clientserver.c

   1 /*
   2    Copyright (C) Andrew Tridgell 1998
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19 /* the socket based protocol for setting up a connection wit rsyncd */
  20
  21 #include "rsync.h"
  22
  23 extern int module_id;
  24 extern int read_only;
  25 extern int verbose;
  26 extern int rsync_port;
  27 char *auth_user;
  28 int sanitize_paths = 0;
  29
  30 int start_socket_client(char *host, char *path, int argc, char *argv[])
  31 {
  32         int fd, i;
  33         char *sargs[MAX_ARGS];
  34         int sargc=0;
  35         char line[MAXPATHLEN];
  36         char *p, *user=NULL;
  37         extern int remote_version;
  38         extern int am_sender;
  39         extern struct in_addr socket_address;
  40
  41         if (*path == '/') {
  42                 rprintf(FERROR,"ERROR: The remote path must start with a module name\n");
  43                 return -1;
  44         }
  45
  46         p = strchr(host, '@');
  47         if (p) {
  48                 user = host;
  49                 host = p+1;
  50                 *p = 0;
  51         }
  52
  53         if (!user) user = getenv("USER");
  54         if (!user) user = getenv("LOGNAME");
  55
  56         fd = open_socket_out(host, rsync_port, &socket_address);
  57         if (fd == -1) {
  58                 exit_cleanup(RERR_SOCKETIO);
  59         }
  60
  61         server_options(sargs,&sargc);
  62
  63         sargs[sargc++] = ".";
  64
  65         if (path && *path)
  66                 sargs[sargc++] = path;
  67
  68         sargs[sargc] = NULL;
  69
  70         io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
  71
  72         if (!read_line(fd, line, sizeof(line)-1)) {
  73                 return -1;
  74         }
  75
  76         if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
  77                 return -1;
  78         }
  79
  80         p = strchr(path,'/');
  81         if (p) *p = 0;
  82         io_printf(fd,"%s\n",path);
  83         if (p) *p = '/';
  84
  85         while (1) {
  86                 if (!read_line(fd, line, sizeof(line)-1)) {
  87                         return -1;
  88                 }
  89
  90                 if (strncmp(line,"@RSYNCD: AUTHREQD ",18) == 0) {
  91                         auth_client(fd, user, line+18);
  92                         continue;
  93                 }
  94
  95                 if (strcmp(line,"@RSYNCD: OK") == 0) break;
  96                 rprintf(FINFO,"%s\n", line);
  97         }
  98
  99         for (i=0;i<sargc;i++) {
 100                 io_printf(fd,"%s\n", sargs[i]);
 101         }
 102         io_printf(fd,"\n");
 103
 104         if (remote_version < 23) {
 105                 if (remote_version == 22 || (remote_version > 17 && !am_sender))
 106                         io_start_multiplex_in(fd);
 107         }
 108
 109         return client_run(fd, fd, -1, argc, argv);
 110 }
 111
 112
 113
 114 static int rsync_module(int fd, int i)
 115 {
 116         int argc=0;
 117         char *argv[MAX_ARGS];
 118         char **argp;
 119         char line[MAXPATHLEN];
 120         uid_t uid = (uid_t)-2;
 121         gid_t gid = (gid_t)-2;
 122         char *p;
 123         char *addr = client_addr(fd);
 124         char *host = client_name(fd);
 125         char *name = lp_name(i);
 126         int use_chroot = lp_use_chroot(i);
 127         int start_glob=0;
 128         int ret;
 129         char *request=NULL;
 130         extern int am_sender;
 131         extern int remote_version;
 132         extern int am_root;
 133
 134         if (!allow_access(addr, host, lp_hosts_allow(i), lp_hosts_deny(i))) {
 135                 rprintf(FERROR,"rsync denied on module %s from %s (%s)\n",
 136                         name, client_name(fd), client_addr(fd));
 137                 io_printf(fd,"@ERROR: access denied to %s from %s (%s)\n",
 138                           name, client_name(fd), client_addr(fd));
 139                 return -1;
 140         }
 141
 142         if (!claim_connection(lp_lock_file(i), lp_max_connections(i))) {
 143                 if (errno) {
 144                         rprintf(FERROR,"failed to open lock file %s : %s\n",
 145                                 lp_lock_file(i), strerror(errno));
 146                         io_printf(fd,"@ERROR: failed to open lock file %s : %s\n",
 147                                   lp_lock_file(i), strerror(errno));
 148                 } else {
 149                         rprintf(FERROR,"max connections (%d) reached\n",
 150                                 lp_max_connections(i));
 151                         io_printf(fd,"@ERROR: max connections (%d) reached - try again later\n", lp_max_connections(i));
 152                 }
 153                 return -1;
