1: /*
2: * The socket based protocol for setting up a connection with rsyncd.
3: *
4: * Copyright (C) 1998-2001 Andrew Tridgell <tridge@samba.org>
5: * Copyright (C) 2001-2002 Martin Pool <mbp@samba.org>
6: * Copyright (C) 2002-2009 Wayne Davison
7: *
8: * This program is free software; you can redistribute it and/or modify
9: * it under the terms of the GNU General Public License as published by
10: * the Free Software Foundation; either version 3 of the License, or
11: * (at your option) any later version.
12: *
13: * This program is distributed in the hope that it will be useful,
14: * but WITHOUT ANY WARRANTY; without even the implied warranty of
15: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16: * GNU General Public License for more details.
17: *
18: * You should have received a copy of the GNU General Public License along
19: * with this program; if not, visit the http://fsf.org website.
20: */
21:
22: #include "rsync.h"
23: #include "ifuncs.h"
24:
25: extern int quiet;
26: extern int verbose;
27: extern int dry_run;
28: extern int output_motd;
29: extern int list_only;
30: extern int am_sender;
31: extern int am_server;
32: extern int am_daemon;
33: extern int am_root;
34: extern int rsync_port;
35: extern int protect_args;
36: extern int ignore_errors;
37: extern int preserve_xattrs;
38: extern int kluge_around_eof;
39: extern int daemon_over_rsh;
40: extern int sanitize_paths;
41: extern int numeric_ids;
42: extern int filesfrom_fd;
43: extern int remote_protocol;
44: extern int protocol_version;
45: extern int io_timeout;
46: extern int no_detach;
47: extern int write_batch;
48: extern int default_af_hint;
49: extern int logfile_format_has_i;
50: extern int logfile_format_has_o_or_i;
51: extern mode_t orig_umask;
52: extern char *bind_address;
53: extern char *config_file;
54: extern char *logfile_format;
55: extern char *files_from;
56: extern char *tmpdir;
57: extern struct chmod_mode_struct *chmod_modes;
58: extern struct filter_list_struct daemon_filter_list;
59: #ifdef ICONV_OPTION
60: extern char *iconv_opt;
61: extern iconv_t ic_send, ic_recv;
62: #endif
63:
64: char *auth_user;
65: int read_only = 0;
66: int module_id = -1;
67: int munge_symlinks = 0;
68: struct chmod_mode_struct *daemon_chmod_modes;
69:
70: /* module_dirlen is the length of the module_dir string when in daemon
71: * mode and module_dir is not "/"; otherwise 0. (Note that a chroot-
72: * enabled module can have a non-"/" module_dir these days.) */
73: char *module_dir = NULL;
74: unsigned int module_dirlen = 0;
75:
76: char *full_module_path;
77:
78: static int rl_nulls = 0;
79:
80: #ifdef HAVE_SIGACTION
81: static struct sigaction sigact;
82: #endif
83:
84: /**
85: * Run a client connected to an rsyncd. The alternative to this
86: * function for remote-shell connections is do_cmd().
87: *
88: * After negotiating which module to use and reading the server's
89: * motd, this hands over to client_run(). Telling the server the
90: * module will cause it to chroot/setuid/etc.
91: *
92: * Instead of doing a transfer, the client may at this stage instead
93: * get a listing of remote modules and exit.
94: *
95: * @return -1 for error in startup, or the result of client_run().
96: * Either way, it eventually gets passed to exit_cleanup().
