xref: /openssh-portable/scp.c (revision 77e05394)
1 /* $OpenBSD: scp.c,v 1.195 2018/02/10 06:15:12 djm 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 #ifdef HAVE_STDINT_H
103 #include <stdint.h>
104 #endif
105 #include <stdio.h>
106 #include <stdlib.h>
107 #include <string.h>
108 #include <time.h>
109 #include <unistd.h>
110 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
111 #include <vis.h>
112 #endif
113 
114 #include "xmalloc.h"
115 #include "ssh.h"
116 #include "atomicio.h"
117 #include "pathnames.h"
118 #include "log.h"
119 #include "misc.h"
120 #include "progressmeter.h"
121 #include "utf8.h"
122 
123 extern char *__progname;
124 
125 #define COPY_BUFLEN	16384
126 
127 int do_cmd(char *host, char *remuser, int port, char *cmd, int *fdin, int *fdout);
128 int do_cmd2(char *host, char *remuser, int port, char *cmd, int fdin, int fdout);
129 
130 /* Struct for addargs */
131 arglist args;
132 arglist remote_remote_args;
133 
134 /* Bandwidth limit */
135 long long limit_kbps = 0;
136 struct bwlimit bwlimit;
137 
138 /* Name of current file being transferred. */
139 char *curfile;
140 
141 /* This is set to non-zero to enable verbose mode. */
142 int verbose_mode = 0;
143 
144 /* This is set to zero if the progressmeter is not desired. */
145 int showprogress = 1;
146 
147 /*
148  * This is set to non-zero if remote-remote copy should be piped
149  * through this process.
150  */
151 int throughlocal = 0;
152 
153 /* Non-standard port to use for the ssh connection or -1. */
154 int sshport = -1;
155 
156 /* This is the program to execute for the secured connection. ("ssh" or -S) */
157 char *ssh_program = _PATH_SSH_PROGRAM;
158 
159 /* This is used to store the pid of ssh_program */
160 pid_t do_cmd_pid = -1;
161 
162 static void
163 killchild(int signo)
164 {
165 	if (do_cmd_pid > 1) {
166 		kill(do_cmd_pid, signo ? signo : SIGTERM);
167 		waitpid(do_cmd_pid, NULL, 0);
168 	}
169 
170 	if (signo)
171 		_exit(1);
172 	exit(1);
173 }
174 
175 static void
176 suspchild(int signo)
177 {
178 	int status;
179 
180 	if (do_cmd_pid > 1) {
181 		kill(do_cmd_pid, signo);
182 		while (waitpid(do_cmd_pid, &status, WUNTRACED) == -1 &&
183 		    errno == EINTR)
184 			;
185 		kill(getpid(), SIGSTOP);
186 	}
187 }
188 
189 static int
190 do_local_cmd(arglist *a)
191 {
192 	u_int i;
193 	int status;
194 	pid_t pid;
195 
196 	if (a->num == 0)
197 		fatal("do_local_cmd: no arguments");
198 
199 	if (verbose_mode) {
200 		fprintf(stderr, "Executing:");
201 		for (i = 0; i < a->num; i++)
202 			fmprintf(stderr, " %s", a->list[i]);
203 		fprintf(stderr, "\n");
204 	}
205 	if ((pid = fork()) == -1)
206 		fatal("do_local_cmd: fork: %s", strerror(errno));
207 
208 	if (pid == 0) {
209 		execvp(a->list[0], a->list);
210 		perror(a->list[0]);
211 		exit(1);
212 	}
213 
214 	do_cmd_pid = pid;
215 	signal(SIGTERM, killchild);
216 	signal(SIGINT, killchild);
217 	signal(SIGHUP, killchild);
218 
219 	while (waitpid(pid, &status, 0) == -1)
220 		if (errno != EINTR)
221 			fatal("do_local_cmd: waitpid: %s", strerror(errno));
222 
223 	do_cmd_pid = -1;
224 
225 	if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
226 		return (-1);
227 
228 	return (0);
229 }
230 
231 /*
232  * This function executes the given command as the specified user on the
233  * given host.  This returns < 0 if execution fails, and >= 0 otherwise. This
234  * assigns the input and output file descriptors on success.
235  */
236 
237 int
238 do_cmd(char *host, char *remuser, int port, char *cmd, int *fdin, int *fdout)
239 {
240 	int pin[2], pout[2], reserved[2];
241 
242 	if (verbose_mode)
243 		fmprintf(stderr,
244 		    "Executing: program %s host %s, user %s, command %s\n",
245 		    ssh_program, host,
246 		    remuser ? remuser : "(unspecified)", cmd);
247 
248 	if (port == -1)
249 		port = sshport;
250 
251 	/*
252 	 * Reserve two descriptors so that the real pipes won't get
253 	 * descriptors 0 and 1 because that will screw up dup2 below.
