2 * The socket based protocol for setting up a connection with rsyncd.
4 * Copyright (C) 1998-2001 Andrew Tridgell <tridge@samba.org>
5 * Copyright (C) 2001-2002 Martin Pool <mbp@samba.org>
6 * Copyright (C) 2002-2007 Wayne Davison
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
26 extern int output_motd
;
32 extern int rsync_port
;
33 extern int ignore_errors
;
34 extern int kluge_around_eof
;
35 extern int daemon_over_rsh
;
36 extern int sanitize_paths
;
37 extern int filesfrom_fd
;
38 extern int remote_protocol
;
39 extern int protocol_version
;
40 extern int io_timeout
;
42 extern int default_af_hint
;
43 extern int logfile_format_has_i
;
44 extern int logfile_format_has_o_or_i
;
45 extern mode_t orig_umask
;
46 extern char *bind_address
;
47 extern char *sockopts
;
48 extern char *config_file
;
49 extern char *logfile_format
;
50 extern char *files_from
;
52 extern struct chmod_mode_struct
*chmod_modes
;
53 extern struct filter_list_struct server_filter_list
;
58 struct chmod_mode_struct
*daemon_chmod_modes
;
60 /* Length of lp_path() string when in daemon mode & not chrooted, else 0. */
61 unsigned int module_dirlen
= 0;
64 static struct sigaction sigact
;
68 * Run a client connected to an rsyncd. The alternative to this
69 * function for remote-shell connections is do_cmd().
71 * After negotiating which module to use and reading the server's
72 * motd, this hands over to client_run(). Telling the server the
73 * module will cause it to chroot/setuid/etc.
75 * Instead of doing a transfer, the client may at this stage instead
76 * get a listing of remote modules and exit.
78 * @return -1 for error in startup, or the result of client_run().
79 * Either way, it eventually gets passed to exit_cleanup().
81 int start_socket_client(char *host
, char *path
, int argc
, char *argv
[])
84 char *p
, *user
= NULL
;
86 /* This is redundant with code in start_inband_exchange(), but this
87 * short-circuits a problem in the client before we open a socket,
88 * and the extra check won't hurt. */
91 "ERROR: The remote path must start with a module name not a /\n");
95 if ((p
= strrchr(host
, '@')) != NULL
) {
101 fd
= open_socket_out_wrapped(host
, rsync_port
, bind_address
,
104 exit_cleanup(RERR_SOCKETIO
);
106 set_socket_options(fd
, sockopts
);
108 ret
= start_inband_exchange(user
, path
, fd
, fd
, argc
);
110 return ret
? ret
: client_run(fd
, fd
, -1, argc
, argv
);
113 int start_inband_exchange(const char *user
, char *path
, int f_in
, int f_out
,
117 char *sargs
[MAX_ARGS
];
119 char line
[BIGPATHBUFLEN
];
122 if (argc
== 0 && !am_sender
)
127 "ERROR: The remote path must start with a module name\n");
132 user
= getenv("USER");
134 user
= getenv("LOGNAME");
136 io_printf(f_out
, "@RSYNCD: %d\n", protocol_version
);
138 if (!read_line(f_in
, line
, sizeof line
- 1)) {
139 rprintf(FERROR
, "rsync: did not see server greeting\n");
143 if (sscanf(line
,"@RSYNCD: %d", &remote_protocol
) != 1) {
144 /* note that read_line strips of \n or \r */
145 rprintf(FERROR
, "rsync: server sent \"%s\" rather than greeting\n",
149 if (protocol_version
> remote_protocol
)
150 protocol_version
= remote_protocol
;
152 if (list_only
&& protocol_version
>= 29)
155 /* set daemon_over_rsh to false since we need to build the
156 * true set of args passed through the rsh/ssh connection;
157 * this is a no-op for direct-socket-connection mode */
159 server_options(sargs
, &sargc
);
161 sargs
[sargc
++] = ".";
164 sargs
[sargc
++] = path
;
169 print_child_argv(sargs
);
171 p
= strchr(path
,'/');
173 io_printf(f_out
, "%s\n", path
);
176 /* Old servers may just drop the connection here,
177 rather than sending a proper EXIT command. Yuck. */
178 kluge_around_eof
= list_only
&& protocol_version
< 25 ? 1 : 0;
181 if (!read_line(f_in
, line
, sizeof line
- 1)) {
182 rprintf(FERROR
, "rsync: didn't get server startup line\n");
186 if (strncmp(line
,"@RSYNCD: AUTHREQD ",18) == 0) {
187 auth_client(f_out
, user
, line
+18);
191 if (strcmp(line
,"@RSYNCD: OK") == 0)
194 if (strcmp(line
,"@RSYNCD: EXIT") == 0) {
195 /* This is sent by recent versions of the
196 * server to terminate the listing of modules.
