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) 2002-2022 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 as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
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.
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.
28 extern int output_motd;
34 extern int msgs2stderr;
35 extern int rsync_port;
36 extern int protect_args;
37 extern int ignore_errors;
38 extern int preserve_xattrs;
39 extern int kluge_around_eof;
40 extern int munge_symlinks;
41 extern int open_noatime;
42 extern int sanitize_paths;
43 extern int numeric_ids;
44 extern int filesfrom_fd;
45 extern int remote_protocol;
46 extern int protocol_version;
47 extern int io_timeout;
49 extern int write_batch;
50 extern int old_style_args;
51 extern int default_af_hint;
52 extern int logfile_format_has_i;
53 extern int logfile_format_has_o_or_i;
54 extern char *bind_address;
55 extern char *config_file;
56 extern char *logfile_format;
57 extern char *files_from;
59 extern char *early_input_file;
60 extern struct chmod_mode_struct *chmod_modes;
61 extern filter_rule_list daemon_filter_list;
63 extern char *iconv_opt;
64 extern iconv_t ic_send, ic_recv;
73 int early_input_len = 0;
74 char *early_input = NULL;
75 pid_t namecvt_pid = 0;
76 struct chmod_mode_struct *daemon_chmod_modes;
78 #define EARLY_INPUT_CMD "#early_input="
79 #define EARLY_INPUT_CMDLEN (sizeof EARLY_INPUT_CMD - 1)
81 /* module_dirlen is the length of the module_dir string when in daemon
82 * mode and module_dir is not "/"; otherwise 0. (Note that a chroot-
83 * enabled module can have a non-"/" module_dir these days.) */
84 char *module_dir = NULL;
85 unsigned int module_dirlen = 0;
87 char *full_module_path;
89 static int rl_nulls = 0;
90 static int namecvt_fd_req = -1, namecvt_fd_ans = -1;
93 static struct sigaction sigact;
96 static item_list gid_list = EMPTY_ITEM_LIST;
98 /* Used when "reverse lookup" is off. */
99 const char undetermined_hostname[] = "UNDETERMINED";
102 * Run a client connected to an rsyncd. The alternative to this
103 * function for remote-shell connections is do_cmd().
105 * After negotiating which module to use and reading the server's
106 * motd, this hands over to client_run(). Telling the server the
107 * module will cause it to chroot/setuid/etc.
109 * Instead of doing a transfer, the client may at this stage instead
110 * get a listing of remote modules and exit.
112 * @return -1 for error in startup, or the result of client_run().
113 * Either way, it eventually gets passed to exit_cleanup().
115 int start_socket_client(char *host, int remote_argc, char *remote_argv[],
116 int argc, char *argv[])
119 char *p, *user = NULL;
121 /* This is redundant with code in start_inband_exchange(), but this
122 * short-circuits a problem in the client before we open a socket,
123 * and the extra check won't hurt. */
124 if (**remote_argv == '/') {
126 "ERROR: The remote path must start with a module name not a /\n");
130 if ((p = strrchr(host, '@')) != NULL) {
136 fd = open_socket_out_wrapped(host, rsync_port, bind_address, default_af_hint);
138 exit_cleanup(RERR_SOCKETIO);
144 ret = start_inband_exchange(fd, fd, user, remote_argc, remote_argv);
146 return ret ? ret : client_run(fd, fd, -1, argc, argv);
149 static int exchange_protocols(int f_in, int f_out, char *buf, size_t bufsiz, int am_client)
152 #if SUBPROTOCOL_VERSION != 0
153 int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
158 io_printf(f_out, "@RSYNCD: %d.%d\n", protocol_version, our_sub);
160 char *motd = lp_motd_file();
162 FILE *f = fopen(motd, "r");
163 while (f && !feof(f)) {
164 int len = fread(buf, 1, bufsiz - 1, f);
166 write_buf(f_out, buf, len);
170 write_sbuf(f_out, "\n");
174 /* This strips the \n. */
175 if (!read_line_old(f_in, buf, bufsiz, 0)) {
177 rprintf(FERROR, "rsync: did not see server greeting\n");
181 if (sscanf(buf, "@RSYNCD: %d.%d", &remote_protocol, &remote_sub) < 1) {
183 rprintf(FERROR, "rsync: server sent \"%s\" rather than greeting\n", buf);
185 io_printf(f_out, "@ERROR: protocol startup error\n");
189 if (remote_sub < 0) {
