X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/56c473b795bad9d29430bf794f9204bd096c9c3d..1b42f628f495ff0cdaa8a7c219d8ce33192281fe:/clientserver.c

diff --git a/clientserver.c b/clientserver.c
index 32deee76..43bfdf4a 100644
--- a/clientserver.c
+++ b/clientserver.c
@@ -1,191 +1,759 @@
-/* 
-   Copyright (C) Andrew Tridgell 1998
-   
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
-   
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-   
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-/* the socket based protocol for setting up a connection wit rsyncd */
+/*
+ * The socket based protocol for setting up a connection with rsyncd.
+ *
+ * Copyright (C) 1998-2001 Andrew Tridgell <tridge@samba.org>
+ * Copyright (C) 2001-2002 Martin Pool <mbp@samba.org>
+ * Copyright (C) 2002-2007 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
 
 #include "rsync.h"
+#include "ifuncs.h"
 
-extern int module_id;
-extern int read_only;
 extern int verbose;
+extern int quiet;
+extern int output_motd;
+extern int list_only;
+extern int am_sender;
+extern int am_server;
+extern int am_daemon;
+extern int am_root;
 extern int rsync_port;
+extern int ignore_errors;
+extern int kluge_around_eof;
+extern int daemon_over_rsh;
+extern int sanitize_paths;
+extern int filesfrom_fd;
+extern int remote_protocol;
+extern int protocol_version;
+extern int io_timeout;
+extern int no_detach;
+extern int default_af_hint;
+extern int logfile_format_has_i;
+extern int logfile_format_has_o_or_i;
+extern mode_t orig_umask;
+extern char *bind_address;
+extern char *sockopts;
+extern char *config_file;
+extern char *logfile_format;
+extern char *files_from;
+extern char *tmpdir;
+extern struct chmod_mode_struct *chmod_modes;
+extern struct filter_list_struct server_filter_list;
+extern char curr_dir[];
+
+char *auth_user;
+int read_only = 0;
+int module_id = -1;
+struct chmod_mode_struct *daemon_chmod_modes;
+
+/* module_dirlen is the length of the module_dir string when in daemon
+ * mode, not chrooted, and the path is not "/"; otherwise 0. */
+char *module_dir = NULL;
+unsigned int module_dirlen = 0;
+
+static int rl_nulls = 0;
+
+#ifdef HAVE_SIGACTION
+static struct sigaction sigact;
+#endif
 
-int start_socket_client(char *host, char *path, int argc, char *argv[])
+/**
+ * Run a client connected to an rsyncd.  The alternative to this
+ * function for remote-shell connections is do_cmd().
+ *
+ * After negotiating which module to use and reading the server's
+ * motd, this hands over to client_run().  Telling the server the
+ * module will cause it to chroot/setuid/etc.
+ *
+ * Instead of doing a transfer, the client may at this stage instead
+ * get a listing of remote modules and exit.
+ *
+ * @return -1 for error in startup, or the result of client_run().
+ * Either way, it eventually gets passed to exit_cleanup().
+ **/
+int start_socket_client(char *host, int remote_argc, char *remote_argv[],
+			int argc, char *argv[])
 {
-	int fd, i;
-	char *sargs[MAX_ARGS];
-	int sargc=0;
-	char line[1024];
-	char *p;
-	int version;
+	int fd, ret;
+	char *p, *user = NULL;
+
+	/* This is redundant with code in start_inband_exchange(), but this
+	 * short-circuits a problem in the client before we open a socket,
+	 * and the extra check won't hurt. */
+	if (**remote_argv == '/') {
+		rprintf(FERROR,
+			"ERROR: The remote path must start with a module name not a /\n");
+		return -1;
+	}
 
-	fd = open_socket_out(host, rsync_port);
-	if (fd == -1) {
-		exit_cleanup(1);
+	if ((p = strrchr(host, '@')) != NULL) {
+		user = host;
+		host = p+1;
+		*p = '\0';
 	}
-	
-	server_options(sargs,&sargc);
 
-	sargs[sargc++] = ".";
+	fd = open_socket_out_wrapped(host, rsync_port, bind_address,
+				     default_af_hint);
+	if (fd == -1)
+		exit_cleanup(RERR_SOCKETIO);
 
-	if (path && *path) 
-		sargs[sargc++] = path;
+	set_socket_options(fd, sockopts);
 
-	sargs[sargc] = NULL;
+	ret = start_inband_exchange(fd, fd, user, remote_argc, remote_argv);
 