 154         }
 155
 156
 157         auth_user = auth_server(fd, i, addr, "@RSYNCD: AUTHREQD ");
 158
 159         if (!auth_user) {
 160                 rprintf(FERROR,"auth failed on module %s from %s (%s)\n",
 161                         name, client_name(fd), client_addr(fd));
 162                 io_printf(fd,"@ERROR: auth failed on module %s\n",name);
 163                 return -1;
 164         }
 165
 166         module_id = i;
 167
 168         am_root = (getuid() == 0);
 169
 170         if (am_root) {
 171                 p = lp_uid(i);
 172                 if (!name_to_uid(p, &uid)) {
 173                         if (!isdigit(*p)) {
 174                                 rprintf(FERROR,"Invalid uid %s\n", p);
 175                                 io_printf(fd,"@ERROR: invalid uid\n");
 176                                 return -1;
 177                         }
 178                         uid = atoi(p);
 179                 }
 180
 181                 p = lp_gid(i);
 182                 if (!name_to_gid(p, &gid)) {
 183                         if (!isdigit(*p)) {
 184                                 rprintf(FERROR,"Invalid gid %s\n", p);
 185                                 io_printf(fd,"@ERROR: invalid gid\n");
 186                                 return -1;
 187                         }
 188                         gid = atoi(p);
 189                 }
 190         }
 191
 192         p = lp_include_from(i);
 193         add_exclude_file(p, 1, 1);
 194
 195         p = lp_include(i);
 196         add_include_line(p);
 197
 198         p = lp_exclude_from(i);
 199         add_exclude_file(p, 1, 0);
 200
 201         p = lp_exclude(i);
 202         add_exclude_line(p);
 203
 204         log_open();
 205
 206         if (use_chroot) {
 207                 if (chroot(lp_path(i))) {
 208                         rprintf(FERROR,"chroot %s failed\n", lp_path(i));
 209                         io_printf(fd,"@ERROR: chroot failed\n");
 210                         return -1;
 211                 }
 212
 213                 if (!push_dir("/", 0)) {
 214                         rprintf(FERROR,"chdir %s failed\n", lp_path(i));
 215                         io_printf(fd,"@ERROR: chdir failed\n");
 216                         return -1;
 217                 }
 218
 219         } else {
 220                 if (!push_dir(lp_path(i), 0)) {
 221                         rprintf(FERROR,"chdir %s failed\n", lp_path(i));
 222                         io_printf(fd,"@ERROR: chdir failed\n");
 223                         return -1;
 224                 }
 225                 sanitize_paths = 1;
 226         }
 227
 228         if (am_root) {
 229                 if (setgid(gid)) {
 230                         rprintf(FERROR,"setgid %d failed\n", gid);
 231                         io_printf(fd,"@ERROR: setgid failed\n");
 232                         return -1;
 233                 }
 234
 235                 if (setuid(uid)) {
 236                         rprintf(FERROR,"setuid %d failed\n", uid);
 237                         io_printf(fd,"@ERROR: setuid failed\n");
 238                         return -1;
 239                 }
 240
 241                 am_root = (getuid() == 0);
 242         }
 243
 244         io_printf(fd,"@RSYNCD: OK\n");
 245
 246         argv[argc++] = "rsyncd";
 247
 248         while (1) {
 249                 if (!read_line(fd, line, sizeof(line)-1)) {
 250                         return -1;
 251                 }
 252
 253                 if (!*line) break;
 254
 255                 p = line;
 256
 257                 argv[argc] = strdup(p);
 258                 if (!argv[argc]) {
 259                         return -1;
 260                 }
 261
 262                 if (start_glob) {
 263                         if (start_glob == 1) {
 264                                 request = strdup(p);
 265                                 start_glob++;
 266                         }
 267                         glob_expand(name, argv, &argc, MAX_ARGS);
 268                 } else {
 269                         argc++;
 270                 }
 271
 272                 if (strcmp(line,".") == 0) {
 273                         start_glob = 1;
 274                 }
 275
 276                 if (argc == MAX_ARGS) {
 277                         return -1;
 278                 }
 279         }
 280
 281         if (sanitize_paths) {
 282                 /*
 283                  * Note that this is applied to all parameters, whether or not
 284                  *    they are filenames, but no other legal parameters contain
 285                  *    the forms that need to be sanitized so it doesn't hurt;
 286                  *    it is not known at this point which parameters are files
 287                  *    and which aren't.
