| 1 | /* |
| 2 | * The socket based protocol for setting up a connection with rsyncd. |
| 3 | * |
| 4 | * Copyright (C) 1998-2001 Andrew Tridgell <tridge@samba.org> |
| 5 | * Copyright (C) 2001-2002 Martin Pool <mbp@samba.org> |
| 6 | * Copyright (C) 2002-2008 Wayne Davison |
| 7 | * |
| 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. |
| 12 | * |
| 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. |
| 17 | * |
| 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. |
| 20 | */ |
| 21 | |
| 22 | #include "rsync.h" |
| 23 | #include "ifuncs.h" |
| 24 | |
| 25 | extern int quiet; |
| 26 | extern int dry_run; |
| 27 | extern int output_motd; |
| 28 | extern int list_only; |
| 29 | extern int am_sender; |
| 30 | extern int am_server; |
| 31 | extern int am_daemon; |
| 32 | extern int am_root; |
| 33 | extern int rsync_port; |
| 34 | extern int protect_args; |
| 35 | extern int ignore_errors; |
| 36 | extern int preserve_xattrs; |
| 37 | extern int kluge_around_eof; |
| 38 | extern int daemon_over_rsh; |
| 39 | extern int munge_symlinks; |
| 40 | extern int sanitize_paths; |
| 41 | extern int numeric_ids; |
| 42 | extern int filesfrom_fd; |
| 43 | extern int remote_protocol; |
| 44 | extern int protocol_version; |
| 45 | extern int io_timeout; |
| 46 | extern int no_detach; |
| 47 | extern int write_batch; |
| 48 | extern int default_af_hint; |
| 49 | extern int logfile_format_has_i; |
| 50 | extern int logfile_format_has_o_or_i; |
| 51 | extern mode_t orig_umask; |
| 52 | extern char *bind_address; |
| 53 | extern char *config_file; |
| 54 | extern char *logfile_format; |
| 55 | extern char *files_from; |
| 56 | extern char *tmpdir; |
| 57 | extern struct chmod_mode_struct *chmod_modes; |
| 58 | extern struct filter_list_struct daemon_filter_list; |
| 59 | extern char curr_dir[MAXPATHLEN]; |
| 60 | #ifdef ICONV_OPTION |
| 61 | extern char *iconv_opt; |
| 62 | extern iconv_t ic_send, ic_recv; |
| 63 | #endif |
| 64 | |
| 65 | char *auth_user; |
| 66 | int read_only = 0; |
| 67 | int module_id = -1; |
| 68 | struct chmod_mode_struct *daemon_chmod_modes; |
| 69 | |
| 70 | /* module_dirlen is the length of the module_dir string when in daemon |
| 71 | * mode and module_dir is not "/"; otherwise 0. (Note that a chroot- |
| 72 | * enabled module can have a non-"/" module_dir these days.) */ |
| 73 | char *module_dir = NULL; |
| 74 | unsigned int module_dirlen = 0; |
| 75 | |
| 76 | static int rl_nulls = 0; |
| 77 | |
| 78 | #ifdef HAVE_SIGACTION |
| 79 | static struct sigaction sigact; |
| 80 | #endif |
| 81 | |
| 82 | /** |
| 83 | * Run a client connected to an rsyncd. The alternative to this |
| 84 | * function for remote-shell connections is do_cmd(). |
| 85 | * |
| 86 | * After negotiating which module to use and reading the server's |
| 87 | * motd, this hands over to client_run(). Telling the server the |
| 88 | * module will cause it to chroot/setuid/etc. |
| 89 | * |
| 90 | * Instead of doing a transfer, the client may at this stage instead |
| 91 | * get a listing of remote modules and exit. |
| 92 | * |
| 93 | * @return -1 for error in startup, or the result of client_run(). |
| 94 | * Either way, it eventually gets passed to exit_cleanup(). |
| 95 | **/ |
| 96 | int start_socket_client(char *host, int remote_argc, char *remote_argv[], |
| 97 | int argc, char *argv[]) |
| 98 | { |
| 99 | int fd, ret; |
| 100 | char *p, *user = NULL; |
| 101 | |
| 102 | /* This is redundant with code in start_inband_exchange(), but this |
| 103 | * short-circuits a problem in the client before we open a socket, |
| 104 | * and the extra check won't hurt. */ |
| 105 | if (**remote_argv == '/') { |
| 106 | rprintf(FERROR, |
| 107 | "ERROR: The remote path must start with a module name not a /\n"); |
| 108 | return -1; |
| 109 | } |
| 110 | |
| 111 | if ((p = strrchr(host, '@')) != NULL) { |
| 112 | user = host; |
| 113 | host = p+1; |
| 114 | *p = '\0'; |
| 115 | } |
| 116 | |
| 117 | fd = open_socket_out_wrapped(host, rsync_port, bind_address, |
| 118 | default_af_hint); |
| 119 | if (fd == -1) |
| 120 | exit_cleanup(RERR_SOCKETIO); |
| 121 | |
| 122 | #ifdef ICONV_CONST |
| 123 | setup_iconv(); |
| 124 | #endif |
| 125 | |
| 126 | ret = start_inband_exchange(fd, fd, user, remote_argc, remote_argv); |
| 127 | |
| 128 | return ret ? ret : client_run(fd, fd, -1, argc, argv); |
| 129 | } |
| 130 | |
| 131 | static int exchange_protocols(int f_in, int f_out, char *buf, size_t bufsiz, int am_client) |
| 132 | { |
| 133 | int remote_sub = -1; |
