Sync rsh(1) with FreeBSD.
[dragonfly.git] / usr.bin / rsh / rsh.c
CommitLineData
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1/*-
2 * Copyright (c) 1983, 1990, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
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4 * Copyright (c) 2002 Networks Associates Technology, Inc.
5 * All rights reserved.
6 *
7 * Portions of this software were developed for the FreeBSD Project by
8 * ThinkSec AS and NAI Labs, the Security Research Division of Network
9 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
10 * ("CBOSS"), as part of the DARPA CHATS research program.
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11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the University of
23 * California, Berkeley and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 * may be used to endorse or promote products derived from this software
26 * without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
1de703da 39 *
1de703da 40 * @(#)rsh.c 8.3 (Berkeley) 4/6/94
d7f0d5a6 41 * $FreeBSD: src/usr.bin/rsh/rsh.c,v 1.35 2005/05/21 09:55:07 ru Exp $
e5d03018 42 * $DragonFly: src/usr.bin/rsh/rsh.c,v 1.7 2007/05/18 17:05:12 dillon Exp $
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43 */
44
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45#include <sys/param.h>
46#include <sys/signal.h>
47#include <sys/socket.h>
48#include <sys/ioctl.h>
49#include <sys/file.h>
50#include <sys/time.h>
51
52#include <netinet/in.h>
53#include <netdb.h>
54
55#include <err.h>
56#include <errno.h>
57#include <libutil.h>
d7f0d5a6 58#include <paths.h>
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59#include <pwd.h>
60#include <signal.h>
61#include <stdio.h>
62#include <stdlib.h>
63#include <string.h>
64#include <unistd.h>
984263bc 65
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66/*
67 * rsh - remote shell
68 */
69int rfd2;
70
71int family = PF_UNSPEC;
d7f0d5a6 72char rlogin[] = "rlogin";
984263bc 73
2d8a3be7 74void connect_timeout(int);
d7f0d5a6 75char *copyargs(char * const *);
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76void sendsig(int);
77void talk(int, long, pid_t, int, int);
78void usage(void);
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79
80int
ac83dddc 81main(int argc, char **argv)
984263bc 82{
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83 struct passwd const *pw;
84 struct servent const *sp;
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85 long omask;
86 int argoff, asrsh, ch, dflag, nflag, one, rem;
87 pid_t pid = 0;
88 uid_t uid;
89 char *args, *host, *p, *user;
90 int timeout = 0;
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91
92 argoff = asrsh = dflag = nflag = 0;
93 one = 1;
94 host = user = NULL;
95
96 /* if called as something other than "rsh", use it as the host name */
97 if ((p = strrchr(argv[0], '/')))
98 ++p;
99 else
100 p = argv[0];
101 if (strcmp(p, "rsh"))
102 host = p;
103 else
104 asrsh = 1;
105
106 /* handle "rsh host flags" */
107 if (!host && argc > 2 && argv[1][0] != '-') {
108 host = argv[1];
109 argoff = 1;
110 }
111
d7f0d5a6 112#define OPTIONS "468Lde:l:nt:w"
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113 while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != -1)
114 switch(ch) {
115 case '4':
116 family = PF_INET;
117 break;
118
119 case '6':
120 family = PF_INET6;
121 break;
122
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123 case 'L': /* -8Lew are ignored to allow rlogin aliases */
124 case 'e':
125 case 'w':
126 case '8':
127 break;
128 case 'd':
129 dflag = 1;
130 break;
131 case 'l':
132 user = optarg;
133 break;
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134 case 'n':
135 nflag = 1;
136 break;
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137 case 't':
138 timeout = atoi(optarg);
139 break;
140 case '?':
141 default:
142 usage();
143 }
144 optind += argoff;
145
146 /* if haven't gotten a host yet, do so */
147 if (!host && !(host = argv[optind++]))
148 usage();
149
150 /* if no further arguments, must have been called as rlogin. */
151 if (!argv[optind]) {
152 if (asrsh)
ac83dddc 153 *argv = rlogin;
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154 execv(_PATH_RLOGIN, argv);
155 err(1, "can't exec %s", _PATH_RLOGIN);
156 }
157
158 argc -= optind;
159 argv += optind;
160
161 if (!(pw = getpwuid(uid = getuid())))
162 errx(1, "unknown user id");
163 if (!user)
164 user = pw->pw_name;
165
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166 args = copyargs(argv);
167
168 sp = NULL;
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169 if (sp == NULL)
170 sp = getservbyname("shell", "tcp");
171 if (sp == NULL)
172 errx(1, "shell/tcp: unknown service");
173
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174 if (timeout) {
175 signal(SIGALRM, connect_timeout);
176 alarm(timeout);
177 }
178 rem = rcmd_af(&host, sp->s_port, pw->pw_name, user, args, &rfd2,
179 family);
180 if (timeout) {
181 signal(SIGALRM, SIG_DFL);
182 alarm(0);
183 }
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184
185 if (rem < 0)
186 exit(1);
187
188 if (rfd2 < 0)
189 errx(1, "can't establish stderr");
190 if (dflag) {
191 if (setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one,
192 sizeof(one)) < 0)
193 warn("setsockopt");
194 if (setsockopt(rfd2, SOL_SOCKET, SO_DEBUG, &one,