190 if (remote_protocol == 30) {
192 rprintf(FERROR, "rsync: server is speaking an incompatible beta of protocol 30\n");
194 io_printf(f_out, "@ERROR: your client is speaking an incompatible beta of protocol 30\n");
200 if (protocol_version > remote_protocol) {
201 protocol_version = remote_protocol;
204 } else if (protocol_version == remote_protocol) {
205 if (remote_sub != our_sub)
208 #if SUBPROTOCOL_VERSION != 0
209 else if (protocol_version < remote_protocol) {
215 if (protocol_version >= 30)
221 int start_inband_exchange(int f_in, int f_out, const char *user, int argc, char *argv[])
224 char line[BIGPATHBUFLEN];
225 char *sargs[MAX_ARGS];
229 assert(argc > 0 && *argv != NULL);
233 "ERROR: The remote path must start with a module name\n");
237 if (!(p = strchr(*argv, '/')))
238 modlen = strlen(*argv);
242 modname = new_array(char, modlen+1+1); /* room for '/' & '\0' */
243 strlcpy(modname, *argv, modlen + 1);
244 modname[modlen] = '/';
245 modname[modlen+1] = '\0';
248 user = getenv("USER");
250 user = getenv("LOGNAME");
252 if (exchange_protocols(f_in, f_out, line, sizeof line, 1) < 0)
255 if (early_input_file) {
257 FILE *f = fopen(early_input_file, "rb");
258 if (!f || do_fstat(fileno(f), &st) < 0) {
259 rsyserr(FERROR, errno, "failed to open %s", early_input_file);
262 early_input_len = st.st_size;
263 if (early_input_len > (int)sizeof line) {
264 rprintf(FERROR, "%s is > %d bytes.\n", early_input_file, (int)sizeof line);
267 if (early_input_len > 0) {
268 io_printf(f_out, EARLY_INPUT_CMD "%d\n", early_input_len);
269 while (early_input_len > 0) {
272 rprintf(FERROR, "Early EOF in %s\n", early_input_file);
275 len = fread(line, 1, early_input_len, f);
277 write_buf(f_out, line, len);
278 early_input_len -= len;
285 server_options(sargs, &sargc);
287 if (sargc >= MAX_ARGS - 2)
290 sargs[sargc++] = ".";
293 snprintf(line, sizeof line, " %.*s/", modlen, modname);
296 if (sargc >= MAX_ARGS - 1) {
298 rprintf(FERROR, "internal: args[] overflowed in do_cmd()\n");
299 exit_cleanup(RERR_SYNTAX);
301 if (strncmp(*argv, modname, modlen) == 0 && argv[0][modlen] == '\0')
302 sargs[sargc++] = modname; /* we send "modname/" */
305 int extra_chars = *arg == '-' ? 2 : 0; /* a leading dash needs a "./" prefix. */
306 /* If --old-args was not specified, make sure that the arg won't split at a mod name! */
307 if (!old_style_args && (p = strstr(arg, line)) != NULL) {
310 } while ((p = strstr(p+1, line)) != NULL);
314 char *t = arg = new_array(char, strlen(arg) + extra_chars + 1);
320 if (*f == ' ' && strncmp(f, line, modlen+2) == 0) {
329 sargs[sargc++] = arg;
337 if (DEBUG_GTE(CMD, 1))
338 print_child_argv("sending daemon args:", sargs);
340 io_printf(f_out, "%.*s\n", modlen, modname);
342 /* Old servers may just drop the connection here,
343 rather than sending a proper EXIT command. Yuck. */
344 kluge_around_eof = list_only && protocol_version < 25 ? 1 : 0;
347 if (!read_line_old(f_in, line, sizeof line, 0)) {
348 rprintf(FERROR, "rsync: didn't get server startup line\n");
352 if (strncmp(line,"@RSYNCD: AUTHREQD ",18) == 0) {
353 auth_client(f_out, user, line+18);
357 if (strcmp(line,"@RSYNCD: OK") == 0)
360 if (strcmp(line,"@RSYNCD: EXIT") == 0) {
361 /* This is sent by recent versions of the
362 * server to terminate the listing of modules.
363 * We don't want to go on and transfer
364 * anything; just exit. */
368 if (strncmp(line, "@ERROR", 6) == 0) {
369 rprintf(FERROR, "%s\n", line);
370 /* This is always fatal; the server will now
371 * close the socket. */
375 /* This might be a MOTD line or a module listing, but there is
376 * no way to differentiate it. The manpage mentions this. */
378 rprintf(FINFO, "%s\n", line);
380 kluge_around_eof = 0;
383 for (i = 0; i < sargc; i++) {
384 if (!sargs[i]) /* stop at --protect-args NULL */
386 write_sbuf(f_out, sargs[i]);
387 write_byte(f_out, 0);
389 write_byte(f_out, 0);
391 for (i = 0; i < sargc; i++)
392 io_printf(f_out, "%s\n", sargs[i]);
393 write_sbuf(f_out, "\n");
397 send_protected_args(f_out, sargs);
399 if (protocol_version < 23) {
400 if (protocol_version == 22 || !am_sender)