| 134 | #if SUBPROTOCOL_VERSION != 0 |
| 135 | int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION; |
| 136 | #else |
| 137 | int our_sub = 0; |
| 138 | #endif |
| 139 | char *motd; |
| 140 | |
| 141 | io_printf(f_out, "@RSYNCD: %d.%d\n", protocol_version, our_sub); |
| 142 | |
| 143 | if (!am_client) { |
| 144 | motd = lp_motd_file(); |
| 145 | if (motd && *motd) { |
| 146 | FILE *f = fopen(motd,"r"); |
| 147 | while (f && !feof(f)) { |
| 148 | int len = fread(buf, 1, bufsiz - 1, f); |
| 149 | if (len > 0) |
| 150 | write_buf(f_out, buf, len); |
| 151 | } |
| 152 | if (f) |
| 153 | fclose(f); |
| 154 | write_sbuf(f_out, "\n"); |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | /* This strips the \n. */ |
| 159 | if (!read_line_old(f_in, buf, bufsiz)) { |
| 160 | if (am_client) |
| 161 | rprintf(FERROR, "rsync: did not see server greeting\n"); |
| 162 | return -1; |
| 163 | } |
| 164 | |
| 165 | if (sscanf(buf, "@RSYNCD: %d.%d", &remote_protocol, &remote_sub) < 1) { |
| 166 | if (am_client) |
| 167 | rprintf(FERROR, "rsync: server sent \"%s\" rather than greeting\n", buf); |
| 168 | else |
| 169 | io_printf(f_out, "@ERROR: protocol startup error\n"); |
| 170 | return -1; |
| 171 | } |
| 172 | |
| 173 | if (remote_sub < 0) { |
| 174 | if (remote_protocol == 30) { |
| 175 | if (am_client) |
| 176 | rprintf(FERROR, "rsync: server is speaking an incompatible beta of protocol 30\n"); |
| 177 | else |
| 178 | io_printf(f_out, "@ERROR: your client is speaking an incompatible beta of protocol 30\n"); |
| 179 | return -1; |
| 180 | } |
| 181 | remote_sub = 0; |
| 182 | } |
| 183 | |
| 184 | if (protocol_version > remote_protocol) { |
| 185 | protocol_version = remote_protocol; |
| 186 | if (remote_sub) |
| 187 | protocol_version--; |
| 188 | } else if (protocol_version == remote_protocol) { |
| 189 | if (remote_sub != our_sub) |
| 190 | protocol_version--; |
| 191 | } |
| 192 | #if SUBPROTOCOL_VERSION != 0 |
| 193 | else if (protocol_version < remote_protocol) { |
| 194 | if (our_sub) |
| 195 | protocol_version--; |
| 196 | } |
| 197 | #endif |
| 198 | |
| 199 | if (protocol_version >= 30) |
| 200 | rl_nulls = 1; |
| 201 | |
| 202 | return 0; |
| 203 | } |
| 204 | |
| 205 | int start_inband_exchange(int f_in, int f_out, const char *user, int argc, char *argv[]) |
| 206 | { |
| 207 | int i, modlen; |
| 208 | char line[BIGPATHBUFLEN]; |
| 209 | char *sargs[MAX_ARGS]; |
| 210 | int sargc = 0; |
| 211 | char *p, *modname; |
| 212 | |
| 213 | assert(argc > 0 && *argv != NULL); |
| 214 | |
| 215 | if (**argv == '/') { |
| 216 | rprintf(FERROR, |
| 217 | "ERROR: The remote path must start with a module name\n"); |
| 218 | return -1; |
| 219 | } |
| 220 | |
| 221 | if (!(p = strchr(*argv, '/'))) |
| 222 | modlen = strlen(*argv); |
| 223 | else |
| 224 | modlen = p - *argv; |
| 225 | |
| 226 | if (!(modname = new_array(char, modlen+1+1))) /* room for '/' & '\0' */ |
| 227 | out_of_memory("start_inband_exchange"); |
| 228 | strlcpy(modname, *argv, modlen + 1); |
| 229 | modname[modlen] = '/'; |
| 230 | modname[modlen+1] = '\0'; |
| 231 | |
| 232 | if (!user) |
| 233 | user = getenv("USER"); |
| 234 | if (!user) |
| 235 | user = getenv("LOGNAME"); |
| 236 | |
| 237 | if (exchange_protocols(f_in, f_out, line, sizeof line, 1) < 0) |
| 238 | return -1; |
| 239 | |
| 240 | /* set daemon_over_rsh to false since we need to build the |
| 241 | * true set of args passed through the rsh/ssh connection; |
| 242 | * this is a no-op for direct-socket-connection mode */ |
| 243 | daemon_over_rsh = 0; |
| 244 | server_options(sargs, &sargc); |
| 245 | |
| 246 | if (sargc >= MAX_ARGS - 2) |
| 247 | goto arg_overflow; |
| 248 | |
| 249 | sargs[sargc++] = "."; |
| 250 | |
| 251 | while (argc > 0) { |
| 252 | if (sargc >= MAX_ARGS - 1) { |
| 253 | arg_overflow: |
| 254 | rprintf(FERROR, "internal: args[] overflowed in do_cmd()\n"); |
| 255 | exit_cleanup(RERR_SYNTAX); |
| 256 | } |
| 257 | if (strncmp(*argv, modname, modlen) == 0 |
| 258 | && argv[0][modlen] == '\0') |
| 259 | sargs[sargc++] = modname; /* we send "modname/" */ |
| 260 | else |
| 261 | sargs[sargc++] = *argv; |
| 262 | argv++; |
| 263 | argc--; |
| 264 | } |
| 265 | |
| 266 | sargs[sargc] = NULL; |
| 267 | |
| 268 | if (DEBUG_GTE(CMD, 1)) |
| 269 | print_child_argv("sending daemon args:", sargs); |
| 270 | |
| 271 | io_printf(f_out, "%.*s\n", modlen, modname); |
| 272 | |
| 273 | /* Old servers may just drop the connection here, |
| 274 | rather than sending a proper EXIT command. Yuck. */ |