254 	 */
255 	if (pipe(reserved) < 0)
256 		fatal("pipe: %s", strerror(errno));
257 
258 	/* Create a socket pair for communicating with ssh. */
259 	if (pipe(pin) < 0)
260 		fatal("pipe: %s", strerror(errno));
261 	if (pipe(pout) < 0)
262 		fatal("pipe: %s", strerror(errno));
263 
264 	/* Free the reserved descriptors. */
265 	close(reserved[0]);
266 	close(reserved[1]);
267 
268 	signal(SIGTSTP, suspchild);
269 	signal(SIGTTIN, suspchild);
270 	signal(SIGTTOU, suspchild);
271 
272 	/* Fork a child to execute the command on the remote host using ssh. */
273 	do_cmd_pid = fork();
274 	if (do_cmd_pid == 0) {
275 		/* Child. */
276 		close(pin[1]);
277 		close(pout[0]);
278 		dup2(pin[0], 0);
279 		dup2(pout[1], 1);
280 		close(pin[0]);
281 		close(pout[1]);
282 
283 		replacearg(&args, 0, "%s", ssh_program);
284 		if (port != -1) {
285 			addargs(&args, "-p");
286 			addargs(&args, "%d", port);
287 		}
288 		if (remuser != NULL) {
289 			addargs(&args, "-l");
290 			addargs(&args, "%s", remuser);
291 		}
292 		addargs(&args, "--");
293 		addargs(&args, "%s", host);
294 		addargs(&args, "%s", cmd);
295 
296 		execvp(ssh_program, args.list);
297 		perror(ssh_program);
298 		exit(1);
299 	} else if (do_cmd_pid == -1) {
300 		fatal("fork: %s", strerror(errno));
301 	}
302 	/* Parent.  Close the other side, and return the local side. */
303 	close(pin[0]);
304 	*fdout = pin[1];
305 	close(pout[1]);
306 	*fdin = pout[0];
307 	signal(SIGTERM, killchild);
308 	signal(SIGINT, killchild);
309 	signal(SIGHUP, killchild);
310 	return 0;
311 }
312 
313 /*
314  * This functions executes a command simlar to do_cmd(), but expects the
315  * input and output descriptors to be setup by a previous call to do_cmd().
316  * This way the input and output of two commands can be connected.
317  */
318 int
319 do_cmd2(char *host, char *remuser, int port, char *cmd, int fdin, int fdout)
320 {
321 	pid_t pid;
322 	int status;
323 
324 	if (verbose_mode)
325 		fmprintf(stderr,
326 		    "Executing: 2nd program %s host %s, user %s, command %s\n",
327 		    ssh_program, host,
328 		    remuser ? remuser : "(unspecified)", cmd);
329 
330 	if (port == -1)
331 		port = sshport;
332 
333 	/* Fork a child to execute the command on the remote host using ssh. */
334 	pid = fork();
335 	if (pid == 0) {
336 		dup2(fdin, 0);
337 		dup2(fdout, 1);
338 
339 		replacearg(&args, 0, "%s", ssh_program);
340 		if (port != -1) {
341 			addargs(&args, "-p");
342 			addargs(&args, "%d", port);
343 		}
344 		if (remuser != NULL) {
345 			addargs(&args, "-l");
346 			addargs(&args, "%s", remuser);
347 		}
348 		addargs(&args, "--");
349 		addargs(&args, "%s", host);
350 		addargs(&args, "%s", cmd);
351 
352 		execvp(ssh_program, args.list);
353 		perror(ssh_program);
354 		exit(1);
355 	} else if (pid == -1) {
356 		fatal("fork: %s", strerror(errno));
357 	}
358 	while (waitpid(pid, &status, 0) == -1)
359 		if (errno != EINTR)
360 			fatal("do_cmd2: waitpid: %s", strerror(errno));
361 	return 0;
362 }
363 
364 typedef struct {
365 	size_t cnt;
366 	char *buf;
367 } BUF;
368 
369 BUF *allocbuf(BUF *, int, int);
370 void lostconn(int);
371 int okname(char *);
372 void run_err(const char *,...);
373 void verifydir(char *);
374 
375 struct passwd *pwd;
376 uid_t userid;
377 int errs, remin, remout;
378 int pflag, iamremote, iamrecursive, targetshouldbedirectory;
379 
380 #define	CMDNEEDS	64
381 char cmd[CMDNEEDS];		/* must hold "rcp -r -p -d\0" */
382 
383 int response(void);
384 void rsource(char *, struct stat *);
385 void sink(int, char *[]);
386 void source(int, char *[]);
387 void tolocal(int, char *[]);
388 void toremote(int, char *[]);
389 void usage(void);
390 
391 int
392 main(int argc, char **argv)
393 {
394 	int ch, fflag, tflag, status, n;
395 	char **newargv;
396 	const char *errstr;
397 	extern char *optarg;
398 	extern int optind;
399 
400 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
401 	sanitise_stdfd();
402 
403 	msetlocale();
404 
405 	/* Copy argv, because we modify it */
406 	newargv = xcalloc(MAXIMUM(argc + 1, 1), sizeof(*newargv));
407 	for (n = 0; n < argc; n++)
408 		newargv[n] = xstrdup(argv[n]);
409 	argv = newargv;
410 
411 	__progname = ssh_get_progname(argv[0]);
412 
413 	memset(&args, '\0', sizeof(args));
414 	memset(&remote_remote_args, '\0', sizeof(remote_remote_args));
415 	args.list = remote_remote_args.list = NULL;
416 	addargs(&args, "%s", ssh_program);
417 	addargs(&args, "-x");
418 	addargs(&args, "-oForwardAgent=no");
419 	addargs(&args, "-oPermitLocalCommand=no");
420 	addargs(&args, "-oClearAllForwardings=yes");
421 	addargs(&args, "-oRemoteCommand=none");
422 	addargs(&args, "-oRequestTTY=no");
423 
424 	fflag = tflag = 0;
