compat.c

   1 /*
   2  * Compatibility routines for older rsync protocol versions.
   3  *
   4  * Copyright (C) Andrew Tridgell 1996
   5  * Copyright (C) Paul Mackerras 1996
   6  * Copyright (C) 2004-2020 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
  24 int remote_protocol = 0;
  25 int file_extra_cnt = 0; /* count of file-list extras that everyone gets */
  26 int inc_recurse = 0;
  27 int compat_flags = 0;
  28 int use_safe_inc_flist = 0;
  29 int want_xattr_optim = 0;
  30 int proper_seed_order = 0;
  31 int inplace_partial = 0;
  32
  33 extern int am_server;
  34 extern int am_sender;
  35 extern int local_server;
  36 extern int inplace;
  37 extern int recurse;
  38 extern int use_qsort;
  39 extern int allow_inc_recurse;
  40 extern int preallocate_files;
  41 extern int append_mode;
  42 extern int fuzzy_basis;
  43 extern int read_batch;
  44 extern int write_batch;
  45 extern int delay_updates;
  46 extern int checksum_seed;
  47 extern int basis_dir_cnt;
  48 extern int prune_empty_dirs;
  49 extern int protocol_version;
  50 extern int protect_args;
  51 extern int preserve_uid;
  52 extern int preserve_gid;
  53 extern int preserve_atimes;
  54 extern int preserve_acls;
  55 extern int preserve_xattrs;
  56 extern int xfer_flags_as_varint;
  57 extern int need_messages_from_generator;
  58 extern int delete_mode, delete_before, delete_during, delete_after;
  59 extern char *shell_cmd;
  60 extern char *partial_dir;
  61 extern char *dest_option;
  62 extern char *files_from;
  63 extern char *filesfrom_host;
  64 extern char *checksum_choice;
  65 extern filter_rule_list filter_list;
  66 extern int need_unsorted_flist;
  67 #ifdef ICONV_OPTION
  68 extern iconv_t ic_send, ic_recv;
  69 extern char *iconv_opt;
  70 #endif
  71 extern const char *negotiated_csum_name;
  72
  73 /* These index values are for the file-list's extra-attribute array. */
  74 int pathname_ndx, depth_ndx, atimes_ndx, uid_ndx, gid_ndx, acls_ndx, xattrs_ndx, unsort_ndx;
  75
  76 int receiver_symlink_times = 0; /* receiver can set the time on a symlink */
  77 int sender_symlink_iconv = 0;   /* sender should convert symlink content */
  78
  79 #ifdef ICONV_OPTION
  80 int filesfrom_convert = 0;
  81 #endif
  82
  83 #define CF_INC_RECURSE   (1<<0)
  84 #define CF_SYMLINK_TIMES (1<<1)
  85 #define CF_SYMLINK_ICONV (1<<2)
  86 #define CF_SAFE_FLIST    (1<<3)
  87 #define CF_AVOID_XATTR_OPTIM (1<<4)
  88 #define CF_CHKSUM_SEED_FIX (1<<5)
  89 #define CF_INPLACE_PARTIAL_DIR (1<<6)
  90 #define CF_VARINT_FLIST_FLAGS (1<<7)
  91
  92 static const char *client_info;
  93
  94 /* The server makes sure that if either side only supports a pre-release
  95  * version of a protocol, that both sides must speak a compatible version
  96  * of that protocol for it to be advertised as available. */
  97 static void check_sub_protocol(void)
  98 {
  99         char *dot;
 100         int their_protocol, their_sub;
 101 #if SUBPROTOCOL_VERSION != 0
 102         int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
 103 #else
 104         int our_sub = 0;
 105 #endif
 106
 107         /* client_info starts with VER.SUB string if client is a pre-release. */
 108         if (!(their_protocol = atoi(client_info))
 109          || !(dot = strchr(client_info, '.'))
