xref: /openbsd-src/usr.bin/rsync/main.c (revision c02cd12511bd98f410ea5913f5c4488a8730ee33)
1 /*	$OpenBSD: main.c,v 1.56 2021/07/14 11:14:27 claudio Exp $ */
2 /*
3  * Copyright (c) 2019 Kristaps Dzonsons <kristaps@bsd.lv>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 #include <sys/stat.h>
18 #include <sys/socket.h>
19 #include <sys/wait.h>
20 
21 #include <assert.h>
22 #include <err.h>
23 #include <getopt.h>
24 #include <stdint.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29 
30 #include "extern.h"
31 
32 int verbose;
33 int poll_timeout;
34 
35 /*
36  * A remote host is has a colon before the first path separator.
37  * This works for rsh remote hosts (host:/foo/bar), implicit rsync
38  * remote hosts (host::/foo/bar), and explicit (rsync://host/foo).
39  * Return zero if local, non-zero if remote.
40  */
41 static int
42 fargs_is_remote(const char *v)
43 {
44 	size_t	 pos;
45 
46 	pos = strcspn(v, ":/");
47 	return v[pos] == ':';
48 }
49 
50 /*
51  * Test whether a remote host is specifically an rsync daemon.
52  * Return zero if not, non-zero if so.
53  */
54 static int
55 fargs_is_daemon(const char *v)
56 {
57 	size_t	 pos;
58 
59 	if (strncasecmp(v, "rsync://", 8) == 0)
60 		return 1;
61 
62 	pos = strcspn(v, ":/");
63 	return v[pos] == ':' && v[pos + 1] == ':';
64 }
65 
66 /*
67  * Take the command-line filenames (e.g., rsync foo/ bar/ baz/) and
68  * determine our operating mode.
69  * For example, if the first argument is a remote file, this means that
70  * we're going to transfer from the remote to the local.
71  * We also make sure that the arguments are consistent, that is, if
72  * we're going to transfer from the local to the remote, that no
73  * filenames for the local transfer indicate remote hosts.
74  * Always returns the parsed and sanitised options.
75  */
76 static struct fargs *
77 fargs_parse(size_t argc, char *argv[], struct opts *opts)
78 {
79 	struct fargs	*f = NULL;
80 	char		*cp, *ccp;
81 	size_t		 i, j, len = 0;
82 
83 	/* Allocations. */
84 
85 	if ((f = calloc(1, sizeof(struct fargs))) == NULL)
86 		err(ERR_NOMEM, NULL);
87 
88 	f->sourcesz = argc - 1;
89 	if ((f->sources = calloc(f->sourcesz, sizeof(char *))) == NULL)
90 		err(ERR_NOMEM, NULL);
91 
92 	for (i = 0; i < argc - 1; i++)
93 		if ((f->sources[i] = strdup(argv[i])) == NULL)
94 			err(ERR_NOMEM, NULL);
95 
96 	if ((f->sink = strdup(argv[i])) == NULL)
97 		err(ERR_NOMEM, NULL);
98 
99 	/*
100 	 * Test files for its locality.
101 	 * If the last is a remote host, then we're sending from the
102 	 * local to the remote host ("sender" mode).
103 	 * If the first, remote to local ("receiver" mode).
104 	 * If neither, a local transfer in sender style.