97: **/
98: int start_socket_client(char *host, int remote_argc, char *remote_argv[],
99: int argc, char *argv[])
100: {
101: int fd, ret;
102: char *p, *user = NULL;
103:
104: /* This is redundant with code in start_inband_exchange(), but this
105: * short-circuits a problem in the client before we open a socket,
106: * and the extra check won't hurt. */
107: if (**remote_argv == '/') {
108: rprintf(FERROR,
109: "ERROR: The remote path must start with a module name not a /\n");
110: return -1;
111: }
112:
113: if ((p = strrchr(host, '@')) != NULL) {
114: user = host;
115: host = p+1;
116: *p = '\0';
117: }
118:
119: fd = open_socket_out_wrapped(host, rsync_port, bind_address,
120: default_af_hint);
121: if (fd == -1)
122: exit_cleanup(RERR_SOCKETIO);
123:
124: #ifdef ICONV_CONST
125: setup_iconv();
126: #endif
127:
128: ret = start_inband_exchange(fd, fd, user, remote_argc, remote_argv);
129:
130: return ret ? ret : client_run(fd, fd, -1, argc, argv);
131: }
132:
133: static int exchange_protocols(int f_in, int f_out, char *buf, size_t bufsiz, int am_client)
134: {
135: int remote_sub = -1;
136: #if SUBPROTOCOL_VERSION != 0
137: int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
138: #else
139: int our_sub = 0;
140: #endif
141: char *motd;
142:
143: io_printf(f_out, "@RSYNCD: %d.%d\n", protocol_version, our_sub);
144:
145: if (!am_client) {
146: motd = lp_motd_file();
147: if (motd && *motd) {
148: FILE *f = fopen(motd,"r");
149: while (f && !feof(f)) {
150: int len = fread(buf, 1, bufsiz - 1, f);
151: if (len > 0)
152: write_buf(f_out, buf, len);
153: }
154: if (f)
155: fclose(f);
156: write_sbuf(f_out, "\n");
157: }
158: }
159:
160: /* This strips the \n. */
161: if (!read_line_old(f_in, buf, bufsiz)) {
162: if (am_client)
163: rprintf(FERROR, "rsync: did not see server greeting\n");
164: return -1;
165: }
166:
167: if (sscanf(buf, "@RSYNCD: %d.%d", &remote_protocol, &remote_sub) < 1) {
168: if (am_client)
169: rprintf(FERROR, "rsync: server sent \"%s\" rather than greeting\n", buf);
170: else
171: io_printf(f_out, "@ERROR: protocol startup error\n");
172: return -1;
173: }
174:
175: if (remote_sub < 0) {
176: if (remote_protocol == 30) {
177: if (am_client)
178: rprintf(FERROR, "rsync: server is speaking an incompatible beta of protocol 30\n");
179: else
180: io_printf(f_out, "@ERROR: your client is speaking an incompatible beta of protocol 30\n");
181: return -1;
182: }
183: remote_sub = 0;
184: }
185:
186: if (protocol_version > remote_protocol) {
187: protocol_version = remote_protocol;
188: if (remote_sub)
189: protocol_version--;
190: } else if (protocol_version == remote_protocol) {
191: if (remote_sub != our_sub)
192: protocol_version--;
193: }
194: #if SUBPROTOCOL_VERSION != 0
195: else if (protocol_version < remote_protocol) {
196: if (our_sub)
197: protocol_version--;
198: }
199: #endif
200:
201: if (protocol_version >= 30)
202: rl_nulls = 1;
203:
204: return 0;
205: }
206:
207: int start_inband_exchange(int f_in, int f_out, const char *user, int argc, char *argv[])
208: {
209: int i, modlen;
210: char line[BIGPATHBUFLEN];
211: char *sargs[MAX_ARGS];
212: int sargc = 0;
213: char *p, *modname;
214:
215: assert(argc > 0 && *argv != NULL);
216:
217: if (**argv == '/') {
218: rprintf(FERROR,
219: "ERROR: The remote path must start with a module name\n");
220: return -1;
221: }
222:
223: if (!(p = strchr(*argv, '/')))
224: modlen = strlen(*argv);
225: else
226: modlen = p - *argv;
227:
228: if (!(modname = new_array(char, modlen+1+1))) /* room for '/' & '\0' */
229: out_of_memory("start_inband_exchange");
230: strlcpy(modname, *argv, modlen + 1);
231: modname[modlen] = '/';
232: modname[modlen+1] = '\0';
233:
234: if (!user)
235: user = getenv("USER");
236: if (!user)
237: user = getenv("LOGNAME");
238:
239: if (exchange_protocols(f_in, f_out, line, sizeof line, 1) < 0)
240: return -1;
241:
242: /* set daemon_over_rsh to false since we need to build the
243: * true set of args passed through the rsh/ssh connection;
244: * this is a no-op for direct-socket-connection mode */
245: daemon_over_rsh = 0;
246: server_options(sargs, &sargc);
247:
248: if (sargc >= MAX_ARGS - 2)
249: goto arg_overflow;
250:
251: sargs[sargc++] = ".";
252:
253: while (argc > 0) {
254: if (sargc >= MAX_ARGS - 1) {
255: arg_overflow:
256: rprintf(FERROR, "internal: args[] overflowed in do_cmd()\n");
257: exit_cleanup(RERR_SYNTAX);
258: }
259: if (strncmp(*argv, modname, modlen) == 0
260: && argv[0][modlen] == '\0')
261: sargs[sargc++] = modname; /* we send "modname/" */
262: else if (**argv == '-') {
263: if (asprintf(sargs + sargc++, "./%s", *argv) < 0)
264: out_of_memory("start_inband_exchange");
265: } else
266: sargs[sargc++] = *argv;
267: argv++;
268: argc--;
269: }
270:
271: sargs[sargc] = NULL;
272:
273: if (verbose > 1)
274: print_child_argv("sending daemon args:", sargs);
275:
276: io_printf(f_out, "%.*s\n", modlen, modname);
277:
278: /* Old servers may just drop the connection here,
279: rather than sending a proper EXIT command. Yuck. */
280: kluge_around_eof = list_only && protocol_version < 25 ? 1 : 0;
281:
282: while (1) {
283: if (!read_line_old(f_in, line, sizeof line)) {
284: rprintf(FERROR, "rsync: didn't get server startup line\n");
285: return -1;
286: }
287:
288: if (strncmp(line,"@RSYNCD: AUTHREQD ",18) == 0) {
289: auth_client(f_out, user, line+18);
290: continue;
291: }
292:
293: if (strcmp(line,"@RSYNCD: OK") == 0)
294: break;
295:
296: if (strcmp(line,"@RSYNCD: EXIT") == 0) {
297: /* This is sent by recent versions of the
298: * server to terminate the listing of modules.