-	if (!read_line(fd, line, sizeof(line)-1)) {
-		return -1;
+	return ret ? ret : client_run(fd, fd, -1, argc, argv);
+}
+
+static int exchange_protocols(int f_in, int f_out, char *buf, size_t bufsiz, int am_client)
+{
+	int remote_sub = -1;
+#if SUBPROTOCOL_VERSION != 0
+	int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
+#else
+	int our_sub = 0;
+#endif
+	char *motd;
+
+	io_printf(f_out, "@RSYNCD: %d.%d\n", protocol_version, our_sub);
+
+	if (!am_client) {
+		motd = lp_motd_file();
+		if (motd && *motd) {
+			FILE *f = fopen(motd,"r");
+			while (f && !feof(f)) {
+				int len = fread(buf, 1, bufsiz - 1, f);
+				if (len > 0)
+					write_buf(f_out, buf, len);
+			}
+			if (f)
+				fclose(f);
+			write_sbuf(f_out, "\n");
+		}
 	}
 
-	if (sscanf(line,"@RSYNCD: %d", &version) != 1) {
+	/* This strips the \n. */
+	if (!read_line_old(f_in, buf, bufsiz)) {
+		if (am_client)
+			rprintf(FERROR, "rsync: did not see server greeting\n");
 		return -1;
 	}
 
-	io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
-
-	p = strchr(path,'/');
-	if (p) *p = 0;
-	io_printf(fd,"%s\n",path);
-	if (p) *p = '/';
+	if (sscanf(buf, "@RSYNCD: %d.%d", &remote_protocol, &remote_sub) < 1) {
+		if (am_client)
+			rprintf(FERROR, "rsync: server sent \"%s\" rather than greeting\n", buf);
+		else
+			io_printf(f_out, "@ERROR: protocol startup error\n");
+		return -1;
+	}
 
-	while (1) {
-		if (!read_line(fd, line, sizeof(line)-1)) {
+	if (remote_sub < 0) {
+		if (remote_protocol == 30) {
+			if (am_client)
+				rprintf(FERROR, "rsync: server is speaking an incompatible beta of protocol 30\n");
+			else
+				io_printf(f_out, "@ERROR: your client is speaking an incompatible beta of protocol 30\n");
 			return -1;
 		}
-		if (strcmp(line,"@RSYNCD: OK") == 0) break;
-		rprintf(FINFO,"%s\n", line);
+		remote_sub = 0;
 	}
 
-	for (i=0;i<sargc;i++) {
-		io_printf(fd,"%s\n", sargs[i]);
+	if (protocol_version > remote_protocol) {
+		protocol_version = remote_protocol;
+		if (remote_sub)
+			protocol_version--;
+	} else if (protocol_version == remote_protocol) {
+		if (remote_sub != our_sub)
+			protocol_version--;
 	}
-	io_printf(fd,"\n");
-
-#if 0
-	while (1) {
-		if (!read_line(fd, line, sizeof(line)-1)) {
-			return -1;
-		}
-		rprintf(FINFO,"%s\n", line);
+#if SUBPROTOCOL_VERSION != 0
+	else if (protocol_version < remote_protocol) {
+		if (our_sub)
+			protocol_version--;
 	}
 #endif
 
-	return client_run(fd, fd, -1, argc, argv);
+	if (protocol_version >= 30)
+		rl_nulls = 1;
+
+	return 0;
 }
 
+int start_inband_exchange(int f_in, int f_out, const char *user, int argc, char *argv[])
+{
+	int i;
+	char line[BIGPATHBUFLEN];
+	char *sargs[MAX_ARGS];
+	int sargc = 0;
+	char *p, *path = *argv;
+
+	if (argc == 0 && !am_sender)
+		list_only |= 1;
 
+	if (*path == '/') {
+		rprintf(FERROR,
+			"ERROR: The remote path must start with a module name\n");
+		return -1;
+	}
 
-static int rsync_module(int fd, int i)
-{
-	int argc=0;
-	char *argv[MAX_ARGS];
-	char **argp;
-	char line[1024];
-	uid_t uid;
-	gid_t gid;
-	char *p;
-	char *addr = client_addr(fd);
-	char *host = client_name(fd);
+	if (!user)
+		user = getenv("USER");
+	if (!user)
+		user = getenv("LOGNAME");
 