 288                  */
 289                 for (i = 1; i < argc; i++) {
 290                         sanitize_path(argv[i], NULL);
 291                 }
 292         }
 293
 294         ret = parse_arguments(argc, argv, 0);
 295
 296         if (request) {
 297                 if (*auth_user) {
 298                         rprintf(FINFO,"rsync %s %s from %s@%s (%s)\n",
 299                                 am_sender?"on":"to",
 300                                 request, auth_user, host, addr);
 301                 } else {
 302                         rprintf(FINFO,"rsync %s %s from %s (%s)\n",
 303                                 am_sender?"on":"to",
 304                                 request, host, addr);
 305                 }
 306                 free(request);
 307         }
 308
 309 #if !TRIDGE
 310         /* don't allow the logs to be flooded too fast */
 311         if (verbose > 1) verbose = 1;
 312 #endif
 313
 314         argc -= optind;
 315         argp = argv + optind;
 316         optind = 0;
 317
 318         if (remote_version < 23) {
 319                 if (remote_version == 22 || (remote_version > 17 && am_sender))
 320                         io_start_multiplex_out(fd);
 321         }
 322
 323         if (!ret) {
 324                 option_error();
 325         }
 326
 327         if (lp_timeout(i)) {
 328                 extern int io_timeout;
 329                 io_timeout = lp_timeout(i);
 330         }
 331
 332         start_server(fd, fd, argc, argp);
 333
 334         return 0;
 335 }
 336
 337 /* send a list of available modules to the client. Don't list those
 338    with "list = False". */
 339 static void send_listing(int fd)
 340 {
 341         int n = lp_numservices();
 342         int i;
 343
 344         for (i=0;i<n;i++)
 345                 if (lp_list(i))
 346                     io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i));
 347 }
 348
 349 /* this is called when a socket connection is established to a client
 350    and we want to start talking. The setup of the system is done from
 351    here */
 352 static int start_daemon(int fd)
 353 {
 354         char line[200];
 355         char *motd;
 356         int i = -1;
 357         extern char *config_file;
 358         extern int remote_version;
 359
 360         if (!lp_load(config_file, 0)) {
 361                 exit_cleanup(RERR_SYNTAX);
 362         }
 363
 364         set_socket_options(fd,"SO_KEEPALIVE");
 365         set_socket_options(fd,lp_socket_options());
 366         set_nonblocking(fd);
 367
 368         io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
 369
 370         motd = lp_motd_file();
 371         if (motd && *motd) {
 372                 FILE *f = fopen(motd,"r");
 373                 while (f && !feof(f)) {
 374                         int len = fread(line, 1, sizeof(line)-1, f);
 375                         if (len > 0) {
 376                                 line[len] = 0;
 377                                 io_printf(fd,"%s", line);
 378                         }
 379                 }
 380                 if (f) fclose(f);
 381                 io_printf(fd,"\n");
 382         }
 383
 384         if (!read_line(fd, line, sizeof(line)-1)) {
 385                 return -1;
 386         }
 387
 388         if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
 389                 io_printf(fd,"@ERROR: protocol startup error\n");
 390                 return -1;
 391         }
 392
 393         while (i == -1) {
 394                 line[0] = 0;
 395                 if (!read_line(fd, line, sizeof(line)-1)) {
 396                         return -1;
 397                 }
 398
 399                 if (!*line || strcmp(line,"#list")==0) {
 400                         send_listing(fd);
 401                         return -1;
 402                 }
 403
 404                 if (*line == '#') {
 405                         /* it's some sort of command that I don't understand */
 406                         io_printf(fd,"@ERROR: Unknown command '%s'\n", line);
 407                         return -1;
 408                 }
 409
 410                 i = lp_number(line);
 411                 if (i == -1) {
 412                         io_printf(fd,"@ERROR: Unknown module '%s'\n", line);
 413                         return -1;
 414                 }
 415         }
 416
 417         return rsync_module(fd, i);
 418 }
 419
 420
 421 int daemon_main(void)
 422 {
 423         extern char *config_file;
 424         extern int orig_umask;
 425         char *pid_file;
 426
 427         if (is_a_socket(STDIN_FILENO)) {
 428                 int i;
 429
 430                 /* we are running via inetd - close off stdout and
 431                    stderr so that library functions (and getopt) don't
 432                    try to use them. Redirect them to /dev/null */
 433                 for (i=1;i<3;i++) {
 434                         close(i);
 435                         open("/dev/null", O_RDWR);
 436                 }
 437
 438                 return start_daemon(STDIN_FILENO);
 439         }
 440
 441         become_daemon();
 442
 443         if (!lp_load(config_file, 1)) {
 444                 exit_cleanup(RERR_SYNTAX);
 445         }
 446
 447         log_open();
 448
 449         rprintf(FINFO,"rsyncd version %s starting\n",VERSION);
 450
 451         if (((pid_file = lp_pid_file()) != NULL) && (*pid_file != '\0')) {
 452                 char pidbuf[16];
 453                 int fd;
 454                 int pid = (int) getpid();
 455                 cleanup_set_pid(pid);
 456                 if ((fd = do_open(lp_pid_file(), O_WRONLY|O_CREAT|O_TRUNC,
 457                                         0666 & ~orig_umask)) == -1) {
 458                     cleanup_set_pid(0);
 459                     rprintf(FLOG,"failed to create pid file %s\n", pid_file);
 460                     exit_cleanup(RERR_FILEIO);
 461                 }
 462                 slprintf(pidbuf, sizeof(pidbuf), "%d\n", pid);
 463                 write(fd, pidbuf, strlen(pidbuf));
 464                 close(fd);
 465         }
 466
 467         start_accept_loop(rsync_port, start_daemon);
 468         return -1;
 469 }
 470