197 * We don't want to go on and transfer
198 * anything; just exit. */
202 if (strncmp(line
, "@ERROR", 6) == 0) {
203 rprintf(FERROR
, "%s\n", line
);
204 /* This is always fatal; the server will now
205 * close the socket. */
209 /* This might be a MOTD line or a module listing, but there is
210 * no way to differentiate it. The manpage mentions this. */
212 rprintf(FINFO
, "%s\n", line
);
214 kluge_around_eof
= 0;
216 for (i
= 0; i
< sargc
; i
++) {
217 io_printf(f_out
, "%s\n", sargs
[i
]);
219 io_printf(f_out
, "\n");
221 if (protocol_version
< 23) {
222 if (protocol_version
== 22 || !am_sender
)
223 io_start_multiplex_in();
229 static char *finish_pre_exec(pid_t pid
, int fd
, char *request
,
230 int argc
, char *argv
[])
235 write_buf(fd
, request
, strlen(request
)+1);
236 for (j
= 0; j
< argc
; j
++)
237 write_buf(fd
, argv
[j
], strlen(argv
[j
])+1);
244 if (wait_process(pid
, &status
, 0) < 0
245 || !WIFEXITED(status
) || WEXITSTATUS(status
) != 0) {
247 if (asprintf(&e
, "pre-xfer exec returned failure (%d)%s%s\n",
248 status
, status
< 0 ? ": " : "",
249 status
< 0 ? strerror(errno
) : "") < 0)
250 out_of_memory("finish_pre_exec");
256 static int read_arg_from_pipe(int fd
, char *buf
, int limit
)
258 char *bp
= buf
, *eob
= buf
+ limit
- 1;
261 if (read(fd
, bp
, 1) != 1)
273 static int rsync_module(int f_in
, int f_out
, int i
, char *addr
, char *host
)
278 char line
[BIGPATHBUFLEN
];
279 uid_t uid
= (uid_t
)-2; /* canonically "nobody" */
280 gid_t gid
= (gid_t
)-2;
281 char *p
, *err_msg
= NULL
;
282 char *name
= lp_name(i
);
283 int use_chroot
= lp_use_chroot(i
);
285 int ret
, pre_exec_fd
= -1;
286 pid_t pre_exec_pid
= 0;
287 char *request
= NULL
;
289 if (!allow_access(addr
, host
, lp_hosts_allow(i
), lp_hosts_deny(i
))) {
290 rprintf(FLOG
, "rsync denied on module %s from %s (%s)\n",
293 io_printf(f_out
, "@ERROR: Unknown module '%s'\n", name
);
296 "@ERROR: access denied to %s from %s (%s)\n",
302 if (am_daemon
&& am_server
) {
303 rprintf(FLOG
, "rsync allowed access on module %s from %s (%s)\n",
307 if (!claim_connection(lp_lock_file(i
), lp_max_connections(i
))) {
309 rsyserr(FLOG
, errno
, "failed to open lock file %s",
311 io_printf(f_out
, "@ERROR: failed to open lock file\n");
313 rprintf(FLOG
, "max connections (%d) reached\n",
314 lp_max_connections(i
));
315 io_printf(f_out
, "@ERROR: max connections (%d) reached -- try again later\n",
316 lp_max_connections(i
));
321 auth_user
= auth_server(f_in
, f_out
, i
, host
, addr
, "@RSYNCD: AUTHREQD ");
324 io_printf(f_out
, "@ERROR: auth failed on module %s\n", name
);
333 if (lp_transfer_logging(i
) && !logfile_format
)
334 logfile_format
= lp_log_format(i
);
335 if (log_format_has(logfile_format
, 'i'))
336 logfile_format_has_i
= 1;
337 if (logfile_format_has_i
|| log_format_has(logfile_format
, 'o'))
338 logfile_format_has_o_or_i
= 1;
340 am_root
= (MY_UID() == 0);
344 if (!name_to_uid(p