 110          || !(their_sub = atoi(dot+1))) {
 111 #if SUBPROTOCOL_VERSION != 0
 112                 if (our_sub)
 113                         protocol_version--;
 114 #endif
 115                 return;
 116         }
 117
 118         if (their_protocol < protocol_version) {
 119                 if (their_sub)
 120                         protocol_version = their_protocol - 1;
 121                 return;
 122         }
 123
 124         if (their_protocol > protocol_version)
 125                 their_sub = 0; /* 0 == final version of older protocol */
 126         if (their_sub != our_sub)
 127                 protocol_version--;
 128 }
 129
 130 void set_allow_inc_recurse(void)
 131 {
 132         client_info = shell_cmd ? shell_cmd : "";
 133
 134         if (!recurse || use_qsort)
 135                 allow_inc_recurse = 0;
 136         else if (!am_sender
 137          && (delete_before || delete_after
 138           || delay_updates || prune_empty_dirs))
 139                 allow_inc_recurse = 0;
 140         else if (am_server && !local_server
 141          && (strchr(client_info, 'i') == NULL))
 142                 allow_inc_recurse = 0;
 143 }
 144
 145 void setup_protocol(int f_out,int f_in)
 146 {
 147         int csum_exchange = 0;
 148
 149         assert(file_extra_cnt == 0);
 150         assert(EXTRA64_CNT == 2 || EXTRA64_CNT == 1);
 151
 152         /* All int64 values must be set first so that they are guaranteed to be
 153          * aligned for direct int64-pointer memory access. */
 154         if (preserve_atimes)
 155                 atimes_ndx = (file_extra_cnt += EXTRA64_CNT);
 156         if (am_sender) /* This is most likely in the in64 union as well. */
 157                 pathname_ndx = (file_extra_cnt += PTR_EXTRA_CNT);
 158         else
 159                 depth_ndx = ++file_extra_cnt;
 160         if (preserve_uid)
 161                 uid_ndx = ++file_extra_cnt;
 162         if (preserve_gid)
 163                 gid_ndx = ++file_extra_cnt;
 164         if (preserve_acls && !am_sender)
 165                 acls_ndx = ++file_extra_cnt;
 166         if (preserve_xattrs)
 167                 xattrs_ndx = ++file_extra_cnt;
 168
 169         if (am_server)
 170                 set_allow_inc_recurse();
 171
 172         if (remote_protocol == 0) {
 173                 if (am_server && !local_server)
 174                         check_sub_protocol();
 175                 if (!read_batch)
 176                         write_int(f_out, protocol_version);
 177                 remote_protocol = read_int(f_in);
 178                 if (protocol_version > remote_protocol)
 179                         protocol_version = remote_protocol;
 180         }
 181         if (read_batch && remote_protocol > protocol_version) {
 182                 rprintf(FERROR, "The protocol version in the batch file is too new (%d > %d).\n",
 183                         remote_protocol, protocol_version);
 184                 exit_cleanup(RERR_PROTOCOL);
 185         }
 186
 187         if (DEBUG_GTE(PROTO, 1)) {
 188                 rprintf(FINFO, "(%s) Protocol versions: remote=%d, negotiated=%d\n",
 189                         am_server? "Server" : "Client", remote_protocol, protocol_version);
 190         }
 191         if (remote_protocol < MIN_PROTOCOL_VERSION
 192          || remote_protocol > MAX_PROTOCOL_VERSION) {
 193                 rprintf(FERROR,"protocol version mismatch -- is your shell clean?\n");
 194                 rprintf(FERROR,"(see the rsync man page for an explanation)\n");
 195                 exit_cleanup(RERR_PROTOCOL);
 196         }
 197         if (remote_protocol < OLD_PROTOCOL_VERSION) {
 198                 rprintf(FINFO,"%s is very old version of rsync, upgrade recommended.\n",
 199                         am_server? "Client" : "Server");
 200         }
 201         if (protocol_version < MIN_PROTOCOL_VERSION) {
 202                 rprintf(FERROR, "--protocol must be at least %d on the %s.\n",
 203                         MIN_PROTOCOL_VERSION, am_server? "Server" : "Client");
 204                 exit_cleanup(RERR_PROTOCOL);
 205         }
 206         if (protocol_version > PROTOCOL_VERSION) {
 207                 rprintf(FERROR, "--protocol must be no more than %d on the %s.\n",
 208                         PROTOCOL_VERSION, am_server? "Server" : "Client");
 209                 exit_cleanup(RERR_PROTOCOL);
 210         }
 211         if (read_batch)
 212                 check_batch_flags();
 213