299: * We don't want to go on and transfer
300: * anything; just exit. */
301: exit(0);
302: }
303:
304: if (strncmp(line, "@ERROR", 6) == 0) {
305: rprintf(FERROR, "%s\n", line);
306: /* This is always fatal; the server will now
307: * close the socket. */
308: return -1;
309: }
310:
311: /* This might be a MOTD line or a module listing, but there is
312: * no way to differentiate it. The manpage mentions this. */
313: if (output_motd)
314: rprintf(FINFO, "%s\n", line);
315: }
316: kluge_around_eof = 0;
317:
318: if (rl_nulls) {
319: for (i = 0; i < sargc; i++) {
320: if (!sargs[i]) /* stop at --protect-args NULL */
321: break;
322: write_sbuf(f_out, sargs[i]);
323: write_byte(f_out, 0);
324: }
325: write_byte(f_out, 0);
326: } else {
327: for (i = 0; i < sargc; i++)
328: io_printf(f_out, "%s\n", sargs[i]);
329: write_sbuf(f_out, "\n");
330: }
331:
332: if (protect_args)
333: send_protected_args(f_out, sargs);
334:
335: if (protocol_version < 23) {
336: if (protocol_version == 22 || !am_sender)
337: io_start_multiplex_in();
338: }
339:
340: free(modname);
341:
342: return 0;
343: }
344:
345: static char *finish_pre_exec(pid_t pid, int fd, char *request,
346: char **early_argv, char **argv)
347: {
348: int j = 0, status = -1;
349:
350: if (!request)
351: request = "(NONE)";
352:
353: write_buf(fd, request, strlen(request)+1);
354: if (early_argv) {
355: for ( ; *early_argv; early_argv++)
356: write_buf(fd, *early_argv, strlen(*early_argv)+1);
357: j = 1; /* Skip arg0 name in argv. */
358: }
359: for ( ; argv[j]; j++) {
360: write_buf(fd, argv[j], strlen(argv[j])+1);
361: if (argv[j][0] == '.' && argv[j][1] == '\0')
362: break;
363: }
364: write_byte(fd, 0);
365:
366: close(fd);
367:
368: if (wait_process(pid, &status, 0) < 0
369: || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
370: char *e;
371: if (asprintf(&e, "pre-xfer exec returned failure (%d)%s%s\n",
372: status, status < 0 ? ": " : "",
373: status < 0 ? strerror(errno) : "") < 0)
374: out_of_memory("finish_pre_exec");
375: return e;
376: }
377: return NULL;
378: }
379:
380: static int read_arg_from_pipe(int fd, char *buf, int limit)
381: {
382: char *bp = buf, *eob = buf + limit - 1;
383:
384: while (1) {
385: int got = read(fd, bp, 1);
386: if (got != 1) {
387: if (got < 0 && errno == EINTR)
388: continue;
389: return -1;
390: }
391: if (*bp == '\0')
392: break;
393: if (bp < eob)
394: bp++;
395: }
396: *bp = '\0';
397:
398: return bp - buf;
399: }
400:
401: static int path_failure(int f_out, const char *dir, BOOL was_chdir)
402: {
403: if (was_chdir)
404: rsyserr(FLOG, errno, "chdir %s failed\n", dir);
405: else
406: rprintf(FLOG, "normalize_path(%s) failed\n", dir);
407: io_printf(f_out, "@ERROR: chdir failed\n");
408: return -1;
409: }
410:
411: static int rsync_module(int f_in, int f_out, int i, char *addr, char *host)
412: {
413: int argc;
414: char **argv, **orig_argv, **orig_early_argv, *module_chdir;
415: char line[BIGPATHBUFLEN];
416: uid_t uid = (uid_t)-2; /* canonically "nobody" */
417: gid_t gid = (gid_t)-2;
418: char *p, *err_msg = NULL;
419: char *name = lp_name(i);
420: int use_chroot = lp_use_chroot(i);
421: int ret, pre_exec_fd = -1;
422: pid_t pre_exec_pid = 0;
423: char *request = NULL;
424:
425: #ifdef ICONV_OPTION
426: iconv_opt = lp_charset(i);
427: if (*iconv_opt)
428: setup_iconv();
429: iconv_opt = NULL;
430: #endif
431:
432: if (!allow_access(addr, host, lp_hosts_allow(i), lp_hosts_deny(i))) {
433: rprintf(FLOG, "rsync denied on module %s from %s (%s)\n",
434: name, host, addr);
435: if (!lp_list(i))
436: io_printf(f_out, "@ERROR: Unknown module '%s'\n", name);
437: else {
438: io_printf(f_out,
439: "@ERROR: access denied to %s from %s (%s)\n",