, &uid
)) {
346 rprintf(FLOG
, "Invalid uid %s\n", p
);
347 io_printf(f_out
, "@ERROR: invalid uid %s\n", p
);
354 if (!name_to_gid(p
, &gid
)) {
356 rprintf(FLOG
, "Invalid gid %s\n", p
);
357 io_printf(f_out
, "@ERROR: invalid gid %s\n", p
);
364 /* TODO: If we're not root, but the configuration requests
365 * that we change to some uid other than the current one, then
368 /* TODO: Perhaps take a list of gids, and make them into the
369 * supplementary groups. */
371 if (use_chroot
|| (module_dirlen
= strlen(lp_path(i
))) == 1) {
373 set_filter_dir("/", 1);
375 set_filter_dir(lp_path(i
), module_dirlen
);
378 parse_rule(&server_filter_list
, p
, MATCHFLG_WORD_SPLIT
,
381 p
= lp_include_from(i
);
382 parse_filter_file(&server_filter_list
, p
, MATCHFLG_INCLUDE
,
383 XFLG_ABS_IF_SLASH
| XFLG_OLD_PREFIXES
| XFLG_FATAL_ERRORS
);
386 parse_rule(&server_filter_list
, p
,
387 MATCHFLG_INCLUDE
| MATCHFLG_WORD_SPLIT
,
388 XFLG_ABS_IF_SLASH
| XFLG_OLD_PREFIXES
);
390 p
= lp_exclude_from(i
);
391 parse_filter_file(&server_filter_list
, p
, 0,
392 XFLG_ABS_IF_SLASH
| XFLG_OLD_PREFIXES
| XFLG_FATAL_ERRORS
);
395 parse_rule(&server_filter_list
, p
, MATCHFLG_WORD_SPLIT
,
396 XFLG_ABS_IF_SLASH
| XFLG_OLD_PREFIXES
);
401 if (*lp_prexfer_exec(i
) || *lp_postxfer_exec(i
)) {
402 char *modname
, *modpath
, *hostaddr
, *hostname
, *username
;
404 if (asprintf(&modname
, "RSYNC_MODULE_NAME=%s", name
) < 0
405 || asprintf(&modpath
, "RSYNC_MODULE_PATH=%s", lp_path(i
)) < 0
406 || asprintf(&hostaddr
, "RSYNC_HOST_ADDR=%s", addr
) < 0
407 || asprintf(&hostname
, "RSYNC_HOST_NAME=%s", host
) < 0
408 || asprintf(&username
, "RSYNC_USER_NAME=%s", auth_user
) < 0)
409 out_of_memory("rsync_module");
416 /* For post-xfer exec, fork a new process to run the rsync
417 * daemon while this process waits for the exit status and
418 * runs the indicated command at that point. */
419 if (*lp_postxfer_exec(i
)) {
422 rsyserr(FLOG
, errno
, "fork failed");
423 io_printf(f_out
, "@ERROR: fork failed\n");
427 if (asprintf(&p
, "RSYNC_PID=%ld", (long)pid
) > 0)
429 if (wait_process(pid
, &status
, 0) < 0)
431 if (asprintf(&p
, "RSYNC_RAW_STATUS=%d", status
) > 0)
433 if (WIFEXITED(status
))
434 status
= WEXITSTATUS(status
);
437 if (asprintf(&p
, "RSYNC_EXIT_STATUS=%d", status
) > 0)
439 system(lp_postxfer_exec(i
));
443 /* For pre-xfer exec, fork a child process to run the indicated
444 * command, though it first waits for the parent process to
445 * send us the user's request via a pipe. */
446 if (*lp_prexfer_exec(i
)) {
448 if (asprintf(&p
, "RSYNC_PID=%ld", (long)getpid()) > 0)
450 if (pipe(fds
) < 0 || (pre_exec_pid
= fork()) < 0) {
451 rsyserr(FLOG
, errno
, "pre-xfer exec preparation failed");
452 io_printf(f_out
, "@ERROR: pre-xfer exec preparation failed\n");
455 if (pre_exec_pid
== 0) {
456 char buf
[BIGPATHBUFLEN
];
459 set_blocking(fds
[0]);
460 len
= read_arg_from_pipe(fds
[0], buf