-	if (!allow_access(addr, host, lp_hosts_allow(i), lp_hosts_deny(i))) {
-		rprintf(FERROR,"rsync denied on module %s from %s (%s)\n",
-			lp_name(i), client_name(fd), client_addr(fd));
+	if (exchange_protocols(f_in, f_out, line, sizeof line, 1) < 0)
 		return -1;
+
+	if (list_only && protocol_version >= 29)
+		list_only |= 2;
+
+	/* set daemon_over_rsh to false since we need to build the
+	 * true set of args passed through the rsh/ssh connection;
+	 * this is a no-op for direct-socket-connection mode */
+	daemon_over_rsh = 0;
+	server_options(sargs, &sargc);
+
+	if (sargc >= MAX_ARGS - 2)
+		goto arg_overflow;
+
+	sargs[sargc++] = ".";
+
+	while (argc > 0) {
+		if (sargc >= MAX_ARGS - 1) {
+		  arg_overflow:
+			rprintf(FERROR, "internal: args[] overflowed in do_cmd()\n");
+			exit_cleanup(RERR_SYNTAX);
+		}
+		sargs[sargc++] = *argv++;
+		argc--;
 	}
 
-	rprintf(FINFO,"rsync on module %s from %s (%s)\n",
-		lp_name(i), host, addr);
+	sargs[sargc] = NULL;
 
-	module_id = i;
+	if (verbose > 1)
+		print_child_argv("sending daemon args:", sargs);
 
-	if (lp_read_only(i))
-		read_only = 1;
+	p = strchr(path, '/');
+	if (p) *p = '\0';
+	io_printf(f_out, "%s\n", path);
+	if (p) *p = '/';
 
-	p = lp_uid(i);
-	if (!name_to_uid(p, &uid)) {
-		if (!isdigit(*p)) {
-			rprintf(FERROR,"Invalid uid %s\n", p);
+	/* Old servers may just drop the connection here,
+	 rather than sending a proper EXIT command.  Yuck. */
+	kluge_around_eof = list_only && protocol_version < 25 ? 1 : 0;
+
+	while (1) {
+		if (!read_line_old(f_in, line, sizeof line)) {
+			rprintf(FERROR, "rsync: didn't get server startup line\n");
 			return -1;
-		} 
-		uid = atoi(p);
-	}
+		}
+
+		if (strncmp(line,"@RSYNCD: AUTHREQD ",18) == 0) {
+			auth_client(f_out, user, line+18);
+			continue;
+		}
+
+		if (strcmp(line,"@RSYNCD: OK") == 0)
+			break;
 
-	p = lp_gid(i);
-	if (!name_to_gid(p, &gid)) {
-		if (!isdigit(*p)) {
-			rprintf(FERROR,"Invalid gid %s\n", p);
+		if (strcmp(line,"@RSYNCD: EXIT") == 0) {
+			/* This is sent by recent versions of the
+			 * server to terminate the listing of modules.
+			 * We don't want to go on and transfer
+			 * anything; just exit. */
+			exit(0);
+		}
+
+		if (strncmp(line, "@ERROR", 6) == 0) {
+			rprintf(FERROR, "%s\n", line);
+			/* This is always fatal; the server will now
+			 * close the socket. */
 			return -1;
-		} 
-		gid = atoi(p);
+		}
+
+		/* This might be a MOTD line or a module listing, but there is
+		 * no way to differentiate it.  The manpage mentions this. */
+		if (output_motd)
+			rprintf(FINFO, "%s\n", line);
+	}
+	kluge_around_eof = 0;
+
+	if (rl_nulls) {
+		for (i = 0; i < sargc; i++) {
+			write_sbuf(f_out, sargs[i]);
+			write_byte(f_out, 0);
+		}
+		write_byte(f_out, 0);
+	} else {
+		for (i = 0; i < sargc; i++)
+			io_printf(f_out, "%s\n", sargs[i]);
+		write_sbuf(f_out, "\n");
+	}
+
+	if (protocol_version < 23) {
+		if (protocol_version == 22 || !am_sender)
+			io_start_multiplex_in();
+	}
+
+	return 0;
+}
+
+static char *finish_pre_exec(pid_t pid, int fd, char *request,
+			     int argc, char *argv[])
+{
+	int j, status = -1;
+
+	if (!request)
+		request = "(NONE)";
+
+	write_buf(fd, request, strlen(request)+1);
+	for (j = 0; j < argc; j++)
+		write_buf(fd, argv[j], strlen(argv[j])+1);
+	write_byte(fd, 0);
+
+	close(fd);
+
+	if (wait_process(pid, &status, 0) < 0
+	 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+		char *e;
+		if (asprintf(&e, "pre-xfer exec returned failure (%d)%s%s\n",
+			     status, status < 0 ? ": " : "",
+			     status < 0 ? strerror(errno) : "") < 0)
+			out_of_memory("finish_pre_exec");
+		return e;
 	}
+	return NULL;
+}
+
+static int read_arg_from_pipe(int fd, char *buf, int limit)
+{
+	char *bp = buf, *eob = buf + limit - 1;
 
