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
  40         if (*path == '/') {
  41                 rprintf(FERROR,"ERROR: The remote path must start with a module name\n");
  42                 return -1;
  43         }
  44
  45         p = strchr(host, '@');
  46         if (p) {
  47                 user = host;
  48                 host = p+1;
  49                 *p = 0;
  50         }
  51
  52         if (!user) user = getenv("USER");
  53         if (!user) user = getenv("LOGNAME");
  54
  55         fd = open_socket_out(host, rsync_port);
  56         if (fd == -1) {
  57                 exit_cleanup(RERR_SOCKETIO);
  58         }
  59
  60         server_options(sargs,&sargc);
  61
  62         sargs[sargc++] = ".";
  63
  64         if (path && *path)
  65                 sargs[sargc++] = path;
  66
  67         sargs[sargc] = NULL;
  68
  69         io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
  70
  71         if (!read_line(fd, line, sizeof(line)-1)) {
  72                 return -1;
  73         }
  74
  75         if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
  76                 return -1;
  77         }
  78
  79         p = strchr(path,'/');
  80         if (p) *p = 0;
  81         io_printf(fd,"%s\n",path);
  82         if (p) *p = '/';
  83
  84         while (1) {
  85                 if (!read_line(fd, line, sizeof(line)-1)) {
  86                         return -1;
  87                 }
  88
  89                 if (strncmp(line,"@RSYNCD: AUTHREQD ",18) == 0) {
  90                         auth_client(fd, user, line+18);
  91                         continue;
  92                 }
  93
  94                 if (strcmp(line,"@RSYNCD: OK") == 0) break;
  95                 rprintf(FINFO,"%s\n", line);
  96         }
  97
  98         for (i=0;i<sargc;i++) {
  99                 io_printf(fd,"%s\n", sargs[i]);
 100         }
 101         io_printf(fd,"\n");
 102
 103         if (remote_version > 17 && !am_sender)
 104                 io_start_multiplex_in(fd);
 105
 106         return client_run(fd, fd, -1, argc, argv);
 107 }
 108
 109
 110
 111 static int rsync_module(int fd, int i)
 112 {
 113         int argc=0;
 114         char *argv[MAX_ARGS];
 115         char **argp;
 116         char line[MAXPATHLEN];
 117         uid_t uid = (uid_t)-2;
 118         gid_t gid = (gid_t)-2;
 119         char *p;
 120         char *addr = client_addr(fd);
 121         char *host = client_name(fd);
 122         char *name = lp_name(i);
 123         int use_chroot = lp_use_chroot(i);
 124         int start_glob=0;
 125         int ret;
 126         char *request=NULL;
 127         extern int am_sender;
 128         extern int remote_version;
 129         extern int am_root;
 130
 131         if (!allow_access(addr, host, lp_hosts_allow(i), lp_hosts_deny(i))) {
 132                 rprintf(FERROR,"rsync denied on module %s from %s (%s)\n",
 133                         name, client_name(fd), client_addr(fd));
 134                 io_printf(fd,"@ERROR: access denied to %s from %s (%s)\n",
 135                           name, client_name(fd), client_addr(fd));
 136                 return -1;
 137         }
 138
 139         if (!claim_connection(lp_lock_file(i), lp_max_connections(i))) {
 140                 if (errno) {
 141                         rprintf(FERROR,"failed to open lock file %s : %s\n",
 142                                 lp_lock_file(i), strerror(errno));
 143                         io_printf(fd,"@ERROR: failed to open lock file %s : %s\n",
 144                                   lp_lock_file(i), strerror(errno));
 145                 } else {
 146                         rprintf(FERROR,"max connections (%d) reached\n",
 147                                 lp_max_connections(i));
 148                         io_printf(fd,"@ERROR: max connections (%d) reached - try again later\n", lp_max_connections(i));
 149                 }
 150                 return -1;
 151         }
 152
 153
 154         auth_user = auth_server(fd, i, addr, "@RSYNCD: AUTHREQD ");
 155
 156         if (!auth_user) {
 157                 rprintf(FERROR,"auth failed on module %s from %s (%s)\n",
 158                         name, client_name(fd), client_addr(fd));
 159                 io_printf(fd,"@ERROR: auth failed on module %s\n",name);
 160                 return -1;
 161         }
 162
 163         module_id = i;
 164
 165         if (lp_read_only(i))
 166                 read_only = 1;
 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 > 17 && am_sender)
 319                 io_start_multiplex_out(fd);
 320
 321         if (!ret) {
 322                 option_error();
 323         }
 324
 325         if (lp_timeout(i)) {
 326                 extern int io_timeout;
 327                 io_timeout = lp_timeout(i);
 328         }
 329