440: name, host, addr);
441: }
442: return -1;
443: }
444:
445: if (am_daemon && am_server) {
446: rprintf(FLOG, "rsync allowed access on module %s from %s (%s)\n",
447: name, host, addr);
448: }
449:
450: if (!claim_connection(lp_lock_file(i), lp_max_connections(i))) {
451: if (errno) {
452: rsyserr(FLOG, errno, "failed to open lock file %s",
453: lp_lock_file(i));
454: io_printf(f_out, "@ERROR: failed to open lock file\n");
455: } else {
456: rprintf(FLOG, "max connections (%d) reached\n",
457: lp_max_connections(i));
458: io_printf(f_out, "@ERROR: max connections (%d) reached -- try again later\n",
459: lp_max_connections(i));
460: }
461: return -1;
462: }
463:
464: auth_user = auth_server(f_in, f_out, i, host, addr, "@RSYNCD: AUTHREQD ");
465:
466: if (!auth_user) {
467: io_printf(f_out, "@ERROR: auth failed on module %s\n", name);
468: return -1;
469: }
470:
471: module_id = i;
472:
473: if (lp_read_only(i))
474: read_only = 1;
475:
476: if (lp_transfer_logging(i) && !logfile_format)
477: logfile_format = lp_log_format(i);
478: if (log_format_has(logfile_format, 'i'))
479: logfile_format_has_i = 1;
480: if (logfile_format_has_i || log_format_has(logfile_format, 'o'))
481: logfile_format_has_o_or_i = 1;
482:
483: am_root = (MY_UID() == 0);
484:
485: if (am_root) {
486: p = lp_uid(i);
487: if (!name_to_uid(p, &uid)) {
488: if (!isDigit(p)) {
489: rprintf(FLOG, "Invalid uid %s\n", p);
490: io_printf(f_out, "@ERROR: invalid uid %s\n", p);
491: return -1;
492: }
493: uid = atoi(p);
494: }
495:
496: p = lp_gid(i);
497: if (!name_to_gid(p, &gid)) {
498: if (!isDigit(p)) {
499: rprintf(FLOG, "Invalid gid %s\n", p);
500: io_printf(f_out, "@ERROR: invalid gid %s\n", p);
501: return -1;
502: }
503: gid = atoi(p);
504: }
505: }
506:
507: /* TODO: If we're not root, but the configuration requests
508: * that we change to some uid other than the current one, then
509: * log a warning. */
510:
511: /* TODO: Perhaps take a list of gids, and make them into the
512: * supplementary groups. */
513:
514: module_dir = lp_path(i);
515: if (*module_dir == '\0') {
516: rprintf(FLOG, "No path specified for module %s\n", name);
517: io_printf(f_out, "@ERROR: no path setting.\n");
518: return -1;
519: }
520: if (use_chroot) {
521: if ((p = strstr(module_dir, "/./")) != NULL) {
522: *p = '\0'; /* Temporary... */
523: if (!(module_chdir = normalize_path(module_dir, True, NULL)))
524: return path_failure(f_out, module_dir, False);
525: *p = '/';
526: if (!(p = normalize_path(p + 2, True, &module_dirlen)))
527: return path_failure(f_out, strstr(module_dir, "/./"), False);
528: if (!(full_module_path = normalize_path(module_dir, False, NULL)))
529: full_module_path = module_dir;
530: module_dir = p;
531: } else {
532: if (!(module_chdir = normalize_path(module_dir, False, NULL)))
533: return path_failure(f_out, module_dir, False);
534: full_module_path = module_chdir;
535: module_dir = "/";
536: module_dirlen = 1;
537: }
538: } else {
539: if (!(module_chdir = normalize_path(module_dir, False, &module_dirlen)))
540: return path_failure(f_out, module_dir, False);
541: full_module_path = module_dir = module_chdir;
542: }
543:
544: if (module_dirlen == 1) {
545: module_dirlen = 0;
546: set_filter_dir("/", 1);
547: } else
548: set_filter_dir(module_dir, module_dirlen);
549:
550: p = lp_filter(i);
551: parse_rule(&daemon_filter_list, p, MATCHFLG_WORD_SPLIT,
552: XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3);
553:
554: p = lp_include_from(i);
555: parse_filter_file(&daemon_filter_list, p, MATCHFLG_INCLUDE,
556: XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS);
557:
558: p = lp_include(i);