-	if (chroot(lp_path(i))) {
-		io_printf(fd,"@ERROR: chroot failed\n");
+	while (1) {
+	    if (read(fd, bp, 1) != 1)
 		return -1;
+	    if (*bp == '\0')
+		break;
+	    if (bp < eob)
+		bp++;
 	}
+	*bp = '\0';
+
+	return bp - buf;
+}
+
+static int rsync_module(int f_in, int f_out, int i, char *addr, char *host)
+{
+	int argc, opt_cnt;
+	char **argv;
+	char line[BIGPATHBUFLEN];
+	uid_t uid = (uid_t)-2;  /* canonically "nobody" */
+	gid_t gid = (gid_t)-2;
+	char *p, *err_msg = NULL;
+	char *name = lp_name(i);
+	int use_chroot = lp_use_chroot(i);
+	int ret, pre_exec_fd = -1;
+	pid_t pre_exec_pid = 0;
+	char *request = NULL;
 
-	if (chdir("/")) {
-		io_printf(fd,"@ERROR: chdir failed\n");
+	if (!allow_access(addr, host, lp_hosts_allow(i), lp_hosts_deny(i))) {
+		rprintf(FLOG, "rsync denied on module %s from %s (%s)\n",
+			name, host, addr);
+		if (!lp_list(i))
+			io_printf(f_out, "@ERROR: Unknown module '%s'\n", name);
+		else {
+			io_printf(f_out,
+				  "@ERROR: access denied to %s from %s (%s)\n",
+				  name, host, addr);
+		}
 		return -1;
 	}
 
-	if (setgid(gid)) {
-		io_printf(fd,"@ERROR: setgid failed\n");
+	if (am_daemon && am_server) {
+		rprintf(FLOG, "rsync allowed access on module %s from %s (%s)\n",
+			name, host, addr);
+	}
+
+	if (!claim_connection(lp_lock_file(i), lp_max_connections(i))) {
+		if (errno) {
+			rsyserr(FLOG, errno, "failed to open lock file %s",
+				lp_lock_file(i));
+			io_printf(f_out, "@ERROR: failed to open lock file\n");
+		} else {
+			rprintf(FLOG, "max connections (%d) reached\n",
+				lp_max_connections(i));
+			io_printf(f_out, "@ERROR: max connections (%d) reached -- try again later\n",
+				lp_max_connections(i));
+		}
 		return -1;
 	}
 
-	if (setuid(uid)) {
-		io_printf(fd,"@ERROR: setuid failed\n");
+	auth_user = auth_server(f_in, f_out, i, host, addr, "@RSYNCD: AUTHREQD ");
+
+	if (!auth_user) {
+		io_printf(f_out, "@ERROR: auth failed on module %s\n", name);
 		return -1;
 	}
 
-	io_printf(fd,"@RSYNCD: OK\n");
+	module_id = i;
 
-	argv[argc++] = "rsyncd";
+	if (lp_read_only(i))
+		read_only = 1;
 
