216 int
1217 response(void)
1218 {
1219 	char ch, *cp, resp, rbuf[2048], visbuf[2048];
1220 
1221 	if (atomicio(read, remin, &resp, sizeof(resp)) != sizeof(resp))
1222 		lostconn(0);
1223 
1224 	cp = rbuf;
1225 	switch (resp) {
1226 	case 0:		/* ok */
1227 		return (0);
1228 	default:
1229 		*cp++ = resp;
1230 		/* FALLTHROUGH */
1231 	case 1:		/* error, followed by error msg */
1232 	case 2:		/* fatal error, "" */
1233 		do {
1234 			if (atomicio(read, remin, &ch, sizeof(ch)) != sizeof(ch))
1235 				lostconn(0);
1236 			*cp++ = ch;
1237 		} while (cp < &rbuf[sizeof(rbuf) - 1] && ch != '\n');
1238 
1239 		if (!iamremote) {
1240 			cp[-1] = '\0';
1241 			(void) snmprintf(visbuf, sizeof(visbuf),
1242 			    NULL, "%s\n", rbuf);
1243 			(void) atomicio(vwrite, STDERR_FILENO,
1244 			    visbuf, strlen(visbuf));
1245 		}
1246 		++errs;
1247 		if (resp == 1)
1248 			return (-1);
1249 		exit(1);
1250 	}
1251 	/* NOTREACHED */
1252 }
1253 
1254 void
1255 usage(void)
1256 {
1257 	(void) fprintf(stderr,
1258 	    "usage: scp [-346BCpqrv] [-c cipher] [-F ssh_config] [-i identity_file]\n"
1259 	    "           [-l limit] [-o ssh_option] [-P port] [-S program] source ... target\n");
1260 	exit(1);
1261 }
1262 
1263 void
1264 run_err(const char *fmt,...)
1265 {
1266 	static FILE *fp;
1267 	va_list ap;
1268 
1269 	++errs;
1270 	if (fp != NULL || (remout != -1 && (fp = fdopen(remout, "w")))) {
1271 		(void) fprintf(fp, "%c", 0x01);
1272 		(void) fprintf(fp, "scp: ");
1273 		va_start(ap, fmt);
1274 		(void) vfprintf(fp, fmt, ap);
1275 		va_end(ap);
1276 		(void) fprintf(fp, "\n");
1277 		(void) fflush(fp);
1278 	}
1279 
1280 	if (!iamremote) {
1281 		va_start(ap, fmt);
1282 		vfmprintf(stderr, fmt, ap);
1283 		va_end(ap);
1284 		fprintf(stderr, "\n");
1285 	}
1286 }
1287 
1288 void
1289 verifydir(char *cp)
1290 {
1291 	struct stat stb;
1292 
1293 	if (!stat(cp, &stb)) {
1294 		if (S_ISDIR(stb.st_mode))
1295 			return;
1296 		errno = ENOTDIR;
1297 	}
1298 	run_err("%s: %s", cp, strerror(errno));
1299 	killchild(0);
1300 }
1301 
1302 int
1303 okname(char *cp0)
1304 {
1305 	int c;
1306 	char *cp;
1307 
1308 	cp = cp0;
1309 	do {
1310 		c = (int)*cp;
1311 		if (c & 0200)
1312 			goto bad;
1313 		if (!isalpha(c) && !isdigit((unsigned char)c)) {
1314 			switch (c) {
1315 			case '\'':
1316 			case '"':
1317 			case '`':
1318 			case ' ':
1319 			case '#':
1320 				goto bad;
1321 			default:
1322 				break;
1323 			}
1324 		}
1325 	} while (*++cp);
1326 	return (1);
1327 
1328 bad:	fmprintf(stderr, "%s: invalid user name\n", cp0);
1329 	return (0);
1330 }
1331 
1332 BUF *
1333 allocbuf(BUF *bp, int fd, int blksize)
1334 {
1335 	size_t size;
1336 	struct stat stb;
1337 
1338 	if (fstat(fd, &stb) < 0) {
1339 		run_err("fstat: %s", strerror(errno));
1340 		return (0);
1341 	}
1342 	size = ROUNDUP(stb.st_blksize, blksize);
1343 	if (size == 0)
1344 		size = blksize;
1345 	if (bp->cnt >= size)
1346 		return (bp);
1347 	bp->buf = xrecallocarray(bp->buf, bp->cnt, size, 1);
1348 	bp->cnt = size;
1349 	return (bp);
1350 }
1351 
1352 void
1353 lostconn(int signo)
1354 {
1355 	if (!iamremote)
1356 		(void)write(STDERR_FILENO, "lost connection\n", 16);
1357 	if (signo)
1358 		_exit(1);
1359 	else
1360 		exit(1);
1361 }
1362