| 275 | kluge_around_eof = list_only && protocol_version < 25 ? 1 : 0; |
| 276 | |
| 277 | while (1) { |
| 278 | if (!read_line_old(f_in, line, sizeof line)) { |
| 279 | rprintf(FERROR, "rsync: didn't get server startup line\n"); |
| 280 | return -1; |
| 281 | } |
| 282 | |
| 283 | if (strncmp(line,"@RSYNCD: AUTHREQD ",18) == 0) { |
| 284 | auth_client(f_out, user, line+18); |
| 285 | continue; |
| 286 | } |
| 287 | |
| 288 | if (strcmp(line,"@RSYNCD: OK") == 0) |
| 289 | break; |
| 290 | |
| 291 | if (strcmp(line,"@RSYNCD: EXIT") == 0) { |
| 292 | /* This is sent by recent versions of the |
| 293 | * server to terminate the listing of modules. |
| 294 | * We don't want to go on and transfer |
| 295 | * anything; just exit. */ |
| 296 | exit(0); |
| 297 | } |
| 298 | |
| 299 | if (strncmp(line, "@ERROR", 6) == 0) { |
| 300 | rprintf(FERROR, "%s\n", line); |
| 301 | /* This is always fatal; the server will now |
| 302 | * close the socket. */ |
| 303 | return -1; |
| 304 | } |
| 305 | |
| 306 | /* This might be a MOTD line or a module listing, but there is |
| 307 | * no way to differentiate it. The manpage mentions this. */ |
| 308 | if (output_motd) |
| 309 | rprintf(FINFO, "%s\n", line); |
| 310 | } |
| 311 | kluge_around_eof = 0; |
| 312 | |
| 313 | if (rl_nulls) { |
| 314 | for (i = 0; i < sargc; i++) { |
| 315 | if (!sargs[i]) /* stop at --protect-args NULL */ |
| 316 | break; |
| 317 | write_sbuf(f_out, sargs[i]); |
| 318 | write_byte(f_out, 0); |
| 319 | } |
| 320 | write_byte(f_out, 0); |
| 321 | } else { |
| 322 | for (i = 0; i < sargc; i++) |
| 323 | io_printf(f_out, "%s\n", sargs[i]); |
| 324 | write_sbuf(f_out, "\n"); |
| 325 | } |
| 326 | |
| 327 | if (protect_args) |
| 328 | send_protected_args(f_out, sargs); |
| 329 | |
| 330 | if (protocol_version < 23) { |
| 331 | if (protocol_version == 22 || !am_sender) |
| 332 | io_start_multiplex_in(); |
| 333 | } |
| 334 | |
| 335 | free(modname); |
| 336 | |
| 337 | return 0; |
| 338 | } |
| 339 | |
| 340 | static char *finish_pre_exec(pid_t pid, int fd, char *request, |
| 341 | char **early_argv, char **argv) |
| 342 | { |
| 343 | int j = 0, status = -1; |
| 344 | |
| 345 | if (!request) |
| 346 | request = "(NONE)"; |
| 347 | |
| 348 | write_buf(fd, request, strlen(request)+1); |
| 349 | if (early_argv) { |
| 350 | for ( ; *early_argv; early_argv++) |
| 351 | write_buf(fd, *early_argv, strlen(*early_argv)+1); |
| 352 | j = 1; /* Skip arg0 name in argv. */ |
| 353 | } |
| 354 | for ( ; argv[j]; j++) { |
| 355 | write_buf(fd, argv[j], strlen(argv[j])+1); |
| 356 | if (argv[j][0] == '.' && argv[j][1] == '\0') |
| 357 | break; |
| 358 | } |
| 359 | write_byte(fd, 0); |
| 360 | |
| 361 | close(fd); |
| 362 | |
| 363 | if (wait_process(pid, &status, 0) < 0 |
| 364 | || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
| 365 | char *e; |
| 366 | if (asprintf(&e, "pre-xfer exec returned failure (%d)%s%s\n", |
| 367 | status, status < 0 ? ": " : "", |
| 368 | status < 0 ? strerror(errno) : "") < 0) |
| 369 | out_of_memory("finish_pre_exec"); |
| 370 | return e; |
| 371 | } |
| 372 | return NULL; |
| 373 | } |
| 374 | |
| 375 | static int read_arg_from_pipe(int fd, char *buf, int limit) |
| 376 | { |
| 377 | char *bp = buf, *eob = buf + limit - 1; |
| 378 | |
| 379 | while (1) { |
| 380 | int got = read(fd, bp, 1); |
| 381 | if (got != 1) { |
| 382 | if (got < 0 && errno == EINTR) |
| 383 | continue; |
| 384 | return -1; |
| 385 | } |
| 386 | if (*bp == '\0') |
| 387 | break; |
| 388 | if (bp < eob) |
| 389 | bp++; |
| 390 | } |
| 391 | *bp = '\0'; |
| 392 | |
| 393 | return bp - buf; |
| 394 | } |
| 395 | |
| 396 | static int rsync_module(int f_in, int f_out, int i, char *addr, char *host) |
| 397 | { |
| 398 | int argc; |
| 399 | char **argv, **orig_argv, **orig_early_argv, *chroot_path = NULL; |
| 400 | char line[BIGPATHBUFLEN]; |
| 401 | uid_t uid = (uid_t)-2; /* canonically "nobody" */ |
| 402 | gid_t gid = (gid_t)-2; |
| 403 | char *p, *err_msg = NULL; |
| 404 | char *name = lp_name(i); |
| 405 | int use_chroot = lp_use_chroot(i); |
| 406 | int ret, pre_exec_fd = -1; |
| 407 | int save_munge_symlinks; |
| 408 | pid_t pre_exec_pid = 0; |
| 409 | char *request = NULL; |
| 410 | |
| 411 | #ifdef ICONV_OPTION |
| 412 | iconv_opt = lp_charset(i); |
| 413 | if (*iconv_opt) |
| 414 | setup_iconv(); |
| 415 | iconv_opt = NULL; |
| 416 | #endif |
| 417 | |
| 418 | if (!allow_access(addr, host, lp_hosts_allow(i), lp_hosts_deny(i))) { |
| 419 | rprintf(FLOG, "rsync denied on module %s from %s (%s)\n", |
| 420 | name, host, addr); |