-	while (1) {
-		if (!read_line(fd, line, sizeof(line)-1)) {
+	if (lp_transfer_logging(i) && !logfile_format)
+		logfile_format = lp_log_format(i);
+	if (log_format_has(logfile_format, 'i'))
+		logfile_format_has_i = 1;
+	if (logfile_format_has_i || log_format_has(logfile_format, 'o'))
+		logfile_format_has_o_or_i = 1;
+
+	am_root = (MY_UID() == 0);
+
+	if (am_root) {
+		p = lp_uid(i);
+		if (!name_to_uid(p, &uid)) {
+			if (!isDigit(p)) {
+				rprintf(FLOG, "Invalid uid %s\n", p);
+				io_printf(f_out, "@ERROR: invalid uid %s\n", p);
+				return -1;
+			}
+			uid = atoi(p);
+		}
+
+		p = lp_gid(i);
+		if (!name_to_gid(p, &gid)) {
+			if (!isDigit(p)) {
+				rprintf(FLOG, "Invalid gid %s\n", p);
+				io_printf(f_out, "@ERROR: invalid gid %s\n", p);
+				return -1;
+			}
+			gid = atoi(p);
+		}
+	}
+
+	/* TODO: If we're not root, but the configuration requests
+	 * that we change to some uid other than the current one, then
+	 * log a warning. */
+
+	/* TODO: Perhaps take a list of gids, and make them into the
+	 * supplementary groups. */
+
+	/* We do a push_dir() without actually calling chdir() in order
+	 * to make sure that the module's path is absolute.  After this
+	 * check, module_dir will be set to an absolute path. */
+	module_dir = lp_path(i);
+	strlcpy(line, curr_dir, sizeof line);
+	if (!push_dir(module_dir, 1))
+		goto chdir_failed;
+	if (strcmp(curr_dir, module_dir) != 0)
+		module_dir = strdup(curr_dir);
+	push_dir(line, 1); /* Restore curr_dir. */
+
+	if (use_chroot || (module_dirlen = strlen(module_dir)) == 1) {
+		module_dirlen = 0;
+		set_filter_dir("/", 1);
+	} else
+		set_filter_dir(module_dir, module_dirlen);
+
+	p = lp_filter(i);
+	parse_rule(&server_filter_list, p, MATCHFLG_WORD_SPLIT,
+		   XFLG_ABS_IF_SLASH);
+
+	p = lp_include_from(i);
+	parse_filter_file(&server_filter_list, p, MATCHFLG_INCLUDE,
+	    XFLG_ABS_IF_SLASH | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS);
+
+	p = lp_include(i);
+	parse_rule(&server_filter_list, p,
+		   MATCHFLG_INCLUDE | MATCHFLG_WORD_SPLIT,
+		   XFLG_ABS_IF_SLASH | XFLG_OLD_PREFIXES);
+
+	p = lp_exclude_from(i);
+	parse_filter_file(&server_filter_list, p, 0,
+	    XFLG_ABS_IF_SLASH | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS);
+
+	p = lp_exclude(i);
+	parse_rule(&server_filter_list, p, MATCHFLG_WORD_SPLIT,
+		   XFLG_ABS_IF_SLASH | XFLG_OLD_PREFIXES);
+
+	log_init(1);
+
+#ifdef HAVE_PUTENV
+	if (*lp_prexfer_exec(i) || *lp_postxfer_exec(i)) {
+		char *modname, *modpath, *hostaddr, *hostname, *username;
+		int status;
+		if (asprintf(&modname, "RSYNC_MODULE_NAME=%s", name) < 0
+		 || asprintf(&modpath, "RSYNC_MODULE_PATH=%s", module_dir) < 0
+		 || asprintf(&hostaddr, "RSYNC_HOST_ADDR=%s", addr) < 0
+		 || asprintf(&hostname, "RSYNC_HOST_NAME=%s", host) < 0
+		 || asprintf(&username, "RSYNC_USER_NAME=%s", auth_user) < 0)
+			out_of_memory("rsync_module");
+		putenv(modname);
+		putenv(modpath);
+		putenv(hostaddr);
+		putenv(hostname);
+		putenv(username);
+		umask(orig_umask);
+		/* For post-xfer exec, fork a new process to run the rsync
+		 * daemon while this process waits for the exit status and
+		 * runs the indicated command at that point. */
+		if (*lp_postxfer_exec(i)) {
+			pid_t pid = fork();
+			if (pid < 0) {
+				rsyserr(FLOG, errno, "fork failed");
+				io_printf(f_out, "@ERROR: fork failed\n");
+				return -1;
+			}
+			if (pid) {
+				if (asprintf(&p, "RSYNC_PID=%ld", (long)pid) > 0)
+					putenv(p);
+				if (wait_process(pid, &status, 0) < 0)
+					status = -1;
+				if (asprintf(&p, "RSYNC_RAW_STATUS=%d", status) > 0)
+					putenv(p);
+				if (WIFEXITED(status))
+					status = WEXITSTATUS(status);
+				else
+					status = -1;
+				if (asprintf(&p, "RSYNC_EXIT_STATUS=%d", status) > 0)
+					putenv(p);
+				system(lp_postxfer_exec(i));
+				_exit(status);
+			}
+		}
+		/* For pre-xfer exec, fork a child process to run the indicated
+		 * command, though it first waits for the parent process to
+		 * send us the user's request via a pipe. */
+		if (*lp_prexfer_exec(i)) {
+			int fds[2];
+			if (asprintf(&p, "RSYNC_PID=%ld", (long)getpid()) > 0)
+				putenv(p);
+			if (pipe(fds) < 0 || (pre_exec_pid = fork()) < 0) {
+				rsyserr(FLOG, errno, "pre-xfer exec preparation failed");
+				io_printf(f_out, "@ERROR: pre-xfer exec preparation failed\n");
+				return -1;
+			}
+			if (pre_exec_pid == 0) {
+				char buf[BIGPATHBUFLEN];
+				int j, len;
+				close(fds[1]);
+				set_blocking(fds[0]);
+				len = read_arg_from_pipe(fds[0], buf, BIGPATHBUFLEN);
+				if (len <= 0)
+					_exit(1);
+				if (asprintf(&p, "RSYNC_REQUEST=%s", buf) > 0)
+					putenv(p);
+				for (j = 0; ; j++) {
+					len = read_arg_from_pipe(fds[0], buf,
+								 BIGPATHBUFLEN);
+					if (len <= 0) {
+						if (!len)
+							break;
+						_exit(1);
+					}
+					if (asprintf(&p, "RSYNC_ARG%d=%s", j, buf) > 0)
+						putenv(p);
+				}
+				close(fds[0]);
+				close(STDIN_FILENO);
+				close(STDOUT_FILENO);
+				status = system(lp_prexfer_exec(i));
+				if (!WIFEXITED(status))
+					_exit(1);
+				_exit(WEXITSTATUS(status));
+			}
+			close(fds[0]);
+			set_blocking(fds[1]);
+			pre_exec_fd = fds[1];
+		}
+		umask(0);
+	}
+#endif
+
+	if (use_chroot) {
+		/*
+		 * XXX: The 'use chroot' flag is a fairly reliable
+		 * source of confusion, because it fails under two
+		 * important circumstances: running as non-root,
+		 * running on Win32 (or possibly others).  On the
+		 * other hand, if you are running as root, then it
+		 * might be better to always use chroot.
+		 *
+		 * So, perhaps if we can't chroot we should just issue
+		 * a warning, unless a "require chroot" flag is set,
+		 * in which case we fail.
+		 */
+		if (chroot(module_dir)) {
+			rsyserr(FLOG, errno, "chroot %s failed", module_dir);
+			io_printf(f_out, "@ERROR: chroot failed\n");
+			return -1;
+		}
+		if (!push_dir("/", 0))
+			goto chdir_failed;
+	} else {
+		if (!push_dir(module_dir, 0)) {
+		  chdir_failed:
+			rsyserr(FLOG, errno, "chdir %s failed\n", module_dir);
+			io_printf(f_out, "@ERROR: chdir failed\n");
 			return -1;
 		}
+		sanitize_paths = 1;
+	}
+
+	if (am_root) {
+		/* XXXX: You could argue that if the daemon is started
+		 * by a non-root user and they explicitly specify a
+		 * gid, then we should try to change to that gid --
+		 * this could be possible if it's already in their
+		 * supplementary groups. */
 
