X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/7a6421fa764dd0f609e2a5024ec8b3bc577575a1..973007daac25a8cd64c617fe57f566a037fad179:/clientserver.c

diff --git a/clientserver.c b/clientserver.c
index 38bb171d..43d9e541 100644
--- a/clientserver.c
+++ b/clientserver.c
@@ -1,22 +1,29 @@
-/* 
-   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 */
+/* -*- c-file-style: "linux"; -*-
+ * 
+ * Copyright (C) 1998-2001 by Andrew Tridgell <tridge@samba.org>
+ * Copyright (C) 2001-2002 by Martin Pool <mbp@samba.org>
+ * 
+ * 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.
+ */
+
+/**
+ * @file
+ *
+ * The socket based protocol for setting up a connection with
+ * rsyncd.
+ **/
 
 #include "rsync.h"
 
@@ -24,19 +31,81 @@ extern int module_id;
 extern int read_only;
 extern int verbose;
 extern int rsync_port;
-
+char *auth_user;
+extern int sanitize_paths;
+
+/**
+ * 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, char *path, int argc, char *argv[])
 {
 	int fd, i;
 	char *sargs[MAX_ARGS];
 	int sargc=0;
-	char line[1024];
-	char *p;
-	int version;
+	char line[MAXPATHLEN];
+	char *p, *user=NULL;
+	extern int remote_version;
+	extern int am_sender;
+	extern char *shell_cmd;
+	extern int list_only;
+	extern int kludge_around_eof;
+	extern char *bind_address;
+	extern int default_af_hint;
+       
+	if (argc == 0 && !am_sender) {
+		extern int list_only;
+		list_only = 1;
+	}
+
+        /* This is just a friendliness enhancement: if the connection
+         * is to an rsyncd then there is no point specifying the -e option.
+         * Note that this is only set if the -e was explicitly specified,
+         * not if the environment variable just happens to be set.
+         * See http://lists.samba.org/pipermail/rsync/2000-September/002744.html
+         */
+        if (shell_cmd) {
+                rprintf(FINFO, "WARNING: --rsh or -e option ignored when "
+                        "connecting to rsync daemon\n");
+                /* continue */
+        }
+        
+	if (*path == '/') {
+		rprintf(FERROR,"ERROR: The remote path must start with a module name not a /\n");
+		return -1;
+	}
+
+	p = strchr(host, '@');
+	if (p) {
+		user = host;
+		host = p+1;
+		*p = 0;
+	}
 
-	fd = open_socket_out(host, rsync_port);
+	if (!user) user = getenv("USER");
+	if (!user) user = getenv("LOGNAME");
+
+	if (verbose >= 2) {
+		/* FIXME: If we're going to use a socket program for
+		 * testing, then this message is wrong.  We need to
+		 * say something like "(except really using %s)" */
+		rprintf(FINFO, "opening tcp connection to %s port %d\n",
+			host, rsync_port);
+	}
+	fd = open_socket_out_wrapped (host, rsync_port, bind_address,
+				      default_af_hint);
 	if (fd == -1) {
-		exit_cleanup(1);
+		exit_cleanup(RERR_SOCKETIO);
 	}
 	
 	server_options(sargs,&sargc);
@@ -48,42 +117,70 @@ int start_socket_client(char *host, char *path, int argc, char *argv[])
 
 	sargs[sargc] = NULL;
 
+	io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
+
 	if (!read_line(fd, line, sizeof(line)-1)) {
+		rprintf(FERROR, "rsync: did not see server greeting\n");
 		return -1;
 	}
 
-	if (sscanf(line,"@RSYNCD: %d", &version) != 1) {
+	if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
+		/* note that read_line strips of \n or \r */
+		rprintf(FERROR, "rsync: server sent \"%s\" rather than greeting\n",
+			line);
 		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 = '/';
 