| 421 | if (!lp_list(i)) |
| 422 | io_printf(f_out, "@ERROR: Unknown module '%s'\n", name); |
| 423 | else { |
| 424 | io_printf(f_out, |
| 425 | "@ERROR: access denied to %s from %s (%s)\n", |
| 426 | name, host, addr); |
| 427 | } |
| 428 | return -1; |
| 429 | } |
| 430 | |
| 431 | if (am_daemon && am_server) { |
| 432 | rprintf(FLOG, "rsync allowed access on module %s from %s (%s)\n", |
| 433 | name, host, addr); |
| 434 | } |
| 435 | |
| 436 | if (!claim_connection(lp_lock_file(i), lp_max_connections(i))) { |
| 437 | if (errno) { |
| 438 | rsyserr(FLOG, errno, "failed to open lock file %s", |
| 439 | lp_lock_file(i)); |
| 440 | io_printf(f_out, "@ERROR: failed to open lock file\n"); |
| 441 | } else { |
| 442 | rprintf(FLOG, "max connections (%d) reached\n", |
| 443 | lp_max_connections(i)); |
| 444 | io_printf(f_out, "@ERROR: max connections (%d) reached -- try again later\n", |
| 445 | lp_max_connections(i)); |
| 446 | } |
| 447 | return -1; |
| 448 | } |
| 449 | |
| 450 | auth_user = auth_server(f_in, f_out, i, host, addr, "@RSYNCD: AUTHREQD "); |
| 451 | |
| 452 | if (!auth_user) { |
| 453 | io_printf(f_out, "@ERROR: auth failed on module %s\n", name); |
| 454 | return -1; |
| 455 | } |
| 456 | |
| 457 | module_id = i; |
| 458 | |
| 459 | if (lp_read_only(i)) |
| 460 | read_only = 1; |
| 461 | |
| 462 | if (lp_transfer_logging(i) && !logfile_format) |
| 463 | logfile_format = lp_log_format(i); |
| 464 | if (log_format_has(logfile_format, 'i')) |
| 465 | logfile_format_has_i = 1; |
| 466 | if (logfile_format_has_i || log_format_has(logfile_format, 'o')) |
| 467 | logfile_format_has_o_or_i = 1; |
| 468 | |
| 469 | am_root = (MY_UID() == 0); |
| 470 | |
| 471 | if (am_root) { |
| 472 | p = lp_uid(i); |
| 473 | if (!name_to_uid(p, &uid)) { |
| 474 | if (!isDigit(p)) { |
| 475 | rprintf(FLOG, "Invalid uid %s\n", p); |
| 476 | io_printf(f_out, "@ERROR: invalid uid %s\n", p); |
| 477 | return -1; |
| 478 | } |
| 479 | uid = atoi(p); |
| 480 | } |
| 481 | |
| 482 | p = lp_gid(i); |
| 483 | if (!name_to_gid(p, &gid)) { |
| 484 | if (!isDigit(p)) { |
| 485 | rprintf(FLOG, "Invalid gid %s\n", p); |
| 486 | io_printf(f_out, "@ERROR: invalid gid %s\n", p); |
| 487 | return -1; |
| 488 | } |
| 489 | gid = atoi(p); |
| 490 | } |
| 491 | } |
| 492 | |
| 493 | /* TODO: If we're not root, but the configuration requests |
| 494 | * that we change to some uid other than the current one, then |
| 495 | * log a warning. */ |
| 496 | |
| 497 | /* TODO: Perhaps take a list of gids, and make them into the |
| 498 | * supplementary groups. */ |
| 499 | |
| 500 | module_dir = lp_path(i); |
| 501 | if (use_chroot) { |
| 502 | if ((p = strstr(module_dir, "/./")) != NULL) { |
| 503 | *p = '\0'; |
| 504 | p += 2; |
| 505 | } else if ((p = strdup("/")) == NULL) /* MEMORY LEAK */ |
| 506 | out_of_memory("rsync_module"); |
| 507 | } |
| 508 | |
| 509 | /* We do a change_dir() that doesn't actually call chdir() |
| 510 | * just to make a relative path absolute. */ |
| 511 | strlcpy(line, curr_dir, sizeof line); |
| 512 | if (!change_dir(module_dir, CD_SKIP_CHDIR)) |
| 513 | goto chdir_failed; |
| 514 | if (strcmp(curr_dir, module_dir) != 0 |
| 515 | && (module_dir = strdup(curr_dir)) == NULL) |
| 516 | out_of_memory("rsync_module"); |
| 517 | change_dir(line, CD_SKIP_CHDIR); /* Restore curr_dir. */ |
| 518 | |
| 519 | if (use_chroot) { |
| 520 | chroot_path = module_dir; |
| 521 | module_dir = p; /* p is "/" or our inside-chroot path */ |
| 522 | } |
| 523 | module_dirlen = clean_fname(module_dir, CFN_COLLAPSE_DOT_DOT_DIRS | CFN_DROP_TRAILING_DOT_DIR); |
| 524 | |
| 525 | if (module_dirlen == 1) { |
| 526 | module_dirlen = 0; |
| 527 | set_filter_dir("/", 1); |
| 528 | } else |
| 529 | set_filter_dir(module_dir, module_dirlen); |
| 530 | |
| 531 | p = lp_filter(i); |
| 532 | parse_rule(&daemon_filter_list, p, MATCHFLG_WORD_SPLIT, |
| 533 | XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3); |
| 534 | |
| 535 | p = lp_include_from(i); |
| 536 | parse_filter_file(&daemon_filter_list, p, MATCHFLG_INCLUDE, |
| 537 | XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS); |
| 538 | |
| 539 | p = lp_include(i); |
| 540 | parse_rule(&daemon_filter_list, p, |
| 541 | MATCHFLG_INCLUDE | MATCHFLG_WORD_SPLIT, |
| 542 | XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES); |
| 543 | |
| 544 | p = lp_exclude_from(i); |
| 545 | parse_filter_file(&daemon_filter_list, p, 0, |
| 546 | XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES | XFLG_FATAL_ERRORS); |
| 547 | |