, BIGPATHBUFLEN
);
463 if (asprintf(&p
, "RSYNC_REQUEST=%s", buf
) > 0)
466 len
= read_arg_from_pipe(fds
[0], buf
,
473 if (asprintf(&p
, "RSYNC_ARG%d=%s", j
, buf
) > 0)
478 close(STDOUT_FILENO
);
479 status
= system(lp_prexfer_exec(i
));
480 if (!WIFEXITED(status
))
482 _exit(WEXITSTATUS(status
));
485 set_blocking(fds
[1]);
486 pre_exec_fd
= fds
[1];
494 * XXX: The 'use chroot' flag is a fairly reliable
495 * source of confusion, because it fails under two
496 * important circumstances: running as non-root,
497 * running on Win32 (or possibly others). On the
498 * other hand, if you are running as root, then it
499 * might be better to always use chroot.
501 * So, perhaps if we can't chroot we should just issue
502 * a warning, unless a "require chroot" flag is set,
503 * in which case we fail.
505 if (chroot(lp_path(i
))) {
506 rsyserr(FLOG
, errno
, "chroot %s failed",
508 io_printf(f_out
, "@ERROR: chroot failed\n");
512 if (!push_dir("/", 0)) {
513 rsyserr(FLOG
, errno
, "chdir %s failed\n",
515 io_printf(f_out
, "@ERROR: chdir failed\n");
520 if (!push_dir(lp_path(i
), 0)) {
521 rsyserr(FLOG
, errno
, "chdir %s failed\n",
523 io_printf(f_out
, "@ERROR: chdir failed\n");
530 /* XXXX: You could argue that if the daemon is started
531 * by a non-root user and they explicitly specify a
532 * gid, then we should try to change to that gid --
533 * this could be possible if it's already in their
534 * supplementary groups. */
536 /* TODO: Perhaps we need to document that if rsyncd is
537 * started by somebody other than root it will inherit
538 * all their supplementary groups. */
541 rsyserr(FLOG
, errno
, "setgid %d failed", (int)gid
);
542 io_printf(f_out
, "@ERROR: setgid failed\n");
545 #ifdef HAVE_SETGROUPS
546 /* Get rid of any supplementary groups this process
547 * might have inheristed. */
548 if (setgroups(1, &gid
)) {
549 rsyserr(FLOG
, errno
, "setgroups failed");
550 io_printf(f_out
, "@ERROR: setgroups failed\n");
556 rsyserr(FLOG
, errno
, "setuid %d failed", (int)uid
);
557 io_printf(f_out
, "@ERROR: setuid failed\n");
561 am_root
= (MY_UID() == 0);
564 if (lp_temp_dir(i
) && *lp_temp_dir(i
)) {
565 tmpdir
= lp_temp_dir(i
);
566 if (strlen(tmpdir
) >= MAXPATHLEN
- 10) {
568 "the 'temp dir' value for %s is WAY too long -- ignoring.\n",
574 io_printf(f_out
, "@RSYNCD: OK\n");
577 if (!(argv
= new_array(char *, maxargs
)))
578 out_of_memory("rsync_module");
579 argv
[argc
++] = "rsyncd";
582 if (!read_line(f_in
, line
, sizeof line
- 1))
590 if (argc
== maxargs
) {
592 if (!(argv
= realloc_array(argv
, char *, maxargs
)))
593 out_of_memory("rsync_module");
595 if (!(argv
[argc
] = strdup(p
)))
596 out_of_memory("rsync_module");
598 switch (start_glob
) {
601 if (strcmp(line
, ".") == 0)
606 err_msg
= finish_pre_exec(pre_exec_pid
,
616 glob_expand(name
, &argv
, &argc
, &maxargs
);
622 err_msg
= finish_pre_exec(pre_exec_pid
, pre_exec_fd
, request