+	/* Old servers may just drop the connection here,
+	 rather than sending a proper EXIT command.  Yuck. */
+	kludge_around_eof = list_only && (remote_version < 25);
+
 	while (1) {
 		if (!read_line(fd, line, sizeof(line)-1)) {
+			rprintf(FERROR, "rsync: didn't get server startup line\n");
 			return -1;
 		}
+
+		if (strncmp(line,"@RSYNCD: AUTHREQD ",18) == 0) {
+			auth_client(fd, user, line+18);
+			continue;
+		}
+
 		if (strcmp(line,"@RSYNCD: OK") == 0) break;
-		rprintf(FINFO,"%s\n", line);
+
+		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 RERR_STARTCLIENT;
+		} else {
+			rprintf(FINFO,"%s\n", line);
+		}
 	}
+	kludge_around_eof = False;
 
 	for (i=0;i<sargc;i++) {
 		io_printf(fd,"%s\n", sargs[i]);
 	}
 	io_printf(fd,"\n");
 
-#if 0
-	while (1) {
-		if (!read_line(fd, line, sizeof(line)-1)) {
-			return -1;
-		}
-		rprintf(FINFO,"%s\n", line);
+	if (remote_version < 23) {
+		if (remote_version == 22 || (remote_version > 17 && !am_sender))
+			io_start_multiplex_in(fd);
 	}
-#endif
 
 	return client_run(fd, fd, -1, argc, argv);
 }
@@ -95,33 +192,168 @@ static int rsync_module(int fd, int i)
 	int argc=0;
 	char *argv[MAX_ARGS];
 	char **argp;
-	char line[1024];
-
-	module_id = i;
+	char line[MAXPATHLEN];
+	uid_t uid = (uid_t)-2;  /* canonically "nobody" */
+	gid_t gid = (gid_t)-2;
+	char *p;
+	char *addr = client_addr(fd);
+	char *host = client_name(fd);
+	char *name = lp_name(i);
+	int use_chroot = lp_use_chroot(i);
+	int start_glob=0;
+	int ret;
+	char *request=NULL;
+	extern int am_sender;
+	extern int remote_version;
+	extern int am_root;
+
+	if (!allow_access(addr, host, lp_hosts_allow(i), lp_hosts_deny(i))) {
+		rprintf(FERROR,"rsync denied on module %s from %s (%s)\n",
+			name, host, addr);
+		io_printf(fd,"@ERROR: access denied to %s from %s (%s)\n",
+			  name, host, addr);
+		return -1;
+	}
 
-	if (lp_read_only(i))
-		read_only = 1;
+	if (!claim_connection(lp_lock_file(i), lp_max_connections(i))) {
+		if (errno) {
+			rprintf(FERROR,"failed to open lock file %s : %s\n",
+				lp_lock_file(i), strerror(errno));
+			io_printf(fd,"@ERROR: failed to open lock file %s : %s\n",
+				  lp_lock_file(i), strerror(errno));
+		} else {
+			rprintf(FERROR,"max connections (%d) reached\n",
+				lp_max_connections(i));
+			io_printf(fd,"@ERROR: max connections (%d) reached - try again later\n", lp_max_connections(i));
+		}
+		return -1;
+	}
 
-	rprintf(FERROR,"rsyncd starting\n");
+	
+	auth_user = auth_server(fd, i, addr, "@RSYNCD: AUTHREQD ");
 
-	if (chroot(lp_path(i))) {
-		io_printf(fd,"@ERROR: chroot failed\n");
-		return -1;
+	if (!auth_user) {
+		rprintf(FERROR,"auth failed on module %s from %s (%s)\n",
+			name, client_name(fd), client_addr(fd));
+		io_printf(fd,"@ERROR: auth failed on module %s\n",name);
+		return -1;		
 	}
 
-	if (chdir("/")) {
-		io_printf(fd,"@ERROR: chdir failed\n");
-		return -1;
+	module_id = i;
+
+	am_root = (getuid() == 0);
+
+	if (am_root) {
+		p = lp_uid(i);
+		if (!name_to_uid(p, &uid)) {
+			if (!isdigit(* (unsigned char *) p)) {
+				rprintf(FERROR,"Invalid uid %s\n", p);
+				io_printf(fd,"@ERROR: invalid uid %s\n", p);
+				return -1;
+			} 
+			uid = atoi(p);
+		}
+
+		p = lp_gid(i);
+		if (!name_to_gid(p, &gid)) {
+			if (!isdigit(* (unsigned char *) p)) {
+				rprintf(FERROR,"Invalid gid %s\n", p);
+				io_printf(fd,"@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. */
+
+	p = lp_include_from(i);
+	add_exclude_file(p, 1, 1);
+
+	p = lp_include(i);
+	add_include_line(p);
+
+	p = lp_exclude_from(i);
+	add_exclude_file(p, 1, 0);
+
+	p = lp_exclude(i);
+	add_exclude_line(p);
+
+	log_init();
+
+	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(lp_path(i))) {
+			rsyserr(FERROR, errno, "chroot %s failed", lp_path(i));
+			io_printf(fd,"@ERROR: chroot failed\n");
+			return -1;
+		}
 