425 	while ((ch = getopt(argc, argv, "dfl:prtvBCc:i:P:q12346S:o:F:")) != -1)
426 		switch (ch) {
427 		/* User-visible flags. */
428 		case '1':
429 			fatal("SSH protocol v.1 is no longer supported");
430 			break;
431 		case '2':
432 			/* Ignored */
433 			break;
434 		case '4':
435 		case '6':
436 		case 'C':
437 			addargs(&args, "-%c", ch);
438 			addargs(&remote_remote_args, "-%c", ch);
439 			break;
440 		case '3':
441 			throughlocal = 1;
442 			break;
443 		case 'o':
444 		case 'c':
445 		case 'i':
446 		case 'F':
447 			addargs(&remote_remote_args, "-%c", ch);
448 			addargs(&remote_remote_args, "%s", optarg);
449 			addargs(&args, "-%c", ch);
450 			addargs(&args, "%s", optarg);
451 			break;
452 		case 'P':
453 			sshport = a2port(optarg);
454 			if (sshport <= 0)
455 				fatal("bad port \"%s\"\n", optarg);
456 			break;
457 		case 'B':
458 			addargs(&remote_remote_args, "-oBatchmode=yes");
459 			addargs(&args, "-oBatchmode=yes");
460 			break;
461 		case 'l':
462 			limit_kbps = strtonum(optarg, 1, 100 * 1024 * 1024,
463 			    &errstr);
464 			if (errstr != NULL)
465 				usage();
466 			limit_kbps *= 1024; /* kbps */
467 			bandwidth_limit_init(&bwlimit, limit_kbps, COPY_BUFLEN);
468 			break;
469 		case 'p':
470 			pflag = 1;
471 			break;
472 		case 'r':
473 			iamrecursive = 1;
474 			break;
475 		case 'S':
476 			ssh_program = xstrdup(optarg);
477 			break;
478 		case 'v':
479 			addargs(&args, "-v");
480 			addargs(&remote_remote_args, "-v");
481 			verbose_mode = 1;
482 			break;
483 		case 'q':
484 			addargs(&args, "-q");
485 			addargs(&remote_remote_args, "-q");
486 			showprogress = 0;
487 			break;
488 
489 		/* Server options. */
490 		case 'd':
491 			targetshouldbedirectory = 1;
492 			break;
493 		case 'f':	/* "from" */
494 			iamremote = 1;
495 			fflag = 1;
496 			break;
497 		case 't':	/* "to" */
498 			iamremote = 1;
499 			tflag = 1;
500 #ifdef HAVE_CYGWIN
501 			setmode(0, O_BINARY);
502 #endif
503 			break;
504 		default:
505 			usage();
506 		}
507 	argc -= optind;
508 	argv += optind;
509 
510 	if ((pwd = getpwuid(userid = getuid())) == NULL)
511 		fatal("unknown user %u", (u_int) userid);
512 
513 	if (!isatty(STDOUT_FILENO))
514 		showprogress = 0;
515 
516 	if (pflag) {
517 		/* Cannot pledge: -p allows setuid/setgid files... */
518 	} else {
519 		if (pledge("stdio rpath wpath cpath fattr tty proc exec",
520 		    NULL) == -1) {
521 			perror("pledge");
522 			exit(1);
523 		}
524 	}
525 
526 	remin = STDIN_FILENO;
527 	remout = STDOUT_FILENO;
528 
529 	if (fflag) {
530 		/* Follow "protocol", send data. */
531 		(void) response();
532 		source(argc, argv);
533 		exit(errs != 0);
534 	}
535 	if (tflag) {
536 		/* Receive data. */
537 		sink(argc, argv);
538 		exit(errs != 0);
539 	}
540 	if (argc < 2)
541 		usage();
542 	if (argc > 2)
543 		targetshouldbedirectory = 1;
544 
545 	remin = remout = -1;
546 	do_cmd_pid = -1;
547 	/* Command to be executed on remote system using "ssh". */
548 	(void) snprintf(cmd, sizeof cmd, "scp%s%s%s%s",
549 	    verbose_mode ? " -v" : "",
550 	    iamrecursive ? " -r" : "", pflag ? " -p" : "",
551 	    targetshouldbedirectory ? " -d" : "");
552 
553 	(void) signal(SIGPIPE, lostconn);
554 
555 	if (colon(argv[argc - 1]))	/* Dest is remote host. */
556 		toremote(argc, argv);
557 	else {
558 		if (targetshouldbedirectory)
559 			verifydir(argv[argc - 1]);
560 		tolocal(argc, argv);	/* Dest is local host. */
561 	}
562 	/*
563 	 * Finally check the exit status of the ssh process, if one was forked
564 	 * and no error has occurred yet
565 	 */
566 	if (do_cmd_pid != -1 && errs == 0) {
567 		if (remin != -1)
568 		    (void) close(remin);
569 		if (remout != -1)
570 		    (void) close(remout);
571 		if (waitpid(do_cmd_pid, &status, 0) == -1)
572 			errs = 1;
573 		else {
574 			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
575 				errs = 1;
576 		}
577 	}
578 	exit(errs != 0);
579 }
580 
581 /* Callback from atomicio6 to update progress meter and limit bandwidth */
582 static int
583 scpio(void *_cnt, size_t s)
584 {
585 	off_t *cnt = (off_t *)_cnt;
586 
587 	*cnt += s;
588 	if (limit_kbps > 0)
589 		bandwidth_limit(&bwlimit, s);
590 	return 0;
591 }
592 
593 static int
594 do_times(int fd, int verb, const struct stat *sb)
595 {
596 	/* strlen(2^64) == 20; strlen(10^6) == 7 */
597 	char buf[(20 + 7 + 2) * 2 + 2];
598 
599 	(void)snprintf(buf, sizeof(buf), "T%llu 0 %llu 0\n",
600 	    (unsigned long long) (sb->st_mtime < 0 ? 0 : sb->st_mtime),
601 	    (unsigned long long) (sb->st_atime < 0 ? 0 : sb->st_atime));
602 	if (verb) {
603 		fprintf(stderr, "File mtime %lld atime %lld\n",
604 		    (long long)sb->st_mtime, (long long)sb->st_atime);