401 io_start_multiplex_in(f_in);
409 #if defined HAVE_SETENV || defined HAVE_PUTENV
410 static int read_arg_from_pipe(int fd, char *buf, int limit)
412 char *bp = buf, *eob = buf + limit - 1;
415 int got = read(fd, bp, 1);
417 if (got < 0 && errno == EINTR)
432 static void set_env_str(const char *var, const char *str)
435 if (setenv(var, str, 1) < 0)
436 out_of_memory("set_env_str");
440 if (asprintf(&mem, "%s=%s", var, str) < 0)
441 out_of_memory("set_env_str");
450 #if defined HAVE_SETENV || defined HAVE_PUTENV
452 static void set_envN_str(const char *var, int num, const char *str)
456 (void)snprintf(buf, sizeof buf, "%s%d", var, num);
457 if (setenv(buf, str, 1) < 0)
458 out_of_memory("set_env_str");
462 if (asprintf(&mem, "%s%d=%s", var, num, str) < 0)
463 out_of_memory("set_envN_str");
469 void set_env_num(const char *var, long num)
473 (void)snprintf(val, sizeof val, "%ld", num);
474 if (setenv(var, val, 1) < 0)
475 out_of_memory("set_env_str");
479 if (asprintf(&mem, "%s=%ld", var, num) < 0)
480 out_of_memory("set_env_num");
486 /* Used for "early exec", "pre-xfer exec", and the "name converter" script. */
487 static pid_t start_pre_exec(const char *cmd, int *arg_fd_ptr, int *error_fd_ptr)
489 int arg_fds[2], error_fds[2], arg_fd;
492 if ((error_fd_ptr && pipe(error_fds) < 0) || pipe(arg_fds) < 0 || (pid = fork()) < 0)
496 char buf[BIGPATHBUFLEN];
501 set_blocking(error_fds[1]);
506 set_blocking(arg_fd);
508 len = read_arg_from_pipe(arg_fd, buf, BIGPATHBUFLEN);
511 set_env_str("RSYNC_REQUEST", buf);
514 len = read_arg_from_pipe(arg_fd, buf, BIGPATHBUFLEN);
520 set_envN_str("RSYNC_ARG", j, buf);
523 dup2(arg_fd, STDIN_FILENO);
527 dup2(error_fds[1], STDOUT_FILENO);
531 status = shell_exec(cmd);
533 if (!WIFEXITED(status))
535 _exit(WEXITSTATUS(status));
540 *error_fd_ptr = error_fds[0];
541 set_blocking(error_fds[0]);
545 arg_fd = *arg_fd_ptr = arg_fds[1];
546 set_blocking(arg_fd);
553 static void write_pre_exec_args(int write_fd, char *request, char **early_argv, char **argv, int exec_type)
560 write_buf(write_fd, request, strlen(request)+1);
562 for ( ; *early_argv; early_argv++)
563 write_buf(write_fd, *early_argv, strlen(*early_argv)+1);
564 j = 1; /* Skip arg0 name in argv. */
567 for ( ; argv[j]; j++)
568 write_buf(write_fd, argv[j], strlen(argv[j])+1);
570 write_byte(write_fd, 0);
572 if (exec_type == 1 && early_input_len)
573 write_buf(write_fd, early_input, early_input_len);
575 if (exec_type != 2) /* the name converter needs this left open */
579 static char *finish_pre_exec(const char *desc, pid_t pid, int read_fd)
581 char buf[BIGPATHBUFLEN], *bp, *cr;
582 int j, status = -1, msglen = sizeof buf - 1;
585 /* Read the stdout from the program. This it is only displayed
586 * to the user if the script also returns an error status. */
587 for (bp = buf, cr = buf; msglen > 0; msglen -= j) {
588 if ((j = read(read_fd, bp, msglen)) <= 0) {
593 break; /* Just ignore the read error for now... */
597 if ((cr = strchr(cr, '\r')) == NULL) {
602 break; /* wait for more data before we decide what to do */
604 memmove(cr, cr+1, j - (cr - bp));
617 if (wait_process(pid, &status, 0) < 0
618 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
620 if (asprintf(&e, "%s returned failure (%d)%s%s%s\n%s",
621 desc, status, status < 0 ? ": " : "",
622 status < 0 ? strerror(errno) : "",
623 *buf ? ":" : "", buf) < 0)
624 return "out_of_memory in finish_pre_exec\n";
630 static int path_failure(int f_out, const char *dir, BOOL was_chdir)
633 rsyserr(FLOG, errno, "chdir %s failed", dir);
635 rprintf(FLOG, "normalize_path(%s) failed\n", dir);
636 io_printf(f_out, "@ERROR: chdir failed\n");
640 static int add_a_group(int f_out, const char *gname)
643 if (!group_to_gid(gname, &gid, True)) {
644 rprintf(FLOG, "Invalid gid %s\n", gname);
645 io_printf(f_out, "@ERROR: invalid gid %s\n", gname);
648 gid_p = EXPAND_ITEM_LIST(&gid_list, gid_t, -32);
653 #ifdef HAVE_GETGROUPLIST
654 static int want_all_groups(int f_out, uid_t uid)
657 if ((err = getallgroups(uid, &gid_list)) != NULL) {
658 rsyserr(FLOG, errno, "%s", err);
659 io_printf(f_out, "@ERROR: %s\n", err);