| 548 | p = lp_exclude(i); |
| 549 | parse_rule(&daemon_filter_list, p, MATCHFLG_WORD_SPLIT, |
| 550 | XFLG_ABS_IF_SLASH | XFLG_DIR2WILD3 | XFLG_OLD_PREFIXES); |
| 551 | |
| 552 | log_init(1); |
| 553 | |
| 554 | #ifdef HAVE_PUTENV |
| 555 | if (*lp_prexfer_exec(i) || *lp_postxfer_exec(i)) { |
| 556 | char *modname, *modpath, *hostaddr, *hostname, *username; |
| 557 | int status; |
| 558 | |
| 559 | if (!use_chroot) |
| 560 | p = module_dir; |
| 561 | else if (module_dirlen) { |
| 562 | pathjoin(line, sizeof line, chroot_path, module_dir+1); |
| 563 | p = line; |
| 564 | } else |
| 565 | p = chroot_path; |
| 566 | |
| 567 | if (asprintf(&modname, "RSYNC_MODULE_NAME=%s", name) < 0 |
| 568 | || asprintf(&modpath, "RSYNC_MODULE_PATH=%s", p) < 0 |
| 569 | || asprintf(&hostaddr, "RSYNC_HOST_ADDR=%s", addr) < 0 |
| 570 | || asprintf(&hostname, "RSYNC_HOST_NAME=%s", host) < 0 |
| 571 | || asprintf(&username, "RSYNC_USER_NAME=%s", auth_user) < 0) |
| 572 | out_of_memory("rsync_module"); |
| 573 | putenv(modname); |
| 574 | putenv(modpath); |
| 575 | putenv(hostaddr); |
| 576 | putenv(hostname); |
| 577 | putenv(username); |
| 578 | umask(orig_umask); |
| 579 | /* For post-xfer exec, fork a new process to run the rsync |
| 580 | * daemon while this process waits for the exit status and |
| 581 | * runs the indicated command at that point. */ |
| 582 | if (*lp_postxfer_exec(i)) { |
| 583 | pid_t pid = fork(); |
| 584 | if (pid < 0) { |
| 585 | rsyserr(FLOG, errno, "fork failed"); |
| 586 | io_printf(f_out, "@ERROR: fork failed\n"); |
| 587 | return -1; |
| 588 | } |
| 589 | if (pid) { |
| 590 | if (asprintf(&p, "RSYNC_PID=%ld", (long)pid) > 0) |
| 591 | putenv(p); |
| 592 | if (wait_process(pid, &status, 0) < 0) |
| 593 | status = -1; |
| 594 | if (asprintf(&p, "RSYNC_RAW_STATUS=%d", status) > 0) |
| 595 | putenv(p); |
| 596 | if (WIFEXITED(status)) |
| 597 | status = WEXITSTATUS(status); |
| 598 | else |
| 599 | status = -1; |
| 600 | if (asprintf(&p, "RSYNC_EXIT_STATUS=%d", status) > 0) |
| 601 | putenv(p); |
| 602 | system(lp_postxfer_exec(i)); |
| 603 | _exit(status); |
| 604 | } |
| 605 | } |
| 606 | /* For pre-xfer exec, fork a child process to run the indicated |
| 607 | * command, though it first waits for the parent process to |
| 608 | * send us the user's request via a pipe. */ |
| 609 | if (*lp_prexfer_exec(i)) { |
| 610 | int fds[2]; |
| 611 | if (asprintf(&p, "RSYNC_PID=%ld", (long)getpid()) > 0) |
| 612 | putenv(p); |
| 613 | if (pipe(fds) < 0 || (pre_exec_pid = fork()) < 0) { |
| 614 | rsyserr(FLOG, errno, "pre-xfer exec preparation failed"); |
| 615 | io_printf(f_out, "@ERROR: pre-xfer exec preparation failed\n"); |
| 616 | return -1; |
| 617 | } |
| 618 | if (pre_exec_pid == 0) { |
| 619 | char buf[BIGPATHBUFLEN]; |
| 620 | int j, len; |
| 621 | close(fds[1]); |
| 622 | set_blocking(fds[0]); |
| 623 | len = read_arg_from_pipe(fds[0], buf, BIGPATHBUFLEN); |
| 624 | if (len <= 0) |
| 625 | _exit(1); |
| 626 | if (asprintf(&p, "RSYNC_REQUEST=%s", buf) > 0) |
| 627 | putenv(p); |
| 628 | for (j = 0; ; j++) { |
| 629 | len = read_arg_from_pipe(fds[0], buf, |
| 630 | BIGPATHBUFLEN); |
| 631 | if (len <= 0) { |
| 632 | if (!len) |
| 633 | break; |
| 634 | _exit(1); |
| 635 | } |
| 636 | if (asprintf(&p, "RSYNC_ARG%d=%s", j, buf) > 0) |
| 637 | putenv(p); |
| 638 | } |
| 639 | close(fds[0]); |
| 640 | close(STDIN_FILENO); |
| 641 | close(STDOUT_FILENO); |
| 642 | status = system(lp_prexfer_exec(i)); |
| 643 | if (!WIFEXITED(status)) |
| 644 | _exit(1); |
| 645 | _exit(WEXITSTATUS(status)); |
| 646 | } |
| 647 | close(fds[0]); |
| 648 | set_blocking(fds[1]); |
| 649 | pre_exec_fd = fds[1]; |
| 650 | } |
| 651 | umask(0); |
| 652 | } |
| 653 | #endif |
| 654 | |
| 655 | if (use_chroot) { |
| 656 | /* |
| 657 | * XXX: The 'use chroot' flag is a fairly reliable |
| 658 | * source of confusion, because it fails under two |
| 659 | * important circumstances: running as non-root, |
| 660 | * running on Win32 (or possibly others). On the |
| 661 | * other hand, if you are running as root, then it |
| 662 | * might be better to always use chroot. |
| 663 | * |
| 664 | * So, perhaps if we can't chroot we should just issue |
| 665 | * a warning, unless a "require chroot" flag is set, |
| 666 | * in which case we fail. |
| 667 | */ |
| 668 | if (chroot(chroot_path)) { |
| 669 | rsyserr(FLOG, errno, "chroot %s failed", chroot_path); |
| 670 | io_printf(f_out, "@ERROR: chroot failed\n"); |
| 671 | return -1; |
| 672 | } |
| 673 | if (!change_dir(module_dir, CD_NORMAL)) |
