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
  28 int start_socket_client(char *host, char *path, int argc, char *argv[])
  29 {
  30         int fd, i;
  31         char *sargs[MAX_ARGS];
  32         int sargc=0;
  33         char line[MAXPATHLEN];
  34         char *p, *user=NULL;
  35         extern int remote_version;
  36         extern int am_client;
  37         extern int am_sender;
  38
  39         p = strchr(host, '@');
  40         if (p) {
  41                 user = host;
  42                 host = p+1;
  43                 *p = 0;
  44         }
  45
  46         if (!user) user = getenv("USER");
  47         if (!user) user = getenv("LOGNAME");
  48
  49         am_client = 1;
  50
  51         fd = open_socket_out(host, rsync_port);
  52         if (fd == -1) {
  53                 exit_cleanup(1);
  54         }
  55
  56         server_options(sargs,&sargc);
  57
  58         sargs[sargc++] = ".";
  59
  60         if (path && *path)
  61                 sargs[sargc++] = path;
  62
  63         sargs[sargc] = NULL;
  64
  65         io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
  66
  67         if (!read_line(fd, line, sizeof(line)-1)) {
  68                 return -1;
  69         }
  70
  71         if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
  72                 return -1;
  73         }
  74
  75         p = strchr(path,'/');
  76         if (p) *p = 0;
  77         io_printf(fd,"%s\n",path);
  78         if (p) *p = '/';
  79
  80         while (1) {
  81                 if (!read_line(fd, line, sizeof(line)-1)) {
  82                         return -1;
  83                 }
  84
  85                 if (strncmp(line,"@RSYNCD: AUTHREQD ",18) == 0) {
  86                         auth_client(fd, user, line+18);
  87                         continue;
  88                 }
  89
  90                 if (strcmp(line,"@RSYNCD: OK") == 0) break;
  91                 rprintf(FINFO,"%s\n", line);
  92         }
  93
  94         for (i=0;i<sargc;i++) {
  95                 io_printf(fd,"%s\n", sargs[i]);
  96         }
  97         io_printf(fd,"\n");
  98
  99         if (remote_version > 17 && !am_sender)
 100                 io_start_multiplex_in(fd);
 101
 102         return client_run(fd, fd, -1, argc, argv);
 103 }
 104
 105
 106
 107 static int rsync_module(int fd, int i)
 108 {
 109         int argc=0;
 110         char *argv[MAX_ARGS];
 111         char **argp;
 112         char line[MAXPATHLEN];
 113         uid_t uid = (uid_t)-2;
 114         gid_t gid = (gid_t)-2;
 115         char *p;
 116         char *addr = client_addr(fd);
 117         char *host = client_name(fd);
 118         char *name = lp_name(i);
 119         char *user;
 120         int start_glob=0;
 121         char *request=NULL;
 122         extern int am_sender;
 123         extern int remote_version;
 124         extern int am_root;
 125
 126         if (!allow_access(addr, host, lp_hosts_allow(i), lp_hosts_deny(i))) {
 127                 rprintf(FERROR,"rsync denied on module %s from %s (%s)\n",
 128                         name, client_name(fd), client_addr(fd));
 129                 io_printf(fd,"@ERROR: access denied to %s from %s (%s)\n",
 130                           name, client_name(fd), client_addr(fd));
 131                 return -1;
 132         }
 133
 134         if (!claim_connection(lp_lock_file(), lp_max_connections())) {
 135                 rprintf(FERROR,"max connections (%d) reached\n",
 136                         lp_max_connections());
 137                 io_printf(fd,"@ERROR: max connections (%d) reached - try again later\n", lp_max_connections());
 138                 return -1;
 139         }
 140
 141
 142         user = auth_server(fd, i, addr, "@RSYNCD: AUTHREQD ");
 143
 144         if (!user) {
 145                 rprintf(FERROR,"auth failed on module %s from %s (%s)\n",
 146                         name, client_name(fd), client_addr(fd));
 147                 io_printf(fd,"@ERROR: auth failed on module %s\n",name);
 148                 return -1;
 149         }
 150
 151         module_id = i;
 152
 153         if (lp_read_only(i))
 154                 read_only = 1;
 155
 156         p = lp_uid(i);
 157         if (!name_to_uid(p, &uid)) {
 158                 if (!isdigit(*p)) {
 159                         rprintf(FERROR,"Invalid uid %s\n", p);
 160                         io_printf(fd,"@ERROR: invalid uid\n");
 161                         return -1;
 162                 }
 163                 uid = atoi(p);
 164         }
 165
 166         p = lp_gid(i);
 167         if (!name_to_gid(p, &gid)) {
 168                 if (!isdigit(*p)) {
 169                         rprintf(FERROR,"Invalid gid %s\n", p);
 170                         io_printf(fd,"@ERROR: invalid gid\n");
 171                         return -1;
 172                 }
 173                 gid = atoi(p);
 174         }
 175
 176         p = lp_exclude_from(i);
 177         add_exclude_file(p, 1, 0);
 178
 179         p = lp_exclude(i);
 180         add_exclude_line(p);
 181
 182         log_open();
 183
 184         if (chroot(lp_path(i))) {
 185                 rprintf(FERROR,"chroot %s failed\n", lp_path(i));
 186                 io_printf(fd,"@ERROR: chroot failed\n");
 187                 return -1;
 188         }
 189
 190         if (chdir("/")) {
 191                 rprintf(FERROR,"chdir %s failed\n", lp_path(i));
 192                 io_printf(fd,"@ERROR: chdir failed\n");
 193                 return -1;
 194         }
 195
 196         if (setgid(gid) || getgid() != gid) {
 197                 rprintf(FERROR,"setgid %d failed\n", gid);
 198                 io_printf(fd,"@ERROR: setgid failed\n");
 199                 return -1;
 200         }
 201
 202         if (setuid(uid) || getuid() != uid) {
 203                 rprintf(FERROR,"setuid %d failed\n", uid);
 204                 io_printf(fd,"@ERROR: setuid failed\n");
