xref: /illumos-gate/usr/src/cmd/backup/lib/myrcmd.c (revision 7c478bd9)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 1999 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * Portions of this source code were derived from Berkeley 4.3 BSD
32  * under license from the Regents of the University of California.
33  */
34 
35 #pragma ident	"%Z%%M%	%I%	%E% SMI"
36 
37 #include <myrcmd.h>
38 #include <limits.h>
39 #include <stdio.h>
40 #include <string.h>
41 #include <pwd.h>
42 #include <errno.h>
43 #include <unistd.h>
44 #include <sys/types.h>
45 #include <sys/file.h>
46 #include <signal.h>
47 #include <sys/socket.h>
48 
49 #include <netinet/in.h>
50 #include <arpa/inet.h>
51 
52 #include <netdb.h>
53 #include <fcntl.h>
54 #include <libintl.h>
55 
56 #include <memutils.h>
57 
58 #define	index(s, c)		strchr(s, c)
59 char	*strchr();
60 
61 char	*inet_ntoa();
62 
63 char myrcmd_stderr[1024];
64 
65 int
myrcmd(char ** ahost,unsigned short rport,char * locuser,char * remuser,char * cmd)66 myrcmd(char **ahost, unsigned short rport, char *locuser, char *remuser,
67     char *cmd)
68 {
69 	uint_t loclen, remlen, cmdlen;
70 	int s, timo, retval;
71 	int tries = 0;
72 	pid_t pid;
73 	struct sockaddr_in sin;
74 	char c;
75 	int lport;
76 	int saverr;
77 	struct hostent *hp;
78 	sigset_t oldmask;
79 	sigset_t newmask;
80 	struct sigaction oldaction;
81 	struct sigaction newaction;
82 	static struct hostent numhp;
83 	static char numhostname[32];	/* big enough for "255.255.255.255" */
84 	struct in_addr numaddr;
85 	struct in_addr *numaddrlist[2];
86 
87 	myrcmd_stderr[0] = '\0';	/* empty error string */
88 	pid = getpid();
89 	hp = gethostbyname(*ahost);
90 	if (hp == 0) {
91 		char *straddr;
92 
93 		bzero((char *)numaddrlist, sizeof (numaddrlist));
94 		if ((numaddr.s_addr = inet_addr(*ahost)) == (in_addr_t)-1) {
95 			(void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
96 			    gettext("%s: unknown host\n"), *ahost);
97 			return (MYRCMD_NOHOST);
98 		} else {
99 			bzero((char *)&numhp, sizeof (numhp));
100 			bzero(numhostname, sizeof (numhostname));
101 
102 			if ((straddr = inet_ntoa(numaddr)) == (char *)0) {
103 				(void) snprintf(myrcmd_stderr,
104 				    sizeof (myrcmd_stderr),
105 				    gettext("%s: unknown host\n"), *ahost);
106 				return (MYRCMD_NOHOST);
107 			}
108 			(void) strncpy(numhostname, straddr,
109 			    sizeof (numhostname));
110 			numhostname[sizeof (numhostname) - 1] = '\0';
111 			numhp.h_name = numhostname;
112 			numhp.h_addrtype = AF_INET;
113 			numhp.h_length = sizeof (numaddr);
114 			numaddrlist[0] = &numaddr;
115 			numaddrlist[1] = NULL;
116 			numhp.h_addr_list = (char **)numaddrlist;
117 			hp = &numhp;
118 		}
119 	}
120 	*ahost = hp->h_name;
121 
122 	/* This provides a bounds-test for the bcopy()s below. */
123 	if ((unsigned)(hp->h_length) > sizeof (sin.sin_addr)) {
124 		(void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
125 		    gettext("rcmd: address size: %d larger than limit %d\n"),
126 		    hp->h_length, sizeof (sin.sin_addr));
127 		return (MYRCMD_EBAD);
128 	}
129 
130 	/* ignore SIGPIPE */
131 	bzero((char *)&newaction, sizeof (newaction));
132 	newaction.sa_handler = SIG_IGN;
133 	newaction.sa_flags = SA_ONSTACK;
134 	(void) sigaction(SIGPIPE, &newaction, &oldaction);
135 
136 	/* block SIGURG */
137 	bzero((char *)&newmask, sizeof (newmask));
138 	(void) sigaddset(&newmask, SIGURG);
139 	(void) sigprocmask(SIG_BLOCK, &newmask, &oldmask);
140 again:
141 	timo = 1;
142 	/*
143 	 * Use 0 as lport means that rresvport() will bind to a port in
144 	 * the anonymous priviledged port range.