605 		fprintf(stderr, "Sending file timestamps: %s", buf);
606 	}
607 	(void) atomicio(vwrite, fd, buf, strlen(buf));
608 	return (response());
609 }
610 
611 static int
612 parse_scp_uri(const char *uri, char **userp, char **hostp, int *portp,
613      char **pathp)
614 {
615 	int r;
616 
617 	r = parse_uri("scp", uri, userp, hostp, portp, pathp);
618 	if (r == 0 && *pathp == NULL)
619 		*pathp = xstrdup(".");
620 	return r;
621 }
622 
623 void
624 toremote(int argc, char **argv)
625 {
626 	char *suser = NULL, *host = NULL, *src = NULL;
627 	char *bp, *tuser, *thost, *targ;
628 	int sport = -1, tport = -1;
629 	arglist alist;
630 	int i, r;
631 	u_int j;
632 
633 	memset(&alist, '\0', sizeof(alist));
634 	alist.list = NULL;
635 
636 	/* Parse target */
637 	r = parse_scp_uri(argv[argc - 1], &tuser, &thost, &tport, &targ);
638 	if (r == -1) {
639 		fmprintf(stderr, "%s: invalid uri\n", argv[argc - 1]);
640 		++errs;
641 		goto out;
642 	}
643 	if (r != 0) {
644 		if (parse_user_host_path(argv[argc - 1], &tuser, &thost,
645 		    &targ) == -1) {
646 			fmprintf(stderr, "%s: invalid target\n", argv[argc - 1]);
647 			++errs;
648 			goto out;
649 		}
650 	}
651 	if (tuser != NULL && !okname(tuser)) {
652 		++errs;
653 		goto out;
654 	}
655 
656 	/* Parse source files */
657 	for (i = 0; i < argc - 1; i++) {
658 		free(suser);
659 		free(host);
660 		free(src);
661 		r = parse_scp_uri(argv[i], &suser, &host, &sport, &src);
662 		if (r == -1) {
663 			fmprintf(stderr, "%s: invalid uri\n", argv[i]);
664 			++errs;
665 			continue;
666 		}
667 		if (r != 0) {
668 			parse_user_host_path(argv[i], &suser, &host, &src);
669 		}
670 		if (suser != NULL && !okname(suser)) {
671 			++errs;
672 			continue;
673 		}
674 		if (host && throughlocal) {	/* extended remote to remote */
675 			xasprintf(&bp, "%s -f %s%s", cmd,
676 			    *src == '-' ? "-- " : "", src);
677 			if (do_cmd(host, suser, sport, bp, &remin, &remout) < 0)
678 				exit(1);
679 			free(bp);
680 			xasprintf(&bp, "%s -t %s%s", cmd,
681 			    *targ == '-' ? "-- " : "", targ);
682 			if (do_cmd2(thost, tuser, tport, bp, remin, remout) < 0)
683 				exit(1);
684 			free(bp);
685 			(void) close(remin);
686 			(void) close(remout);
687 			remin = remout = -1;
688 		} else if (host) {	/* standard remote to remote */
689 			if (tport != -1 && tport != SSH_DEFAULT_PORT) {
690 				/* This would require the remote support URIs */
691 				fatal("target port not supported with two "
692 				    "remote hosts without the -3 option");
693 			}
694 
695 			freeargs(&alist);
696 			addargs(&alist, "%s", ssh_program);
697 			addargs(&alist, "-x");
698 			addargs(&alist, "-oClearAllForwardings=yes");
699 			addargs(&alist, "-n");
700 			for (j = 0; j < remote_remote_args.num; j++) {
701 				addargs(&alist, "%s",
702 				    remote_remote_args.list[j]);
703 			}
704 
705 			if (sport != -1) {
706 				addargs(&alist, "-p");
707 				addargs(&alist, "%d", sport);
708 			}
709 			if (suser) {
710 				addargs(&alist, "-l");
711 				addargs(&alist, "%s", suser);
712 			}
713 			addargs(&alist, "--");
714 			addargs(&alist, "%s", host);
715 			addargs(&alist, "%s", cmd);
716 			addargs(&alist, "%s", src);
717 			addargs(&alist, "%s%s%s:%s",
718 			    tuser ? tuser : "", tuser ? "@" : "",
719 			    thost, targ);
720 			if (do_local_cmd(&alist) != 0)
721 				errs = 1;
722 		} else {	/* local to remote */
723 			if (remin == -1) {
724 				xasprintf(&bp, "%s -t %s%s", cmd,
725 				    *targ == '-' ? "-- " : "", targ);
726 				if (do_cmd(thost, tuser, tport, bp, &remin,
727 				    &remout) < 0)
728 					exit(1);
729 				if (response() < 0)
730 					exit(1);
731 				free(bp);
732 			}
733 			source(1, argv + i);
734 		}
735 	}
736 out:
737 	free(tuser);
738 	free(thost);
739 	free(targ);
740 	free(suser);
741 	free(host);
742 	free(src);
743 }
744 
745 void
746 tolocal(int argc, char **argv)
747 {
748 	char *bp, *host = NULL, *src = NULL, *suser = NULL;
749 	arglist alist;
750 	int i, r, sport = -1;
751 
752 	memset(&alist, '\0', sizeof(alist));
753 	alist.list = NULL;
754 
755 	for (i = 0; i < argc - 1; i++) {
756 		free(suser);
757 		free(host);
758 		free(src);
759 		r = parse_scp_uri(argv[i], &suser, &host, &sport, &src);
760 		if (r == -1) {
761 			fmprintf(stderr, "%s: invalid uri\n", argv[i]);
762 			++errs;
763 			continue;
764 		}
765 		if (r != 0)
766 			parse_user_host_path(argv[i], &suser, &host, &src);
767 		if (suser != NULL && !okname(suser)) {
768 			++errs;
769 			continue;
770 		}
771 		if (!host) {	/* Local to local. */
772 			freeargs(&alist);
773 			addargs(&alist, "%s", _PATH_CP);
774 			if (iamrecursive)
775 				addargs(&alist, "-r");
