X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/3591c0660c52cec9fa06e7539b56604a7499fa10..ecc7623e7faf75f6ba3dd7b5a416c52e2346ac7d:/clientserver.c diff --git a/clientserver.c b/clientserver.c index 6d6e01d6..8c42631e 100644 --- a/clientserver.c +++ b/clientserver.c @@ -1,245 +1,868 @@ -/* - 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 + * Copyright (C) 2001-2002 Martin Pool + * Copyright (C) 2002, 2003, 2004, 2005, 2006 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 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., + * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. + */ #include "rsync.h" -extern int module_id; -extern int read_only; extern int verbose; +extern int quiet; +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 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; + +char *auth_user; +int read_only = 0; +int module_id = -1; +struct chmod_mode_struct *daemon_chmod_modes; + +/* Length of lp_path() string when in daemon mode & not chrooted, else 0. */ +unsigned int module_dirlen = 0; + +#ifdef HAVE_SIGACTION +static struct sigaction sigact; +#endif +/** + * 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; + 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 (*path == '/') { + rprintf(FERROR, + "ERROR: The remote path must start with a module name not a /\n"); + return -1; + } + + if ((p = strrchr(host, '@')) != NULL) { + user = host; + host = p+1; + *p = '\0'; + } + + fd = open_socket_out_wrapped(host, rsync_port, bind_address, + default_af_hint); + if (fd == -1) + exit_cleanup(RERR_SOCKETIO); + + set_socket_options(fd, sockopts); + + ret = start_inband_exchange(user, path, fd, fd, argc); + + return ret ? ret : client_run(fd, fd, -1, argc, argv); +} + +int start_inband_exchange(char *user, char *path, int f_in, int f_out, + int argc) +{ + int i; char *sargs[MAX_ARGS]; - int sargc=0; - char line[1024]; + int sargc = 0; + char line[BIGPATHBUFLEN]; char *p; - int version; - fd = open_socket_out(host, rsync_port); - if (fd == -1) { - exit_cleanup(1); + 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; + } + + if (!user) + user = getenv("USER"); + if (!user) + user = getenv("LOGNAME"); + + io_printf(f_out, "@RSYNCD: %d\n", protocol_version); + + if (!read_line(f_in, line, sizeof line - 1)) { + rprintf(FERROR, "rsync: did not see server greeting\n"); + return -1; } - - server_options(sargs,&sargc); + + if (sscanf(line,"@RSYNCD: %d", &remote_protocol) != 1) { + /* note that read_line strips of \n or \r */ + rprintf(FERROR, "rsync: server sent \"%s\" rather than greeting\n", + line); + return -1; + } + if (protocol_version > remote_protocol) + protocol_version = remote_protocol; + + 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); sargs[sargc++] = "."; - if (path && *path) + if (path && *path) sargs[sargc++] = path; sargs[sargc] = NULL; + if (verbose > 1) + print_child_argv(sargs); + p = strchr(path,'/'); if (p) *p = 0; - io_printf(fd,"%s\n",path); + io_printf(f_out, "%s\n", path); if (p) *p = '/'; - if (!read_line(fd, line, sizeof(line)-1)) { - return -1; - } - - if (sscanf(line,"@RSYNCD: %d", &version) != 1) { - return -1; - } + /* 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(fd, line, sizeof(line)-1)) { + if (!read_line(f_in, line, sizeof line - 1)) { + rprintf(FERROR, "rsync: didn't get server startup line\n"); return -1; } - if (strcmp(line,"@RSYNCD: OK") == 0) break; - rprintf(FINFO,"%s\n", line); - } - for (i=0;i 0) + putenv(ret1); + if (WIFEXITED(status)) + status = WEXITSTATUS(status); + else + status = -1; + if (asprintf(&ret2, "RSYNC_EXIT_STATUS=%d", status) > 0) + putenv(ret2); + 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 (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) + out_of_memory("rsync_module"); + 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) + out_of_memory("rsync_module"); + 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(lp_path(i))) { + rsyserr(FLOG, errno, "chroot %s failed", + lp_path(i)); + io_printf(f_out, "@ERROR: chroot failed\n"); return -1; } - if (!