-		if (!*line) break;
+		/* TODO: Perhaps we need to document that if rsyncd is
+		 * started by somebody other than root it will inherit
+		 * all their supplementary groups. */
 
-		argv[argc] = strdup(line);
-		if (!argv[argc]) {
+		if (setgid(gid)) {
+			rsyserr(FLOG, errno, "setgid %d failed", (int)gid);
+			io_printf(f_out, "@ERROR: setgid failed\n");
+			return -1;
+		}
+#ifdef HAVE_SETGROUPS
+		/* Get rid of any supplementary groups this process
+		 * might have inheristed. */
+		if (setgroups(1, &gid)) {
+			rsyserr(FLOG, errno, "setgroups failed");
+			io_printf(f_out, "@ERROR: setgroups failed\n");
 			return -1;
 		}
+#endif
 
-		argc++;
-		if (argc == MAX_ARGS) {
+		if (setuid(uid)) {
+			rsyserr(FLOG, errno, "setuid %d failed", (int)uid);
+			io_printf(f_out, "@ERROR: setuid failed\n");
 			return -1;
 		}
+
+		am_root = (MY_UID() == 0);
+	}
+
+	if (lp_temp_dir(i) && *lp_temp_dir(i)) {
+		tmpdir = lp_temp_dir(i);
+		if (strlen(tmpdir) >= MAXPATHLEN - 10) {
+			rprintf(FLOG,
+				"the 'temp dir' value for %s is WAY too long -- ignoring.\n",
+				name);
+			tmpdir = NULL;
+		}
 	}
 
-	parse_arguments(argc, argv);
+	io_printf(f_out, "@RSYNCD: OK\n");
+
+	opt_cnt = read_args(f_in, name, line, sizeof line, rl_nulls, &argv, &argc, &request);
+
+	if (pre_exec_pid) {
+		err_msg = finish_pre_exec(pre_exec_pid, pre_exec_fd, request,
+					  opt_cnt, argv);
+	}
+
+	verbose = 0; /* future verbosity is controlled by client options */
+	ret = parse_arguments(&argc, (const char ***) &argv, 0);
+	am_server = 1; /* Don't let someone try to be tricky. */
+	if (lp_ignore_errors(module_id))
+		ignore_errors = 1;
+
+	if (lp_fake_super(i))
+		am_root = -1;
+	else if (am_root < 0) /* Treat --fake-super from client as --super. */
+		am_root = 2;
+
+	if (filesfrom_fd == 0)
+		filesfrom_fd = f_in;
+
+	if (request) {
+		if (*auth_user) {
+			rprintf(FLOG, "rsync %s %s from %s@%s (%s)\n",
+				am_sender ? "on" : "to",
+				request, auth_user, host, addr);
+		} else {
+			rprintf(FLOG, "rsync %s %s from %s (%s)\n",
+				am_sender ? "on" : "to",
+				request, host, addr);
+		}
+		free(request);
+	}
 