105 	 */
106 
107 	f->mode = FARGS_SENDER;
108 
109 	if (fargs_is_remote(f->sink)) {
110 		f->mode = FARGS_SENDER;
111 		if ((f->host = strdup(f->sink)) == NULL)
112 			err(ERR_NOMEM, NULL);
113 	}
114 
115 	if (fargs_is_remote(f->sources[0])) {
116 		if (f->host != NULL)
117 			errx(ERR_SYNTAX, "both source and destination "
118 			    "cannot be remote files");
119 		f->mode = FARGS_RECEIVER;
120 		if ((f->host = strdup(f->sources[0])) == NULL)
121 			err(ERR_NOMEM, NULL);
122 	}
123 
124 	if (f->host != NULL) {
125 		if (strncasecmp(f->host, "rsync://", 8) == 0) {
126 			/* rsync://host[:port]/module[/path] */
127 			f->remote = 1;
128 			len = strlen(f->host) - 8 + 1;
129 			memmove(f->host, f->host + 8, len);
130 			if ((cp = strchr(f->host, '/')) == NULL)
131 				errx(ERR_SYNTAX,
132 				    "rsync protocol requires a module name");
133 			*cp++ = '\0';
134 			f->module = cp;
135 			if ((cp = strchr(f->module, '/')) != NULL)
136 				*cp = '\0';
137 			if ((cp = strchr(f->host, ':')) != NULL) {
138 				/* host:port --> extract port */
139 				*cp++ = '\0';
140 				opts->port = cp;
141 			}
142 		} else {
143 			/* host:[/path] */
144 			cp = strchr(f->host, ':');
145 			assert(cp != NULL);
146 			*cp++ = '\0';
147 			if (*cp == ':') {
148 				/* host::module[/path] */
149 				f->remote = 1;
150 				f->module = ++cp;
151 				cp = strchr(f->module, '/');
152 				if (cp != NULL)
153 					*cp = '\0';
154 			}
155 		}
156 		if ((len = strlen(f->host)) == 0)
157 			errx(ERR_SYNTAX, "empty remote host");
158 		if (f->remote && strlen(f->module) == 0)
159 			errx(ERR_SYNTAX, "empty remote module");
160 	}
161 
162 	/* Make sure we have the same "hostspec" for all files. */
163 
164 	if (!f->remote) {
165 		if (f->mode == FARGS_SENDER)
166 			for (i = 0; i < f->sourcesz; i++) {
167 				if (!fargs_is_remote(f->sources[i]))
168 					continue;
169 				errx(ERR_SYNTAX,
170 				    "remote file in list of local sources: %s",
171 				    f->sources[i]);
172 			}
173 		if (f->mode == FARGS_RECEIVER)
174 			for (i = 0; i < f->sourcesz; i++) {
175 				if (fargs_is_remote(f->sources[i]) &&
176 				    !fargs_is_daemon(f->sources[i]))
177 					continue;
178 				if (fargs_is_daemon(f->sources[i]))
179 					errx(ERR_SYNTAX,
180 					    "remote daemon in list of remote "
181 					    "sources: %s", f->sources[i]);
182 				errx(ERR_SYNTAX, "local file in list of "
183 				    "remote sources: %s", f->sources[i]);
184 			}
185 	} else {
186 		if (f->mode != FARGS_RECEIVER)
187 			errx(ERR_SYNTAX, "sender mode for remote "
188 				"daemon receivers not yet supported");
189 		for (i = 0; i < f->sourcesz; i++) {
190 			if (fargs_is_daemon(f->sources[i]))
191 				continue;
192 			errx(ERR_SYNTAX, "non-remote daemon file "
193 				"in list of remote daemon sources: "
194 				"%s", f->sources[i]);
195 		}
196 	}
197 
198 	/*
199 	 * If we're not remote and a sender, strip our hostname.
200 	 * Then exit if we're a sender or a local connection.
201 	 */
202 
203 	if (!f->remote) {
204 		if (f->host == NULL)
205 			return f;
206 		if (f->mode == FARGS_SENDER) {
207 			assert(f->host != NULL);
208 			assert(len > 0);
209 			j = strlen(f->sink);
210 			memmove(f->sink, f->sink + len + 1, j - len);
211 			return f;
212 		} else if (f->mode != FARGS_RECEIVER)
213 			return f;
214 	}
215 
216 	/*
217 	 * Now strip the hostnames from the remote host.
218 	 *   rsync://host/module/path -> module/path
219 	 *   host::module/path -> module/path
220 	 *   host:path -> path
221 	 * Also make sure that the remote hosts are the same.