 205                 return -1;
 206         }
 207
 208         am_root = (getuid() == 0);
 209
 210         io_printf(fd,"@RSYNCD: OK\n");
 211
 212         argv[argc++] = "rsyncd";
 213
 214         while (1) {
 215                 if (!read_line(fd, line, sizeof(line)-1)) {
 216                         return -1;
 217                 }
 218
 219                 if (!*line) break;
 220
 221                 p = line;
 222
 223                 argv[argc] = strdup(p);
 224                 if (!argv[argc]) {
 225                         return -1;
 226                 }
 227
 228                 if (start_glob) {
 229                         if (start_glob == 1) {
 230                                 request = strdup(p);
 231                                 start_glob++;
 232                         }
 233                         glob_expand(name, argv, &argc, MAX_ARGS);
 234                 } else {
 235                         argc++;
 236                 }
 237
 238                 if (strcmp(line,".") == 0) {
 239                         start_glob = 1;
 240                 }
 241
 242                 if (argc == MAX_ARGS) {
 243                         return -1;
 244                 }
 245         }
 246
 247         parse_arguments(argc, argv);
 248
 249         if (request) {
 250                 if (*user) {
 251                         rprintf(FINFO,"rsync %s %s from %s@%s (%s)\n",
 252                                 am_sender?"on":"to",
 253                                 request, user, host, addr);
 254                 } else {
 255                         rprintf(FINFO,"rsync %s %s from %s (%s)\n",
 256                                 am_sender?"on":"to",
 257                                 request, host, addr);
 258                 }
 259                 free(request);
 260         }
 261
 262         /* don't allow the logs to be flooded too fast */
 263         if (verbose > 1) verbose = 1;
 264
 265         argc -= optind;
 266         argp = argv + optind;
 267         optind = 0;
 268
 269         if (remote_version > 17 && am_sender)
 270                 io_start_multiplex_out(fd);
 271
 272         start_server(fd, fd, argc, argp);
 273
 274         return 0;
 275 }
 276
 277 /* send a list of available modules to the client. Don't list those
 278    with "list = False". */
 279 static void send_listing(int fd)
 280 {
 281         int n = lp_numservices();
 282         int i;
 283
 284         for (i=0;i<n;i++)
 285                 if (lp_list(i))
 286                     io_printf(fd, "%-15s\t%s\n", lp_name(i), lp_comment(i));
 287 }
 288
 289 /* this is called when a socket connection is established to a client
 290    and we want to start talking. The setup of the system is done from
 291    here */
 292 static int start_daemon(int fd)
 293 {
 294         char line[200];
 295         char *motd;
 296         int i = -1;
 297         extern char *config_file;
 298         extern int remote_version;
 299
 300         if (!lp_load(config_file, 0)) {
 301                 exit_cleanup(1);
 302         }
 303
 304         set_socket_options(fd,"SO_KEEPALIVE");
 305         set_socket_options(fd,lp_socket_options());
 306
 307
 308         io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
 309
 310         motd = lp_motd_file();
 311         if (*motd) {
 312                 FILE *f = fopen(motd,"r");
 313                 while (f && !feof(f)) {
 314                         int len = fread(line, 1, sizeof(line)-1, f);
 315                         if (len > 0) {
 316                                 line[len] = 0;
 317                                 io_printf(fd,"%s", line);
 318                         }
 319                 }
 320                 if (f) fclose(f);
 321                 io_printf(fd,"\n");
 322         }
 323
 324         if (!read_line(fd, line, sizeof(line)-1)) {
 325                 return -1;
 326         }
 327
 328         if (sscanf(line,"@RSYNCD: %d", &remote_version) != 1) {
 329                 io_printf(fd,"@ERROR: protocol startup error\n");
 330                 return -1;
 331         }
 332
 333         while (i == -1) {
 334                 line[0] = 0;
 335                 if (!read_line(fd, line, sizeof(line)-1)) {
 336                         return -1;
 337                 }
 338
 339                 if (!*line || strcmp(line,"#list")==0) {
 340                         send_listing(fd);
 341                         return -1;
 342                 }
 343
 344                 if (*line == '#') {
 345                         /* it's some sort of command that I don't understand */
 346                         io_printf(fd,"@ERROR: Unknown command '%s'\n", line);
 347                         return -1;
 348                 }
 349
 350                 i = lp_number(line);
 351                 if (i == -1) {
 352                         io_printf(fd,"@ERROR: Unknown module '%s'\n", line);
 353                         return -1;
 354                 }
 355         }
 356
 357         return rsync_module(fd, i);
 358 }
 359
 360
 361 int daemon_main(void)
 362 {
 363         extern char *config_file;
 364
 365         /* this ensures that we don't call getcwd after the chroot,
 366            which doesn't work on platforms that use popen("pwd","r")
 367            for getcwd */
 368         push_dir("/", 0);
 369
 370         if (is_a_socket(STDIN_FILENO)) {
 371                 /* we are running via inetd */
 372                 return start_daemon(STDIN_FILENO);
 373         }
 374
 375         become_daemon();
 376
 377         if (!lp_load(config_file, 1)) {
 378                 fprintf(stderr,"failed to load config file %s\n", config_file);
 379                 exit_cleanup(1);
 380         }
 381
 382         log_open();
 383
 384         rprintf(FINFO,"rsyncd version %s starting\n",VERSION);
 385
 386         start_accept_loop(rsync_port, start_daemon);
 387         return -1;
 388 }
 389