| 674 | goto chdir_failed; |
| 675 | if (module_dirlen) |
| 676 | sanitize_paths = 1; |
| 677 | } else { |
| 678 | if (!change_dir(module_dir, CD_NORMAL)) { |
| 679 | chdir_failed: |
| 680 | rsyserr(FLOG, errno, "chdir %s failed\n", module_dir); |
| 681 | io_printf(f_out, "@ERROR: chdir failed\n"); |
| 682 | return -1; |
| 683 | } |
| 684 | sanitize_paths = 1; |
| 685 | } |
| 686 | |
| 687 | if ((munge_symlinks = lp_munge_symlinks(i)) < 0) |
| 688 | munge_symlinks = !use_chroot || module_dirlen; |
| 689 | if (munge_symlinks) { |
| 690 | STRUCT_STAT st; |
| 691 | char prefix[SYMLINK_PREFIX_LEN]; /* NOT +1 ! */ |
| 692 | strlcpy(prefix, SYMLINK_PREFIX, sizeof prefix); /* trim the trailing slash */ |
| 693 | if (do_stat(prefix, &st) == 0 && S_ISDIR(st.st_mode)) { |
| 694 | rprintf(FLOG, "Symlink munging is unsafe when a %s directory exists.\n", |
| 695 | prefix); |
| 696 | io_printf(f_out, "@ERROR: daemon security issue -- contact admin\n", name); |
| 697 | exit_cleanup(RERR_UNSUPPORTED); |
| 698 | } |
| 699 | } |
| 700 | |
| 701 | if (am_root) { |
| 702 | /* XXXX: You could argue that if the daemon is started |
| 703 | * by a non-root user and they explicitly specify a |
| 704 | * gid, then we should try to change to that gid -- |
| 705 | * this could be possible if it's already in their |
| 706 | * supplementary groups. */ |
| 707 | |
| 708 | /* TODO: Perhaps we need to document that if rsyncd is |
| 709 | * started by somebody other than root it will inherit |
| 710 | * all their supplementary groups. */ |
| 711 | |
| 712 | if (setgid(gid)) { |
| 713 | rsyserr(FLOG, errno, "setgid %d failed", (int)gid); |
| 714 | io_printf(f_out, "@ERROR: setgid failed\n"); |
| 715 | return -1; |
| 716 | } |
| 717 | #ifdef HAVE_SETGROUPS |
| 718 | /* Get rid of any supplementary groups this process |
| 719 | * might have inheristed. */ |
| 720 | if (setgroups(1, &gid)) { |
| 721 | rsyserr(FLOG, errno, "setgroups failed"); |
| 722 | io_printf(f_out, "@ERROR: setgroups failed\n"); |
| 723 | return -1; |
| 724 | } |
| 725 | #endif |
| 726 | |
| 727 | if (setuid(uid)) { |
| 728 | rsyserr(FLOG, errno, "setuid %d failed", (int)uid); |
| 729 | io_printf(f_out, "@ERROR: setuid failed\n"); |
| 730 | return -1; |
| 731 | } |
| 732 | |
| 733 | am_root = (MY_UID() == 0); |
| 734 | } |
| 735 | |
| 736 | if (lp_temp_dir(i) && *lp_temp_dir(i)) { |
| 737 | tmpdir = lp_temp_dir(i); |
| 738 | if (strlen(tmpdir) >= MAXPATHLEN - 10) { |
| 739 | rprintf(FLOG, |
| 740 | "the 'temp dir' value for %s is WAY too long -- ignoring.\n", |
| 741 | name); |
| 742 | tmpdir = NULL; |
| 743 | } |
| 744 | } |
| 745 | |
| 746 | io_printf(f_out, "@RSYNCD: OK\n"); |
| 747 | |
| 748 | read_args(f_in, name, line, sizeof line, rl_nulls, &argv, &argc, &request); |
| 749 | orig_argv = argv; |
| 750 | |
| 751 | save_munge_symlinks = munge_symlinks; |
| 752 | |
| 753 | reset_output_levels(); /* future verbosity is controlled by client options */ |
| 754 | ret = parse_arguments(&argc, (const char ***) &argv); |
| 755 | if (protect_args && ret) { |
| 756 | orig_early_argv = orig_argv; |
| 757 | protect_args = 2; |
| 758 | read_args(f_in, name, line, sizeof line, 1, &argv, &argc, &request); |
| 759 | orig_argv = argv; |
| 760 | ret = parse_arguments(&argc, (const char ***) &argv); |
| 761 | } else |
| 762 | orig_early_argv = NULL; |
| 763 | |
| 764 | munge_symlinks = save_munge_symlinks; /* The client mustn't control this. */ |
| 765 | |
| 766 | if (pre_exec_pid) { |
| 767 | err_msg = finish_pre_exec(pre_exec_pid, pre_exec_fd, request, |
| 768 | orig_early_argv, orig_argv); |
| 769 | } |
| 770 | |
| 771 | if (orig_early_argv) |
| 772 | free(orig_early_argv); |
| 773 | |
| 774 | am_server = 1; /* Don't let someone try to be tricky. */ |
| 775 | quiet = 0; |
| 776 | if (lp_ignore_errors(module_id)) |
| 777 | ignore_errors = 1; |
| 778 | if (write_batch < 0) |
| 779 | dry_run = 1; |
| 780 | |
| 781 | if (lp_fake_super(i)) { |
| 782 | if (preserve_xattrs > 1) |
| 783 | preserve_xattrs = 1; |
| 784 | am_root = -1; |
| 785 | } else if (am_root < 0) /* Treat --fake-super from client as --super. */ |
| 786 | am_root = 2; |
| 787 | |
| 788 | if (filesfrom_fd == 0) |
| 789 | filesfrom_fd = f_in; |
| 790 | |
| 791 | if (request) { |
| 792 | if (*auth_user) { |
| 793 | rprintf(FLOG, "rsync %s %s from %s@%s (%s)\n", |
| 794 | am_sender ? "on" : "to", |
| 795 | request, auth_user, host, addr); |
| 796 | } else { |
| 797 | rprintf(FLOG, "rsync %s %s from %s (%s)\n", |
| 798 | am_sender ? "on" : "to", |
| 799 | request, host, addr); |