222 	 */
223 
224 	assert(f->host != NULL);
225 	assert(len > 0);
226 
227 	for (i = 0; i < f->sourcesz; i++) {
228 		cp = f->sources[i];
229 		j = strlen(cp);
230 		if (f->remote &&
231 		    strncasecmp(cp, "rsync://", 8) == 0) {
232 			/* rsync://path */
233 			cp += 8;
234 			if ((ccp = strchr(cp, ':')))	/* skip :port */
235 				*ccp = '\0';
236 			if (strncmp(cp, f->host, len) ||
237 			    (cp[len] != '/' && cp[len] != '\0'))
238 				errx(ERR_SYNTAX, "different remote host: %s",
239 				    f->sources[i]);
240 			memmove(f->sources[i],
241 				f->sources[i] + len + 8 + 1,
242 				j - len - 8);
243 		} else if (f->remote && strncmp(cp, "::", 2) == 0) {
244 			/* ::path */
245 			memmove(f->sources[i],
246 				f->sources[i] + 2, j - 1);
247 		} else if (f->remote) {
248 			/* host::path */
249 			if (strncmp(cp, f->host, len) ||
250 			    (cp[len] != ':' && cp[len] != '\0'))
251 				errx(ERR_SYNTAX, "different remote host: %s",
252 				    f->sources[i]);
253 			memmove(f->sources[i], f->sources[i] + len + 2,
254 			    j - len - 1);
255 		} else if (cp[0] == ':') {
256 			/* :path */
257 			memmove(f->sources[i], f->sources[i] + 1, j);
258 		} else {
259 			/* host:path */
260 			if (strncmp(cp, f->host, len) ||
261 			    (cp[len] != ':' && cp[len] != '\0'))
262 				errx(ERR_SYNTAX, "different remote host: %s",
263 				    f->sources[i]);
264 			memmove(f->sources[i],
265 				f->sources[i] + len + 1, j - len);
266 		}
267 	}
268 
269 	return f;
270 }
271 
272 static struct opts	 opts;
273 
274 #define OP_ADDRESS	1000
275 #define OP_PORT		1001
276 #define OP_RSYNCPATH	1002
277 #define OP_TIMEOUT	1003
278 #define OP_VERSION	1004
279 
280 const struct option	 lopts[] = {
281     { "address",	required_argument, NULL,		OP_ADDRESS },
282     { "archive",	no_argument,	NULL,			'a' },
283     { "compress",	no_argument,	NULL,			'z' },
284     { "del",		no_argument,	&opts.del,		1 },
285     { "delete",		no_argument,	&opts.del,		1 },
286     { "devices",	no_argument,	&opts.devices,		1 },
287     { "no-devices",	no_argument,	&opts.devices,		0 },
288     { "dry-run",	no_argument,	&opts.dry_run,		1 },
289     { "group",		no_argument,	&opts.preserve_gids,	1 },
290     { "no-group",	no_argument,	&opts.preserve_gids,	0 },
291     { "help",		no_argument,	NULL,			'h' },
292     { "links",		no_argument,	&opts.preserve_links,	1 },
293     { "no-links",	no_argument,	&opts.preserve_links,	0 },
294     { "no-motd",	no_argument,	&opts.no_motd,		1 },
295     { "numeric-ids",	no_argument,	&opts.numeric_ids,	1 },
296     { "owner",		no_argument,	&opts.preserve_uids,	1 },
297     { "no-owner",	no_argument,	&opts.preserve_uids,	0 },
298     { "perms",		no_argument,	&opts.preserve_perms,	1 },
299     { "no-perms",	no_argument,	&opts.preserve_perms,	0 },
300     { "port",		required_argument, NULL,		OP_PORT },
301     { "recursive",	no_argument,	&opts.recursive,	1 },
302     { "no-recursive",	no_argument,	&opts.recursive,	0 },
303     { "rsh",		required_argument, NULL,		'e' },
304     { "rsync-path",	required_argument, NULL,		OP_RSYNCPATH },
305     { "sender",		no_argument,	&opts.sender,		1 },
306     { "server",		no_argument,	&opts.server,		1 },
307     { "specials",	no_argument,	&opts.specials,		1 },