776 			if (pflag)
777 				addargs(&alist, "-p");
778 			addargs(&alist, "--");
779 			addargs(&alist, "%s", argv[i]);
780 			addargs(&alist, "%s", argv[argc-1]);
781 			if (do_local_cmd(&alist))
782 				++errs;
783 			continue;
784 		}
785 		/* Remote to local. */
786 		xasprintf(&bp, "%s -f %s%s",
787 		    cmd, *src == '-' ? "-- " : "", src);
788 		if (do_cmd(host, suser, sport, bp, &remin, &remout) < 0) {
789 			free(bp);
790 			++errs;
791 			continue;
792 		}
793 		free(bp);
794 		sink(1, argv + argc - 1);
795 		(void) close(remin);
796 		remin = remout = -1;
797 	}
798 	free(suser);
799 	free(host);
800 	free(src);
801 }
802 
803 void
804 source(int argc, char **argv)
805 {
806 	struct stat stb;
807 	static BUF buffer;
808 	BUF *bp;
809 	off_t i, statbytes;
810 	size_t amt, nr;
811 	int fd = -1, haderr, indx;
812 	char *last, *name, buf[2048], encname[PATH_MAX];
813 	int len;
814 
815 	for (indx = 0; indx < argc; ++indx) {
816 		name = argv[indx];
817 		statbytes = 0;
818 		len = strlen(name);
819 		while (len > 1 && name[len-1] == '/')
820 			name[--len] = '\0';
821 		if ((fd = open(name, O_RDONLY|O_NONBLOCK, 0)) < 0)
822 			goto syserr;
823 		if (strchr(name, '\n') != NULL) {
824 			strnvis(encname, name, sizeof(encname), VIS_NL);
825 			name = encname;
826 		}
827 		if (fstat(fd, &stb) < 0) {
828 syserr:			run_err("%s: %s", name, strerror(errno));
829 			goto next;
830 		}
831 		if (stb.st_size < 0) {
832 			run_err("%s: %s", name, "Negative file size");
833 			goto next;
834 		}
835 		unset_nonblock(fd);
836 		switch (stb.st_mode & S_IFMT) {
837 		case S_IFREG:
838 			break;
839 		case S_IFDIR:
840 			if (iamrecursive) {
841 				rsource(name, &stb);
842 				goto next;
843 			}
844 			/* FALLTHROUGH */
845 		default:
846 			run_err("%s: not a regular file", name);
847 			goto next;
848 		}
849 		if ((last = strrchr(name, '/')) == NULL)
850 			last = name;
851 		else
852 			++last;
853 		curfile = last;
854 		if (pflag) {
855 			if (do_times(remout, verbose_mode, &stb) < 0)
856 				goto next;
857 		}
858 #define	FILEMODEMASK	(S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
859 		snprintf(buf, sizeof buf, "C%04o %lld %s\n",
860 		    (u_int) (stb.st_mode & FILEMODEMASK),
861 		    (long long)stb.st_size, last);
862 		if (verbose_mode)
863 			fmprintf(stderr, "Sending file modes: %s", buf);
864 		(void) atomicio(vwrite, remout, buf, strlen(buf));
865 		if (response() < 0)
866 			goto next;
867 		if ((bp = allocbuf(&buffer, fd, COPY_BUFLEN)) == NULL) {
868 next:			if (fd != -1) {
869 				(void) close(fd);
870 				fd = -1;
871 			}
872 			continue;
873 		}
874 		if (showprogress)
875 			start_progress_meter(curfile, stb.st_size, &statbytes);
876 		set_nonblock(remout);
877 		for (haderr = i = 0; i < stb.st_size; i += bp->cnt) {
878 			amt = bp->cnt;
879 			if (i + (off_t)amt > stb.st_size)
880 				amt = stb.st_size - i;
881 			if (!haderr) {
882 				if ((nr = atomicio(read, fd,
883 				    bp->buf, amt)) != amt) {
884 					haderr = errno;
885 					memset(bp->buf + nr, 0, amt - nr);
886 				}
887 			}
888 			/* Keep writing after error to retain sync */
889 			if (haderr) {
890 				(void)atomicio(vwrite, remout, bp->buf, amt);
891 				memset(bp->buf, 0, amt);
892 				continue;
893 			}
894 			if (atomicio6(vwrite, remout, bp->buf, amt, scpio,
895 			    &statbytes) != amt)
896 				haderr = errno;
897 		}
898 		unset_nonblock(remout);
899 
900 		if (fd != -1) {
901 			if (close(fd) < 0 && !haderr)
902 				haderr = errno;
903 			fd = -1;
904 		}
905 		if (!haderr)
906 			(void) atomicio(vwrite, remout, "", 1);
907 		else
908 			run_err("%s: %s", name, strerror(haderr));
909 		(void) response();
910 		if (showprogress)
911 			stop_progress_meter();
912 	}
913 }
914 
915 void
916 rsource(char *name, struct stat *statp)
917 {
918 	DIR *dirp;
919 	struct dirent *dp;
920 	char *last, *vect[1], path[PATH_MAX];
921 
922 	if (!(dirp = opendir(name))) {
923 		run_err("%s: %s", name, strerror(errno));
924 		return;
925 	}
926 	last = strrchr(name, '/');
927 	if (last == NULL)
928 		last = name;
929 	else
930 		last++;
931 	if (pflag) {
932 		if (do_times(remout, verbose_mode, statp) < 0) {
933 			closedir(dirp);
934 			return;
935 		}
936 	}
937 	(void) snprintf(path, sizeof path, "D%04o %d %.1024s\n",
938 	    (u_int) (statp->st_mode & FILEMODEMASK), 0, last);
939 	if (verbose_mode)
940 		fmprintf(stderr, "Entering directory: %s", path);
941 	(void) atomicio(vwrite, remout, path, strlen(path));
942 	if (response() < 0) {
943 		closedir(dirp);
944 		return;
945 	}
946 	while ((dp = readdir(dirp)) != NULL) {
947 		if (dp->d_ino == 0)
948 			continue;
949 		if (!strcmp(dp->d_name, ".") || !strcmp(dp->d_name, ".."))