-	if (setgid(lp_gid(i))) {
-		io_printf(fd,"@ERROR: setgid failed\n");
-		return -1;
+		if (!push_dir("/", 0)) {
+                        rsyserr(FERROR, errno, "chdir %s failed\n", lp_path(i));
+			io_printf(fd,"@ERROR: chdir failed\n");
+			return -1;
+		}
+
+	} else {
+		if (!push_dir(lp_path(i), 0)) {
+			rsyserr(FERROR, errno, "chdir %s failed\n", lp_path(i));
+			io_printf(fd,"@ERROR: chdir failed\n");
+			return -1;
+		}
+		sanitize_paths = 1;
 	}
 
-	if (setuid(lp_uid(i))) {
-		io_printf(fd,"@ERROR: setuid failed\n");
-		return -1;
+	if (am_root) {
+#ifdef HAVE_SETGROUPS
+		/* Get rid of any supplementary groups this process
+		 * might have inheristed. */
+		if (setgroups(0, NULL)) {
+			rsyserr(FERROR, errno, "setgroups failed");
+			io_printf(fd, "@ERROR: setgroups failed\n");
+			return -1;
+		}
+#endif
+
+		/* 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. */
+
+		/* TODO: Perhaps we need to document that if rsyncd is
+		 * started by somebody other than root it will inherit
+		 * all their supplementary groups. */
+
+		if (setgid(gid)) {
+			rsyserr(FERROR, errno, "setgid %d failed", (int) gid);
+			io_printf(fd,"@ERROR: setgid failed\n");
+			return -1;
+		}
+
+		if (setuid(uid)) {
+			rsyserr(FERROR, errno, "setuid %d failed", (int) uid);
+			io_printf(fd,"@ERROR: setuid failed\n");
+			return -1;
+		}
+
+		am_root = (getuid() == 0);
 	}
 
 	io_printf(fd,"@RSYNCD: OK\n");
@@ -135,25 +367,88 @@ static int rsync_module(int fd, int i)
 
 		if (!*line) break;
 
-		argv[argc] = strdup(line);
+		p = line;
+
+		argv[argc] = strdup(p);
 		if (!argv[argc]) {
 			return -1;
 		}
 
-		argc++;
+		if (start_glob) {
+			if (start_glob == 1) {
+				request = strdup(p);
+				start_glob++;
+			}
+			glob_expand(name, argv, &argc, MAX_ARGS);
+		} else {
+			argc++;
+		}
+
+		if (strcmp(line,".") == 0) {
+			start_glob = 1;
+		}
+
 		if (argc == MAX_ARGS) {
 			return -1;
 		}
 	}
 
-	parse_arguments(argc, argv);
+	if (sanitize_paths) {
+		/*
+		 * Note that this is applied to all parameters, whether or not
+		 *    they are filenames, but no other legal parameters contain
+		 *    the forms that need to be sanitized so it doesn't hurt;
+		 *    it is not known at this point which parameters are files
+		 *    and which aren't.
+		 */
+		for (i = 1; i < argc; i++) {
+			sanitize_path(argv[i], NULL);
+		}
+	}
 