308     { "no-specials",	no_argument,	&opts.specials,		0 },
309     { "timeout",	required_argument, NULL,		OP_TIMEOUT },
310     { "times",		no_argument,	&opts.preserve_times,	1 },
311     { "no-times",	no_argument,	&opts.preserve_times,	0 },
312     { "verbose",	no_argument,	&verbose,		1 },
313     { "no-verbose",	no_argument,	&verbose,		0 },
314     { "version",	no_argument,	NULL,			OP_VERSION },
315     { NULL,		0,		NULL,			0 }
316 };
317 
318 int
319 main(int argc, char *argv[])
320 {
321 	pid_t		 child;
322 	int		 fds[2], sd = -1, rc, c, st, i;
323 	struct sess	  sess;
324 	struct fargs	*fargs;
325 	char		**args;
326 	const char 	*errstr;
327 	/* Global pledge. */
328 
329 	if (pledge("stdio unix rpath wpath cpath dpath inet fattr chown dns getpw proc exec unveil",
330 	    NULL) == -1)
331 		err(ERR_IPC, "pledge");
332 
333 	while ((c = getopt_long(argc, argv, "Dae:ghlnoprtvxz", lopts, NULL))
334 	    != -1) {
335 		switch (c) {
336 		case 'D':
337 			opts.devices = 1;
338 			opts.specials = 1;
339 			break;
340 		case 'a':
341 			opts.recursive = 1;
342 			opts.preserve_links = 1;
343 			opts.preserve_perms = 1;
344 			opts.preserve_times = 1;
345 			opts.preserve_gids = 1;
346 			opts.preserve_uids = 1;
347 			opts.devices = 1;
348 			opts.specials = 1;
349 			break;
350 		case 'e':
351 			opts.ssh_prog = optarg;
352 			break;
353 		case 'g':
354 			opts.preserve_gids = 1;
355 			break;
356 		case 'l':
357 			opts.preserve_links = 1;
358 			break;
359 		case 'n':
360 			opts.dry_run = 1;
361 			break;
362 		case 'o':
363 			opts.preserve_uids = 1;
364 			break;
365 		case 'p':
366 			opts.preserve_perms = 1;
367 			break;
368 		case 'r':
369 			opts.recursive = 1;
370 			break;
371 		case 't':
372 			opts.preserve_times = 1;
373 			break;
374 		case 'v':
375 			verbose++;
376 			break;
377 		case 'x':
378 			opts.one_file_system++;
379 			break;
380 		case 'z':
381 			fprintf(stderr, "%s: -z not supported yet\n", getprogname());
382 			break;
383 		case 0:
384 			/* Non-NULL flag values (e.g., --sender). */
385 			break;
386 		case OP_ADDRESS:
387 			opts.address = optarg;
388 			break;
389 		case OP_PORT:
390 			opts.port = optarg;
391 			break;
392 		case OP_RSYNCPATH:
393 			opts.rsync_path = optarg;
394 			break;
395 		case OP_TIMEOUT:
396 			poll_timeout = strtonum(optarg, 0, 60*60, &errstr);
397 			if (errstr != NULL)
398 				errx(ERR_SYNTAX, "timeout is %s: %s",
399 				    errstr, optarg);
400 			break;
401 		case OP_VERSION:
402 			fprintf(stderr, "openrsync: protocol version %u\n",
403 			    RSYNC_PROTOCOL);
404 			exit(0);
405 		case 'h':
406 		default:
407 			goto usage;
408 		}
409 	}
410 
411 	argc -= optind;
412 	argv += optind;
413 
414 	/* FIXME: reference implementation rsync accepts this. */
415 
416 	if (argc < 2)
417 		goto usage;
418 
419 	if (opts.port == NULL)
420 		opts.port = "rsync";
421 
422 	/* by default and for --timeout=0 disable poll_timeout */
423 	if (poll_timeout == 0)
424 		poll_timeout = -1;
425 	else
426 		poll_timeout *= 1000;
427 
428 	/*
429 	 * This is what happens when we're started with the "hidden"
430 	 * --server option, which is invoked for the rsync on the remote
431 	 * host by the parent.