950 			continue;
951 		if (strlen(name) + 1 + strlen(dp->d_name) >= sizeof(path) - 1) {
952 			run_err("%s/%s: name too long", name, dp->d_name);
953 			continue;
954 		}
955 		(void) snprintf(path, sizeof path, "%s/%s", name, dp->d_name);
956 		vect[0] = path;
957 		source(1, vect);
958 	}
959 	(void) closedir(dirp);
960 	(void) atomicio(vwrite, remout, "E\n", 2);
961 	(void) response();
962 }
963 
964 #define TYPE_OVERFLOW(type, val) \
965 	((sizeof(type) == 4 && (val) > INT32_MAX) || \
966 	 (sizeof(type) == 8 && (val) > INT64_MAX) || \
967 	 (sizeof(type) != 4 && sizeof(type) != 8))
968 
969 void
970 sink(int argc, char **argv)
971 {
972 	static BUF buffer;
973 	struct stat stb;
974 	enum {
975 		YES, NO, DISPLAYED
976 	} wrerr;
977 	BUF *bp;
978 	off_t i;
979 	size_t j, count;
980 	int amt, exists, first, ofd;
981 	mode_t mode, omode, mask;
982 	off_t size, statbytes;
983 	unsigned long long ull;
984 	int setimes, targisdir, wrerrno = 0;
985 	char ch, *cp, *np, *targ, *why, *vect[1], buf[2048], visbuf[2048];
986 	struct timeval tv[2];
987 
988 #define	atime	tv[0]
989 #define	mtime	tv[1]
990 #define	SCREWUP(str)	{ why = str; goto screwup; }
991 
992 	if (TYPE_OVERFLOW(time_t, 0) || TYPE_OVERFLOW(off_t, 0))
993 		SCREWUP("Unexpected off_t/time_t size");
994 
995 	setimes = targisdir = 0;
996 	mask = umask(0);
997 	if (!pflag)
998 		(void) umask(mask);
999 	if (argc != 1) {
1000 		run_err("ambiguous target");
1001 		exit(1);
1002 	}
1003 	targ = *argv;
1004 	if (targetshouldbedirectory)
1005 		verifydir(targ);
1006 
1007 	(void) atomicio(vwrite, remout, "", 1);
1008 	if (stat(targ, &stb) == 0 && S_ISDIR(stb.st_mode))
1009 		targisdir = 1;
1010 	for (first = 1;; first = 0) {
1011 		cp = buf;
1012 		if (atomicio(read, remin, cp, 1) != 1)
1013 			return;
1014 		if (*cp++ == '\n')
1015 			SCREWUP("unexpected <newline>");
1016 		do {
1017 			if (atomicio(read, remin, &ch, sizeof(ch)) != sizeof(ch))
1018 				SCREWUP("lost connection");
1019 			*cp++ = ch;
1020 		} while (cp < &buf[sizeof(buf) - 1] && ch != '\n');
1021 		*cp = 0;
1022 		if (verbose_mode)
1023 			fmprintf(stderr, "Sink: %s", buf);
1024 
1025 		if (buf[0] == '\01' || buf[0] == '\02') {
1026 			if (iamremote == 0) {
1027 				(void) snmprintf(visbuf, sizeof(visbuf),
1028 				    NULL, "%s", buf + 1);
1029 				(void) atomicio(vwrite, STDERR_FILENO,
1030 				    visbuf, strlen(visbuf));
1031 			}
1032 			if (buf[0] == '\02')
1033 				exit(1);
1034 			++errs;
1035 			continue;
1036 		}
1037 		if (buf[0] == 'E') {
1038 			(void) atomicio(vwrite, remout, "", 1);
1039 			return;
1040 		}
1041 		if (ch == '\n')
1042 			*--cp = 0;
1043 
1044 		cp = buf;
1045 		if (*cp == 'T') {
1046 			setimes++;
1047 			cp++;
1048 			if (!isdigit((unsigned char)*cp))
1049 				SCREWUP("mtime.sec not present");
1050 			ull = strtoull(cp, &cp, 10);
1051 			if (!cp || *cp++ != ' ')
1052 				SCREWUP("mtime.sec not delimited");
1053 			if (TYPE_OVERFLOW(time_t, ull))
1054 				setimes = 0;	/* out of range */
1055 			mtime.tv_sec = ull;
1056 			mtime.tv_usec = strtol(cp, &cp, 10);
1057 			if (!cp || *cp++ != ' ' || mtime.tv_usec < 0 ||
1058 			    mtime.tv_usec > 999999)
1059 				SCREWUP("mtime.usec not delimited");
1060 			if (!isdigit((unsigned char)*cp))
1061 				SCREWUP("atime.sec not present");
1062 			ull = strtoull(cp, &cp, 10);
1063 			if (!cp || *cp++ != ' ')
1064 				SCREWUP("atime.sec not delimited");
1065 			if (TYPE_OVERFLOW(time_t, ull))
1066 				setimes = 0;	/* out of range */
1067 			atime.tv_sec = ull;
1068 			atime.tv_usec = strtol(cp, &cp, 10);
1069 			if (!cp || *cp++ != '\0' || atime.tv_usec < 0 ||
1070 			    atime.tv_usec > 999999)
1071 				SCREWUP("atime.usec not delimited");
1072 			(void) atomicio(vwrite, remout, "", 1);
1073 			continue;
1074 		}
1075 		if (*cp != 'C' && *cp != 'D') {
1076 			/*
1077 			 * Check for the case "rcp remote:foo\* local:bar".
1078 			 * In this case, the line "No match." can be returned
1079 			 * by the shell before the rcp command on the remote is
1080 			 * executed so the ^Aerror_message convention isn't
1081 			 * followed.