+#ifndef DEBUG
 	/* don't allow the logs to be flooded too fast */
-	if (verbose > 1) verbose = 1;
+	if (verbose > lp_max_verbosity(i))
+		verbose = lp_max_verbosity(i);
+#endif
+
+	if (protocol_version < 23
+	    && (protocol_version == 22 || am_sender))
+		io_start_multiplex_out();
+	else if (!ret || err_msg) {
+		/* We have to get I/O multiplexing started so that we can
+		 * get the error back to the client.  This means getting
+		 * the protocol setup finished first in later versions. */
+		setup_protocol(f_out, f_in);
+		if (!am_sender) {
+			/* Since we failed in our option parsing, we may not
+			 * have finished parsing that the client sent us a
+			 * --files-from option, so look for it manually.
+			 * Without this, the socket would be in the wrong
+			 * state for the upcoming error message. */
+			if (!files_from) {
+				int i;
+				for (i = 0; i < argc; i++) {
+					if (strncmp(argv[i], "--files-from", 12) == 0) {
+						files_from = "";
+						break;
+					}
+				}
+			}
+			if (files_from)
+				write_byte(f_out, 0);
+		}
+		io_start_multiplex_out();
+	}
 
-	argc -= optind;
-	argp = argv + optind;
-	optind = 0;
+	if (!ret || err_msg) {
+		if (err_msg)
+			rwrite(FERROR, err_msg, strlen(err_msg), 0);
+		else
+			option_error();
+		msleep(400);
+		exit_cleanup(RERR_UNSUPPORTED);
+	}
 
-	start_server(fd, fd, argc, argp);
+	if (lp_timeout(i) && lp_timeout(i) > io_timeout)
+		set_io_timeout(lp_timeout(i));
+
+	/* If we have some incoming/outgoing chmod changes, append them to
+	 * any user-specified changes (making our changes have priority).
+	 * We also get a pointer to just our changes so that a receiver
+	 * process can use them separately if --perms wasn't specified. */
+	if (am_sender)
+		p = lp_outgoing_chmod(i);
+	else
+		p = lp_incoming_chmod(i);
+	if (*p && !(daemon_chmod_modes = parse_chmod(p, &chmod_modes))) {
+		rprintf(FLOG, "Invalid \"%sing chmod\" directive: %s\n",
+			am_sender ? "outgo" : "incom", p);
+	}
+
+	start_server(f_in, f_out, argc, argv);
 
 	return 0;
 }
@@ -196,92 +764,136 @@ static void send_listing(int fd)
 {
 	int n = lp_numservices();
 	int i;
-	
-	for (i=0;i<n;i++)
+
+	for (i = 0; i < n; i++) {
 		if (lp_list(i))
-		    io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i));
+			io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i));
+	}
+
+	if (protocol_version >= 25)
+		io_printf(fd,"@RSYNCD: EXIT\n");
 }
 
-/* this is called when a socket connection is established to a client
+/* this is called when a connection is established to a client
    and we want to start talking. The setup of the system is done from
    here */
-static int start_daemon(int fd)
+int start_daemon(int f_in, int f_out)
 {
-	char line[200];
-	char *motd;
-	int version;
-	int i = -1;
-	extern char *config_file;
+	char line[1024];
+	char *addr, *host;
+	int i;
 
-	if (!lp_load(config_file)) {
-		exit_cleanup(1);
+	io_set_sock_fds(f_in, f_out);
+
+	/* We must load the config file before calling any function that
+	 * might cause log-file output to occur.  This ensures that the
+	 * "log file" param gets honored for the 2 non-forked use-cases
+	 * (when rsync is run by init and run by a remote shell). */
+	if (!lp_load(config_file, 0))
+		exit_cleanup(RERR_SYNTAX);
+
+	addr = client_addr(f_in);
+	host = client_name(f_in);
+	rprintf(FLOG, "connect from %s (%s)\n", host, addr);
+
+	if (!am_server) {
+		set_socket_options(f_in, "SO_KEEPALIVE");
+		if (sockopts)
+			set_socket_options(f_in, sockopts);
+		else
+			set_socket_options(f_in, lp_socket_options());
+		set_nonblocking(f_in);
 	}
 