432 	 */
433 
434 	if (opts.server)
435 		exit(rsync_server(&opts, (size_t)argc, argv));
436 
437 	/*
438 	 * Now we know that we're the client on the local machine
439 	 * invoking rsync(1).
440 	 * At this point, we need to start the client and server
441 	 * initiation logic.
442 	 * The client is what we continue running on this host; the
443 	 * server is what we'll use to connect to the remote and
444 	 * invoke rsync with the --server option.
445 	 */
446 
447 	fargs = fargs_parse(argc, argv, &opts);
448 	assert(fargs != NULL);
449 
450 	/*
451 	 * If we're contacting an rsync:// daemon, then we don't need to
452 	 * fork, because we won't start a server ourselves.
453 	 * Route directly into the socket code, unless a remote shell
454 	 * has explicitly been specified.
455 	 */
456 
457 	if (fargs->remote && opts.ssh_prog == NULL) {
458 		assert(fargs->mode == FARGS_RECEIVER);
459 		if ((rc = rsync_connect(&opts, &sd, fargs)) == 0) {
460 			rc = rsync_socket(&opts, sd, fargs);
461 			close(sd);
462 		}
463 		exit(rc);
464 	}
465 
466 	/* Drop the dns/inet possibility. */
467 
468 	if (pledge("stdio unix rpath wpath cpath dpath fattr chown getpw proc exec unveil",
469 	    NULL) == -1)
470 		err(ERR_IPC, "pledge");
471 
472 	/* Create a bidirectional socket and start our child. */
473 
474 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0, fds) == -1)
475 		err(ERR_IPC, "socketpair");
476 
477 	switch ((child = fork())) {
478 	case -1:
479 		err(ERR_IPC, "fork");
480 	case 0:
481 		close(fds[0]);
482 		if (pledge("stdio exec", NULL) == -1)
483 			err(ERR_IPC, "pledge");
484 
485 		memset(&sess, 0, sizeof(struct sess));
486 		sess.opts = &opts;
487 
488 		args = fargs_cmdline(&sess, fargs, NULL);
489 
490 		for (i = 0; args[i] != NULL; i++)
491 			LOG2("exec[%d] = %s", i, args[i]);
492 
493 		/* Make sure the child's stdin is from the sender. */
494 		if (dup2(fds[1], STDIN_FILENO) == -1)
495 			err(ERR_IPC, "dup2");
496 		if (dup2(fds[1], STDOUT_FILENO) == -1)
497 			err(ERR_IPC, "dup2");
498 		execvp(args[0], args);
499 		_exit(ERR_IPC);
500 		/* NOTREACHED */
501 	default:
502 		close(fds[1]);
503 		if (!fargs->remote)
504 			rc = rsync_client(&opts, fds[0], fargs);
505 		else
506 			rc = rsync_socket(&opts, fds[0], fargs);
507 		break;
508 	}
509 
510 	close(fds[0]);
511 
512 	if (waitpid(child, &st, 0) == -1)
513 		err(ERR_WAITPID, "waitpid");
514 
515 	/*
516 	 * If we don't already have an error (rc == 0), then inherit the
517 	 * error code of rsync_server() if it has exited.
518 	 * If it hasn't exited, it overrides our return value.
519 	 */
520 
521 	if (rc == 0) {
522 		if (WIFEXITED(st))
523 			rc = WEXITSTATUS(st);
524 		else if (WIFSIGNALED(st))
525 			rc = ERR_TERMIMATED;
526 		else
527 			rc = ERR_WAITPID;
528 	}
529 
530 	exit(rc);
531 usage:
532 	fprintf(stderr, "usage: %s"
533 	    " [-aDglnoprtvx] [-e program] [--address=sourceaddr] [--del]\n"
534 	    "\t[--no-motd] [--numeric-ids] [--port=portnumber] "
535 	    "[--rsync-path=program]\n\t[--timeout=seconds] [--version] "
536             "source ... directory\n",
537 	    getprogname());
538 	exit(ERR_SYNTAX);
539 }
540