195 sizeof(one)) < 0)
196 warn("setsockopt");
197 }
198
ac83dddc 199 setuid(uid);
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200 omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGTERM));
201 if (signal(SIGINT, SIG_IGN) != SIG_IGN)
ac83dddc 202 signal(SIGINT, sendsig);
984263bc 203 if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
ac83dddc 204 signal(SIGQUIT, sendsig);
984263bc 205 if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
ac83dddc 206 signal(SIGTERM, sendsig);
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207
208 if (!nflag) {
209 pid = fork();
210 if (pid < 0)
211 err(1, "fork");
212 }
d7f0d5a6 213 else
e5d03018 214 shutdown(rem, SHUT_WR);
984263bc 215
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216 ioctl(rfd2, FIONBIO, &one);
217 ioctl(rem, FIONBIO, &one);
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218
219 talk(nflag, omask, pid, rem, timeout);
220
221 if (!nflag)
ac83dddc 222 kill(pid, SIGKILL);
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223 exit(0);
224}
225
226void
ac83dddc 227talk(int nflag, long omask, pid_t pid, int rem, int timeout)
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228{
229 int cc, wc;
230 fd_set readfrom, ready, rembits;
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231 char buf[BUFSIZ];
232 const char *bp;
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233 struct timeval tvtimeout;
234 int nfds, srval;
235
236 if (!nflag && pid == 0) {
ac83dddc 237 close(rfd2);
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238
239reread: errno = 0;
ac83dddc 240 if ((cc = read(STDIN_FILENO, buf, sizeof(buf))) <= 0)
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241 goto done;
242 bp = buf;
243
244rewrite:
245 if (rem >= FD_SETSIZE)
246 errx(1, "descriptor too big");
247 FD_ZERO(&rembits);
248 FD_SET(rem, &rembits);
249 nfds = rem + 1;
250 if (select(nfds, 0, &rembits, 0, 0) < 0) {
251 if (errno != EINTR)
252 err(1, "select");
253 goto rewrite;
254 }
255 if (!FD_ISSET(rem, &rembits))
256 goto rewrite;
d7f0d5a6 257 wc = write(rem, bp, cc);
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258 if (wc < 0) {
259 if (errno == EWOULDBLOCK)
260 goto rewrite;
261 goto done;
262 }
263 bp += wc;
264 cc -= wc;
265 if (cc == 0)
266 goto reread;
267 goto rewrite;
268done:
e5d03018 269 shutdown(rem, SHUT_WR);
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270 exit(0);
271 }
272
273 tvtimeout.tv_sec = timeout;
274 tvtimeout.tv_usec = 0;
275
ac83dddc 276 sigsetmask(omask);
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277 if (rfd2 >= FD_SETSIZE || rem >= FD_SETSIZE)
278 errx(1, "descriptor too big");
279 FD_ZERO(&readfrom);
280 FD_SET(rfd2, &readfrom);
281 FD_SET(rem, &readfrom);
282 nfds = MAX(rfd2+1, rem+1);
283 do {
284 ready = readfrom;
285 if (timeout) {
286 srval = select(nfds, &ready, 0, 0, &tvtimeout);
287 } else {
288 srval = select(nfds, &ready, 0, 0, 0);
289 }
290
291 if (srval < 0) {
292 if (errno != EINTR)
293 err(1, "select");
294 continue;
295 }
296 if (srval == 0)
8c79f17c 297 errx(1, "timeout reached (%d seconds)", timeout);
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298 if (FD_ISSET(rfd2, &ready)) {
299 errno = 0;
d7f0d5a6 300 cc = read(rfd2, buf, sizeof(buf));
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301 if (cc <= 0) {
302 if (errno != EWOULDBLOCK)
303 FD_CLR(rfd2, &readfrom);
304 } else
ac83dddc 305 write(STDERR_FILENO, buf, cc);
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306 }
307 if (FD_ISSET(rem, &ready)) {
308 errno = 0;
d7f0d5a6 309 cc = read(rem, buf, sizeof(buf));
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310 if (cc <= 0) {
311 if (errno != EWOULDBLOCK)
312 FD_CLR(rem, &readfrom);
313 } else
ac83dddc 314 write(STDOUT_FILENO, buf, cc);
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315 }
316 } while (FD_ISSET(rfd2, &readfrom) || FD_ISSET(rem, &readfrom));
317}
318
319void
d7f0d5a6 320connect_timeout(int sig __unused)
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321{
322 char message[] = "timeout reached before connection completed.\n";
323
324 write(STDERR_FILENO, message, sizeof(message) - 1);
325 _exit(1);
326}
327
328void
ac83dddc 329sendsig(int sig)
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330{
331 char signo;
332
333 signo = sig;
d7f0d5a6 334 write(rfd2, &signo, 1);
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335}
336
337char *
d7f0d5a6 338copyargs(char * const *argv)
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339{
340 int cc;
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341 char *args, *p;
342 char * const *ap;
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343
344 cc = 0;
345 for (ap = argv; *ap; ++ap)
346 cc += strlen(*ap) + 1;
347 if (!(args = malloc((u_int)cc)))
348 err(1, NULL);
349 for (p = args, ap = argv; *ap; ++ap) {
ac83dddc 350 strcpy(p, *ap);
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351 for (p = strcpy(p, *ap); *p; ++p);
352 if (ap[1])
353 *p++ = ' ';
354 }
355 return (args);
356}
357
358void
ac83dddc 359usage(void)
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360{
361
ac83dddc 362 fprintf(stderr,
d7f0d5a6 363 "usage: rsh [-46dn] [-l username] [-t timeout] host [command]\n");
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364 exit(1);
365}