664 #elif defined HAVE_INITGROUPS
665 static struct passwd *want_all_groups(int f_out, uid_t uid)
669 if ((pw = getpwuid(uid)) == NULL) {
670 rsyserr(FLOG, errno, "getpwuid failed");
671 io_printf(f_out, "@ERROR: getpwuid failed\n");
674 /* Start with the default group and initgroups() will add the rest. */
675 gid_p = EXPAND_ITEM_LIST(&gid_list, gid_t, -32);
681 static int rsync_module(int f_in, int f_out, int i, const char *addr, const char *host)
684 char **argv, **orig_argv, **orig_early_argv, *module_chdir;
685 char line[BIGPATHBUFLEN];
686 #if defined HAVE_INITGROUPS && !defined HAVE_GETGROUPLIST
687 struct passwd *pw = NULL;
691 char *p, *err_msg = NULL;
692 char *name = lp_name(i);
693 int use_chroot = lp_use_chroot(i);
694 int ret, pre_exec_arg_fd = -1, pre_exec_error_fd = -1;
695 int save_munge_symlinks;
696 pid_t pre_exec_pid = 0;
697 char *request = NULL;
699 set_env_str("RSYNC_MODULE_NAME", name);
702 iconv_opt = lp_charset(i);
708 /* If reverse lookup is disabled globally but enabled for this module,
709 * we need to do it now before the access check. */
710 if (host == undetermined_hostname && lp_reverse_lookup(i))
711 host = client_name(client_addr(f_in));
712 set_env_str("RSYNC_HOST_NAME", host);
713 set_env_str("RSYNC_HOST_ADDR", addr);
715 if (!allow_access(addr, &host, i)) {
716 rprintf(FLOG, "rsync denied on module %s from %s (%s)\n",
719 io_printf(f_out, "@ERROR: Unknown module '%s'\n", name);
722 "@ERROR: access denied to %s from %s (%s)\n",
729 rprintf(FLOG, "rsync allowed access on module %s from %s (%s)\n",
733 if (!claim_connection(lp_lock_file(i), lp_max_connections(i))) {
735 rsyserr(FLOG, errno, "failed to open lock file %s",
737 io_printf(f_out, "@ERROR: failed to open lock file\n");
739 rprintf(FLOG, "max connections (%d) reached\n",
740 lp_max_connections(i));
741 io_printf(f_out, "@ERROR: max connections (%d) reached -- try again later\n",
742 lp_max_connections(i));
747 read_only = lp_read_only(i); /* may also be overridden by auth_server() */
748 auth_user = auth_server(f_in, f_out, i, host, addr, "@RSYNCD: AUTHREQD ");
751 io_printf(f_out, "@ERROR: auth failed on module %s\n", name);
754 set_env_str("RSYNC_USER_NAME", auth_user);
758 if (lp_transfer_logging(module_id) && !logfile_format)
759 logfile_format = lp_log_format(module_id);
760 if (log_format_has(logfile_format, 'i'))
761 logfile_format_has_i = 1;
762 if (logfile_format_has_i || log_format_has(logfile_format, 'o'))
763 logfile_format_has_o_or_i = 1;
766 am_root = (uid == ROOT_UID);
768 p = *lp_uid(module_id) ? lp_uid(module_id) : am_root ? NOBODY_USER : NULL;
770 if (!user_to_uid(p, &uid, True)) {
771 rprintf(FLOG, "Invalid uid %s\n", p);
772 io_printf(f_out, "@ERROR: invalid uid %s\n", p);
779 p = *lp_gid(module_id) ? conf_strtok(lp_gid(module_id)) : NULL;
781 /* The "*" gid must be the first item in the list. */
782 if (strcmp(p, "*") == 0) {
783 #ifdef HAVE_GETGROUPLIST
784 if (want_all_groups(f_out, uid) < 0)
786 #elif defined HAVE_INITGROUPS
787 if ((pw = want_all_groups(f_out, uid)) == NULL)
790 rprintf(FLOG, "This rsync does not support a gid of \"*\"\n");
791 io_printf(f_out, "@ERROR: invalid gid setting.\n");
794 } else if (add_a_group(f_out, p) < 0)
796 while ((p = conf_strtok(NULL)) != NULL) {
797 #if defined HAVE_INITGROUPS && !defined HAVE_GETGROUPLIST
799 rprintf(FLOG, "This rsync cannot add groups after \"*\".\n");
800 io_printf(f_out, "@ERROR: invalid gid setting.\n");
804 if (add_a_group(f_out, p) < 0)
807 } else if (am_root) {
808 if (add_a_group(f_out, NOBODY_GROUP) < 0)
812 module_dir = lp_path(module_id);
813 if (*module_dir == '\0') {
814 rprintf(FLOG, "No path specified for module %s\n", name);
815 io_printf(f_out, "@ERROR: no path setting.\n");
819 if ((p = strstr(module_dir, "/./")) != NULL) {
820 *p = '\0'; /* Temporary... */
821 if (!(module_chdir = normalize_path(module_dir, True, NULL)))
822 return path_failure(f_out, module_dir, False);
824 if (!(p = normalize_path(p + 2, True, &module_dirlen)))
825 return path_failure(f_out, strstr(module_dir, "/./"), False);
826 if (!(full_module_path = normalize_path(module_dir, False, NULL)))