+        argp = argv;
+	ret = parse_arguments(&argc, (const char ***) &argp, 0);
+
+	if (request) {
+		if (*auth_user) {
+			rprintf(FINFO,"rsync %s %s from %s@%s (%s)\n",
+				am_sender?"on":"to",
+				request, auth_user, host, addr);
+		} else {
+			rprintf(FINFO,"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;
+#endif
+
+	if (remote_version < 23) {
+		if (remote_version == 22 || (remote_version > 17 && am_sender))
+			io_start_multiplex_out(fd);
+	}
+        
+        /* For later protocol versions, we don't start multiplexing
+         * until we've configured nonblocking in start_server.  That
+         * means we're in a sticky situation now: there's no way to
+         * convey errors to the client. */
+
+        /* FIXME: Hold off on reporting option processing errors until
+         * we've set up nonblocking and multiplexed IO and can get the
+         * message back to them. */
+	if (!ret) {
+                option_error();
+                exit_cleanup(RERR_UNSUPPORTED);
+	}
 
-	argc -= optind;
-	argp = argv + optind;
-	optind = 0;
+	if (lp_timeout(i)) {
+		extern int io_timeout;
+		io_timeout = lp_timeout(i);
+	}
 
 	start_server(fd, fd, argc, argp);
 
@@ -166,10 +461,14 @@ static void send_listing(int fd)
 {
 	int n = lp_numservices();
 	int i;
-	
+	extern int remote_version;
+
 	for (i=0;i<n;i++)
 		if (lp_list(i))
 		    io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i));
+
+	if (remote_version >= 25)
+		io_printf(fd,"@RSYNCD: EXIT\n");
 }
 
 /* this is called when a socket connection is established to a client
@@ -179,22 +478,22 @@ static int start_daemon(int fd)
 {
 	char line[200];
 	char *motd;
-	int version;
+	int i = -1;
+	extern char *config_file;
+	extern int remote_version;
+
+	if (!lp_load(config_file, 0)) {
+		exit_cleanup(RERR_SYNTAX);
+	}
 
 	set_socket_options(fd,"SO_KEEPALIVE");
+	set_socket_options(fd,lp_socket_options());
+	set_nonblocking(fd);
 
 	io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
 
-	if (!read_line(fd, line, sizeof(line)-1)) {
-		return -1;
-	}
-
-	if (sscanf(line,"@RSYNCD: %d", &version) != 1) {
-		return -1;
-	}	
-
 	motd = lp_motd_file();
-	if (*motd) {
+	if (motd && *motd) {
 		FILE *f = fopen(motd,"r");
 		while (f && !feof(f)) {
 			int len = fread(line, 1, sizeof(line)-1, f);
@@ -207,9 +506,16 @@ static int start_daemon(int fd)
 		io_printf(fd,"\n");
 	}
 
-	while (1) {
-		int i;
+	if (!read_line(fd, line, sizeof(line)-1)) {
+		return -1;
+	}
+
+	if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
+		io_printf(fd,"@ERROR: protocol startup error\n");
+		return -1;
+	}	
 
+	while (i == -1) {
 		line[0] = 0;
 		if (!read_line(fd, line, sizeof(line)-1)) {
 			return -1;
@@ -222,38 +528,75 @@ static int start_daemon(int fd)
 
 		if (*line == '#') {
 			/* it's some sort of command that I don't understand */
-			io_printf(fd,"ERROR: Unknown command '%s'\n", line);
+			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);
+			io_printf(fd,"@ERROR: Unknown module '%s'\n", line);
 			return -1;
 		}
-
-		return rsync_module(fd, i);
 	}
 
-	return 0;
+	return rsync_module(fd, i);
 }
 
 
 int daemon_main(void)
 {
 	extern char *config_file;
-
-	if (!lp_load(config_file)) {
-		exit_cleanup(1);
-	}
+	extern int orig_umask;
+	char *pid_file;
+	extern int no_detach;
 
 	if (is_a_socket(STDIN_FILENO)) {
-		/* we are running via inetd */
+		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);
 	}
 
-	become_daemon();
+	if (!no_detach)
+	    become_daemon();
+
+	if (!lp_load(config_file, 1)) {
+		exit_cleanup(RERR_SYNTAX);
+	}
+
+	log_init();
+
+	rprintf(FINFO, "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;
+		int pid = (int) 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), "%d\n", pid);
+		write(fd, pidbuf, strlen(pidbuf));
+		close(fd);
+	}
 
-	return start_accept_loop(rsync_port, start_daemon);
+	start_accept_loop(rsync_port, start_daemon);
+	return -1;
 }