 214 #ifndef SUPPORT_PREALLOCATION
 215         if (preallocate_files && !am_sender) {
 216                 rprintf(FERROR, "preallocation is not supported on this %s\n",
 217                         am_server ? "Server" : "Client");
 218                 exit_cleanup(RERR_SYNTAX);
 219         }
 220 #endif
 221
 222         if (protocol_version < 30) {
 223                 if (append_mode == 1)
 224                         append_mode = 2;
 225                 if (preserve_acls && !local_server) {
 226                         rprintf(FERROR,
 227                             "--acls requires protocol 30 or higher"
 228                             " (negotiated %d).\n",
 229                             protocol_version);
 230                         exit_cleanup(RERR_PROTOCOL);
 231                 }
 232                 if (preserve_xattrs && !local_server) {
 233                         rprintf(FERROR,
 234                             "--xattrs requires protocol 30 or higher"
 235                             " (negotiated %d).\n",
 236                             protocol_version);
 237                         exit_cleanup(RERR_PROTOCOL);
 238                 }
 239         }
 240
 241         if (delete_mode && !(delete_before+delete_during+delete_after)) {
 242                 if (protocol_version < 30)
 243                         delete_before = 1;
 244                 else
 245                         delete_during = 1;
 246         }
 247
 248         if (protocol_version < 29) {
 249                 if (fuzzy_basis) {
 250                         rprintf(FERROR,
 251                             "--fuzzy requires protocol 29 or higher"
 252                             " (negotiated %d).\n",
 253                             protocol_version);
 254                         exit_cleanup(RERR_PROTOCOL);
 255                 }
 256
 257                 if (basis_dir_cnt && inplace) {
 258                         rprintf(FERROR,
 259                             "%s with --inplace requires protocol 29 or higher"
 260                             " (negotiated %d).\n",
 261                             dest_option, protocol_version);
 262                         exit_cleanup(RERR_PROTOCOL);
 263                 }
 264
 265                 if (basis_dir_cnt > 1) {
 266                         rprintf(FERROR,
 267                             "Using more than one %s option requires protocol"
 268                             " 29 or higher (negotiated %d).\n",
 269                             dest_option, protocol_version);
 270                         exit_cleanup(RERR_PROTOCOL);
 271                 }
 272
 273                 if (prune_empty_dirs) {
 274                         rprintf(FERROR,
 275                             "--prune-empty-dirs requires protocol 29 or higher"
 276                             " (negotiated %d).\n",
 277                             protocol_version);
 278                         exit_cleanup(RERR_PROTOCOL);
 279                 }
 280         } else if (protocol_version >= 30) {
 281                 if (am_server) {
 282                         compat_flags = allow_inc_recurse ? CF_INC_RECURSE : 0;
 283 #ifdef CAN_SET_SYMLINK_TIMES
 284                         compat_flags |= CF_SYMLINK_TIMES;
 285 #endif
 286 #ifdef ICONV_OPTION
 287                         compat_flags |= CF_SYMLINK_ICONV;
 288 #endif
 289                         if (local_server || strchr(client_info, 'f') != NULL)
 290                                 compat_flags |= CF_SAFE_FLIST;
 291                         if (local_server || strchr(client_info, 'x') != NULL)
 292                                 compat_flags |= CF_AVOID_XATTR_OPTIM;
 293                         if (local_server || strchr(client_info, 'C') != NULL)
 294                                 compat_flags |= CF_CHKSUM_SEED_FIX;
 295                         if (local_server || strchr(client_info, 'I') != NULL)
 296                                 compat_flags |= CF_INPLACE_PARTIAL_DIR;
 297                         if (local_server || strchr(client_info, 'v') != NULL) {
 298                                 if (!write_batch || protocol_version >= 30) {
 299                                         csum_exchange = 1;
 300                                         compat_flags |= CF_VARINT_FLIST_FLAGS;
 301                                 }
 302                         }
 303                         if (strchr(client_info, 'V') != NULL) { /* Support a pre-release 'V' that got superseded */
