475 lines
9.6 KiB
C
475 lines
9.6 KiB
C
/* $NetBSD: rsh.c,v 1.33 2011/08/29 14:22:46 joerg Exp $ */
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/*-
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* Copyright (c) 1983, 1990, 1993, 1994
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#ifndef lint
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__COPYRIGHT("@(#) Copyright (c) 1983, 1990, 1993, 1994\
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The Regents of the University of California. All rights reserved.");
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#endif /* not lint */
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#ifndef lint
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#if 0
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static char sccsid[] = "@(#)rsh.c 8.4 (Berkeley) 4/29/95";
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#else
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__RCSID("$NetBSD: rsh.c,v 1.33 2011/08/29 14:22:46 joerg Exp $");
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#endif
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#endif /* not lint */
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/ioctl.h>
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#include <sys/file.h>
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#include <poll.h>
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#include <netinet/in.h>
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#include <netinet/tcp.h>
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#include <netdb.h>
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#include <err.h>
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#include <errno.h>
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#include <limits.h>
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#include <pwd.h>
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#include <signal.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "pathnames.h"
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#include "getport.h"
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/*
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* rsh - remote shell
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*/
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int remerr;
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static int sigs[] = { SIGINT, SIGTERM, SIGQUIT };
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static char *copyargs(char **);
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static void sendsig(int);
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static int checkfd(struct pollfd *, int);
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static void talk(int, sigset_t *, pid_t, int);
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__dead static void usage(void);
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#ifdef IN_RCMD
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int orcmd(char **, int, const char *,
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const char *, const char *, int *);
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int orcmd_af(char **, int, const char *,
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const char *, const char *, int *, int);
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#endif
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int
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main(int argc, char **argv)
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{
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struct passwd *pw;
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struct servent *sp;
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sigset_t oset, nset;
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struct protoent *proto;
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#ifdef IN_RCMD
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char *locuser = 0, *loop;
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#endif /* IN_RCMD */
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int argoff, asrsh, ch, dflag, nflag, one, rem;
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size_t i;
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int family = AF_UNSPEC;
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pid_t pid;
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uid_t uid;
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char *args, *host, *p, *user, *name;
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argoff = asrsh = dflag = nflag = 0;
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one = 1;
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host = user = NULL;
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sp = NULL;
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#ifndef IN_RCMD
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/*
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* If called as something other than "rsh" use it as the host name,
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* only for rsh.
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*/
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if (strcmp(getprogname(), "rsh") == 0)
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asrsh = 1;
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else {
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host = strdup(getprogname());
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if (host == NULL)
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err(1, NULL);
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}
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#endif /* IN_RCMD */
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/* handle "rsh host flags" */
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if (!host && argc > 2 && argv[1][0] != '-') {
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host = argv[1];
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argoff = 1;
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}
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#ifdef IN_RCMD
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if ((loop = getenv("RCMD_LOOP")) && strcmp(loop, "YES") == 0)
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warnx("rcmd appears to be looping!");
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setenv("RCMD_LOOP", "YES", 1);
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# define OPTIONS "468KLdel:np:u:w"
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#else /* IN_RCMD */
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# define OPTIONS "468KLdel:np:w"
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#endif /* IN_RCMD */
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if (!(pw = getpwuid(uid = getuid())))
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errx(1, "unknown user id");
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if ((name = strdup(pw->pw_name)) == NULL)
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err(1, "malloc");
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while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != -1)
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switch(ch) {
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case '4':
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family = AF_INET;
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break;
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case '6':
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family = AF_INET6;
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break;
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case 'K':
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break;
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case 'L': /* -8Lew are ignored to allow rlogin aliases */
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case 'e':
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case 'w':
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case '8':
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break;
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case 'd':
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dflag = 1;
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break;
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case 'l':
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user = optarg;
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break;
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case 'n':
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nflag = 1;
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break;
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case 'p':
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sp = getport(optarg, "tcp");
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break;
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#ifdef IN_RCMD
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case 'u':
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if (getuid() != 0 && optarg && name &&
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strcmp(name, optarg) != 0)
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errx(1,"only super user can use the -u option");
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locuser = optarg;
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break;
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#endif /* IN_RCMD */
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case '?':
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default:
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usage();
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}
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optind += argoff;
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/* if haven't gotten a host yet, do so */
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if (!host && !(host = argv[optind++]))
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usage();
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/* if no further arguments, must have been called as rlogin. */
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if (!argv[optind]) {
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#ifdef IN_RCMD
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usage();
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#else
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if (asrsh)
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*argv = __UNCONST("rlogin");
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execv(_PATH_RLOGIN, argv);
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err(1, "can't exec %s", _PATH_RLOGIN);
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#endif
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}
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argc -= optind;
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argv += optind;
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/* Accept user1@host format, though "-l user2" overrides user1 */
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p = strchr(host, '@');
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if (p) {
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*p = '\0';
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if (!user && p > host)
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user = host;
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host = p + 1;
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if (*host == '\0')
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usage();
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}
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if (!user)
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user = name;
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args = copyargs(argv);
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if (sp == NULL)
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sp = getservbyname("shell", "tcp");
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if (sp == NULL)
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errx(1, "shell/tcp: unknown service");
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#ifdef IN_RCMD
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rem = orcmd_af(&host, sp->s_port, locuser ? locuser :
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#else
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rem = rcmd_af(&host, sp->s_port,
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#endif
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name, user, args, &remerr, family);
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(void)free(name);
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if (rem < 0)
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exit(1);
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if (remerr < 0)
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errx(1, "can't establish stderr");
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if (dflag) {
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if (setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one,
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sizeof(one)) < 0)
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warn("setsockopt remote");