559: parse_rule(&daemon_filter_list, p,
560: MATCHFLG_INCLUDE | MATCHFLG_WORD_SPLIT,
561: XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES);
562:
563: p = lp_exclude_from(i);
564: parse_filter_file(&daemon_filter_list, p, 0,
565: XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS);
566:
567: p = lp_exclude(i);
568: parse_rule(&daemon_filter_list, p, MATCHFLG_WORD_SPLIT,
569: XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES);
570:
571: log_init(1);
572:
573: #ifdef HAVE_PUTENV
574: if (*lp_prexfer_exec(i) || *lp_postxfer_exec(i)) {
575: char *modname, *modpath, *hostaddr, *hostname, *username;
576: int status;
577:
578: if (asprintf(&modname, "RSYNC_MODULE_NAME=%s", name) < 0
579: || asprintf(&modpath, "RSYNC_MODULE_PATH=%s", full_module_path) < 0
580: || asprintf(&hostaddr, "RSYNC_HOST_ADDR=%s", addr) < 0
581: || asprintf(&hostname, "RSYNC_HOST_NAME=%s", host) < 0
582: || asprintf(&username, "RSYNC_USER_NAME=%s", auth_user) < 0)
583: out_of_memory("rsync_module");
584: putenv(modname);
585: putenv(modpath);
586: putenv(hostaddr);
587: putenv(hostname);
588: putenv(username);
589: umask(orig_umask);
590: /* For post-xfer exec, fork a new process to run the rsync
591: * daemon while this process waits for the exit status and
592: * runs the indicated command at that point. */
593: if (*lp_postxfer_exec(i)) {
594: pid_t pid = fork();
595: if (pid < 0) {
596: rsyserr(FLOG, errno, "fork failed");
597: io_printf(f_out, "@ERROR: fork failed\n");
598: return -1;
599: }
600: if (pid) {
601: if (asprintf(&p, "RSYNC_PID=%ld", (long)pid) > 0)
602: putenv(p);
603: if (wait_process(pid, &status, 0) < 0)
604: status = -1;
605: if (asprintf(&p, "RSYNC_RAW_STATUS=%d", status) > 0)
606: putenv(p);
607: if (WIFEXITED(status))
608: status = WEXITSTATUS(status);
609: else
610: status = -1;
611: if (asprintf(&p, "RSYNC_EXIT_STATUS=%d", status) > 0)
612: putenv(p);
613: if (system(lp_postxfer_exec(i)) < 0)
614: status = -1;
615: _exit(status);
616: }
617: }
618: /* For pre-xfer exec, fork a child process to run the indicated
619: * command, though it first waits for the parent process to
620: * send us the user's request via a pipe. */
621: if (*lp_prexfer_exec(i)) {
622: int fds[2];
623: if (asprintf(&p, "RSYNC_PID=%ld", (long)getpid()) > 0)
624: putenv(p);
625: if (pipe(fds) < 0 || (pre_exec_pid = fork()) < 0) {
626: rsyserr(FLOG, errno, "pre-xfer exec preparation failed");
627: io_printf(f_out, "@ERROR: pre-xfer exec preparation failed\n");
628: return -1;
629: }
630: if (pre_exec_pid == 0) {
631: char buf[BIGPATHBUFLEN];
632: int j, len;
633: close(fds[1]);
634: set_blocking(fds[0]);
635: len = read_arg_from_pipe(fds[0], buf, BIGPATHBUFLEN);
636: if (len <= 0)
637: _exit(1);
638: if (asprintf(&p, "RSYNC_REQUEST=%s", buf) > 0)
639: putenv(p);
640: for (j = 0; ; j++) {
641: len = read_arg_from_pipe(fds[0], buf,
642: BIGPATHBUFLEN);
643: if (len <= 0) {
644: if (!len)
645: break;
646: _exit(1);
647: }
648: if (asprintf(&p, "RSYNC_ARG%d=%s", j, buf) > 0)
649: putenv(p);
650: }
651: close(fds[0]);
652: close(STDIN_FILENO);
653: close(STDOUT_FILENO);
654: status = system(lp_prexfer_exec(i));
655: if (!WIFEXITED(status))
656: _exit(1);
657: _exit(WEXITSTATUS(status));
658: }
659: close(fds[0]);
660: set_blocking(fds[1]);
661: pre_exec_fd = fds[1];
662: }
663: umask(0);
664: }
665: #endif
666:
667: if (use_chroot) {
668: /*
669: * XXX: The 'use chroot' flag is a fairly reliable
670: * source of confusion, because it fails under two
671: * important circumstances: running as non-root,
672: * running on Win32 (or possibly others). On the
673: * other hand, if you are running as root, then it
674: * might be better to always use chroot.