827 full_module_path = module_dir;
830 if (!(module_chdir = normalize_path(module_dir, False, NULL)))
831 return path_failure(f_out, module_dir, False);
832 full_module_path = module_chdir;
837 if (!(module_chdir = normalize_path(module_dir, False, &module_dirlen)))
838 return path_failure(f_out, module_dir, False);
839 full_module_path = module_dir = module_chdir;
841 set_env_str("RSYNC_MODULE_PATH", full_module_path);
843 if (module_dirlen == 1) {
845 set_filter_dir("/", 1);
847 set_filter_dir(module_dir, module_dirlen);
849 p = lp_filter(module_id);
850 parse_filter_str(&daemon_filter_list, p, rule_template(FILTRULE_WORD_SPLIT),
851 XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3);
853 p = lp_include_from(module_id);
854 parse_filter_file(&daemon_filter_list, p, rule_template(FILTRULE_INCLUDE),
855 XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS);
857 p = lp_include(module_id);
858 parse_filter_str(&daemon_filter_list, p,
859 rule_template(FILTRULE_INCLUDE | FILTRULE_WORD_SPLIT),
860 XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES);
862 p = lp_exclude_from(module_id);
863 parse_filter_file(&daemon_filter_list, p, rule_template(0),
864 XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS);
866 p = lp_exclude(module_id);
867 parse_filter_str(&daemon_filter_list, p, rule_template(FILTRULE_WORD_SPLIT),
868 XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES);
872 #if defined HAVE_SETENV || defined HAVE_PUTENV
873 if ((*lp_early_exec(module_id) || *lp_prexfer_exec(module_id)
874 || *lp_postxfer_exec(module_id) || *lp_name_converter(module_id))
875 && !getenv("RSYNC_NO_XFER_EXEC")) {
876 set_env_num("RSYNC_PID", (long)getpid());
878 /* For post-xfer exec, fork a new process to run the rsync
879 * daemon while this process waits for the exit status and
880 * runs the indicated command at that point. */
881 if (*lp_postxfer_exec(module_id)) {
884 rsyserr(FLOG, errno, "fork failed");
885 io_printf(f_out, "@ERROR: fork failed\n");
893 if (wait_process(pid, &status, 0) < 0)
895 set_env_num("RSYNC_RAW_STATUS", status);
896 if (WIFEXITED(status))
897 status = WEXITSTATUS(status);
900 set_env_num("RSYNC_EXIT_STATUS", status);
901 if (shell_exec(lp_postxfer_exec(module_id)) < 0)
907 /* For early exec, fork a child process to run the indicated
908 * command and wait for it to exit. */
909 if (*lp_early_exec(module_id)) {
911 pid_t pid = start_pre_exec(lp_early_exec(module_id), &arg_fd, NULL);
912 if (pid == (pid_t)-1) {
913 rsyserr(FLOG, errno, "early exec preparation failed");
914 io_printf(f_out, "@ERROR: early exec preparation failed\n");
917 write_pre_exec_args(arg_fd, NULL, NULL, NULL, 1);
918 if (finish_pre_exec("early exec", pid, -1) != NULL) {
919 rsyserr(FLOG, errno, "early exec failed");
920 io_printf(f_out, "@ERROR: early exec failed\n");
925 /* For pre-xfer exec, fork a child process to run the indicated
926 * command, though it first waits for the parent process to
927 * send us the user's request via a pipe. */
928 if (*lp_prexfer_exec(module_id)) {
929 pre_exec_pid = start_pre_exec(lp_prexfer_exec(module_id), &pre_exec_arg_fd, &pre_exec_error_fd);
930 if (pre_exec_pid == (pid_t)-1) {
931 rsyserr(FLOG, errno, "pre-xfer exec preparation failed");
932 io_printf(f_out, "@ERROR: pre-xfer exec preparation failed\n");
937 if (*lp_name_converter(module_id)) {
938 namecvt_pid = start_pre_exec(lp_name_converter(module_id), &namecvt_fd_req, &namecvt_fd_ans);
939 if (namecvt_pid == (pid_t)-1) {
940 rsyserr(FLOG, errno, "name-converter exec preparation failed");
941 io_printf(f_out, "@ERROR: name-converter exec preparation failed\n");
955 * XXX: The 'use chroot' flag is a fairly reliable
956 * source of confusion, because it fails under two
957 * important circumstances: running as non-root,
958 * running on Win32 (or possibly others). On the
959 * other hand, if you are running as root, then it
960 * might be better to always use chroot.
962 * So, perhaps if we can't chroot we should just issue
963 * a warning, unless a "require chroot" flag is set,
964 * in which case we fail.