-	set_socket_options(fd,"SO_KEEPALIVE");
+	if (exchange_protocols(f_in, f_out, line, sizeof line, 0) < 0)
+		return -1;
 
-	io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
+	line[0] = 0;
+	if (!read_line_old(f_in, line, sizeof line))
+		return -1;
 
-	if (!read_line(fd, line, sizeof(line)-1)) {
+	if (!*line || strcmp(line, "#list") == 0) {
+		rprintf(FLOG, "module-list request from %s (%s)\n",
+			host, addr);
+		send_listing(f_out);
 		return -1;
 	}
 
-	if (sscanf(line,"@RSYNCD: %d", &version) != 1) {
+	if (*line == '#') {
+		/* it's some sort of command that I don't understand */
+		io_printf(f_out, "@ERROR: Unknown command '%s'\n", line);
 		return -1;
-	}	
-
-	motd = lp_motd_file();
-	if (*motd) {
-		FILE *f = fopen(motd,"r");
-		while (f && !feof(f)) {
-			int len = fread(line, 1, sizeof(line)-1, f);
-			if (len > 0) {
-				line[len] = 0;
-				io_printf(fd,"%s", line);
-			}
-		}
-		if (f) fclose(f);
-		io_printf(fd,"\n");
 	}
 
-	while (i == -1) {
-
-		line[0] = 0;
-		if (!read_line(fd, line, sizeof(line)-1)) {
-			return -1;
-		}
-
-		if (!*line || strcmp(line,"#list")==0) {
-			send_listing(fd);
-			return -1;
-		} 
-
-		if (*line == '#') {
-			/* it's some sort of command that I don't understand */
-			io_printf(fd,"ERROR: Unknown command '%s'\n", line);
-			return -1;
-		}
-
-		i = lp_number(line);
-		if (i == -1) {
-			io_printf(fd,"ERROR: Unknown module '%s'\n", line);
-			return -1;
-		}
+	if ((i = lp_number(line)) < 0) {
+		rprintf(FLOG, "unknown module '%s' tried from %s (%s)\n",
+			line, host, addr);
+		io_printf(f_out, "@ERROR: Unknown module '%s'\n", line);
+		return -1;
 	}
 
-	return rsync_module(fd, i);
-}
+#ifdef HAVE_SIGACTION
+	sigact.sa_flags = SA_NOCLDSTOP;
+#endif
+	SIGACTION(SIGCHLD, remember_children);
 
+	return rsync_module(f_in, f_out, i, addr, host);
+}
 
 int daemon_main(void)
 {
+	char *pid_file;
+
 	if (is_a_socket(STDIN_FILENO)) {
-		/* we are running via inetd */
-		return start_daemon(STDIN_FILENO);
+		int i;
+
+		/* we are running via inetd - close off stdout and
+		 * stderr so that library functions (and getopt) don't
+		 * try to use them. Redirect them to /dev/null */
+		for (i = 1; i < 3; i++) {
+			close(i);
+			open("/dev/null", O_RDWR);
+		}
+
+		return start_daemon(STDIN_FILENO, STDIN_FILENO);
 	}
 
-	become_daemon();
+	if (!no_detach)
+		become_daemon();
+
+	if (!lp_load(config_file, 1))
+		exit_cleanup(RERR_SYNTAX);
+
+	if (rsync_port == 0 && (rsync_port = lp_rsync_port()) == 0)
+		rsync_port = RSYNC_PORT;
+	if (bind_address == NULL && *lp_bind_address())
+		bind_address = lp_bind_address();
+
+	log_init(0);
+
+	rprintf(FLOG, "rsyncd version %s starting, listening on port %d\n",
+		RSYNC_VERSION, rsync_port);
+	/* TODO: If listening on a particular address, then show that
+	 * address too.  In fact, why not just do inet_ntop on the
+	 * local address??? */
+
+	if (((pid_file = lp_pid_file()) != NULL) && (*pid_file != '\0')) {
+		char pidbuf[16];
+		int fd;
+		pid_t pid = getpid();
+		cleanup_set_pid(pid);
+		if ((fd = do_open(lp_pid_file(), O_WRONLY|O_CREAT|O_TRUNC,
+					0666 & ~orig_umask)) == -1) {
+			cleanup_set_pid(0);
+			rsyserr(FLOG, errno, "failed to create pid file %s",
+				pid_file);
+			exit_cleanup(RERR_FILEIO);
+		}
+		snprintf(pidbuf, sizeof pidbuf, "%ld\n", (long)pid);
+		write(fd, pidbuf, strlen(pidbuf));
+		close(fd);
+	}
 
 	start_accept_loop(rsync_port, start_daemon);
 	return -1;
 }
-