/* -*- c-file-style: "linux"; -*- Copyright (C) 1998-2001 by Andrew Tridgell Copyright (C) 2001-2002 by Martin Pool 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 with rsyncd */ #include "rsync.h" 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 initial server startup, hands over to client_run(). * * @return -1 for error in startup, or the result of client_run(). **/ int start_socket_client(char *host, char *path, int argc, char *argv[]) { int fd, i; char *sargs[MAX_ARGS]; int sargc=0; 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(FERROR, "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; } 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(RERR_SOCKETIO); } server_options(sargs,&sargc); sargs[sargc++] = "."; if (path && *path) sargs[sargc++] = path; 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", &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; } 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; if (strcmp(line,"@RSYNCD: EXIT") == 0) exit(0); if (strncmp(line, "@ERROR", 6) == 0) rprintf(FERROR,"%s\n", line); else rprintf(FINFO,"%s\n", line); } kludge_around_eof = False; for (i=0;i 17 && !am_sender)) io_start_multiplex_in(fd); } return client_run(fd, fd, -1, argc, argv); } static int rsync_module(int fd, int i) { int argc=0; char *argv[MAX_ARGS]; char **argp; 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 (!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; } auth_user = auth_server(fd, i, addr, "@RSYNCD: AUTHREQD "); 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; } module_id = i; am_root = (getuid() == 0); if (am_root) { p = lp_uid(i); if (!name_to_uid(p, &uid)) { if (!isdigit(*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(*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 (!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 (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"); argv[argc++] = "rsyncd"; while (1) { if (!read_line(fd, line, sizeof(line)-1)) { return -1; } if (!*line) break; p = line; argv[argc] = strdup(p); if (!argv[argc]) { return -1; } 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; } } 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); } if (lp_timeout(i)) { extern int io_timeout; io_timeout = lp_timeout(i); } start_server(fd, fd, argc, argp); return 0; } /* send a list of available modules to the client. Don't list those with "list = False". */ static void send_listing(int fd) { int n = lp_numservices(); int i; extern int remote_version; for (i=0;i= 25) io_printf(fd,"@RSYNCD: EXIT\n"); } /* this is called when a socket 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) { char line[200]; char *motd; 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); motd = lp_motd_file(); if (motd && *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"); } 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; } 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; } } return rsync_module(fd, i); } int daemon_main(void) { extern char *config_file; extern int orig_umask; char *pid_file; extern int no_detach; if (is_a_socket(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); } 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); } start_accept_loop(rsync_port, start_daemon); return -1; }