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if (setsockopt(remerr, SOL_SOCKET, SO_DEBUG, &one,
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sizeof(one)) < 0)
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warn("setsockopt stderr");
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}
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proto = getprotobyname("tcp");
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setsockopt(rem, proto->p_proto, TCP_NODELAY, &one, sizeof(one));
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setsockopt(remerr, proto->p_proto, TCP_NODELAY, &one, sizeof(one));
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(void)setuid(uid);
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(void)sigemptyset(&nset);
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for (i = 0; i < sizeof(sigs) / sizeof(sigs[0]); i++)
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(void)sigaddset(&nset, sigs[i]);
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(void)sigprocmask(SIG_BLOCK, &nset, &oset);
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for (i = 0; i < sizeof(sigs) / sizeof(sigs[0]); i++) {
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struct sigaction sa;
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if (sa.sa_handler != SIG_IGN) {
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sa.sa_handler = sendsig;
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(void)sigaction(sigs[i], &sa, NULL);
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}
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}
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if (!nflag) {
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pid = fork();
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if (pid < 0)
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err(1, "fork");
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}
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else
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pid = -1;
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#if defined(KERBEROS) && defined(CRYPT)
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if (!doencrypt)
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#endif
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{
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(void)ioctl(remerr, FIONBIO, &one);
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(void)ioctl(rem, FIONBIO, &one);
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}
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talk(nflag, &oset, pid, rem);
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if (!nflag)
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(void)kill(pid, SIGKILL);
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exit(0);
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}
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static int
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checkfd(struct pollfd *fdp, int outfd)
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{
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int nr, nw;
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char buf[BUFSIZ];
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if (fdp->revents & (POLLNVAL|POLLERR|POLLHUP))
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return -1;
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if ((fdp->revents & POLLIN) == 0)
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return 0;
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errno = 0;
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#if defined(KERBEROS) && defined(CRYPT)
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if (doencrypt)
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nr = des_read(fdp->fd, buf, sizeof buf);
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else
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#endif
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nr = read(fdp->fd, buf, sizeof buf);
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if (nr <= 0) {
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if (errno != EAGAIN)
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return -1;
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else
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return 0;
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}
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else {
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char *bc = buf;
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while (nr) {
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if ((nw = write(outfd, bc, nr)) <= 0)
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return -1;
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nr -= nw;
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bc += nw;
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}
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return 0;
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}
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}
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static void
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talk(int nflag, sigset_t *oset, __pid_t pid, int rem)
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{
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int nr, nw, nfds;
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struct pollfd fds[2], *fdp = &fds[0];
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char *bp, buf[BUFSIZ];
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if (!nflag && pid == 0) {
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(void)close(remerr);
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fdp->events = POLLOUT|POLLNVAL|POLLERR|POLLHUP;
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fdp->fd = rem;
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nr = 0;
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bp = buf;
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for (;;) {
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errno = 0;
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if (nr == 0) {
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if ((nr = read(0, buf, sizeof buf)) == 0)
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goto done;
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if (nr == -1) {
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if (errno == EIO)
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goto done;
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if (errno == EINTR) {
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nr = 0;
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continue;
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}
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err(1, "read");
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}
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bp = buf;
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}
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rewrite: if (poll(fdp, 1, INFTIM) == -1) {
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if (errno != EINTR)
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err(1, "poll");
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goto rewrite;
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}
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if (fdp->revents & (POLLNVAL|POLLERR|POLLHUP))
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err(1, "poll");
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if ((fdp->revents & POLLOUT) == 0)
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goto rewrite;
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#if defined(KERBEROS) && defined(CRYPT)
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if (doencrypt)
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nw = des_write(rem, bp, nr);
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else
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#endif
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nw = write(rem, bp, nr);
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if (nw < 0) {
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if (errno == EAGAIN)
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continue;
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err(1, "write");
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}
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bp += nw;
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nr -= nw;
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}
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done:
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(void)shutdown(rem, 1);
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exit(0);
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}
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(void)sigprocmask(SIG_SETMASK, oset, NULL);
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fds[0].events = fds[1].events = POLLIN|POLLNVAL|POLLERR|POLLHUP;
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fds[0].fd = remerr;
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fds[1].fd = rem;
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fdp = &fds[0];
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nfds = 2;
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do {
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if (poll(fdp, nfds, INFTIM) == -1) {
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if (errno != EINTR)
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err(1, "poll");
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continue;
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}
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if (fds[0].events != 0 && checkfd(&fds[0], 2) == -1) {
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nfds--;
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fds[0].events = 0;
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fdp = &fds[1];
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}
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if (fds[1].events != 0 && checkfd(&fds[1], 1) == -1) {
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nfds--;
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fds[1].events = 0;
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}
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}
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while (nfds);
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}
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static void
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sendsig(int sig)
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{
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char signo;
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signo = sig;
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(void)write(remerr, &signo, 1);
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}
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static char *
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copyargs(char **argv)
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{
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int cc;
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char **ap, *args, *p, *ep;
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cc = 0;
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for (ap = argv; *ap; ++ap)
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cc += strlen(*ap) + 1;
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if (!(args = malloc((u_int)cc)))
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err(1, "malloc");
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ep = args + cc;
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for (p = args, *p = '\0', ap = argv; *ap; ++ap) {
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(void)strlcpy(p, *ap, ep - p);
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p += strlen(p);
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if (ap[1])
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*p++ = ' ';
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}
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*p = '\0';
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return (args);
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}
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static void
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usage(void)
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{
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(void)fprintf(stderr,
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"usage: %s [-46dn] [-l login] [-p port]%s [login@]host command\n",
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getprogname(),
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#ifdef IN_RCMD
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" [-u locuser]"
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#else
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""
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#endif
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);
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exit(1);
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}
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