| 800 | } |
| 801 | free(request); |
| 802 | } |
| 803 | |
| 804 | #ifndef DEBUG |
| 805 | /* don't allow the logs to be flooded too fast */ |
| 806 | limit_output_verbosity(lp_max_verbosity(i)); |
| 807 | #endif |
| 808 | |
| 809 | if (protocol_version < 23 |
| 810 | && (protocol_version == 22 || am_sender)) |
| 811 | io_start_multiplex_out(); |
| 812 | else if (!ret || err_msg) { |
| 813 | /* We have to get I/O multiplexing started so that we can |
| 814 | * get the error back to the client. This means getting |
| 815 | * the protocol setup finished first in later versions. */ |
| 816 | setup_protocol(f_out, f_in); |
| 817 | if (!am_sender) { |
| 818 | /* Since we failed in our option parsing, we may not |
| 819 | * have finished parsing that the client sent us a |
| 820 | * --files-from option, so look for it manually. |
| 821 | * Without this, the socket would be in the wrong |
| 822 | * state for the upcoming error message. */ |
| 823 | if (!files_from) { |
| 824 | int i; |
| 825 | for (i = 0; i < argc; i++) { |
| 826 | if (strncmp(argv[i], "--files-from", 12) == 0) { |
| 827 | files_from = ""; |
| 828 | break; |
| 829 | } |
| 830 | } |
| 831 | } |
| 832 | if (files_from) |
| 833 | write_byte(f_out, 0); |
| 834 | } |
| 835 | io_start_multiplex_out(); |
| 836 | } |
| 837 | |
| 838 | if (!ret || err_msg) { |
| 839 | if (err_msg) |
| 840 | rwrite(FERROR, err_msg, strlen(err_msg), 0); |
| 841 | else |
| 842 | option_error(); |
| 843 | msleep(400); |
| 844 | exit_cleanup(RERR_UNSUPPORTED); |
| 845 | } |
| 846 | |
| 847 | #ifdef ICONV_OPTION |
| 848 | if (!iconv_opt) { |
| 849 | if (ic_send != (iconv_t)-1) { |
| 850 | iconv_close(ic_send); |
| 851 | ic_send = (iconv_t)-1; |
| 852 | } |
| 853 | if (ic_recv != (iconv_t)-1) { |
| 854 | iconv_close(ic_recv); |
| 855 | ic_recv = (iconv_t)-1; |
| 856 | } |
| 857 | } |
| 858 | #endif |
| 859 | |
| 860 | if (!numeric_ids |
| 861 | && (use_chroot ? lp_numeric_ids(i) != False : lp_numeric_ids(i) == True)) |
| 862 | numeric_ids = -1; /* Set --numeric-ids w/o breaking protocol. */ |
| 863 | |
| 864 | if (lp_timeout(i) && lp_timeout(i) > io_timeout) |
| 865 | set_io_timeout(lp_timeout(i)); |
| 866 | |
| 867 | /* If we have some incoming/outgoing chmod changes, append them to |
| 868 | * any user-specified changes (making our changes have priority). |
| 869 | * We also get a pointer to just our changes so that a receiver |
| 870 | * process can use them separately if --perms wasn't specified. */ |
| 871 | if (am_sender) |
| 872 | p = lp_outgoing_chmod(i); |
| 873 | else |
| 874 | p = lp_incoming_chmod(i); |
| 875 | if (*p && !(daemon_chmod_modes = parse_chmod(p, &chmod_modes))) { |
| 876 | rprintf(FLOG, "Invalid \"%sing chmod\" directive: %s\n", |
| 877 | am_sender ? "outgo" : "incom", p); |
| 878 | } |
| 879 | |
| 880 | start_server(f_in, f_out, argc, argv); |
| 881 | |
| 882 | return 0; |
| 883 | } |
| 884 | |
| 885 | /* send a list of available modules to the client. Don't list those |
| 886 | with "list = False". */ |
| 887 | static void send_listing(int fd) |
| 888 | { |
| 889 | int n = lp_num_modules(); |
| 890 | int i; |
| 891 | |
| 892 | for (i = 0; i < n; i++) { |
| 893 | if (lp_list(i)) |
| 894 | io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i)); |
| 895 | } |
| 896 | |
| 897 | if (protocol_version >= 25) |
| 898 | io_printf(fd,"@RSYNCD: EXIT\n"); |
| 899 | } |
| 900 | |
| 901 | static int load_config(int globals_only) |
| 902 | { |
| 903 | if (!config_file) { |
| 904 | if (am_server && am_root <= 0) |
| 905 | config_file = RSYNCD_USERCONF; |
| 906 | else |
| 907 | config_file = RSYNCD_SYSCONF; |
| 908 | } |
| 909 | return lp_load(config_file, globals_only); |
| 910 | } |
| 911 | |
| 912 | /* this is called when a connection is established to a client |
| 913 | and we want to start talking. The setup of the system is done from |
| 914 | here */ |
| 915 | int start_daemon(int f_in, int f_out) |
| 916 | { |
| 917 | char line[1024]; |
| 918 | char *addr, *host; |
| 919 | int i; |
| 920 | |
| 921 | io_set_sock_fds(f_in, f_out); |
| 922 | |
| 923 | /* We must load the config file before calling any function that |
| 924 | * might cause log-file output to occur. This ensures that the |
| 925 | * "log file" param gets honored for the 2 non-forked use-cases |
| 926 | * (when rsync is run by init and run by a remote shell). */ |
| 927 | if (!load_config(0)) |
| 928 | exit_cleanup(RERR_SYNTAX); |
| 929 | |
| 930 | addr = client_addr(f_in); |
| 931 | host = client_name(f_in); |