675: *
676: * So, perhaps if we can't chroot we should just issue
677: * a warning, unless a "require chroot" flag is set,
678: * in which case we fail.
679: */
680: if (chroot(module_chdir)) {
681: rsyserr(FLOG, errno, "chroot %s failed", module_chdir);
682: io_printf(f_out, "@ERROR: chroot failed\n");
683: return -1;
684: }
685: module_chdir = module_dir;
686: }
687:
688: if (!change_dir(module_chdir, CD_NORMAL))
689: return path_failure(f_out, module_chdir, True);
690: if (module_dirlen || !use_chroot)
691: sanitize_paths = 1;
692:
693: if ((munge_symlinks = lp_munge_symlinks(i)) < 0)
694: munge_symlinks = !use_chroot || module_dirlen;
695: if (munge_symlinks) {
696: STRUCT_STAT st;
697: if (do_stat(SYMLINK_PREFIX, &st) == 0 && S_ISDIR(st.st_mode)) {
698: rprintf(FLOG, "Symlink munging is unsupported when a %s directory exists.\n",
699: SYMLINK_PREFIX);
700: io_printf(f_out, "@ERROR: daemon security issue -- contact admin\n", name);
701: exit_cleanup(RERR_UNSUPPORTED);
702: }
703: }
704:
705: if (am_root) {
706: /* XXXX: You could argue that if the daemon is started
707: * by a non-root user and they explicitly specify a
708: * gid, then we should try to change to that gid --
709: * this could be possible if it's already in their
710: * supplementary groups. */
711:
712: /* TODO: Perhaps we need to document that if rsyncd is
713: * started by somebody other than root it will inherit
714: * all their supplementary groups. */
715:
716: if (setgid(gid)) {
717: rsyserr(FLOG, errno, "setgid %d failed", (int)gid);
718: io_printf(f_out, "@ERROR: setgid failed\n");
719: return -1;
720: }
721: #ifdef HAVE_SETGROUPS
722: /* Get rid of any supplementary groups this process
723: * might have inheristed. */
724: if (setgroups(1, &gid)) {
725: rsyserr(FLOG, errno, "setgroups failed");
726: io_printf(f_out, "@ERROR: setgroups failed\n");
727: return -1;
728: }
729: #endif
730:
731: if (setuid(uid) < 0
732: #ifdef HAVE_SETEUID
733: || seteuid(uid) < 0
734: #endif
735: ) {
736: rsyserr(FLOG, errno, "setuid %d failed", (int)uid);
737: io_printf(f_out, "@ERROR: setuid failed\n");
738: return -1;
739: }
740:
741: am_root = (MY_UID() == 0);
742: }
743:
744: if (lp_temp_dir(i) && *lp_temp_dir(i)) {
745: tmpdir = lp_temp_dir(i);
746: if (strlen(tmpdir) >= MAXPATHLEN - 10) {
747: rprintf(FLOG,
748: "the 'temp dir' value for %s is WAY too long -- ignoring.\n",
749: name);
750: tmpdir = NULL;
751: }
752: }
753:
754: io_printf(f_out, "@RSYNCD: OK\n");
755:
756: read_args(f_in, name, line, sizeof line, rl_nulls, &argv, &argc, &request);
757: orig_argv = argv;
758:
759: verbose = 0; /* future verbosity is controlled by client options */
760: ret = parse_arguments(&argc, (const char ***) &argv);
761: if (protect_args && ret) {
762: orig_early_argv = orig_argv;
763: protect_args = 2;
764: read_args(f_in, name, line, sizeof line, 1, &argv, &argc, &request);
765: orig_argv = argv;
766: ret = parse_arguments(&argc, (const char ***) &argv);
767: } else
768: orig_early_argv = NULL;
769:
770: if (pre_exec_pid) {
771: err_msg = finish_pre_exec(pre_exec_pid, pre_exec_fd, request,
772: orig_early_argv, orig_argv);
773: }
774:
775: if (orig_early_argv)
776: free(orig_early_argv);
777:
778: am_server = 1; /* Don't let someone try to be tricky. */
779: quiet = 0;
780: if (lp_ignore_errors(module_id))
781: ignore_errors = 1;
782: if (write_batch < 0)
783: dry_run = 1;
784:
785: if (lp_fake_super(i)) {
786: if (preserve_xattrs > 1)
787: preserve_xattrs = 1;
788: am_root = -1;
789: } else if (am_root < 0) /* Treat --fake-super from client as --super. */
790: am_root = 2;
791:
792: if (filesfrom_fd == 0)
793: filesfrom_fd = f_in;
794:
795: if (request) {
796: if (*auth_user) {
797: rprintf(FLOG, "rsync %s %s from %s@%s (%s)\n",
798: am_sender ? "on" : "to",
799: request, auth_user, host, addr);
800: } else {
801: rprintf(FLOG, "rsync %s %s from %s (%s)\n",
802: am_sender ? "on" : "to",
803: request, host, addr);
804: }
805: free(request);
806: }
807:
808: #ifndef DEBUG
809: /* don't allow the logs to be flooded too fast */
810: if (verbose > lp_max_verbosity(i))
811: verbose = lp_max_verbosity(i);
812: #endif
813:
814: if (protocol_version < 23
815: && (protocol_version == 22 || am_sender))
816: io_start_multiplex_out();
817: else if (!ret || err_msg) {
818: /* We have to get I/O multiplexing started so that we can
819: * get the error back to the client. This means getting
820: * the protocol setup finished first in later versions. */
821: setup_protocol(f_out, f_in);
822: if (!am_sender) {
823: /* Since we failed in our option parsing, we may not
824: * have finished parsing that the client sent us a
825: * --files-from option, so look for it manually.