,
626 verbose
= 0; /* future verbosity is controlled by client options */
627 ret
= parse_arguments(&argc
, (const char ***) &argv
, 0);
628 am_server
= 1; /* Don't let someone try to be tricky. */
629 if (lp_ignore_errors(module_id
))
632 if (filesfrom_fd
== 0)
637 rprintf(FLOG
, "rsync %s %s from %s@%s (%s)\n",
638 am_sender
? "on" : "to",
639 request
, auth_user
, host
, addr
);
641 rprintf(FLOG
, "rsync %s %s from %s (%s)\n",
642 am_sender
? "on" : "to",
643 request
, host
, addr
);
649 /* don't allow the logs to be flooded too fast */
650 if (verbose
> lp_max_verbosity(i
))
651 verbose
= lp_max_verbosity(i
);
654 if (protocol_version
< 23
655 && (protocol_version
== 22 || am_sender
))
656 io_start_multiplex_out();
657 else if (!ret
|| err_msg
) {
658 /* We have to get I/O multiplexing started so that we can
659 * get the error back to the client. This means getting
660 * the protocol setup finished first in later versions. */
661 setup_protocol(f_out
, f_in
);
663 /* Since we failed in our option parsing, we may not
664 * have finished parsing that the client sent us a
665 * --files-from option, so look for it manually.
666 * Without this, the socket would be in the wrong
667 * state for the upcoming error message. */
670 for (i
= 0; i
< argc
; i
++) {
671 if (strncmp(argv
[i
], "--files-from", 12) == 0) {
678 write_byte(f_out
, 0);
680 io_start_multiplex_out();
683 if (!ret
|| err_msg
) {
685 rwrite(FERROR
, err_msg
, strlen(err_msg
));
689 exit_cleanup(RERR_UNSUPPORTED
);
692 if (lp_timeout(i
) && lp_timeout(i
) > io_timeout
)
693 set_io_timeout(lp_timeout(i
));
695 /* If we have some incoming/outgoing chmod changes, append them to
696 * any user-specified changes (making our changes have priority).
697 * We also get a pointer to just our changes so that a receiver
698 * process can use them separately if --perms wasn't specified. */
700 p
= lp_outgoing_chmod(i
);
702 p
= lp_incoming_chmod(i
);
703 if (*p
&& !(daemon_chmod_modes
= parse_chmod(p
, &chmod_modes
))) {
704 rprintf(FLOG
, "Invalid \"%sing chmod\" directive: %s\n",
705 am_sender
? "outgo" : "incom", p
);
708 start_server(f_in
, f_out
, argc
, argv
);
713 /* send a list of available modules to the client. Don't list those
714 with "list = False". */
715 static void send_listing(int fd
)
717 int n
= lp_numservices();
720 for (i
= 0; i
< n
; i
++) {
722 io_printf(fd
, "%-15s\t%s\n", lp_name(i
), lp_comment(i
));
725 if (protocol_version
>= 25)
726 io_printf(fd
,"@RSYNCD: EXIT\n");
729 /* this is called when a connection is established to a client
730 and we want to start talking. The setup of the system is done from
732 int start_daemon(int f_in
, int f_out
)
735 char *motd
, *addr
, *host
;
738 io_set_sock_fds(f_in
, f_out
);
740 /* We must load the config file before calling any function that
741 * might cause log-file output to occur. This ensures that the
742 * "log file" param gets honored for the 2 non-forked use-cases