*line) break; + if (!push_dir("/")) { + rsyserr(FLOG, errno, "chdir %s failed\n", + lp_path(i)); + io_printf(f_out, "@ERROR: chdir failed\n"); + return -1; + } - argv[argc] = strdup(line); - if (!argv[argc]) { + } else { + if (!push_dir(lp_path(i))) { + rsyserr(FLOG, errno, "chdir %s failed\n", + lp_path(i)); + 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. */ - argc++; - if (argc == MAX_ARGS) { + /* 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(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 + + 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); } - parse_arguments(argc, argv); + 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; + } + } + io_printf(f_out, "@RSYNCD: OK\n"); + + maxargs = MAX_ARGS; + if (!(argv = new_array(char *, maxargs))) + out_of_memory("rsync_module"); + argv[argc++] = "rsyncd"; + + while (1) { + if (!read_line(f_in, line, sizeof line - 1)) + return -1; + + if (!*line) + break; + + p = line; + + if (argc == maxargs) { + maxargs += MAX_ARGS; + if (!(argv = realloc_array(argv, char *, maxargs))) + out_of_memory("rsync_module"); + } + if (!(argv[argc] = strdup(p))) + out_of_memory("rsync_module"); + + switch (start_glob) { + case 0: + argc++; + if (strcmp(line, ".") == 0) + start_glob = 1; + break; + case 1: + if (pre_exec_pid) { + err_msg = finish_pre_exec(pre_exec_pid, + pre_exec_fd, p, + argc, argv); + pre_exec_pid = 0; + } + request = strdup(p); + start_glob = 2; + /* FALL THROUGH */ + default: + if (!err_msg) + glob_expand(name, &argv, &argc, &maxargs); + break; + } + } + + if (pre_exec_pid) { + err_msg = finish_pre_exec(pre_exec_pid, pre_exec_fd, request, + argc, argv); + } + + verbose = 0; /* future verbosity is controlled by client options */ + ret = parse_arguments(&argc, (const char ***) &argv, 0); + quiet = 0; /* Don't let someone try to be tricky. */ + + 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) + rprintf(FERROR, err_msg); + else + option_error(); + msleep(400); + exit_cleanup(RERR_UNSUPPORTED); + } + + 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(fd, fd, argc, argp); + start_server(f_in, f_out, argc, argv); 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; - - for (i=0;i= 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[1024]; - char *motd; + char *motd, *addr, *host; + int i; - set_socket_options(fd,"SO_KEEPALIVE"); + 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); + } - io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION); + io_printf(f_out, "@RSYNCD: %d\n", protocol_version); 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); + int len = fread(line, 1, sizeof line - 1, f); if (len > 0) { line[len] = 0; - io_printf(fd,"%s", line); + io_printf(f_out, "%s", line); } } - if (f) fclose(f); - io_printf(fd,"\n"); + if (f) + fclose(f); + io_printf(f_out, "\n"); } - /* read a single line indicating the resource that is wanted */ - while (1) { - int i; + if (!read_line(f_in, line, sizeof line - 1)) + return -1; - line[0] = 0; - if (!read_line(fd, line, sizeof(line)-1)) { - return -1; - } + if (sscanf(line,"@RSYNCD: %d", &remote_protocol) != 1) { + io_printf(f_out, "@ERROR: protocol startup error\n"); + return -1; + } + if (protocol_version > remote_protocol) + protocol_version = remote_protocol; - if (!*line || strcmp(line,"#list")==0) { - send_listing(fd); - return -1; - } + line[0] = 0; + if (!read_line(f_in, line, sizeof line - 1)) + 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; - } + if (!*line || strcmp(line, "#list") == 0) { + rprintf(FLOG, "module-list request from %s (%s)\n", + host, addr); + send_listing(f_out); + return -1; + } - i = lp_number(line); - if (i == -1) { - io_printf(fd,"ERROR: Unknown module '%s'\n", line); - return -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; + } - return rsync_module(fd, i); + 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 0; -} +#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) { - if (!lp_load(RSYNCD_CONF)) { - exit_cleanup(1); - } + 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(); + + 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); + } - return start_accept_loop(rsync_port, start_daemon); + start_accept_loop(rsync_port, start_daemon); + return -1; } -