145 	 */
146 	lport = 0;
147 	for (;;) {
148 		s = rresvport(&lport);
149 		if (s < 0) {
150 			int err;
151 
152 			if (errno == EAGAIN) {
153 				(void) snprintf(myrcmd_stderr,
154 				    sizeof (myrcmd_stderr),
155 				    gettext("socket: All ports in use\n"));
156 				err = MYRCMD_ENOPORT;
157 			} else {
158 				saverr = errno;
159 				(void) snprintf(myrcmd_stderr,
160 				    sizeof (myrcmd_stderr),
161 				    gettext("rcmd: socket: %s\n"),
162 				    strerror(saverr));
163 				err = MYRCMD_ENOSOCK;
164 			}
165 			/* restore original SIGPIPE handler */
166 			(void) sigaction(SIGPIPE, &oldaction,
167 			    (struct sigaction *)0);
168 
169 			/* restore original signal mask */
170 			(void) sigprocmask(SIG_SETMASK, &oldmask,
171 			    (sigset_t *)0);
172 			return (err);
173 		}
174 		/* Can't fail, according to fcntl(2) */
175 		(void) fcntl(s, F_SETOWN, pid);
176 		sin.sin_family = hp->h_addrtype;
177 		bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr, hp->h_length);
178 		sin.sin_port = rport;
179 		if (connect(s, (struct sockaddr *)&sin, sizeof (sin)) >= 0)
180 			break;
181 		saverr = errno;
182 		(void) close(s);
183 		if (saverr == EADDRINUSE) {
184 			continue;
185 		}
186 		if (saverr == ECONNREFUSED && timo <= 16) {
187 			sleep(timo);
188 			timo *= 2;
189 			continue;
190 		}
191 		if (hp->h_addr_list[1] != NULL) {
192 			saverr = errno;
193 
194 			fprintf(stderr,
195 			    gettext("connect to address %s: "),
196 			    inet_ntoa(sin.sin_addr));
197 			errno = saverr;
198 			perror(0);
199 			hp->h_addr_list++;
200 			bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr,
201 			    hp->h_length);
202 			fprintf(stderr, gettext("Trying %s...\n"),
203 				inet_ntoa(sin.sin_addr));
204 			continue;
205 		}
206 		(void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
207 		    "%s: %s\n", hp->h_name, strerror(saverr));
208 		/* restore original SIGPIPE handler */
209 		(void) sigaction(SIGPIPE, &oldaction,
210 		    (struct sigaction *)0);
211 
212 		/* restore original signal mask */
213 		(void) sigprocmask(SIG_SETMASK, &oldmask, (sigset_t *)0);
214 		return (MYRCMD_ENOCONNECT);
215 	}
216 	if (write(s, "", 1) < 0) {
217 		(void) close(s);
218 		return (MYRCMD_ENOCONNECT);
219 	}
220 
221 	loclen = strlen(locuser) + 1;
222 	remlen = strlen(remuser) + 1;
223 	cmdlen = strlen(cmd) + 1;
224 
225 	if (((retval = write(s, locuser, loclen)) != loclen) ||
226 	    ((retval = write(s, remuser, remlen)) != remlen) ||
227 	    ((retval = write(s, cmd, cmdlen)) != cmdlen)) {
228 		if (retval == -1)
229 			(void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
230 			    "write: %s\n", strerror(errno));
231 		else
232 			(void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
233 			    gettext("write unexpectedly truncated\n"));
234 		goto bad;
235 	}
236 	retval = read(s, &c, 1);
237 	if (retval != 1) {
238 		if (retval == 0) {
239 			/*
240 			 * Solaris 2.0 bug alert.  Sometimes, if the
241 			 * tapehost is a Solaris 2.0 system, the connection
242 			 * will be dropped at this point.  Let's try again,
243 			 * three times, before we throw in the towel.
244 			 */
245 			if (++tries < 3) {
246 				(void) close(s);
247 				goto again;
248 			}
249 			(void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
250 			    gettext("Protocol error, %s closed connection\n"),
251 			    *ahost);
252 		} else if (retval < 0) {
253 			(void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
254 			    "%s: %s\n", *ahost, strerror(errno));
255 		} else {
256 			(void) snprintf(myrcmd_stderr, sizeof (myrcmd_stderr),
257 			    gettext("Protocol error, %s sent %d bytes\n"),
258 			    *ahost, retval);
259 		}
260 		goto bad;
261 	}
262 	if (c != 0) {
263 		char *cp = myrcmd_stderr;
264 		char *ecp = &myrcmd_stderr[sizeof (myrcmd_stderr) - 1];
265 
266 		while (read(s, &c, 1) == 1) {
267 			*cp++ = c;
268 			if (c == '\n' || cp >= ecp)
269 				break;
270 		}
271 		*cp = '\0';
272 		goto bad;
273 	}
274 	/* restore original SIGPIPE handler */
275 	(void) sigaction(SIGPIPE, &oldaction, (struct sigaction *)0);
276 
277 	/* restore original signal mask */
278 	(void) sigprocmask(SIG_SETMASK, &oldmask, (sigset_t *)0);
279 	return (s);
280 bad:
281 	(void) close(s);
282 	/* restore original SIGPIPE handler */
283 	(void) sigaction(SIGPIPE, &oldaction, (struct sigaction *)0);
284 
285 	/* restore original signal mask */
286 	(void) sigprocmask(SIG_SETMASK, &oldmask, (sigset_t *)0);
287 	return (MYRCMD_EBAD);
288 }
289