966 if (chroot(module_chdir)) {
967 rsyserr(FLOG, errno, "chroot %s failed", module_chdir);
968 io_printf(f_out, "@ERROR: chroot failed\n");
971 module_chdir = module_dir;
974 if (!change_dir(module_chdir, CD_NORMAL))
975 return path_failure(f_out, module_chdir, True);
976 if (module_dirlen || (!use_chroot && !*lp_daemon_chroot()))
979 if ((munge_symlinks = lp_munge_symlinks(module_id)) < 0)
980 munge_symlinks = !use_chroot || module_dirlen;
981 if (munge_symlinks) {
983 char prefix[SYMLINK_PREFIX_LEN]; /* NOT +1 ! */
984 strlcpy(prefix, SYMLINK_PREFIX, sizeof prefix); /* trim the trailing slash */
985 if (do_stat(prefix, &st) == 0 && S_ISDIR(st.st_mode)) {
986 rprintf(FLOG, "Symlink munging is unsafe when a %s directory exists.\n",
988 io_printf(f_out, "@ERROR: daemon security issue -- contact admin\n", name);
989 exit_cleanup(RERR_UNSUPPORTED);
993 if (gid_list.count) {
994 gid_t *gid_array = gid_list.items;
995 if (setgid(gid_array[0])) {
996 rsyserr(FLOG, errno, "setgid %ld failed", (long)gid_array[0]);
997 io_printf(f_out, "@ERROR: setgid failed\n");
1000 #ifdef HAVE_SETGROUPS
1001 /* Set the group(s) we want to be active. */
1002 if (setgroups(gid_list.count, gid_array)) {
1003 rsyserr(FLOG, errno, "setgroups failed");
1004 io_printf(f_out, "@ERROR: setgroups failed\n");
1008 #if defined HAVE_INITGROUPS && !defined HAVE_GETGROUPLIST
1009 /* pw is set if the user wants all the user's groups. */
1010 if (pw && initgroups(pw->pw_name, pw->pw_gid) < 0) {
1011 rsyserr(FLOG, errno, "initgroups failed");
1012 io_printf(f_out, "@ERROR: initgroups failed\n");
1025 rsyserr(FLOG, errno, "setuid %ld failed", (long)uid);
1026 io_printf(f_out, "@ERROR: setuid failed\n");
1031 am_root = (our_uid == ROOT_UID);
1034 if (lp_temp_dir(module_id) && *lp_temp_dir(module_id)) {
1035 tmpdir = lp_temp_dir(module_id);
1036 if (strlen(tmpdir) >= MAXPATHLEN - 10) {
1038 "the 'temp dir' value for %s is WAY too long -- ignoring.\n",
1044 io_printf(f_out, "@RSYNCD: OK\n");
1046 read_args(f_in, name, line, sizeof line, rl_nulls, &argv, &argc, &request);
1049 save_munge_symlinks = munge_symlinks;
1051 reset_output_levels(); /* future verbosity is controlled by client options */
1052 ret = parse_arguments(&argc, (const char ***) &argv);
1053 if (protect_args && ret) {
1054 orig_early_argv = orig_argv;
1056 read_args(f_in, name, line, sizeof line, 1, &argv, &argc, &request);
1058 ret = parse_arguments(&argc, (const char ***) &argv);
1060 orig_early_argv = NULL;
1062 /* The default is to use the user's setting unless the module sets True or False. */
1063 if (lp_open_noatime(module_id) >= 0)
1064 open_noatime = lp_open_noatime(module_id);
1066 munge_symlinks = save_munge_symlinks; /* The client mustn't control this. */
1069 msgs2stderr = 0; /* A non-rsh-run daemon doesn't have stderr for msgs. */
1072 write_pre_exec_args(pre_exec_arg_fd, request, orig_early_argv, orig_argv, 0);
1073 err_msg = finish_pre_exec("pre-xfer exec", pre_exec_pid, pre_exec_error_fd);
1077 write_pre_exec_args(namecvt_fd_req, request, orig_early_argv, orig_argv, 2);
1079 if (orig_early_argv)
1080 free(orig_early_argv);
1082 am_server = 1; /* Don't let someone try to be tricky. */
1084 if (lp_ignore_errors(module_id))
1086 if (write_batch < 0)
1089 if (lp_fake_super(module_id)) {
1090 if (preserve_xattrs > 1)
1091 preserve_xattrs = 1;
1093 } else if (am_root < 0) /* Treat --fake-super from client as --super. */
1096 if (filesfrom_fd == 0)
1097 filesfrom_fd = f_in;
1101 rprintf(FLOG, "rsync %s %s from %s@%s (%s)\n",
1102 am_sender ? "on" : "to",
1103 request, auth_user, host, addr);
1105 rprintf(FLOG, "rsync %s %s from %s (%s)\n",
1106 am_sender ? "on" : "to",
1107 request, host, addr);
1113 /* don't allow the logs to be flooded too fast */
1114 limit_output_verbosity(lp_max_verbosity(module_id));
1117 if (protocol_version < 23 && (protocol_version == 22 || am_sender))
1118 io_start_multiplex_out(f_out);
1119 else if (!ret || err_msg) {
1120 /* We have to get I/O multiplexing started so that we can
1121 * get the error back to the client. This means getting
1122 * the protocol setup finished first in later versions. */
1123 setup_protocol(f_out, f_in);
1125 /* Since we failed in our option parsing, we may not
1126 * have finished parsing that the client sent us a
1127 * --files-from option, so look for it manually.
1128 * Without this, the socket would be in the wrong
1129 * state for the upcoming error message. */
1132 for (i = 0; i < argc; i++) {
1133 if (strncmp(argv[i], "--files-from", 12) == 0) {
1140 write_byte(f_out, 0);
1142 io_start_multiplex_out(f_out);
1145 if (!ret || err_msg) {
1147 while ((p = strchr(err_msg, '\n')) != NULL) {
1148 int len = p - err_msg + 1;
1149 rwrite(FERROR, err_msg, len, 0);
1153 rprintf(FERROR, "%s\n", err_msg);
1154 io_flush(MSG_FLUSH);
1158 exit_cleanup(RERR_UNSUPPORTED);
1163 if (ic_send != (iconv_t)-1) {
1164 iconv_close(ic_send);
1165 ic_send = (iconv_t)-1;
1167 if (ic_recv != (iconv_t)-1) {
1168 iconv_close(ic_recv);
1169 ic_recv = (iconv_t)-1;
1175 && (use_chroot ? lp_numeric_ids(module_id) != False && !*lp_name_converter(module_id)
1176 : lp_numeric_ids(module_id) == True))
1177 numeric_ids = -1; /* Set --numeric-ids w/o breaking protocol. */
1179 if (lp_timeout(module_id) && (!io_timeout || lp_timeout(module_id) < io_timeout))
1180 set_io_timeout(lp_timeout(module_id));
1182 /* If we have some incoming/outgoing chmod changes, append them to
1183 * any user-specified changes (making our changes have priority).