743 * (when rsync is run by init and run by a remote shell). */
744 if (!lp_load(config_file
, 0))
745 exit_cleanup(RERR_SYNTAX
);
747 addr
= client_addr(f_in
);
748 host
= client_name(f_in
);
749 rprintf(FLOG
, "connect from %s (%s)\n", host
, addr
);
752 set_socket_options(f_in
, "SO_KEEPALIVE");
754 set_socket_options(f_in
, sockopts
);
756 set_socket_options(f_in
, lp_socket_options());
757 set_nonblocking(f_in
);
760 io_printf(f_out
, "@RSYNCD: %d\n", protocol_version
);
762 motd
= lp_motd_file();
764 FILE *f
= fopen(motd
,"r");
765 while (f
&& !feof(f
)) {
766 int len
= fread(line
, 1, sizeof line
- 1, f
);
769 io_printf(f_out
, "%s", line
);
774 io_printf(f_out
, "\n");
777 if (!read_line(f_in
, line
, sizeof line
- 1))
780 if (sscanf(line
,"@RSYNCD: %d", &remote_protocol
) != 1) {
781 io_printf(f_out
, "@ERROR: protocol startup error\n");
784 if (protocol_version
> remote_protocol
)
785 protocol_version
= remote_protocol
;
788 if (!read_line(f_in
, line
, sizeof line
- 1))
791 if (!*line
|| strcmp(line
, "#list") == 0) {
792 rprintf(FLOG
, "module-list request from %s (%s)\n",
799 /* it's some sort of command that I don't understand */
800 io_printf(f_out
, "@ERROR: Unknown command '%s'\n", line
);
804 if ((i
= lp_number(line
)) < 0) {
805 rprintf(FLOG
, "unknown module '%s' tried from %s (%s)\n",
807 io_printf(f_out
, "@ERROR: Unknown module '%s'\n", line
);
811 #ifdef HAVE_SIGACTION
812 sigact
.sa_flags
= SA_NOCLDSTOP
;
814 SIGACTION(SIGCHLD
, remember_children
);
816 return rsync_module(f_in
, f_out
, i
, addr
, host
);
819 int daemon_main(void)
823 if (is_a_socket(STDIN_FILENO
)) {
826 /* we are running via inetd - close off stdout and
827 * stderr so that library functions (and getopt) don't
828 * try to use them. Redirect them to /dev/null */
829 for (i
= 1; i
< 3; i
++) {
831 open("/dev/null", O_RDWR
);
834 return start_daemon(STDIN_FILENO
, STDIN_FILENO
);
840 if (!lp_load(config_file
, 1))
841 exit_cleanup(RERR_SYNTAX
);
843 if (rsync_port
== 0 && (rsync_port
= lp_rsync_port()) == 0)
844 rsync_port
= RSYNC_PORT
;
845 if (bind_address
== NULL
&& *lp_bind_address())
846 bind_address
= lp_bind_address();
850 rprintf(FLOG
, "rsyncd version %s starting, listening on port %d\n",
851 RSYNC_VERSION
, rsync_port
);
852 /* TODO: If listening on a particular address, then show that
853 * address too. In fact, why not just do inet_ntop on the
854 * local address??? */
856 if (((pid_file
= lp_pid_file()) != NULL
) && (*pid_file
!= '\0')) {
859 pid_t pid
= getpid();
860 cleanup_set_pid(pid
);
861 if ((fd
= do_open(lp_pid_file(), O_WRONLY
|O_CREAT
|O_TRUNC
,
862 0666 & ~orig_umask
)) == -1) {
864 rsyserr(FLOG
, errno
, "failed to create pid file %s",
866 exit_cleanup(RERR_FILEIO
);
868 snprintf(pidbuf
, sizeof pidbuf
, "%ld\n", (long)pid
);
869 write(fd
, pidbuf
, strlen(pidbuf
));
873 start_accept_loop(rsync_port
, start_daemon
);