826: * Without this, the socket would be in the wrong
827: * state for the upcoming error message. */
828: if (!files_from) {
829: int i;
830: for (i = 0; i < argc; i++) {
831: if (strncmp(argv[i], "--files-from", 12) == 0) {
832: files_from = "";
833: break;
834: }
835: }
836: }
837: if (files_from)
838: write_byte(f_out, 0);
839: }
840: io_start_multiplex_out();
841: }
842:
843: if (!ret || err_msg) {
844: if (err_msg)
845: rwrite(FERROR, err_msg, strlen(err_msg), 0);
846: else
847: option_error();
848: msleep(400);
849: exit_cleanup(RERR_UNSUPPORTED);
850: }
851:
852: #ifdef ICONV_OPTION
853: if (!iconv_opt) {
854: if (ic_send != (iconv_t)-1) {
855: iconv_close(ic_send);
856: ic_send = (iconv_t)-1;
857: }
858: if (ic_recv != (iconv_t)-1) {
859: iconv_close(ic_recv);
860: ic_recv = (iconv_t)-1;
861: }
862: }
863: #endif
864:
865: if (!numeric_ids
866: && (use_chroot ? lp_numeric_ids(i) != False : lp_numeric_ids(i) == True))
867: numeric_ids = -1; /* Set --numeric-ids w/o breaking protocol. */
868:
869: if (lp_timeout(i) && (!io_timeout || lp_timeout(i) < io_timeout))
870: set_io_timeout(lp_timeout(i));
871:
872: /* If we have some incoming/outgoing chmod changes, append them to
873: * any user-specified changes (making our changes have priority).
874: * We also get a pointer to just our changes so that a receiver
875: * process can use them separately if --perms wasn't specified. */
876: if (am_sender)
877: p = lp_outgoing_chmod(i);
878: else
879: p = lp_incoming_chmod(i);
880: if (*p && !(daemon_chmod_modes = parse_chmod(p, &chmod_modes))) {
881: rprintf(FLOG, "Invalid \"%sing chmod\" directive: %s\n",
882: am_sender ? "outgo" : "incom", p);
883: }
884:
885: start_server(f_in, f_out, argc, argv);
886:
887: return 0;
888: }
889:
890: /* send a list of available modules to the client. Don't list those
891: with "list = False". */
892: static void send_listing(int fd)
893: {
894: int n = lp_numservices();
895: int i;
896:
897: for (i = 0; i < n; i++) {
898: if (lp_list(i))
899: io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i));
900: }
901:
902: if (protocol_version >= 25)
903: io_printf(fd,"@RSYNCD: EXIT\n");
904: }
905:
906: static int load_config(int globals_only)
907: {
908: if (!config_file) {
909: if (am_server && am_root <= 0)
910: config_file = RSYNCD_USERCONF;
911: else
912: config_file = RSYNCD_SYSCONF;
913: }
914: return lp_load(config_file, globals_only);
915: }
916:
917: /* this is called when a connection is established to a client
918: and we want to start talking. The setup of the system is done from
919: here */
920: int start_daemon(int f_in, int f_out)
921: {
922: char line[1024];
923: char *addr, *host;
924: int i;
925:
926: io_set_sock_fds(f_in, f_out);
927:
928: /* We must load the config file before calling any function that
929: * might cause log-file output to occur. This ensures that the
930: * "log file" param gets honored for the 2 non-forked use-cases
931: * (when rsync is run by init and run by a remote shell). */
932: if (!load_config(0))
933: exit_cleanup(RERR_SYNTAX);
934:
935: addr = client_addr(f_in);
936: host = client_name(f_in);
937: rprintf(FLOG, "connect from %s (%s)\n", host, addr);
938:
939: if (!am_server) {
940: set_socket_options(f_in, "SO_KEEPALIVE");
941: set_nonblocking(f_in);
942: }
943:
944: if (exchange_protocols(f_in, f_out, line, sizeof line, 0) < 0)
945: return -1;
946:
947: line[0] = 0;
948: if (!read_line_old(f_in, line, sizeof line))
949: return -1;
950:
951: if (!*line || strcmp(line, "#list") == 0) {