1184 * We also get a pointer to just our changes so that a receiver
1185 * process can use them separately if --perms wasn't specified. */
1187 p = lp_outgoing_chmod(module_id);
1189 p = lp_incoming_chmod(module_id);
1190 if (*p && !(daemon_chmod_modes = parse_chmod(p, &chmod_modes))) {
1191 rprintf(FLOG, "Invalid \"%sing chmod\" directive: %s\n",
1192 am_sender ? "outgo" : "incom", p);
1195 start_server(f_in, f_out, argc, argv);
1200 BOOL namecvt_call(const char *cmd, const char **name_p, id_t *id_p)
1206 len = snprintf(buf, sizeof buf, "%s %s\n", cmd, *name_p);
1208 len = snprintf(buf, sizeof buf, "%s %ld\n", cmd, (long)*id_p);
1209 if (len >= (int)sizeof buf) {
1210 rprintf(FERROR, "namecvt_call() request was too large.\n");
1211 exit_cleanup(RERR_UNSUPPORTED);
1214 while ((got = write(namecvt_fd_req, buf, len)) != len) {
1215 if (got < 0 && errno == EINTR)
1217 rprintf(FERROR, "Connection to name-converter failed.\n");
1218 exit_cleanup(RERR_SOCKETIO);
1221 if (!read_line_old(namecvt_fd_ans, buf, sizeof buf, 0))
1225 *id_p = (id_t)atol(buf);
1227 *name_p = strdup(buf);
1232 /* send a list of available modules to the client. Don't list those
1233 with "list = False". */
1234 static void send_listing(int fd)
1236 int n = lp_num_modules();
1239 for (i = 0; i < n; i++) {
1241 io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i));
1244 if (protocol_version >= 25)
1245 io_printf(fd,"@RSYNCD: EXIT\n");
1248 static int load_config(int globals_only)
1251 if (am_daemon < 0 && am_root <= 0)
1252 config_file = RSYNCD_USERCONF;
1254 config_file = RSYNCD_SYSCONF;
1256 return lp_load(config_file, globals_only);
1259 /* this is called when a connection is established to a client
1260 and we want to start talking. The setup of the system is done from
1262 int start_daemon(int f_in, int f_out)
1265 const char *addr, *host;
1269 /* At this point, am_server is only set for a daemon started via rsh.
1270 * Because am_server gets forced on soon, we'll set am_daemon to -1 as
1271 * a flag that can be checked later on to distinguish a normal daemon
1272 * from an rsh-run daemon. */
1276 io_set_sock_fds(f_in, f_out);
1278 /* We must load the config file before calling any function that
1279 * might cause log-file output to occur. This ensures that the
1280 * "log file" param gets honored for the 2 non-forked use-cases
1281 * (when rsync is run by init and run by a remote shell). */
1282 if (!load_config(0))
1283 exit_cleanup(RERR_SYNTAX);
1285 if (lp_proxy_protocol() && !read_proxy_protocol_header(f_in))
1288 p = lp_daemon_chroot();
1290 log_init(0); /* Make use we've initialized syslog before chrooting. */
1291 if (chroot(p) < 0 || chdir("/") < 0) {
1292 rsyserr(FLOG, errno, "daemon chroot %s failed", p);
1296 p = lp_daemon_gid();
1299 if (!group_to_gid(p, &gid, True)) {
1300 rprintf(FLOG, "Invalid daemon gid: %s\n", p);
1303 if (setgid(gid) < 0) {
1304 rsyserr(FLOG, errno, "Unable to set group to daemon gid %ld", (long)gid);
1309 p = lp_daemon_uid();
1312 if (!user_to_uid(p, &uid, True)) {
1313 rprintf(FLOG, "Invalid daemon uid: %s\n", p);
1316 if (setuid(uid) < 0) {
1317 rsyserr(FLOG, errno, "Unable to set user to daemon uid %ld", (long)uid);
1321 am_root = (our_uid == ROOT_UID);
1324 addr = client_addr(f_in);
1325 host = lp_reverse_lookup(-1) ? client_name(addr) : undetermined_hostname;
1326 rprintf(FLOG, "connect from %s (%s)\n", host, addr);
1328 if (am_daemon > 0) {
1329 set_socket_options(f_in, "SO_KEEPALIVE");
1330 set_nonblocking(f_in);
1333 if (exchange_protocols(f_in, f_out, line, sizeof line, 0) < 0)
1337 if (!read_line_old(f_in, line, sizeof line, 0))
1340 if (strncmp(line, EARLY_INPUT_CMD, EARLY_INPUT_CMDLEN) == 0) {
1341 early_input_len = strtol(line + EARLY_INPUT_CMDLEN, NULL, 10);
1342 if (early_input_len <= 0 || early_input_len > BIGPATHBUFLEN) {
1343 io_printf(f_out, "@ERROR: invalid early_input length\n");
1346 early_input = new_array(char, early_input_len);
1347 read_buf(f_in, early_input, early_input_len);