1082 			 */
1083 			if (first) {
1084 				run_err("%s", cp);
1085 				exit(1);
1086 			}
1087 			SCREWUP("expected control record");
1088 		}
1089 		mode = 0;
1090 		for (++cp; cp < buf + 5; cp++) {
1091 			if (*cp < '0' || *cp > '7')
1092 				SCREWUP("bad mode");
1093 			mode = (mode << 3) | (*cp - '0');
1094 		}
1095 		if (*cp++ != ' ')
1096 			SCREWUP("mode not delimited");
1097 
1098 		if (!isdigit((unsigned char)*cp))
1099 			SCREWUP("size not present");
1100 		ull = strtoull(cp, &cp, 10);
1101 		if (!cp || *cp++ != ' ')
1102 			SCREWUP("size not delimited");
1103 		if (TYPE_OVERFLOW(off_t, ull))
1104 			SCREWUP("size out of range");
1105 		size = (off_t)ull;
1106 
1107 		if ((strchr(cp, '/') != NULL) || (strcmp(cp, "..") == 0)) {
1108 			run_err("error: unexpected filename: %s", cp);
1109 			exit(1);
1110 		}
1111 		if (targisdir) {
1112 			static char *namebuf;
1113 			static size_t cursize;
1114 			size_t need;
1115 
1116 			need = strlen(targ) + strlen(cp) + 250;
1117 			if (need > cursize) {
1118 				free(namebuf);
1119 				namebuf = xmalloc(need);
1120 				cursize = need;
1121 			}
1122 			(void) snprintf(namebuf, need, "%s%s%s", targ,
1123 			    strcmp(targ, "/") ? "/" : "", cp);
1124 			np = namebuf;
1125 		} else
1126 			np = targ;
1127 		curfile = cp;
1128 		exists = stat(np, &stb) == 0;
1129 		if (buf[0] == 'D') {
1130 			int mod_flag = pflag;
1131 			if (!iamrecursive)
1132 				SCREWUP("received directory without -r");
1133 			if (exists) {
1134 				if (!S_ISDIR(stb.st_mode)) {
1135 					errno = ENOTDIR;
1136 					goto bad;
1137 				}
1138 				if (pflag)
1139 					(void) chmod(np, mode);
1140 			} else {
1141 				/* Handle copying from a read-only
1142 				   directory */
1143 				mod_flag = 1;
1144 				if (mkdir(np, mode | S_IRWXU) < 0)
1145 					goto bad;
1146 			}
1147 			vect[0] = xstrdup(np);
1148 			sink(1, vect);
1149 			if (setimes) {
1150 				setimes = 0;
1151 				if (utimes(vect[0], tv) < 0)
1152 					run_err("%s: set times: %s",
1153 					    vect[0], strerror(errno));
1154 			}
1155 			if (mod_flag)
1156 				(void) chmod(vect[0], mode);
1157 			free(vect[0]);
1158 			continue;
1159 		}
1160 		omode = mode;
1161 		mode |= S_IWUSR;
1162 		if ((ofd = open(np, O_WRONLY|O_CREAT, mode)) < 0) {
1163 bad:			run_err("%s: %s", np, strerror(errno));
1164 			continue;
1165 		}
1166 		(void) atomicio(vwrite, remout, "", 1);
1167 		if ((bp = allocbuf(&buffer, ofd, COPY_BUFLEN)) == NULL) {
1168 			(void) close(ofd);
1169 			continue;
1170 		}
1171 		cp = bp->buf;
1172 		wrerr = NO;
1173 
1174 		statbytes = 0;
1175 		if (showprogress)
1176 			start_progress_meter(curfile, size, &statbytes);
1177 		set_nonblock(remin);
1178 		for (count = i = 0; i < size; i += bp->cnt) {
1179 			amt = bp->cnt;
1180 			if (i + amt > size)
1181 				amt = size - i;
1182 			count += amt;
1183 			do {
1184 				j = atomicio6(read, remin, cp, amt,
1185 				    scpio, &statbytes);
1186 				if (j == 0) {
1187 					run_err("%s", j != EPIPE ?
1188 					    strerror(errno) :
1189 					    "dropped connection");
1190 					exit(1);
1191 				}
1192 				amt -= j;
1193 				cp += j;
1194 			} while (amt > 0);
1195 
1196 			if (count == bp->cnt) {
1197 				/* Keep reading so we stay sync'd up. */
1198 				if (wrerr == NO) {
1199 					if (atomicio(vwrite, ofd, bp->buf,
1200 					    count) != count) {
1201 						wrerr = YES;
1202 						wrerrno = errno;
1203 					}
1204 				}
1205 				count = 0;
1206 				cp = bp->buf;
1207 			}
1208 		}
1209 		unset_nonblock(remin);
1210 		if (count != 0 && wrerr == NO &&
1211 		    atomicio(vwrite, ofd, bp->buf, count) != count) {
1212 			wrerr = YES;
1213 			wrerrno = errno;
1214 		}
1215 		if (wrerr == NO && (!exists || S_ISREG(stb.st_mode)) &&
1216 		    ftruncate(ofd, size) != 0) {
1217 			run_err("%s: truncate: %s", np, strerror(errno));
1218 			wrerr = DISPLAYED;
1219 		}
1220 		if (pflag) {
1221 			if (exists || omode != mode)
1222 #ifdef HAVE_FCHMOD
1223 				if (fchmod(ofd, omode)) {
1224 #else /* HAVE_FCHMOD */
1225 				if (chmod(np, omode)) {
1226 #endif /* HAVE_FCHMOD */
1227 					run_err("%s: set mode: %s",
1228 					    np, strerror(errno));
1229 					wrerr = DISPLAYED;
1230 				}
1231 		} else {
1232 			if (!exists && omode != mode)
1233 #ifdef HAVE_FCHMOD
1234 				if (fchmod(ofd, omode & ~mask)) {
1235 #else /* HAVE_FCHMOD */