 330         start_server(fd, fd, argc, argp);
 331
 332         return 0;
 333 }
 334
 335 /* send a list of available modules to the client. Don't list those
 336    with "list = False". */
 337 static void send_listing(int fd)
 338 {
 339         int n = lp_numservices();
 340         int i;
 341
 342         for (i=0;i<n;i++)
 343                 if (lp_list(i))
 344                     io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i));
 345 }
 346
 347 /* this is called when a socket connection is established to a client
 348    and we want to start talking. The setup of the system is done from
 349    here */
 350 static int start_daemon(int fd)
 351 {
 352         char line[200];
 353         char *motd;
 354         int i = -1;
 355         extern char *config_file;
 356         extern int remote_version;
 357
 358         if (!lp_load(config_file, 0)) {
 359                 exit_cleanup(RERR_SYNTAX);
 360         }
 361
 362         set_socket_options(fd,"SO_KEEPALIVE");
 363         set_socket_options(fd,lp_socket_options());
 364
 365
 366         io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
 367
 368         motd = lp_motd_file();
 369         if (motd && *motd) {
 370                 FILE *f = fopen(motd,"r");
 371                 while (f && !feof(f)) {
 372                         int len = fread(line, 1, sizeof(line)-1, f);
 373                         if (len > 0) {
 374                                 line[len] = 0;
 375                                 io_printf(fd,"%s", line);
 376                         }
 377                 }
 378                 if (f) fclose(f);
 379                 io_printf(fd,"\n");
 380         }
 381
 382         if (!read_line(fd, line, sizeof(line)-1)) {
 383                 return -1;
 384         }
 385
 386         if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
 387                 io_printf(fd,"@ERROR: protocol startup error\n");
 388                 return -1;
 389         }
 390
 391         while (i == -1) {
 392                 line[0] = 0;
 393                 if (!read_line(fd, line, sizeof(line)-1)) {
 394                         return -1;
 395                 }
 396
 397                 if (!*line || strcmp(line,"#list")==0) {
 398                         send_listing(fd);
 399                         return -1;
 400                 }
 401
 402                 if (*line == '#') {
 403                         /* it's some sort of command that I don't understand */
 404                         io_printf(fd,"@ERROR: Unknown command '%s'\n", line);
 405                         return -1;
 406                 }
 407
 408                 i = lp_number(line);
 409                 if (i == -1) {
 410                         io_printf(fd,"@ERROR: Unknown module '%s'\n", line);
 411                         return -1;
 412                 }
 413         }
 414
 415         return rsync_module(fd, i);
 416 }
 417
 418
 419 int daemon_main(void)
 420 {
 421         extern char *config_file;
 422         extern int orig_umask;
 423         char *pid_file;
 424
 425         if (is_a_socket(STDIN_FILENO)) {
 426                 int i;
 427
 428                 /* we are running via inetd - close off stdout and
 429                    stderr so that library functions (and getopt) don't
 430                    try to use them. Redirect them to /dev/null */
 431                 for (i=1;i<3;i++) {
 432                         close(i);
 433                         open("/dev/null", O_RDWR);
 434                 }
 435
 436                 set_nonblocking(STDIN_FILENO);
 437
 438                 return start_daemon(STDIN_FILENO);
 439         }
 440
 441         become_daemon();
 442
 443         if (!lp_load(config_file, 1)) {
 444                 fprintf(stderr,"failed to load config file %s\n", config_file);
 445                 exit_cleanup(RERR_SYNTAX);
 446         }
 447
 448         log_open();
 449
 450         rprintf(FINFO,"rsyncd version %s starting\n",VERSION);
 451
 452         if (((pid_file = lp_pid_file()) != NULL) && (*pid_file != '\0')) {
 453                 char pidbuf[16];
 454                 int fd;
 455                 int pid = (int) getpid();
 456                 cleanup_set_pid(pid);
 457                 if ((fd = do_open(lp_pid_file(), O_WRONLY|O_CREAT|O_TRUNC,
 458                                         0666 & ~orig_umask)) == -1) {
 459                     cleanup_set_pid(0);
 460                     fprintf(stderr,"failed to create pid file %s\n", pid_file);
 461                     exit_cleanup(RERR_FILEIO);
 462                 }
 463                 slprintf(pidbuf, sizeof(pidbuf), "%d\n", pid);
 464                 write(fd, pidbuf, strlen(pidbuf));
 465                 close(fd);
 466         }
 467
 468         start_accept_loop(rsync_port, start_daemon);
 469         return -1;
 470 }
 471