| 932 | rprintf(FLOG, "connect from %s (%s)\n", host, addr); |
| 933 | |
| 934 | if (!am_server) { |
| 935 | set_socket_options(f_in, "SO_KEEPALIVE"); |
| 936 | set_nonblocking(f_in); |
| 937 | } |
| 938 | |
| 939 | if (exchange_protocols(f_in, f_out, line, sizeof line, 0) < 0) |
| 940 | return -1; |
| 941 | |
| 942 | line[0] = 0; |
| 943 | if (!read_line_old(f_in, line, sizeof line)) |
| 944 | return -1; |
| 945 | |
| 946 | if (!*line || strcmp(line, "#list") == 0) { |
| 947 | rprintf(FLOG, "module-list request from %s (%s)\n", |
| 948 | host, addr); |
| 949 | send_listing(f_out); |
| 950 | return -1; |
| 951 | } |
| 952 | |
| 953 | if (*line == '#') { |
| 954 | /* it's some sort of command that I don't understand */ |
| 955 | io_printf(f_out, "@ERROR: Unknown command '%s'\n", line); |
| 956 | return -1; |
| 957 | } |
| 958 | |
| 959 | if ((i = lp_number(line)) < 0) { |
| 960 | rprintf(FLOG, "unknown module '%s' tried from %s (%s)\n", |
| 961 | line, host, addr); |
| 962 | io_printf(f_out, "@ERROR: Unknown module '%s'\n", line); |
| 963 | return -1; |
| 964 | } |
| 965 | |
| 966 | #ifdef HAVE_SIGACTION |
| 967 | sigact.sa_flags = SA_NOCLDSTOP; |
| 968 | #endif |
| 969 | SIGACTION(SIGCHLD, remember_children); |
| 970 | |
| 971 | return rsync_module(f_in, f_out, i, addr, host); |
| 972 | } |
| 973 | |
| 974 | static void create_pid_file(void) |
| 975 | { |
| 976 | char *pid_file = lp_pid_file(); |
| 977 | char pidbuf[16]; |
| 978 | pid_t pid = getpid(); |
| 979 | int fd; |
| 980 | |
| 981 | if (!pid_file || !*pid_file) |
| 982 | return; |
| 983 | |
| 984 | cleanup_set_pid(pid); |
| 985 | if ((fd = do_open(pid_file, O_WRONLY|O_CREAT|O_EXCL, 0666 & ~orig_umask)) == -1) { |
| 986 | cleanup_set_pid(0); |
| 987 | fprintf(stderr, "failed to create pid file %s: %s\n", pid_file, strerror(errno)); |
| 988 | rsyserr(FLOG, errno, "failed to create pid file %s", pid_file); |
| 989 | exit_cleanup(RERR_FILEIO); |
| 990 | } |
| 991 | snprintf(pidbuf, sizeof pidbuf, "%ld\n", (long)pid); |
| 992 | write(fd, pidbuf, strlen(pidbuf)); |
| 993 | close(fd); |
| 994 | } |
| 995 | |
| 996 | /* Become a daemon, discarding the controlling terminal. */ |
| 997 | static void become_daemon(void) |
| 998 | { |
| 999 | int i; |
| 1000 | pid_t pid = fork(); |
| 1001 | |
| 1002 | if (pid) { |
| 1003 | if (pid < 0) { |
| 1004 | fprintf(stderr, "failed to fork: %s\n", strerror(errno)); |
| 1005 | exit_cleanup(RERR_FILEIO); |
| 1006 | } |
| 1007 | _exit(0); |
| 1008 | } |
| 1009 | |
| 1010 | create_pid_file(); |
| 1011 | |
| 1012 | /* detach from the terminal */ |
| 1013 | #ifdef HAVE_SETSID |
| 1014 | setsid(); |
| 1015 | #elif defined TIOCNOTTY |
| 1016 | i = open("/dev/tty", O_RDWR); |
| 1017 | if (i >= 0) { |
| 1018 | ioctl(i, (int)TIOCNOTTY, (char *)0); |
| 1019 | close(i); |
| 1020 | } |
| 1021 | #endif |
| 1022 | /* make sure that stdin, stdout an stderr don't stuff things |
| 1023 | * up (library functions, for example) */ |
| 1024 | for (i = 0; i < 3; i++) { |
| 1025 | close(i); |
| 1026 | open("/dev/null", O_RDWR); |
| 1027 | } |
| 1028 | } |
| 1029 | |
| 1030 | int daemon_main(void) |
| 1031 | { |
| 1032 | if (is_a_socket(STDIN_FILENO)) { |
| 1033 | int i; |
| 1034 | |
| 1035 | /* we are running via inetd - close off stdout and |
| 1036 | * stderr so that library functions (and getopt) don't |
| 1037 | * try to use them. Redirect them to /dev/null */ |
| 1038 | for (i = 1; i < 3; i++) { |
| 1039 | close(i); |
| 1040 | open("/dev/null", O_RDWR); |
| 1041 | } |
| 1042 | |
| 1043 | return start_daemon(STDIN_FILENO, STDIN_FILENO); |
| 1044 | } |
| 1045 | |
| 1046 | if (!load_config(1)) { |
| 1047 | fprintf(stderr, "Failed to parse config file: %s\n", config_file); |
| 1048 | exit_cleanup(RERR_SYNTAX); |
| 1049 | } |
| 1050 | set_dparams(0); |
| 1051 | |
| 1052 | if (no_detach) |
| 1053 | create_pid_file(); |
| 1054 | else |
| 1055 | become_daemon(); |
| 1056 | |
| 1057 | if (rsync_port == 0 && (rsync_port = lp_rsync_port()) == 0) |
| 1058 | rsync_port = RSYNC_PORT; |
| 1059 | if (bind_address == NULL && *lp_bind_address()) |
| 1060 | bind_address = lp_bind_address(); |
| 1061 | |
| 1062 | log_init(0); |
| 1063 | |
| 1064 | rprintf(FLOG, "rsyncd version %s starting, listening on port %d\n", |
| 1065 | RSYNC_VERSION, rsync_port); |
| 1066 | /* TODO: If listening on a particular address, then show that |
| 1067 | * address too. In fact, why not just do inet_ntop on the |
| 1068 | * local address??? */ |
| 1069 | |
| 1070 | start_accept_loop(rsync_port, start_daemon); |
| 1071 | return -1; |
| 1072 | } |