1236 				if (chmod(np, omode & ~mask)) {
1237 #endif /* HAVE_FCHMOD */
1238 					run_err("%s: set mode: %s",
1239 					    np, strerror(errno));
1240 					wrerr = DISPLAYED;
1241 				}
1242 		}
1243 		if (close(ofd) == -1) {
1244 			wrerr = YES;
1245 			wrerrno = errno;
1246 		}
1247 		(void) response();
1248 		if (showprogress)
1249 			stop_progress_meter();
1250 		if (setimes && wrerr == NO) {
1251 			setimes = 0;
1252 			if (utimes(np, tv) < 0) {
1253 				run_err("%s: set times: %s",
1254 				    np, strerror(errno));
1255 				wrerr = DISPLAYED;
1256 			}
1257 		}
1258 		switch (wrerr) {
1259 		case YES:
1260 			run_err("%s: %s", np, strerror(wrerrno));
1261 			break;
1262 		case NO:
1263 			(void) atomicio(vwrite, remout, "", 1);
1264 			break;
1265 		case DISPLAYED:
1266 			break;
1267 		}
1268 	}
1269 screwup:
1270 	run_err("protocol error: %s", why);
1271 	exit(1);
1272 }
1273 
1274 int
1275 response(void)
1276 {
1277 	char ch, *cp, resp, rbuf[2048], visbuf[2048];
1278 
1279 	if (atomicio(read, remin, &resp, sizeof(resp)) != sizeof(resp))
1280 		lostconn(0);
1281 
1282 	cp = rbuf;
1283 	switch (resp) {
1284 	case 0:		/* ok */
1285 		return (0);
1286 	default:
1287 		*cp++ = resp;
1288 		/* FALLTHROUGH */
1289 	case 1:		/* error, followed by error msg */
1290 	case 2:		/* fatal error, "" */
1291 		do {
1292 			if (atomicio(read, remin, &ch, sizeof(ch)) != sizeof(ch))
1293 				lostconn(0);
1294 			*cp++ = ch;
1295 		} while (cp < &rbuf[sizeof(rbuf) - 1] && ch != '\n');
1296 
1297 		if (!iamremote) {
1298 			cp[-1] = '\0';
1299 			(void) snmprintf(visbuf, sizeof(visbuf),
1300 			    NULL, "%s\n", rbuf);
1301 			(void) atomicio(vwrite, STDERR_FILENO,
1302 			    visbuf, strlen(visbuf));
1303 		}
1304 		++errs;
1305 		if (resp == 1)
1306 			return (-1);
1307 		exit(1);
1308 	}
1309 	/* NOTREACHED */
1310 }
1311 
1312 void
1313 usage(void)
1314 {
1315 	(void) fprintf(stderr,
1316 	    "usage: scp [-346BCpqrv] [-c cipher] [-F ssh_config] [-i identity_file]\n"
1317 	    "           [-l limit] [-o ssh_option] [-P port] [-S program] source ... target\n");
1318 	exit(1);
1319 }
1320 
1321 void
1322 run_err(const char *fmt,...)
1323 {
1324 	static FILE *fp;
1325 	va_list ap;
1326 
1327 	++errs;
1328 	if (fp != NULL || (remout != -1 && (fp = fdopen(remout, "w")))) {
1329 		(void) fprintf(fp, "%c", 0x01);
1330 		(void) fprintf(fp, "scp: ");
1331 		va_start(ap, fmt);
1332 		(void) vfprintf(fp, fmt, ap);
1333 		va_end(ap);
1334 		(void) fprintf(fp, "\n");
1335 		(void) fflush(fp);
1336 	}
1337 
1338 	if (!iamremote) {
1339 		va_start(ap, fmt);
1340 		vfmprintf(stderr, fmt, ap);
1341 		va_end(ap);
1342 		fprintf(stderr, "\n");
1343 	}
1344 }
1345 
1346 void
1347 verifydir(char *cp)
1348 {
1349 	struct stat stb;
1350 
1351 	if (!stat(cp, &stb)) {
1352 		if (S_ISDIR(stb.st_mode))
1353 			return;
1354 		errno = ENOTDIR;
1355 	}
1356 	run_err("%s: %s", cp, strerror(errno));
1357 	killchild(0);
1358 }
1359 
1360 int
1361 okname(char *cp0)
1362 {
1363 	int c;
1364 	char *cp;
1365 
1366 	cp = cp0;
1367 	do {
1368 		c = (int)*cp;
1369 		if (c & 0200)
1370 			goto bad;
1371 		if (!isalpha(c) && !isdigit((unsigned char)c)) {
1372 			switch (c) {
1373 			case '\'':
1374 			case '"':
1375 			case '`':
1376 			case ' ':
1377 			case '#':
1378 				goto bad;
1379 			default:
1380 				break;
1381 			}
1382 		}
1383 	} while (*++cp);
1384 	return (1);
1385 
1386 bad:	fmprintf(stderr, "%s: invalid user name\n", cp0);
1387 	return (0);
1388 }
1389 
1390 BUF *
1391 allocbuf(BUF *bp, int fd, int blksize)
1392 {
1393 	size_t size;
1394 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
1395 	struct stat stb;
1396 
1397 	if (fstat(fd, &stb) < 0) {
1398 		run_err("fstat: %s", strerror(errno));
1399 		return (0);
1400 	}
1401 	size = ROUNDUP(stb.st_blksize, blksize);
1402 	if (size == 0)
1403 		size = blksize;
1404 #else /* HAVE_STRUCT_STAT_ST_BLKSIZE */
1405 	size = blksize;
1406 #endif /* HAVE_STRUCT_STAT_ST_BLKSIZE */
1407 	if (bp->cnt >= size)
1408 		return (bp);
1409 	bp->buf = xrecallocarray(bp->buf, bp->cnt, size, 1);
1410 	bp->cnt = size;
1411 	return (bp);
1412 }
1413 
1414 void
1415 lostconn(int signo)
1416 {
1417 	if (!iamremote)
1418 		(void)write(STDERR_FILENO, "lost connection\n", 16);
1419 	if (signo)
1420 		_exit(1);
1421 	else
1422 		exit(1);
1423 }
1424