952: rprintf(FLOG, "module-list request from %s (%s)\n",
953: host, addr);
954: send_listing(f_out);
955: return -1;
956: }
957:
958: if (*line == '#') {
959: /* it's some sort of command that I don't understand */
960: io_printf(f_out, "@ERROR: Unknown command '%s'\n", line);
961: return -1;
962: }
963:
964: if ((i = lp_number(line)) < 0) {
965: rprintf(FLOG, "unknown module '%s' tried from %s (%s)\n",
966: line, host, addr);
967: io_printf(f_out, "@ERROR: Unknown module '%s'\n", line);
968: return -1;
969: }
970:
971: #ifdef HAVE_SIGACTION
972: sigact.sa_flags = SA_NOCLDSTOP;
973: #endif
974: SIGACTION(SIGCHLD, remember_children);
975:
976: return rsync_module(f_in, f_out, i, addr, host);
977: }
978:
979: static void create_pid_file(void)
980: {
981: char *pid_file = lp_pid_file();
982: char pidbuf[16];
983: pid_t pid = getpid();
984: int fd, len;
985:
986: if (!pid_file || !*pid_file)
987: return;
988:
989: cleanup_set_pid(pid);
990: if ((fd = do_open(pid_file, O_WRONLY|O_CREAT|O_EXCL, 0666 & ~orig_umask)) == -1) {
991: failure:
992: cleanup_set_pid(0);
993: fprintf(stderr, "failed to create pid file %s: %s\n", pid_file, strerror(errno));
994: rsyserr(FLOG, errno, "failed to create pid file %s", pid_file);
995: exit_cleanup(RERR_FILEIO);
996: }
997: snprintf(pidbuf, sizeof pidbuf, "%ld\n", (long)pid);
998: len = strlen(pidbuf);
999: if (write(fd, pidbuf, len) != len)
1000: goto failure;
1001: close(fd);
1002: }
1003:
1004: /* Become a daemon, discarding the controlling terminal. */
1005: static void become_daemon(void)
1006: {
1007: int i;
1008: pid_t pid = fork();
1009:
1010: if (pid) {
1011: if (pid < 0) {
1012: fprintf(stderr, "failed to fork: %s\n", strerror(errno));
1013: exit_cleanup(RERR_FILEIO);
1014: }
1015: _exit(0);
1016: }
1017:
1018: create_pid_file();
1019:
1020: /* detach from the terminal */
1021: #ifdef HAVE_SETSID
1022: setsid();
1023: #elif defined TIOCNOTTY
1024: i = open("/dev/tty", O_RDWR);
1025: if (i >= 0) {
1026: ioctl(i, (int)TIOCNOTTY, (char *)0);
1027: close(i);
1028: }
1029: #endif
1030: /* make sure that stdin, stdout an stderr don't stuff things
1031: * up (library functions, for example) */
1032: for (i = 0; i < 3; i++) {
1033: close(i);
1034: open("/dev/null", O_RDWR);
1035: }
1036: }
1037:
1038: int daemon_main(void)
1039: {
1040: if (is_a_socket(STDIN_FILENO)) {
1041: int i;
1042:
1043: /* we are running via inetd - close off stdout and
1044: * stderr so that library functions (and getopt) don't
1045: * try to use them. Redirect them to /dev/null */
1046: for (i = 1; i < 3; i++) {
1047: close(i);
1048: open("/dev/null", O_RDWR);
1049: }
1050:
1051: return start_daemon(STDIN_FILENO, STDIN_FILENO);
1052: }
1053:
1054: if (!load_config(1)) {
1055: fprintf(stderr, "Failed to parse config file: %s\n", config_file);
1056: exit_cleanup(RERR_SYNTAX);
1057: }
1058:
1059: if (no_detach)
1060: create_pid_file();
1061: else
1062: become_daemon();
1063:
1064: if (rsync_port == 0 && (rsync_port = lp_rsync_port()) == 0)
1065: rsync_port = RSYNC_PORT;
1066: if (bind_address == NULL && *lp_bind_address())
1067: bind_address = lp_bind_address();
1068:
1069: log_init(0);
1070:
1071: rprintf(FLOG, "rsyncd version %s starting, listening on port %d\n",
1072: RSYNC_VERSION, rsync_port);
1073: /* TODO: If listening on a particular address, then show that
1074: * address too. In fact, why not just do getnameinfo on the
1075: * local address??? */
1076:
1077: start_accept_loop(rsync_port, start_daemon);
1078: return -1;
1079: }
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