 304                                 if (!write_batch)
 305                                         compat_flags |= CF_VARINT_FLIST_FLAGS;
 306                                 write_byte(f_out, compat_flags);
 307                         } else
 308                                 write_varint(f_out, compat_flags);
 309                 } else { /* read_varint() is compatible with the older write_byte() when the 0x80 bit isn't on. */
 310                         compat_flags = read_varint(f_in);
 311                         if  (compat_flags & CF_VARINT_FLIST_FLAGS)
 312                                 csum_exchange = 1;
 313                 }
 314                 /* The inc_recurse var MUST be set to 0 or 1. */
 315                 inc_recurse = compat_flags & CF_INC_RECURSE ? 1 : 0;
 316                 want_xattr_optim = protocol_version >= 31 && !(compat_flags & CF_AVOID_XATTR_OPTIM);
 317                 proper_seed_order = compat_flags & CF_CHKSUM_SEED_FIX ? 1 : 0;
 318                 xfer_flags_as_varint = compat_flags & CF_VARINT_FLIST_FLAGS ? 1 : 0;
 319                 if (am_sender) {
 320                         receiver_symlink_times = am_server
 321                             ? strchr(client_info, 'L') != NULL
 322                             : !!(compat_flags & CF_SYMLINK_TIMES);
 323                 }
 324 #ifdef CAN_SET_SYMLINK_TIMES
 325                 else
 326                         receiver_symlink_times = 1;
 327 #endif
 328 #ifdef ICONV_OPTION
 329                 sender_symlink_iconv = iconv_opt && (am_server
 330                     ? local_server || strchr(client_info, 's') != NULL
 331                     : !!(compat_flags & CF_SYMLINK_ICONV));
 332 #endif
 333                 if (inc_recurse && !allow_inc_recurse) {
 334                         /* This should only be able to happen in a batch. */
 335                         fprintf(stderr,
 336                             "Incompatible options specified for inc-recursive %s.\n",
 337                             read_batch ? "batch file" : "connection");
 338                         exit_cleanup(RERR_SYNTAX);
 339                 }
 340                 use_safe_inc_flist = (compat_flags & CF_SAFE_FLIST) || protocol_version >= 31;
 341                 need_messages_from_generator = 1;
 342                 if (compat_flags & CF_INPLACE_PARTIAL_DIR)
 343                         inplace_partial = 1;
 344 #ifdef CAN_SET_SYMLINK_TIMES
 345         } else if (!am_sender) {
 346                 receiver_symlink_times = 1;
 347 #endif
 348         }
 349
 350         if (need_unsorted_flist && (!am_sender || inc_recurse))
 351                 unsort_ndx = ++file_extra_cnt;
 352
 353         if (partial_dir && *partial_dir != '/' && (!am_server || local_server)) {
 354                 int rflags = FILTRULE_NO_PREFIXES | FILTRULE_DIRECTORY;
 355                 if (!am_sender || protocol_version >= 30)
 356                         rflags |= FILTRULE_PERISHABLE;
 357                 parse_filter_str(&filter_list, partial_dir, rule_template(rflags), 0);
 358         }
 359
 360
 361 #ifdef ICONV_OPTION
 362         if (protect_args && files_from) {
 363                 if (am_sender)
 364                         filesfrom_convert = filesfrom_host && ic_send != (iconv_t)-1;
 365                 else
 366                         filesfrom_convert = !filesfrom_host && ic_recv != (iconv_t)-1;
 367         }
 368 #endif
 369
 370         if (am_server) {
 371                 if (!checksum_seed)
 372                         checksum_seed = time(NULL) ^ (getpid() << 6);
 373                 write_int(f_out, checksum_seed);
 374         } else {
 375                 checksum_seed = read_int(f_in);
 376         }
 377
 378         if (!checksum_choice) {
 379                 const char *rcl = getenv("RSYNC_CHECKSUM_LIST");
 380                 if (csum_exchange)
 381                         negotiate_checksum(f_in, f_out, rcl);
 382                 else if (!am_server && rcl && *rcl && strstr(rcl, "FAIL")) {
 383                         rprintf(FERROR, "Remote rsync is too old for checksum negotation\n");
 384                         exit_cleanup(RERR_UNSUPPORTED);
 385                 }
 386         }
 387
 388         init_flist();
 389 }
 390
 391 void maybe_write_checksum(int batch_fd)
 392 {
 393         assert(negotiated_csum_name != NULL);
 394         if (compat_flags & CF_VARINT_FLIST_FLAGS)
 395                 write_vstring(batch_fd, negotiated_csum_name, strlen(negotiated_csum_name));
 396 }