1349 if (!read_line_old(f_in, line, sizeof line, 0))
1353 if (!*line || strcmp(line, "#list") == 0) {
1354 rprintf(FLOG, "module-list request from %s (%s)\n",
1356 send_listing(f_out);
1361 /* it's some sort of command that I don't understand */
1362 io_printf(f_out, "@ERROR: Unknown command '%s'\n", line);
1366 if ((i = lp_number(line)) < 0) {
1367 rprintf(FLOG, "unknown module '%s' tried from %s (%s)\n",
1369 io_printf(f_out, "@ERROR: Unknown module '%s'\n", line);
1373 #ifdef HAVE_SIGACTION
1374 sigact.sa_flags = SA_NOCLDSTOP;
1376 SIGACTION(SIGCHLD, remember_children);
1378 return rsync_module(f_in, f_out, i, addr, host);
1381 static void create_pid_file(void)
1383 char *pid_file = lp_pid_file();
1385 STRUCT_STAT st1, st2;
1388 if (!pid_file || !*pid_file)
1392 #define SAFE_OPEN_FLAGS (O_CREAT|O_NOFOLLOW)
1394 #define SAFE_OPEN_FLAGS (O_CREAT)
1397 /* These tests make sure that a temp-style lock dir is handled safely. */
1399 if (do_lstat(pid_file, &st1) == 0 && !S_ISREG(st1.st_mode) && unlink(pid_file) < 0)
1401 else if ((pid_file_fd = do_open(pid_file, O_RDWR|SAFE_OPEN_FLAGS, 0664)) < 0)
1402 fail = S_ISREG(st1.st_mode) ? "open" : "create";
1403 else if (!lock_range(pid_file_fd, 0, 4))
1405 else if (do_fstat(pid_file_fd, &st1) < 0)
1406 fail = "fstat opened";
1407 else if (st1.st_size > (int)sizeof pidbuf)
1408 fail = "find small";
1409 else if (do_lstat(pid_file, &st2) < 0)
1411 else if (!S_ISREG(st1.st_mode))
1412 fail = "avoid file overwrite race for";
1413 else if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
1414 fail = "verify stat info for";
1415 #ifdef HAVE_FTRUNCATE
1416 else if (do_ftruncate(pid_file_fd, 0) < 0)
1420 pid_t pid = getpid();
1421 int len = snprintf(pidbuf, sizeof pidbuf, "%d\n", (int)pid);
1422 #ifndef HAVE_FTRUNCATE
1423 /* What can we do with a too-long file and no truncate? I guess we'll add extra newlines. */
1424 while (len < st1.st_size) /* We already verified that st_size chars fits in the buffer. */
1425 pidbuf[len++] = '\n';
1426 /* We don't need the buffer to end in a '\0' (and we may not have room to add it). */
1428 if (write(pid_file_fd, pidbuf, len) != len)
1430 cleanup_set_pid(pid); /* Mark the file for removal on exit, even if the write failed. */
1435 snprintf(msg, sizeof msg, "failed to %s pid file %s: %s\n",
1436 fail, pid_file, strerror(errno));
1438 rprintf(FLOG, "%s", msg);
1439 exit_cleanup(RERR_FILEIO);
1442 /* The file is left open so that the lock remains valid. It is closed in our forked child procs. */
1445 /* Become a daemon, discarding the controlling terminal. */
1446 static void become_daemon(void)
1453 fprintf(stderr, "failed to fork: %s\n", strerror(errno));
1454 exit_cleanup(RERR_FILEIO);
1461 /* detach from the terminal */
1464 #elif defined TIOCNOTTY
1465 i = open("/dev/tty", O_RDWR);
1467 ioctl(i, (int)TIOCNOTTY, (char *)0);
1471 /* make sure that stdin, stdout an stderr don't stuff things
1472 * up (library functions, for example) */
1473 for (i = 0; i < 3; i++) {
1475 open("/dev/null", O_RDWR);
1479 int daemon_main(void)
1481 if (is_a_socket(STDIN_FILENO)) {
1484 /* we are running via inetd - close off stdout and
1485 * stderr so that library functions (and getopt) don't
1486 * try to use them. Redirect them to /dev/null */
1487 for (i = 1; i < 3; i++) {
1489 open("/dev/null", O_RDWR);
1492 return start_daemon(STDIN_FILENO, STDIN_FILENO);
1495 if (!load_config(1)) {
1496 fprintf(stderr, "Failed to parse config file: %s\n", config_file);
1497 exit_cleanup(RERR_SYNTAX);
1506 if (rsync_port == 0 && (rsync_port = lp_rsync_port()) == 0)
1507 rsync_port = RSYNC_PORT;
1508 if (bind_address == NULL && *lp_bind_address())
1509 bind_address = lp_bind_address();
1513 rprintf(FLOG, "rsyncd version %s starting, listening on port %d\n",
1514 rsync_version(), rsync_port);
1515 /* TODO: If listening on a particular address, then show that
1516 * address too. In fact, why not just do getnameinfo on the
1517 * local address??? */
1519 start_accept_loop(rsync_port, start_daemon);